火焰原子吸收光谱测定花椒及椒皮、椒籽中铜、锌、铁、锰含量

用硝酸、高氯酸混合酸消解样品。原子吸收光谱法测定河南太行山区的花椒及椒皮、椒籽中铜、锌、铁、锰的含量。并对其结果进行了分析。结果显示：各元素在实验范围内。线性关系良好。回收率在92％-103％之间。花椒及椒皮、椒籽中均含有微量元素。花椒中铜、锌、铁、锰的含量分别为11．571、90．868、18．818、78．851μg·g^-1。其中铁、锰含量丰富。铜、锌、铁的分布量为椒籽〉椒皮;锰的分布量为椒皮〉椒籽。测定结果为探讨花椒的高药用价值提供了有力的证据,椒籽中铜、锌、铁含量高于椒皮,应该大力开发利用。     

原子吸收分光光度法测定利心丸中钙、镁、铁、锰、铜、锌的含量

本文采用原子吸收分光光度法测定利心丸中钙、镁、铁、锰、铜、锌六种元素的含量。结果表明,利心丸中含有较为丰富的钙、镁、铁、锰、铜、锌元素,宏量元素含量,钙＞镁,微量元素含量,铁＞锌＞锰＞铜,尤以铁的含量最为丰富。本实验结果为探讨中成药利心丸中钙、镁、铁、锰、铜、锌的含量与治疗心血管疾病的关系提供了有用的数据。     

速效胃宁冲剂中锌、铜、铁、锰和镍含量分析

用原子吸收法测定五批速效胃宁冲剂中锌、铜、铁、锰、镍的含量。结果表明,速效胃宁冲剂中铁含量较丰富,铜含量较少,其含量由大到小的顺序为：铁＞锌＞锰＞镍＞铜。探讨了速效胃宁冲剂中微量元素与疗效的关系。     

野生葛不同部位铜、锌、铁、钙、镁含量测定

用硝酸、高氯酸混合酸消解样品,采用原子吸收光谱法,测定了河南大别山区野生葛不同部位即葛根、葛藤、葛叶及花蕾中铜、锌、铁、钙、镁的含量,并对其结果进行了分析。结果显示：葛根、葛藤、葛叶及葛花中含有丰富的宏量元素钙、镁和有益的微量元素铜、锌、铁。铜的分布量依次为：叶〉花蕾〉葛藤〉葛根;锌的分布量依次为：叶〉花蕾〉葛藤〉葛根;铁的分布量依次为：葛根〉葛藤〉叶〉花蕾;钙的分布量依次为：叶〉葛根〉花蕾〉葛藤;镁的分布量依次为花蕾〉葛根〉叶〉葛藤。测定结果为探讨中草药中宏量、微量元素与治疗心脑血管疾病功效的关系提供了有用的数据;测定结果还显示：葛叶中铜、锌、钙含量居其他部位含量之首,适宜大力开发葛叶产品。     

藻类植物中钙、镁、铁、锰、铜和锌含量分析

本文采用火焰原子吸收光谱法测定了七种藻类植物中钙 ,镁 ,铁 ,锰 ,铜 ,锌六种元素的含量。结果表明 ,藻类植物中含有较丰富的钙 ,镁 ,铁 ,锰 ,锌元素 ,其含量由大到小顺序为Ca >Mg >Fe >Zn >Mn >Cu ,尤以钙的含量最为丰富 ,铜含量较少。本实验结果为探讨藻类植物作为资源开发利用提供了有用数据。     

原子吸收法测定椒目中不同化学形态的锌含量

结合椒目的市场前景与药效,采用原子吸收分光光度法,分析了不同产地椒目中的锌含量及其形态。使用0.45 μm滤膜、CHCL₃将椒目水煎液中的锌分为悬浮态和可溶态、有机态和无机态,建立了锌的四种形态分离分析方法;探讨了正辛醇-水分配体系模拟水煎液中锌在人体胃肠中的分配情况;并采用原子吸收分光光度法测定了椒目中的锌在不同溶剂中的化学形态和溶出特性。结果表明,椒目中的锌以水可煎出态为主,不同产地椒目锌含量不同,但水可煎出态总锌百分率、有机态总锌百分率基本接近。该方法回收率在97.5%～104.0%范围内,相对标准偏差均小于2.36%。应用于实际,结果表明其灵敏度高,重现性好。     

