Heavy metal(loid)s in fruit-growing soils of tropical Hainan Island in China:Pollution,ecological-health risks,spatial assessment,and source analyses

Hainan Island is the most important tropical fruit production area in China.In this study,372 soil samples and corresponding fruit and irrigation water samples were collected from Hainan orchards and analysed to determine the concentrations of six heavy metal(loid)s:Cd,Hg,As,Pb,Cr,and Cu.The pollution status,potential risks,possible sources,and spatial distribution patterns of soil heavy metal(loid)s were comprehensively investigated.The fruit and irrigation water samples had negligible amounts of heavy metal(loid)s,and the potential human health risk for fruit consumers was at a safe level.The heavy metal(loid)concentrations in most soil samples were lower than the national risk screening values.However,significant local accumulation of heavy metal(loid)s,especially Cd,Cr,and Cu,relative to their background values was observed.Moreover,the combined effects of the heavy metal(loid)s only led to a mild pollution level and low ecological risk throughout the study area.Noncarcinogenic risks were not observed among the local residents,and carcinogenic risks were within an acceptable range.The acidic soil in the study area increased the risk of soil Cd pollution,and organic matter affected the distribution of the tested metal(loid)s in the soil.Uncommon geogenic sources with high background values were the sources of Cr and Cu,anthropogenic activities primarily led to Cd,Pb,and As contamination,and a combination of anthropogenic and natural sources was responsible for Hg emissions.The research suggested that appropriate strategies must be implemented to track and reduce soil heavy metal contaminants in the northern and western region of the Hainan orchard area.The results can provide valuable information for policies on pollution prevention and management,the environment,and human health protection in the study region.

Study on the oxidation mechanism of Al-SiC composite at elevated temperature

Resin-bonded Al-SiC composite was sintered at 1100,1300,and 1500℃ in the air,the oxidation mechanism was investigated.The reaction models were also established.The oxidation resistance of the Al-SiC composite was significantly enhanced with temperature increase.SiC in the exterior of the composite was partially oxidized slightly,while the transformation of metastable Al_(4)C_(3) to stable Al_(4)SiC_(4) existed in the interior.At 1100℃,Al in the interior reacted with residual C to form Al_(4)C_(3).With increasing to 1300℃,high temperature and low oxygen partial pressure lead to active oxidation of SiC,and internal gas composition transforms to Al_(2)O(g)+CO(g)+SiO(g)as the reaction proceeds.After Al_(4)C_(3) is formed,CO(g)and SiO(g)are continuously deposited on its surface,transforming to Al_(4)SiC_(4).At 1500℃,a dense layer consisting of SiC and Al_(4)SiC_(4) whiskers is formed which cuts off the diffusion channel of oxygen.The active oxidation of SiC is accelerated,enabling more gas to participate in the synthesis of Al_(4)SiC_(4),eventually forming hexagonal lamellar Al_(4)SiC_(4) with mutual accumulation between SiC particles.Introducing Al enhances the oxidation resistance of SiC.In addition,the in situ generated non-oxide is uniformly dispersed on a micro-scale and bonds SiC stably.

社会投资国家的发展路径如何行之有道?——基于日本、韩国和中国社会支出的比较分析

既有文献指出,西方国家的社会投资国家发展路径有两条,分别是社会民主主义路径和自由主义路径。社会民主主义路径的基本特征在于,社会投资政策支出水平高,社会投资政策的主体是公共部门,社会补偿和社会投资政策两者支出同步增长。而自由主义路径的发展特征是,社会投资政策支出水平低,社会投资政策的主体是私人部门,强调工作福利,社会补偿和社会投资政策两者支出此消彼长。进一步分析东亚的日本、韩国的社会支出发现,东亚生产主义的发展路径与自由主义路径相似,但韩国社会投资国家路径呈现转型的趋势。相比较而言,作为一个人口大国,在老龄化加速发展的今天,中国社会投资国家建设必须超越竞争关系,确立发展型社会政策的理念,重视社会服务的基础性作用,走中国特色社会投资国家的发展道路。

我国城市就业救助政策研究——以广州市H社区为例

我国'城市最低生活保障制度'下的就业就助政策,被赋予期待低收入者积极脱贫自立的目标,但是效果不如预期。本文以广州市H社区为研究个案,从基层管理者、低保对象的视角出发,试图对政策过程包括'进入与退出'机制、方案施行和政策效果做全面评价。研究结果显示:现有的制度设计大大减少了福利依赖的可能性,在扩展低保户人际关系方面起到了正面作用,但是在工作岗位提供、就业培训等相关配套措施上都无法满足目标群体的需要,从而导致政策目标功效有限。同样,西方'激活'政策脉络在于如何设计再就业机制的有效衔接,避免社会排斥和福利依赖。与我国城市就业救助政策相比较,二者的制度理念、制度背景均不同,因此在应用相关概念时应当谨慎。

Effect of Qilongtoutong granule on calcitonin gene-related peptide,beta-endorphin, serotonin, dopamine, and noradrenalin in migraine model rats and mice

