中国城市能源消费碳排放的区域差异、空间溢出效应及影响因素

基于1992-2013年中国城市遥感模拟反演碳排放数据,采用空间自相关、空间马尔科夫矩阵和动态空间面板数据模型,在同时考虑碳排放的时空滞后效应和不同地理经济空间权重矩阵的条件下,对城市碳排放的演化路径和关键影响因素进行了定量识别和减排政策探讨。研究表明,中国城市能源消费碳排放的区域差异正逐步缩小,空间上呈现出明显的高排放俱乐部集聚特征,同时碳排放类型演化具有明显的路径依赖特征;面板数据模型估计结果表明经济增长与人均碳排放呈现显著的倒“U”型曲线关系,而绝大多数城市的人均碳排放处于随经济发展而增加的阶段,二产偏重的经济结构和投资的粗放增长共同正向作用于城市碳排放,而人口的集聚效应、技术水平的提升、对外开放度和公路运输强度的增加则共同抑制城市碳排放水平的提高。因此未来要抑制促增因素和发挥促降因素的作用才能有效降低城市碳排放;优化产业结构、精简粗放投资、增加研发强度以及提升公路通达性是未来实现中国城市节能减排的有效途径。     

Embodied land in China’s provinces from the perspective of regional trade

With the continuous enhancement of regional connectivity, the indirect use of land resources through the pathways of trade in goods and services plays an increasingly important role in the overall utilization of land resources. Despite this, relevant research in this field is still in its infancy, and few papers have addressed this issue. This paper uses a multi-regional input-output model to calculate the embodied land in the 30 provinces (autonomous regions and municipalities) and eight regions of China from the perspective of regional trade and further analyzes the spatial pattern of characteristics associated with embodied land flows. The results show that the amount of embodied land occupied by China’s inter-regional trade accounts for 21.39% of the country’s total land, and an average of 38.54% of China’s provincial land demand is met by land exports from other provinces. More than 80% of land consumed by Beijing, Tianjin, and Shanghai is from other provinces. The provinces of Heilongjiang, Inner Mongolia, Xinjiang, and Hebei are the largest net exporters of cultivated land, forest and grazing and aquatic land, fishery land, and built-up land, respectively (the outflows account for 42.26%, 27.53%, 38.66%, and 35.28% of the corresponding land types in the province); and Guangdong, Shandong, and Zhejiang are the main net importers. The flow of agricultural land (cultivated land, forest land, grazing land, and aquatic land) generally shows a shift from west to east and from north to south. The regions in northeast and northwest China have the largest scale of agricultural land outflows, mainly into East and South China. In addition, 8.43% of cultivated land, 7.47% of forest land, 6.41% of grazing land, 6.88% of aquatic land, and 18.35% of built-up land in China are provided for foreign use through international trade. This paper provides feasible ideas and a theoretical basis for solving the contradiction between land use and ecological protection, which could potentially help to achieve sustainable land use in China.     

Physical Properties of Sediments on the Northern Continental Shelf of the South China Sea

ABSTRACT

Using physical (acoustical engineering mechanics and scanning electron microscope) and other technical methods, is study makes a comprehensive analysis of the structural characteristics and engineering mechanics properties of sediments, the sediment structure, microstructure and their classification characteristics and in the light of the physical-mechanical characteristic parameters, the relations between the grain contact, grain accumulation, and porosity with the physical-mechanical characteristics of sediment, and reports the relationship between the acoustic physical parameters and the stress-strain properties of sediment. Results show that there are six structural types in the shelf seabed sediment of the northern South China Sea, among which, the mixed contact structural type sediment has a higher compressive strength and a higher sound velocity than others, and that in the shallow seabed there exists a mesoscale structure with high and low velocity layers.     

RJG─92多用工程振动测量仪

介绍了以微机配套设计的多用工程振动测量仪的硬件和软件的设计方法。本仪器性能稳定、可靠，有较大的实用价值。     

中国国有建设用地供应规模时空特征及影响因素

本文利用Python程序抓取了中国土地市场网上的2010-2015年土地供应结果公告,采用空间分布重心、区位基尼系数、热点分析等方法探究了中国县域国有建设用地供应规模时空特征,并用面板数据模型解析了不同发展阶段的区域供地规模影响因素。研究发现：① 该期间供地规模总体经历了先增后减,县域供地规模空间集聚度、热点区和次热点区总体在扩散;② 受“西部大开发战略”“援疆”和“中部崛起战略”的实施,县域供地规模空间分布重心向西移动明显;③ 土地供应集中在城市群范围内,县域所在的城市行政等级与供地规模密切关联;④ 不同发展阶段的区域供地总规模变化和平均供地结构存在差异,高等级发展阶段的区域平均供地规模较大;⑤ 公共财政支出、固定资产投资、第二产业增长率、第三产业增长率、人口规模增长率和人均GDP对不同发展阶段的区域供地规模影响差异明显,投资建设对各个发展阶段的区域供地规模均有较强推动作用。     

