检索结果-南通市图书馆

Chemical Research in Chinese Universities 2009年第4期25卷 560-563页

作者： LIU Xiao-qing LI Xiao-hui TENG Hu xiu Zhi-long Department of Bioscience and Biotechnology School of Environmental and Biological Science and Technology Dalian University of Technology Dalian 116024 P. R. China

Stylopeptide 1 synthesized and isolated from different sources exhibits a large activity difference in inhibitory effect on the growth of a cancer *** on the different amounts of methanol and water during synthesis,isolation and purification of the cyclic peptides,molecular dynamics(MD) was employed to simulate the conformation of stylopeptide 1 in methanol and aqueous *** comparative results show that the backbone ring was more rigid in methanol than in *** methanol,two β-turns and three hydrogen bonds were well conserved throughout the simulation,whereas no hydrogen bonds or turns were preserved in *** activity difference of stylopeptide 1 seemed to be attributed to the solvent effect on its conformation.

关键词： Cyclic peptide Methanol Water Molecular dynamics

Fluid Model Modulated by an M/M/1 Working Vacation Queue with Negative Customer

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2018年第2期34卷 404-415页

作者： xiu-li XU Xian-ying WANG Xiao-feng SONG Xiao-qing LI College of Science Yanshan University

This paper investigates a fluid model driven by an M/M/1 queue with working vacations and RCE （Removal of customer in the end） policy of negative customer. In the external environment, the negative customer is not served by the server and only removes the positive customer in the end one-to-one. We establish a fluid flow model based on this stochastic process, and obtain the mean buffer content and the probability of empty buffer for this fluid queue using the LT （Laplace transform） method. Moreover, several special cases of the model here are obtained. Finally, some numerical examples are presented to demonstrate the effects of parameters on the performance indices of the fluid model.

关键词： fluid model negative customer RCE (Removal of customer in the end) policy buffer content LT(Laplace transform)

Immobilization of radioactive fluoride waste in aluminophosphate glass:a molecular dynamics simulation

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2018年第7期29卷 91-102页

作者： Ling-Wei Gao Xiao-Bin Xia xiu-qing Xu Chang-Qi Chen Shanghai Institute of Applied Physics Chinese Academy ofSciencesJiading Campus Shanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

Molecular dynamics(MD) simulations were conducted to investigate the structural and chemical environment of aluminum in aluminophosphate *** glasses have the potential for application in the disposal of radioactive fluoride waste from molten salt reactors(MSR).due to the risks of studying these materials and the limitations of realistic research conditions,MD simulations were used as an alternative method to study the vitrification of radioactive fluoride *** the past decades,aluminophosphate glasses have been studied and they exhibit certain favorable properties for high-level radioactive waste *** work focuses on the effects of fluorine addition on structural changes in the *** observed that glass with composition P_2O_5–Al_2O_3–Na_2O–CaO exhibited a good performance in immobilizing fluoride at low F concentrations(approximately under25 mol%).Significant changes were observed where PO_3F_2 units replaced PO_3F units in the *** fourcoordinated AlO_4 units were increasingly converted into five-coordinated [AlO_xF_y] with the increasing F *** radionuclide Sr in the simulation had the tendency to form six-coordinated octahedrons in the *** conclude that the structural changes resulting from the fluoridewaste added to aluminophosphate glasses does not adversely affect their chemical stability at relatively low F concentrations,i.e.,under 25 mol%.Hence,the use of phosphate glasses is a potential alternative method of fluoride waste disposal.

关键词：动力学模拟放射性核种废物管理氟化物玻璃化分子化学稳定性现实主义

K-Shell Ionization of Molybdenum and Iron by Electron Bombardment

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1996年第3期13卷 175-177页

作者： HE Fu-qing LONG Xian-guan PENG xiu-feng LUO Zheng-ming AN Zhu Institute of Nuclear Science and Technology Sichuan UniversityChengdu 610064

K-ionization cross sections of Mo and Fe by electron impact were measured by detecting characteristic x-ray emitted by thin solid Him targets of known mass thickness with a Si(Li)*** correction of a substrate was done by bipartition model of electron *** experrmenta.1 results are compared with theoretical calculation and empirical formula calculation.

