硫氰酸铵树脂相分光光度法同时测定天然水中微量铁和钴

研究了在Ｔｗｅｅｎ－８０存在的酸性介质中，Ｆｅ（Ⅲ）和Ｃｏ（Ⅱ）与ＳＣＮ＾－形成稳定的有色络阴离子与阴树脂交换吸附，有色络合物富集显色于树脂组上，进行树脂组分光光度集显色于树脂相上，进行树脂相分光光度法同时测定铁和钴的实验条件，Ｆｅ（Ⅲ）和Ｃｏ（Ⅱ）树脂具有色络合物最大吸收波长λｍａｘ分别为４９０ｎｍ和６３０ｎｍ，摩尔吸光系数，ε为２．４×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１和２．１×１０＾５Ｌ．     

乳酸亚铁中总铁的溶样及比色测定

本文研究在ＨＮＯ３－ＨＣｌ体系乳酸亚铁中的Ｆｅ＾２＋会被氧化成Ｆｅ＾３＋，用碘基水杨酸比色法就能准确测定总铁量，回收率在９８％－１００％，相对标准偏差为１．１４％，摩尔吸光系数为５．６×１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，含铁量在０－７００μｇ／１００ｍＬ范围内符合比耳定律。     

罗丹明6G.四溴荧光素双显色体系浮选光度法测定锗的研究

向锗与茜素氨羧络合剂罗丹明６Ｇ形成的Ｇｅ（ＡＷＬＣ３（Ｒ６Ｇ）５甲苯浮选物，加入０．１ｍｏｌ／Ｌ的ＮａＯＨ的溶液，使Ｒ６ＧＹ颜色相同的四溴荧光互，形成等色染料离子对Ｒ６Ｇ＾＋；ＴＢＦ＾－再被甲苯浮选。将浮先物溶于丙酮，于５３０处进行光度测定，由于１０个染料分子同时吸光，使本方法具有很高的灵敏度：ε＝５．８×１０＾５Ｌ．ｍｏｉｌ＾－１，ｃｍ＾－１，锗含量在０．００４０－０．１ｍｇ／Ｌ服从比耳定律。     

析相光度法测定铁(Ⅲ)的研究

本研究了铁（Ⅲ）－ＰＥＧ（聚乙二醇－２０００）－铬锖Ｒ－Ｎａ２ＳＯ４体系的上光度法并应用于测定Ｆｅ（Ⅲ）。最适酸并为４．５￣６．５（ＮａＡｃ－ＨＡｃ）缓冲溶液,其络合物的最大吸收位于５６０ｎｍ,表观摩尔吸光系数为５．３６×１０＾４Ｌ·ｍｏｌ＾－１·ｃｍ＾－１,Ｆｅ（Ⅲ）浓度在０￣４μｇ范围内服从比尔定律,铁与铬菁Ｒ形成组成为１：２的稳定络合物。该方法用于蔡叶中铁的测定,获得了满意的结果。     

铁酸盐的水热氧化晶化法制备及其生成条件研究

研究了空气氧化Ｍ＾２＋（Ｍ＝Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ）和Ｆｅ＾２＋的碱性悬浮液制备铁酸盐ＭＦｅ２Ｏ４的条件，考察了原料配比、ｐＨ值、氧化温度、氧化时间对生成ＭＦｅ２Ｏ４的影响。利用ＸＲＤ及ＳＥＭ检测氧化过程中沉淀物的形态和结构表明，在３４３￣３５８Ｋ和Ｒ＝２ＯＨ＾－／（Ｍ＾２＋Ｆｅ＾２＋）＝１．０、Ｍ＾２／Ｆｅ＾２＋＝０．５（摩尔比）下用３００ｍＬ／ｈ的空气氧化Ｍｘ／３Ｆｅ１－ｘ／３（ＯＨ）２悬浮液     

新显色剂8-喹啉偶氮槲皮素的合成及其与Fe(Ⅲ)显色反应的研究

本文研究了新显色试剂８－喹啉偶氮槲皮素的合成方法及其理化性质,显色性能和与Ｆｅ（Ⅲ）的显色反应条件,在ＴｗｅｅＮ－８０存在下,ＰＨ＝１０．３的ＮＨ３－ＮＨ４Ｃｌ缓冲介质中,Ｆｅ（Ⅲ）与８－ＱＡＱ的络合物在５００ｎｍ处有最大吸收,表观摩尔吸光系数为１．０６×１０＾５Ｌ·ｍｏｌ＾－１·ｃｍ＾－１,Ｆｅ（Ⅲ）含量在０－２．６μｇ／１０ｍＬ范围内符合比耳定律。在室温下,络合物至少稳定１５ｈ,络合比为１：３     

