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   1896篇
  免费   1篇
电工技术   39篇
化学工业   131篇
金属工艺   55篇
机械仪表   25篇
建筑科学   7篇
矿业工程   20篇
能源动力   2篇
轻工业   2篇
水利工程   11篇
石油天然气   42篇
无线电   87篇
一般工业技术   228篇
冶金工业   1158篇
原子能技术   51篇
自动化技术   39篇
  2022年   9篇
  2021年   13篇
  2020年   11篇
  2019年   21篇
  2018年   19篇
  2017年   33篇
  2016年   32篇
  2015年   26篇
  2014年   23篇
  2013年   22篇
  2012年   28篇
  2011年   33篇
  2010年   20篇
  2009年   18篇
  2008年   27篇
  2007年   31篇
  2006年   22篇
  2005年   14篇
  2004年   24篇
  2003年   25篇
  2002年   15篇
  2001年   23篇
  2000年   23篇
  1999年   38篇
  1998年   333篇
  1997年   166篇
  1996年   126篇
  1995年   68篇
  1994年   74篇
  1993年   72篇
  1992年   13篇
  1991年   38篇
  1990年   28篇
  1989年   22篇
  1988年   35篇
  1987年   23篇
  1986年   17篇
  1985年   18篇
  1982年   19篇
  1981年   16篇
  1980年   20篇
  1978年   18篇
  1977年   38篇
  1976年   65篇
  1974年   14篇
  1972年   14篇
  1971年   8篇
  1970年   16篇
  1969年   9篇
  1966年   9篇
排序方式: 共有1897条查询结果,搜索用时 0 毫秒
901.
Extraction and sorption recovery of Pd from nitric acid solutions with extractants containing carbamoyl phosphine oxides (CMPO) was studied. The Pd distribution coefficients under different extraction conditions were determined. The possibility of Pd recovery in the course of spent nuclear fuel processing was demonstrated. A number of solid extractants composed of carbamoyl phosphine oxides and inert matrices (styrene-divinylbenzene polymer and silica gel) were tested. The Pd distribution coefficients in the course of sorption and desorption under the static and dynamic conditions were measured.__________Translated from Radiokhimiya, Vol. 47, No. 4, 2005, pp. 343–346.Original Russian Text Copyright © 2005 by Zaitsev, Kvasnitskii, Korolev, Babain, Pokhitonov.  相似文献   
902.
Older adults are an important segment of the population that has specific health care needs. Their unique biopsychosocial characteristics impact the presentation, evaluation, and management of psychiatric illnesses. This article describes how common psychiatric disorders present in an aging population. Research in this area is relatively new and much more information is still needed. Close attention should be paid to new knowledge as it emerges about this growing population.  相似文献   
903.
OBJECTIVE: To find a means of bladder augmentation that would avoid the complications encountered with the use of bowel segments, using a newly developed acellular biomaterial, the bladder acellular matrix graft (BAMG), as a homologous graft. MATERIALS AND METHODS: Thirty-four rats underwent a partial cystectomy (40-50%) and grafting with a BAMG of equal size. Eleven rats died within the first 72 h. probably from urinary leakage caused by obstruction of the bladder neck with stones or coagula; the surviving 23 were killed at varying intervals after cystectomy and examined. RESULTS: After providing initial bladder enlargement, the graft was progressively infiltrated by the vessels and smooth muscle cells of the host: furthermore, the mucosal lining was complete within 10 days. After 4 weeks, all bladder wall components were evident histologically in the graft. The ingrowth was complete after 8 weeks, except for neural regeneration, which was only partial. At 12 weeks, the bladder wall muscle structure in the graft was so well developed that it was difficult to delineate the junction between host bladder and BAMG. Neural regeneration continued to improve. Normal bladder capacities were maintained throughout the study. CONCLUSION: The BAMG appears to serve, without rejection, as a framework of collagen and elastin for the ingrowth of all bladder wall components. The reason for the better acceptance of the BAMG than of other bladder augmentation grafts requires further investigation.  相似文献   
904.
905.
906.
The clinical, haematological and cytogenetic data for 20 patients with an acquired abnormality of 11q23 and 10p have been reviewed at this workshop. Patients predominantly presented with de novo AML M5a and the most common cytogenetic finding was an inversion of part of the long arm of chromosome 11 followed by a translocation between 11q and 10p. Band p12 represented the most common breakpoint on chromosome 10. The t(10;11) subgroup defined a subset of younger 11q23 patients, the majority of whom achieve a first complete remission despite the differing treatment regimens.  相似文献   
907.
908.
909.
To improve the quality of winding of fibres on bobbins on precision machines, it is necessary to install a speed variator thread guide in the spindle—cam chain and decrease the free fibre segment between the spreading and winding points. Dimitrovgrad Institute of Technology, Management, and Design. Translated fromKhimicheskie Volokna, No. 2, pp. 35–37, March–April, 1999.  相似文献   
910.
Febrile seizures (FSs) in early life are significant risk factors of neurological disorders and cognitive impairment in later life. However, existing data about the impact of FSs on the developing brain are conflicting. We aimed to investigate morphological and functional changes in the hippocampus of young rats exposed to hyperthermia-induced seizures at postnatal day 10. We found that FSs led to a slight morphological disturbance. The cell numbers decreased by 10% in the CA1 and hilus but did not reduce in the CA3 or dentate gyrus areas. In contrast, functional impairments were robust. Long-term potentiation (LTP) in CA3-CA1 synapses was strongly reduced, which we attribute to the insufficient activity of N-methyl-D-aspartate receptors (NMDARs). Using whole-cell recordings, we found higher desensitization of NMDAR currents in the FS group. Since the desensitization of NMDARs depends on subunit composition, we analyzed NMDAR current decays and gene expression of subunits, which revealed no differences between control and FS rats. We suggest that an increased desensitization is due to insufficient activation of the glycine site of NMDARs, as the application of D-serine, the glycine site agonist, allows the restoration of LTP to a control value. Our results reveal a new molecular mechanism of FS impact on the developing brain.  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