Identifying factors that influence soil heavy metals by using categorical regression analysis: A case study in Beijing,China

A method was proposed to identify the main influence factors of soil heavy metals. The influence degree of different environmental factors was ranked. Parent material, soil type, land use and industrial activity were main factors. Interactions between some factors obviously affected soil heavy metal distribution. Identifying the factors that influence the heavy metal contents of soil could reveal the sources of soil heavy metal pollution. In this study, a categorical regression was used to identify the factors that influence soil heavy metals. First, environmental factors were associated with soil heavy metal data, and then, the degree of influence of different factors on the soil heavy metal contents in Beijing was analyzed using a categorical regression. The results showed that the soil parent material, soil type, land use type, and industrial activity were the main influencing factors, which suggested that these four factors were important sources of soil heavy metals in Beijing. In addition, population density had a certain influence on the soil Pb and Zn contents. The distribution of soil As, Cd, Pb, and Zn was markedly influenced by interactions, such as traffic activity and land use type, industrial activity and population density. The spatial distribution of soil heavy metal hotspots corresponded well with the influencing factors, such as industrial activity, population density, and soil parent material. In this study, the main factors affecting soil heavy metals were identified, and the degree of their influence was ranked. A categorical regression represents a suitable method for identifying the factors that influence soil heavy metal contents and could be used to study the genetic process of regional soil heavy metal pollution.     

沈阳市水污染物排放总量控制的研究

以沈阳市为实例，详细地介绍了城市水污染物排放总量控制的系统结构，探讨和论述了总量控制因子和总量控制目标的制定原则、方法，实现总量控制目标的措施，总量的考核与管理．     

乙烯裂解废碱氧化影响因素分析

就影响独山子石化公司乙烯裂解装置废碱液氧化反应的因素，在实验室小试规模试验的基础上，对影响因素进行分析和探讨，着重分析了装置在运行过程中出现的问题和存在的不足，在对现有装置工艺不做大的改动的前提下，提出了装置的技术改造建议。     

Indoor air particles in research vessel from Shanghai to Antarctic: Characteristics, influencing factors, and potential controlling pathway

Despite millions of seafarers and passengers staying on ships each year, few studies have been conducted on the indoor air quality inside ship hulls. In this study, we investigated the levels and size distribution of indoor particulate matter during two cruises of the research vessel “Xuelong” from Shanghai to Antarctica. The results showed that the particle size less than 2.5 µm (PM_2.5), and particle size less than 10 µm (PM₁₀) concentrations in different rooms of the ship widely varied. We observed high particulate matter (PM) levels in some of the rooms. The mass concentration distribution was dominated by 1–4 µm particles, which may have been caused by the hygroscopic growth of fine particles. The dominant factors influencing PM concentrations were indoor temperature, relative humidity, and human activity. We quantified contributions of these factors to the levels of indoor particles using a generalized additive model. In clean rooms, the levels of indoor particles were controlled by temperature and relative humidity, whereas in polluted rooms, the levels of indoor particles were mainly influenced by temperature and human activity, which implied that controlling temperature and human activity would efficiently reduce the levels of indoor particles.     

浅谈绿色生态住宅供需双方应注意的问题

介绍了绿色生态住宅理念的提出背景、绿色生态住宅所遵循的战略及其内涵,指出绿色生态住宅的核心是遵循住宅可持续发展战略.一方面,重点从环境规划设计、室内环境质量、小区水环境、材料与资源及建筑节能等6个方面论述了开发商在开发建设绿色生态住宅时应达到的技术和标准,以规范绿色生态住宅的开发与建设;另一方面,提醒消费者在购买绿色生态住宅时应着重考虑日照时间、空气湿度、主导风向和空气质量等气象因素及环境要素.     

