硝酸活化花生壳处理含铬废水研究

通过硝酸活化花生壳,用于吸附废水中Cr(VI),并通过傅里叶变换红外光谱仪对活化前后的花生壳表面官能团进行表征。结果表明:经硝酸活化后的花生壳对Cr(VI)的最佳吸附条件为:pH=2、吸附温度为60℃、投料量为5g/L、吸附时间为95min,此时吸附效率高达95.14%,比未经活化处理的花生壳的吸附效率提高了21.02%;经硝酸活化后,花生壳表面含有大量羟基和羧基,从而提高了对Cr(VI)的吸附作用。     

NaClO改性碳纳米管的制备及对重金属离子吸附性能的研究

吸附性能尤其是对重金属离子的吸附性能是碳纳米管的重要特征之一。通过使用恰当的改性剂对碳纳米管进行表面改性,是提高碳纳米管对重金属离子吸附效果的一种有效方法。本实验所使用的改性剂为质量分数为20%的NaClO溶液,使其对碳纳米管进行氧化改性处理。表征分析方法主要有:比表面积的测定、傅立叶变化红外谱图测定、X-射线衍射及Boehm官能团滴定等方法。实验结果表明:羟基、羰基、羧基等官能团分布在碳纳米管表面;碳纳米管比表面积和表面官能团结构在经过NaClO溶液改性后均发生了明显变化。本实验还研究了NaClO改性后的碳纳米管对重金属离子(Zn2+)的吸附性能,同时还证实了吸附时间、吸附剂用量、吸附温度等影响因素的增大对其吸附效果的影响增强。     

Cu（II）和Ni（II）对四环素在官能团化碳纳米管上吸附的影响

研究目的：探究四环素在不同官能团化碳纳米管上的吸附机制,并揭示Cu（II）和Ni（II）对四环素与碳纳米管间作用的影响机制。创新要点：1.碳纳米管对四环素的吸附与其表面官能团种类密切相关;2.金属离子对碳纳米管吸附四环素的影响能力与金属离子络合性能相关。研究方法：采用批量吸附试验和谱学手段表征相结合的研究方法。重要结论：四环素在不同官能化碳纳米管上吸附能力的强弱顺序为：石墨化碳纳米管（G-MWCNTs）〉羟基化碳纳米管（OH-MWCNTs）〉羧基化碳纳米管（COOH-MWCNTs）〉氨基化碳纳米管（NH2-MWCNTs）,碳纳米管表面的官能团类型和数量对四环素与碳纳米管间的作用机制有重要影响（表1和图2）。Cu（II）和Ni（II）对四环素在G-MWCNTs 上的吸附几乎没有影响,但对在其它三种官能团化的碳纳米管上的吸附表现出不同的影响能力（图3）。与Ni（II）相比,Cu（II）与碳纳米管上官能团具有更强的络合能力,因此Cu（II）对四环素在不同碳纳米管上吸附的影响要比Ni（II）更显著。     

巯基改性的硅藻土性能研究

采用γ-巯丙基三甲氧基硅烷与表面硅羟基的反应,对硅藻土进行了巯基改性,并对其进行了表征.XRD、TG和SEM的测定结果均表明,硅藻土表面成功地接枝上了巯丙基.重金属吸附实验表明,巯基改性后硅藻土的吸附性能有所提高.     

石墨烯的改性修饰及其复合材料研究进展

主要综述了石墨烯的氧化、表面修饰改性及其复合材料的研究进展.氧化石墨烯是通过Hummers法、Brodie法或Staudenmaier法氧化石墨,然后再经过热解膨胀或超声分散方法制备.氧化石墨烯的表面修饰改性有非共价键修饰和共价键修饰.非共价键修饰是利用氧化石墨烯的共轭体系与其他共轭体系的小分子或高分子聚合物具有相亲性,来制备复合材料.共价键修饰则是利用氧化石墨烯中含有的大量羧基、羟基和环氧基等活性基团与有机链段进行反应,达到改性目的,以有利于制备复合材料.     

