AEYFI 05实验‘温度-声简正波传播时间'起伏特性研究

处理分析AEYFI 05声学实验温度链和声传播数据,研究温度时-空间统计、相关特性及其声传播时间统计特性。分析表明1号声简正波的传播时间起伏的功率谱与温跃层附近温度时间序列的功率谱存在明显的相似：在高频区域f〉30cpd呈ω-β（β≌1.7-1.8）的幂次衰减,包含相干结构。应用简正波传播时间与声速起伏的对应关系式,给出了上述对应关系的理论解释。     

Turbulent natural convection in an enclosure with localized heating from below

This study reports the results of a numerical investigation of turbulent natural convection in a square enclosure with localized heating from below and symmetrical cooling from the vertical side walls. The present study simulates the case of an accidental heat generation due to fire in a typical isolated building of a nuclear reactor or electronic components cabin. The source of fire is considered to be centrally located at the bottom wall with different heated widths, which is assumed to be either isothermal or with isoflux. For the purpose of the analysis, the source length is varied from 20 to 80% of the total width of the bottom wall. The top wall and the unheated portion of the bottom wall are considered to be adiabatic, whereas sidewalls are isothermal. Steady as well as transient forms of two-dimensional Reynolds–Averaged-Navier–Stokes equations and conservation equations of mass and energy, coupled with the Boussinesq approximation, are solved by the control volume based discretisation method employing the SIMPLE algorithm for pressure–velocity coupling. Turbulence is modeled using the standard k–ε model. Rayleigh number, Ra, based on the enclosure height is varied from 10⁸ to 10¹². Stream lines and isotherms are presented for various combinations of Ra and the heated width. A double cell flow pattern is observed with marginal loss in symmetry as Ra increases. The results are reported in the form of local and average Nusselt number on the heated floor. Correlations are developed to predict the heat transfer rates from the enclosure as a function of dimensionless heated width of the bottom wall and Ra, by least square linear regression analysis.     

Patterns in Performance-Orientated Design: An Approach towards Pattern Recognition,Generation and Instrumentalisation

The question of pattern in architecture generally divides architects into two distinct groups: those with an aesthetic interest in man-made ornament; and those who take a deeper interest in the processes that underlie the formation of pattern in the natural world. An investigation of the performative, though, enables an exploration of pattern that arises out of the interaction of man-made interventions with the natural environment. Michael Hensel , Professor for research by Design at AHO, the Oslo School of Architecture and Design, and Achim Menges of the Emtech (Emergent Technologies and Design programme) at the Architectural Association in London, explore this arena based on their research and educational work at the AA and other international institutions, which focuses on aspects of performance in the built environment. Copyright © 2009 John Wiley & Sons, Ltd.     

Potential method in the theory of thermoviscoelastic mixtures

In this article, the linear theory of binary thermoviscoelastic mixtures is considered and the basic boundary value problems (BVPs) of steady vibrations are investigated. Namely, the fundamental solution of the system of equations of steady vibrations is constructed explicitly and its basic properties are established. Green’s second and third identities are obtained and the uniqueness theorems for classical solutions of the internal and external basic BVPs of steady vibrations are proved. The surface and volume potentials are constructed and their basic properties are given. The determinants of symbolic matrices are calculated explicitly. The BVPs are reduced to the always solvable singular integral equations for which Fredholm’s theorems are valid. Finally, the existence theorems for classical solutions of the internal and external BVPs of steady vibrations are proved by the potential method and the theory of singular integral equations.     

基于ICE2PCS05高功率因数校正电路的设计

以单相Boost有源功率因数校正电路为研究对象,分析有源功率因数校正技术的基本原理及其分类,并对每一类型电路的拓扑结构、工作特点及工作方式进行比较。逆变焊机输入整流电路中的滤波电容是导致输入电流波形畸变的原因所在,产生高次谐波,并降低电源的功率因数。基于新型功率因数校正芯片ICE2PCS05,设计一款功率为300 W,输出为400 V的高功率因数校正电路,详细分析该电路的工作原理、升压电感、电容、功率开关管、二极管、开关频率和ICE2PCS05外围电路等部分参数的设计方式,并给出其测试结果。实验结果表明,该设计电路合理可行、输入电流畸变小,输出电压恒定,可获得高功率因数。     

焦炉煤气制甲醇催化剂的工业应用

介绍了RK-05型催化剂在神华乌海能源西来峰煤化工分公司焦炉煤气制甲醇中的升温还原、生产工艺指标控制以及工业运行中出现的问题。RK-05型催化剂在工业应用中表现出机械强度高、易还原和选择性较好等优点。     

Purification of S-PG05 using Simulated Moving Bed Chromatography

Abstract

S-PG05 ((15S)-15-methyl-prostaglandin F₂ α methyl ester) was separated from the epimer R-PG05 and other impurities using SMB, combined with batch chromatography. Based on this technical procedure, 94% pure S-PG05 was obtained. Different column configurations and separation conditions of SMB have been selected. A non-synchronous shift with a “partial extract withdrawal” strategy has been employed, resulting in the saving of desorbent and the increase of the purity of S-PG05.     

基于iButton(R)的智能门禁安全管理系统

利用DS1961 GUID和用户密码作为密匙,实现智能开门和记录用户进出门信息的门禁安全管理系统.系统主要由上位机和门禁子系统组成:上位机负责管理本地数据库和获取门禁子系统的登录信息等工作;子系统负责受控门开启和用户信息的无线通信传送.用户使用iButton和输入密码后,由nRF905将STM32处理后信息传至上位机,由上位机查询和匹配本地数据库并将核对信息发送给控制端,从而决定门道是否开启.系统很好地满足了智能门禁的要求,在智能安防系统中有很高的推广应用前景.     

Geometric Orbital Transfer Using Averaging Techniques

In this article, we focus on the coplanar orbital transfer of a satellite between Keplerian orbits, with low propulsion. We compute and analyze averaged systems associated with the energy minimization problem with the full control or control oriented in a single direction, tangential-normal or radial-orthoradial. This allows to understand the properties of each control direction in the optimal control problems.      

串行E2PROM芯片CAT24WC03/05/09/17及其应用

本文介绍了基于Ｉ＾２Ｃ总线串行工作的ＣＡＴ２４ＷＣ０３／０５／０９／１７芯片的管脚说明及功能描述,最后给出ＣＡＴ２４ＷＣ０３／０５／０９／１７芯片与单片机ＡＴ８９Ｃ５１的接口电路及程序框图。