黄土高原村域多维贫困空间异质性研究——以宁夏彭阳县为例

黄土高原属于生态环境脆弱与农村经济贫困的复合区域,研究其村域多维贫困及空间异质性有助揭示乡村贫困原因及空间格局。以宁夏彭阳县为研究区,运用A-F法对村域多维贫困进行测度,并结合空间自相关、地理探测器和回归分析方法对其空间异质性进行了系统分析。结果表明：① 研究区农户多维贫困程度较深,K = 3时,多维贫困指数（MPI）为0.045,平均剥夺份额0.361,主要致贫维度是住房、健康和教育,贡献率分别为0.263、0.245、0.227,收入维度贡献率仅占0.130;② MPI空间自相关Moran's I值为0.2,即存在正相关,呈现“南北高,中部低”的格局;③ 地理探测器结果显示行政村到镇中心的距离、村平均高程、村委会到主要河流的距离是影响MPI空间异质性的主要因子,其决定力q值分别为0.552、0.396、0.326,且在最小二乘线性回归（OLSR）和分位数回归（QR）中均通过了1%的显著性检验;④ 各因子间的相互作用形成了黄土高原农户福利缺失、基础设施落后与产业发展受阻、乡镇政府职能被削弱的村域多维贫困空间分异机制。⑤ 最后提出推进新型城镇化建设,实现公共服务均等化,从根源上解决农村医疗、住房、交通设施落后等难题的建议。     

中国新企业成立空间差异的影响因素——以金属制品业为例

新企业是产业空间重构的重要驱动力。采用1998-2007年中国工业企业数据库,以金属制品业为例,发现金属制品业新企业成立的活跃地区由东部沿海转向中西部地区,特别是中部地区。随后建立“全球链接、区域竞争和地方环境”的分析框架,通过城市层面的面板Tobit模型,考察新企业成立空间差异的影响因素,并突出企业效率在这些因素作用过程中的影响。研究发现：① 外向型城市有利于新企业成立;低效率的新企业只是追求劳动力的低成本,但是高效率的新企业还能兼顾劳动力的高质量。② 区域市场潜力大的城市有利于新企业成立。③ 市场化环境好的城市有利于新企业成立,地方化经济对新企业成立无显著影响,而适度的相关多样化能够促进高效率新企业成立。     

多元主体视角下城市人居环境需求异质性研究——以昆山经济技术开发区为例

以大样本问卷调查为基础,利用多种统计分析工具对不同属性设定下居住主体人居环境需求的因子结构、因子载荷、需求指向以及空间分布进行了探索和分析,结果表明：地缘、收入、年龄、学历以及职业等属性对主体人居环境需求影响较为显著,据此可将主体划分为具有较强代表性的不同类型群体,不同类群主体的人居环境需求结构表现出较为明显的差异性和指向性;各类群主体的人居环境需求维度均打破了需求层次结构,更多地体现在居住、交通、公共设施等功能结构上;不同类群主体在空间分布上具有一定集聚性和差异性,经济情况较好群体的聚居地的人居环境质量较高,经济水平偏低群体的聚居地的宜居性较差,区域人居环境的优劣差距使得主体人居环境需求异质性特征更加突出。据此认为进行基于资源供需平衡的区域建设分类指导很重要,并根据不同性质群体的人居环境需求情况提出了有针对性的城市规划建设的政策建议。     

基于水稳定同位素的地下水型陆地植被识别:研究进展、面临挑战及未来研究展望

地下水型陆地植被具有重要的生态服务功能,但正遭受严重威胁,亟需在水资源管理中予以关注和保护.准确识别地下水型陆地植被是其管理和保护的前提.水稳定同位素方法是识别地下水型陆地植被的唯一直接方法,其中:①直接比较法只能获得植物对地下水利用的定性信息,但目前的应用最为广泛;②同位素混合模型能定量评估植物对地下水的依赖性,近期随贝叶斯模型的引入取得了较大进展.当前,植物对地下水利用的时空异质性增加了基于水稳定同位素的地下水型陆地植被的识别难度,还限制了小尺度上的研究成果向大尺度上的拓展;部分植物以间接方式利用地下水,对地下水型陆地植被的识别造成了困扰;根系吸水过程中的同位素分馏和同一植株内木质部水同位素组成的时空异质性常使植物样品的代表性受到质疑;采集到具有代表性的地下水和土壤样品也是当前面临的一个主要挑战.为应对上述挑战,未来应加强3个方面的研究:①研发植物木质部水同位素组成的原位在线连续观测技术,提升基于水稳定同位素的地下水型陆地植被识别的时空分辨率;②借助控制性的同位素标记实验,精细刻画地下水-土壤-植物体系内同位素体的迁移和分馏过程;③将同位素观测与具有物理学意义的生态水文模型相耦合,提高定量评估的分辨率和降低不确定性,探索解决时空异质性和升尺度难题的途径.     

