Research Express@NCKU - Articles Digest

Research Express@NCKU Volume 8 Issue 8 - May 8, 2009 [ http://research.ncku.edu.tw/re/articles/e/20090508/1.html ]

Flavors and Phases in Unparticle Physics Chuan-Hung Chen1,2,*, Chao-Qiang Geng3

1Department of Physics, College of Sciences, National Cheng-Kung University, Tainan 701, Taiwan 2National Center for Theoretical Sciences,Hsinchu 300, Taiwan 3Department of Physics, National Tsing-Hua University, Hsinchu 300, Taiwan physchen@mail.ncku.edu.tw Phys. Lett. B661, 118-123 (2008)

Recently, it has been argued in Georgi’s paper that a scale

invariant sector with scale dimension is associated with

“unparticle stuff”which looks like a non-integral number of

invisible particles. The production of unparticles might be

detectable by measuring the missing energy and momentum

distributions in various processes. Although it is still unclear how far

the unparticle physics can be carried out, there exist many possible

interesting experimental tests on unparticles. In particular, it has

been shown that the peculiar CP conserving phases associated with

the unparticle propagators in the time-like region lead to unusual CP

conserving interference patterns between the time-like unparticle

exchange amplitudes and the standard model (SM) amplitudes in

. It should be interesting to ask if there are other odd

effects due to this type of the phases. In this study, we will examine the effects of these phases on CP

violation.

We start from the scheme proposed by Georgi. For the system with the scale invariance there exist so-

called Banks-Zaks (BZ) fields that have a nontrivial infrared fixed point at a very high energy scale.

Above the electroweak scale, since all SM particles are massless, we cannot tell the differences between

down-type quarks or up-type quarks. In the SM, we have flavor

symmetries, where D and U denote the singlet states for down and up-type quarks, respectively, while Q

stands for the quark doublet. Therefore, if BZ fields are flavor blind, plausibly new flavor mixing effects

cannot be generated for vector and axial-vector currents after the electroweak symmetry breaking

(EWSB). It is worthy to mention that scalar-type couplings, illustrated by in weak eigenstates,

could basically produce FCNCs after the spontaneous symmetry breaking. For example

, will be induced where are unitary matrices to diagonalize the down-type

quark Yukawa matrix. For the convention of and , is just the CKM matrix.

Immediately, we suffer a serious problem from the mixing due to the coupling for

being associated with ( ) where λ is the Wolfenstein parameter. To avoid the large FCNC

problem, one can set the Yukawa matrix be hermitian so that . As a result, the FCNCs at tree

level via scalar-type interactions are removed. In any event, despite the property of Yukawa matrices, to

get natural small FCNCs at tree level for scalar and vector-type interactions, we need some internal

degrees of freedom for fermions that could differentiate flavors by the scale invariant stuff.

1 of 3

Research Express@NCKU - Articles Digest

In order to reveal the new flavor mixing effects due to the involvement of unparticles, we assume that the

SM particles carry some kind of BZ charges so that BZ fields could distinguish flavor species. In terms of

the prescription in Georgi’s paper,the interactions between BZ and SM fields are given by

where is the high energy mass scale of the messenger, is a free parameter,

denote the 3-generation of fermions in the SM, are the corresponding BZ

charges, is the possible Dirac matrix and is the operator composed of BZ fields. We note that

although are different for each generation,the interactions are still flavor conserved. To simplify

our discussion, we regard that all fermions in each generation have the same BZ charge at the high

energy scale and we assume that the interactions with the BZ fields are invariant under parity.

Subsequently, with the dimensional transmutation at the scale, the BZ operators will match onto

unparticle operators. The effective interactions are obtained to be

where is a Wilson-like coefficient function and is the scaling dimension of the BZ (unparticle)

operator. Here the unparticle operators have been set to be hermitian. In principle, could be related

to by a complicated matching procedure. However, at the current stage, it is impossible to give any

explicit calculations for the matching. With the property of the diagonal matrix, we know that

should be also a diagonal one, parametrized by . Hence, below the scale,

could be regarded as unparticle charges carried by the SM fermions to distinguish the flavors by the

unparticle stuff.

When the energy scale goes down below the EWSB scale,described by the vacuum expectation value

(VEV) of the Higgs field < H > =v/ , the flavor symmetry will be broken by the Yukawa terms and the

charged fermions become massive. Afterward,the weak eigenstates of the fermions need to be

transformed to the physical eigenstates by proper unitary transformations. To demonstrate the FCNC

effects, we have adopted the simplest Fritzsch ansatz for quarks. Consequently, we have found that the

FCNC effects are associated with the square roots of the mass ratios, i.e., .

With the inputs and the allowed values for the parameters,the branching ratios for [solid]

and [dashed] and CPA for as functions of are presented in Fig.1. Due to

the current upper limit on , should be less than 1.66. The flat curves in Fig.1(a)

correspond to the SM predictions. Amazingly, from Fig.1(b) we see that an unusual direct CPA of

is generated in . Besides the necessary weak CP violating phase β existed in the

SM, the result mainly depends on the CP conserving phase carried by the unparticle in its propagator.

