全文获取类型
收费全文 | 719篇 |
免费 | 12篇 |
国内免费 | 18篇 |
专业分类
电工技术 | 38篇 |
综合类 | 24篇 |
化学工业 | 134篇 |
金属工艺 | 8篇 |
机械仪表 | 34篇 |
建筑科学 | 137篇 |
矿业工程 | 8篇 |
能源动力 | 58篇 |
轻工业 | 23篇 |
水利工程 | 13篇 |
石油天然气 | 17篇 |
武器工业 | 11篇 |
无线电 | 89篇 |
一般工业技术 | 64篇 |
冶金工业 | 16篇 |
原子能技术 | 2篇 |
自动化技术 | 73篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 21篇 |
2020年 | 19篇 |
2018年 | 7篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 11篇 |
2014年 | 5篇 |
2013年 | 25篇 |
2012年 | 32篇 |
2011年 | 47篇 |
2010年 | 43篇 |
2009年 | 55篇 |
2008年 | 46篇 |
2007年 | 49篇 |
2006年 | 64篇 |
2005年 | 101篇 |
2004年 | 24篇 |
2003年 | 14篇 |
2002年 | 15篇 |
2001年 | 15篇 |
2000年 | 15篇 |
1999年 | 10篇 |
1998年 | 11篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 9篇 |
1994年 | 7篇 |
1993年 | 11篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 9篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1971年 | 1篇 |
1970年 | 4篇 |
1969年 | 2篇 |
1967年 | 2篇 |
排序方式: 共有749条查询结果,搜索用时 0 毫秒
1.
频谱分解技术在塔里木盆地北部TH地区碳酸盐岩缝洞型储层预测中的应用 总被引:6,自引:0,他引:6
本文从频谱分解技术的基本原理及计算方法入手,根据正演模型,通过对比缝洞型储层与地震反射特征的关系,总结出储层发育的反射特征,相应地精细调整频谱分解处理参数,进而进行预测。通过与钻井资料对比可知,频谱分解技术可以刻画不同频率强反射、弱反射的边界。 相似文献
2.
《广播与电视技术》编辑部 《广播与电视技术》2006,33(5):17-17
深圳是国家广电总局确定的首批有线数字电视试点城市之一。深圳有线数字电视整体转换工作自2005年7月1日正式启动以来,仅用短短8个月的时间就完成了特区内60万用户的整体转换,并顺利通过了广电总局的数字电视试点验收。创造出一项新的“深圳速度”,走出一条具有深圳特色的整体转换道路。 相似文献
3.
果胶的制备、性质及应用 总被引:4,自引:0,他引:4
本刊第21卷第4期第195~203页“卡拉胶的制备及应用”一文介绍了可与明胶混用或取代明胶的多糖类海藻胶。这里,编辑部信息组再向读者介绍一种在食品工业中广泛使用的性能与明胶相近的多糖类植物胶——果胶,供读者们在研究开发工作中参考。 相似文献
4.
《电力需求侧管理》编辑部 《电力需求侧管理》2017,19(1):5-5
《电力需求侧管理》2017年选题方向
《电力需求侧管理》编辑部
(国家电网公司 电力需求侧管理指导中心,南京 210024)
Topic directions of journal Power Demand Side Management in the year 2017
Editorial Department
(State Grid Corporation DSM Instruction Center, Nanjing 210024, China)
文章编号:1009-1831(2017)01-0005-01
DOI:10.3969/j.issn.1009-1831.2017.01.003
中图分类号:F407.61 文献标志码:C
(本栏责任编辑 徐文红) 相似文献
5.
Theory of a novel voltage-sustaining layer for power devices 总被引:3,自引:0,他引:3
The theory of a novel voltage-sustaining layer for power devices, called a Composite Buffer layer (CB-layer for short) is proposed. The CB-layer can be implemented in several ways, one particular implementation is used here, which consists of alternating n- and p-type regions, that are parallel to the direction of the applied electric field. In the off-state, the fields induced by the depletion charges of both region types compensate each other to allowing the doping in both n-regions and p-regions to be very high without causing a reduction of the breakdown voltage. In the onstate the heavy doping ensures the voltage drop is very low and that the saturation current density high. A simple relationship between the specific on-resistance and Ron and the sustaining voltage VB can be shown to be Ron=2.53 × 10−7bVB1.23 ωcm2, where the breadth b (in μm) of each region is much smaller than the thickness W. The design method of the CB-layer is discussed in some detail. The simulation results are shown to be in perfect agreement with the theory. The structure has application to a wide variety of different power devices. An RMOST structure has been used to demonstrate the benefits of the technique in the paper, for which excellent performance is demonstrated. 相似文献
6.
S Kangsadalampai M Coggan SH Caglayan G Aktuglu PG Board 《Canadian Metallurgical Quarterly》1996,76(6):879-882
Deficiency of the A subunit of coagulation factor XIII causes a severe bleeding disorder requiring life long replacement therapy. The mutations causing A subunit deficiency appear to be very heterogeneous, and it is impractical to identify each mutation before genetic counselling or prenatal diagnosis can be attempted. In this study we have shown that a highly polymorphic short tandem repeat element, HUMF13A01 (AAAG)n that occurs in the 5' flanking sequence of the factor XIII A subunit gene, can be used to follow the segregation of deficiency causing mutations. We studied 6 families with factor XIII A subunit deficiency from 5 different ethnic groups. All parents were heterozygous for the repetitive element and therefore all the families were informative. The linked polymorphism was used to carry out the first prenatal diagnosis of factor XIII A subunit deficiency. The analysis of this polymorphism by the polymerase chain reaction is rapid, reliable, requires little DNA and is ideal for the genetic analysis of factor XIII A subunit deficiency. 相似文献
7.
8.
An optimization design model for surface termination of off-state semiconductor devices under reverse-bias conditions is presented. The multivariable design model is used to optimize the surface profile shapes for nonplanar devices and the doping profiles of material regions along the surface for planar devices. The effectiveness of the design model in reducing the peak surface electric field to below 50% of the bulk value is demonstrated for two examples of each type of device 相似文献
9.
Two forms of glutathione synthetase deficiency have been described. While one form is mild, causing hemolytic anemia, the other more severe form causes 5-oxo-prolinuria with secondary neurological involvement. Despite the existence of two deficiency phenotypes, Southern blots hybridized with a glutathione synthetase cDNA suggest that there is a single glutathione synthetase gene in the human genome. Analysis of somatic cell hybrids showed the human glutathione synthetase gene (GSS) to be located on chromosome 20, and this assignment has been refined to subband 20q11.2 using in situ hybridization. 相似文献
10.