邻苯二甲酸二丁酯影响阿尔茨海默病大鼠学习记忆能力的分子机制研究

为探究邻苯二甲酸二丁酯(DBP)影响阿尔茨海默病(AD)大鼠学习记忆能力的分子机制,将56只SPF级5～6周龄雌性Wistar大鼠随机平均分为7组:阴性对照组、0.25 mg·kg-1·d-1 DBP 组、2.5 mg·kg-1·d-1 DBP 组、25 mg·kg-1·d-1 DBP 组、250 mg·kg-1·d-...     

水质氨氮自动分析仪分析方法研究

氨氮自动分析仪是根据纳氏试剂分光光度法的原理,通过自动进样,自动蒸馏,来实现快速准确的分析水质氨氮样品。近年来,氨氮自动分析仪广泛应用于环境监测领域,该方法能够快速、准确、方便地测定水质中的氨氮。利用标准方法纳氏试剂分光光度法进行实验室内的比对实验,通过实验分析,氨氮自动分析仪的分析曲线线性较好,相关系数达到0．9998,方法检出限、准确率和精密度能够满足当前环境监测标准的要求,实际样品测定结果理想,适合在环境监测领域推广应用。     

中原经济区城市资源环境绩效指标体系构建与实证

为了识别城市或“相似群体”最重要的资源环境“短板”问题,以中原经济区31个城市为研究区域,选择水土资源、能源、环境质量和污染物排放及治理水平等4个方面共计33项指标,利用层次分析修正法确定指标权重,采用正向指标极大化、负向指标极小化、适中指标平均化的标准化方法对研究区域内各市资源环境绩效进行测算. 研究表明:①从资源环境绩效角度来看,中原经济区城市可分为“双高”超载型、农业型、“双低”超载型、资源型四大类. ②占中原经济区城市总数2/5的资源型城市,由于过度强调资源产出、忽视环境保护而成为经济区环境问题高发、资源环境矛盾较为突出的集中区域. ③在对4个Ⅰ级指标(资源利用效率、能源利用效率、环境质量指数、污染物排放及治理水平)设定均衡权重情况下,15个城市的能源利用效率居末位,10个城市的资源利用效率居末位,表明中原经济区提高资源环境绩效应率先在能源、资源利用效率领域实现突破. 所构建的资源环境绩效评估指标体系仍有待进一步优化,今后应加大对可再生资源能源利用、农村生态环境特别是农村土地重金属及有机物污染等问题的关注.      

多氯联苯电容器焚烧系统预处理装置的工程设计

介绍了多氯联苯电力电容器焚烧系统预处理装置的工程设计及多氯联苯电力电容器切割装置实用新型专利技术 (专利号 96 115 4 4 9.7)的具体实施情况 ,并借鉴国外处理固体废物设备的设计 ,对切割后的电力电容器进行分选     

检测管法与纳氏试剂光度法测定氨氮的比较研究

对氨氮真空玻璃检测管法和纳氏试剂光度法进行检出限、精密度、准确度,以及实际样品测试方面的比较研究。研究表明,氨氮检测管的检出限为0．2mg／L,精密度测定的相对标准偏差为0％～5．75％,准确度测定的加标回收率为93％～124％。检测管法和纳氏剂法同时测定多种实际样品,结果两种方法的相对误差为-37．8％～11．8％,结论：检测管法能够满足半定量测试的需求。     

改进测定水中氨氮分子吸收光谱法的试验研究

水中氨氮含量是反应水质状况的重要指标。文章对测定水中氨氮气相分子吸收光谱法(标准号HJ/T195-2005)进行了改进试验研究。第一,对氧化剂的配比进行了改进,使氨氮的测定范围扩展至100μg。第二,对标准HJ/T195-2005中直接使用亚硝酸钠标准溶液做标准曲线的处理方式也做了探讨。通过一系列对比实验认为,应用硫酸铵标准溶液做工作曲线更加准确合理。最后应用改进后的气相分子吸收光谱法和纳氏比色法或滴定法对多种实际废水样品进行同时测定。结果表明,改进后的气相分子吸收光谱法测定氨氮的范围更宽,灵敏度更高和准确度更好。     

Prenatal exclusion of Hurler's disease by leucocyte α-L-iduronidase assay

Hurler's disease was excluded in a fetus at 23 weeks' gestation by demonstrating normal iduronidase activity in fetal leucocytes following failure of amniotic cell culture after amnic-centesis at 16 and 19 weeks' gestation. The diagnosis was confirmed in the neonate.     

