家庭借贷、经营规模与农户土地经营意愿基于小农户、中农户和大农户分化视角

以陕西、甘肃、宁夏及青海4省区农户调查数据为依据,实证分析家庭借贷、经营规模对农户土地经营意愿的影响,并基于分化视角对农户土地经营行为选择问题进行探讨.结果 表明:(1)家庭借贷获得是农户进行差异化土地经营决策的重要机理因素,在农业信贷刺激下现有农户多选择转入、转出或参与土地入股,表明农贷扩张有益于土地经营规模适度集中;(2)经营规模显著影响农户的土地经营意愿,但随规模分化产生效应不同.以小农户为参照组,中等规模和大规模农户选择转出土地经营权的意愿最强,选择转入土地经营权意愿最弱;(3)经营收益对农户土地经营意愿的影响最为敏感.可以认为,土地经营收益的稳定增长及其保障制度的不断完善是农户从事土地经营发展的基础性支撑.研究在一定程度上拓展了新古典经济学中有关规模经济与效率的理论解释,并为促进农户土地经营规模适度、比较收益提高的农业发展方式提供了有效的参考与建议.     

城市规模、集聚与空气质量

在STIRPAT模型的基础上,通过加入能源消费需求、工业化水平和产业集聚度变量,建立了拓展的STIRPAT模型,并使用动态面板GMM方法,分析了我国30个省会城市和直辖市2003-2012年间的面板数据,指出不同的城市规模与集聚程度会对空气质量有不同的影响。首先。从总体上来说,城市人口规模、富裕程度和技术水平是影响城市空气质量的主要因素,其中人口规模和技术水平对空气质量的影响均为正效应,而富裕程度对空气质量的影响呈现出倒N型EKC曲线形状;较高的能源消费需求和工业化水平会恶化空气质量,而较高的技术水平和产业集聚度会改善空气质量,这表明相关部门可以从不断提高科技水平和产业集聚度入手,通过各种方法减少能源消费需求、降低工业化水平。来达到改善空气质量的目的。其次,在总体回归的基础上,本文重点按照人口规模、经济规模和经济集聚度、人口集中度分析了城市规模与集聚对空气质量的影响情况。结果表明:欠发达城市和大中城市的回归结果与总体回归结果一致,而经济发达城市和特大城市的回归结果与总体回归结果有一定差异,本文认为导致这些差异的主要原因是科学事业费支出方向、社会消费品结构以及工业清洁能源利用及其利用效率等因素;低产业集聚度和低人口集中度城市的情形与总体较为相近,而高产业集聚度和高人口集中度城市的EKC曲线形状与工业化水平系数与总体结果相反,这两种差异分别与城市的发展阶段和城市的人口素质有关。因此,城市的相关部门在追求规模经济的同时应该注重科技投入结构的改善,注重提高能源使用效率和清洁能源的使用率,并且在不断提高产业集聚度与人口集中度的同时追求绿色GDP的实现,注重人口的文化教育以提高人口素质,从而提升公众的环保意识,以抵消随人口集中度提高带来的环境压力。     

人口规模、资源禀赋与经济增长实证分析

虽然在学界人口规模假说和资源诅咒假说至今还没有取得共识,但在当今人口危机和资源危机的大背景下,重新审视人口规模与资源禀赋在经济增长中的作用显得尤为紧迫。我国是否存在人口规模假说和资源诅咒假说?本文构建了新兴古典经济学模型和面板数据模型,得出以下结论:两种假说在中国根本不存在;无论人口规模或资源禀赋状况如何,不同地区均可通过交易效率传导机制实现经济增长。具体来说,不同人口规模或资源禀赋的地区可以积极探索制度改革,提高社会分工水平,大幅改善交易效率,诱导不同类型的社会实验和组织创新,就有可能创造出新的生产力,实现区域经济增长。这些结论一定程度上解决了学界存在的争论,具有重要的理论价值。在政策层面上,由于人口规模、资源禀赋仅是经济增长的两种要素,交易效率才是经济增长的支撑点和动力源,所以政府应该更加重视如何扩大市场容量、促进分工深化和提高交易效率。     