OBJECTIVE: To study the effect of Qilongtoutong granule(QLTT) on plasma calcitonin gene-related peptide(CGRP), beta-endorphin(β-EP), 5-HT, dopamine(DA), noradrenalin(NE), and blood viscosity in migraine model rats and mice.METHODS: Both the acute blood stasis model group and nitroglycerin-induced migraine model group included 60 Sprague-Dawley rats. The reserpine-reduced model group had 60 Kunming mice.Rats from each test were grouped into normal control group, model group, Zhengtian pill(ZTP)group, and high, moderate, or low-dose QLTT groups. In the acute blood stasis model test, after gavage for 7 days, rats were given 0.8 mL/kg adrenaline hydrochloride subcutaneously twice, and kept in ice water for 5 min. After fasting for 12 h,rats were anesthetized and blood samples were col-lected for detection of blood viscosity. In the nitroglycerin-induced migraine group, after gavage for7 days, rats were intraperitoneally injected nitroglycerin(10 mg/kg), and 4 h later, blood samples were collected from postcava for measuring the plasma CGRP and β-EP levels. In the reserpine-reduced model test, except the normal control group, mice were administered reserpine(0.25 mg/kg, i.h.) for 9 days. Mice received intragastric administration from the third day to the ninth day. One hour after the last gavage, blood and brain tissue samples were obtained. Then, blood clotting time and the contents of neurotransmitters were determined.RESULTS: QLTT-(3.6, 1.8, and 0.9 g/kg) and ZTP-treated rats had lower blood viscosity than that in model rats under different shear rates(P<0.01). QLTT-(3.6, 1.8 g/kg) and ZTP-treated rats had significantly lower plasma CGRP levels and higher plasma β-EP levels than those in model rats(P<0.01). QLTT treatment at dose of 0.9 g/kg had lower plasma CGRP levels as well(P<0.05). QLTT-(5.2,2.6 g/kg) and ZTP-treated mice had longer blood clotting time than that in model mice(P<0.01).QLTT-(2.6 g/kg) and ZTP-treated mice had higher plasma serotonin(5-HT) levels than those in model mice(P<0.05).CONCLUSION: QLTT-treated animals had lower plasma CGRP level, higher plasma β-EP, 5-HT, higher brain tissue 5-HT, NE, DA levels, and lower blood viscosity than those in the migraine model animals.

Embodied water analysis for Hebei Province, China by input-output modelling

With the accelerating coordinated development of the Beijing-Tianjin-Hebei region, regional eco- nomic integration is recognized as a national strategy. As water scarcity places Hebei Province in a dilemma, it is of critical importance for Hebei Province to balance water resources as well as make full use of its unique advantages in the transition to sustainable development. To our knowledge, related embodied water accounting analysis has been conducted for Beijing and Tianjin, while similar works with the focus on Hebei are not found. In this paper, using the most complete and recent statistics available for Hebei Province, the embodied water use in Hebei Province is analyzed in detail. Based on input-output analysis, it presents a complete set of systems accounting framework for water resources. In addition, a database of embodied water intensity is proposed which is applicable to both intermediate inputs and final demand. The result suggests that the total amount of embodied water in final demand is 10.62 billion m3, of which the water embodied in urban household consumption accounts for more than half. As a net embodied water importer, the water embodied in the commodity trade in Hebei Province is 17.20 billion m3. The outcome of this work implies that it is particularly urgent to adjust industrial structure and trade policies for water conservation, to upgrade technology and to improve water utilization. As a result, to relieve water shortages in Hebei Province, it is of crucial importance to regulate the balance of water use within the province, thus balancing water distribution in the various industrial sectors.

Regional study on investment for transmission infrastructure in China based on the State Grid data

Transmission infrastructure is an integral component of safeguarding the stability of electricity delivery. However, existing studies of transmission infra- structure mostly rely on a simple review of the network, while the analysis of investments remains rudimentary. This study conducted the first regionally focused analysis of investments in transmission infrastructure in China to help optimize its structure and reduce investment costs. Using State Grid data, the investment costs, under various voltages, for transmission lines and transformer substa- tions are calculated. By analyzing the regional profile of cumulative investment in transmission infrastructure, we assess correlations between investment, population, and economic development across the regions. The recent development of ultra-high-voltage transmission networks will provide policy-makers new options for policy development.

Exports-driven primary energy requirements and the structural paths of Chinese regions

As the major primary energy importer in the world,China has engaged in considerable efforts to ensure energy security.However,little attention has been paid to China’s embodied primary energy exports.Separating the international export from regional final demand,this paper focuses on quantifying provincial primary energy requirement arising from China’s exports,and tracing its concrete interprovincial supply chains using multi-regional input-output analysis and structural path analysis.Results show that China’s embodied primary energy uses in exports(EEE)reached 633.01 Mtce in 2012,compared to 565.15 Mtce in 2007.Four fifths of the EEE were supplied through interprovincial trade.Eastern coastal provinces accounted for nearly 70%of the national total EEE,while their primary energy supply mainly sourced from the central and western provinces.Most interprovincial supply chain paths of embodied primary energy exports were traced to the coal mining sectors of Shanxi,Inner Mongolia and Shaanxi.Critical receiving sectors in the final export provinces were Chemical industry,Metallurgy,Electronic equipment,Textile and other manufacturing sectors.Important transmission sectors were Electricity and hot water production and supply and Petroleum refining,coking,etc.In view of the specific role of exports in primary energy requirements,provincial energy uses are largely dependent on its domestic trade position and degrees of industrial participation in the global economy.Managing critical industrial sectors and supply chain paths associated with the international exports provide new insights to ensure China’s energy security and to formulate targeted energy policies.