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1.
文章使用文献资料法、问卷调查法、实地访谈法等方法,对尖草坪三中体育游戏的开展现状进行调查,结果发现,体育游戏在初中阶段体育教学中具有重要作用,大部分同学喜欢体育游戏,且呈现出性别差异,但游戏的组织与评价可能会影响到游戏的效果。在此基础上,对体育游戏自身的特点,体育游戏的利用价值,学生喜欢游戏的种类以及对体育游戏的态度等方面提出了一些相应对策,建议在体育教学中要从学生出发,注重德育教育,使体育游戏在体育教学中不断发展完善。  相似文献   

2.
当今社会,各级教育部门越发重视地方音乐如何走进高校课堂,重视民族音乐文化传承也成为近年来国际音乐教育的发展趋势。本文以冀南地方戏曲"平调"为例,尝试突破传统音乐课堂教学模式,也为我省非遗文化传播与传承奠定一定理论基础。  相似文献   

3.
当前,重视学生自身个性的发展不仅是新时代创新的要求,也是素质教育的新要求。在这一形势下,让学生成为教育的中心并根据自身的兴趣爱好来选择学习内容的选项教学法成为了提高体育教学效率的主要方法之一。本文从高中体育教学中应用选项教学法的重要性入手,对选项教学法的应用现状进行了研究,并对如何有效地实施选项教学法提出了具体的改进措施,希望能够为广大同仁的教学提供一些帮助。  相似文献   

4.
《黑龙江环境通报》2014,(2):136-137
当前,重视学生自身个性的发展不仅是新时代创新的要求,也是素质教育的新要求。在这一形势下,让学生成为教育的中心并根据自身的兴趣爱好来选择学习内容的选项教学法成为了提高体育教学效率的主要方法之一。本文从高中体育教学中应用选项教学法的重要性入手,对选项教学法的应用现状进行了研究,并对如何有效地实施选项教学法提出了具体的改进措施,希望能够为广大同仁的教学提供一些帮助。  相似文献   

5.
刘昌文 《环保科技》2005,11(3):36-37
通过对CODCr消解方法的改进,使得CODCr的检测结果重现性好,数据之间的可比性增强,能耗降低、操作方便、安全。  相似文献   

6.
孙杰  曾沛  张晗 《环境科学学报》2014,34(12):3017-3021
将易生物降解的天然螯合剂乙二胺-N,N'-二琥珀酸(EDDS)与Fe(Ⅲ)结合形成Fe(Ⅲ)-EDDS体系并用于处理水中Cr(Ⅵ).在紫外光照射下利用该体系对Cr(Ⅵ)进行光还原,考察了溶液p H值、Fe(Ⅲ)-EDDS和Cr(Ⅵ)的初始浓度对Cr(Ⅵ)去除率的影响.结果表明,UV/Fe(Ⅲ)-EDDS体系对Cr(Ⅵ)有光还原作用,且紫外光是反应进行的必要条件.在p H为3.0~8.0的范围内,反应顺利进行,且溶液的p H值越小,Cr(Ⅵ)的还原效果越好,去除率越高.Fe(Ⅲ)-EDDS浓度的增加对Cr(Ⅵ)还原有促进作用,Fe(Ⅲ)-EDDS浓度在0.10~0.30 mmol·L-1之间时,随着Fe(Ⅲ)-EDDS浓度的增大,Cr(Ⅵ)的还原率增大;当溶液中Fe(Ⅲ)-EDDS浓度不变,Cr(Ⅵ)浓度在5~20 mg·L-1之间时,Cr(Ⅵ)的去除率随其浓度的增加而降低.  相似文献   

7.
N,N-二甲基甲酰胺(DMF)废水处理研究进展   总被引:16,自引:0,他引:16  
DMF是一种性能优良的有机溶剂和精细化工产品中间体,工业用途广泛,但DMF有毒性,难生物降解.在此综述了DMF废水的主要处理方法,包括生物降解、吸附、萃取、化学氧化、碱性水解等,分析了各种方法的优缺点及适用范围,并展望了DMF废水处理工业化应用的研究方向.  相似文献   

8.
安徽沿江地区广泛分布的新近沉积软土,由于其埋藏厚度大、强度低、变形大、透水性低的工程特性而产生过大的路基沉降和路堤稳定性等工程地质问题,影响公路工程建设的质量和正常使用。本文对池州至安庆高速公路大渡口段软土路基的沉降和路堤稳定性进行了计算和工程地质评价。首先用分层总和法进行总沉降量计算,然后利用单向固结理论进行工后沉降计算。计算结果表明,软土路基工后沉降不能满足设计要求,须对其进行处理; 而填土路堤稳定性分析结果说明该路段路堤稳定。  相似文献   