溶液表面张力最低值现象的热力学分析

本文用热力学方法证明在γ—α_1,α_2曲面上不会有最低值存在,论述了在CMC附近多组分表面活性剂溶液的表面张力和溶质活度随浓度的变化关系,以及表面吸附物的转变。     

竹炭/羟基磷灰石复合材料的制备及其性能

通过液相合成法制备了竹炭/羟基磷灰石复合材料.研究了竹炭与羟基磷灰石的配比、吸附时间、溶液的pH值、温度以及复合材料用量等因素对复合材料吸附Cu2＋效果的影响.研究结果表明：竹炭与羟基磷灰石的质量比为3/5,在pH值为5～6条件下吸附120 min,竹炭/羟基磷灰石复合材料对Cu2＋吸附效果最佳,吸附率可达96.08%,同时复合材料对Cu2＋吸附受温度影响不大.认为竹炭/羟基磷灰石复合材料可作为除铜吸附材料.     

WO3(001)表面活性氧物种的理论研究

采用第一性原理结合周期性平板模型的方法,对O2在完整和缺陷WO3 (001)表面的吸附行为进行了系统研究.计算结果表明:WO3 (001)完整表面上吸附态的O2不易成为表面氧化反应的活性氧物种,当吸附质与表面作用时,将优先与表面晶格氧(Ot)成键,进而形成表面缺陷态,体系呈现金属性,电导率增大.比较O2在缺陷表面上各吸附构型的吸附能发现,O2的吸附倾向于发生在缺陷位置(Wv)上,且表现为氧气分子中的两个氧原子均与缺陷位Wv作用,形成新的活性氧物种(O2-);吸附后表面被氧化,电导率降低.     

高考考点——羟基酸

分子组成里既含有醇羟基又含有羧基的有机物称为羟基酸,依据分子里羟基的位置不同,羟基酸可分为α-羟基酸(如β-羟基酸(如γ-羟基酸(:如等,由于羟基酸分子中含有醇羟基和羧基两种官能团,因而羟基酸既具有醇的性质又具有羧酸的性质,对羟基酸的考查,不但能够考查学生对基础知识的掌握情况,而且还能考查学生的逻辑推断能力和创造性思维能力.     

氨基酸Schiff碱LB膜的界面配位及分子取向

本文合成了在同一个分子中具有Schiff碱和羧基两个可与金属离子配位的两亲分子,利用等温曲线、紫外光谱和红外光谱研究了其在不同亚相表面LB膜的金属配位和分子结构.对于合成的HSA两亲分子,只有Cu2+离子才能同时与羧基和Schiff碱片段发生配位作用,其它金属离子只与羧基发生配位作用.Cu2+与Schiff碱配位后,Schiff碱片段相对于表面法线倾斜取向,其它金属离子配位后Schiff碱片段的长轴倾向于垂直基底表面取向.     

Effect of polyoxypropylene chain length on the critical micelle concentration of propylene oxide-ethylene oxide block copolymers

In this work, the surface activity of block copolymer nonionic surfactants (RPE) has been determined, i.e., critical micelle concentration (CMC), surface excess concentration (Γ), surface area demand per molecule (A), surface tension at CMC (γCMC). A linear decrease of in[CMC] vs number of oxypropylene units in copolymer molecule was observed. The change in the work of cohesion per oxypropylene group when passing from molecular into micellar state, calculated from the Shinoda equation,was 0.43kT for the studied compounds.     

Effect of polyoxypropylene chain length on the critical micelle concentration of propylene oxide-ethylene oxide block copolymers

In this work, the surface activity of block copolymer nonionic surfactants (RPE) has been determined, i.e., critical micelle concentration (CMC), surface excess concentration (Γ), surface area demand per molecule (A), surface tension at CMC (yCMC). A linear decrease of ln[CMC] vs number of oxypropylene units in copolymer molecule was observed. The change in the work of cohesion per oxypropylene group when passing from molecular into micellar state, calculated from the Shinoda equation, was 0.43kT for the studied compounds.     

