首页 | 官方网站   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   826099篇
  免费   10787篇
  国内免费   2059篇
工业技术   838945篇
  2021年   7603篇
  2020年   5776篇
  2019年   7367篇
  2018年   12563篇
  2017年   12682篇
  2016年   13369篇
  2015年   8570篇
  2014年   14316篇
  2013年   39190篇
  2012年   22537篇
  2011年   30722篇
  2010年   24535篇
  2009年   27552篇
  2008年   28057篇
  2007年   27665篇
  2006年   24247篇
  2005年   21920篇
  2004年   20921篇
  2003年   20688篇
  2002年   19671篇
  2001年   19282篇
  2000年   18301篇
  1999年   18576篇
  1998年   45422篇
  1997年   32210篇
  1996年   25002篇
  1995年   18902篇
  1994年   16911篇
  1993年   16702篇
  1992年   12361篇
  1991年   11775篇
  1990年   11666篇
  1989年   11206篇
  1988年   10639篇
  1987年   9604篇
  1986年   9254篇
  1985年   10600篇
  1984年   9633篇
  1983年   8990篇
  1982年   8185篇
  1981年   8350篇
  1980年   7817篇
  1979年   7891篇
  1978年   7734篇
  1977年   8740篇
  1976年   11122篇
  1975年   6849篇
  1974年   6563篇
  1973年   6672篇
  1972年   5647篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
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   
92.
93.
In this paper, we present an aero‐structural model of a tethered swept wing for airborne wind energy generation. The carbon composite wing has neither fuselage nor actuated aerodynamic control surfaces and is controlled entirely from the ground using three separate tethers. The computational model is efficient enough to be used for weight optimisation at the initial design stage. The main load‐bearing wing component is a nontypical “D”‐shaped wing‐box, which is represented as a slender carbon composite shell and further idealised as a stack of two‐dimensional cross section models arranged along an anisotropic one‐dimensional beam model. This reduced 2+1D finite element model is then combined with a nonlinear vortex step method that determines the aerodynamic load. A bridle model is utilised to calculate the individual forces as a function of the aerodynamic load in the bridle lines that connect the main tether to the wing. The entire computational model is used to explore the influence of the bride on the D‐box structure. Considering a reference D‐box design along with a reference aerodynamic load case, the structural response is analysed for typical bridle configurations. Subsequently, an optimisation of the internal geometry and laminate fibre orientations is carried out using the structural computation models, for a fixed aerodynamic and bridle configuration. Aiming at a minimal weight of the wing structure, we find that for the typical load case of the system, an overall weight savings of approximately 20% can be achieved compared with the initial reference design.  相似文献   
94.
Russian Engineering Research - The strategic efficiency of a project is defined. An approach to assessing the strategic efficiency of projects is outlined. This approach, incorporated in the State...  相似文献   
95.
96.
97.
98.
This study aimed to evaluate the physicochemical characteristics and sensory attributes of beef burgers with the addition of pea fibre as a partial substitute of meat or fat. Three formulations were prepared: control (CON) – similar to the commercial formulation; fibre/less meat (FLM)—5% meat reduction and addition of 1% pea fibre; fibre/less fat (FLF)—7% fat reduction and addition of 1% pea fibre. Non-significant differences were obtained for pH, colour parameters (L* and b*), texture profile, cooking loss and size reduction among formulations. Moreover, sensory analysis with consumers of beef burgers did not indicate differences among the formulations for all the analysed attributes. Therefore, pea fibre is a promising partial replacer for meat and fat in beef burgers due to the preservation of technological parameters and sensory acceptance.  相似文献   
99.
Topics in Catalysis - In this work, a simple thermal-catalytic system was used to valorize peanut shells (Arachis hypogaea), the residual biomass from the peanut industry. To accomplish this...  相似文献   
100.
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-23

京公网安备 11010802026262号