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   8999篇
  免费   152篇
  国内免费   7篇
电工技术   226篇
综合类   1篇
化学工业   2056篇
金属工艺   263篇
机械仪表   173篇
建筑科学   438篇
矿业工程   88篇
能源动力   254篇
轻工业   210篇
水利工程   49篇
石油天然气   45篇
武器工业   1篇
无线电   1734篇
一般工业技术   1299篇
冶金工业   1181篇
原子能技术   163篇
自动化技术   977篇
  2021年   60篇
  2016年   60篇
  2015年   88篇
  2014年   137篇
  2013年   651篇
  2012年   133篇
  2011年   207篇
  2010年   195篇
  2009年   257篇
  2008年   218篇
  2007年   190篇
  2006年   236篇
  2005年   220篇
  2004年   196篇
  2003年   214篇
  2002年   243篇
  2001年   235篇
  2000年   219篇
  1999年   213篇
  1998年   245篇
  1997年   235篇
  1996年   228篇
  1995年   197篇
  1994年   229篇
  1993年   212篇
  1992年   218篇
  1991年   188篇
  1990年   216篇
  1989年   219篇
  1988年   167篇
  1987年   149篇
  1986年   137篇
  1985年   105篇
  1984年   113篇
  1983年   93篇
  1982年   97篇
  1981年   112篇
  1980年   95篇
  1979年   96篇
  1978年   94篇
  1977年   105篇
  1976年   85篇
  1975年   97篇
  1974年   74篇
  1973年   73篇
  1972年   89篇
  1971年   78篇
  1970年   78篇
  1969年   68篇
  1965年   68篇
排序方式: 共有9158条查询结果,搜索用时 15 毫秒
941.
942.
Thermal conductivity determinations have been made on superduty fire-clay, silica, and kaolin refractories, using the Globar-heated, water calorimeter apparatus previously described. The arrangement, which is satisfactory for insulating firebrick, gives considerable error when firebrick samples are tested. Results obtained by different arrangements of the guard samples and heating elements are shown as well as a final arrangement which gives a satisfactory condition of parallel heat flow.  相似文献   
943.
944.
945.
Summary The acetone-insoluble material from soybean “lecithin” has been fractionated by submitting alcohol-soluble and alcohol-insoluble portions to countercurrent distribution between hexane and methanol. The alcohol-soluble portion was found to contain lecithin, cephalin, and sugars or glycosides; the alcohol-insoluble portion was separated into two major inositol-containing phosphatides and sugars or glycosides. While the commonly accepted value of 30–35% for lecithin in the phosphatides was confirmed, it appears that the accepted value of 65% of cephalin needs revision. The approximate composition for one sample of soybean phosphatides is estimated to be 29% lecithin, 31% cephalin, and 40% inositol-phosphatides. Presented at the 39th Annual Meeting of the American Oil Chemists' Society, May 4–6, 1948, in New Orleans, Louisiana. This paper reports results obtained from a research project financed by the Research Marketing Act of 1946. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.  相似文献   
946.
Summary The electric pH meter has served to fix the limits for the optimum pH range of the acid-alum treatment of spent-lyes, to predetermine the proportions of acid and aluminum sulfate to be used for each treament, and to check the actual treatment prior to filtration. As a result of this close control, time and materials have been saved, a consistently good clear yield of crude glycerine has been obtained, and production has been uninterrupted.  相似文献   
947.
948.
949.
950.
Malignant pleural effusion (MPE) provides a liquid tumor microenvironment model that includes cancer cells and immune cells. However, the characteristics of tumor antigen-specific CD8+ T cells have not been investigated in detail. Here, we analyzed MPE samples taken from a patient with pancreatic cancer who received a dendritic cell vaccine targeting Wilms’ Tumor 1 (WT1) antigen over the disease course (two points at MPE1st and 2nd, two months after MPE1st). Epithelial cell adhesion molecule (EpCAM)+ cancer cells (PD-L1 or T cell immunoglobulin mucin-3, TIM-3), both PD-1 or TIM-3 positive CD8+ T cells, and CD14+CD68+CD163+TIM-3+ macrophages increased from the MPE1st to MPE2nd. The ratio of WT1-specific cytotoxic lymphocytes (WT1-CTLs) to MPE CD8+ T cells and IFN-γ secretion of WT1-CTLs were reduced with disease progression. Coincidentally, the fraction of central memory T (TCM) of WT1-CTLs was decreased. On the other hand, CD8+ T cells in response to SMAD4P130L, which is homogeneously expressed in EpCAM+ cancer cells, were detected using in vitro expansion with the HLA-A*11:01 restrictive SVCVNLYH neoantigen. Furthermore, the CD8+ T cell response to SMAD4P130L was diminished following remarkably decreased numbers of CD8+ TCM in MPE samples. In conclusion, CD8+ T cells responding to WT1 or SMAD4P130L neoantigen expressed in EpCAM+ pancreatic cancer cells were detected in MPE. A tumor antigen-specific immune response would provide novel insight into the MPE microenvironment.  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