辽宁海洋经济持续发展与海洋生态环境保护

海洋经济正在成为世界各沿海国家国民经济新的增长点。本文分析了辽宁发展海洋经济的巨大潜力和优势 ,探讨了发展海洋经济存在的制约因素 ,提出了保护海洋环境实现海洋经济可持续发展的相应对策     

烟囱排烟扩散的影响因素初步研究

为减少和控制工业锅炉烟囱排放中的有害气体对自然生态环境的污染，设计单位的专业工程设计人员在锅炉房设计布置中，除了应根据锅炉的蒸发量来确定风，烟道的截面外，还须根据不同地区的气象条件，局部地形等实际情况，来决定锅炉房烟囱的设计。文章简妻介绍了风速、风向，湍流强度及大气稳定度对烟囱排烟扩散的影响。     

Exploring the abundance and influencing factors of antimicrobial resistance genes in manure plasmidome from swine farms

Plasmids play a critical role in the dissemination of antimicrobial resistance genes (ARGs), however, a systematical understanding of ARGs originated from plasmids in swine production is currently lacking. Herein, quantitative polymerase chain reaction was applied to determine the prevalence of ten ARGs and the class1 integron gene intI1 of plasmid source in swine manure from 44 farms in Sichuan, Hubei and Hebei provinces, China. All assayed ARGs were observed in plasmid DNA samples, and the average absolute abundance of aac(6’)-Ib-cr, bla_NDM, bla_CTX-M, optrA, ermB, floR, mcr-1, qnrS, tetM, sul1 and intI1 were 7.09, 2.90, 4.67, 6.62, 7.55, 7.14, 4.08, 4.85, 7.16, 7.11 and 8.07 of 10 log copies/gram, respectively. IntI1 showed a high correlation (r > 0.8, P < 0.01) with the abundance of aac(6’)-Ib-cr and sul1 in swine manure. Moreover, the farm scale (i.e., herd population) and geographical location were not found to be critical factors influencing the absolute abundance of ARGs of plasmid DNA in swine farms. However, the concentrations of florfenicol, Cu, Zn, Fe, total phosphorus (TP) and total potassium (TK) demonstrated a significant correlation with the abundance of several ARGs. Particularly, Cu and Zn had high correlations with optrA and bla_CTX-M, respectively. Our results demonstrated that antibiotics, heavy metals and environmental nutrients are likely jointly contributing to the long-term persistence of ARGs in swine production. This study provides insights into the abundance and influencing factors of ARGs from swine manure, which is of significance for assessing and reducing the public health risks in livestock production.     

湿地土壤有机碳及其活性组分分布特征影响因素研究

红碱淖湖泊湿地是西北半干旱荒漠区重要的生态屏障,随着湖泊面积的减少以及土壤退化程度的加剧,逐渐形成5种典型的景观类型(盐碱沼泽、沼泽化草甸、草地、草原化沙地、沙地)。基于野外实地调查,选取红碱淖湖泊湿地流域蟒盖兔和尔林兔2个典型子流域,研究湖泊退化后不同景观类型土壤有机碳及其活性组分的分布特征及其影响因素。结果表明,5种景观类型土壤有机碳(SOC)、土壤可溶性有机碳(DOC)、土壤易氧化态有机碳(EOC)含量均较低。土壤SOC和EOC在垂直剖面上分布特征一致,土壤EOC与土壤有机质动态变化密切相关,土壤砂砾含量高是研究区土壤有机碳含量较低的主要原因。     

基于STIRPAT模型的黑龙江省碳排放影响因素研究

2005年以来,黑龙江省社会经济持续稳步发展,截至2017年,全省GDP达到15903亿元,增长近3倍,人均GDP增长2.89倍,城镇化率达到60%,第三产业占全省生产总值比重达到55.82%。与此同时,全省碳排放量从19095万吨增加到27251万吨,增长1.43倍。通过对黑龙江省13年间社会经济数据的系统分析研判,人均GDP、城镇化率、碳排放强度等因素对全省碳排放量影响显著。