Paddy soil — A suitable target for monitoring heavy metal pollution by magnetic proxies

A preliminary magnetic study around Meishan steel mill in Nanjing (SE China) was carried out combining geochemical analysis with scanning electron microscopy (SEM) to prove that paddy soil can be a suitable target for environmental study on heavy metal pollution. Magnetic background investigation showed a strong variation in this area due to different land uses and soil types. Magnetic susceptibilities (MS) measured on forest soils are much higher than in paddy fields, and values below 20 cm of the soil surface in forest with parent material of Xiashu loess are several times higher than in paddy soil with parent material of fluvisol. Measurements on vertical profiles show that paddy soil has a very low and stable magnetic background with mass-specific MS around 15 × 10^{− 8} m³ kg^{− 1}. A strong enhancement of MS values is found in the upper ~ 20 cm of paddy soil predominated by multidomain and pseudo single domain magnetite. However, relatively low S-ratios (0.57 to 0.85) reveal a significant contribution of imperfect anti-ferromagnetic minerals. Detailed research on a paddy soil core at site C719 near the steel mill indicates strong correlation between magnetic mineral concentration-related parameters (χ, ARM, SIRM) and heavy metal concentrations of Cu, Pb and Zn. In addition, typical anthropogenic Fe-spherules are detected in top paddy soil by means of SEM, which indicates that the increase of susceptibility in upper soil is mainly caused by steel mill emission. Mapping of MS in paddy fields across the steel mill area shows a decrease of MS with the distance to the major emission zone. Positive correlation between χ and Zn is found by measuring surface soil samples around the steel mill. Because of low background and high homogeneity of the ~ 20 cm uppermost mixing layer paddy fields are especially suitable for magnetic surface mapping of heavy metal pollution.     

Responses of Different Chinese Flowering Cabbage (Brassica parachinensis L.) Cultivars to Cadmium and Lead Exposure: Screening for Cd + Pb Pollution‐Safe Cultivars

To reduce the potential risks of cadmium (Cd) and lead (Pb) entering the human food chain in vegetables, two pot experiments (Exp. 1 and Exp. 2) were carried out to screen for Cd and Pb pollution‐safe cultivars (PSCs) of Chinese flowering cabbage (Brassica parachinensis L.). The three Cd treatments in Exp. 1 (0.114, 0.667, and 1.127 mg kg^?1) showed that Chinese flowering cabbage could easily take up Cd from polluted soils, and there were wide variations in Cd accumulation among different cultivars. The Cd accumulation trait at cultivar level was rather stable under different soil Cd treatments. In Exp. 2, seven cultivars that had been shown in Exp. 1 to be typical high or low accumulators of Cd were selected and six Cd + Pb joint exposure treatments were applied to them. The results showed that there were similar trends of accumulation between Cd and Pb for the tested cultivars, but Pb accumulation by the species was much poorer than that of Cd. It was worth noting that an increase in soil Pb levels significantly (p < 0.01) depressed shoot Cd accumulation. Six cultivars were selected as Cd + Pb PSCs. This study showed that it is feasible to apply a PSC strategy in Chinese flowering cabbage cultivation, to cope with the Cd and Pb contamination commonly found in agricultural soils.     

煤炭地质图新时期的制印工艺

传统的煤炭地质制图过程工艺烦琐复杂、成图周期长、劳动强度大,一幅图要经过编辑、出版、印刷等十几道工序,且中间还要经历若干个成图步骤。显然,在计算机技术越来越发达的今天,传统的地质制图方法在某种程度上已不能适应地质科学发展的需要。而随着煤炭地质图计算机制图技术的日益成熟和GIS的出现为地质制图提供了现代化的技术手段,这使得CTP技术进一步发展,更为后期的精确印刷提供了有力的保障。     

Health impacts of liquid biofuel production and use: A review

The dramatic growth in the production and use of liquid biofuels has led to concerns about associated impacts on human health. To date however, there has been no attempt to comprehensively synthesize the literature on this topic, despite a wealth of new research published over the past few years. We searched the Medline and Embase databases, as well as Google Scholar, in order to review the state of evidence linking liquid biofuels to human health, to characterize the magnitude of potential impacts, and to identify areas in need of more empirical research. The search results indicate that the key pathways to health associated with liquid biofuels consist of four sets of exposures: occupational hazards; water/soil pollution; air pollution relating both to the production and use of the fuel; and the price of food (affecting nutrition). Of these, only air pollution and food price seem likely to meaningfully influence health at the population level: liquid biofuels may improve air quality – at least in urban environments – but could have serious adverse effects on nutrition in food-insecure populations. However, much more work is needed in both areas. Very few studies have explored more indirect pathways to health, such as those relating to land-use change, climate change and economic factors.     

