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   1062篇
  免费   0篇
  国内免费   2篇
电工技术   4篇
综合类   1篇
化学工业   60篇
金属工艺   38篇
机械仪表   46篇
建筑科学   15篇
矿业工程   3篇
能源动力   1篇
轻工业   10篇
水利工程   22篇
石油天然气   28篇
武器工业   1篇
无线电   32篇
一般工业技术   114篇
冶金工业   628篇
原子能技术   41篇
自动化技术   20篇
  2022年   10篇
  2021年   9篇
  2020年   5篇
  2018年   10篇
  2017年   9篇
  2016年   24篇
  2015年   11篇
  2014年   8篇
  2013年   17篇
  2012年   9篇
  2011年   16篇
  2010年   28篇
  2009年   12篇
  2008年   14篇
  2007年   20篇
  2006年   18篇
  2005年   14篇
  2004年   10篇
  2003年   11篇
  2002年   17篇
  2001年   11篇
  2000年   7篇
  1999年   11篇
  1998年   123篇
  1997年   94篇
  1996年   90篇
  1995年   54篇
  1994年   35篇
  1993年   39篇
  1992年   12篇
  1991年   9篇
  1990年   12篇
  1989年   9篇
  1988年   10篇
  1987年   7篇
  1986年   12篇
  1985年   10篇
  1984年   5篇
  1983年   8篇
  1982年   10篇
  1981年   10篇
  1980年   13篇
  1979年   7篇
  1978年   10篇
  1977年   34篇
  1976年   87篇
  1975年   12篇
  1974年   7篇
  1972年   6篇
  1971年   4篇
排序方式: 共有1064条查询结果,搜索用时 5 毫秒
21.
Acute graft rejection and delayed function are considered to be the major risk factors of short-term as well as long-term graft survival. We studied the impact of these factors on graft outcome among 109 renal transplant recipients. All recipients were treated with triple drug protocol. The recipients were divided into two groups: I group included 57 patients with delayed graft function (DGF), II group included 52 patients with immediate graft function (IGF). We studied graft survival, incidence of acute rejection, serum creatinine levels and the cause of graft loss for patients in both groups. Acute rejection episodes occurred in 49% of patients from DGF group and 45% of patients from IGF group. Graft survival in IGF group was better than in DGF group. Actuarial graft survival at 1, 2, 3 and 4 years in examined groups was 84%, 82%, 72%, 65% vs. 92%, 86%, 84%, 84%, respectively. One-year graft survival in patients with acute rejection from DGF group and IGF group was significantly lower than in patients who remained rejection free (69%, 74% vs. 94%, 96%). We concluded that delayed graft function decreases long-term graft survival, while immediate graft function has an excellent impact on graft outcome. Acute graft rejection is the strongest risk factor of graft loss.  相似文献   
22.
23.
Access and visualization in the implant-abutment area are often compromised. Tissue impingement and lack of abutment position verification may result in inaccurate fit.  相似文献   
24.
The model of complex formation between polypeptide adopted lefthanded conformation of polyproline II type and minor groove of B-DNA presented. The specific recognition is attained due to possibility of hydrogen bond between Gly NH-group and Thymine O2-group and in addition between Pro CO-group and Guanine NH2-group and between Gly CO-group and Guanine NH2-group. Stereochemical satisfactory of the complex is observed.  相似文献   
25.
26.
27.
The article covers complex evaluation of health state in building industry workers engaged into ferro-concrete production in St. Petersburg. The health state was considered under combined action of infrasound, noise and general vibration. Clinical and functional evaluation included medical examination by doctors, blood biochemistry and CBC, ECG, computer integral rheography, voice audiometry. Data for 62 moulders helped to assess acoustic environment at workplace and to reveal the morbidity structure.  相似文献   
28.
29.
Poor performance of livestock that graze tall fescue (Festuca arundinacea Schreb.) has been associated with the endophyte fungus Neotyphodium coenophialum [Morgan-Jones and Gams] Glenn, Bacon, and Hanlin). Recent evidence suggests lowered Cu status and a depression of Cu-related immune function in steers that graze endophyte-infected (E+) tall fescue. Greenhouse and field studies investigated relationships between the endophyte and Cu concentrations in tall fescue. Seventeen infected 'Kenhy' clones were divided, and one plant of each pair was treated three times with Benomyl to remove the endophyte (E-). Plants were watered with nutrient solution in a greenhouse for 6 mo before sampling. Copper concentrations were greater (P < .001) in E- than in E+ clones (3.4 vs 2.8 microg/g; SE, .06). In the second greenhouse experiment, genetically similar E+ and E- 'Kentucky'-31 (KY-31) and 'Georgia Jessup' were grown from seed and fertilized with nutrient solution to produce mature plants. Copper concentrations were higher (P < .05) in E- than in E+ tall fescue (8.6 vs 7.6 microg/g; SE, .3). In a field plot experiment in Texas, E+ and E- KY-31 were grown with 0, 50, and 100% replacement of potential evapotranspiration. By September, Cu concentrations were higher (P < .05) in E- than in E+ tall fescue (7.3 vs 6.6 microg/g; SE, .2). In pasture experiments, KY-31 E+ (> 70% infection level) and E- (< 5% infection level) tall fescue were grown in Virginia at two locations with three rates of N fertilizer. Copper concentrations were higher (P < .05) in E- than in E+ tall fescue (4.8 vs 4.5 microg/g; SE, .1) and increased (P < .01) linearly in response to N. Our data demonstrate that the presence of the endophyte is associated with lower Cu concentrations in tall fescue, which may contribute to lowered Cu status in animals and thus contribute to the etiology of fescue toxicity.  相似文献   
30.
The course of diffuse peritonitis has been followed up in 219 patients, 20 of these with the reactive, 165 with toxic, and 34 with the terminal stages of the condition. Multiple-modality intensive care included, besides routine therapy, local abdominal hypothermia, UV irradiation of autoblood (UVIAB), and, if indicated, hyperbaric oxygenation (HBO) and hemoperfusion. In addition to clinical tests, immunobiochemical monitoring of medium-molecular peptide fractions MM1 and MM2 and index of their distribution, as well as of circulating immune complexes CIC1 and CIC2 and the levels of immunoglobulins IgA, IgM, and IgG were the criteria for assessing the severity of intoxication and efficacy of intensive care and for predicting the course and outcome of the disease. The results indicate that HBO in combination with hemoperfusion, local abdominal hypothermia, and UVIAB have a positive impact on the clinical picture of the disease and on the time course of markers of endogenous intoxication and humoral immunity in patients with the terminal and toxic phases of diffuse peritonitis.  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