全文获取类型
收费全文 | 21464篇 |
免费 | 1757篇 |
国内免费 | 905篇 |
专业分类
电工技术 | 1184篇 |
技术理论 | 2篇 |
综合类 | 1369篇 |
化学工业 | 3617篇 |
金属工艺 | 1165篇 |
机械仪表 | 1365篇 |
建筑科学 | 1954篇 |
矿业工程 | 763篇 |
能源动力 | 576篇 |
轻工业 | 1205篇 |
水利工程 | 346篇 |
石油天然气 | 1505篇 |
武器工业 | 121篇 |
无线电 | 2213篇 |
一般工业技术 | 2592篇 |
冶金工业 | 1052篇 |
原子能技术 | 232篇 |
自动化技术 | 2865篇 |
出版年
2024年 | 106篇 |
2023年 | 434篇 |
2022年 | 637篇 |
2021年 | 891篇 |
2020年 | 739篇 |
2019年 | 619篇 |
2018年 | 662篇 |
2017年 | 746篇 |
2016年 | 627篇 |
2015年 | 817篇 |
2014年 | 1115篇 |
2013年 | 1217篇 |
2012年 | 1392篇 |
2011年 | 1435篇 |
2010年 | 1294篇 |
2009年 | 1160篇 |
2008年 | 1144篇 |
2007年 | 1110篇 |
2006年 | 1169篇 |
2005年 | 1102篇 |
2004年 | 653篇 |
2003年 | 568篇 |
2002年 | 509篇 |
2001年 | 478篇 |
2000年 | 445篇 |
1999年 | 586篇 |
1998年 | 459篇 |
1997年 | 392篇 |
1996年 | 359篇 |
1995年 | 313篇 |
1994年 | 240篇 |
1993年 | 142篇 |
1992年 | 130篇 |
1991年 | 118篇 |
1990年 | 87篇 |
1989年 | 70篇 |
1988年 | 53篇 |
1987年 | 28篇 |
1986年 | 30篇 |
1985年 | 10篇 |
1984年 | 11篇 |
1983年 | 7篇 |
1982年 | 11篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Claudia Kuster Jean‐Charles Bazin Cengiz Öztireli Teng Deng Tobias Martin Tiberiu Popa Markus Gross 《Computer Graphics Forum》2014,33(2):1-10
Multi‐view reconstruction aims at computing the geometry of a scene observed by a set of cameras. Accurate 3D reconstruction of dynamic scenes is a key component for a large variety of applications, ranging from special effects to telepresence and medical imaging. In this paper we propose a method based on Moving Least Squares surfaces which robustly and efficiently reconstructs dynamic scenes captured by a calibrated set of hybrid color+depth cameras. Our reconstruction provides spatio‐temporal consistency and seamlessly fuses color and geometric information. We illustrate our approach on a variety of real sequences and demonstrate that it favorably compares to state‐of‐the‐art methods. 相似文献
62.
Hong-Yang Lu Jong-Shing Bow Wen-How Deng 《Journal of the American Ceramic Society》1990,73(12):3562-3568
Pure BaTiO3 exhibits a paraelectric-to-ferroelectric phase transition at 130°C. When stoichiometric BaTiO3 is combined with 10 mol% ZrO2 , the relative permittivity (ε) changes to a broad, relatively insignificant temperature dependence, and the Curie point, T c , is not sharply defined. However, the transition sharpens at T = 95°C when these samples are sintered for a longer period of 60 h. SEM, EDAX analysis coupled with TEM observation gives three types of core-shell structures of different microstructural characteristics which are related to the diffuse phase transition. Chemical inhomogeneity, due to Zr4+ distribution in the core-shell structure, is proposed to account for the diffuse phase transition behavior. 相似文献
63.
Large volume of online review data can reveal consumers’ major interests on domain product, which attracts great research interests from the academic community. Most of the existing works focus on the problems of review summarization, aspect identification or opinion mining from an item’s point of view such as the quality or popularity of products. Considering the fact that users who generate those review texts draw different attentions to product aspects with respect to their own interests, in this article, we aim to learn K users’ interest groups indicated by their review writings. Such K interest groups’ identification can facilitate better understanding of major and potential consumers’ concerns which are crucial for applications like product improvement on customer-oriented design or diverse marketing strategies. Instead of using a traditional text clustering approach, we treat the groupId/clusterId as a hidden variable and use a permutation-based structural topic model called KMM. Through this model, we infer K interest groups’ distribution by discovering not only the frequency of product aspects (Topic Frequency), but also the occurrence priority of respective aspects (Topic Order). They jointly present an informative summarization on the raw review corpus. Our experiment on several real-world review datasets demonstrates a competitive solution. 相似文献
64.
65.
再保险是保险人将其承担的保险业务,以承保形式,部分转移给其他保险人。再保险业务的网络化和信息化管理,很大程度上满足了现代再保险业务管理的需求,推动了再保险公司管理的发展。介绍个险再保险信息管理系统的需求背景,描述系统的总体设计。在系统总体实现方面详细阐述了软件开发平台、相关设备性能容量需求分析和再保险业务风险评估模型。最后对相关设备性能容量进行了评估。 相似文献
66.
67.
用透射电镜和高分辨电镜观察研究了PTC型BaTiO_3陶瓷的孪晶和孪晶界结构,并提出了可能的{111}孪晶及孪晶界的原子结构模型。结果表明,{111}孪晶形成氧八面体共面的共格倾斜孪晶界,在孪晶界处可能存在一定量的A空位且原子密度要低于孪晶体内。同时还发现两种其它特征的孪晶现象。 相似文献
68.
在以通用伺服电机控制系统为下位机的基础上,开发了以实时内核μC/OS-II、DSP、CPLD控制模块为核心的软硬件平台。通过移植uIP协议栈到DSP,在通信应用层上将Modbus帧嵌入到TCP帧中,简单可靠地实现了Modbus/TCP协议。同时将Modbus/TCP协议与μC/OS-II实时内核进行整合,更好地保证了系统调度的实时性。 相似文献
69.
邓少华 《网络安全技术与应用》2014,(1):34-34,37
本文分析了多媒体教室管理的现状,提出通过桌面虚拟化技术解决日常管理中存在的管理难度大、维护人员多、管理效率低等问题,努力提高多媒体教室管理的集中化、安全性和高效率。 相似文献
70.
Huan Deng Qiong‐Hua Wang Cheng‐Gao Luo Chun‐Ling Liu Chen Li 《Journal of the Society for Information Display》2014,22(3):158-162
In this paper, we analyze the visual fatigue of integral imaging three‐dimensional (3D) display by studying the accommodation and convergence when viewing the integral imaging 3D images. The theoretical analyses show that there is no inconsistency between the accommodation and convergence distances, which means that the integral imaging 3D display has no visual fatigue. Experiments are implemented, and the results finally demonstrate the rationality of the theoretical analyses. These analyses can be quite beneficial for researchers to better understand the performances and promote the practical applications of the integral imaging 3D display. 相似文献