全文获取类型
收费全文 | 3331篇 |
免费 | 200篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 57篇 |
综合类 | 14篇 |
化学工业 | 697篇 |
金属工艺 | 60篇 |
机械仪表 | 66篇 |
建筑科学 | 192篇 |
矿业工程 | 4篇 |
能源动力 | 97篇 |
轻工业 | 347篇 |
水利工程 | 35篇 |
石油天然气 | 23篇 |
无线电 | 245篇 |
一般工业技术 | 570篇 |
冶金工业 | 452篇 |
原子能技术 | 22篇 |
自动化技术 | 651篇 |
出版年
2023年 | 51篇 |
2022年 | 78篇 |
2021年 | 112篇 |
2020年 | 58篇 |
2019年 | 63篇 |
2018年 | 77篇 |
2017年 | 77篇 |
2016年 | 125篇 |
2015年 | 115篇 |
2014年 | 123篇 |
2013年 | 195篇 |
2012年 | 169篇 |
2011年 | 223篇 |
2010年 | 211篇 |
2009年 | 162篇 |
2008年 | 159篇 |
2007年 | 141篇 |
2006年 | 144篇 |
2005年 | 117篇 |
2004年 | 98篇 |
2003年 | 76篇 |
2002年 | 80篇 |
2001年 | 72篇 |
2000年 | 52篇 |
1999年 | 66篇 |
1998年 | 137篇 |
1997年 | 80篇 |
1996年 | 55篇 |
1995年 | 48篇 |
1994年 | 27篇 |
1993年 | 38篇 |
1992年 | 18篇 |
1991年 | 15篇 |
1990年 | 18篇 |
1989年 | 24篇 |
1988年 | 20篇 |
1987年 | 20篇 |
1986年 | 16篇 |
1985年 | 23篇 |
1984年 | 13篇 |
1983年 | 18篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 9篇 |
1977年 | 5篇 |
1976年 | 23篇 |
1974年 | 5篇 |
1973年 | 6篇 |
1968年 | 6篇 |
排序方式: 共有3532条查询结果,搜索用时 31 毫秒
71.
72.
73.
74.
75.
Olivier Guillon Christian Elsässer Oliver Gutfleisch Jürgen Janek Sandra Korte-Kerzel Dierk Raabe Cynthia A. Volkert 《Materials Today》2018,21(5):527-536
The use of external electric and magnetic fields for the synthesis and processing of inorganic materials such as metals and ceramics has seen renewed interest in recent years. Electromagnetic energy can be utilized in different ways to improve or accelerate phase formation and stabilization, chemical ordering, densification and coarsening of particle-based materials (pore elimination and grain growth), and mechanical deformation (plasticity and creep). In these new synthesis and processing routes, the resulting microstructures and macroscopic material behavior are determined by the interaction of the applied fields with defects such as single or clustered point defects, dislocation networks, and interfaces. Multiscale experimental investigations and modeling are necessary to unveil the mechanisms underlying this field-assisted manipulation of matter. 相似文献
76.
We present a robust optimization framework that is applicable to general nonlinear programs (NLP) with uncertain parameters. We focus on design problems with partial differential equations (PDE), which involve high computational cost. Our framework addresses the uncertainty with a deterministic worst-case approach. Since the resulting min–max problem is computationally intractable, we propose an approximate robust formulation that employs quadratic models of the involved functions that can be handled efficiently with standard NLP solvers. We outline numerical methods to build the quadratic models, compute their derivatives, and deal with high-dimensional uncertainties. We apply the presented approach to the parametrized shape optimization of systems that are governed by different kinds of PDE and present numerical results. 相似文献
77.
