全文获取类型
收费全文 | 73501篇 |
免费 | 7139篇 |
国内免费 | 4218篇 |
专业分类
电工技术 | 5173篇 |
技术理论 | 4篇 |
综合类 | 5566篇 |
化学工业 | 11004篇 |
金属工艺 | 4215篇 |
机械仪表 | 4541篇 |
建筑科学 | 5230篇 |
矿业工程 | 1923篇 |
能源动力 | 2064篇 |
轻工业 | 8514篇 |
水利工程 | 1646篇 |
石油天然气 | 2877篇 |
武器工业 | 780篇 |
无线电 | 8336篇 |
一般工业技术 | 7974篇 |
冶金工业 | 3748篇 |
原子能技术 | 791篇 |
自动化技术 | 10472篇 |
出版年
2024年 | 342篇 |
2023年 | 1150篇 |
2022年 | 2329篇 |
2021年 | 3065篇 |
2020年 | 2362篇 |
2019年 | 1852篇 |
2018年 | 2182篇 |
2017年 | 2440篇 |
2016年 | 2309篇 |
2015年 | 3257篇 |
2014年 | 4002篇 |
2013年 | 4897篇 |
2012年 | 5721篇 |
2011年 | 6121篇 |
2010年 | 5474篇 |
2009年 | 5178篇 |
2008年 | 5331篇 |
2007年 | 4814篇 |
2006年 | 4191篇 |
2005年 | 3392篇 |
2004年 | 2509篇 |
2003年 | 2076篇 |
2002年 | 1992篇 |
2001年 | 1670篇 |
2000年 | 1205篇 |
1999年 | 911篇 |
1998年 | 970篇 |
1997年 | 707篇 |
1996年 | 544篇 |
1995年 | 414篇 |
1994年 | 288篇 |
1993年 | 252篇 |
1992年 | 143篇 |
1991年 | 145篇 |
1990年 | 116篇 |
1989年 | 70篇 |
1988年 | 60篇 |
1987年 | 55篇 |
1986年 | 36篇 |
1985年 | 32篇 |
1984年 | 23篇 |
1983年 | 24篇 |
1982年 | 18篇 |
1981年 | 19篇 |
1980年 | 35篇 |
1979年 | 10篇 |
1978年 | 12篇 |
1977年 | 20篇 |
1976年 | 38篇 |
1959年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Molecular structure and granule morphology of native and heat‐moisture‐treated pinhão starch 下载免费PDF全文
Vania Z. Pinto Khalid Moomand Nathan L. Vanier Rosana Colussi Franciene A. Villanova Elessandra R. Zavareze Loong‐Tak Lim Alvaro R. G. Dias 《International Journal of Food Science & Technology》2015,50(2):282-289
Pinhão seed is an unconventional source of starch and the pines grow up in native forests of southern Latin America. In this study, pinhão starch was adjusted at 15, 20 and 25% moisture content and heated to 100, 110 and 120 °C for 1 h. A decrease in λ max (starch/iodine complex) was observed as a result of increase in temperature and moisture content of HMT. The ratio of crystalline to amorphous phase in pinhão starch was determined via Fourier transform infra red by taking 1045/1022 band ratio. A decrease in crystallinity occurred as a result of HMT. Polarised light microscopy indicated a loss of birefringence of starch granules under 120 °C at 25% moisture content. Granule size distribution was further confirmed via scanning electron microscopy which showed the HMT effects. These results increased the understanding on molecular and structural properties of HMT pinhão starch and broadened its food and nonfood industrial applications. 相似文献
3.
4.
5.
6.
7.
To realize joint optimization of spatial diversity and equalization combining in the intersymbol interference (ISI) channel, an iterative equalization combining algorithm is proposed. The proposed algorithm uses the coefficients of Turbo equalization to calculate the combination weights without estimating the signal to noise ratio in each diversity branch. The equalized symbols from different diversity branches are combined, and the extrinsic information output from the decoder is fed back to the equalizers, so as to exchange soft information between the equalizers and the decoder. The performance of the proposed algorithm is analyzed using the extrinsic information transfer (EXIT) chart and verified by simulations. Results show that our approach fully exploits time domain information from the multipath channel and spatial domain information from multi receiving antennas, which efficiently improve the performance of the receiver in the severe ISI channel. 相似文献
8.
Harshavardhan Mohan Jeong-Muk Lim Se-Won Lee Min Cho Yool-Jin Park Kamala-Kannan Seralathan Byung-Taek Oh 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2020,95(1):297-307
The cover image is based on the Research Article V2O5/RGO/Pt nanocomposite on oxytetracycline degradation and pharmaceutical effluent detoxification by Mohan, H et al., DOI: 10.1002/jctb.6238 .
9.
Zhang Xi Wang Xianhai Zhao Hongke Ordóñez de Pablos Patricia Sun Yongqiang Xiong Hui 《Scientometrics》2019,119(3):1311-1344
Scientometrics - Altmetrics indices are increasingly applied to measure scholarly influence in recent years because they can reflect the influence of research outputs more timely comparing with... 相似文献
10.
Hwansoo Lee Dongwon Lim Hyerin Kim Andrew P. Ciganek 《Behaviour & Information Technology》2015,34(1):45-56
Many e-commerce companies collect users’ personal data for marketing purposes despite privacy concerns. Information-collecting companies often offer a monetary reward to users to alleviate privacy concerns and ease the collection of personal information. This study focused on the negative effects of monetary rewards on both information privacy concerns (IPC) and information disclosure. A survey approach was used to collect data and 370 final responses were analysed using a two-way analysis of variance and a binomial logistic regression model. The results show that monetary rewards increase IPC when an information-collecting company requires sensitive information. Additional results indicate that building trust is a more effective way of collecting personal data. This study identifies how organisations can best execute information-collection activities and contributes additional insights for academia and practitioners. 相似文献