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A MODIFIED VARIABLE-PENALTY ALTERNATING DIRECTIONS METHOD FOR MONOTONE VARIATIONAL INEQUALITIES

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Journal of Computational Mathematics 2003年第4期21卷 495-504页

作者： Bing-shengHe Sheng-liWang HaiYang DepartmentofMathematics NanjingUniversityNanjing210093China DepartmentofCivilEngineering TheHongKongUniversityofScience~TechnologyClearWaterBayKowloonHongKong

Alternating directions method is one of the approaches for solving linearly constrained separate monotone variational inequalities. Experience on applications has shown that the number of iteration significantly depends on the penalty for the system of linearly constrained equations and therefore the method with variable penalties is advantageous in practice. In this paper, we extend the Kontogiorgis and Meyer method [12] by removing the monotonicity assumption on the variable penalty matrices. Moreover, we introduce a self-adaptive rule that leads the method to be more efficient and insensitive for various initial penalties. Numerical results for a class of Fermat-Weber problems show that the modified method and its self-adaptive technique are proper and necessary in practice.

关键词： Monotone variational inequalities Alternating directions method Fermat-Weber problem.

SYNTHESIS OF HYPERBRANCHED CONJUGATIVE POLY(ARYLENEETHYNYLENE)S BY ALKYNE POLYCYCLOTRIMERIZATION

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Chinese Journal of Polymer Science 2005年第1期23卷 1-3页

作者： HanPeng Rong-huaZheng Hong-chenDong De-minJia Ben-zhongTangb DepartmentofChemistry TheHongKongUniversityofScience＆TechnologyClearWaterBayKowloonHongKongChina InstituteofMaterialScienceandEngineering SouthChinaUniversityofTechnologyGuangzhou510641China

A series of new hyperbranched poly(aryleneethynylene)s are synthesized by the copolycyclotrimerizations oftetraynes(Ⅰand Ⅱ)with aliphatic monoynes(A-C)catalyzed by tantalum-,niobium-,and cobalt-based *** thereactions proceed smoothly and soluble polymers of high molecular weights(M_w up to 3.8×10~4)are obtained in high yields(up to 97%).

关键词： Polycyclotrimerization Hyperbranched polymers Poly(aryleneethynylene)s.

An Exact Anisotropic Quark Star Model

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Chinese Journal of Astronomy and Astrophysics 2002年第3期2卷 248-259页

作者： M.K.Mak T.Harko DepartmentofPhysics TheHongKongUniversityofScienceandTechnologyClearWaterBayHongKong DepartmentofPhysics TheUniversityofHongKongPokfulamHongKong

We present an exact analytical solution of the gravitational field equations describing a static spherically symmetric anisotropic quark matter distribution. The radial pressure inside the star is assumed to obey a linear equation of state, while the tangential pressure is a complicated function of the radial coordinate. In order to obtain the general solution of the field equations a particular density profile inside the star is also assumed. The anisotropic pressure distribution leads to an increase in the maximum radius and mass of the quark star, which in the present model is around three solar masses.

关键词： Stars - quark: interior solution: anisotropy

Morphological dependence of passive epitaxial oxide films on nanoparticles of iron

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电子显微学报 2002年第5期21卷 601-602页

作者： FUNGKwokKwong ZHANGXi0xiang DepartmentofPhysics TheHongKongUniversityofScienceandTechnologyClearWaterBayKowloonHongKongSARCHina DepartmentofPhysics TheHongKongUniversityofScienceandTechnologyClearWaterBayKowloonHongKongSA

Nanoparticles of iron passivated by thin oxide films are {110} rhombic dodecahedra truncated by {100} planes with various degree of truncation. The degree of truncation is defined as the ratio of the edge length of the truncated part to the full edge length of the rhombic dodecahedron. Uyeda and coworkers have shown that nanoparticles with low degree of truncation are bounded by six small {100} and twelve large {110} facets while nanoparticles with high degree of truncation are bounded by large {100} and small {110} facets.

关键词：电子显微镜组织形貌晶体生长氧化物薄膜铁耐蚀防护

A Minor New Flavone from Scutellaria baicalensis Georgi

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Chinese Chemical Letters 2002年第5期13卷 428-429页

作者： HongYanWANG SuiXuXU 等 DepartmentofBiochemistry HongKongUniversityofScienceandTechnologyClearWaterBayHongKong DpeartmentofChemistry ShenyangPharmaceuticalUniversityShenyang110016

A new flavone, 6, 2-dihydroxy-5, 7, 8, 6-tetramethoxyflavone, was isolated from the roots of Scutellaria baicalensis. Its structure was established on the basis of spectral evidences.

关键词： Flavone 6,2-dihydroxy-5,7,8,6-tetramethoxyflavone Scutellaria baicalensis Georgi.

