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   416篇
  免费   2篇
电工技术   11篇
化学工业   32篇
金属工艺   31篇
机械仪表   7篇
建筑科学   2篇
能源动力   2篇
轻工业   11篇
无线电   32篇
一般工业技术   49篇
冶金工业   198篇
自动化技术   43篇
  2022年   4篇
  2021年   7篇
  2018年   4篇
  2016年   11篇
  2015年   3篇
  2014年   4篇
  2013年   11篇
  2012年   12篇
  2011年   12篇
  2010年   13篇
  2009年   11篇
  2008年   9篇
  2007年   6篇
  2006年   15篇
  2005年   4篇
  2004年   7篇
  2003年   5篇
  2002年   8篇
  2001年   5篇
  2000年   8篇
  1999年   7篇
  1998年   44篇
  1997年   42篇
  1996年   15篇
  1995年   10篇
  1994年   12篇
  1993年   12篇
  1992年   11篇
  1991年   7篇
  1990年   7篇
  1989年   11篇
  1988年   8篇
  1987年   12篇
  1986年   5篇
  1985年   3篇
  1983年   2篇
  1982年   3篇
  1981年   4篇
  1980年   2篇
  1979年   3篇
  1977年   4篇
  1976年   5篇
  1975年   3篇
  1974年   4篇
  1972年   5篇
  1971年   1篇
  1970年   4篇
  1969年   4篇
  1968年   3篇
  1964年   1篇
排序方式: 共有418条查询结果,搜索用时 15 毫秒
411.
Fourteen patients with hyperlipoproteinaemia and peripheral vascular disease have been investigated to determine the effect on limb blood flow of hypolipidaemic therapy. Satisfactory lowering of serum lipoprotein levels was achieved in the treated group. There was a significant deterioration in peak reactive blood flow measurements in the placebo group compared with the treated group. Treatment of hyperlipoproteinaemia may, therefore, be of value in preventing the progression of peripheral atherosclerosis.  相似文献   
412.
A 35 GHz millimeter-wave radar system has been studied for space debris tracking. The objective is to track the particles ranging in size from 4 mm to 80 mm up to a range of 25 km. The system requires various state-of-the-art technologies including phased arrays, monopulse tracking, pulse compression, high power transmitters, low noise receivers, and pulse integration signal processing techniques.  相似文献   
413.
This paper investigates decision-theoretic planning in sophisticated autonomous agents operating in environments of real-world complexity. An example might be a planetary rover exploring a largely unknown planet. It is argued that existing algorithms for decision-theoretic planning are based on a logically incorrect theory of rational decision making. Plans cannot be evaluated directly in terms of their expected values, because plans can be of different scopes, and they can interact with other previously adopted plans. Furthermore, in the real world, the search for optimal plans is completely intractable. An alternative theory of rational decision making is proposed, called "locally global planning."  相似文献   
414.
415.
By extraction of acidified aqueous extracts of malt with organic solvents, methylation of the resulting extracts, gas chromatography and detection with a nitrosamine-specific detector, it is shown that N-nitrosoproline is present in malt and that N-nitrososarcosine is sometimes present. N-Nitrosopipecolinic acid has not been observed.  相似文献   
416.
Cyclic fatigue experiments in the high and very high cycle fatigue regimes have been performed on a René 88DT polycrystalline nickel-based superalloy. The microstructural configurations that favor early strain localization and fatigue crack initiation at high temperature from 400 °C to 650 °C have been investigated. Competing failure modes are observed in the high to the very high cycle fatigue regime. Fatigue cracks initiate from non-metallic inclusions and from intrinsic internal microstructural features. Interestingly, as stresses are reduced into the very high cycle regime, there is a transition to initiation only at crystallographic facets. At higher stress in the high cycle fatigue regime, a significant fraction of specimens initiate cracks at non-metallic inclusions. This transition is analyzed with regard to microstructural features that favor strain localization and accumulate damage early during cycling.  相似文献   
417.
Chronic kidney disease (CKD) is a growing global public health problem. The implementation of evidence-based clinical practices only defers the development of kidney failure. Death, transplantation, or dialysis are the consequences of kidney failure, resulting in a significant burden on the health system. Hence, innovative therapeutic strategies are urgently needed due to the limitations of current interventions. Photobiomodulation (PBM), a form of non-thermal light therapy, effectively mitigates mitochondrial dysfunction, reactive oxidative stress, inflammation, and gut microbiota dysbiosis, all of which are inherent in CKD. Preliminary studies suggest the benefits of PBM in multiple diseases, including CKD. Hence, this review will provide a concise summary of the underlying action mechanisms of PBM and its potential therapeutic effects on CKD. Based on the findings, PBM may represent a novel, non-invasive and non-pharmacological therapy for CKD, although more studies are necessary before PBM can be widely recommended.  相似文献   
418.
Chronic kidney disease (CKD) is a global health issue, affecting more than 10% of the worldwide population. The current approach for formal diagnosis and prognostication of CKD typically relies on non-invasive serum and urine biomarkers such as serum creatinine and albuminuria. However, histological evidence of tubulointerstitial fibrosis is the ‘gold standard’ marker of the likelihood of disease progression. The development of novel biomedical technologies to evaluate exfoliated kidney cells from urine for non-invasive diagnosis and prognostication of CKD presents opportunities to avoid kidney biopsy for the purpose of prognostication. Efforts to apply these technologies more widely in clinical practice are encouraged, given their potential as a cost-effective approach, and no risk of post-biopsy complications such as bleeding, pain and hospitalization. The identification of biomarkers in exfoliated kidney cells from urine via western blotting, enzyme-linked immunosorbent assay (ELISA), immunofluorescence techniques, measurement of cell and protein-specific messenger ribonucleic acid (mRNA)/micro-RNA and other techniques have been reported. Recent innovations such as multispectral autofluorescence imaging and single-cell RNA sequencing (scRNA-seq) have brought additional dimensions to the clinical application of exfoliated kidney cells from urine. In this review, we discuss the current evidence regarding the utility of exfoliated proximal tubule cells (PTC), podocytes, mesangial cells, extracellular vesicles and stem/progenitor cells as surrogate markers for the early diagnosis and prognostication of CKD. Future directions for development within this research area are also identified.  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