Temporal evolution of atmospheric cascade glow discharge with pulsed discharge and radio frequency discharge

Atmospheric cascade discharges with pulsed discharge and radio frequency(RF)discharge were experimentally investigated by the temporal evolution of discharge spatial profile and intensity.The indium tin oxide(ITO)coated glass was employed as the transparent electrode to capture the discharge distribution above the electrode surface.It is demonstrated that in the pulsed discharge with dielectric barrier,the first discharge at the rising edge of pulse voltage is uniformly ignited and then forms an expanding plasma ring on the ITO electrode surface,which shrinks to the same diameter as that of bare stainless steel electrode with the generation of second discharge at the falling edge of pulse voltage.The discharge profiles along the electrode surface and discharge gap of the successive RF discharge are dependent on the intensity and spatial distribution of residual plasma species generated by the pulsed discharge,which is determined by the time interval between the pulsed discharge and RF discharge.It is demonstrated that the residual plasma species before the RF discharge ignition help to achieve the stable operation of RF discharge with elevated intensity.     

钢筋混凝土小变形阻尼研究

材料的阻尼是衡量材料本身减振性能的主要指标。采用自由振动法测试得到了一批钢筋混凝土小变形阻尼比的基础性数据。试验结果表明：所采用的阻尼比测试方法和试验过程是可靠的；对同类型的混凝土，其小变形阻尼比均随抗压强度和弹性模量提高而降低；普通混凝土小变形阻尼比在0.9％～2.0％之间；纵筋变化对小变形阻尼影响较大，而箍筋变化对小变形阻尼的影响较小。     

羧基丁苯胶水泥混凝土阻尼值的探索性研究

以羧基丁苯胶水泥混凝土为研究对象，采用自由振动法测试了不同掺量丁苯胶水泥混凝土的阻尼值，同时又测试其弹性模量和抗压强度，试图获得一种有较高阻尼，同时又有较高弹性模量和较高抗压强度的混凝土。     

The Gas Nucleation Process Study of Anatase TiO2 in Atmospheric Non-Thermal Plasma EnhancedChemical Vapor Deposition简

Abstract The gas phase nucleation process of anatase TiO2 in atmospheric non-thermal plasma enhanced chemical vapor deposition is studied. The particles synthesized in the plasma gas phase at different power density were collected outside of the reactor. The structure of the collected particles has been investigated by field scanning electron microscope （FESEM）, X-ray diffraction （XRD）, high resolution transmission electron microscopy （HRTEM） and selected area electron diffraction （SAED）. The analysis shows that uniform crystalline nuclei with average size of several nanometers have been formed in the scale of micro second through this reactive atmo- spheric plasma gas process. The crystallinity of the nanoparticles increases with power density. The high density of crystalline nanonuclei in the plasma gas phase and the low gas temperature are beneficial to the fast deposition of the 3D porous anatase TiO2 film.     

Gas Breakdown of Radio Frequency Glow Discharges in Helium at near Atmospheric Pressure

A one-dimensional self-consistent fluid model was developed for radio frequency glow discharge in helium at near atmospheric pressure, and was employed to study the gas breakdown characteristics in terms of breakdown voltage. The effective secondary electron emission coefficient and the effective electric field for ions were demonstrated to be important for determining the breakdown voltage of radio frequency glow discharge at near atmospheric pressure. The constant of A was estimated to be 64±4 cm 1 Torr 1 , which was proportional to the first Townsend coefficient and could be employed to evaluate the gas breakdown voltage. The reduction in the breakdown voltage of radio frequency glow discharge with excitation frequency was studied and attributed to the electron trapping effect in the discharge gap.     

水平低周反复荷载作用下高效预应力叠合框架抗震性能的试验研究

介绍了两榀高效预应力混凝土 (HPC)叠合框架和 1榀 (RC)整浇框架模型试验 ,并对试验结果进行了比较。分析了 HPC叠合框架在水平低周反复荷载作用下的受力特点、裂缝开展、延性指标、耗能能力及破坏形式 ,为 HPC叠合框架结构在地震区的应用提供了试验依据。     

自密实混凝土测试方法与技术研究

简要介绍了自密实混凝土及其工作性的定义,详细论述了国际上自密实混凝土工作性测试方法与技术的研究及应用现状,并对今后要解决的问题及发展前景进行了展望.     

APG／AES表面活性剂复配体系热力学函数研究

通过对非离子表面活性剂烷基多糖苷（APG）和阴离子表面活性剂脂肪醇聚氧乙烯醚硫酸钠（AES）复配体系胶束形成过程中热力学函数变化的研究,应用物理化学的基本原理,阐明了混合胶束的形成过程是一个自发性的过程,形成的混合胶束是稳定的,为进一步研究混合表现活性剂提供了理论基础。     

粉末注射成形材料微波烧结过程的有限元模拟

基于传统电阻加热烧结过程的建模与模拟,通过对粉末注射成形材料微波烧结过程的机理分析,结合电磁场、热力学以及连续介质力学原理,确定了微波烧结全过程的数学模型和模拟方法;通过建立合理的力学模型和控制方程,采用COMSOL Multi-physics软件模拟微波烧结过程,并将模拟结果与试验结果进行了对比。结果表明:氧化锆粉末成形件在微波烧结初始阶段加热缓慢,当温度升至400℃之后,成形件内部温度持续急剧升高;当加热至1 360℃时,烧结件的相对密度高达92%,可满足粉末烧结工艺要求;建立的数学模型能有效模拟微波烧结过程中粉末成形材料内部的电场、温度场分布以及密度的衍化过程。     

埋入SMA对CFRP疲劳性能的影响

通过研究埋入形状记忆合金（Shape Memory Alloy，简称SMA）的碳纤维环氧树脂复合材料单向板的疲莩孽验，得知埋入SMA并加热激励后的单向板的剩余刚度、剩余强度、以及在特定应力水平下的疲劳寿命等抗疲劳性能指标有所改善。将它们与未埋入SMA的空白单向板的相应性能比较，发现埋入SMA并加热激励后的复合材料单向板的抗疲劳性得到很大程度的提高。