全文获取类型
收费全文 | 4547篇 |
免费 | 62篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 47篇 |
化学工业 | 399篇 |
金属工艺 | 70篇 |
机械仪表 | 59篇 |
建筑科学 | 124篇 |
矿业工程 | 15篇 |
能源动力 | 44篇 |
轻工业 | 295篇 |
水利工程 | 29篇 |
石油天然气 | 7篇 |
无线电 | 295篇 |
一般工业技术 | 451篇 |
冶金工业 | 2354篇 |
原子能技术 | 20篇 |
自动化技术 | 404篇 |
出版年
2021年 | 29篇 |
2019年 | 20篇 |
2018年 | 25篇 |
2017年 | 33篇 |
2016年 | 17篇 |
2015年 | 34篇 |
2014年 | 58篇 |
2013年 | 158篇 |
2012年 | 104篇 |
2011年 | 102篇 |
2010年 | 56篇 |
2009年 | 61篇 |
2008年 | 90篇 |
2007年 | 106篇 |
2006年 | 103篇 |
2005年 | 72篇 |
2004年 | 79篇 |
2003年 | 87篇 |
2002年 | 75篇 |
2001年 | 57篇 |
2000年 | 54篇 |
1999年 | 131篇 |
1998年 | 713篇 |
1997年 | 428篇 |
1996年 | 257篇 |
1995年 | 177篇 |
1994年 | 139篇 |
1993年 | 162篇 |
1992年 | 65篇 |
1991年 | 63篇 |
1990年 | 63篇 |
1989年 | 65篇 |
1988年 | 64篇 |
1987年 | 47篇 |
1986年 | 48篇 |
1985年 | 58篇 |
1984年 | 30篇 |
1983年 | 27篇 |
1982年 | 28篇 |
1981年 | 48篇 |
1980年 | 40篇 |
1979年 | 27篇 |
1978年 | 33篇 |
1977年 | 77篇 |
1976年 | 118篇 |
1975年 | 28篇 |
1974年 | 23篇 |
1973年 | 28篇 |
1972年 | 19篇 |
1971年 | 18篇 |
排序方式: 共有4613条查询结果,搜索用时 0 毫秒
1.
Zenan Yu Julian Moore Jean Calderon Lei Zhai Jayan Thomas 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(39):5289-5295
Cable‐shaped supercapacitors (SCs) have recently aroused significant attention due to their attractive properties such as small size, lightweight, and bendability. Current cable‐shaped SCs have symmetric device configuration. However, if an asymmetric design is used in cable‐shaped supercapacitors, they would become more attractive due to broader cell operation voltages, which results in higher energy densities. Here, a novel coil‐type asymmetric supercapacitor electrical cable (CASEC) is reported with enhanced cell operation voltage and extraordinary mechanical‐electrochemical stability. The CASECs show excellent charge–discharge profiles, extraordinary rate capability (95.4%), high energy density (0.85 mWh cm−3), remarkable flexibility and bendability, and superior bending cycle stability (≈93.0% after 4000 cycles at different bending states). In addition, the CASECs not only exhibit the capability to store energy but also to transmit electricity simultaneously and independently. The integrated electrical conduction and storage capability of CASECS offer many potential applications in solar energy storage and electronic gadgets. 相似文献
2.
3.
4.
NC Moore 《Canadian Metallurgical Quarterly》1997,86(2):81-82
The nation's health care system is undergoing a period of rapid change that will profoundly affect women's health care services and, ultimately, women's health. Although managed care is quickly becoming the predominant mode of health care delivery in the United States, a new, more consumer-focused, and accountable model known as organized systems of care (OSC) is emerging. OSC development has been driven by large private and public employers seeking to purchase the highest quality health care for the best price. The changes in health care delivery encouraged by these innovative employers will provide women with optimal care and attention, which will in turn help them attract and retain a competitive and productive workforce. 相似文献
5.
6.
7.
WR Volger RS Weiner JO Moore GA Omura AA Bartolucci M Stagg 《Canadian Metallurgical Quarterly》1995,9(9):1456-1460
A phase III clinical trial was designed to determine if more intensive induction and consolidation therapy for acute myeloblastic leukemia increases the remission rate and prolongs survival. A minor objective was to determine if the use of non-cross resistant drugs was more effective than the same drugs used for induction. Patients with untreated leukemia between the ages of 15 and 50 were given daunorubicin 45 mg/m2 for the first 3 days of a 10-day continuous infusion of cytosine arabinoside, initially at a dose of 2000 mg/m2 but reduced to 100 mg/m2 because of toxicity. Those under 36 achieving a complete remission and with an histocompatible donor were assigned to a transplant arm. The rest were randomized to receive one of three consolidation arms: A, cytosine arabinoside, 200 mg/m2 daily for 7 days and daunorubicin 45 mg/m2 daily for 3 days for three courses; B, one course as in Arm A followed by amsacrine, 120 mg/m2 daily for 5 days followed by a 5-day continuous infusion of azacytidine, 150 mg/m2/day; C, thioguanine and cytosine arabinoside, 100 mg/m2 every 12 h and daunorubicin 10 mg/m2 daily for 5 days for three courses followed by four maintenance courses of cytosine arabinoside, 100 mg/m2 daily for 5 days and daunorubicin, 45 mg/m2 for 2 days every 13 weeks. From 1981 to 1986, 398 eligible patients were enrolled and 219 achieved a complete remission. The initial induction dose of cytosine arabinoside was reduced after five of 29 patients exhibited fatal gastrointestinal toxicity. Only 11 patients were assigned to the transplant arm. There were no significant differences in the consolidation arms. The 5 year disease-free survivals were 38, 31 and 27% in arms A, B, and C respectively. Intensive consolidation therapy with the same or different drugs used in induction was as effective as lower dose consolidation followed by maintenance therapy. 相似文献
8.
DC Reynolds CE Leak KK Bajaj CE Stutz RL Jones KR Evans PW Yu WM Theis 《Canadian Metallurgical Quarterly》1989,40(9):6210-6217
9.
A real-time neural system for color constancy 总被引:11,自引:0,他引:11
A neural network approach to the problem of color constancy is presented. Various algorithms based on Land's retinex theory are discussed with respect to neurobiological parallels, computational efficiency, and suitability for VLSI implementation. The efficiency of one algorithm is improved by the application of resistive grids and is tested in computer simulations; the simulations make clear the strengths and weaknesses of the algorithm. A novel extension to the algorithm is developed to address its weaknesses. An electronic system that is based on the original algorithm and that operates at video rates was built using subthreshold analog CMOS VLSI resistive grids. The system displays color constancy abilities and qualitatively mimics aspects of human color perception. 相似文献
10.
Fuzzy logic was first suggested as the mechanism by which humans drive cars. This paper addresses the use of fuzzy logic and algorithms towards the intelligent autonomous motion control of land vehicles. To cope with vehicle complexities, internal parametric changes, and with unpredictable environmental effects, the controllers that are presented, whilst heuristic in nature, are self-organizing or self-learning in that they generate automatically by observation an experiential rule base that models the vehicle, and via an appropriate performance index an optimal control rule base that is robust to large parametric changes. The methodology presented is applicable to any complex process which is too difficult to model or control using conventional methods, or which has relied on the experience of a human operator. An overview of fuzzy logic and static fuzzy logic control (akin to expert systems) is provided, together with illustrative examples. 相似文献