Change of Volume of Air Dissolved in Water Imposed to Millimeter Waves of Low Intensity

We discuss an experimental evidence for a decrease in the volume of air dissolved in water caused by millimeter electromagnetic waves of low intensity. The changes obtained were much greater than the expected conditioned by a pure thermal effect. The result observed is explained by air bubbles that take an active part in a mechanism of withdrawing dissolved air from water. The variation of restoring the dissolved air volume up to an equilibrium level after ceasing irradiation of water by millimeter waves was investigated as well.     

Variations of Free Volume of the Air Abundant in the Water by the Millimeter Waves of Low Intensity

We have found that low power millimeter electromagnetic radiation causes an increase in the volume pertinent to the free air abundant in water. This change is caused by the transition of some part of the dissolved air into a bubble state under decreasing dissolubility of the gas due to its thermal heating by the waves. The increase in the free air may occur only under those conditions when there is no convection in the liquid, i.e. in the case of irradiating by means of low-intense waves.     

On Causes of Biological Efficiency of Low-Intensive Millimeter Waves

The process of the ions transport through the biological membrane is considered. A role of air microbubbles efficiently mixing a near-membrane liquid layer in the presence of a temperature gradient is pointed out. These circumstances result in lowering an energy barrier height of the transmembrane ion-transport. It is shown that even low-level irradiation by the millimeter waves creates the temperature gradient, which is enough for effective mixing of near-membrane liquid's layer. It is demonstrated that a process of restoration an equilibrium air-distribution in the intercellar medium after ceasing the microwave irradiation proceeds according to the diffusion mechanism, i.e. rather slow.     

Sensitivity of Homogeneity Mapping of Dielectric Wafer Using Millimeter Waves

A plane electromagnetic wave normally falling on a surface of a dielectric plate has been considered to investigate the sensitivity of the dielectric constant homogeneity mapping in the dielectric wafer by measuring the phase and/or the amplitude of the millimeter wave reflected from or transmitted through it. Measurement conditions at which the highest sensitivity might be achieved are established. The sensitivity at Fabry-Perot resonance conditions as well as at frequency shifted from resonance has been considered.     

Sensitivity of Homogeneity Mapping of Semiconducting Wafer Using Millimeter Waves

The homogeneity mapping by measuring the phase or the amplitude of millimeter wave reflected from or transmitted through the semiconducting wafer is considered. The sensitivity of the conductivity homogeneity mapping is determined and conditions at which conductivity inhomogeneities can be distinguished from dielectric constant inhomogeneities are established.     

Computation of the Backscattering Power Density for Rainfall in Millimeter Waves Band

The size distribution and canting angle distribution for non-spherical rain drops are taken into account. Utilizing the Muller matrix, the backscattering power densities are computed at different rain rate and different polarization in millimeter waves band, according the rainfall condition in Xi'an, China. Finally the results obtained are discussed.     

The Effects Induced by Turbulence and Dust Storms on Millimeter Waves

Dust storms and turbulence consist of a random medium system, its effects on milimeter waves propagation are studied. Attenuation of millimeter waves, its phase shift and cross- polar discrimination are presented. Results show that dust storms mainly effects XPD and phase shift of millimeter waves, turbulence chiefly produces attenuation, in mediocre fluctuation.     

Analysis for Transmission Properties of Arbitrarily Trapezoidal-Groove Waveguide for Millimeter Waves

In this paper, the transmission properties such as the dispersion and attenuation characteristics for the dominant mode of the trapezoidal-groove waveguide with arbitrarily inclined angle are analyzed and discussed by using the mode-matching method. Some calculated results are in very good agreement with the published data. The obtained conclusions are of important significance in theoretical studies and actual applications of trapezoidal-groove waveguides for millimeter and submillimeter waves.     

Waveguide Filter on Base of Dielectric the Bragg Structure for Millimeter Waves Applications

It is considered and offered the waveguide band elimination filter with the working mode H₁₀ that can be used in millimeter waves devices such as up, down- converters, mixer, etc. The characteristics of the filter was calculated by using analogy in electromagnetic the waveguide propagation and optical the wave propagation in the medium with the specific refractive index N. This conception can be applied for party-filled waveguide in the case when the Brillouin decomposition of the waveguide waves into plane waves is correct and the transformation of the incident (propagating) mode into other the mode types is absent.In this work were calculated the spectrum energy transmittance T(f) in the filter stop band and the wavelength ₀ in the center of this band using the characteristic equation obtained in the result of theoretical consideration. Theoretical results are compared with experimental measurements.     

Impedance Characteristics of Closed Elliptic-Groove Waveguide for Millimeter Waves

A characteristic equation and impedance characteristic for the dominant mode of closed elliptic-groove guide have been analyzed and discussed by using the mode-matching method. The reference size of the closed elliptic-groove guide for the good impedance matching with rectangular guide in actual application is given. The obtained conclusions are of important significance in theoretical studies and actual applications of closed elliptic-groove guide for millimeter waves.     

