Exploring the formation potential and optical properties of secondary organic aerosol from the photooxidation of selected short aliphatic ethers

Secondary organic aerosol (SOA) formation potential for six kinds of short aliphatic ethers has been studied. The size distribution, mass concentration, and yield of SOA formed by ethers photooxidation were determined under different conditions. The results showed that all six ethers can generate SOA via reaction with OH radicals even under no seed and NO_x-free condition. The mass concentration for six seedless experiments was less than 10 µg/m³ and the SOA yields were all below 1%. The strong increase in the SOA formation was observed when the system contained ammonium sulfate seed particles, while SOA yield decreased under the high-NO_x condition. SOA composition was analyzed using offline methods. Infrared spectra indicated that there are complex components in the particle-phase including carbonyls acid and aldehydes species. Moreover, the aqueous filter extracts were analyzed using ultraviolet-visible spectrometer and fluorescence spectrophotometer. For the fresh methyl n-butyl ether SOA, the largest absorption peak occurs at 280 nm and there exists slightly absorption in the 300–400 nm. Excitation-emission matrices display the distinct peak at excitation/emission = 470 nm/480 nm according to the fluorescence spectrum. These findings are important considerations of formation for ether SOA that can eventually be included in atmospheric models.     

砂砾质地表不同粒径颗粒地球化学特征分析

风沙运动造成地表沉积物组分发生改变,伴随其沉积物地球化学特征发生改变。选取苏宏图洪积扇扇缘戈壁、沙积洼地地表沉积物,基于X射线衍射仪、扫描电镜能谱仪进行其不同组分矿物、地球化学元素测试。结果表明:风沙运动导致不同地表沉积物的风蚀和风积情况不同,但其均处于化学风化的初、中级阶段,具有相似性;该砂砾质地表不同粒径组分以石英、长石、云母、方解石等矿物为主,各沉积物组分矿物衍射峰强具有显著差异性;该区域不同粒径颗粒化学元素组成以SiO_2、Al_2O_3、Fe_2O_3为主,约占总含量的85%左右,沉积物颗粒粒径越大,SiO_2含量越多,Fe_2O_3、MgO、CaO、TiO_2等氧化物表现为在细颗粒组分中富集,而Al_2O_3、K_2O、Na_2O等随颗粒粒径变化无显著差异。     

Toxicity assessment and histopathological analysis of nano-ZnO against marine fish (Mugilogobius chulae) embryos

The toxicity of nano-materials has received increasing attention in recent years.Nevertheless,relatively few studies have focused on their oceanic distributions and toxicities.In this study,we assessed nano-ZnO toxicity in marine organisms using the yellowstriped goby(Mugilogobius chulae).The relative differences in nano-ZnO dissolution and dispersal in seawater and fresh water were also investigated.The effects of nano-ZnO on embryonic development,deformity,hatching,mortality,and histopathology were analyzed.In addition,the effects of the Zn~(2+) concentration on M.chulae hatching and mortality were compared.The results showed that nano-ZnO had higher solubility in seawater than in fresh water.Nano-ZnO significantly inhibited hatching.By the fifth day of exposure,the LC_(50) of nano-ZnO was 45.40 mg/L,and the mortality rate spiked.Hatching inhibition and lethality were dose-dependent over a range of1–25 mg/L nano-ZnO.Zn~(2+) inhibited hatching and increased lethality,but its effects were weaker than those of nano-ZnO at the same concentrations.Nano-ZnO also induced spinal bending,oedema,hypoplasia,and other deformities in M.chulae embryos and larvae.Histopathology revealed vacuolar degeneration,hepatocyte and enterocyte enlargement,and morphological abnormalities of the vertebrae.Therefore,nano-ZnO caused malformations in M.chulae by affecting embryonic growth and development.We conclude that nano-ZnO toxicity in seawater was significantly positively correlated with the associated Zn~(2+) concentration and sedimentary behaviour.The toxicity of nano-ZnO was cumulative and showed a critical point,beyond which embryonic and developmental toxicity in marine fish was observed.     

中国矿业大学南湖校区噪声污染等级监测研究

以中国矿业大学南湖校区为例,采用分功能区监测布点的方法对校园各功能区人群密集地点的噪声污染等级进行监测和分析,以探明大学校园内各功能区人员密集时噪声所能达到的最大声级,并进行评价分析.结果表明:在人流密集状态下,校园内的各测点噪声等级均在60dB以上,处于噪声超限状态.故虽然校园内各测点全天的等效声级不超限或基本达到《声环境质量标准》(GB 3096-2008)的要求,但实质上校园声环境却时常处于"亚健康"状态.     

