全文获取类型
收费全文 | 1310篇 |
免费 | 9篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 100篇 |
金属工艺 | 24篇 |
机械仪表 | 9篇 |
建筑科学 | 8篇 |
矿业工程 | 2篇 |
能源动力 | 6篇 |
轻工业 | 105篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 36篇 |
一般工业技术 | 63篇 |
冶金工业 | 921篇 |
原子能技术 | 3篇 |
自动化技术 | 34篇 |
出版年
2023年 | 5篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 10篇 |
2013年 | 18篇 |
2012年 | 12篇 |
2011年 | 16篇 |
2010年 | 19篇 |
2009年 | 6篇 |
2008年 | 12篇 |
2007年 | 19篇 |
2006年 | 15篇 |
2005年 | 12篇 |
2004年 | 15篇 |
2003年 | 15篇 |
2002年 | 4篇 |
2001年 | 7篇 |
2000年 | 6篇 |
1999年 | 26篇 |
1998年 | 240篇 |
1997年 | 158篇 |
1996年 | 105篇 |
1995年 | 74篇 |
1994年 | 49篇 |
1993年 | 62篇 |
1992年 | 29篇 |
1991年 | 28篇 |
1990年 | 29篇 |
1989年 | 25篇 |
1988年 | 36篇 |
1987年 | 15篇 |
1986年 | 14篇 |
1985年 | 16篇 |
1984年 | 5篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 31篇 |
1976年 | 67篇 |
1975年 | 7篇 |
1974年 | 5篇 |
1973年 | 7篇 |
1970年 | 3篇 |
1967年 | 3篇 |
1955年 | 3篇 |
排序方式: 共有1319条查询结果,搜索用时 31 毫秒
1.
2.
3.
AV Stefano LF Canosa JL D'Eramo O Fridman JM Affanni GM Somoza 《Canadian Metallurgical Quarterly》1997,118(3):335-345
Gonadotropin-releasing hormone (GnRH) molecular variants in the brain and pituitary gland of pejerrey, Odontesthes bonariensis (Atheriniformes), were characterized by gradient reverse phase high performance liquid chromatography (RP-HPLC). Eluted fractions were tested in radioimmunoassays with different antisera. The results show that the brain extract contains three forms of GnRH: one is immunologically and chromatographically similar to cIIGnRH (chicken II), and another is similar to sGnRH (salmon). A third GnRH appears to be chromatographic and immunologically different from the nine other known forms of the vertebrate hormone. This is the only variant present in the pituitary gland. 相似文献
4.
5.
J. Voigt 《Molecular nutrition & food research》1993,37(1):104-104
6.
On a phenomenon of the limitation of pitting corrosion at high alloyed special stainless steels and NiCrMo-alloys in chloride solutions Testing the pitting corrosion resistance of high alloyed special stainless steels and NiCrMo-alloys in chloride solutions there was observed a limitation of the pitting corrosion range toward more positive potentials. Above this limitation, the so-called pitting corrosion limitation potential, the pit initiation by all means is prevented, but the growth of pits which had been initiated before in the pitting corrosion range not necessarily comes to a stop. Therefore current density-potential curves which are obtained by downward polarization after an initial potential jump into the transpassive region and chronopotentiostatic tests are more suitable to investigate this phenomenon than cyclic polarization measurements and potentiostatic alteration tests. There is indicated a dependence of this phenomenon on temperature. The phenomenon of a limitation of the pitting corrosion range toward more positive potentials has been found until now at alloy 926, alloy 31, alloy 28, alloy 59 and alloy C-276. 相似文献
7.
RC Smith JS Lyles JA Mettler AA Marshall LF Van Egeren BE Stoffelmayr GG Osborn V Shebroe 《Canadian Metallurgical Quarterly》1995,70(8):729-732
PURPOSE: To use a controlled, randomized design to assess the effect on patient satisfaction of an intensive psychosocial training program for residents. METHOD: Twenty-six first-year residents, in two internal medicine and family practice community-based programs affiliated with the Michigan State University College of Human Medicine, were randomly assigned during 1991 and 1992 to a control group or a one-month intensive training program. Experiential teaching focused on many psychosocial skills required in primary care. A 29-item questionnaire administered before and after the residents' training evaluated their patients' satisfaction regarding patient disclosure, physician empathy, confidence in physician, general satisfaction, and comparison of the physician with other physicians. Analyses of covariance with groups and gender as factors and pre-training patient satisfaction scores as the covariate evaluated the effect of the training. RESULTS: The patients of the trained residents expressed more confidence in their physicians (p = .01) and more general satisfaction (p = .02) than did the patients of controls. The effect of training on patient satisfaction with patient disclosure (p < .01) and physician empathy (p < .05) was greater for female than for male residents. CONCLUSION: The intensive psychosocial training program for residents improved their patients' satisfaction. 相似文献
8.
9.
Learning navigational maps through potentiation and modulation of hippocampal place cells 总被引:1,自引:0,他引:1
We analyze a model of navigational map formation based on correlation-based, temporally asymmetric potentiation and depression of synapses between hippocampal place cells. We show that synaptic modification during random exploration of an environment shifts the location encoded by place cell activity in such a way that it indicates the direction from any location to a fixed target avoiding walls and other obstacles. Multiple maps to different targets can be simultaneously stored if we introduce target-dependent modulation of place cell activity. Once maps to a number of target locations in a given environment have been stored, novel maps to previously unknown target locations are automatically constructed by interpolation between existing maps. 相似文献
10.