全文获取类型
收费全文 | 1787篇 |
免费 | 77篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 1865篇 |
出版年
2024年 | 2篇 |
2023年 | 17篇 |
2022年 | 16篇 |
2021年 | 31篇 |
2020年 | 21篇 |
2019年 | 32篇 |
2018年 | 36篇 |
2017年 | 32篇 |
2016年 | 51篇 |
2015年 | 26篇 |
2014年 | 51篇 |
2013年 | 56篇 |
2012年 | 77篇 |
2011年 | 66篇 |
2010年 | 69篇 |
2009年 | 40篇 |
2008年 | 49篇 |
2007年 | 33篇 |
2006年 | 24篇 |
2005年 | 24篇 |
2004年 | 20篇 |
2003年 | 22篇 |
2002年 | 12篇 |
2001年 | 11篇 |
2000年 | 16篇 |
1999年 | 42篇 |
1998年 | 305篇 |
1997年 | 152篇 |
1996年 | 102篇 |
1995年 | 77篇 |
1994年 | 67篇 |
1993年 | 63篇 |
1992年 | 17篇 |
1991年 | 20篇 |
1990年 | 17篇 |
1989年 | 24篇 |
1988年 | 22篇 |
1987年 | 20篇 |
1986年 | 18篇 |
1985年 | 8篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1978年 | 1篇 |
1977年 | 15篇 |
1976年 | 41篇 |
排序方式: 共有1865条查询结果,搜索用时 0 毫秒
1.
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
2.
3.
4.
5.
A W-band divide-by-3 frequency divider with wide bandwidth and low power dissipation is presented using harmonic injection-locking technique. A cascode FET is employed for a self-oscillating second-harmonic mixer which is injection-locked by third-harmonic input to obtain the division order of three. The fabricated frequency divider using 0.1 /spl mu/m GaAs metamorphic HEMT technology shows superior performance such as large bandwidth of 6.1 GHz around 83.1 GHz (7.3%) under small DC power consumption of 12 mW. 相似文献
6.
7.
8.
RM Bionta G Blewitt CB Bratton D Casper A Ciocio R Claus M Crouch ST Dye S Errede GW Foster W Gajewski KS Ganezer M Goldhaber TJ Haines TW Jones D Kielczewska WR Kropp JG Learned JM LoSecco J Matthews HS Park LR Price F Reines J Schulz S Seidel E Shumard D Sinclair HW Sobel JL Stone L Sulak R Svoboda G Thornton van der Velde JC C Wuest 《Canadian Metallurgical Quarterly》1987,36(1):30-36
9.
10.
Follicular dendritic cell tumour of the liver is a recently recognized entity. To date, only two cases have been described, both in the pathology literature. Histologically, it resembles an inflammatory pseudotumour and immunohistochemical and ultrastructural studies are required for its diagnosis. The ultrasound, computed tomography and angiographic features of two cases of follicular dendritic cell tumour of the liver are described in detail. One of the patients had multiple recurrences of this tumour. The imaging features are very similar to those of hepatocellular carcinoma. As follicular dendritic cell tumour is considered to be of low-grade malignant potential, in contrast to the dismal prognosis for hepatocellular carcinoma, it is important to be able to accurately distinguish between the two types of tumour prior to initiating definitive therapy. 相似文献