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101.
In the beach well intake system, heat is transferred from soil to fluid when seawater is filtered through the aquifer, providing higher temperature source water to the seawater source heat pump (SWHP) system in winter. A 3-D coupled seepage and heat transfer model for studying beach well intake system is established by adopting the computer code FLUENT. Numerical results of this model are compared with the experimental results under the same conditions. Based on the experiment-verified coupled model, numerical simulation of the supply water temperature is studied over a heating season. Results show that the minimum temperature of supply water is 275.2 K when this intake system continuously provides seawater with flow rate of 35 m3/h to SWHP. Results also indicate that the supply water temperature is higher than seawater, and that the minimum temperature of supply water lags behind seawater, ensuring effective and reliable operation of SWHP. 相似文献
102.
Objective: In addition to pH regulation, Na+/H+ exchange (NHE) has been shown to facilitate cell growth and proliferation. However, the effects of long-term inhibition of
Na+/H+ exchange on cardiac structural and functional remodeling post myocardial infarction (MI) are still controversial. The present
study was therefore carried out to further investigate the effects of long-term treatment with cariporide, a specific inhibitor
of NHE-1, on cardiac remodeling after MI in rats; Methods: Male Wistar rats that underwent coronary ligation were randomly
selected for cariporide treatment starting 6 h after induction of MI or no treatment. Treatment was continued up to 6 weeks
post MI, after which, the arterial, venous and left ventricular catheters were chronically implanted. Twenty-four h later,
after hemodynamic signals were recorded in conscious rats, they were sacrificed and hearts were taken out for morphological
examinations; Results: Cariporide treatment decreased the heart weight and heart weight to body weight ratio (bothP<0.05), decreased left ventricular end-diastolic pressure (P<0.001), improved myocardial contractility (dP/dt
max) (P<0.05) and tended to increase the survival of treated rats compared to that of untreated infarct rats; Conclusion: The results
of the present study indicate that the long-term inhibition of NHE with cariporide can attenuate cardiac structural remodeling
and improve left ventricular dysfunction in infarcted rats, and suggest that Na+/H+ exchange inhibition could be an effective therapeutic strategy for myocardial infarction-induced heart failure. 相似文献
103.
泥桨泵复垦土壤生产力的评价及其土壤重构 总被引:12,自引:0,他引:12
通过对泥浆泵复垦土壤理化特性的测试分析、土壤生产力的定量评价,揭示了泥浆泵复垦土壤生产力低下的主要原因,并有针对性地提出了泥浆泵复垦土壤重构的主要措施。 相似文献
104.
105.
The orientation strategy of side pipe and the heat transfer performance of six ground heat exchangers(GHEs) were optimized by numerical simulation,with soil being treated as a porous medium.An experiment on the heat transfer of four GHEs was carried out in 2010.Results indicate that the velocity field is disturbed by GHEs.The optimal orientation strategy of side pipe is that the upward pipe is located upstream and the downward pipe downstream.The space between GHEs should be appropriately adjusted,depending on the direction and flow velocity.Groups of GHEs should be installed perpendicular to the mainstream in a single row,but if the acreage does not meet the requirements,GHEs should be installed in staggered multiple rows.Fewer GHEs parallel to the mainstream strengthen the heat transfer.Moreover,numerical results agree well with the test data,with the maximum relative error being less than 7.7%. 相似文献
106.
通过离子交换、凝胶过滤、亲和层析及反向高效液相色谱操作,分析鉴定了棒纹牛蛭体内主要抗凝血物质成分为凝血酶抑制蛋白,其组成是三个相对分子质量分别为。7528,7446和7016的小分子量蛋白质,综合分析后认为属水蛭素类物质. 相似文献
107.
氮肥缓释剂对水稻土壤脲酶活性、氮素转化及产量的影响 总被引:3,自引:0,他引:3
主要研究水田使用尿素和生物肥料时,配加脲醇抑制剂以缓解尿素的集中水解,减少氨挥发和硝态氮的淋失,达到减少氮素损失的目的.试验结果表明:脲醇抑制剂对脲醇活性抑制持续时间及其尿素水解速度,随其用量增加而延长,而且随着时间的推移脲醇活性逐渐提高.当施用生物肥料时,由于土壤微生物数量大幅度增加,土壤脲醇活性增强,其抑制率略低于不施生物肥料,其它规律基本相同. 相似文献
108.
109.
湿式绕组结构的再循环泵广泛应用于热电厂超临界直流机组中。再循环泵电动机工作环境恶劣,加之电机绝缘及工艺的不良,检修维护不精细以及运行操作不当等原因,频发电机失效事故。根据恢复电机绝缘的实际工作经验,电机故障的预防可从以下方面进行:提高值班人员操作水平,增强岗位责任心,加强系统运行中的检查,定期安排电动机的解体大修,严格验收检修的设备,提高电动机控制和保护机构的动作可靠性。 相似文献
110.
为提高大型油船货油泵透平驱动装置的安全性,保证船舶的正常航行,通过对大型油船货油泵透平驱动装置结构、工况、故障模式的分析研究,建立故障树模型,并通过Bayesian网络对模型进行分析。建立故障诊断系统,并通过案例对模型进行验证。结果表明,将Bayesian网络应用于货油泵透平驱动装置的故障诊断是合理的,模型是可靠的。 相似文献