含砂雾封层在桥面铺装工程中的应用

结合含砂雾封层在国道205桥面铺装上的应用,深入分析了含砂雾封层的防水、防老化作用机理,本文系统总结了国道205桥面雾封层施工质量的控制要点,并对施工前后封层各项性能指标进行跟踪检测,分析结果表明采取含砂雾封层措施确实能对桥面早期微裂缝进行有效封水,延缓桥面病害的发生,延长沥青路面的使用寿命。     

Optimal investment problem for an insurer and a reinsurer

This paper studies the optimal investment problem for an insurer and a reinsurer. The basic claim process is assumed to follow a Brownian motion with drift and the insurer can purchase proportional reinsurance from the reinsurer. The insurer and the reinsurer are allowed to invest in a risk-free asset and a risky asset. Moreover, the authors consider the correlation between the claim process and the price process of the risky asset. The authors ?rst study the optimization problem of maximizing the expected exponential utility of terminal wealth for the insurer. Then with the optimal reinsurance strategy chosen by the insurer, the authors consider two optimization problems for the reinsurer: The problem of maximizing the expected exponential utility of terminal wealth and the problem of minimizing the ruin probability. By solving the corresponding Hamilton-Jacobi-Bellman equations, the authors derive the optimal reinsurance and investment strategies, explicitly. Finally, the authors illustrate the equality of the reinsurer's optimal investment strategies under the two cases.     

Synthesis and Largely Enhanced Nonlinear Refraction of Au@Cu_2O Core-Shell Nanorods

Au@Cu_2O core-shell nanorods with tunable thickness of Cu_2O shell were synthesized and their linear and nonlinear optical responses were investigated. Two transverse plasmon resonance peaks were observed when the Au nanorods were coated with Cu_2O shells, which were adjusted by the Cu_2O shell thickness. The nonlinear absorption of the Au@Cu_2O nanorods is enhanced by 5 times at the longitudinal plasmon resonance wavelength compared with that of bare Au nanorods. More intriguingly, largely enhanced nonlinear refraction and suppressed nonlinear absorption at the transverse plasmon resonance wavelength were observed in the Au@Cu_2O nanorods. Our findings indicate the existence of strong local field enhancement at the interface between the Au core and the Cu_2O shell, which would provide a promising strategy in designing plasmonic nonlinear nanodevices with good nonlinear figures of merit.     

Effects of Strain Rate,Temperature and Grain Size on the Mechanical Properties and Microstructure Evolutions of Polycrystalline Nickel Nanowires: A Molecular Dynamics Simulation

Through molecular dynamics(MD)simulation,the dependencies of temperature,grain size and strain rate on the mechanical properties were studied.The simulation results demonstrated that the strain rate from 0.05 to 2 ns~(–1 )affected the Young’s modulus of nickel nanowires slightly,whereas the yield stress increased.The Young’s modulus decreased approximately linearly;however,the yield stress firstly increased and subsequently dropped as the temperature increased.The Young’s modulus and yield stress increased as the mean grain size increased from 2.66 to6.72 nm.Moreover,certain efforts have been made in the microstructure evolution with mechanical properties association under uniaxial tension.Certain phenomena such as the formation of twin structures,which were found in nanowires with larger grain size at higher strain rate and lower temperature,as well as the movement of grain boundaries and dislocation,were detected and discussed in detail.The results demonstrated that the plastic deformation was mainly accommodated by the motion of grain boundaries for smaller grain size.However,for larger grain size,the formations of stacking faults and twins were the main mechanisms of plastic deformation in the polycrystalline nickel nanowire.     

海上电泵结蜡井热循环洗井工艺参数优化设计

为探索海上油田电泵举升结蜡井热循环洗井工艺井筒温度场分布规律，综合考虑潜油电机增温、电缆散热、热流体注入量、注入深度、注入温度、结蜡管段传热和海水空气导热的影响，基于热能守恒原理，建立了电泵井结蜡热循环洗井工艺井筒温度场计算模型，分析了热流体注入温度和注入量对混合产出流体的井筒温度分布的影响。研究结果表明，随着注入量的增加混合产出液沿程井筒温度增加，随着注入温度的增加混合产出液沿程井筒温度增加。该方法可有效指导现场措施工艺的实施，达到延长结蜡井的清蜡周期、延缓产液/产油量下降速度的目的。     

Fuzzy Views on Black-Litterman Portfolio Selection Model

In this paper, views of investor are described in fuzzy sets, and two fuzzy Black-Litterman models are constructed with fuzzy views and fuzzy random views respectively. In the models, expected returns and uncertainty matrix of views are redefined and the views are formulated by fuzzy approaches suitably. Then the models are tested with data from Chinese financial markets. Empirical results show that the fuzzy random views model performs the best, and both the fuzzy models are better than the traditional ones, demonstrating that the fuzzy approaches can contain more information in the views and measure the uncertainty more correctly.     

新生代农民工收入消费统计分析——基于郑州市817位新生代农民工调查数据

近年来,我国农民工群体正处在代际更替的阶段,新生代农民工有其独特的消费观念、消费结构和消费行为。同时,新生代农民工也面临生产生活方式和消费方式的变化,其收入提高与消费行为转变更是实现我国经济转型的重要推动力。基于此,本文选取郑州市作为样本地区,对新生代农民工的收入状况、消费观念和消费行为进行实地调查,运用Logist模型分析其收入状况、消费观念对其消费行为选择的影响。最后,从改善新生代农民工收入状况、人力资本提升和消费观念的引导等方面提出科学、合理的建议。     

人类卫生健康共同体视域下的全球科技合作研究——以新冠肺炎疫情为背景

新冠疫情暴发以来,中国政府和人民秉持人类命运共同体理念,运用一系列先进技术,在较短时间内扭转了国内疫情的严峻形势.在此背景下,为了更好地发挥中国方案在全球抗疫中的作用,文章运用内容分析法和归纳分析法,首先梳理了从人类命运共同体到人类卫生健康共同体的理论逻辑,其次探究了人类卫生健康共同体、全球科技合作与疫情防控之间的结构关系,最后分析了中国疫情防控的有效举措,进而得出结论:中国疫情防控工作的成效离不开人类命运共同体理念的指引和全球科技合作的开展,而中国在平台建设、机制整合及合作网络等领域的方案共享将有助于遏制全球疫情的蔓延.     

Speeding Up the GVW Algorithm via a Substituting Method

Journal of Systems Science and Complexity - The GVW algorithm is an efficient signature-based algorithm for computing Gröbner bases. In this paper, the authors consider the implementation of...