Influence of wave normal angle on gyroresonance between chorus waves and outer radiation belt electrons

In this paper,using a Gaussian distribution of wave normal angle X=tan,and considering contributions of harmonic resonances n up to±5,we analyze the effect of normal angle on diffusion coefficients induced by gyroresonance between chorus waves and electrons with energies 0.1 and 1.0 MeV on the dayside and nightside at L=4.5.When pitch angle e>10°,for 0.1and 1.0 MeV electrons on the dayside and nightside,diffusion coefficients of five orders(2,1,0,1,2)decrease with increasing normal angle peak,leading to the total diffusion coefficients decreasing with increasing peak.When e<10°,for 1.0MeV electrons on the dayside and 0.1 MeV electrons on the dayside and nightside,the positive order diffusion coefficients are generally smaller than the same negative order ones;in the meanwhile,diffusion coefficients of orders(2,1,2)are very small,the dominant order n=1 diffusion coefficients change very little,hence the total diffusion coefficients almost remain unchanged.However,for 1.0 MeV electrons on the nightside,diffusion coefficients of orders(2,1,2)which are larger than those of the order(1)resonance increase with increasing peak,hence the total diffusion coefficients increase with increasing peak.The current results show that the wave normal angle plays an important role in the quantitative analysis of gyroresonance between chorus waves and electrons in the outer radiation belt.     

降雨诱发黄土边坡失稳室内试验研究

为研究降雨诱发滑坡失稳破坏机理和演化特征,开展了人工降雨条件下黄土滑坡室内研究,通过对土体的体积含水率、基质吸力及坡体变形破坏监测,分析降雨入渗对黄土边坡稳定性的影响.结果表明:在一定的降雨强度范围内,降雨强度越大,降雨入渗速度越快,越易发生滑坡;边坡坡度越缓,坡面降雨入渗速度越快;湿润锋移动在坡脚和坡顶较坡面更快,对滑坡的发生发展有较大影响;试验滑坡为多级后退式破坏模式.     

Mechanism analysis on pillar instability induced by micro-disturbance under critical condition

A simplified mechanical model of ultra-high pillar was established and its potential energy expression was derived under axial load on the basis of energy theory. Under critical conditions according to the nonlinear theory, the critical behaviors and the forming mechanism of pillar instability were discussed by external disturbance , such as stresses waves by blasting , axial force eccentricity ratherish and imperfections in pillar. The results show that the micro-disturbances attenuate with time and they are independence each other when pillar is in the stability state. Their effects on the stability of system are inessential. The correlation degree of disturbances increases sharply and various micro-disturbances are relative and nested reciprocally when the system is in critical state and they also cooperate with each other, which induces system to reach a new state.     

燃烧诱发热声不稳定控制的研究进展

针对贫燃预混低NOx燃气轮机的燃烧诱发热声不稳定问题,说明了燃烧热声不稳定的起源、特点和危害,详细阐述了当前燃烧热声不稳定控制研究的现状,分析了热声不稳定的被动控制和主动控制的概念、应用和各自特点。被动控制和主动控制的核心思想是一致的,通过重新设计或外加干扰解耦火焰热释放脉动与声场的相互作用。     

bExperimental and discrete element numerical analysis of side slope instability induced by fissure water underlying impervious bed

When the sliding mass contains impervious bed, rainfall can infiltrate into mountain via crevices and form higher artesian aquifer at impervious bed inferior. This will decrease slip resistance and increase sliding forces of the sliding mass, thus lowering the safety factor, and inducing landslide disasters. In this paper, a landslide experimental apparatus is designed for experimental studies on the mechanism of this type of landslides. Meanwhile, the non-dimensional parameters in the model experiment are taken into account using dimensional analysis. The experimental results show that (1) the ratio of the cleft water pressure to the overlying pressure is a crucial parameter affecting the stability of the slope; (2) when the shut-in pressure reaches 80% of the normal component of the pressure on the slip surface made up of rock and soil, landslide will occur: (3) the whole slope will start to slide when the shut-in pressure is equal to the normal component of the pressure formed by the overlying rock and soil on the upper 30% area. In this article, a discrete element method simulation is used to investigate the influence of cleft water pressure and shearing strength on the landslide stability. It can be concluded that the critical value of C_cr, ρ_cr, which determines the slide mass stability, increases with the increase of the water pressure; if the water pressure reaches a high level, the stability of the slide mass depends mainly on C, while the influence of ? becomes smaller than C.     

Experimental and discrete element numerical analysis of side slope instability induced by fissure water underlying impervious bed

1 Introduction The in situ observations and analysis on the landslide events indicate that water is one of the key factors which induce landslide of the mountain mass[1―8]. The mechanism offissure water inducing landslide can be generalized into three aspects: (1) the softening influence of water weakens the strength of materials on the slip surface[9―11]; (2) the cleft water pressure towards the slide slope free face increases sliding force[12―15]; (3) water pressure on the slip surface lo…     

管道联接件参数识别的波动方法

基于波动理论,提出了一种识别管道联接件物理参数的新方法.以直管在平面内的弯曲振动为例,将弯曲波分解为左、右行波和衰减波,建立起管道单元上各测量点功率谱与波谱的关系,并由联接件处位移连续及力平衡条件,将联接件刚度及阻尼表示成波谱的函数.由联接件物理参数的辨识转化为与联接件相连管道单元上波谱的辨识.最后通过数值算例验证了波动方法在管道联接件物理参数辨识中的可行性.结果表明,波动方法在参数辨识中具有良好的识别精度和数值稳定性,是一种极有潜力的参数辨识方法.     

