Assessment of Heavy Metal Pollution in Urban Agricultural Soils of Jilin City,China

Due to rapid industrialization and urbanization during the last two decades, contamination of urban agricultural soils by heavy metals is on an increase all over China. In this study, fifty soil samples were collected from urban vegetable fields in a chemical industrial area and non chemical industrial area in Jilin City to investigate the heavy metal pollution level. The mean Pb, Cr, Cu, Ni, Zn, and Cd contents (30.84, 65.65, 26.41, 23.07, 135.14, and 0.1434 mg kg^?1 dry weight, respectively) in the urban vegetable soils were higher than their corresponding natural background values. The principal component analysis (PCA) was performed to identify the possible sources of metal contamination in the study area. The results indicated that Cu and Zn were mainly from industrial activities, while Pb and Cd were derived from traffic activities and agricultural activities, and Cr and Ni tended to be from parent material. The distribution of comprehensive pollution index values showed that Pb, Cr, Cu, Ni, Zn, and Cd concentrations in most of the agricultural fields did not exceed the baseline values affecting the safety of agricultural production and human health according to the soil environmental quality standard of China, indicating an insignificant contamination of these metals in Jilin City.     

辽宁大连晚更新世马类牙齿釉质结构的研究

大连晚更新世的马类共包括三个种类:野驴(Equus hemionus)、小型的普氏野马中国马亚种(E. przewalskyi sinensis)、大型的大连马(E. dalianensis)。从它们颊齿的釉质层微观结构、釉柱大小及釉质层的厚度分析,晚更新世的野驴和现生的野驴是十分接近的,可以归于同一个种。大连马与现在的普氏野马也比较接近,可归于同一个大的类别。然而,普氏野马中国马亚种却与现生的普氏野马有着比较显著的区别:中国马颊齿釉质层的釉柱平均直径比现生的普氏野马大得多,而釉质层的厚度又比现生的普氏野马更薄,所以,原来的分类未必合适,中国马似不应归于普氏野马,它可能代表一个比较特殊的种类。     

Sheep farming business in Uşak city of Turkey: Economic structure,problems and solutions

The current study was conducted to reveal the current states, structural features and primary problems of the sheep raising businesses in the city of U?ak. The study group of the current study is comprised of 429 sheep raising businesses selected through stratified sampling (provinces) and a questionnaire consisted of 112 items was administered to these businesses. Through the items in the questionnaire, data were collected about the general features of the businesses and their owners, the state of grazing lands, mating of sheep, birth, milking, clipping, health protection, marketing of animals and the states of tools and equipments in the businesses.The findings of the study have revealed that 82.2% of the owners of the sheep raising businesses are elementary school graduates, their average time of being involved in the activity of sheep raising is 9.8?years, 90% of their shepherds are from the family members, 23.5% of them practice additional feeding before mating and the most preferred method for mating is free insemination with 89%.Of the owners of the businesses, 81.1% learned sheep raising from their elders; for 54% of them sheep raising is the sole source of income and 25.6% of them are engaged in sheep raising to support their families. The main problems of the sheep raisers were found to be the high cost of feed, the low prices paid for their products, inadequate and poor quality grazing lands and animal diseases. In order to make sheep raising more attractive, the prices of the products should be increased, grazing lands should be improved, the genetic structure of the herd should be enhanced, the amount of land area where feed crops are cultivated should be extended and suitable credit conditions should be provided. On the other hand, they need to be informed about sheep mating, lamb growing, stock, milking hygiene, general sheep feeding practices and marketing.     

