华北几次大震前弱震分布参数R(t)的异常变化

本文详细研究了1974年以来华北地区9次Ms≥5.0级大震前,小震时空分布参数R(t)的变化特征.结果表明:华北地区9次Ms≥5.0级大震前小震时空分布参数R(t)值均出现了先上升,然后下降直至主震发生的异常图象。根据R(t)值异常可能对未来发生的大震作出一定程度的预报.文中对R(t)值异常变化的机制进行了初步讨论.     

二龙山水库流域土壤资源与可持续利用研究

介绍了二龙山流域的土壤分类系统,对土壤资源分别进行了总体评价和质量评价,指出了二龙山土壤资源存在的问题,并针对存在问题提出了土壤资源可持续利用的建议.      

Selection of poly(R)-3-hydroxybutyric acid utilising bacteria by enrichment,optimisation and compatibility testing for consortia development

Bacterial strains with poly-3-hydroxybutyrate (PHB) degradation potential were isolated from waste yard soil samples of selected industrial sites in Uttarakhand, India, and two microbial consortia were developed, i.e. Consortium I comprises Pseudomonas sp. strain Rb10, Pseudomonas sp. strain Rb11 and Bacillus sp. strain Rb18, and Consortium II is composed of Lysinibacillus sp. strain Rb1, Pseudomonas sp. strain Rb13 and Pseudomonas sp. strain Rb19. The current study involved enrichment selection via liquid and semi-solid media, followed by isolation and screening of bacterial strains using PHB pellets and films. Furthermore, the identification and characterisation was done by triphasic approach. The utilisation of PHB by the characterised strains was confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy. Moreover, the minimum inhibitory concentration of solubilised PHB was found to be 2.5?mg/mL, which was detected through ‘clear zone assay’. Further, the selection and biocompatibility testing of potential isolates were performed for the formation of bacterial consortia. Thus, the present work would provide direct and standardised protocol for screening and selection of potential microbiomes for biodegradation of polymers by overcoming the negative effect of organic solvents. Moreover, indigenously developed consortia would be evaluated for their in situ biodegradation potential against various bioplastic films.     

汽车排气污染影响因素分析

目前,汽车排气污染已成为城市空气污染的主要因素。江苏油田通过对汽车尾气的现场监测,以及尾气治理中的一些问题分析,总结出影响汽车尾气中污染物浓度的六大因素,并提出相应的解决措施。     

基于 M －MP2R 的现代安全管理方法研究

如何减少事故造成的人员伤亡和经济损失,有效预防事故及高效处置事故是现代安全管理研究的方向。基于PDCA理论的研究以及现代应急管理和现代安全管理的发展趋势,提出M －MP2R动态的现代安全管理新方法,构建M－MP2R模型与体系,模拟出M－MP2R运行流程,分析M－MP2R的特点,并指出其存在的问题,丰富了现代安全管理的研究内容。     

Acute toxicity of ammonia to a freshwater teleost,Labeo bata larvae

Ammonia toxicity tests were performed with Labeo bata (bata) larvae of three different size groups. One hundred percent survival of larvae (500.0?±?4.0?mg) was recorded when exposed to ammonia concentrations of 1.0–13.56?mg?L^?1 at 96?h of exposure. Bata larvae exposed to ammonia concentrations of 15.8–25?mg?L^?1 showed 10–74% mortalities. The 96?h LC₅₀ value for 200 (±5), 250 (±2) and 500 (±4) mg bata larvae were 11.5, 16.8 and 22.5?mg?L^?1 un-ionised ammonia concentrations, respectively. When fish were exposed to different doses of ammonia, behavioural changes immediately occurred even at the lowest dose. At first, the fish became hyperexcitable, the skin darkened and they showed an increased ventilation frequency, fish behaviour became normal, 24?h after exposure. A 96?h LC₅₀ value of un-ionised ammonia showed direct relationship with the increasing size of bata larvae.     

A factor analysis study: Air pollution,meteorology, and hospital admissions for respiratory diseases

It is well known that air pollution exerts adverse effects on health and environment. Bal?kesir located in the Marmara region (Turkey) has serious air pollution problems produced by heating in the months of winter. In this study, the effect of exposure to air pollution on hospital admission for respiratory illnesses among children and adults was examined. Epidemiological data from records of hospitals, air pollutants and meteorological data were used. During July 2005–July 2007 period, there was a total of 280,426 hospital admissions for respiratory diseases. In a population-based analysis, 9 children were admitted for asthma, 17 children for acute bronchitis, and 20 children for lower respiratory diseases out of 100 children. There was a significant increase in the hospital admissions for respiratory diseases and air pollutants from October to March. It was concluded that children living in the city suffer from respiratory diseases such as asthma, pneumonia, and lower respiratory diseases. Three factors that account for approximately 90% of total variance of hospital admissions, air pollution, and meteorology were identified by means of principal component factor analysis.     

Distributions of total metals in the surface sediments of the Bandirma and Erdek Gulfs,Marmara Sea,Turkey

The aim of this study is to determine the contents of aluminum, iron, manganese, nickel, copper, zinc, chromium, cadmium, lead, and mercury in sediments at 1–30?m depths of the Band?rma and Erdek Gulfs in the Southern Inner Shelf of the Marmara Sea. Sediment samples were collected from different depths (1?m, 5?m, 10?m, 20?m, 30?m) at each region in February 2008. Primary hydrographic conditions, such as temperature (6.6–14.5°C), salinity (22.6–26.875 psu), percentage of dissolved oxygen saturation (35–83 %), and pH (8.0–8.4) were recorded for each sampling point. Moreover the total organic carbon (0.5–2.9%) and the total calcium carbonate contents (0.8–60%) of sediment samples were determined. In surface sediments of both gulfs, Pb (21–62?mg?kg^?1) and Cd (0.52–0.86?mg?kg^?1) contents were determined to be higher than the shale average (Pb 20?mg?kg^?1, Cd 0.2?mg?kg^?1) while the other metal contents were measured to be lower in general. On the other hand, generally Hg (0.06–1.1?mg?kg^?1) contents were higher than the shale average (0.3?mg?kg^?1)at all of the examined stations in the Band?rma Gulf and lower than the shale average in the Erdek Gulf.     

Accumulation trends of metals and a metalloid in the freshwater crayfish Astacus leptodactylus from Lake Yeniçağa (Turkey)

This study aims to determine the extent of metal pollution in Lake Yeniça?a (Bolu, Turkey) by investigating the accumulation trends of five metals (Al, Cu, Fe, Ni and Zn) and a metalloid (As) in gills, exoskeleton, hepatopancreas and abdominal muscles of the freshwater crayfish Astacus leptodactylus. Principal component analysis (PCA), cluster analysis (CA), correlation analysis and analysis of variance (ANOVA) were utilised to determine the accumulation profiles of each element over four seasons. The greatest element accumulation was found to occur in the gills. All elements in exoskeletal tissue displayed positive correlations with each other, a similar trend was also observed in the hepatopancreas samples. Strong (r=0.868) and very strong (r=0.960) positive correlations were found between the accumulations of Al and Fe in gills and the exoskeleton, respectively. Correlations in tissue accumulation rates are discussed in the context of metabolic roles and impacts associated with the elements tested. Elemental compositions of Yeniça?a water and sediment samples were also investigated to determine whether the composition of the surrounding environment matches the metal accumulation trends of tissue samples. We demonstrate that, by the criteria set by the United States Environmental Protection Agency, Lake Yeniça?a is heavily polluted in terms of As and Ni.