EFFECT OF ZINC ON THE INTERACTION OF COPPER AND A SIMPLE PEPTIDE MOLECULE WITH HYDROGEN PEROXIDE

Abstract

Reaction of copper and of copper in presence of zinc with glycylglycine H₂Gg, H₂NCH₂CONHCH₂COOH (in ratios 1:2 and 1:1:2, respectively), and an excess of hydrogen peroxide results in the formation of a novel peroxy complex [Cu(O₂ ^2-) (H₂Gg)₂].2H₂O and a mixed metal peroxo carbonate complex [Cu, Zn(O₂ ^2-(CO₃)(H₂O)₄], respectively. A notable feature of the reaction is the facile decomposition of the peptide bond at room temperature on addition of zinc to the system.     

THEORETICAL STUDY OF THE EFFECT OF rGO/GO COMPOSITE COMPOSITION ON THE HYDROGEN FUEL CELL CHARACTERISTICS

Journal of Structural Chemistry - Properties of the hydrogen fuel cell composed only of graphene oxide (GO) and reduced graphene oxide (rGO) are theoretically studied. The optimal parameters of...     

EFFECT OF FAR-UV AND NEAR-UV RADIATION ON THE CELL SURFACE CHARGE OF THE PROTOZOAN

Abstract— Cell electrophoresis was used to detect the effect of far-UV or near-UV radiation on the cell surface charge of the pathogenic protozoan Tritrichomonas foerus . Either far-UV or near-UV radiation interfered with the surface charge of T. foetus at fluences which inhibited cell growth by 50%. Both UV-radiations induced a significant decrease on surface charge of T. foetus , as evaluated by measurement of its electrophoretic mobility (EPM). Determinations of EPM of protozoa in solution of low ionic strength indicated that the decrease in the EPM induced by far-UV is much less pronounced than that observed for near-UV or control cells.     

离子束修饰对电极表面结构和析氢活性的影响

采用了离子束对工业钛电极进行表面改性，用电化学方法研究了改性电极在Ｈ２ＳＯ４溶液中的析氢活性，用表面能谱分析了电极表面的组分和结构。结果表明：通过离子束修饰在电极表面引入微量的活性元素即可明显改善工业纯钛电极的析氢催化活性；离子束修饰改变了电极表面的组分和相结构，从而达到了改性的目的。     

NO与Ag(110)表面的相互作用

采用Ｘ射线光电子能谱、紫外光电子能谱和原位Ｒａｍａｎ光谱研究了ＮＯ和Ｏ２在Ａｇ（１１０）表面的吸附和反应。结果表明，室温条件下，ＮＯ在银表面不发生明显的吸附和分解，氧的加入导致了ＮＯ在角表面的氧化反应生成吸附态的氮氧化物和原子态氧。     

吡啶与Rh(111)面相互作用的EHMO研究

吡啶作为加氢脱氮的模型化合物,与过渡金属Pt(111),Ni(100),Pd(110,111),Mo(110),Rh(111)面的吸附作用已有大量的实验研究,所采用的技术基本上是LEED,TDS,XPS,HREELS等,然而吡啶与Rh(111)面作用的理论研究尚未见报道.本文用EHMO法研究了吡啶与Rh(111)面的吸附作用,得到了最优吸附构型、结合能、集居数以及电荷分布和转移等,为新的脱氮催化剂开发提供了理论依据. 计算采用EHMO法,其中非对角矩阵元采用MWH近似:     

Pd(510)台阶面对氢分子解离吸附的影响

本文应用对势方法构造了Ｈ２－Ｐｄ（１００）和Ｈ２－Ｐｄ（５１０）体系相互作用的ＬＥＰＳ势能面．考察了氢分子在Ｐｄ（１００）面上的非活化前驱态解离吸附特性，理论结果和实验符合得很好．对氢分子在Ｐｄ（５１０）台阶面上的解离吸附行为的研究表明，由于台阶的影响，在台阶下形成了非活化直接解离通道，在台阶上及台阶边棱处，主要存在非活化前驱态解离通道；在台阶面上发现了氢分子的活化吸附．     

