安全科学与灾害学探讨

本文探讨了安全科学与灾害学之间的关系,分析了安全科学的发展历史及其学科体系,对发展我国安全科学提出了建议。     

可口可乐饮料公司安全生产监督管理经验探讨

太原可口可乐饮料有限公司具有完善的安全生产管理体系,分别从安全理念、经费投入、培训考核、监督制度、认证审核和安全文化6个方面介绍公司安全生产管理方面的经验,有一定的推广价值.     

微量元素在癌变过程中的作用

近些年来一些方面进展使得有可能对微量元素在癌变过程中的作用提出新认识,这些新认识可以归纳如下: 1.微量元素具有直接致癌作用。 2.擞量元素具有促癌作用。即: (1)可能促进或加强化学致癌物在体内的活化过程; (2)可能活化肿瘤病病毒; (3)一般认为造成内分沁失调而加速癌变过程; 3.微量元素具抑癌作用。     

城乡交通一体化驱动下江苏农村医疗卫生服务可达性

农村医疗卫生服务均等化是国家乡村振兴规划的主要目标。在城乡交通一体化驱动下，机动化出行已然成为广大农户交通出行的优先偏好，在此背景下，农村医疗卫生服务均等化研究具有时代紧迫性和必要性。以江苏为例，基于GIS网络分析方法分别测度步行、电动车和汽车出行方式下农村医疗卫生服务可达性水平，力图揭示城乡交通一体化驱动下农村医疗卫生服务可达性与供需匹配特征。研究表明：步行方式下农村医疗卫生可达性水平低，而电动车能保证大部分农村享受较高水平卫生站可达性，汽车则使大多数农户享受高水平的医院可达性，城乡交通一体化是促进农村医疗卫生服务均等化发展的关键因素，它能够有效地破解农村医疗服务均等化过程中农村医疗卫生服务供给不足、供需不符和利用率低下问题，为农户共享高质量医疗卫生服务创造必要条件。有鉴于此，为了实现城乡医疗卫生服务均等化目标，应继续加快城乡交通一体化步伐，探讨构建城乡交通一体化框架下医疗卫生服务体系规划方案，优化城乡医疗卫生服务设施布局。     

灰色预测法在南宁市可持续发展趋势分析中的应用

本文运用灰色系统理论 ,建立灰色预测模型 ,对南宁市社会、经济及生态环境发展趋势进行了分析 ,并针对南宁市发展中的不合理状况 ,提出相应的调控对策。     

Three-dimensional modeling of air flow and pollutant dispersion in an urban street canyon with thermal effects

Effects of excess ground and building temperatures on airflow and dispersion of pollutants in an urban street canyon with an aspect ratio of 0.8 and a length-to-width ratio of 3 were investigated numerically. Three-dimensional governing equations of mass, momentum, energy, and species were modeled using the RNG k-epsilon turbulence model and Boussinesq approximation, which were solved using the finite volume method. Vehicle emissions were estimated from the measured traffic flow rates and modeled as banded line sources, with a street length and bandwidths equal to typical vehicle widths. Both measurements and simulations reveal that pollutant concentrations typically follow the traffic flow rate; they decline as the height increases and are higher on the leeward side than on the windward side. Three-dimensional simulations reveal that the vortex line, joining the centers of cross-sectional vortexes of the street canyon, meanders between street buildings and shifts toward the windward side when heating strength is increased. Thermal boundary layers are very thin. Entrainment of outside air increases, and pollutant concentration decreases with increasing heating condition. Also, traffic-produced turbulence enhances the turbulent kinetic energy and the mixing of temperature and admixtures in the canyon. Factors affecting the inaccuracy of the simulations are addressed.     

Development of an ELISA for the detection of bromoxynil in water

For development of an indirect competitive enzyme-linked immunosorbent assay (ELISA) for the nitrile herbicide bromoxynil, the polyclonal antibodies raised against 2,6-dibromo-4-cyano-phenoxyacetic acid (hapten) conjugated to bovine serum albumin (BSA) by the N-hydroxysuccinimide-activated ester method. Antiserum with a sufficiently high titer to provide the determinations of targeted compounds was obtained only 77 days after the primary immunization. Antiserum A2 was applied to the residual analysis of some water samples, under optimized ELISA condition, the quantitative working range was from 10 to 500 ppb with a limit of detection of 5 ppb. Cross-reactivity to structurally similar agrochemicals and related chemicals was determined. The antiserum showed little cross-reactivity with 2,6-dibromophenol and bromoxynil octanoate ester which have a dibromophenol group as common structure, but showed no cross-reactivity with other herbicides. Each water sample (river water, tap water, purified water, and bottled water) had a matrix effect and was investigated by adding Tween20 in the assay buffer. These four kinds of water samples were fortified with bromoxynil at several concentration levels and were directly analyzed with only dilution with an equal volume of antiserum solution, the mean recovery was 102.3%, and the mean coefficient of variation was 5.96%. The proposed ELISA turned out to be a powerful tool for monitoring of residual bromoxynil in water samples at trace level.     

Mathematical model for carbon dioxide evolution from the thermophilic composting of synthetic food wastes made of dog food

The impacts of the aeration and the agitation on the composting process of synthetic food wastes made of dog food were studied in a laboratory-scale reactor. Two major peaks of CO(2) evolution rate were observed. Each peak represented an independent stage of composting associated with the activities of thermophilic bacteria. CO(2) evolutions known to correlate well with microbial activities and reactor temperatures were fitted successfully to a modified Gompertz equation, which incorporated three biokinetic parameters, namely, CO(2) evolution potential, specific CO(2) evolution rate, and lag phase time. No parameters that describe the impact of operating variables are involved. The model is only valid for the specified experimental conditions and may look different with others. The effects of operating parameters such as aeration and agitation were studied statistically with multivariate regression technique. Contour plots were constructed using regression equations for the examination of the dependence of CO(2) evolution potentials on aeration and agitation. In the first stage, a maximum CO(2) evolution potential was found when the aeration rate and the agitation parameter were set at 1.75 l/kg solids-min and 0.35, respectively. In the second stage, a maximum existed when the aeration rate and the agitation parameter were set at 1.8 l/kg solids-min and 0.5, respectively. The methods presented here can also be applied for the optimization of large-scale composting facilities that are operated differently and take longer time.     

我国小康生活水平的测量尺度与标准

本文在分析我国经济、社会发展规划、目标和现代化进程的基础上,借鉴国际上的通用标准,并结合我国国情,提出了我国小康生活水平的测量标准,建立了由20个指标构成的小康生活水平指标体系。     

PRED问题与地理工程

本文首先定义了由人口、资源、环境和发展构成的PRED问题的思路,讨论了它的性质;然后提出用地理工程解决PRED问题,并构建了地理工程的理论框架。