全文获取类型
收费全文 | 6496篇 |
免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 13篇 |
建筑科学 | 2篇 |
轻工业 | 4篇 |
水利工程 | 1篇 |
石油天然气 | 1篇 |
无线电 | 7篇 |
一般工业技术 | 5篇 |
冶金工业 | 6454篇 |
自动化技术 | 9篇 |
出版年
2024年 | 3篇 |
2023年 | 1篇 |
2019年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2003年 | 9篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 158篇 |
1998年 | 1920篇 |
1997年 | 1132篇 |
1996年 | 755篇 |
1995年 | 386篇 |
1994年 | 344篇 |
1993年 | 386篇 |
1992年 | 49篇 |
1991年 | 101篇 |
1990年 | 104篇 |
1989年 | 89篇 |
1988年 | 101篇 |
1987年 | 87篇 |
1986年 | 76篇 |
1985年 | 59篇 |
1983年 | 12篇 |
1982年 | 32篇 |
1981年 | 47篇 |
1980年 | 57篇 |
1978年 | 26篇 |
1977年 | 180篇 |
1976年 | 350篇 |
1975年 | 10篇 |
1955年 | 4篇 |
1954年 | 3篇 |
排序方式: 共有6498条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
15.
16.
JP Bosch R Geronemus S Glabman M Lysaght T Kahn B von Albertini 《Canadian Metallurgical Quarterly》1978,2(4):339-342
Experiments were performed using a new hollow fiber hemofilter. Ultrafiltration rates and whole blood urea clearances were measured in post-dilution hemofiltration. High ultrafiltration rates were obtained with the new hemofilter. No adverse effects were detected despite filtration fractions above 45%. These experiments suggest that it is possible in post-dilution hemofiltration to obtain small solute clearances comparable to those of hemodialysis without apparent deleterious effects. 相似文献
17.
Two children with acute glomerulonephritis, cutaneous vasculitis, and abdominal pain are reported. One child also had transient arthralgia and gastrointestinal hemorrhage. Although the clinical presentation mimicked many of the features of Henoch-Sch?nlein purpura, both patients had unusual variants of poststreptococcal glomerulonephritis. 相似文献
18.
In the suckling newborn rat, blood ketone bodies begin to increase slowly 4h after birth and then rise sharply between 12 and 16h, whereas the major increase in plasma non-esterified fatty acids and liver carnitine occurs during the first 2h of life, parallel with the onset of suckling. In the starved newborn rat, which shows no increase in liver carnitine unless it is fed with a carnitine solution, the developmental pattern of the ketogenic capacity (tested by feeding a triacylglycerol emulsion, which increases plasma non-esterified fatty acids by 3-fold) is the same as in the suckling animal. This suggests that the increases in plasma non-esterified fatty acids and liver carnitine seen 2h after birth in the suckling animal are not the predominant factors inducing the switch-on of ketogenesis. Injection of butyrate to starved newborn pups resulted in a pattern of blood ketone bodies which was similar to that found after administration of triacylglycerols, but, at all time points studied, the hyperketonaemia was more pronounced with butyrate. It is suggested that, even if the entry of long-chain fatty acids into the mitochondria is a rate-limiting step, it is not the only factor controlling ketogenesis after birth in the rat. As in the adult rat, there is a reciprocal correlation between the liver glycogen content and the concentration of ketone bodies in the blood. 相似文献
19.
The effects of 27 mM K+ and of 6.7 mM theophylline on the release of growth hormone (GH) by rat hemipituitaries in vitro were investigated using bioassay (rat tibia test) and radioimmunoassay (RIA). Both agents markedly increased the release of immunoreactive GH. High K+ also promoted the release of bioactive GH but to a much lesser degree than RIA-GH. Theophylline did not consistently affect the release of bioassay-detectable GH. The results suggest that these agents promote massive release of a form of immunoreactive GH (possibly "immature") that has little or no activity in the bioassay. Theophylline is relatively more effective in this regard than is elevated K+. 相似文献
20.
MR Britt RA Garibaldi WA Miller RM Hebertson JP Burke 《Canadian Metallurgical Quarterly》1977,11(2):240-243
We evaluated short-term systemic antimicrobial prophylaxis for catheter-associated bacteriuria in women undergoing elective gynecological operations in a prospective, controlled, double-masked study. Nine of 100 placebo-treated patients acquired bacteriuria during catheterization compared with 3 of 96 of the drug-treated group. However, at the time of hospital discharge, clean-voided urine specimens were positive as frequently in the drug-treated group (8 of 82 patients cultured) as in the placebo group (8 of 75 patients cultured). No difference in febrile morbidity due to bacteriuria was noted between the prophylaxis and placebo groups. The incidence of catheter-associated bacteriuria may be reduced by antimicrobial prophylaxis. However, because the protective effect is transient and is associated with the selection of resistant organisms, prophylaxis is not indicated for patients at low risk for acquired bacteriuria and in whom the sequelae of catheter-associated infections are infrequent. 相似文献