首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   140篇
  免费   4篇
电工技术   1篇
化学工业   16篇
金属工艺   2篇
机械仪表   3篇
建筑科学   7篇
能源动力   5篇
轻工业   5篇
无线电   22篇
一般工业技术   11篇
冶金工业   43篇
原子能技术   5篇
自动化技术   24篇
  2022年   2篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   3篇
  2016年   1篇
  2015年   2篇
  2014年   3篇
  2013年   6篇
  2012年   3篇
  2011年   5篇
  2010年   4篇
  2009年   4篇
  2008年   3篇
  2007年   4篇
  2006年   7篇
  2005年   4篇
  2004年   1篇
  2003年   2篇
  2002年   5篇
  2001年   1篇
  2000年   3篇
  1999年   3篇
  1998年   17篇
  1997年   11篇
  1996年   3篇
  1995年   5篇
  1994年   2篇
  1993年   3篇
  1992年   5篇
  1991年   5篇
  1990年   2篇
  1989年   1篇
  1988年   2篇
  1987年   1篇
  1985年   2篇
  1984年   4篇
  1983年   3篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1976年   2篇
  1967年   2篇
  1966年   1篇
排序方式: 共有144条查询结果,搜索用时 15 毫秒
41.
Experimental and theoretical results on stable as well as unstable fractures for Type 304 stainless steel plates with a central crack subjected to tension force are given.In the experiment using a testing machine with a special spring for high compliance, the transition points from the stable to the unstable crack growth are observed and comparisons are made between the test results and the finite element solutions.A round robin calculation for the elastic-plastic stable crack growth using one of the specimens mentioned above is also given.  相似文献   
42.
We compared four tests for antibodies to CagA or VacA, HelicoBlot 2. 0, RIDA Blot Helicobacter, CHIRON RIBA H. pylori SIA, and an enzyme-linked immunosorbent assay using recombinant CagA. Immunoblot assays were accurate for determining Helicobacter pylori status but poor for determining CagA or VacA status (accuracy, 66 to 80% for CagA status and 34 to 67% for VacA status). None can be recommended for determining CagA or VacA status.  相似文献   
43.
In seems there are two dimensions that underlie most judgments of traits, people, groups, and cultures. Although the definitions vary, the first makes reference to attributes such as competence, agency, and individualism, and the second to warmth, communality, and collectivism. But the relationship between the two dimensions seems unclear. In trait and person judgment, they are often positively related; in group and cultural stereotypes, they are often negatively related. The authors report 4 studies that examine the dynamic relationship between these two dimensions, experimentally manipulating the location of a target of judgment on one and examining the consequences for the other. In general, the authors' data suggest a negative dynamic relationship between the two, moderated by factors the impact of which they explore. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
44.
Recently, due to an increasing global concern on environmental safety, titanium dioxide (TiO2) photocatalyst has been extensively researched for use as air and water pollution treatments. This study was initiative for producing an economically viable TiO2 photocatalyst material with recyclability for degradation of CHP contaminated wastewater. TiO2 P‐25, a well‐known photocatalyst, with a proper amount (15% w/w of CAC) was coated on porous silica beads (ECOLITE®) by granulation technique, using high calcium aluminate cement (CAC) as a binder (EC+CAC+15% w/w TiO2 P‐25). The experiments revealed that high concentration CHP solutions were completely degraded by EC+CAC+15% w/w TiO2 P‐25 within 5 and 7 hours. The recyclability of EC+CAC+15% w/w TiO2 P‐25 was evaluated by investigation the degradation activity of freshly prepared CHP solution under UV light irradiation using the repetitive photocatalyst beads for 6 runs. HPLC analyses indicated that the CHP degradation was completed in the 1st run and down to over 90% in the 6th run. Hence, EC+CAC+15% w/w TiO2 P‐25 showed a long durability and good recyclability for CHP degradation, resulted from the good adherence of hydration product layer of CAC for TiO2 particles as well as its large surface area that offered good adsorption for CHP.  相似文献   
45.
