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   91119篇
  免费   1260篇
  国内免费   442篇
电工技术   884篇
综合类   2318篇
化学工业   13009篇
金属工艺   5029篇
机械仪表   3235篇
建筑科学   2276篇
矿业工程   570篇
能源动力   1514篇
轻工业   3904篇
水利工程   1321篇
石油天然气   364篇
无线电   10284篇
一般工业技术   17935篇
冶金工业   3507篇
原子能技术   338篇
自动化技术   26333篇
  2023年   88篇
  2022年   194篇
  2021年   238篇
  2020年   222篇
  2019年   189篇
  2018年   14643篇
  2017年   13540篇
  2016年   10145篇
  2015年   739篇
  2014年   499篇
  2013年   711篇
  2012年   3406篇
  2011年   9746篇
  2010年   8522篇
  2009年   5856篇
  2008年   7043篇
  2007年   7988篇
  2006年   355篇
  2005年   1395篇
  2004年   1281篇
  2003年   1307篇
  2002年   682篇
  2001年   237篇
  2000年   312篇
  1999年   173篇
  1998年   324篇
  1997年   218篇
  1996年   177篇
  1995年   145篇
  1994年   124篇
  1993年   142篇
  1992年   125篇
  1991年   117篇
  1990年   85篇
  1989年   75篇
  1988年   81篇
  1987年   77篇
  1986年   86篇
  1985年   108篇
  1984年   97篇
  1983年   95篇
  1982年   78篇
  1981年   63篇
  1978年   49篇
  1977年   62篇
  1976年   82篇
  1968年   60篇
  1966年   49篇
  1955年   64篇
  1954年   69篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Multimedia Tools and Applications - Currently, Deep Learning is playing an influential role for Image analysis and object classification. Maize’s diseases reduce production that subsequently...  相似文献   
2.

A large amount of data and applications need to be shared with various parties and stakeholders in the cloud environment for storage, computation, and data utilization. Since a third party operates the cloud platform, owners cannot fully trust this environment. However, it has become a challenge to ensure privacy preservation when sharing data effectively among different parties. This paper proposes a novel model that partitions data into sensitive and non-sensitive parts, injects the noise into sensitive data, and performs classification tasks using k-anonymization, differential privacy, and machine learning approaches. It allows multiple owners to share their data in the cloud environment for various purposes. The model specifies communication protocol among involved multiple untrusted parties to process owners’ data. The proposed model preserves actual data by providing a robust mechanism. The experiments are performed over Heart Disease, Arrhythmia, Hepatitis, Indian-liver-patient, and Framingham datasets for Support Vector Machine, K-Nearest Neighbor, Random Forest, Naive Bayes, and Artificial Neural Network classifiers to compute the efficiency in terms of accuracy, precision, recall, and F1-score of the proposed model. The achieved results provide high accuracy, precision, recall, and F1-score up to 93.75%, 94.11%, 100%, and 87.99% and improvement up to 16%, 29%, 12%, and 11%, respectively, compared to previous works.

  相似文献   
3.
Wireless Personal Communications - Recently, the theory of effective rate has attracted much attention, since it can take the delay aspect into account when performing channel capacity analysis. In...  相似文献   
4.
5.
Neural Processing Letters - Part of Speech (POS) tagging is a sequential labelling task and one of the core applications of Natural Language Processing. It has been a challenging problem for the...  相似文献   
6.
ABSTRACT

Solvent extraction studies were performed to understand the extraction behavior of Np4+ and NpO2 2+ from acidic feeds with CMPO (octyl (phenyl)-N,N-diisobutyl carbamoyl methyl phosphine oxide) dissolved in 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide, a water immiscible ionic liquid. Slope analyses on the distribution data revealed the extraction of ML2 type species, where M = Np4+ or NpO2 2+, and L = CMPO. Studies were also carried out with Pu4+ and UO2 2+ under identical conditions. The nature of the extracted species was found to vary with the nature of the ionic species.  相似文献   
7.
The Journal of Supercomputing - Currently, all online social networks (OSNs) are considered to follow a power-law distribution. In this paper, the degree distribution for multiple OSNs has been...  相似文献   
8.
Wireless Personal Communications - The orthogonal frequency division multiplexing (OFDM) is the most encouraging multi-carrier modulation system chosen for the high data rates but the objective is...  相似文献   
9.
Diffusional limitations (the gel, glass, and cage effects) are manifested in several bulk free radical homopolymerizations as well as in random copolymerizations. These are associated with decreases of several orders of magnitude of the rate constants of termination, propagation, and initiation (the initiator efficiency), respectively. These phenomena have been modeled earlier using the free volume theory for the diffusivities of primary radicals, macro‐radicals, and monomer molecules, and have been applied to homopolymerizations. In this study, a similar model is developed for random bulk copolymerizations. The parameters of the model are fitted using isothermal data on styrene acrylonitrile random copolymerization carried out in small ampoules. Thereafter, best‐fit global correlations have been developed for this system. This enables the model to be used for studying non‐isothermal copolymerizations, as well as for carrying out optimization of industrial reactors, where non‐isothermal conditions are a norm. POLYM. ENG. SCI., 55:2098–2110, 2015. © 2014 Society of Plastics Engineers  相似文献   
10.
Wireless Personal Communications - The efficient management of resource sharing plays a crucial role in the cloud execution environment. The constraints such as heterogeneity and dynamic nature of...  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