发电机励磁系统参数测试及PSS参数整定

通过试验测出发电机励磁系统及PSS的数学模型及相关参数,并对参数进行优化,使励磁系统的各项性能指标均满足国标要求,保证了电网安全运行,具有重要的社会意义和经济效益。     

配偶收入如何影响自身生活幸福感？——基于中国综合社会调查（2006）的实证分析

本文从理论上梳理了配偶收入影响自身幸福感的两种影响渠道:经济支持渠道和收入比较渠道.通过这两种渠道,配偶收入对自身幸福感分别产生正效应和负效应,综合影响取决于这两种效应的相对大小.进而,基于中国综合社会调查(2006)的微观数据,我们采用有序Probit模型进行了经验分析.研究发现,第一,配偶收入和自己的收入均对自身“潜在幸福感”有显著的正向影响,但配偶收入的影响程度小于自己的收入.这表明,就对幸福感的影响而言,自己的收入和配偶的收入并不完全是同质的.第二,对年龄较大的群体和高收入群体,配偶收入的正向影响不显著,而对年龄较小的群体和低收入群体,配偶收入的正向影响则是显著的.这表明,人们在不同经济体制下接受的价值观念以及自身收入水平的高低是配偶收入影响自身幸福感的调节变量.     

企业物流管理的现代化创新与应用

文中主要针对企业的物流管理,联系目前社会上的现代化技术,提出一些有利于物流管理的方法以及解决问题的措施,进而帮助企业更好的应对其物流的管理。     

基于蚁群算法的配送路径规划研究

物流配送路径规划一直是物流领域研究的热点和难点问题,文章提出了一种基于蚁群算法的物流配送路径选择方法,从最优路线选择的角度,阐述了各种最优参数的选取,基于精英蚂蚁系统模拟的方法,找出算法约束参数最优解,并且应用到实例中进行验证,可为物流配送中心路径选择提供评估模型。     

降压药用药方案评估伴高血压的慢性肾脏病患者

目的评估伴高血压的慢性肾脏病（CKD）患者应用降血压药的临床治疗方案和血压达标率。方法本研究为回顾性横断面研究。对204例成年慢性肾脏病患者在肾病专科门诊至少随访6个月后,于观察期内以末次就诊时的血压达标率和用药方案与其在首诊时血压控制情况和用药方案加以比较。结果末次就诊时,超过70%的患者使用了血管紧张素转换酶抑制剂（ACEI）或血管紧张素受体Ⅱ受体拮抗剂（ARB）,其次是钙通道阻滞剂（CCB）（51.96%）和利尿药（19.12%）。单药治疗方案中最常用的降血压药是ACEI或ARB,近50%的患者接受2药或3药联合治疗。治疗结果显示,只有31.86%的CKD患者血压达标（〈130/80mmHg）,收缩压（SBP）比舒张压（DBP）更难控制。单药和多药治疗的CKD患者血压达标率分别是39.64%和22.58%,（P〈0.01）,结论大多数的CKD患者血压未达标,所应用降血压药的临床治疗方案基本符合高血压治疗指南。需要继续优化治疗方案,正确联合用药,提高CKD患者的血压控制率。临床药师在协助医师,共同控制CKD患者血压方面将大有可为。     

中国纸业上市公司经营绩效分化的实证研究——以沪市造纸业上市公司为例

以11家沪市纸业上市公司为研究样本,利用样本公司2004—2007年公开披露的财务数据,运用因子分析法和主成分分析法,对我国纸业上市公司的经营绩效进行了实证分析。研究发现:我国纸业上市公司的经营绩效存在分化现象;11家沪市纸业上市公司2005年的经营绩效总体上好于2004年,但2006年、2007年两年的经营绩效呈下滑趋势。最后,分析了影响纸业上市公司绩效分化的原因。     

The time cost of food at home: general and food stamp participant profiles

Little is known about the cost of time in food preparation at home. Yet, this economic variable is a common thread running through recent concerns about obesity and the Food Stamp (FS) program. This article provides initial estimates of the time cost in food preparation at home for the United States. Two standard methods of estimation are implemented and three demographic profiles are considered: (i) the general population, (ii) the typical FS participant and (iii) the typical FS participant following the United States Department of Agriculture Thrifty Food Plan. For the general population and averaging across methods, the time cost share of total food cost is about 30% if the individual works in the market and at home, but it is about 49% if the individual does not work in the market. For the typical FS participant, especially one following the Thrifty Food plan, the time cost share of total food cost can be as much as 26% higher than the general population. These substantial percentages provide strong incentives to purchase food away from home and help undermine overall diet quality and the efficacy of the FS program, which ignores the time cost in food at home production.     

2010~2011年广州市越秀区手足口病发例数与气象因素和空气污染指数的相关性分析

目的探讨越秀区手足口病发例数与气象因素和空气污染指数的关系,为手足口病预防控制提供科学依据。方法对越秀区2010~2011年手足口病疫情与气象因素和空气污染指数资料进行相关分析。结果 2010~2011年越秀区手足口病发例数与当月的降雨量、平均温度呈中度正相关关系(r=0.678、0.566,P<0.01),与湿度呈中度正相关关系(r=0.441,P<0.05),与污染物PM10呈负相关关系(r=-0.445,P<0.05),与日照时间的相关无统计学意义(r=0.191,P>0.05);与污染物NO2和SO2的相关无统计学意义(r=-0.289、-0.366,P>0.05)。结论越秀区手足口病月发病数与当月的降雨量、平均温度、湿度、污染物PM10有关。     

Some Taxation Theorems in the Hotelling Model

In this paper, we investigate the relationship between the demand ad valorem, cost ad valorem and unit taxes in terms of price, quantity and tax revenue. In particular, we prove that the Musgravian transformation holds in the Hotelling model. In addition, we show that the Suits‐Musgrave theorem must be revised as output in the Hotelling model remains invariant in the presence of different taxes. That is, for a given price instead of a given output, the tax revenue under demand ad valorem tax exceeds that under the corresponding unit tax as long as profit levels for both stores are positive, a very general assumption. The exception is when the two stores are located close to each other and transportation cost is zero. Only in this case, are tax revenues and price under both tax regimes the same. If both stores are symmetrically located, the superiority of the ad valorem tax holds true except when the two stores are located back to back. Finally the farther away the location of a firm from the end point is, the smaller the difference in tax revenues between demand ad valorem and unit tax will be: the effect of the Suits‐Musgrave theorem weakens in the presence of location clustering.     

Nesting Horizontal and Vertical Differentiation with Location Choices

This study solves a location‐then‐price game in which horizontal and vertical differentiation are combined using an asymmetric distribution of consumers’ taste. Boundary locations are robust when the taste disparity of the population is not large and out‐of‐market locations are not allowed. Firms may have incentives to move either inside or outside the market in other situations, so the equilibrium prices are never differentiated. The restrictions of vertical differentiation under this framework are further examined. A model with the entrance of a vertically differentiated product is also discussed.