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Effect of Nitrogen Ion Implantation on the Structure and Corrosion Resistance of Equiatomic NiTi Shape Memory Alloy

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Journal of Wuhan university of Technology(Materials Science) 2006年第4期21卷 36-39页

作者：华英杰 department of Chemistry Hainan Normal University Haikou 571158China

To protect the surface of NiTi from corrosion, an ion implantation method was proposed. In the present work, a surface oxidized sample was implanted with nitrogen at energy of 100 keV. The corrosion resistarwe property was examined by the anodic polarization method in a simulated body fluid （SBF） at a temperature of 37 ℃ and contrasted to non-implanted NiTi samples. The composition and structure of the implanted layers were investigated by XPS. The experimental results from the electrochemical measurements provide an evidence that the nitrogen ion-implantation increases the corrosion resistance of NiTi shape memory alloy.

关键词： biocompatibility NiTi shape memory alloy ion implantation corrosion resistance

Kinetics Study on the Thermal Decomposition of Europium p-methyl-benzoate Complex with 1,10-penanthroline under Non-isothermal Con-ditions

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Rare Metals 2001年第2期20卷 133-136页

作者： Huifang Yang, Jianjun Zhang, Ruifen wang (department of Material, Shjiazhuang Railway College, Shijiazhuang 050043,{2. Experimental Center, Hebei normal university, Shijiazhuang 050016,{2.) Shijiazhuang Railway Coll Dept Mat Shijiazhuang 050043 Peoples R China Hebei normal Univ Expt Ctr Shijiazhuang 050016 Peoples R China

The thermal decomposition reaction of Eu-2.p-MBA)(6)(PHEN)(2. (p-MBA=CH3C6H4COO, methylbenzoate; PHEN=C12.8N2. 1,10-phenanthroline) was studied in a static atmosphere using TG-DTG method. The thermal decomposition process of the complex was determined and its kinetics was investigated. Kinetic parameters were obtained from the analysis of TG-DTG curves by means of the Achar method and the Madhusudanan-Krishnan-Ninan (MKN) method. The most probable mechanism functions of the thermal decomposition reaction for the first stage are: f(alpha) =(1-alpha)(2., g(alpha) = (1-alpha)(-1)-1. The activation energy for the first stage is 2.5.18 kJ/mol, the entropy of activation DeltaS is 2.7.32.J/mol and the Gibbs free energy of activation DeltaG is 12..04 W/mol.

关键词： thermal decomposition non-isothermal kinetics mechanisms Eu(III) complex

Design and implementation of an optical simulation environment for bioluminescent tomography studies

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Progress in Natural Science:Materials International 2007年第1期17卷 87-94页

作者： LI Hui, TIAN Jie, LUO Jie, LU Yujie, CONG Wenxiang and wang Ge ( department of Education Technology, Capital {2. university, beijing 100037, china Key Laboratory of Complex Systems and Intelligence Science, Institute of Automation, Chinese Academy of Sciences, beijing 100080, china Bioluminescent Tomography Laboratory, department of Radiology & department of Biomedical Engineering, university of Iowa, Iowa City, Iowa 52.42. USA) [a]Departhent of Education Technology Capital Normal University Beijing China [b]Key Laboratoiy of Omplex Systems and Intelligence Science Institute of Automation Chinese Academy of Sciences Beijing China [c]Bioluminescent Tomography Laboratoiy Department of Radiology & Department of Biomedical Engineering University of Iowa Iowa City tIowa USA

As a challenging task for bioluminescent tomography simulation, a virtual optical environment is needed to solve the forward problem accurately, that is, to achieve a high precision for bioluminescent signal synthesis on the external body surface of a small animal. The molecular optical simulation environment named MOSE is implemented using the C++ programming language and the OpenGL techniques, including a user-friendly interface with interactive tools facilitating users' operations. The accuracy of the virtual optical environment is verified by error analysis of mesh simplification and comparison between MOSE results and experimental data. This virtual optical environment is accurate, flexible and efficient to simulate the photon propagation in complicated tissues, which has a great potential to become a software platform for bioluminescent tomography studies and other molecular imaging applications.

关键词： molecular imaging biolumlnescent tomography photon propagation Monte Carlo method.

HIGH-ENERGY PROTON IRRADIATION EFFECTS ON GaAs/Ge SPACE SOLAR CELLS

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Acta Metallurgica Sinica(English Letters) 2001年第6期14卷 463-466页

作者： R. wang (The Key Laboratory of Beam Technology and Materials Modification of Ministry of Education, Institute of Low Energy Nuclear Physics, beijing normal university {2. Radiation Center, {2. 100875, china) S.D. Yao (department of Technical Phys Inst. of Energy Nucl. Phys. Beijing Normal Univ. Beijing 100875 China

This paper reports the high-energy proton irradiation effects on GaAs/Ge space solar cells. The solar cells were irradiated by protons with energy of 5-2. MeV at fluence ranging from 1×109 to 7×1013 cm-2. and then their electric parameters were measured at AM0. It was shown that the Isc, Voc and Pmax decrease as the proton energy increasing, and the degradation is relative to proton irradiation-induced defect with a level of Ec-0.41 eV in irradiated GaAs/Ge cells.