The CagA protein of Helicobacter pylori is an immunogenic antigen of variable size and unknown function that has been associated with increased virulence as well as two mutually exclusive diseases, duodenal ulcer and gastric carcinoma. The 3' region of the cagA gene contains repeated sequences. To determine whether there are structural changes in the 3' region of cagA that predict outcome of H. pylori infection, we examined 155 cagA gene-positive H. pylori isolates from Japanese patients including 50 patients with simple gastritis, 40 with gastric ulcer, 35 with duodenal ulcer, and 30 with gastric cancer. The 3' region of the cagA gene was amplified by PCR followed by sequencing. CagA proteins were detected by immunoblotting using a polyclonal antibody against recombinant CagA. One hundred forty-five strains yielded PCR products of 642 to 651 bp; 10 strains had products of 756 to 813 bp. The sequence of the 3' region of the cagA gene in Japan differs markedly from the primary sequence of cagA genes from Western isolates. Sequence analysis of the PCR products showed four types of primary gene structure (designated types A, B, C, and D) depending on the type and number of repeats. Six of the seven type C strains were found in patients with gastric cancer (P < 0.01 in comparison to noncancer patients). Comparison of type A and type C strains from patients with gastric cancer showed that type C was associated with higher levels of CagA antibody and more severe degrees of atrophy. Differences in cagA genotype may be useful for molecular epidemiology and may provide a marker for differences in virulence among cagA-positive H. pylori strains.  相似文献   
46.
Thirty three patients with severe infections associated with hematological disorders were treated with panipenem/betamipron as a second line chemotherapy. Of these, 30 patients were evaluated for effectiveness. An excellent response was obtained in 14 patients (46.7%) and a good response in 5 (16.7%), and the overall efficacy rate was 63.3%. Efficacy rates were 3/6 in patients with sepsis, 68.4% (13/19) in patients with fever of undetermined origin, 2/4 in patients with pneumonia. In patients whose peripheral granulocyte count was below 100/microliter at the start of chemotherapy, the efficacy rate was 3/7. Side effects were observed in 5 of 33 patients (15.2%). These results show that PAPM/BP is useful as a second line chemotherapy for the treatment of severe infections in patients with hematological disorders.  相似文献   
47.
48.
The DPLEX shield method employs a shield having a parallel link-type excavation mechanism to build shield tunnels of various cross-sectional shapes (rectangle, oval, etc.). The segment used with the DPLEX method has a rational cross-sectional shape, that is, a rounded rectangle obtained by putting together curved sections having different radius of curvature. This paper describes the results of experiments conducted using a shield in work and segment models for the development of the DPLEX shield method.  相似文献   
49.
The influence of fiber parameters on skew has been experimentally clarified by using single-mode 16-fiber ribbons with different fiber parameters. The skews are measured for fibers in 16-fiber ribbons. It is found that not only the relative refractive index difference Δ but also the ratio of the mode field diameter to the core diameter influence the skew. The time of flight is measured for 16-fiber ribbons under several temperature and strain values. Although the time of flight is influenced both by temperature and strain, it is confirmed experimentally that skew is independent of fiber parameters. These results indicate that the skew of a fiber ribbon under a uniform environment can be determined from fiber parameter differences. Previously proposed equations for evaluating the skew are used to design fibers in a fiber ribbon in order to realize fiber ribbons with the desired skew value  相似文献   
50.
We have been investigating the feasibility of a superconducting fault current limiting transformer (SFCLT) with the functions of fault current suppression and system stability improvement. This paper discusses these functions with consideration of overvoltage and thermal characteristics of SFCLT, and their dependence on recovery time into superconducting state after the quench of SFCLT. Simulation results using EMTP suggested that SFCLT would be coordinated with the background power system under the appropriate superconducting recovery time. The operating parameters of SFCLT were also optimized in a simplified power transmission model system. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(2): 40–47, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10070  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号