X射线荧光光谱法测定花草茶中22种元素

采用粉末压片法制样,应用X射线荧光光谱法对花草茶中N,Na,Mg,Al,Si,P,S,Cl,K,Ca,Ti,Cr,Mn,Fe,Ni,Cu,Zn,Br,Rb,Sr,Ba,Pb共22种元素进行了分析。讨论了测量条件的选择,对于22种目标元素的分析线,除Ba,Pb采用L线外,其余都选择K_α线,在对Rh靶K_α线的康普顿散射进行测量时,应适当降低管电压,选择合适的管电流。采用经验系数法和3条散射谱线(Rh靶L_α线的瑞利散射、0.1876nm处的散射线、Rh靶K_α线的康普顿散射)作内标进行基体效应校正,并对N,Na,Ca,Ti,Mn,Sr,Ba等部分元素进行了谱线重叠干扰校正。实验结果表明,该方法对N,Na,Mg,Al,Si,P,S,Cl,K,Ca,Ti,Cr,Mn,Fe,Ni,Cu,Zn,Br,Rb,Sr,Ba,Pb各目标元素的检出限较低,且准确度较好,精密度较高。采用该方法对花草茶中元素的种类和含量信息进行分析发现,花草茶元素组成较为丰富,不同种类花草茶元素种类和含量有差异,且同一种类不同来源花草茶略有差异,但元素组成含量特征大体相似。综上可知,该方法操作简单,能够实现花草茶的低成本、快速、准确、多元素测定。     

偏振能量色散X射线荧光光谱法在土壤环境监测中的应用

以土壤和水系沉积物标准物质为校准样品,采用粉末样品压片制样.建立了偏振能量色散X射线荧光光谱仪测定土壤中As、Ba、Cu、Co、Cd、Cr、Mo、Mn、Ni、Pb、Sr、Ti、V、Zn、Rb、Sc、Bi、Si、Al、Fe、Ca、Mg、Na、K 24种元素的方法.该方法采用Al、CaF2、Fe、Zn、KBr、Al2O3、...     

X射线荧光光谱法快速分析盐湖粘土矿物元素含量

以低压聚乙烯粉镶边垫底粉末压片法制样,用X射线荧光光谱法测定盐湖粘土矿物中主次组分含量的定量分析曲线,测量了粘土矿物中As, Mn, Co, Cu, Cr, Dy, Ga, Mo, P, Pb, Rb, S, Sr, Ba, Cs, Ta, Th, Ti, U, V, Y, Zn, Zr, MgO, K₂O, Na₂O , CaO, Fe₂O₃, Al₂O₃, SiO₂含量。研究了各元素的谱线干扰特别是谱线的间接干扰,同时提出了元素周期表中各周期元素相互之间干扰的判别方法; 使用α经验系数法及康普顿内标法校正基体效应,经对国家标准物及实际样品进行分析,测量值与标准值结果吻合。方法的检出限和准确度均满足分析要求,除了Mo,Cs,Ta ３个元素RSD较高,其他元素RSD 为0.01%～5.45%。     

ICP-AES测定钾混盐中的钾、钠、钙、镁和硫酸根

用蒸馏水溶解盐湖钾混盐矿,电感耦合等离子体原子发射光谱法同时测定K＋、Na＋、Ca2＋、Mg2＋、SO42-.方法检出限：K＋2.4mg/L Na＋ 4.8mg/L、Ca2＋2.4mg/L、Mg2＋2.4mg/L、SO42-7.2mg/L.方法精密度（RSD,n=10）：K＋ 1.23％、Na＋0.87％、Ca2＋ 3.15％、Mg2＋3.02％、SO42-2.28％.加标回收率：K＋101.8％、Na＋ 103.2％、Ca2＋ 98.20％、Mg2＋ 104.8％、SO42-96.80％.     

微波消解ICP-AES法测定牛黄解毒片中的微量元素

采用HNO₃-H₂O₂消解体系对牛黄解毒片样品进行微波消解制样,利用ICP-AES法同时测定了牛黄解毒片中As,Ca,Mg,Al,Mn,Sr,Ba,Se,Ni,Cd,Cu,Zn,Mo和Pb等14种微量元素的含量,对样品的前处理条件进行了探讨,通过添加标准回收实验,验证了分析数据的可靠性。结果表明, 该方法快速、简便、数据准确可靠, 结果令人满意, 适合常规分析。     

ICP-AES测定蒙成药阿嘎日-17中的微量元素

硝酸加盐酸消解样品,用电感耦合等离子体-原子发射光谱法(ICP-AES)在选定的最佳条件下,对传统蒙药阿嘎日-17中Mn、Fe、Ca,Al、Mg、Zn、Ba、Sr等8种微量元素进行了同时测定,该方法采用一次溶样,多元素同时测定,回收率为93.4%-106.4%,RSD小于3.1%.测定灌木枝叶标准物质GBW070602,结果与标准值基本一致.该方法简便、快速、准确.适用于蒙药样品的测定,结果令人满意.     

