考虑多种上网价格规制的光伏微网运营对比研究

光伏微网是促进光伏就地消纳利用,发挥分布式光伏发电系统效能的有效方式。在光伏微网发展进程中,微网成本-收益的非对称性和光伏发电的正外部性会导致光伏微网投资效益不明显,必须由政府进行干预以扶持其发展,上网价格规制为其中最有效的方式。当前,我国短时间内大幅提高可再生能源发电比例,在政策制定上缺乏系统规划,造成规制效率水平低,不能充分发挥规制工具对光伏微网投资运营的指导作用。因此,该文对不同电价场景下上网电价规制类型对微网各主体收益的影响进行分析。首先,建立微网商业模型,分析微网运营模式及各主体收益分配;其次,基于价格信号构建多场景,即用户电价分别为固定电价和分时电价,上网电价分别为固定电价模型、固定溢价模型和可变溢价模型,提出多场景下微网内储能的充放电策略及整体运行策略,并进行时序仿真,得出典型日内不同微网主体间能量交换关系及收益分配;最后,对多场景下电价模型对各主体收益的影响进行灵敏度分析;将模型应用于广东某微网,验证了所述方法的有效性和可行性,对有关部门进行不同电价场景下微网上网电价的规制决策有较好的借鉴意义。     

采用预期电压矢量调制的PMSM直接转矩控制

为了解决永磁同步电机传统直接转矩控制中存在转矩和磁链脉动大的问题,设计了基于空间电压矢量调制(SVM)策略的直接转矩控制,通过SVM产生定子的预期电压,并且采用PI控制器代替传统直接转矩控制中的滞环比较器.同时在定子磁链观测中采用基于转子位置和定子电流的定子磁链估计方法.实验结果表明,与传统直接转矩控制项相比,所提出的方法能够可靠而有效地估计定子磁链,改善了电磁转矩和定子磁链的脉动,同时减小了电流和转速波动,并具有很好的动态、静态性能.     

New algorithms for optimal reduction of technical risks

The article features exact algorithms for reduction of technical risk by (1) optimal allocation of resources in the case where the total potential loss from several sources of risk is a sum of the potential losses from the individual sources; (2) optimal allocation of resources to achieve a maximum reduction of system failure; and (3) making an optimal choice among competing risky prospects. The article demonstrates that the number of activities in a risky prospect is a key consideration in selecting the risky prospect. As a result, the maximum expected profit criterion, widely used for making risk decisions, is fundamentally flawed, because it does not consider the impact of the number of risk-reward activities in the risky prospects. A popular view, that if a single risk-reward bet with positive expected profit is unacceptable then a sequence of such identical risk-reward bets is also unacceptable, has been analysed and proved incorrect.     

城市不同收入家庭住房支付能力研究

住房支付能力度量方法分为比率法和剩余收入法.基于我国住房供应体系,构建了剩余收入法方法论框架,定义了住房支付能力、首付款支付能力、还款(或租金)支付能力等概念.并以2005年我国城市不同收入家庭为实例进行了分析,得出如下结论:低收入到中等收入家庭住房供应不足;低收入家庭对经济波动极为敏感,购房风险大于高收入家庭;低收入以下家庭住房保障有收入扶持和住房补贴两种方式;贷款期限延长,可支付购房家庭比例增加;降低住房面积可缓解我国城市土地开发压力,增加住房覆盖面,提高家庭住房支付能力.本文构建的剩余收入法方法论框架可用于研究不同城市不同收入家庭住房支付能力.     

The Effect of Housing Expenses and Subsidies on the Income Distribution in Flanders and the Netherlands

This study explores the role of housing expenses and subsidies with respect to income distribution in Flanders (the northern part of Belgium) and the Netherlands in 2005–2006. It analyses income poverty and inequality by comparing equivalent disposable income before and after housing expenses with a relative poverty threshold and the Gini coefficient. Poverty and income inequality increase in both ‘countries’ when equivalent disposable income is corrected for housing expenses. Furthermore, the relative position of outright owners and social tenants regarding poverty improves. Housing subsidies play a (partly) different role in Flanders and the Netherlands. The implicit social rent subsidy in Flanders and the explicit housing allowance in the Netherlands serve the same goal; however, they both redistribute income relatively strongly in favour of low-income tenants. The tax relief system on the other hand increases income inequality in society, in both Flanders and the Netherlands, whereas our comparative analysis suggests that tax relief does not have a moderating effect on net housing expenses.     

油气处理终端山体滑坡风险评估及治理措施研究

某陆上油气终端处理厂作为海洋石油开采过程中的重要组成部分,计划在温州洞头县新建,终端场地为原采石场开挖后所形成,由于人工开挖,终端场地一侧为梯形开挖山体,山体表面情况复杂,滑坡风险大,通过采用边坡稳定性分析工具对山体滑坡风险进行分析,并结合滑坡灾害破坏机理对滑坡后的破坏范围和程度进行了分析研究,在此基础上提出了相应的治理措施和建议。风险评估技术路线可以应用于类似工程施工山体滑坡风险评估和治理项目中,进而有效控制山体滑坡风险。     

城市居民茶叶消费收入弹性研究——基于扩展线性支出模型(ELES)的估计

了解居民茶叶消费与收入之间的内在联系,不仅对保持产业供求平衡有重要意义,且对于茶叶经营主体制定茶叶营销策略也有参考价值。本文基于12城市居民茶叶消费调查数据,运用扩展线性支出模型(ELES)估计了城市居民茶叶消费收入弹性系数,结果表明我国城市居民茶叶消费收入弹性为0.23,说明茶叶消费在我国城市居民生活中具有必需品的性质,且不同类型消费群体的消费收入弹性系数表现出了显著的差异。基于此,提出了茶叶营销的相关建议。     

Spatial and numerical predictors of measurement performance: The moderating effects of community income and gender.

Spatial reasoning and numerical predictors of measurement performance were investigated in 4th graders from low-income and affluent communities. Predictors of 2 subtypes of measurement performance (spatial–conceptual and formula based) were assessed while controlling for verbal and spatial working memory. Consistent with prior findings, students from the affluent community outperformed students from the low-income community on all measures examined. More importantly, the study revealed different patterns of relations between cognitive skills and academic performance in the 2 communities. Specifically, spatial skills were related to measurement performance in the affluent but not in the low-income community. These findings demonstrate that socioeconomic context impacts not only children's levels of performance but also their capacity to apply basic cognitive skills, like spatial reasoning, to their academic performance. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

促进教育事业发展的税收政策刍议

中国目前与教育有关的税收优惠政策在一定程度上减轻了学校办学的负担,在促进教育公平和发展上起到积极的作用,但也存在一定的不足。为更好地解决教育公平问题,应从流转税和所得税两个层面逐步建立鼓励国民教育投入的税收体制,加大对非营利性民办教育的税收优惠力度,完善职业教育的税收制度改革。     

如何改善农民贫困现状策略分析

改革开放自今,虽然我国已经步入了全面建设小康社会新阶段,但是如何解决好农民贫困问题依然是全面建设小康社会的一扇软肋,而农民增收滞后却是农民问题解决的关键。就目前城乡收入差距呈拉大趋势来看,增加农民收入,缩小差距,实现人均GDP达到3000美元的全面小康社会指标难度犹存。因此,本文通过以西南广大农村地区农民贫困现状为研究对象,全面分析制约山区农民增收的因素,并提出解决此问题的具体方案。