柱透镜和弯月透镜实现半导体激光器光束整形

针对半导体激光器的发光特点,设计了半导体激光器的光束整形系统。首先采用柱透镜准直和偏转沿Y轴发散的光束;然后再采用望远系统对X轴发散的光束进行准直和扩束;最后采用弯月透镜对发射光束压缩,实现半导体激光器的光束整形,降低光束发散角,提高光束质量。利用ZEMAX软件模拟系统,结果表明,整形后输出光束沿X轴和Y轴的发散角变为4.922mrad,输出光斑直径为1.2707mm,整形系统总长度为65.6618mm,各元件的最大直径为20.52mm,输出光束质量和系统结构都优于同类产品。     

Thermospin effects in parallel coupled double quantum dots in the presence of the Rashba spinben orbit interaction and Zeeman splitting

The thermoelectric and the thermospin transport properties, including electrical conductivity, Seebeck coefficient, thermal conductivity, and thermoelectric figure of merit, of a parallel coupled double-quantum-dot Aharonov-Bohm interferometer are investigated by means of the Green function technique. The periodic Anderson model is used to describe the quantum dot system, the Rashba spin-orbit interaction and the Zeeman splitting under a magnetic field are considered. The theoretical results show the constructive contribution of the Rashba effect and the influence of the magnetic field on the thermospin effects. We also show theoretically that material with a high figure of merit can be obtained by tuning the Zeeman splitting energy only.     

A Simple Polyoxometallate for Selective Oxidation of Benzyl Alcohol to Benzaldehyde with Hydrogen Peroxide

A series of Keggin‐type polyoxometallates, M₃(PW₁₂O₄₀)₂ [M=Ni, Zn, Co, Mn, Cu], FePW₁₂O₄₀, Ni₃(PMo₁₂O₄₀)₂ and Ni₂SiW₁₂O₄₀, were prepared and used as catalysts for selective oxidation of benzyl alcohol into benzaldehyde with H₂O₂ as an oxidant under solvent‐free condition. Ni₃(PW₁₂O₄₀)₂·26H₂O afforded high catalytic activity with TON of 550.6 mol/(mol cat.) and 87.3% selectivity. However, this catalyst can be easily recovered and reused.     

Effects of 160 keV electron irradiation on the optical properties and microstructure of “Panda” type Polarization-Maintaining optical fibers

In this paper, effects of 160 keV electron irradiated “Panda” type Polarization-Maintaining optical fiber at 1310 nm are investigated by us. Attenuation coefficient induced in optical fiber by electron beams at 1310 nm increases with increase in electron fluence. Electron irradiation-induced damage mechanism are studied by means of CASINO simulation program, the X-ray photoelectron spectroscopy (XPS), electron spin resonance spectrometer (EPR) and Fourier transform infrared spectroscopy (FTIR). The results show that Si-OH impurity defect concentration is the main reason of increasing attenuation coefficient at 1310 nm.     

Hydrothermal synthesis, structure and properties of a new arsenotungstate

A new arsenotungstate, Na[{Cu(2,2′-bpy)(imi)}{Cu(2,2′-bpy)}₂AsW₉O₃₃As(OH)]·8H₂O (1) (2,2′-bpy=2,2′-bipyridine, imi=imidazole), has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. The compound 1 represents the first example of an unusual trilacunary arsenotungstate substituted simultaneously arsenide fragment and copper complexes. The compound 1 was used as solid bulk modifier to fabricate bulk-modified carbon paste electrodes (1-CPE) by direct mixing. The electrochemical behavior and electrocatalysis of 1-CPE have been studied in detail. Magnetic measurement for 1 shows the presence of antiferromagnetic interactions within the Cu²⁺ cations.     

离子色谱-直接电导法测定碱土金属和过渡金属离子

本文报道离子色谱-直接电导法测定碱土金属和过渡金属离子。研究了流动相pH值、乙二胺浓度及柠檬酸和酒石酸浓度对金属离子分离的影响。结果表明,以乙二胺-柠檬酸为流动相可以同时分离碱土金属和过渡金属离子。用乙二胺-酒石酸作为流动相可以分离碱土金属离子。方法检出限为0.09~1.88 mg/L,加标回收率为97.6%~98.7%。该方法用于叶面肥试样的分析,结果良好。     

Hydrothermal synthesis,structure and properties of copper–bipyridine complexes substituted mono-vacant Keggin arsenotungstate

A new arsenotungstate, [H₂AsW₁₁O₃₉][Cu₃(2,2′-bipy)₃(H₂O)₂(OH)]·2H₂O (1) (2,2′-bipy = 2,2′-bipyridine), has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, UV–Vis, TG and single-crystal X-ray diffraction. The compound 1 represents the first example of copper–bipyridine complexes substituted mono-vacant Keggin polyoxotungstate containing As^V. Compound 1 exhibits fluorescent property at room temperature. Furthermore, compound 1 has been used as a solid bulk-modifier to fabricate bulk-modified carbon paste electrodes (1-CPE) by direct mixing. The electrochemical behavior and electrocatalysis of 1-CPE have been studied in detail.     

Synthesis and characteristics of nanostructured Li(Co1/3Ni1/3Mn1/3)O2 cathode material prepared at 0 °C

Special synthetic conditions at 0 °C were used to prepare nanostructured Li[Ni_1/3Co_1/3Mn_1/3]O₂ via chemical coprecipitation synthesis. The precursor preparation shows platelet shape with thickness of 10 nm and width of 100 nm. After calcination, the particles change to spherical or rectangle shape with a size of 100~200 nm. The nanostructured Li[Ni_1/3Co_1/3Mn_1/3]O₂ shows a well-ordered layered hexagonal lattice with low cation mixing. Galvanostatic testing showed good electrochemical properties and high rate capability, which may be due to its unique morphological and structural characteristics. Synthesis at 0 °C effectively prevented growth of the precursor particles and produced nanosize Li[Ni_1/3Co_1/3Mn_1/3]O₂, which gave improvement in high rate performance and favoring the future use of this cathode material for high power applications.