Study on Quenching Effect of Holmium (Ⅲ) Ion in Chemiluminescence System of Luminol H_2O_2-Cr(Ⅲ) by Flow Injection Technique

1 ＩｎｔｒｏｄｕｃｔｉｏｎＡｔｐｒｅｓｅｎｔ ,ｔｈｅｒｅａｒｅｍａｎｙｒｅｐｏｒｔｓａｂｏｕｔｔｈｅｄｅｔｅｒｍｉｎａｔｉｏｎｏｆＨｏ(Ⅲ ) [1 ,2 ],ｗｈｉｃｈ ,ｈｏｗｅｖｅｒ ,ｈａｖｅｓｅｌｄｏｍｂｅｅｎｉｎ ｖｏｌｖｅｄｗｉｔｈｃｈｅｍｉｌｕｍｉｎｅｓｃｅｎｃｅ (ＣＬ)ａｎａｌ ｙｓｉｓ .Ｉｎｔｈｉｓｐａｐｅｒ ,ａｎｅｗＣＬａｎａｌｙｔｉｃａｌｍｅｔｈｏｄｆｏｒｔｈｅｄｅｔｅｒｍｉｎａｔｉｏｎｏｆＨｏ(Ⅲ )ｉｏｎｂｙｆｌｏｗｉｎｊｅｃｔｉｏｎｔｅｃｈｎｉｑｕｅｉｓｐｒｅｓｅｎｔ ｅｄ .Ｉｔｉｓｂａ…     

Reaction process of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2

The decomposition reactions of monazite and bastnaesite mixed rare earth minerals calcined by CaO-NaCl-CaCl2 were studied by means of TG-DTA and XRD. The results show that the process of the minerals decomposed by CaO involves two steps. The first step occurs in the temperature range of 425-540 ℃, and the main reactions are bastnaesite decomposition, i.e. REOF reacts with CaO to produce RE2O3 and CaF2, and Ce2O3 is oxidized to CeO2. During this step, CaCO3 is formed at about 500 ℃. The second step takes place in the temperature range of 610-700 ℃, and the reactions are monazite decomposition into RE2O3, Ca5F（PO4）3 and Ca3（PO4）2 by CaO and CaF2. In this process, the decomposition ability is improved because CaO from CaCO3 decomposing has high chemical activity. In calcining process, the new formed Ca5F（PO4）3 restrains fluorine that can escape in form of gaseous compound. The decomposition ratio of the mixed rare earth minerals reaches 90.8% at 700 ℃.     

A novel process of extraction and separation of RE and Mn from Panxi rare earth mud

A novel process to extract and separate rare earth (RE) and manganese (Mn) from Panxi rare earth mud was devdoped. The process involves roasting the mud at 480℃ with NH4Cl as chlorinating agent, and leaching the calcine with hot water to obtain a rare earth chloride solution. After the solution was further purified, HD(DIBM)P (P507) was applied as extractant to separate RE and Mn. By seven stages of fractional extraction, the RECl3 and MnCl2 solutionswith 99.8% purity were obtained. Finally, the purified RECI3 and MnClz solution were precipitated by NH4HCO3 to obtain a crystal RE2(CO3)3 and MnCO3 products respectively.     

不锈钢热浸镀铝抗高温氧化性能研究

用X射线衍射仪（XRD）、电子探针（EPMA）分析高温氧化腐蚀等方法，对1Cr13不锈钢热浸镀稀土铝合金（Al-6%Si-4%RE)的镀层组织结构与性能进行了研究，结果表明，在高温长时间保温过程中热浸镀层与基体金属相互扩散形成了热力学稳定的Al2O3,Cr2O3氧化膜，使该钢获得优良的抗高温氧化腐蚀性能。经热浸镀铝后，镀层具有良好的抗高温氧化腐蚀性能。     

First-principles calculations on magnetic property of Cu-doped Zn O tuned by Na and Al dopants

The effect of a second dopant on the magnetic property of Cu-doped ZnO by first-principles calculations based on the density functional theory was studied. It is found that the Cu-doped ZnO shows ferromagnetism due to the hybridization between Cu-3d and O-2p orbitals. When Na is introduced to the Cu-doped ZnO system, Cu cations tend to take on a bivalent state. Therefore, the magnetic moments on both Cu and coordinated oxygen sites increase due to Na doping. On the contrary, the magnetic moments decrease dramatically in the(Cu, Al) co-doped ZnO, which can be attributed to the fully occupied 3d states of Cu+ and O-2p states.     

