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941.
含噻二唑环苯甲酰脲化合物的合成及杀虫活性   总被引:12,自引:0,他引:12  
李兴海  凌云  杨新玲 《化学通报》2003,66(5):333-336,322
用活性亚结构连接法设计合成了6个新的含1,3,4-噻二唑杂环苯甲酰脲类化合物,其结构经红外光谱、核磁氢谱、元素分析方法确证。同时对其杀虫活性进行了初步研究,发现该类化合物在普筛浓度下对淡色库蚊幼虫具有较好的杀虫活性。化合物Ⅲb(R1=Cl,R2=n-C5H11),Ⅲd(R1=CH3,R2=n-C5H11),Ⅲf(R1=2,6-difluoro,R2=-C5H11)在10mg/L浓度下对淡色库蚊幼虫的杀虫死亡率大于90%。  相似文献   
942.
Cu(CH3COO)2·H2O脱水反应动力学探讨   总被引:6,自引:1,他引:6  
唐定兴  赵芸 《应用化学》2003,20(8):760-0
水合乙酸铜;;脱水动力学;热分析;等温等转化率法;Cu(CH3COO)2·H2O脱水反应动力学探讨  相似文献   
943.
The reaction of CuCN and KCN with (NH4)2[WS4] followed by cation exchange with PPh4Br produced the title compound, (C24H20P)2[Cu2WS4(CN)2]·CH3CN·H2O or (PPh4)2[(NC)Cu(μ‐S)2W(μ‐S)2Cu(CN)]·MeCN·H2O. In the structure of the dianion, [(NC)Cu(μ‐S)2W(μ‐S)2Cu(CN)]2−, the WS4 moiety acts as a bidentate ligand that binds two CuCN groups, thus forming a slightly bent WCu2 core with approximate D2d symmetry. The W—Cu distances are in the range 2.6463 (6)–2.6545 (6) Å.  相似文献   
944.
多羰基甾酮的选择性还原反应研究   总被引:8,自引:0,他引:8  
在不同金属离子存在下,多羰基甾酮的甾核及支链上都发生了羰基与硼氢化钠的还原反应,得到具有不同的区域选择性和立体选择性的还原产物.  相似文献   
945.
在真空条件下完成了X2 (X=Cl、Br)与AgOCN间的气-固异相反应,利用紫外光电子能谱(PES)仪,探测与确定反应产物是XNCO (X=Cl、Br),并推断其可能为一过渡态反应,生成中间络合物,新键产生与旧键断裂同时进行.  相似文献   
946.
液相还原法制备超细球形镍粉   总被引:11,自引:0,他引:11  
廖戎  张云  周大利  潘高峰 《无机化学学报》2003,19(10):1047-1052
本文论述了液相还原法直接制备高振实密度球形镍粉的新工艺。采用NiSO_4·5H_2O为原料,利用NaOH调节溶液的pH值并形成Ni(OH)_2,还原剂采用N_2H_4·H_2O,还原过程中加入晶核引发剂及表面活性剂。采用正交实验表安排实验,对影响镍粉振实密度及粒径的因素进行了极差分析。实验数据表明,溶液中镍的初始浓度对产品质量的影响最大,较优工艺组合条件为:初始Ni~(2+)的浓度1.5mol·L~(-1),NaOH用量为理论量的1.1倍,反应温度80℃,表面活性剂用量为每克镍5mg,晶种添加量为还原剂理论用量的0.1%。新工艺可制备振实密度高达3.0以上、质量中位径为1μm的球形镍粉。  相似文献   
947.
A novel bis(beta-cyclodextrin) was synthesized, and its binding behavior with steroids was investigated to demonstrate that the cooperative co-inclusion of guest and tether by two cyclodextrin moieties is operative to afford the highest molecular selectivity of up to 3.6 for deoxycholate over taurocholate.  相似文献   
948.
Mei SR  Yao QH  Cai LS  Xing J  Xu GW  Wu CY 《Electrophoresis》2003,24(9):1411-1415
Urinary 8-hydroxy-2'-deoxyguanosine (8OHdG) is an excellent marker of oxidative DNA damage. Until now, urinary 8OHdG has been measured by high-performance liquid chromatography with electrochemical detection. A simple and sensitive method for the analysis of urinary 8OHdG by capillary electrophoresis with end-column amperometric detection has been developed in our laboratory. A single-step solid-phase extraction procedure was optimized and used for extracting 8OHdG from human urine. To improve the sensitivity of this method, a new focusing technique based on a dynamic pH junction was used. The limit of detection was 20 nM (signal-to-noise ratio S/N = 3), the linear range was 50 nM-10 microM, and the correlation coefficient was better than 0.999. The relative standard deviation (RSD) was found to be 0.57% for migration time, and 4.79% for peak current. To show the usefulness of the method, the urinary concentration of 8OHdG in nine healthy persons and ten cancer patients was determined. The urinary concentration of 8OHdG in cancer patients was significantly higher than that in healthy persons.  相似文献   
949.
A fluorescent aminoacid was designed for selective and sensitive detection of Cu(II) in aqueous solution. The designing of this Cu(II) fluorescent chemosensing molecule, N ± (1‐naphthyl). aminoacetic acid (NAA), was based on the binding of Cu(II) to aminoacetic acid and the novel charge transfer photophysics of 1‐aminonaphthalenes. The fluorescence of NAA was found quenched by Cu (II) and several other metal ions of similar electronic structure such as Co(II), Ni(II) and Zn(II). The quenching was shown to occur via electron transfer within the metal‐NAA complex, which required an optimal combination of high binding affinity and favorable redox properties of the components in the metal‐NAA complex and hence afforded selective fluorometric detection of Cu(II). The calibration graph obeyed Stern‐Volmer theory and was shown for Cu(II) over the range of 0–2.75 ± 10–4 mol/L. The quenching constant of Cu(II) was measured as 8.0 ± 103 mol/L that was two orders of magnitude higher than those of Co(II), Ni(II) and Zn(II). The 3SD limit of detection for Cu(II) was 8.00 ± 10?6 mol/L with a coefficient of variation of 1.65%. Linear range for quantitative detection of Cu(II) was 2.67 ± 10?5‐2.75 ± 10?4 mol/L. The method was applied to synthetic sample measurements which gave recoveries of 105%‐112%.  相似文献   
950.
Li BY  Liang YZ  Hu Y  Du YP  Song YQ  Cui H 《Talanta》2003,61(6):803-809
A chemometric resolution method is described for the identification of nitrogen compounds in crude oil. Prefractionation of crude oil into discrete chemical classes was performed by adsorption column chromatography using small quantities of neutral aluminum oxide and silicic acid. Subsequent high-resolution separation of individual components was achieved by using capillary column gas chromatography, and compound types were detected by mass spectrometer. In conjunction with a combined chemometric method, each principal chemical class was further resolved and separated, which made it possible to identify some nitrogen compounds in the investigated oils. To a certain extent, this method could relieve classical analysis of difficulty in identifying those species with poorly low contents or partially chromatographic overlaps, particularly in the cases where authentic standards were not available for addition into the unknown analytical systems to reveal what indeed existed in them.  相似文献   
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