全文获取类型
收费全文 | 135886篇 |
免费 | 21618篇 |
国内免费 | 3828篇 |
专业分类
电工技术 | 6068篇 |
技术理论 | 10篇 |
综合类 | 5939篇 |
化学工业 | 33957篇 |
金属工艺 | 5490篇 |
机械仪表 | 6808篇 |
建筑科学 | 9654篇 |
矿业工程 | 2379篇 |
能源动力 | 3937篇 |
轻工业 | 12992篇 |
水利工程 | 2066篇 |
石油天然气 | 5038篇 |
武器工业 | 586篇 |
无线电 | 18642篇 |
一般工业技术 | 23391篇 |
冶金工业 | 5895篇 |
原子能技术 | 1056篇 |
自动化技术 | 17424篇 |
出版年
2024年 | 366篇 |
2023年 | 1481篇 |
2022年 | 2661篇 |
2021年 | 3774篇 |
2020年 | 3971篇 |
2019年 | 5297篇 |
2018年 | 5430篇 |
2017年 | 6105篇 |
2016年 | 6350篇 |
2015年 | 7191篇 |
2014年 | 8331篇 |
2013年 | 10569篇 |
2012年 | 8746篇 |
2011年 | 8727篇 |
2010年 | 8328篇 |
2009年 | 7958篇 |
2008年 | 7267篇 |
2007年 | 7097篇 |
2006年 | 7029篇 |
2005年 | 6124篇 |
2004年 | 4671篇 |
2003年 | 4489篇 |
2002年 | 4400篇 |
2001年 | 3908篇 |
2000年 | 3744篇 |
1999年 | 3289篇 |
1998年 | 2586篇 |
1997年 | 2081篇 |
1996年 | 1905篇 |
1995年 | 1569篇 |
1994年 | 1292篇 |
1993年 | 959篇 |
1992年 | 711篇 |
1991年 | 598篇 |
1990年 | 444篇 |
1989年 | 414篇 |
1988年 | 339篇 |
1987年 | 201篇 |
1986年 | 190篇 |
1985年 | 139篇 |
1984年 | 114篇 |
1983年 | 73篇 |
1982年 | 69篇 |
1981年 | 66篇 |
1980年 | 51篇 |
1979年 | 38篇 |
1978年 | 18篇 |
1977年 | 44篇 |
1976年 | 19篇 |
1975年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 24 毫秒
31.
SPEEK/cSMM membrane for simultaneous electricity generation and wastewater treatment in microbial fuel cell
下载免费PDF全文
![点击此处可从《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
32.
Efficacy of Crude and Purified Chitinases (SsChi50) Extracted from Offal Red Scorpion Fish in Biological Control of Chickpea Weevil (Callosobruchus maculatus L.)
下载免费PDF全文
![点击此处可从《Journal of Food Processing and Preservation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
33.
Quality enhancement of the abundant under‐valued crustacean,lobster krill (Munida spp.), during its chilled storage
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Bibiana García‐Soto José M. Miranda Jorge Barros‐Velázquez Santiago P. Aubourg 《International Journal of Food Science & Technology》2015,50(3):708-716
Lobster krill (Munida genus) represents an under‐valued crustacean frequently caught on European fishing banks. In this work, its sensory, microbiological and biochemical qualities were evaluated during chilled storage. Additionally, the effects of a prestorage antimelanosic treatment consisting of soaking in sodium metabisulphite (SMB) solutions at two different concentrations (0.25% and 0.75%) were also studied. SMB prestorage treatment provided lobster specimens that still exhibited acceptable sensory quality after 10 days of storage, while control specimens were unacceptable at that time. SMB treatment also resulted in a significant (P < 0.05) inhibition of microbial growth, mainly of Enterobacteriaceae, psychrotrophes and proteolytic bacteria. Low lipid oxidation levels were observed for all batches; however, a significantly higher (P < 0.05) retention of polyunsaturated fatty acids was found in SMB‐treated lobster, especially in the 0.75% SMB batch. The results presented here open the way to the potential commercialisation of currently under‐utilised lobster krill as a chilled product. 相似文献
34.
To improve the convertibility of reconfigurable manufacturing system (RMS), the concept of delayed reconfigurable manufacturing system (D-RMS) was proposed. RMS and D-RMS are both constructed around part family. However, D-RMS may suffer from ultra-long system problem with unacceptable idle machines using generic RMS part families. Besides, considering the complex basic system structure of D-RMS, machine selection of D-RMS should be addressed, including dedicated machine, flexible machine, and reconfigurable machine. Therefore, a system design method for D-RMS based on part family grouping and machine selection is proposed. Firstly, a part family grouping method is proposed for D-RMS that groups the parts with more former common operations into the same part family. The concept of longest relative position common operation subsequence (LPCS) is proposed. The similarity coefficient among the parts is calculated based on LPCS. The reciprocal value of the operation position of LPCS is adopted as the characteristic value. The average linkage clustering (ALC) algorithm is used to cluster the parts. Secondly, a machine selection method is proposed to complete the system design of D-RMS, including machine selection rules and the dividing point decision model. Finally, a case study is given to implement and verify the proposed system design method for D-RMS. The results show that the proposed system design method is effective, which can group parts with more former common operations into the same part family and select appropriate machine types. 相似文献
35.
既有公共建筑能耗中,围护结构节能潜力巨大。以兰州某既有办公建筑为例,采用DeST-C软件模拟围护结构不同材料厚度、窗型,得出系列负荷,通过对数据分析、比较,得出如下结论:外墙外保温适宜材料为50mm的挤塑板,最大热负荷节能率为45.66%;屋面适宜保温材料为65mm的挤塑板,最大热负荷节能率为4.25%;外窗各个朝向全部更换玻璃,推荐选用内张膜中空玻璃(双膜),最大热负荷节能率为7.36%;单独更换南向外窗材料,推荐选用真空镀膜复合中空玻璃,最大热负荷节能率为1.78%。 相似文献
36.
Lin Haicheng Huang Wantong Zhao Kun Qiao Shuang Liu Zheng Wu Jian Chen Xi Ji Shuai-Hua 《Nano Research》2020,13(1):133-137
Nano Research - The isostructural and isoelectronic transition-metal-dichalcogenides 1T-TaS2 and 1T-TaSe2 are layered materials with intricate electronic structures. Combining the molecular beam... 相似文献
37.
38.
39.
40.
Molecular structure and granule morphology of native and heat‐moisture‐treated pinhão starch
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
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