Design and fabrication of GeAsSeS chalcogenide waveguides with thermal annealing

We reported a chalcogenide glass-based rib waveguide fabricated using photolithography and dry etching method. A commercial software(COMSOL Multiphysics) was used to optimize the waveguide structure and the distribution of the fundamental modes in the waveguide based on the complete vector finite component. We further employed thermal annealing to optimize the surface and sidewalls of the rib waveguides. It was found that the optimal annealing temperature for Ge As Se S films is 220℃, and the roughness of the films could be significantly reduced by annealing. The zero-dispersion wavelength(ZDW) could be shifted to a short wavelength around ~2.1 μm via waveguide structural optimization, which promotes supercontinuum generation with a short wavelength pump laser source. The insertion loss of the waveguides with cross-sectional areas of 4.0 μm×3.5 μm and 6.0 μm×3.5 μm was measured using lens fiber and the cut-back method. The propagation loss of the 220℃ annealed waveguides could be as low as 1.9 d B/cm at 1550 nm.     

Solubility Calculations of Methane and Ethane in Aqueous Electrolyte Solutions

Journal of Solution Chemistry - Accurate calculation of light hydrocarbon solubilities in aqueous electrolyte solutions is critical for petroleum and geochemical applications. However, very few...     

Preparation of spherical spinel LiMn2O4 cathode material for lithium ion batteries

A novel process is proposed for synthesis of spinel LiMn₂O₄ with spherical particles from the inexpensive materials MnSO₄, NH₄HCO₃, and NH₃H₂O. The successful preparation started with carefully controlled crystallization of MnCO₃, leading to particles of spherical shape and high tap density. Thermal decomposition of MnCO₃ was investigated by both DTA and TG analysis and XRD analysis of products. A precursor of product, spherical Mn₂O₃, was then obtained by heating MnCO₃. A mixture of Mn₂O₃ and Li₂CO₃ was then sintered to produce LiMn₂O₄ with retention of spherical particle shape. It was found that if lithium was in stoichiometric excess of 5% in the calcination of spinel LiMn₂O₄, the product had the largest initial specific capacity. In this way spherical particles of spinel LiMn₂O₄ were of excellent fluidity and dispersivity, and had a tap density as high as 1.9 g cm^–3 and an initial discharge capacity reaching 125 mAh g^–1. When surface-doped with cobalt in a 0.01 Co/Mn mole ratio, although the initial discharge capacity decreased to 118 mAh g^–1, the 100th cycle capacity retention reached 92.4% at 25°C. Even at 55°C the initial discharge capacity reached 113 mAh g^–1 and the 50th cycle capacity retention was in excess of 83.8%.     

单光子纠缠态的纠缠转移和量子隐形传态

使用光学分束器和单光子源，利用单光子态和真空态制备出了纠缠单光子态.利用光学分束器作用和单光子探测，实现了三个通讯伙伴之间的纠缠转移.提出了一个关于纠缠单光子态的量子隐形传态方案.在这个方案中，被传送的是一个未知的单光子纠缠态.通讯双方使用的量子信道是两个单光子纠缠态.通过使用分束器作用和对输出态进行光子测量以及在经典信息的帮助下，纠缠转移和量子隐形传态的过程被完成.     

Prediction of DNA separation by capillary electrophoresis with polymer additives

The paper is focused on the powerful prediction ability of the quantitative DNA sieving model in DNA separations by capillary electrophoresis, which was proposed by us previously. First, the DNA resolution can be predicted by the theory. The model predicts that the most difficult and easiest separation will be 184bp/192bp and 234bp/267bp respectively, which is consist with experimental results. Furthermore, the average relative differences of predicted and experimental resolution values (R(S)) for ssDNA 184b/192b or dsDNA 184bp/192bp were all smaller than 2.8% if the diffuse parameter D considered was 8×10(-5) cm(2)/s. Secondly, the optimum polymer concentrations for DNA separation were also calculated by the model, and the results show that polymer concentration should be as high as possible in DNA separation. Thirdly, the sieving ability of polymer will be predicted by the model. Polymer with smaller k, a polymer parameter calculated by the model, is prior to use as DNA sieving media.     

等离子体修饰TiO2及其响应光谱红移

TiO2在光催化方面应用前景十分广阔,而阻碍其应用的是它的宽禁带,因此研究开发响应光谱红移的TiO2就成为当前光催化剂研究的重要课题.等离子体处理是修饰TiO2的一种有效方法,目前等离子体修饰TiO2及其响应光谱红移的研究取得了一定进展,等离子体修饰的TiO2表面生成了氧空穴,并形成了原子掺杂,减小了禁带宽度,使其响应光谱红移.本文综述了目前该领域的研究现状,并对今后的研究做了展望.     

Preparation of V-LiFePO4 cathode material for Li-ion batteries

The preparation of vanadium-modified olivine LiFePO₄ was attempted using vanadium-modified FePO₄ precursor which was synthesized by controlled crystallization. The structure and electrochemical behavior of V-LiFePO₄ with different vanadium contents were investigated. The electrochemical behavior of V-LiFePO₄ materials at high rate and low temperature was compared with that of the LiFePO₄ material. Incorporation of vanadium improved the electrochemical performance of LiFePO₄. The investigation showed that the 3%V-modified LiFePO₄ presented the best electrochemical performance.     

用丁二酮激光诱导磷光测量流场可能性的研究

对混合在氮气中丁二酮三重态~3Au的激光诱导磷光性质的实验结果表明,磷光寿命是温度的函数,与密度及浓度无关;而初始磷光强度是密度的线性函数,对温度变化不敏感,用观察氮气中少量丁二酮磷光寿命与磷光初始强度的方法可以测量流场的温度与密度分布,磷光寿命长的特点可以用来测量速度分布,它在很大程度上克服了多普勒测速中因固体微粒质量大而滞后于气流的问题,因而可以在具有高加速度的流场中使用,本文还对磷光衰减机理进行了分析,结果与实验一致,上述同时测温度与密度的方法尚未见诸文献报道。     

毛细管电泳柱及微流控芯片通道涂层的发展

综述了用于毛细管电泳柱和微流控芯片通道的涂层材料和涂层技术的发展状况,以及涂层对分离效果和分离结果重现性的影响。将涂层材料按照动态和静态分类,静态涂层又分别按照均聚物、共聚物、杂环类等进行讨论;综述了交联反应法、溶胶-凝胶法、辐照法、化学沉积法等涂层的制备方法。对毛细管电泳柱和微流控芯片通道的改良具有一定的参考价值。     

Plasma sterilization using the RF glow discharge

In the present work, glow discharge oxygen plasma was used to sterilize the Pseudomonas aeruginosa on the polyethylene terephthalate (PET) sheets. In a self-designed plasma reaction equipment, active species (electron, ion, radical, UV light, etc.) were separated effectively, and the discharge area, afterglow area and remote area were plotted out in the plasma field. Before and after plasma treatment the cell morphology was studied by scanning electron microscopy (SEM). The results showed that after treatment of 30 s the germicidal effect is 4.26, 3. 84, 2.61, respectively in the three areas on the following conditions: discharge power was 40 W and gas flux was 20 cm³/min. SEM results revealed the cell morphology before and after plasma treatment. The walls or cell membrane cracking was testified by determining the content of protein using coomassie light blue technique. The results from electron spin resonance spectroscopy (ESR) and double Langmuir electron probe showed that electron, ion and oxygen free radical played important roles in sterilization in the discharge area, but only oxygen radicals acted to sterilize the bacteria in the afterglow area and the remote area.