基于高斯伪谱法的无线传感器网络能耗模型研究

为了解决无线传感器网络能耗大的问题,延长节点生命周期,提出了一种结合高斯伪谱法的能耗模型。该方法给出了无线传感器簇之间的Hausdorff距离和数据传输能耗与距离之间的关系,建立了簇头节点消耗能量的计算方法,利用高斯伪谱法对该能耗模型进行了求解,并通过仿真实验,深入分析了影响该能耗模型的关键因素。与其他算法相比,该模型在剩余能量、误判率、能量消耗、网络寿命等方面具有较大优势。     

基于Zigbee的矿山井下人员定位技术研究

针对矿山井下人员定位及巷道特点,设计了一种电源节能算法的ZigBee无线传感器节点布设拓扑及井下人员无线定位系统模型,在此基础上提出了一种改进型无线双重质心人员定位算法。经矿山井下实地调研,并通过Matlab软件进行仿真试验,结果表明改进型无线双重质心人员定位算法比传统质心算法、RSSI算法的定位精度提高了近50%,可有效解决节点能量受限问题,并延长系统寿命。该Zigbee井下人员无线定位系统技术简便、定位精度较高、成本较低,且节约巷道空间、算法简单,适合矿山井下矿工人员定位和考勤。     

自适应时槽分配的机械振动WSNs传输休眠时序调度方法

目的针对均匀时槽分配方法在机械振动无线传感器网络大量原始数据传输需求下,节点传输能耗升高、传输速率降低的问题,降低机械振动无线传感器网络传输能耗。方法提出一种自适应时槽分配的机械振动无线传感器网络传输休眠时序调度方法,首先利用信标调度的自适应时槽分配时钟同步方法使各节点不需晶振补偿就可校准本地时钟误差,然后测量LQI预测节点数据传输速率,为各个节点分配最优传输时槽,最后设置休眠机制,让未进行数据传输的节点处于休眠状态待机,直到下一个同步时槽时,自动唤醒,并侦听网关信标帧。采用三种方法进行冲突次数、传输能量消耗和传输速率的对比实验。结果所提方法的传输能耗比CSMA-CA机制降低23.4%,比均匀时槽分配降低10.6%。结论所提方法能有效降低机械振动无线传感器网络数据传输能耗。     

无线传感器网络在气象领域的应用与研究

基于无线传感器网络,将无线传感器网络应用在气象领域,采用分布式智能传感器节点组成无线局域网,融合了微电机技术、数据采集技术、现代网络与无线通信技术、信息处理技术等多个领域。通过传感器对现场环境进行实时监测,并通过无线网络进行数据通信,主控PC系统软件将千万个节点采集的数据进行综合分析处理及控制,最终在用户端处理显示等。     

侵彻引信用磁电传感器的输出特性仿真分析

目的 解决侵彻引信用磁电传感器在不同侵彻环境下输出特性难以预知的问题,掌握不同结构参数对传感器输出的影响。方法 基于一种新型磁电传感器的结构原理,提出一种联合仿真研究方法,研究过程分为2部分,一部分是利用ADAMS软件进行磁电传感器惯性系统的力学特性仿真,另一部分是利用COMSOL软件进行传感器机电转换元件的磁电特性仿真,仿真模型的输入是战斗部在穿靶过程中的过载信息。通过磁电传感器在多次冲击加载试验中获取的实测数据,对仿真模型的仿真结果进行验证。改变仿真模型的相关参数,模拟并分析传感器结构对仿真输出特性的影响。结果 仿真穿靶时间的平均绝对误差约为138 μs,穿靶时刻仿真电压值的平均相对误差约为5.9%。在给定力学环境的前提下,侵彻引信用磁电传感器中的线圈与磁铁的相对高度会影响输出信号的正负、幅值以及波峰出现的时间,线圈匝数、线圈与磁铁之间的间隔仅对信号的幅值产生影响。结论 仿真误差在可控范围内,验证了联合仿真模型的正确性与该研究方法的可行性。该仿真模型可以为侵彻引信用磁电传感器的设计提供指导,并为后续进一步验证侵彻引信起爆控制系统的性能工作提供了新的思路。     

