Teleportation and thermal entanglement in two-qubit Heisenberg XYZ spin chain with the Dzyaloshinski—Moriya interaction and the inhomogeneous magnetic field

This paper studies the average fidelity of teleportation and thermal entanglement for a two-qubit Heisenberg XYZ chain in the presence of both an inhomogeneous magnetic field and a Dzyaloshinski--Moriya interaction. It shows that for a fixed D_z, the increase of b_z will broaden the critical temperature at the cost of decreasing the thermal entanglement. And it can modulate the inhomogeneous magnetic field and the Dzyaloshinski--Moriya interaction for the average fidelity of teleportation to be optimal.     

A laboratory study of directional spectra with maximum likelihood method-Ⅰ Developing wind wave

measurements by a circular array consisting of 18 wave gauges in a large wave tank, directional spectra of wind-generated waves in deep water are systematically determined by using maximum likelihood method The investigations reveal that the angular spreading of the wave energy is consistent with cos^2s(θ/2) proposed by Longuet-Higgins et al.(1963, Ocean Wave Spectra, 111-136), if the bimodal distributions of wave energy are not taken into account. Bimodality occurring on higher frequency than peak frequency is too rare to affect our whole resalts. Surprisingly, a much broader directional spreading than that of the field, which is interpreted by the strongly nonlinear energy transfer because of the very young waves in laboratory, is found. The parameter s depends on frequency in the same way as observed by Mitsuyasu et al.(1975, Journal of Physical Oceanography, 5, 750-760) and Hasselmann et al.(1980, Journal of Physical Oceanography, 10, 1264-1280) in the field, and the relationship between the four nondimensional parameters s_m, f_o, b₁ and b₂, determining the directional width, and ū₁₀ (corresponding to the inverse of wave age) are given respectively. The observed distributions are found to agree well with the suggestion of Donelan et al.(1985, Philosophical Transaction of Royal Society of London, A315, 509-562) when applied to field waves.     

深圳大鹏湾大鹏半岛沿岸海域的一次调查与分析

一九九八年三月,我们在大鹏半岛海域调查时,恰逢深圳大鹏半岛近岸海域赤潮发生。结合我们对该区域内沿海水域调查结果进行分析,给出该海域的潮汐、潮流的基本特征及当时该海域的水质状况,为规划、保护该海域的海洋环境提供科学依据,并为研究赤潮发生成因提供参考资料。     

Settlement Prediction Under Linearly Loading Condition

The relationship between time and settlement is a key problem in geotechnical engineering. Current methods used to predict the time-dependant settlement are based mainly on instantaneous loading condition. In this paper, the settlement curve under linearly loading condition, which is suitable for building and embankment projects, is mathematically proved to be “S” shaped. Subsequently, a new model, the Poison model, is raised to predict the settlement, and the method of parameter solution is also introduced. Finally, several problems about the Poisson prediction model are discussed.     

基于皮肤转录组的半滑舌鳎无眼侧黑化相关基因的筛选鉴定

半滑舌鳎(Cynoglossus semilaevis)作为比目鱼(Pleuronectiformes)中的代表物种,是我国沿海地区重要的海水经济鱼类.半滑舌鳎体色异常的问题长期以来一直困扰着从业者.导致体色变化的原因多种多样,遗传因素是最根本原因.针对半滑舌鳎无眼侧黑化的研究多在环境、营养、生理、常见色素基因克隆等方...     

半球形多向波聚合波道振荡水柱气室优化设计

为了解决振动水柱式波浪能转换装置收集多向波浪问题,本文设计了半球形多向聚合波道振荡水柱气室结构,以适合远海单点波浪能采集和发电。在规则波正向入射条件下,基于流体仿真分析软件(FLUENT)、流体动力学连续性假设和粘性不可压缩流体动量守恒的运动方程(Navier-Stokes方程)建立半球形振荡气室和三维数值波浪水槽模型。仿真结果表明:增设气室后壁,合理设计波道开口角度实现多向迎波捕获波浪能,优化前壁形状可降低波浪触底反射带来的能量耗散,同时提高了气室内空气压强和出气口速度,有效提升波浪能俘获效率,为后续发电的二次能量转换提供高效的空气动力。     

含水合物粉细砂的三轴试验及模拟

利用水饱和法制备含天然气水合物试样,进行等向压缩试验和不排水三轴试验.采用天然气水合物临界状态(M HCS)模型同时预测排水条件和不排水条件下的三轴试验,并进行变动参数分析.不排水条件下,密实纯砂发生应变硬化,而相近密实度的含水合物试样出现应变软化,峰值偏应力随水合物饱和度和围压增大.通过与排水和不排水三轴试验结果的对...     

带内全双工水声通信自干扰成分及信道特性分析

在传统以半双工体制为主的水声通信系统中,常将通信信号传播信道假设为稀疏信道以便于后续处理。但通过目前的实测结果来看,在以单独设备的形式进行带内全双工水声通信实现时,由于发射换能器到近端接收端这一短程传播过程受到通信机电子舱的影响,造成了自干扰成分与信道的复杂性。为了进一步了解壳体材料对自干扰强度、传播路径复杂度的影响,以及不同接收端布置下接收到的自干扰信号成分差异,拟基于有限元法对2种壳体材料及不同近端接收端位置处的环路自干扰信号进行仿真,并通过辅助仿真验证各接收位置处接收到的自干扰信号最主要成分,对自干扰信道特征进行分析,为后续自干扰抑制及各域干扰抵消提供初步的理论支持与依据。     

Submarine groundwater discharge and benthic biogeochemical zonation in the Huanghe River Estuary

Submarine groundwater discharge(SGD) has received increasing attention by studies on coastal areas; however,its effects on biogeochemical zonation have not been investigated to date. The Huanghe River Estuary(HRE) is a world class river estuary with high turbidity, and heavy human regulation. This study investigated how SGD is related to the benthic biogeochemistry of the HRE. Based on the distribution of several parameters(e.g., salinity,temperature, dissolved oxygen(DO) levels, p H, radium iso...     

不同受损情况下珊瑚礁海岸动力地貌差异性分析

探索珊瑚礁与海滩地貌之间动力地貌联系是认识珊瑚礁海岸变化的重要一环。本文以雷州半岛徐闻西落港珊瑚礁海岸为研究对象,应用RTK-GPS和无人船开展岸滩剖面和近岸水下地形的测量、结合海滩沉积物分析,基于FUNWAVE-TVD数值模型模拟并分析不同珊瑚礁地形地貌条件下波浪动力传播过程。结果显示,研究区珊瑚礁水下地形是影响礁后海滩地貌的主要因素。礁体形态不同,导致其礁后海滩在珊瑚礁地形控制下,短波波能和次重力波波能沿程呈现不同变化规律,最终导致礁后海滩的近岸波能主控频段的差异,在较窄的珊瑚礁海岸,次重力波占比较大。在不同主控频段波浪驱动下,礁后海滩平衡剖面呈现差异性特征,Muñóz-Pérez提出的珊瑚礁后海滩平衡剖面拟合中未考虑该因素的影响,需要在此认识基础上进一步改进。