不同培养介质中纳米氧化铜对小麦毒性的影响（Influence of Culture Media on the Phytotoxicity of CuO Nanoparticles to Wheat（Triticum aestivum L.））

通过比较纳米氧化铜(CuONPs)和微米氧化铜(CuOMPs)在两种土壤中Cu2+的溶出及其对脲酶活性影响,结合产生脲酶活性抑制效应的Cu2+浓度阈值,研究了CuONPs和CuOMPs对土壤脲酶活性的毒性效应机制.结果表明:CuONPs和CuOMPs的Cu2+溶出量随其浓度增加而增加,溶出比率随浓度增加而减少,两者在红壤中Cu2+的溶出均比在乌栅土中高;在1～1000mg·kg-1范围内,CuONPs对土壤脲酶活性产生了显著(p≤0.05)或极显著(p≤0.01)的抑制效应;同浓度下,CuONPs在土壤中的Cu2+溶出及其对脲酶活性的抑制效应均大于CuOMPs;在相对低浓度(1～10mg·kg-1,红壤;1～100mg·kg-1,乌栅土)下,CuO的纳米态对土壤脲酶活性具有抑制毒性,在相对高浓度(≥50mg·kg-1,红壤;≥500mg·kg-1,乌栅土)下,CuO的纳米态和溶出Cu2+共同作用引起了脲酶活性抑制;与CuONPs不同,CuOMPs只有通过溶出Cu2+抑制土壤脲酶活性,其颗粒态对脲酶活性无显著影响;值得注意的是,在低浓度(1mg·kg-1)下CuONPs对土壤脲酶活性具有微米态和离子态所没有的抑制毒性,说明其对土壤酶影响应存在特殊机理,值得进一步深入研究.     

木麻黄根区土壤理化特性及酶活性与青枯病发生关联分析

为探究木麻黄(Casuarina spp.)根区土壤理化特性及酶活性与青枯病发生的关系,进而为加强生物防治提供参考.选取位于广东省潮州市饶平县大埕镇、湛江市吴川市塘尾镇和湛江市徐闻县前山镇的3个木麻黄人工林为研究对象,在每个林分下分别设置3个样地,每个样地采集木麻黄青枯病感病植株和健康植株根区土壤各3份,共54个土壤样...     

An Observation Method for Analyzing Operators’ Routine Activity in Computerized Control Rooms

An activity analysis method was developed for studying the structure and dynamics of control room operators’ activity during normal operation based on directly observable elements of the operators’ behavior. The method assesses current activity along three dimensions in each 5-min period of the shift. Intensity characterizes arousal level, direction shows whether the activity is directed predominantly at the process control task, at something else, or miscellaneous. Motivation reflects if the activity is driven by intrinsic or extrinsic motivation. A case study is presented, in which 3 morning, 3 afternoon, and 3 night shifts of a Nuclear Power Plant operator crew are involved. The obtained results gave a deeper understanding of the operators’ activity and also revealed an “arousal compensation” tendency.     

Aspects of Tests and Assessment of Filtering Materials Used for Respiratory Protection Against Bioaerosols. Part I: Type of Active Substance,Contact Time,Microorganism Species

This paper presents the results of a study on antimicrobial activity of polymer filter nonwovens produced by needle-punching or melt-blowing with an addition of disinfecting agents. The first part of the paper discusses how the biocidal activity of nonwovens is a function of the active agent added to the nonwovens, the duration of the contact of microorganisms with nonwovens and the type of microorganisms. The types of fibres and disinfecting agents had a considerable effect on the biocidal activity of nonwovens. The biocidal effect of nonwovens increased with the duration of their contact with microorganisms. Fibre activity differed considerably depending on the species of the microorganism. The microorganisms most sensitive to biocidal activity of the active filter nonwoven were S. aureus, M. flavus and E. coli. There were no biocidal effects on spore-forming bacterium B. subtilis.     

The Potential of Using Solar Energy to Process Full-Fat Soybeans (Glycine max) to Reduce Urease Activity

The objective of this study was to investigate the efficacy of panel solar cookers in reducing urease activity in full-fat soybeans (Glycine max). Changes in urease activity of soaked (SM), coarse-milled (CM) and whole dry (WM) full fat soybeans were investigated by roasting for 0, 30, 60, 90, 120, 150 and 180 min in multiple reflector panel solar cookers, in a 3 3 3 factorial experiment. Soaking soybeans for 14 h reduced (p<0.05) ^{1 1}P < 0.05 means that the probability (p) of falsely concluding significant difference between values obtained after statistical analysis was less than 5% (0.05). urease activity by 9%, from 6.58 meqNH₃/g DM to 5.98 meqNH₃/g DM. After 180 min of solar roasting, urease activity levels had declined by 81%, 67% and 23% in soaked, milled and whole dry soybeans respectively. Full fat soybean urease activity can be reduced faster in soaked than in dry soybeans. Findings suggest that there is potential in using multiple reflector panel solar cookers to reduce urease activity in full fat soybeans.     