关键词： Germanium High energy physics Irradiation Protons Semiconducting gallium arsenide

Geomorphologic evidence of phased uplift of the northeastern Qinghai-Tibet Plateau since 14 million years ago

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Science china Earth Sciences 2004年第9期47卷 822-833页

作者： LU Huayu1, wang Xiaoyong1, AN Zhisheng1, MIAO Xiaodong1, ZHU Rixiang3, MA Haizhou2. LI Zhen4, TAN Hongbing2.& wang Xianyan1 1. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075{2. 2. Qinghai Institute of Salt Lakes, Chinese Academy of Sciences. Xining 810008,{2. 3. Institute of Geology and Geophysics, Chinese Academy of Sciences, beijing 10002.,{2. 4. department of Geography, Qinghai normal university, Xining 810008,{2. Chinese Acad Sci Inst Earth Environm State Key Lab Loess & Quaternary Geol Xian 710075 Peoples R China Chinese Acad Sci Qinghai Inst Salt Lakes Xining 810008 Peoples R China Chinese Acad Sci Inst Geol & Geophys Beijing 100029 Peoples R China Qinghai normal Univ Dept Geog Xining 810008 Peoples R China

A typical sequence of fluvial terraces and aeolian deposits overlying these ter- races were multidisciplinary investigated. New evidences for uplift process of the northeastern Qinghai-Tibetan Plateau in the past 14 million years were obtained. At least 11 river terraces along Huangshui, the first-class tributary of Yellow River, at the Xining-Huzhu region are identi- fied. While the first one (T1) is classified as an accumulation terrace, the others are all basement river terraces, which consist of the Tertiary sandstone and siltstone bedrock, fluvial gravel and pebbles and the overlying aeolian loess-Red Clay deposit. Samples from the aeolian deposits were examined for paleomagnetic stratigraphic reconstruction (1030 samples), luminescence dating (16 samples), magnetic susceptibility and grain-size distribution (more than 4000 sam- ples). The luminescence dating and stratigraphic correlation suggest that terraces of Tll, T10, T8, T7, T3, T2. T1 were formed at 14, 11.3, 1.55, 1.2. 0.15, 0.07 and 0.01 million years ago, re- spectively. Sedimentological analysis and geomorphological observation indicate that formation and evolution of these terraces were mainly driven by tectonic uplift. Therefore, the terrace se- quence provides an ideal geological record, of the uplift process of the northeastern during the past 14 million years, and the timings of the terraces formation are regarded as the timings of tectonic uplift. The significant uplifting events took place at 14, 11.3, 1.2.and 0.15 mil- lion years ago, respectively. The fluvial incision at the Xining-Huzhu region is less than 100 m during a period of ~12.million years in the Miocene era (between the Tll and T9), while the Huangshui River had incised 432.m during the past 1.2.million years (from T7 to the present floodplain). The river incision process clearly demonstrates that accelerated rising of the north- eastern Qinghai-Tibet Plateau during the late Cenozoic, and provides new evidence of previous thoughts

关键词： river terrace, tectonic uplift, loess-Red Clay, the past 14 million years, northeastern Qinghai-Tibet Plateau.

Geochemical constraints from hydrothermal fluid inclusions of altered deformation zone type Au(Ag)deposits in Yunkai area, South china

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Chinese Science Bulletin 1999年第S2期44卷 230-232页

作者： wang Zuwei~1, ZHANG Haihua~2. YAO Dongliang~2.and ZHOU Yongzhang~3 1. department of Geography, Tianjin {2. university, Tianjin 300071, china 2. Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, china 3. department of Earth Sciences, Zhongshan university, Guangzhou 5102.5, china eeszhou@*** department of Geography Tianjin Normal University Tianjin 300071 China Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China department of Earth Sciences Zhongshan University Guangzhou 510275 China

THE altered deformation zone type Au (Ag) deposits share an important part from the precious metallicore deposits in the Yunkai area, South china. Their formation is a history of poly-stage evolution. Pre- liminary source strata, Calidoniam metamorphism, Indosinian-Yanshanian ductile shear deformation andassociated hydrotheraml alteration all play certain roles in the history. This note discusses the geochemical conditional of the hydrothermal fluids during mineralization. Two representative ore deposits, the Pangxidong Ag(Au) deposit and Hetai Au deposits are selectedfor this study. They are hosted in altered ductile shear zones. Wall-rock hydrothermal alteration is bothspatially and temporally associated with the development of the ductile shear system. Silicification occurred throughout the whole alteration process. There are three groups of quartz: thepredeformational quartz, the early stage hydrothermal quartz, and the late stage hydrothermal quartz asso-

关键词： precious metallic deposit fluid inclusions mineralizing fluid South china.

