全文获取类型
收费全文 | 108篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
林业 | 7篇 |
农学 | 8篇 |
22篇 | |
综合类 | 6篇 |
农作物 | 8篇 |
水产渔业 | 7篇 |
畜牧兽医 | 34篇 |
园艺 | 4篇 |
植物保护 | 17篇 |
出版年
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 9篇 |
2012年 | 11篇 |
2011年 | 5篇 |
2010年 | 9篇 |
2009年 | 7篇 |
2008年 | 5篇 |
2007年 | 3篇 |
2006年 | 1篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 2篇 |
排序方式: 共有113条查询结果,搜索用时 15 毫秒
1.
Praveen C. Verma Debasis Chakrabarty Satya Narayan Jena Devesh K. Mishra Pradhyumna K. Singh Samir V. Sawant Rakesh Tuli 《Industrial Crops and Products》2009,29(2-3):581-589
Vanilla is a large genus of about 110 species in the orchid family (Orchidaceae), including the species Vanilla planifolia from which commercial vanilla flavoring is derived. Since most species of vanilla are considered rare and endangered there is an urgent need to conserve them through genetic analysis and propagation/conservation studies on this crop.The present study investigated the genetic diversity among nine leafy- and leaf-less Vanilla species employing 30 decamer RAPD primers and 10 ISSR primers. The species under study were diverse and displayed a range of variability (0–66% and 0–81% for RAPD and ISSR, respectively). A total of 154 RAPD polymorphic markers (83.24%, h = 0.378) and 93 ISSR polymorphic markers (86.11%, h = 0.363) were used to generate a genetic similarity matrix followed by the cluster analysis. Specific groupings were revealed by each cluster analysis with slight variation between two different markers. Among the nine species studied, V. planifolia, Vanilla aphylla and Vanilla tahitensis revealed very low level of variation within their collections, thus indicating a narrow genetic base. The large genetic distance of Vanilla andamanica from other species suggests its different origin. A close genetic affinity was observed between the pairs V. planifolia, V. tahitensis and Vanilla albida, V. aphylla. These are the first comparative results for RAPD and ISSR reporting inter-relationship among nine cultivated, wild and hybrid Vanilla species. 相似文献
2.
Genetic and phylogenetic analysis of glycoprotein of rabies virus isolated from several species in Brazil 总被引:10,自引:0,他引:10
Sato G Itou T Shoji Y Miura Y Mikami T Ito M Kurane I Samara SI Carvalho AA Nociti DP Ito FH Sakai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(7):747-753
Genetic and phylogenetic analyses of the region containing the glycoprotein (G) gene, which is related to pathogenicity and antigenicity, and the G-L intergenic region were carried out in 14 Brazilian rabies virus isolates. The isolates were classified as dog-related rabies virus (DRRV) or vampire bat-related rabies virus (VRRV), by nucleoprotein (N) analysis. The nucleotide and amino acid (AA) homologies of the area containing the G protein gene and G-L intergenic region were generally lower than those of the ectodomain. In both regions, nucleotide and deduced AA homologies were lower among VRRVs than among DRRVs. There were AA differences between DRRV and VRRV at 3 antigenic sites and epitopes (IIa, WB+ and III), suggesting that DRRV and VRRV can be distinguished by differences of antigenicity. In a comparison of phylogenetic trees between the ectodomain and the area containing the G protein gene and G-L intergenic region, the branching patterns of the chiropteran and carnivoran rabies virus groups differed, whereas there were clear similarities in patterns within the DRRV and VRRV groups. Additionally, the VRRV isolates were more closely related to chiropteran strains isolated from Latin America than to Brazilian DRRV. These results indicate that Brazilian rabies virus isolates can be classified as DRRV or VRRV by analysis of the G gene and the G-L intergenic region, as well as by N gene analysis. 相似文献
3.
Grimaud P Mpairwe D Chalimbaud J Messad S Faye B 《Tropical animal health and production》2007,39(3):217-227
A survey was carried out on milk production and reproductive performance of dairy cattle: 24 farms, with a total of 900 animals
and distributed in four agro-ecological zones, were visited every 15 days over 18 months. Cows were fed on natural pastures
as the only source of feed, and animal performance was dependent on the season and exhibited a dramatic drop in dry spells.
Numeric productivity indices integrating productive performance for settler’s, multipurpose, crop–livestock integrated and
modern farms were 0.56, 0.74, 0.69 and 0.63, respectively. Milk productivity was higher on modern farms (6.7 L/cow per day)
than in the other systems, and higher with Holstein-Friesian cows (7.7 L/cow per day) than with indigenous cattle (1.8 L/cow
per day) or crossbred animals (3.7 L/cow per day). This paper speculates on the opportunity to improve the genetic potential
of indigenous cattle, concomitantly with the efforts to adapt exotic cattle to a mountainous equatorial environment. 相似文献
4.
