检索结果-南通市图书馆

MICROSTRUCTURE　OF　Ti－B－NFILM　AND　INTERFACEFORMED　BY　N　ION　BOMBARDMENTON　A　Ti－B　FILM

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 1996年第3期9卷 211-216页

作者： YANG Qiaoqin ZHAO Lihua WU Lijun LI Xueqian and DU Haiqing(Materials Test and Research center, Hunan University, Changsha 410082, china)WEN Lishi(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, china)

Ti-B-N film was deposited on W18Cr4 V high speed steels by using N ion bombardment on an EB-ion plating Ti-B film. It was found that Ti, B and N in the film are homogeneous, but there exists an extended diffusion zone at the film / substrate interface on the basis of the results of IPMA, EPMA and TEM. The boron content of the film is 9.5 at.%, as given by nuclear reaction analysis. The ratio of nitrogen to titanium of the film is about 0.94, as given by EPMA. The width of a high N concentration region in the Ti-B-N film fowned by N ion bombardment of a Ti-B film is about 100 nm; N and Ti penetrates into the substrate, resulting in a wide interfacial diffusion zone. The width of the diffusion zone obtained with TEM and EDAX is about 20 nm. μ-diffraction patterns of the interface show that FeTi, Fe_2 Ti, and Ti_2N existin the interfacial diffusion zone. TEM observation of film and interface show a dense and fine nano-crystalline structure of the film and a dense close interfactal bonding of the film to substrate. Electron diffraction patterns and the values of electrun binding energy by XPS show that the film consists mainly of fcc TiN, with dispersed simple orthorhombic TiB, cubic BN and simple hexagonal Ti-B-N phases. The results show that the N ion hombardment extends the film / substrate interfacial diffusion zone and stimulates chemical reaction both in the film and interface.

关键词： microstructure Ti-B-N film N ion bombardment interface

Studying of HTAC for Very Low Heat Value Gas and Regenerative Burners Structure

在线全文

学校读者我要写书评

暂无评论

Studying of HTAC for Very Low Heat Value Gas and Regenerativ...

Urgent Need for Contraceptive Education and Services in Chinese Unmarried Undergraduates:A Multi-campus Survey

2004年世界工程师大会

作者： Rao Wentao Baosteel Technology center, Shanghai, 201900, china,

High tempreature air combustion (HTAC) technology is introduced in this paper. HTAC technology for burning very low heat value gas is discussed by theoretical calculation. The very low heat value gas would not be released into air for no user if the combustion air and gas would be preheated through recoverying the waste heat from exit flue gas.. By means of calculating the the temperature distribution and Nox, a kind new regenerative burner is developed.

关键词： low heat value gas regenerative burner structure

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Huazhong University of Science and Technology(Medical Sciences) 2011年第4期31卷 426-432页

作者：周远忠熊锦文李洁黄诗韵商学军刘国辉张玫玫尹平魏晟熊承良 Institute of Family Planning Tongji Medical CollegeHuazhong University of Science and Technology School of Public Health Zunyi Medical College Department of O&G Hubei Provincial Corps HospitalChinese People's Armed Police Forces Reproductive Medical center Renmin Hospital of Wuhan University Department of Andrology Nanjing General Hospital of Nanjing Military Region Institute for Population and Family Planning of Chongqing City Sexual Health Education Research center Capital Normal University Department of Epidemiology School of Public HealthTongji Medical CollegeHuazhong University of Science and Technology

In order to ascertain prevalence rate of premarital sexual intercourse,unintended pregnancy and abortion,and evaluate associated factors of unintended pregnancy among undergraduates from all over china,the representative sample of unmarried undergraduates was obtained by using a multi-stage,stratified,probability cluster design,and data were collected by using a survey questionnaire.62 3.6 available responders were gained.11.6% of them acknowledged having experiences of premarital sexual intercourse（standardized prevalence rate of sexual intercourse was 13.8%）.3..5% of students active in premarital sex acknowledged undergoing unintended pregnancy.76.2% of pregnant students selected abortion to end *** students active in premarital sex,46.2% used contraception at the first sexual intercourse,28.2% replied ＂always＂ using contraception in sexual *** rate of using condoms,oral contraceptives（OCs）,and withdrawal among students who had used contraception was 52.0%,3..0%,and 27.2% respectively.＂No preparation for sex＂（40.3.）,＂pleasure decrement＂（3..1%）,＂won＇t-be-pregnancy in occasional sexual intercourse＂（3..2%） were their common excuses for using no *** identified risk factors for unintended pregnancy among students active in premarital sex by multivariate analysis were as follows：having no steady lover [having no steady lover vs having a steady lover：odds ratio（OR）,1.875;95% confidence interval（CI）,1.629-2.158],unaware of the course of conception（unaware vs aware：OR,2.023.95% CI,1.811-2.260）,considering abortion not endanger women＇s physical and mental health（no endangerment vs endangerment：OR,2.659;95% CI,2.265-3.121）,nonuse of contraception（never use vs always use：OR,1.682;95% CI,1.295-2.185）.Medical students were not less likely to experience an unintended pregnancy than nonmedical students（OR,1.111;95% CI,0.906-1.287）.The substantial proportion of unintended pregnancy among undergraduates indicates a need for convenient and targeted contra

