混凝土小型空心砌块墙体裂损原因分析及防治

1．屋面温差应力问题。甲屋面保温隔热层性能差，或是屋面隔热层上下温度差大到20℃～30℃，使屋面系统产生了剧烈的温度变形，加上屋顶墙体轻、墙体自重产生的正应力小，使之引起的砌块间的摩擦力也减小；而在门窗口的四角又会出现应力集中现象，所以在产生较大的屋面温度变形推力作用下，剪应力、推拉力超过墙体抗剪或抗拉强度时，就会在建筑物内约束力小的部位，     

变压器室温过高原因及散热相关问题的思考

一、变压器室温度过高的原因国家标准中的变压器室通风窗的面积，是按变压器室夏季通风计算温度不超过＋35℃（进风计算温度）、出风温度＋45℃、进出风温差不超过15℃的条件要求，设计出变压器室通风窗的面积。而我们有些变压器制造厂规定，变压器正常使用周围空气温度不超过＋40℃。国家标准中通风条件比我们有些变压器制造厂规定的变压器正常使用环境温度差了5℃，     

内保温墙体面层裂缝的原因及措施

一、保温板材变形 多数面层都出现了不同程度的开裂，板接缝处尤为明显。其原因是外墙结构暴露在大气中受温差变化影响结构整体外形尺寸也发生变化，而附在外墙上的每一块保温板材都单独地收缩和膨胀。墙体变形量大，保温板变形量小，由此产生墙体与保温板材体型变化的应力方向和大小不同，各部份的这种变化随温度升降而轮回出现。内保温板材附着在一个不稳定的基础上，常规情况下，板块裂缝出现只是一个时间早晚的问题。对这种裂缝的对策是板缝应考虑采用弹性软联接材料。     

住宅墙体裂缝分析及预防措施

一、墙体裂缝分析及防治措施墙体产生裂缝、裂缝的形态有：斜缝、垂直裂缝、水平裂缝、八字裂缝等。l温度裂缝预防措施。（1）温度裂缝产生特征。温度裂缝是从顶部开始，越往下层裂缝越轻。房屋长高比越大，裂缝越严重；条式房屋的中间单元裂缝轻，两端部单元裂缝较严重。整体上看，房屋外部墙体比内部墙体裂缝严重，而内横墙裂缝较轻，外纵墙裂缝较严重。从施工角度看，夏天施工时的裂缝轻，冬天施工裂缝重。     

低温热水地板辐射供暖系统在设计施工与运行管理中须注意的问题

一、低温热水地板辐射供暖系统在设计中须注意的问题 1．供暖热负荷的计算。在热负荷计算时要适当考虑地板装饰层的厚度、材料对热负荷计算的影响。另一方面，由于地板辐射供暖是在辐射强度和温度的双重作用下对房间进行供暖，形成较合理的室内温度场分布和热辐射作用，可有2～3℃的等效热舒适度效应，因此供暖热负荷计算宜将室内计算温度降低2～3℃，     

双元联盟网络如何影响突破式创新——技术能力与网络惯例的调节作用

不同类型联盟网络涉及不同程度的知识共享和知识泄露风险，并有可能对突破式创新产生差异化影响。选取合肥、南京和苏州253个企业为样本，探究企业探索性联盟网络和开发性联盟网络分别对突破式创新的直接效应，以及技术能力和网络惯例等内外部情境变量对两种关系的调节效应。结果发现：探索性联盟网络对突破式创新具有倒U型效应；开发性联盟网络对突破式创新不具有曲线效应，仅是正向线性关系；内外部不同情境变量对探索性、开发性联盟网络具有不同调节效应。其中，技术能力仅对探索性联盟网络与突破式创新间关系具有显著正向调节作用；网络惯例对开发性联盟网络与突破式创新间关系具有显著正向调节作用。研究结论对组建企业联盟和推动企业技术创新发展具有一定指导意义。     

企业金融资产配置对双元创新的影响

以2014-2016年非金融上市公司为样本，研究不同种类的金融资产配置对双元创新的影响，考察高管激励方式在两者之间的调节效应，并基于产权异质性作进一步检验。引入ITCV方法测量内生性问题是否改变了回归结果，以检验结论的稳健性。研究发现：①短期金融资产配置对双元创新不产生蓄水池效应；②长期金融资产配置对探索式创新具有挤出效应，而对开发式创新挤出效应受到产权异质性的影响；③相对于开发式创新，长期金融资产对探索式创新的挤出效应更加显著；④国有企业中，股权激励有助于弱化长期金融资产配置对双元创新的挤出效应，而在非国有企业中，这一调节效应并不显著；⑤相对于探索式创新，薪酬激励弱化长期金融资产配置对开发式创新的挤出效应更加显著。     