Expansion of Urban Space and Land Use Control in the Process of Urbanization: an Overview

Urban expansion brought by the rapid progress of urbanization has caused many problems in China. It is a significant issue to evaluate the extent of urban expansion and to make appropriate controls over the sprawl of urban areas. With a comparative study of international experiences, this article analyzed the mechanism and consequences of urban expansion, reviewed the typical planning and financial policies adopted by other countries for controlling urban sprawl, and discussed the suitable densities of urba...     

Displacement as a predictor of functional impairment in tsunami‐exposed children

Thirty months after the Indian Ocean tsunami of 26 December 2004, thousands of families in Aceh Province, Indonesia, remained in temporary barracks while sanitation conditions and non‐governmental organisation support deteriorated. This study sought to determine the factors associated with functional impairment in a sample of 138 displaced and non‐displaced Acehnese children. Using multivariate linear regression models, it was found that displacement distance was a consistent predictor of impairment using the Brief Impairment Scale. Exposure to tsunami‐related trauma markers was not significantly linked with impairment in the model. Paternal employment was a consistent protective factor for child functioning. These findings suggest that post‐disaster displacement and the subsequent familial economic disruption are significant predictors of impaired functioning in children's daily activities. Post‐disaster interventions should consider the disruption of familiar environments for families and children when relocating vulnerable populations to avoid deleterious impacts on children's functioning.     

Mercury in the Mediterranean. Part 2: processes and mass balance

Mass balance of contaminants can provide useful information on the processes that influence their concentrations in various environmental compartments. The most important sources, sinks and the equilibrium or non-equilibrium state of the contaminant in individual environmental compartments can also be identified. Using the latest mercury speciation data, the results of numerical models and the results of recent studies on mercury transport and transformation processes in the marine environment, we have re-evaluated the total mercury (HgT) mass balance in the Mediterranean Sea. New calculations have been performed employing three distinct marine layers: the surface layer, the thermocline and the deep sea. New transport mechanisms, deep water formation and density-driven sinking and upwelling, were included in the mass balance calculations. The most recent data have even enabled the calculation of an approximate methylmercury (MeHg) mass balance. HgT is well balanced in the entire Mediterranean, and the discrepancies between inputs and outputs in individual layers do not exceed 20 %. The MeHg balance shows larger discrepancies between gains and losses due to measurement uncertainties and gaps in our knowledge of Hg species transformation processes. Nonetheless, the main sources and sinks of HgT (deposition and evasion) and MeHg (fluxes from sediment, outflow through the Gibraltar Strait) are in accordance with previous studies on mercury in the Mediterranean Basin. Mercury in the Mediterranean fish harvest is the second largest MeHg sink; about 300 kg of this toxic substance is consumed annually with sea food.     

Species identification and mutation breeding of silicon-activating bacteria isolated from electrolytic manganese residue

Environmental Science and Pollution Research - A strain of silicon-activating bacteria was isolated from electrolytic manganese residue (EMR); identified as a species of Ochrobactrum by integrated...     

A Protocol for Plant Conservation by Translocation in Threatened Lowland Fynbos

Abstract: A form of lowland, sandplain Fynbos restricted to the Cape Flats near the city of Cape Town is the South African vegetation type most threatened by urban and agricultural development. Cape Flats Fynbos remnants, totaling 4.8 km², contain 14 plant species endemic to the Cape Flats scattered through four protected areas and 11 unprotected vegetation fragments on public land. Despite their small size and management problems, the remaining protected areas are under pressure from the public and developers to function as "lifeboats," or places of safety, for attractive indigenous plant species from the unprotected areas destined for development because the popular perception is that any indigenous plant population threatened by habitat destruction should be saved by being transplanted into a protected area. The urgency for dealing with the issue of plant rescue in the Cape Town metropolitan area was the catalyst for a workshop held at the University of Cape Town in 1998 to develop protocols for Fynbos plant species translocations. We report on points raised by managers and academics at the workshop, including the selection of target taxa, individuals, and establishment sites, and methods for introduction, and present case histories illustrating possible solutions to the problems encountered.