全文获取类型
收费全文 | 507529篇 |
免费 | 7323篇 |
国内免费 | 1209篇 |
专业分类
电工技术 | 8707篇 |
综合类 | 431篇 |
化学工业 | 82091篇 |
金属工艺 | 19782篇 |
机械仪表 | 15010篇 |
建筑科学 | 12271篇 |
矿业工程 | 3000篇 |
能源动力 | 11406篇 |
轻工业 | 50036篇 |
水利工程 | 5457篇 |
石油天然气 | 10840篇 |
武器工业 | 49篇 |
无线电 | 52253篇 |
一般工业技术 | 96833篇 |
冶金工业 | 94862篇 |
原子能技术 | 11893篇 |
自动化技术 | 41140篇 |
出版年
2021年 | 4450篇 |
2019年 | 4219篇 |
2018年 | 7482篇 |
2017年 | 7357篇 |
2016年 | 7923篇 |
2015年 | 5173篇 |
2014年 | 8355篇 |
2013年 | 22582篇 |
2012年 | 13294篇 |
2011年 | 17357篇 |
2010年 | 13984篇 |
2009年 | 15558篇 |
2008年 | 16058篇 |
2007年 | 15947篇 |
2006年 | 13936篇 |
2005年 | 12671篇 |
2004年 | 11921篇 |
2003年 | 11469篇 |
2002年 | 11573篇 |
2001年 | 11179篇 |
2000年 | 10802篇 |
1999年 | 10788篇 |
1998年 | 26645篇 |
1997年 | 19367篇 |
1996年 | 14904篇 |
1995年 | 11285篇 |
1994年 | 10171篇 |
1993年 | 9975篇 |
1992年 | 7631篇 |
1991年 | 7316篇 |
1990年 | 7293篇 |
1989年 | 7209篇 |
1988年 | 7031篇 |
1987年 | 6044篇 |
1986年 | 6090篇 |
1985年 | 7026篇 |
1984年 | 6709篇 |
1983年 | 6086篇 |
1982年 | 5738篇 |
1981年 | 5946篇 |
1980年 | 5759篇 |
1979年 | 5544篇 |
1978年 | 5619篇 |
1977年 | 6523篇 |
1976年 | 8604篇 |
1975年 | 5065篇 |
1974年 | 4818篇 |
1973年 | 4961篇 |
1972年 | 4206篇 |
1971年 | 3896篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Klimis?S.?NtalianisEmail author Anastasios?D.?Doulamis Nikolaos?D.?Doulamis Nikos?E.?Mastorakis Athanasios?S.?Drigas 《Journal of Signal Processing Systems》2015,80(2):153-161
In this paper, we present a novel memory access reduction scheme (MARS) for two-dimension fast cosine transform (2-D FCT). It targets programmable DSPs with high memory-access latency. It reduces the number of memory accesses by: 1) reducing the number of weighting factors and 2) combining butterflies in vector-radix 2-D FCT pruning diagram from two stages to one stage with an efficient structure. Hardware platform based on general purpose processor is used to verify the effectiveness of the proposed method for vector-radix 2-D FCT pruning implementation. Experimental results validate the benefits of the proposed method with reduced memory access, less clock cycle and fewer memory space compared with the conventional implementation. 相似文献
2.
Ana Clara Sabbione Santiago Suárez María Cristina Añón Adriana Scilingo 《International Journal of Food Science & Technology》2019,54(5):1506-1513
In this study, amaranth flour was used as an ingredient to prepare gluten-free cookies. The production process and attributes of amaranth cookies were characterised, and the potential use of amaranth flour as a functional ingredient was analysed. Cookies exhibited a non-uniform reddish brown colour and a cookie factor ratio of 4.5 ± 0.6. Storage studies indicated that after 3 weeks at room temperature cookies presented slight variations in the texture. Simulated gastrointestinal digestion of this product was able to release peptides capable of exerting potential antithrombotic and antihypertensive activities, IC50 values of 0.22 ± 0.04 and 0.23 ± 0.03 mg mL−1 protein, respectively. This work demonstrates for the first time that food made with amaranth flour exerts potential antithrombotic and antihypertensive activity. In conclusion, these amaranth cookies could be an alternative way of incorporating potentially health beneficial products for people who choose a conscious diet, including coeliac or vegan consumers. 相似文献
3.
4.
鄂竟平 《中国水能及电气化》2020,(3):1-2
3月22日是第二十八届“世界水日”,第三十三届“中国水周”的宣传活动也同时拉开帷幕。联合国确定今年“世界水日”的宣传主题是“水与气候变化”,我国纪念“世界水日”和开展“中国水周”活动的宣传主题是“坚持节水优先,建设幸福河湖”。党的十八大以来,以习近平同志为核心的党中央高度重视水利工作。习近平总书记多次就治水发表重要讲话、作出重要指示,明确提出“节水优先、空间均衡、系统治理、两手发力”的治水思路,对长江经济带共抓大保护、不搞大开发,黄河流域共同抓好大保护、协同推进大治理等作出重要部署,发出了建设造福人民的幸福河的伟大号召,为推进新时代治水提供了科学指南和根本遵循。 相似文献
5.
6.
7.
8.
Kobrakov K. I. Kurnetsov D. N. Ruchkina A. G. Sharpar N. M. 《Theoretical Foundations of Chemical Engineering》2020,54(5):1052-1056
Theoretical Foundations of Chemical Engineering - New research results, as well as those published earlier by the authors, on the synthesis of azo compounds based on nitroanilines obtained by the... 相似文献
9.
A. L. Rudenko V. V. Mishakin A. V. Gonchar K. V. Kurashkin A. E. Fomin 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2020,53(6):687-689
At the hydroelectric unit No. 11 of the Nizhnekamsk hydroelectric power plant, the filling wedges of a rotor were investigated by ultrasound in the free st 相似文献
10.
Nurullah Bulut Bahar Atmaca Gülsün Akdemir Evrendilek Sibel Uzuner 《Journal of Food Safety》2020,40(6):e12855
Seed processing technologies are essential for seed safety and functionality through protection of physicochemical quality, pathogen inactivation, aflatoxin detoxification and alleviation of mutagenicity. Design of a pilot-scale unit of pulsed electric fields (PEF) to treat sesame seeds with respect to quality parameters, Aspergillus parasiticus inactivation and aflatoxin reduction as well as alleviation of aflatoxin mutagenicity were prompted in this study. PEF energy ranged from 0.97 to 17.28 J achieved maximum reductions of peroxide value and acidity number of 67.4 and 85.7%, respectively, and did not change color L*, a*, b* and hue values. A 60% reduction of A. parasiticus counts occurred at the maximum PEF energy. Aflatoxins G1, G2, B1, and B2 contents decreased by 94.7, 92.7, 86.9, and 98.7%, respectively. Except for the samples treated by 2.16 J with 100 μg/plate and by 6.80 J with 10 μg/plate, PEF treatment provided elimination of aflatoxin mutagenity. It is concluded that PEF treatment can be used to treat sesame seeds with preservation of physicochemical properties, inactivation of A. parasiticus and decomposition of aflatoxins with reduced mutagenicity. 相似文献