遥测台网尾波持续时间震级公式探讨

本文用回归方法探讨建立用尾波持续时间τ确定震级的经验公式,以安徽省无线遥测台网的资料为例用lg~aτ和震中距Δ作为自变量,选择较佳形式。本文比较了使用τ的平均值(?)和各台各自持续时间的方法,也考虑了台站的校正值问题,最后提出了适合安徽台网的公式。M_D=0. 573lg~2τ+0. 00025Δ+0. 581+δ_i     

安全投资技术经济分析的研究

在分析安全投资项目特殊性的基础上，提出了较为完整的安全投资技术经济分析方法，为企业进行安全投资决策提供了充分的依据。     

溴甲酚绿──甲基红分光光度法测定空气中的痕量氨

本文研究了用溴甲酚绿－甲基红分光光度法测定空气中的痕量氨。在５ｍｌ吸收液中氨浓度０－２．７２μｇ／５ｍｌ遵守比尔定律。表观摩尔吸光系数ε＇６１５＝１．５５×１０４Ｌ／ｍｏｌ·ｃｍ。在采样过程中，吸收液颜色由红变绿。     

饮水中三卤甲烷形成机理与处理技术现状

综述了水中腐酸氯化产物及其形成三卤甲烷的反应历程及各种环境条件如ｐＨ值，光照及自由基对ＴＨＭｓ形成的影响，并提出控制和去除饮水ＴＨＭｓ的方法。     

广西来宾栖霞组缺氧沉积环境地球化学特征

地层的岩石地球化学特征是判断其形成环境氧化还原条件的重要手段之一。本文对广西来宾铁桥剖面栖霞组中层纹状灰岩和含泥质灰岩进行地球化学分析 ,结合栖霞组沉积学和古生态学特征 ,对栖霞组沉积环境进行了探讨。岩石微量元素含量、黄铁矿矿化程度 (DOP值 )、痕量元素V/Cr、Ni/Co、U/Th、V/(V +Ni)等比值的研究结果显示 ,研究区具有缺氧沉积成因的地球化学特征。     

微生物降解炼油厂含酚废水的实验研究

采用燕化集团公司炼油事业部污水厂的活性污泥为菌源 ,好氧条件下通过分离、驯化筛选出三种高效降酚微生物。并在实验室模拟三相生物流化床分别对人工含酚废水和燕山石化炼油厂含酚废水进行降解实验 ,结果显示 ,在三相生物流化床中使用微生物包埋法制作的海藻酸钙载体处理含酚废水 ,3小时段内降酚显著 ,t -testP <0 0 1,处理效果良好 ,并以海藻酸钠为主要原料制作载体可以极大降低处理成本     

膜法解吸CO_2吸收富液

采用中空纤维膜接触器(FMC)作为解吸装置,对吸收了CO_2的N-甲基二乙醇胺(MDEA)溶液(富液)进行膜法解吸实验。考察了CO_2负荷、解吸温度、解吸压力、富液流速和N_2吹扫流量对CO_2解吸率的影响。结果表明,富液中CO_2负荷越大、解吸温度越高、解吸压力越低、富液流速越大、N_2吹扫流量越大,则CO_2解吸率越高。综合考虑,本实验优选的工艺条件为解吸温度45~65℃,解吸压力10~30 k Pa,富液流速0.08 m/s,N_2吹扫流量200 m L/min。     

Bacterial community structure and diversity responses to the direct revegetation of an artisanal zinc smelting slag after 5 years

This comparative field study examined the responses of bacterial community structure and diversity to the revegetation of zinc (Zn) smelting waste slag with eight plant species after 5 years. The microbial community structure of waste slag with and without vegetation was evaluated using high-throughput sequencing. The physiochemical properties of Zn smelting slag after revegetation with eight plant rhizospheres for 5 years were improved compared to those of bulk slag. Revegetation significantly increased the microbial community diversity in plant rhizospheres, and at the phylum level, Proteobacteria, Acidobacteria, and Bacteroidetes were notably more abundant in rhizosphere slags than those in bulk waste slag. Additionally, revegetation increased the relative abundance of plant growth-promoting rhizobacteria such as Flavobacterium, Streptomyces, and Arthrobacter as well as symbiotic N₂ fixers such as Bradyrhizobium. Three dominant native plant species (Arundo donax, Broussonetia papyrifera, and Robinia pseudoacacia) greatly increased the quality of the rhizosphere slags. Canonical correspondence analysis showed that the differences in bacterial community structure between the bulk and rhizosphere slags were explained by slag properties, i.e., pH, available copper (Cu) and lead (Pb), moisture, available nitrogen (N), phosphorus (P), and potassium (K), and organic matter (OM); however, available Zn and cadmium (Cd) contents were the slag parameters that best explained the differences between the rhizosphere communities of the eight plant species. The results suggested that revegetation plays an important role in enhancing bacterial community abundance and diversity in rhizosphere slags and that revegetation may also regulate microbiological properties and diversity mainly through changes in heavy metal bioavailability and physiochemical slag characteristics.

     

Occurrence and human dietary assessment of sulfonamide antibiotics in cultured fish around Tai Lake,China

As the most important fishery medicines, sulfonamides are widely used to prevent diseases caused by pathogens in aquaculture. However, relatively little is known about the residues and dietary risks associated with cultured fish around Tai Lake. In the present study, a sampling strategy for a complete aquaculture period was conducted. Specifically, 12 selected sulfonamide antibiotics were measured among 116 fish samples recruited from four sampling periods, four species, four areas, and 18 fish ponds. All 12 antibiotics were detected at detection frequencies of 4.31–28.45%. Total sulfonamides were detected in 77.59% of the fish samples, with 57.76% of fish samples containing from 0.1 to 10 μg kg^?1. Sulfadiazine (SDZ), sulfamethoxazole (SMZ), sulfamethazine (SDD), and sulfamonomethoxine (SMM) were the main types of antibiotics used, and these were present at high concentrations (>100 μg kg^?1) with high occurrences, especially in the middle of the aquaculture season. Dietary assessment showed that residual antibiotics in all fish that were being sent to market were far below the maximum residue limit (MRL) of total sulfonamides and that there was almost no risk associated with fish consumption. The results of the present study will facilitate development of effective measures to produce safe aquatic products and meaningful suggestions for consuming aquatic products.     

Occurrence and risk assessment of trace metals and metalloids in sediments and benthic invertebrates from Dianshan Lake,China

Environmental Science and Pollution Research - The present study measured concentrations of Cr, Ni, Cu, Zn, As, Cd, Sb, and Pb in surface sediments and two benthic invertebrate species (Anodonta...