9.
施凤宁 《云南环境科学》2006,25(Z1):167-169
提出了测定水样中As(Ⅲ)、As(Ⅴ)、总As的原子荧光法用邻苯二甲酸氢钾-NaOH缓冲溶液控制pH5.5时测定As(Ⅲ);用抗坏血酸、碘化钾及硫脲预还原As(Ⅴ)后测定样品中的总As;用差减法求出As(Ⅴ).该方法线性范围宽,检出限小,灵敏度、精密度较高、干扰小.  相似文献   

10.
重铬酸盐法测定化学需氧量是国家标准方法,采用硫酸银作催化剂,浪费了贵金属银,增加分析成本,不适用于长期、大批量样品分析。本文采用Mn SO4-Cu SO4-KAl(SO4)2协同作为催化剂的新方法,确定最佳试验条件,并应用该催化剂用于实际废水测定的效果。  相似文献   

11.
从美国《濒危物种法》对我国《野生动物保护法》的反思   总被引:2,自引:0,他引:2  
濒危物种是人类的宝贵遗产,各国在1973年的濒危动植物种国际贸易公约(简称CITES)影响下,纷纷制定国内法以期有效保护和管理濒危物种。仅就1973年美国《濒危物种法》和1988年我国《野生动物保护法》的某些方面作一初步比较,寻求差异的原因,希望对我国濒危物种立法完善有所裨益。  相似文献   

12.
Black carbon (BC) in ten contaminated sediments from the Song-Liao watershed, NE China, was isolated upon treatments using a combustion method at 375°C, and the isolates’ sorption isotherms for phenanthrene (Phen) were determined. All sorption isotherms were nonlinear and fitted well by the Freundlich model. A negative relation was found between Freundlich sorption nonlinearity parameter (n values) and BC/total organic carbon (TOC) content of the original sediments (r 2 = 0.687, p<0.01), indicating the dominance of BC in Phen sorption nonlinearity. The BC isolates from this industrialized region had n values of 0.342 to 0.505 and logK FOC values of 6.02 to 6.42 (μg·kg−1·OC−1)/(μg·L−1) n for Phen. At a given C e, the BC had higher K oc value than the original sediments, revealing a higher sorption capacity for BC. BC was responsible for 50.0% to 87.3% of the total sorption at C e= 0.05 S w, clearly indicating the dominance of BC particles in overall sorption of Phen by sediments.  相似文献   

13.
大气中二次有机气溶胶(SOA)是PM25中的重要组成部分,挥发性有机物(VOCs)的光化学氧化是其主要来源之一.从VOCs转化生成SOA的过程非常复杂,参数化方法是一种相对简化的估算方式,可以用于区分不同VOCs物种对SOA生成的贡献.本文介绍了基于二产物和基于挥发性分级两种常用的参数化估算方法,并总结分析文献报道的SOA估算结果.文章中也指出现在的参数化估算还存在一些问题,如何准确量化VOCs向SOA的转化过程将是大气化学未来的重要研究工作.  相似文献   

14.
Per-and polyfluoroalkyl substances(PFASs) are ubiquitous in sludge and water from waste water treatment plants, as a result of their incorporation in everyday products and industrial processes. In this study, we measured several classes of persistent PFASs,precursors, transformation intermediates, and newly identified PFASs in influent and effluent sewage water and sludge from three municipal waste water treatment plants in Sweden, sampled in 2015. For sludge, samples from 2012 and 2014 were analyzed as well.Levels of precursors in sludge exceeded those of perfluoroalkyl acids and sulfonic acids(PFCAs and PFSAs), in 2015 the sum of polyfluoroalkyl phosphoric acid esters(PAPs) were 15–20 ng/g dry weight, the sum of fluorotelomer sulfonic acids(FTSAs) was 0.8–1.3 ng/g,and the sum of perfluorooctane sulfonamides and ethanols ranged from non-detected to 3.2 ng/g. Persistent PFSAs and PFCAs were detected at 1.9–3.9 ng/g and 2.4–7.3 ng/g dry weight, respectively. The influence of precursor compounds was further demonstrated by an observed substantial increase for a majority of the persistent PFCAs and PFSAs in water after waste water treatment. Perfluorohexanoic acid(PFHxA), perfluorooctanoic acid(PFOA), perfluorohexane sulfonic acid(PFHxS), and perfluorooctane sulfonic acid(PFOS)had a net mass increase in all WWTPs, with mean values of 83%, 28%, 37% and 58%,respectively. The load of precursors and intermediates in influent water and sludge combined with net mass increase support the hypothesis that degradation of precursor compounds is a significant contributor to PFAS contamination in the environment.  相似文献   