X射线荧光分析钒钛铁矿中主次量元素

四硼酸锂为熔剂 ,硝酸锂为氧化剂防止硫元素挥发损失 ,溴化锂作脱模剂 ,玻璃熔片法制备样品。干扰曲线法结合理论α系数法对谱线重叠干扰和基体效应进行校正 ,建立了 XRF测定钒钛铁矿中 Mg,Al,Si,P,S,Ca,Ti,V,Mn,TFe等主次量元素的分析方法。该方法经标准样品验证 ,与推荐值符合较好。 10次制样测量各组分 RSD在 0 .2 7%— 5 .2 4 %范围内     

薰衣草花穗中几种金属元素含量分析

采用HNO3-H2O2消解体系对薰衣草花穗进行程序升温微波消解制样,应用火焰原子吸收光谱法测定了薰衣草花穗中的金属元素Ca、K、Mn、Zn、Mg、Fe、Cu、Na、Sr等的含量.对样品前处理方法、酸度、共存元素干扰及元素线性范围进行了实验条件的筛选,在选定的最佳实验条件下,确定了合适的样品微波消解体系并做了消解结果的准确度和精密度实验,该方法的加标回收率为90.0％-104.0％,相对标准偏差RSD≤2.37％.实验结果表明新疆薰衣草花穗中富含Ca、Mg、K、Na等对人体有益的金属元素,而Sr、Cu的含量较低.     

Tb3+离子在碱土金属正硅酸盐中的发光

Tb3+离子激活的Me2SiO4(Me=Ca、Sr、Ba)发光材料是用分析纯试剂合成并加以提纯的BaCO3、SrCO3、CaCO3、H2SiO3、Li2CO3和Tb2(C2O4)3为原料,通过固态反应的合成方法而制成的。由X-光衔射谱,确定了样品的结构。通过荧光测量,探讨了Tb3+离子在碱土金属正硅酸盐中的发光行为。     

红色长余辉材料Y_2O_2S:Eu,Si,M(M=Mg,Ca,Sr,Ba)的制备及发光性能

采用高温固相法合成了红色长余辉材料Y2O2S:Eu,Si,M(M=Mg,Ca,Sr,Ba),利用X晶体衍射、发光光谱、热释光测量等对材料的性能进行了表征。结果分析表明:Y2O2S:Eu,Si,M(M=Mg,Ca,Sr,Ba)长余辉材料的最大荧光发射和余辉发射峰完全一致都位于627nm,产生红光发射,是典型的Eu3+离子的5D0-7F2跃迁。激发停止后,能够产生较好的余辉性能。碱土金属离子能够增强其荧光发射峰强度并对余辉性能有一定促进作用,其中以Mg2+最好,其次是Ba2+。     

Fabrication of barium/strontium carbonate coated amorphous carbon nanotubes as an improved field emitter

Amorphous carbon nanotubes (aCNTs) were synthesized by a chemical reaction between ferrocene and ammonium chloride at a temperature ～250 ^°C in an air furnace. As-synthesized aCNTs were coated with the barium/strontium carbonate through a simple chemical process. The coating of barium/strontium carbonate was confirmed by a high resolution transmission electron microscopy, X-ray diffraction, and Fourier transformed infrared spectroscopy. Morphology of the as-prepared samples was studied by field emission scanning electron microscopy. Thermal gravimetric analysis showed that barium/strontium carbonate coated aCNTs are more stable than the pristine aCNTs. As-prepared barium/strontium carbonate coated aCNTs showed significantly improved field emission properties with a turn-on field as low as 2.5 V/μm. The variation of field emission characteristics of the barium/strontium carbonate coated aCNTs with interelectrode distances was also studied.     

原子吸收光谱法测定天青石中高含量锶

碳酸钠半熔分离硫酸根 ,原子吸收光谱法测定天青石中高含量锶 ,方法简便、快速、易于掌握 ,能满足常规分析要求     

Effect of strontium ranelate on bone mineral: Analysis of nanoscale compositional changes

Strontium ranelate has been used to prevent bone loss and stimulate bone regeneration. Although strontium may integrate into the bone crystal lattice, the chemical and structural modifications of the bone when strontium interacts with the mineral phase are not completely understood. The objective of this study was to evaluate apatite from the mandibles of rats treated with strontium ranelate in the drinking water and compare its characteristics with those from untreated rats and synthetic apatites with and without strontium. Electron energy loss near edge structures from phosphorus, carbon, calcium and strontium were obtained by electron energy loss spectroscopy in a transmission electron microscope. The strontium signal was detected in the biological and synthetic samples containing strontium. The relative quantification of carbon by analyzing the C_K edge at an energy loss of ΔE = 284 eV showed an increase in the number of carbonate groups in the bone mineral of treated rats. A synthetic strontium-containing sample used as control did not exhibit a carbon signal. This study showed physicochemical modifications in the bone mineral at the nanoscale caused by the systemic administration of strontium ranelate.     