Transmission Properties of Closed Trapezoidal-Groove Guide for Millimeter Waves

The transmission characteristics of the mode TE₁₁ for a new type of closed trapezoidal-groove guide with arbitrary inclined angle are analysed in detail with the mode-matching method in this paper. The calculated results are in good agreement with the experimental values in the published reference. The dispersion of the closed trapezoidal-groove guide is very low. The relationships of the cut-off wavelength and the attenuation constant with the structural sizes of the closed trapezoidal-groove waveguide are also obtained. The given results have very important value in study, design, manufacture and application for closed trapezoidal-groove waveguide.     

The Improvement of PML Approach for the Calculation of Microwave and Millimeter Waves Circuit

The improved PML absorbing boundary condition have been introduced in this paper. The reflection coefficient of the absorbing boundary condition is less than the reflection coefficient of Berenger's PML algorithm. And in order to validate the theory and its effectiveness, We have applied the absorbing boundary condition to the calculation of microwave and millimeter waves circuit and get its reflection coefficient S ₁₁. The numerical result is shown in this paper.     

水下气泡高速摄影光学系统设计

为了研究水下气泡的粒径、速度和浓度特性,提出基于高速电荷耦合器件(CCD)的气泡照明和三维摄影光学系统.采用532nm半导体激光器,基于伽利略结构用三个柱面镜设计了厚度1.5mm,宽度44mm的片光源。设计物像距530mm,放大率为0.4,1,2.5倍(×)的摄影光学系统,每组均由共用前组镜和会聚镜组成,中间以平行光中继。通过同步移动片光源和共用前组镜实现60mm×40mm视场内二维高速成像和纵向5mm扫描,具有结构简单、性能可靠的特点。对设计结果进行评价,0.4,1,2.5×成像光学系统在0.707ω,50lp/mm时调制传递函数值分别为0.58,0.55和0.38,能够分辨粒径范围为10～450μm的气泡。     

Transmission Modes of Closed Elliptic-Groove Waveguides for Millimeter Waves

In this paper, a new type of horizontal-flat and vertical-flat closed elliptic-groove guides is firstly presented. The field components and characteristic equations for some main transmission modes of the closed elliptic-groove guides are derived by with the help of the mode-matching method and Mathieu function. The variations of the cut-off wavelengths along with eccentricities, widths and lengths of the parallel plates for a number of lower order transmission modes of the closed elliptic-groove guides are also analysed in detail. The calculated results in good agreement with ones in the relevant references are of very important values in theoretical researches and actual applications of closed elliptic-groove guides for millimeter and submillimeter waves.     

水中气泡激光散射的图像识别方法研究

采用Q调制高功率脉冲激光光源和水下数码相机拍摄到水中气泡群光散射的图像。对水中群聚气泡的光散射图像进行了初步的定性研究。利用MATLAB处理并分析图像,结果表明气泡光散射图像的梯度与气泡的尺度有关,用图像方法来识别气泡群是可行的。     

Mode Distribution and Bandwidth Characteristic of Arbitrarily Trapezoidal-Groove Guide for Millimeter Waves

The modes TE and TM of arbitrarily trapezoidal-groove guide are analyzed by using the mode-matching method. The mode TE₁₁ is the dominant mode of the trapezoidal-groove guide under different conditions. The bandwidth characteristic and the operation condition for the single dominant mode are discussed. The obtained conclusions are of very important significance in theoretical study and practical application of trapeziodal-groove guides for millimeter waves.     

激光在水中气泡微粒的后向散射特性

从激光能量、目标位置、视场大小及气泡厚度等方面对气泡后向散射特性进行研究.采用实验方法研究脉冲激光气泡后向散射特性.实验结果表明,增大激光能量在一定程度上可以有效地改善气泡探测的效果,而气泡发生器位置和视场的合理选择使得气泡探测更容易些,气泡区域厚度的变化对气泡后向散射并没有明显的影响.该实验结论与蒙特卡洛数值模拟的结果一致.     

Comparison of Volume and Integrated P-I-N Modulators in Millimeter Wave Range

Volume and based on surface oriented integrated p-i-n-structures modulators have demonstrated high efficiency in millimeter wave range as quasi-optical modulators and phase shifters. These structures possess high modulation and high-speed properties; sustain great EM powers. However, the modulation characteristics of p-i-n modulators of both mentioned types in millimeter wave range have not been investigated yet. Here, a comparison and criteria of volume and integrated based on Si surface oriented structure modulators in millimeter wave range are presented.     

基于HBHE的毫米波辐照下大鼠皮肤温度场研究

推导出了基于高斯分布的毫米波的功率分布函数,并分别根据传统的pennes方程和新提出的HBHE方程以及毫米波在动物皮肤内的传播特性,建立了33.5 GHz毫米波不同辐照强度下的大鼠皮肤的非稳态多层传热模型,在二维柱坐标下进行离散计算,得到了长时间辐照条件的温度变化规律,并将理论结果与实验数据进行了比较,发现HBHE的结果与实测结果更为吻合,特别是在高功率条件辐照下,与实测结果基本一致,验证该理论模型的优越性。     

关于炮长微光指挥镜(二代)气密性和水密性问题的探讨

通过对炮长微光指挥镜Ｃ２组试验中质量问题的解剖，分析了气密性检查方法的缺陷，特殊结构的光学产品气密性检查和水密性检查不能等效代替，并提出了改进产品的密封质量的措施