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Preparation and Properties of High Hardness and Oxidation Resisting Coating Using Electric Arc Spray

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材料热处理学报 2004年第05B期25卷 984-987页

作者： liZhuo-xin CUIli WANGjiang-ping TANGChun-tian BeijingUniversityofTechnology Beijing100022

A coating with high hardness, wear and oxidation resistance was prepared by electric arc spray. The hardness, bonding strength, abrasive wear and values of porosity and oxidation resistance of the coating were investigated. The microstructures and function of Cr3C2 of the coating were analyzed. The results showed surface Rockness Hardness HR30 reached 72.5 and average bond strength reached 49.1Mpa. Also porosity value was less than 2%. In addition, it was found from the comparison between the coating and 45CT coating that, oxidation resistance of the coating was less than that of 45CT, but the abrasive wear of the coating was obvious better than that of 45CT.

关键词：硬度磨损性能高温氧化电弧喷镀

Responsivity and noise characteristics of AlGaN/GaN-HEMTterahertz detectors at elevated temperatures

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Chinese Physics B 2019年第5期28卷 355-360页

作者： Zhi-Feng Tian Peng Xu Yao Yu jian-Dong Sun Wei Feng Qing-Feng Ding Zhan-Wei Meng Xiang li Jin-Hua Cai Zhong-xin Zheng xin-xing li lin Jin Hua Qin Yun-Fei Sun Key Laboratory of Nano Devices and Applications Suzhou Institute of Nano-tech and Nano-bionics Chinese Academy of Sciences School of Physical Science and Technology Shanghai Technology University Shanghai Institute of Ceramics Chinese Academy of Sciences University of Chinese Academy of Sciences Nano Science and Technology Institute University of Science and Technology of China School of Nano Technology and Nano Bionics University of Science and Technology of China Beijing Huahang Radio Measurement & Research Institute College of Electronic and Information Engineering Suzhou University of Sciences and Technology

The responsivity and the noise of a detector determine the sensitivity. Thermal energy usually affects both the responsivity and the noise spectral density. In this work, the noise characteristics and responsivity of an antenna-coupled AlGaN/GaN high-electron-mobility-transistor(HEMT) terahertz detector are evaluated at temperatures elevated from 300 K to 473 K. Noise spectrum measurement and a simultaneous measurement of the source–drain conductance and the terahertz photocurrent allow for detailed analysis of the electrical characteristics, the photoresponse, and the noise behavior. The responsivity is reduced from 59 mA/W to 11 mA/W by increasing the detector temperature from 300 K to 473 K. However,the noise spectral density maintains rather constantly around 1–2 pA/Hz^(1/2) at temperatures below 448 K, above which the noise spectrum abruptly shifts from Johnson-noise type into flicker-noise type and the noise density is increased up to one order of magnitude. The noise-equivalent power(NEP) is increased from 22 pW/Hz^(1/2) at 300 K to 60 pW/Hz^(1/2) at 448 K mainly due to the reduction in mobility. Above 448 K, the NEP is increased up to 1000 pW/Hz^(1/2) due to the strongly enhanced noise. The sensitivity can be recovered by cooling the detector back to room temperature.

关键词： terahertz detection gallium nitride noise spectrum responsivity

Role of CD80 in stimulating T lymphocyte activation

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World Journal of Gastroenterology 2006年第6期12卷 880-884页

作者： De-Chun li xing-Guo Zhu Yong Zhang jian-xin Fu Departmentof General Surgery the First Affiliated Hospital of Soochow UniversitySuzhou 215006 Jiangsu Province China

AIM： To observe biological characteristics of hepatocarcinoma cells before and after CD80 transfection and to compare the effect of CD80-transfected hepatocarcinoma cells on T lymphocyte activation. METHODS： Retro virus vector carrying CD80 gene was transfected into HepG2 cells to establish CD80transfected hepatocarcinoma cells （HepG2/hCD80）. Flow cytometry （FCM） was performed to detect CD80 expression in the transfected cells. RT-PCR was used to evaluate CD80 expression at mRNA level. In the presence of anti-CD3 mAb, the proliferation of T lymphocyte was observed by M＇n＇. Meanwhile, the expression of activated molecule marker CD25 was analyzed through FCM. RESULTS： A stable cell line HepG2/hCD80 expressing the human CD80 was established. Growth curve showed that the molecule CD80 could obviously decrease the growth of tumor cells. HepG2/hCD80 was evidenced to have a potency to enhance T cell proliferation and upregulate CD25 expression. CONCLUSION： CD80 transfection can lower malignant phenotype of hepatocarcinoma cells. CD80 transfection has a down-regulatory effect to activated T cells in vitro.

