盐析分相萃取法分离Ni^2＋和Fe^3＋ 的研究

研究了丙醇溶液的盐析分相条件,选择出适宜的分相无相盐,并找出了分相时丙醇溶液的浓度与盐的用量的关系,用盐析分相萃取法对Ni^2 ,Fe^3 进行了分离,使Ni^2 ,Fe^3 分离得较为完全。     

Fe^2＋对金针菇菌丝生长的影响

本实验主要研究Fe^2＋对金针菇茵丝生长的影响;在PDA培养基中分别加入不同浓度的Fe^2＋,接入金针菇母种,适宜条件下培养,通过测量茵丝圈直径的方法测出茵丝的日长速;通过抽滤、干燥等手段测定茵丝体的干重,并计算出茵丝日生长量．实验结果表明Fe^2＋浓度为0．5g／L时,金针菇茵丝的日长速和日生长量最佳．     

例谈解几例化学题的方法

例1 无色液体A中，可能含有Cu^2＋、Al^3＋、Mg^2＋、Fe^3＋、Na^＋、CO^2-3、SO^2-4等离子中的某几种．若取A溶液加入用盐酸化的BaCl2溶液，只出现白色沉淀．若取A溶液加入Na2O2，有无色无臭气体放出，同时生成白色沉淀．加Na2O2的量与生成白色沉淀的量关系如图1所示．     

高考化学能力月月赛（13）获奖名单

将3．96g组成为X2YZ4的盐（不是复盐）溶于水，滴加适量稀硫酸后再加入2．24g还原铁粉，恰好完全反应生成Fe^2＋．向反应后的溶液中加入足量的KOH溶液至刚好将Fe^2＋沉淀完全．过滤，将沉淀充分加热后得到红色Fe2O3粉末4．80g；将此滤液在一定条件下蒸发可得到一种纯净的不含结晶水的含氧酸盐（不是复盐）13．92g．试通过计算和讨论确定X2YZ4的化学式．     

Fe^3＋、Cu^2＋掺杂TiO2光催化降解日落黄的研究

通过溶胶-凝胶法分别制备了掺杂Fe^3＋、Cu^2＋的TiO2.以日落黄为目标降解物,研究Fe^3＋、Cu^2＋掺杂TiO2为催化剂的紫外光催化反应,考察了金属离子的掺杂量、催化剂的加入量、光照时间、溶液pH值、溶液初始浓度对脱色率的影响.结果表明：Fe3＋掺杂对提高TiO2光催化活性的效果优于Cu^2＋掺杂.在Fe^3＋、Cu^2＋掺杂比为1.5%,Fe^3＋、Cu^2＋掺杂催化剂用量分别为0.04、0.1 g/L,紫外光催化降解2 h,pH为10,初始浓度为6 mg/L的日落黄100 mL的条件下,Fe^3＋、Cu^2＋掺杂的催化剂脱色率分别达92.14%、58.68%.     

Fe^2 及Fe^2 、Zn^2 相互作用对蒜根尖生长和细胞分裂的影响

用不同浓度(100—400mg/L)的Fe^2 和Fe^2 Zn^2 溶液处理蒜鳞茎发现：随着浓度的增大和处理时间的延长，Fe^2 使细胞有丝分裂指数下降，而核异常细胞比率提高，就蒜而言，Fe^2 的毒害作用大于Zn^2 ；Fe^2 Zn^2 共同作用时，细胞分裂比率高于单Fe^2 而低于单Zn^2 ，核异常细胞比率比单Fe^2 单Zn^2 都下降，说明二者既相互促进又相互抑制，具有双重作用。     

高砷酸性废水除砷新工艺

对高含砷废水(砷含量为10000mg／L左右)采用分步、催化氧化后絮凝沉淀的处理方法。一步处理：采用石灰乳，调pH=3～4去除SO4^2-；二步处理：采用NaOH溶液使PH=9～10的范围，回收重金属；三步处理：加入催化剂-活性炭和Fe^2 通入空气氧化，使溶液中的As(Ⅲ)和Fe^2 氧化成As(V)和Fe^3 ，然后用石灰乳控制pH=6-9，使高价砷酸根与Fe^3 生成难溶的FeAsO4沉淀。经过上述处理后溶液中的砷小于0．5mg/L。     