关键词： students unsafe sex contraception unplanned pregnancy china

The intracellular mechanism of alpha-fetoprotein promoting the proliferation of NIH 3.3.cells

在线全文

学校读者我要写书评

暂无评论

Cell Research 2002年第2期12卷 151-156页

作者： MENG SEN LI, PING FENG LI, FBI YI YANG, SHI PENG HE, Guo GUANG DU, GANG LI1 Department of Biochemistry and Molecular Biology, 2 Department of Biophysics, Health Science center, Peking University, Beijing 100083. china 1Department of Biochemistry and Molecular Biology Health Science Center Peking University Beijing 100083 China 1Department of Biochemistry and Molecular Biology Health Science Center Peking University Beijing 100083 China 1Department of Biochemistry and Molecular Biology Health Science Center Peking University Beijing 100083 China 2Department of Biophysics Health Science Center Peking University Beijing 100083 China 1Department of Biochemistry and Molecular Biology Health Science Center Peking University Beijing 100083 China 1Department of Biochemistry and Molecular Biology Health Science Center Peking University Beijing 100083 China

AIM The existence and properties of alpha-fetoprotein (AFP) receptor on the surface of NIH 3.3.cells and the effects of AFP on cellular signal transduction pathway were investigated. METHODS The effect of AFP on the proliferation of NIH 3.3.cells was measured by incorporation of 3.-TdR. Receptor-binding assay of 125I-AFP was performed to detect the properties of AFP receptor in NIH 3.3.cells. The influences of AFP on the [cAMP]i and the activities of protein kinase A (PKA) were determined. Western blot was used to detect the change of K-ras P21 protein expression. RESULTS The proliferation of NIH 3.3.cells treated with 0-80 mg/L of AFP was significantly enhanced. The Scatchard analysis indicated that there were two classes of binding sites with KD of 2.722×10-9M (Bmax=12810 sites per cell) and 8.93.× 10-8M (Bmax=119700 sites per cell) respectively. In the presence of AFP (20 mg/L), the content of cAMP and activities of PKA were significantly elevated . The level of K-ras P21 protein was upregulated by

关键词： Alpha-fetoprotein receptor signal transduction monoclonal antibody gene expression.

血吸虫病低度流行区化疗对象筛查方法的比较及费用-效果分析

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

实用寄生虫病杂志 2002年第4期10卷 145-148页

作者：李军宏汪天平肖祥吴维铎吕大兵方国仁蔡伟郑江许静王蓉蓉中国疾病预防控制中心寄生虫病预防控制所上海200025 安徽省寄生虫病防治研究所安徽芜湖241000 安徽省当涂县血吸虫病防治站安徽当涂243100

目的寻找血吸虫病低度流行区简便、有效、经济、适用的化疗对象筛查方法。方法分别以粪检、询检、间接血凝法 (IHA)及胶体染料试纸条法 (DSIA)对居民进行血吸虫病筛查 ,并分析和评价。结果各项评价指标 IHA均优于其它方法 ,与粪检总符... 详细信息

目的寻找血吸虫病低度流行区简便、有效、经济、适用的化疗对象筛查方法。方法分别以粪检、询检、间接血凝法 (IHA)及胶体染料试纸条法 (DSIA)对居民进行血吸虫病筛查 ,并分析和评价。结果各项评价指标 IHA均优于其它方法 ,与粪检总符合率为 93..5 1 % ,阳性预告值为 2 4.49% ;DSIA各指标略低于 IHA;询检法相对较差。卫生经济学费用 -效果分析 ,IHA检出 1例感染者所需费用明显高于其他方法。结论 IHA具有简便、有效的优点 ,在感染率 <5 %的低度流行区是一种较可取的筛查方法 ,但所需费用仍较高 ;DSIA较 IHA更为简便、快速、廉价。

