WDM光网络中一种新的备用路由算法

文章基于负载均衡和禁忌搜索提出一种新的备用路由算法,实现了优化解搜索及对链路负载方差和拥塞的优化。路由选择后,采用首次命中按长通道优先原则为各光通道分配波长。在环网和网状网静态业务模式下对不同路由算法进行了仿真,仿真结果表明,新算法能充分利用网络资源安排最佳路由,有效降低了对波长的需求

果树库源关系改变对源叶光合作用的影响机制研究进展

为了解果树库源关系中叶片末端产物含量的改变对光合作用的调控机制,归纳和总结了库源关系改变后,果树中叶片末端产物的积累对光合作用的几种可能的调控机制,指出了反馈抑制等假说存在的不足,并认为气孔导度为启动因子,温度为作用因子,实现对光合作用的调控是可能的途径之一,最后提出了今后的研究重点

A Study of the Time Scaling Law of the β-Coefficient:Based on the Fractal Market Hypothesis

魏益华，吉林大学经济学院教授；程九思，吉林大学经济学院博士研究生；周佰成，吉林大学经济学院教授。【中文摘要】资本资产定价模型旨在衡量均衡资本市场中风险与收益之间的关系，β系数是该模型提出的计量系统性风险的一种指标。证券价格的波动具有两类分形特征：一是市场的波动具有状态持续性，其波动的方差具有时间标度性；二是证券的波动与市场的波动之间的协方差具有时间标度性。当这两个标度特征不一致时，β系数具有时间标度性，且其标度指数为两者之差。理论推导和对沪深300成分股5分钟高频数据的实证检验表明，标度可变资本资产定价模型（SV- CAPM)可以有效描述β系数的标度幂律特征，并具有更高的稳健性和对系统性风险的识别度。 【Abstract】The Capital Asset Pricing Model (CAPM) is aimed at measuring the relationship between risks and returns in the equilibrium market，and the β-coefficient is an index to measure the systemic risk of this model. The fluctuation of prices of portfolio bears fractal characteristics in two ways: (1)the volatility of the market portfolio presents persistence，and the variance of fluctuations shows a time scaling law； (2)the covariance between portfolio fluctuations and the market portfolio fluctuations presents，too，a time scaling law. When one scaling exponent differs from another，the β-coefficient shows a certain time scaling law and this scaling exponent will be the difference between the two above-mentioned exponents. Both theoretical and empirical studies of the CSI 300 components'5-min high-frequency data indicate that SVCAPM can effciently describe the existence of a time scaling law of the β-coefficient，and that it posesses greater stability and is able to increase the ability to recognize systemic risks.国家社会科学基金青年项目“中国与全球股票市场价格波动的动态相关性研究”（11CJY105

Synthesis of Zinc Polyhedral Microspheres and Applications in Alkaline Zn-MnO_(2)Battery

应用加热蒸发高纯锌粉气相传输法,制备锌多面体微球.产物的结构和形貌经XRD、SEM等测试表征,结果表明与该产物为结晶度较好的直径2~3μm的多面体微球.分别以所制锌微球或市售熔融锌作负极,γ-MnO2纳米线为正极,组装AA型碱性锌锰电池.电化学测试表明以锌微球为负极的碱性锌锰电池能显著提高其放电性能,100 mA下的放电容量达到3.14 Ah,显示出它在高能化学电源领域的应用前景.The zinc polyhedral microspheres were synthesized by evaporation of pure zinc powders via a vapor-transport process.The results characterized by XRD and SEM show that the as-synthesized zinc powders are polyhedral microspheres with the diameter of 2~3 μm.The electrochemical investigation showed that the capacity of the as-assembled AA-size primary alkaline Zn-MnO_(2)battery was increased to 3.14 Ah under the constant discharge current of 100 mA by using the as-deposited microspherical zinc powders as the anode active materials and γ-MnO_(2)nanowires as the cathode active materials,indicating their potential application in high-energy batteries.作者联系地址：南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所,南开大学新能源材料化学研究所 天津300071,天津300071,天津300071,天津300071,天津300071,天津300071Author's Address: *Institute of New Energy Material Chemistry,Nankai University,Tianjin 300071,Chin

Electroless-deposition Synthesis of Highly Active PtRu/C and PtRuSn/C as Anode Catalysts for DEFC

应用化学镀方法,以活化-敏化处理的活性炭作载体,制备高分散催化剂PtRu/C和PtRuSn/C.XRD、TEM及电化学测试表明,该催化剂Pt、Ru、Sn形成合金.金属颗粒的平均粒径约为3 nm.PtRu/C和PtRuSn/C二者对乙醇的阳极氧化都具有良好的催化活性和稳定性.In this paper,the preparation,characterization,and ethanol electrocatalytic oxidation of Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C electrocatalysts were reported.The electroless-deposition with sensitization-activation pretreatment was applied to prepare Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C electrocatalysts. The XRD and TEM analyses showed that the as-prepared catalysts were composed of well-dispersed PtRu or PtRuSn nanoparticles with an average particle size of about 3 nm.The electrochemical measurements demonstrated that the as-prepared Pt0.5Ru0.5/C and Pt0.5Ru0.15Sn0.35/C catalysts exhibited much enhanced peak current density for ethanol electrooxidation as compared to that synthesized without pretreatment.This result revealed that the pretreatment is favorable to the dispersion,size distribution and alloy degree of the nanocatalysts on the carbon support.In particular,the peak current density of ethanol oxidation on Pt0.5Ru0.15Sn0.35/C was nearly twice larger than that of Pt0.5Ru0.5/C,indicating their potential application in DEFC with a synergic effect of Ru and Sn.作者联系地址：南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室,南开大学化学学院新能源材料化学研究所和能源材料化学天津市重点实验室 天津300071,天津300071,天津300071,天津300071,天津300071,天津300071,天津300071Author's Address: Institute of New Energy Material Chemistry and Key Laboratory of Energy Meterial Chemistry, Nankai University,Tianjin 300071,Chin