关键词： calculation. correction partition

Wear response of metastable b-type Ti–25Nb–2Mo–4Sn alloy for biomedical applications

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2015年第8期34卷 564-568页

作者： Shun Guo Qi Zheng xiu-Li Hou Xiao-Nong Cheng Xin-qing Zhao Institute for Advanced Materials Jiangsu University School of Materials Science and Engineering Beihang University

The wear response of a newly developed metastable b-type Ti–25Nb–2Mo–4Sn(abbreviated as Ti-2524) alloy was investigated and compared with that of(a+b)-type Ti–6Al–4V alloy. Experimental results show that solution-treated(ST) Ti-2524 specimen has the lowest wear rate due to the combined effects of excellent ductility and lubricative Nb2O5. Although similar Nb2O5 forms on the surface of the cold rolled plus annealed(CRA) Ti-2524 specimen, the beneficial effect of Nb2O5 on the wear resistance is counteracted by the increase in wear rate caused by low elongation. Thus, the wear rate of the CRA Ti-2524 alloy is higher than that of ST Ti-2524 *** for the ST Ti–6Al–4V alloy, no lubricative Nb2O5 forms on its worn surface owing to the absence of Nb. In addition, the ST Ti–6Al–4V alloy exhibits an elongation roughly similar to the CRA Ti-2524 specimen. Therefore,the ST Ti–6Al–4V specimen possesses a higher wear rate than the CRA Ti-2524 specimen.

关键词： Titanium alloy Wear response Low elastic modulus H

Hydrothermal Synthesis and Crystal Structure of a Zinc(Ⅱ)Coordination Polymer Assembled by Dpphen and H_2btec/btec

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2010年第7期29卷 1122-1126页

作者： LI xiu-Mei NIU Yan-Ling WANG qing-Wei LIU Bo Department of Chemistry Tonghua Teachers College Tonghua Jilin 134002 China Department of Chemistry Jilin Normal University Siping Jilin 136000 China

A new metal-organic coordination polymer [Zn2（dpphen）2（H2btec）（btec）0.5]n （dpphen = 4,7-diphenyl- 1,10-phenanthroline, H4btec = 1,2,4, xylic acid） 1 was obtained via hydrotherrnal synthesis and characterized by elemental analysis, TG; IR spectrum and single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group P2 1/n with a = 16.2996（14）, b = 14.3332（12）, c = 25.247（2） A, β = 103.4050（10）°, V= 5737.7（9） A）, C63H37N4O12Zn2, Mr = 1172.71, Dc = 1.358 g/cm3,μ（MoKα） = 0.902 mm^-1, F（000） = 2396, Z = 4, the final R = 0.0684 and wR = 0.1281 for 3728 observed reflections （1 〉 2σ（I））. It exhibits a two-dimensional network structure constructed by mixed ligands of dpphen and H2btec/btec.

关键词： hydrogen bond crystal structure coordination polymer

Gastric carcinoma with osteoclast-like giant cells:a case report and review of the literature

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第3期10卷 237-241页

作者： Li-duan ZHENG xiu-ping YANG Hua-xiong PAN xiu NIE Jun HE qing LV Qiang-song TONG Department of PathologyUnion Hospital of Tongji Medical College Huazhong University of Science and Technology Wuhan 430022 China Department of Surgery Union Hospital of Tongji Medical College Huazhong University of Science and Technology Wuhan 430022 China

Gastric carcinoma with osteoclast-like giant cells （OGCs） is an extremely rare tumor. So far, only six cases have been reported in the literature. Here we report an additional case of this tumor in a Chinese 78-year-old man presented with abdominal pain, vomiting, and hematemesis. Physical examination and gastroscopy revealed a tumor in the gastric antrum. The biopsy and pathological findings indicated a gastric adenocarcinoma with OGCs, which were present in both the tumor and the metastatic lymph nodes. Further immunohistochemical staining indicated that OGCs were reactive with CD68, CD45, and vimentin protein, but not with pancytokeratin, carcinoembryonic antigen, or epithelial membrane antigen, suggesting the monocytic/histiocytic derivation of these OGCs. In situ hybridization for Epstein-Burr virus showed no nuclear positivity in either adenocarcinoma or OGCs. Postoperative follow-up showed that the patient had survived for at least 6 months without recurrence. Further investigation is warranted to clearly define the prognostic significance of OGCs in gastric carcinoma.