THE INTERACTION OF MELANIN WITH 8-METHOXYPSORALEN: EFFECT ON RADIATIVE AND NONRADIATTVE TRANSITIONS. A FLUORESCENCE AND PULSED PHOTOACOUSTIC STUDY

Abstract: The interaction of 8-methoxypsoralen (8-MOP) with synthetic eumelanin was investigated using static and time-resolved fluorescence and pulsed photoacoustic calorimetry. Due to the strong overlap of the absorption bands of melanin and 8-MOP, a method is presented to account for the systematic errors introduced by the optical filter effect exerted by each absorbing species in the fluorescence and the photoacoustic measurements. As a preliminary step to the understanding of the nonradiative behavior of the psoralen-melanin complexes, the photoacoustic parameters of 8-MOP in various solvents were determined. Spectroscopic data indicate the absence of interaction at the ground-state level, whereas the singlet excited state of 8-MOP is quenched by the pigment; the average fluorescence lifetimes are independent of the melanin concentration, thus indicating a static quenching mechanism. The photoacoustic data show that the quenching process involves an increased intersystem crossing probability, which is almost unaffected by the presence of oxygen, as expected for a molecule essentially acting as a type I photosensitizing agent.     

STUDY ON THE SYNTHESIS AND PROPERTIES OF POLY(ESTER-IMIDEETHER)MULTIBLOCK COPOLYMERS

A new class of poly(ester-imide-ether) multiblock copolymers was synthesized by transes-terification and meltcopolymerization of dimethyl terephthalate (DMT) and N-(4-carbomethoxyphenyl)-4-(carbomethoxy)-phthalimide withethylene glycol (EG) and polytetramethylene glycol (PTMG). The structure of the above copolymers was characterized by~1H-NMR and IR spectroscopy. Some properties of the coplymers were also examined. It was found that their mechanicalproperties and heat stability, compared with poly(ether-ester) copolymers, were obviously improved.     

丁醛等离子体处理云母粉对其表面特性及与聚合物界面特性的影响

用电容耦合式等离子体聚合方法对云母粉进行丁醛等离子体处理,通过测定各种液体对密堆积云母粉的渗透速度,确定了液体在云母粉表面的接触角,估算了云母粉的表面张力及与典型线形聚合物的界面张力。结果表明,极性液体在云母粉表面的浸润性因处理而削弱,非极性液体的浸润性基本来变;云母粉表面张力由处理前的41.34(N·m~(-1)·10~(-3))下降到处理5min时的31.51和处理30min时的25.59(N·m~(-1)·10~(-3));处理对云母粉与线形聚合物界面张力的影响因聚合物而不同,但该界面张力的极性分量均因处理而减小。     

增塑剂对对二氧环己酮均聚物及共聚物可吸收缝合线结构与性能的影响

以对二氧环己酮均聚物和对二氧环己酮 乙交酯共聚物为原料 ,加入无毒性增塑剂 (邻苯二甲酸酯 )进行纺丝 ,得到聚对二氧环己酮单丝缝合线 (PDS)和对二氧环己酮 乙交酯共聚物单丝缝合线 (PDG) .用DSC、WAXD、声速法对缝合线的结构与性能进行了测试 ,研究了增塑剂含量对缝合线的物理力学性能的影响 .研究结果表明 ,增塑剂使样品的玻璃化转变温度Tg 降低 ,聚合物结晶完善程度降低 .一定含量的增塑剂能够赋予缝合线较好的柔性 ,并使缝合线的初始强度有不同程度的提高     

等离子体处理云母粉对其表面特性及对其与聚合物界面特性的影响

采用等离子体方法处理填料及增强体表面,是提高填料及增强体与聚合物基体的粘合性、改善复合材料性能的一个新的有效途径。目前研究工作集中于处理条件与复合体系宏观性能的关系上,对处理前后填料表面性质以及填料与聚合物界而性质变化的探讨却很少。而只有了解上述变化才能从本质上认识处理条件与复合体系宏观性能的关系。本文首次对云母粉进行丁醛等离子体处理,测定了处理前后液体在云母粉表面的接触角,估算了处理条件     

