Thermochemistry on coordination behavior of samaric chloride hydrate with diethylammonium diethyldithiocarbamate

The complex of samaric chloride lower hydrate with diethylammoniumdiethyldithiocarbamate (D-DDC) was synthesized conveniently in absolute alcohol and dry N_2atmosphere. The title complex was identified as Et_2NH_2[Sm(S_2CNEt_2)_4] by chemical and elementalanalyses, the bonding characteristics of which was characterized by IR. The enthalpies of solutionof samaric chloride hydrate and D-DDC in absolute alcohol at 298.15 K and the enthalpies change ofliquid-phase reaction of formation for Et_2NH_2[Sm(S_2CNEt_2)_4] at different temperatures weredetermined by mi-crocalorimetry. On the basis of experimental and calculated results, threethermodynamic parameters (the activation enthalpy, the activation entropy, and the activation freeenergy), the rate constant, and three kinetic parameters (the apparent activation energy, thepre-exponential constant, and the reaction order) of liquid phase reaction of formation wereobtained. The enthalpy change of the solid-phase title reaction at 298.15 K was calculated by athermochemical cycle.

Heterotetranuclear Cu_2~IPd_2~Ⅱ Complex with Bis(diphenylphosphino)methane and Diethyldithiocarbamate

Self-assembly between the building blocks of Pd(Et2dtc)2 (Et2dtc = diethyldithio- carbamate) and [Cu2(m-dppm)2(MeCN)2]2+ (dppm = bis(diphenylphosphino)methane) gave a new heterotetranuclear complex [Cu2Pd2(m-dppm)2(m-Et2dtc)2(m3-Et2dtc)2](ClO4)2H2O (C70H86Cl2Cu2- N4O9P4Pd2S8, Mr = 1932.56), and its crystal structure has been determined by X-ray crystallo- graphy. It crystallizes in triclinic, space group P with a = 11.9834(6), b = 12.5624(6), c = 14.5603(8) ? a = 101.393 (1), b = 103.300 (1), g = 96.310(1), V = 2063.2(2) 3, Z = 1, Dc = 1.544 g/cm3, m(MoKa) = 1336 cm-1 and F(000) = 978. The total and unique reflections are 8710 and 5400, respectively. The structure was refined to R = 0.0860 and wR = 0.1996 for 3914 observed reflections with I > 2s(I). The title complex consists of the cation [Cu2Pd2(m-dppm)2(m-Et2dtc)2(m3- Et2dtc)2]2+, anion ClO4- and solvate H2O. The Pd(Ⅱ) atoms are located at the approximately square-planar environments with PS3 donors and the Cu(I) atoms display distorted tetrahedral geometries.

Thermochemical Study of Coordination of Holmium Chloride Hydrate with Diethylammonium Diethyldithiocarbamate

The complex of holmium chloride hydrate with diethylammonium diethyldithiocarbamate(D-DDC) was synthesized via mixing their solutions in absolute alcohol under a dry N 2 atmosphere. The elemental and chemical analyses show that the complex has the general formula Et 2NH 2[Ho(S 2CNEt 2) 4]. It was also characterized by IR spectroscopy. The enthalpies of the dissolution of holmium chloride hydrate and D-DDC in absolute alcohol at 298.15 K, and the enthalpy changes of liquid-phase reactions of the formation of Et 2NH 2[Ho(S 2CNEt 2) 4] at different temperatures were determined by microcalorimetry. On the basis of experimental and calculated results, three thermodynamic parameters(the activation enthalpy, the activation entropy and the activation free energy), the rate constant and three kinetic parameters(the apparent activation energy, the pre-exponential constant and the reaction order) of the liquid-phase reaction of the complex formation were obtained. The enthalpy change of the solid-phase complex formation reaction at 298.15 K was calculated by means of a thermochemical cycle.