服务业与多维城镇化的耦合协调研究 ——以广州市为例

通过借鉴物理学耦合模型测算广州市服务业与综合城镇化及其子系统的耦合协调性,对不同层次内部耦合协调状态的特点以及服务业和城镇化协调发展的内在机制进行了深入探讨。研究发现：2000-2017 年,广州的服务业和综合城镇化水平大幅持续上升,二者整体协调发展态势良好,其耦合协调度跨度较大,由 0.171 0 增长到 0.974 1,从低协调耦合阶段上升至极耦合协调阶段。服务业与 4 类城镇化子系统的耦合结果显示：人口城镇化、经济城镇化和服务业的耦合协调度处于持续上升状态,而社会城镇化、空间城镇化,尤其是后者和服务业的耦合协调度的上升波动性相对较大;人口城镇化、社会城镇化、空间城镇化与服务业的良好耦合对综合城镇化与服务业的协调发展起拉动作用,而经济城镇化这一子系统则起阻滞作用;保持拉动优势,解决阻滞劣势是加快广州城市发展的良好路径。     

珠江三角洲地区城镇化与生态韧性的耦合协调研究

Urban resilience is an emerging research topic of urban studies, and its essence is described by the ability of cities to resist, recover, and adapt to uncertain disturbances. This paper constructs a "Size-Density-Morphology" urban ecological resilience evaluation system, uses a coupling coordination degree model to measure the degree of coupling coordination between urbanization and ecological resilience in the Pearl River Delta from 2000 to 2015, and conducts an in-depth discussion on its spatiotemporal characteristics. The results show the following.(1) From 2000 to 2015, the urbanization level of cities in the study area generally increased while the level of ecological resilience declined. The coupling coordination degree between the two systems decreased from basic coordination to basic imbalance.(2) In terms of spatial distribution, the coupling coordination degree between urbanization and ecological resilience of cities presented a circular pattern that centered on the cities at the estuary of the Pearl River and increased toward the periphery.(3) Ecological resilience sub-systems played variable roles in the coupling coordination between urbanization and ecological resilience. Specifically, size resilience mainly played a reverse blocking role;the influence of morphology resilience was generally positive and continued to increase over time;the effect of density resilience was positive and continued to decline and further became negative after falling below zero. The main pathways for achieving coordinated and sustainable development of future urbanization and ecological resilience in the Pearl River Delta include: leading the coordinated development of regions with new urbanization, improving ecological resilience by strictly observing the three areas and three lines, adapting to ecological carrying capacity, and rationally arranging urban green spaces.     

广州市中心城区餐饮店空间分异与机制差异研究——基于传统店与外卖店的对比

O2O模式（Online to Offline）使餐饮店经营模式与空间分布发生巨大变化,餐饮店空间分布现象与机制成为研究热点。本文将餐饮店分为仅提供堂食服务的传统店和同时提供堂食与餐饮配送服务的外卖店,利用核密度、双变量空间自相关、半变异函数、标准差椭圆、空间计量模型等方法,分析广州市中心城区传统店与外卖店的空间分异与机制。研究发现：① 2020年传统店主要集聚于自荔湾区多宝街道东至天河区石牌街道;外卖店呈多中心分布,以天河区天河南街道、冼村街道、海珠区江南中街道和赤岗街道为核心;二者在越秀区中部、天河区西南部、车陂街道、海珠区西北部等有多处高高集聚区。② 两种餐饮店空间分异较明显,易受随机性因子影响;外卖店较少分布在越秀区和荔湾区,整体分布范围较小,仅有很弱的空间自相关性,更多呈零散分布特征。③ 餐饮店空间分布受人口密度和餐饮店集聚的正作用;但受教育程度、路网密度、邻近高等院校、公交站、商圈等因素能提高外卖店比例,外卖店有更高店铺付租能力,更邻近地铁站和低经济密度地区,传统店则与其相反。     

Discrimination of Seafloor Sediment Properties by VWA

Analytical results of sound velocity and spectrum for seafloor sediment ore obtained by VWA (velocity-wave-amplitude) discrimination technique. Based on velocity-wave-amplitude, an understanding is gained of the physical condition and structural characteristics of seafloor sediment, which is combined with other geological information of the sedimentary layer to synthetically discriminate the properties of seafloor sediment. Experimental results show that, by using the relationship between sound velocity, wave form envelope, amplitude shape and size, and such parameters as sedimentary structure, microstructure, bedding, grain composition, mineral composition, and physical-mechanics, etc., the basic properties of the shallow surface seafloor sediment in the experimental sea area can be discriminated and the burial depth of traces of ancient marine transgression and regression events in the borehole cores of seafloor sediment can be divided, thus making an attempt of and contribution to the practice of acoustically remote-sensing and telemetering seafloor sediment.     

A study of stability of the seafloor foundation on a gently sloping continental shelf

Abstract

The possibility of seafloor failure under external loadings on a gently sloping continental shelf is controlled, to a large extent, by the geotechnical characters of subbottom sediments (e.g., shear strength, compressibility, and liquefaction potential) and structural factors (e.g., sedimentary stratification). By means of undis‐turbing coring, in‐situ acoustic measurement, and subbottom profiling, the authors conducted an investigation into the seafloor instabilities and possibilities of sediment slope failure within the continental shelf off the Pearl River mouth, which is one of the most important areas for offshore development in the northern South China Sea. Based on in‐situ and laboratory measurements and tests for sediment physical properties, static and dynamic behavior, and acoustic characteristics, the analyses indicate: (1) subbottom sediments that originated from terrigenous clay during the Pleistocene are compact and overconsolidated, and the mean sound velocity in such sediments is relatively high; (2) the maximum vertical bearing capacity of subbottom sediments is efficiently conservative on the safe side for dead loads of light structures, and the trench walls are stable enough while trenching to a depth of about 2 m below the seafloor under still water; and (3) it is quite improbable that the subbottom sediments liquefy under earthquake (M ≤ 6) or storm wave loading.