亲子乐园空调送风方式的数值模拟研究

大型综合室内亲子乐园属于高大空间,设有游乐设施和游戏的特殊性使得对空间的舒适性要求一致,但是送风气流遇阻严重,室内存在较多气流死角,影响室内空气质量和儿童健康。因此其空调设计不仅需要考虑温度、风速的空间均匀度,还要考虑各点的空气龄和PMV-PPD指标。以天津某亲子乐园为研究对象,利用scSTREAM软件对适用于该房间的辐射供冷加新风、置换通风、混合通风三种空调方式的送风效果进行数值模拟分析,从流场的均匀性、人员的热舒适性等方面对模拟结果进行探讨,研究结果表明辐射供冷加新风方式的空间均匀性和PMV指标最佳,混合通风方式的空气龄最小。     

Crystal-field engineering of ultrabroadband mid-infrared emission in Co2+-doped nano-chalcogenide glass composites

Tunable and ultrabroadband mid-infrared (MIR) emissions in the range of 2.5–4.5 μm are firstly reported from Co²⁺-doped nano-chalcogenide (ChG) glass composites. The composites embedded with a variety of binary (ZnS, CdS, ZnSe) and ternary (ZnCdS, ZnSSe) ChG nanocrystals (NCs) can be readily obtained by a simple one-step thermal annealing method. They are highly transparent in the near- and mid-infrared wavelength region. Low-cost and commercially available Er³⁺-doped fiber lasers can be used as the excitation source. By crystal-field engineering of the embedded NCs through cation- or anion-substitution, the emission properties of Co²⁺ including its emission peak wavelength and bandwidth can be tailored in a broad spectral range. The phenomena can be accounted for by crystal-field theory. Such nano-ChG composites, perfectly filling the 3–4 μm spectral gap between the oscillations of Cr²⁺ and Fe²⁺ doped IIVI ChG crystals, may find important MIR photonic applications (e.g., gas sensing), or can be used directly as an efficient pump source for Fe²⁺: IIVI crystals which are suffering from lack of pump sources.     

Systematic convergence of nonlinear stochastic estimators on the Special Orthogonal Group SO(3)

This paper introduces two novel nonlinear stochastic attitude estimators developed on the Special Orthogonal Group with the tracking error of the normalized Euclidean distance meeting predefined transient and steady‐state characteristics. The tracking error is confined to initially start within a predetermined large set such that the transient performance is guaranteed to obey dynamically reducing boundaries and decrease smoothly and asymptotically to the origin in probability from almost any initial condition. The proposed estimators produce accurate attitude estimates with remarkable convergence properties using measurements obtained from low‐cost inertial measurement units. The estimators proposed in continuous form are complemented by their discrete versions for the implementation purposes. The simulation results illustrate the effectiveness and robustness of the proposed estimators against uncertain measurements and large initialization error, whether in continuous or discrete form.     

垦71井区三维VSP资料波场分离方法应用研究

三维VSP资料是多偏移距VSP资料，资料中多种类型的波叠合在一起形成复杂波场。从复杂波场中分离出单一的保幅反射波波场是三维VSP波场分离的重要工作。常规二维VSP波场处理方法单一，难以适用于复杂的三维波场处理。针对三维VSP资料的波场特点，以分离上行反射P波为例，将单一波场分离方法加以适当组合，对垦71井区三维VSP实际资料进行了应用研究。结果表明，波场分离处理中叠加消去法和中值滤波相结合以及F—K滤波和中值滤波相结合的方法克服了单一方法的缺陷，波场处理后获得了波组特征明显、波场清晰单一的上行反射P波保幅波场，取得了较好的波场分离效果。     

电路电磁兼容建模与仿真

提出了对暴露在任意外场中的传输线进行时频分析的新方法，这种方法非常稳定，它能够与任意的传输线模型和电路仿真方法兼容，并且使用这种方法得到的仿真值和实际值之间的差别小于1％。     

稠油微生物开采技术现状及进展

综述了用微生物方法开采稠油的技术现状与进展，论题如下。①概述。②基本方法：异源微生物采油，包括微生物吞吐和微生物驱；本源微生物采油压大港孔店油田的实例。③主要机理，包括产表面活性剂，降解稠油中重质组分及其他。④技术研究，包括机理性、可行性及经济效益研究，列举了国内外6个实例。⑤现场应用，包括国外1个、国内6个实例。⑥该技术的优势及问题。参22。     

AlSb晶体内二维磁极化子的磁场与温度效应

在考虑声子之间相互作用的同时，本文应用线性组合算符和微扰法研究了电子自旋对弱耦合二维磁极化子特性的影响。对AlSb晶体所作的数值计算结果表明，随着磁场的加强，磁极化子平均数减少；随着温度的增加，磁极化子平均数也增加；随着温度的增加，电子自旋作用以及声子之间相互作用都加强；随着磁场的加强，电子自旋作用增加而声子之间相互作用基本不变。     

Inhibition of microbial growth in ready‐to‐eat food stored at ambient temperature by modified atmosphere packaging

This study was undertaken to develop a modified atmosphere package to control microbial growth in ready‐to‐eat (RTE) products stored at ambient temperature. Ethanol and/or limonene associated with modified atmosphere (CO₂ : O₂ : N₂ = 30% : 5% : 65%) was used to inhibit the growth of total air‐borne microorganisms and Escherichia coli in RTE products stored at 25°C. The results indicated that 0.05% ethanol vapour in the headspace was effective to inhibit the growth of air‐borne microorganisms and E. coli at 25°C for 72 h in a model study, and the effectiveness was related to ethanol content. Both 73 ppm limonene and 0.05% ethanol vapour enhanced the bacteriostatic effect of modified atmosphere in RTE sushi roll products, and no off‐flavour was detected using this formulated gas; however, no significant inhibitory effect was observed for RTE cold noodle products. This study concludes that combinations of carbon dioxide, ethanol or limonene vapours are effective to inhibit microbial growth in RTE food at ambient temperature, and the outcome may be due to the hurdle effect. Copyright © 2003 John Wiley & Sons, Ltd.     

Oligo(ethylene oxide) side‐chain steric screening effects on conductimetric properties of grafted poly(4‐vinylpyridinium) salts in aqueous solutions

A set of poly[N‐oligo(ethylene oxide)yl 4‐vinylpyridinium tosylate] (P4VOEOOTs) has been prepared by spontaneous polymerization of 4‐vinylpyridine. This method gives a grafted polyelectrolyte having a positive charge on every backbone pyridinic moiety. The P4VP15Ts, P4VP164Ts, P4VP350Ts and P4VP750Ts aqueous solution conductivities were determined in the concentration range from 6 × 10^?4 to 10^?2 M at 25 °C. The variation of the conductivity versus concentration of the investigated system exhibits typical polyelectrolyte behaviour. The polyelectrolyte mobility was found to be dependent on the oligo(ethylene oxide) (OEO) side‐chain length. Manning's rod‐like model fails to describe these results. A simple steric effect is proposed to explain the influence of the OEO length. Copyright © 2003 Society of Chemical Industry