NH4Cl作助熔剂合成CaS：Ce的光谱特性及其浓度效应

以ＮＨ４Ｃｌ作助溶剂，碳还原硫酸钙的方法合成了ＣａＳ：Ｃｅ。在紫外光激发下，ＣａＳ：Ｃｅ中存在着Ｃｅ＾３＋的＾２Ｄ－＾２Ｆ５／２（５００ｎｍ）和＾２Ｄ－＾２Ｆ７／２（５５０ｎｍ）跃迁发射，但在蓝色光激发下，只有波峰为５３２ｎｍ半宽度为９２ｎｍ的宽带发射。当Ｃｅ＾３＋的浓度为０．０７５ｍｏｌ％时，＾２Ｄ－＾２Ｆ５／２跃迁发射强度与＾２Ｄ－＾２Ｆ７／２跃迁发射强度相等，而５３２ｎｍ发射猝灭。     

新型显色剂2-(H-酸偶氮)-4,5-二硝基苯酚测定铁(Ⅲ)

本文研究了新试剂２－（Ｈ－酸偶氮）－４,５－二硝基苯酚与铁的显色反应,在ＰＨ５．３的ＮａＡｃ－ＨＡｃ缓冲介质中,ＨＡＤＮＰ与Ｆｅ（Ⅲ）生成３：１稳定紫色配合物,λｍａｘ＝５９０ｎｍ,ε＝１．７０＊１０＾４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１,铁含量在０－１．０ｍｇ／Ｌ范围内符合比耳定律,该法用于自来水样中总铁的测定,结果令人满意。     

Co（1，10－phen·）_3~（2＋）－KIO_4－鲁米诺化学发光体系与应用

本文研究了Ｃｏ（１，１０－ｐｈｅｎ·）３（２＋）配合物对ＫＩＯ４氧化鲁米诺所产生的强化学发光反应．以１，１０－ｐｈｅｎ·为配位体时，Ｃｏ（Ⅱ）的检出限为８×１０（－８）ｇ／Ｌ，工作曲线响应浓度范围在１×１０（－６）～１×１０（－４）ｇ／Ｌ，测定１×１０（－４）ｇ／ＬＣｏ（Ⅱ）离子的相对标准偏差为２．５％．配合物化学发光法检测啤酒、维生素Ｂ（１２）针剂中微量Ｃｏ（Ⅱ）可获得满意结果．     

取代苯胺基亚胺二茂铁类化合物莫斯鲍尔谱及分子光谱研究

本文报道了６种取代苯胺基亚胺二茂铁类化合物Ｒ－Ｎ＝ＣＨ－Ｆｅ（－Ｆｅ为二茂铁基，Ｒ为－Ｃ６Ｈ４Ｘ，（Ｘ＝Ｈ，４－Ｂｒ，４－ＯＨ，２－ＣＨ３，４－ＣＯＯＨ）及４－ＮＨＣ６Ｈ４ＮＯ２）的Ｍｏｓｓｂａｕｅｒ谱数据，其化学位移分别为（ｍｍ．ｓ＾－１）：０．３２３，０．３３２，０．３３８，０．３２４，０．３１５和０．３１０。其四极矩分裂值分别为（ｍｍ．ｓ＾－１）：２．２６３，２．２８５，２．２８７，２．２１     

A comparison study of scratch and wear properties using atomic force microscopy

The patterning technique that uses an AFM (atomic force microscopy) tip as a scratch tool, also known as AFM scratching, has been a vital technique for nanofabrication because of its low cost and potential to reach a resolution into the sub-nanometer domain. The AFM scratching technique was first used to study the scratch characteristics of silicon, with an emphasis on establishing its scratchability or the nanoscale machinability. The effects of the scratch parameters, including the applied tip force and number of scratches, on the size of the scratched geometry were specifically evaluated. The primary property that measures the scratchability was identified and assessed. To illustrate its suitability and reliability, the value of the scratchability, based on the present Si scratching experiments, was compared with the values based on the data available in the literatures for different scratching conditions or for materials other than Si. Since AFM scratching is in some aspects similar to the nanoscale wear test, the scratchability property identified is also compared with two major wear resistance indicators, wear coefficient and hardness. All comparison results indicate that the scratchability property identified, the scratch ratio, is an appropriate manufacturability indicator for measuring the degree of the ease or difficulty of a material scratched by an AFM tip and more suitable than the wear coefficient and hardness to gauge the nanoscale AFM scratchability.     

