中国农村居民点布局优化研究综述

当前中国农村正步入转型发展的新阶段,在社会主义新农村建设、快速城镇化、城乡一体化、农村土地综合整治等推动下,农村土地利用面临着巨大的压力和挑战,尤其是各类规划与整理的实施深刻地影响着农村居民点的布局形态与优化调整。在此背景下,农村居民点布局优化研究作为推动农村转型发展的重要内容日益受到重视,研究丰度、深度和广度不断加强,有必要对这些研究成果进行系统梳理和总结,以指明中国相关研究未来发展方向。本文在查阅大量相关文献的基础上,首先将中国农村居民点布局优化研究历程归纳为:西方乡村地理学影响下的农村聚落景观描述阶段、人民公社化运动背景下的感性认知阶段、农村聚落地理学视野下的理论框架构建阶段、乡村转型发展驱动下的居民点空间理性重构阶段等4个阶段。其次,从居民点布局优化研究的相关理论、区位评价与影响因素、形态特征、布局演化及驱动机制、布局优化策略以及研究技术方法 6个方面对其进行归纳和总结。最后,在与国际相关研究比较的基础上提出未来中国农村居民点布局优化的重点研究领域应当集中在:制度变革背景下的农村居民点布局优化理论框架的完善;城乡一体化引导下的农村居民点用地空间重配与体系重构;规划与整理推动下的农村居民点空间要素的细化与深入分析;资源约束与生态可持续发展下的农村居民点增长边界控制;GIS技术支持下的农村居民点时空演变机理探索与趋势预测;多学科融合视角下的综合性分析与研究成果的应用性研究。     

中国人力资本、人力资本结构与产业结构升级

人力资本及其结构作为推动产业结构转型和升级的重要因素,长期以来没能得到学术界的重视.中国改革开放以来人力资本及其结构水平迅速提升,但各地区间的人力资本及结构水平差异颇大,这可能也是导致中国各地区间经济增长和产业结构水平存在很大差异的原因.中国独特的社会经济环境,为本文直接研究人力资本在产业结构升级中的作用提供了极为理想的样本.文章在增长回归框架下,以中国各省份1978-2008年动态面板数据为基础,从国家和区域层面考察了人力资本及其结构对产业结构升级的影响.结果发现:人力资本对我国及东部地区的产业结构升级有显著促进作用;人力资本分布结构不利于产业结构升级且效应显著;人力资本内部结构与产业结构的显著性相关得到东部地区数据的支持,而在我国及中西部地区的效应不够明显,这主要是由我国投入导向的增长模式和劳动力质量水平不高所决定的.结论表明,人力资本水平提升及结构优化将会加速我国产业结构转型与升级,形成未来我国持续、稳定发展的强大动力.     

京津唐地区农村-城市转型研究

以农村发展为视角，城乡一体化为背景。详细分析了京津唐地区农村—城市转型的特征、动力机制和类型。通过分析，文章认为促进京津唐地区农村一城市转型的因素一部分来自于农村内部的改革和发展．一部分来自于中心城市的经济技术辐射。在此基础上．作者提出了推进京津唐地区农村-城市转型的主要对策。     

多维视域下中国城乡融合水平测度、时空演变与影响机制

高质量发展阶段的城乡融合应是"人口-空间-经济-社会-环境"的多维融合,据此构建中国城乡融合水平测度指标体系,重新审视并分析了1999—2016年中国各省份城乡融合水平的时空演变特征,并通过设定面板数据空间计量经济学模型对城乡融合的影响因素进行实证检验。研究发现:①中国城乡融合水平整体较低,但正经历从"量变"到"质变"的转化过程,其整体趋势向好。②城乡融合空间集聚效应明显,俱乐部趋同和内部分异同时存在。以"胡焕庸线"为界,城乡融合水平相对高值区主要集中在东部经济发达地区,中西部以低值为主; HH区空间分布重心由东部向中部迁移,LH区和HL区空间分布重心由中部向东西部渗透,LL区始终位于西部。③新常态下,积极推动构建"善治型"政府,合理调节政府"扶持之手"与"掠夺之手"之间的博弈力量;优化调整财政支出结构,提高资本配置效率,打好财政支出"组合拳";并通过金融"开源"和"增效"以及发挥产业结构高度化对劳动就业的"吸纳效应",警惕产业结构偏离造成的"就业破坏"效应等,都是推进中国城乡融合持续健康发展的有效举措。     

城乡收入差距加剧还是抑制了大气污染?

