NATURAL RESOURCE ABUNDANCE,INSTITUTIONS AND TAX REVENUE MOBILISATION IN SUB‐SAHARA AFRICA

The contribution of natural resources to tax revenues has generally yielded mixed results in the literature. This study asserts that the missing link to explaining these differences is the quality of institutions. More resource revenues reduce tax revenues when institutions are poor. Using an interaction term for natural resources and institutional quality, we show that institutions are decisive for the contribution of natural resources to tax revenue mobilisation. The interaction effect is statistically significant after controlling for per capita gross domestic product (GDP), an alternative measure of quality of institutions and additional regressors. This finding is robust to different econometric specifications and the type of natural resources.     

人文学的毗邻大类

人文学不是通常意义上的一级学科，而是笼罩众多人文一级学科的学科大场合。要找人文学的左邻右舍，可以举出自然学、科学学和社会学三大门类。它们是好邻居。在人文学与自然学之间，科学学的科连科接，让文明成就非凡；社会学的经世致用，给世界许多关切。在人文学与科学学之间，自然学的泰然而然，使世界永远有其深远；社会学的励精图治，为使天下常有祥和的炊烟。在人文学与社会学之间，自然学的避熟避俗，提供了许多足令人文社科资始资生的前提性资源。用某一个笼统的学科涵摄一切失之芜杂，而日见繁琐的学科分裂又积重难返。揭示人文学、自然学、社会学和科学学相分相连的联系，关照的是当今世界文教发展的一种知其通而统其类的必然。     

经济学研究的两大基本内容及其对知识结构的要求——对日益狭隘化的现代主流经济学之反思

经济学的根本目的是提高国民和社会的福利,这不仅关涉到自然资源的利用问题,而且关涉到人与人之间的社会关系。相应地,经济学的研究内容包含了伦理学和工程学两个方面:它们是相辅相成的,共同构建了整个经济学的理论大厦。事实上,不仅经济学与伦理学之间的关系源远流长,而且即使是专注于研究自然资源配置问题的主流经济学,也根本无法脱离具体的社会关系。正因如此,经济学的研究需要非常广泛的知识;否则,根本无法理解具体的经济现象,也无法提供合理的政策建议。然而,现代主流经济学日益局限于工程学一个方面,并极端地采取抽象化的分析路线,偏重于数理的训练而疏忽其他社会科学领域知识的吸收,从而造成了理论与现实的脱节。     

Critical natural capital revisited: Ecological resilience and sustainable development

The maintenance of critical natural capital is an important objective of sustainable development. Critical natural capital represents a multidimensional concept, as it mirrors the different frameworks of various scientific disciplines and social groups in valuing nature. This article revisits the concept of critical natural capital and examines its relation to the concept of ecological resilience. I propose that ecological resilience can help a great deal in specifying the ‘ecological criticality’ of specific renewable parts of the natural capital. More specifically, I suggest that the degree of ecological resilience is inversely related to the degree of threat ecosystems are prone to. The concept of ecological resilience may complement other measures, such as integrity or vulnerability, in estimating the degree of threat specific ecosystems are exposed to. The empirical estimates of ecological resilience add a further criterion in order to build a comprehensive and clear conception of critical natural capital.     

传统自然资源利用伦理与可持续发展

自然资源利用伦理与可持续发展密切相关。传统文化中的自然资源利用伦理主张人类要仁爱自然万物,在利用自然资源时,必须遵循用物有节、取物有时等原则,保持人口与自然资源的平衡。这些对当今社会可持续发展战略的实施有一定的借鉴意义。     

预应力混凝土梁桥自振特性分析

建立双折线预应力钢筋混凝土等直梁的强迫振动的运动微分方程,分析了梁在预应力钢筋作用下的横向振动问题,将运动微分方程解耦,得到梁在预应力作用下自振频率的解析解,分析了梁的自振频率与预应力和偏心距的关系,通过实例计算,得到了梁在不同预应力时梁桥的自振频率曲线。     

自然人流动对中国双边贸易的影响效应——基才引力模型的实证分析

近年来，自然人流动规模不断扩大，成为各国服务贸易发展的新动向。通过扩展基本引力模型研究自然人流动对中国双边贸易的实证影响，发现存在正效应，但影响低于发达国家水平。其影响有限的原因为国内严格管制流入和专业人员流出能力有限两方面，因此，要加强我国自然人流动自由化的发展并增强对专业服务人才的培养，才能促进我国自然人流动和服务贸易的发展。     

西双版纳自然保护区自然资源的传统利用及管理问题

本文研究了西双版纳勐养自然保护区两个彝族村寨利用土地及其它自然资源的方式和特点，分析了存在的问题，并从协调保护与发展的角度讨论了相关的管理问题。     

建立柳江盆地地质遗迹自然保护区之管见

柳江盆地分布着中国北方新元古代—新生代中各时段地层，其中记录了各时段地壳变动、岩浆活动、沉积环境变迁和生物演化等重大地质事件，被喻为“地学研究的天然实验室和自然博物馆”、“哺育新一代地学人才的摇篮”等，成为具有重要科学价值与社会价值的地质遗迹区。目前该区许多地质遗迹面临人为破坏的威胁，应当尽快建立地质遗迹自然保护区。     

Statistical Thinking in Computer-Based Learning Environments

The theme of technology is particularly important for statistics education because of the role of technology in changing views of statistical knowledge, pedagogy and learning. The interactive multimedia technology of today allows for the creation of powerful learning environments where the focus is on the process that produced the data and its associated variation and the statistical thinking required to solve the problem. However, despite this optimistic view, students' self‐regulation and intrinsic motivation seem to be key concepts for learning in complex interactive computer‐based learning environments. We conclude with observations of teachers and students working with applets. More of these evaluations should be published and/or made available to the statistical community so that both positive and negative teaching experiences can be shared.