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1.
用ICP-AES方法,对30例大肠癌,26例溃疡性结肠炎进行血清钼,锌,铬铁,铜,锰,铅,铝,硒,铋,钡,钛,钴,钒等微量元素测定,并与20例健康者对照。结果显示大肠癌组血清钼,锌,铬,低于对照组钼,锌,铬,P分别〈0.01,〈0.05,〈0.05;溃疡性结肠炎组钼低于对照组,P〈0.05。提示微量元素代谢异常可能直接影响酶系统,使自由基失控,体内促氧化和抗氧化平衡失调,促使肿瘤的发生。  相似文献   

2.
用ICP研究鹿科动物骨质疏松症的微量元素特征   总被引:1,自引:0,他引:1  
鹿科动物的骨质疏松症是近几年出现的一种疾病,它影响鹿的生长发育和繁殖,病重者死亡。我们采集梅花鹿和白唇鹿的毛,血样,用低温灰化方法和温法消解处理样品,用ICP分析了毛,血清中微量元素的含量。病梅花鹿毛样中Mg,Al,Ca,Ti,Fe,Cu,Zn的含量比正常组高,Ti,Cu,Zn的偏差率大于15%,而Si,Mn,P,P,Ag,Ba,La,Ce,Pb比正常组低,V,Ag,Ba,La,Ce,Pb存在...  相似文献   

3.
利用火焰原子吸收法测定了中国银行韶关节市分行458名职工头发中Cu,Fe,Zn,Ca含量,运用统计学方法求出该人群中正常者与白发,脱发者Cu,Fe,ZnCa的特征含量,通过数据比较可看出,白发者Cu,Fe,Zn,Ca的含量均低于正常组,而脱发者与正常组较接近,经相关性检验,证明了Cu,Fe,Zn,Ca偏低的血发存在的相关性,与脱发没有相关性,经过性别比对,女性发中Cu,Fe,Zn,Ca含量均高于男  相似文献   

4.
聚苯乙烯,聚甲基丙烯酸甲酯对聚氯乙烯/氯化聚乙烯共混体流变性的影响杨文君,吴其晔,杜华(青岛化工学院高分子材料系,青岛,266042)王建民,李应华,张宝善(齐鲁石化研究院,淄博,255434)关键词塑料改性,流变性,聚氯乙烯,氯化聚乙烯,刚性粒子我...  相似文献   

5.
一种全自动光度滴定仪   总被引:1,自引:0,他引:1  
汪敬武  魏琼雄 《分析化学》1998,26(7):904-908
报道了改装721型分光光度计为光度滴定仪并联用8031单片微机构成一台全自动光度滴定仪,在单片机的控制下,实现取样,加试液,搅拌,开关光门,调零,调参比,滴定,测吸光度,数据处理,显示结果并打印,排除废液,冲洗滴定池等操作过程的全自动化,约110s可完成一次测定,误差〈0.2%,RSD〈1.5%,测定快速,准确,重复性好,可胜任在线监测工作,也可作常规滴定分析。  相似文献   

6.
固体物理、固体化学与新材料424Tin'",YP"共掺ZBLAN玻璃中的能量传递与转换,冯衍等,物理学报,1997,46(12),2454.425LqO。基导电白瓷高祖电用率的国试和研究,李友芬等,中国有色金属学报,1997,7(l),159.4M环氧树脂粘结SIDZFq,N。磁体的矫顽力机理,于申军等,磁性材料及器件,1997,28(l),16.427SmZFq7Nyq稀土永巴材料的最近进展,吴安国,磁性材料及器件,1997,28(l),46.428重稀土锰基化合物Gd(回n,Co)St的结构与殓性,林钢等,磁性材料及器件,1997,28(2),19.4N制粉过程对SwFq,N。各向异性…  相似文献   

