Florisil柱层析与GC-ECD测定海洋环境样品中OCPs

建立了ＧＣ－ＥＣＤ测定海洋环境样品中ＯＣＰs的分析方法。通过Ｆｌｏｒｉｓｉｌ柱层 析的分类分析和毛细管ＧＣ－ＥＣＤ的测定，得出了ＯＣＰs柱层析的分离点（所需正己烷 的最小淋洗体积为１５０ｍｌ）和ＯＣＰs的回收率（其范围为２１．８％～１０８．７％），给出了海洋环境样品中ＯＣＰs的含量。结果表明，本方法是可行的。     

基于SPA模型的煤矿瓦斯危险源风险评价

根据危险源理论和三类危险源的观点,采用集对分析(SPA)方法,进行了安全一事故集对的同异反分析,指出应采取措施控制不确定项,尤其要控制其中的第二类、第三类危险源才能使系统趋于安全状态;同时建立了煤矿瓦斯危险源风险评价模型,通过联系度的计算得出煤矿瓦斯的安全等级.研究表明,将集对分析方法应用于某煤矿瓦斯危险源风险评价,计算简单,结果较为精确、可靠,为不确定系统的评价提供了一条新思路.     

干旱区内陆河流域土地利用程度变化与生态安全评价——以新疆玛纳斯河流域为例

以天山北坡玛纳斯河流域为例,在遥感与GIS支持下揭示了流域1989-2002年间土地利用程度变化状况,并进一步对流域生态安全进行了综合评价,最后分析了土地利用程度变化与生态安全的关系。结果表明：①玛纳斯河流域土地利用程度稳定上升,土地利用总体处于发展时期;②1989-2002年,流域生态安全状况整体有所好转,但局部生态环境出现恶化趋势;③流域土地利用程度综合指数在18~100间的区域生态安全等级有所提高,由1989年主体属于中警状态提高到2002年的预警状态;④不同土地利用程度下流域在较安全和预警状态面积之和有以下顺序：Ⅴ＞Ⅳ＞Ⅰ＞Ⅵ＞Ⅲ＞Ⅱ,表明Ⅴ级土地利用程度区即林草地是流域生态恢复和重建的首选和重要组成部分,而沙地则是生态环境治理的难题和关键。最后,提出了通过提高低利用程度区的土地利用程度来确保生态安全的观点。     

Footedness and Mounting—Short Review and Two Case Studies

Footedness is a personal quality like handedness. Footedness may be associated with moving ability during mounting, dismounting, and jumping movements. Occupational accidents have occurred during movement at different working levels, during the use of access and exit systems, and during the mounting of vehicles. Aging can also affect accident risk and body laterality. For example, falling accidents on stairs are common among the elderly. One reason for accidents may be that the structure of the access system or stair system is unsuitable for individual moving patterns depending partly on body laterality. Footedness and the way the feet are used may be contradictory to the demands of the moving situation, especially during uncommon or rapid situations. This contradiction may trigger disturbance during moving. The aims of this pilot study were (a) to review the literature briefly and (b) to describe the use of the dominant and nondominant foot by farmers and the elderly when mounting a tractor and stairs, respectively. The study also gives ideas for future studies based on both (a) and (b).     

道路车辆电气和电子设备样品在振动冲击等动力学试验中的安装

在试验方法和要求标准化后,振动冲击等动力学试验中的安装问题是决定试验是否合理和试验成败的关键要素。道路车辆电子元件和设备型样品的动力学试验是考核样品安装在车辆上使用条件下的适用性。振动试验还叠加了温度和温度变化环境,条件尤为复杂严酷。文内介绍了动力学试验中的安装需要考虑的技术要素,为试验实施中妥善合理地进行样品安装提供支持.     

