全文获取类型
收费全文 | 805篇 |
免费 | 0篇 |
专业分类
化学工业 | 17篇 |
金属工艺 | 13篇 |
机械仪表 | 5篇 |
建筑科学 | 10篇 |
能源动力 | 3篇 |
轻工业 | 32篇 |
石油天然气 | 1篇 |
无线电 | 16篇 |
一般工业技术 | 11篇 |
冶金工业 | 688篇 |
原子能技术 | 1篇 |
自动化技术 | 8篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2014年 | 5篇 |
2013年 | 15篇 |
2012年 | 2篇 |
2011年 | 3篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 5篇 |
2007年 | 1篇 |
2006年 | 7篇 |
2004年 | 4篇 |
2003年 | 1篇 |
1999年 | 22篇 |
1998年 | 197篇 |
1997年 | 120篇 |
1996年 | 76篇 |
1995年 | 43篇 |
1994年 | 34篇 |
1993年 | 41篇 |
1992年 | 8篇 |
1991年 | 10篇 |
1990年 | 16篇 |
1989年 | 23篇 |
1988年 | 16篇 |
1987年 | 16篇 |
1986年 | 10篇 |
1985年 | 12篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1977年 | 28篇 |
1976年 | 41篇 |
1975年 | 1篇 |
1955年 | 3篇 |
排序方式: 共有805条查询结果,搜索用时 15 毫秒
21.
22.
Plausible costs of photovoltaic power plants of concentration are presented. Costs are based as much as possible on the recent experience of solar thermal plants. Efficiencies, on the existing world experience of PV power plants. The result is that the costs of concentrating photovoltaic plants should be of 0.08 ECUs/ kWh, about 1/3 of that of flat module plants, and of the same order of magnitude, even lower, than those attributed to solar thermal plants of present technology. For the future, high concentration systems based on Si or tandem cells seem to be the most promising, also in the range of costs of the advanced solar thermal plants. 相似文献
23.
Dora Fenn Gavin Humphreys Paul G. Fields Joyce I. Boye 《International Journal of Food Properties》2013,16(2):381-393
Wheat-legume composite flours were produced by blending Canada Western Extra Strong (CWES) and Canada Western Red Spring (CWRS) wheat with varying amounts of three legume proteins. Legume protein addition produced breads with lower specific loaf volume, coarser crumb and firmer texture, and cooked white-salted noodles with greater compression stress and less cutting stress than the wheat controls. The CWES wheat compensated for the negative baking effects of the legume proteins as much as the CWRS wheat. End-use quality did not change at 2% soybean protein addition. Yellow pea protein produced the greatest quality changes, followed by chickpea and soybean protein. 相似文献
24.
25.
PH Allaire JM Messick JE Oesterling DE Byer RP Myers MM Lieber RC Chantigian JO Welna DE Patterson ML Blute 《Canadian Metallurgical Quarterly》1992,67(11):1031-1041
In a prospective, randomized study, continuous infusion of epidural fentanyl citrate (group E) was compared with patient-controlled intravenously administered morphine sulfate (group P) for analgesia in 66 men after radical retropubic prostatectomy. Although both methods provided satisfactory analgesia, the mean comfort level scores were lower (that is, greater comfort) in group E than in group P at all observation times. The difference in mean resting comfort level scores between groups E and P was statistically significant (P < or = 0.05) at 9 of the 11 observation times. In addition, significant differences in comfort level scores were noted at 8 of the 11 observation times during deep breathing, 5 of 11 during coughing, and 3 of 9 during ambulation. Maximal and minimal comfort level scores recorded by each patient during the course of the study were significantly lower (that is, less pain) in group E than in group P for all four categories of activity. The percentage of patients who reported no pain was significantly higher in group E than in group P at 9 of 11 observation times during resting and 5 of 11 observation times during deep breathing. No significant differences were noted in side effect profiles or duration of hospital stay. In summary, when two effective methods of analgesia used after radical retropubic prostatectomy were compared prospectively, patients who received epidural infusion of fentanyl were more comfortable than those with patient-controlled intravenous administration of morphine, as evidenced by lower mean, maximal, and minimal comfort level scores and a greater proportion of patients with complete relief of pain. 相似文献
26.
27.
SB Christensen A Guider CJ Forster JG Gleason PE Bender JM Karpinski WE DeWolf MS Barnette DC Underwood DE Griswold LB Cieslinski M Burman S Bochnowicz RR Osborn CD Manning M Grous LM Hillegas JO Bartus MD Ryan DS Eggleston RC Haltiwanger TJ Torphy 《Canadian Metallurgical Quarterly》1998,41(6):821-835
Evaluation of a variety of PDE4 inhibitors in a series of cellular and in vivo assays suggested a strategy to improve the therapeutic index of PDE4 inhibitors by increasing their selectivity for the ability to inhibit PDE4 catalytic activity versus the ability to compete for high affinity [3H]rolipram-binding sites in the central nervous system. Use of this strategy led ultimately to the identification of cis-4-cyano-4-[3-(cyclopentyloxy)-4-methoxyphenyl]cyclohexane-1-carboxyl ic acid (1, SB 207499, Ariflo), a potent second-generation inhibitor of PDE4 with a decreased potential for side effects versus the archetypic first generation inhibitor, (R)-rolipram. 相似文献
28.
29.
KM Mattila C Forsell T Pirttil? JO Rinne T Lehtim?ki M R?ytt? L Lilius A Eerola PH St George-Hyslop H Frey L Lannfelt 《Canadian Metallurgical Quarterly》1998,44(6):965-967
In early-onset familial Alzheimer's disease (AD) pathogenic mutations have been found in the amyloid precursor protein (APP) gene and in the presenilin (PS)-1 and PS-2 genes. We screened for mutations in these genes in 20 patients with familial AD from the Finnish population. In addition, we sampled 41 sporadic AD patients and 59 controls to test for mutations identified in our familial AD cases. We detected an A-to-G transition in the PS-1 gene, resulting in a glutamic acid (Glu)-to-glycine (Gly) substitution at codon 318 in 2 familial and 2 sporadic AD patients. The Glu318Gly mutation has previously been reported to cause AD. We also found the Glu318Gly mutation in 4 healthy aged controls (range, 74-87 years). We thus conclude that the mutation is most likely a rare polymorphism not related to AD. 相似文献
30.
BR Babu SJ Zhu AV Ramayya JH Hamilton LK Peker MG Wang TN Ginter J Kormicki WC Ma JD Cole R Aryaeinejad K Butler-Moore YX Dardenne MW Drigert GM Ter-Akopian YT Oganessian JO Rasmussen S Asztalos IY Lee AO Macchiavelli SY Chu KE Gregorich MF Mohar S Prussin MA Stoyer RW Lougheed KJ Moody JF Wild 《Canadian Metallurgical Quarterly》1996,54(2):568-571