以六方液晶为模板合成了CdS纳米线. 纳米线生长在表面活性剂分子形成的六方堆积的空隙水相内,呈平行排布,直径为1-5nm.
采用表面修饰的方法,在醇水体系中制备了双十八烷基二硫代磷酸(DDP)表面修饰的硫化锰(MnS)纳米微粒. 用XPS、FTIR、TGA、TEM和HREM等技术对用表面修饰法得到的MnS纳米微粒的结构、化学稳定性和热稳定性进行研究,结果表明:表面修饰得到的MnS纳米微粒有较好的化学稳定性和热稳定性,并且微粒的分散件好、不团聚,制备出的MnS纳米晶核具有γ-MnS的晶型结构.
采用自洽场分子轨道UHF/6-311G**从头计算法,获得了HCN+Cl→HCl+CN反应的内禀反应坐标(IRC). 沿着IRC,计算了反应的动态学性质,根据传统过渡态、变分过渡态理论,得到了反应的理论速率常数,可供实验工作者参考,利用SCP-IOS近似下的产物振动跃迁几率公式,自编程序计算了HCN(004,302)+Cl→HCl+CN反应中产物CN的振动态分布,获得了和实验相一致的结果.
采用柠檬酸络合法制备并应用XRD、ICP和微反活性等方法研究了Cu-Ce-O催化剂体系,当体系中铜含量较少,焙烧温度较低时,以萤石矿型结构存在,CuO掺杂进入CeO2的晶格中;当铜含量较多,焙烧温度较高时,除了以萤石矿型结构存在外,还伴随有单斜晶系CuO的生成,焙烧温度高达1000℃时,体系无其它结构型式的晶相形成,研究发现少量的CuO使体系催化氧化CO的活性大大提高;只有极少量的CuO进入CeO2的晶格内部,该催化剂最佳配方是Cu/(Cu+Ce)原子百分比为15%,700℃焙烧4h,其中起高催化氧化作用的是由CuO掺杂调变而成的萤石矿型复合氧化物,其组成为Cu0.06Ce0.94O1.94.
用激光直接溅射和串级溅射两种方法产生铅/硫二元团簇,并用串级飞行时间质谱仪研究了二元团簇的组份及光解规律,用激光直接溅射铜+硫混合样品时,组成为PbnSn-1+和PbnSn-的团簇丰度最大,是二元团簇的结构骨架和稳定组份,而用激光串级溅射铅样品和硫样品,通过铅团簇与硫团簇的反应,则可得到PbnSm+(n=1-3,m=0-9)和PbnSm-(n=1-7,m=0-9). 这两种二元团簇的产生方法对应两种不同的团簇形成机理.
用交联剂M(NH3)42+(M2+为Zn2+、Cu2+、Ni2+和Co2+)络合交联丙烯酸酯无皂水溶胶形成涂膜,用差示量热法和重量分析法考察了涂膜的交联程度,得出一致的结论,均表明交联剂Zn(NH3)42+的交联效果最佳,适宜的交联固化条件是80℃加热30min;用透射电镜观察到Zn(NH3)42+与丙烯酸酯水溶胶形成交联网状结构的过程;还用差示扫描量热法初步分析了交联反应的动力学,求出反应级数为3.3,活化能为34.0kJ•mol-1.
利用HF/6-31G*及半经验分子轨道AM1法,研究了硫代双烯酮及双三氟甲基硫代双烯酮二聚反应的反应机理,采用Berny梯度法优化得到反应的过渡态,并进行了振动分析确认,计算结果表明:(1)所有的二聚反应均是按照非同步的协同途径,经过扭曲的四元环过渡态进行的;(2)硫代双烯酮的二聚反应,三种可能的二聚方式中,生成对称四元杂环产物的二聚反应的活化焓最高;(3)双三氟甲基硫代双烯酮的二聚反应,生成对称四元杂环产物的二聚方式其活化焓比另外两种二聚方式的活化焓要低得多,这与实验中只观察到生成对称四元杂环产物的结果是一致的.
