基于现场试验的海上风电大直径单桩三维水平承载力研究

p－y 曲线法是计算分析水平受荷桩常采用的方法。但现场多为 3 m 以内直径试桩,对于海上风电大直径单桩( 4～8 m) 结构的桩土相互作用计算分析,其适用性值得商榷。结合江苏某海上风电大直径钢管桩水平静载荷试验,得到桩身挠度曲线和弯矩曲线; 采用 ABAQUS 建立单桩三维数值模型,将数值模拟结果与试验结果进行了对比分析,并对桩土接触法向刚度进行初步的敏感性分析,验证数值模型的有效性和适用性。随后对大直径单桩进行水平静载数值模拟,与规范推荐的 p－y 曲线法计算结果进行对比,结果表明,规范推荐的 p－y 曲线法过于保守,规范推荐的 p－y 曲线法不适于直接应用在大直径钢管桩的水平承载力分析; 所得结论对该区域海上风电大直径钢管桩设计优化具有指导意义。     

素域上椭圆曲线密码IP的高效VLSI实现

基于素域上的椭圆曲线密码算法,提出一种新型ECC IP的VLSI设计,采用层次化方法,新的点运算策略和改进的Montgomery模乘器,实现了ECC点标量乘、倍点和点加减运算并支持RSA功能。应用NIST推荐的256 bit和521 bit椭圆曲线,每秒分别能运行 120次和18次的点乘运算。设计通过了ASIC综合和FPGA验证。     

基于移动Agent的P2P入侵检测系统模型研究

该文先分析了网络结构变化带来的问题和C/S模式的不足。并简述了移动Agent和P2P技术的优点,提出了一种采用移动Agent技术和P2P结构的入侵检测系统的模型。该模型避免了分布式入侵检测系统存在的单点失效问题和传输瓶颈问题,提高了系统的自身安全性。最后指出了模型的优缺点,并提出了下一步的工作。     

一种移动机器人在三维动态环境下的路径规划方法

提出一种基于遗传算法的三维动态环境下的路径规划方法,通过对机器人的运动行为进行编码,将各种约束条件融入到遗传算法当中,规划出可实际应用的避障路径,仿真研究表明该方法是简单有效的.     

网格计算技术分析及展望

本文对网格计算的原理,关键技术及其应用领域作了具体分析,并与其他分布式计算作了比较,对网格计算技术的发展趋势进行了探讨。     

Magnetic order and evolution of the electronic state aroundx=0.12 in La2?xBaxCuO4 and La2?xSrxCuO4

Muon spin rotation ( ⁺SR) measurement provides clear evidence of the antiferromagnetic order of Cu moments below 35 K for La_2–x Ba _x CuO₄ and below 15 K for La_2–x Sr _x CuO₄ in the narrow range ofx where the high-T _c superconductivity (SC) is suppressed remarkably. The results suggest that the change of the electronic state coupled with the lattice instability is relevant to the local suppression of SC and freezing of spin fluctuations of the Cu moment.     

A mathematical programming approach to a problem in variance penalised Markov decision processes

In this paper we present three algorithms for solving a problem in which it is required to get an optimal compromise between the average expected reward per unit time and the variance of the reward per unit time. The algorithms lead to an-optimal solution, where>0 is arbitrary.     

Role of electron-phonon interaction in lattice dynamics and superconductivity of oxide spinel LiTi2O4

The lattice dynamics of an oxide spinel LiTi₂O₄ is studied by taking account of the electron-phonon (EP) interaction derived on the basis of the realistic tight-binding bands fitted to the first-principles bands. Due to the characteristic dependences of the EP interaction on wavevectors and vibrational modes, a remarkable frequency renormalization of the O vibrational modes, which hybridize with the Ti vibrational modes, is obtained over a wide region of the Brillouin zone. The overall features of the calculated phonon density of states are in agreement with those observed by the inelastic neutron scattering measurements. By using the EP interaction and the renormalized phonon frequencies we have calculated the EP spectral function ² F(). The superconducting transition temperature, gap function, and tunneling spectra are calculated by solving the Éliashberg equation. The results agree well with the observations.     

Lateral WSe2 Homojunction through Metal Contact Doping: Excellent Self-powered Photovoltaic Photodetector

Here an IR-heating chemical vapor deposition (CVD) approach enabling fast 2D-growth of WSe₂ thin films is reported, and the great potential of metal contact doping in building CVD-grown WSe₂-based lateral homojunction is demonstrated by contacting with TiN/Ni metals in favor of holes/electrons injection. Shortening nanosheet channel to ≈2 µm leads to pronounced enhancement in the performance of diode. The fabricated WSe₂-based diode exhibits high rectification ratios without the need of gate modulation and can work efficiently as photovoltaic cell, with maximum open circuit voltage reaching up to 620 mV and a high power conversion efficiency over 15%, empowering it as superb self-powered photodetector for visible to near-infrared lights, with photoresponsivity over 0.5 A W⁻¹ and a fast photoresponse speed of 10 µs under 520 nm illumination. It is of practical significance to achieve well-performed photovoltaic devices with CVD-grown WSe₂ using fab-friendly metals and simple processing, which will help pave the way toward future mass production of optoelectronic chips.