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21.
The purpose of this study was to evaluate the effect of cooling ovarian tissue on pig pre-antral follicles. Ovaries were maintained in saline solution (0.9%) at 4 or 20 degrees C for 6, 12 or 18 h. After storage, pre-antral follicles were morphologically evaluated. While primordial follicles were not affected by the storage, the percentage of morphologically normal growing follicles was significantly reduced in ovarian tissue stored at 20 degrees C for 12 or 18 h. To test the viability of stored follicles, growing follicles isolated from ovaries stored at 4 degrees C for 18 h and at 20 degrees C for 6 h were cultured for 3 days. Follicles stored in either condition presented the same growth pattern in vitro as fresh follicles. We conclude that storage of pig ovaries at 4 degrees C for up to 18 h or at 20 degrees C for up to 6 h does not affect the morphology of growing follicles or their ability to grow in vitro.  相似文献   
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There is a growing need for both science and practice domains to collaboratively and systematically seek knowledge-based strategies for sustainable development.In recent years,transdisciplinary research has emerged as a new approach that enables joint problem solving among scientists and stakeholders in various fields. In this paper,we aim to introduce transdisciplinary research for supporting the integration of the concept of ecosystem services into land and water management in the Tarim River Basin,Xinjiang,Northwest China.While a large number of ecosystem service studies have helped to raise the awareness for the value of nature in China,a number of challenges remain,including an improved understanding of the relationships between ecosystem structure, functions and services,and the interaction of the various ecosystem services.A meaningful valuation of ecosystem services also requires the consideration of their strong spatial heterogeneity.In addition,ways to introduce the concept of ecosystem services into decision-making in China need to be explored.Thus,successful integration of the concept of ecosystem services into actual land and water management requires a broad knowledge base that only a number of scientific disciplines and stakeholders can provide jointly,via a transdisciplinary research process.We regard transdisciplinary research as a recursive process to support adaptive management that includes joint knowledge generation and integration among scientists and stakeholders.System,target,and transformation knowledge are generated and integrated during the process of(1)problem(re)definition,(2)problem analysis and strategy development,and(3)evaluation of the impact of the derived strategy.Methods to support transdisciplinary research comprise participatory modelling(actor-based modelling and Bayesian Networks modelling)and participatory scenario development.Actor-based modelling is a semi-quantitative method that is based on the analysis of problem perspectives of individual stakeholders as depicted in perception graphs.With Bayesian Networks,complex problem fields are modelled probabilistically in a simplified manner,using both quantitative data and qualitative expert judgments.These participatory methods serve to integrate diverse scientific and stakeholder knowledge and to support the generation of actually implementable management strategies for sustainable development.For the purpose of integrating ecosystem services in land and water management in the Tarim River Basin through transdisciplinary research,collaboration among scientists and institutional stakeholders from different sectors including water,agriculture,forestry,and nature conservation is required.The challenge is to adapt methods of transdisciplinary research to socio-cultural conditions in China,particularly regarding ways of communication and decision-making.  相似文献   
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Elevated ocean temperatures have been predicted to lead to a poleward shift in the latitudinal distribution ranges of fish species. Different responses of fish species to increased temperatures might lead to changes in assemblage structure and local species richness. In this study, the assemblage structure and diversity of groundfish in Icelandic waters were examined using data from a standardized groundfish survey conducted annually in 1996–2007. We used hierarchical cluster analysis to define assemblages in two time periods and canonical correspondence analysis to explore the relationships between the assemblages and temperature, depth, latitude, longitude and year. We further used two estimates of diversity, species richness and the Shannon index. Four major species assemblages were identified. Assemblages in the hydrographically stable deep waters north of the country were consistent during the study, while assemblage structure in the more variable shallow waters underwent some changes. For this period of generally increasing sea temperature, the canonical correspondence analysis also revealed a shift towards species representative of warmer temperatures. Diversity was shown to be highly variable both temporally and spatially, and also to vary with depth and temperature. Species richness increased with temperature and time southwest of the country, but decreased northeast of the country. The different trends detected between the northern and southern areas illustrate the importance of performing analyses at the most appropriate scale.  相似文献   
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The authenticity of weed distribution maps prepared by the geostatistical estimation method, kriging, was investigated. We concentrated on the total number of weed plants and the dominant weed genus Veronica spp. in a 2.1-ha field of winter wheat. Different sampling distances were evaluated. Our analyses showed that kriging weed densities based on seedling counts collected in, 0.25.m2 circles in a sampling grid of approximately 10 m × 10 m gave good agreement with actual observations. Reducing the sampling grid to 20 m × 30 m gave poor agreement. New sampling methods combined with positioning devices and injection sprayers are discussed with reference to site-specific weed management.  相似文献   
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紫外分光光度法测定氟苯尼考及其注射液的含量   总被引:1,自引:0,他引:1  
采用紫外分光光度法测定氟苯尼考原料药及其注射液的含量。实验结果表明,在0.05~0.5 mg/mL浓度范围内,氟苯尼考的吸光度与浓度呈现良好的线性关系(r=0.9997,n=6);与法定的高效液相色谱法检测结果无差异。  相似文献   
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Established populations of Asian longhorned ticks (ALT), Haemaphysalis longicornis, were first identified in the United States (US) in 2017 by sequencing the mitochondrial cytochrome c oxidase subunit I (cox1) ‘barcoding’ locus followed by morphological confirmation. Subsequent investigations detected ALT infestations in 12, mostly eastern, US states. To gain information on the origin and spread of US ALT, we (1) sequenced cox1 from ALT populations across 9 US states and (2) obtained cox1 sequences from potential source populations [China, Japan and Republic of Korea (ROK) as well as Australia, New Zealand and the Kingdom of Tonga (KOT)] both by sequencing and by downloading publicly available sequences in NCBI GenBank. Additionally, we conducted epidemiological investigations of properties near its initial detection locale in Hunterdon County, NJ, as well as a broader risk analysis for importation of ectoparasites into the area. In eastern Asian populations (China/Japan/ROK), we detected 35 cox1 haplotypes that neatly clustered into two clades with known bisexual versus parthenogenetic phenotypes. In Australia/New Zealand/KOT, we detected 10 cox1 haplotypes all falling within the parthenogenetic cluster. In the United States, we detected three differentially distributed cox1 haplotypes from the parthenogenetic cluster, supporting phenotypic evidence that US ALT are parthenogenetic. While none of the source populations examined had all three US cox1 haplotypes, a phylogeographic network analysis supports a northeast Asian source for the US populations. Within the United States, epidemiological investigations indicate ALT can be moved long distances by human transport of animals, such as horses and dogs, with smaller scale movements on wildlife. These results have relevant implications for efforts aimed at minimizing the spread of ALT in the United States and preventing additional exotic tick introductions.  相似文献   
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Rice-milk and rice-toasted mung bean diets, and a high-protein rice (IR58 milled rice) were evaluated as part of a study on the protein requirements of toddlers consuming rice-based diets following the multilevel N balance method. Milk or mung bean contributed 1/3 of dietary N. At a daily energy intake of 418 kJ/kg body weight, weight losses were observed for all diets. The safe level of protein intakes obtained allowing 10 mg N/kg body weight/day for miscellaneous integumental losses and 15 mg N/kg body weight/day for growth was 1.11 g/kg body weight/day for the rice-milk diet and 1.34 g for the rice-mung bean diet. Preliminary data on four children indicate a safe level of protein intake of 1.44 g/kg/day for the IR58 milled rice. The protein quality of the high-protein rice as determined by the very short term N balance index on three children was 79–80% relative to milk.  相似文献   
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