低温等离子体改善聚苯硫醚非织毡吸碱性能研究

利用低温等离子体技术对聚苯硫醚非织毡表面进行了改性处理。研究结果表明:低温等离子表面处理显著提高了聚苯硫醚非织毡的吸碱率和吸碱速率,等离子体两极板距离、放电功率、处理时间等对聚苯硫醚非织毡的吸碱性能有很大的影响,合理的等离子体工作参数为极板间距1.5cm,等离子体处理功率50W,等离子体处理时间120s。     

抑制烧结矿低温粉化的机理探讨

研究了采用硼酸抑制剂烧结矿粉化的机理。结果表明硼酸能有效地抑制烧结矿的粉化，且不影响软化温度和高温还原率，硼酸的这种作用可解释为减小烧结矿表面的气孔率。     

光度法研究十二烷基硫酸钠的临界胶束浓度

在碘的水溶液和I-3溶液2种体系中测定了十二烷基硫酸钠(SDS)的临界胶束浓度(CMC),讨论了在I-3体系中,不同硫酸钠和氯化钾对测定结果的影响,在碘的水溶液中研究了不同碘浓度对SDS的CMC的影响。采用分光光度法求得SDS在两种体系中的CMC值,硫酸钠与氯化钾对CMC的值有影响,且硫酸钠对SDS的表面活性影响大于氯化钾;在碘的水溶液中,随碘的浓度增大,CMC呈增大趋势。     

Developing,testing and refining of a model to understand the relationship between peer interaction and learning outcomes in computer‐mediated conferencing

Our pervasive adoption of CMC in higher education has far outpaced our understanding of the nature of CMC and, accordingly, how this medium should best be used to promote higher‐order learning (Garrison, Anderson, & Archer, American Journal of Distance Education, 15(1), 7–23, 2001). Therefore, this study examined the relationship between peer interaction and learning outcomes by creating and testing through structural equation modeling a model of five variables—learner characteristics measured by self‐construal, perceived teaching style, task design, course requirements, and prior CMC experience—that influence self‐reported peer interaction and self‐reported learning outcomes. The results showed that perceived teaching style had a small direct effect (0.23) and prior CMC experience had a moderate direct effect (0.31) on self‐reported peer interaction; self‐reported peer interaction had a strong direct effect (0.66) on self‐reported learning outcomes.     

从硫化铜矿制取硫酸铜工艺研究

硫化铜经粉碎，催化焙烧，浸取，铁屑置换制海绵铜，再制取符合GB473－93优等品的硫酸铜产品。     

Interaction of nonionic surfactant AEO9 with ionic surfactants

INTRODUCTION Long chain nonionic surfactants such as poly-oxyethylenated alcohols C12H25O(CH2CH2O)9H (AEO9), are widely used in the chemical industry in fabric detergency and tertiary oil recovery due to their excellent surface-active properties. In many practical applications, surfactants are used in formulations containing mixtures of different compounds, and synergism can often be observed. Synergism is de-fined here as the condition in which the properties of a mixture are better…     

对MgO重新水合及两类羟基的研究

本文采用IR、XRD、TG、DTA等测试手段对MgO重新水合及其两类羟基进行了研究。发现:MgO水解在实验条件下仅发生在表面浅层;水合得到自由、水合两类羟基;600℃灼烧使两类羟基脱除;自由羟基由水合羟基在碱作用下生成;适量添加Li~+于真空,实验温度的条件下能使自由羟基消失生成Li~+OH~-,进而发生2Li~+OH~-→Li_2O+H_2O,     

Differences in electronic exchanges in synchronous and asynchronous computer-mediated communication: the effect of culture as a mediating variable

Two hundred and eighty undergraduates from universities in two countries were asked to read didactic material, and then think and write about potential solutions to an ill-defined problem. The writing was conducted within a synchronous or asynchronous computer-mediated communication (CMC) environment. Asynchronous CMC took the form of email exchanges between American learners only, Southern European learners only, and American and Southern European learners together. Synchronous CMC was restricted to dyads consisting of American–American, Southern European–Southern European, and American–Southern European students dialoguing. Additionally, a number of Americans and Southern Europeans were each paired with a content-“mirroring” computer-generated partner to account of the effect of thinking with an unresponsive partner in synchronous CMC. Results revealed that dyadic learners in asynchronous CMC used significantly more reasoning skills to think about solutions to the problem, while dyadic learners in synchronous CMC exchanged significantly more personal knowledge and features of emotion. However, the tendency among dyadic learners to include emotional features in their dialogues was mediated by their cultural background.