全文获取类型
收费全文 | 342篇 |
免费 | 17篇 |
国内免费 | 1篇 |
专业分类
林业 | 28篇 |
农学 | 29篇 |
基础科学 | 2篇 |
80篇 | |
综合类 | 13篇 |
农作物 | 16篇 |
水产渔业 | 65篇 |
畜牧兽医 | 82篇 |
园艺 | 15篇 |
植物保护 | 30篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 13篇 |
2020年 | 11篇 |
2019年 | 9篇 |
2018年 | 10篇 |
2017年 | 19篇 |
2016年 | 21篇 |
2015年 | 8篇 |
2014年 | 16篇 |
2013年 | 39篇 |
2012年 | 19篇 |
2011年 | 21篇 |
2010年 | 18篇 |
2009年 | 11篇 |
2008年 | 7篇 |
2007年 | 11篇 |
2006年 | 10篇 |
2005年 | 9篇 |
2004年 | 3篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 8篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 4篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 3篇 |
1959年 | 1篇 |
排序方式: 共有360条查询结果,搜索用时 15 毫秒
141.
Kalyan De Shashi Pal Shiv Prasad Ajay Kumar Dang 《Tropical animal health and production》2014,46(1):203-211
This study assessed the effect of micronutrient supplementation around peripartum period on immune function, reproductive performance, milk yield and milk quality of crossbred cows. Thirty pregnant crossbred cows in their late gestation were selected and randomly divided into five groups for study. Six cows in each group were supplemented with vitamin E (VE) (2000 IU/cow/day), vitamin A (VA) (100,000 IU/cow/day), copper (Cu) (20 ppm/cow/day), zinc (Zn) (80 ppm/cow/day) individually from 45 days pre-calving to 45 days post-calving and one group without any supplementation served as control. Immune function was studied by in vitro phagocytic activity (PA) of blood neutrophils, lymphocyte proliferation response (LPR) and plasma interleukin-8 (IL-8) concentration. Supplementation of VA significantly (P?<?0.05) increased the in vitro PA of blood neutrophils and decreased milk somatic cell counts (SCC). Zn supplementation significantly (P?<?0.05) increased the T lymphocyte proliferation response, whereas B lymphocyte LPR was significantly (P?<?0.05) increased with both VA and Zn supplementation as compared to the control cows. Plasma IL-8 concentration was significantly (P?<?0.05) higher in all supplemented cows. Supplementation of VE, VA and Zn significantly (P?<?0.05) reduces days open, whereas VA significantly (P?<?0.05) reduced the service per conception. In this study, it is concluded that VE, VA and Zn supplementation around peripartum period can boost the immunity and improve the reproductive performance of crossbred cows in a semi-arid tropical environment. 相似文献
142.
The methanol extracts of Cuscuta reflexa stem and Corchorus olitorius seed showed a broad spectrum of antibacterial activity. 相似文献
143.
R. Rakshit A. K. Patra D. Pal M. ‐Kumar R. Singh 《Journal of Agronomy and Crop Science》2012,198(6):452-465
Using phytotron growth chambers, a short‐term pot experiment under non‐limiting water condition was conducted to investigate the individual and interactive effects of elevated carbon dioxide (650 ± 10 μmol mol?1 vs. ambient), temperature (3 °C above ambient vs. ambient) and different levels of urea–N (control, 100 % N and 200 % N of recommended dose) on growth and yields of wheat crop and changes in potential nitrogen mineralization (PNM), nitrification and denitrification activities, microbial biomass carbon (MBC), nitrogen (MBN), dissolved organic carbon (DOC), and nitrifying and denitrifying organisms in a semiarid Inceptisol. The plant parameters (root, shoot and grain) responded positively (10–23 %) to elevated CO2 and negatively (?17 to ?38 %) to higher temperature. Interactive effect of elevated CO2 and temperature caused a negligible impact on root, shoot (≈?5 %) and grain yields of wheat. Soil –N content was not affected, but –N was reduced significantly. Nitrate reductase activity was decreased by 14–20 % at elevated CO2. There was positive effect of elevated temperature on PNM (+9–16 %), whereas negative effects were observed for potential nitrification activity (PNA), MBC, MBN and DOC. Elevation of atmospheric CO2 or temperature did not affect the population of ammonia (AOB) and nitrite oxidizers (NOB), but elevation of CO2 has decreased the population of denitrifiers by 4–14 %. 相似文献
144.
Inheritance of resistance to Yellow Mosaic Virus (YMV) was studied in crosses of mungbean, black-gram and their interspecific crosses with Vigna sub-lobata. Resistance to YMV was recessive in the three Vigna species. The segregation ratios in F2 and back crosses indicated that the resistance was digenic recessive in the crosses of mungbean and in interspecific crosses of mungbean with blackgram and Vigna subiobata but YMV resistance was monogenic recessive in blackgram crosses. 相似文献
145.