流域系统复杂性与适应性管理

资源、环境与生态已经成为制约我国长期可持续发展的主要瓶颈。本文在分析我国面临的流域性水危机主要特征的基础上,一方面,从复杂系统角度对流域社会-经济-自然复合系统进行分析,揭示了流域管理面临的复杂性与不确定性导致其必定是一个长期、复杂、艰巨的系统工程;另一方面,结合我国重点流域治理历程对现行流域管理模式进行剖析,总结现行管理模式在管理范式与手段、政策与规划制定、社会参与等方面存在的不足与缺陷,它并不能从根本上解决流域性问题。进而通过对适应性管理的分析及其与现行管理模式的比较,强调了适应性管理是完善流域综合管理的有效策略。最终,从管理环境、管理体系、决策机制、管理手段以及科学研究职能等五个方面对我国流域管理转型提出政策建议。     

Systems of Knowledge: Dialogue, Relationships and Process

During the last 20 years, the existence of rich systems of local knowledge, and their vital support to resource use and management regimes, has been demonstrated in a wide range of biological, physical and geographical domains, such as agriculture, animal husbandry, forestry and agroforestry, medicine, and marine science and fisheries.Local knowledge includes empirical and practical components that are fundamental to sustainable resource management. Among coastal-marine fishers, for example, regular catches and, often, long-term resource sustainment are ensured through the application of knowledge that encompasses empirical information on fish behaviour, marine physical environments, fish habitats and the interactions among ecosystem components, as well as complex fish taxonomies. Local knowledge is therefore an important cultural resource that guides and sustains the operation of customary management systems. The sets of rules that compose a fisheries management system derive directly from local concepts and knowledge of the resources on which the fishery is based.Beyond the practical and the empirical, it is essential to recognise the fundamental socio-cultural importance of local knowledge to any society. It is through knowledge transmission and socialisation that worldviews are constructed, social institutions perpetuated, customary practices established, and social roles defined. In this manner, local knowledge and its transmission, shape society and culture, and culture and society shape knowledge.Local knowledge is of great potential practical value. It can provide an important information base for local resources management, especially in the tropics, where conventionally-used data are usually scarce to non-existent, as well as providing a shortcut to pinpoint essential scientific research needs. To be useful for resources management, however, it must be systematically collected and scientifically verified, before being blended with complementary information derived from Western-based sciences.But local knowledge should not be looked on with only a short-term utilitarian eye. Arguments widely accepted for conserving biodiversity, for example, are also applicable to the intellectual cultural diversity encompassed in local knowledge systems: they should be conserved because their utility may only be revealed at some later date or owing to their intrinsic value as part of the world's global heritage.At least in cultures with a Western liberal tradition, more than lip-service is now being paid to alternative systems of knowledge. The denigration of alternative knowledge systems as backward, inefficient, inferior, and founded on myth and ignorance has recently begun to change. Many such practices are a logical, sophisticated and often still-evolving adaptation to risk, based on generations of empirical experience and arranged according to principles, philosophies and institutions that are radically different from those prevailing in Western scientific circles, and hence all-but incomprehensible to them. But steadfastly held prejudices remain powerful.In this presentation I describe the 'design principles' of local knowledge systems, with particular reference to coastal-marine fishing communities, and their social and practical usefulness. I then examine the economic, ideological and institutional factors that combine to perpetuate the marginalisation and neglect of local knowledge, and discuss some of the requirements for applying local knowledge in modern management.     

Reform,Justice, and Sovereignty: A Food Systems Agenda for Environmental Communication

Food ecologies and economies are vital to the survival of communities, non-human species, and our planet. While environmental communication scholars have legitimated food as a topic of inquiry, the entangled ecological, cultural, economic, racial, colonial, and alimentary relations that sustain food systems demand greater attention. In this essay, we review literature within and beyond environmental communication, charting the landscape of critical food work in our field. We then illustrate how environmental justice commitments can invigorate interdisciplinary food systems-focused communication scholarship articulating issues of, and critical responses to, injustice and inequity across the food chain. We stake an agenda for food systems communication by mapping three orientations—food system reform, justice, and sovereignty—that can assist in our critical engagements with and interventions into the food system. Ultimately, we entreat environmental communication scholars to attend to the bends, textures, and confluences of these orientations so that we may deepen our future food-related inquiries.     

