PROANTHOCYANIDIN-FREE BARLEY—MALTING AND BREWING

Colloidal haze in beer is due to the precipitation of proteins by proanthocyanidins. Carlsberg Research Center reported in 1977 that the use of barley mutants which block the biosynthesis of catechins and proanthocyanidins in the grain prevents the formation of haze in beer. The results from ten years of malting and brewing research with proanthocyanidin-free barley and malt are reviewed.     

结合最小滤波和引导滤波的暗原色去雾

用基于暗原色信息的去雾方法处理雾化图像时,需要考虑消除景深边缘处的白色晕块并降低修复透射率过程所耗费的时间。为了既能够有效地去除白色晕块又能够降低修复透射率的处理时间,本文分析了最小滤波和引导滤波分别用于修复透射率的优缺点,提出了采用最小滤波和引导滤波相结合的方法来修复透射率。该方法综合了两者的优点,同时又弥补了各自的不足。较之于软抠图法,不仅有效消除了白色晕块,并且大大地降低了透射率处理时间,提高了处理效率。另外,针对传统暗原色去雾方法的缺点进行了改进。根据天空区域像素亮白的特性,将颜色和大气光相近的像素视为天空区域像素,然后对其进行颜色原值保留处理,从而有效地消除天空区域颜色的失真和跳变,从整体上改善了去雾复原图像的视觉效果。     

基于多变量气象因子的LMBP电力日负荷预测

提出基于主成分分析处理多天气因素的LMBP电力负荷预测模型。采用主成分分析技术对多气象因素进行降维处理,提取多天气因素特征量,既全面表征天气因素对电力负荷的影响,又简化预测模型。将得到的新气象特征量与历史负荷数据共同作为建模对象。采用基于L-M优化算法的BP神经网络(LMBP)进行预测分析,通过最速梯度下降法和牛顿法之间的自适应调整优化网络权值,有效提高网络的收敛速度和泛化能力。通过对美国南部某地区实际电力负荷系统进行预测分析表明该方法可以有效提高预测精度和预测效率。     

援外工程电气设计

援外工程因其特殊的政治和经济意义,及受援国家的地域经济文化的不同,与国内建筑工程存在很大差异。以援汤加政府综合办公大楼项目为例,探讨援外工程电气设计(包括供配电系统、照明系统、防雷与接地、设备选型与安装)应注意的问题。     

严寒天气立井装备快速安装技术

母杜柴登煤矿副立井,净直径9.4m,井深712m,井筒内布置2套提升系统(1套带平衡锤的双层宽罐笼和1套带平衡锤的单层窄罐笼)。井筒装备主要有方钢罐道8趟、管路5趟、电缆19趟、梯子间1趟、井下套架及四角稳罐装置1套、井下导向罐道及防撞梁1套、井上套架及过卷(放)保护装置1套。井筒装备安装在严寒天气施工,采取供热、保温措施和配套快速施工技术,实现了安全快速安装。     

Influence of water and magnesium ion on the optical properties in various plasticized poly(vinyl butyral) sheets

The study is focused on influences of optical properties change of poly(vinyl butyral) (PVB) sheets determined for safety glass preparing. Optic measurements were evaluated itself and after, the laminated glass was observed. The study deals with a cognizance of causation of the optical properties change in different PVB sheets in dependence on adsorbed water content into the polymer matrix. Results of this work describe the influence of ? OH group content on PVB chain and type and amount of additives adjusting adhesion of PVB towards glass. However, the most important discovery of this work is evaluation of critical water content that leads to haze generation. The evaluation of various types of sheets was performed. At the same time the artificial addition of Mg²⁺ salts of organic acids (with various polarity of the molecule) was evaluated to assess their influence on haze generation. It was found that haze caused by Mg²⁺ salt is possible to eliminate when there is certain water content in PVB. Obtained values and comparisons are very important for PVB sheets industry and for industry dealing with lamination of PVB between glasses. Influence of these factors and comparison of haze generation for various PVB sheets has not been published yet. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

中美天气雷达速调管性能对比研究

文中对比介绍中美多普勒天气雷达速调管的性能、使用寿命及频率分布特点等,分析了国内外速调管性能价格比,提出了我国速调管业务需求备份比例,为我国今后速调管的资金分配提供科学依据;提出了速调管寿命实时跟踪技术和速调管维护保养技术,用以提高速调管的工作性能、延长其使用寿命。同时,针对我国雷达速调管供、需、用中存在的问题,提出了改进建议,以实现雷达的稳定可靠运行。     

Control of Snow Falling Flow around NACA0015 Blade using a Plasma Electrode with Weather Resistant Design

The plasma actuation (PA) effect on the snow falling flow was investigated using a plasma electrode with weather resistant design and the natural snow wind facility of the Hokkaido University of Science. NACA0015 test blade with chord length c of 300 mm was used. Wind tunnel tests were carried out under the angle of the attack of the blade was fixed at 15 degrees, and the main flow velocity is U=5 m/s. PIV (Particle image velocimetry) measurements were conducted on various PA conditions using natural dry snowflakes as a tracer. When the actuator was driven under the condition of the fundamental frequency of F=50 kHz, and the pulsed modulated frequency f of fc/U=1 and Duty ratio (Ratio of plasma ON time to pulse duration time) =1%, movement of snowflakes was controlled the most effectively tested. It was clarified that the fundamental frequency of PA also affects the control of snow flow. Under snowfall conditions, the weather resistant designed plasma electrode has suffered no damage and operated successfully.     

Optimization of fused filament fabrication process parameters for mechanical responses of weather-resistant polymer (acrylonitrile styrene acrylate)

Additively manufactured polymeric products for automotive, aerospace, and biomedical applications are usually intended for service in an outdoor environment with high mechanical loading conditions. The strength and sustainability of the products can be significantly degraded due to the outdoor environmental conditions such as UV light, moisture, heat, and so forth. In this research work, a novel weather-resistant polymer (WRP) material, that is, acrylonitrile styrene acrylate (ASA), has been studied. Furthermore, this work aims to study the effect of process parameters and enhance the strength of WRP (ASA) specimens using the FFF process. The optimized process parameters, that is, build orientation (BO), extrusion temperature (ET), layer thickness (LT), and printing speed (PS), were identified based on the tensile and flexural strength using the Taguchi technique and statistical analysis. The best tensile and flexural strengths for the specimen were achieved at both orientations (XYZ and ZXY) TS: 255°C ET, 0.14 mm LT, 50 mm/s PS; and FS: 245°C ET, 0.28 mm LT, 50 mm/s PS, respectively. Regression model was developed to investigate the correlation between the process parameters with tensile and flexural strength. A validation test confirmed the findings, and the error between the actual and predicted values is less than ±10%.     

Deep-bed simulation of the cooling of stored grain with ambient air: a test bed for ventilation control strategies

A simulation model for grain cooling is presented and verified against experimental data. The model is applied to grain cooling during a typical season at a location in the southeast of the U.K. Fan control strategies are investigated, and the use of differential control based on the grain to air temperature difference is found to be effective. In the simulation, barley placed in store at 16% w.b. moisture content (0.191 d.b.) and 30 °C in late July was cooled to 15 °C in 1 month using a 2 °C differential, whereas for malting barley it was necessary to use a 6 °C differential to reduce rewetting. Rewetting of the bed at the air entry region was significant in all situations simulated and, for malting barley, the heat of absorption significantly affected cooling. The simulations for wheat and barley were very similar. The results indicate that cooling, even during this warm period, can achieve temperatures which will greatly decelerate insect development.