原子吸收光谱法测定牡丹皮中的微量金属元素铁、锌、铜和锰

采用原子吸收光谱法测定了牡丹皮中铁、锌、铜、锰4种微量元素的含量。结果表明,牡丹皮中含有较丰富的铁、锌、铜、锰元素。为牡丹皮药物的进一步研究和综合开发利用提供新的科学依据。     

非完全消解-火焰原子吸收光谱法测定虾皮中的铁、铜、锌和锰

用非完全消解法处理虾皮样品,即在低温下用浓硝酸-过氧化氢(3+1)混合酸消解样品,再用乳化剂OP溶解未消解的油脂而配制成无色透明的溶液,将此溶液用火焰原子吸收光谱法测定其中铁、铜、锌和锰元素的含量。建立了快速测定虾皮中微量元素的火焰原子吸收光谱法。对样品处理条件、混合酸中杂质及共存OP的干扰进行了实验,铁、铜、锌和锰的检出限(3S/k)分别为0.021、0.047、0.008、0.026m g.L-1。该法测定虾皮中铁、铜、锌和锰的含量,所得结果与灰化法测定结果一致。     

FAAS测定进口铜锍中的铜、铁、铅、锌、镉和锰

铜锍及含铜烧结物料经混合酸溶解后,在10％ HCl介质中,采用火焰原子吸收光谱法测定其铜、铁、铅、锌、镉、锰元素的含量.讨论了溶样条件、基体效应和共存元素干扰等影响因素,采用基体匹配校正了基体成分的光谱干扰.在选定的仪器最佳条件下对样品进行测试,共存元素之间没用明显的干扰,方法的检出限低,且简便快速、结果可靠,适用于大批量铜锍进出口检验.     

金诃脑血康胶囊中微量、宏量元素的测定分析

文章采用火焰原子吸收分光光度法测定了5批藏成药金诃脑血康胶囊中镉、铬、钴、铜、铁、镁、锰、镍、铅、锌等10种微量、宏量金属元素的含量,并对其结果进行了分析。结果表明,金诃脑血康胶囊中含有丰富的宏量元素Mg和有益的微量元素Cu,Zn,Fe,Mn,Ni等,有毒元素Pb,Cd含量较低,金属元素的含量高低顺序为：Fe＞Mg＞Zn＞Mn＞Cu＞Ni＞Cr＞Pb＞Co＞Cd。测定结果为探讨藏成药中微量、宏量元素与治疗心脑血管疾病功效的关系提供了有用的数据。     

Solution absorption and luminescence studies of tetraphenylboron, -carbon, -silicon, -germanium, -tin, -lead, -phosphorus, -arsenic,and -antimony

The lowest absorption band of the tetraphenyl compounds resembles that of the lowest absorption band of benzene with the following difference. In benzene the electronic origin is strictly forbidden, and all intensity is associated with a symmetric progression built on one mode of asymmetric vibration. In the tetraphenyl compounds the intensity associated with the asymmetric vibration is relatively unaffected; however, there is increasing intensity associated with the electronic origin and a symmetric progression built on it along the series

$\text{φ}{}_4\text{Pb}\text{< φ}{}_4\text{Sn}\text{< φ}{}_4\text{Ge}\text{< φ}{}_4\text{Si}\text{< φ}{}_4\text{C}\text{? φ}{}_4\text{B}{}^{\mathrm{?}}\text{< φ}{}_4\text{Sb}{}^{\mathrm{+}}\text{< φ}{}_4\text{As}{}^{\mathrm{+}}\text{< φ}{}_4\text{P}{}^{\mathrm{+}}$

