关于高速动车组齿轮箱磨损光谱铁元素监测标准的优化方法研究

基于经典摩擦理论,提出了动车组齿轮箱微颗粒磨损量变化趋势,结合随机过程的磨损分析了动车组齿轮箱在用润滑油光谱Fe含量数据的分布规律,提出基于光谱Fe含量监测的趋势建模方法。引入可靠性理论研究了动车组齿轮箱磨损油液光谱铁元素监测标准,并以某型动车组齿轮箱在用油监测为案例建立模型,并通过动车组实际运行过程中的在用油实测数据和拆解分析验证了所建立的模型。

电感耦合等离子体发射光谱法测定硅铁中多元素影响因素的探讨

本文通过对样品分解条件、光谱仪工作参数、基体和共存元素干扰等影响因素的探讨，确定了采用电感耦合等离子体发射光谱法（ICP—OES）快速检测硅铁中多元素的分析方法。试验中标准样品的加标回收率在96％～108％之间，结果令人满意；通过对部分国家标准样品和实际生产试样进行分析，结果与认定值和化学法测定值基本一致，相对标准偏差在0．61％～4．30％（n=11）之间，说明改进后的方法具有较好的精密度和准确度。

关于氢原子光谱实验中杂谱的初探

用光谱分析法对氢原子光谱实验中所用的“纯铁棒”进行定性和定量分析 ,以期解释铁光谱中的杂谱的成因和解决杂谱问题 .

红外吸收与ICP-AES联合测定含铁尘灰多组分

研究了除尘灰中多个组分的分析方法，采用红外法测定含铁尘灰中碳、硫含量，ICP—AES光谱法测定ZnO、TFe、Si02、A1203、CaO、K20、Na20,MgO、Pb，方法快速、准确。

利用标记谱分区摄谱方法研究

利用汞光谱简单而又分布于整个可见光区的特点,作为标记谱,辅助标准铁光谱,先按顺序分区再识谱(读谱)。该方法使得应用棱镜摄谱仪进行摄谱、读谱变得简单、准确,大大节省了时间,实验设备同时也简化。

Investigation of Residual Donor Defects in Undopedan d Fe-Doped LEC InP

The free electron concentration of as-grown liquid encapsulated Czochralski (LE C) InP measured by Hall effect is much higher than the concentration of net dono r impurity determined by glow discharge mass spectroscopy.Evidence of the existe nce of a native donor hydrogen-indium vacancy complex in LEC undoped and Fe-do ped InP materials can be obseved with infrared absorption spectra.The concentra tion increase of the donor complex correlates with the increase of ionized deep acceptor iron impurity Fe concentration in Fe-doped semi-insulating (S I) InP.These results indicate that the hydrogen-indium vacancy complex is an im portant donor defect in as-grown LEC InP,and that it has significant influence on the compensation in Fe-doped SI InP

TBM施工中的油液监测

介绍了油液状态监测在TBM施工中的应用,包括监测方法、数据处理与设备状态预测。特别是提出了基于统计学原理的油液光谱与铁谱处理分析标准。对保障设备状态、实现按需维修和预防性维修具有重要意义。

Fe-Mn/Al_2O_3 catalysts for low temperature selective catalytic reduction of NO with NH_3

A series of Fe‐Mn/Al2O3 catalysts were prepared and studied for low temperature selective catalytic reduction （SCR） of NO with NH3 in a fixed‐bed reactor. The effects of Fe and Mn on NO conversion and the deactivation of the catalysts were studied. N2 adsorption‐desorption, X‐ray diffraction, transmission electron microscopy, energy dispersive spectroscopy, H2 temperature‐programmed reduction, NH3 temperature‐programmed desorption, X‐ray photoelectron spectroscopy （XPS）, thermal gravimetric analysis and Fourier transform infrared spectroscopy were used to character‐ize the catalysts. The 8Fe‐8Mn/Al2O3 catalyst gave 99%of NO conversion at 150？？ and more than 92.6%NO conversion was obtained in a wide low temperature range of 90–210？？. XPS analysis demonstrated that the Fe3＋was the main iron valence state on the catalyst surface and the addition of Mn increased the accumulation of Fe on the surface. The higher specific surface area, enhanced dispersion of amorphous Fe and Mn, improved reduction properties and surface acidity, lower binding energy, higher Mn4＋/Mn3＋ratio and more adsorbed oxygen species resulted in higher NO conversion for the 8Fe‐8Mn/Al2O3 catalyst. In addition, the SCR activity of the 8Fe‐8Mn/Al2O3 cata‐lyst was only slightly decreased in the presence of H2O and SO2, which indicated that the catalyst had better tolerance to H2O and SO2. The reaction temperature was crucial for the SO2 resistance of catalyst and the decrease of catalytic activity caused by SO2 was mainly due to the sulfate salts formed on the catalyst.

