全文获取类型
收费全文 | 683074篇 |
免费 | 7711篇 |
国内免费 | 1622篇 |
专业分类
电工技术 | 12599篇 |
综合类 | 542篇 |
化学工业 | 108001篇 |
金属工艺 | 28447篇 |
机械仪表 | 21738篇 |
建筑科学 | 15814篇 |
矿业工程 | 4767篇 |
能源动力 | 17543篇 |
轻工业 | 56686篇 |
水利工程 | 8006篇 |
石油天然气 | 16378篇 |
武器工业 | 41篇 |
无线电 | 73467篇 |
一般工业技术 | 137172篇 |
冶金工业 | 118716篇 |
原子能技术 | 16803篇 |
自动化技术 | 55687篇 |
出版年
2021年 | 6242篇 |
2019年 | 5977篇 |
2018年 | 10347篇 |
2017年 | 10566篇 |
2016年 | 11073篇 |
2015年 | 7014篇 |
2014年 | 11853篇 |
2013年 | 31311篇 |
2012年 | 18515篇 |
2011年 | 25054篇 |
2010年 | 20112篇 |
2009年 | 22497篇 |
2008年 | 22787篇 |
2007年 | 22454篇 |
2006年 | 19459篇 |
2005年 | 17789篇 |
2004年 | 16950篇 |
2003年 | 16400篇 |
2002年 | 15961篇 |
2001年 | 15594篇 |
2000年 | 14892篇 |
1999年 | 14720篇 |
1998年 | 34624篇 |
1997年 | 25103篇 |
1996年 | 19586篇 |
1995年 | 15035篇 |
1994年 | 13393篇 |
1993年 | 13150篇 |
1992年 | 10149篇 |
1991年 | 9749篇 |
1990年 | 9637篇 |
1989年 | 9381篇 |
1988年 | 9078篇 |
1987年 | 8169篇 |
1986年 | 7967篇 |
1985年 | 9026篇 |
1984年 | 8217篇 |
1983年 | 7767篇 |
1982年 | 7028篇 |
1981年 | 7190篇 |
1980年 | 6848篇 |
1979年 | 6984篇 |
1978年 | 6886篇 |
1977年 | 7651篇 |
1976年 | 9666篇 |
1975年 | 6148篇 |
1974年 | 5920篇 |
1973年 | 6071篇 |
1972年 | 5176篇 |
1971年 | 4853篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Rapeseed protein concentrate (RC), prepared with 2% hexameta-phosphate, was tested for its functionality and performance in some foods. The RC had good nitrogen solubility, fat absorption, emulsification, and whipping capacities but poor water absorption and gelling properties. It increased the emulsion stability, and protein but lowered the fat content of wieners. It also increased the cooking yield, reduced the shrinkage and tenderized meat patties. Results were similar to soybean isolate except for the poorer color and flavor. The cooking yield of RC supplemented wieners was less than the all-meat control and soybean-supplemented wieners. A 9% RC dispersion mixed with an equal volume of eggwhite produced a meringue of comparable stability and texture to that of eggwhite alone. 相似文献
92.
Translated from Atomnaya Énergiya, Vol. 66, No. 6, pp. 423–424, June, 1989. 相似文献
93.
A. A. Konstantinov N. V. Kurenkov A. B. Malinin T. E. Sazonova S. V. Sepman 《Atomic Energy》1989,67(3):696-698
Translated from Atomnaya Énergiya, Vol. 67, No. 3, pp. 215–216, September, 1989. 相似文献
94.
Nagpal R. Zambonelli F. Sirer E.G. Chaouchi H. Smirnov M. 《Intelligent Systems, IEEE》2006,21(2):50-58
No generally accepted principles and guidelines currently exist to help engineers design local interaction mechanisms that result in a desired global behavior. However, several communities have developed ways of approaching this problem in the context of niched application areas. Because the ideas underlying these approaches are often obscured or underemphasized in technical papers, the authors review the role of self-organization in their work. They provide a better picture of the status of the emerging field of self-organizing systems or autonomic computing. 相似文献
95.
A.S. Fraser 《Journal of Great Lakes research》1980,6(1):83-87
An apparent decrease in total phosphorus concentrations of approximately 4.l μgP/L has been reported recently for the spring values of 1977 and 1978 in Lake Ontario. Investigation of the loading reduction for this period independent of sedimentation factors can account for only 10% of the change. The results indicate that changes in the sedimentation rate of total phosphorus during this period offer an explanation for the majority of the change in concentration. 相似文献
96.
S. F. Edwards 《Polymer International》1985,17(2):122-125
Elasticity is discussed as an aspect of viscoelasticity, which is described by the tube model. The effects of both crosslinks and entanglements contribute to this model and a discussion of how these effects can be quantified is given. At high enough concentration, entanglements ensure the existence of elastic effects even without crosslinks, and a theory is presented on how this dynamical phase change comes about. 相似文献
97.
K. A. Abdikalikov V. K. Zadiraka O. S. Kondratenko S. S. Mel'nikova 《Cybernetics and Systems Analysis》1991,27(3):414-419
A fast algorithm is proposed for estimating the auto- and cross-correlation functions of a large signal. The algorithm is based on the sectioning method by the fast Fourier transform. We determine the optimal length of the portion of data read from external memory into RAM which achieves Tmin—a minimum processing time. An estimate of Tmin is obtained.Translated from Kibernetika, No. 3, pp. 78–81, May–June, 1991. 相似文献
98.
99.
100.
Antoniades N. Boskovic A. Tomkos I. Madamopoulos N. Lee M. Roudas I. Pastel D. Sharma M. Yadlowsky M.J. 《Selected Areas in Communications, IEEE Journal on》2002,20(1):149-165
This paper demonstrates the use of computer simulation for topological design and performance engineering of transparent wavelength-division multiplexing metropolitan-area networks. Engineering of these networks involves the study of various transport-layer impairments such as amplifier noise, component ripple, chirp/dispersion, optical crosstalk, waveform distortion due to filter concatenation, fiber nonlinearities, and polarization effects. A computer simulation methodology composed of three main simulation steps is derived and implemented. This methodology obtains performance estimations by applying efficient wavelength-domain simulations on the entire network topology, followed by time-/frequency-domain simulations on selected paths of the network and finally Q-budgeting on an identified worst case path. The above technique provides an efficient tool for topological design and network performance engineering. Accurate simulation models are presented for each of the performance impairments, and the computer simulation methodology is used for the design and engineering of a number of actual metro network architectures 相似文献