在全面建成小康社会的新形势下,城乡收入差距已经成为中国转型过程中影响社会全面进步的重要因素,并且目前处于城镇化和工业化的快速发展阶段,经济增长带来的生态环境问题依然较为严重。因此,缩小城乡收入差距、治理大气污染成为中国必须大力解决的问题。该研究以2003—2018年中国274个地级以上城市面板数据为研究对象,以城镇居民人均可支配收入和农村居民人均可支配收入比值反映城乡收入差距,以PM_(2.5)浓度反映大气污染,运用时期固定效应的空间杜宾模型模拟城乡收入差距对大气污染的影响。研究表明,在控制了经济增长、产业结构、对外开放程度、技术进步、能源利用、环境规制等变量后,城乡收入差距对大气污染具有显著的正向影响,扩大城乡收入差距将会明显带来大气污染程度提高,加入核心解释变量的二次项和替换核心解释变量后依然证实了这一结论,并且西部地区这种正向影响比东部和中部地区更加明显。说明缩小城乡收入差距和治理大气污染在政策目标上具有趋同性,需要切实提高农民收入,提高农村地区环境规制水平,提高农民环保意识。     

中国能源低碳转型(2015—2050):可再生能源发展与可行路径

在新一轮产业革命的背景下,第三次能源革命正悄然发生,中国也已走入能源转型的"十字路口"。现有关于能源转型路径的研究,大多关注于能源转型本身,忽视了能源转型需要与经济发展阶段相契合的重要特征,即中国能源转型所面临的问题是何种能源转型方案在近期所带来的成本能够被经济系统消纳包容,而在长期又能够推动经济的可持续增长?鉴于此,本文通过跨国比较以及CGE模型研究中国的能源转型与经济发展。跨国比较分析发现,人均收入水平及一定的产业结构基础是能源转型的重要条件,从产业结构及人均GDP的对比看,中国在近5年内如注重节能减排政策实施以提升能源利用效率,人均二氧化碳将在2035年甚至更早进入排放的"下降期",选择何种能源转型道路是当前中国所必须面临的重要问题。本文根据模型演化结果及跨国经验分析,将中国能源转型的可行路径分为三个阶段:2015—2025年,中国经济进入"新常态",正经历经济增长换挡期、结构调整阵痛期和前期刺激政策消化期"三期叠加"的关键阶段,也是跨越"中等收入陷阱"的重要时期,能源转型应采取"温和"手段,高比例的可再生能源发展目标将对经济产生较大负向冲击,不具备可行性;2025—2035年,是能源转型方向确定期,可以制定较高比例的可再生能源发展目标,亦可逐步挖掘化石能源自身的"清洁潜力",转型方向应与新一轮产业革命紧密联系;2035—2050年,为能源转型的成熟期,可再生能源发展将步入崭新阶段,中国能源系统或将呈现两种可能,一是到2050年实现一次能源消费结构中可再生能源占比达到60%以上;二是局部地区实现100%的可再生能源供应,而整个能源供应体系呈现出化石能源与非化石能源平分秋色的局面。     

中国特色城镇化道路研究

城镇化是我国社会经济健康稳定发展必然面临并需要科学引导与管理的重大问题.我国城镇化的发展过程具有农业经济向工业经济、计划经济向市场经济转型的"双重转型"背景;表现为人口城市化(异地转移)和农村城镇化(就地转移)"双重城镇化方向";是在"政府推动"和"市场拉动"双重动力驱动下的城镇化;是在制度变迁方面自上而下的城镇化和自下而上的城镇化的"双重发展模式".认为,中国的城镇化不能照搬别国的模式,必须从自己的国情出发,走有中国特色的城镇化道路,要在产业转型与体制转型的背景下,将人口城市化与农村城镇化、"政府推动"和"市场拉动"的城镇化机制结合起来,并积极多渠道地解决农民工市民化问题.     

