首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 162 毫秒
1.
电感耦合等离子体(ICP)被应用于Freon12(CF2CCl2)的焚烧处理。通过观察引入Fre-on12前后ICP电子密度分布的变化,可在一定程度上间接了解焚烧的效果。由于Hβ线在低观察高度受到较为严重的光谱干扰,本文采用Hα线进行ICP电子密度的测定。发射强度与电子密度测定的结果显示了Freon12在ICP的不同观测高度产生不同的影响,表明ICP在导入Freon12后出现了明显的“热箍缩”效应,从而有利于该化合物的完全分解。  相似文献   

2.
用漫反射红外光谱和光声红外光谱研究了金属羰基化合物(CpFe(CO)2)2Cp=η^5-C5H5与酸性,中性和碱性Al2O3及TiO2的相互作用,结果表明,在Al2O3表面生成的洗生物种类及浓度与Al2O3的酸碱度明显相关,在酸性Al2O3表面,主要存在衍生物(CpFe(CO)2Fe-H-Fe(CO2Cp)^+及少量的CpFe(CO)2(-O-);在中性Al2O3表面存在的CpFe(CO)2(-O  相似文献   

3.
新型环保制冷剂氟化醚类物质的热力学分析   总被引:7,自引:1,他引:6  
本文筛选了可能作为替代制冷剂的氟化醚类(HFEs)纯物质和混合物,然后对这些工质的制冷循环性能进行了热力学分析。分析结果表明:在醚类纯质及混合物中 c-HFE216、 HFE143a、 c-E2-216、 c-HFE216/HFE143a和c-HFE216/c-E2-216适合替代 CFC12和 HFC134a ; HFE125适合替代 CFC115; HFE134、 HFE245cb β和 HFE143/HFE31-10适合替代 CFC114 ; HFE338mf、 HFE245fa、 HFE143、 HPE263fb、 HFE236ea/HPE245fa和 HFE236ea/HFE143有望成为CFC11的替代物。  相似文献   

4.
负载型铁催化剂上费托合成的反应机理   总被引:1,自引:0,他引:1  
用瞬时应答技术对费托合成的初始态动力学行为进行跟踪,研究了Fe/γ-Al2O3,Fe-Co/γ-AL2O3和Fe-Co-K2O/γ-Al2O3催化剂上CO氢化生成轻的催化性能和C2烃的生成机理。结果表明,在Fe-Co-K2O/γ-A2O3上CO解离吸附形成的表面碳是合成烃反应的活性中心,表面碳的逐步氢化,生成亚甲基物种而亚甲基物种的聚合促成了烃键的增长。  相似文献   

5.
以NH4Cl作助溶剂,碳还原硫酸钙的方法合成了CaS:Ce。在紫外光激发下,CaS:Ce中存在着Ce^3+的^2D-^2F5/2(500nm)和^2D-^2F7/2(550nm)跃迁发射,但在蓝色光激发下,只有波峰为532nm半宽度为92nm的宽带发射。当Ce^3+的浓度为0.075mol%时,^2D-^2F5/2跃迁发射强度与^2D-^2F7/2跃迁发射强度相等,而532nm发射猝灭。  相似文献   

6.
热稳定法拉第旋转TbYbBiIG磁光单晶及性能   总被引:1,自引:0,他引:1  
张守业  张志良 《光学学报》1997,17(5):26-629
采用高温溶液法,以Bi2O3/B2O3为助熔剂成功地生长出掺铋复合稀土铁石榴石(TbYbBi)3Fe5O12(简称TbYbBiIG)晶体。晶体外形规则,最大尺寸为7×6×4mm3,X射线衍射分析证实,生长的晶体为TbYbBiIG单相单晶体,扫描电镜能谱分析其组成为Tb2.06Yb0.46Bi0.48Fe5O12。在1.0μm~1.7μm波段测量出晶体法拉第旋转谱和光吸收谱。当λ=1.55μm时,在10°C~80°C温度范围内测得法拉第旋转θF的温度系数为dθF/dT=-2.3×10-2deg·mm-1K-1。研究结果表明,TbYbBiIG单晶体在近红外波段θF约为YIG单晶的3倍,温度系数小,是制作高性能光隔离器的一种好材料  相似文献   

7.
亚稳态分子CO(α^3П)猝灭过程   总被引:3,自引:1,他引:2  
用流动余辉技术测定了亚稳态分子CO(α^3П)被CS2,SO2,SO,NOC12,IC1,SO2C12,SC12,H2O,CHC13,CH2C12,He和Ne猝灭的速率常数,并较为详细地讨论了CO(α)和CS2,SO2,SO,NO等分子的猝灭反应的可能出口通道,指出CO(α)被其他分子猝灭时,主要出口通道是化学反应,E-E和E-V能量转移,有时是几种不同的出口通道同时存在。  相似文献   

