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1.
试析我国竞争情报研究   总被引:5,自引:0,他引:5  
随着信息社会的发展,竞争情报研究倍受人们的关注。本文概括了我国竞争情报研究的现状并予以分析,同时对我国竞争情报研究的发展趋势进行了初步的探讨。  相似文献   
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合理调整我国人民的食物结构是提高全民族身体素质,推进社会文明进步,具有深远的战略意义的一项国策。调整国民食物结构是一个科学性,政策性很强,社会涉及面广,地区人群民食习惯差别大的极为复杂的动态系统工程。作者针对山西省情实际,从追朔我国饮食传统,膳食民习,食物资源及演变趋向探求,提出合理调整山西人民食物结构的策略与途径。  相似文献   
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做好读者服务,关键在管理服务队伍,处理好服务队伍的人际关系。因此,高校图书馆管理者要处理好与被管理者的关系。即:依赖与被依赖的关系,整体利益、分享利益与独享利益的关系,竞争对手与合作伙伴的关系,监督与被监督的关系。  相似文献   
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Abstract

The shelf-life of Spanish mackerel caught by line fishing in Northern Australian waters was evaluated. Spiked fish were stored in ice either headed and gutted or left uncut and subjected to sensory, nucleotide, pH, histamine and microbial analysts and the rigor pattern recorded. There was little difference between the two product forms. Rigor in uncut fish lasted for 14 ± 9.8 hours and in headed and gutted fish for 19.6 ± 16.3 hours. Spanish mackerel retained good sensory quality for up to 14 days. The bacterial load reached 105 cfu/g by 18 days. K values were low for most of the storage time, < 40%. Histamine levels did not develop more than 10 mg/kg during storage. The pH of Spanish mackerel did not change much even though bacterial levels become high.  相似文献   
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Genomic selection (GS) is now practiced successfully across many species. However, many questions remain, such as long-term effects, estimations of genomic parameters, robustness of genome-wide association study (GWAS) with small and large datasets, and stability of genomic predictions. This study summarizes presentations from the authors at the 2020 American Society of Animal Science (ASAS) symposium. The focus of many studies until now is on linkage disequilibrium between two loci. Ignoring higher-level equilibrium may lead to phantom dominance and epistasis. The Bulmer effect leads to a reduction of the additive variance; however, the selection for increased recombination rate can release anew genetic variance. With genomic information, estimates of genetic parameters may be biased by genomic preselection, but costs of estimation can increase drastically due to the dense form of the genomic information. To make the computation of estimates feasible, genotypes could be retained only for the most important animals, and methods of estimation should use algorithms that can recognize dense blocks in sparse matrices. GWASs using small genomic datasets frequently find many marker-trait associations, whereas studies using much bigger datasets find only a few. Most of the current tools use very simple models for GWAS, possibly causing artifacts. These models are adequate for large datasets where pseudo-phenotypes such as deregressed proofs indirectly account for important effects for traits of interest. Artifacts arising in GWAS with small datasets can be minimized by using data from all animals (whether genotyped or not), realistic models, and methods that account for population structure. Recent developments permit the computation of P-values from genomic best linear unbiased prediction (GBLUP), where models can be arbitrarily complex but restricted to genotyped animals only, and single-step GBLUP that also uses phenotypes from ungenotyped animals. Stability was an important part of nongenomic evaluations, where genetic predictions were stable in the absence of new data even with low prediction accuracies. Unfortunately, genomic evaluations for such animals change because all animals with genotypes are connected. A top-ranked animal can easily drop in the next evaluation, causing a crisis of confidence in genomic evaluations. While correlations between consecutive genomic evaluations are high, outliers can have differences as high as 1 SD. A solution to fluctuating genomic evaluations is to base selection decisions on groups of animals. Although many issues in GS have been solved, many new issues that require additional research continue to surface.  相似文献   
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This paper studies asymmetric exhaustive service polling system with Bernoulli feedback,gives the distributions of queue lengths and sojoun times,and obtains some other results,in stationary condition.  相似文献   
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分析了造成471QE发动机排气温度高的原因,提出对471QE发动机气缸盖改进设计的技术措施,并进行有针对性的试验研究。通过试验分析得出了燃烧室容积、点火提前角、燃烧室结构和气缸盖冷却水道内表面粗糙度对发动机排气温度的影响程度。  相似文献   
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