芬顿试剂氧化对污泥脱水性能的影响

利用芬顿试剂调理污泥,以W_C(污泥滤饼含水率)和CST(毛细吸水时间)作为评价污泥脱水性能的指标,通过分析污泥中各层ρ(EPS)(EPS为胞外聚合物)和上清液中小分子有机物质量浓度来阐明污泥脱水性能的变化. 结果表明:芬顿试剂调理可促进EPS氧化分解,TB-EPS(紧密结合的胞外聚合物)破解转化为LB-EPS(松散结合的胞外聚合物)和S-EPS(上清液层胞外聚合物),大幅降低W_C和CST. 试验中当pH为4,w(H₂O₂)和 w(Fe2+)均为40 mg/g时,ρ(EPS)降低了33.04%,W_C和CST分别降至63.36%和28.7 s. Pearson相关性分析表明,ρ(TB-EPS)与W_C和CST均存在显著的正相关性(P＜0.01),是影响污泥脱水性能的重要因素,而ρ(LB-EPS)和ρ(S-EPS)与污泥脱水性能的相关性较低. 液相色谱分析表明,随着芬顿试剂投加量的增大,EPS等有机物分解程度增大,污泥上清液中小分子有机物种类明显增多,其质量浓度显著升高,ρ(甲酸)和ρ(乙酸)分别由原污泥的52.72、15.99 mg/L升至446.05、522.36 mg/L.      

Simplified model for the evaluation of the effects of explosions on industrial target

The evaluation of vulnerability of process equipment to explosion is a central issue in the analysis of industrial risks. In this work, we have developed a simplified model, however based on fundamental equations, which includes structural and fluid–dynamic parameters for the target (the industrial equipment) and for the impacting pressure wave (shock waves) or object (fragment, debris) produced by different type of chemical explosions.The validity of methodology has been assessed by case histories. Several insights on the dynamic of structural interaction of the explosion with the target have been obtained, with specific reference to escalation effects.The model derives from the well-known Johnson's number, often adopted in impact engineering.     

Rank-related partner choice in the fission–fusion society of the spotted hyena (<Emphasis Type="Italic">Crocuta crocuta</Emphasis>)

When social partners vary in their relative value, individuals should theoretically initiate partnerships with conspecifics of the highest value. Here, we tested this prediction in a wild population of spotted hyenas (Crocuta crocuta). Crocuta live in complex, fission–fusion societies structured by dominance hierarchies in which individuals vary greatly in their value as social companions. Because patterns of association among Crocuta reflect social preferences, we calculated association indices (AIs) to examine how social rank influences intrasexual partner choice among unrelated adults of both sexes. The highest-ranking individuals were generally most gregarious in both sexes. Females associated most often with dominant and adjacent-ranking females. Females joined subgroups based on the presence of particular conspecifics such that subordinates joined focal females at higher rates than did dominants. Dominants benefit from associations with subordinates by enjoying priority of access to resources obtained and defended by multiple group members, but the benefits of these associations to subordinates are unknown. To investigate this, we tested three hypotheses suggesting how subordinates might benefit from rank-related partner choice among unrelated females. We found that subordinates who initiated group formation benefited by gaining social and feeding tolerance from dominants. However, rates at which dominants provided coalitionary support to subordinates did not vary with AIs. Overall, our data resemble those documenting patterns of association among cercopithecine primates. We consider our results in light of optimal reproductive skew theory, Seyfarth’s rank attractiveness model, and biological market theory. Our data are more consistent with the predictions of Seyfarth’s model and of biological market theory than with those of skew theory.