中国对外直接投资影响母国环境的理论机理与实证研究

经济全球化背景下,中国工业化进程深度融入全球价值链分工体系,在以资源能源消耗与要素投入增加为特征的粗放型经济增长模式下,国际贸易与国际投资在带动中国经济迅速发展的同时,也不可避免地影响国内的资源环境形势。基于此,本文以中国为研究对象,探究对外直接投资对母国环境的影响及其作用机制,对于“一带一路”战略背景下中国改善生态环境质量、推动经济绿色发展,具有重要的现实意义。本文首先从经济规模扩张、产业结构转型以及技术水平增进等三个视角,构建起对外直接投资影响母国环境的理论框架,并提出相应研究假说。随后,基于中介效应法,构建动态面板模型,在核算各省综合污染指数基础上,结合省级面板数据与系统GMM估计方法,实证探究对外直接投资对母国环境的基本影响,并对其作用机制进行了检验、识别与分析。多个角度开展的稳健性检验依然表明实证结果是稳健的。研究结论如下:一是对外直接投资通过推动母国经济规模扩张,导致其污染物排放增加;二是对外直接投资通过促进母国产业结构朝向服务化转型,有利于减少其污染物排放;三是对外直接投资通过引致反向技术溢出效应,有利于母国污染物排放减少;四是综合来看,当前中国推动对外直接投资,有利于减少母国污染物排放。最后,本文从优化国际投资结构、强化技术领域国际合作等方面提出促进中国环境治理的政策建议。     

特大城市圈典型地市产业结构与生态建设关系分析

特大城市圈内处在二元经济结构向一元经济结构转型的县(市),因其相对低廉的环境和用工用地成本和海量资金投入,其产业结构得以飞速发展。但很多地市经济体在发展的同时,忽略了自身的生态建设,导致快速发展的经济与生态环境之间产生巨大的矛盾。本研究利用地市城市产业结构演变与生态文明建设的协调耦合关系模型,以武汉特大城市圈的咸宁市为研究对象,论证了咸宁市产业结构升级与生态文明建设相互协调发展的几个阶段,提出相应的产业结构升级建议:充分发挥自身优势,以生态文明建设为指导,优化经济结构,补缺特大城市生态圈,缓解其核心城市社会经济发展与生态环境之间的矛盾,以期为中国其他类似城市的发展提供有益借鉴。     

经济转型背景下工业污染时空格局演变及其驱动因素研究——以长江三角洲地区为例

合力打好污染防治攻坚战、强化区域生态环境共保是全面贯彻落实绿色发展理念,推动长三角地区更高质量一体化发展的重要内容。在中国区域经济转型发展背景下,利用城市工业污染物排放和经济社会发展统计数据,重点分析了2003～2015年长三角地区主要工业污染物排放相对规模和强度的时空格局演变规律,探讨了经济转型发展等因素对工业污染时空格局的动态影响机制。研究结果表明:(1)长三角地区主要工业污染物排放相对规模和强度总体呈下降趋势,2003～2015年工业废水、SO_2排放总量分别削减约13%和24%,每万亿元工业总产值的废水、SO_2和烟(粉)尘排放量分别削减87%、88%和71%左右。(2)工业污染排放仍主要集聚在沿沪宁、沿长江和沿沪杭甬等工业发达地区以及部分资源型城市,并呈现由核心区向皖江城市带、苏北等外围区转移扩散的态势,但不同污染物之间差异较为显著。(3)外围区工业污染物排放相对强度较高(多为1.0以上),但近年来南京、杭州等核心区的工业污染物(尤其是工业粉尘)排放相对强度有所上升。(4)经济转型是工业污染时空格局演变的重要驱动力,其中产业结构升级、创新与消费驱动转型增长等是抑制工业污染物排放规模扩张的重要因素;而创新投入及技术进步、企业质效提升、外资外贸结构优化等则有利于降低工业污染物排放相对强度;但由于各地经济转型阶段不同,上述因素对工业污染的影响机制存在显著的空间差异。该研究揭示了经济转型背景下工业污染时空格局演变及驱动因素,对于强化新时期长三角地区工业污染协同防治等具有一定政策参考价值。     