8.
高温下CF4在H2中解离的反应动力学研究   总被引:2,自引:1,他引:1  
用单脉冲激波管研究了有少量CF3Cl参予下的CF4与H2的混合在高温下的反应动力学,发现主要产物为C2F4和CF3H。对实验结果的分析表明,反应过程为一个双中心链反应。始发反应为CF3Cl的C-Cl键的断裂,继之以由H2和CF4为媒介的双中心链传递,最后测得温度由1000至1080K,压力为0.1MPa下的CF4表观分解速率常数为keff=10^13.7exp(-55000/RT)l^1/2mol  相似文献   

9.
本文以BaFClxBr-1-x:Sm2+D2→7F0的跃迁几率随x变化为中心对BaFClxBr-1-x:Sm2+体系4f5d带的激发光谱、5D2→7F0跃迁的荧光衰减随温度的变化特性、5D2→7F0的跃迁几率等进行了研究.从而得出结论:在BaFClxBr1-x:Sm2+中,随Br含量的增大,4f5d带与5D2能级更加接近,使7F0→D2的吸收截面增大,从而可能提高在5D2:能级烧孔的效率.  相似文献   

10.
本文报道了6种取代苯胺基亚胺二茂铁类化合物R-N=CH-Fe(-Fe为二茂铁基,R为-C6H4X,(X=H,4-Br,4-OH,2-CH3,4-COOH)及4-NHC6H4NO2)的Mossbauer谱数据,其化学位移分别为(mm.s^-1):0.323,0.332,0.338,0.324,0.315和0.310。其四极矩分裂值分别为(mm.s^-1):2.263,2.285,2.287,2.21  相似文献   

11.
This paper presents a two-dimensional model for the analysis of freely vibrating laminated plates. The governing differential equations, associated boundary conditions and constitutive equations are derived from Reissner's mixed variational theorem. Both the governing differential equations and the related boundary conditions are presented in terms of resultant stresses and displacements. The model is able to provide the results for the corresponding three-dimensional theory. Such a performance is guaranteed from an appropriate expansion of relevant kinetic and stress quantities through the thickness of the multilayered plate. The expansion is realized by using a novel selection of global piecewise-smooth functions (GPSFs). The number of GPSFs can be arbitrarily increased to achieve a two-dimensional plate theory which is, at least, as accurate as that of a full layerwise theory. It is also shown that GPSFs permit to deal a multilayered plate as if it was virtually made of a single layer. Indeed, the theory need not explicitly introduce continuity conditions for both displacements and relevant stresses. The performance of the present two-dimensional model in conjunction with the global piecewise-smooth functions is tested and discussed by comparing its resulting eigen-parameters, for a class of simply supported plates, with those of other two-dimensional models and with those existing of the exact three-dimensional theory.  相似文献   

12.
结构光传感器模型及特性分析   总被引:10,自引:2,他引:8  
给出了结构光传感器的数学模型,并依此模型详细分析了结构光传感器的各项参量,讨论了这些参量对结构光传感器性能的影响,得到了关于传感器参量和传感器特性之间关系的公式,给出了传感器设计必须遵守的条件。利用所给出的公式可以方便地讨论传感器的性能,对结构光传感器的设计起指导作用。  相似文献   

13.
An analytical model has been developed to predict the performance of open-cycle absorption systems for waste heat recovery. The model is based on the integral control volume approach. The system conservation equations as well as constitutive relations are presented.Predicted results demonstrated the capabilities of the model and showed that the model compared well with other existing models and data.  相似文献   

14.
Diffuse optical tomography (DOT) is a non-linear, ill-posed, boundary value and optimization problem which necessitates regularization. Also, Bayesian methods are suitable owing to measurements data are sparse and correlated. In such problems which are solved with iterative methods, for stabilization and better convergence, the solution space must be small. These constraints subject to extensive and overdetermined system of equations which model retrieving criteria specially total least squares (TLS) must to refine model error. Using TLS is limited to linear systems which is not achievable when applying traditional Bayesian methods. This paper presents an efficient method for model refinement using regularized total least squares (RTLS) for treating on linearized DOT problem, having maximum a posteriori (MAP) estimator and Tikhonov regulator. This is done with combination Bayesian and regularization tools as preconditioner matrices, applying them to equations and then using RTLS to the resulting linear equations. The preconditioning matrixes are guided by patient specific information as well as a priori knowledge gained from the training set. Simulation results illustrate that proposed method improves the image reconstruction performance and localize the abnormally well.  相似文献   

