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231.
农药微乳剂热力学稳定性微观机制研究 总被引:7,自引:0,他引:7
利用冷冻断裂电镜研究方法研究了表观稳定的农药微乳剂的微观结构 ,并通过光散射技术测定了O/W型微乳剂分散质点的流体力学半径 ,同时还测定了相关样品的主要表观指标。试验结果表明 ,随着微乳体系中表面活性剂 /水 (w/w)比值的减小 ,微乳剂分散质点流体力学半径变大 ,直至成为双连续结构 ,并依此提出了一种农药微乳剂热力学稳定的可能机制。这一发现使得从微观机制上解释农药微乳剂的热力学稳定性 ,指导热力学稳定的农药微乳剂的研究开发 ,并从根本上解决农药水基化制剂热贮稳定性这一关键技术问题成为可能。 相似文献
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A 10-day-old Standardbred filly sustained a complex Salter–Harris type III fracture of the right, lateral, distal femoral condyle. The lateral condyle was fractured in transverse, sagittal and frontal planes. The filly was treated by restricting it and its dam to a small, level paddock until lameness was no longer apparent. The filly, when weaned at 7 months of age, was turned out to pasture with three other weanlings. The filly entered race training as a 2-year-old, qualified to race as a trotter, was placed second in its first start and won its third race. Conservative treatment should be considered as an option for a young horse with a minimally displaced, Salter–Harris type III fracture of the distal lateral femoral condyle. 相似文献
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Reasons for performing study: To enhance understanding of the nature and pathogenesis of scapular fractures in racehorses. Hypothesis: Scapular fractures in racehorses have a consistent configuration related to sites of pre‐existing stress modelling and remodelling. Methods: Fractured and intact scapulae collected post mortem were examined visually and with computed tomography (CT). Scapular fracture configuration, bone modelling changes and standardised CT morphometry and density measurements were recorded. Statistical comparisons were made between fractured, nonfractured contralateral and control scapulae. Results: Thirty‐nine scapulae from 10 Thoroughbred (TB) and 10 Quarter Horse (QH) racehorses were obtained. All 14 fractured scapulae (from 12 horses) had a consistent comminuted fracture configuration. A complete fracture coursed transversely through the neck of the scapula at the level of the distal aspect of the spine (8.9 ± 0.9 cm proximal to the lateral articular margin of the glenoid cavity). The distal fragment of 13 fractured scapulae was split into 2 major fragments by a fracture in the frontal plane that entered the glenoid cavity (2.8 ± 0.4 cm caudal to the cranial articular margin). Focal areas of periosteal proliferation and/or radiolucency were present in the distal aspect of the scapular spine of all fractured and intact contralateral scapulae, but less commonly (P<0.01) in intact scapula from horses without a scapular fracture. Fractured scapulae had 7–10% lower mean density and 46–104% greater density heterogeneity in the spine adjacent to the transverse fracture compared to control scapulae (P<0.03). Conclusions and clinical relevance: Thoroughbred and QH racehorses have a characteristic scapular fracture configuration that is associated with pre‐existing pathology of the distal aspect of the spine. This location is consistent with scapular stress fractures diagnosed in lame TB racehorses. Catastrophic fracture is the acute manifestation of a more chronic process. Consequently, there are opportunities for early detection and prevention of fatalities. 相似文献
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通过管道许用应力计算和管道当量应力、组合应力和稳定性的验算,对发生在沧临输油管道裂口漏油的实例进行了理论分析,结果表明,输油管道的组合应力(σz)为243.5 MPa,大于管道的许用应力([σ])210.6 MPa,且水平直径方向的变形量已超过3%,管道发生断裂是必然的.并指出了同类管道在运行管理中应注意的问题. 相似文献
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炭纤维增强壳聚糖内固定棒的生物相容性研究 总被引:2,自引:0,他引:2
目的:对自制炭纤维增强壳聚糖内固定棒进行生物相容性评价,为其临床应用提供实验依据.方法:采用实验动物对该内固定棒进行刺激试验与致敏试验、急性毒性试验、溶血试验,并按医疗器械生物学评价国家标准对试验结果进行生物相容性评价.结果:体内外生物相容性试验显示该材料的兔皮肤、皮内刺激未见红斑、丘疹、结节现象发生;急性金身毒性试验为阴性反应;致敏试验动物未出现过敏反应;溶血率1.64%,符合医用材料溶血率不大于5%的要求.结论:内固定棒具有良好的生物相容性,能初步满足生物内固定装置的生物相容性要求. 相似文献
239.
To know the dynamic characteristics of shale gas reservoirs’ production and to improve shale gas wells production, it is very important to research on shale gas seepage mechanism and production evaluation. The main difference between shale gas reservoir and conventional gas reservoir is that shale gas reservoir has the adsorption and desorption characteristics. Combined with shale gas seepage characteristics, using point source function, the mass conservation law and Langmuir isotherm equation to describe the shale gas adsorption and desorption phenomena, it establishes dual media shale fracturing wells’ seepage model. By the numerical inversion and computer programming, it draws production decline curve charts and analysises the Langmuir volume, Langmuir pressure, elastic storativity ratio, cross flow coefficient, borders, fracture length and other factors on the impact of shale gas wells production. 相似文献
240.