. For the cations it is the electronic origin and the progression built on it that are the primary source of intensity. This effect is attributed to an inductive perturbation. A similar effect is observed in the fluorescence spectrum. In phosphorescence, the relative enhancement of the electronic origin and the progression built on it is far less marked. The phosphorescence emission of φ₄Pb and φ₄Sb⁺ are red shifted from the others by ～0.5 eV, an effect attributed to formation of a triplet excimer. Increasing spin-orbit coupling in the triplet due to a heavy atom effect can be seen in the decreasing phosphorescence lifetime (range 4 sec to 4 msec) and decreasing ratio of $\text{φ}{}_{\mathrm{f}}\text{φ}{}_{\mathrm{p}}$ (fluorescence to phosphorescence quantum yields) in the order

$\text{φ}{}_4\text{C}\text{> φ}{}_4\text{B}\text{> φ}{}_4\text{Si}\text{> φ}{}_4\text{P}{}^{\mathrm{+}}\text{> φ}{}_4\text{Ge}\text{> φ}{}_4\text{As}{}^{\mathrm{+}}\text{> φ}{}_4\text{Sn}$

In all cases nonexponential decay of phosphorescence is observed.     

Mesomorphic, dielectric, and optical properties of fluorosubstituted biphenyls, terphenyls, and quaterphenyls

Compounds with moderate and large negative dielectric anisotropy (Δɛ) are very attractive liquid crystal (LC) for vertical alignment mode (VA). Materials with such properties can be achieved by lateral substitution of a polar group into a mesogenic molecule. We synthesized some new LC materials with a negative value of Δɛ, a moderately high birefringence (Δn), and a low viscosity. The mesomorphic and physical behaviour of the novel biphenyls, terphenyls and quaterphenyls fluorosubstituted in the rigid core and also with fluorinated alkyl and alkoxy chains are investigated. The prepared series of four LC compounds are promising for new LC mixtures for various applications. Examples of nematic mixtures with Δɛ∼−3.25 will be presented.     

Structural, energetic, and electronic properties of Sin, Gen, and SinGen clusters

Results of a theoretical study of the properties of Si_n, Ge_n, and Si_nGe_n clusters are presented. An approximate density-functional method in combination with genetic algorithms have been used in an unbiased determination of the structures of the lowest total energy. The resulting structural, energetic, and electronic properties are analysed and compared with each other for the different systems.     

Intrinsic and Zn-, Ce-, Tb-, Er-, Sm-, and Eu-Activated photoluminescence of pseudoamorphous GaN and InGaN thin films

Thin films of pseudoamorphous GaN (a-nc-GaN), as well as of its alloys with indium, In_xGa_1−x N (x=0.04, 0.16), were prepared by magnetron sputtering of a metallic target in the plasma of a reactive nitrogen and argon mixture. The a-nc-GaN films were codoped by the Zn acceptor impurity and a set of rare-earth metal (REM) dopants, namely, Ce, Tb, Er, Sm, and Eu. Photoluminescence (PL) spectra excited by a nitrogen laser with wavelength λ=337 nm at room temperature and 77 K were measured for all compositions and a set of impurities. It was shown that the high-energy PL edge of the pseudoamorphous (a-nc) GaN matrix lies at the same energy as that of the crystalline (epitaxial) c-GaN. As in c-GaN, the Zn acceptor impurity stimulates blue luminescence; however, the PL spectrum is substantially more diffuse, with practically no temperature quenching of the PL present. Indium doping in an amount of 16 at. % results in strong PL with a diffuse peak at 2.1–2.2 eV; the PL of the alloy exhibits temperature quenching as high as a factor of three to four in the interval 77–300 K. The decay time of the PL response increases up to 50 μs. RE impurities enter the amorphous GaN host as trivalent ions and produce narrow-band (except Ce) high-intensity spectra, thus indicating both a high solubility of RE impurities in a-nc-GaN and the generation of an effective crystal field (by the GaN anion sublattice) whose local symmetry makes the intracenter f-f transitions partly allowed. __________ Translated from Fizika Tverdogo Tela, Vol. 45, No. 3, 2003, pp. 395–402. Original Russian Text Copyright ? 2003 by Andreev.     

