全文获取类型
收费全文 | 4917篇 |
免费 | 124篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 100篇 |
化学工业 | 667篇 |
金属工艺 | 102篇 |
机械仪表 | 86篇 |
建筑科学 | 158篇 |
矿业工程 | 21篇 |
能源动力 | 77篇 |
轻工业 | 394篇 |
水利工程 | 52篇 |
石油天然气 | 14篇 |
无线电 | 550篇 |
一般工业技术 | 652篇 |
冶金工业 | 1529篇 |
原子能技术 | 31篇 |
自动化技术 | 613篇 |
出版年
2021年 | 38篇 |
2020年 | 27篇 |
2019年 | 31篇 |
2018年 | 37篇 |
2017年 | 52篇 |
2016年 | 38篇 |
2015年 | 59篇 |
2014年 | 91篇 |
2013年 | 261篇 |
2012年 | 128篇 |
2011年 | 139篇 |
2010年 | 106篇 |
2009年 | 118篇 |
2008年 | 129篇 |
2007年 | 140篇 |
2006年 | 161篇 |
2005年 | 108篇 |
2004年 | 119篇 |
2003年 | 123篇 |
2002年 | 118篇 |
2001年 | 114篇 |
2000年 | 99篇 |
1999年 | 137篇 |
1998年 | 403篇 |
1997年 | 263篇 |
1996年 | 197篇 |
1995年 | 149篇 |
1994年 | 116篇 |
1993年 | 133篇 |
1992年 | 72篇 |
1991年 | 77篇 |
1990年 | 91篇 |
1989年 | 84篇 |
1988年 | 93篇 |
1987年 | 70篇 |
1986年 | 55篇 |
1985年 | 69篇 |
1984年 | 43篇 |
1983年 | 39篇 |
1982年 | 38篇 |
1981年 | 53篇 |
1980年 | 45篇 |
1979年 | 41篇 |
1978年 | 40篇 |
1977年 | 66篇 |
1976年 | 84篇 |
1975年 | 46篇 |
1974年 | 26篇 |
1973年 | 34篇 |
1972年 | 27篇 |
排序方式: 共有5046条查询结果,搜索用时 22 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.
Juana Maria de Lourdes Medina-Contreras Patrick Mailloux-Salinas Juventino III Colado-Velazquez Norma Leticia Gomez Viquez Gómez-Viquez Rodrigo Velázquez-Espejel Ana del Carmen Susunaga-Notario David Julian Arias-Chávez Guadalupe Bravo 《Journal of the science of food and agriculture》2020,100(7):3212-3219
3.
P. L. Sun E. K. Cerreta G. T. Gray III J. F. Bingert 《Metallurgical and Materials Transactions A》2006,37(10):2983-2994
Commercial purity aluminum AA1050 was subjected to equal channel angular extrusion (ECAE) that resulted in an ultrafine-grained
(UFG) microstructure with an as-received grain size of 0.35 μm. This UFG material was then annealed to obtain microstructures
with grain sizes ranging from 0.47 to 20 μm. Specimens were compressed at quasi-static, intermediate, and dynamic strain rates
at temperatures of 77 and 298 K. The mechanical properties were found to vary significantly with grain size, strain rate,
and temperature. Yield stress was found to increase with decreasing grain size, decreasing temperature, and increasing strain
rate. The work hardening rate was seen to increase with increasing grain size, decreasing temperature, and increasing strain
rate. The influence of strain rate and temperature is most significant in the smallest grain size specimens. The rate of work
hardening is also influenced by strain rate, temperature, and grain size with negative rates of work hardening observed at
298 K and quasi-static strain rates in the smallest grain sizes and increasing rates of work hardening with increasing loading
rate and grain size. Work hardening behavior is correlated with the substructural evolution of these specimens. 相似文献
4.
5.
6.
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
7.
8.
9.
Jack J. Domet III T.M. Rajkumar Domet III David Yen 《Information Systems Management》1994,11(4):39-45
The realization of digital multimedia's full business potential requires networking. This article discusses the value-added benefits to the corporation of networked multimedia as well as the choice of architectures and technologies needed to deliver multimedia networking solutions. 相似文献
10.
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