某汽车展馆维修厅的加固设计分析

通过分析某展馆汽车维修厅的各种不利荷载工况组合来确定该展区楼板、梁的最大内力,并根据计算所得的最大内力对维修厅区域相关框架梁、楼板进行了加固设计,确保了加固方案的安全可靠性,实践证明效果很好.     

Effects of salt and ammonium hydroxide on the quality of ground buffalo meat

The objective of this study was to evaluate the effects of ammonium hydroxide (AH) and sodium chloride on the quality of ground buffalo meat patties. Ground buffalo meat was treated with distilled water (control), 0.5% v/w AH, 1.0% v/w AH, 2.0% v/w AH and 1.0% w/w sodium chloride was added for all the samples. Treatment with AH increased (P<0.05) the pH and water holding capacity (WHC) of ground buffalo meat patties during storage relative to their controls. Hunterlab a* (redness) and chroma values increased (P<0.05) and hue decreased (P<0.05) in all AH treated samples in comparison to controls during storage. Ammonium hydroxide significantly (P<0.05) inhibited metmyoglobin formation compared to control after 3rd day of storage. There was a significant (P<0.05) reduction in thiobarbituric acid reactive substances (TBARS) values in all AH treated samples compared to control throughout storage. These results indicate the potential antioxidant and myoglobin redox stabilizing effect of AH in ground buffalo meat patties.     

引进纯碱自动包装系统简介

介绍了从英国引进的Ｅ＿５５精密称量包装系统，阐述了该包装系统的组成、侧重原理及装置特点。     

Surface decomposition and annealing behavior of GaN implanted with Eu

Investigations on surface decomposition of GaN implanted with low energy (80keV) Eu ion to a low dose (1×1014cm-2), and its annealing behavior under high temperature (1050℃) in N2 are performed. The as-grown, as-implanted and annealed GaN films are characterized by proton elastic scattering (PES), Rutherford backscattering spectrometry (RBS), photoluminescence (PL) and atomic force microscopy (AFM). The results show that Eu ion implantation induces radiation defects and decomposition of GaN. The GaN surface decomposition is more serious during high temperature annealing. The atomic ratio of N in as-grown, as-implanted and annealed GaN film is 47 at.%, 44 at.% and 40 at.%, respectively. As a result, a rough Ga-rich layer is formed at the surface, though the lattice defects are partly removed after high temperature annealing.     

从悬浮液中分离亚筛粒度的颗粒

在矿物加工过程中,经常会产生一些极细的颗粒,这些难以用普通的分离技术回收,因而在工厂中同废水一起被废弃。现在发展了一种方法,使细颗粒悬浮液流过一个旋转的圆管,以便连续回收这些非常细的颗粒。颗粒轨迹的理论分析表明,分离效率随管子转速和直径、颗粒直径和密度的增加而增加。用粒度范围为2—10微米的水力旋流器溢流进行实验,当管子转速为3500转/分时,达到60—70%的分离效率。     

Low-thermal-budget Au-free ohmic contact to an ultrathin barrier AlGaN/GaN heterostructure utilizing a micro-patterned ohmic recess

A pre-ohmic micro-patterned recess process,is utilized to fabricate Ti/Al/Ti/TiN ohmic contact to an ultrathin-barrier(UTB) AlGaN/GaN heterostructure,featuring a significantly reduced ohmic contact resistivity of 0.56 Ω.mm at an alloy temperat-ure of 550 ℃.The sheet resistances increase with the temperature following a power law with the index of +2.58,while the spe-cific contact resistivity decreases with the temperature.The contact mechanism can be well described by thermionic field emis-sion (TFE).The extracted Schottky barrier height and electron concentration are 0.31 eV and 5.52 × 1018 cm-3,which suggests an intimate contact between ohmic metal and the UTB-AlGaN as well as GaN buffer.A good correlation between ohmic trans-fer length and the micro-pattern size is revealed,though in-depth investigation is needed.A preliminary CMOS-process-compat-ible metal-insulator-semiconductor high-mobility transistor (MIS-HEMT) was fabricated with the proposed Au-free ohmic con-tact technique.     

Coherent H∞Control for Linear Quantum Systems With Uncertainties in the Interaction Hamiltonian

This work conducts robust H^∞analysis for a class of quantum systems subject to perturbations in the interaction Hamiltonian.A necessary and sufficient condition for the robustly strict bounded real property of this type of uncertain quantum system is proposed.This paper focuses on the study of coherent robust H^∞controller design for quantum systems with uncertainties in the interaction Hamiltonian.The desired controller is connected with the uncertain quantum system through direct and indirect couplings.A necessary and sufficient condition is provided to build a connection between the robust H^∞control problem and the scaled H^∞control problem.A numerical procedure is provided to obtain coefficients of a coherent controller.An example is presented to illustrate the controller design method.     

The survival of foodborne pathogens during domestic washing-up and subsequent transfer onto washing-up sponges,kitchen surfaces and food

In this study, the survival of Salmonella, Campylobacter and Escherichia coli O157: H7, when exposed to a range of constant temperatures (47-60 degrees C), in hard or soft water, in the presence/absence of detergent (0-0.3%) and organic matter, and during drying, was investigated. Further experiments used a washing-up process simulation, where soiled dishes contaminated with bacteria were washed in a bowl of warm water containing detergent. In addition, this study considered the risk of bacterial transfer onto (1) sterile dishes and sponges via contaminated water, (2) kitchen surfaces wiped with a contaminated sponge, (3) items placed in direct contact with a contaminated kitchen surface, (4) food placed on a contaminated dish or (5) dishes from contaminated food. A proportion of dishes remained contaminated with all pathogen types after a typical washing-up. Water hardness did not appear to affect survival. E. coli, and to a lesser extent Salmonella, survived towel- or air-drying on dishes and after towel-drying the cloth became contaminated on every occasion, regardless of the test organism. A proportion of sterile dishes washed after contaminated dishes became contaminated with pathogens but transfer from dishes onto food was rare. Washing-up sponges frequently became contaminated with pathogens. The results of this study highlight the potential for survival and cross contamination of food borne pathogens in the kitchen environment.     

生命之糖——海藻糖

糖类作为与人们日常饮食息息相关的食品原料,始终吸引着国内外的食品工作者致力于其实用性和功能性的研究.而海藻糖由于其许多特殊的功能特性,在食品、医药等许多领域有着极为良好的应用前景,从而引起了人们的浓厚兴趣.