Cointegration of output, capital, labor, and energy

Cointegration analysis is applied to the linear combinations of the time series of (the logarithms of) output, capital, labor, and energy for Germany, Japan, and the USA since 1960. The computed cointegration vectors represent the output elasticities of the aggregate energy-dependent Cobb-Douglas function. The output elasticities give the economic weights of the production factors capital, labor, and energy. We find that they are for labor much smaller and for energy much larger than the cost shares of these factors. In standard economic theory output elasticities equal cost shares. Our heterodox findings support results obtained with LINEX production functions.     

Fabrication,Microstructure, and Properties of Nanoporous Pd,Ni, and Their Alloys by Dealloying

Nanoporous metals can be fabricated by dealloying, which is one of the reactions that occur during the corrosion of alloys. Nanoporous gold has been widely investigated for several decades, and it has recently been found that other metals, such as platinum, palladium, nickel, and copper, can form nanoporous structures through the dealloying of binary alloys. This article mainly shows fabrication and properties of nanoporous palladium and nickel after introduction of nanoporous metals by referring to nanoporous gold as an example. It is necessary to select binary alloys with suitable elements, in which the dissolution of the less noble element and the aggregation of the nobler element at the solid/electrolyte interface are simultaneously allowed. Postprocessing by thermal or acid treatment alters the nanoporous structure. Various properties of nanoporous metals (including mechanical, catalytic, piezoelectric, hydrogenation, and magnetic ones) are different from those of bulk and nanocrystalline materials and nanoparticles because of their specific three-dimensional network structures consisting of nanosized pores and ligaments. Hydrogenation and magnetic properties are reviewed in terms of lattice strain at curved surfaces. These new metallic nanomaterials are now being investigated from the viewpoint of functional applications, and provide much room for study in various fields.     

Sonochemical synthesis of carbon dots,mechanism, effect of parameters,and catalytic,energy, biomedical and tissue engineering applications

Carbon-based nanomaterials are gaining more and more interest because of their wide range of applications. Carbon dots (CDs) have shown exclusive interest due to unique and novel physicochemical, optical, electrical, and biological properties. Since their discovery, CDs became a promising material for wide range of research applications from energy to biomedical and tissue engineering applications. At same time several new methods have been developed for the synthesis of CDs. Compared to many of these methods, the sonochemical preparation is a green method with advantages such as facile, mild experimental conditions, green energy sources, and feasibility to formulate CDs and doped CDs with controlled physicochemical properties and lower toxicity. In the last five years, the sonochemically synthesized CDs were extensively studied in a wide range of applications. In this review, we discussed the sonochemical assisted synthesis of CDs, doped CDs and their nanocomposites. In addition to the synthetic route, we will discuss the effect of various experimental parameters on the physicochemical properties of CDs; and their applications in different research areas such as bioimaging, drug delivery, catalysis, antibacterial, polymerization, neural tissue engineering, dye absorption, ointments, electronic devices, lithium ion batteries, and supercapacitors. This review concludes with further research directions to be explored for the applications of sonochemical synthesized CDs.     

Density functional theory study of structural,electronic,and thermal properties of Pt,Pd, Rh,Ir, Os and PtPdX(X= Ir,Os, and Rh) alloys

The structural, electronic, mechanical, and thermal properties of Pt, Pd, Rh, Ir, Os metals and their alloys Pt Pd X(X= Ir, Os and Rh) are studied systematically using ab initio density functional theory. The groundstate properties such as lattice constant and bulk modulus are calculated to find the equilibrium atomic position for stable alloys. The electronic band structure and density of states are calculated to study the electronic behavior of metals on making their alloys. The electronic properties substantiate the metallic behavior for all studied materials. The firstprinciples density functional perturbation theory as implemented in quasi-harmonic approximation is used for the calculations of thermal properties.We have calculated the thermal properties such as the Debye temperature, vibrational energy, entropy and constant-volume specific heat. The calculated properties are compared with the previously reported experimental and theoretical data for metals and are found to be in good agreement. Calculated results for alloys could not be compared because there is no data available in the literature with such alloy composition.