15.
Pyrolysis has the potential of transforming waste into valuable recyclable products. Pyrolytic char (PC) is one of the most important products from the pyrolysis of used tires. One of the most significant applications for pyrolytic char recovered is used for the removal of Cr( Ⅵ ) in the wastewater effluent to control waste by waste. The surface chemistry properties of surface element distribution/concentration and chemical structure were examined for the pyrolytic char and the commercial activated carbon(CAC) respectively. The results showed that surfaces of PC possesses a large amount of ester and hydrocarbon graft, whereas there are mainly carbon functional components of C-OH, C=O and COOH on the surface of CAC. Therefore the surface electronegativity of PC is lower than that of CAC in the water. The repulsive interactions between the surfaces of PC and the negatively charged Cr(Ⅵ ) ion are weaker than that of CAC,which results in an intensification of the adsorption process by the utilization of PC. The adsorption isotherms of Cr( Ⅵ ) ion on the two kinds of carbons were determined experimentally. The larger adsorption amount on the PC in the case of Cr( Ⅵ ) may be attributed mainly to its special surface micro-chemical environment. The mechanism of the removal Cr( Ⅵ ) from aqueous solution was assumed to be the integration of adsorption and redox reaction. The adsorption was the rate-controlled step for Cr( Ⅵ ) removal. The adsorption of Cr( Ⅵ )was identified as pseudo-second-order kinetics. The rate constants of adsorption were evaluated.  相似文献   

16.
以壳聚糖为原材料,通过原位共沉淀法和柠檬酸钠交联法制备了一种新型多孔磁性壳聚糖凝胶微球吸附剂CS-citrate/Fe3O4.利用扫描电镜(SEM)、透射电镜(TEM)、傅里叶红外光谱(FTIR)、热重分析(TG)对吸附剂进行了表征.结果表明,吸附剂内部具有发达的孔隙结构,并均匀分布有平均直径为(4.79±1.09)nm的Fe3O4纳米颗粒;吸附剂中引入Fe3O4后,仍存在羟基、氨基和羧基等功能基团,且吸附剂磁性良好可用于磁场分离;吸附剂对Pb(Ⅱ)的吸附等温线和动力学研究表明,吸附过程以化学吸附为主,最大吸附容量可达178.25mg/g.  相似文献   

17.
18.
碱预处理提高污泥产甲烷潜力(BMP)研究   总被引:1,自引:0,他引:1  
以济南某生活污水处理厂的污泥为研究对象,考察碱预处理对污泥粒径和产甲烷潜力(BMP)的影响。调节污泥混和液的pH值至11左右后与未作处理的原污泥进行对比分析,结果表明,碱预处理对污泥有很好的分散作用,可以将较大粒径的污泥絮体分散为较小粒径的污泥絮体;未处理的污泥10d左右产甲烷量达到最高约为165ml/gVSS,而碱预处理后的污泥在6d左右产甲烷量就高这245ml/gVSS,碱预处理后污泥的产甲烷量不但明显增加,而且产甲烷所需时间也大大缩短。  相似文献   

19.
废水有机物对亚硝化 厌氧氨氧化(ANAMMOX)生物膜系统的影响借助已建立的自养生物膜模型(CANON)与活性污泥3号模型结合进行了理论模拟.被结合的数学模型可以模拟生物膜中自养菌与异养菌活性以及所涉及的全部内在反应(碳氧化、硝化、反硝化、厌氧氨氧化).模拟显示,废水有机物对亚硝化 厌氧氨氧化生物膜系统影响不大;生长稳定的生物膜系统中异养菌反硝化不是脱氮的主反应(最大脱氮作用20%);厌氧氨氧化左右着脱氮功能.除废水中有机物可被全部去除外,当溶解氧最佳时,系统总氮去除率亦可高达90%.  相似文献   

20.
A temnospondyl ilium from the uppermost Toutunhe Formation (Middle Jurassic, Callovian) of the southern Junggar Basin is described. Among the known temnospondyls it is very unusual in morphology because of its very long and slender shaft. It compares closely only to the ilium of one of the latest known trematosaurids from the Ladinian of southern Germany. The Toutunhe Formation has also yielded vertebrae and skull fragments of temnospondyls which belong to the brachyopid Gobiops from the Upper Jurassic of Mongolia. Brachyopoid ilia do not, however, display a morphology similar to that of the new specimen. It is therefore concluded that this specimen represents a second taxon of temnospondyl from the Toutunhe Formation, which probably represents the latest surviving trematosauroid. The Trematosauroidea, which was hitherto exclusively known from the Lower to early Upper Triassic, therefore joins the Brachyopoidea – and possibly the Capitosauroidea – as another group of temnospondyls which survived the end-Triassic mass extinction.  相似文献   

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