Electrode process of diethyldithiocarbamate on surface of pyrrhotite

The electrode process of diethyldithiocarbamate on the surface of pyrrhotite was studied using systematic electrochemical analysis, including cyclic voltammetry, chronopotentiometry and galvanostatic. Experimental results show that tetraethylthioram disulphide（TETD） is electrodeposited on pyrrhotite electrode surface in the presence of 1.0×10^-4 mol/L diethyldithiocarbamate when the electrode potential is higher than 0.25 V. The electrochemical kinetics parameters of the electrode process of diethyldithiocarbamate on surface of pyrrhotite are calculated as follows： the exchange current density is 2.48μA/cm^2 , and the transmission coefficient is 0.46. The electrodeposition includes two steps electrochemical reaction. The first reaction is electrochemical adsorption of diethyldithiocarbamatc ion, then the adsorbed ion associates with a diethyldithiocarbamate ion from the solution and forms tetraethylthioram disulphide on the surface of pyrrhotite.

FTIR spectroscopic study of electrochemical flotation of jamesonite-diethyldithiocarbamate system

The flotation behavior of jamesonite was investigated with sodium diethyldithiocarbamate(DDTC) as a collector. The results show that jamesonite has good floatability from pH 2 to pH 13. The flotation of jamesonite is also dependent on the pulp potential. The potential-pH range for jamesonite flotation is established. The FTIR spectroscopy analysis shows that the major adsorption product of sodium diethyldithiocarbamate on jamesonite is lead diethyldithiocarbamate. The intensity of the FTIR signals of metal diethyldithiocarbamate adsorption on jamesonite and the flotation response of jamesonite are correlated with the pulp potential.

DIETHYLDITHIOCARBAMATE MAY ENHANCE THE ANTITUMOR EFFECT OF ADRIAMYCIN NANOPARTICLE-LIPIODOL EMULSION

Objective: To studied the effect of Diethyldithiocarbamate (DDC) on the antitumor activity of adriamycin (ADM) nanoparticle-lipiodol emulsion. Methods: The SD rats bearing liver carcinoma were divided into six groups and treated by saline, adriamycin, adriamycin nanoparticle-lipiodol emulsion, adriamycin liposome-lipiodol emulsion, DDC plus adriamycin nanoparticle-lipiodol emulsion, DDC plus adriamycin liposome-lipiodol emulsion respectively. The volume of the tumors, tumor growth rate (G%) and life prolonging rate PL% in six groups were determined. Results: The values of the IC50 (μg/ml) of adriamycin were reduced from 18.40 to 0.74 for the resistant cells SGC7901/CVR, and from 4.00 to 0.32 for the sensitive cells SGC7901/WT by pretreating the tumor cells with DDC. The tumor growth rate (G%) and life prolonging rate PL% increased significantly (P<0.05) in the DDC pretreated groups than adriamycin nanoparticle-lipiodol or adriamycin liposome-lipiodol emulsion groups. Conclusion: The antitumor effect of adriamycin can be enhanced by inhibiting the superoxide dismutase (SOD) in tumor cells by DDC.

SYNTHESIS AND APPLICATION OF ANTIMONY N,N-DIETHYLDITHIOCARBAMATE

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Inhibition of nitrification in soil by metal diethyldithiocarbamates

Nitrification acts as a key process in determining fertilizer use efficiency by crops as well as nitrogen losses from soils. Metal dithiocarbamates in addition to their pesticidal properties can also inhibit biological oxidation of ammonium(nitrification) in soil. Metal [M=V(Ⅲ), Cr(Ⅲ), Mn(Ⅱ), Fe(Ⅲ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ) and Co(Ⅱ)] diethyldithiocarbamates (DEDTC) were synthesized by the reaction of sodium diethyldithiocarbamate with metal chloride in dichloromethane/water mixture. These metal diethyldithiocarbamates were screened for their ability to inhibit nitrification at different concentrations(10 μg/g soil, 50 μg/g soil and 100 μg/g soil). With increasing concentration of the complex, capacity to retard nitrification increased but the extent of increase varied for different metals. At 100 μg/g soil, different complexes showed nitrification inhibition from 22 36% to 46 45%. Among the diethyldithiocarbamates tested, Zn(DEDTC) 2 proved to be the most effective nitrification inhibitor at 100 μg/g soil. Manganese, iron and chromium diethyldithiocarbamates also proved to be effective nitrification inhibitors than the others at 100 μg/g soil. The order of percent nitrification inhibition in soil by metal diethyldithiocarbamates was: Zn(Ⅱ) > Mn(Ⅱ) > Fe(Ⅲ) > Cr(Ⅲ) >V(Ⅲ) > Co(Ⅱ) > Ni(Ⅱ) > Cu(Ⅱ).

