全文获取类型
收费全文 | 2008篇 |
免费 | 67篇 |
国内免费 | 45篇 |
专业分类
电工技术 | 53篇 |
综合类 | 174篇 |
化学工业 | 153篇 |
金属工艺 | 105篇 |
机械仪表 | 149篇 |
建筑科学 | 117篇 |
矿业工程 | 58篇 |
能源动力 | 40篇 |
轻工业 | 177篇 |
水利工程 | 50篇 |
石油天然气 | 70篇 |
武器工业 | 4篇 |
无线电 | 228篇 |
一般工业技术 | 156篇 |
冶金工业 | 82篇 |
原子能技术 | 10篇 |
自动化技术 | 494篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 19篇 |
2021年 | 26篇 |
2020年 | 20篇 |
2019年 | 39篇 |
2018年 | 49篇 |
2017年 | 36篇 |
2016年 | 49篇 |
2015年 | 70篇 |
2014年 | 86篇 |
2013年 | 95篇 |
2012年 | 63篇 |
2011年 | 102篇 |
2010年 | 99篇 |
2009年 | 116篇 |
2008年 | 99篇 |
2007年 | 111篇 |
2006年 | 114篇 |
2005年 | 72篇 |
2004年 | 73篇 |
2003年 | 109篇 |
2002年 | 128篇 |
2001年 | 266篇 |
2000年 | 94篇 |
1999年 | 45篇 |
1998年 | 25篇 |
1997年 | 27篇 |
1996年 | 30篇 |
1995年 | 12篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1977年 | 1篇 |
排序方式: 共有2120条查询结果,搜索用时 31 毫秒
1.
性能效率是APP软件的重要质量属性,但目前缺乏APP软件性能效率的通用模型。分析了APP软件的性能特征,基于ISO/IEC 25010标准提出了APP软件的性能效率模型,定义了APP软件性能效率的子特性和度量指标。基于提出的APP软件性能效率模型,通过实验对APP软件的性能效率进行了度量及相关分析。 相似文献
2.
Cecilia Arriagada Viviana A. Cavieres Charlotte Luchsinger Alexis E. Gonzlez Vanessa C. Muoz Jorge Cancino Patricia V. Burgos Gonzalo A. Mardones 《International journal of molecular sciences》2020,21(22)
Protein trafficking is altered when normal cells acquire a tumor phenotype. A key subcellular compartment in regulating protein trafficking is the Golgi apparatus, but its role in carcinogenesis is still not well defined. Golgi phosphoprotein 3 (GOLPH3), a peripheral membrane protein mostly localized at the trans-Golgi network, is overexpressed in several tumor types including glioblastoma multiforme (GBM), the most lethal primary brain tumor. Moreover, GOLPH3 is currently considered an oncoprotein, however its precise function in GBM is not fully understood. Here, we analyzed in T98G cells of GBM, which express high levels of epidermal growth factor receptor (EGFR), the effect of stable RNAi-mediated knockdown of GOLPH3. We found that silencing GOLPH3 caused a significant reduction in the proliferation of T98G cells and an unexpected increase in total EGFR levels, even at the cell surface, which was however less prone to ligand-induced autophosphorylation. Furthermore, silencing GOLPH3 decreased EGFR sialylation and fucosylation, which correlated with delayed ligand-induced EGFR downregulation and its accumulation at endo-lysosomal compartments. Finally, we found that EGF failed at promoting EGFR ubiquitylation when the levels of GOLPH3 were reduced. Altogether, our results show that GOLPH3 in T98G cells regulates the endocytic trafficking and activation of EGFR likely by affecting its extent of glycosylation and ubiquitylation. 相似文献
3.
基于多线程技术的监控系统的设计 总被引:1,自引:0,他引:1
详细介绍在32位操作系统Windows95/98下,用C Builder3.0开发基于多线程技术的监控系统的有关方法。 相似文献
4.
胡正国 《现代测量与实验室管理》2003,11(5):44-45,48
本文从设备管理工作中最为基本的设备采购及设备建档两个方面探讨了如何将GB/T15481-2000《检测和校准实验室能力的通用要求》用于指导检测实验室的设备管理实际工作。 相似文献
5.
EPSW98是面向对理信息系统(简称GIS)的GIS前端软件,可实现内外业一体化,能与GIS数据、CAD数据相互转换,达到一图多用的目的。对EPSW98系统概述、作业流程、应用技巧作了详细论述。 相似文献
6.
评述了ISO 5 75 5“烧结金属材料—规范”和美国MPIF标准 35的变迁和趋向统一。阐述了“最小强度值”的意义。说明了我国粉末冶金结构零件材料标准的现状 相似文献
7.
Michael E. Becker 《Journal of the Society for Information Display》2006,14(11):1003-1017
Abstract— In this paper, methods and instruments for measurement and evaluation of reflection characteristics are reviewed as needed for research and development of electronic displays and for material and surface modeling with ray‐tracing and rendering software packages. Contrast under ambient illumination and recognizability under daylight illumination are prime development targets in the electronic‐display field, while computation and synthesis of realistic scenes and objects are pushing the need for physical data in computer graphics applications. Three categories of instruments are available for detailed reflection analysis. They are based on (1) gonioscopic (mechanical) and conoscopic (optical) directional scanning, (2) imaging approaches, and (3) on arrangements with variable source or receiver aperture. The capabilities, advantages, and limitations of these methods are introduced and discussed in order to facilitate appropriate selection of methods and instruments. For illustration purposes we present typical results obtained from commercial electronic display screens. A basis for continued widespread implementation and standardization of reflection metrology as required for objective rating and comparison of electronic‐display screen performance under ambient illumination is provided. 相似文献
8.
9.
J Strother Moore 《Formal Aspects of Computing》1994,6(1):60-91
We present a formal model of asynchronous communication between two digital hardware devices. The model takes the form of a function in the Boyer-Moore logic. The function transforms the signal stream generated by one processor into that consumed by an independently clocked processor, given the phases and rates of the two clocks and the communications delay. The model can be used quantitatively to derive concrete performance bounds on communications at ISO protocol level 1 (physical level). We use the model to show that an 18-bit/cell biphase mark protocol reliably sends messages of arbitrary length between two processors provided the ratio of the clock rates is within 5% of unity. 相似文献
10.