经营规模、地权稳定与农户有机肥施用行为——基于调节效应和中介效应模型的研究

以湖北和山东两省的农户调查数据为依据,实证分析经营规模对农户有机肥施用行为的影响,在此基础上,进一步研究了地权稳定性的调节作用以及经营规模影响有机肥施用行为的内在传导机制。研究发现：(1)经营规模对农户有机肥施用行为具有显著的正向促进作用;(2)地权稳定对经营规模影响农户有机肥施用的作用效果存在调节效应;(3)经营规模通过影响农户有机肥施用的行为态度和能力,正向激励农户有机肥施用;(4)有机肥施用行为能力的中介效应强于行为态度。本研究在一定程度上拓展了新古典经济学中有关经济偏好的理论解释,并对有效激励农户有机肥施用行为的对策措施提供了参考与建议。     

排污权交易条件下古诺市场动态系统的均衡及复杂性研究

目前国内外关于排污权交易方面的研究很多,但是大多数学者在排污权交易的理论研究和实践讨论中忽略了排污权交易对产品市场结构的影响问题.实际上,在中国市场体制并不完善的条件下实施排污权交易制度,有可能导致排污权交易市场以及产品市场的扭曲,必须对此加以研究.文章建立了排污权交易条件下的古诺离散动态系统模型,分析了排污权交易条件下古诺市场动态均衡及其稳定性问题.理论研究和数值模拟的结果表明:当排污权交易价格、厂商调整产量的相对速度、边际污染治理成本以及边际生产成本等参数发生变化时,纳什均衡点失去稳定性,经倍周期分叉后出现混沌状态.厂商调整产量的相对速度越慢,厂商的利润越稳定;厂商的边际生产成本、边际污染治理成本、污染排放系数以及排污权交易价格等参数越大,厂商要承受的风险也就越大,厂商对产量的调整余地也越小,厂商的利润相对稳定.     

Land use Systems and Erosion in the Uplands of the Central Coast, Vietnam

Soil erosion is a significant problem in the uplands of the Central Coast, Vietnam. It affects the livelihood of farmers and could hinder the long-term economic development efforts in the uplands. Yet, trapped in poverty, upland farmers, especially the ethnic minority, are still mining the soil using erosive land use systems to meet their urgent needs. This study demonstrates that the level of soil erosion varies across the typical land use systems. The fruit tree-based agroforestry (AF) system is least erosive and most financially profitable. The choice of land use system is influenced by farmers' attributes, land plot characteristics, and policy-related variables. The set of policy variables is important in explaining land use choice by upland farmers. Promoting the switch to AF system and the adoption of soil conservation is of great importance to reducing soil erosion and sustaining development in the uplands. However, it is a very challenging task.     

湖南境内武陵山片区旅游产出规模分异、质量与空间结构初探

旅游产出规模与旅游产业的辐射带动作用息息相关,综合运用位序-规模理论模型、基尼系数（G）、离散系数（CV）、赫芬达尔指数（Hn）、首位度（S）定量分析了湖南境内武陵山片区的县市2010～2015年旅游产出规模分布与规模差异变化;通过旅游规模的质量指数来评价具体县市的旅游产出规模质量,并根据规模高、低和质量的优、良、普、差划分为8个等级类型,在此基础上,采用社会网络分析方法对片区旅游产出规模的网络节点、空间结构再分析,通过Pajek和GIS进行可视化展现。研究发现：⑴湖南境内武陵山片区的旅游产出规模的集聚程度较高,旅游收入规模与旅游人次规模在分布演进的趋势上存在非同步性,当前阶段旅游产出规模的绝对差异程度表现在旅游收入与旅游人次上较高,但是相对差异程度在逐渐减弱;⑵旅游产出规模质量等级Ⅰ型占比仅1/4,Ⅱ型、Ⅲ型、Ⅳ型空缺,总数占3/4的低规模的4种类型的县市旅游产出规模质量亟待改善;⑶中心度、结构洞等指标的变化反映了随着片区内旅游流的流动与扩散效果的加强,传统旅游县市在整个网络结构中的重要程度在降低,而新兴旅游县市的影响力在逐渐提高,因此缩小了县市间旅游经济发展的差距;⑷大片区旅游发展规划有利于武陵山片区旅游产出规模的均衡化,更大程度的释放旅游扶贫的效用     

