An Empirical Study on the Environmental Kuznets Curve for China’s Carbon Emissions:Based on Provincial Panel Data

Based on the Environmental Kuznets Curve theory,the authors choose provincial panel data of China in 1990 2007 and adopt panel unit root and co-integration testing method to study whether there is Environmental Kuznets Curve for China’s carbon emissions.The research results show that:carbon emissions per capita of the eastern region and the central region of China fit into Environmental Kuznets Curve,but that of the western region does not.On this basis,the authors carry out scenario analysis on the occurrence time of the inflection point of carbon emissions per capita of different regions,and describe a specific time path.     

万山汞矿区稻田土壤甲基汞的分布特征及其影响因素分析

运用等温气相色谱冷原子荧光技术(GC-CVAFS)对贵州万山汞矿区主要河流范围内稻田土壤甲基汞(MeHg)等含量进行了测定,并从区域层面对土壤甲基汞(MeHg)的分布特征及影响因素进行了研究。结果表明:万山汞矿区稻田土壤MeHg和总汞(THg)含量范围分别为0.72~6.70ng/g和0.49~188.00μg/g,甲基化率范围为0.002%~0.470%;在水平空间分布上,6个检测区域的土壤MeHg含量均随着远离汞矿核心区而降低,但是不同区域之间的降低变化程度不尽相同。通过对稻田土壤SiO2、Al2O3、Fe2O3、TS、TP、TN、有机质、pH等土壤性质与土壤MeHg以及甲基化率进行相关性分析发现,MeHg与THg、TS、TP、TN、有机质存在显著的正相关关系,与SiO2表现出显著性负相关,表明土壤甲基汞不但和总汞含量有关,还受到土壤其它理化因子,尤其是一些营养因子所控制。     

Distribution and dissipation pathways of nonylphenol polyethoxylates in the Yellow River: Site investigation and lab-scale studies

Spatial distribution of nonylphenol polyethoxylates (NPEOs) and nonylphenol (NP) was investigated in a field study in Lanzhou Reach of the Yellow River. NPEOs and their metabolites were found in the river, with the maximum dissolved concentrations of 6.38 nmol/L for NPEOs, 0.19 nmol/L for nonylphenol ethoxy acetic acids (NPECs) and 0.79 nmol/L for NP, respectively. The maximum concentrations in the sediment and suspended particle samples were 1.50 and 5.09 nmol/g for NPEOs and NP, respectively. The effects of particles, light and microorganism on the dissipation of NPEOs in the river water were investigated based on lab-scale experiments. When natural particles were removed, 72% and 22% degradation of NPEOs were achieved at 120 h in non-sterile and sterile conditions with light, respectively. Different concentrations of NPECs were also observed in these experiments. When suspended particle matters (SPMs) were present, about 38-50% of NPEOs were sorbed to the particulate phase in only 1 h. As a result, the degradation of NPEOs and production of NPECs were inhibited. However, the combined sorption and degradation in the presence of SPMs resulted in lower dissolved NPEO concentrations than those in the absence of SPMs. Biodegradation was the most important pathway for NPEOs degradation in the river water, while NPECs seemed to be produced through both biological and abiological pathways.     

Fabrication and photoelectrocatalytic properties of nanocrystalline monoclinic BiVO4 thin-film electrode

Monoclinic bismuth vanadate(BiVO4) thin film was fabricated on indium-tin oxide glass from an amorphous heteronuclear complex via dip-coating.After annealation at 400,500,and 600°C,the thin films were characterized by X-ray diffraction,field emission scanning electron microscopy,X-ray photoelectron spectroscopy,and UV-Vis spectrophotometry.The BiVO4 particles on the ITO glass surface had a monoclinic structure.The UV-Visible diffuse reflection spectra showed the BiVO4 thin film had photoabsorption propertie...     

上埋式管道穿越高填方填挖结合部位的受力状态研究

以延安新区黄土高填方工程中的上埋式排水管道为原型,开展了相似比为1:2的室内试验,试验前在模型箱底部一定位置预设沉降底板模拟实际填方的工后沉降过程,在试验土体和管道中布设压力盒、位移计和应变片,以采集试验过程中的管土接触压力、管-土相对位移和管道应变等数据。研究表明,负土拱效应对管道的上部压力影响明显,竖向压力系数最大达3.4,与沉降量的关系符合三次多项式曲线,负土拱效应对管道的影响不可忽略。开挖纵向剖面后发现管道下部土层间出现明显的脱空裂缝,是管道下部管-土接触压力减小的原因。该成果为黄土高填方场地中管周土压力的计算、管道变形控制提供参考。     

渭河干流(宝鸡段)表层沉积物Cu、Zn、Pb污染特征与评价

对渭河干流（宝鸡段）表层沉积物中重金属Cu、Zn、Pb含量进行了调查,用潜在生态危害系数法对其污染水平进行了评价,并与松花江（吉林市段）、淮河（江苏段）、长江（下游）、苏州河、珠江（广州段）5条河流表层沉积物中Cu、Zn、Pb的含量做了对比研究。结果表明,3种重金属元素平均含量均超出相应的土壤背景值,出现了一定程度上的富集;生态危害系数均〈40,属轻微生态危害。重金属含量水平在国内诸河中处于中间位置。     

