摘要：Large-scale,fine,and efficient numerical simulation of a geothermal field plays an important role in geothermal energy *** with the problem of large computation and high storage requirements for complex underground models in a three-dimensional(3-D)numerical simulation of a geothermal fi eld,a mixed space-wavenumber domain 3-D numerical simulation algorithm is proposed in this *** to the superposition principle of temperature field,the geothermal field is decomposed into background and abnormal temperature fi elds for *** uniform layered model is used to solve the background *** the abnormal field is solved,the horizontal two-dimensional(2-D)Fourier transform is used to transform the 3-D diff erential equation satisfi ed by an abnormal field into a series of one-dimensional ordinary differential equations with diff erent wavenumbers,which greatly reduces the calculation and *** unit division of an ordinary diff erential equation is fl exible,and the calculation amount is *** algorithm fully takes advantage of the effi ciency of the Fourier transform and the quickness of the catch-up method to solve linear equations with a fixed bandwidth,which effectively improves the computational *** with the COMSOL Multiphysics professional simulation finite element software,the time consumption and memory requirements of the algorithm proposed in this paper are reduced by multiple orders of magnitude in terms of ensuring accuracy and the same mesh *** more the number of calculated nodes is,the more obvious is the *** design models to study the thermal conductivity,heat fl ux boundary,regional tectonic morphology,and topographic relief of the geothermal fi eld distribution.A 3-D geophysical model is developed based on topographic elevation data,geothermal geology,and geophysical exploration data in the Qiabuqia area of Gonghe Basin,Qinghai Province,*** simulation of the g

摘要：在坑道超前探测方法中,直流电阻率法原理和操作简单,应用前景广阔,其中侧向聚焦电阻率法应用在测井中已经成为一种常用方法.本文研究了三维坑道直流聚焦法电极组合,首先计算分析了两个同性点电源的电流分布规律,指出由于电流的相互排斥作用,电流密度在这两个点电源的中垂线下一定深度处产生最大值,这个深度与这两个点源之间的距离成正比.基于上述原理,设计出三种电极组合:四点电源、五点电源和九点电源布极方式.其次,用三维有限单元数值模拟的方法计算了上述三种电极系的空间电位分布,得出九点电源方式对电流聚束效果较好,而且当主电极电流小于屏蔽电极电流时效果最好.

摘要：对坑道超前探测方法中的三维坑道直流聚焦法的电极组合作了研究。计算、分析了2个同性点电源的电流分布规律,指出由于电流的相互排斥作用,电流密度在这两个点电源的中垂线下一定深度处产生最大值,这个深度与这两个点源之间的距离成正比。基于上述理由,设计出3种电极组合:四点电源、五点电源和九点电源布极方式。用三维有限单元数值模拟的方法计算了上述3种电极系的空间电位分布,发现九点电源方式对电流聚束效果较好,而且当主电极电流小于屏蔽电极电流时效果最好。

摘要：深入分析了现行地面瞬变电磁法中存在关断电流斜坡响应的计算方法,指出其中存在的不合理之处,提出用冲激响应积分算法计算存在关断电流斜坡时的瞬变电磁响应,并应用于航空瞬变电磁法一维正演计算中.计算结果表明,当存在关断电流斜坡时,早期的感应电动势明显大于没有断电后沿的值,且受影响的时间范围约为十倍的电流后沿宽度;当后沿宽度较大时,甚至晚期的感应电动势也出现了明显的误差.由此得出,在航空瞬变电磁法仪器设计和实测资料处理过程中,关断电流斜坡的响应不容忽视.

摘要：基于一种新的白光LED发光模型,对室内可见光通信系统多白光LED阵元发射天线进行了优化设计.分析了多阵元发射天线的阵元分布、阵元光轴极角、阵元层间距、阵元数目等参数对室内光功率分布的影响,给出了设计参数的优化选择方法和原则.并通过控制发射光功率的方法,实现了光功率分布为平顶形的多阵元天线设计.通过仿真和实验研究验证了所提出的优化设计方法.

摘要：在可见光通信系统中,光源具有照明和通信的双重作用。不同的光源布局必然会导致室内不同的光功率分布,因此必须对光源的布局进行合理的设计,使得室内接收光功率的分布趋向均匀。本文给出了室内光通信的传输模型,分析了布局设计与接收光功率分布的关系,并给出了房间内的四个通信光源的最优化布局设计。通过对光源布局与接收功率关系的仿真,验证了本文提出的最优化光源布局设计方法。

摘要：针对基于xPC的硬件在环仿真系统,研究了Matlab GUI监控软件的相关开发技术,以解决时钟驱动模式下,数据更新速率慢、显示停顿的问题。在设计监控系统模块化方案的基础上,利用ActiveX控件技术建立虚拟仪表交互界面,提出S函数驱动GUI界面的实时显示方法,实现仿真数据的动态显示。试验台的使用表明,开发的监控系统具有良好的人机交互功能,对仿真数据的采集频率可达100Hz,虚拟仪表的更新速率超过20Hz,数据传输及显示过程耗时小于21毫秒,满足实时监控的要求。

摘要：We propose the construction of a compact linac as the injector of a cancer therapy facility at the Institute of Modern Physics(IMP) of the Chinese Academy of Sciences(CAS). Based on a traditional setup, a new compact fast-bunching design is first introduced to optimize the 600 keV/u RFQ with a 0.05 pm A ^(12)C^(4+) beam. This shortens the RFQ structure length from the standard design value of272–230 cm while effectively regulating the particle loss and emittance growth. In addition, a detailed error analysis was performed after the optimization process. The error sources cover input beam parameters errors, machining errors and alignment errors. The simulation results show that the beam loss and emittance growth of the RFQ are acceptable and within typical ranges of error.

摘要：最少传感器跟车系统中,跟踪误差收敛缓慢和对前车干扰鲁棒性差是两个主要问题.基于终端滑模(TSM)控制方法,设计一种控制量非奇异且收敛快速的跟车控制律,并实现其实车应用.回顾已有非奇异快速终端滑模控制方法的基本原理;分析最少传感器跟车系统的特点,建立包含车辆和车间纵向动力学特性的两状态模型,设计非奇异快速终端滑模控制律;证明闭环系统到达阶段和滑动阶段的快速收敛特性,以及它对前车加减速干扰的强鲁棒性.仿真分析及实车实验表明,该控制器输出的节气门开度光滑无抖振,本车平稳快速跟随前车行驶,且当前车加速度有界时,闭环系统鲁棒收敛.

摘要：针对SWATH在波浪中航行时,其湿甲板底部易遭受砰击从而引起船体振动的现象,对SWATH的砰击动态响应和强度进行了研究。利用SWATH在规则波中船波相对运动推导了随空间和时间变化的砰击载荷,采用有限元数值仿真,计算了SWATH湿甲板受砰击载荷作用的动态响应,分析了其位移和应力分布规律;并与静强度法砰击响应进行了比较,对湿甲板强度设计方法进行了探讨,为船舶结构设计提供参考。