ICP-AES测定工业碳酸锶中的钙、钡、钠和磷

试料经酸分解后,于王水介质中同时测定碳酸锶中的钙、钡、钠和磷的含量,操作简便、快速,最终结果与现行国家标准分析方法测得结果一致。     

Fabrication of quantum semiconductor structures by high energy electron beam lithography of an inorganic epitaxial resist on GaAs

Epitaxially grown calcium strontium fluoride on gallium arsenide has been patterned by high energy electron beam lithography and wet development. Fabrication of lines and dots of 8nm size is reported. Electron diffraction experiments indicate that fluorine is removed under electron bombardment with the formation of a calcium and strontium oxide. The end product of the radiolysis can be selectively etched in an acetic acid solution. A dose requirement of around 2×10⁴C/cm² was necessary to form these features but a large dose latitude was observed. Possible applications of this epitaxial inorganic resist for the fabrication of quantum semiconductor structures are discussed.     

Effect of small additives on the combustion of composite solid propellants

The efficiency of controlling the burning rate law of composite systems with small additives of combustion catalysts and inhibitors was experimentally studied. The combustion catalysts were colloidal and bis(dicarbollylic) complexes of transition metals and liquid ferrocene plasticizer, whereas strontium carbonate and lithium fluoride served as combustion inhibitor. Information on the regularities of action of each of the additives tested and of catalyst-inhibitor binary additives on the ballistic characteristics of composite solid propellants were obtained.     

Metallo-organic decomposition derived (Ca, Sr)ZrO3 dielectric thin films on Pt coated Si substrate

Metallo-organic decomposition derived dielectric thin films of calcium zirconate doped with various concentrations of strontium ((Ca, Sr)ZrO₃) were prepared on Pt coated silicon substrate. Mainly in this paper, we present the investigations of their structural developments and present their electric and dielectric properties as well. The structural developments show that the CaZrO₃ film has amorphous structure with carbonate existing when annealed at 600 °C, while annealed at 650 °C and above, the carbonate is decomposed and those films crystallize into perovskite phase without preferred orientation. In addition, the prepared (Ca, Sr)ZrO₃ films with their Zr-O bonds affected by strontium doping are homogenous and stable as solid solutions in any concentration of strontium and all Bragg diffraction characteristics for the films shift downward with the increase in the concentration of strontium. Moreover, the electric properties show that the (Ca, Sr)ZrO₃ films have very low leakage current density and high breakdown strength; typically, the CaZrO₃ film annealed at 650 °C has the leakage current density approximately 9.5 × 10⁻⁸ A cm⁻² in the field strength of 2.6 MV cm⁻¹. Furthermore, the dielectric properties show that their dielectric constants are higher than 12.8 with very little dispersion in the frequency range from 100 Hz to 1 MHz and are independent of applied dc bias as well. The dielectric properties, in combination with the electric properties, make the materials promising candidates for high-voltage and high-reliability capacitor applications.     

四氧化三钴粉末的沉淀法制备及表征

以硝酸钴为钴源,碳酸铵为沉淀剂,采用沉淀法制备四氧化三钴粉体。采用TG、XRD、IR、激光粒度分析仪等对前驱体碱式碳酸钴和产物四氧化三钴进行了表征及分析。研究了焙烧温度、反应物浓度和反应时间等因素对产物的影响。     

Mechanochemically assisted synthesis of La0.7Sr0.3MnO3 nanoparticles and induction heating properties of the composites with hydroxyapatite

Perovskite lanthanum strontium manganese oxide (LSMO, strontium-substituted lanthanum manganite) La_0.7Sr_0.3MnO₃ nanoparticles were synthesized via the low-temperature calcination of the precursor, which was prepared using a mechanochemical route. A powder mixture of lanthanum chloride, strontium chloride, manganese chloride and sodium carbonate was high-energy milled by a planetary ball mill under semiwet (moist) conditions to obtain the precursor. To study the mechanochemical effects on the formation of LSMO, a thermogravimetric (TG) analysis was conducted for the precursors prepared under various conditions; the precursors and the intermediates formed during calcination were identified by X-ray diffraction (XRD). The calcination of the milled precursor at 600 °C resulted in the formation of LSMO nanoparticles with good induction heating properties. The LSMO/hydroxyapatite composites exhibited rapid temperature increases in an AC magnetic field. The obtained results demonstrate that the LSMO nanoparticles and LSMO/hydroxyapatite composites are promising candidates for magnetic hyperthermia treatments.     

Synthesis of dinitrochalcones by using ultrasonic irradiation in the presence of potassium carbonate

The synthesis of dinitrochalcones was studied by using ultrasonic irradiation in the presence of potassium carbonate as a catalyst, which provided a conventional procedure with the advantages of a short reaction period and as high as 90% product yield.