Regional Economic Efficiency and Its Influencing Factors of Beijing-Tianjin-Hebei Metropolitans in China Based on a Heterogeneity Stochastic Frontier Model

Using a heterogeneity stochastic frontier model(HSFM),we empirically investigated the economic efficiency of Beijing-Tianjin-Hebei from 2003 to 2016 and its influencing factors.The key findings of the paper lie in:1)in Beijing-Tianjin-Hebei,the overall economic and technological efficiency tended to increase in a wavelike manner,economic growth slowed down,and there was an obvious imbalance in economic efficiency between the different districts,counties and cities;2)the heterogeneity stochastic frontier production functions(SFPFs)of Beijing,Tianjin and Hebei were different from each other,and investment was still an important impetus of economic growth in Beijing-Tianjin-Hebei;3)economic efficiency was positively correlated with economic agglomeration,human capital,industrial structure,infrastructure,the informatization level,and institutional factors,but negatively correlated with the government role and economic opening.The following policy suggestions are offered:1)to improve regional economic efficiency and reduce the economic gap in Beijing-Tianjin-Hebei,governments must reduce their intervention in economic activities,stimulate the potentials of labor and capital,optimize the structure of human resources,and foster new demographic incentives;2)governments must guide economic factors that are reasonable throughout Beijing-Tianjin-Hebei and strengthen infrastructure construction in underdeveloped regions,thus attaining sustainable economic development;3)governments must plan overall economic growth factors of Beijing-Tianjin-Hebei and promote reasonable economic factors(e.g.,labor,resources,and innovations)across different regions,thus attaining complementary advantages between Beijing,Tianjin,and Hebei.     

Evaluation of Atmosphere–Land Interactions in an LES from the Perspective of Heterogeneity Propagation

Atmosphere–land interactions simulated by an LES model are evaluated from the perspective of heterogeneity propagation by comparison with airborne measurements. It is found that the footprints of surface heterogeneity, though as 2D patterns can be dissipated quickly due to turbulent mixing, as 1D projections can persist and propagate to the top of the atmospheric boundary layer. Direct comparison and length scale analysis show that the simulated heterogeneity patterns are comparable to the observation. The results highlight the model's capability in simulating the complex effects of surface heterogeneity on atmosphere–land interactions.     

Spatial variability of the surf zone fish and macroinvertebrate community within dissipative sandy beaches in Oregon,USA

Habitat heterogeneity can influence biological communities by providing a diversity of areas that can be occupied by different species. Sandy beach surf zones are often considered homogenous environments; however, sand bars moved by currents and waves can produce trench‐like shapes or troughs that provide heterogeneity. The influence of habitat heterogeneity produced by sand movement is unclear despite the fact that surf zones are an important habitat for larval and juvenile fish and macrocrustaceans. To determine if, and how, the fish and macroinvertebrate communities present in trough and non‐trough or flat areas of Oregon surf zones differ, we compared species assemblages in both areas at three beaches adjacent to estuary mouths over 2 years. Troughs had different communities compared with flat areas, with higher total catch (mean ± SD = 123.2 ± 122.1 versus 43.6 ± 44.5 individuals × 100 m^?2) and taxon richness (6.7 ± 2.7 versus 4.0 ± 2.3 taxa); these differences were potentially due to water movement, prey availability and sediment size. The fish and macroinvertebrate communities did not vary between years but there were significant differences among beaches, with the most distinct community present at the only beach adjacent to an estuary without a jetty at its mouth, which was possibly due to higher species movement between the surf zones and estuary. Fish and macrocrustacean surf zone communities varied spatially within and among beaches in relation to habitat heterogeneity provided by sand movement and, potentially, the influence of adjacent habitats.     

陆相煤系页岩气储层孔隙特征及其主控因素

认识储层特殊性并遴选优质层段是进行陆相煤系页岩勘探开发的首要工作。本文运用TOC、Ro、有机岩石热解、XRD、SEM、高压压汞、低温液氮吸附等实验,对大同组陆相页岩储层特征进行定性与定量表征,探讨孔隙结构特殊性及主控因素。结果表明,宁武地区大同组泥页岩厚度大,成熟度中等,具有生烃潜力,按照岩性可划分为4个层段。大同组微纳米孔隙可划分为“双峰型”、“单峰型”和“弱峰型”,孔隙比表面积与TOC呈正相关趋势,比表面积与黏土矿物含量正相关,相关性较好,大孔和微孔分别由脆性矿物和黏土矿物提供。陆相页岩孔隙主要受沉积成岩和构造改造影响,分流河道沉积表现为由下至上黏土矿物含量增多,沉积物颗粒变细,泥页岩孔隙度逐渐减小,深湖相沉积表现为由下至上黏土矿物含量降低,碎屑矿物颗粒增多,沉积物颗粒变粗,孔隙度增大,成岩作用对页岩有机质生烃孔隙具有贡献,同时发生压实作用使孔隙率降低,构造改造对页岩气渗流和逸散利弊并存。     

古尔班通古特沙漠生境对植物群落格局的影响

沿87^o37'09"~88^o24'04"E纵穿古尔班通古特沙漠,对44^o14'04"~45^o41'52"N的范围进行11个样地的地貌景观调查、植被分布参数采集和土壤取样。研究区统计到的植物种数占古尔班通古特沙漠文献资料中植物种数的1/3,出现的植物群落构建了该沙漠大面积成片分布的荒漠植被景观。调查发现,随着宏观生境的空间变化,植物群落作相应的演替。在此基础上,利用因子分析 (PCA)和相关分析 (CA) 查明了沙漠风沙土理化属性,如土壤养分、盐分、水分、碱性 (pH) 等微生境的异质性仅对沙漠植被草本层片的多样性 (PIE草) 产生显著影响。同时,这些微生境因相互拮抗使沙漠环境处于暂时的脆弱平衡之中。     

高寒草甸土壤水分的影响因子及其空间变异研究

以黄河源区典型高寒草甸草地类型为对象,运用旋转主成分分析法对影响高寒草甸土壤水分的植被盖度、群落高度、土层根系深度、草地类型等9个环境因子进行了分析,将这些环境因子分为4个主成分因子依次为:立地与草地类型因子、植被因子、坡向风速因子和地形因子.同时,采用统计方法对于不同深度土壤水分进行了统计分析,揭示了土壤水分在整个土壤剖面上的空间变异可划分为:速变层(0~30 cm)、活跃层(40 cm)、次活跃层(50 cm)和相对稳定层(60 cm).