对产业生态系统规模经济特征的研究

由于废物和副产品成为主要生产原料,产业生态系统在规模经济性方面表现出了与传统产业系统的不同。本文分析了影响产业生态系统规模经济性的5大因素：废料作为原材料的主要来源;以可更新能源替代化石能源;经济活动主体之间大量的物质交流;与周围环境在物质输入输出上保持平衡;信息不对称明显阻碍废物和回收市场的动作。这些因素导致了产业生态系统与传统产业系统在边际成本上的差异,即边际成本并不是随着规模的增加而降低的。论文指出,产业生态系统具有适度规模经济特征,在生产聚焦和生活聚居上表现出小规模化的趋势,表现为相对较小的空间分布和相对局限的生产规模。这样的规模对于处理分散的、高熵值的资源和能源与集约化生产和消费模式之间的矛盾有相当的灵活性。论文最后对进一步开展研究的方向和内容提出了建议。     

A Short Survey Instrument to Segment Populations According to Their Attitudes Toward Science. Scale Development,Optimization and Assessment

ABSTRACT

Surveys play a key role in researching public perceptions of and attitudes toward science. Accordingly, there is a breadth of often-used survey instruments available which have also been adopted for segmentation analyses. Even though many of these segmentation solutions are similar in their aims, they often include a large numbers of variables, making it more difficult for other researchers to build on these solutions, as survey time is scarce. Therefore, we demonstrate how a large number of variables that were used for a comprehensive segmentation analysis can be reduced considerably without losing too much information. We develop and test a short survey instrument to segment populations according to their attitudes toward science. Results show that segmentation results can be replicated with over 90% accuracy by reducing the instrument from 20 to 10 variables. This reduction does not significantly affect the predictive power of segment attribution on three dependent variables, which suggests that many segmentation analyses could be similarly optimized, helping researchers save survey time and standardize segmentation analyses more.     

FORUM Communicative Action in Response to a Nuclear Crisis: Representations of Fukushima across Communication Contexts

The 2011 disaster at Japan's Fukushima-Daiichi nuclear power plant poses important questions for environmental communication scholarship and practice. This forum examines questions that were emerging one month into the Fukushima crisis, when a panel examined its implications as part of North Carolina State University's second annual research symposium on Communication, Rhetoric, and Digital Media (details available at http://crdm.chass.ncsu.edu/symposium2011/). Expanding those initial analyses, we identify implications across the contexts of environmental communication, expert-public engagement, public discourses of nuclear energy, uses of new media, risk and crisis communication, and organizational and institutional communication. The first essay (Kinsella) addresses some implications of Fukushima from the perspectives of constitutive communication theory, risk analysis, and risk communication. The second essay (Ionescu) examines an effort to foster dialog between technical experts and a concerned public audience, made by a nuclear energy institute in Germany. The third essay (Binder) explores uses of Twitter by people in the USA as a tool for following the rapidly evolving events at Fukushima. The final essay (Kittle Autry and Kelly) analyzes public discourse surrounding a proposed merger of two US energy companies with substantial nuclear operations, before and after the onset of the Fukushima disaster.     