Some Simple Estimates for the Singular Values of Matrices

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Acta Mathematicae Applicatae Sinica 2002年第1期18卷 117-122页

作者： Chuan-long wang, Guo-jian ZHANGdepartment of {2., normal College of Shanxi university, Taiyuan 030012. chinadepartment of Applied {2., Taiyuan university of Technology, Taiyuan, 03002., china Institute of mathematics Normal College of Shanxi University Taiyuan China department of Applied mathematics Taiyuan University of Technology Taiyuan China

We first provide a simple estimate for || A-1||∞and||A-1||1 of a strictly diagonally dominant matrix A. On the Basis of the result, we obtain an estimate for the smallest singular value of A. Secondly, by scaling with a positive diagonal matrix D, we obtain some simple estimates for the smallest singular value of an H-matrix, which is not necessarily positive definite. Finally, we give some examples to show the effectiveness of the new bounds.

关键词： Singular value estimates H-matrix

Distinguishing malignant from normal stomach tissues and its in vivo, in situ measurement in operating process using FTIR Fiber-Optic techniques

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Science china Chemistry 2005年第2期48卷 167-175页

作者： XU Yizhuang1, YANG Limin1, XU Zhi3, ZHAO Ying2. LING Xiaofeng3, LI Qingbo1, wang Jiansheng4, ZHANG Nengwei3, ZHANG Yuanfu1 & WU Jinguang1 1. The State Key Laboratory of Rare Earth Materials and Applications, College of Chemistry and Molecular Engineering, Peking university, {2. 100871, china 2. Institute of Chemistry, Chinese Academy of Sciences, {2. 100080, china 3. department of Surgery, Third Hospital, Peking university, {2. 100083, china 4. department of Oncology Surgery, the First Hospital of Xi’an Jiaotong university, Xi’an 710061, china Correspondence should be addressed to Wu Jinguang (email: wujg@***) 1. The State Key Laboratory of Rare Earth Materials and Applications College of Chemistry and Molecular Engineering Peking University 100871 Beijing China 2. department of Surgery Third Hospital Peking University 100083 Beijing China 3. Institute of Chemistry Chinese Academy of Sciences 100080 Beijing China 4. department of Oncology Surgery the First Hospital of Xi’an Jiaotong University 710061 Xi’an China

Gastric tissue samples were studied using mid-IR fiber-optic attenuated total reflectance (ATR) spectroscopy. FTIR spectra of 90 tissue samples from 48 patients, including 32.normal and 58 malignant tissue samples, were chosen as examples. Malignancy was usually characterized by the absence of CH and C=O bands, a weak amide II band near 1545 cm-1, a shift of the amide I band to lower wave number, a decrease in the ～1450 cm-1 peak to less than the～1400 cm-1 peak. Subtraction spectra indicate that the amide I and amide II bands of normal and malignant tissues have larger differences in peak positions and relative intensities. The statistical analysis results confirm this conclusion. The results indicate that FTIR fiber optic techniques provide important information about cancerous tissue of the stomach, which can be used to differentiate the malignant tissue from the normal tissue. Based on the above results we successfully realize the detection of the tumor tissues of digestive tract in vivo and in situ. And the results of detection cancer near operating room and in vivo and in situ in the operating room are consistent with the conclusions for the samples stored in liquid N2. which is the basis for the clinical application.

关键词： FTIR, Fiber-Optics, stomach tissues, cancer, diagnosis.

Cubic Lienard Equations with Quadratic Damping (Ⅱ)

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Acta Mathematicae Applicatae Sinica 2002年第1期18卷 103-116页

作者： Yu-quan wang, Zhu-jun Jingdepartment of Applied {2., College of Science, Nanjing Agricultural university, Nanjing 2.0095,chinadepartment of {2., Hunan normal university, Changsha 410081, china & Academy of {2.and System Sciences, Chinese Academy of Sciences, beijing 100080, china Institute of Applied mathematics College of Science Nanjing Agricultural University Nanjing China department of mathematics Hunan Normal University Changsha China Academy of mathematics and System Sciences Chinese Academy of Sciences Beijing China

Applying Hopf bifurcation theory and qualitative theory, we show that the general cubic Lienard equations with quadratic damping have at most three limit cycles. This implies that the guess in which the system has at most two limit cycles is false. We give the sufficient conditions for the system has at most three limit cycles or two limit cycles. We present two examples with three limit cycles or two limit cycles by using numerical simulation.

关键词： Cubic lienard equations limit cycles stability Hopf bifurcation