脉冲变频电磁场对水华鱼腥藻生长的效应

对脉冲变频电磁场作用下,扫描频率和磁感应强度的变化对水华鱼腥藻细胞活性和生长的影响进行了研究。结果显示,扫描频率从25-27 Hz增大到1-60 kHz时,磁场对藻细胞活性的抑制作用减小,但增大到60 kHz以上,磁场对藻细胞产生强烈抑制作用,累积水力停留时间4 min的藻样在48 h培养时间内已失去活性停止生长。扫描频率为50-100 Hz和1-60 kHz时,累积水力停留时间2 min的藻样,细胞受到磁场刺激生长加快;只有累积水力停留时间〉6 min,才表现出对藻活性的抑制作用。磁感应强度增大至120 G,磁场对细胞活性产生明显抑制作用,增大磁感应强度有利于对细胞活性和生长的抑制。     

离子色谱法测定饮用水和面包中的溴酸根

选用ＡＳ９－ＨＣ高容量阴离子交换色谱柱,不需处理除去干扰离子,可直接进样。测定了两种水样,其中一种检出溴酸根,方法检出根０．００５ｍｇ．１＾－１水样加标回收率９１．３－９３．４％。采用全新的自动化样品处理技术－加速溶剂萃取萃取面包中的溴酸根。经ＡＳ９－ＳＣ阴离子交换色谱柱分离,选择最佳淋洗条件。电导检测,方法检 ０．０７ｍｇ．１＾－１,对十二种市售包进行测定,均未检出溴酸根,样品加标回收率７９．９     

潖江蓄滞洪区洪灾风险分析及避难转移安置研究

以潖江蓄滞洪区洪灾避难转移安置为研究对象,利用Mike21技术,建立潖江蓄滞洪区洪水演进数值模型,模拟北江遭遇300年一遇洪水时,在潖江口泄洪,潖江蓄滞洪区内洪水演进,分析潖江蓄滞洪区洪灾风险.通过实地调查,结合历史洪水情况,利用潖江蓄滞洪区DEM数据、Google地图及最快避难转移安置时间分析法,详细设计了潖江蓄滞洪区内各行政村落遭遇洪灾时避难转移与人员安置,为潖江蓄滞洪区启用预案科学编制及防洪减灾提供科学依据.     

汶川地震后砌体结构房屋震害调查分析

2008年5月12日汶川8.0级地震后,根据四川省什邡市5幢砌体结构房屋震害的现场检测记录,以案例形式比较了房屋不同的结构形式、墙体布局、层间刚度比、构造柱设置、悬挑阳台、变形缝和选址等概念设计因素对结构抗震性能的影响,分析了结构发生各种损坏的原因,并对砌体结构房屋抗震设计提出建议。     

Perception of people for the risk of Tianwan nuclear power plant

A questionnaire survey of residents’ risk perceptions related to Taiwan nuclear power plant in China was carried out to explore the determining factors that affect individual risk perception. This study proposed to pursue a more comprehensive understanding of factors that affected individual risk perception to nuclear power plants. Covariance structure analysis was conducted using risk perceptions of nuclear power as dependent variable and including interest and knowledge levels of nuclear power, acceptability, benefit perception, trust in nuclear power operation, and trust in government as independent variables. The use of the hypothesis of Elaboration likelihood model (ELM) was also proposed. The results showed that persons with higher levels of interest and knowledge of nuclear power had their own perceptions of risk closely associated with acceptability and potential benefits of nuclear power. In contrast, persons with no interest in and knowledge of nuclear power would have risk perceptions related to their trust in nuclear operation and the government, which partially supported the ELM hypothesis. All these results indicated that the government in China plays an important role in rational risk perceptions, and well-designed communication of risks will help the public to be involved in risk management and improve people’s rational acceptance of risk.     

沙罗竹人工林生长与立地条件的关系研究

对广东省罗定市泗纶镇沙罗竹人工林生长与地形因子和土壤理化性质之间的关系进行了分析研究。结果表明,地形部位、坡型、坡向、土壤质地、立竹密度等对沙罗竹平均胸径有显著影响;沙罗竹平均胸径与土壤水分、有机质、全氮、速效氮、速效磷、有效硅质量分数呈显著正相关关系。回归分析结果表明,土壤有机质、速效氮、速效磷、有效镁质量分数及其组合是影响沙罗竹生长的主要养分因子。研究结果对沙罗竹林地选择和制定营林管理措施具有科学指导意义。     

镉对花生苗期的毒害效应及其品种间差异

重金属在籽粒中的积累与植物对镉的生物学耐性和吸收特性有一定的内在联系。本研究通过比较不同花生（Arachis hypogaea L.）品种对镉胁迫的生物学耐性,旨在为进一步揭示花生籽粒镉积累的种内差异形成机制提供实验参数。在人工气候箱控制环境下的含镉的营养液砂培试验中,花生苗期对镉胁迫的反应具有显著的品种间遗传差异。基于植株生物量变化,可将花生的镉胁迫反应分为3种类型,即镉钝感型,品种有平度01、花育23和莱农13;敏感型,品种有中花4号、花育20、丰花3号、莱农29、豫花15和祁阳小籽;普通型,品种有湘农3010-w、湘农312、湘农55、丰花2号和湘农小果w2-7等。钝感型品种在5个加Cd水平下的茎叶干物量比对照平均降低22.8%,全株生物量平均降低11.7%;敏感型品种茎叶干物量平均降低38.0%,全株生物量降低29.2%;普通型品种茎叶干物量平均降低33.2%,全株生物量降低25.1%。随着Cd质量浓度提高和暴露时间延长,花生叶片的叶绿素质量分数显著降低,叶片和根系丙二醛质量分数及细胞膜透性显著提高,与钝感型品种相比,敏感型品种的上述生理指标变化速率较高,而且随着镉暴露时间延长,两者之间的差异性持续扩大。     

Pollutant decontamination by polyethyleneimine-engineered agricultural waste materials: a review

Environmental Chemistry Letters - The direct discharge of untreated contaminants into global water systems has jeopardized our water security worldwide. This environmental concern has prompted...     

Improved lithium-ion batteries with coral-like anodes made of recycled spherical porous silicon coated with nitrogen-doped carbon

Environmental Chemistry Letters - With the development of the silicon smelting industry, the increase of microsilica waste has become a serious concern calling...     

Seasonal variations in microcystin concentrations in Lake Taihu, China

An enzyme-limited immunosorbent assay (ELISA) was used to monitor spatial and temporal variation of microcystins (MCs) in Lake Taihu. MC concentrations were higher in summer and autumn than in other seasons. Maximal MC concentration was 15.6 mug L(-1). Compared to central Lake Taihu and Wuli Bay, Meiliang Bay had higher MC concentrations due to high biomass of Microcystis.