S2O82-/ZrO2-Ce2 O3固体超强酸的制备及催化合成环缩酮的研究

分别以H2SO4和(NH4)2S2O8为浸渍溶液,采用共沉淀法合成了固体超强酸SO42-/ZrO2、SO42-/ZrO2及SO42-/ZrO2-Ce2O3。用红外光谱和Hamm ett指示剂表征了合成的固体超强酸,并用环己酮和乙二醇的缩合反应为探针反应,研究了它们的催化活性。实验表明:(1)SO42-/ZrO2-Ce2O3在缩合反应中的催化活性比SO42-/ZrO2和SO42-/ZrO2要强;(2)引入适当数量的Ce2O3使得固体超强酸的酸强度增大;(3)当固体超强酸SO42-/ZrO2-Ce2O3的制备条件为焙烧温度550℃、焙烧时间4h、Ce2O3质量与ZrO2质量比2%时,酸对缩合反应的催化活性最高。     

新型吸附式冷管的最低制冷温度影响因素研究

提出了一种新型的余热固体吸附式制冷管．该种制冷管无节流装置、无运动部件、结构简单、强度较高，且每根管子自成一个完整独立的制冷系统，所以其密封性好、使用方便；研究了在吸附剂量不变的情况下，制冷剂(吸附质)充注量对制冷管性能的影响。由于该种制冷管的性能跟外部环境参数具有较强的耦合性，本文就热源温度、环境温度、风速和环境空气湿度等参数对其最低制冷温度的影响进行了实验研究，实验采用的工质对为13X沸石分子筛-水．     

固体火箭发动机壳体的模态分析

不稳定燃烧是固体火箭发动机的一种不正常的工作状态,这种不稳定燃烧可使燃烧室压强振荡的振幅达到相当大的量级,使发动机产生强烈的振动,可能使燃烧室壳体或推进剂装药受到破坏,从而引起发动机爆炸.利用大型有限元分析软件AN SY S对固体火箭发动机壳体进行了模态分析,并获得了对其强度和性能影响强烈的频率,此结果对研究固体火箭发动机的动力学特性及不稳定燃烧进行了理论分析、预测和防止压强发生振荡具有重要作用.     

指数型变幅杆的模态分析

应用AN SYS通用有限元程序对指数型变幅杆进行了模态分析,得到了纵振动共振频率,位移节点,放大系数等参数。与理论分析结果比较,表明有限元法获得了较高精度。     

对高等教育资源浪费根源的制度性分析及对策

在我国高等教育资源相对匮乏的情况下,高校内部资源浪费现象仍大量存在。在高校资源投入的过程中,教育资源配置结构的不合理造成的结构性资源浪费;人力资源结构比例不协调、物力资源利用效率低下、财力资源开支不合理等教育浪费现象,给教育的发展带来了沉重的负担,影响了高等教育的可持续发展。本文在揭示我国高等教育浪费表现及其危害性的基础上,借鉴了新经济制度学对制度问题的研究理论,试图分析高等教育利用效率低下、浪费现象存在的制度根源。针对其产生的制度根源,结合高校的实际,提出相应的对策。     

People as partners: Facilitating people's participation in public–private partnerships for solid waste management

Cities in developing countries are facing a double dilemma. On one hand, the urban population is growing rapidly, causing a huge increase in demand for waste management services. On the other hand, the traditional public sector is failing to respond to the increased demand for service. The public sector is constrained by resource and institutional limitations. It is often proposed that the solution lies in private sector participation. It is expected that the private sector, with its dynamism and flexibility, may fill in the service delivery gaps by forming partnership with the public sector. However, a third tier—the people—is often overlooked in the service delivery framework. Citizens can contribute significantly to service delivery. They can support the private sector with payment of service charges. But more importantly, they can play an active role in improving accountability and service quality of both public and private sector. This radical shift in people's role, from passive service receivers to active service partners, however, may not occur endogenously. External help from facilitating agencies may enable the public and private sector to form partnership with people for better service delivery. This article examines the role of facilitating agencies in developing tripartite partnership for solid waste management service in Bangladesh. The key lessons learned are: a number of obstacles prevented spontaneous partnership among the public sector, private sector and people; facilitating agencies were able to overcome the obstacles to form partnership of the three; and, the tripartite arrangement resulted in higher accountability and better service delivery.     

A Review of the High-Level Nuclear Waste Repository Siting Analysis

We critique two 1986 Department of Energy reports concerning the selection of sites for characterization as the nation's first high-level nuclear waste repository. We find that the multiattribute utility analysis of the five nominated sites was well done, although we express concern about the assessed probabilities, question the construction of two important attribute scales, and disagree with some of the value tradeoffs that were used. In contrast, we find the logic of the recommendations report to be weak and unconvincing.     

论新城市群建设

如果我们将城市群界定为被高速交通轴缩短了时空距离的大城市空间,那么,未来中国将形成23个新的城市群。但并不能因为地缘相近就其称为城市群或城市圈,相反,需要打破行政边界,逐步建立区域经济系统;完善基础设施建设机制,建立立体交通体系;建立开放型的城市经济系统,强化城市之间的经济联系;实行资源节约型的城市群发展战略,力促新城市群形成,带动中国步入现代化行列。     

Attitudes Toward Managing Hazardous Waste: What Should Be Cleaned Up and Who Should Pay for It?

Hazardous waste policy in the United States uses a liability-based approach, including strict, retroactive, and joint and several liability. To assess attitudes toward these basic principles of liability, and toward priorities for clean-up of wastes, a questionnaire was mailed to legislators, judges, executives of oil and chemical companies, environmentalists, and economists. The questionnaire consisted of abstract, simplified cases, which contrasted basic principles rather than dealing with real-world scenarios. Subjects were asked how they would allocate clean-up costs between companies and government as a function of such factors as adherence to standards, adoption of best available technology (BAT), and influence of penalties on future behavior. Most subjects felt that, if the company followed government standards or used the best available technology (BAT), it should pay for only a portion of the clean-up cost, with the government paying the rest. In general, responses did not support the principles underlying current law–strict, retroactive, and joint-and-several liability. Most subjects were more interested in polluters paying for damages than in deterrence or future benefit–even to the extent that they would have "harmless" waste sites cleaned up. A bias was found toward complete clean-up of some sites, or "zero risk." Different groups of subjects gave similar answers, although more committed environmentalists were more willing to make companies pay and to clean up waste regardless of the cost.     

社会学视域中的电子废弃物回收再利用问题——以呼和浩特市为例

随着社会经济的发展,我国电子废弃物的产生量和废弃量呈现逐年递增的趋势,如何有效地变废为宝及减少电子废弃物对环境的污染,引起了人们越来越多的关注。将呼和浩特市作为一个研究案例,分析其电子废弃物回收再利用的主要现状及影响,并尝试从环境社会学的角度提出能够促进电子废弃物合理、高效回收再利用的建议。