关键词： Hepatocarcinoma cells CD80 Transfection T lymphocyte activation

A microcosmic discrete occupant evacuation model based on individual characteristics

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Science China(Technological Sciences) 2004年第5期47卷 608-615页

作者： YANG lizhong li jian ZHAO Daoliang FANG Weifeng FAN Weicheng State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230026 China State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230026 China State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230026 China State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230026 China State Key Laboratory of Fire Science University of Science and Technology of China Hefei 230026 China

The research of occupant evacuation in an emergency is of great benefit to building design and evacuation guidance. In this paper a microcosmic discrete evacuation model based on Cellular Automata (CA) is presented, in which the occupants?individual characteristics are considered. Thus, our model has given a description of evacuation route choice with influencing factors, including: individual knowledge of the building, individual realization of the emergency development, and the attractive and repulsive force between occupants. This model differs somewhat from other models in the attention to the associative and separate effect of influencing factors, based on occupants behaviors. In addition, the model could reveal the phenomenon of escape in fire, as those simulations involving a fire condition have shown.

关键词： evacuation, cellular automata, microcosmic discrete model, occupant behavior, fire.

Synthesis and antioxidant activities of flavonoids derivatives,troxerutin and 3',4',7-triacetoxyethoxyquercetin

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Chinese Chemical Letters 2013年第3期24卷 223-226页

作者： jian-Dong Xu li-Wei Zhang Yu-Fa liu College of Chemistry Chemical Engineering and Materials ScienceEngineering Research Center of Pesticide and Medicine Intermediate Clean ProductionMinistry of EducationShandong Normal University

Syntheses of two very important derivatives of quercetin, troxerutin and 3＇, 4＇, 7-triacetoxyethoxyquercetin were described. The latter was synthesized by highly selective esterification reaction in first time. The compounds were characterized by NMR, 1R and Mass spectroscopy. Additionally, the antioxidant activities of the compounds were tested by means of improved pyrogallol autoxidation method. This was the first in using this method to test the antioxidant activities of these two compounds in vitro, The optimum system of pyorgallol autoxidation spectrophotometry was investigated and established according to the reaction rules, The assay indicated that these compounds showed noticeable antioxidant activities, and compound 2 was much more effective as a free radical scavenger than the compound 1 vitamin C was used as a reference material,

关键词： QuercetinTroxerutin3' 4'. 7-TriacetoxyethoxyquercetinAntioxidant

The Material Behavior and Fracture Mechanism of a Frangible Bullet Composite

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Chinese Physics Letters 2013年第7期30卷 143-147页

作者： li jian RONG Ji-li ZHANG Yu-Ning XU Tian-Fu li Bin Guangxi Key Laboratory of Automobile Components and Vehicle Technology Guangxi University of Science and TechnologyLiuzhou 545006 School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081

The quasi-static and dynamic compressive mechanical properties of a bullet composite are investigated using the scattered spot technique,an electronic universal testing machine,and a Split–Hopkinson pressure *** stress-strain curves under static and dynamic loading are also obtained,and the strain rate effect is *** rupture structure is observed under a scanning electron microscope,and the microscopic damage mechanism of the bullet composite is *** show that the composite is sensitive to the strain rate,such that the compressive strength of the composite increases with increased strain *** relationship of the compressive strength and elastic modulus with the logarithmic strain rate is nonlinear.