A Kinetic Spectrophotometric Method for the Determination of Iron (Ⅲ) in Water Samples

A new kinetic spectrophotometric method has been developed for the determination of iron （Ⅲ）. The method is based on the catalytic effect of iron （Ⅲ） on the oxidation of weak acid brilliant blue dye （RAWL） by KIO4 in acid medium. The advantages of the proposed method are that it is sensitive, accurate, rapid, inexpensive, can be operated under room temperature and has a large determination concentration range compared to other techniques. The obtained optimum conditions are： pH 3.15, RAWL （200 mgL^-1） 5.00mL, Potassium periodate solution （0.01 molL^-1） 0.30mL, phenanthroline （0.02 molL^-1） 1.00mL, reaction temperature 25℃ and reaction time 7 min. With this method iron could quantitively be determined in the range 0.00-0.02 mgL^-1, the detection limit being 4.10 × 10^10gmL^-1. The relative standard deviations （RSD） in five replicate determinations for 3 μgL^-1and 5 μgL^-1 iron （Ⅲ） are 3.1% and 1.9%, respectively. The method has been applied to the determination of iron （Ⅲ） in tap water samples and seawater samples （from the South China Sea）, the recovery rates being 98.0% and 100.5%, respectively.

Germanium separation and purification by leaching and precipitation

In this research work, extraction and purification of germanium from zinc leach residues(ZLR) were investigated. The results of ICP, XRF, and atomic adsorption spectroscopy(AAS) tests show that contents of germanium, iron, lead, and zinc within the leaching residue were 105×10^(-6), 3.53%, 10.35%, and 8.8%, respectively. XRD results indicate that the main minerals were in different forms of sulfates(CaSO_4·2H_2O, PbSO_4 and ZnSO_4·6H__2O), silicate(SiO_2), and oxide(Fe_2O_3). Dissolution of leaching filter cake was carried out using 5 parameters and each in 4 levels(acid concentration, temperature, time, liquid-to-solid ratio, and stirring speed) by Taguchi method(L_(16)), and then optimization of the effective parameters by response surface method. Under optimum conditions, zinc and germanium dissolution efficiencies were 88.71% and 8%, respectively. Leaching tests with sulfuric acid(added di-ammonium oxalate monohydrate) and hydrochloric acid(HCl) on the residues obtained from previous-stage sulfuric acid dissolution, yielded germanium and iron recoveries of 83%, 88%, 40%, and 90%, respectively. Thus, leaching experiment with sulfuric acid(added di-ammonium oxalate monohydrate) was superior to that with hydrochloric acid due to high and low extraction amounts of germanium and iron, respectively. Precipitation experiments revealed that germanium purification with tannic acid presented a better result compared to sodium hydroxide and ammonia. Under optimum conditions, contents of germanium and iron in the solution after precipitation were 0.1505% and 14.7% with precipitation yields of 91% and 52%, respectively.

Determination of trace impurity elements in MnZn ferrite powder by direct current glow discharge mass spectrometry

An analytical method for the determination of 26 impurity elements （such as Li, Be, Na, Mg, Al, Si, P, S, K, Ca, Sc, Ti, V, Cr, Co, Ni, Ga, Ge, Y, Nb, Mo, Ag, Cd, Sb, W and Pb） in MnZn ferrite powder by direct current glow discharge mass spectrometry （GD-MS） was established. MnZn ferrite powder was mixed with copper powder, used as a conductor, and pressed. The effects of MnZn ferrite powder preparation conditions and glow discharge parameters for the sensitivity and stability of signal analysis were investigated. By determining the choice of isotope and the application of the mass resolutions of 4000 （MR, medium resolution） and 10000 （HR, high resolution）, mass spectral interference was eliminated. The contents of impurity elements in MnZn ferrite powder was calculated by subtraction after normalizing the total signal of Mn, Zn, Fe, O and Cu. The results showed that the detection limit of 26 kinds of impurity elements was between 0.002 and 0.57 μg/g, and the relative standard deviation （RSD） was between 3.33% and 32.35%. The accuracy of this method was verified by the ICP-MS. The method was simple and practical, which is applied to the determination of impurity elements in MnZn ferrite powder.

