城镇化对粮食生产环境技术效率影响研究

我国粮食生产在实现了"十一连增"之后正面临着城镇化所带来的资源约束和环境挑战,如何实现城镇化与粮食生产的协调发展,是我国当前需要高度关注的一个重大问题。本文以1994-2012年我国29个省(市、区)为研究对象,利用方向距离函数将环境因素纳入到粮食生产技术效率测算框架,对我国粮食生产环境技术效率值进行了测算,并对不同阶段各粮食生产功能区粮食生产环境技术效率的演变特征进行了分析,在此基础上将城镇化细分并设置了人口城镇化指标、土地城镇化指标、产业发展城镇化指标和生态环境压力城镇化指标,利用所构建面板数据模型探讨了城镇化对粮食生产环境技术效率的影响。研究结果表明:11994-2012年城镇化加速期,我国粮食主产区和主销区的粮食生产与环境的协调度要优于粮食平衡区,但是粮食主产区和主销区的粮食生产环境在逐步恶化,粮食平衡区则在逐步好转;2人口城镇化有利于粮食主销区和平衡区粮食生产环境技术效率提升,对粮食主产区则相反。土地城镇化、产业发展城镇化和生态环境压力城镇化不利于全国及各粮食生产功能区粮食生产环境技术效率的提升;3城镇化对粮食生产环境技术效率的影响存在功能区差异性。     

环境测试舱自吸附甲醛重释放规律与影响因素研究

广泛用于板材污染物释放量测试、空气净化产品净化效果测试等实验中的环境测试舱,往往由于其内壁黏附性杂质而对目标测试物产生不可忽视的自吸附作用,自吸附污染物将作为二次释放源出现重释放,研究目标测试物的自吸附消耗量及重释放规律,探索有效控制措施,有利于对环境测试舱实验应用及室内污染控制提出指导性实际意义。分别选取0.2%甲醛溶液、大芯板作为同一自制玻璃环境测试舱2期实验(I期、Ⅱ期)的不同甲醛释放源,通过近90 d追踪测试,经不同释放源、不同控制条件下舱内壁自吸附甲醛的多次重释放实验,结合非线性拟合分析方法,总结出舱内壁自吸附甲醛重释放甲醛浓度变化符合一阶递增指数函数:y=A1×exp(-x/t1)+y0,(A1<0、t1>0)。曲线参数y0值可用于评价实验条件下测试舱内自吸附甲醛残余量;y0值与环境舱舱体材质、环境温湿度、舱外甲醛浓度及空气交换手段有关,而与释放源及其释放平衡浓度高低无明显关系。大开舱门短时间抽气式空气交换对舱内自吸附甲醛残余有适度清除效果,使y0值降低,同时有利于再次平衡状态的快速建立;而长时间的无动力空气交换,或者自来水洗及去离子水洗等处理手段对舱内壁自吸附甲醛残余无明显清除作用。     

Mathematical Model for Pollution Source Identification in Rivers

Release of pollution into rivers is required to be handled with special consideration to environmental standards. For this purpose, it is essential to specify the contribution of each pollution source in contamination of water resources. In this study, a mathematical model is proposed for determining locations and concentration release histories of polluting point sources using measured downstream river concentrations via an inverse problem framework. The inverse solution is based on the integral equation obtained from applying the Green's function method on the one-dimensional advection-dispersion contaminant transport equation. Discretization of this integral equation results in a linear, over-determined and ill-posed system of algebraic equations that are solved by using the Tikhonov regularization method. Several examples and some real field data are investigated to illustrate the abilities of the proposed model. Results imply that the proposed method is effective and can identify the pollution sources in rivers with acceptable accuracy.     

论创建环境友好型交通工程——以泰州大桥为例

在加快建设资源节约型、环境友好型社会的背景下,以生态学和环境科学角度论述交通工程的生态功能。从泰州大桥建设实际出发,阐述创建环境友好型工程须遵循的理论基础及方法原理,提出创建工作要点,为泰州大桥创建环境友好型工程提供理论和技术参考。     

Energy management in hybrid electric vehicles using optimized radial basis function neural network

This paper deals with energy management in hybrid electric vehicles. Use of radial basis function neural network (RBFNN) for the problem of energy management gains importance in the present decade. Use of genetic algorithm (GA) and particle swarm optimization (PSO) as optimization algorithms for parameter estimation is also well known. However, none of the researchers in the area tried to use GA and PSO as training algorithms for the problem. Hence in this paper, we propose two novel methods, based on RBFNN. The difference between RBFNN-based approaches in the literature and those used in this paper is the use of GA and PSO (i.e. optimising algorithms) as training algorithm to train RBFNNs. Interestingly, it is seen that the proposed approaches of this paper outperform RBFNN-based approaches in the literature with traditional training.     