Effects of diethyldithiocarbamate on myelin basic protein expression in the rat lateral olfactory tract

BACKGROUND： Dithiocarbamates can cause demyelination of axons in the peripheral nervous system. Its derivate, diethyldithiocarbamate, is cytotoxic, and causes olfactory mucosal damage and atrophy of the olfactory bulb. However, it is still unclear whether the myelin sheath of the lateral olfactory tract is affected by diethyldithiocarbamate. OBJECTIVE： To investigate the effects of diethyldithiocarbamate on the myelin sheath of the rat lateral olfactory tract. This was done by examining changes in myelin basic protein expression after diethyldithiocarbamate treatment. DESIGN, TIME AND SETTING： A randomized, controlled, animal study was performed at the Laboratory of the Department of Human Anatomy and Neurobiology, Xiangya School of Medicine, Central South University, China from July to November 2007. MATERIALS： A total of 72 Sprague Dawley rats were randomly assigned into a diethyldithiocarbamate group （n = 32）, a solvent control group （n = 32）, and a blank control group （n = 8）. The diethyldithiocarbamate and solvent control groups were separately divided into 3-d, 7-d, 14-d and 28-d survival subgroups, with eight rats in each. Diethyldithiocarbamate （Sigma, USA） and goat anti-myelin basic protein polyclonal antibody （Santa Cruz, USA） were used in this study. METHODS： Rats in the diethyldithiocarbamate and solvent control groups were subcutaneously injected with diethyldithiocarbamate （600 mg/kg） and 0.01 mol/L phosphate buffered saline （600 mg/kg） at the posterior neck, respectively. Rats in the blank control group received no treatment. MAIN OUTCOME MEASURES： Immunohistochemical staining and Western blot assay were used to measure myelin basic protein expression in the rat lateral olfactory tract. RESULTS： Following immunohistochemical staining, myelin basic protein was uniformly distributed in the rat lateral olfactory tract in the blank control and solvent control groups. Western blot assay showed 21.5, 18, 17 and 14 ku positive bands. No significant difference was found in myelin basic protein distribution and blot pattern, in the rat lateral olfactory tract, in the diethyldithiocarbamate group, following immunohistochemical staining and Western blot assay. Myelin basic protein expression gradually decreased at day 3, reached the lowest level at day 7, and gradually increased again at days 14 and 28. CONCLUSION： Demyelination is induced by diethyldithiocarbamate in the rat lateral olfactory tract in an early stage, followed by remyelination at later stages.

Synthesis, Structure and Transesterification of the Derivatives of β-Alkoxycarbonylethyltin Trichlorides with Diethyldithiocarbamate

The derivatives of β-alkoxycarbonylethyltin trichlorides with diethyldithiocarbamate,ROCOCH2CH2Sn(S2CNEt2)Cl2, were synthesized and characterized by the means of elemental analysis, IR, 1H NMR and X-ray single crystal diffraction. The structural features of the compounds were described, and the possible mechanism of transesterification for compound 2a was suggested.

