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   524篇
  免费   0篇
电工技术   1篇
化学工业   10篇
金属工艺   14篇
机械仪表   1篇
轻工业   1篇
水利工程   4篇
石油天然气   9篇
无线电   1篇
一般工业技术   14篇
冶金工业   464篇
原子能技术   5篇
  2022年   1篇
  2021年   1篇
  2018年   3篇
  2017年   1篇
  2016年   5篇
  2015年   1篇
  2014年   4篇
  2013年   6篇
  2012年   1篇
  2011年   4篇
  2010年   4篇
  2009年   2篇
  2008年   6篇
  2007年   6篇
  2006年   3篇
  2004年   3篇
  2003年   3篇
  2000年   1篇
  1999年   10篇
  1998年   134篇
  1997年   85篇
  1996年   53篇
  1995年   26篇
  1994年   23篇
  1993年   32篇
  1992年   1篇
  1991年   5篇
  1990年   3篇
  1989年   2篇
  1988年   2篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1983年   1篇
  1982年   4篇
  1981年   3篇
  1980年   6篇
  1979年   1篇
  1978年   3篇
  1977年   27篇
  1976年   39篇
  1975年   2篇
排序方式: 共有524条查询结果,搜索用时 15 毫秒
31.
Translated from Poroshkovaya Metallurgiya No. 10 (346), pp. 15–17, October, 1991.  相似文献   
32.
Distinct differences in in vivo stability of the two diastereomeric C-Functionalized CyDTPA chelating agents, (CHX-A DTPA and CHX-B DTPA, both racemates), as recently reported prompted further investigation as to why differences in configuration produced striking effects on the in vivo stability of their yttrium complexes. To this end, the four individual component stereoisomers of CHX-A and CHX-B were synthesized and ability to bind yttrium was investigated both in vitro and in vivo.  相似文献   
33.
We investigated the influence of nutrition and exercise interventions within cognitive/behavioral and public health formats on weight and blood lipid profiles in obese children. Compliance was also examined as well as the relationship of the compliance measures with clinical outcome variables. Three conditions were compared over 16 sessions: nutrition and eating-habit change followed by exercise (NE), exercise followed by nutrition and eating-habit change (EN), and an information control (INFO). NE and EN were presented in a cognitive/ behavioral framework which focused on the development of self-regulation whereas the INFO condition received the same material in a public health/educational model. NE and EN participants evidenced modest, yet significant, reductions in weight and blood lipids, and the impact of these two interventions endured at a five-year follow-up. In contrast, INFO participants displayed stable weight and blood lipids during the course of the program, and most remained morbidly obese at follow-up. Improved nutrition, increased physical activity and fitness were significantly correlated with weight and lipid reductions.  相似文献   
34.
ULTRA was established on the 1st April 1990, to consider applications made by registered medical practitioners seeking approval to transplant an organ between 2 living unrelated persons in the United Kingdom.  相似文献   
35.
The aim of this study is to derive an asymptotic expression for the probability that an infectious disease will disappear from a population at the end of a major outbreak ('fade-out'). The study deals with a stochastic SIR-model. Local asymptotic expansions are constructed for the deterministic trajectories of the corresponding deterministic system, in particular for the deterministic trajectory starting in the saddle point. The analytical expression for the probability of extinction is derived by asymptotically solving a boundary value problem based on the Fokker-Planck equation for the stochastic system. The asymptotic results are compared with results obtained by random walk simulations.  相似文献   
36.
We have generated several transgenic mouse lines and rabbits expressing efficiently (up to 0.3 mg/ml in mice and up to 0.5 mg/ml in rabbits) human erythropoietin in their milk as bovine beta-lactoglobulin fusion protein. Human erythropoietin cDNA was inserted in frame into exon 5 of the bovine beta-lactoglobulin gene with a linker oligonucleotide encoding the cleavage site for bacterial IgA protease. RNA analysis performed on one lactating transgenic mouse and one transgenic rabbit revealed that the fusion gene was expressed almost exlusively in the mammary gland, although low amounts of transgene-derived RNA were detectable in salivary glands and uterus or in the kidney. The fusion protein was specifically cleaved with IgA protease. The erythropoietin part obtained upon digestion had a lower molecular mass than recombinant erythropoietin produced in Chinese hamster ovary cells. By deglycosylation analysis it was shown that the difference in size was due to a different type of glycosylation. Biological activity of the fusion protein, as determined by growth stimulation of TF-1 erythroleukemia cells, was less than 15% of that of human recombinant erythropoietin. Upon digestion of the fusion protein with IgA protease, biological activity comparable to that of the recombinant erythropoietin was recovered. Transgenic males and virgin females did not show signs of enhanced erythropoiesis, but lactating females expressing the transgene displayed transient increases in their hematocrit values.  相似文献   
37.
38.
We have studied chemical interaction between the intermetallic compound TiFe and ammonia at temperatures from 150 to 500°C in the presence of NH4Cl as an activator of the process. We have derived schemes of the reactions involved and have shown that the use of ammonia for hydriding/nitriding enables the preparation of fine powders of TiFe and its hydride. Original Russian Text ? V.N. Fokin, E.E. Fokina, I.I. Korobov, B.P. Tarasov, 2008, published in Neorganicheskie Materialy, 2008, Vol. 44, No. 2, pp. 184–188.  相似文献   
39.
Scleroderma is a multisystem disease of unknown cause characterized by synthesis and deposition of excessive extracellular matrix and vascular anti-GBM antibodies, leading to pulmonary hemorrhage and glomerulonephritis with rapidly progressive renal insufficiency. Recent advances in the understanding of disease pathogenesis and diagnosis and treatment have significantly improved our ability to recognize the syndrome, distinguish it from other similar disorders, and offer successful treatment. This article focuses on the pathogenetic features, clinical manifestations, diagnostic strategies, and therapeutic principles of anti-GBM disease.  相似文献   
40.
A 47-year-old woman on long-term hemodialysis due to a chronic isolated abdominal aortic dissection was admitted to our department with severe abdominal pain. She had not suffered any hematemesis or melena. An emergency laparotomy revealed an abdominal aortic aneurysm with a diameter of 60mm, densely adhered to the ileum. An aortoenteric fistula manifesting as intramural rupture into the ileum was found after infrarenal abdominal aortic and bilateral common iliac cross-clamping. The fistula on the ileac side was nontransmural, but that on the aortic side communicated with the pseudolumen of the abdominal aorta, and contained mural thrombus. The infrarenal abdominal aorta and bilateral common iliac arteries were replaced with a collagen-sealed woven Dacron bifurcated graft. Histological examination of the ileum in this portion showed intramural bleeding and xanthomatous granulation with foam cell infiltration in the thickened subserosa. While it is difficult to diagnose nonpenetrating aortoenteric fistula preoperatively, such a fistula must be considered in a patient with severe abdominal pain, for whom previous abdominal aortic surgery has been performed or when an abdominal aneurysm is observed. To our knowledge, no other case of an aortoenteric fistula presenting as an intramural rupture into the ileum in an isolated abdominal aortic dissection has ever been reported.  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