Spatial Variations in Fish Abundance in the Mekong Delta

Russian Journal of Ecology - For the first time, the density of fish population has been quantitatively assessed in the Mekong River delta in the territory of the Socialist Republic of Vietnam. The...     

天然橡胶减震垫减震性能研究分析

采用相同结构的两种天然橡胶减震垫,进行了三种条件下的冲击试验和一种条件的振动试验,研究了减震材料硬度、产品质量对减震性能的影响.承受60g以上冲击时,使用该减震垫的产品经受的冲击能量可衰减50%以上,谐振频率在20Hz～40Hz的产品不宜使用该减震垫.     

基于产品功能的装备环境工程管理思考

首先详细分析了目前装备环境工程实施的现状,指出环境工程管理在其中的核心地位,提出了环境工程管理的三大任务,即保障设计的正确性、保障装备实现过程中各项技术活动与设计的一致性、以及保障后续装备的持续改进完善和升级。在环境适应性设计方面,结合具体工程案例,强调了关注产品顶层环境设计分析、总体与各部分的环境匹配性、全寿命周期环境集合的完备性、环境响应特性调查试验,以及数字仿真的重要性。可为装备环境工程的持续改进和提高提供新思路。     

炼厂"三泥"的生物处理研究

从大港油田筛选和分离出3株以原油为碳源的石油降解菌,初步鉴定为假单胞菌属(Pseudomonas sp.),用这3株菌混合处理某炼厂的"三泥",在适宜的降解条件下,仅需投加混合菌液,无需添加营养物(N,P),可使含油污泥A的残油量从67g/kg降至7.7g/kg,混合油泥试样AB的残油量从19.7g/kg降至3.1g/kg,平均去除率为84%以上,可以实现含油污泥的较为经济的、有效的处理.经生物处理后含油污泥的恶臭味完全消失.     

活性污泥1号模型废水特性的测定研究

废水的水质特性是活性污泥数学模型研究和应用的重要方面。采用呼吸计量法及常规化学分析法对污水处理厂的废水特性进行了测定,通过研究发现,污水处理厂的曝气沉砂池出水中SS占总COD的比例平均为10．49％;Xs占总COD的比例平均为14．24％;S1占总COD的比例平均为5．52％。初沉池出水中Ss占总COD的平均比例为9．62％;Xs占总COD的比例平均为16．97％;S1占总COD的比例平均为11．38％。     

Unanswered questions on the airborne transmission of COVID-19

Environmental Chemistry Letters - Policies and measures to control pandemics are often failing. While biological factors controlling transmission are usually well explored, little is known about...     

镉对孕鼠胎盘激素合成功能的毒性效应

为探究孕期低剂量镉暴露对胎盘激素合成功能的毒性效应,选择雌三醇和孕酮激素作为研究对象,基于研究的孕期低剂量镉暴露小鼠模型,通过生物化学方法检测镉暴露小鼠的血液和胎盘中的雌三醇和孕酮激素含量及其合成底物浓度,并通过实时定量PCR法对胎盘中相关激素合成基因的表达水平进行检测.结果表明,孕期低剂量镉暴露可导致小鼠血清和胎盘中...     

南京市典型水域沉积物中重金属形态分布特征

采用顺序提取的方法对南京市典型河流和湖泊水域的沉积物进行重金属化学形态研究,分析了Cu、Zn、Pb、Cd、Ni、Cr 6种重金属元素在不同水体沉积物中各个形态赋存的含量分布特征。结果表明,6种元素生物有效性排序为:Cd PbZn Cu Ni Cr,其中Cd和Pb以弱酸提取态和可还原态为主要存在形态,其不仅会对上覆水体产生二次污染,对水生动植物也具有较强的危害性。另外,通过结果间接反映出受人类生产生活影响大的水体,受污染的程度更高,各种金属元素赋存的形态也更易迁移转化,在环境治理方面更应受到重视。     

稻农低碳生产行为影响因素与引导策略——基于人际行为改进理论的多组比较分析

水稻种植是我国农业温室气体的主要排放源,有效引导农户进行水稻低碳化生产对减少农业温室气体排放,实现我国农业绿色可持续发展具有重要意义。基于改进的人际行为理论,建立稻农低碳生产行为影响机制理论框架,继而运用结构方程模型,实证检验了影响稻农低碳生产行为的主要因素及其影响路径。研究表明,低碳行为意愿与能力是激发稻农低碳生产行为的直接动因。行为态度、社会规范、环境情感通过影响低碳行为意愿作用于低碳生产行为。其中,行为态度的影响最大（0555）,其次是社会规范（0232）,环境情感作用最小（0153）。促进条件在意愿-行为、能力-行为的转化过程中具有显著的调节作用。进一步的多群组分析发现,受教育程度、家庭年收入、种植规模等变量在不同群组间的调节效应存在显著差异。由此表明,鼓励稻农适度扩大水稻种植规模,完善农业绿色生产补贴,加强水稻低碳生产教育与专业技术培训等是提高农户低碳认知与行为意愿,引导稻农从事低碳生产的有效手段     

Wet deposition of nitrogen and sulfur in Guangzhou, a subtropical area in South China

Understanding the exchange mechanism between stratosphere and troposphere is one of the most important concerns of meteorologists and climatologists for decades. Different methods are being adopted to study those mechanisms. One of those methods is the study upon the tropospheric concentration of conserve or passive entities with stratospheric origin. One of those passive entities is ⁷Be that is produced upon the incident of cosmic rays on light atmospheric nuclei in the stratosphere. The availability of 5 years observations of ⁷Be concentration in surface air in Tehran (35°41^′ N, 51°18^′ E) encouraged us to investigate meteorological condition effect on the surface concentration of ⁷Be. Also, the intention was to see if there was any intrusion of stratospheric air into the troposphere at the time of high surface concentration of ⁷Be and scavenging mechanism when the concentration was low. During the course of this study, it has been found that ⁷Be concentration is high whenever there is a jet stream over Tehran. Since high-level jet streams normally form near tropopause folding, it could be interpreted as a sign of the intrusion of stratospheric air into the troposphere. It was also found that high concentration of ⁷Be in the Tehran surface air in summer is associated with an upper ridge on 500 hPa surface located east of the city, and low concentration in winter is associated with an upper trough. The latter normally is seen whenever there is precipitation that suggests wet scavenging could be the reason for that observed low concentration.