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   10547篇
  免费   551篇
  国内免费   21篇
电工技术   125篇
综合类   20篇
化学工业   2343篇
金属工艺   172篇
机械仪表   211篇
建筑科学   332篇
矿业工程   36篇
能源动力   225篇
轻工业   403篇
水利工程   68篇
石油天然气   28篇
无线电   761篇
一般工业技术   2299篇
冶金工业   2428篇
原子能技术   78篇
自动化技术   1590篇
  2023年   153篇
  2022年   374篇
  2021年   418篇
  2020年   286篇
  2019年   246篇
  2018年   304篇
  2017年   256篇
  2016年   349篇
  2015年   297篇
  2014年   439篇
  2013年   556篇
  2012年   549篇
  2011年   624篇
  2010年   423篇
  2009年   412篇
  2008年   436篇
  2007年   416篇
  2006年   325篇
  2005年   253篇
  2004年   223篇
  2003年   205篇
  2002年   191篇
  2001年   123篇
  2000年   113篇
  1999年   168篇
  1998年   657篇
  1997年   409篇
  1996年   251篇
  1995年   178篇
  1994年   160篇
  1993年   177篇
  1992年   74篇
  1991年   66篇
  1990年   69篇
  1989年   49篇
  1988年   58篇
  1987年   54篇
  1986年   44篇
  1985年   57篇
  1984年   37篇
  1983年   36篇
  1982年   31篇
  1981年   35篇
  1980年   40篇
  1979年   19篇
  1978年   34篇
  1977年   61篇
  1976年   141篇
  1975年   30篇
  1971年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Since the thyroid gland is one of the organs most affected by autoimmune processes, many patients with thyroiditis of Hashimoto (TH) seek medical advice on lifestyle variance and dietary modifications to improve and maintain their hyroid function. In this review, we aim to present and discuss some challenges associated with the nutritional management of TH, focusing on environmental and dietary deficits, inflammatory and toxic nutrients, cyanotoxins, etc. We discuss the relationships among different diets, chronic inflammation, and microbiota, and their impact on the development and exacerbation of TH in detail. We share some novel insights into the role of vitamin D and melatonin for preserving thyroid function during chronic inflammation in autoimmune predisposed subjects. A comprehensive overview is provided on anti-inflammatory nutrients and ecological diets, including foods for cleansing and detoxification, which represent strategies to prevent relapses and achieve overall improvement of life quality. In conclusion, data from biomedical and clinical studies provide evidence that an appropriate dietary and lighting regimen could significantly improve the function of the thyroid gland and reduce the reactivity of autoantibodies in TH. Compliance with nutritional guidelines may help TH patients to reduce the need for medicines.  相似文献   
52.
Increasing evidence links the RAGE (receptor for advanced glycation end products)/DIAPH1 (Diaphanous 1) signaling axis to the pathogenesis of diabetic complications. RAGE is a multi-ligand receptor and through these ligand–receptor interactions, extensive maladaptive effects are exerted on cell types and tissues targeted for dysfunction in hyperglycemia observed in both type 1 and type 2 diabetes. Recent evidence indicates that RAGE ligands, acting as damage-associated molecular patterns molecules, or DAMPs, through RAGE may impact interferon signaling pathways, specifically through upregulation of IRF7 (interferon regulatory factor 7), thereby heralding and evoking pro-inflammatory effects on vulnerable tissues. Although successful targeting of RAGE in the clinical milieu has, to date, not been met with success, recent approaches to target RAGE intracellular signaling may hold promise to fill this critical gap. This review focuses on recent examples of highlights and updates to the pathobiology of RAGE and DIAPH1 in diabetic complications.  相似文献   
53.
54.
55.
56.
正确选择煤粉,其性能要求同时具有低灰分、高挥发分和高膨胀指数,以及具有合适的筛分粒度这一关键因素,以确保所生产的铸件没有机械粘砂缺陷和表面质量问题.通过仔细选择、安全操作和加工处理,煤粉仍然是一个优良的、简易的、经济的有效解决方案.煤粉在储存、加工和运输过程中易于调节,然后经过进一步的安全处理,最终被铸造厂使用.尽管煤粉有诸多不足之处,对于最终用户来说,它仍然是经济合算的.而且现代加工和筛分方法确保它在最佳条件下使用.  相似文献   
57.
In case of a reinforced concrete structure being exposed to bond stresses that transfer great forces, a relative displacement between reinforcing bar and concrete occurs. The slip is an important parameter in order to evaluate the quality of the bond concerning repeated pullout loads. A rapid slip increase is caused by bond weakening due to longitudinal cracks resulting from transverse tension. Within the bond area the slip is not uniformly distributed along the reinforcing bar. It is still unexplained how far fatigue and transverse tension affect the distribution. This paper focuses on the development of the slip curve under repeated loading and transverse tension. Results from cyclic pullout tests were applied and particularly the slip difference between the loaded and unloaded end of the pullout bar was investigated. It could be observed that both an increase in load cycles and transverse tension did not cause an appreciable change in slip difference.  相似文献   
58.
59.
We present results of low-temperature experiments on dilute mixtures of 3He in 4He and on pure 3He, obtained by means of two kinds of mechanical oscillators immersed in the liquid sample: vibrating wires and quartz tuning forks. The helium sample was cooled either by adiabatic demagnetization of an immersed copper nuclear stage or by adiabatic melting of 4He in superfluid 3He. The measured effect of the surrounding fluid on the mechanical resonance of the oscillators is compared with existing theories. We also discuss resonances of second sound and the state of supersaturation, both observed by a tuning fork in helium mixtures.  相似文献   
60.
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