基于城乡人口变动视角的中国城镇化地域类型时空演变

城镇化是城镇和乡村人口变动共同作用的结果。本文从城乡人口变动的视角提出了城镇化地域类型的划分方法,基于历次全国人口普查数据,考察了中国城镇化地域类型的时空演变及其影响因素。研究发现中国的城镇化于1990年后进入快速阶段且当前仍在加速,但城镇化的实现路径存在较强的时空动态性：① 随着人口自然增长减缓和乡城迁移扩张,全国城镇化地域类型由城乡扩张型转变为城镇吸引型,乡村人口减少对城镇化的贡献持续增强;② 城镇吸引型是各地最主要的城镇化地域类型,但2010年以来大量地区因乡村人口加速外流而转变为乡村流失型,城乡扩张型地域的空间范围大幅收缩至西藏、上海等地,而城乡收缩型地域在东北地区的非省会城市大范围扩张;③ 经济性因素仍是当前中国城镇化的核心驱动因素,经济增长带动乡村人口外迁,工业化长期有利于城乡协调共进,而公共服务等社会性因素的作用仍然有限;④ 新型城镇化和乡村振兴的政策效应还有待发掘,西部城市群、中小城市的吸引力以及乡村地区的人口发展等问题仍需更多的研究关注。本文最后对中国城镇化的趋势性、动力机制和未来研究重点展开了讨论。     

Evaluation of chemical immobilization treatments for reducing arsenic transport in red mud

Red mud (RM) was produced during alumina production from bauxite known as the Bayer process. Arsenic was detected in the solid phase of RM (RMsf) which was disposed in the disposal area. This study investigates the effectiveness of using Zero-valent iron (ZVI), ferrihydrite, ferrous sulfate (FeSO₄), waste acid (WA) or CO₂ for immobilization of arsenic in the RMsf. To test the effect of the amendments on the arsenic leachability, the RMsf samples were amended with the iron-based materials or acidifiers at various w/w (weight/weight) ratios (1–10 %) for 30 days. The leachability of arsenic in the RMsf was evaluated by a 4-step water elusion process. After 30-day treatment of the RMsf, the leachability of As decreased from an initial (12.7 %) to (7.0 %) with a w/w ratio of 5 % ZVI (0 %) with 5 % FeSO₄·7H₂O, (3.4 %) with 5 % ferryhydrite, (2.0 %) with 6 % WA and (11.8 %) with 6 % CO₂. FeSO₄·7H₂O and WA showed more effectively than other amendments for immobilizing arsenic. Arsenic fractionation with a sequential extraction procedure was used to evaluate the arsenic migration potential in the RMsf. FeSO₄ and WA were effective in increasing the hydrous oxide combined arsenic in the RMsf. The leachable Cl^? and SO₄ ^2? in the RMsf increased from 2.9 to 14.1 mg/g and 19.9–44.4 mg/g with 6 % WA and 5 % FeSO₄·7H₂O added, respectively. The estimated cost of the FeSO₄ and WA treatment was 0.47 and 0.49 USD per ton, respectively.     

Comparative Analysis of Seismic Response of Pile-Soil-Structure Interaction System

The study on the earthquake-resistant performance of a pile-soil-structure interaction system is a relatively complicated and primarily important issue in civil engineering practice. In this paper, a computational model and computation procedures for pile-supported structures, which can duly consider the pile-soil interaction effect, arc established by the finite clement method. Numerical implementation is made in the time domain. A simplified approximation for the seismic response analysis of pile-soil-structure systems is briefly presented. Then a comparative study is performed for an engineering example with numerical results computed respectively by the finite clement method and the simplified method. Through comparative analysis, it is shown that the results obtained by the simplified method well agree with those achieved by the finite element method. The numerical results and findings will offer instructive guidelines for earthquake-resistant analysis and design of pile-supported structures.     