Formation of nanotubes TiO2 from layered titanate particles by a soft chemical process

Nanotubes TiO₂ were synthesized from layered titanate Na₂Ti₃O₇ particles by a soft chemical process. These nanotubes have a hollow structure with an opening end. The wall of nanotubes is very well crystallized multi-wall structure. The inner diameters of nanotubes are ca. 30-40 nm and the length up to several hundreds nanometers. XRD results show that TiO₂ phase was formed during the procedure of exfoliating Na₂Ti₃O₇ particles into nanosheets. Based on our experimental results, an exfoliating-rolling model was proposed for formation of nanotube structure.     

Influence of borate content on the radiative properties of Nd ions in fluorophosphate glasses

Spectroscopic properties of Nd³⁺ in barium fluoroborophosphate glassy matrix have been analyzed by fitting the experimental data with the standard Judd-Ofelt theory. Various spectroscopic parameters viz. radiative transition probabilities, radiative decay time, fluorescence branching ratios, electric dipole line strengths, stimulated emission cross-sections and optical gain of the principal fluorescence transitions from the ⁴F_3/2 metastable level are obtained. Results show that addition of borate content to the fluorophosphate matrix will reduce the fluorescence spectral properties of Nd³⁺. However, the radiative properties of the present fluoroborophosphate glassy matrix are found to be well improved over that of pure borate and phosphate matrix and is attributed to the influence of fluorine content in the glassy matrix. The changes in the position and the Judd-Ofelt intensity parameters are correlated with the structural changes in the host glass matrix. The shift of the hypersensitive band shows that the covalency of the rare earth to oxygen bond increases with the increase of Na₂O content. This covalency effect and the formation of the BO₄ groups with the addition of Na₂O content are responsible for the increase in the radiative properties of the present system. Quantitative estimation of the non-radiative processes such as multiphonon relaxation and quenching by water content was carried out and the results show that both are below the critical level for optimum laser performance.     

Estimation of the cleavage force of crystalline semiconductors with diamond and zinc-blende structure

The cleavage force in several semiconductors with diamond and zinc-blende structure is studied within a simplified approach. It is shown that the cleavage in these systems is characterized by maximum forces from 0.45×10¹⁰ to 1.33×10¹⁰ N/m². For most of the crystals, the cleavage planes are in correspondence with the experimental data.     

Valence force field theory, elastic, acoustic and thermodynamic properties and a potential function of TeO2 glass

A short survey has been made on the extensive work that is being done on the pressure derivatives of the second order elastic constants (SOEC) to ascertain various properties of substances. Hence an attempt has been made to correlate the pressure derivatives to some properties of the substances. Thus some equations have been derived to correlate the Grüneisen parameter which is evaluated from Schofield's equations and Bhatia-Singh's (BS) parameters. They have been used to compute the longitudinal (γ_g^L) and transverse (γ_g^T) Grüneisen constants. γ_g^L calculated by different methods agree well with experiment. γ_g^T obtained from BS parameters gives rather higher value while Schofield's equations give results in agreement with experiment. The DeLaunay-Nath-Smith (DNS) equation has been used to derive a relation to compute γ_g^el (elastic). A method has been extended to calculate the third order elastic constants (TOEC) and it is found to give excellent values of TOECs in agreement with experiment. The absorption band position of TeO₂ has been predicted to occur at 276 cm⁻¹. The phonon dispersion curves have been calculated through BS equations for TeO₂. Several other properties of TeO₂ have been computed such as thermal Grüneisen parameter γ_g^th, its pressure derivatives (γ_g^th)′≡(dγ_g^th/dP), the pressure variation of bulk modulus C₁≡(dK_T/dP)_T and its pressure derivatives that is (dC₁/dP)_T which is in turn related to (γ_g^th)′, the heat capacity at constant volume C_V, and the second Grüneisen constant Q. In some cases we calculated these quantities by different methods and the agreement between them is good. Besides we evaluated δ_T^AG the Anderson Grüneisen parameter. Another important aspect of the present investigations is the formulation of the potential function (PF) of TeO₂ from which we calculated SOECs and these are found to be in excellent agreement with experiment. All other properties mentioned already have also been calculated through the use of the newly formulated PF and the calculated values obtained through various other equations are in good agreement with those obtained from PF. According to valence force field (VFF) all atomic forces can be resolved into bond bending β and bond stretching α forces. It is shown that TeO₂ does not satisfy Martins unity rule. Hence it is concluded that there is an effective dynamic charge on Te in TeO₂. Using the experimental elastic constants the bond bending force β and bond stretching force α and also their pressure derivatives have been evaluated. In addition the reststrauhlen optic frequency ω has been calculated. A self consistent check has been made by evaluating C₄₄ through the calculated values of α and β.     

