全文获取类型
收费全文 | 5433篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 1篇 |
综合类 | 2篇 |
化学工业 | 14篇 |
建筑科学 | 2篇 |
轻工业 | 7篇 |
水利工程 | 1篇 |
无线电 | 6篇 |
一般工业技术 | 9篇 |
冶金工业 | 5379篇 |
自动化技术 | 15篇 |
出版年
2017年 | 1篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 4篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 4篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 165篇 |
1998年 | 1668篇 |
1997年 | 918篇 |
1996年 | 581篇 |
1995年 | 334篇 |
1994年 | 293篇 |
1993年 | 311篇 |
1992年 | 40篇 |
1991年 | 61篇 |
1990年 | 70篇 |
1989年 | 61篇 |
1988年 | 68篇 |
1987年 | 69篇 |
1986年 | 54篇 |
1985年 | 62篇 |
1984年 | 1篇 |
1983年 | 10篇 |
1982年 | 27篇 |
1981年 | 27篇 |
1980年 | 53篇 |
1979年 | 3篇 |
1978年 | 13篇 |
1977年 | 156篇 |
1976年 | 340篇 |
1975年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1955年 | 4篇 |
排序方式: 共有5436条查询结果,搜索用时 15 毫秒
101.
Delayed aorto-pulmonary artery fistula represents an uncommon delayed sequelae of penetrating cardiac trauma. A case is presented that demonstrates the need for a high index of suspicion, follow-up, and a complete evaluation of the patient who survives a penetrating heart injury. The mechanisms of delayed presentation, diagnosis, and management of the fistula are discussed. 相似文献
102.
Human adipose tissue was transplanted to the mouse mutant nude (nu/nu). All the grafts were accepted and contained fat cells easily distinguishable from those of the mouse. No detectable relation between the histological pictures before and after grafting was found. In some transplants nerve tissue, and in others macrophages containing fat droplets, were found. The fat tissue graft might be useful for investigation of the influence of various hormones on human fat cells. 相似文献
103.
Peripheral blood eosinophils from patients with eosinophilia and from healthy subjects were studied for surface immunoglobulins, receptors for the Fc region of IgG, complement receptors, and spontaneous rosette formation with sheep and mouse erythrocytes. Eosinophils were found to have receptors for complement and for aggregated IgG, and to have the same two types of complement receptors as do lymphocytes and monocytes. Immune adherence type receptors were specific for C4 or C3b, while C3d receptors were specific for C3d but unreactive with C4. Eosinophils differed from fully mature neutrophils in that the former had C3d receptors and relatively weak immune adherence (C4 or C3b) receptors, while the later did not have the C3d receptors and had strong immune adherence receptors. Eosinophil phagocytosis of complement-receptor bound erythrocytes was dependent on the presence of IgG in the antibody coating the red blood cells; this requirement for IgG resembled that found in neutrophil phagocytosis. No surface Ig or spontaneous erythrocyte rosette formation was observed with eosinophils. 相似文献
104.
RA Thoft 《Canadian Metallurgical Quarterly》1982,89(4):335-339
Long-term follow-up (two to five years) of 12 unilateral chemical burn patients treated by conjunctival transplantation shows permanent stabilization of the ocular surface. The procedure was used in another group of five patients with unilateral recalcitrant epithelial defects. Regardless of the etiology of the epithelial defect, prompt healing of the surface occurs after conjunctival transplantation with no further stromal loss and long-term stabilization of the surface. Such results suggest that epithelial replacement may be a valuable therapeutic approach to a variety of ocular surface disorders. 相似文献
105.
Isolation of high molecular weight ribosomal RNA from the wall-less alga Olisthodiscus luteus and the angiospermous plant Sauromatum guttatum is described. It has been found that a buffer which contains magnesium must be used to successfully isolate Olisthodiscus rRNA whereas the isolation of intact Sauromatum rRNA requires a buffer system containing a high amount of the chelator EDTA. Sauromatum but not Olisthodiscus extracts were contaminated with ribonuclease unless the inhibitor diethylpyrocarbonate was used during the ribonucleic acid extraction procedure. Nuclease levels were monitored by coincubating [3H]-labeled Escherichia coli ribosomal RNA with the experimental RNA samples. The effects of detergents on the isolation and quantitation of RNA are presented, and methods to avoid loss of highly thermolabile plant ribosomal RNA species are discussed. 相似文献
106.
107.
108.
109.
110.