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   130篇
  免费   11篇
  国内免费   2篇
  2022年   1篇
  2021年   2篇
  2019年   4篇
  2018年   5篇
  2017年   2篇
  2016年   2篇
  2015年   3篇
  2014年   11篇
  2013年   8篇
  2012年   9篇
  2011年   6篇
  2010年   5篇
  2009年   5篇
  2008年   5篇
  2007年   5篇
  2006年   3篇
  2005年   2篇
  2004年   3篇
  2003年   3篇
  2002年   4篇
  2001年   3篇
  2000年   2篇
  1999年   5篇
  1998年   3篇
  1997年   5篇
  1995年   1篇
  1994年   2篇
  1993年   1篇
  1992年   4篇
  1991年   2篇
  1990年   4篇
  1989年   4篇
  1988年   3篇
  1987年   2篇
  1985年   1篇
  1984年   1篇
  1983年   3篇
  1982年   3篇
  1981年   1篇
  1973年   1篇
  1970年   1篇
  1968年   1篇
  1961年   1篇
  1950年   1篇
排序方式: 共有143条查询结果,搜索用时 0 毫秒
11.
12.
The potential role of biosensors in the food and drink industries.   总被引:1,自引:0,他引:1  
Despite their apparent potential as analytical tools in the food and drink industries, only a few biosensors are used routinely. This article describes the development of biosensors for these sectors and discusses the technical and economic problems of applying this technology to the monitoring of food and drink products.  相似文献   
13.
14.
The potential of a Cu/Ni mining slag to act as a substrate for the growth of the bacteria Thiobacillus ferrooxidans, Thiobacillus thiooxidants, and Thiobacillus thioparus was examined. As well, slag and seepage samples were screened for the presence of the Thiobacillus species. For the 28 samples employed in the environmental recovery studies, T. ferrooxidans was recovered in 25 samples, T. thiooxidans in 19 samples, and T. thioparus in 27 samples. For T. ferrooxidans, the development of a colour change in the medium corresponded with the presence of motile bacilli as detected microscopically. For T. thiooxidans and T. thioparus, a decrease in culture pH of greater than 0.2 units usually corresponded with the presence of motile bacilli. The potential for growth on slag was determined by adding slag samples to media (devoid of an electron donor) appropriate for the growth of the three Thiobacillus species. All pulverized slag samples supported the growth of the three species.  相似文献   
15.
Human Pin1 is a peptidyl prolyl cis/trans isomerase with a unique preference for phosphorylated Ser/Thr-Pro substrate motifs.Here we report that MCM3 (minichromosome maintenance complex component 3) is a novel target of Pin1. MCM3 interacts directly with the WW domain of Pin1. Proline-directed phosphorylation of MCM3 at S112 and T722 are crucial for the interaction with Pin1. MCM3 as a subunit of the minichromosome maintenance heterocomplex MCM2–7 is part of the pre-replication complex responsible for replication licensing and is implicated in the formation of the replicative helicase during progression of replication. Our data suggest that Pin1 coordinates phosphorylation-dependently MCM3 loading onto chromatin and its unloading from chromatin, thereby mediating S phase control.  相似文献   
16.
Many animals use hoarding as a long-term strategy to ensure a food supply at times of shortage. We suggest that long-term scatter hoarders, whose caches are vulnerable to potentially high pilferage, should hoard in ways to reduce cache loss. This could be achieved by manipulating the density and dispersal patterns of caches to reduce the foraging efficiency of pilferers. This study explores the effect of distribution patterns on cache loss in the laboratory. We recorded the discovery of food items in different dispersal patterns by two bird species: coal tits Periparus ater (a hoarder) and great tits Parus major (a non-hoarder). Hyper-dispersed distributions reduced foraging efficiency because both species used systematic local search patterns. This study shows that hyper-dispersed distributions would be advantageous to hoarding animals to reduce cache loss.  相似文献   
17.
18.

Background  

This paper introduces the notion of optimizing different norms in the dual problem of support vector machines with multiple kernels. The selection of norms yields different extensions of multiple kernel learning (MKL) such as L , L 1, and L 2 MKL. In particular, L 2 MKL is a novel method that leads to non-sparse optimal kernel coefficients, which is different from the sparse kernel coefficients optimized by the existing L MKL method. In real biomedical applications, L 2 MKL may have more advantages over sparse integration method for thoroughly combining complementary information in heterogeneous data sources.  相似文献   
19.
As methicillin-resistant Staphylococcus aureus (MRSA) has been found in pigs, we sought to determine if MRSA is present in pork production shower facilities. In two production systems tested, 3% and 26% of shower samples were positive for MRSA. spa types identified included t034, t189, t753, and t1746.  相似文献   
20.
The Indian black berry (Syzygium cumini Skeels) has a great nutraceutical and medicinal properties. As in other fruit crops, the fruit characteristics are important attributes for differentiation were also determined for different accessions of S. cumini. The fruit weight, length, breadth, length: breadth ratio, pulp weight, pulp content, seed weight and pulp: seed ratio significantly varied in different accessions. Molecular characterization was carried out using PCR based RAPD technique. Out of 80 RAPD primers, only 18 primers produced stable polymorphisms that were used to examine the phylogenetic relationship. A sum of 207 loci were generated out of which 201 loci found polymorphic. The average genetic dissimilarity was 97 per cent among jamun accessions. The phylogenetic relationship was also determined by principal coordinates analysis (PCoA) that explained 46.95 per cent cumulative variance. The two-dimensional PCoA analysis showed grouping of the different accessions that were plotted into four sub-plots, representing clustering of accessions. The UPGMA (r = 0.967) and NJ (r = 0.987) dendrogram constructed based on the dissimilarity matrix revealed a good degree of fit with the cophenetic correlation value. The dendrogram grouped the accessions into three main clusters according to their eco-geographical regions which given useful insight into their phylogenetic relationships.  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