Formaldehyde in conventional homes in Taiwan

A survey was conducted in the humid environment of Taipei City during April and May of 1991, to investigate the indoor formaldehyde exposure and its health effects on 117 conventional households. The levels of formaldehyde were measured by the pararosaniline method. The details regarding construction, ventilation, combustion of fuel, burning of Chinese incense, and the complaints concerning the respiratory system were obtained by a questionnaire. The results show that the age of the pressed wood used in furniture and indoor decoration, the ventilation rate, the combustion of fuel, and the burning of Chinese incense significantly affect the levels of formaldehyde. The respiratory complaints found in this study were concluded here to be only partially accounted for by exposure to formaldehyde.     

Natural radionuclides in bottled water in Austria

Concentration levels of 226Ra, 222Rn and 210Pb were analyzed in domestic bottled waters commercially available in Austria. Concentrations up to 0.23 Bq/l, with a geometric mean of 0.041 Bq/l were found for 226Ra. Concentrations for 222Rn ranged from <0.12-18 Bq/l, the geometric mean being 0.54 Bq/l. Lead-210 was analyzed in selected samples, the concentrations ranging from <2 to 34 mBq/l, with a geometric mean of 4.7 mBq/l. Ingestion doses resulting from consumption of these waters were calculated for the geometric mean and the maximum concentrations of the three radionuclides. The effective dose equivalents for different age groups of the population due to the intake of 226Ra range from 0.001 to 0.22 mSv/y and of 210Pb from 0.0003 to 0.05 mSv/y. Ingestion doses from 222Rn are low compared to those from 226Ra and 210Pb, ranging from 0.0001 to 0.011 mSv/y for adults and children, respectively. The doses are compared to the total ingestion dose from dietary intake of natural radionuclides on an annual basis.     

Radon concentrations in a spa in Serbia

The paper presents the results of indoor radon concentration survey in 201 homes and offices in Niska Banja (the Spa of Nis), a well-known health resort and a spa in the South-East of Serbia. Radon indoor concentrations were determined by active charcoal method, according to standard EPA procedure. The indoor radon concentrations were in the range of up to 200 Bq/m(3) (47%), from 200-600 Bq/m(3) (26%) and over 600 Bq/m(3) (27%). Three areas of extremely high average radon concentrations were found (1,340-4,340 Bq/m(3)), with a maximum above 13,000 Bq/m(3). The content of natural radionuclides ((226)Ra, (214)Pb, (214)Bi, (235)U, (228)Ac, (212)Pb, (212)Bi, (208)Tl, (40)K) and (137)Cs, as well as the content of total uranium, thorium and potassium in mud used in peloidotherapy in the Health Institute "Niska Banja" was determined, too. The activities of the radionuclides were determined on an HPGe detector, by standard gamma spectroscopy. The results indicated considerably high amounts of total uranium and thorium (0.021 g/kg mud and 0.003 g/kg mud, respectively), due to the karsts origin of the soil.     

Precipitation-driven decrease in wildfires in British Columbia

Trends of summer precipitation and summer temperature and their influence on trends in summer drought and area burned in British Columbia (BC) were investigated for the period 1920–2000. The complexity imposed by topography was taken into account by incorporating high spatial resolution climate and fire data. Considerable regional variation in trends and in climate–fire relationships was observed. A weak but significant increase in summer temperature was detected in northeastern and coastal BC, whereas summer precipitation increased significantly in all regions—by up to 45.9 %. A significant decrease in province-wide area burned and at the level of sub-units was strongly related to increasing precipitation, more so than to changing temperature or drought severity. A stronger dependence of area burned on precipitation, a variable difficult to predict, implies that projected changes in future area burned in this region may yield higher uncertainties than in regions where temperature is predominantly the limiting factor for fire activity. We argue that analyses of fire–climate relationships must be undertaken at a sufficiently high resolution such that spatial variability in limiting factors on area burned like precipitation, temperature, and drought is captured within units.     