同步辐射技术在环境纳米金属组学研究中的应用

随着我国工业的发展,在工业产值不断提升的同时,向环境中释放出的各类污染物也逐渐增加,其中包括多种金属纳米颗粒物。这些金属纳米颗粒物进入大气、水源及土壤中,累积到一定程度引起环境安全问题;进一步可被动植物所吸收,经过食物链富集和传递,造成直接或间接人体暴露,危害人体健康。环境纳米金属组学,研究的范畴主要涉及自然或人为因素产生的金属纳米颗粒在环境介质和生物有机体中的生物/化学行为、转化归趋,并且据此评价金属纳米颗粒物的环境安全性及其生物健康效应。随着对金属纳米颗粒环境效应研究的不断深入,对传统的研究方法提出了更多的挑战。同步辐射具有高亮度、高准直和宽频谱等特性,在金属元素分析方面具有无可比拟的优势。本文主要介绍了同步辐射技术,如同步辐射X射线荧光分析技术(SR-XRF)和同步辐射X射线吸收光谱技术(SR-XAS)等,在金属纳米颗粒物的环境行为及其生物健康效应研究中的应用;结合本实验室及国内外的一些研究工作,阐述了同步辐射技术应用于环境纳米金属组学研究领域所取得的一些新进展,以期为拓展同步辐射技术在环境金属纳米颗粒物分析的应用研究提供参考价值。     

估算天津环境中γ-HCH归宿的逸度模型

以全天津市为研究区域,利用稳态假设的逸度模型,用Matlab软件计算了γ-HCH(林丹)在环境各相中的浓度和相间迁移通量.γ-HCH在天津气、水、土壤、沉积物、鱼、作物、蔬菜各相中的浓度分别为1.57×10^-11、7.95×10^-7、1.17 × 10^-4、4.58×10^-4、6.03×10^-4、1.60×10^-4和6.42×10^-5mol/m³,在数量级上与实测值吻合很好.估算结果表明农业施用和农药厂废水是该地区环境中γ-HCH最主要的来源,最大的汇是土壤和沉积相(占环境中总量的99%),最主要的迁移过程是水-沉、气-土的扩散和沉降,土壤和沉积物中的降解是γ-HCH消失的最主要途径.     

我国危险化学品产业转移及安全风险分析*

为深入分析我国国内（不含港澳台,下同）危险化学品产业转移及安全风险,通过调研产业转移现状,统计典型地区产业政策、转移企业数量、转移时间及安全生产形势,分析产业转移带来的安全风险。研究结果表明:危险化学品产业转移呈现明显地域趋势,从以江苏、浙江为主的东部沿海地区向中西部等地区转移;转移时间集中在2个阶段,分别是:2002—2008年、2017—2020年;转移集中在精细化工、炼焦、煤化工等产业,医药等高端产业未发生转移;危险化学品产业转移安全风险主要表现在:“重经济,轻安全”现象突出、转移项目安全风险高、承接地基础薄弱、人才储备不足等方面;针对呈现的产业转移安全风险,提出相关对策措施及建议。研究结果可为我国危险化学品产业转移安全风险管控政策措施制定提供相关数据与理论支撑。     

Identification of close relationship between atmospheric oxidation and ozone formation regimes in a photochemically active region

Understanding ozone (O₃) formation regime is a prerequisite in formulating an effective O₃ pollution control strategy. Photochemical indicator is a simple and direct method in identifying O₃ formation regimes. Most used indicators are derived from observations, whereas the role of atmospheric oxidation is not in consideration, which is the core driver of O₃ formation. Thus, it may impact accuracy in signaling O₃ formation regimes. In this study, an advanced three-dimensional numerical modeling system was used to investigate the relationship between atmospheric oxidation and O₃ formation regimes during a long-lasting O₃ exceedance event in September 2017 over the Pearl River Delta (PRD) of China. We discovered a clear relationship between atmospheric oxidative capacity and O₃ formation regime. Over eastern PRD, O₃ formation was mainly in a NO_x-limited regime when HO₂/OH ratio was higher than 11, while in a VOC-limited regime when the ratio was lower than 9.5. Over central and western PRD, an HO₂/OH ratio higher than 5 and lower than 2 was indicative of NO_x-limited and VOC-limited regime, respectively. Physical contribution, including horizontal transport and vertical transport, may pose uncertainties on the indication of O₃ formation regime by HO₂/OH ratio. In comparison with other commonly used photochemical indicators, HO₂/OH ratio had the best performance in differentiating O₃ formation regimes. This study highlighted the necessities in using an atmospheric oxidative capacity-based indicator to infer O₃ formation regime, and underscored the importance of characterizing behaviors of radicals to gain insight in atmospheric processes leading to O₃ pollution over a photochemically active region.