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MORPHOLOGICAL STUDY ON THE ORIENTED CHITOSAN FILM OBTAINED FROM PRE-SHEARED LIQUID CRYSTALLINE SOLUTION IN DICHLOROACETIC ACID

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Chinese Journal of Polymer Science 2001年第4期19卷 385-390页

作者： Zhong-ming Hu Li-heng Wu Da-cheng Wu Shou-xi Chen State Key Laboratory of Polymer physics and Chemistry, Center for Molecular Science, Institute of Chemistry Chinese Academy of Sciences, Beijing 100080, china china Textile Academy Beijing 100025, china Textile {4., sichuan university chengdu 610065. china china Text Acad Beijing 100025 Peoples R China Chinese Acad Sci Inst Chem Ctr Mol Sci State Key Lab Polymer Phys & Chem Beijing 100080 Peoples R China sichuan Univ Coll Text Chengdu 610065 Peoples R China

The oriented chitosan films obtained from pre-sheared liquid crystalline chitosan/dichloroacetic acid (DCA) solutions were studied by means of polarized optical microscopy (POM), scanning electron microscopy (SEM), infra-red dichroism technique and wide angle X-ray diffraction (WAXD). The sheer induced band texture in the film was found to correspond to the sinusoidal fibrillar microstructure along the shearing direction on the basis of POM and SEM observations. The sinusoidal fibril was found to be lying within the film plane. The model of chitosan molecular orientation in the pre-sheared film with band texture can be established assuming that the main chain orients in the shearing direction and the side group is perpendicular to the shearing direction. The WAXD azimuthal scanning at 2 theta = 20 degrees indicates that the (002) plane orients perpendicular to the shearing direction.

关键词： chitosan morphology orientation shear induced band texture liquid crystalline solution

Preliminary results of the study on wind erosion in the Qinghai-Tibetan Plateau using 137Cs technique

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Chinese Science Bulletin 2000年第11期45卷 1019-1025页

作者： YAN Ping, DONG Guangrong, ZHANG Xinbao & ZHANG Yiyun1. Key Laboratory of Environmental Change and Natural Disaster, the Ministry of Education of china, Beijing Normal university, Beijing 100875, china 2. Institute of Desert Research, Chinese Academy of Sciences, Lanzhou 730000, china 3. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, {4. 61004., china 4. Department of physics, sichuan Union university, {4. 61004., china Key Laboratory of Environmental Change and Natural Disaster the Ministry of Education of China Beijing Normal University Beijing China Institute of Desert Research Chinese Academy of Sciences Lanzhou China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China Department of physics Sichuan Union University Chengdu China

The worldwide fallout of caesium-137 (137Cs) associated with the nuclear weapon tests during the 1950s and 1960s has provided a valuable man-made tracer for studies of soil erosion and sediment delivery. But relatively few researchers have used it to estimate wind erosion. In this note, the 137Cs technique is introduced into the studies of wind erosion and its modern processes inthe Qinghai-Tibetan Plateau. Two 137Cs reference inventories of 982.11 and 2 376.04.Bq · m-2 wereestablished preminarily, distributed in the south and middle-north parts of the studied arearespectively. By analyzing the patterns of 137Cs depth profiles from sampling sites, the aeolianprocesses of erosion and deposition in nearly 4. years have been revealed, i.e. the shrub coppicedunes (S1) and semi-fixed dunefields (S3) experienced the alternation of erosion and deposition,while the grasslands (S4. S6 and S7) and dry farmlands (S5) suffered erosion only. By using 137Csmodel, the average wind erosion rates for shrub coppice

关键词： 137Cs technique Qinghai-Tibetan Plateau wind erosion.

Energy Spectra of the Tunable Laser Crystal Gd3GasO12:Cr3+ and Their Pressure-Induced Shifts

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Communications in Theoretical physics 2004年第1期 141-150页

作者： MA Dong-Ping~(1,2) 1 Department of Applied physics,sichuan university,chengdu {4.china 2 International Centre for Materials physics,Academia Sinica,Shenyang 110015,china

By means of both the theory for pressure-induced shifts（PS）of energy spectra and the theory for shiftsof energy spectra due to electron-phonon interaction（EPI）,at 300K,the‘pure electronic’contributions and the contri-butions from EPI to R1line,R2line,and U band of GGG:Cr3+as well as their PS have been calculated,*** total calculated results are in good agreement with all the experimental *** physical origins have *** is found that the mixing-degree of|t（2～2）(3T1)e4.2〉and|t232E〉base-wavefunctions in the wavefunctions ofR1level of GGG:Cr3+is considerable under normal pressure,and the mixing-degree rapidly decreases with *** change of the mixing-degree with pressure plays a key role for PS of R1line or *** 300K,boththe temperature-independent contribution to R1line（or R2line or U band）from EPI and the temperature-dependentone are *** remarkable difference between pressure-dependent behaviors of PS of R1lines of GGG:Cr3+andGSGG:Cr3+results from the differences of their microscopic *** features of emission spectra of GGG:Cr3+at various pressures have satisfactorily been explained.