A new semiconducting organic-inorganic nanocomposite, 1,5-diaminonphthalene-saponite intercalation compound

We synthesized a new intercalation compound, 1,5-diaminonaphathalene(DAN)-saponite where intercalated DAN molecules were shown to have a formal charge of +0.67 The measurement of optical diffuse reflectance spectra revealed the formation of electronic bands with a gap of ca. 1 eV suggesting semiconducting behaviour of this system. From ESR measurements, the radical formation in DAN-saponite was confirmed and the spin concentration was determined to be 1 spin per 200 and 300 DAN-molecules at 290 and 7.9 K, respectively. This temperature dependence of the spin density also implies the semiconductive nature of DAN-saponite.     

Role of effective mass in modulating linear and non-linear response properties of single carrier quantum dots: Interplay with system parameters

We explore the pattern of effective mass dependence of linear and non-linear optical (NLO) response of one electron quantum dots harmonically confined in two dimensions. For different combinations of transverse magnetic field strength (ω_c), harmonic confinement potential (ω₀), and anharmonic interaction, the influence of the effective mass (m^*) of the dot on linear (α), and the first (β), and second (γ) NLO responses of the system is computed through linear variational route. The investigation reveals a complicated interplay between the effective mass and the system parameters.     

Phosphorus-based nanothermites: A new generation of energetic materials

Thermites are energetic materials that are classically made of a transition metal oxide mixed with a reducing metal. Contrary to explosives, thermites do not detonate because their combustion is relatively slow and their reaction by-products are often solid or liquid. The use of nanoparticles to prepare superthermites is very promising. The dramatic changes observed in their reactivity were reported by numerous recent papers dealing with the use of aluminium as fuel.Red phosphorus is widely used in pyrotechnic devices. Highly explosive compositions are classically obtained by mixing this substance with strong oxidizers such as oxygenated potassium salts (chlorate, nitrate). But to our knowledge, the idea to prepare P-nanothermites with metallic oxide nanoparticles was never reported before. In order to illustrate this new concept of energetic formulations, P-nanothermites were prepared from nickel oxide (NiO), iron oxide (Fe₂O₃), and copper oxide (CuO) nanopowders. The reactivity of these compositions was studied by thermogravimetric analysis, impact and friction tests, electrostatic discharge and high-speed cinematography. P-nanothermites are very insensitive to thermal and impact stress. Their combustion rates strongly depend on the nature of the oxide (NiO <Fe₂O₃?CuO). The SEM observation of the microstructure of the residues produced by the combustion clearly indicates that they were formed by the solidification of molten phases. In other words, the energy released by the combustion of P-nanothermites provokes the melting of the reaction products. The temperatures reached are thus high enough to cause the gasification of phosphoric anhydride produced by the combustion. For this reason, P-nanothermites can be considered gas-generating materials.     

Spatially controlled dissolution of Ag nanoparticles in irradiated SiO2 sol-gel film

In this paper, we report the spatially controlled dissolution of silver nanoparticles in irradiated SiO₂ sol-gel films. The Ag nanoparticles have been formed in the sol-gel solution before the film deposition by adding Triton and ascorbic acid and also after the film deposition using a heat treatment at 700 °C for few minutes or at 550 °C for 6 h in reducing atmosphere. Using a spectrometer, a new view white light interferometer and a micro-thermal analyzer, we demonstrate that the silver nanoparticles can be dissolved using a continuous black ray UV lamp or with a near-infrared (NIR) femtosecond laser, due to a significantly increase in the local temperature. We confirm that the micro-thermal analyzer can be used as a new tool to study the dissolution of metallic nanoparticles in thin film if located at the surface of the films.     

Creeping instability in YBCO ceramics under non-isothermal superconducting transition

A high number of normal-superconductor transitions of sintered YBCO samples have been monitored by AC susceptibility measurements simultaneously in three different regions of samples, in the presence of strong thermal gradient. With this method, different accidental mesoscopic vortex structure instabilities have not only been observed but also located. Even if local magnetothermal instabilities of oscillatory nature (f=0.1–0.02 Hz) appear in strong thermal gradient fields, their evolution remains localized. However, when such instabilities appear in superposed temperature and electric (DC) potential gradient fields, they travel together with the mixed-state zone (v=0.06–0.1 mms⁻¹) along the macroscopic specimen. The interaction of transport currents with shielding current instabilities of the mixed-state — modifying some percolative network paths — can be considered as a possible macroscopic scenario for the traveling instabilities.