This is a unique phenomenon since it is supposed to be vanishing small even some new CP violating

phases are introduced. In other words, if a signal of the CPA in is observed, it must be the

unparticle effect. Similar results are also expected in the dielectron and ditau modes. However, there is

no direct CPA for decays due to in the SM.

2 of 3

Research Express@NCKU - Articles Digest

Fig 1 (a) BRs for [solid] and [dashed] and (b) CPA for as

functions of the scale dimension , where the horizontal lines correspond to the current experimental

upper limits.

In summary, we have studied the flavor structures of the SM fermions when they couple to the scale

invariant stuff. In order to get naturally suppressed FCNC effects at tree level and more correlative

transitions among three generations, we have introduced the BZ charges that are universal in each

generation but generation un-blind. The BZ charges could be regarded as the internal degrees of

freedom carried by the fermions for which the BZ-fields can distinguish the flavor generations. By the

dimensional transmutation, the BZ charges are matched onto the unparticle charges when the BZ

operators onto the unparticle operators. After the EWSB, the FCNCs are induced by the

rediagonalizations of the fermion mass matrices. To demonstrate the FCNC effects, we have adopted the

simplest Fritzsch ansatz for quarks. Consequently, we have found that the FCNC effects are associated

with the square roots of the mass ratios, i.e., . We have used decays to

illustrate the influence of unparticles. In particular, with the peculiar CP conserving phases carried by

unparticles, a unique phenomenon is generated in the direct CPAs of If any CP violating

signal is found in these decays, it must indicate the existence of unparticles.

3 of 3

Research Express@NCKU - Articles Digest

Research Express@NCKU Volume 8 Issue 8 - May 8, 2009 [ http://research.ncku.edu.tw/re/articles/e/20090508/2.html ]

Dietary supplement of onion decreases ovariectomy induced bone loss in rats Tsang-hai Huang1,*, Roman C. Mühlbauer7, Chih-Hsin Tang5, Hsiun-Ing Chen2, Guan-Liang Chang3, Yi-Wei Huang4, Yu-Ting Lai4, Hsin-Shi Lin1, Wei-Ting Yang3, Rong-Sen Yang6 1Institute of Physical Education, Health and Leisure Studies, National Cheng-Kung University 2Department of Physiology, National Cheng-kung University, Tainan, Taiwan 3Institute of Biomedical Engineering, National Cheng-kung University, Tainan, Taiwan 4Department of Life Sciences, National Cheng-kung University, Tainan, Taiwan 5Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan 6Department of Orthopaedics, National Taiwan University and Hospital, Taipei, Taiwan 7 Department of Clinical Research, University of Bern, Bern, Switzerland tsanghai@mail.ncku.edu.tw Onion decreases the ovariectomy-induced osteopenia in young adult rats. Bone 42 (6): 1154-1163; 2008.

Due to the increasing average age of human being, osteoporosis as well as

its related fractures have become importantly global issues. Moreover, it

had been anticipated that more than 50% of worldwide osteoporosis-related

hip fractures would occur in Asia.

Clinically, patients with osteoporosis are regularly treated with hormone

replacement therapy (HRT), selective estrogen receptor modulators

(SERMs) as well as bisphosphonate, which have already been well proved

about their efficacy either in increasing bone mineral density (BMD) and/or

reducing fracture rates. However, there are side effects showed by these

medications, such as gastrointestinal tolerance by bisphosphonate and the

potential malignancies in HRT, which may preclude their long-term use. Therefore, it seems not every

osteoporosis patient suitable for the medical treatments mentioned above.

For the past decades, increasing number of studies verified the benefits of natural foods for bone health,

providing alternative options for prevention and/or treatment of osteoporosis. Scientists have proved

that people, including postmenopausal women, healthy women, elderly men and even young people,

who consume more fruits and vegetables, tend to accumulated a higher bone mineral density (BMD).

Onion, as one of the popular vegetables, had been preliminarily investigated and verified about its

efficacy on bone metabolism by Dr. Roman C. Mühlbauer. However, it’s unknown whether the effects of

onion-enriched dietary are strong enough to prevent or slow down estrogen deficiency induced bone loss

during menopause.

1 of 5

Research Express@NCKU - Articles Digest

We used young adult female rats as subjects. After sham or ovariectomy surgery, animals were randomly

assigned into six groups and underwent different treatments (Table 1). Similar to women during

menopause, ovariectomized animals can not adequately secret estrogen and subsequently increase their

bone mineral loss. Except for the sham operated group and one ovariectomized group, other four

ovariectomized groups were treated by alendronate and three different onion-enriched diets for six

weeks.

Animals underwent sham operation or ovariectomy at age of 13 weeks old. Three day after surgery,

animals were assigned into six different groups: CON group, sham operated control group; OVX group,

ovariectomized group without any treatment; ALN group, ovariectomized rats oral treated with

alendronate at a dose of 1mg/kg/day; three onion-enriched diet groups (ovariectomized rats treated with

3%, 7% and 14%, respectively, onion-enriched diets)

Comparing to life cycle of human being, rodents’ life were relative shorter. Therefore, a course of several-

week pharmacological or dietary intervention would be a long-term treatment for rodents. Three days

after surgery, in the present study, animals underwent different intervention for six weeks. After the six-

week treatment was completed, the animals were sacrificed under anesthesia. Blood samples as well as

bone tissues were collected and stored appropriately for further various analyses.

