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   91篇
  免费   4篇
化学工业   33篇
机械仪表   4篇
能源动力   4篇
轻工业   18篇
石油天然气   2篇
无线电   11篇
一般工业技术   10篇
冶金工业   5篇
原子能技术   1篇
自动化技术   7篇
  2023年   1篇
  2022年   7篇
  2021年   13篇
  2020年   4篇
  2019年   7篇
  2018年   5篇
  2017年   5篇
  2016年   3篇
  2015年   1篇
  2014年   1篇
  2013年   6篇
  2012年   2篇
  2011年   2篇
  2010年   3篇
  2009年   4篇
  2008年   3篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2004年   5篇
  2002年   1篇
  2001年   1篇
  1999年   1篇
  1997年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1985年   2篇
  1984年   4篇
  1982年   1篇
  1976年   4篇
  1974年   2篇
排序方式: 共有95条查询结果,搜索用时 15 毫秒
51.
Four tropical fruits and three citrus fruits were analyzed for moisture, ash, antinutritional factors (phytate, oxalate, and polyphenols) contents, and total and available minerals. Moisture contents ranged from 6.0 to 83.17% for tropical fruits while that of citrus fruits ranged from 88.20 to 89.50%. Ash contents ranged from 2.56 to 4.50% and from 3.83 to 4.83%, for tropical and citrus fruits, respectively. All fruits contained no oxalate while phytate and polyphenols ranged from 48.1 to 134.1 mg/ 100 g and from 0.115 to 0.34%, respectively. For all fruits major minerals contents ranged from 7.7 to 433.3 while trace ones ranged from 0.116 to 1.91 mg/100 g. In vitro availabilities of major minerals (% of total) varied from 11.1 to 86.2% while for minor ones it ranged from 13 to 72.5%.  相似文献   
52.
53.
Hydrogen (H2) is considered an alternative energy carrier for future clean energy systems in many applications. The three-dimensional (3D) graphene is one of the promising candidates for various applications especially in photocatalytic H2 production due to its high electron conductivity, mechanical stability, fast electron transfer, and large surface area. Exploring the changes in the physical properties from different dimensionalities can be interesting because a 3D structure may improve the photocatalytic efficiency in terms of enhancing the light adsorption, increasing the accessible active surface, and improving the charge transport. Graphene can act as an electron acceptor and cocatalyst, and combining the graphene with metal oxides, transition metal dichalcogenides, or other semiconducting materials can enhance the photocatalytic activity of composites. Therefore, the synthesis, characterization, mechanism, and performance of the 3D graphene-based photocatalyst in the photocatalytic H2 production are comprehensively discussed. The current progress and future challenges in the H2 generation is also discussed in this review.  相似文献   
54.
Cyclopropane fatty acids, which can be simply converted to methylated fatty acids, are good unusual fatty acid candidates for long-term resistance to oxidization and low-temperature fluidity useful for oleochemistry and biofuels. Cyclopropane fatty acids are present in low amounts in plants or bacteria. In order to develop a process for large-scale biolipid production, we expressed 10 cyclopropane fatty acid synthases from various organisms in the oleaginous yeast Yarrowia lipolytica, a model yeast for lipid metabolism and naturally capable of producing large amounts of lipids. The Escherichia coli cyclopropane fatty acid synthase expression in Y. lipolytica allows the production of two classes of cyclopropane fatty acids, a C17:0 cyclopropanated form and a C19:0 cyclopropanated form, whereas others produce only the C17:0 form. Expression optimization and fed-batch fermentation set-up enable us to reach a specific productivity of 0.032 g·L−1·hr−1 with a genetically modified strain containing cyclopropane fatty acid up to 45% of the total lipid content corresponding to a titre of 2.3 ± 0.2 g/L and a yield of 56.2 ± 4.4 mg/g.  相似文献   
55.
56.
57.
Wireless Networks - In recent years, the decentralized wireless Vehicular Ad hoc Networks (VANETs) have emerged as a key technology for Intelligent Transportation Systems (ITS). The need...  相似文献   
58.
Hydrogen generation from electrocatalytic water splitting is of supreme significance for resolving energy crisis and environmental concerns. However, developing earth-abundant, efficient, and durable electrocatalyst for high-performance hydrogen evolution and complete water splitting catalysis is a rare instance. We present here the first demonstration of unique copper tellurides nano-structures (CuTe-NS) based electrocatalyst executing HER with high activity and remarkable stability. CuTe-NS based electrocatalysts grown over conductive NiF via drop-casting approach and employed for HER, while achieving a current decade and a current density of 100 mA/cm2 just at 0.25 V vs. RHE and 0.27 V vs. RHE, which is comparable to the benchmark Pt/C based HER catalyst. The catalyst demonstrates well-balanced kinetic behavior, low Tafel slope of 36 mV/dec, low charge transfer resistance of 1.71 Ω, high roughness factor, and remarkable stability for more than 60 h of electrolysis. Furthermore, post-catalysis characterizations demonstrate no change in catalyst integrity, morphological, and structural attributes even after many hours of electrolysis which show sustainable behavior of catalyst for long term HER activity. Because of electrochemical and structural stabilities after long term electrolysis experiments, accessible method of preparations, and cost-effectiveness, the catalysis is highly encouraging for real-life applications.  相似文献   
59.
Telecommunication Systems - Embedded Machine-to-Machine (M2M) is one of the hottest research topics in recent industrial Internet of Things. In order to serve the communication to effectively...  相似文献   
60.
This article aimed to assess the anti‐inflammatory and anticancer potential of water‐soluble peptide (WSP) extracts from buffalo and cow milk Cheddar cheeses. Anti‐inflammatory activity was evaluated on the basis of nitric oxide (NO) production in lipopolysaccharide‐stimulated macrophage (RAW‐264.7) cells. A cell viability assay, cell cycle arrest and apoptosis were performed to explore anticancer activity in a colon cancer model (HT‐29). The WSP extracts of both Cheddar cheeses effectively inhibited NO production in activated macrophages. Maximum growth inhibition was observed in the HT‐29 cells at concentrations of 400 and 500 μg/mL. A significant increase in cell population at G0/G1 phase of the cell cycle was observed. Moreover, the WSP extracts also induced extensive apoptosis in colon cancer cells.  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