跨市轨道交通溢价回收策略与多层级管治：以珠三角为例

随着城市化和机动化的发展,跨市轨道交通建设成为应对交通拥堵,引导土地开发与通勤结构,促进区域一体化的策略。面对轨道交通巨额建设运营成本,多层级政府管治（Multi-level Governance）下的投融资模式和溢价回收（Value Capture）策略成为推动跨市轨道交通建设的基础。目前,对跨市交通设施的溢价回收和多层级管治还缺乏系统讨论。以珠三角为例,实证分析跨市轨道交通多层级政府的合作博弈、投融资模式与溢价回收策略,重点论述由“省部合作”向“省市合作”联合开发的溢价回收策略转变。研究发现,珠三角跨市轨道交通联合开发面临土地、规划和财税等制度约束以及政府间利益博弈,省政府主导的“省市合作”交通土地综合开发模式超越单个城市政府,实现区域层面的交通溢价回收,能为中国城际轨道交通融资和多层级管治提供参考。     

中国流动人口空间格局的演变特征、形成机制及城镇化效应——基于2000和2010年人口普查分县数据的分析（英文）

China has witnessed unprecedented urbanization over the past decades.The rapid expansion of urban population has been dominantly contributed by the floating population from rural areas,of which the spatiotemporal patterns,driving forces,and multidimensional effects are scrutinized and evaluated in this study by using the latest national censuses conducted in 2000 and 2010.Analysis based on the county-level data comes to conclusions as follows.The spatial pattern of floating population has remained stable over the first decade of the new century.The top 1%cities with the largest floating population received 45.5% of all migrants in China.As the rapid development of mega-city regions,the coastal concentration areas of floating population tended to geographically united as a whole,whereas the spatial distribution of migrants within each region varied significantly.The migrant concentration area in the Yangtze River Delta was the largest and its expansion was also the most salient.However,the floating population has growingly moved into provincial capitals and other big cities in the inland regions and its gravity center has moved northward for around 110 km during the study period.The spatial pattern of floating population has been formed jointly by the state and market forces in transitional China and the impacts of state forces have been surpassed by those of market forces in the country as a whole.The attractiveness of coastal cities and counties to the floating population comes mainly from the nonagricultural employment opportunities and public services,reflecting that long-distance and long-term migrants have moved coastward not only to gain employment but also to enjoy city life.By contrast,in the central and western regions,places with a higher economic development level and at a higher administrative level are more attractive to floating populations,demonstrating that the state remains to play an important role in allocating economic resources and promoting regional development in inland China.As the main body of new urban residents,the floating population has contributed substantially to the elevation of the urbanization levels of migrant-sending and-receiving places,by 20.0% nd 49.5% respectively.Compared with extensively investigated interprovincial migrants,intra-provincial migrants have higher intention and ability to permanently live in cities and thus might become the main force of China’s urbanization in the coming decades.The internal migration has also reshaped China’s urban system in terms of its hierarchical organization and spatial structure.     

重力模型探寻南海北部陆坡特提斯痕迹

The South China Sea is the largest marginal sea of west Paicfic Ocean.Its valuable to the continental margin.The evolution of Tethyan structure is a very important part of the evolution of the South China Sea.Its formation is due to a sequence opening and closing of Tethys Ocean loke a horn,and made violent influence to the evolution history of the global geologic strcture.When Gondwana continent separated from Euro-Asian continent in the norh,there produced a series of small oceanic basins. The fromation of new oceanic basin was in company with the extinction of the older ones. This recyeling of new oceanic basin was in company with the extinction of the older ones. This reaycling function made the formation of a huge strucfor successive continental margin and oil-gas exploring. Furthermore, it is impirtant for discovering the relationship brtween Tethyan realm and Pacfic realm. In this paper,the authors have done 3 gravtational models basing on deep crustal research,and they want to discuss the reace of Tethyan structure in the northern slope of the South China Sea.     

