Theoretical and experimental studies of the bell-jar-top inductively coupled plasma

The present paper describes a systematic study of argon plasmas in a bell-jar inductively coupled plasma (ICP) source over the range of pressure 5-20 mtorr and power input 0.2-0.5 kW, Experimental measurements as well as results of numerical simulations are presented. The models used in the study include the well-known global balance model (or the global model) as well as a detailed two-dimensional (2-D) fluid model of the system, The global model is able to provide reasonably accurate values for the global electron temperature and plasma density, The 2-D model provides spatial distributions of various plasma parameters that make it possible to compare with data measured in the experiments, The experimental measurements were obtained using a tuned Langmuir double-probe technique to reduce the RF interference and obtain the light versus current (I-V) characteristics of the probe. Time-averaged electron temperature and plasma density were measured for various combinations of pressure and applied RF power, The predictions of the 2-D model were found to be in good qualitative agreement with measured data, It was found that the electron temperature distribution T-e was more or less uniform in the chamber, It was also seen that the electron temperature depends primarily on pressure, but is almost independent of the power input, except in the very low-pressure regime. The plasma density goes up almost linearly with the power input.

Two-dimensional fluid model simulation of bell jar top inductively coupled plasma

In the present paper, argon (Ar) plasmas in a bell jar inductively coupled plasma (ICP) source are systematically studied over pressures from 5 to 20 mtorr and power inputs from 0.2 to 0.5 kW. In this study, both a two-dimensional (2-D) fluid model simulation and global model calculation are compared, The 2-D fluid model simulation with a self-consistent power deposition is developed to describe the Ar plasma behavior as well as predict the plasma parameter distributions, Finally, a quantitative comparison between the global model and the fluid model is made to test their validity.

Entanglement purification with higher error threshold for imperfection of local operations and bell state measurements

We analyse further the entanglement purification protocol proposed by Feng et al. (Phys. Lett. A 271 (2000) 44) in the case of imperfect local operations and measurements. It is found that this protocol allows of higher error threshold. Compared with the standard entanglement purification proposed by Bennett et al. [Phys. Rev. Lett. 76 (1996) 722], it turns out that this protocol is remarkably robust against the influences of imperfect local operations and measurements.

Bell-shaped D-serine actions on hippocampal long-term depression and spatial memory retrieval

D-Serine, the endogenous coagonist of N-methyl-D-aspartate receptors (NMDARs), is considered to be an important gliotransmitter, and is essential for the induction of long-term potentiation. However, less is known about the role of D-serine in another for

Local transformation of mixed states of two qubits to Bell diagonal states

The optimal entanglement manipulation for a single copy of mixed states of two qubits is to transform it to a Bell diagonal state. In this paper we derive an explicit form of the local operation that can realize such a transformation. The result obtained is universal for arbitrary entangled two-qubit states and it discloses that the corresponding local filter is not unique for density matrices with rank n = 2 and can be exclusively determined for that with n = 3 and 4. As illustrations, a four-parameter family of mixed states are explored, the local filter as well as the transformation probability are given explicitly, which verify the validity of the general result.

Damage assessment and preservation of suspending system of Yongle-Big-Bell

The Yongle-Big-Bell is an exquisite heritage of ancient China and has more than 600 years history. The long history renders the suspending wooden rack serious damage. Therefore, the security is of our great concern. In order to know if the wooden rack is safe or not for the conventional striking in the festival service, a systemic research work has been done. At first the existing deformation and response to the strike of the beetle were measured, and then calculations using method of material mechanics and finite element analysis were conducted. Based on the results of our research, some concluding remarks and suggestion were given: The Yongle-Big-Bell can be struck regularly without urgent danger of collapse. In view of the existence of serious rotten damage, the repair and protection of wooden rack are pressing.

永乐大钟及悬挂支撑系统的撞钟过程瞬态分析

采用ANSYS有限元分析软件对永乐大钟及其悬挂支撑系统建立了有限元模型,进行了撞钟过程有限元瞬态分析及动力强度校核。通过有限元计算,获得了大钟各局部考察对象及整体的应力、位移分布情况和各部分的动力响应和对强度的影响,为合理撞钟和加固提供了科学依据与技术指导。

永乐大钟梯形木架稳定性初探

对北京市大钟寺悬挂永乐大钟的梯形木架结构的稳定性进行了初步分析,根据弹性结构稳定性理论的能量法和中国古建筑结构"卯榫"接头抗弯性能的简化的本构模型,采用"对比法"分析了二维梯形木架的结构稳定性;结果表明中国古建筑木架结构的"收分"形状设计对增大木架稳定性有很大作用,立柱"侧角"越大,稳定性越好,收分形式设计凸现中国古代工程技术人员的聪明智慧.

Universal Greenberger-Horne-Zeilinger-state analyzer based on two-photon polarization parity detection

We present a universal analyzer for the three-particle Greenberger-Horne-Zeilinger (GHZ) states with quantum nondemolition parity detectors and linear-optics elements. In our scheme, all of the three-photon GHZ states can be discriminated with nearly unity probability in the regime of weak nonlinearity feasible at the present state of the art experimentally. We also show that our scheme can be easily extended to the analysis of the multi-particle GHZ states.

A novel bradykinin-related peptide from skin secretions of toad Bombina maxima and its precursor containing six identical copies of the final product

Amphibian skin contains rich bradykinin-related peptides, but the mode of biosynthesis of these peptides is unknown. In the present study, a novel bradykinin-related peptide, termed bombinakinin M, was purified from skin secretions of the Chinese red bell

网湖鲫鱼的生长与资源评估

根据1984—1986年在湖北省网湖进行渔业资源调查的资料,应用Von Bertalanffy生长方程描述该湖鲫鱼的生长模式,同时按照Joneo体长股分析模型和Thompson-Bell体长预测模型分别推算鲫鱼资源量和不同捕捞强度下资源量和渔获量的理论值,并求得最大持续渔获量。据此,对该湖鲫鱼资源的合理开发和利用进行了分析和讨论,并提出渔业对策。