关键词： high-pressure effect line shift spin-orbit interaction electron-phonon interaction d-orbital coupling between t22(3T1)e4.2 and t23 2E tunable laser crystal

Synthesis of potassium hexatitanate whiskers using hydrothermal method

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Rare Metals 2009年第1期28卷 24-32页

作者： WANG Ju LI Chun LIANG Bin WANG Xiaoqing college of Chemical Engineering Siehuan University Chengdu 610065 China Department of Chemistry Tsinghua University Beijing 100084 China

High quality potassium hexatitanate whiskers were hydrothermally synthesized in one step under moderate temperature and pressure conditions. Effects of the titanium source and reaction conditions on the hydrothermal reaction rate, product phase component, and morphology of whiskers were investigated. The results show that the reactivity of hydrated titania, anatase TiO2, and rutile TiO2 with KOH decreases in turn, and with hydrated titania as titanium source, it is difficult to obtain potassium hexatitanate whiskers with good morphology. In contrast, uniform potassium hexatitanate whiskers with a length of 10-20 μm and a diameter of 200-700 nm were obtained using anatase TiO2 as titanium source. The investigation demonstrates that the initial KOH concentration, annealing temperature and time, molar ratio of K2O/TiO2, etc. significantly affect the morphology of the as-synthesized whiskers. The optimized synthesis condition is as follows： anatase as a titanium source 10 wt.% KOH solution; annealing temperature and time of 300℃ and 5 h, respectively; K2O/TiO2 molar ratio of 5, etc. A rhombic potassium hexatitanate was prepared under the optimum condition and the whisker grew along the [110] direction. The reaction mechanism was discussed.

关键词： potassium hexatitanate whiskers hydrothermal method synthesis

Optical waveguides in LiNbO_3 and stoichiometric LiNbO_3 crystals by proton exchange

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Science china(physics,Mechanics & Astronomy) 2008年第10期51卷 1479-1488页

作者： LI ShiLing college of physics and Engineering, Qufu Normal university, Qufu 273165, china School of physics and Microelectronics, Shandong university, Jinan 250100, china 1. college of physics and Engineering Qufu Normal University Qufu 273165 China 2. School of physics and Microelectronics Shandong University Jinan 250100 China

The formation of optical planar waveguides in LiNbO3 and stoichiometric LiNbO3 crystals by proton exchange was reported. The prism-coupling method was used to characterize the dark-line spectroscopy at the wavelength of 633 and 1539 nm, re-spectively. The mode optical near-field outputs from proton-exchanged LiNbO3 and SLN waveguides at 633 nm were presented. The mode field from stoichiometric LiNbO3 (SLN) waveguide is lighter and more uniform than that from LiNbO3 waveguide, which means the quality of the waveguide in SLN crystal is better than that of the LiNbO3 waveguide. For proton-exchanged LiNbO3 waveguides, the evo-lution of the refractive index profile with annealing was presented. The disorder profiles of Nb atoms in proton-exchanged LiNbO3 waveguides were obtained by Rutherford backscattering/channeling technique. It is shown that the longer the exchange time, the larger the displacement of Nb atoms.

关键词： optical waveguide proton exchange LiNbO3 crystal stoichiometric LiNbO3 crystal

Image space analysis for variational inequalities with cone constraints and applications to traffic equilibria

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Science china Mathematics 2012年第4期55卷 851-868页

作者： LI Jun 1,& HUANG NanJing 2 1 college of Mathematics and Information,china West Normal university,Nanchong 637009,china 2 Department of Mathematics,{4. university,chengdu 610064.china 1. college of Mathematics and Information China West Normal University Nanchong 637009 China2. Department of Mathematics Sichuan University Chengdu 610064 China

In this paper,the image space analysis (for short,ISA) is employed to investigate variational in- equalities (for short,VI) with cone *** separation for VI with cone constraints is characterized by using the normal cone to a regularization of the image,and saddle points of the generalized Lagrangian func- ***-type necessary and sufficient optimality conditions for VI with cone constraints are presented by using a separation *** functions and weak sharpness for VI with cone constraints are also investi- ***,the obtained results are applied to standard and time-dependent traffic equilibria introduced by Daniele,Maugeri and Oettli.