为了研究2,15-十六烷二酮在氧化铝表面的环合机理,选择小分子丙酮为模型化合物,用量子化学半经验AM1方法研究双分子丙酮在氧化铝表面的醛醇缩合机理,给出了反应过程中的5个过渡态和4个中间体的结构和几何参数,该催化反应可以认为是氧化铝分子与两分子丙酮分子发生静电络合作用,然后借助氧原子的负电荷导致脱氢并实现缩合,根据中间体的能量变化,推测有较稳定的铝复合物生成.
通过对Sr、Ba混合掺杂体系(x=0.27、0.165、0.06)和非计量体系Nd0.67SrxBaxMnOz(x=0.27,0.06),导电性能的研究发现:混合二价离子掺杂体系Nd0.67SrxBa0.33-xMnO3与单一二价离子掺杂体系(Nd0.67Sr0.33MnO3和Nd0.67Ba0.33MnO3)具有不同的导电机制,非计量比使Nd0.67SrxBaxMnOz体系出现晶格收缩,电阻率随温度的降低出现半导体-金属转变,与此同时体系的电阻率减小,另外还发现,Mn离子的非计量与A位离子的相比对体系晶格收缩和导电性能的影响都更为显著.
研究了以含Co水滑石类化合物为前体、经焙烧制得的复合氧化物催化剂对CO催化还原NO的催化作用,结果表明,这样制得的催化剂的活性远远高于由传统方法制备的具有尖晶石结构的催化剂. 反应分步进行,NO先与CO反应生成N2O和CO2,随着反应温度的升高,最终得到的是N2和CO2,在所考察的催化剂中,反应活性随催化剂中Co含量的增加而升高,随焙烧温度的升高而降低,催化剂中晶格缺陷对活性有重要影响.
对壬基酚聚氧乙烯醚(Igepal CO)系列表面活性剂,生成何种溶致液晶与其EO基团数n有关,而在何浓度范围内生成溶致液晶则与生成溶致液晶的最低水含量及最大水增溶量有关.EO基团数n小于10时,生成层状液晶,n大于10时则生成六角状液晶,层状液晶两亲双层内,水与表面活性剂的最低摩尔比rmin和最高摩尔比rmax随EO基团数n增加分别是非线型增加与线型增加,在Igepal CO 520(n=5)中加入Igepal CO 710(n=10.5),对层状液晶的生成无显著影响,在Igepal CO 710中加入Igepal CO 520,则对六角状液晶的生成产生显著影响,出现了六角状液晶向层状液晶的转变.
The variation of interfacial tension with temperature of two different systems, water-oil (liquid paraffin, C18H38, solution of solid paraffin)and silicone oil-vegetable oil was determined and the factors that influence the variation of the shape of the relation curves were examined. It is found that the presence of minute amount of surface active impurity was the main cause of the shape variation of the relation curves. The shape variation was eliminated by adsorptive agent. Therefore, it is important to insure purity of the experimental system in order to obtain reliable results on the study of thermocapillary flow caused by interfacial tension.
A novel material, uncoated polyamline/bentonite layered nanocomposits has been prepared successfully and characterized by XRD、FTIR、CV、TGA. Experiments suggest that it still has the layered structure of bentonite, but has larger interlayer space. The properties of both polyaniline and bentonite are reserved. This material has potential applications as electrode material for electrochemical battery and electrode modifyiny materials.
The microstructures of the middle-phase microemulsions were studied by using ESR and NMR techniques. The results from the two methods show that the microstructures of the middle-phase microemulsions undergo the change from O/W to bicontinuous(BC), and to W/O with the variation of NaCl concentration, and BC structure includes O/W and W/O. The models of the bicontinous structure were constructed on the base of the studies.
The mechanism of the cycloadditohn reaction of singlet difluorosilylene with formaldehyde have been studied by RHF/6-311G* gradient method. The electron correlation energy corrections of energies for all the structures were computed using second-order Moller-Plesset perturbation theory(MP2). The results show that this reaction proceeds via two steps:1)Difluorosilylene and formaldehyde form an intermediate complex, it is an exothermal reaction with no barrier.2) The intermediate complex isomerizes to form the product, after being corrected by zero-point energies, the barrier is 127.28 kJ•mol-1 (MP2/6-311G* 6-311G*).
