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1.
不同品种的黄芪微量元素比较   总被引:2,自引:0,他引:2  
采用原子吸收光谱测定了商品黄芪、梭果黄芪、金翼黄芪及云南栽培黄芪中Cu、Fe、Zn、Mn、Ca、Mg、Co、Al等元素,不同品种的黄芪中微量元素含量均有差异。  相似文献   

2.
健康人及尿石患者头发中微量元素的相关性研究   总被引:6,自引:0,他引:6  
用ICP-AES测定了尿石症高发现地区-广东省东莞市尿石症患者发中Ca,Mg,Al,Cd,Co,Cr,Mn,Fe,Cu,Mo,Zn,Ba,Sr等十三种微量元素,并和健康人进行比较,经t检验发现:Ba,Cd,Mo,Sr,Mn,Zn和Mg/Ca比值间存在显著性差异。  相似文献   

3.
用WFX-Ⅱ型原子吸收分光光度计测定了玉津酒中Zn,Cu,Mn,Fe,Cr,Ni,Cd,Pb,Ca,Mg,Na,K等12种金属元素含量。结果表明,其中玉津酒1号样品Zn,Fe含量高于其它3个样品,玉津酒中所含微量元素具有调节机体免疫功能的作用,可改善类风湿性关节炎的症状体征。  相似文献   

4.
使用常规湿法和干法消化方法对酸枣叶进行预处理,用火焰原子吸收法测定了其中的Cu、Fe、Zn、Mn、Sr、Ca、Mg等七种金属元素的含量。结果表明,不同消化方法对某些元素产生的影响不同,损失度也有所差别,为样品预处理方法的选择提供了参考数据,也为进一步研究酸枣叶中金属元素的存在形态打下了基础。  相似文献   

5.
用原子吸收光谱法测定了70例健康老年人、30例健康成年人和30例老年高血压病人血清中Cu、Zn、Fe、Mn、Ca、Mg6种元素的含量.结果表明,健康老年人组与健康成年人组(对照组)相比,除Fe以外,Cu、Zn、Mn、Ca、Mg均有显著性差异;与老年高血压病人组相比,除Mg以外,Cu、Zn、Fe、Mn、Ca均有显著性差异.我们认为稳定的Cu/Zn比值及较高的血Mg水平是健康老年人未发生心血管疾病及糖尿病的重要原因之一,而高Cu、高Ca及显著偏高的Cu/Zn比值,则是发生高血压的一个重要原因。  相似文献   

6.
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   

7.
菊花微量及宏量元素分析   总被引:9,自引:0,他引:9  
用ICP-AES法测定了药用野菊花和抗白菊及6种人工栽培菊花中As,B、Ba、Ca、Cd、Co、Cu、Fe、Mg、Mn、Mo、Ni、Pb、Se、Si、V、Zn、P、S、K等元素的含量。结果表明:(1)菊花中Ca、Mg、P、S、K含量很高,B、Fe、Mn、Zn也有较高的含量;(2)野菊花中B、Ca、Fe、Mg含量较其他品种高、,抗白菊中Mn、Se、S含量高地其他品种;(3)代栽培的菊花K、P含量高于  相似文献   

8.
应用装有EPM-810Q电子探针扫描分析电镜,对50例乙肝患者头发中Mg、Al、Cd、Ca、Cr、Mn、Fe、Cu、Zn、Pb、Se11种元素含量进行分析,并与健康人头发进行比较。结果表明:乙肝组中Zn含量低于健康组,Cu、Cd、Fe含量高于健康组(P〈0.01)。  相似文献   

9.
电感耦合等离子体光谱和质谱法分析贻贝标准物质   总被引:5,自引:0,他引:5  
采用电感耦合等离子体光谱和质谱法分析了贻贝标准物质,光谱法测定K、Na、Ca、Mg、P、Al、Fe、Zn、Mn和Sr,质谱法测定As、B、Cd、Co、Cr、CuGa、Ge、Mn、Mo、Ni、Pb、Se、Sr、U和V。在优化的工作条件下,测定了来自基体元素K、Na、Ca、P、Cl的C的多原子离子^39K^16O、^39K2、^40Ar^23Na、^43Ca^16O、^42Ca^16O、^31P^16  相似文献   

10.
导电高聚物聚2,5-二甲基苯胺的化学合成与特性   总被引:2,自引:0,他引:2  
报道了聚2,5-二甲基苯胺(PDMeAn)的化学合成,并用标准四探针方法测定其电导率,以FTIR、UV-Vis吸收光谱、元素分析和CV法对其性质进行了研究,PDMeAn的结构与聚苯胺和聚2,5-二甲氧基苯胺的结构类似,是由其单元通过氮原子(N)在对位上键合而成,本征态的PDMeAn能溶于多种有机溶剂,如CH2Cl2、CHCl3、DMSO、DMF等。  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

13.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

14.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.  相似文献   

15.
16.
《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.  相似文献   

17.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

18.
Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.  相似文献   

19.
A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.  相似文献   

20.
A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).  相似文献   

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