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61.
西气东输二线项目规模庞大,面对众多的业务接口和信息接口,极易在设计质量、设计进度、配合施工、变更处理等方面出现问题。例如:下游用户分输量和分输口变化,设备资料不完备,运行单位在施工阶段对设计提出修改意见,地方规划导致路由确定困难,与地方协调能力欠缺,初设和地质勘察深度不够,专项评估和文件报批周期长等。同时,施工图设计漏项、地质勘探不详、设计不细,设计勘察分包缺乏有效的资质审查和管理,不及时执行集团公司的标准要求,设计联合体各单位之间缺乏有效的沟通与协调,设计单位工作效率低,图纸设计变更频繁等问题,均对施工进度和施工成本产生较大影响。基于对项目实施过程中设计管理问题的梳理和剖析,提出设计改进的可行性建议。 相似文献
62.
针对中亚天然气管道项目工艺设计中钢管低温脆性、管道水压试验、阀门压力等级和材质选择、放空立管防雨水功能4个代表性问题进行了分析。在低温时,通过采取保温措施、控制材料低温韧性或制定相应站场操作原则,避免管道出现低温脆性断裂;关于管道水压设计,设计方在提交给钢管厂家的技术条款中应增加现场强度试压的压力值和试压所维持时间的信息项,钢管厂家投标时应将工厂内的水试验压力指标列入标书中;在选择阀门压力等级和材质方面,采用标准磅级、特殊磅级、提高磅级或者中间额定4种方案,以解决阀门不满足设计压力和设计温度要求的问题;针对目前中亚项目放空立管防雨水存在的缺陷,提出了新的放空立管设计方案。 相似文献
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在线信息素质教育(OILI)是信息素质教育的良好平台和发展趋势。通过调查研究,分析我国高校OILI的特点,发现当前OILI普遍存在的问题,如缺乏统一标准、教学内容和媒体单一、缺乏信息素质评估功能等,并提出了高校图书馆OILI的发展对策。 相似文献
66.
在西南油气田工程水土保持措施的统计及工程量的分析基础上,对西南地区油气田建设当前的水土保持措施情况进行宏观评价。同时详细介绍了油气田工程中水土保持措施实施的现状、水土保持措施实施的类型以及水土保持措施实施效果。将油气田水土保持措施进行分区统计分析,利用多元相关性分析手段,总结出水土保持措施的实施与水土保持效果影响之间的相关关系。结果表明:当前油气田建设过程中,工程措施使用频率最高;然而植物措施与临时措施对水土保持效果却最为显著,应加强植物措施及临时措施规划,旨在为指导西南油气田建设措施政策的制定,给出合理性参考意见。 相似文献
67.
金堂县淮口镇于2009年开始先后引进7个油橄榄品种进行栽培试验,试验通过设置标准样地进行物候期观测,表型性状比较,含油率及油脂成分分析;结果表明:各油橄榄品种花期主要集中在4月下旬,果实成熟集中为10月上旬,阿贝基纳成熟期稍稍晚—点为10月中旬;各品种表型性状差异大部分两两显著;鲜重含油率高低顺序依次为鄂植8号>佛奥>阿贝基纳>皮削利>皮瓜儿>小苹果>莱星;单果重依次为皮削利>莱星>鄂植8号>小苹果>佛奥>皮瓜儿>阿贝基纳;果肉占单果比重依次为小苹果、皮削利>莱星>鄂植8号>皮瓜儿>阿贝基纳>佛奥;在引种的7个品种中,阿贝基纳表现出较好的适应性,佛奥和鄂植号次之. 相似文献
68.
A grazing trial was conducted at the Kokstad Agricultural Station to compare the dry matter digestibility (DMD) and crude protein content (CP) of diets selected by four fistulated cattle which were continuously and rotationally grazing sourveld. Two stocking rates of 1,0 and 2,3 animals/ha (0,5 and 1,2 LSU/ha) were applied under each grazing method. The mean DMD and CP values of diets selected in the continuous and rotational grazing treatments, respectively, were: DMD=64,3%, 62,3%; CP=6,63%, 6,88%. The effect of stocking rate on the quality of the diet selected varied between the two grazing methods. DMD and CP of diets selected under rotational grazing decreased with time during the week‐long period of stay in each paddock. On average, DMD and CP values on the first and sixth day respectively, were: DMD=66,6%, 60,5%; CP=8,37%, 6,01%. These differences were more pronounced at the higher than at the lower stocking rate. It was concluded that, although some of the treatment differences were small, grazing method differences in the DMD of diets might at least partially account for observed differences in livemass gains under the two grazing systems. 相似文献
69.
M. Trytsman A.J. Kruger V.D. Wassermann M.A. Stoltz 《African Journal of Range and Forage Science》2013,30(3):81-86
Abstract The productivity of Trifolium repens L. cv. Ladino, under irrigation in the subtropical region of Gauteng, South Africa, is unknown. The performance of T. repens was determined over five years (1981/1982 to 1985/1986), at two defoliation frequencies, four levels of nitrogen (0, 400, 800 and 1 600 kg N ha?1 ‐ total applied over five years), and either the removal or recycling of harvested material. Frequent, compared to infrequent defoliation, resulted in higher dry matter (DM) yields from the second year onwards. Dry matter yields were positively affected by the recycling of material, compared to no recycling. A mean DM yield of 191 ha?1 in the first year and 12 t ha?1 in the final year, was obtained. The highest DM yields occurred during October for all years and lowest DM yields from January to March. The first and final year showed similar peaks (late October) and troughs (March till April). Crude protein (CP) content of the herbage was influenced more by frequency of defoliation than recycling of material, where the highest CP content in any year was obtained from frequent defoliation. Nitrogen fertiliser applied up to a total of 1 600 kg N ha?1 over five years had no effect on either DM yield or crude protein content. This study has shown that T. repens could be a productive pasture for at least five years in the subtropical region of Gauteng, South Africa. Productivity and quality of T. repens were enhanced by a defoliation interval of less than five weeks and when soil high fertility was maintained by recycled plant material. 相似文献
70.
Christian Swensson Gösta Gustafsson 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(2):49-56
The effects of manure handling system and feeding of dairy cows were studied using a simple method to analyse the level of ammonia release in cow stables. Two ratios based on the balances of ammonia and sensible heat, and ammonia and carbon dioxide, respectively, in animal houses were determined and considered to give characteristic levels of the release of ammonia in relation to the animal density independently of the ventilation rate. This required measurements of ammonia, carbon dioxide and temperature with hand-held instruments in the buildings and in outside air. In total, 34 dairy herds were investigated in the south of Sweden. The results clearly demonstrated higher release of ammonia from free stall barn with liquid manure than from conventional tie stall barn with solid manure. There was a clear effect of the content of crude protein, gram per kg dry matter, in the total feed ration on ammonia release in tie stall barn with liquid manure. 相似文献