7.
压电液相化学分析   总被引:10,自引:1,他引:10  
聂利华  姚守拙 《分析化学》1996,24(2):234-241
压电液相分析方法有吸附,电解沉积,频移滴定,化学频移,萃取频移,介电分析,内电解,选择性络合,催化,催化,化学倍增,氧瓶燃烧测频,多元混合物速测等法,可用于无机物,有机物,药物,环境,冶金,食品和饮料等分析。  相似文献   

8.
《高分子科学》2007,25(6):I0007-I0009
AUthor Index甘。!.25目0.卜‘.2007 Li,Hua Li,Ji Li,J ian一ling Li,Ji一Peng Li,Kai一un Li,Meng一yan Li,Shi一ben Li,Shi一yun Li,Shu一ning Li,51一dong Li,X iao一yu Li,Yan一guo Li,Yue一sheng Li,Ting Liang,Dong Liang,51 Ling,Fang Liu,Bin Liu,Jing Liu,Jing一yu Liu,Lan Liu,Qun一feng Liu,Zong一tang L6tzseh,D. Lu,Man一geng Lu,Yl Luo,Hong一xin Luo,Jing Luo,Yuan一fang Luo,Zheng一hong Lv,Rui 331 181 3 11 227 651 331 525 1 87 555 635 2 17 325 325 207 59…  相似文献   

9.
中华猕猴桃果实香气成分的GC-MS分析   总被引:9,自引:0,他引:9       下载免费PDF全文
采用溶液萃取法,提取“早鲜”猕猴桃果实中的香气成分,经气相色谱-质谱联机分析,鉴定出45个香气组分,占总峰面积的95.9%,其相对含量,以棕榈酸,辛酸,油酸,3-羟基丁酸乙酯,(Z,Z)-9,12-十八二烯酸,1,2,4-三羟基-(对)-萜烷,(E)-2-己烯醛,1,2-苯二甲酸双(2-甲氧基乙基)酯,硬脂酸,2-己烯醛等为主。  相似文献   

10.
《天然气化学杂志》2006,15(4):I0007-I0008
A G Abdullah,Zalizawati,247 Ah6n,Vfotor R.,307 Alavi,S.M.,327 Amin,Nor Aishah Saidina 191,259,340 Ammasi,Sriraj,191 An,G的jun,127 Anggoro,Didi Dwi,340 Ge,Zhonghua,164 Gu,Y.,73 Guo,Bo,223 Guo,Jianjun,52 Guo,Xiaohui,105 H B Bai,Liang,105 Bakar,W.Azelee W.Abu,259 Bao,Xinhe,181 Batuev,Lubsan,149 Burgina,Elena,149 Ha£axlioglu,P.,73 Han,Huajun,303 Hong,Kong Bee,266 Hu,Xiaofang,58 Hu,Xi加jun,100 Huang,Shengjun,93 Huang,Xingyun,3…  相似文献   