关于对混凝土裂缝的认识

混凝土是一种非匀质脆性材料，在化学反应、荷载、温度和湿度变化等条件下，由于各种材料的变形不一致而在其间产生应力，造成骨料与水泥石的粘结面或水泥石本身微粒的粘结面产生微细裂缝。随着荷载的继续作用或进一步的温差和湿度变化，微细裂缝逐渐扩展、贯通，从而产生较大裂缝。     

浅谈住宅墙体裂缝的成因

在日常工程质量监督过程中，常会遇到各种形式的墙体裂缝，墙体出现裂缝不仅会影响建筑物的美观，同时也会造成建筑物的渗漏并且直接影响到使用功能乃至涉及到建筑物的强度、刚性及稳定性，造成不同程度的损失，严重者有可能造成建筑的倒塌。因此，安全是广大用户最关注的焦点问题。笔者根据多年的建筑管理经验及现场实践的分析，产生墙体裂缝的主要原因为：1．温度应力；2．设计结构不合理；     

浅析外墙渗水的原因及其防治

一、建筑物外墙渗水原因 1．温度影响。 在相同的温度条件下，混凝土的线膨胀系数比砖墙要大1倍。同样在太阳照射下，混凝土屋盖吸收的热量要远大于砖墙，由于存在温差，屋盖的膨胀变形相对于墙体就显得更大，两者的接触部位由此产生剪应力。温差愈大，变形差异就愈大，剪力也愈大，当它超过砌体的抗拉强度时，砖混结构建筑顶层檐口下的纵墙部位特别是两端就会产生裂缝，引起渗水。     

我国房地产税制的现状及改革构想

房地产税制是维护房地产市场公平竞争，实现国家对房地产业宏观调控的有力杠杆。然而，我国现行的房地产税制却存在税费不分、税制不统一、税制结构不合理等诸多问题。严重影响了其对房地产业应有的宏观调控作用。因此，适时地推进房地产税制的改革应是当务之急，应统一内外税制，合理界定税费的范围，建立统一、规范、合理的房地产税收体系。     

上海生态农业发展影响因素研究

文章分析了上海生态农业发展的影响因素,并利用计量模型进行检验,认为影响上海生态农业发展的主要因素有农业基础设施、农业劳动力资源、农业产业化水平、农业科技实力状况。     

Public participation in forestry in Turkey

Recently public participation in forestry has been seriously considered in Turkey. Participation is however quite a challenge for a country with a long tradition of top-down management and a strong bottom-up dependence on public provisioning. In such a setting, it may not be surprising that the experiences with public participation in forestry in Turkey are mixed. There are some positive initiatives like the creation of farmer's cooperatives and NGOs, but their role is quite limited and small of scale. This paper is bringing together different views based on existing studies in Turkish related to Turkey's experience with implementing public participation in forestry.     

西部地区人力资本投资与知识化发展

人力资本投资在推动知识化发展的过程中存在自增强机制，通过促进人力资本保值增值，进行人力资源合理配置，改善配置环境和配置政策、完善配套措施，有助于充分发挥这一机制的功能，从而实现西部地区知识化发展。     

Inter-enterprise arrears in economies in transition

In the context of economies in transition, the paper argues that an excessive liquidity squeeze could throw the economy into a persistent state of low economic activity. In such bad equilibrium, enterprise transactions become largely demonetized, with a chain of arrears, a form of involuntary credit, spreading over the entire system. The empirical analysis of the Romanian experience seems to support the view advanced in the paper.     

