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   115篇
  免费   11篇
林业   4篇
农学   21篇
  24篇
综合类   6篇
农作物   11篇
水产渔业   6篇
畜牧兽医   50篇
园艺   1篇
植物保护   3篇
  2022年   4篇
  2021年   6篇
  2020年   4篇
  2019年   4篇
  2018年   5篇
  2017年   2篇
  2016年   3篇
  2015年   7篇
  2014年   4篇
  2013年   11篇
  2012年   8篇
  2011年   10篇
  2010年   5篇
  2009年   6篇
  2008年   7篇
  2007年   6篇
  2006年   2篇
  2005年   7篇
  2004年   7篇
  2003年   11篇
  2002年   1篇
  2001年   2篇
  2000年   2篇
  1999年   1篇
  1991年   1篇
排序方式: 共有126条查询结果,搜索用时 15 毫秒
81.
Twenty mammary lymph node samples were collected from cattle on a farm in the Republic of Korea. These cattle were serologically negative for Brucella by tube agglutination test (≤ 1:50) and serum agglutination test (≤ 1:50). Out of 20 lymph node samples, two samples were positive for Brucella growth on Brucella agar as well as blood agar. Tests for urease, hydrogen sulphide and reactions against monospecific sera A and M indicated that these two isolates (No. 15 and 16) belong to the genus Brucella. Genus specific, AMOS (abortus, melitensis, ovis, suis) and Bruce-ladder multiplex polymerase chain reaction (PCR) assays confirmed the Brucella isolates as either a B. abortus or a B. canis strain. This is the first report of the occurrence of a B. canis infection in cattle in Korea. More survey data are needed to determine whether B. canis is a significant aetiology in the cases of cattle brucellosis in Korea.  相似文献   
82.
83.
This study was performed to determine the pharmacokinetic profile of mosapride in fasting and fed states. A single 5‐mg oral dose of mosapride was administered to fasted (n = 15) and fed (n = 12) beagle dogs, and the plasma concentrations of mosapride were measured by liquid chromatography–tandem mass spectrometry. The resultant data were analyzed by noncompartmental analysis (NCA). Mosapride was absorbed in fasted and fed dogs with similar Tmax. Both Cmax and AUC were significantly higher in the fasting group than in fed dogs, being four times (10.51 μg/mL vs. 2.76 μg/mL) and 3.5 times higher (38.53 h·μg/mL vs. 10.22 h·μg/mL), respectively. These findings suggest that food intake affects the pharmacokinetics of mosapride and that the dosage regimen for this drug need to be reconsidered.  相似文献   
84.
Ascorbic acid (1), a natural antioxidant, was modified by employing transglycosylation activity of Bacillus stearothermophilus maltogenic amylase with maltotriose and acarbose as donor molecules to enhance its oxidative stability. The transglycosylation reaction with maltotriose as donor created mono- and di-glycosyl transfer products with an alpha-(1,6)-glycosidic linkage. In addition, two acarviosine-glucosyl transfer products were generated when transglycosylation was performed with acarbose as a donor. All transfer products were observed by TLC and HPLC, and purified by Q-sepharose anion exchange and Biogel P-2 gel permeation chromatographies. LC/MS and (13)C NMR analyses revealed that the structures of the transfer products were 6-O-alpha-D-glucosyl- (2) and 6-O-alpha-D-maltosyl-ascorbic acids (3) in the reaction of maltotriose, and 6-O-alpha-acarviosine-D-glucosyl- (4) and 2-O-alpha-acarviosine-D-glucosyl ascorbic acids (5) in the reaction of acarbose. The stability of the transglycosylated ascorbic acid derivatives was greatly enhanced against oxidation by Cu(2+) ion and ascorbate oxidase. Among them, compound 3 proved to be the most stable against in vitro oxidation. The antioxidant effects of glycosyl-derivatives of ascorbic acid on the lipid oxidation in cooked chicken breast meat patties indicated that they had antioxidant activities similar to that of ascorbic acid. It is suggested that the transglycosylated ascorbic acids can possibly be applied as effective antioxidants with improved stability in food, cosmetic, and other applications.  相似文献   
85.