关键词：血吸虫病低度流行区化疗筛查方法询检法间接血凝法胶体染料试纸条法费用-效果分析

Breast cancer screening guideline for Chinese women

在线全文

学校读者我要写书评

暂无评论

Cancer Biology & Medicine 2019年第4期16卷 822-824页

作者： china Anti-Cancer Association,National C china Anti-Cancer Association National Clinical Research Center for Cancer(Tianjin Medical University Cancer Institute and Hospital)

The incidence of breast cancer is increasing year-by-year and is the most common malignant tumor in Chinese *** the past half century, numerous studies in various countries around the world have confirmed that breast cancer screening is the most effective way of improving the rate of early diagnosis, survival rate, and the quality of life of breast cancer patients. Developed countries such as European countries, the United States.

关键词： cancer diagnosis breast

在线全文

学校读者我要写书评

暂无评论

凹腔火焰稳定器回流区稳焰机理

推进技术 2011年第5期32卷 684-689页

作者：黄思源桂业伟白菡尘黄恩源中国空气动力研究与发展中心高超声速冲压发动机技术重点实验室四川绵阳621000 中国空气动力研究与发展中心四川绵阳621000

借助凹腔火焰稳定器模型的数值计算结果研究了高总焓超声速流条件下凹腔火焰稳定器回流区中可能存在的稳焰机制。研究表明,高总焓来流条件下凹腔火焰稳定器回流区中至少存在着三种稳焰机制:回流区燃烧机制、回流区点燃机制和回流区整流... 详细信息

借助凹腔火焰稳定器模型的数值计算结果研究了高总焓超声速流条件下凹腔火焰稳定器回流区中可能存在的稳焰机制。研究表明,高总焓来流条件下凹腔火焰稳定器回流区中至少存在着三种稳焰机制:回流区燃烧机制、回流区点燃机制和回流区整流机制。三种稳焰机制分别利用了高焓来流条件下回流区的三种不同特性:回流区燃烧机制利用了回流区的混合特性;回流区点燃机制利用了回流区的高温特性;回流区整流机制利用了回流区的阻流特性。计算结果表明,三种稳焰机制都有可能成为凹腔火焰稳定器回流区中起主导作用的稳焰机制。

关键词：回流区燃烧机制点燃机制整流机制

HOW TO OBTAIN HIGH RESOLUTION DNA MALDI MASS SPECTRA

在线全文

学校读者我要写书评

暂无评论

质谱学报 1999年第Z1期 91-92页

作者： ZHAO Shankai, DENG Huimin, LI Jun, LAI Zhihui, REN Sanxiang (Instrumental Analysis & Research center, Zhongshan University, Guangzhou 510275 china)

Microstructure of fibrils separated from polyacrylonitrile fibers by ultrasonic etching

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2010年第6期53卷 1489-1494页

作者： WANG QiFen,WANG ChengGuo,YU MeiJie,MA Jie,HU XiuYing & ZHU Bo Carbon Fiber Engineering Research center,Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education),Shandong University,Jinan 250061,china 1. Carbon Fiber Engineering Research center Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) Shandong University Jinan 250061 China

Polyacrylonitrile (PAN) fiber is an important precursor fiber for high performance carbon *** properties of the final carbon fiber depend strongly on the nature of the PAN *** PAN fibrils were separated successfully from fibers by ultrasonic etching and were systematically investigated by field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM).It is found that in certain ultrasonic etching conditions (at 75±2oC for 6 h with a frequency of 40 kHz) the PAN fibers are dissolved in the 95 wt.% aqueous dimethylsulphoxide (DMSO) solution;the fibrils consisting of numerous periodic lamellae with thickness of 3.-45 nm and perpendicular to the fiber axis are separated in the 90 wt.% aqueous DMSO solution;and the fibrils with smooth surface exfoliated from the PAN fibers are obtained in the 70-90 wt.% aqueous DMSO *** periodical structure of fibrils was observed in HRTEM,which indicates that there are different densities and two phases in *** PAN fibers are dissolved layer by layer with increasing ultrasonic etching *** fiber surface experiences ultrasonic cleaning,selective etching,excessive etching and dissolution,and then the sublayer experiences the same *** are numerous periodic lamellae in fibrils of nascent *** means that the fibrils with lamellae are formed by orientation and crystallization in shearing field of spinning pipe and drawing stress field of coagulation bath.

关键词： carbon fibers PAN fibers fibrils microstructure