Oxidative stress in the kidney injury of mice following exposure to lanthanides trichloride

Environmental pollution from lanthanides (Ln) has been recognized as a major problem due to a grab exploitation of Ln mine in China. Exposure to Ln has been demonstrated to cause the nephrotoxicity, very little is known about the mechanism of oxidative damage to kidney in animals. In order to understand Ln-induced nephrotoxicity, various biochemical and chemical parameters were assayed in mouse kidney. Intragastric exposures of LaCl₃, CeCl₃, and NdCl₃ at doses of 2, 5, and 10 mg kg⁻¹ BW for 90 consecutive days caused nephritis or epithelial cell necrosis and oxidative stress to kidney. An increase in coefficients of the kidney, La, Ce, and Nd accumulation and histopathological changes in the kidney could be observed, followed by increased reactive oxygen species production and peroxidation levels of lipid, protein and DNA, and decreased activities of superoxide dismutase, catalase, glutathione-S-transferase and glutathione reductase as well as antioxidants such as glutathione, ascorbic acid and thiol contents. Furthermore, La, Ce, and Nd significantly suppressed expression of genes and proteins of these antioxidative enzymes in mouse kidney. In addition, kidney functions were disrupted, including an increase of the creatinine, and reductions of uric acid, urea nitrogen, calcium and phosphonium. These findings suggest that nephritis generation or epithelial cell necrosis in mice following exposure to Ln is closely associated with oxidative stress. Of these damages, the most severe was in the Ce³⁺-exposed kidneys, next in the Nd³⁺-exposed kidneys, and the least in the La³⁺-exposed kidneys, which may be attributed to the 4f electron of Ln.     

饮用水功能区水环境健康风险阈值体系研究

结合天津市饮用水功能区水环境现状,筛选出14种特征污染物,通过危害识别将其分为化学致癌物、非致癌有毒物和特殊物质3类。针对不同类别污染物建立健康风险评价模型,给出化学致癌物的致癌强度系数、非致癌有毒物参考剂量、人均寿命、不同年龄段人群日均饮水量和平均体重等参数,建立针对不同人群的饮用水功能区水质风险阈值体系。在此基础上,对天津市饮用水功能区——于桥水库进行水质风险进行评价。结果显示,于桥水库国控监测点位10个监测指标中,氨氮、挥发酚、汞、铅具有健康风险,4个指标的浓度均处于10-7的风险水平以下,说明于桥水库水环境健康程度较好,4个指标对成人及儿童的风险水平排序为铅氨氮汞挥发酚,重金属铅是主要健康风险污染物。     

危机管理与员工疲劳预防

笔者通过课题小组所做的调查统计以及国内几家知名咨询公司发布的统计结果,强调员工工作疲劳问题的普遍性和严重性。在分析其原因及危害的基础上,论述国家及企业应从危机管理紧迫性的高度,实施带有战略性、系统性和全局性的员工工作疲劳防范对策;并为研究和预防疲劳提出包括借鉴日本疲劳研究经验在内的几点建议。同时呼吁:政府应采取必要措施,在提高国民健康素质、减少"疲劳"或"过劳"人群、遏制"过劳死"现象的频发方面发挥主导作用。     

Relating dissolved organic matter fluorescence and functional properties

The fluorescence excitation–emission matrix properties of 25 dissolved organic matter samples from three rivers and one lake are analysed. All sites are sampled in duplicate, and the 25 samples include ten taken from the lake site, and nine from one of the rivers, to cover variations in dissolved organic matter composition due to season and river flow. Fluorescence properties are compared to the functional properties of the dissolved organic matter; the functional assays provide quantitative information on photochemical fading, buffering capacity, copper binding, benzo[a]pyrene binding, hydrophilicity and adsorption to alumina. Optical (absorbance and fluorescence) characterization of the dissolved organic matter samples demonstrates that (1) peak C (excitation 300–350 nm; emission 400–460 nm) fluorescence emission wavelength; (2) the ratio of peak T (excitation 220–235 nm; emission 330–370 nm) to peak C fluorescence intensity; and (3) the peak C fluorescence intensity: absorbance at 340 nm ratio have strong correlations with many of the functional assays. Strongest correlations are with benzo[a]pyrene binding, alumina adsorption, hydrophilicity and buffering capacity, and in many cases linear regression equations with a correlation coefficient >0.8 are obtained. These optical properties are independent of freshwater dissolved organic carbon concentration (for concentrations <10 mg L⁻¹) and therefore hold the potential for laboratory, field and on-line monitoring and prediction of organic matter functional properties.     

乌鲁木齐市噪声污染状况及治理对策

乌鲁木齐声环境功能区可分为四类,通过对这些有代表性的噪声监测点进行长期定点监测,了解各类功能区声环境质量特征及受污染情况。通过对近3 a四类声环境功能区的噪声昼间、夜间连续等效声级及污染情况的统计分析,掌握乌鲁木齐市噪声污染状况,研究治理对策。