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Light transmission in thermal stress-induced birefringent medium
热应力双折射介质中的光传输研究

Cen Zhao-Feng,Li Xiao-Tong,
,李晓彤

物理学报 , 2010,
Abstract: In this paper the temperature and thermal stress distribution in a simplified-mode transparent slab is calculated and then variation of refractive index is acquired based on the photo-elastic theory. Using the vector differential algorithm the refractive behavior of rays in such media is simulated, and luminous intensity distribution and shape of fringes at the receiving plane is predicted. The output of the program is in coincidence with the check experiment based on photo-elasticity technique, which indicates the correctness of our analysis method and light transmission calculation method. This research provides a practical means for improving the imaging quality of optical instruments.
高应变率单轴压缩下岩体裂隙扩展的细观位移模式
,黄达
煤炭学报 , 2014,
Abstract: 为了研究动态荷载作用下岩体裂隙扩展机制,通过细观颗粒平行黏结模型(PBM)的模拟,分析了高应变率单轴压缩条件下单裂隙岩样的损伤演化及细观位移场。高应变率大小对岩样最终破裂形态影响不大,但随应变率的增大,细观裂纹越多且局部化程度越强。随着裂隙倾角的增大,裂纹分叉交织越密,并在裂隙倾角≤45°和≥60°范围内分别具有相似的破裂形态。裂隙尖端翼裂纹是倾斜裂隙面相对滑移致使尖端撕裂的结果,高应变率下翼裂纹在峰后不再扩展。应变率越小,裂隙倾角越小,翼裂纹扩展的长度越长。定义了3类细观颗粒间的位移模式及其所形成的3类裂纹性质。将裂纹扩展概括为6种基本模式:翼裂纹+张拉、顺翼裂纹、反翼复合裂纹+张拉、顺翼复合裂纹+张拉、共面复合裂纹和倾斜复合裂纹,其中复合裂纹为拉剪裂纹或压剪裂纹。
Simulation and analysis of nonlinear self-focusing phenomenon based on ray-tracing
基于光线光学的非线性自聚焦现象的仿真分析

Ruan Wang-Chao,Cen Zhao-Feng,Li Xiao-Tong,Liu Yang-Zhou,Pang Wu-Bin,
阮望超
,,李晓彤,刘洋舟,庞武斌

物理学报 , 2013,
Abstract: The simulation of nonlinear self-focusing phenomenon using ray-tracing method can macroscopically provide an intuitive picture of the propagation of light in a self-focusing material, without adopting paraxial approximation or self-similar hypothesis. In this paper, propagation of light is sampled by discrete slices along a certain direction. Thus nonlinear propagation is turned into the combination of optical modulation of the refractive index on separate slices and linear propagation between each two adjacent slices. On each slice, after calculating the flux, we use a novel algorithm to suppress the quantized errors. For the linear propagating process, Adams method is adopted to solve the ray equations, which solve the problem that the widely used Runge-Kutta method cannot be used in simulation of light in nonlinear materials. The simulation results reveal that there are several foci along the propagating axis and the location of the first focus becomes closer to the incident plane as the power of light goes up. Furthermore, because the program traces real rays, it is possible to reach the non-paraxial region and reveal the phenomenon of ring-structure flux distributions caused by self-focusing. This is significant for the safety of high-power laser systems. Some commercial optical design and simulation software are also based on ray-tracing methods. Thus the systems including both nonlinear and linear materials are possible to simulate, which can guide people to set up the corresponding experimental systems.
成庄矿3#煤层瓦斯赋存影响因素分析

煤炭工程 , 2011,
Abstract: 通过分析成庄矿3#煤层瓦斯含量值与井田地质构造关系,运用地质构造理论及相应的瓦斯含量变化数学模型,分析了成庄井田的瓦斯赋存特征,从瓦斯地质学的角度阐述了3#煤层瓦斯赋存与井田地质构造、煤层埋藏深度、煤层水分含量、煤层基岩厚度及顶板岩石厚度的关系,初步分析了井田内瓦斯赋存的有效影响因素,为今后有效地进行瓦斯预测及防治提供理论依据。
几种主要固沙措施的价值分析

中国沙漠 , 1995,
Abstract: 以甘肃民勤沙区为例,采用ABC分析法选取了当地6种主要固沙措施,将其功能分解为主要功能和次要功能。主要功能定义为固阻流沙的功能,以1-蚀积系数表示;次要功能定义为改善土壤理化性质的功能,以增加土壤有机质、全氮量和<0.1mm的沙粒的相对值表示,调查计算了固沙措施功能周期内的全部成本,从功能和成本两方面进行了价值分析,为选用固沙效果显著且投资相对低廉的固沙措施提供科学依据。
东北蝲蛄逆水移行习性的研究

动物学杂志 , 1983,
Abstract:
狐狸膀胱毛细线虫在辽宁的发现

动物学杂志 , 1984,
Abstract:
沙漠人工植被的生态学取向及其途径

生态学杂志 , 2004,
Abstract: ?水是干旱沙漠植物生态系统中的最重要的限制因子。在干旱沙漠生境中建造人工植被的正确方向是要建造沙漠人工植被,就必须以提供额外的水资源为前提;在不能增加额外水资源的情况下不应增加沙漠人工植被;增加沙漠植被应保护现有植被和建造半人工植被为主。考察种群生态适应性的一般过程:一是目前有无这种植物的天然种群,二是历史上是否有过这种植物的种群,三是目前的生境条件是否满足这种种群或群落的需要,四是有无人工提供生态资源的可能性。封育保护和建造半人工植被是建造沙漠植被的主要途径,保护地下水资源是根本途径。
民勤西沙窝生态气候变化特征

气象 , 2000, DOI: 10.7519/j.issn.1000-0526.2000.05.012
Abstract: (1)分析得到勤试验站13个观测指标中的145个统计项中的前6个主成分最大载荷因子的多年变化特征是:年日照时数70~80年代持续下降;年平均气温60~80年代下降,90年代以后显著增高;10月份平均风速70年代中期至80年代中期下降,之后增大;年大风日数呈波浪式上升;年最大风速有增无减;8月降水量相对稳定。当地的气候环境在80年代中期以前朝良性方向发展,80年代中期以来进一步恶化。(2)年沙尘暴日数的多年变化特征与年日照时数有较大的相似性;年平均最高气温、年平均地温和7月份极端最高气温与年平均气温的多年分
希望大厦深基坑围护结构设计的优化

武汉理工大学学报 , 1999,
Abstract: ?根据希望大厦的工程地质情况、周边环境及工程特点,合理地选取深基坑的支护结构形式,叙述了支护结构设计原则及步骤,给出了优化方案,取得了可观的经济效益
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