Synthesis,characterization, thermal stability,conductivity and band gap of oligo-4-[(2-hydroxybenzylidene)amino]benzoic acid

In this study, the oxidative polycondensation reaction conditions of 4-[(2-hydroxybenzylidene)amino]benzoic acid (4-HBAB) by using oxidants such as air O₂, H₂O₂ and NaOCl were studied in an aqueous alkaline medium between 40 and 90 °C. The structures of the synthesized monomer and oligomer were confirmed by FT-IR, UV–vis, NMR and elemental analysis. The characterization was made by TG-DTA, size exclusion chromatography (SEC) and solubility tests. At the optimum reaction conditions, the yield of oligo-4-[(2-hydroxybenzylidene)amino]benzoic acid (O-4-HBAB) was found to be 68% (for air O₂ oxidant), 70% (for air H₂O₂ oxidant) 53% (for NaOCl oxidant). According to the SEC analysis, the number-average molecular weight (M_n), weight-average molecular weight (M_w) and polydispersity index (PDI) values of O-4-HBAB were found to be 932, 1469 g mol⁻¹ and 1.576, using H₂O₂, and 1895, 2560 g mol⁻¹ and 1.354, using air O₂ and 2320, 3015 g mol⁻¹ and 1.300, using NaOCl, respectively. According to TG analysis, the weight losses of 4-HBAB and O-4-HBAB were found to be 96.86% and 73.10% at 1000 °C, respectively. O-4-HBAB was shown higher stability against thermal decomposition. Also, electrical conductivity of the O-4-HBAB was measured, showing that the polymer is a typical semiconductor. Electrochemical HOMO, LUMO and energy gaps (E_g) of 4-HBAB and O-4-HBAB were found to be −6.28, −6.36; −2.39, −2.64; 3.89 and 3.72 eV, respectively. According to UV–vis measurements, optical band gap (E_g) of 4-HBAB and O-4-HBAB were found to be 3.23 and 3.09 eV, respectively.     

热处理对甲醇氧化催化剂Nb2O5·nH2O-Pt/C的影响

采用沉淀法制备甲醇氧化电催化剂10%Nb2O5·nH2O-20%Pt/C,并在Ar气氛下对它进行热处理。用XRD和HRTEM研究热处理对10%Nb2O5·nH2O-20%Pt/C结构和形貌的影响,用循环伏安法和计时电流法研究热处理对10%Nb2O5·nH2O-20%Pt/C电化学性能的影响。结果表明：随着热处理温度的升高,催化剂Pt尺寸增大、活性提高;与无热处理的20%Pt/C相比较,700 ℃热处理的10%Nb2O5·nH2O-20%Pt/C对甲醇的催化氧化性能最好,它对甲醇氧化的起始电位降低了150 mV,对甲醇的氧化峰电流提高了2.48倍     

正火处理对SA387Gr11CL2钢焊接接头抗接强度的影响

通过模拟试验,研究了正火处理对ＳＡ３８７Ｇｒ１１ＣＬ２钢焊接接头抗拉强度的影响,并通过试验结果分析和验证性试验,提出了ＳＡ３８７Ｇｒ１１ＣＬ２钢正火间接接头合理选用焊接材料的建议。     

Structure and resistance of concentration polar layer on cation exchange membrane-solution interface

1Introduction Ion exchange membrane is widely used in many aspects such as eletrodialysis,chlorin alkali industry and fuel cell.Much attention has been kept on its importance in the fields of environment science,biology and material science.The concentrat…     

An alkaline fusion mechanism for aluminate rare earth phosphor:cation-oxoanion synergies theory

Waste aluminate rare earth phosphor is an important rare earth elements(REEs) secondary resource,which mainly consists of BaMgAl_(10)O_(17):Eu~(2+)(BAM) and CeMgAl_(11)O_(19):Tb~(3+)(CMAT). Alkaline fusion process is widely used to recycle REEs from aluminate phosphor, but the related theory remains imperfect. In this paper,a series of alkaline fusion experiments of CMAT were performed to describe the phase change law of CMAT reactions.Based on comprehensive analysis, cation-oxoanion synergies theory(COST) was proposed to explain the aluminate phosphor structure damage. On the mirror plane of aluminate phosphor crystal structure, alkali metal cations(Na~+, K~+) would substitute rare earth ions, while free oxoanion(OH~-,CO_3~(2-),O_2~(2-)) can combine with rare earth ions. These two ionic forces ensure that rare earth ions can be substituted by cations. Then, the structure is decomposed. Morphological analysis shows that observable expression of COST can be described by shrinking core model after simplification. Reaction rate constant calculated indicates that the reaction degree is nanometers per second. COST provides a more complete mechanism, and it can help improve rare earth recycling technology furtherly.     

