Spatio-temporal Dynamic Evolution and the Factors Impacting Eco-efficiency in Chengdu-Chongqing Economic Circle     

LI Hongli  CHEN Yunping 《资源与生态学报(英文版)》2022,13(6):986-998

In response to the 14th National Five-year Plan of China and to better explore new strategies for promoting regional coordinated green development, the eco-efficiency values of Chengdu-Chongqing Economic Circle and the corresponding temporal analysis from 2004 to 2018 were assessed in this paper using the super-SBM model and Markov chain. Meanwhile, the spatial analysis of eco-efficiency was conducted by a geographically weighted regression model. Although eco-efficiency has risen at an increasing rate, the economic development of Chengdu-Chongqing Economic Circle was still ecologically ineffective. This means there is an urgent need to improve the efficiency of resource utilization and promote technological innovation. During the study period, the evolution of the eco-efficiency presented as a “π” shape, and was accompanied by the phenomenon of “club convergence”. There was also a strong tendency for eco-efficiency to maintain the original status quo, which indicates that it lacked sufficient momentum for improvement, so it was difficult to achieve a leapfrog transfer. Spatially, the eco-efficiency was distributed from northwest to southeast in a high-low-high manner. The spatial-temporal differences of eco-efficiency narrowed but the effect of agglomeration was relatively weak and there was a polarization trend. Further investigation suggests that the differences in the development level of urbanization, opening, technology, environmental regulation and advancement of industrial structure led to the spatial differences of eco-efficiency. Each city in the Economic Circle should make every effort to improve eco-efficiency accordingly, and thus to promote the green development of the whole region, so as to lay a foundation for driving the green and coordinated development of the central and western regions.  相似文献   

Generation of unusual branched long chain alkanes from hydrous pyrolysis of anammox bacterial biomass     

《Organic Geochemistry》2014

Anammox, the microbial anaerobic oxidation of NH₄⁺ by NO₂⁻ to produce N₂, is recognised as a key process in the marine, freshwater and soil N cycles, and has been found to be a major sink for fixed inorganic N in the ocean. Ladderane lipids are unique anammox bacterial membrane lipids used as biomarkers for such bacteria in recent and past environmental settings. However, their fate during diagenesis and early catagenesis is not well constrained. In this study, hydrous pyrolysis experiments were performed on anammox bacterial biomass and the generated aliphatic hydrocarbons, present in oil generated at 220–365 °C, were analysed. A unique class of hydrocarbons was detected, and a representative component was isolated and rigorously identified using 2D nuclear magnetic resonance (NMR) spectroscopy. It consisted of C₂₄ to C₃₁ branched long chain alkanes with two internal ethyl and/or propyl substituents. The alkanes were generated above 260 °C, with maximum generation at 320 and 335 °C. Their stable carbon isotopic values were depleted in ¹³C, similar to carbon isotope values of the original anammox lipids, indicating that they were thermal products generated from lipids of anammox bacterial biomass. A range of sediments from different geological periods where anammox may have been an important process was screened for the presence of these compounds as possible catagenetic products. They were not detected, either because the concentration was too low, or the sediments screened were too immature for them to have been generated, or because the artificially produced products of anammox lipids may not reflect the natural diagenetic and catagenetic products of ladderane lipids.  相似文献   

Modeling the particle breakage of rockfill materials with the cohesive crack model     

《Computers and Geotechnics》2014

A practical combined finite–discrete element method was developed to simulate the breakage of irregularly shaped particles in granular geomaterials, e.g., rockfill. Using this method, each particle is discretized into a finite element mesh. The potential fracture paths are represented by pre-inserted cohesive interface elements (CIEs) with a progressive damage model. The Mohr–Coulomb model with a tension cut-off is employed as the damage initiation criterion to rupture the predominant failure mode occurs at the particle scale. Two series of biaxial tests were simulated for both the breakable and unbreakable particle assemblies. The two assemblies have identical configurations, with the exception that the former is inserted with CIEs and is breakable. The simulated stress–strain–dilation responses obtained for both assemblies are in agreement with experimental observations. We present a comprehensive study of the role of particle breakage on the mechanical behavior of rockfill materials at both the macroscopic and microscopic scales. The underlying mechanism of particle breakage can be explained by the force chain in the assemblies.  相似文献   

