首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   48530篇
  免费   14301篇
  国内免费   38篇
电工技术   887篇
综合类   19篇
化学工业   19036篇
金属工艺   776篇
机械仪表   1389篇
建筑科学   1869篇
矿业工程   3篇
能源动力   1276篇
轻工业   7931篇
水利工程   323篇
石油天然气   61篇
无线电   8780篇
一般工业技术   13281篇
冶金工业   1408篇
原子能技术   157篇
自动化技术   5673篇
  2024年   11篇
  2023年   151篇
  2022年   223篇
  2021年   549篇
  2020年   1595篇
  2019年   3339篇
  2018年   3355篇
  2017年   3637篇
  2016年   4164篇
  2015年   4156篇
  2014年   4224篇
  2013年   5603篇
  2012年   3345篇
  2011年   3175篇
  2010年   3174篇
  2009年   3106篇
  2008年   2597篇
  2007年   2324篇
  2006年   2069篇
  2005年   1747篇
  2004年   1644篇
  2003年   1598篇
  2002年   1526篇
  2001年   1332篇
  2000年   1270篇
  1999年   659篇
  1998年   475篇
  1997年   299篇
  1996年   216篇
  1995年   204篇
  1994年   161篇
  1993年   157篇
  1992年   110篇
  1991年   102篇
  1990年   83篇
  1989年   68篇
  1988年   44篇
  1987年   52篇
  1986年   45篇
  1985年   35篇
  1984年   40篇
  1983年   30篇
  1982年   26篇
  1981年   17篇
  1980年   23篇
  1979年   13篇
  1978年   10篇
  1977年   14篇
  1976年   23篇
  1975年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
International Journal of Information Security - This paper deals with a well-known problem in the area of the smudge attacks: when a user draws a pattern to unlock the pattern lock on a smartphone...  相似文献   
3.
Food Science and Biotechnology - Various hilling materials (rice hulls, pine sawdust, and perlite) were compared to produce sprout vegetables using beach silvertop (Glehnia littoralis Fr. Schm. ex...  相似文献   
4.
The aim of this exploratory study has been to investigate the fire properties and environmental aspects of different upholstery material combinations, mainly for domestic applications. An analysis of the sustainability and circularity of selected textiles, along with lifecycle assessment, is used to qualitatively evaluate materials from an environmental perspective. The cone calorimeter was the primary tool used to screen 20 different material combinations from a fire performance perspective. It was found that textile covers of conventional fibres such as wool, cotton and polyester, can be improved by blending them with fire resistant speciality fibres. A new three‐dimensional web structure has been examined as an alternative padding material, showing preliminary promising fire properties with regard to ignition time, heat release rates and smoke production.  相似文献   
5.
The germline carrier of the BRCA1 pathogenic mutation has been well proven to confer an increased risk of breast and ovarian cancer. Despite BRCA1 biallelic pathogenic mutations being extremely rare, they have been reported to be embryonically lethal or to cause Fanconi anemia (FA). Here we describe a patient who was a 48-year-old female identified with biallelic pathogenic mutations of the BRCA1 gene, with no or very subtle FA-features. She was diagnosed with ovarian cancer and breast cancer at the ages of 43 and 44 and had a strong family history of breast and gynecological cancers.  相似文献   
6.
7.
8.
9.
10.
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   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号