Fernando Maccari Tarini Prasad Mishra Monica Keszler Tobias Braun Esmaeil Adabifiroozjaei Iliya Radulov Tianshu Jiang Enrico Bruder Olivier Guillon Leopoldo Molina-Luna Martin Bram Oliver Gutfleisch 《Advanced Engineering Materials》2023,25(18):2300252
Flash spark plasma sintering (flash SPS) is an attractive method to obtain Nd–Fe–B magnets with anisotropic magnetic properties when starting from melt-spun powders. Compared to the benchmark processing route via hot pressing with subsequent die upsetting, flash SPS promises electroplasticity as an additional deformation mechanism and reduced tool wear, while maximizing magnetic properties by tailoring the microstructure—fully dense and high texture. A detailed parameter study is conducted to understand the influence of Flash SPS parameters on the densification and magnetic properties of commercial MQU-F powder. It is revealed that the presintering conditions and preheating temperature before applying the power pulse play a major role for tailoring grain size and texture in the case of hot deformation via Flash SPS. Detailed microstructure and magnetic domain evaluation disclose the texture enhancement with increasing flash SPS temperature at the expense of coercivity. The best compromise between remanence and coercivity (1.37 T and 1195 kA m−1, respectively) is achieved through a combination of presintering at 500 °C for 120 s and preheating temperature of 600 °C, resulting in a magnet with energy product (BH)max of 350 kJm−3. These findings show the potential of flash SPS to obtain fully dense anisotropic nanocrystalline magnets with high magnetic performance. 相似文献
78.
KJ Zucker SJ Bradley G Oliver J Blake S Fleming J Hood 《Canadian Metallurgical Quarterly》1996,30(4):300-318
Women with congenital adrenal hyperplasia (CAH) (N = 31) and their unaffected sisters or female cousins (N = 15) participated in a study of psychosexual development. All participants were > or = 18 years of age (mean age, 25 years; range, 18-40). Comparisons were also made between the CAH women with the salt-wasting (SW) form of the disorder and those with simple virilization (SV). A psychosexual assessment protocol examined six variables: (1) sex assignment at birth (probands only); (2) recalled sex-typed behavior during childhood; (3) gender identity and gender role identification in adulthood; (4) relationship status; (5) sexual orientation in fantasy; and (6) sexual orientation in behavior. Salt-wasting status and sex assignment at birth were also ascertained for the CAH women who either refused to participate in the study (N = 10) or could not be traced (N = 13). Compared to the controls, the women with CAH recalled more cross-gender role behavior and less comfort with their sense of "femininity" during childhood. The two groups did not differ in degree of gender dysphoria in adulthood, although the probands showed more cross-gender role identification. Three of the nonparticipant probands were living, as adults, in the male social role (2 reared from birth as boys and 1 who changed from the female to the male social role during adolescence). The CAH women and the controls did not differ in relationship status (married/cohabiting vs. single). The CAH women had lower rates of exclusive heterosexual fantasy and fewer sexual experiences with men than the controls; however, the CAH women did not have more sexual experiences with women than the controls. Comparisons between the SW and SV revealed several differences: the SW were less likely to be assigned to the female sex at birth, recalled more cross-gender role behavior during childhood, were less likely to be married or cohabiting, and had lower rates of sexual experiences with men. The results were discussed in relation to the effects of prenatal androgens on psychosexual differentiation. 相似文献
79.
Lars Mönch John W. Fowler Stéphane Dauzère-Pérès Scott J. Mason Oliver Rose 《Journal of Scheduling》2011,14(6):583-599
In this paper, we discuss scheduling problems in semiconductor manufacturing. Starting from describing the manufacturing process,
we identify typical scheduling problems found in semiconductor manufacturing systems. We describe batch scheduling problems,
parallel machine scheduling problems, job shop scheduling problems, scheduling problems with auxiliary resources, multiple
orders per job scheduling problems, and scheduling problems related to cluster tools. We also present important solution techniques
that are used to solve these scheduling problems by means of specific examples, and report on known implementations. Finally,
we summarize some of the challenges in scheduling semiconductor manufacturing operations. 相似文献
80.