11.
The binuclear molybdenum carbonyls Mo(2)(CO)(n) (n = 11, 10, 9, 8) have been studied by density functional theory using the BP86 and MPW1PW91 functionals. The lowest energy Mo(2)(CO)(11) structure is a singly bridged singlet structure with a Mo-Mo single bond. This structure is essentially thermoneutral toward dissociation into Mo(CO)(6) + Mo(CO)(5), suggesting limited viability similar to the analogous Cr(2)(CO)(11). The lowest energy Mo(2)(CO)(10) structure is a doubly semibridged singlet structure with a Mo═Mo double bond. This structure is essentially thermoneutral toward disproportionation into Mo(2)(CO)(11) + Mo(2)(CO)(9), suggesting limited viability. The lowest energy Mo(2)(CO)(9) structure has three semibridging CO groups and a Mo≡Mo triple bond analogous to the lowest energy Cr(2)(CO)(9) structure. This structure appears to be viable toward CO dissociation, disproportionation into Mo(2)(CO)(10) + Mo(2)(CO)(8), and fragmentation into Mo(CO)(5) + Mo(CO)(4) and thus appears to be a possible synthetic objective. The lowest energy Mo(2)(CO)(8) structure has one semibridging CO group and a Mo≡Mo triple bond similar to that in the lowest energy Mo(2)(CO)(9) structure. This differs from the lowest energy Cr(2)(CO)(8) structure, which is a triply bridged structure. A higher energy unbridged D(2d) Mo(2)(CO)(8) structure was found with a very short Mo-Mo distance of 2.6 ?. This interesting structure has two degenerate imaginary vibrational frequencies. Following the corresponding normal modes leads to a Mo(2)(CO)(8) structure, lying ~5 kcal/mol above the global minimum, with two four-electron donor bridging CO groups and a Mo═Mo distance suggesting a formal double bond. All of the triplet Mo(2)(CO)(n) (n = 10, 9, 8) structures were found to be relatively high energy structures, lying at least 22 kcal/mol above the corresponding global minimum. The singlet-triplet splittings for the Mo(2)(CO)(n) (n = 10, 9, 8) structures are significantly higher than those of the Cr(2)(CO)(n) analogues. The Mo-Mo Wiberg bond indices confirm our assigned bond orders based on predicted bond distances.  相似文献   

12.
利用H2O2-KI-鲁米诺体系化学发光法测定痕量钼   总被引:2,自引:0,他引:2  
钼(Ⅵ)可以催化H2O2氧化I-的反应,生成的I2在碱性水溶液中能氧化鲁米诺而产生化学发光[1],本文将这两个反应结合起来,建立了铝的化学发光分析法,方法有较高的灵敏度,检出限为6×10-10g/cm3Mo,测定的相对标准偏差小于6%,工作曲线的线性范围是1×10-9~1×10-7g/cm3Mo,用EDTA作掩蔽剂,排除了大多数金属离子的干扰,方法有较好的选择性,应用此法对一些粮食样品中的痕量钼进行了测定,结果比较满意。  相似文献   

13.
<正> In recent years, our research group has succeeded in synthesizing a series of {Mo2}, {Mo3}, and {Mo4} clusters by reacting mononuclear Mo(III) or Mo(V) compounds with P2S5 in a C2H5OH/C2H5OH-HCl medium under different controlled Mo:P and acidity conditions, and determining their crystal and molecular structures by single-crystal X-ray diffraction methods. The following is a list of some such clusters.  相似文献   

14.
A new, simple and specific spectrophotometric method for the determination of Mo in the soil extracts is described. Mo(VI) is reduced to Mo(V) with sodium borohydride and allowed to react with SCN ions in the presence of cationic and neutral surfactants e.g. CPC and TX-100 in the acidic aqueous solution. The molar absorptivity of the complex in both the aqueous, and toluene solutions is (2.30) × 104 1mol–1 cm–1 at absorption maximum, 460 nm. The extraction-procedure preconcentrated Mo at least 3-folds. the detection limit is 125ng Mo/g soil. The analytical variables of the method have been optimised and composition of the complex is proposed. None of the tested foreign ion interfered in the determination of Mo up to a large amount. An attempt for the removal of Fe-interference in the determination of Mo in soil extract has been described. The method has been found to be satisfactorily applicable for the determination of Mo in hot water leachates and acid digested soil solutions at lower ppm levels.  相似文献   

15.
利用电子自旋共振谱(ESR)和X射线光电子谱(XPS)研究了MoS2摩擦表面的氧化行为和摩擦表面氧化的电子转移,发现MoS2在摩擦失效过程中Mo4+与氧作用生成稳定的Mo6+终态氧化物,其间经过Mo5+过渡态。深入揭示了MoS2摩擦表面氧化过程的复杂性,指出Mo在摩擦表面氧化过程中以多种化学状态存在,Mo原子的氧化是Mo4d轨道上的单电子转移过程。  相似文献   

