全文获取类型
收费全文 | 86篇 |
免费 | 8篇 |
国内免费 | 27篇 |
专业分类
电工技术 | 1篇 |
综合类 | 9篇 |
化学工业 | 6篇 |
机械仪表 | 14篇 |
轻工业 | 4篇 |
石油天然气 | 1篇 |
无线电 | 26篇 |
一般工业技术 | 14篇 |
冶金工业 | 4篇 |
原子能技术 | 31篇 |
自动化技术 | 11篇 |
出版年
2020年 | 2篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 6篇 |
2011年 | 9篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 10篇 |
2007年 | 9篇 |
2006年 | 6篇 |
2005年 | 5篇 |
2004年 | 1篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 3篇 |
排序方式: 共有121条查询结果,搜索用时 15 毫秒
51.
Jones Gwyn C.; Rovner Barry W.; Crews John E.; Danielson Melissa L. 《Canadian Metallurgical Quarterly》2009,54(2):164
Objective: The authors examined the interface between visual impairment and depressive symptoms on health behaviors, self-care, and social participation among adults ages 65 and older. Method: The authors analyzed data from the 1997–2004 National Health Interview Survey on visual impairment and depressive symptoms for 49,278 adults ages 65 and older, comparing visually impaired adults (n = 8,787) with and without depressive symptoms with a reference group of adults with neither condition (n = 3,136) for outcome measures: physical health, health behaviors, and difficulties with self-care and social participation. Results: Adults with visual impairment and severe depressive symptoms were more likely than adults with neither condition to smoke (14.9%, adjusted odds ratio [AOR] = 1.6), be obese (28.2%, AOR = 1.9), be physically inactive (80.5%, AOR = 3.0), have fair–poor health (76.0%, AOR = 26.5), and have difficulties with self-care (27.9%, AOR = 11.8) and social participation (52.1%, AOR = 10.9). Discussion and Conclusions: Older visually impaired adults with depressive symptoms are vulnerable to health decline and further disablement without timely interventions that target smoking cessation, healthy eating, and increased physical activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
52.
Henrietta N. Ene-Obong Rasaki A. Sanusi Elizabeth A. Udenta Ima O. Williams Kola M. Anigo Elizabeth C. Chibuzo Hassan M. Aliyu Onot O. Ekpe Gloria I. Davidson 《Food chemistry》2013
A cross-sectional study was undertaken to collect and assess commonly consumed foods/recipes from the six geopolitical zones in Nigeria for the production of food composition database (FCDB) for dietary assessment. Communities used were selected using a multi-stage sampling plan. Focus group discussions, interviews, recipe documentation, food preparations and literature reviews were employed. Qualitative methods were used to analyse and present data. SWOT (strengths, weaknesses, opportunities, and threats) analysis was used to evaluate the project. A total of 322 recipes were collected out of which 110 were soups. Food consumption patterns across the geographical zones were found to be changing. Variations in recipes and methods of preparation of similar foods were observed. Factors to be considered in the development of a country-specific FCDB were identified. There were challenges with the use of values reported in literature for Nigerian foods. The study justifies the need for a country-specific FCDB that will include traditional recipes. 相似文献
53.
在ICF实验中,激光光路参数的设定是关键之一。本程序是基于Windows在Cbuilder环境下用C^++编写的,模拟给出打靶后球靶表面的光强分布情况可以给实验人员在打靶前调整激光参数做参考,对ICF实验提高效率很有帮助;经过适当改进也可以方便用于其他靶型。 相似文献
54.
《Journal of Nuclear Science and Technology》2013,50(6):548-551
The Criticality Safety Benchmark Evaluation Project (CSBEP) was initiated in 1992 by the United States Department of Energy. The project quickly became an international effort as scientists from other interested countries became involved. The International Criticality Safety Benchmark Evaluation Project (ICSBEP) is now an official activity of the Organization for Economic Cooperation and Development-Nuclear Energy Agency (OECD-NEA). “International Handbook of Criticality Safety Benchmark Experiments” was prepared and is updated yearly by the working group of the project. This handbook contains criticality safety benchmark specifications that have been derived from experiments that were performed at various nuclear criticality facilities around the world. However, the handbook lacks criticality data of 20 wt%-enriched uranium fuel. The author proposes to make benchmark specifications derived from, modern research reactors in Asia. Future evaluations of these reactors will facilitate to fill the “enrichment gap”. 相似文献
55.
大口径光学元件透射率全口径检测系统研究 总被引:3,自引:2,他引:1
提出了利用双光束分光光度和扩束系统相结合方法实现光学元件透射率全口径检测,建立了相应的检测系统,通过实验对系统的透射率检测精度进行分析和验证。结果表明,系统透射率检测精度优于±0.05%,并具有很好的重复性,能够用于ICF系统中大口径光学元件透射率的高精度、全口径检测。 相似文献
56.
介绍了纳秒量级的门控积分器。多路积分器采用模块化结构设计,每路门完全导通的时间约为7ns,用信号源信号作输入,积分非线性不超过2.9%,在“星光”装置上的性约束为实验中,每路门控积分器测量结果,与示波器积分测量结果对比,最大误差不超过满量程的3.3%。 相似文献
57.
H atom Rydberg matter (RM) in excitation state n = 1 is concluded to be a form of metallic hydrogen [Badiei S, Holmlid L (2004) J Phys Condens Matter 16:7017]. This material
can be produced at low pressure. This condensed form of hydrogen may be very useful as a dense hydrogen inertial confinement
fusion (ICF) target, being almost metallic and ten times denser than solid (frozen) diatomic hydrogen used at present. Coulomb
explosions and plasma formation are initiated in condensed atomic hydrogen even by relatively weak nanosecond pulsed lasers.
The protons emitted with high directivity in these explosions are energetic, corresponding to T = 105 K, and they may be utilized to give strong compression of the material. The fastest protons observed at up to 1 keV indicate
a compression considerably higher than that required for “fast ignition” fusion. 相似文献
58.
59.
60.
干凝胶法是我国目前制备惯性约束聚变(ICF)靶用空心玻璃微球(HGM)的主要方法,其制备的HGM可在较宽的范围内满足ICF物理实验的要求。从干凝胶粒子/微球的溶胶-凝胶法制备技术和HGM的炉内成球原理出发,系统综述了近三十年来ICF靶用HGM干凝胶法制备技术研究的相关报道,分析总结了干凝胶法制备技术在HGM成分设计、元素掺杂、直径及球形度、壁厚及均匀性、耐压强度、渗透性能、表面粗糙度、性能一致性等方面的技术现状及难点,对干凝胶法制备HGM技术的瓶颈性问题及可能的解决方案进行了讨论。 相似文献