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采用中国石油天然气管道科学研究院研制的GY型流动性改进剂,对哈萨克斯坦的乌津原油进行了加剂改性的试验研究。加剂后改善了原油的低温流动性,在25℃时测定的凝点为10.5℃,凝点降低22.5℃,粘度降低了96.9%,为乌津原油外运方案的设计奠定了基础。 相似文献
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《Wood material science & engineering》2013,8(3-4):125-130
Abstract The transmission of footfall-excited impact sound is commonly reduced using floating wood floors. These constructions contain three layers: a load-bearing wood floor, a resilient material and a floating wood slab. For wood construction excited by transient load (e.g. footsteps), sound reduction estimations may contain uncertainties due to inadequate modelling of footsteps and floor components. This paper presents a multiple degree-of-freedom system model using Working Model 2D® (WM2D). The model includes orthotropic behavior of wood and equivalent spring stiffness determination of the resilient layer. Sound reduction is determined and it is shown that larger reductions are possible through the inclusion of floating wood slabs in the load-bearing floor. 相似文献
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结合实际工作经验,分析新农村施工项目中如何降低物资采购成本的方法,指出只有强化内部管理,提升综合管理水平,才能使项目施工利润达到最大化。 相似文献
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Cell numbers of known species of nitrate- and nitrite-reducing bacteria, Selenomonas ruminantium, Veillonella parvula and Wollinella succinogenes , in the rumen of goats (25–30 kg) were estimated by competitive polymerase chain reaction (PCR). The number of S. ruminantium was the largest of the three species examined, and tended to be greater in goats fed a high-concentrate diet (5.6 × 107 cells/mL rumen fluid) than in goats fed a high-roughage diet (1.3 × 107 cells/mL). The number of V. parvula tended to be greater when goats were fed a high-roughage diet (6.7 × 103 /mL) than when fed a high-concentrate diet (3.2 × 103 /mL). The number of W. succinogenes was below the detectable level (< 1.0 × 102 /mL) when a high-concentrate diet was fed, but was significantly increased by feeding a high-roughage diet (1.6 × 103 /mL). Addition of potassium nitrate (6 g/day) to the high-concentrate diet tended to increase V. parvula , and significantly increased W. succinogenes , indicating that these two bacteria can be increased by feeding a diet containing nitrate. 相似文献
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Atien Priyanti Rob Cramb Vyta W. Hanifah I. G. A. P. Mahendri 《Asia Pacific viewpoint》2015,56(3):335-350
Despite its small area and intensively cropped landscape, East Java accounts for 30% of Indonesia's cattle population. About two million households draw on family labour to raise cattle in backyard sheds and small enclosures, largely for cash income. In this paper, we examine the opportunity for such small‐scale producers to benefit from Indonesia's economic transformation, given the rising urban demand for beef. The paper reports on a study in two contrasting sites in East Java – irrigated lowlands and rainfed uplands – to explore the constraints facing small‐scale cattle producers in these environments, the means by which they have adapted to these constraints (especially by going beyond the farm household to access feed supplies) and possible means to enhance their production systems and incomes. The findings suggest that such cattle production systems can provide a viable source of livelihood, even for resource‐poor households; hence, appropriately adapted cattle improvement programmes are a sensible component of a pro‐poor development strategy. 相似文献