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81.
随着我国农业的发展,农田分布范围不断扩大,产生的农田信息繁多而复杂。基于WebGIS的农业决策支持系统已在一些地区的现代化农业生产中得到了示范应用,但由于其客户端采用Ajax或Flex技术实现,存在多媒体功能不足及平台可移植性较差等问题。为此,借助WebGIS开放性平台,采用微软Silverlight技术,设计开发了基于Silverlight的农田信息管理决策支持系统,实现了地图基本操作、地块信息管理决策及环境信息管理决策等功能。该系统可以辅助用户管理农田信息,并为施肥及生产计划提供决策支持。在黑龙江红星农场的试用结果表明:系统自投入使用后运行正常,并能提供信息管理及适宜辅助决策支持。  相似文献   
82.
文章以为汽车行业的健康发展提供指导和借鉴为目的,主要对汽车的纵梁平面图纸集成化制造中诸如参数提取、纵梁3D模型构建技术和Agent的网络集成技术的应用方法等进行了相关论述,以此为实现汽车行业的可持续发展而做出贡献。  相似文献   
83.
There is an increasing interest in using whole‐genome sequence data in genomic selection breeding programmes. Prediction of breeding values is expected to be more accurate when whole‐genome sequence is used, because the causal mutations are assumed to be in the data. We performed genomic prediction for the number of eggs in white layers using imputed whole‐genome resequence data including ~4.6 million SNPs. The prediction accuracies based on sequence data were compared with the accuracies from the 60 K SNP panel. Predictions were based on genomic best linear unbiased prediction (GBLUP) as well as a Bayesian variable selection model (BayesC). Moreover, the prediction accuracy from using different types of variants (synonymous, non‐synonymous and non‐coding SNPs) was evaluated. Genomic prediction using the 60 K SNP panel resulted in a prediction accuracy of 0.74 when GBLUP was applied. With sequence data, there was a small increase (~1%) in prediction accuracy over the 60 K genotypes. With both 60 K SNP panel and sequence data, GBLUP slightly outperformed BayesC in predicting the breeding values. Selection of SNPs more likely to affect the phenotype (i.e. non‐synonymous SNPs) did not improve the accuracy of genomic prediction. The fact that sequence data were based on imputation from a small number of sequenced animals may have limited the potential to improve the prediction accuracy. A small reference population (n = 1004) and possible exclusion of many causal SNPs during quality control can be other possible reasons for limited benefit of sequence data. We expect, however, that the limited improvement is because the 60 K SNP panel was already sufficiently dense to accurately determine the relationships between animals in our data.  相似文献   
84.
以陕西长武旱塬为例,分别对研究区农地和5个不同林龄(9、12、16、19 a和23 a)苹果园的土壤剖面氢氧稳定同位素进行测定,利用Craig-Gordon模型定量估算其土壤平均蒸发量,并基于“空间换时间”方法分析果园种植及生长对土壤蒸发的影响。结果表明:农地及9、12、16、19、23 a林龄苹果园的土壤蒸发量均随苹果树的种植及生长呈现先减少再增大的趋势,年均蒸发量分别为129、104、89、119、128、136 mm;苹果园的土壤蒸发量变化与叶面积指数呈显著负相关(R=-0.713);苹果园种植的前中期(9~12 a)土壤蒸发量随叶面积指数增加逐渐减小,而在中后期(12~23 a)深层土壤水被大量消耗造成的干旱胁迫使得果树叶面积减少,从而导致林下土壤蒸发量又逐渐增大。  相似文献   
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87.
This paper proposes a model framework, which describes the function requirements and the common characterstics of vehicle transport management. With the frame, a computer vehicle transportation managerment information system(QCMIS)is in troduced here and it has already been put into practice. The key technical points is also explained in the paper.  相似文献   
88.
Considering information asymmetry between inside and outside of the firms,this paper discusses the financing strategy of M&A,and builds a model.According to the model,we can see that the firm with relatively expected low-productivity will choose equity financing for M&A,and the firm with relatively expected high-productivity will choose debt financing for M&A,and the firm with expected medium-productivity will not choose financing from outside.In the case of undeveloped capital market and financing tools in China,the conclusion of the model has some extent significance for helping firms to choose financing strategy for M&A rationally.  相似文献   
89.
Maintenance cost is one of the most difficult parts to calculate in variant-cost, for it s decided by the reliability of components. As an important factor of reliability, life is largely affected by maintenance. The proportional life prolonged model based on maintenance is presented firsdy. Based on this model, the function of Mainenance--Life--Cost is deduced. Which provides a new method for power plant to calculate maintenance cost more accurately.  相似文献   
90.
Today the information globalization is the trend of society development. The information technology has great influence not only on the mode of life and production, but also on the urban social and economic structure. In order to fit in with the change in this regard, the urban land-use distribution, residential mode, traffic pattern and so on should be changed correspondingly. Therefore, this change will lead to the development and evolution of whole urban spatial structure. In this paper, the development tendency of urban spatial structure in the information age is analyzed and some proposals on city planning and construction are put forward.  相似文献   
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