关键词： composite strain dynamic

A new C_(27)-steroidal glycoside from Ophiopogon japonicus

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Chinese Chemical Letters 2008年第1期19卷 82-84页

作者： jian Zhong Wang li Ming Ye Xiao Bing Chen West China College of Pharmacy Sichuan University Chengdu 610041 China

A new C27-steroidal glycoside with three known compounds were isolated from the tuber of Ophiopogonjaponicus （Thunb.） Ker-Gawl. Based on the spectral analysis, including HRMS, 1H NMR, 13C NMR, DEPT, 1H-1H COSY, HMQC and HMBC, their chemical structures were determined as pennogenin-3-O-α-L-rhamnopyranosyl-（1→ 2）-β-D-xylopyranosyl-（1→ 4）-13-D-gluco- pyranoside （1）, pennogenin-3-O-α-L-rhamnopyranosyl-（1→ 2）-β-D-glucopyranoside （2）, ophiopojaponin C （3） and ophiopogonin D （4）. 2007 jian Zhong Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

关键词： Ophiopogon japonicus C27-steroidal glycoside

Excitation of Annual Polar Motion by the Pacific,Atlantic and Indian Oceans

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Chinese Journal of Astronomy and Astrophysics 2007年第6期7卷 831-838页

作者： JinMa Yong-Hong Zhou De-Chun liao jian-li Chen Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 Graduate School of Chinese Academy of Sciences Beijing 100049 Center for Space Research University of Texas at Austin Austin TX 78712 USA

The global oceans play important roles in exciting the annual polar motion besides the atmosphere. However, it is still unclear about how large the regional oceans contribute to the annual polar motion. We investigate systemically the contributions of the Pacific, Atlantic and Indian Oceans to the excitation of the annual polar motion, based on the output data of ocean current velocity field and ocean bottom pressure field from ＂Estimating the Circulation and Climate of the Ocean （ECCO）＂ ocean circulation model over the period 1993-2005. The result shows that due to its particular location and shape, the Atlantic Ocean makes a less significant contribution to the x-component of the annual polar motion excitation than the Pacific and Indian Oceans, while all these three oceans contribute to the y-component of the annual polar motion excitation to some extent.

关键词： annual polar motion excitation oceanic angular momentum function(OAMF) -- atmospheric angular momentum function (AAMF)

Occurrence and conceptual sedimentary model of Cambrian gypsum-bearing evaporites in the Sichuan Basin, SW China

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Geoscience Frontiers 2018年第4期9卷 1179-1191页

作者： Hong liu Xiucheng Tan Yonghao li jian Cao Bin Luo State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Division of Sedimentology and Hydrocarbon Accumulation Petro China Key Laboratory of Carbonate ReservoirSouthwest Petroleum University School of Earth Science and Technology Southwest Petroleum University School of Earth Sciences and Engineering Nanjing University Research Institute of Exploration and Development PetroChina Southwest Oil and Gas Field Company

During the Cambrian, gypsum-bearing evaporites formed in the Sichuan Basin, SW China. These rocks are important for oil and gas sealing, but details of their distribution and origin are not well established. This study examines the regional distribution and origin of the gypsum-bearing evaporites using a comprehensive analysis of drilling data from 34 wells, 5 measured cross-sections in the basin and surrounding area, and 96 maps of area-survey data. Results show that in the stratigraphic succession, the gypsum-bearing evaporites occur mainly in the Lower Cambrian Longwangmiao Formation, the Middle Cambrian Douposi Formation, and the Middle-Upper Cambrian Xixiangchi Group. Geographically, the rocks are found mainly in the southeastern part of the basin, and the distribution of deposits shows an overall SW-NE trend. The sedimentary environments for evaporite formation were evaporative lagoon and inter-platform basin in a platform setting. Gypsum was generated by the underwater concentration of sea water in a strongly evaporative environment. Both an evaporative restricted platform and a mixeddeposition restricted platform model appear to be applicable to the development of gypsum in the Sichuan Basin. The gypsum-bearing evaporites with the best sealing capacity are located mostly in the southeastern part of the basin. These constraints can be applied directly to regional exploration, and have implications for the regional paleogeography and paleoclimate.

关键词： Sichuan Basin Cambrian Gypsum-bearing evaporite Evaporative lagoon Inter-platform basin Platform