Zizimin2: a novel, DOCK180-related Cdc42 guanine nucleotide exchange factor expressed predominantly in lymphocytes

A novel superfamily of guanine nucleotide exchange factors for Rho GTPases includes DOCK180 and zizimin1. The zizimin subfamily includes three genes of which only zizimin1 has been cloned. We report here the cloning of zizimin2, identified in a screen for genes enriched in germinal center B cells. Zizimin2 and zizimin1 have similar primary structures and both proteins bound and activated Cdc42 but not the Cdc42-related proteins TC10 or TCL. Their tissue distributions are distinct, however, with zizimin2 expressed predominantly in lymphocytes and an opposite pattern for zizimin1. Zizimin3 was also analyzed and showed distinct GTPase specificity and tissue distribution.     

铜陵市铜尾矿生物群落的恢复与重建

铜陵市位于安徽省中部,长江南岸,属皖南丘陵的一部分,是我国重要的产铜地区之一,治铜历史悠久,解放后大规模进行开采,对我国经济发展起了很大作用。但是,开采过程中形成的废弃物占用大量土地,污染周围环境。矿业弃置地的治理与生物群落的恢复已成为持续发展的关键问题之一。1995年9月到1998年4月,对铜陵市不同弃置时间和不同利用现状的尾矿,进行尾矿基质理化性质和生物群落调查,试图探明不同弃置时间的尾矿上植被和土壤动物的组成、数量和分布特点及其与尾矿理化性质变化的关系,对尾矿的治理和生物群落的重建有一定的理论和实践意义。1　调…     

番禺市生态公益林林分改造与立法管理研究

针对番禺市森林资源偏少,林分质量欠佳的情况,近１０年来,对和天府以僧林林分改造和城市林业建设和管理进行不断的实践和探索。从番禺市生态公益林的基本情况和分布入手,总结了进行林改造的主要技术措施和行之有效的立法管理办法。     

福建永安植物资源特点、现状及保护利用

永安市位于福建省中部,自然条件优越,植物资源丰富。本文阐述该区植物资源特点、现状,并提出保护利用对策。     

Urban atmospheric environmental capacity and atmospheric environmental carrying capacity constrained by GDP–PM2.5

China faces a contradictory period of economic development and environmental protection, with it being essential to control total emissions within the limit of atmospheric environmental capacity (AEC) by promoting atmospheric environmental carrying capacity (AECC). This implies that well-calculated AEC and AECC values are the key macro-criteria for improving environmental quality and supporting the challenging coordinated development of economy and environment. When considering compound air pollution characterised as fine particulate matter (PM_2.5), conventional methods are not capable of calculating AEC and AECC, but the system dynamics (SD) method retains the advantage of simplicity in resolving complex problems. In the present study, we first describe the background and definitions of AEC and AECC, which are different from Western concepts, and their dialectical relationships. Then, with the statistical data from Wuhan city in 2014, we establish an ‘economy–energy–atmospheric environment’ dynamic model using the SD method, which does not need to simulate the complicated physicochemical processes of atmospheric transmission and diffusion. Instead, it uses the pollutants’ proportionality factors and conversion rates to establish quantitative connections among different types of variables. Finally, we simulate the dynamic trends of gross domestic production (GDP), PM_2.5, and six air pollutant emissions between 2015 and 2030 in four different scenarios and calculate the results of AEC and AECC constrained by GDP and PM_2.5.     

基于CA-Markov模型和多目标优化的大连市土地利用格局

运用马尔科夫转移矩阵、多准则评估以及元胞自动机耦合的CA-Markov模型,基于1990、2000、2010年土地利用图、地形因子和地理要素等,模拟大连市未来土地利用景观格局变化趋势.基于大连市土地利用结构、经济社会、自然环境等特点,结合大连市城市总体规划和土地利用规划,建立经济、社会、环境3个目标导向的模糊多目标优化模型,优化配置了大连市未来土地利用格局.结果表明:1990-2010年,大连的快速发展呈现出建设用地持续扩张而耕地、林地面积缩小的特点,以现有城市化速度发展,到2020年大连市景观格局土地覆盖将发生很大变化,景观破碎化程度将加剧.优化调整土地利用数量结构,能满足未来大连可持续发展的要求.