Thermochemistry on Coordination Behavior of Neodymium Chloride Hydrate with Diethylammonium Diethyldithiocarbamate

The complex of neodymium chloride lower hydrate with diethylammonium diethyldithiocarbamate (D-DDC) was synthesized conveniently in absolute alcohol and dry N_2 atmosphere. The title complex was identified as Et_2NH_2[Nd(S_2CNEt_2)_4] by chemical and elemental analyses and the bonding characteristics of which was characterized by IR. The enthalpies of solution of neodymium chloride hydrate and D-DDC in absolute alcohol at 298.15 K and the enthalpies change of liquid-phase reaction of formation for Et_2NH_2[Nd (S_2CNEt_2)_4] at different temperatures were determined by microcalorimetry. On the basis of experimental and calculated results, three thermodynamic parameters (the activation enthalpy, the activation entropy and the activation free energy), the rate constant and three kinetic parameters (the apparent activation energy, the pre-exponential constant and the reaction order) of liquid-phase reaction of formation were obtained. The enthalpy change of the solid-phase title reaction at 298.15 K was calculated by a thermochemical cycle.

Cu(DDC)_(2)纳米给药系统的抗肿瘤研究进展

二乙氨基硫代甲酸铜[copper diethyldithiocarbamate,Cu(DDC)_(2)]可通过多种机制诱导肿瘤细胞死亡,是一种潜在的抗肿瘤药物.但Cu(DDC)_(2)极低的水溶性使其应用受到很大限制.Cu(DDC)_(2)纳米给药系统在细胞和动物模型中显示出良好的抗肿瘤作用.文章基于近年来关于Cu(DDC)_(2)纳米给药系统的抗肿瘤研究进行总结和展望,为新型Cu(DDC)_(2)纳米给药系统的设计提供参考.

Electrochemical flotation of diethyldithiocarbamate-pyrrhotite system

Using sodium diethyldithiocarbamate as a collector the flotation behavior of pyrrhotite was investigated. The relationship between potential and pH range for pyrrhotite flotation was established. The results show that the flotation of pyrrhotite is dependent on pulp potential at certain pH values. Pyrrhotite has good floatability from pH 2 to pH 12, and poor flotability at pH>12. Cyclic voltammetry and Fourier transform infrared spectrum analysis show that the major adsorption product of DDTC on pyrrhotite is tetraethylthiuram disulfide. The intensity of Fourier transform infrared signals of tetraethylthiuram disulfide adsorbed on pyrrhotite and the anode current of a pyrrhotite electrode and flotation response of pyrrhotite are correlated with pulp potentials.

Synthesis and Crystal Structure of a Dicopper(Ⅰ) Complex with Bis(diphenylphosphino)methane and Diethyldithiocarbamate

The title complex [Cu2(-dppm)2(-Et2dtc)](ClO4)EtOH0.25H2O (dppm = bis- (diphenylphosphino)methane, Et2dtc = diethyldithiocarbamate) has been synthesized and characterized by single-crystal X-ray diffraction analysis. The crystal structure is of monoclinic, space group C2/c with a = 42.587(1), b = 14.1653(4), c = 20.5649(5) ? = 105.945(1)? V =11928.6 3, C57H60.5ClCu2NO5.25P4S2, Mr = 1194.09, Z = 8, Dc = 1.330 g/cm3, (MoK) = 0.98 mm-1 and F(000) = 4948. A total of 15243 reflections were collected, of which 7322 were unique. The structure was refined to R = 0.0739 and wR = 0.1846 for 5135 observed reflections with I > 2(I). The crystal structure consists of the complex cation [Cu2(-dppm)2(-Et2dtc)]+, anion ClO4- and solvate H2O and EtOH, where the dinuclear Cu(Ⅰ) atoms are bridged doubly by two dppm ligands and singly by Et2dtc to give three five-membered rings. The Cu(Ⅰ) atom is in an approxi- mately trigonal-planar environment with the P2S chromophore. The short Cu贩稢u separation (2.7111 ? suggests the presence of metal-metal contact.