16.
Mo2N的表面性质和加氢脱氮活性   总被引:1,自引:0,他引:1  
以XRD、H2-TPD、TPS方法研究了钝化和硫化处理对Mo2N体相结构和表面性质、以及对吡啶加氢脱氮(HDN)催化活性的影响。Mo2N经钝化或在673K硫化后,虽然其体相结构不发生变化,但其表面性质却发生了明显的异变,并伴随其加氢脱氮活性的显著降低.由Mo2N在不同钝化条件下生成的部分氧化产物以及H2-TPD结果,推测在缓慢钝化条件下,Mo2N表面钝化层为MoO2根据Mo2N硫化后的H2-TPD和相应HDN活性变化,以及Mo2N的TPS结果,认为Mo2N经673K硫化后其表面结构发生了硫化异变.  相似文献   

17.
The reaction of the molybdenum oxypentathiocyanate ion with the dyestuff Rhodamine B (RhB) produces the ternary complex. MoO(SCN)(5)(RhB)(2) The formation of this complex is accompanied by a colour change and by extinction of the fluorescence of RhB. A spectrophotometric and fluorometric method for the determination of Mo has been developed from these observations. The method is free from interferences and has detection limits of 0.1 mug and 0.05 mug of Mo for absorption and fluorescence measurements, respectively. The spectrophotometric method is applicable to the determination of Mo in soils and the fluorometric method is suited to the determination of Mo in plants.  相似文献   

18.
Migdalski J  Kowalski Z 《Talanta》1990,37(4):447-453
The effect of reduction on the stability of molybdosilicic acids (MSA) has been investigated. It has been found that when two or more of the 12 Mo(VI) atoms in alpha or beta-MSA are reduced to Mo(V), the products are stable in alkaline medium. Also, beta-MSA reduced to this extent is stable at higher temperature and is not transformed into alpha-MSA. Solutions in which the apparent degree of reduction is less than 2 Mo(V) per MSA ion should be treated as a mixture of unreduced MSA and MSA reduced exactly to 2 Mo(V) per MSA ion. A mixture of unreduced MSA and MSA reduced to contain 4 Mo(V) per MSA ion is not a stable system. The yellow unreduced MSA is reduced by the reduced form to give the product with 2 Mo(V) per MSA ion. The consequences for determining silicon as MSA are given, as well as a method of obtaining pure beta-MSA from a mixture of alpha-MSA and beta-MSA.  相似文献   

19.
γ-Mo2N和分子筛负载的钼氮化物的结构表征   总被引:2,自引:0,他引:2  
采用程序升温氮化的方法制备了分子筛负载的钼氮化物催化剂,并用EXAFS方法研究了 氮化前后Mo原子的局域配位情况.氮化前负载MoO3样品的径向结构函数中有三个峰,其中前两 个峰对应着最近的Mo-O配位壳层,但是第一个峰与第二个峰的比例比晶体MoO3中的比例大很 多,表明分子筛负载的MoO3具有更紧密的结构.氮化以后,Mo2N样品的径向结构函数中有三个 峰,对应于一个Mo-N和两个Mo-Mo配位壳层,与面心立方模型符合得很好.根据XRD和EXAFS谱 的计算表明,Mo2N中的N原子使Mo-Mo键拉长并削弱.分子筛负载的Mo2N样品具有与非负载Mo2 N样品近似相同的径向结构函数,只是对应于Mo-N壳层的峰较弱,表明负载的Mo2N具有更大的 结构无序性.  相似文献   

20.
本文研究了在钼(Ⅵ)螯合物催化下,用叔丁基氢过氧化物进行辛烯-1环氧化反应动力学。比较了不同配位基的钼(Ⅵ)螯合物催化性能的差异。配位基与钼(Ⅵ)的结合愈不牢固,反应速度常数愈大,而催化剂稳定性愈差。当存在过量给予体时,钼(Ⅵ)螯合物因解离受到抑制,则没有催化活性。如给予体适量,既可以保持催化剂的活性,又可增加催化剂的稳定性。  相似文献   

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