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171.
OGSA, as a universal grid computing frame, has resolved a good many problems in the CSCD, and provides a new solution for the network-based collaborative design. This paper studied the main problems in application of the grid technology to network-based collaborative design system by the OGSA based the WSRF, which is used as the basic platform of collaborative design grid. The meaning of the collaborative design grid is explained, and then the opening architecture of collaborative design grid design process on the condition of eoll is presented based on the function analysis in detail. Meanwhile, the collaborative aborative design grid is explained, and the key technologies of the collaborative design grid are analyzed deeply. The results provide a solution and groundwork for the more research on the collaborative design grid and its implementation.  相似文献   
172.
How to effectively locate resources is a very important factor affecting the performance of Grid environment.The authors propose a novel method which utilizes trust relations existed implicitly among network nodes to construct a secure and available resource trust network(SARTN),meanwhile provide the theory and method of SARTN.Combining passively discovery with actively discovery,applying Small World theory,optimized time complexity is achieved, and the performance of Grid resource discovery is promoted.Through analysis,the proposed solution is scalable,secure and efficient in Grid.  相似文献   
173.
魏媛  陈其 《水土保持通报》2023,43(1):388-398
[目的]研究土地利用转型的生态环境效应及其发展趋势,为促进土地利用转型、低碳循环发展及实现“双碳”目标提供依据。[方法]基于贵州省遵义市2005,2010,2015,2020年4期的土地利用数据,运用空间分析技术,对该区土地利用转型的生态环境效应及其发展趋势进行研究。[结果](1)2005—2020年土地转型主要表现为碳汇用地之间的相互转换,以及碳汇用地向碳源用地转型。(2)净碳排放量由2005年的5.99×105 t增加到2020年的9.87×106 t,增加了9.27×106 t,增幅达1 548.15%。但增量却呈逐渐减少的趋势,增幅也逐渐降低。(3)遵义市生态系统服务价值量由2005年的7.64×1010元增加到2020年的7.73×1010元,呈波动上升趋势,共增加了9.14×108元,增长率为1.2%。(4)通过灰色预测模型得出遵义市未来净碳排放量和生态系统服务价值量会持续增加,且都呈规律上升趋势。[结论]遵义市在生态环境方面仍面临着不小的压力...  相似文献   
174.
从胶水类型、施胶方法以及关键工艺参数等方面探讨了竹木复合刨花板的生产工艺,综合结果表明,竹木复合刨花板批量生产的工艺参数为:低摩尔比环保树脂胶、搅拌气流式喷胶法、竹刨花比例40%~60%、用胶量70 kg(干胶)·m-3、热压压力2.0 MPa、热压温度170℃、热压时间20 s·mm-1、刨花颗粒(芯层)0.5~1.0 mm、板厚8.8 mm。生产的竹木复合刨花板产品质量执行国家标准,质量可以达到国标A类刨花板一等品标准。  相似文献   
175.
以都阳湖信江流域为研究区,分析了网格大小选择对大尺度分布式水文模型水文过程模拟的影响.研究结果显示,在同样参数条件下,1,2和4 km这3种不同尺寸网格对模拟的总径流量影响较小,但网格大小显著地改变着模拟水流在地表径流和地下径流间的分配;不同网格的模型计算的实际蒸发量的差别不显著;大网格的模型计算的地下水补给量大.经过率定后的3种不同网格的模型均能较好地模拟流域的径流过程,但2 km网格模型模拟的总体效果要好于1 km网格模型和4 km网格模型.研究表明,对于分布式水文模型,网格的精细并不一定提高模型的模拟效果,一定精度空间数据的翰人条件下,分布式水文模型存在一个合适的网格大小使得模型的模拟效果最佳.在流域水文模型的具体应用中,应考虑流域本身的尺度以及模拟的目的和精度要求,选择合适的网格大小,同时应结合模型机理,解释模拟结果.  相似文献   
176.