Serum markers assay, including levels of calcium, osteocalcin and enzyme activity of serum tartrate-

resistant acid phosphatase (TRAP), were performed in our study. Through measuring those serum

markers, we can further understanding the status of bone metabolism. High serum calcium may imply a

vigorous bone metabolism status but couldn’t really tell us the bone is under modeling or losing. On the

other hand, osteocalcin specifically represent bone formation while TRAP activity is a marker of bone

resorption (bone loss). Generally, menopausal females show very high bone metabolism and the lean

effect would be an enormous bone loss. In other words, though menopausal females show a high bone

formation activity, the bone resorption activity is relatively higher than bone formation, which then

causes a bone loss.

Clinically, most medical therapies retard osteoporosis through inhibiting bone loss and slow down bone

turn over rate. That is, we confront osteoporosis via slowing down bone loss but not through increasing

bone formation.

In our study, we treated one group of ovariectomized rats with bisphosphonate as a positive control (the

ALN group). The major action of bisphosphonate is to inhibit osteoclastic activity and, then, decreases

rate of bone loss as well as bone metabolic rate. Though the serum TRAP activity assay could not provide

direct evidence (Note 1), the results of serum calcium and osteocalcin still indirectly suggested that both

2 of 5

Research Express@NCKU - Articles Digest

bisphosphonate and onion-enriched diet significantly slowed down the bone metabolism rate (Table 2).

Regarding the details of serum bone markers, please refer to our original publication.

Data were presented as mean ± SEM.a-c Mean ± SEM values within a group not sharing the same

superscript are significantly different (p < 0.05).

Due to various limitations in human studies, animal studies provide more possibilities for scientists to

investigate the phenomenon in details. Therefore, serum bone marker assays are relatively indirect

methods. Through tissue level analysis, such as pathological section and staining, we can explore the

issue of interest deeper.

In addition to serum marker assays, we performed a series of histomorphometric analysis. Bone tissues

were fixed, embedded, sectioned, stained and image analyzed in purpose of observing the efficacy of

experimental treatments. As shown by Figure 1, tissue of ovariectomized rats presented serious loss of

spongy bone. Trabeculae almost disappeared within bone marrow cavity. Conversely, animals treated by

oral bisphosphonate showed a significant preservation of spongy bone and, similarly, ovariectomized

rats treated with the highest percentage (14%) of onion-enriched diet also presented a well protection of

bone loss from estrogen deficiency. In addition to histomorphometry, we performed osteoclast staining

and counted the number of osteoclasts. The results showed that both bisphosphonate and onion treated

groups significantly decreased in osteoclast number per area of spongy bone as compared to the non-

treated group (OVX group).

Figure 1 Histology section of groups. Tissues of the ALN and 14%onion groups showed well prevention

of spongy bone (trabecular bone) loss. Arrows, spongy bone unit ─ trabeculae.

3 of 5

Research Express@NCKU - Articles Digest

Moreover, for more directly understanding the effects of different treatments on bone strength, we

measured the biomaterial properties of bone tissue through a typical three-point bending test on femur.

As show by Figure 2, the highest onion-enriched diet group and bisphosphonate group presented

significant higher values in maximal load and energy for maximal load as compared to OVX group.

Figure 2 Biomaterial properties testing of long bone tissue. A. Tissue maximal load; B. Energy for tissue

maximal load; a-c Mean±SEM values within a group not sharing the same superscript are significantly

different (p < 0.05).

Obviously, onion-enriched diet showed an efficacy in protecting bone health, but what would be the

mechanism through which onion benefits bone? Numerous previous studies suggested that high protein

content diets would lower body fluid pH level. This acidic environment might induce more calcium

release from bone and further cause a bone loss. On the other hand, onion-enriched or other high fruit

and vegetable diets would cause an elevation of pH level of body fluid. Then, bone mineral might be

preserve under this base environment.

However, interestingly, previous evidences provided by Dr. Mühlbauer seemed not entirely agree with

this acid-base theory. As shown in Dr. Mühlbauer’s several recently study, onion and/or other fruits and

vegetables probably benefit bone health through a pharmacological pathway.

There are growing number of compounds have been extracted. And, those extracts were separately

verified regarding their efficacy in reducing bone mineral loss. From our point of view, extracts or

specific compounds from onion might be able to benefit bone but the synergistic action among those

extracts or compounds within a natural food might be more valuable than their single effect. For

example, Quercetin-3-0-rutinoside (also called rutin), as one of onion extracts, had been proved to

decrease bone loss of ovariectomized rats. However, the working dose of rutin in previous studies is

about six times higher than naturally consuming onion. Moreover, leeks and wild garlic, which were also

proved about their efficacy on bone mineral loss inhibition, contain rutin with 700-800 times lower than

single-used dose. Thus, the combined or synergistic action from those various components in onion

might be the merit we eat onion naturally. Besides, commercial availability of those extracts might cost

time and money. Therefore, naturally and directly consumption might be a most appropriate way for

people to receive benefits from onion.