关键词： Gastric carcinoma Adenocarcinoma Osteoclast-like giant cell (OGC)

基于色散光学模型的^(40)Ca核子散射数据计算

在线全文

学校读者我要写书评

暂无评论

物理学报 2023年第22期72卷 111-116页

作者：赵岫鸟杜文青渤海大学物理科学与技术学院锦州121013

对钙同位素核数据的研究具有重要的理论价值和应用前景,其中^(40)Ca作为天然钙最主要的同位素,是一种重要的材料核素.本文采用色散光学模型对球形核^(40)Ca的核子弹性散射数据进行计算.通过考虑色散光学模型势中实部势的非定域性以及虚... 详细信息

对钙同位素核数据的研究具有重要的理论价值和应用前景,其中^(40)Ca作为天然钙最主要的同位素,是一种重要的材料核素.本文采用色散光学模型对球形核^(40)Ca的核子弹性散射数据进行计算.通过考虑色散光学模型势中实部势的非定域性以及虚部势的壳间隙结构,实现了对^(40)Ca相关核子散射数据的良好描述,其中包括中子总截面、核子弹性散射角分布以及分析本领.此外,本文计算了色散光学模型势的实部体积分,其随能量的变化图像在费米能附近出现了明显的色散峰结构.

关键词：核子散射色散光学模型弹性散射

Hot deformation behavior and microstructure evolution of a Mg–Gd–Nd–Y–Zn alloy

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2016年第7期35卷 532-536页

作者： xiu-Li Hou Yan Li Peng Lv Jie Cai Le Ji qing-Feng Guan School of Materials Science and Engineering Jiangsu University

The hot deformation behavior of homogenized Mg-6.5Gd-l.3Nd4）.7Y-0.3Zn alloy was investigated during compression at temperatures of 250-400 ℃ and at strain rates ranging from 0.001 to 0.100 s- 1. Microstructure analyses show that the flow behaviors are associated with the deformation mechanisms. At the lower temperatures （250-300 ℃）, defor- mation twinning is triggered due to the difficult activation of dislocation cross-slip. Dynamic recrystallization （DRX） ac- companied by dynamic precipitation occurs at the temperature of 350 ℃ and influences the softening behavior of the flow. DRX that develops extensively at original grain boundaries is the main softening mechanism at the high temperature of 400 ℃ and eventually brings a more homogeneous mi- crostructure than that in other deformation conditions. The volume fraction of the DRXed grains increases with tem- perature increasing and decreases with strain rate increasing.

关键词： Mg-Gd-Nd-Y-Zn alloy Hot deformation Microstructure Dynamic recrystallization

Hydrothermal synthesis and characterization of nano-petal nickel hydroxide

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2015年第9期34卷 667-672页

作者： Wen-xiu He Yong-Qiang Zhang Qian-qing Liang Wen-Quan Jiang Hai-Feng Sun School of Chemistry Engineering Inner Mongolia University of Science and Technology Analysis & Measurements Research Center General Rearch Institute for Non-Ferrous Metals

The current article reports a preparation method of nano-petal nickel hydroxide, which was synthesized using urea as a precipitator by hydrothermal method. Nickel hydroxide samples with different microstructural characteristics were prepared by changing molar ratio of nickel/urea and reaction time. The prepared nickel hydroxide samples were characterized using X-ray diffraction(XRD) and scanning electron micrography(SEM).Electrochemical performances of the samples were then determined under charging–discharging rate of 0.2C. The influences of different conditions of the hydrothermal synthesis method on microstructure parameters of nickel hydroxide were analyzed, while relationships between microstructural characteristics parameters of nickel hydroxide and the electrochemical performances of nickel electrode were also explored.

关键词： Hydrothermal synthesis Nano-petal Electrochemical