三硫化二铁的制取方法

采用升高溶液pH等方法，降低Fe^3 浓度，避免Fe^3 氧化硫化物，从而制得了通常认为不能得到的Fe2S3。     

黄铁矿阳极氧化电化学机理的研究

利用LK98微机电化学分析系统，对黄铁矿在两种不同体系中的阳极氧化行为采用线性扫描伏安法研究，得到了黄铁矿阳极在氯化铁与氯化钠混合溶液、硫酸钠溶液中稳定电位范围为0．235～0．473V和0．30～0．7V，黄铁矿阳极溶解可能发生的反应是FeS2=Fe^2 2S 2e^-；FeS2=Fe^2 2S 3e^-．     

以问题带动学生进行化学研究性学习的案例及体会

一、以问题教学带动学生进行研究性学习的案例 1．发现问题，展开讨论 高二化学有关铁及其化合物的教学中，总会碰到Fe^2＋和Fe^3＋的鉴别问题，高中教学中对于Fe^2＋只能采用加入NaOH溶液，通过生成的沉淀颜色变化来加以鉴别。     

Towards an ethical ecology of international service learning

International Service-Learning (ISL) is a pedagogical activity that seeks to blend student learning with community engagement overseas and the development of a more just society. ISL programmes have grown as educational institutions and non-governmental organizations have sought to achieve the goal of developing ‘global citizens’. However, Service Learning (SL) in general and International Service-Learning (ISL) in particular remain deeply under-theorized. These educational initiatives provide policy-makers with a practical response to their quest for a ‘Big Society’ and present alluring pedagogical approaches for Universities as they react to reforms in Higher Education and seek to enhance both the student learning experience and graduate employability. After outlining the development of ISL in policy and practice, this paper draws on the rich tradition of ISL at one British university to argue that ISL is a form of engagement that has the potential to be ethical in character, although a number of factors are identified that militate against this. The contention is that ISL which promotes rational and instrumental learning represents a deficit model and, therefore, ISL is conceptualized here as a transformative learning experience that evinces distinctly aesthetic and even spiritual dimensions. Upon this theoretical groundwork is laid the foundations for conceptualizing ISL in ways that ensure its ethical integrity.     

Enacting Informal Science Learning: Exploring the Battle for Informal Learning

Informal Science Learning (ISL) is a policy narrative of interest in the United Kingdom and abroad. This paper explores how a group of English secondary school science teachers, enacted ISL science clubs through employing the Periodic Table of Videos. It examines how these teachers ‘battled’ to enact ISL policy in performative conditions at the micro-scale, and how this battle reflected macro-scale epistemological and political considerations. Data from the study suggests that for some, ISL was low stakes as it was seen to have negligible impact upon performance data. As a result, there was some resistance towards enacting ISL and conflict between the formal and informal curriculum processes. Nonetheless, analysis indicates that the informants highly valued ISL despite the requirement for them to justify it over more formal and ‘effective’ approaches to learning science.     

葎草的开发利用及防治措施

葎草为桑科草本野生植物,除西藏自治区、青海省外,我国南北各地均有分布．由于它具有多种营养成分,因此在畜禽饲养、医疗保健、水土保持和绿化荒山等方面有较大开发利用价值．葎草常与作物杂草混生,且蔓延快,会造成作物减产、阻碍树木正常生长,使果树结果减少,还会使草坪荒废,伤人皮肤,妨碍人类活动．其防治措施主要包括人工清除与化学方法清除．     

Service learning and intercultural citizenship in foreign-language education

Service Learning, a pedagogy combining formal learning with community service, has recently developed into Intercultural Service Learning (ISL). Intercultural Citizenship Education (ICE) combines foreign-language education and education for (intercultural) citizenship. They have different origins and applications but recent work in ISL is linked to foreign language education, as is ICE. A comparison of the two reveals considerable similarities and the potential for mutual enrichment. The article first explains the two types of education and their origins and theory, and examples of each are then provided. Thus the ways in which they complement each other and the potential for further coherence and enrichment are demonstrated. In particular it is argued that foreign language education can gain from the experience and rigour of ISL to give new possibilities for language teachers.     