4 of 5

Research Express@NCKU - Articles Digest

Regarding the applicability of our study, it would not be practical to eat great quantity of onion as a daily

diet habit. According to Dr. Mühlbauer’s previous studies, there were numerous popular fruits, vegetable

and herbs also verified to inhibit bone mineral loss, such as garlic, potato, carrot, cabbage, cauliflower…

etc. Therefore, base on the discoveries described above, eat more and various fruits and vegetables

would be a most direct and applicable knowledge for the multitude.

Note 1: According to the manual of serum TRAP assay kit, serum TRAP is secreted from osteoclasts.

Therefore, the activity of TRAP would correlate with the total number of osteoclast. In the initial two to

three weeks after ovariectomy, young adult female rats suffer a serious spongy bone losing. Then, this

decreased spongy bone reduces the surface for osteoclast to erode. And, thus, the total osteoclast

number as well as serum TRAP activity decreases.

5 of 5

Research Express@NCKU - Articles Digest

Research Express@NCKU Volume 8 Issue 8 - May 8, 2009 [ http://research.ncku.edu.tw/re/articles/e/20090508/3.html ]

Proteomic analysis of proteins from bronchoalveolar lavage fluid reveals the action mechanism of ultrafine carbon black-induced lung injury in mice Chih-Ching Chang1, Shu-Hui Chen2, Shih-Hsin Ho2, Chun-Yuh Yang3, Hong-Da Wang4, Mei-Ling Tsai4,*

1Department of Environmental and Occupational Health, National Cheng Kung University, Tainan, Taiwan 2Department of Chemistry, National Cheng Kung University, Tainan, Taiwan 3Graduate Institute of Public Health, Kaohsiung Medical University, Kaohsiung, Taiwan 4Department of Physiology, National Cheng Kung University, Tainan, Taiwan mltsai@mail.ncku.edu.tw Proteomics 2007; 7:4388-4397

Recently, there are rapid increases of airborne and engineered

nanoparticles (≦100 nm in diameter; Smaller than bacteria and

epithelial cells). This is due to the strict environmental protection

regulations and the development of nanotechnology. Environmental

protection agency (EPA) around the world regulates industrial or

vehicular emissions on mass output. To meet the regulations, new

internal combustion engines are designed to generate more

nanoparticles because nanoparticles contributes very little to the mass

output. On the highway, nanoparticles can reach 1x107 particles per

cm3 of air. Epidemiologic studies have demonstrated that nanoparticles

play a more significant role in producing respiratory disease and detrimental respiratory effects than larger

particles. At the same time, engineered nano-structured materials are rapidly developed by material

scientists. For example, ultrafine titanium dioxide (ufTiO2) serves as photocatalyst, capable of generating

oxygen radicals to kill pathogens. Carbon nanotubes are one of the most attractive nanomaterials. They are

lightweight materials with strong tensile strength and can conduct electricity better than copper. So, they

have wide applications in electric and aerospace industry. With the increased production and use of these

new nanomaterials, this has created great concern on their possible health effects.

Nanoparticles have the greatest particle number, surface area and surface molecules per unit of deposited

particle mass, compared with other larger particles. These properties enable nanoparticles to escape

phagocytosis by macrophage and induce oxidative stress of target cells. In vivo studies have found that

nanoparticles provoke influxes of polymorphonuclear cells, enhance protein exudation into alveolar space,

prolong particle interstitial retention, and increase lung lymph node burden to a greater extent than fine

particles in rats. After inhaled into the lung, nanoparticles can easily translocate to heart, liver, brain and

kidney within 30 min. They can cause reduced heart rate variability and enhanced thrombosis. Our

previous study has shown that nanoparticle can act through a ROS-dependent pathway to cause pulmonary

edema, through the production of vascular endothelial growth factor (VEGF), and lung injury in mice (1).

1 of 3

Research Express@NCKU - Articles Digest

As for carbon nanotubes, it is found to induce pulmonary interstitial inflammation and granulomatous/

fibrotic changes in mice. These histopathological findings are similar to those found in asbestos-exposed

animals and human.

Figure 1.

Proteomic studies allow qualitative identification or quantitative comparison of proteins from biological

samples of particular disease stage. It is a descriptive

study and offers a powerful alternative first-step to

hypothesis generation. In order to understand more

on the mechanisms involved in the pathogenesis of

nanoparticle-induced lung injury, we take advantage

of proteomic analysis to establish the proteome of

bronchoalveolar fluid (BALF) by 1-D geLC/MS/MS

in the mice exposed to nanoparticle (Ultrafine

carbon black, 14 nm in diameter) (2). The use of 1-D

geLC/MS/MS increases the chance of identifying

high molecular weight proteins, low abundant

cellular receptor and poorly water-soluble membrane and nuclear proteins, which are frequently missed in

conventional 2-D MALDI-MS analysis. A total of thirty-three proteins are identified, including three

membrane proteins [leukemia inhibitor factor receptor (LIFR), epidermal growth factor receptor (EGFR)

and SEC14-like 3] and one high molecular weight protein [protease inhibitor α2M] (Figure 1). In the

validation study, western blot analysis find that LIFR, EGFR, anti-oxidant ceruloplasmin and α2M are

significantly increased in BALF of ufCB group. Furthermore, ufCB exposure reduces the protein

abundances of LIFR and EGFR in the lung tissue (Figure 2). Nanoparticle exposure also increases the

production of ceruloplasmin from pulmonary epithelial cells, indicating increased oxidative stress after

exposure (Figure 3). Taken together, we propose that acute exposure to ufCB caused oxidative stress and

protease release, resulting in epithelial shedding with significantly increased LIFR and EGFR in BALF.

