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   27902篇
  免费   1126篇
  国内免费   14篇
电工技术   104篇
综合类   12篇
化学工业   3496篇
金属工艺   304篇
机械仪表   335篇
建筑科学   511篇
矿业工程   40篇
能源动力   286篇
轻工业   3425篇
水利工程   217篇
石油天然气   68篇
武器工业   2篇
无线电   777篇
一般工业技术   2920篇
冶金工业   14151篇
原子能技术   72篇
自动化技术   2322篇
  2024年   45篇
  2023年   146篇
  2022年   164篇
  2021年   402篇
  2020年   393篇
  2019年   429篇
  2018年   782篇
  2017年   739篇
  2016年   745篇
  2015年   590篇
  2014年   732篇
  2013年   1428篇
  2012年   1129篇
  2011年   943篇
  2010年   804篇
  2009年   729篇
  2008年   748篇
  2007年   715篇
  2006年   457篇
  2005年   352篇
  2004年   378篇
  2003年   340篇
  2002年   302篇
  2001年   211篇
  2000年   191篇
  1999年   543篇
  1998年   4605篇
  1997年   2770篇
  1996年   1714篇
  1995年   939篇
  1994年   759篇
  1993年   890篇
  1992年   149篇
  1991年   206篇
  1990年   178篇
  1989年   196篇
  1988年   203篇
  1987年   158篇
  1986年   151篇
  1985年   136篇
  1984年   50篇
  1983年   50篇
  1982年   99篇
  1981年   110篇
  1980年   118篇
  1979年   27篇
  1978年   46篇
  1977年   286篇
  1976年   644篇
  1975年   27篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
4.
ABSTRACT

This paper presents an empirical assessment of four state-of-the-art risk-averse approaches to deal with the capacitated lot-sizing problem under stochastic demand. We analyse two mean-risk models based on the semideviation and on the conditional value-at-risk risk measures, and alternate first and second-order stochastic dominance approaches. The extensive computational experiments based on different instances characteristics and on a case-study suggest that CVaR exhibits a good trade-off between risk and performance, followed by the semideviation and first-order stochastic dominance approach. For all approaches, enforcing risk-aversion helps to reduce the cost-standard deviation substantially, which is usually accomplished via increasing production rates. Overall, we can say that very risk-averse decision-makers would be willing to pay an increased price to have a much less risky solution given by CVaR. In less risk-averse settings, though, semideviation and first-order stochastic dominance can be appealing alternatives to provide significantly more stable production planning costs with a marginal increase of the expected costs.  相似文献   
5.
6.
7.
Zhang  Xi  Wang  Xianhai  Zhao  Hongke  Ordóñez de Pablos  Patricia  Sun  Yongqiang  Xiong  Hui 《Scientometrics》2019,119(3):1311-1344
Scientometrics - Altmetrics indices are increasingly applied to measure scholarly influence in recent years because they can reflect the influence of research outputs more timely comparing with...  相似文献   
8.
9.
This study evaluated several physical and sensory parameters of different types of cheese available in the Polish market. The measurements of textural properties were conducted in an Instron universal testing machine, while the colour properties of cheeses were measured using a Minolta chromameter. The chemical composition was determined by means of the near‐infrared spectroscopy (NIRs). Moreover, a trained sensory panel was invited to assess the cheese texture‐related properties. Generally, cheeses with reduced fat content were characterised by higher hardness, adhesiveness, cohesiveness and elasticity. Texture‐related parameters of cheese with canola oil were comparable to that of most of full‐fat cheeses. The correlation analysis between physical and sensory attributes related to cheese textural properties indicated the potential applications of TPA, shear and penetration tests (= 0.766, = 0.75 and = 0.765, respectively) for the evaluation of sensory properties related to the hardness. Meanwhile, the elasticity of cheese obtained from sensory evaluation was strongly correlated with the elasticity determined from the shear test (= 0.722) and moderately correlated with the elasticity from penetration test (= 0.588), indicating a need to refine the method of penetration test. In addition, cheeses exhibited higher meltability during convection heating at 230 °C than microwave heating. The values of meltability for cheese with reduced fat content were lower than those of full‐fat cheese.  相似文献   
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