建筑智能化DDC系统和安防系统有效融合软件设计探索

智能建筑已成为城市建设的新趋势,其中,建筑自动化集成控制系统(DDC)和安防系统是其重要组成部分。然而,传统的DDC和安防系统常常独立运作,系统融合的难度大,信息交流不畅。本研究针对以上问题,设计了一款基于智能建筑DDC系统和安防系统有效融合的软件。该软件以中控系统为基础,利用物联网技术,实现DDC系统和安防系统的数据共享、双向通信,达到了资源共享、互联互通和远程监控的目的。测试结果显示,该软件能够有效地实现DDC和安防系统的融合与优化,提升了建筑智能化的水平,并降低了运行成本。同时,软件操作界面友好,能够为建筑物业管理提供强大的支持。这样的研究成果对于促进智能建筑的研究与发展有着重要的理论和实践意义。

DDC关联数据实现研究

分类法作为规范的知识组织工具,实现其关联数据化,对书目数据的开放和网络知识组织体系的构建具有重要意义。《杜威十进分类法》是图书情报领域使用最为广泛的分类法,现已将其类目以关联数据的形式发布。本文基于Dewey.info平台,以DDC关联数据为例,通过对DDC关联数据发展脉络的梳理和技术构成的分析,从授权模型确定、实体对象的明确、URI命名、SKOS模型化、RDF表示五个方面解析DDC关联数据的具体实现。以此为我国《中图法》及其它分类法的关联数据化提供一定的参考。

DDC与《中图法》组合类目映射探讨

国内分类法映射研究多关注于间接映射方法的实现,对词表类目复杂语义关系研究较少。当前分类法采用大量的组合类目形式表达一些复杂的概念,由于不同类表之间组合类目的特点及作用不同,导致组合类目之间映射存在一定难度。针对DDC和《中图法》除生物科学以外的理学领域类目,分析了组合类目的分布特点,从语义层将组合类目划分为并列关系、属分关系、限制关系、交叉关系四种类型,总结组合类目的两种基本功能,从等同、包含和交叉三种关系类型研究组合类目直接映射的匹配规则,为进一步构建《中图法》和DDC的自动映射系统提供参考依据。表10。参考文献11。

DDC到《中图法》类目映射方法研究

对于中外分类法的映射研究,国内多关注于对计算机自动映射方法的探讨,缺乏对词表类目复杂语义关系的具体研究。本文在对DDC和《中图法》理学领域共计4639个类目进行人工直接映射的基础上,通过统计其匹配依据,得出结论:理学类目下数学、物理、化学、天文、地理等不同学科内匹配依据的总体分布呈现一致性的特点,这为检验计算机自动匹配准确性提供了方法。实验表明,类目名称、注释、主题词、类目关系作为主要的判断依据,占映射类目的63%,依据匹配规则占映射的5.14%,依据书目记录的匹配占31.87%,因此论文建议实现计算机自动匹配时,除类目自身信息外,还需考虑书目记录的匹配。

智能控制系统中DDC控制器对电磁脉冲的敏感度试验

组建了典型 DDC控制系统的试验模型 ,分别在 2种电磁脉冲模拟器中对其进行了干扰试验 ,测量了不同试验状态下 DDC控制系统受干扰的场强阈值。对系统不同环节的脉冲干扰试验表明 ,DDC通讯线路是引入干扰的主要途径 ,受控设备电源线引入的干扰也会通过其附近 DDC通讯线路对系统形成较强的耦合并导致系统误动作 ,在此基础上讨论了 DDC控制系统的防护措施。

建筑智能节水DDC控制系统设计

针对建筑中大量浪费的日常用水排水现状,提出了一种建筑智能节水减排系统,在介绍系统组成和工作原理的基础上,重点介绍了DDC电气控制系统的构成、DDC控制器输入输出接口分配以及节水系统DDC控制变量的分配和控制过程,实现了对建筑中日常用水排出水的水质检测、判断和控制,对较洁净的水自动分类存储和消毒后使用,促进建筑日常用水排水健康循环,提高水资源利用率。