Figure 2.

Figure 3.

Moreover, nanoparticle exposure increases the production of LIF in BAL fluid and decreases the expression

of LIFR in pulmonary epithelial cells. Conceivably, nanoparticle exposure can activate LIF/LIFR pathway.

LIF is a member of the interleukin-6 superfamily. LIF exaggerates inflammatory responses by inducing

2 of 3

Research Express@NCKU - Articles Digest

leukocyte differentiation. It can influence airway inflammation by modulating the expressions of

tachykinin and its receptor. Importantly, LIFR is also present on cholinergic nerve and excitatory non-

cholinergic non-adrenergic (eNANC) sensory nerves of airways. Via its receptor, LIF can upregulate the

contractile effects of sensory nerves and cholinergic nerves on smooth muscle. As a result, LIF may provide

a bi-directional cross-talk between immune systems and neural tissues in inflammation insult. However,

little is known about LIF in the context of nanoparticles-induced pulmonary inflammation and adverse

respiratory effects. Currently, our lab is investigating the role of LIF and its interactions with neural

systems in the development of adverse respiratory outcome after nanoparticle exposure.

References:

1. Chang CC, Chiu HF, Wu YS, Li YC, Tsai ML, Shen CK, Yang CY. The induction of vascular

endothelial growth factor by ultrafine carbon black contributes to the increase of alveolar-capillary

permeability. Environ Health Perspect 2005, 113, 454-460

2. Chang CC, Chen SH, Ho SH, Yang CY, Wang HD, Tsai ML. Proteomic analysis of proteins from

bronchoalveolar lavage fluid reveals the action mechanism of ultrafine carbon black-induced lung

injury in mice. Proteomics 2007; 7:4388-4397

3 of 3

Research Express@NCKU - Articles Digest

Research Express@NCKU Volume 8 Issue 8 - May 8, 2009 [ http://research.ncku.edu.tw/re/articles/e/20090508/4.html ]

Growth of GaAs Oxide Layer Using Photoelectrochemical Method Hsin-Ying Lee Department of Electro-optical Engineering, College of Electrical Engineering and Computer Science, National Cheng Kung University hylee@ee.ncku.edu.tw J. Electrochem. Soci., vol. 155, pp. G141-G143 (2008)

Recently, the conventional silicon-based metal-oxide-semiconductor

field effect transistors (MOSFETs) have enjoyed a tremendous success

in the IC industry. Their performances can be further enhanced, of

course, if the silicon-based MOSFETs are replaced with compound

semiconductors. III-V based MOSFETs would operate with a higher

speed, a lower leakage current, a higher breakdown voltage, and a

higher working temperature capability. These attractive features have

motivated many researchers to investigate the potentials and

performance characteristics of III-V-based MOSFETs. However, unlike

silicon, it is difficult to directly grow the oxide layer with an acceptable

quality on the III-V compound semiconductors. The quality of the

device is limited by the interface contaminants between external

deposited oxide and GaAs, which inherently exist on the surface of the

GaAs wafer before insulator layer deposition. Exploiting new oxidation methods to avoid these possible

disadvantages are obviously of interests. The wet photoelectrochemical (PEC) etching method is a typical

example of this kind, although it is usually used to etch III-V semiconductor. In this work, we were trying to

use the PEC oxidation method to grow an oxide layer on the GaAs surface directly. The parameters of the

PEC method for forming GaAs oxide layer were experimentally examined. The chemical composition, the

atomic bonding and the structure of the resulted surface layers were measured. The results confirmed the

layers to be the required oxides. The influence of the thermal treatment to the oxide layer was also studied.

The general mechanism of the PEC method has been well understood [1]. Consider a PEC system composed

of an n-type GaAs immersed in an electrolyte solution. The band diagram of the n-GaAs/electrolyte

interface resembles the band diagram of the Schottky contact. When above-bandgap photons are absorbed

at the surface layer of the GaAs sample, electron-hole pairs are created. The built-in electric field in the

surface space-charge region will drive holes to the semiconductor/electrolyte interface and electrons to the

interior of the n-type GaAs. Because of the existence of holes at the liquid-solid interface, GaAs will be

oxidized via the following half reactions [2]:

GaAs+6h+→Ga3++As3+ (1)

where h+ indicates the holes.

In the PEC oxidation system, a He-Ne laser with a wavelength of 632.8 nm is used as the light source, which

is compatible with the smaller bandgap of the sample n-type GaAs used in the study. The laser beam is

expanded and then reflected onto the sample dipped in a bath of the electrolytic solution. The pH value of

1 of 4

Research Express@NCKU - Articles Digest

the solution is monitored with a pH meter. An amperometer is connected between two Pt electrodes, of

which one is contacted with the metal mask on the sample and the other is just immersed in the solution.

The sample surface other than the central circular area was covered with a AuGeNi/Au metal mask for

electric contact with the Pt electrode. The diluted HCl or NH4OH were used as the electrolytic solution, of

which the pH value was adjusted by varying the concentration. During the PEC process the GaAs samples

dipped in the solution were illuminated with a He-Ne laser of an intensity of 6.8 mW/cm2 for 30min to

induce the PEC reaction on the GaAs surface.