The microstructural characteristics of P-25 TiO2 photocatalysts calcined at 600, 650,700, 750, 800, 900 and 1000℃ have been studied using XRD, TEM and BET. The photocatalytic activity of the samples were also examined using the degradation of phenol as a model reaction. The results indicate that the calcination significantly affects both microstructural characteristics and photoactivity, and there is an apparent relationship between photocatalytic activity and centain mocrostructural characteristics. Over the range of calcination temperatures and durations studied, the sample calcined at 650℃ for 3 h revealed the highest photoreactivity, which can be ascribed to an improvement in crystallinity on calcination. The increase in the rutile content and grain size caused by the calcination at higher temperatures were observed to decrease the photocatalytic activities of the TiO2 samples.
The flocculation of two kinds of silica particles with different surface properties have been studied on the addition of PAM. In certain pH range, PAM can flocculate suspensions of SiO2particles which have been calcined with a little water added. Although PAM doesn’t flocculate suspensions of SiO2 particles calcined with no water added, it produces good coordinate flocculating effect on mixing with PA.
研究了一些氧化物的H2-TPR及CO-TPR行为,结果发现,Co3O4/Al2O3,NiO/SiO2,NiO和Pd/NiO的H2-TPR温度要低于它们的CO-TPR温度,特别是Pd/NiO样品,它的H2-TPR温度为598K,而其CO-TPR温度高达949K,差别为351K,因此有可能利用Pd/NiO在一定温度下选择性地与CO中的H2反应而将其除去. 实验结果表明,Pd/NiO可在603K及4000h-1的条件下从H2(0.34%),CO(50%)和N2(余)的混合气中选择性地除去90%以上的H2,吸氢容量为每克样品55mL标准态H2.
The effect of CO2 on catalytic activity for CO oxidation on Cu-Ce-O fluorite-type complex oxides has been investigated. CO2 played an inhibiting role in CO oxidation on the catalyst similar to what happened on CeO2. As CO2 was introduced into the feed, the coliversion of CO to CO2 on the catalyst was reduced a little. At room temperature, the catalyst could easily adsorb CO2 in large amounts from the air to form carbonate on its surface, as well as from the yields at low reaction temperature As a result, the catalyst could be poisoned by CO2 tentatively .The catalytic activity could be recovered to its initial value on being heated at 300 ℃ or higher temperature. Cu-Ce-O catalyst showed high activity with CO conversion over 98% after being pretreated to desorb CO2 previously.
In the present paper it is reported that glycolipid was successfully inserted into colorchangeable TCDA/DGG and PCDA/DGG polydiacetylene vesicles based on physical force rather than covalent binding. And the effects on polyinerization of diacetylene and the change of the polymer vesicles' color due to the relative quantity of glycolipid versus diacctylene molecules were also reported. The experimental results demonstrated that this approach is available and the colorchangeable property of such polydiacetylenic vesicles was not affected due to the inceorporation of glycolipid. This provided a simple and useful method of functonalizing the polymer vesicles for their wide applications.
用高温高压苯热合成方法制备了GaP纳米晶,用X射线衍射、光吸收谱及透射电子显微镜对所得样品进行了分析测试.结果表明,GaP纳米晶在苯热条件下是亚稳定态的,反应时间过长及反应温度过高均不利于它的生成和生长.文中还讨论了晶粒度分布与合成条件间的关系,并进行了理论上的定性分析.
研究了脂肪酸盐和烷基吡啶盐混合水溶液中双水相的形成规律和性质.考察了形成双水相的组成范围和烷基碳链长的影响. 测定了两相的密度及化学组成.应用电子显微镜观察了两相的微观结构.结果表明,两相均存在囊泡结构.两相含水均在95%以上.上相为表面活性剂富集的囊泡絮凝相,浓度远远大于下相,相差均在二十倍以上.下相为含有分散的囊泡的表面活性剂稀溶液.
在RHF/3-21GRHF/321G*,RHF/6-31+G*,MP2/6-31+G*,RHF/lanl2dz, MP2/lanl2dz和MP2/6-31+G*水平上,对CH2=CH(OM)(M=Li,Na,K,Rb,Cs)进行了研究.结果表明,所有化合物都有平面式和非平面桥式两种构型. 结构参数、自然轨道布局分析和反应热均反映出碱金属对烯酸负离子的共振有很大程度的限制,不同的碱金属盐差别不十分明显.