EST‐SSR analysis provides insights about genetic relatedness,population structure and gene flow in grass pea (Lathyrus sativus)
下载免费PDF全文
![点击此处可从《Plant Breeding》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Khela R. Soren Ashutosh Yadav Gaurav Pandey Priyanka Gangwar Ashok K. Parihar Abhishek Bohra Girish P. Dixit Subhojit Datta Narendra Pratap Singh 《Plant Breeding》2015,134(3):338-344
Grass pea (Lathyrus sativus) is an important food‐legume crop for resource‐poor farmers in the developing world. However, given its cultivation in the most underprivileged regions, the crop has not received appropriate scientific attention particularly from the genomic perspective, thereby giving it a status of genomic orphan. Nevertheless, some recent studies have attempted to develop modern molecular tools to strengthen the genetic and genomic research. In the present investigation, a comprehensive collection comprising 176 accessions was analysed using EST‐simple sequence repeats (SSRs). The SSR analysis revealed existence of a total of 51 alleles with an average polymorphic information content value of 0.35. A moderate level of gene diversity was noticed that ranged from 0.04 to 0.73 with an average of 0.43. Noticeably, two distinct subpopulations were recovered using cluster analysis. In addition, the presence of admixtures in population reflected the strong possibilities of gene flow between the accessions across the geographical boundary. In summary, we provide additional insights about the informativeness of available EST‐SSR markers along with an extended understanding of relatedness, genetic structure and gene flow in an under‐researched legume crop. 相似文献
146.
Fish Saccobranchus fossilis were exposed to various subacute levels (0.45, 0.56, 0.75, 1.12, and 2.24 mg l?1) of sodium lauryl sulphate (SLS) for periods of 30 and 60 days, and the haematological response in blood was investigated. A significant fall (P < 0.05) in coagulation time was observed after 30 days exposure to 2.24 mg l?1 and 60 days exposure to 1.12 and 2.24 mg l?1 of this syndet. Reduction of haemoglobin, at RBC and WBC was observed at all the syndet levels and at both the exposure periods. Significant (P < 0.05) increases in hematocrit values were noted at 2.24 mg l?1 of SLS at both exposures. 相似文献
147.
Effect of novaluron on microbial biomass,respiration, and fluorescein diacetate-hydrolyzing activity in tropical soils 总被引:1,自引:0,他引:1
The aim of this study was to assess the potential harmful effects of novaluron on soil microbiological parameters in clay
loam alluvial soil (Typic udifluvent) and coastal saline soil (Typic endoaquept) under controlled laboratory tests. The applications
of novaluron were made at or above the recommended rates, which includes field rate (FR), two times (2FR), and ten times (10FR)
the FR. The laboratory incubation study was carried out at 60% of maximum water holding capacity of soils and at 30°C. Novaluron
application rate even up to 10FR resulted in a short-lived and transitory toxic effect on soil microbial biomass C and fluorescein
diacetate-hydrolyzing activity. Microbial metabolic quotient changed but for a short period. It can be concluded that novaluron
had a transient and negligible harmful effect on the soil microbiological parameters studied at higher rates than those usually
used in the field. 相似文献
148.
149.
Manoj Kumar Vivek Kumar Ajit Varma Ram Prasad Amarish Kumar Sharma Abhradip Pal Anfal Arshi Joginder Singh 《Journal of Soils and Sediments》2016,16(8):2118-2127
Purpose
The synthetic soil based bioremediation approach as reasonable and sustainable practice at the farming level where desired bioremediation could be established at lower cost.Materials and methods
Metal-tolerant bacteria from different environmental field samples, (a) a municipal dump site, (b) an agricultural field and (c) sludge of electro-plating industries, were screened and characterized. Bioremediation of metal contaminants through isolated bacteria was compared under two different conditions, synthetic soil and basic minimal media containing copper, cobalt and nickel.Results and discussion
The pollutants arising from industrial effluents are imparting a huge negative impact on agricultural land. Microbes are predominant in heavy metal-contaminated sites, which signifies as a potential opportunity for the researchers towards bioremediation. Three bacterial species showed high metal tolerance; 16S ribosomal DNA (rDNA) analysis revealed that the organisms were Proteus vulgaris strain, Stenotrophomonas sp. and Bacillus thuringiensis. Percentage removal of metals was also analysed under different concentrations and pH.Conclusions
The current tested methods are helpful in streamlining the natural compliance of fragile elements and its uptake into the microbial system under in vitro and in situ conditions.150.
Metabolic profiling of root exudates of Arabidopsis thaliana 总被引:5,自引:0,他引:5
Walker TS Bais HP Halligan KM Stermitz FR Vivanco JM 《Journal of agricultural and food chemistry》2003,51(9):2548-2554
In addition to accumulating biologically active chemicals, plant roots continuously produce and secrete compounds into their immediate rhizosphere. However, the mechanisms that drive and regulate root secretion of secondary metabolites are not fully understood. To enlighten two neglected areas of root biology, root secretion and secondary metabolism, an in vitro system implementing root-specific elicitation over a 48-day time course was developed. After roots of Arabidopsis thaliana had been elicited with salicylic acid, jasmonic acid, chitosan, and two fungal cell wall elicitors, the secondary metabolites subsequently secreted were profiled. High-performance liquid chromatography was used to metabolically profile compounds in the root exudates, and 289 possible secondary metabolites were quantified. The chemical structures of 10 compounds were further characterized by (1)H and (13)C NMR: butanoic acid, trans-cinnamic acid, o-coumaric acid, p-coumaric acid, ferulic acid, p-hydroxybenzamide, methyl p-hydroxybenzoate, 3-indolepropanoic acid, syringic acid, and vanillic acid. Several of these compounds exhibited a wide range of antimicrobial activity against both soil-borne bacteria and fungi at the concentration detected in the root exudates. 相似文献