Participatory approach in vision setting: emerging initiatives in local municipalities in Japan

In this paper, we present the emerging practices in Japanese local municipalities, in which participatory methods are applied to envision sustainable future and relevant target settings. We selected three local cases: Higashiomi city, Kizugawa city and Nagakute city as emerging initiatives. A comparative analysis was carried out to identify commonalities and differences, and to derive lessons for appropriate governance and systems for participatory deliberation in future visioning. We argue that the deliberation processes served as a platform for effective communication, and that installing a mechanism that allows reflexive deliberation processes is the key to make participatory methods fully functional.     

Trends in lung cancer in London in relation to exposure to diesel fumes

Mortality from lung cancer among males in England and Wales is now beginning to decline, and the urban excess that has persisted for many years is also becoming smaller. There is nothing in these national trends to suggest that pollution from diesel vehicles, which has been increasing in recent decades, would be involved. Some preliminary results are presented from a long-term study of the incidence of lung cancer among London Transport staff, including men who work in bus garages where there are high concentrations of smoke from diesel buses. Over the 25 year period from 1950–1974 the numbers of cases reported in each of the several job categories have been below those expected on the basis of Greater London rates. The absence of data on smoking habits makes it difficult to determine whether the small differences in rates between job categories are of any importance, but the standardised mortality ratios are all well within the range of those found in national studies of lung cancer mortality and smoking in relation to occupation.     

Seasonal changes in radon concentrations in buildings in the region of northeastern Poland

In this study, seasonal observations of radon concentration changes inside buildings carried out in the northeastern region of Poland is presented. One-year measurements of radon concentrations were performed in chosen buildings. The integral method of Cr-39 trace detectors in diffusive chambers was used. Mean values of radon concentrations were determined in monthly, 2-, 3-, 6-month, and annual observations. The fraction of a mean annual concentration of the value obtained in a shorter observation was calculated. Monthly concentration values were from about 0.2 to 14.9 of the annual mean. All buildings revealed seasonal fluctuation of radon concentration. Negative correlation of indoor radon concentration in the buildings and the mean temperature outside was observed in most examined buildings. The lowest coefficient range, determining which part of the annual mean value would be obtained in the 6-month observation, was gained for exposure begun in April or October.     

流域土地利用变化的水质响应研究进展

探讨流域土地利用变化的水质响应,有利于从源头上控制水污染。不同学者在多种边界条件下研究了流域土地利用变化的水质响应,发现流域土地利用变化是造成河流水质发生变化的重要原因。根据是否可以将土地利用活动概化为点状,流域土地利用变化的水质响应研究可分为点状土地利用的水质响应和非点状土地利用的水质响应。准确边界土地利用的水质响应一般是研究流域土地利用空间特征和土地利用结构与水质变化的关系。对于用全流域尺度还是用缓冲区的尺度分析土地利用的水质响应更准确仍存在争论。水域边缘几何形状影响了土地利用与水质的关系。     

Radium equivalent activity concentrations in concrete building blocks in eight cities in Southwestern Nigeria

The radioactivity concentrations of (226)Ra, (232)Th and (40)K were measured by using gamma ray spectroscopy in 130 concrete building blocks collected from block making sites in eight cities in Southwestern Nigeria. The results were used to compute the radium equivalent activity concentration for each city. The values of the concentrations of the primordial radionuclides varied widely within each city and among the cities. The weighted means for the cities range between 13.3 and 18.4, 28.2 and 71.6, and 176.2 and 336.8 Bq/kg for (226)Ra, (232)Th and (40)K, respectively. The city weighted means of radium equivalent activity concentrations for the eight cities range from 81 to 145 with a mean of 101 Bq/kg. The maximum for external hazard index was determined as 0.39. All the values are within the safety limits recommended by UNSCEAR [United Nations Scientific Committee on the Effects of Atomic Radiation 1982. Report to the General Assembly, with annexes. New York, United Nations.].