N-1安全准则下的增供电量实用计算方法研究

增供电量是输变电工程后评价中技术性能和经济性能评价的重要指标。为了准确、简捷计算增供电量,根据新建输变电工程对网络结构和运行方式的改变,提出划分其影响范围应遵循的原则。在影响范围内,基于N-1安全准则,采用有无对比法,摒除其他工程影响,分析工程投运前后对区域电网供电能力的影响。将供电能力与最大负荷进行比较,根据新增供电能力的利用情况来计算增供电量。通过实际算例,验证了该方法的正确性和有效性。     

β-Adrenergic receptors and nitric oxide generation in the cardiovascular system

Nitric oxide plays a crucial role in cardiovascular homeostasis, with important vasodilatory, anti-thrombotic and anti-atherogenic properties. β-Adrenergic receptors (βARs), present on a wide variety of cardiovascular cells, including vascular endothelial cells, platelets, cardiac myocytes and leukocytes, have long been established as key players in maintaining cardiovascular homeostatic control. During the last few years a wealth of evidence has emerged which directly links stimulation of these cardiovascular βARs to nitric oxide (NO) generation, suggesting a new and important mechanism of adrenergic control of cardiovascular function. This review explores the cardiovascular cell systems in which this coupling of βARs and NO occurs, the intracellular signalling and regulatory mechanisms involved and the abnormalities in βAR-NO oxide coupling found in cardiovascular disease states. Received 30 September 2005; received after revision 24 November 2005; accepted 24 January 2006     

层状钒酸钡纳米带正极在高性能锌离子电池中应用

Aqueous zinc-ion batteries (ZIBs) are deemed as the idea option for large-scale energy storage systems owing to many alluring merits including low manufacture cost, environmental friendliness, and high operations safety. However, to develop high-performance cathode is still significant for practical application of ZIBs. Herein, Ba_0.23V₂O₅·1.1H₂O (BaVO) nanobelts were fabricated as cathode materials of ZIBs by a typical hydrothermal synthesis method. Benefiting from the increased interlayer distance of 1.31 nm by Ba2+ and H₂O pre-intercalated, the obtained BaVO nanobelts showed an excellent initial discharge capacity of 378 mAh·g?1 at 0.1 A·g?1, a great rate performance (e.g., 172 mAh·g?1 at 5 A·g?1), and a superior capacity retention (93% after 2000 cycles at 5 A·g?1).     

应变上限递增的混凝土高压应变循环受力试验

为了建立考虑高应变低周疲劳性能的混凝土受压本构模型,利用全数字化电液伺服式试验机及其位移控制加卸载功能,在已经完成的混凝土棱柱体等应变幅多次重复受压试验(最大应变以不同幅度超过ε0,ε0为与峰值应力对应的应变)的基础上,进一步完成了压应变上限逐步加大的混凝土棱柱体多次重复加卸载试验,获得了其独特的低周疲劳特征及加卸载应力-应变规律.结果表明,有必要根据实测结果对以往假定的卸载-再加载本构模型作出重要调整.     

水力振动采油微生物技术在西区油田的应用

振动和微生物采油均是技术含量较高的能有效提高采收率的＂三次采油＂技术,将这两项先进技术各自发挥优势综合应用于西区油田庄1井确定其增产效果,为该项技术的推广提供依据。采用在油井注入微生物原液,然后由DSY地层多级水力震源对其进行推进,向油层纵深转移和扩散。结果注入微生物后,原油粘度下降,流动性能得到改善;振动作业后,地层渗滤条件得到较大改善。结论油井获得了增产,经济效益明显,该技术具有良好的发展前景。     

扩招背景下公共体育课实行俱乐部教学模式的意义

由于连续扩招,许多高校正面临着学生数量增加和运动场地、器材、师资不足等矛盾,制约着公共体育教学质量的提高.分析了在扩招背景下对公共体育课实行俱乐部教学模式的理论和实践意义.理论意义包括:俱乐部教学模式符合体育与健康新课程的基本理念,是现代学校体育教学的发展趋势,有利于把体育教学过程延伸到教育的全过程;实践意义包括:俱乐部教学模式有利于维持和提高学生的运动兴趣,有利于凸显学生的主体地位,有利于促使教师不断提高自身素质,有利于提高场地器材的利用率,减少教师的工作量和强度,有利于提高学生的运动水平,对学校体育教学起到了很好的补充作用.     

Optimization study on the rehydration process of lyophilized human platelets

Long-term preservation of human platelets will greatly reduce the risk of their shortage. Lyophilization has been proved feasible for this purpose. For the recovery of lyophilized platelets,rehydration is an important process. In this paper,the rehydration proc-esses for 1 mL and 2 mL samples were studied. The effects of prehydration duration(15,30,60,90,120 and 150 min) in 37°C water vapor and the concentration of rehydration solution(25%,50%,75%,100% platelet-poor plasma) on the recovery rate,MPV(mean platelet volume) and PDW(platelet distribution width) were investigated. The mass changes during the prehydration process were weighed. The optimized rehydration conditions are as follows:(1) for 1 mL sample,the prehydration duration was 15 min and for 2 mL sample the prehydration duration was 90 min;(2) the rehydration solution was 75% platelet-poor plasma. Under optimized conditions,the morphology of the rehydrated platelets kept normal and their ultrastructures kept intact,their aggregation capacity to thrombin(1 U/mL) was 82.8% of the fresh ones. These results will be helpful for designing the freeze-drying protocols for human platelets.     

Effect of AD6 (8-monochloro-3-beta-diethylamino-ethyl-4-methyl-7-ethoxycarbonylmethoxy coumarin) on cyclic nucleotide phosphodiesterases in human platelets

Summary The effect of AD6 (8-monochloro-3-beta-diethylamino-ethyl-4-methyl-7-ethoxycarbonylmethoxy coumarin), an inhibitor of platelet aggregation, on cyclic nucleotide metabolism was investigated. AD6 inhibited selectively human platelet cyclic GMP phosphodiesterase, which was separated from cyclic AMP phosphodiesterase by DEAE-cellulose chromatography. Addition of AD6 to washed platelets increased cyclic GMP levels significantly in two minutes. These results could be useful in elucidating the action of AD6 on intact platelets.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.     

基于灰色增量的陕西省人口组合预测模型

利用陕西省人口原始数据资料,建立了陕西省人口数量的灰色增量预测模型,并给出了模型的检验。在此基础上,利用单个灰色增量预测模型建立了陕西省人口数量的组合预测模型。预测结果表明未来4年陕西省人口数有逐年缓慢上升的趋势。