Fig. 1 The oxide growth rate and dissolution rate as

a function of the pH value of the electrolytic

solution. The PEC treatment time is 30 min.

Figure 1 shows the oxide growth rate and dissolution rate, averaged over 30 min, as a function of the pH

value of the electrolytic solution. The experimental

results show when the pH value is between 4.5 and

8.5, i.e. the solution is weak acidic or alkaline, nearly

no PEC reaction can be observed. When the pH value

is below 3 or above 9 the etching (oxide dissolution)

rate is much larger than the growth rate. Only when

the pH values lies in a narrow region around 3.5 the

growth rate is larger than the etching (dissolution)

rate. In other words, the pH value of 3.5 is the only

suitable condition to be used to directly grow the

oxide layer on GaAs surface. Figure 2 shows that the

thickness of the resulted layer grown on the GaAs

surface under that condition varies with the PEC

treatment time. As shown in Fig. 2, the layer

thickness increases but the growth rate decreases

with the oxidation time. This kind of time

dependence can be understood considering the fact

that the electrolytic solution was more difficult to

permeate through the previously formed oxide layer

to react with the generated holes. Figure 3 shows the

thicknesses of the oxide layers as a function of the

thermal treatment time at different temperature. It

can be seen that in all the cases the thickness of the

GaAs oxide film decreases with both the annealing temperature and the annealing time. Moreover, the

thickness of the oxide layer decreases rapidly within the first 10 min of the treatment and then tends to a

stabilized value for the treatment time above 30 min. This phenomenon indicates that the as-grown GaAs

oxide film has a lower density and become a denser oxide film by thermal treating process. The elements

ratio of O/(Ga+As) in the surface layer derived from the AES data were 1.39, 1.43, 1.51 and 1.52 for the as-

grown GaAs oxide and the oxides annealed at 200, 300 and 400℃ for 30 min in O2 ambience, respectively.

It is evident that the ratio is very close to the value for Ga2O3 and/or As2O3, especially for the annealed

sample. In order to get further information about the bonding structure the XPS spectra of the core-level

Ga3d and As3d of the GaAs oxide films were analyzed. Figures 4(a) shows the XPS spectra of Ga3d, from

which it can be seen that for the as-grown sample the Ga3d spectrum is composed of two bands located at

21 eV and 19.4 eV, corresponding to Ga2O3 and GaAs, respectively. But for samples annealed in O2 ambient

at temperatures 200, 300 and 400℃ only the Ga2O3 signal exists in the spectra. Similarly, as shown in Fig.

4(b), the spectrum of As3d of as-grown sample contains two bands at 44.9 eV and 41 eV, which correspond

2 of 4

Research Express@NCKU - Articles Digest

to As2O3 and GaAs, respectively, but only the As2O3 signal exists in the spectra of the heat treated oxide

films. Based on the above discussion we can reach the observation that the layer formed at the surface of

GaAs by PEC method is really an oxide film of Ga and As. Therefore, the half reaction (1) could be rewritten

as the following reaction:

2GaAs+6H2O+12h+→Ga2O3+As2O3+12H+ (2)

The glancing incident angle X-ray diffraction (GIXRD) measurement gives further information about

the crystallography of the resulted GaAs oxide film. Figure 5 shows the diffraction patterns of the GaAs

oxide films formed by PEC method. It can be seen that for the as-grown GaAs oxide film, no diffraction

peaks can be found. It indicates that the as-grown oxide film has an amorphous structure. But the peaks of

(401) Ga2O3, (111) β-Ga2O3 and (210) As2O3 occurred in the GIXRD spectra of the samples annealed at

temperature 300℃ and 400℃. It indicates that the microstructure of the oxide films changed from an

amorphous to a polycrystalline phase by the thermal treatment.

Fig. 2 The growth rate and thickness of the oxide

layer produced on GaAs surface by PEC method at

pH value of 3.5 as a function of oxidation time.

Fig. 3 Thicknesses of the oxide layers as a function

of the thermal treatment time at various

temperatures.

Fig. 4 XPS spectra for the core-level (a) Ga3d and (b) As3d of the PEC oxide layers, as-grown and

annealed at various temperatures for 30 min.

3 of 4

Research Express@NCKU - Articles Digest

Fig. 5 X-ray diffraction patterns of the PEC oxide layers, as-grown and annealed at various temperatures

for 30 min.

The photoelectrochemical oxidation method was successfully used to directly grow the GaAs oxide film on

the GaAs surface. Only the pH value of about 3.5 is suited to directly grow the oxide layer on GaAs surface.

From the experimental results of EDS, XPS and GIXRD, these results confirmed that the layer could be

identified as Ga2O3 and As2O3, mainly the former. The PEC method is promising in oxide layer growth and

all the fundamental information reported here about the method and the resulted oxide layers would be

useful for developing new isolating layers in various semiconductor devices.

[1] E. H. Chen, D. T. Mclnturff, T. P. Chin, M. R. Melloch and J. M. Woodall, “Use of annealed low-

temperature grown GaAs as a selective photoetch-stop layer”, Appl. Phys. Lett., vol. 68, pp. 1678-1680

(1996).