Changes in Cu–silica interfacial chemistry with oxygen chemical potential

Interfacial chemistry and equilibrium morphology of SiO₂ glass precipitates in a solid copper matrix are studied as a function of the oxygen chemical potential. Spherical SiO₂–glass precipitates are formed within copper by internal oxidation of (Cu,Si) single crystals at different oxygen activities. The metal–glass interfaces are rough at an atomic level. Atomic and electronic structures of the different interfaces are analyzed by high spatial resolution EELS. At high oxygen activity, two interfacial zones with specific electronic states are distinguished: on the metal-side of the interface, the correlated modifications in the O-1s and Cu-2p edges indicate O-2p–Cu-3d hybridization; on the glass-side of the interface, a modification of the Cu-2p edge is observed, which is interpreted in terms of a weak interaction of highly perturbed metallic copper with the constituents of the adjacent glass network. At intermediate oxygen activity, only the latter modification is observed at the interface.Oxygen adsorption and desorption to the silica–copper interface are modeled by a continuum approach; model results are compared to those obtained by experiments.     

微Ti处理380CL车轮钢闪光对焊工艺与组织调控

为解决轮辋闪光对焊(FBW)后微裂纹率和炸裂率偏高的问题,选取6.75 mm厚380CL车轮钢为研究对象,通过研究一元化闪光对焊参数对接头硬度的影响规律,建立闪光对焊温度场控制机制. 通过Ti微合金化技术思路进一步降低380CL闪光对焊焊缝的硬化倾向. 结果表明,为保证380CL闪光对焊后的成材率,需采取温度梯度较大的焊接规范,配合合理的顶锻量,从而获得最优的焊接接头. 在烧化量19 mm,钳口距离36 mm,烧化速度1.2 mm/s,带点顶锻时间0.5 s,顶锻量7 mm的闪光对焊参数下,6.75 mm厚380CL车轮钢可获得最低的硬度值140HV2. 对微Ti处理的380CL车轮钢进行了焊接热模拟,在1 000 ℃以上时的顶锻变形抗力降低,组织晶粒细化,显著降低了380CL闪光对焊后微裂纹率和炸裂率. 以上研究具备向高强度轮辋用钢的闪光对焊做进一步推广和应用示范.     

二氧化氯介质中脂肪醇聚氧乙烯醚及其复配缓蚀剂对Q235 钢的缓蚀作用

通过静态失重法、动电位极化曲线法及观察显微形貌,研究了脂肪醇聚氧乙烯醚(平平加O-20)及其复配缓蚀剂在100 mg/L二氧化氯介质中对Q235钢的缓蚀效应。结果表明:平平加O-20对Q235钢有一定的缓蚀效果,但单独使用时的用量较大;平平加O-20与硝酸钠、钼酸钠、苯甲酸钠均有缓蚀协同效果,与苯甲酸钠复配的缓蚀协同效应最明显;当苯甲酸钠和平平加O-20复配的质量浓度比为6:4,总用量为300 mg/L时,最大缓蚀效率可达92.55%。     

Kinetic and spectral aspects in chemiluminescence system Eu(III)/HCO3/H2O2

Chemiluminescence (CL) of the systems containing Eu₂⁺ or HCO₃⁻ ions and hydrogen peroxide was studied. The kinetic curves and CL emission spectra of the systems were discussed. The emission spectrum of the system containing carbonates revealed two emission maxima: the first directly after initiation of the reaction by hydrogen peroxide and the second in several seconds after the first. On the basis of the characteristic bands in the CL spectrum the emitters in the system Eu₂⁺/HCO₃⁻/H₂O₂ were identified as: excited Eu³⁺ ions and excited products of carbonate decomposition. The emission bands for λ=600 and 420 nm appeared in a time distance of a few ten seconds.     

COMPOSITION AND SPECTROSCOPIC STUDIES OF HYDRATED SODIUM ALUMINATE COMPOUNDS

ＣＯＭＰＯＳＩＴＩＯＮＡＮＤＳＰＥＣＴＲＯＳＣＯＰＩＣＳＴＵＤＩＥＳＯＦＨＹＤＲＡＴＥＤＳＯＤＩＵＭＡＬＵＭＩＮＡＴＥＣＯＭＰＯＵＮＤＳＱＩＵＧｕｏｆａｎｇ,ＤＥＮＧＨｏｎｇｍｅｉ,ＺＥＮＧＷｅｎｍｉｎｇａｎｄＣＨＥＮＨｉａｎｙｉ（ＳｈａｎｇｈａｉＩ...     

