全文获取类型
收费全文 | 704篇 |
免费 | 0篇 |
专业分类
化学工业 | 2篇 |
机械仪表 | 2篇 |
矿业工程 | 1篇 |
轻工业 | 2篇 |
冶金工业 | 696篇 |
原子能技术 | 1篇 |
出版年
2015年 | 1篇 |
2013年 | 2篇 |
2011年 | 1篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 4篇 |
2007年 | 1篇 |
2006年 | 7篇 |
2005年 | 1篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2000年 | 2篇 |
1999年 | 17篇 |
1998年 | 181篇 |
1997年 | 115篇 |
1996年 | 54篇 |
1995年 | 38篇 |
1994年 | 29篇 |
1993年 | 50篇 |
1992年 | 8篇 |
1991年 | 11篇 |
1990年 | 12篇 |
1989年 | 10篇 |
1988年 | 10篇 |
1987年 | 11篇 |
1986年 | 11篇 |
1985年 | 7篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1980年 | 6篇 |
1979年 | 1篇 |
1978年 | 5篇 |
1977年 | 27篇 |
1976年 | 55篇 |
1975年 | 4篇 |
1955年 | 3篇 |
排序方式: 共有704条查询结果,搜索用时 0 毫秒
701.
MM Scheinman FW Kunkel RW Peters DS Hirschfeld PL Schoenfeld JA Abbott G Modin 《Canadian Metallurgical Quarterly》1976,61(5):641-649
Sinus nod recovery time (SNRT) at paced atrial rates of 100 (SNRT100) and 120 (SNRT120) beats/min, atrial effective refractory periods at spontaneous heart rates (AERP) and at paced rates of 100 (AERP100) and 120 (AERP120) beats/min, and premature atrial stimulation were among the studies in evaluating 33 patients with symptomatic sinus node disease and 42 normal subjects. Although mean SNRT100 and SNRT120 were statistically significantly greater in patients than in control subjects, there was a significant overlap between patient and control groups, and SNRT100 or SNRT120 was associated with a 30.3 per cent false-negative and 5 per cent false-positive incidence. Correction for heart rate (SNRT-spontaneous cycle length) failed to improve the sensitivity or specificity of this test. There was no significant difference in mean AERP, AERP100 or AERP120, or in sinoatrial conduction time in patients compared with control subjects. Analyses of curves derived from plots of test and return cycles showed abnormal curves in only five of the 24 patients studied by progressively premature atrial stimulation. Two of these five patients showed normal zone I and II phenomena followed by a progressive linear increase in the return cycle that was thought to be due to abnormal refractoriness of the perinodal fibers. 相似文献
702.
This study attempted to replicate the results of F. W. Willoughby and J. F. Edens (1996), who identified motivational subtypes of alcohol-dependent veterans on the basis of the University of Rhode Island Change Assessment Scale (McConnaughy, Prochaska, & Velicer, 1983). Using cluster analysis, 2 subgroups were delineated that corresponded to the precontemplation (n?=?63) and contemplation–action (n?=?99) stages of change. Theoretically consistent differences on various dependent (i.e., nonclustering) variables were replicated. Patients in the precontemplation cluster reported being less concerned over their drinking and less receptive to help, and they acknowledged fewer mood enhancing benefits of alcohol use. Unlike prior findings, motivational profiles were also associated with treatment outcome, with precontemplation-stage patients being less likely to complete treatment successfully. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
703.
704.
EM Rzucidlo WC Quist AD Hamdan FW LoGerfo 《Canadian Metallurgical Quarterly》1999,29(2):317-23; discussion 324-5
PURPOSE: By means of the technique of messenger RNA (mRNA) differential display, we previously isolated a partial DNA clone found to be down-regulated at the polytetrafluoroethylene (PTFE) hyperplastic arterial anastomosis compared with the normal artery. The partial DNA gene sequence was found to be homologous with interferon gamma up-regulated protein (IGUP) first found in human psoriatic keratinocytes. We cloned the entire IGUP gene from human vascular smooth muscle cells (VSMCs) to determine its regulation by gamma interferon (gamma-IFN) and other cytokines in cultured human VSMCs. METHODS: By means of polymerase chain reaction, the IGUP gene was amplified from a QUICK-Clone complementary DNA human aorta kit using 5' and 3' oligonucleotide primers to the known IGUP sequence. Immunohistocytochemistry studies compared normal artery and distal anastomotic IH. Human VSMCs were stimulated with 1000 U/mL of gamma-IFN, 5 ng/mL of platelet-derived growth factor BB (PDGF-BB), 3. 2 ng/mL basic fibroblast growth factor, 3.3 ng/mL transforming growth factor beta(TGF-beta), 10 ng/mL of vascular endothelial growth factor, and 10% fetal bovine serum (FBS) for zero, 24, 48 and 72 hours. Western blot analysis of lysates of the stimulated VSMCs was performed to determine up-regulation of IGUP. RESULTS: DNA sequencing confirmed the cloning of the entire coding region of the IGUP gene with 100% homology to the known IGUP DNA sequence. There was strong expression of IGUP in quiescent VSMCs and marked reduction of expression of IGUP in proliferating smooth muscle cells. gamma-IFN was the only cytokine, of the cytokines evaluated, to up-regulate production of IGUP in VSMCs. CONCLUSION: IGUP is a novel protein in VSMCs found to be down-regulated in areas of anastomotic IH, as compared with a normal artery. We have now shown IGUP to be up-regulated only by gamma-IFN in human VSMCs. IGUP may, therefore, be the intermediary for the known gamma-IFN inhibition of human VSMC proliferation. 相似文献