Evaluating Flow Metric‐Based Stream Classification Systems to Support the Determination of Ecological Flows in North Carolina

Hydroecological classification systems are typically based on an assemblage of streamflow metrics and seek to divide streams into ecologically relevant classes. Assignment of streams to classes is suggested as an initial step in the process of establishing ecological flow standards. We used two distinct hydroecological river classification systems available within North Carolina to evaluate the ability of a hydrologic model to assign the same classes as those determined by observed streamflows and to assess the transferability of such systems to ungaged streams. Class assignments were examined by rate of overall matches, rate of class matches, spatial variability in matches, and time period used in class assignment. The findings of this study indicate assignments of stream class: (1) are inconsistent among different classification systems; (2) differ between observed and modeled data; and (3) are sensitive to the period of record within observed data. One clear source of inconsistency/sensitivity in class assignments lies with the use of threshold values for metrics that distinguish stream classes, such that even small changes in metric values can result in different class assignments. Because these two hydroecological classification systems are representative of other classification systems that rely on quantitative decision thresholds, it can be surmised that the use of such systems based on stream flow metrics is not a reliable approach for guiding ecological flow determinations.     

Metabolism of nC11 fatty acid fed to Trichoderma koningii and Penicillium janthinellum II: Production of intracellular and extracellular lipids

Abstract

Little is known about the fungal metabolism of nC₁₀ and nC₁₁ fatty acids and their conversion into lipids. A mixed batch culture of soil fungi, T. koningii and P. janthinellum, was grown on undecanoic acid (UDA), a mixture of UDA and potato dextrose broth (UDA+PDB), and PDB alone to examine their metabolic conversion during growth. We quantified seven intracellular and extracellular lipid classes using Iatroscan thin-layer chromatography with flame ionization detection (TLC-FID). Gas chromatography with flame ionization detection (GC-FID) was used to quantify 42 individual fatty acids. Per 150 mL culture, the mixed fungal culture grown on UDA+PDB produced the highest amount of intracellular (531 mg) and extracellular (14.7 mg) lipids during the exponential phase. The content of total intracellular lipids represented 25% of the total biomass-carbon, or 10% of the total biomass dry weight produced. Fatty acids made up the largest class of intracellular lipids (457 mg/150 mL culture) and they were synthesized at a rate of 2.4 mg/h during the exponential phase, and decomposed at a rate of 1.8 mg/h during the stationary phase, when UDA+PDB was the carbon source. Palmitic acid (C_16:0), stearic acid (C_18:0), oleic acid (C_18:1), linoleic acid (C_18:2) and vaccenic acid (C_18:1) accounted for >80% of the total intracellular fatty acids. During exponential growth on UDA+PDB, hydrocarbons were the largest pool of all extracellular lipids (6.5 mg), and intracellularly they were synthesized at a rate of 64 μg/h. The mixed fungal species culture of T. koningii and P. janthinellum produced many lipids for potential use as industrial feedstocks or bioproducts in biorefineries.     

舰载机机载设备弹射和拦阻冲击试验条件研究

弹射和拦阻冲击试验是舰载机机载设备必要的考核试验之一,而目前相关标准并未明确试验具体量值,且国内缺少试验经验,这会影响试验工作的开展。基于此,从GJB 150.18A—2009规定的阻尼正弦波出发,结合项目研制过程数据,提出波形频率和振幅的确定方法。波形频率可根据类似机型的地面共振试验数据或全机振动模态分析结果确定,这里利用弹性缩比模型地面动响应试验和带通滤波法来预计瞬态波振幅,并说明了阻尼正弦波实施案例和对试验设备冲程的要求。从累积损伤角度出发,认为采用随机振动试验替代弹射和拦阻冲击试验是可行的,而不能采用常规冲击试验进行替代。根据随机振动3σ响应谱和冲击响应谱的对比分析,提出了采用振动功能试验替代弹射和拦阻冲击试验的前提条件——设备安装频率应高于要求值。     

Important meteorological data for use in risk assessment

This paper presents a methodology for the calculation of atmospheric stability classes in correlation with wind velocities for six sites of the Greek territory, namely Ellinikon (Athens), Elefsis, Megara, Heraklion, Chania and Patras, based on real data obtained from meteorological observations in these sites and on computations related with their geographic position. In addition to that, a comparison is presented of the atmospheric stability classes produced with online measurements for the Ellinikon (Athens) site with significant coincidence in the results.

These calculated values of the meteorological parameters (particularly of atmospheric stability) are most appropriate for uncertainty calculations in quantified risk assessments (QRAs) of hazardous installations sited in the above-mentioned areas, especially when risk and safety-related decisions need to be taken. Consequent results obtained with these parameters are more realistic compared to the “classical” assumption of D5/F2, which leads to significant diversification in the estimation of risk.