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   43086篇
  免费   2305篇
  国内免费   48篇
电工技术   369篇
综合类   26篇
化学工业   9122篇
金属工艺   819篇
机械仪表   859篇
建筑科学   1337篇
矿业工程   84篇
能源动力   986篇
轻工业   6902篇
水利工程   396篇
石油天然气   150篇
武器工业   5篇
无线电   1878篇
一般工业技术   7085篇
冶金工业   9117篇
原子能技术   192篇
自动化技术   6112篇
  2024年   88篇
  2023年   361篇
  2022年   712篇
  2021年   1172篇
  2020年   845篇
  2019年   997篇
  2018年   1673篇
  2017年   1607篇
  2016年   1700篇
  2015年   1270篇
  2014年   1576篇
  2013年   3109篇
  2012年   2472篇
  2011年   2473篇
  2010年   1939篇
  2009年   1785篇
  2008年   1719篇
  2007年   1622篇
  2006年   1142篇
  2005年   1009篇
  2004年   886篇
  2003年   802篇
  2002年   765篇
  2001年   589篇
  2000年   558篇
  1999年   587篇
  1998年   2859篇
  1997年   1901篇
  1996年   1237篇
  1995年   750篇
  1994年   581篇
  1993年   658篇
  1992年   255篇
  1991年   262篇
  1990年   194篇
  1989年   194篇
  1988年   197篇
  1987年   172篇
  1986年   154篇
  1985年   177篇
  1984年   145篇
  1983年   125篇
  1982年   157篇
  1981年   179篇
  1980年   177篇
  1979年   89篇
  1978年   98篇
  1977年   309篇
  1976年   663篇
  1973年   82篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
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   
2.
3.
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   
4.
5.
6.
This study deals with the formulation of natural drugs into hydrogels. For the first time, compounds from the sage essential oil were formulated into chitosan hydrogels. A sample preparation procedure for hydrophobic volatile analytes present in a hydrophilic water matrix along with an analytical method based on the gas chromatography coupled with the mass spectrometry (GC-MS) was developed and applied for the evaluation of the identity and quantity of essential oil components in the hydrogels and saline samples. The experimental results revealed that the chitosan hydrogels are suitable for the formulation of sage essential oil. The monoterpene release can be effectively controlled by both chitosan and caffeine concentration in the hydrogels. Permeation experiment, based on a hydrogel with the optimized composition [3.5% (w/w) sage essential oil, 2.0% (w/w) caffeine, 2.5% (w/w) chitosan and 0.1% (w/w) Tween-80] in donor compartment, saline solution in acceptor compartment, and semi-permeable cellophane membrane, demonstrated the useful permeation selectivity. Here, (according to lipophilicity) an enhanced permeation of the bicyclic monoterpenes with antiflogistic and antiseptic properties (eucalyptol, camphor and borneol) and, at the same time, suppressed permeation of toxic thujone (not exceeding its permitted applicable concentration) was observed. These properties highlight the pharmaceutical importance of the developed chitosan hydrogel formulating sage essential oil in the dermal applications.  相似文献   
7.
8.
9.
10.
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