15.
掺Er及Yb-Er共掺Al2O3光波导放大器的理论与实验研究   总被引:3,自引:0,他引:3  
抽运波长为0.98μm时,考虑合作上转换、交叉弛豫、激发态吸收等上转换机理给出了掺Er及Yb-Er共掺系统的速率方程,并利用二维波导的有限元理论及包含正反向放大的自发辐射的场传输方程,建立了一套分析光波导放大器增益特性的综合理论模型。得到掺Er及Yb-Er共掺Al2O3光波导放大器增益与波导长度、抽运功率、掺杂浓度等多个参量的关系,绘制出具有实用性的优化设计曲线。将该理论模型应用于实际制作的Yb-Er共掺Al2O3光波导放大器,结果与实验数据相符。  相似文献   

16.
The Maxwell–Liouville–von Neumann (MLN) equations are a valuable tool in nonlinear optics in general and to model quantum cascade lasers in particular. Several numerical methods to solve these equations with different accuracy and computational complexity have been proposed in related literature. We present an open-source framework for solving the MLN equations and parallel implementations of three numerical methods using OpenMP. The performance measurements demonstrate the efficiency of the parallelization.  相似文献   

17.
Dynamic behaviours and stability of an automatic ball balancer (ABB) in an optical disk drive are analyzed based on the proposed three-dimensional dynamic model. For dynamic analysis, the feeding deck with the ball balancer and a spindle motor is modelled as a rigid body with six degrees of freedom. The nonlinear equations of motion are derived using Lagrange's equation in order to describe the translational and rotational motions of the system. From the derived nonlinear equations, the linearized equations of motion in the neighbourhood of a balanced equilibrium position are obtained by the perturbation method. These equations are coupled, linear, differential equations with time-dependent periodic coefficients, from which the stability of the system is analyzed by using the Floquet theory. Finally, the time responses are computed to verify the results of the stability analysis, and to investigate the balancing performance of the ABB.  相似文献   

18.
The present paper deals with the development of a mathematical model for the performance prediction of air-cooled condensers. The model considers the heat exchanger as formed by three distinct zones: de-superheater, condenser and subcooler. To make the model as generally applicable as possible, each piece of straight tube, between two return bends, is treated as a separate heat exchanger. The coil can thus be formed by any particular composition of straihgt tubes, enabling the overall effectiveness of each zone to be determined, with the use of correlations available in the literature. Zone-ending (starting of condensation or subcooling half-way along a tube) is also considered, with appropriate modelling. The energy balances over each zone, for both air and refrigerant streams, together with the effectiveness equations, form a set of non-linear equations, which are solved numerically. Despite its simplicity the method produces results comparable with those produced by more sophisticated local analyses. In the present paper six coil configurations are studied. Predicted results are compared with existing experimental data, with generally good agreement. A few possible applications of the method are also presented.  相似文献   

19.
A heat-driven thermoacoustic refrigerator has been designed and tested. A detailed thermal model of the device is presented. Energy balances within the system are discussed using external, heat exchanger, and stack control volumes in order to clarify the relationships of work and heat fluxes below and above onset. Thermal modeling is discussed as a tool for performance analysis as well as for determining system heat losses and finding input heat flows required by a thermoacoustic code. A method of using the control volume balance equations to find stack work and device efficiencies is presented. Experimental measurements are compared to DELTAE thermoacoustic modeling predictions. Modeling results show that viscous losses within the system have a significant impact on the device performance as well as on the ability of DELTAE to accurately predict performance. Modeling has led to an understanding of system performance and highlighted loss sources that are areas for improvement in a redesign.  相似文献   

20.
赵海波  王秀明  陈浩 《中国物理》2006,15(12):2819-2827
In modelling elastic wave propagation in a porous medium, when the ratio between the fluid viscosity and the medium permeability is comparatively large, the stiffness problem of Blot's poroelastic equations will be encountered. In the paper, a partition method is developed to solve the stiffness problem with a staggered high-order finite-difference. The method splits the Biot equations into two systems. One is stiff, and solved analytically, the other is nonstiff, and solved numerically by using a high-order staggered-grid finite-difference scheme. The time step is determined by the staggered finite-difference algorithm in solving the nonstiff equations, thus a coarse time step may be employed. Therefore, the computation efficiency and computational stability are improved greatly. Also a perfect by matched layer technology is used in the split method as absorbing boundary conditions. The numerical results are compared with the analytical results and those obtained from the conventional staggered-grid finite-difference method in a homogeneous model, respectively. They are in good agreement with each other. Finally, a slightly more complex model is investigated and compared with related equivalent model to illustrate the good performance of the staggered-grid finite-difference scheme in the partition method.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号