Genetic improvement on Chinese shrimp （Fenneropenaeus chinensis）： growth and viability performance in F1 hybrids of different populations

Fenneropenaeus chinensis distributed in the Yellow Sea and Bohai Sea of China and the west coast of the Korean Peninsula. Different geographical populations represent potentially different genetic resources. To learn further the characteristics of different geographical population, crosses among two wild and three farmed populations were produced. The two wild populations were from the Yellow Sea and Bohai Sea （WYP）, and the west coast of the Korean Peninsula and coast （WKN）. The three farmed populations included the offspring of first generation of wild shrimp from coast in Korea （FKN）, the Huang Hai （the Yellow Sea in Chinese） No.1 （HH1）, and JK98. The phenotypes growth and survival rates of these populations were compared to confirm the feasibility for crossbreeding. The body length （BL）, carapace length （CL）. carapace width （CW）, height of the second and third abdominal segment （HST）, width of the second and third abdominal segment （WST）, length of the first abdominal segment （LF）, length of the last abdominal segment （LL）, live body weight （BW）, and survival rate were measured, Different combinations were statistically performed with ANOVA and Duncan＇s Multiple Range Test. The results show that the survival rate of JK98（♀）×WKN（♂） was the highest, followed by WYP（♀）×WKN（♂）, FKN（♀）×WYP（♂）, FKN（♀）×HHI（♂） and WYP（♀）×FKN（♂）; the body weight of FKN（♀）×HHI（♂） was the highest, followed by FKN（♀）×WYP（♂）, WYP（♀）×WKN（♂）, WYP（♀）×FKN（♂） and JK98（♀）×WKN（♂）; the total length had the same ranking as the body weight. All growth traits in hybrids JK98（♀）×WKN（♂） were the lowest among all combinations. F1 hybrids had significant difference （P〈0.05） in BL, CL, HST, LL, and BW; and insignificant difference （P〉0.05） in other growth traits and survival rate. The results of Duncan＇s Multiple Range Test are that BL and CL of J     

康定-攀枝花地区区域金矿化特征

本文从康定群、区域构造和绿岩带的特征讨论了与金矿化的关系。指出康定群为康定-攀枝花地区主要含金岩系;由泸定-孔玉一带72条断裂带痕金分析结果表明,北北东和北北西向压性、压扭性断裂为含金断裂;康定瓦斯沟-孔玉地区遥感图象中所显示出的近20个环形构造,在其边部和内部常有金矿形成;康滇地轴中段西部绿岩带中各类岩石的含金量普遍较高,可为金矿化提供充足的矿质。文中依据各类金矿床(点)分布特征,将区内金矿化划为康定-泸定等四个成矿区。     

强人类活动下半干旱地区湖泊水资源损失过程重建——以岱海为例

湖泊水资源持续损失已经成为影响半干旱地区经济社会发展的主要问题之一.然而,由于缺少长期连续的湖泊动态监测数据,该地区湖泊水资源损失过程及其与气候变化和经济社会发展之间的关系没有得到详细的评估.针对此问题,本文以位于半干旱地区的岱海为研究对象,利用改进型归一化差异水体指数从1986—2020年258景Landsat遥感影像中提取湖泊水体边界,结合湖泊水位数据,重建了近60a岱海水资源量动态变化过程.结果表明：1961—2019年期间,岱海急剧萎缩,湖泊水量共减少9.88×10⁸m³.同时水量变化趋势分段函数拟合结果表明,岱海水量变化可分为3个阶段：1961—1978年,水量损失速率为0.726×10⁷m³/a的缓慢损失阶段;1979—2004年,水量损失速率为2.10×10⁷m³/a的快速损失阶段;2005—2019年,水量损失速率为3.39×10⁷m³/a的加速损失阶段.相关分析表明：岱海水量损失与流域经济社会发...     

我国岩溶地下水系统中的快速流

<正> 七十年代以来,不少学者注意到岩溶水系统中存在快速流(D.I.Smith,T.C.Atkinson.H.Paloc,C.Droque,D.C.Ford,V.Yevjevich,P.W.williem),并进行了定量分析和专门性的研究。于浩然等在水文地质研究总结中也提过类似的问题。岩溶水系统中快速流与慢速流是相对而言,不同系统间岩溶水流速差别很大,难以规定统一的快速流值域。一般地说,快速流赋存于溶洞、管道或岩溶发育的裂隙网络介质中,它是流速较快,对降水反应敏感的集中性水流。研究快速流的特征,将有助于揭示复杂的岩溶地下水系统的规律性,更好地开发利用岩溶水资源。