全文获取类型
收费全文 | 9200篇 |
免费 | 143篇 |
国内免费 | 10篇 |
学科分类
工业技术 | 9353篇 |
出版年
2022年 | 48篇 |
2021年 | 54篇 |
2020年 | 40篇 |
2019年 | 55篇 |
2018年 | 78篇 |
2017年 | 72篇 |
2016年 | 84篇 |
2015年 | 78篇 |
2014年 | 99篇 |
2013年 | 354篇 |
2012年 | 193篇 |
2011年 | 250篇 |
2010年 | 252篇 |
2009年 | 236篇 |
2008年 | 254篇 |
2007年 | 250篇 |
2006年 | 213篇 |
2005年 | 239篇 |
2004年 | 175篇 |
2003年 | 192篇 |
2002年 | 189篇 |
2001年 | 158篇 |
2000年 | 172篇 |
1999年 | 177篇 |
1998年 | 960篇 |
1997年 | 627篇 |
1996年 | 437篇 |
1995年 | 349篇 |
1994年 | 296篇 |
1993年 | 301篇 |
1992年 | 126篇 |
1991年 | 121篇 |
1990年 | 130篇 |
1989年 | 143篇 |
1988年 | 134篇 |
1987年 | 103篇 |
1986年 | 95篇 |
1985年 | 114篇 |
1984年 | 114篇 |
1983年 | 86篇 |
1982年 | 77篇 |
1981年 | 74篇 |
1980年 | 87篇 |
1979年 | 79篇 |
1978年 | 89篇 |
1977年 | 137篇 |
1976年 | 248篇 |
1975年 | 60篇 |
1974年 | 63篇 |
1973年 | 57篇 |
排序方式: 共有9353条查询结果,搜索用时 15 毫秒
1.
Thin Film Thermoelectric Metal–Organic Framework with High Seebeck Coefficient and Low Thermal Conductivity 下载免费PDF全文
2.
3.
4.
BS Kendrick BS Chang T Arakawa B Peterson TW Randolph MC Manning JF Carpenter 《Canadian Metallurgical Quarterly》1997,94(22):11917-11922
Understanding the mechanism for sucrose-induced protein stabilization is important in many diverse fields, ranging from biochemistry and environmental physiology to pharmaceutical science. Timasheff and Lee [Lee, J. C. & Timasheff, S. N. (1981) J. Biol. Chem. 256, 7193-7201] have established that thermodynamic stabilization of proteins by sucrose is due to preferential exclusion of the sugar from the protein's surface, which increases protein chemical potential. The current study measures the preferential exclusion of 1 M sucrose from a protein drug, recombinant interleukin 1 receptor antagonist (rhIL-1ra). It is proposed that the degree of preferential exclusion and increase in chemical potential are directly proportional to the protein surface area and that, hence, the system will favor the protein state with the smallest surface area. This mechanism explains the observed sucrose-induced restriction of rhIL-1ra conformational fluctuations, which were studied by hydrogen-deuterium exchange and cysteine reactivity measurements. Furthermore, infrared spectroscopy of rhlL-1ra suggested that a more ordered native conformation is induced by sucrose. Electron paramagnetic resonance spectroscopy demonstrated that in the presence of sucrose, spin-labeled cysteine 116 becomes more buried in the protein's interior and that the hydrodynamic diameter of the protein is reduced. The preferential exclusion of sucrose from the protein and the resulting shift in the equilibrium between protein states toward the most compact conformation account for sucrose-induced effects on rhIL-1ra. 相似文献
5.
6.
Capers Jones 《Information Systems Management》1994,11(4):28-33
If you don't know the current productivity rates, usage volumes, and other quantitative baseline data for your software operations, then software might not be a key component of the company's core business. The evaluation criteria in this article can help the IS executive determine the outsourcing options for software operations. 相似文献
7.
Current cementing techniques of distal plugging, pulsatile water cleaning of the canal, and retrograde filling with PMMA in a low-viscous state prepared using porosity reduction techniques and then pressurized have been shown to give excellent results at 10 or more years after operation. However, physical and aging characteristics of PMMA do not guarantee that those results will hold up in the 20- to 30-year time frame. Fifteen-year experience with bony ingrowth systems indicate the development of a durable interface without PMMA, although the interface does appear more vulnerable to attack by the biologic reaction to HMWPE debris. Bone remodeling appears more favorable around proximally fixed bone ingrowth prostheses than around distally fixed prostheses. Softening of the physical characteristics of the stem tip may reduce the incidence of thigh pain. Patients with high activity potential and a life expectancy of greater than 25 years should be strongly considered for a proximally fixed bone ingrowth or ongrowth prosthesis. 相似文献
8.
9.
10.
This paper derives the governing equations for the thermomechanical behaviour of composites. When the basic equations for the thermoelastic behaviour of solids were first derived in the nineteenth century several approximations were made. The effect of these assumptions are discussed and illustrated by the results of a simple laboratory test. The implications of this work on the analysis of impact damaged laminates are then discussed. 相似文献