国际连锁酒店跨国扩张时空演变及驱动因素研究——以万豪酒店集团为例     

张祥  马晨娇  董霞  王昭辉  李星明 《世界地理研究》2023,32(1):31-42

通过梳理国际连锁酒店跨国扩张时空演变过程,选择万豪酒店集团作为典型案例,对其跨国扩张空间范围演变进行了描述,采用ArcGIS聚类分析法对其跨国扩张方向特征进行了刻画,采用空间分布碎化指数、均匀度指数和集聚力指数,对其跨国扩张时空演变及驱动因素进行了测度和解释。研究发现（：1）国际连锁酒店跨国扩张空间范围不断拓展,国际化程度不断提升;（2）国际连锁酒店跨国扩张在早期呈现接触扩散特征,后期加速向发展中国家和地区扩张,逐渐呈现接触扩散和等级扩散相混合的特征（;3）国际连锁酒店跨国扩张呈多中心趋向均质发展,向更多的核心国家和非核心国家分布的空间格局演变（;4）国际连锁酒店跨国扩张从核心区向腹地扩散（;5）国际连锁酒店跨国扩张空间差异主要受政府干预、市场需求、产业环境驱动,政府干预起最为关键的作用;外部机遇、区域竞争力和资源条件的驱动触发机制表现出明显滞后性和迟缓性。  相似文献   

Exploring detailed urban-rural development under intersecting population growth and food production scenarios: Trajectories for China’s most populous agricultural province to 2030   总被引：1，自引：0，他引：1  

Gao  Peichao  Xie  Yiru  Song  Changqing  Cheng  Changxiu  Ye  Sijing 《地理学报(英文版)》2023,33(2):222-244

Journal of Geographical Sciences - Henan, China, is likely the most populous agricultural province worldwide. It is China’s major grain-producing area, with a continuously increasing...  相似文献   

Bivariate stochastic modelling of ephemeral streamflow     

H. Kerem Cigizoglu  Peter T. Adamson  Andrew V. Metcalfe 《水文研究》2002,16(7):1451-1465

Streamflow time series in arid and semi‐arid regions can be characterized as a sequence of single discrete flow episodes or clusters of hydrographs separated by periods of zero discharge. Here, two point process models are presented for the joint occurrence of flow events at neighbouring river sites. The first allows for excess clustering by adding autocorrelated errors to an empirically derived seasonally varying probability of an event and is extended to the case of the joint occurrence of flow events in two catchments. The second approach is to explicitly model the occurrences of clusters of events and the bivariate point process of event occurrences within them at both sites. For the two models, the magnitude of event peaks are assumed to be drawn from continuous distributions with seasonally varying parameters. Rises and recessions in discharge are interpolated between the peaks using regression estimates of hydrographs. The models are fitted to mean daily flows at two sites in Namibia and demonstrated to provide realistic simulations of the hydrology. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

SPATIAL-TEMPORAL DYNAMICS OF REGIONAL CONVERGENCE AT COUNTY LEVEL IN JIANGSU   总被引：4，自引：0，他引：4  

PUYing-xia MARong-hua GEYing HUANGXing-yuan 《中国地理科学(英文版)》2005,15(2):113-119

1IN T R O D U C T IO N With therapiddevelopment ofChina's economy ,there- search on regionalconvergence or divergence has at- tracetd a lotof attention(SONG , 1996 ; LUO etal., 2002 ;QIN ,2004 ).At present,the empiricalanalysesare oftenbased on two concep…  相似文献   

Web Service基本特征及其在构造供应链管理系统中的应用   总被引：5，自引：0，他引：5  

谢澍  张洪伟  赵立 《成都信息工程学院学报》2002,17(2):82-87

对Web Service理论和技术的基本特征进行了探讨，并应用该技术的跨平台互操作性和结合XML的数据通信的开放性为大型集团公司构造供应链管理系统，从而证实Web Service为企业间进行信息数据交换提供了强有力的技术支撑。  相似文献   

软包装即食食品——鲻鱼皮加工工艺     

吴燕燕  李来好  陈培基  刁石强  李刘冬  杨贤庆 《广东海洋大学学报》2002,22(3):42-46

研究了鲻鱼皮的加工工艺 ,筛选出鲻鱼皮加工成软包装即食食品的最佳工艺条件。结果表明 :鲻鱼皮的爽脆性主要与鲻鱼皮的烫煮和冰水浸泡工艺条件有关 ,最佳条件是先用 0 8g/L的保水剂浸泡3h,然后用低浓度的有效氯杀菌 ,再在 90℃中烫煮 60s,最后迅速放进无菌冰水中浸泡。研制出的产品为螺纹状 ,具有鱼皮特有的银灰色 ,爽脆且富有韧性 ,在 0～ 5℃下可保质 45d。  相似文献   

Semi classical gravitational effects around global monopole in Kalb-Ramond background     

F. Rahaman  T. Roy  R. Mukherjee  S. Mandal 《Astrophysics and Space Science》2004,291(2):135-141

The problem of semiclassical gravitational effects of globalmonopole in Kalb-Ramond backgroundinvestigated. It is shown that the monopoleexerts repulsive gravitational force on nonrelativistic matter and space around it hasa deficit solid angle.  相似文献