分布作用腔振荡器的大信号研究

本文考虑了空间电荷的作用及互作用间隙宽度的影响,按矩形脉冲轴向高频场分布,建立了分布作用腔振荡器的大信号计算模型,对转换效率进行了计算研究.文中还给出典型情况下的详细结果,并进行了分析讨论。     

CORRELATION OF ANNUAL CHANGE OF LUTEINIZING HORMONE-RELEASING HORMONE (LH-RH) WITH GONADAL DEVELOPMENT IN AMPHIOXUS

The present study demonstrates for the first time by RIA that LH-RH is present in the heads as well as the bodies of the amphioxuses of both sexes. Gonadoliberin increases gradually during the course of gonadal development. At the time of gonadal maturity, LH-RH content reaches a maximum. The annual change of LH-RH correlates well with gonadal development and the gonadosomatic index (GSI). The reproductive season of the amphioxus covers about three months from May to July, and LH-RH content starts to increase in May (66.89±5.26 ng) and reaches the peak in June (158.57±3.17 ng), indicating that LH-RH is likely also to be involved in the reproductive activity of the chordate. This finding is of significance in understanding the evolutionary process of the reproductive endocrine in the vertebrate.     

Effect of Interface Nanotexture on Light Extraction of InGaN-Based Green Light Emitting Diodes

We report the enhancement of the light extraction of InGaN-based green light emitting diodes （LEDs） via the interface nanotexturing. The texture consists of high-density nanocraters on the surface of a sapphire substrate with an in situ etching. The width of nanocraters is about 0.5 μm and the depth is around 0.1 μm. It is demonstrated that the LEDs with interface texture exhibit about a 27% improvement in luminance intensity, compared with standard LEDs. High power InGaN-based green LEDs are obtained by using the interface nanotexture. An optical ray-tracing simulation is performed to investigate the effect of interface nanotexture on light extraction.     

表面修饰的ZnS:Mn量子点的发光性质及其对生物分子的检测

采用水热法制备了ZnS:Mn量子点,探讨了掺杂离子浓度对ZnS:Mn量子点的晶体结构和发光性质的影响。通过荧光光谱对样品进行表征。结果表明:掺杂离子的摩尔分数达到2%时,ZnS:Mn量子点在595 nm附近的发光最强;继续增加掺杂浓度反而出现荧光猝灭的现象。本文还研究了表面修饰对量子点形貌和发光性质的影响。通过透射电子显微镜(TEM)观察样品的形貌,发现经过3-巯基丙酸(MPA)修饰后的样品表面团聚现象得到改善,并且尺寸单一、单分散性较好,平均粒径约为5 nm。经过修饰后的样品减少了表面非辐射性缺陷中心,使掺杂Mn2+所引起的595 nm附近的发射峰强度增大。将MPA修饰后的ZnS:Mn量子点与牛血清白蛋白(BSA)分子进行生物偶联,并利用BCA法对偶联上的蛋白含量进行定量检测,结果显示经过修饰后的量子点偶联蛋白的能力更强。     

Study of superradiance based on a low-voltage backward wave oscillator

According to the small size requirement for wide-band high-power microwave radiation, a superradiance backward wave oscillator (BWO) is proposed to generate such high-power microwave radiation with a low voltage (～20 kV) pulse power supply and low guiding magnet field (～0.1T). In order to get a high-efficiency C-band superradiance BWO with a low beam voltage and a low guiding magnet field, the mechanism of superradiance in a BWO is explored in particle-in-cell simulation. With the oversized structure, the simulation shows that a microwave power of 405 kW with a frequency of 5.6 GHz and a spectrum width of 500 MHz can be obtained with a voltage of 23 kV and magnetic field of 0.1 T.     

Enhanced Peroxymonosulfate Activation by NixCo1-xOOH for Efficient Catalytic Oxidation of Organic Pollutants

Peroxymonosulfate(PMS) has received increasing attention as viable technology for recalcitrant organics removal from polluted waters. Although promising, alternative heterogeneous catalysts with stable structure, strong hydrophilicity, environmental friendliness and excellent catalytic performance are highly desirable to facilitate the wide industrialization of PMS. In this work, Ni doped CoOOH catalyst was employed as PMS activator. Ni dopant had a significant influence on the morphology, structure and catalytic performance of CoOOH. NiojCoo.gOOH exhibited the best catalytic performance. Reaction rate ofNio.2Coo.8OOH was 2, 4, and 4.4 times that of CoOOH, CoFe2O4 and CO3O4, respectively. Moreover, Ni。2C00.8OOH/PMS system had potential application to organic pollutants and displayed a great catalytic activity over a broader pH value(e.g., 4-10). More importantly, Ni doping accelerated the transfonnation of Co(Ⅲ) and Co(Ⅱ) and formed active species CoOH^+ and NiOH^+ which were responsible to the enhancement of PMS activation.OH, SO4^-:O2^- and 1^O2 were detected, indicating both non-radical and radical processes in the Nio.2Coo.8OOH/PMS system. These findings provide a promising alternative to mixed-metal oxyhydroxides catalysts for PMS activation, demonstrating a great potential in environmental remediation and wastewater treatment.     

New Conserved Quantities of Noether-Mei Symmetry for Nonholonomic Mechanical System

Two new types of conserved quantities deduced by Noether-Mei symmetry of nonholonomic mechanical system are studied. The definition and criterion of Noether-Mei symmetry for the system are given. A coordination function is introduced, and the conditions under which the Noether-Mei symmetry leads to the two types of conserved quantities and the forms of the two types of conserved quantities are obtained. An illustrative example is given. The coordination function can be selected according to the demand for finding the gauge function, and the choice of the coordination function has multiformity, so more conserved quantities deduced from Noether-Mei symmetry of mechanical system can be obtained.     

Density and Symmetric Potential Dependences of Isoscaling Behaviour in the Lattice Gas Model

Isoscaling behaviour of the statistical emission fragments from the equilibrated sources with Z=30 and N=30, 33, 36 and 39 is investigated in the framework of the isospin-dependent lattice gas model. The dependences of isoscaling parameters α on source isospin asymmetry, temperature andfreeze-out density are studied, and the `symmetry energy' is deduced from isoscaling parameters. The results show that symmetry energy C_sym is insensitive to the change of temperature but follows the power-law dependence on the freeze-out density ρ. The effect of strength of asymmetry of nucleon--nucleon interaction potential on the density dependence of the symmetry energy is discussed.     

双原子-真空场系统中的纠缠动力学

分别用量子约化熵和量子相对熵研究了双二能级原子与单模真空场相互作用的纠缠动力学.结果表明:通过选择合适的系统参数可以实现双原子纠缠的放大与保持,可以制备出纠缠度为1的双原子纠缠态.     

La2O3对Pd密偶催化剂性能的影响

采用浸渍法制备了不同La2O3含量的Pd密偶催化剂.使用低温N2吸附-脱附、X射线衍射、H2程序升温还原、CO化学吸附和X射线光电子能谱等技术考察了La2O3对催化剂性能的影响.模拟汽车尾气条件考察了催化剂上丙烷的转化活性.活性测试结果表明,La2O3的添加能显著提高催化剂对丙烷的转化活性和催化剂的热稳定性.H2-TP...