聚氧化乙烯大单体与苯乙烯的接枝共聚物对某些有机反应的相转移催化效应

以叔丁氧基钾为引发剂合成了由甲基丙烯酰基封端的聚氧化乙烯大单体,用VPO、GPC与UV进行了表征。其数均官能度接近0.90,分子量分布较窄(Mw/Mn<1.10)。将这类大单体与苯乙烯经自由基共聚,制备了接技共聚物。初步考察了这类接技共聚物对酚类化合物与环氧氯丙烷或β-溴乙苯反应时的相转移催化作用,发现产物收率随接技共聚物中氧化乙烯含量的增加而提高。     

原位FT-IR研究甲烷和氧与SrO-La_2O_3/CaO催化剂表面的相互作用和反应(英文)

用原位FT－IR研究了甲烷和氧与纯CaO,La_2O_3和SrO氧化物以及LC和SLC催化剂的相互作用和反应．当不存在气相氧时,引入的甲烷与表面晶格氧反应生成碳酸盐物种。在室温或高温下,在这些氧化物和催化剂上不能检测到CH_4或O_2的吸附物类。但是,当CH_4和O_2同时存在时,在La_2O_3和LC催化剂上能检测到1118cm~－1的新谱带、这一谱带可能来自于表面碳酸盐在高温下氧气氛中的分解,并可归属为物种。甲烷与这一活性氧物种反应生成C_2H_4。但对SLC催化剂,在高温下不能检测到物种,而甲烷和氧在高温下反应也能产生表面碳酸盐并在气相中形成乙烯,这就表明,气相氧对这些催化剂也起着关键作用,但是在LC和SLC催化剂上甲烷氧化偶联反应可能有本质上的差别。     

镍和铂单晶(111)面上氢解离的比较研究

镍和铂单晶（１１１）面上氢解离的比较研究周鲁，孙本繁，吕日昌，唐向阳，滕礼坚（中国科学院大连化学物理研究所分子反应动力学国家重点实验室，大连１１６０２３）关键词镍晶面，铂晶面，氢解离吸附，位能面，分子催化过渡金属镍和铂是催化加氢、脱氢以及临氢重整的重...     

EFFECTS OF SOLVENT TREATMENT ON SURFACE MORPHOLOGY AND COMPOSITION OF POLY(METHYL METHACRYLATE)-g-POLY(ETHYLENE OXIDE)

Surface morphology and composition of solution-cast films of poly(methyl methacrylate)-g-poly(ethylene oxide)(PMMA-g-PEO) were investigated by using XPS, DSC, SEM and contact angle measurement. The microphase separatedstructure of the copolymers was studied by TEM. Generally, for the same graft copolymer, the surface content of PEO orhydrophilicity can be as follows: Surface treated with petroleum ether or cyclohexane>surface untreated with solvent>surface treated with water or ethyl alcohol. Graft copolymer having longer PEO side chains and higher PEO content shows aseparated PEO phase with even a certain degree of crystallinity on the surface. PEO crystallinity was destroyed by water orethyl alcohol treatment, however, surface treatment with petroleum ether or cyclohexane favors the growth of PEO crystal.TEM shows that graft copolymers with longer PEO side chains (M_n of PEO, 3200) may readily undergo microphase separation and the shape and size of domains depend on the copolymer's composition.     

ANISOTROPIC STRAIN EFFECT ON MORPHOLOGY AND ATOMIC STRUCTURE OF VICINAL Si(001) SURFACE

On vicinal Si(001) surfaces, dependence of growth morphology on the applied strain direction and formation of vacancy lines from Ag-induced missing dimer vacancies are studied. Both phenomena are intimately related to the anisotropic nature of the strain field which originates from the surface dimerization. Strain relief mechanism, reflecting on the surface morphology, is shown to be different in two orthogonal directions. Normal to the steps, step-pair bunching and waving lead to formation of hillocks and pits. Along the step direction, bending of step pairs forms a cusp which later develops into a deep groove. Toward the atomic scale, the formation of the vacancy lines is driven by the short-range attractive interaction between the vacancies in adjacent dimer rows and the long-range repulsive interaction between them in the same dimer row. A full form and magnitudes of the interactions are derived from the thermally-excited wandering of the vacancy lines formed by a nominal amount of Ag depositing onto the surface.