全文获取类型
收费全文 | 719篇 |
免费 | 23篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 49篇 |
综合类 | 4篇 |
化学工业 | 174篇 |
金属工艺 | 9篇 |
机械仪表 | 11篇 |
建筑科学 | 11篇 |
能源动力 | 36篇 |
轻工业 | 76篇 |
水利工程 | 3篇 |
石油天然气 | 2篇 |
无线电 | 54篇 |
一般工业技术 | 163篇 |
冶金工业 | 62篇 |
原子能技术 | 16篇 |
自动化技术 | 74篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 21篇 |
2020年 | 6篇 |
2019年 | 10篇 |
2018年 | 9篇 |
2017年 | 11篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 27篇 |
2013年 | 49篇 |
2012年 | 35篇 |
2011年 | 40篇 |
2010年 | 37篇 |
2009年 | 42篇 |
2008年 | 44篇 |
2007年 | 33篇 |
2006年 | 41篇 |
2005年 | 37篇 |
2004年 | 22篇 |
2003年 | 17篇 |
2002年 | 33篇 |
2001年 | 16篇 |
2000年 | 12篇 |
1999年 | 13篇 |
1998年 | 24篇 |
1997年 | 23篇 |
1996年 | 13篇 |
1995年 | 8篇 |
1994年 | 12篇 |
1993年 | 9篇 |
1992年 | 8篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有744条查询结果,搜索用时 31 毫秒
91.
92.
T Hirayama C Ishida T Kuromori S Obata C Shimoda M Yamamoto K Shinozaki C Ohto 《Canadian Metallurgical Quarterly》1997,413(1):16-20
Aromatherapy has been defined as 'the art--and science--of using essential plant oils in treatments ... a truly holistic therapy, taking into account mind, body and spirit ...' (Davis 1991). Aromatherapy is a valuable means of maintaining optimum health, particularly when the dis-ease of the body or mind is related to stress. The process of hospitalization is a potentially stressful experience that has been well researched (Broome et al 1990, Kachoyeanos & Friedhoff 1993, Strachan 1993, Taylor 1991). This paper examines the ways in which massage and aromatherapy could be of benefit to hospitalized children, particularly those infected with Human Immunodeficiency Virus (HIV). Wright (1995) states that nurses should encourage self-healing by 'putting the patient in the best condition for nature to act'. Aromatherapy massage has the potential to achieve this through inducing relaxation and reducing the stressful aspects of hospitalization. Thus, the author would like to propose the use of this valuable skill as an extension of the nursing role. 相似文献
93.
Toshiya Aono Hiroyuki Yanai Futaba Miki John Davey Chikashi Shimoda 《Yeast (Chichester, England)》1994,10(6):757-770
94.
The fluctuation propagator for the superconducting order parameter belowT c is derived for a gapless superconductor. The fluctuation of the order parameter consists of two distinct modes: the fluctuations of the phase and the modulus of the order parameter. The former fluctuation obeys a phononlike dispersion, while the latter fluctuation is described by a damping diffusion type equation. The present theory gives an account of the fluctuation-induced Josephson effect belowT c observed recently by Carlson and Goldman. 相似文献
95.
Taniguchi M Kato K Shimauchi A Ping X Nakayama H Fujita K Tanaka T Tarui Y Hirasawa E 《Journal of Bioscience and Bioengineering》2005,99(3):245-251
Cross-linked poly-gamma-glutamic acid (C-L gamma-PGA) markedly purified polluted water collected from rivers and ponds by flocculation and precipitation. This effect of C-L gamma-PGA occasionally required pretreatment with polyaluminum chloride (PAC). Components of polluted water in rivers or ponds are generally thought to be clay minerals, microorganisms and chemical compounds. In this study, the flocculating activities of C-L gamma-PGA against suspensions of bentonite, diatomaceous earth, Escherichia coli and Mycrocystis aeruginosa, and against solutions of crystal violet and bisphenol A were investigated. The mode of action of C-L gamma-PGA is thought to be based on electrostatic interaction between flocculants, C-L gamma-PGA and PAC, and the surface of polluted water components, which may lead to neutralization of the zeta-potential of those components. 相似文献
96.
97.
98.
A four-framing Mach-Zehnder interferometer system which has variable intervals from frame to frame is developed. TEA N(2) lasers that are operated with atmospheric-pressure N(2) gas are employed as light sources. Applicability of the system is demonstrated for a rapidly changing plasma in the plasma focus discharge. 相似文献
99.
100.
Tsuyoshi Kijima Yu Nagatomo Hirokatsu Takemoto Masafumi Uota Daisuke Fujikawa Yuzo Sekiya Teppei Kishishita Makoto Shimoda Takumi Yoshimura Hideya Kawasaki Go Sakai 《Advanced functional materials》2009,19(4):545-553
Nanohole‐structured single‐crystalline Pt nanosheets have been synthesized by the borohydride reduction of Na2PtCl6 confined to the lyotropic liquid crystals (LLCs) of polyoxyethylene (20) sorbitan monooleate (Tween 80) with or without nonaethylene‐glycol (C12EO9). The Pt nanosheets of around 4–10 nm in central thickness and up to 500 nm or above in diameter have a number of hexagonal‐shaped nanoholes ∼1.8 nm wide. High‐resolution electron microscope images of the nanosheets showed atomic fringes with a spacing of 0.22 nm indicating that the nanosheets are crystallographically continuous through the nanoholed and non‐holed areas. The inner‐angle distributions for the hexagonal nanoholes indicate that the six sides of the nanoholes are walled with each two Pt (111), Pt (1 1) and Pt (010) planes. The formation mechanism of nanoholed Pt nanosheets is discussed on the basis of structural and compositional data for the resulting solids and their precursory LLCs, with the aid of similar nanohole growth observed for a Tween 80 free but oleic acid‐incorporated system. It is also demonstrated that the nanoholed Pt nanostructures loaded on carbon exhibit fairly high electrocatalytic activity for oxygen reduction reaction and a high performance as a cathode material for polymer‐electrolyte fuel cells, along with their extremely high thermostability revealed through the effect of electron‐irradiation. 相似文献