全文获取类型
收费全文 | 9000篇 |
免费 | 603篇 |
国内免费 | 21篇 |
专业分类
电工技术 | 126篇 |
综合类 | 18篇 |
化学工业 | 2339篇 |
金属工艺 | 170篇 |
机械仪表 | 207篇 |
建筑科学 | 321篇 |
矿业工程 | 36篇 |
能源动力 | 223篇 |
轻工业 | 402篇 |
水利工程 | 68篇 |
石油天然气 | 28篇 |
无线电 | 758篇 |
一般工业技术 | 2286篇 |
冶金工业 | 981篇 |
原子能技术 | 78篇 |
自动化技术 | 1583篇 |
出版年
2023年 | 153篇 |
2022年 | 374篇 |
2021年 | 418篇 |
2020年 | 285篇 |
2019年 | 246篇 |
2018年 | 301篇 |
2017年 | 255篇 |
2016年 | 349篇 |
2015年 | 297篇 |
2014年 | 438篇 |
2013年 | 550篇 |
2012年 | 547篇 |
2011年 | 623篇 |
2010年 | 423篇 |
2009年 | 412篇 |
2008年 | 433篇 |
2007年 | 416篇 |
2006年 | 324篇 |
2005年 | 252篇 |
2004年 | 222篇 |
2003年 | 201篇 |
2002年 | 191篇 |
2001年 | 122篇 |
2000年 | 113篇 |
1999年 | 119篇 |
1998年 | 193篇 |
1997年 | 154篇 |
1996年 | 105篇 |
1995年 | 83篇 |
1994年 | 73篇 |
1993年 | 90篇 |
1992年 | 53篇 |
1991年 | 50篇 |
1990年 | 50篇 |
1989年 | 37篇 |
1988年 | 44篇 |
1987年 | 40篇 |
1986年 | 34篇 |
1985年 | 42篇 |
1984年 | 37篇 |
1983年 | 32篇 |
1982年 | 27篇 |
1981年 | 27篇 |
1980年 | 23篇 |
1979年 | 19篇 |
1978年 | 28篇 |
1977年 | 24篇 |
1976年 | 60篇 |
1975年 | 27篇 |
1971年 | 17篇 |
排序方式: 共有9624条查询结果,搜索用时 15 毫秒
71.
72.
Alexander Vikhansky 《Chemical engineering science》2006,61(15):4966-4972
We consider two stochastic simulation algorithms for the calculation of parametric derivatives of solutions of a population balance equation, namely, forward and adjoint sensitivity methods. The dispersed system is approximated by an N-particle stochastic weighted ensemble. The infinitesimal deviations of the solution are accounted for through infinitesimal deviation of the statistical weights that are recalculated at each coagulation. In the forward method these deviations of the statistical weights immediately give parametric derivatives of the solution. In the second method the deviations of the statistical weights are used to calculate a finite-mode approximation of the linearized version of the population balance equation. The linearized equation allows for the calculation of the eigenmodes and eigenvalues of the process, while the parametric derivatives of the solution are given by a Lagrange formalism. 相似文献
73.
Alexander Weinmann 《e & i Elektrotechnik und Informationstechnik》2008,125(1-2):1-1
Ohne Zusammenfassung 相似文献
74.
75.
Voting in Multi-Agent Systems 总被引:1,自引:0,他引:1
76.
Paustovskii Alexander V. Alfintseva Raisa A. Kurinnaya Tatyana V. Pogorelaya Valentina V. Kirilenko Stepan N. 《Powder Metallurgy and Metal Ceramics》2004,43(5-6):251-257
The main parameters of electrospark alloying of steel 45 with anodes made from Ni – Cr – Al – Y alloys have been investigated. The anodes were fabricated by casting and hot pressing. The highest values of the mass transfer coefficient were observed in the case of electrospark alloying with hot-pressed alloys. Microstructure and x-ray phase analyses of electrospark coatings revealed the presence of solid solutions based on nickel, iron, chromium as well as intermetallic compounds. Coatings obtained by electrospark alloying with hot-pressed alloy are more wear-resistant than are coatings obtained by alloying with cast alloys. 相似文献
77.
Alexander Babich Konstantinos Mavrommatis Dieter Senk Heinrich Wilhelm Gudenau 《国际钢铁研究》2004,75(7):428-432
This contribution deals with advanced educational technologies needed to equip customers from higher education institutions, research and industry with efficient tools supporting their work and operating new skills‐training methods. The challenges are reducing the training costs, improving quality and increasing the number of graduates in engineering departments. The concept of a Virtual Lab based on the combination of various teaching methods and tools is presented. Principles of mathematisation in metallurgical education and training are discussed. An example of online course designed in the form of Virtual Lab is demonstrated. 相似文献
78.
A new high-order accurate continuous Galerkin method for linear elastodynamics problems 总被引:1,自引:1,他引:0
Alexander V. Idesman 《Computational Mechanics》2007,40(2):261-279
A new high-order accurate time-continuous Galerkin (TCG) method for elastodynamics is suggested. The accuracy of the new implicit
TCG method is increased by a factor of two in comparison to that of the standard TCG method and is one order higher than the
accuracy of the standard time-discontinuous Galerkin (TDG) method at the same number of degrees of freedom. The new method
is unconditionally stable and has controllable numerical dissipation at high frequencies. An iterative predictor/multi-corrector
solver that includes the factorization of the effective mass matrix of the same dimension as that of the mass matrix for the
second-order methods is developed for the new TCG method. A new strategy combining numerical methods with small and large
numerical dissipation is developed for elastodynamics. Simple numerical tests show a significant reduction in the computation
time (by 5–25 times) for the new TCG method in comparison to that for second-order methods, and the suppression of spurious
high-frequency oscillations. 相似文献
79.
Psychological health-sickness (PHS) as a predictor of outcomes in dynamic and other psychotherapies.
Luborsky Lester; Diguer Louis; Luborsky Ellen; McLellan A. Thomas; Woody George; Alexander Leslie 《Canadian Metallurgical Quarterly》1993,61(4):542
This is the first dedicated review of quantitative studies on Freud's proposition that the poorer the psychological health, the more limited are the benefits from treatment. Since observer-rated scales for PHS were developed in 1949, many studies have applied them, and the majority show significant prediction of outcomes of psychotherapy, with correlations between .2 and .35. This article reviews (1) the main methods of measurement, (2) the record of predictive success, (3) validity studies, (4) the relation to psychiatric diagnosis, (5) prediction in forms of treatment other than psychotherapy, and (6) theories of why psychological health predicts outcomes of psychotherapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
80.