[2] J. van de Ven and H. J. P. Nabben, “Anisotropic Photoetching of III-V Semiconductors”, J. Electrochem.

Soc., vol. 138, pp. 144-152 (1991).

4 of 4

Research Express@NCKU - Articles Digest

Research Express@NCKU Volume 8 Issue 8 - May 8, 2009 [ http://research.ncku.edu.tw/re/articles/e/20090508/5.html ]

From the Notion of Xing to an Aesthetic of Contrasting – Focusing on the Exploration of Xia Yu’s Poetry Man-Han Yung Department of Chinese Literature, College of Liberal Arts, National Cheng Kung University z9108009@email.ncku.edu.tw Bulletin of Institute of Chinese Literature and Philosophy Academia Sinica, No.31, pp.121-148 (2007)

Author’s attempt in exploring contemporary poetry has

focused on further analyzing poets with different theories. To

be more precisely speaking, the writer intends to unravel

poetic language with different styles and sentence

composition, which aims to find a lead to history involving

misunderstood poets and languages and styles as to their

contributions for modernization in Chinese poetry.

Trace back to source of most ancient poetry – Classic of

Poetry written in a time when poetry is examined for its

structure and style. Han dynasty’s poetry interpreter had passed down “six types of poetry”, which are

“Fong”, ”Ya”, ”Song”, ”Fu”, ”Bi”, and ”Xing”. Until Zhu Xi in Song dynasty (1130-1200), also known as a

philosopher, had recompiled Classic of Poetry’s three hundred poems into three types. We are able to

simply follow instructions of “Fu”, or “Bi”, or “Xing” to fully grasp unbounded imagination of scenes and

emotions. This is a fantastic method to interpret those poets. “Fu”, “Bi”, and “Xing” do not contain

contents; however, they provide connections between external life style images and internal emotions. As

to select particular type of connections, that also affects this poet’s reading method.

This study emphasizes on studying conversion of “Xing” definition that is included into research region of

contemporary poetry, research of aesthetics of contrasting (“contrasting” term is created by the writer to

stimulate aesthetical concept). While the writer was reading and digesting the content of “Xing” type of

poets, they are found that some scenes written in the poems was not completely integrated with emotions

as compared to those in Tong dynasty’s poets. Those scenes in the poem demonstrate occasionally

consistent yet not consistent status. This unknown connection seems to have some similarities with

Taiwan’s postmodern poems few decades ago. However, in order to draw relations between scenes and

emotions in “Xing” type of poets, it is much harder as to rather complicated contents than that in

postmodern poems. Hence, this study picks four scholars from different theories for their explanations of

“Xing” definition as to further extend to modern connotation of “Xing”. For example, Chen Shixiang (1912

– 1971) considers that ‘ “Xing” as sound of group dancers from ancient times, which brought vividly

inspiring atmosphere and held up and are surrounded by one single object….In Classic of Poetry, it wrote

that “Xing” contained characteristic made from fresh world.’

To advance scope of “Xing” definition to a wider level is a philosopher in younger generation, Jiang

1 of 4

Research Express@NCKU - Articles Digest

Nianfong (1955 – 1996). He considers that, “Xing” contains images of human inspiring spirit that can be

seen in many occasions. He also mentions that, in Confucius books, many naturally scenes are portrayed

and many metaphors are conveyed into one feature that is to build up one great character. In Classic of

Poetry, definition of “Xing” can be applied an initial path to unmask mysteries of entire pre-Qin Confucius

theory. From philosophy’s perspective, Jiang rather concerns spiritual scope behind those poetic words.

Yie Jiaying (1924 -), dedicated in study of Classical Poetry and Western Teaching Model, had generated

eight major “abstract images” features of Western poetry from perspective of poetry grammar structure,

such as simile, metaphor, metonymy, symbol, personification, synecdoche, allegory, and objective

correlative, and generated these models into scope of “Bi”. As to relations of “Heart” and “Object”, then

these terms represent simply a relation of “heart” and “object”. As to “Xing” term, in English critic term, it

does not contain a word to translate properly. She also mentions that this implies limited techniques

required to “abstract images” arrangement in Western poetry. As to “Xing”, type of energy for inspiring

writing and reading poems has less connection to direct inspiring type of writing style.

Xu Fuguan (1902 – 1982) has proposed a very impressive description for “Xing” in which he mentions

accidental feature of “Xing”. He has explained that, behind accidental issues, there hides immeasurable

and unconfined emotions. This has huge impacts like a huge magnetic field that can turn anything into

emotional expressions. Consequently, this “accidental issue” did not happen with no cause; on the

contrary, it happened with a significant meaning.

The author had generated four styles from below then combined with own explanations of “Xing” from

Classic of Poetry: ‘ The beauty of “Xing” merges “objects” of different types to build a sense of mystery

towards relationship of contrasting. As for poetry in Tong dynasty, many masterpieces had already been

creating with integrated scenes. However, the unique feature of “Xing” in Classic of Poetry lies in

contrasting instead of integration. In these, there are no comparisons of beauty to ugliness instead there

are meanings as to which objects is located right next to the other. ’

After generating some relevant academic data, the writer is proposing to review “Xing” in Classic of Poetry

from a modern creation perspective. Such as birds, animals, insects, fishes, grasses, trees, lakes, and

rivers, as to daily living tools such as all kinds of timber, mobiles, carts, oils, furs, hair styles, hats, and

clothes can be imagined with different “emotional perspectives” and reproduced in different forms. Even

though all “objects” are not real, they are corresponding with intangible spirits with different emotional

environments.