电磁环境监测传感器部署效率评估方法

目的提升电磁环境的全域、精细化监测能力。方法基于单个传感器监测能力和多个传感器协同监测效率,建立相应的评估指标模型,利用多属性决策方法将多指标量化为单一指标,获得监测传感器部署效率评估结果。结果以待评估方案与理想方案的贴近度作为部署效率评估指标,建立了部署效率评估指标体系,提出了基于逼近理想解排序法(TOPSIS)和网络分析法(ANP)的综合评估方法。结论通过仿真验证了该方法的可行性和有效性,为监测传感器部署方案优化和动态调度提供量化评估数据支撑。     

试论地震勘探的安全生产管理

总结了多年地震勘探安全生产管理的经验．提出从地震勘探的安全教育管理、安全技术培训管理、安全生产目标管理、野外作业安全管理、伤亡事故管理以及安全检查与政府监督六个方面加强安全生产管理的内容和方法，对搞好地震勘探的安全管理、保证地震勘探生产作业人员的身体健康和生命安全以及生产设备的运行安全具有重要指导作用。     

一种多参数小型化飞机结构腐蚀环境监测技术

目的研究腐蚀与环境条件之间的关系,提出一种用于飞机腐蚀环境监测的小型化监测节点的实现方法。方法针对影响腐蚀的4个关键环境参数(温度、相对湿度、湿润时间和氯离子浓度),研究其传感方法并研发选型相应传感器。在此基础上设计基于MSP430处理器的多参数飞机腐蚀环境监测节点。结果通过实验验证了节点中的温湿度传感器、湿润时间传感器和电化学传感器的适用性,能够完成对环境参数的的测量。结论设计的节点满足机载装置小型化、轻量化的要求,可以实现在线的腐蚀环境监测,从而保障飞行安全。     

地震队季节工HSE管理模式探索与实践

<正>地震勘探作业具有季节性强、流动性大、危险点源多、人员分散等特点,易发生安全事故。目前,地震勘探作业的测量、放线、钻井、爆炸等工序多由临时的季节工来完成,庞大的季节工群体已成为了地震勘探作业的主力军。因招收的季节工多来自各省市偏远的农村,人员成分复杂,文化素质参差不齐,组织纪律性较差,习惯性违章时有发生,不仅危及自身和他人的安全,也影响了生产的平稳有序运行。     

页岩气勘探中的地球物理方法综述及展望

地球物理方法是页岩气勘探中最有效、最准确的预测方法之一。在调研国内外利用地球物理方法勘探页岩气研究成果的基础上,分析总结了页岩气勘探中最有效的地震和测井法对页岩气的响应特征,讨论了常规油气勘探中已获得成功的电磁法、重磁勘探以及综合地球物理方法在页岩气勘探中的应用;对我国页岩气勘探技术的发展进行了展望,为我国页岩气勘探与开发提供参考。     

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.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Distribution and ecological effect of mercury in Laogang landfill, Shanghai, China

Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury （HgT）, combinative mercury （Hgc） and gaseous mercury （HgG）, and content of total organic carbon （TOC）, but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of （HgG,/HgT）1992〉（HgG/HgT）1996〉〉（HgG/HgT）2000. A simple outline of Hg release in landfill could be drawn： with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants （e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum） are capable of enriching more Hg than herbaceous plants.     

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.     

Enzymatic oxidation of aqueous pentachlorophenol

The influence of the nonionic surfactant Tween 80 on pentachlorophenol （PCP） oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration （CMC）. Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.     

Decomposition of alachlor by ozonation and its mechanism

Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.     

基于综合水质标识指数和对应分析法的校园河道水质评价

以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.     

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 chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

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

ＲｅｍｏｖａｌｏｆｈｅａｖｙｍｅｔａｌｓｆｒｏｍｓｅｗａｇｅｓｌｕｄｇｅｂｙｌｏｗｃｏｓｔｉｎｇｃｈｅｍｉｃａｌｍｅｔｈｏｄａｎｄｒｅｃｙｃｌｉｎｇｉｎａｇｒｉｃｕｌｔｕｒｅＷｕＱｉｔａｎｇ，ＮｙｉｒａｎｄｅｇｅＰａｓｃａｓｉｅ，ＭｏＣｅｈｕｉＦ...