采用实时测量光学二次谐波产生(SHG)和吸收光谱的方法时芪类有机分子DANS(4’-N,N-dimethylamino-nitrostilbene)及一种新合成的经氰基团修饰的有机分子CNDS(α’-cyano-4’-nitro-4-N,N-dimethylaminostilbene)掺杂PMMA [poly(methyl methacrylate)]极化聚合膜的非线性光学性质进行了研究. 在电晕极化条件下,由于聚合膜的电导率随温度的变化急剧增加,实验中发现两种掺杂极化聚合膜的最佳电导极化温度均低于它们的玻转温度Tg.在最佳极化条件下,从极化前和极化后的吸收光谱变化可看出CNDS的有序度较DANS的差.但实时SHG表明,CNDS/PMMA极化掺杂聚合膜的二阶非线性系数X(2)较DANS/PMMA极化聚合膜的大.结合极化前和极化后吸收峰强度的变化,我们得到CNDS分了的非线性极化率β约为140×10-30esu. 在撤离极化场后,CNDS/PMMA的SHG强度的弛豫也比DANS/PMMA慢,说明CNDS是一种性能较DANS优越的制备二阶光学非线性的掺杂分子.
利用Kamlet-Taft溶致变色比较法,在确定了二种探针化合物的峰值波数与溶剂的溶致变色参数表达式的基础上,研究了一系列不同疏水化修饰的聚N-异丙基丙烯酰胶类共聚物水溶液胶束的极性(π*)和氢键供体能力(α).结果发现,在摩尔投料比相同时,随着共聚物中丙烯酸酯烷基链的增长,共聚物水溶液胶束的π越来越小,α越来越大;在共聚物组成相同时,随着丙烯酸酯投料比的增大,共聚物水溶液波束的π也呈现相同的情况,而α则无明显的规律.对此现象作了讨论.
通过热处理,得到了以密胺树脂为基体的掺杂有磷的碳材料,并用元素分析、XPS、XBD进行了分析.结果表明磷酸加入以后,对氮原子的含量影响不大,但其键合状态发生了变化,使有利于可逆容量提高的graphene氮的相对含量增加,导致碳材料的可逆容量随磷酸加入量的变化而发生变化,最大可逆容量可达516 mA••h•g-1.
采用从头算HF/SCF方法以6-31G基组研究了FOSO2F分子的几何结构、振动谐性力场和红外光谱强度.理论力场由Pulay的标度量子力学方法进行标度,计算得到的振动频率与实验值比较平均偏差为6.3cm-1.根据振动频率的势能分布和从头算红外光谱强度值对此分子的振动基频进行了理论归属.
应用遗传算法对二氧化硅团簇(SiO2)n(n≤20)的结构进行了优化计算. 分析讨论了结构和结合能随团簇尺寸的变化规律,发现(SiO2)n团簇系列不存在明显的幻数,并在n≤20的范围内,不呈现出相应大块物质的结构特征,
采用高温固相反应法,合成了一系列不同组份的磷光体,测定了它们的振动光谱.结果表明,随着Al/B比的减小,在1100~1000cm-1的区域内的振动光谱没有明显变化,铕离子不可能进入Al18B4O33的晶格中;振动光谱的背底升高,非晶相逐渐增加.研究了Al2O3-B2O3-Eu2O3中Eu3+离子的光谱特性,发现随着Al/B比的减少,Eu3+离子的存在相由晶相逐渐向非晶相转化。在非晶相中,Eu3+离子的声子伴带表明电子与声子的耦合强度随着Al/B比的减少而减小,Eu3+离子的发射强度相应的增加,这与多声子弛豫的理论一致.
利用真空紫外同步辐射和自制的飞行时间质谱(TOF-MS)仪,研究了环氧乙烷的光电离与光解离过程, 通过测量各离子的光电高效率(PIE)曲线,获得了该分子的电离势和所有碎片离子的出现势.分析了离子的光电离解离通道,并讨论了它们的竞争情况.结合有关公认的热力学数据,算出它们的标准生成焓.
利用离子讲质谱计和激光溅射技术相结合,研究了Fe2+、CO2+、Ni2+与CO气体的吸附反应,比较了它们的反应活性,给出了化学反应的速率常数及随反应气体压强的变化关系,并从理论上模拟了化学反应过程,测量结果与已有的实验值符合较好.
