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持久性有机污染物,英文简称POPs,是一类对人类健康和环境具有严重危害的天然或人工合成的有机污染物,它具有环境持久性、生物累积性、长距离迁移能力和高生物毒性.本文在简要介绍POPs的定义、特征、种类和来源的基础上,重点阐述了国内外POPs的研究进展及启示. 相似文献
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水环境中持久性有机污染物的污染状况及管理对策 总被引：1，自引：0，他引：1
持久性有机污染物(POPs)因其对生态环境和人体的高危害性而成为当今的研究热点,受到社会各界的普遍关注。文章介绍了POPs的概念、特性,分析了七大流域水环境中的POPs的污染现状、检测技术和处理技术现状,提出了今后在污水处理、水资源利用和水环境保护中POPs的管理对策。 相似文献
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全球性环境污染物——二噁英的形成与危害 总被引：1，自引：0，他引：1
二噁英是持久性有机污染物。污染生态环境。毒害人类健康。为国际社会所关注。就二噁英的基本情况、产生的原因以及对环境、人类的危害等方面进行介绍。概要说明POPs的基本特征和毒性效应。提出我国应对二噁英的一些措施。 相似文献
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持久性有机污染物对人体健康的危害 总被引：1，自引：0，他引：1
本文介绍了持久性有机污染物的含义，特性及典型的持久性有机污染物的污染事件，阐述了持久性有机污染物对人体健康构成威胁的原因，并提出了预防持久性有机污染物污染的措施。 相似文献
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二口恶英是持久性有机污染物,污染生态环境,毒害人类健康,为国际社会所关注。就二口恶英的基本情况、产生的原因以及对环境、人类的危害等方面进行介绍,概要说明POPs的基本特征和毒性效应,提出我国应对二口恶英的一些措施。 相似文献
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本文通过问卷调查及访谈等形式调查了乌兰察布市大学生对持久性有机污染物(POPs)的认知度,调查发现本地区大学生POPs的认知度较低,对斯德哥尔摩公约内容不熟悉.大学生是一个特殊的社会群体,在文化素质和年龄构成等方面与社会的其他群体不同,提高大学生对于POPs的认知度有利于推动全社会来共同关注和认识持久性有机污染物. 相似文献
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李光辉 《安徽科技学院学报》2012,26(5):5-10
环境污染物对人和动物健康的危害,日益受到国际组织、各国政府及人民的极大关注。本文综述了环境污染物对家畜健康的危害及其对策,包括:环境污染物的来源与危害特点;重金属污染物对家畜健康的危害;持久性有机污染物对家畜健康的危害;放射性核素污染对家畜健康的危害及其对策。 相似文献
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张爱军 《中学语文教学参考(高中生版(学语文))》2003,(9)
一、持久性有机污染物 (POPs)的特性和危害POPs结构稳定 ,自然条件下不易降解。研究表明 ,POPs的半衰期在水中大于 2个月 ,在土壤和沉积物中大于 6个月 ,在人体和动物体内则可持续 1年到10年。因此 ,即使是 10年前使用过的POPs,在许多地方依然能够发现残留物。POPs物质不易溶于水 ,但却具有较好的脂溶性 ,因而能通过食物链在生物体内蓄积 ,进而富集并影响高营养等级的生物。POPs物质具有半挥发性 ,能够从水体或土壤中以蒸汽形式进入大气环境或被大气颗粒物吸附 ,通过大气环流远距离迁移 ,在较冷的地方或者受到海拔高度影响时会重新… 相似文献
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化学淋洗法修复重金属污染土壤效果研究 总被引：6，自引：0，他引：6
在国内外相关研究的基础上,文章研究化学淋洗修复技术在重金属污染土壤修复方面的运用．用浓酸消解土样并用火焰原子吸收法测定土壤中重金属含量,选用土壤柱作淋洗实验,分析去离子水和EDTA溶液两种淋洗剂对Cu、Zn、Pb、Cd四种重金属的淋洗效率,并对化学淋洗修复效果进行比较． 相似文献
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Azo dyes discharged in the environment are persistent organic pollutants （POPs）, which are very difficult to remove. We developed a microwave-assisted Fenton-like process to degrade methyl orange （MO）, an azo dye, with hydrogen peroxide （H2O2） catalyzed by chromium compounds coexisting with MO in the solution. Comparison between the Cr（Ⅲ）-H2O2 and Cr（Ⅵ）-H2O2 systems shows＂ that Cr（Ⅵ） has a stronger and more stable catalytical activity than Cr（Ⅲ）, and Cr（Ⅲ） is more susceptible to a change in the acidity or alkalinity of the reaction system. With a Cr（Ⅵ） concentration of 10 mmol L^-1 or a Cr（Ⅲ） concentration of 12 mmol L^-1 in the solution under the microwave irradiation of a power larger than 300 W for 3 min, 10 mmol L^-1 H2O2 can degrade more than 95% of 1 000 mg L^-1 methyl orange; when the microwave power is increased to 700 W, the same amount of H2O2 can degrade all methyl orange in the solution with the same amount of Cr（Ⅵ ） catalyst. Ultraviolet-visible spectrography indicates the cleavage of the azo bond in methyl orange after treatment, suggesting the potential o of this Fenton-like process to degrade azo dye POPs. Reusing waste chromium compounds coexisting with dyestuff in wastewater to catalyze the degradation of azo dyes could be a cost-effective technique for azo dyes and chromate manufacturers and/or users to treat their wastewater and prevent POPs from endangering the environment. This is of particula importance to controlling the water quality of the Three Gorges Reservoir. 相似文献
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组织政治在组织生活中无处不在,对组织运作及效率有重要影响。自组织政治认知提出以来,研究者对其概念、结构及对组织结果的影响都一直存在分歧,并且组织政治认知一直被认为是消极的、黑暗的、对组织百害而无一利的。因此,在综述了组织政治认知概念基础上,扩展了组织政治认知模型,重点对组织政治认知的中立视角进行阐述,认识到它不仅是消极的,也可以是积极的。 相似文献
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Emma Howard Maria Meehan Andrew Parnell 《Assessment & Evaluation in Higher Education》2019,44(1):97-110
