全文获取类型
收费全文 | 19668篇 |
免费 | 1576篇 |
国内免费 | 802篇 |
专业分类
电工技术 | 1085篇 |
技术理论 | 1篇 |
综合类 | 1415篇 |
化学工业 | 3221篇 |
金属工艺 | 1303篇 |
机械仪表 | 1296篇 |
建筑科学 | 1465篇 |
矿业工程 | 475篇 |
能源动力 | 557篇 |
轻工业 | 1287篇 |
水利工程 | 380篇 |
石油天然气 | 1169篇 |
武器工业 | 150篇 |
无线电 | 2055篇 |
一般工业技术 | 2288篇 |
冶金工业 | 1083篇 |
原子能技术 | 186篇 |
自动化技术 | 2630篇 |
出版年
2024年 | 100篇 |
2023年 | 325篇 |
2022年 | 484篇 |
2021年 | 735篇 |
2020年 | 588篇 |
2019年 | 484篇 |
2018年 | 560篇 |
2017年 | 590篇 |
2016年 | 556篇 |
2015年 | 722篇 |
2014年 | 888篇 |
2013年 | 1149篇 |
2012年 | 1178篇 |
2011年 | 1321篇 |
2010年 | 1181篇 |
2009年 | 1137篇 |
2008年 | 1185篇 |
2007年 | 1060篇 |
2006年 | 1052篇 |
2005年 | 933篇 |
2004年 | 646篇 |
2003年 | 646篇 |
2002年 | 688篇 |
2001年 | 601篇 |
2000年 | 486篇 |
1999年 | 566篇 |
1998年 | 413篇 |
1997年 | 369篇 |
1996年 | 303篇 |
1995年 | 252篇 |
1994年 | 198篇 |
1993年 | 161篇 |
1992年 | 125篇 |
1991年 | 90篇 |
1990年 | 73篇 |
1989年 | 65篇 |
1988年 | 39篇 |
1987年 | 24篇 |
1986年 | 24篇 |
1985年 | 11篇 |
1984年 | 11篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
101.
The Journal of Supercomputing - With the wide spread of image information, it is an urgent problem to protect image property rights and crack down on piracy. Watermarking algorithm is an effective... 相似文献
102.
Liang Likeng Hao Tianyong Zhan Choujun Qiu Hong Wang Fu Lee Yan Jun Weng Heng Qu Yingying 《Neural computing & applications》2022,34(19):16311-16324
Neural Computing and Applications - Medical concept normalization aims to construct a semantic mapping between mentions and concepts and to uniformly represent mentions that belong to the same... 相似文献
103.
Computational Economics - Arbitrage opportunity exploration is important to ensure the profitability of statistical arbitrage. Prior studies that concentrate on cointegration model and other... 相似文献
104.
目的本实验探索驾驶负荷累积与轻音乐对驾驶疲劳的影响。方法采用2(驾驶负荷累积)×2(音乐条件)×3(模拟驾驶阶段)混合设计,对32名驾驶员被试进行模拟驾驶实验,采集驾驶员驾驶速度和他们的垂直搜索广度与瞳孔直径。结果第45-60 min时,对于无驾驶负荷累积的被试,轻音乐组车速显著快于无音乐组,轻音乐组垂直搜索广度显著大于无音乐组;对于有驾驶负荷累积的被试,轻音乐组的瞳孔直径小于无音乐组(边缘显著),轻音乐组的车速慢于无音乐组。结论轻音乐对无累积疲劳的驾驶员具有唤醒作用,加快他们的车速,扩大垂直搜索广度,对驾驶绩效具有积极的影响;轻音乐对有累积疲劳的驾驶员会产生催眠作用,缩小瞳孔直径,车速减慢,对驾驶绩效具有消极的影响。 相似文献
105.
A novel drug-loaded pathogen-mimicking nanocomplex (MSN-DOX-SP-LPS) has been constructed for synergistic chemo-immunotherapy. 相似文献
106.
Jiasi Wang Peng Shi Kai Dong Zhengqing Yan Jinsong Ren Xiaogang Qu 《Materials Today》2017,20(8):406-412
Here we develop a strategy using near infrared (NIR) modulation of telomerase activity based on gold nanocage@smart polymer system. Using this biocompatible design, we can regulate cellular behavior. This system has been used in vivo by taking advantages of NIR. This is the first example for optical modulation of telomerase activity in living cells and tissues. 相似文献
107.
108.
109.
Chung Yen Ang Si Yu Tan Cathleen Teh Jia Min Lee Mun Fei Eddy Wong Qiuyu Qu Li Qing Poh Menghuan Li Yuanyuan Zhang Vladimir Korzh Yanli Zhao 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(7)
Responsive nanomaterials have emerged as promising candidates as drug delivery vehicles in order to address biomedical diseases such as cancer. In this work, polymer‐based responsive nanoparticles prepared by a supramolecular approach are loaded with doxorubicin (DOX) for the cancer therapy. The nanoparticles contain disulfide bonds within the polymer network, allowing the release of the DOX payload in a reducing environment within the endoplasm of cancer cells. In addition, the loaded drug can also be released under acidic environment. In vitro anticancer studies using redox and pH dual responsive nanoparticles show excellent performance in inducing cell death and apoptosis. Zebrafish larvae treated with DOX‐loaded nanoparticles exhibit an improved viability as compared with the cases treated with free DOX by the end of a 3 d treatment. Confocal imaging is utilized to provide the daily assessment of tumor size on zebrafish larva models treated with DOX‐loaded nanoparticles, presenting sustainable reduction of tumor. This work demonstrates the development of functional nanoparticles with dual responsive properties for both in vitro and in vivo drug delivery in the cancer therapy. 相似文献
110.
Surface Energy and Surface Stability of Ag Nanocrystals at Elevated Temperatures and Their Dominance in Sublimation‐Induced Shape Evolution 下载免费PDF全文
Long‐Bing He Lei Zhang Xiao‐Dong Tan Lu‐Ping Tang Tao Xu Yi‐Long Zhou Zhan‐Yong Ren Yun Wang Chun‐Yu Teng Li‐Tao Sun Jian‐Feng Nie 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(27)
The surface energy and surface stability of Ag nanocrystals (NCs) are under debate because the measurable values of the surface energy are very inconsistent, and the indices of the observed thermally stable surfaces are apparently in conflict. To clarify this issue, a transmission electron microscope is used to investigate these problems in situ with elaborately designed carbon‐shell‐capsulated Ag NCs. It is demonstrated that the {111} surfaces are still thermally stable at elevated temperatures, and the victory of the formation of {110} surfaces over {111} surfaces on the Ag NCs during sublimation is due to the special crystal geometry. It is found that the Ag NCs behave as quasiliquids during sublimation, and the cubic NCs represent a featured shape evolution, which is codetermined by both the wetting equilibrium at the Ag–C interface and the relaxation of the system surface energy. Small Ag NCs (≈10 nm) no longer maintain the wetting equilibrium observed in larger Ag NCs, and the crystal orientations of ultrafine Ag NCs (≈6 nm) can rotate to achieve further shape relaxation. Using sublimation kinetics, the mean surface energy of Ag NCs at 1073 K is calculated to be 1.1–1.3 J m?2. 相似文献