贸易自由化、经济增长对碳排放的影响

随着中国经济的快速发展和出口贸易的持续扩张,中国碳排放量不断增加已超过美国居世界第一位,有关贸易自由化、经济增长与环境问题的研究亦方兴未艾.本文运用1995年-2007年期间我国省际面板数据,从规模、结构和技术三个角度,就贸易自由化,经济增长对碳排放的影响进行了实证研究.研究表明:代表规模技术效应的人均收入和碳排放量之间存在显著的正相关关系,我国存在碳排放量的环境库兹涅茨曲线;代表结构效应的资本劳动比和碳排放量存在显著的负相关关系;贸易所产生的结构效应是消极的,这为"污染避难所假说"提供了来自中国的证据;贸易自由化的总效应使得我国碳排放量增加.此外,本文还结合实证分析的结果,提出了在促进经济持续发展的同时控制和降低碳排放量的政策建议.     

规模效率和技术进步对CO2排放影响的实证

本文利用DEA的方法从全要素生产率中分解出规模效率、技术进步和纯技术效率三个指标,然后基于1998-2008年的省际面板数据分析了不同地区的工业规模效率及技术进步对CO2排放影响的程度及差异化的原因.研究结果显示:从总体来看,技术进步对单位GDP的CO2排放有抑制作用,而规模效率则与CO2排放呈正向关系,但各个地区的情况不同,东中部地区的技术进步对单位GDP的CO2排放起到了抑制作用,东北地区和西部地区的技术进步则对单位GDP的CO2排放起到了促进作用;东中部地区的规模效率对单位GDP CO2排放的影响程度要远小于东部地区和西部地区;产生这些差异的原因可能是与我国区域间技术进步与规模效率所属的种类不同有关,东部地区的技术进步可能属于节能型技术进步,而西部地区则属于耗能型的技术进步;东北地区和西部地区规模效率的提升可能更多地依靠能源消耗,中东部地区则有所改善.     

城市规模对生态效率的影响及区域差异分析

随着城市规模的不断扩大,城市住房紧张、交通拥堵、环境恶化等问题开始日益凸显,如何从生态视角找到适度的城市规模是我国新型城镇化建设中面临的一个重要问题。本文以中国2003-2013年281个地级市为研究对象,通过建立空间计量和门槛面板模型研究了城市规模对生态效率的影响及其区域差异,研究结果表明,中国城市生态效率整体呈现逐渐上升的趋势,且区域差异较大,溢出效应较为明显;城市规模对生态效率的影响呈现N型曲线的特征,且呈现显著的区间效应,根据门槛内生性分类结果发现,当城市规模低于54.48万人时,生态效率随城市规模的扩张不断增加;当城市规模大于54.48万低于337.22万人时,城市规模扩张对生态效率的促进作用较大,当城市规模超过337.22万人这一门槛值之后,促进作用开始显著减小,说明基于生态效率的最优城市规模为337.22万人左右;而产业结构、技术水平等都对城市生态效率有明显的促进作用。基于以上结论,各城市应加强环境合作,减少环境污染溢出;对于规模较小的城市,应该依托周边大中城市,争取产业合作,通过完善城市基础设施建设,进行户籍、土地等制度改革,促进城市规模的扩大;对于规模居中的城市,应该以节约资源、保护环境为前提,推进适度规模的城镇化,真正实现城市从量到质的转变;对于规模较大的城市,可以建立新城区或城市群,完善城市近郊及周边交通、教育等公共资源配置,充分发挥聚集和发散效应,有效缓解人口过于集中和环境恶化带来的压力。综上,不同规模的城市应采取不同措施提高生态效率,推进城市走集约、智能、绿色、低碳的新型城镇化道路。     

GIS-Supported Precision Agricultural Fertilization Management at Small Scale

Precision agricultural fertilization technique at small scale is the key for regional cultivated land protection and management. Taking Dingzhuang Town (located in Guangrao County, Shandong Province) as a case study, this article explores the precision agricultural fertilization technique at small scale. First, three main cropping systems are identified via field investigation, namely wheat–maize–soybean, garlic–maize and cotton. Then, application amount of fertilizer N, P and K under the three cropping sys...     

Delivering Arsenic-free Drinking Water-Made Practically Possible: Continuous Scale Electrochemical Arsenic Remediation Process Furnished,based on Experimental Studies and ANN Simulation

Environment, Development and Sustainability - Arsenic (As) in groundwater has become a worldwide concern due to its high toxicity as it is classified as a potent carcinogen, when exposed to...