上海开展地理市情监测工作的思考

根据国家开展地理国情监测工作的要求,结合上海规划和土地管理中的实际情况,阐述了对地理市情监测主要内容和技术方法的认识和思考,分析了上海地区开展此项工作的基础以及存在的主要难点。     

浅谈新形势下国土资源执法监察工作

在国家从严土地管理的新形势下,基层国土资源管理部门应科学地分析当前执法监察工作所面临的新形势,冷静地面对新问题,大胆地应对新挑战。要紧抓机遇,破解难题,就要从发挥主观能动性入手,大力推行治根治本之策,坚持"六个结合",重拳出击国土资源违法行为,担负起保护土地,促进地方经济发展的重任。     

云南省公路水毁时空分布与态势

云南省不同尺度地质环境脆弱,公路作为带状建筑展布于复杂、脆弱地质环境中,公路水毁时空分布规律是复杂的。运用统计分析和实地调查方法,分析云南省公路水毁时空分布和发展态势。突降暴雨易即时诱发公路水毁,公路水毁具有单点性;普降暴雨也易即时诱发公路水毁,公路水毁具有带状性,水毁链效应显著;降雨强度不高时,公路水毁发生略有滞后性。云南省公路水毁主要发生在6—8月,7月是高发期;在20世纪,公路水毁周期一般为2～3 a,21世纪公路水毁周期一般为4 a。滇西公路水毁密度大于滇东,滇北大于滇南,滇中公路水毁主要分布在滇中边缘地带;公路等级越低,公路水毁越严重;不同地区公路水毁种类有差别。云南省公路水毁目前仍处于发展的态势。     

对地勘单位项目合同管理的几点思考

地勘单位适应市场经济新的管理制度势在必行,合同管理就是其中一项重要的管理工作.重视并加强经济合同管理,依法维护自身合法权益,是地勘单位一项刻不容缓的任务.     

Mercury in Baltic Sea sediments—Natural background and anthropogenic impact

In total 27 short and one long sediment core, and 278 surface sediment samples from the Baltic Sea were analyzed for mercury (Hg), and organic carbon contents. Thirteen short cores and the long core were dated by radionuclide methods (²¹⁰Pb, ¹³⁷Cs, AMS¹⁴C). The dataset allows discriminating between natural and human induced changes on the Hg levels in Baltic Sea sediments. Preindustrial Holocene background concentrations vary between 20 and 50 μg Hg per kg dry sediment and are positively correlated with organic carbon changes. Strong human induced pollution is recorded for the second half of the past century and caused high Hg concentrations of up to several hundred μg Hg per kg dry sediment even in Baltic Sea basins. Maximum concentrations are found at industrial and war waste dumping sites (local hot spots). An Hg concentration decreasing trend toward the present day is observed at most coring sites, a result of environmental measures undertaken during the last two decades. At sites where it is possible to calculate Hg fluxes, the natural accumulation rates vary between 2.1 and 5.4 μg Hg per m² per year. Anthropogenically sourced Hg accumulation rates vary in a wide range of 30 and 300 μg Hg per m² per year for the time span of maximum pollution. In areas characterized by discontinuous sedimentation only “inventories” of human sourced Hg expressed as the total amount of deposited Hg (above the natural background) per m² can be calculated. The inventories of the investigated cores vary in the range of 1 and 8 mg Hg per m². Additionally, influences of sediment dynamics on spatial distribution pattern of Hg concentrations in surface and subsurface sediments are discussed.     

2000年夏季河南大暴雨的预报特征

以 2 0 0 0年 7月河南省 10站以上连成片、日雨量≥ 10 0mm且降水中心日雨量 >2 0 0mm的 4次大暴雨过程为样本 ,从天气形势、水汽条件、不稳定度和中小尺度等方面进行了分析 ,并辅以部分物理量计算 ,进而揭示出大暴雨过程的部分预报特征