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   219篇
  免费   25篇
电工技术   1篇
化学工业   66篇
金属工艺   2篇
机械仪表   5篇
建筑科学   2篇
能源动力   2篇
轻工业   97篇
石油天然气   1篇
无线电   5篇
一般工业技术   42篇
冶金工业   3篇
自动化技术   18篇
  2024年   2篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   6篇
  2019年   4篇
  2018年   11篇
  2017年   7篇
  2016年   11篇
  2015年   6篇
  2014年   14篇
  2013年   13篇
  2012年   11篇
  2011年   15篇
  2010年   9篇
  2009年   12篇
  2008年   16篇
  2007年   13篇
  2006年   14篇
  2005年   10篇
  2004年   12篇
  2003年   9篇
  2002年   13篇
  2001年   4篇
  2000年   2篇
  1999年   5篇
  1998年   8篇
  1997年   5篇
  1996年   2篇
  1995年   1篇
  1994年   2篇
  1993年   1篇
  1992年   2篇
排序方式: 共有244条查询结果,搜索用时 15 毫秒
51.
52.
In this work, the influence of an Ultra High Temperature (UHT) treatment on chemical and sensory composition of Arabica coffee brews for a longer shelf-life has been studied. A temperature of 120 °C for 2 s allows to obtain a microbiologically safe coffee brew, good valued from the sensory point of view. The behavior of the UHT vs non UHT treated coffee brew was followed throughout 120 days of storage at 4 °C. The UHT treatment keeps the typical acidity of the brews longer, delaying and softening the pH decrease and the development of sourness, which is one of the main causes for the rejection of stored coffee brews. The UHT treatment hardly affects the concentrations of caffeine and trigonelline, and of some phenolic compounds such as 5-caffeoylquinic (5-CQA), caffeic or ferulic acids. Sixteen key odorants and staling volatiles were analyzed by HS–GC–MS and lower changes were observed in the UHT treated coffee brew throughout storage. Higher DPPH scavenging activity was observed in the UHT treated coffee brew from days 60 to 120. In conclusion, the application of an UHT treatment is proposed to extend the shelf-life (up to 60 days) of stored coffee brews.  相似文献   
53.
54.
This article introduces the Impact Factor squared or IF2-index, an h-like indicator of research performance. This indicator reflects the degree to which large entities such as countries and/or their states participate in top-level research in a field or subfield. The IF2-index uses the Journal Impact Factor (JIF) of research publications instead of the number of citations. This concept is applied to other h-type indexes and their results compared to the IF2-index. These JIF-based indexes are then used to assess the overall performance of cancer research in Australia and its states over 8 years from 1999 to 2006. The IF2-index has three advantages when evaluating larger research units: firstly, it provides a stable value that does not change over time, reflecting the degree to which a research unit participated in top-level research in a given year; secondly, it can be calculated closely approximating the publication date of yearly datasets; and finally, it provides an additional dimension when a full article-based citation analysis is not feasible. As the index reflects the degree of participation in top-level research it may favor larger units when units of different sizes are compared.  相似文献   
55.
56.
The fermentation of natural black olives is currently carried out under anaerobic conditions. This work investigates the aerobic fermentation of this product in tanks containing 16 000 kg of Empeltre olives during two seasons. The microorganisms in brines were yeasts in all cases, whereas lactic acid bacteria growth was only observed in some tanks. Consequently, the pH during fermentation was in most cases higher than recommended 4.3 units. However, the Empeltre olive brines displayed bactericidal effect against Salmonella enterica, Sthapylococcus aureus, Escherichia coli and Listeria monocytogenes, with a 5 log population drop in one or 24 h depending on the brine age so that these olive brines are a harsh environment for the growth of these pathogens. It was found HyEDA as the major phenolic compound in both brine and olive pulp at the beginning of fermentation that slowly hydrolysed into hydroxytyrosol that reached a concentration up to 1500 mg kg−1.  相似文献   
57.
58.
The main objective of this study was to evaluate the effect of different deficit irrigation treatments (control, regulated deficit irrigation [RDI]‐1, RDI‐2, and RDI‐3) on the phenolic profile of the olive paste and oil content. Irrigation treatments with more stress water led to a considerable increase in the phenolic compounds of olive paste, especially in oleuropein (60.24%), hydroxytyrosol (82%), tyrosol (195%), and verbascoside (223%) compared to control. A significant increase in the content of total flavonoids and phenolic acids was also observed for these samples. In virgin olive oils (VOO) elaborated from the most stressed olive trees (RDI‐2 and RDI‐3), a noticeable increase in phenolic substances with antioxidant properties (oleuropein, hydroxytyrosol, tyrosol, secoiridoid derivatives, and o‐vanillin) was observed. Consequently, water stress conditions improved antioxidant activity of VOO.  相似文献   
59.
60.
MMORPG (Massively Multiplayer Online Role Playing Games) is the most popular genre among network gamers, and now attract millions of users, who play simultaneously in an evolving virtual world. This huge number of concurrent players requires the availability of high performance computation servers. Additionally, gaming aware distribution mechanisms are needed to distribute game instances among servers to avoid load imbalances that affect performance negatively. In this work, we tackle the problem of game distribution and scalability by means of a hybrid Client-Server/P2P architecture that can scale dynamically according to the demand. To manage peak loads that occur during the game, we distribute game computation across the system according to the behavior of MMORPGs. We distinguish between the computation associated with the Main Game, that affects all players, and the computation of Auxiliary Games that affects only a few players and acts in isolation from the execution of the Main Game. Taking this distinction into account, we propose a mechanism that is focused in the distribution of Auxiliary Games, as an entity, across the pool of servers and peers of the underlying hybrid architecture. We evaluate the performance of the balancing mechanism taking the criteria of latency and reliability into account, and we compare the effectiveness of the mechanism with a classic approach that applies load balancing to individually players in a Client-Server system. We show that the balancing mechanism based on the latency criteria provides lower latency than the classical proposal, while in relation to reliability, we obtain a failure probability of under 0.9 % in the worst case, which is amply compensated by the scalability provided by the use of the P2P area.  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