Biologically active cis-cinnamic acid occurs naturally in Brassica parachinensis

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Chinese Science Bulletin 2003年第6期48卷 555-558页

作者： YINZhiqi TEWenchai 等 DepartmentofBiology TheHongKongUniversityofScieceandTechnologyClearWaterBayHongKongSARChina DeepartmentofChemistry TheHongKongUniversityofScienceandTechnologyClearWaterBa

The biologically active cis-cinnamic acid (cis-CA) has been perceived as a synthetic plant growth regulator for decades. However, in the present study, we found that cis-CA actually exists as a naturally occurring compound in a Brassica plant. This natural growth- regulating substance presents in both the sunlight-irradiated leaf tissue and the non-irradiated root tissue. The concentra-tions of cis-CA in both tissues are comparable to the biologi-cally effective levels of those major plant hormones. The presence of cis-CA in root tissue suggests that it may be pro-duced through both light-dependent and -independent path- ways or it can be transported from a plant organ to another.

关键词：顺式桂皮酸生物活性天然生成植物激素芸苔属植物

RUPTURING OF POLYMER FILMS WITH RUBBING-INDUCED SURFACE DEFECTS

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Chinese Journal of Polymer Science 2003年第2期21卷 123-128页

作者： B.Du F.C.Xie Y.J.Wang O.K.C.Tsui O.K.C.Tsui InstituteofNanoScienceandtechnologyandPhysicsDepartment HongKongUniversityofScienceandTechnologyClearWaterBayKowloonHongKong InvitedlecturepresentedattheInternationalSymposiumonPolymerPhysics 2002QingdaoChinaReceivedJuly9，2002

It has been a long-standing question whether dewetting of polymer film from non-wettable substrate surfaceswherein the bicontinuous morphology never forms in the dewetting film is due to spinodal instability or heterogeneousnucleation. In this experiment, we use a simple method to make the distinction through introduction of topographical defectsof the films by rubbing the sample surface with a rayon cloth. Spinodal dewetting is identified for those films that dewet by acharateristic wavevector, q, independent of the density of rubbing-induced defects. Heterogeneous nucleation, on the otherhand, is identified for those with q increasing with increasing density of defects. Our result shows that PS films on oxidecoated silicon with thickness less than ≈ 13 nm are dominated by spinodal dewetting, but the thicker films are dominated bynucleation dewetting. We also confirm that spinodal dewetting does not necessarily lead to a bicontinuous morphology in thedewetting film, contrary to the classic theory of Cahn.

关键词： Dewetting Polymer thin films Spinodal instability Heterogeneous nucleation

BLOSSOMS： Building Lightweight Optimized Sensor Systems on aMassive Scale

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Journal of Computer Science & technology 2005年第1期20卷 105-117页

作者： WenGao LionelM.Ni Zhi-WeiXu S.C.Cheung LiCui QiongLuo InstituteofComputingtechnology ChineseAcademyofSciencesBeijing100080P.R.China DepartmentofComputerScience TheHongKongUniversityofScienceandTechnologyClearWaterBayKowloonHongKongSpecialAdministrativeRegionP.R.China

As a joint effort between the Chinese Academy of Sciences and the Hong KongUniversity of Science and technology, the BLOSSOMS sensor network project aims to identify researchissues at all levels from practical applications down to the design of sensor nodes. In thisproject, a heterogeneous sensor array including different types of application-dependent sensors aswell as monitoring sensors and intruding sensors are being developed. Application-dependentpower-aware communication protocols are also being studied for communications among sensor nodes. Anontology-based middleware is built to relieve the burden of application developers from collecting,classifying and processing messy sensing contexts. This project is also developing a set of toolsallowing researchers to model, simulate/emulate, analyze, and monitor various functions of sensornetworks.

关键词： sensor network sensor node communication protocol middleware networksimulation network monitor

Dynamics of Below—Band—Gap Carrier in Highly Excited GaN

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Chinese Physics Letters 2003年第5期20卷 749-752页

作者： GUOBing WONGKam-Sing YEZhi-Zhen JIANGHong-Xing LINJing-Yu DepartmentofPhysics TheHongKongUniveristyofScienceandTechnologyClearWaterBaykowloonHongKong StateKeyLaboratoryofsiliconMaterials ZhejiangUniversityHangzhou310027 DepartmentofPhysics KansasStateUniversityManhattanKansas66506-2601USA

Femtosecond time-resolved reflectivity was used to investigate below-band-gap (3.1 eV) carrier dynamics in a nominally undoped GaN epilayer under high excitation. A 2.5-ps rising process can be observed in the transient trace. This shot rising time results from the hot phonon effects which can cause a delayed energy relaxation of the initial photocarriers toward the band edge. From the density dependence of the carrier dynamics, the Mott density was estimated to be 1.51-1.56×1019 cm-3. Below the Mott density, the initial probed carrier dynamics was explained to the effect of acoustic phonon-assisted tunnelling for localized states, where a significant excitation density dependence of the tunnelling probability was observed due to the optically induced bandtail extension to lower energies. Above the Mott density, the measured carrier dynamics reflected the relaxation of an electron-hole plasma, in which a distinct fast decay component of 2.3 ps was observed due to the onset of nonlinear relaxation processes such Auger recombination.

关键词： GaN 氮化镓半导体反射率动力学光谱分析性质热声效应隧道效应