Is wealth found in the soil or in the brain? Investing in farm people in Malawi

Should a typical developing country invest more in agriculture or education? At what stage of development is it optimal to invest more in each of these sectors? These are important questions that governments of developing countries grapple with when designing investment plans. In this paper, I propose a soil–human capital conceptual framework of development and use it to explain estimates of agricultural returns to schooling in Malawi. I use panel survey data for Malawi and rely on the exogenous education policy changes and spatial variation in access to schooling to identify effects of schooling on agricultural incomes. In addition, I correct for selection into income activities within a panel data and instrumental variables estimation framework. I find annual agricultural returns to schooling in Malawi of 3%–4% after correcting for selection and unobserved heterogeneity and 7% in the uncorrected specifications. I also find consistently higher returns to schooling in the nonagricultural sector for those not living in the village of birth and higher returns in the agricultural sector for those living in the village of birth. Given the size of the farm sector, wealth in Malawi is still in the soil, but that future growth in wealth depends on human capital investments.     

Gender Differences in Time-Poverty in Rural Mozambique

Based on time-use data from a 2013 primary household survey, this study examines the nature and extent of time-poverty experienced by men and women in peasant households in Mozambique. The main findings indicate that while women's labor allocation to economic activities is comparable to that of men, household chores and care work are almost entirely women's responsibility. The heavy burden of responsibilities leave women significantly time-poorer compared to men. Women's time-poverty worsens when the burden of simultaneous care work is taken into account. In addition, due to multitasking, the work tends to be more taxing. The examination of determinants of time-poverty shows that common measures of individual economic power, such as assets and education, do not necessarily affect the time-poverty faced by women.     

2010年黑龙江省宏观经济展望

受世界金融危机的影响,从2008年下半年起黑龙江省经济持续走低,2009年一季度跌入谷底。2009年前三季度,在国家扩大内需的政策刺激下,黑龙江省经济企稳回升,但经济运行中还存在出口下滑、物价水平较低等问题,经济下行的压力仍然存在,经济持续回升的基础尚待巩固。展望2010年,国家将继续实施积极的财政政策和适度宽松的货币政策,随着政策效应的逐步释放,内需对经济的拉动作用仍将十分强劲,另外,随着世界经济的复苏,黑龙江省外贸形势也将逐渐好转,在＂投资、消费、出口＂这三驾马车的共同作用下,2010年黑龙江省经济将步入全面复苏通道。     

Agricultural Roots in Intergenerational Transfers in China

Economists have been interested in the motivations of intergenerational transfers, for different motivations affect the effectiveness of anti-poverty public transfers. However, one’s motivation is largely shaped by culture and social conventions. This paper sheds light on the influence of rice cultivation in intergenerational transfers in China. This is also the first time that economists consider cultural factors in the study of intergenerational transfers. Cultivating rice requires elaborate irrigation systems and large amounts of labor input so that rice farmers have to cooperate extensively with their neighbors, which has gradually shaped people’s value to be more inter-dependent. Based on micro-level data from CHARLS and sub-national rice data from China, our empirical results show strong evidence that individuals from rice regions are more likely to provide economic support for their parents. A one-percentage point increase in the share of rice in the total grain planting area will raise transfer incidence by 0.2–0.4 percentage points, and rice region residents transfer on average 300–400 yuan more in 2011 and about 1,000 yuan more in 2013 to their parents than those from wheat regions. Meanwhile they are more inclined to rely on their adult children for elderly support. Urban citizens are less affected. Using instrumental variable estimation, we are able to prove the effect is causal. With future continued deepening of population aging in China, relying on children for old age support may become more and more unrealistic, the government needs to coordinate the relationship between public transfer and private transfer to ensure the quality of life for the elderly.     

Trade-offs in sulfur emission trading in Europe

How to implement emission trading is one question in the current negotiations on a new sulfur protocol in Europe. Whereas the current protocol stipulates a 30 percent uniform reduction, national emission ceilings included in the proposed new protocol imply differentiated reductions. In addition, emission and fuel standards are proposed. This paper examines the costs and environmental impacts of emission trading. Emission trading combined with regulations is a new element in the paper. Calculations using the RAINS (Regional Acidification INformation and Simulation) model suggest that overlaying emission trading on regulations not only reduces the cost savings but has beneficial impacts as well: ecosystem protection is not changed and significant decreases in environmental benefits for countries are largely avoided. Emission trading can also be used to decrease emissions and increase ecosystem protection. If combined with existing legislation, emission trading minimizes losses in expected environmental benefits for some countries, and most countries gain. However, the initial distribution of emission ceilings has to be used so that some countries are not confronted with higher costs. Trade-offs appear to exist between the use of emission trading to achieve cost savings on the one hand, and ecosystem protection and distributional equity on the other.