共查询到20条相似文献，搜索用时 109 毫秒
1.
《淮北师范大学学报》2016,(1)
采用水热法合成了Mg-Al LDHs和Mg-Al LDHs负载型高岭土微纳米层状结构吸附剂,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)对样品进行表征.考察了样品对水体中Cr(Ⅵ)的吸附效果,并进一步探讨其吸附等温和动力学过程.实验结果显示:Mg-Al LDHs高岭土负载前后的吸附动力学和吸附等温曲线分别符合准二级速率方程和Langmuir等温方程,饱和吸附量分别为34.36 mg/g和11.46 mg/g. 相似文献
2.
具有催化、吸附、离子交换等功能的层状结构的双氢氧化物（LDHs）是近年来主客体化学研究领域的一个热点。本文综述了双氢氧化物（LDHs）的插层反应研究，并对今后一个时期该领域的研究和发展的方向做了展望。 相似文献
3.
采用共沉淀法以不同的Mg^2＋、Al^3＋与Cu^2＋摩尔比制备一系列的镁铝铜三元类水滑石（Cu／Mg／Al—HTLc）。并研究了镁铝铜类水滑石的焙烧产（HTLc-500）对阴离子染料茜素黄GG的吸附特征。分别考察了不同镁铝铜摩尔比的HTLc－500、吸附剂投放量、反应温度、染料的初始浓度等因素对HTLc-500吸附阴离子染料茜素黄GG的影响。结果表明,对于合有20mg／L的茜素黄GG模拟废水溶液,镁铝铜摩尔比为8：10：22的类水滑石,投放量为25mg。在25℃下反应360min。去除率可达到99．14％。 相似文献
4.
张新中 《数理化学习(高中版)》2014,(7):47-48
铝位于元素周期表中第三周期第ⅢA族,在地壳中的含量排在第三位,金属的第一位,化学性质比较活泼。铝及其化合物在高考中是考查的重点内容。一、铝的性质图1例1（2009年上海）镁和铝分别与等浓度、等体积的过量稀硫酸反应,产生气体的体积（V）与时间（t）关系如图1。反应中镁和铝的（）（A）物质的量之比为3∶2（B）质量之比为3∶2（C）摩尔质量之比为2∶3（D）反应速率之比为2∶3。 相似文献
5.
镁铝交联膨润土处理含重金属有机废水的研究 总被引：5，自引：0，他引：5
以铝镁双金属离子低聚物为交联剂,制备了复合联膨润土,用于处理含重金属的有机废水.通过改变pH值、用量和处理时间等因素研究了镁铝交联膨润土对重金属及有机物质的吸附特性和处理效果.研究表明,膨润土用镁铝交联剂改性后吸附能力显著增强,对有机染料和重金属有较强的吸附性能,去除率均在96%以上.由于膨润土的储量大、价格低,是一类很有发展前景的优质廉价吸附剂. 相似文献
6.
一、教材内容分析
（一）教材内容
教材内容主要是镁和铝的物理性质、化学性质及其主要用途。教材把镁和铝编排在同一节,就是运用元素周期律知识,根据它们的原子结构特点,结合氧化还原反应原理及相关的化学实验,用对比镁和铝的异同点的方法,学习掌握镁和铝的物理性质、化学性质及其主要用途。 相似文献
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铝热反应的多种引燃剂皖阜阳市大田中学（２３６１２１）马文浩在铝热反应的实验中，用镁带作引燃剂，镁带引燃不方便，且镁带燃烧强光刺目，不利于对铝热反应的观察．为此我们进行了一系列实验，发现用以下几种引燃剂，能克服上述问题，取得较好的实验效果．一、过氧化钠... 相似文献
8.
一、问题的提出"以镁、铝为电极,NaOH溶液为电解质溶液构成的原电池中,正、负极的判断?"是初学原电池原理后经常遇到的问题.人们普遍认为铝是负极,例如以下一些习题:(1)将铝片和镁片用导线连接后插入Na OH溶液的烧杯中组成原电池,下列说法正确的是A.镁为负极,并被氧化B.铝为负极,并被氧化C.镁为正极,并被氧化D.铝为正极,并被还原(2)用镁片和铝片做电极,用导线连接同时插入NaOH溶 相似文献
9.
例1 有铁、镁、铝、锌四种金属．取10g由其中两种金属组成的混合物，使之与足量的稀盐酸反应生成1g氢气．该混合物的组成方式有（ ）
（A）5种 （B）3种 （C）4种 （D）6种 相似文献
10.
掺镍镁铝尖晶石电子和光学性质的理论计算 总被引：1，自引：0，他引：1
采用密度泛函理论的平面波赝势方法（PW—USP）和广义梯度近似（GGA）,对替代式0．086％摩尔浓度掺杂的镁铝尖晶石（Ni：MgAl2O4）的电子和光学性质进行了计算．研究结果表明掺镍镁铝尖晶石是具有2．94eV的窄带隙半导体材料．镍掺杂具有使镁铝尖晶石在费米面附近产生杂质能级,导致光学带隙明显减小的特殊作用．通过分析掺杂晶体的光学性质发现,由于杂质镍的引入,使得可见光及近红外光谱区的吸收明显增强,而这归因于镍3d电子t2g和eg轨道间的d-d跃迁,结果与实验符合较好． 相似文献
11.
罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
12.
Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
13.
Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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16.
《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
17.
陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
18.
邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
19.
《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献