全文获取类型
收费全文 | 1944篇 |
免费 | 77篇 |
国内免费 | 10篇 |
专业分类
电工技术 | 38篇 |
综合类 | 1篇 |
化学工业 | 465篇 |
金属工艺 | 67篇 |
机械仪表 | 30篇 |
建筑科学 | 17篇 |
矿业工程 | 3篇 |
能源动力 | 94篇 |
轻工业 | 99篇 |
水利工程 | 18篇 |
石油天然气 | 19篇 |
无线电 | 267篇 |
一般工业技术 | 435篇 |
冶金工业 | 220篇 |
原子能技术 | 2篇 |
自动化技术 | 256篇 |
出版年
2023年 | 13篇 |
2022年 | 37篇 |
2021年 | 49篇 |
2020年 | 35篇 |
2019年 | 51篇 |
2018年 | 78篇 |
2017年 | 54篇 |
2016年 | 53篇 |
2015年 | 34篇 |
2014年 | 79篇 |
2013年 | 167篇 |
2012年 | 86篇 |
2011年 | 106篇 |
2010年 | 75篇 |
2009年 | 62篇 |
2008年 | 75篇 |
2007年 | 87篇 |
2006年 | 50篇 |
2005年 | 54篇 |
2004年 | 40篇 |
2003年 | 51篇 |
2002年 | 43篇 |
2001年 | 29篇 |
2000年 | 31篇 |
1999年 | 23篇 |
1998年 | 68篇 |
1997年 | 50篇 |
1996年 | 32篇 |
1995年 | 30篇 |
1994年 | 28篇 |
1993年 | 37篇 |
1992年 | 23篇 |
1991年 | 30篇 |
1990年 | 34篇 |
1989年 | 17篇 |
1988年 | 14篇 |
1987年 | 19篇 |
1986年 | 17篇 |
1985年 | 15篇 |
1984年 | 19篇 |
1983年 | 15篇 |
1982年 | 15篇 |
1981年 | 17篇 |
1980年 | 16篇 |
1979年 | 14篇 |
1978年 | 8篇 |
1977年 | 9篇 |
1976年 | 11篇 |
1975年 | 5篇 |
1973年 | 6篇 |
排序方式: 共有2031条查询结果,搜索用时 14 毫秒
1.
Catalysis Letters - An environmentally benign process for synthesizing 4-methoxyphenol through methylation of hydroquinone using polystyrene immobilized Bronsted acidic ionic liquid is presented.... 相似文献
2.
In this article, we have studied the effect of carbonaceous nanofillers viz. fullerenol (0D), carboxylated multi-wall carbon nanotube (MWCNT, 1D), hydroxylated graphene (2D) and combination of carboxylated CNT and hydroxylated graphene as 3D in thermoplastic polyurethane on the tensile properties of the fabricated cellular structures. The concentration of nano-fillers was varied as 0.1, 1, and 5 wt%. Tensile properties of the nanocomposite cellular structures were measured as per ASTM D882 at 20°C (below glass transition temperature, Tg) and 40°C (above Tg). The results have shown that the tensile strength was found to increase by 200%–300% and the tensile modulus was found to increase by 150%–300% for 2D and 3D nano-fillers while significantly poor results were observed for 0D. However, the test data tensile strength and modulus showed marginal increase at 20°C and marginally low at 40°C for 1D filler. The interfacial adhesion was calculated by using experimental tensile data and the predictive models. The interfacial adhesion parameter (Bσ) calculated using Pukanszky equation was found significantly higher value for 2D (Bσ20 = 195.8) and 3D (Bσ20 = 192.0) fillers while poor adhesion was observed for 0D (Bσ20 = −81.6) fillers. The developed cellular structured materials were also evaluated by attenuated total reflection Fourier transform IR spectra, differential scanning calorimetry, X-ray diffraction, scanning electron microscope, and transmission electron microscope. 相似文献
3.
4.
5.
6.
7.
Jha Sudan Seo Changho Yang Eunmok Joshi Gyanendra Prasad 《Multimedia Tools and Applications》2021,80(3):3981-3996
Multimedia Tools and Applications - This paper introduces a system capable of real-time video surveillance in low-end edge computing environment by combining object detection tracking algorithm.... 相似文献
8.
Babu R. Dawadi Danda B. Rawat Shashidhar R. Joshi Pietro Manzoni Martina M. Keitsch 《International Journal of Network Management》2021,31(4):e2145
This paper studies a problem for seamless migration of legacy networks of Internet service providers to a software-defined networking (SDN)-based architecture along with the transition to the full adoption of the Internet protocol version 6 (IPv6) connectivity. Migration of currently running legacy IPv4 networks into such new approaches requires either upgrades or replacement of existing networking devices and technologies that are actively operating. The joint migration to SDN and IPv6 network is considered to be vital in terms of migration cost optimization, skilled human resource management, and other critical factors. In this work, we first present the approaches of SDN and IPv6 migration in service providers' networks. Then, we present the common concerns of IPv6 and SDN migration with joint transition strategies so that the cost associated with joint migration is minimized to lower than that of the individual migration. For the incremental adoption of software-defined IPv6 (SoDIP6) network with optimum migration cost, a greedy algorithm is proposed based on optimal path and the customer priority. Simulation and empirical analysis show that a unified transition planning to SoDIP6 network results in lower migration cost. 相似文献
9.
Wireless Personal Communications - Biometric authentications systems are being recognized as the better way of securing data or personal devices as they are unique. Face is considered the best way... 相似文献
10.
Schuessler Benjamin J. Field David P. Overman Nicole R. Joshi Vineet V. 《Metallurgical and Materials Transactions A》2021,52(9):3871-3879
Metallurgical and Materials Transactions A - Uranium alloyed with 10 wt pct Mo (U-10Mo) undergoes discontinuous precipitation (DP) when subjected to sub-eutectoid heat treatment. It is hypothesized... 相似文献