Globus Toolkit是当前建立网格系统的核心实现工具之一,介绍了Globus工具集的起源、功能与构成,并对Globus Toolkit 4在Linux环境下的安装与配置进行了详细的阐述。  相似文献   
177.
农业数据已经成为一个重要的资源,如何存储、分发、组织、管理、高性能处理、分析和挖掘海量分布数据成为众多应用需要解决的首要问题。本文主要就网格技术与农业信息化的使用进行一定的探讨。  相似文献   
178.
Fecal specimens were composited and a hydrophobic-grid membrane-filter method was used to measure antimicrobial resistance to ampicillin 16 μg/ml, carbadox 30 μg/ml, gentamicin 4 μ/ml, nitrofurantoin 32 μg/ml, spectinomycin 16 μg/ml, sulfisoxazole 32 μg/ml and tetracycline 8 μg/ml among 8119 Escherichia coli isolates from 68 fecal samples collected on 34 farrow-to-finish swine farms marketing over 500 hogs/yr. The overall prevalences of resistance to antimicrobials among these isolates were: ampicillin 29%, carbadox 3.5%, gentamicin 0.6%, nitrofurantoin 27%, spectinomycin 28%, sulfasoxizole 38% and tetracycline 71%. Thirty to seventy-six per cent of the variations in prevalences were explained by between-farm differences.  相似文献   
179.
桧三毛瘿螨(Trisetacus juniperinus Nal.)是引起柏类苗木嫩芽枯萎的主要原因。该瘿螨主要以成螨于12月上旬在被害芽内越冬,翌年3月下旬开始活动。受气温的影响,1年中有2次增殖高峰,旬平均气温超过25℃时,瘿螨数量急骤下降。刺状针叶类型的寄主受害重,鳞状针叶类型的寄主受害轻;成年树受害比幼苗重,但后者引起的损失比前者要大。防治桧三毛瘿螨的时间以在瘿螨增殖高峰之前,5月和8月为好,用40%氧化乐果1000倍液喷洒,效果可达97%以上,不产生药害。  相似文献   
180.
This study was conducted to investigate the effects of rumen-protected tryptophan (125 g tryptophan per day) in heifers and dairy cows. Blood samples from dairy cows and heifers were collected for 24h in 3-h intervals on the day before tryptophan supplementation, on day 2, 5 and 7 of tryptophan supplementation, and in heifers additionally on d 14 after tryptophan supplementation was ceased. Plasma tryptophan, melatonin, serotonin, and prolactin concentrations were determined. Tryptophan plasma concentrations on d 5 were augmented at day (11:00 h) and nighttime (02:00 h), (P<0.05) in response to tryptophan supplementation in heifers by 119% and in dairy cows by 47%, respectively, as compared with d 0. Melatonin increased (P<0.05) in response to tryptophan supplementation in heifers, but not in cows. The effect of tryptophan supplementation on plasma tryptophan and melatonin was reversible as demonstrated in heifers on d 14 after cessation of tryptophan supplementation. Serotonin and prolactin in plasma did not respond to tryptophan supplementation. However, milk yield during morning milking increased significantly in tryptophan supplemented cows on d 1, 3 and 4 as compared to the day before tryptophan supplementation. Additional blood samples were taken during afternoon milking in cows at 1-min intervals for the analyses of oxytocin and prolactin on the day before the start and on d 7 of tryptophan supplementation. Milk flow curves were recorded during milking. No effect of tryptophan supplementation on the milking related release of oxytocin and prolactin and on any characteristic of milk flow was observed. In conclusion, tryptophan supplementation caused increased plasma tryptophan in cows and heifers and plasma melatonin in heifers. However, plasma serotonin, prolactin and oxytocin release in cows remained unchanged by tryptophan supplementation. Milk yield at morning milking increased slightly and transiently in response to tryptophan supplementation.  相似文献   
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