用停流法研究了2,9,16,23-四羧基钴(Ⅱ)酞菁与2-巯基乙醇轴向配位的快速反应动力学,提出了较为合理的反应机理,用非线性及线性拟合的方法求得了各基元步骤的动力学参数,探讨了温度、pH等因素对反应的影响.
用ESR自旋稳定化技术对十六个儿茶酚类底物的漆酶催化氧化反应进行了ESR追踪,捕获到相应的半醌自由基.结果表明,ESR自旋稳定化技术的运用,开辟了一条在静态条件下用漆酶/O2体系获取高稳态浓度半醌自由基的有效途径.
The effect of concentration of Vitamin B1 on the B-Z oscillating reaction, the use of the analysis and the possible mechanism have been studied. Experiment indicated that Vit B1 has an effect on the shape, amplitude and period of the B-Z oscillating wave. The best reaction condition and the reactant's concentrations are reported. The results showed linear relationship between the changes in the oscillation period and amplitude of the chemical system with the concentration of Vit B1 in the range of 5.10×10-6 2.78×10-4 mol L-1.and the related coefficients are 0.995 and 0.093. The possible mechanism of this reaction has been studied in detail.
The thermal properties of porcine brain tubulin polymerization and denaturation and the effects of taxol were studied from 4 ℃ to 115 ℃ with a new highly-sensitive differential scanning calorimeter (Micro DSC Ⅲ, Setaram, France). The DSC results indicated that microtubule polymerization can proceed uia an endothermic process and that taxol could alter the process. A large aggregation peak was found at about 85 ℃ in the course of the denaturation and it disappeared with adding taxol. The heat flow oscillation was observed during the controlled-temperature experiments and taxol could stabilize the structure of the microtubules so that the oscillation disappeared.
PM3 SCF calculations have been carried out to study the thermolyses of o-acetylcycolpentanone and o-acetylcyclohexanone. The results obtained show that these two com-pounds are thermally decomposed into products through an unimolecular elimination involving six-center cyclic transition state, and these two thermolyses are caused by the migration of positive charged β-H.
1,2,4-三唑并[1,5-a]嘧啶-2-磺酰胺类除草剂是继磺酰脲之后所开发出的又一类以ALS为作用耙标的超高效除草剂.本文采用比较分子力场分析方法对该类除草剂进行了三维定量构效关系研究,结果发现立体场和静电场对该类化合物的除草活性均有重要影响,其中以立体场为主.根据我们所得的QSAR模型,可以对该类化合物的结构与活性关系进行很好的解释.
计算表明次氯酸与盐酸通过与水分子形成环状过渡态可以极大地降低反应势垒。 当环上的水分子数为三时,势垒最小。 更多的水分子通过环外的水化作用 ,使势垒进一步降低。这表明我们提出的多分子过渡态机理可以解释次氯酸与盐酸的反应由冰表面催化的实验事实 .
Self Assembled Monolayers(SAMs) of a series of mercapto contained azobenzene derivatives with the structure of CnH2n+1AzoO(CH 2)mSH (where n =4,6,8,10,12; with m =3,5 respectively) were prepared and characterized. Wettability measurement of water on the SAMs demonstrates that molecular packing density in the monolayers increases while the alkyl chain in the molecules is lengthened. Both the n and m values have similar contribution to the wetting property of SAMs. The RA IR spectra reveal that the alkyl chains in the SAMs tilt away dramatically from the surface normal direction with the increase in their length. However, the orientation of azobenzene moiety is found to be influenced slightly by the alkyl chain length, which is due to the tenderness of the molecule.
运用Gaussian 94W量子化学程序包 ,采用LanL2DZ基组, 对草酰胺桥联双核铜配 (聚)合物结构单元Cu2 (oxen) (OH) 2 [H2oxen =N ,N' 二 ( 2-胺乙基 )草酰胺 ](包括顺、反构型及其单、三重态电子组态 )进行从头算研究,探讨该配合物结构单元的稳定性, 并从电荷布居及分子轨道组成等电子结构特征分析这种配合物反式三重态比较稳定的原因. 计算结果与实验规律相符合.