From an overview of Taiwan poems, the writer had selected the poet, Xia Yu, that is considered to be most

capable of demonstrating stimulus-response model. Xia Yu (1956 - ), first poems collection,

“Memorandum” was published in 1984 and had widely influencing younger generation for over 20 years.

The impact has involved advertising proposals and popular songs’ lyrics in Taiwan. As to evaluate Xia Yu’s

work, it is approximately categorized into three directions: (1) Considered as model for postmodern

society; (2) Considered as best model for female-oriented significance; (3) Considered as great example

from peer poets. Nevertheless, female-oriented significance attempting to overthrow male-oriented

society can also be classified as part of postmodern society phenomenon. Therefore, aside from

admirations of different levels from peer poets, to further analyze Xia Yu’s phenomenon can be generated

as: she established a new generation that gradually enhance Taiwan to transform into a postmodern

society in over 20 years.

As a highly self-conscious poet like Xia Yu, even though she has included

2 of 4

Research Express@NCKU - Articles Digest

《Memorandum》1984

discussions relating to society issues and created a new style to exploit and

lead a new generation; however she has also maintained quality in her

works.We considers that, Xia Yu as a contemporary poet is one of rare

poets that can be assessed using strict attitude as with analyzing classical

poems. Each word in her poems seems to be describing daily life actions

and seem to be writing daily conversation and quoting no classic sayings,

but in fact each word’s sound, favor, weight, and color follows a high level

of restriction and rhythm. Her own punctuation and markings are used

with significances. Hence since her first publication, “Memorandum”, was

published, Taiwan had silently engaged with a revolution of language and

words.

《Fuyushu- Ventriloquism》1991

Amongst Xia Yu’s four publications, “Memorandum” was most quoted. The following

three publications were also receiving lots

feedbacks but are harder to be understood. If

“postmodern” term are still used to explain the

following three publications, it is even not possible

for general critics to analyze publication like

“Salsa”. As for now, following clues of “stimulus-

response structure” to review Xia Yu’s works, from

“Fuyushu- Ventriloquism” initial experiment, “Rub

Ineffable” wilder experiment, to “Salsa”, can be

hardly distinguishing which is the major volume

and which is minor, or the imaginative illustration

for “stimulus” or “response” is disappearing. Xia Yu

has transformed “stimulus-response relationship”.

Each set of lyrics can initialize its “Xing-Stimulus”

meaning and also have a corresponding “Response”

meaning. Therefore, all lyrics can be either

independent, transform, wonder, collide, or merge.

As to level of tangibility and meanings, once these

are under controlled, they are integrating with their own rhythm with no boundary. As each time

background is changed, its content must be updated. Xia Yu poems open up this generation’s endless

pursuing “now” and “migrating” features which is connotation of aesthetics of contrasting. If postmodern

term is truly the tag of our generation, as for its connotation is building up for merging other races, this

feature will evolve to a more mainstream style.

This study as per artistic changes of her four volumes of works concluded three types of analysis relating

to “Xing” meaning of Classic of Poetry: (1) Subverting virtual language of poets from last generation and

respond to tangible object giving virtual meaning tradition in Classic of Poetry; (2) In poems, tangible

objects are interacting mutually using stimulus-response relationship and enrich the content; (3) Entire

performance of “stimulus-response relationship”: constantly form transforming. Using this type of “Xing”

definition to observe Xia Yu’s works, it is discovered that what general critics consider to be puzzled and

unsolvable and meaningless parts can be easily untangled; furthermore, it reads revolutions of Xia Yu’s

works regarding progress of her poem writing skills. This study has converted poems writing methods

from two or three thousand years ago into a modern critic concept; moreover, it provides a brand new

perspective for postmodern poetry that provides answers to Xia Yu’s post works, “Salsa” and following

3 of 4

Research Express@NCKU - Articles Digest

publications.

《Rub Ineffable》1995

《Salsa》1999

If “postmodern” term is a tag of our generation, then with merge of each race, its connotation raises to a

higher level of mainstream style as each feature is migrated. In Chinese literature, except for studying

further into Western classics, maybe it is more needed to utilize postmodern previous principles – trace

back own root and find out the puzzles in some local works and from there it enrich foundation of

postmodern values.Certainly, poets are not writing for one particular concept. Hence, carefully absorbing

contexts of poetry, flavors and smells in these works can be found; furthermore, it perceives some valuable

cultural notations. A good poet can sometimes unconsciously writes out status of future world and make

extensive influences.

To combine “Xing” spiritual condition to postmodern poems(or every kind of arts) connotation, it can be a

very meaningful research. As for now, the author had provided language analysis to one particular poet

(style). Even though, Xia Yu had its own importance, her influence is limited. Hence this research had

only submitted one particular concept and is looking forwards other numerous scholars’ achievements.

4 of 4