首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15413篇
  免费   1334篇
  国内免费   1213篇
电工技术   313篇
技术理论   1篇
综合类   1073篇
化学工业   167篇
金属工艺   133篇
机械仪表   860篇
建筑科学   663篇
矿业工程   206篇
能源动力   89篇
轻工业   117篇
水利工程   121篇
石油天然气   90篇
武器工业   102篇
无线电   1885篇
一般工业技术   542篇
冶金工业   540篇
原子能技术   46篇
自动化技术   11012篇
  2024年   12篇
  2023年   115篇
  2022年   209篇
  2021年   270篇
  2020年   277篇
  2019年   232篇
  2018年   245篇
  2017年   299篇
  2016年   387篇
  2015年   407篇
  2014年   895篇
  2013年   745篇
  2012年   954篇
  2011年   1389篇
  2010年   1000篇
  2009年   941篇
  2008年   1200篇
  2007年   1225篇
  2006年   1219篇
  2005年   1041篇
  2004年   890篇
  2003年   861篇
  2002年   685篇
  2001年   537篇
  2000年   387篇
  1999年   335篇
  1998年   243篇
  1997年   177篇
  1996年   139篇
  1995年   133篇
  1994年   79篇
  1993年   59篇
  1992年   44篇
  1991年   48篇
  1990年   24篇
  1989年   30篇
  1988年   17篇
  1987年   17篇
  1986年   23篇
  1985年   35篇
  1984年   20篇
  1983年   19篇
  1982年   12篇
  1981年   19篇
  1980年   12篇
  1979年   14篇
  1977年   5篇
  1976年   9篇
  1975年   7篇
  1972年   4篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
《工程爆破》2022,(4):78-84
介绍了在包头市某工程实施管道穿越黄河施工中,采用爆破法处理卡钻的经验。针对深水环境条件及钻杆内径小不宜采用集团装药的条件,确定采用"小直径爆破筒,钻杆内部装药"的爆破方案,阐述了爆破设计及施工注意事项。可供类似工程参考。  相似文献   
3.
With a sharp increase in the information volume, analyzing and retrieving this vast data volume is much more essential than ever. One of the main techniques that would be beneficial in this regard is called the Clustering method. Clustering aims to classify objects so that all objects within a cluster have similar features while other objects in different clusters are as distinct as possible. One of the most widely used clustering algorithms with the well and approved performance in different applications is the k-means algorithm. The main problem of the k-means algorithm is its performance which can be directly affected by the selection in the primary clusters. Lack of attention to this crucial issue has consequences such as creating empty clusters and decreasing the convergence time. Besides, the selection of appropriate initial seeds can reduce the cluster’s inconsistency. In this paper, we present a new method to determine the initial seeds of the k-mean algorithm to improve the accuracy and decrease the number of iterations of the algorithm. For this purpose, a new method is proposed considering the average distance between objects to determine the initial seeds. Our method attempts to provide a proper tradeoff between the accuracy and speed of the clustering algorithm. The experimental results showed that our proposed approach outperforms the Chithra with 1.7% and 2.1% in terms of clustering accuracy for Wine and Abalone detection data, respectively. Furthermore, achieved results indicate that comparing with the Reverse Nearest Neighbor (RNN) search approach, the proposed method has a higher convergence speed.  相似文献   
4.
5.
We conceptualized security-related stress (SRS) and proposed a theoretical model linking SRS, discrete emotions, coping response, and information security policy (ISP) compliance. We used an experience sampling design, wherein 138 professionals completed surveys. We observed that SRS had a positive association with frustration and fatigue, and these negative emotions were associated with neutralization of ISP violations. Additionally, frustration and fatigue make employees more likely to follow through on their rationalizations of ISP violations by decreased ISP compliance. Our findings provide evidence that neutralization is not a completely stable phenomenon but can vary within individuals from one time point to another.  相似文献   
6.
The Curriculum Vitae (CV, also referred to as “résumé”) is an established representation of a person's academic and professional history. A typical CV is comprised of multiple sections associated with spatio‐temporal, nominal, hierarchical, and ordinal data. The main task of a recruiter is, given a job application with specific requirements, to compare and assess CVs in order to build a short list of promising candidates to interview. Commonly, this is done by viewing CVs in a side‐by‐side fashion. This becomes challenging when comparing more than two CVs, because the reader is required to switch attention between them. Furthermore, there is no guarantee that the CVs are structured similarly, thus making the overview cluttered and significantly slowing down the comparison process. In order to address these challenges, in this paper we propose “CV3”, an interactive exploration environment offering users a new way to explore, assess, and compare multiple CVs, to suggest suitable candidates for specific job requirements. We validate our system by means of domain expert feedback whose results highlight both the efficacy of our approach and its limitations. We learned that CV3 eases the overall burden of recruiters thereby assisting them in the selection process.  相似文献   
7.
ABSTRACT

The purpose of this study was to examine the influence of trust variables (trust: competence, trust: benevolence, trust: integrity) on leadership regarding the organization’s information security policy (ISP) compliance. An instrument with four constructs was used to collect data from 474 non-management subjects from various organizations in the USA. Collected data were analyzed through multiple regression procedure. Results revealed that all trust variables (trust: competence, trust: benevolence, trust: integrity) were influential in predicting the leadership regarding the organization’s ISP compliance. The findings are discussed and implications for practice are outlined. Conclusion, limitations, and recommendations for future research are drawn.  相似文献   
8.
9.
目的 探究一种基于Inception_V3-CNN模型的食品图像识别和分类方法。方法 选取包含20类食品和19609张的食品图像建立数据集Food-101, 通过卷积神经网络(convolutional neural networks, CNN)提取图像候选区域的视觉特征, 并自动进行分类, 使其具有较高的识别率; 此外, 采集来自kaggle库中已标注的食品图像集做预测对比实验, 以保证Inception_V3-CNN模型检测的准确度。结果 该方法能够去除背景噪音, 且仅需部分提取视觉特征, 可以有效解决网络食品图像的分类问题, 与多视图支持向量机(support vector machine, SVM)+方向梯度直方图(histogram of oriented gradients, HOG)和传统CNN方法相比, 在测试时间相近、设备计算能力相同的条件下, 该方法识别率更高, 迭代次数为15000次时, Loss值降至4.92, 准确率可达93.89%。结论 此方法可以快速识别食品图像, 在实际网络图片中能有较好的可移植性。将算法移植到移动设备中实现APP的模块化操作也将成为后续工作探索的重点方向。  相似文献   
10.
Smart cities are built upon information and communication technologies (ICTs) to enable a broad range of advanced services. Through a comprehensive literature review, this study identified four pitfalls brought by the pervasive application of ICT, including information insecurity, privacy leakage, information islands, and digital divide. Therefore, a questionnaire survey together with 27 interviews was conducted in Hong Kong to investigate how the public perceived these pitfalls within the context of mobile apps providing real-time parking information which form a major part of smart mobility. System insecurity and privacy leakage were found to arouse worries among the app-users while their awareness of protecting personal data was found to have room for improvement. Islands of real-time parking information occur as a result of the lack of collaboration among private carpark operators. Digital divide existed widely among the disadvantaged groups and the problem cannot be solved by mere provision of ICT facilities. Overall, technologies alone cannot make a city smart or smarter. It is the suitable way in which ICTs are used to serve all citizens that matters.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号