Silver in Tokyo Bay estuarine waters and Japanese rivers

Dissolved and particulate concentrations of silver in Tokyo Bay estuarine waters and Japanese rivers were determined in this study. The dissolved silver concentrations in the surface water of Tokyo Bay range from 5.9 to 15.1 pmol kg⁻¹, which is comparable to those in the surface water of the Japan Sea, but two or three times higher than those in the surface water of the open ocean. However, elevated concentrations of dissolved silver are not found in Tokyo Bay compared with those in other highly urbanized estuaries, such as San Francisco Bay (20∼243 pmol kg⁻¹). In the Tokyo Bay estuary, silver typically exhibits non-conservative mixing behavior, which is a common feature in the other estuaries reported previously. Dissolved silver concentrations decrease with salinity from the rivers to the mouth of Tokyo Bay. Silver is efficiently scavenged by suspended particulates, as evidenced by the high conditional distribution coefficients for silver throughout the estuary (log K_d > 5.0 ± 0.6). The silver fluxes into Tokyo Bay via inflowing rivers and atmospheric deposition were estimated as 83 kg y⁻¹ and 15 kg y⁻¹, respectively. A simple budget calculation shows that the silver supplied from rivers and atmosphere must be rapidly scavenged within the Tokyo Bay estuary.     

A Numerical Model of Coastal Processes of Sand Beaches Based on Long-Term Wave Series

A numerical model of shoreline change of sand beaches based on long-term field wave data is proposed, the explicit and implicit finite difference forms of the model are described, and an application of the model is presented. Results of the application indicate that the model is sensitive to the order of the input wave data, and that the effects of long-term wave series and the effects of the mean annual wave conditions on the model are different. Instead of a single wave condition, the wave series will make the calibration and the verification of the model more practical and the results of the model more reasonable.     

Combining AHP with GIS in synthetic evaluation of environmental suitability for living in China's 35 major cities

There are nearly 700 cities in China, each with their own particular characteristics of natural environment quality and rates of economic development. When people are able to choose a city to live in, they will take into account these characteristics in order to improve their lifestyles. Based on geographic information system technology and the analytic hierarchy process method, a model of the living environment suitability index (LESI) for the larger cities of China was designed. The LESI was constructed by using the factors of economic condition, convenience and livable degree, natural environment and natural resources. The LESI model was then applied to compare the living conditions in 35 major cities in China in 2007, including 30 provincial capitals and 5 sub-provincial cities. LESI values were higher for cities in southeast China than for cities in the northwest. The highest LESI values were mainly distributed along the Chinese southeast coast and the Yangtze River Delta. Cities with the lowest LESI values were found in the centre and north of China. Of the 35 cities, 4 had highly suitable living environments and 7 had unsuitable living environments.     

Contribution to the Global Warming Mitigation of Marshlands Conversion to Croplands in the Sanjiang Plain,Northeast China

Based on the estimation of greenhouse gases (GHG) emissions and carbon sequestration of the total conversion of marshlands (TMC), marshlands conversion to paddy fields (MCPFs) and marshlands conversion to uplands (MCULs), this study revealed the contribution to the global warming mitigation (CGWM) of paddy fields versus uplands converted from marshlands in the Sanjiang Plain (excluding the Muling‐Xingkai Plain on south of Wanda Mountain), Heilongjiang Province, northeast China. The results showed that the total area of MCPFs and MCULs was 504.23 × 10³ ha between 1982 and 2005. The CGWM per unit area was 45.53 t CO₂eq/ha for MCPFs and that was 23.95 t CO₂eq/ha for MCULs, with an obvious 47.40% reduction. The MCPFs and MCULs ecosystems acted as the carbon sink all of the year. As far as CGWM per unit area is concerned, MCPFs mitigated the greenhouse effect which was greater than MCULs. And it was effective that the implementation of the uplands transformed into paddy fields in Northeast China with regard to marshlands protection and croplands (including paddy fields and uplands) reclamation.     

中国留学人员创业园分布及产业特征

以《中国留学人员创业年鉴》为基础数据,采用GIS空间分析技术,运用核密度估计法、L函数和最近邻层次聚类分析等方法,分析2006~2015年中国留学人员创业园空间分布规律以及园区产业集聚特征,结果表明：中国留学人员创业园集聚特征显著,而且随着时间的推移,其多中心趋势明显,集聚规模迅速增大,集聚强度呈“先升后降,但总体增大”趋势;主要集聚于长三角、京津冀和珠三角等地区,尤以前两者最显著,且三大集聚区的集聚强度与集聚规模差异明显,其中长三角留创园的集聚规模最大,京津冀集聚强度最高,而珠三角则比较复杂,其在很小空间尺度范围内服从集聚分布,而在较大空间尺度范围内则服从随机分布;基于不同主导产业的中国留学人员创业园依然集中于长三角、京津冀和珠三角等地区,其主导产业分布格局则差异显著,规律性不强。     

海南省新型城镇化发展模式及驱动力分析——以琼海市为例

在中国社会经济转型过程中,快速的城镇化导致城镇人口剧增、基础服务设施滞后、城乡差距拉大等系列问题,新型城镇化战略为解决这些问题提供新的思路和方向,为建设可持续城市和城乡一体化发展提供美好蓝图。以城镇化和城乡统筹发展等理论为指导,分析了海南省琼海市城镇化建设过程及成效,并以潭门镇、博鳌镇和龙寿洋国家农业公园为案例,提炼出3种不同类型区域的新型城镇化发展模式,并分析其特征及驱动力,为海南省其他类似地区新型城镇化建设提供借鉴。     

A type of new conserved quantity deduced from Mei symmetry for Appell equations in a holonomic system with unilateral constraints

A type of new conserved quantity deduced from Mei symmetry of Appell equations for a holonomic system with unilateral constraints is investigated. The expressions of new structural equation and new conserved quantity deduced from Mei symmetry of Appell equations for a holonomic system with unilateral constraints expressed by Appell functions are obtained. An example is given to illustrate the application of the results.     

榆林蟒坑滩的自然资源合理利用及沙漠化土地整治意见

本文对榆林地区沙化的一般规律进行了叙述,提出当地现代沙漠化的主要表现形式是固定和半固定沙丘的活化;提出了恢复沙地植被和生产力的设想.对滩地进行了成因划分,对湖沼洼地型滩地的生产条件作了重点分析,初步计算了蟒坑滩的地下水资源,提出为了改变滩地沼泽土"冷板田"土壤水分潴积的状况,应当充分利用滩区丰富的地下水,井灌井排。对蟒坑沙漠化土地的治理和滩地的合理利用也提出了比较切合实际的意见,可供生产部门参考。     

湘西保靖县塘口湾水库岩溶渗漏分析

库区可能渗漏的岩溶形态,特别是岩溶负向形态的观测、钻孔和跨孔电磁波透视及CT层析成像揭示,库区的岩溶渗漏途径有所不同。根据控岩断裂的分布、岩溶发育强度和渗漏途径的变化特征,归纳为3种岩溶渗漏类型(方式): 断裂裂隙间溶裂系统(缝)渗漏,多发生在页岩与碳酸盐岩界面附近;小型溶隙(缝)孔洞渗漏,集中在500m 高程段上下;洞穴复合系统渗漏,主要在510m 高程上下。库区岩溶渗漏严重性由下而上增强。