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991.
原位光学发射光谱仪(OES)已经成为等离子体刻蚀工艺控制过程中的一种非常有潜力的在线传感器系统。采用光谱仪实时采集高密度等离子体刻蚀机中的OES光谱数据,利用BP神经网络算法对特定波长的OES数据进行分析及建模,以便对等离子体刻蚀工艺过程进行反馈控制。由刻蚀产物SiCl发出的405nm谱线被选为特征谱线来确定刻蚀工艺过程的终点。 相似文献
992.
Mathematical programming problems with unattained infima or unbounded optimal solution sets are dual to problems which lackinterior points, e.g., problems for which the Slater condition fails to hold or for which the hypothesis of Fenchel's theorem fails to hold. In such cases, it is possible to project the unbounded problem onto a subspace and to restrict the dual problem to an affine set so that the infima are not altered. After a finite sequence of such projections and restrictions, dual problems are obtained which have bounded optimal solution sets andinterior points. Although results of this kind have occasionally been used in other contexts, it is in geometric programming (both in the original psynomial form and the generalized form) where such methods appear most useful. In this paper, we present a treatment of dual projection and restriction methods developed in terms of dual generalized geometric programming problems. Analogous results are given for Fenchel and ordinary dual problems.This research was supported in part by Grant No. AFOSR-73-2516 from the Air Force Office of Scientific Research and by Grant No. NSF-ENG-76-10260 from the National Science Foundation.The authors wish to express their appreciation to the referees for several helpful comments. 相似文献
993.
本文利用密度泛函理论的B3LYP/6-31G(d, p)和组态相互作用的QCISD/6-31G(d, p)研究了Al6Si+和Al6SiLi+团簇的几何和电子结构及其对H2分子的吸附,两种不同方法计算的H2分子在团簇上的吸附能非常一致。H2分子在Al6Si+团簇上的吸附能仅为-0.018 eV,Al6Si+团簇中掺杂Li原子可以明显增强其对H2分子的吸附。Al6SiLi+团簇吸附一个H2分子的吸附能可以达到-0.157 eV,吸附五个H2分子的平均吸附能为-0.088 eV。态密度和自然键轨道分析表明,电荷从Li原子向Si原子转移,H2分子在带正电的Li离子产生的电场中发生极化,从而在静电相互作用下吸附在Li原子周围。 相似文献
994.
The paper is concerned with a hybrid finite element formulation for the geometrically exact dynamics of rods with applications to chaotic motion. The rod theory is developed for in-plane motions using the direct approach where the rod is treated as a one-dimensional Cosserat line. Shear deformation is included in the formulation. Within the elements, a linear distribution of the kinematical fields is combined with a constant distribution of the normal and shear forces. For time integration, the mid-point rule is employed. Various numerical examples of chaotic motion of straight and initially curved rods are presented proving the powerfulness and applicability of the finite element formulation. 相似文献
995.
Fracture mechanics of laminated glass subjected to blast loading 总被引:2,自引:0,他引:2
A failure criterion based on energy balance approach is introduced for the laminated glass panel subjected to blast loading. Based on this failure criterion, a damage factor is developed to assess the failure of the laminated glass panel. If the damage factor is less than one, the plate is safe otherwise unsafe. Trigonometric function is employed to express the transverse deflection and the Airy’s stress function in von Karman’s large deflection equations of a thin plate. The nonlinear ordinary differential equation of motion obtained using the Galerkin method is solved using Runge–Kutta method. The predicted results indicate that the breakages of the laminated glass may be caused by the negative phase of the blast load if the positive phase blast load is not violent enough to cause failure. Also, the size of glass shards the laminated glass plies breaks in to is predicted using the surface energy based failure model. 相似文献
996.
997.
This study synthesized UiO-66, a typical Zr-Metal Organic Framework (MOF), by using an ultrasound-assisted synthesis method to reduce the synthesis time. This method was short-time ultrasound irradiation at the initial stage of the reaction. As compared with average particle size of conventional solvothermal method (=192 nm), averaged particle size by the ultrasound-assisted synthesis method showed particle sizes that were smaller on average, ranging from 56 to 155 nm. In order to compare the relative reaction rates of the solvothermal method and the ultrasound-assisted synthesis method, the cloudiness of the reaction solution in the reactor was observed with a video camera, and the luminance was calculated from the images obtained by the video camera. It was found that the ultrasound-assisted synthesis method showed a faster increase in luminance and shorter induction time than the solvothermal method. The slope of the luminance increase during the transient period was also found to become increase with the addition of ultrasound, which also affects the growth of particles. Observation of the aliquoted reaction solution confirmed that particle growth was faster in the ultrasound-assisted synthesis method than in the solvothermal method. Numerical simulations were also performed using MATLAB ver. 5.5 to analyze the unique reaction field generated by ultrasound. Bubble radius and temperature inside a cavitation bubble was obtained using the Keller-Miksis equation, which reproduces the motion of a single bubble. The bubble radius expanded and contracted repeatedly according to the ultrasound sound pressure, and eventually collapsed. The temperature at the time of collapse was extremely high, exceeding 17,000 K. It was confirmed that the high-temperature reaction field generated by ultrasound irradiation promoted nucleation, leading to a reduction in particle size and induction time. 相似文献
998.
Let M be a d-dimensional compact Riemannian manifold. We prove existence of a unique global strong solution of the stochastic wave equation , where Y is a C1-smooth transformation and W is a spatially homogeneous Wiener process on whose spectral measure has finite moments up to order 2. 相似文献
999.
The sphere S
n+1 contains a simple family of constant mean curvature (CMC) hypersurfaces of the form C
t
: = S
p
(cos t) × S
q
(sin t) for p + q = n and called the generalized Clifford hypersurfaces. This paper demonstrates that new, topologically non-trivial CMC hypersurfaces
resembling a pair of neighbouring generalized Clifford tori connected to each other by small catenoidal bridges at a sufficiently
symmetric configuration of points can be constructed by perturbative PDE methods. That is, one can create an approximate solution
by gluing a rescaled catenoid into the neighbourhood of each point; and then one can show that a perturbation of this approximate
hypersurface exists, which satisfies the CMC condition. The results of this paper generalize those of the authors in [3]. 相似文献
1000.