The formation of two-dimensional electron gases (2DEGs) at complex oxide interfaces is directly influenced by the oxide electronic properties. We investigated how local electron correlations control the 2DEG by inserting a single atomic layer of a rare-earth oxide (RO) [(R is lanthanum (La), praseodymium (Pr), neodymium (Nd), samarium (Sm), or yttrium (Y)] into an epitaxial strontium titanate oxide (SrTiO(3)) matrix using pulsed-laser deposition with atomic layer control. We find that structures with La, Pr, and Nd ions result in conducting 2DEGs at the inserted layer, whereas the structures with Sm or Y ions are insulating. Our local spectroscopic and theoretical results indicate that the interfacial conductivity is dependent on electronic correlations that decay spatially into the SrTiO(3) matrix. Such correlation effects can lead to new functionalities in designed heterostructures.  相似文献   
86.
Journal of Crop Science and Biotechnology - There are many applications of image-based analysis for phenotyping agronomic traits. However, they are inappropriate or difficult to operate due to lack...  相似文献   
87.
In this study, the flavonoid and isoflavone contents in four checks with seed coat colour altered from yellow to black were determined, and their antioxidant activity was measured. Three anthocyanins (delphinidin‐3‐O‐β‐D‐glucoside, D3G; cyanidin‐3‐O‐β‐D‐glucoside, C3G; and petunidin‐3‐O‐β‐D‐glucoside, Pt3G) were detected in the four checks, while their controls (cvs. ‘Danbaek’ and ‘Daepung’) were not found. Among them, D‐16 derived from cv. ‘Danbaek’ showed the highest anthocyanin contents. The isoflavone contents of all checks showed lower levels compared to their controls. Among six isoflavones, glycitein was only detected in DP‐39. To analyse the radical scavenging activities among the four checks, we conducted DPPH, FRAP and UWLA assays. Significant differences in antioxidant activities were obtainable in the four checks, which contained significant differences in levels of anthocyanins and isoflavones. Based on these results, gamma irradiation may change the isoflavone and anthocyanin contents of soybean. Our four checks selected in this study may be useful for breeding soybean varieties to alter their nutritional values.  相似文献   
88.
β-glucan is the soluble dietary fiber component and occurs at its highest in barley. This study aims to evaluate the inheritance of β-glucan content in barley grains and to map quantitative trait loci (QTL) associated with this trait. F5-derived 107 lines from the cross of the six-rowed waxy hulless barley, ‘Yonezawa Mochi’ and the six rowed non-waxy hulless barley,’ Neulssalbori’ were measured for their agronomic traits and β-glucan level at four different environments. These recombinant lines showed significant genotypic variation (P < 0.01) and normal distribution for β-glucan content with a range of 43.6–62.1 g kg−1 across environments. A significant genotype-by-environment interaction was also found. The broad-sense heritability estimates for β-glucan content ranged from 0.42 to 0.82 across environments. Using one-factor analysis and composite interval mapping, a main effect of QTL associated with β-glucan content was identified in the genomic region near waxy gene (wx) and HVM4 on chromosome 7H. The major QTL at this region explained on average 44.4% of the variation for the mean of β-glucan content across environments with LOD values that ranged from 5.7 in Suwon in 2001 to 13.9 in Suwon in 2003. Two minor QTLs were identified but their significance of association with β-glucan content was inconsistent across environments.  相似文献   
89.
A review has been written to assess the sources, fate and behavior of polycyclic aromatic hydrocarbons (PAH) in the atmosphere. PAH are formed mainly by anthropogenic processes, especially the combustion of organic fuels. PAH concentration in air will reflect the location of source emitters, with high concentrations corresponding with urban and industrial areas. PAH are however ubiquitous contaminants of the environment having been detected in remote areas of the world. This is thought to be due to long term transport in the atmosphere. PAH can also be subjected to chemical and/ or photochemical change whilst resident in the atmosphere prior to their removal by either wet or dry deposition.  相似文献   
90.
Legumes form symbiotic associations with both mycorrhizal fungi and nitrogen-fixing soil bacteria called rhizobia. Several of the plant genes required for transduction of rhizobial signals, the Nod factors, are also necessary for mycorrhizal symbiosis. Here, we describe the cloning and characterization of one such gene from the legume Medicago truncatula. The DMI1 (does not make infections) gene encodes a novel protein with low global similarity to a ligand-gated cation channel domain of archaea. The protein is highly conserved in angiosperms and ancestral to land plants. We suggest that DMI1 represents an ancient plant-specific innovation, potentially enabling mycorrhizal associations.  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