In Maths for Business, a large first-year mathematics module, the continuous assessment component comprises 10 weekly quizzes which combine to contribute 40% of the final module mark. If students did not receive the full five marks on their weekly quiz, they were provided with the opportunity to resubmit their corrected weekly quiz with an explanation of their error(s) for one additional mark. We refer to this process as ‘remediation’. Of the students who had the opportunity to remediate, ～70% did. Through examining learning management system data, we show that the remediation process encouraged students to access module resources. Furthermore, by using a Bayesian hierarchical model to account for students’ level of participation, achievement and prior knowledge, we show that participation in the remediation process positively impacted the final examination marks of moderate to high-achieving students (based on initial continuous assessment marks). However, participation in the remediation process provided limited benefit to low-achieving students. We conjecture this is because these students had not achieved a level of understanding whereby participation in the remediation process could progress their knowledge. 相似文献
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唐人善用“拗救”的格律,“拗救”的情况相当常见。列举“拗救”的各种观点,并对各家的分类情况进行分析,能使人们对近体诗的拗救情况有一个大体的把握。 相似文献
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我国富营养化湖泊底泥污染治理技术展望 总被引：3，自引：0，他引：3
富营养化是水体严重污染的一个重要标志。目前,我国湖泊富营养化比例超过80%。而一般认为造成湖泊富营养化的污染源可以分为外源(点源和非点源)及内源两种。所谓内源,就是指沉积在底泥中的营养盐在适当的条件下进入水体,造成水体的二次污染。当湖泊的外源得到控制后,内源即成为富营养化的主导因子,并且可以在很长一段时间内维持湖泊的富营养化状态。因此,如何处理富营养化湖泊中污染的底泥问题已经引起了很多学者的普遍关注。本文就富营养化湖泊底泥污染治理技术及其应用情况进行了总结,认为底泥治理技术可以分为原位处理技术和异位处理技术两种;并结合我国国情对各种技术的优缺点进行了研究和比较,认为原位处理技术是异位处理技术的重要补充,可以兼顾短期效益和长期效益。并对目前研究的热点———生物处理技术的研究及使用情况进行了讨论,强调了底泥生态修复的理念,并对其应用前景进行了展望,认为生态修复技术是解决湖泊底泥污染问题的必经途径。 相似文献
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认知诊断通过分析被试的项目作答反应,推断被试的认知属性掌握状态,为学习困难学生设计补救教学提供了非常有价值的信息。本文作者在探讨了小学生多位数乘法计算能力的认知属性、编制了2份相同考核模式的认知诊断测验后,选择江西某小学310名高年级学生为被试,先施测第1份认知诊断测验,采用DINA模型,自编参数估计程序进行诊断,得到了每一个被试的属性掌握模式分类及全体被试在各个属性上的掌握情况。然后设计和实施补救教学,在实施补救教学后再施测第2份认知诊断测验以检验补救效果。研究发现：（1）该小学高年级学生对0XN运算法则、多位数乘以两位数的运算程序、乘法进位认知属性的掌握不太理想,特别是乘法进位。（2）属性掌握模式中属全部掌握模式的被试人数占86．47％,其余被试均分类于存在各种认知不足的掌握模式。（3）比较两份认知诊断测验报告,结果表明在认知诊断指导下的补救教学有针对性,补救后被试正确作答项目增多,属性掌握个数也有所增加,补救效果良好。 相似文献
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Ethical standards for counselor training require remediation of students with professional performance deficiencies. However, standards fail to specify the type or extent of remediation necessary to safeguard students' legal rights or justify dismissal if remediation is unsuccessful. Critical assessment of remedial practices in counselor preparation has occurred primarily in the courts when the constitutionality of specific practices was challenged. Prompted by a recent court challenge and its implications for curricular and policy change (C. R. McAdams, V. A. Foster, & T. J. Ward, 2007), this article examines court‐tested methods of student remediation and presents them as a guide for developing just and fair student remediation policies. 相似文献
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Fong Ho Kheong 《Asia Pacific Journal of Education》1988,9(2):43-51
The objectives of the present study are to develop an automated computer system for diagnosis and remediation and to construct a conceptual model of remediation in fractions. The initial stage of the project began with the construction of an instrument to investigate the subjects' performances in addition of fractions. The items were based on a set of four objectives in addition of fractions. The test was administered to 3000 subjects who were classified as below average in fractions. The test was readministered a week later. The responses of the subjects were analysed and systematic errors were classified. An automated computer system for diagnosis and remediation in addition of fractions was developed. It consisted of three subsystems, viz. (a) diagnostic system of errors, (b) drill and practice for remediation, and (c) automated generation of text materials for remediation. To accompany the computer system for diagnosis and remediation, a conceptual model on remediation of addition of fractions was developed which was based on the hypothetical remedial activities. 相似文献