“三权分置”视角下土地经营权的权利属性研究

“三权分置”改革中的土地经营权是指土地经营权的所有人拥有耕地、从事农业生产和获得利益的权利,土地经营权是基于土地所有权或基于土地承包经营权经营管理土地的权利。承包农户可以在承包地上设定土地管理权。集体经济组织可以在其所有的荒滩、荒山、荒丘、荒沟上(以下简称“四荒地”)设立土地经营权,并将其移交给其他经营管理对象。基于土地承包经营权所产生的土地经营权性质应该是不动产用益物权,由于土地承包经营权所具有的成员权性质,承包农户在承包土地上为自己所设定的土地经营权也相应的具有成员权特点;基于土地所有权所设立的土地经营权(“四荒地”的土地经营权)作为物权已得到法律上的确认。     

乾隆时期的新疆移民措施

1759年,清统一新疆后,面对人口锐减、土地荒芜、经济凋零的状况,采取了鼓励移民、奖励垦荒、安置灾民等一系列安民兴疆举措,对恢复生产和巩固统治发挥了重要作用。     

池莉写实小说的思想倾向及艺术特色

1 98 7年 ,池莉发表了《烦恼人生》,标志着新写实小说流派的发端 ;以后 ,池莉陆续发表有关当代人生探索的系列作品 ,提出了物质和精神贫困两大重要人生课题 ,描述了当代都市的烦恼人生及其不断演进的状态、过程 ,颂赞了人们不屈不挠进行生存抗争的精神 ,也展示和批评了当代人身上的不足与缺陷 ,提出了一些社会问题 ;暗示只有彻底摆脱物质和精神的贫困 ,人们才有可能赢得真正的幸福。该文尝试剖析池莉小说创作的思想脉络及倾向 ,概述其写实作品的艺术特色     

玉米醇溶蛋白膜的制备及其在保鲜中的应用

研究了不同提取剂和不同固液比对玉米醇溶蛋白提取效果的影响,结果表明:以1∶6比例的60%丙酮为最佳提取剂.用玉米醇溶蛋白涂被剂保鲜小番茄,最佳涂被剂配方为:玉米醇溶蛋白1.75%,甘油0.18%,蔗糖0.5%,并辅以0.02%乳化剂与防腐剂,不仅可延长小番茄的贮藏期,还可减少小番茄在贮藏期间的营养成分损耗.     

共存重金属和含氧阴离子对U(VI)生物沉淀过程的影响

以硫酸盐还原菌生物还原法消除模拟地浸废水中的放射性铀污染,分别研究了主要共污染离子Zn2+、Cu2+、SO2/4-和NO3-对铀生物沉淀过程的影响.厌氧序批式实验结果表明,初始Cu浓度低于10 mg/L或Zn浓度低于20 mg/L时对铀生物沉淀过程影响不大,当初始Cu浓度超过15 mg/L或Zn浓度超过25 mg/L时,该过程会因重金属的生物毒性作用被完全抑制.初始SO2/4-浓度低于4000 mg/L时时铀生物沉淀过程影响很小,超过5000 mg/L时会产生明显的抑制作用,且抑制作用随着SO2/4-浓度的上升而加强.研究还表明,含有NO3-的氧化性环境不利于铀的生物沉淀过程,通过反硝化反应彻底去除环境中的NO3-成为消除环境中铀污染的前提.本实验结果可望为我国核污染水环境的修复提供生物技术思路.     

“I’m Being a Man Here”: Urban Boys’ Performances of Masculinity and Engagement With Science During a Science Museum Visit

The importance of increasing and widening participation in post-compulsory science and informal science learning (ISL) spaces is widely recognized—particularly for working-class and minority ethnic communities. While there is a growing understanding of the intersection of femininity with class, ethnicity, and science learning across formal and informal settings, there has been little work on how masculinity may shape urban boys’ science (non)participation and (dis)engagement. This article analyzes performances of masculinity enacted by 36 urban, working-class boys (from diverse ethnic backgrounds) during school science museum visits, exploring how these performances relate to science identity and engagement. We identify three main performances of masculinity enacted during the visits (“laddishness,” “muscular intellect,” and “translocational masculinity”), and trace the implications of each for boys’ science engagement. We consider the power implications of these performances, notably the extent to which hegemonic masculinity is normalized within the science museum space, the ways in which this normalization is co-constitutive of the boys’ performances of masculinity, and the implications of the boys’ performances of masculinity for other students (notably girls and less dominant boys). The article concludes with implications for research, policy, and practice regarding how to promote equitable participation and science learning within ISL.