用旋转矢量法研究驻波

用解析法研究驻波比较抽象,利用旋转矢量法直观、形象地研究了驻波的特点。     

TCSC改善波浪发电系统的性能分析

比较各种波能转换装置优缺点,并对振荡水柱式发电装置并网运行进行建模.当波浪发电系统并网时,采用TCSC对系统进行无功控制并提高电压稳定性.在正常运行和线路发生故障2种情况下,分别分析TCSC对波浪发电系统的影响.研究结果表明,TCSC所表现的补偿线路阻抗的能力在稳定电压、抑制系统振荡等方面有较好的作用;采用TCSC后的系统静态输送功率极限和暂态稳定性都得到了较大提高.     

双层介质球波散射的近似计算

文中给出了双层介质球对波散射的一此似计算，包括Ｒａｙｌｅｉｇｈ近似，Ｂａｙｌｅｉｇｈ近似，Ｂｏｒｎ近似及ＷＫＢ近似。在三种近似各自适用的条件下，计算的散射与消光截面同ＭＩＥ解符合很好。最后对粒子尺寸及波长与结果的相关性及三种近拟的适用范围进行了讨论。     

超声波破解污泥的试验研究

研究了超声波破解污泥的情况.在超声波单独作用及超声波/碱作用下,测定SCOD（溶解性COD）的量,分析超声波、超声波/碱对污泥破解的效果.结果表明,从镜检中可以看到,污泥絮体随超声波作用时间的延长越来越散;SCOD随超声波作用时间的延长而增加;超声波与碱协同作用对污泥的破壁效果比超声波单独作用好.     

利用超声波辐射提高废水可生化性试验研究

本文介绍了超声波照射提高废水可生化性的基理,研究了超声波照射时间和超声波照射功率对废水可生化性的影响.     

Cloud and precipitation interference by strong low-frequency sound wave

Acoustic interference of atmosphere has been an attractive research area because of its potential effect on environment, water resources, ecology, agriculture, and other areas. However, it is also a controversial topic because of the difficulty of quantitative assessment and high operating costs. In this study, a novel acoustic interference technology is proposed that uses strong lowfrequency sound waves. There is no chemical pollution or dependence on airborne vehicles, and it can be remotely controlled at low cost. A complete equipment system for acoustic atmospheric interference technology is established, based on which a series of experimental studies on cloud and precipitation response under acoustic action are performed, mainly including the radar echo intensity, cloud microphysical characteristics and the spatial distribution of ground rainfall intensity. The trigger and periodic effect of the acoustic waves on the cloud are proposed to be the key responses of acoustic atmospheric interference. This study is important to further research on atmosphere interference technology based on low frequency strong sound waves.     

超声降解苯胺溶液实验研究

采用超声波辐射降解苯胺溶液对超声波辐射时间、溶液温度、pH值、初始浓度、外加H2O2等因素对降解效果的影响进行了探讨.实验结果表明:该法能有效去除苯胺,去除率随辐射时间的延长而增加;低浓度、碱性有利于苯胺的降解;反应温度控制在30℃以下对超声降解有利;外加H2O2可明显提高苯胺的去除率.     

超声降解苯胺溶液实验研究

采用超声波辐射降解苯胺溶液对超声波辐射时间、溶液温度、pH值、初始浓度、外加H2O2等因素对降解效果的影响进行了探讨．实验结果表明：该法能有效去除苯胺,去除率随辐射时间的延长而增加;低浓度、碱性有利于苯胺的降解;反应温度控制在30℃以下对超声降解有利;外加H2O2可明显提高苯胺的去除率．     

基于滑动载波方式的电梯轿厢信息传输装置

研制的基于滑动载波方式的电梯轿厢信息传输装置,采用磁耦合原理实现了电梯控制信息的非接触式传输,避免了传统方式中轿厢的随行电缆易疲劳破损的弊病。滑动载波装置的调制解调环节采用高集成度载波通信芯片ST7540完成载波信息的收发,装置的总线接口采用集成模块实现CAN-bus网络和UART设备之间的数据通信,磁耦合器的设计考虑了最佳功率传输。该装置具有零误码率的传输可靠性,对外无电波干扰的电磁兼容性,既能满足新装电梯的设计要求又方便对已安装的传统随行电缆通信方式进行升级改造等优点。     

浅析反射波法检测桩完整性应注意的问题

在比较了桩基低应变各种动测方法的基础上，着重介绍了采用反射波法检测桩基完整性应注意的问题，供交流与参考。     

The New Technology of Composite Materials Repairing by Light Wave

The repairing of damaged composite materials becomes a hot research subject in the late 1990s.In this paper a new technology of repairing composite materials is given on the basis of our previous research. The light wave of 675run transmitted by optical fiber is used as repairing light source, special repairable adhesive which can be stimulated by the light is adopted. By comparing the stiffness of the composite material before and after being damaged, it can be concluded that the mechamical property will not be changed with the feasible repairing teehnology.