Mechanism and kinetics of iron extraction from high silica boehmite−kaolinite bauxite by hydrochloric acid leaching

The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine(Arkhangelsk region,Russia)were studied by XRD,ICP-OES,TG/DSC,SEM,TEM,and Mössbauer spectroscopy.The iron-containing minerals of the bauxites were found to comprise alumogoethite(α-Fe_(1−x)Al_(x)OOH),alumohematite(α-(Fe_(1−x)Al_(x))_(2)O_(3)),alumoakaganeite(β-Fe_(1−x)Al_(x)O(OH,Cl)),and chromite(FeCr_(2)O_(4)).The efficiency of Fe extraction from the bauxite by HCl leaching was 82.5%at 100℃,HCl concentration of 10%,solid/liquid ratio of 1:10,and the process duration of 60 min,with aluminum loss from the bauxites below 4.5%of the total Al contents in the bauxite.Analysis of the kinetics of the iron leaching process proved diffusion to be the limiting stage of the process at 90−100℃.Bauxite residue after leaching presented traces of α-Fe_(1−x)Al_(x)OOH and β-Fe_(1−x)Al_(x)O(OH,Cl),and most of the iron content was in the FeCr_(2)O_(4).In bauxite residue after HCl leaching,in addition to iron oxide,the contents of chromium and calcium oxides significantly decreased.The iron chloride liquor after leaching contained the rare earth elements(REE)of 6.8 mg/L Sc,4.1 mg/L Ce and 2.3 mg/L Ga.

Determination of Ca,K,Mg and Fe in Four Fish Species by FAAS

A method for determining calcium （Ca）, potassium （K）, magnesium （Mg） and iron （Fe） in four fish species was opti- mized and validated. It included microwave mineralization of the samples and subsequent quantification by flame atomic absorption spectroscopy （FAAS） with Zeeman-effect background correction. Using HNO3 （65%） and H202 （33%） as extraction solutions, the optimal conditions of extraction were established as follows： 0.5 g of sample mass; microwave time program of 300 W/5 min and 600 W/5 min. The method was free of matrix interferences. The linear correlation coefficients were ≥0.9991, the recovery percentage of analytes was from 99.31% to 103.70% and the RSD （relative standard deviation） was lower than 2.06%. The detection limits obtained were 32.3, 43.2, 14.0 and 68.6ng mL^-1 for Ca, K, Mg and Fe in FAAS respectively. It is shown that the method is rapid, simple, sensitive and accurate. The method was applied to the studies of digestibility and measurement of these nutrients in samples of fish collected from Norway, Japan and China.

Electrochemical flotation of diethyldithiocarbamate-pyrrhotite system

Using sodium diethyldithiocarbamate as a collector the flotation behavior of pyrrhotite was investigated. The relationship between potential and pH range for pyrrhotite flotation was established. The results show that the flotation of pyrrhotite is dependent on pulp potential at certain pH values. Pyrrhotite has good floatability from pH 2 to pH 12, and poor flotability at pH>12. Cyclic voltammetry and Fourier transform infrared spectrum analysis show that the major adsorption product of DDTC on pyrrhotite is tetraethylthiuram disulfide. The intensity of Fourier transform infrared signals of tetraethylthiuram disulfide adsorbed on pyrrhotite and the anode current of a pyrrhotite electrode and flotation response of pyrrhotite are correlated with pulp potentials.

Spin-Polarized Tunneling Spectroscopy and Shot Noise in Ferromagnet／f-WaveSuperconductor Junctions

The tunneling spectroscopy and shot noise in ferromagnet/insulator/triplet-superconductor (FM/I/triplet- SC) structures are studied by taking into account the roughness interracial barrier and exchange splitting in the FM. For the triplet-SG of Sr_2RuO_4,we consider two-dimensional f-wave order parameter symmetries having nodes within the RuO_2 plane,which reasonably describe both thermodynamic and thermal conductivity data.It is shown that the ferromagnetic exchange splitting gives rise to a decrease in the differential conductance,the average current,and the shot noise power,while the noise power-to-current ratio is increased;the interface roughness is found to lead to a decrease in the differential conductance and the average current,and an increase in the noise power-to-current ratio.