高效絮凝菌的培养条件优化

从呼和浩特市污水处理厂筛选分离了1株高效絮凝剂产生菌YS2,通过培养条件优化试验确定了该菌株产絮凝剂的最佳培养条件:碳源为蔗糖、氮源为脲、N/C为2.5∶1、初始pH值为6.0、培养温度为30℃。絮凝试验表明:该菌株产生的生物絮凝剂对高岭土悬浊液有良好的絮凝效果,絮凝率达到95%。絮凝活性分布试验表明其絮凝活性全部存在于离心沉降物中,而上清液没有絮凝活性。16S rDNA测序鉴定其为克雷伯氏菌G。     

Relation of hepatic EROD activity and cytochrome P4501A level in Sebastiscus marmoratus exposed to benzo[a]pyrene

This study was designed to investigate the in vivo effects of benzo[a]pyrene （BaP） on hepatic ethoxyresorufin-O-deethylase （EROD） activity and its correlation with cytochrome P4501A （CYP1A） protein levels in Sebastiscus marmoratus, which were exposed through a water column to BaP （10, 100, 1000 ng/L, respectively） or were treated with intraperitoneal injections of BaP （0.5, 1, 5, 10 mg/kg, respectively） every 7 d. The results showed that after 25 d of waterborne exposure to 1000 ng/L BaP, fish hepatic CYP1A levels and EROD activity were significantly induced. In contrast, EROD activity was not altered 7 d after second intraperitoneal injections, whereas, CYP1A protein levels were increased. Dose-dependent increase of biliary BaP metabolites demonstrated that the catalytic activity of CYP1A was induced by treatment with BaP. The lowest observable effect concentration with regard to biliary BaP metabolites （100 ng/L） was much lower than that with reference to EROD activity （1000 ng/L）. The results suggest that biliary polycyclic aromatic hydrocarbon （PAH） metabolites were shown to better reflect the contamination gradients of PAHs than EROD activity. It appeared to be necessary to measure CYP1A protein levels to complement the EROD activity in relevant toxicological assessments.     

包埋固定化微生物的特性研究

文章通过实验研究了PVA与海藻酸钠混合载体包埋固定化微生物系统降解有机物的过程,并对其特性进行了分析。结果发现运行初期凝胶体有凝胶溶出现象,第一天凝胶有机物溶出高达2 173 mg,随后溶出量减少,7～8天溶出停止;同时发现包埋后的微生物活性有损伤和恢复的过程,损伤时相对活性为0.27经过恢复可达到0.85;另外,凝胶的粒径和比重等物理特性也随时间变化,最后趋于稳定。一年多运行实验发现包埋凝胶体的抗持久性也较好。这些特性的探讨将为工程应用提供理论指导。     

Runoff variation affected by precipitation change and human activity in Hailiutu River basin,China

For recent years, runoff generation and hydrological processes in Hailiutu River basin have been greatly changed by climate change and human activity, especially water and soil conservation construction. In this study, the trends in precipitation, evapotranspiration (ET) and river runoff as well as the effects of precipitation change and human activity on runoff variation have been studied. The results showed that during 1960–2000, annual precipitation and river runoff, monthly precipitation and ET in September and October as well as monthly runoff in all months showed a significant decrease. In addition, peak flow and base flow had a large decrease. Under the joint influence of precipitation change and human activity, the mean annual runoff decreased by 35 million m³ from the baseline period (1960–1985) to the change period (1986–2000), which accounted for 60.9% and 39.1% of the total runoff decrease, respectively. Precipitation change played a primary role in the decrease of annual runoff whereas human activity, particularly water and soil conservation construction, also had remarkable impacts on runoff variation.     

不同改良物质添加对滨海盐碱地土壤重金属及酶活性的影响

改良物质添加在改善土壤理化性质的同时也可能会导致土壤重金属累积.实验设置了对照（CK）、有机肥（OM）、聚丙烯酰胺+有机肥（PAM+OM）、秸秆覆盖+有机肥（SM+OM）、秸秆深埋+有机肥（BS+OM）和生物菌肥+有机肥（BM+OM）共6个处理方式,研究不同改良物质添加对滨海盐碱地土壤重金属和土壤酶活性的影响,以及二者之间的关系.结果表明,与CK处理相比,不同处理下土壤Cr、Cu、Ni和Pb含量呈现上升趋势,其中SM+OM和PAM+OM处理分别对Cr和Cu含量的影响最为显著,而BM+OM处理对Ni和Pb含量影响最为显著.与CK处理相比,改良物质添加后土壤蔗糖酶和脲酶活性显著上升,其中BM+OM处理效果最好;碱性磷酸酶活性呈现上升趋势,但上升程度较小;过氧化氢酶活性无显著变化.冗余分析表明前两轴累积可解释酶活性变异特征的70.3%,单一重金属对土壤酶活性影响的重要性大小依次为：Ni>Cu>Cr>Pb.