关键词： variational inequality image space analysis linear separation necessary and sufficient optimalitycondition traffic equilibrium

Theoretical study of aging effects on LaNi_(5) tritium storage

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Science china(physics,Mechanics & Astronomy) 2005年第6期48卷 676-686页

作者： PING Feilin1,2, JIANG Gang1, ZHANG Lin2 & ZHU Zhenghe1 1. Institute of Atomic and Molecular physics, sichuan university, chengdu 610065. china 2. Research Center of Laser Fusion, Mianyang 621900, china 1. Institute of Atomic and Molecular physics Sichuan University 610065 Chengdu China 2. Research Center of Laser Fusion 621900 Miangyang China

The electronic structure and energy of La2Ni10H12 and La2Ni10H11He (He is at tetrahedral, octahedral or twelve-face polyhedral interstitials) double cells have been calculated using the density functional theory. Their equilibrium structure, energy bands, electronic density of states (DOS) and X-ray diffraction are presented and discussed. The results indicate the helium-3 produced due to the decay of tritium is most possibly sited at twelve-face polyhedral and octahedral interstices and changes the thermodynamic properties of LaNi5 tritide system. The changes due to aging such as the reduction in the isotherm plateau pressure, increase of the isotherm plateau slope, and appearance of deeply trapped hydrogen are caused not only by the lattice expansion, but also by modification of the electronic structure due to the presence of He.

关键词： LaNi5 alloy, density functional theory, electronic structure, aging.

The fundamental theory of abstract majorization inequalities

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Science china Mathematics 2009年第10期52卷 2287-2308页

作者： YANG DingHua college of Mathematics and Software Sciences, sichuan Normal university, chengdu 610066, {4.Abstract college of Mathematics and Software Sciences Sichuan Normal University Chengdu 610066 China

Using the axiomatic method, abstract concepts such as abstract mean, abstract convex function and abstract majorization are proposed. They are the generalizations of concepts of mean, convex function and majorization, respectively. Through the logical deduction, the fundamental theorems about abstract majorization inequalities are established as follows: for arbitrary abstract mean Σ and $ \Sigma ' $ and abstract ∑ ? $ \Sigma ' $ strict convex function f(x) on the interval I, if x i , y i ∈ I (i = 1, 2,..., n) satisfy that $ (x_1 ,x_2 , \ldots ,x_n ) \prec _n^\Sigma (y_1 ,y_2 , \ldots ,y_n ) $ then $ \Sigma ' $ {f(x 1), f(x 2),..., f(x n )} ? $ \Sigma ' $ {f(y 1), f(y 2),..., f(y n )}. This class of inequalities extends and generalizes the fundamental theorem of majorization inequalities. Moreover, concepts such as abstract vector mean are proposed, the fundamental theorems about abstract majorization inequalities are generalized to n-dimensional vector space. The fundamental theorem of majorization inequalities about the abstract vector mean are established as follows: for arbitrary symmetrical convex set $ \mathcal{S} \subset \mathbb{R}^n $ , and n-variable abstract symmetrical $ \overline \Sigma $ ? $ \Sigma ' $ strict convex function $ \phi (\bar x) $ on $ \mathcal{S} $ , if $ \bar x,\bar y \in \mathcal{S} $ , satisfy $ \bar x \prec _n^\Sigma \bar y $ , then $ \phi (\bar x) \geqslant \phi (\bar y) $ ; if vector group $ \bar x_i ,\bar y_i \in \mathcal{S}(i = 1,2, \ldots ,m) $ satisfy $ \{ \bar x_1 ,\bar x_2 , \ldots ,\bar x_m \} \prec _n^{\bar \Sigma } \{ \bar y_1 ,\bar y_2 , \ldots ,\bar y_m \} $ , then $ \Sigma '\{ \phi (\bar x_1 ),\phi (\bar x_2 ), \ldots ,\phi (\bar x_m )\} \geqslant \Sigma '\{ \phi (\bar y_1 ),\phi (\bar y_2 ), \ldots ,\phi (\bar y_m )\} $ .

关键词： abstract mean abstract convex function abstract majorization abstract majorization inequality 26A51 26B25 39B62 52A01 60E15

The abnormal lattice contraction of plutonium hydrides studied by first-principles calculations

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Chinese physics B 2013年第3期22卷 426-430页

作者：敖冰云史鹏郭咏高涛 Science and Technololgy on Surface physics and Chemistry Laboratory Institute of Atomic and Molecular physics Sichuan University

Pu can be loaded with H forming complicated continuous solid solutions and compounds,and causing remarkable electronic and structural *** potential linearized augmented plane wave methods combined with Hubbard parameter U and the spin-orbit effects are employed to investigate the electronic and structural properties of stoichiometric and non-stoichiometric face-centered cubic Pu hydrides（PuHx,x=2,2.25,2.5,2.75,3）.The decreasing trend with increasing x of the calculated lattice parameters is in reasonable agreement with the experimental findings.A comparative analysis of the electronic-structure results for a series of PuH x compositions reveals that the lattice contraction results from the associated effects of the enhanced chemical bonding and the size effects involving the interstitial *** find that the size effects are the driving force for the abnormal lattice contraction.

关键词： plutonium density functional theory strongly correlated electron system crystal structure