GJB 150.17A噪声试验方法介绍与分析

噪声能导致飞行器中机载设备故障以及结构疲劳破坏,国内军用机载设备多采用GJB 150《军用装备环境试验方法》中的噪声试验方法进行试验,以确定其结构设计、选用的器件对噪声环境的适应性。GJB 150A作为GJB 150的修订版,在标准性质、试验程序和试验方法等方面有很大变化,增加了噪声试验实施的难度。对上述变化进行了重点分析,并详细阐述了GJB 150.17A的剪裁思想以及试验程序的应用。     

GJB 150.28—2009酸性大气试验应用中存在的问题探讨

为了使装备研制、环境试验领域相关人员能更好地依据GJB 150.28—2009制定试验大纲和组织实施试验,提高试验的质量和有效性.总结了GJB 150.28—2009酸性大气试验标准应用过程中普遍存在的问题,对贮存条件、试验溶液配制、试验样品放置、酸雾沉降率和沉降溶液pH值的测量、转换时间、标准适用范围、使用典型材料代...     

浅析我国军工产品低气压（高度）试验方法标准

介绍了低气压环境对军工产品的影响。针对目前主要适用于考核军工产品对低气压环境适应能力的我国现行有效标准GJB150．2A-2009与HB5830．14-1996进行探讨,简要分析了两个标准的性质、试验目的、应用范围、试验程序与条件、试验过程控制以及试验中断处理要求等方面的差别,对两个标准的分析理解内容可为相关技术人员在制定军工产品的低气压（高度）环境试验方案和实施大纲时提供有益的参考。     

基于多因子影响的东南沿海地区服役涂层环境试验设计

目的通过分析东南沿海地区车辆服役环境特点,提取了光照、温度、水、化学介质四种影响因素,分析四种影响因素的影响机理、影响方式、影响效果。方法对《GJB 150A—2009军用装备实验室环境试验方法》的基本运用方法及裁剪技术进行初步探讨,依据该标准制定东南沿海地区服役车辆涂层实验室试验的流程方法,并进行试验验证。结果实验室加速腐蚀试验结果与现役涂层腐蚀情况具有较好的相关性。结论为东南沿海地区涂层环境试验的设计、实施及测评,对涂层寿命预测、有效性检验和维修保养方案制定提供了重要的依据。     

基于样品工作状态的爆炸性大气试验方法研究

目的验证并改进在爆炸性大气环境工作状态下的样品防爆能力。方法通过对一种特种环境试验"爆炸性大气试验"的应用背景介绍,划分与归纳处于工作状态中的受试样品在该试验过程中的工作特征,以GJB 150.13A《军用装备实验室环境试验方法第13部分:爆炸性大气》规定的程序I"在爆炸性大气中工作"作为试验标准,对其试验程序进行研究说明。结果通过实际案例对爆炸性大气试验过程进行了描述。结论爆炸性大气试验属于较少见的特种试验,缺乏普遍性试验程序,通过对该试验方法的研究可对我国环境工程领域特种试验实施方法提供理论依据和技术支撑。     

GJB150A在某通信装备低温试验中的应用研究

由于是剪裁标准,GJB 150A发布以来的很长一段时间内,许多使用人员还无法适应,对试验工作造成诸多困扰。为了指导研究人员摆脱菜单式标准的束缚,以GJB 150A为参考标准,根据某通信装备的寿命期剖面和寿命期环境剖面,论述了该装备低温试验的实施要点,对试验程序、试验顺序和试验条件的选择依据及结果给出了详细分析,提出了试验实施的设备与试件要求。     

湖库型水产养殖污染生态环境损害鉴定适用方法研究

生态环境损害鉴定评估是环境损害修复与赔偿的重要依据。为了强力推动中国频发的水产养殖行为致使湖库环境损害事件的赔偿追究制度落地,开展相关鉴定评估方法体系研究尤为必要。该研究基于生态环境损害赔偿制度管理要求和生态环境损害鉴定评估技术规范方法,提出了湖库型水产养殖污染致生态环境损害鉴定方法判定的技术体系,判定过程主要包括污染环境行为确认、环境损害事实确认、损害实物量化、恢复方案制定以及损害价值量化5个阶段,并细化判定分析要点,确定的价值量化方法主要为环境恢复成本法、理论治理成本法和虚拟治理成本法。通过应用该技术体系对2个水产养殖湖泊的生态环境损害进行全流程的判别与鉴定,取得了满意的结果,判定技术体系合理可行。     

GJB 150A淋雨试验强化试验程序数值模拟和试验装置设计研究

目的 研究GJB 150.8A—2009《军用装备实验室环境试验方法第8部分:淋雨试验》中强化试验程序的工程实现方法.方法 在标准解读的基础上,以强化试验程序用喷嘴为对象,建立数值模型,分析喷嘴在强化试验程序过程中的流场分布,并基于分析结果给出强化试验程序试验装置设计的思路和方法.结果 在喷嘴内,压力变化剧烈,极短距离内由276 kPa迅速降至101 kPa.水流经过喷嘴经历了激烈的加速过程,从距离喷嘴出口0.01～0.4 m,水流速度从251 m/s迅速降至17.8 m/s,到远场趋于稳定.结论 分析结果对指导强化试验程序的试验装置的设计和试验实施具有重要参考意义.     

通海阀箱消声器环境试验研究

目的验证通海阀箱消声器的环境适应性。方法分析通海阀箱消声器的结构组成、工作原理、使用环境。综述环境试验的相关标准,并对GJB 150A军用装备实验室环境试验办法中有关水面船舶部分进行剪裁,依据GJB 150A开展倾斜摇摆试验、振动试验、冲击试验,确定上述试验的方法、相关参数,并设计模拟海水环境的工装。结果消声器在施加了上述试验的环境应力后,外观结构无明显变形,紧固件无松脱、断裂等。通海阀箱消声器声学性能无明显下降,插入损失保持大于8 dB。结论通海阀箱消声器在恶劣的环境条件下具有较高的可靠性。GJB 150A部分试验参数设计过于保守,对船舶非电子设备影响较小,可依据实测应力量值进行试验。     

场地环境评价和修复监测参数

根据场地实际的污染特点,选择适当的场地环境评价标准和监测参数对于污染场地调查评价工作及后续修复工程的实施具有非常重要的指导意义和经济效益.本文通过研究国外相关场地环境评价标准,对场地环境调查评价和污染场地修复中监测参数选择及其相应分析方法的选择提出了一些建议.     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

Several main metabolites of benzo[a]pyrene （BaP） formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone （BP 1,6- quinone）, trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene （BP 7,8-diol）, 3-hydroxybenzo[a]pyrene （3-OHBP）, were identified by high-performance liquid chromatography （HPLC）. The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that （1） the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; （2） the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; （3） the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% （w/v）, concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.     

Intraspecific differences in effects of co-contamination of cadmium and

A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p ＜ 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.