Effect of organic depressant lignosulfonate calcium on separation of chalcopyrite from pyrite

In order to selectively separate chalcopyrite from pyrite,the effect of organic depressant lignosulfonate calcium(LSC) on the flotation separation of chalcopyrite from pyrite was investigated by flotation tests. The depression mechanism was studied by Fourier-transform-infrared(FTIR) analysis. The flotation tests of single mineral show that LSC can depress the flotation of pyrite in a certain pH range,but it has little effect on chalcopyrite flotation. Flotation separation of a mixture of chalcopyrite and pyrite can be completed to obtain a copper concentrate grade up to 24.73% with a recovery of 80.36%. IR analysis shows that LSC and butyl xanthate compete in absorption on pyrite surface,and there exists an LSC characteristic peak on pyrite surface. There is little adsorption of LSC on chalcopyrite.

Binding interactions of pefloxacin mesylate with bovine lactoferrin and human serum albumin

The binding of pefloxacin mesylate （PFLX） to bovine lactoferrin （BLf） and human serum albumin （HSA） in dilute aqueous solution was studied using fluorescence spectra and absorbance spectra. The binding constant K and the binding sites n were obtained by fluorescence quenching method. The binding distance r and energy-transfer efficiency E between pefloxacin mesylate and bovine lactoferrin as well as human serum albumin were also obtained according to the mechanism of Forster-type dipole-dipole nonradiative energy-transfer. The effects of pefloxacin mesylate on the conformations of bovine lactoferrin and human serum albumin were also analyzed using synchronous fluorescence spectroscopy.

Effect and mechanism of siderite on reverse anionic flotation of quartz from hematite

Reverse flotation technology is one of the most efficient ways to improve the quality and reduce impurity of iron concentrate. Mineral processors dealing with hematite face a challenge that the flotation results of reverse flotation of hematite are poor in presence of siderite using fatty acid as collector, starch as depressant of iron minerals and calcium ion as activator of quartz at strong alkaline pH. In this work, the effect of siderite on reverse anionic flotation of quartz from hematite was investigated. The effect mechanism of siderite on reverse flotation of hematite was studied by solution chemistry, ultraviolet spectrophotometry(UV) and Fourier transform infrared spectroscopy(FTIR). It was observed that siderite had strong depressive effect on quartz in flotation using sodium oleate as collector, corn starch as depressant of iron minerals and calcium chloride as activator of quartz at strong alkaline pH. The starch was adsorbed onto calcium carbonate by chemical reaction which was formed by CO^(2-)_3 from siderite dissolution and Ca^(2+) from calcium chloride as activator of quartz and precipitated on the surface of quartz, which resulted in improving the hydrophilic ability of quartz.

Coexistence of antiferromagnetic and ferromagnetic in Mn-doped anatase TiO_2 nanowires

A series of Mn-doped TiO2 nanowires(NWs) were prepared by hydrothermal method at the mole fraction of Mn changing from 0 to 12.0%.X-ray powder diffraction(XRD) analysis shows that all the samples have pure anatase structure.SEM and TEM studies show that the diameter and the length of the Mn-doped TiO2 NWs are larger than those of the undoped TiO2 NWs.Energy dispersive X-ray spectroscopy(EDX) reveals that the samples are composed of Ti,Mn and O.According to magnetization measurements,all samples show ferromagnetic behavior,but only the undoped TiO2 NWs are completely ferromagnetic with a saturated magnetization about 1.0 mA·m2/kg.Mn-doped TiO2 samples exhibit antiferromagnetic and ferromagnetic(AF-FM) behaviors simultaneously.Photoluminescence(PL) spectra demonstrate the existence of MnO2 sublattice.These observations indicate that an AF-WF crossover is induced by the coexistence of TiO2 sublattice and MnO2 sublattice.

Two-Dimensional Infrared Spectroscopy of the Photoproduct of π-Cyclopentadienyliron Dicarbonyl Dimer

Equilibrium photoproduct of 7r-cyclopentadienyliron dicarbonyl dimer [CpFe（CO）2]2 in non- polar solvent carbon tetrachloride （CC14） is investigated using time-resolved 2D IR spec- troscopy. One of the several possible visible-light-driven photoreaction pathways is confirmed and the product is found to contain a di-carbonyl group that exhibits quantum beating be- tween two equivalent transitions in time-resolved 2D IR spectra, which turns out to be the anti-symmetric and symmetric stretching of the terminal carbonyl stretching modes of CpFe（CO）2C1. This is the main product and its reaction pathway involves radical formation, followed by chloride addition. Quantum-chemistry computations support these experimental results. Our results indicate that 2D IR method can be used to identify in situ structures and dynamics of chemical species involved in condensed-phase chemical reactions.