论二十一世纪环境文明

人类社会进入21世纪，工业文明带来严重的环境污染已成为全球性问题。人们在建设物质文明和精神文明的同时，呼唤有一个优美的生存环境。可持续发展战略已忧为社会经济发展的主旋律。环境文明成为人们生活新的追求和社会经济发展新的目标。环保产业的充分发展，环境污染得到有效控制，社会各行各业和所有产品都达到环保标准，生态协调平衡，这就铸成21世纪环境文明。     

The CO2 emission changes in China’s transportation sector during 1992–2015: a structural decomposition analysis

Environmental Science and Pollution Research - Based on a structural decomposition approach, the present paper simultaneously analyzes seven driving factors and forty sectors, which contribute to...     

Characteristics and sources of heavy metal pollution in desert steppe soil related to transportation and industrial activities

Environmental Science and Pollution Research - A study area was selected from the industrial region of Gaoshawo Town, Yanchi County, Ningxia, to explore the level of heavy metal pollution in desert...     

CFRP筋增强钢纤维混凝土梁受剪承载力试验与分析∗

对 CFRP 箍筋和纵筋增强钢纤维混凝土梁的受剪承载力进行研究,通过 6 根梁的加载试验研究了剪跨比、配箍率和箍筋种类对受剪承载力的影响。考虑 CFRP 纵筋与混凝土的粘结性能,建立了 CFRP 筋增强钢纤维梁受剪承载力计算方法。结果表明：①CFRP 筋增强钢纤维混凝土梁受剪承载力高,破坏前斜裂缝宽度大,破坏有明显预兆;②钢纤维可有效减小斜截面开裂后前期的 CFRP 箍筋应力,有利于箍筋强度发挥,CFRP 箍筋的极限应变可取为 0.004;③CFRP 纵筋发挥强度高,需注意锚固长度和设计使用应力,防止滑移拔出和销栓破断;④给出的受剪承载力计算方法具有较高的计算精度高。     

载波相位观测对传统双频GPS电离层模型改进研究

详细推导出利用GPS双频码距和载波相位观测联合双频码距进行电离层电子密度求定的2种模型,给出了求定这2种模型参数的数学表达,从理论上指出该2种模型分别适合单历元和多历元解算的基本条件,通过实例进行了2种模型的电离层修正误差的分析和比较.结果表明,载波相位观测联合双频码距建立电离层延迟模型具有观测数据利用率较高、解算精度...     

气升式反应器气液两相流流态特性模拟

为了研究曝气强度对气升式反应器内气液两相流特性的影响,组合多相流Eulerian—Eulerian模型和液相Standardk-ε湍流模型,运用Fluent软件建立了气升式反应器内气液两相流的三维非稳态数值模拟。在曝气管布局方式一定的情况下,模拟计算获得了反应器内x轴截面处不同径向位置的气含率、液速分布情况,计算结果表明,在本文研究的曝气强度范围内,气含率随着曝气强度增加而增加,越靠近曝气池底部,升流区局部气含率越高,且气含率值波动较大;随着曝气强度的增加,曝气孔附近液速增加较明显,但随着气液两相流的上升,液速增加幅度降低;同时采用粒子图像测速（PIV）技术对液相速度进行了实验研究,实验结果与模拟结果吻合性较好。     

生态水利研究的理论基础与重点领域

生态水利是近些年来涌现出的新兴学科研究领域.论文结合国内外相关研究进展和国家重大需求,总结了生态水利的概念内涵和学科发展特点,从系统理论、二元结构和安全边界角度阐释了生态水利研究的理论基础.在此基础上,进一步从水与生态系统的相互作用、水利工程的长期生态效应、河湖连通与湿地水系网络构建、受损生态系统的恢复、生态需水与生态...     

Mineral nutrient imbalance, DNA lesion and DNA-protein crosslink involved in growth retardation of Vicia faba L. seedlings exposed to lanthanum ions

Effects of mineral nutrient imbalance, DNA lesion and DNA-protein crosslink on growth of Vicia faba L. seedlings hydroponically cultivated in concentrations of extraneous lanthanum (La) for 20 days were investigated in the present experiment. The results showed that contents of La, Cu or K elements in roots generally changed synchronously with those in leaves, while Ca, Fe, Zn, Mg, Mn or P in the roots altered inversely to those in the leaves. Thus, the extraneous La led to redistribution and imbalance of mineral nutrient elements in the roots and leaves. DNA lesion and DNA-protein crosslink were investigated by single cell gel electrophoresis (SCGE) and sodium dodecyl sulfate/potassium (SDS/K⁺) precipitation methods, respectively. The results demonstrated that the increasing La induced DNA break and DNA-protein crosslinks (DPCs) in the seedlings. These results suggested that mineral nutrient imbalance, DNA lesion and DNA-protein crosslink were involved in the growth retardation and growth alteration of the seedlings, which may help to understand the mechanisms of rare earth elements (REEs) on plant growth.     

Spatial Patterns of Macrobenthic Communities in Shallow-Water Tidal Embayments and Their Association with Environmental Factors

This study examines the distribution, composition, and structure of benthic communities in nine shallow-water semienclosed embayments on Cape Cod, southeastern Massachusetts. The spatial patterns were used to associate benthic characteristics with local environmental factors. Field data from multiple years were collected to measure macrofaunal abundance, community composition, and environmental characteristics. Multivariate statistics were used to analyze the spatial variations of species composition and the abundance of benthic macrofauna. Canonical ordination, specifically redundancy analysis, was used to determine the relative importance of the environmental factors (nutrients and habitat factors) being studied. The analyses demonstrate that the benthic communities in the shallow tidal embayments are clearly clustered in association with the local environments. Species composition and community structure of the benthic macrofauna are significantly correlated with water column parameters, especially with phytoplankton biomass, total nitrogen, and dissolved oxygen.     

实施清洁生产 创建绿色企业——开展清洁生产工作的几点体会

文章阐述了辽河油田公司开展清洁生产工作的基本情况,结合管理现状,分析总结了开展清洁生产工作的管理经验,阐述了通过科技进步所取得的清洁生产成绩,归纳整理出可借鉴的清洁生产审核经验,为清洁生产审核工作提供了有益的建议。