头孢克洛在中国健康志愿者体内的群体药代动力学研究

目的: 建立头孢克洛口服给药在健康志愿者体内的群体药代动力学模型,探讨个体因素对代谢反应的影响。方法: 基于头孢克洛生物等效性试验数据,应用非线性混合效应模型的群体方法分析头孢克洛口服给药的生物等效性试验数据,估算相关药代动力学参数及变异。结果: 头孢克洛在健康志愿者中符合一级吸收的二室模型。药物表观清除率(CL)、中央分布容积(V2)、中央分布容积(V3)、吸收速率常数(K_A)的群体典型值分别为 0.219 L/min、35.9 L、598 L 和 0.042 min^-1。体重对清除率(CL)有显著影响。结论: 群体药代动力学最终模型可对个体药代参数做出精确的估计,体重对表观清除率有影响。     

Cathodoluminescence Analysis for the Nondestructive Evaluation of Silica Scale on an Iron-Based Alloy

Information on the composition, morphology, and thickness of surface oxide scale helps to control the performance of heat-resistant alloys. Currently, there is a lack of adequate analytical methods that allow the rapid and nondestructive evaluation of these properties. In this study, we demonstrate a nondestructive method for identifying silica (SiO₂) scale and evaluating its morphology and thickness within 1 min by acquiring the cathodoluminescence (CL) images and spectra of SiO₂ scale on an Fe–5%Si alloy heated to 900 °C. SiO₂ scale emitted yellow–orange, violet, or red luminescence, whereas the other scale products that form on Fe–Si alloys, such as FeO, Fe₃O₄, Fe₂O₃, and Fe₂SiO₄, did not. Thus, we can identify SiO₂ scale and observe its morphology on the basis of luminescent color in the CL image. The thickness of SiO₂ scale can be correlated to the intensity of the CL peak at 645 nm. Therefore, the acquisition of CL images and spectra is a novel analytical method, which allows one to control the performance of SiO₂-forming Fe–Si alloys.

     

Cathodoluminescence from organic bilayer induced by field electron emission of carbon nanotubes

We report the observation and studies of cathodoluminescence (CL) of organic bilayer structures, such as tris-(8-hydroxyquinoline) aluminium (Alq3) and 2-tert-butylphenyl-5-biphenyl-1,3,4-oxadiazole (PBD) deposited on ITO-coated glass, with and without hole transport layer, N,N′-diphenyl-N,N′-bis(1-naphthyl)-(1,1′-phenyl)-4,4′-diamine (α-NPD). To excite the CL of such bilayer organic heterostructure, low energy electrons field emitted by single walled carbon nanotube cathodes were utilized. The dependence of CL spectrum and intensity on voltage (V), current (I), type of transport layer and the cathode–anode geometry has been studied. We propose carbon nanotubes as efficient cathodes for stable CL emission from organic multilayer heterostructures. The role of both electron and hole transport layers on stability and spectrum of CL is also discussed.     

Synthesis and characterization of iminothiazole bearing polyphenol with adjustable white–yellow photoluminescence color

A new kind of thiazole based Schiff base, 2-[(benzothiazol-2-ylimino)methyl]phenol (2HBABT), was synthesized and then converted to its oligomer structure (O-2HBABT). Structural characterizations were made by Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR), size exclusion chromatography (SEC), and scanning electron microscopy (SEM) techniques. Optical properties were investigated by UV–vis and fluorescence analyses. Optical band gaps (E_g) were determined by absorption edges. Photoluminescence (PL) properties were determined in solution forms. Changes in PL characteristics in different solvents and applied excitation wavelengths were examined. O-2HBABT showed white and yellow emission colors in DMF by changing of applied excitation wavelength. Solid state electrical conductivities were measured by four-point probe technique. Cyclic voltammetry (CV) measurements were carried out and HOMO–LUMO energy levels and electrochemical band gaps (E′_g) were calculated. Thermal data were obtained by TG-DTA and DSC techniques.     

机械镀锌镀层钝化与耐蚀性能研究

    对机械镀锌层分别用三价铬、稀土和六价铬进行了钝化处理,利用盐雾试验和电化学测试对不同钝化膜的耐蚀性与电化学行为进行了比较研究.盐雾试验结果表明,稀土与三价铬钝化处理的效果均已超过传统的六价铬钝化,比六价铬钝化膜的耐蚀性提高了一倍以上;稀土钝化膜的耐蚀性最好,三价铬钝化膜的耐蚀性仅次于稀土钝化膜的.电化学测试表明,三价铬、稀土和六价铬钝化膜都能够不同程度地抑制腐蚀的阴极电极反应,抑制阴极反应程度最大的是稀土钝化膜,其次是三价铬钝化膜,最小的是六价铬钝化膜.三价铬与稀土钝化工艺的环保和良好的防腐效果使其具有良好的应用前景.