5.
Mohammad H. Ahmad Amani M. D. El Mesallamy Fatma Samir Faten Zahran 《Journal Of Applied Aquaculture》2013,25(4):289-298
Four isonitrogenous (30% crude protein) and isocaloric (4.40 kcal/g) experimental diets were formulated to contain 0.0% (control), 0.5%, 1.0%, or 1.5% cinnamon. The diet containing 1% cinnamon resulted in significantly greater (P < 0.05) specific growth rate (SGR), feed conversion ratio (FCR), feed efficiency ratio (FER), protein efficiency ratio (PER), apparent protein utilization (APU), and energy utilization (EU). In regard to body composition, there was no significant difference in dry matter, protein, lipids, and ash (P > 0.05) contents due to cinnamon supplementation. Blood plasma profile showed an improvement in hemoglobin (HB), red blood cell (RBCS), hematocrite (PCV), total protein, and total lipids, while there was a decrease in creatinin, urea, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and glucose in fish fed 1% cinnamon. Cinnamon was found to have an antibacterial activity antagonistic to Aeromonas hydrophila infection in fish. Performance and FCR improvement translated into a 10% decrease in feed costs associated with the 1% cinnamon diet. 相似文献
6.
7.
Eveline Teixeira Caixeta Aluízio Borém Samir de Azevedo Fagundes Silvia Niestche Everaldo Gonçalves de Barros Maurílio Alves Moreira 《Euphytica》2003,134(3):297-303
The existence of genetic variability for angular leaf spot (ALS) resistance in the common bean germplasm allows the development
of breeding lines resistant to this disease. The BAT 332 line is an important resistance source to common bean ALS. In this
work we determined the inheritance pattern and identified RAPD markers linked to a resistance gene present in BAT 332. Populations
F1, F2,BCs and BCr derived from crosses between BAT 332 and cultivar Rudá were used. Rudá is a commercial cultivar with carioca
type grains and susceptible to ALS. The resistance of BAT 332 to race 61.41 of the pathogen was confirmed. Segregation analysis
of the plants indicated that a single dominant gene confers resistance. For identification of RAPD markers linked to the resistance
gene, bulk segregant analysis (BSA) was used. Two RAPD markers,OPAA07950 and OPAO12950, linked in coupling phase at 5.10 and 5.83 cM of this gene, respectively, were identified. These molecular markers are important
for common bean breeders and geneticists as source of genetic information and for marker assisted selection in breeding programs.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
8.
Nickel activities were measured in 11 alkaline and slightly acidic soils using the chelate method. The measured activities ranged from 10?6.82 to 10?8.78 M and were inversely related to the pH of the soils. The measured Ni2+ activities in the 11 soils could be predicted using the following expression: (Ni2+) = 106.95 (H+)2. The solubility of Ni was plotted on a log (Ni2+) vs. pH solubility diagram for various Ni solid phase compounds. It is most likely that NiFe2O4 (trevorite) is the solid phase controlling Ni solubility in these soils. Identification of the presence of this mineral needs further investigation. 相似文献
9.
Almost universally, women with higher levels of education have fewer children. Better education is associated with lower mortality, better health, and different migration patterns. Hence, the global population outlook depends greatly on further progress in education, particularly of young women. By 2050, the highest and lowest education scenarios--assuming identical education-specific fertility rates--result in world population sizes of 8.9 and 10.0 billion, respectively. Better education also matters for human development, including health, economic growth, and democracy. Existing methods of multi-state demography can quantitatively integrate education into standard demographic analysis, thus adding the "quality" dimension. 相似文献
10.
Lahann J Mitragotri S Tran TN Kaido H Sundaram J Choi IS Hoffer S Somorjai GA Langer R 《Science (New York, N.Y.)》2003,299(5605):371-374
We report the design of surfaces that exhibit dynamic changes in interfacial properties, such as wettability, in response to an electrical potential. The change in wetting behavior was caused by surface-confined, single-layered molecules undergoing conformational transitions between a hydrophilic and a moderately hydrophobic state. Reversible conformational transitions were confirmed at a molecular level with the use of sum-frequency generation spectroscopy and at a macroscopic level with the use of contact angle measurements. This type of surface design enables amplification of molecular-level conformational transitions to macroscopic changes in surface properties without altering the chemical identity of the surface. Such reversibly switching surfaces may open previously unknown opportunities in interfacial engineering. 相似文献