甘肃寨上金矿王足路矿段找矿突破探讨

为了解决寨上矿区王足路矿段地表第四系及新近系覆盖厚造成找矿难度较大的问题,通过引进可控源音频大地电磁测量等技术手段,在王足路矿段布设了3条线（188线、196线、204线）圈定异常,并结合野外地质调查,进行了解译,大致确定寨上矿段内的含金破碎带向西延伸至王足路矿段。经钻孔验证,基本确定寨上矿段的9号和10号矿脉延伸至王足路矿段188线,并且在深部探矿工程中发现有石英闪长玢岩脉,说明王足路矿段成矿物质来源于深部,成矿潜力巨大。实践证明,借助可控源大地音频电磁测量圈定异常、再经深部钻探验证寻找矿化体的勘查模式,在西秦岭西段厚覆盖区的找矿效果显著。     

中重型车用柴油机满足欧-Ⅱ排放法规的技术措施

中重型车用柴油机排放已成为降低车辆排放的主要控制目标。本文论述我国中重型车用柴油机满足欧-Ⅱ排放所需采取的技术措施。讨论了采用增压中冷、提高喷射压力、控制供油速率,优化喷油定时、改进燃烧系统、控制机油耗及燃油质量、降低燃油中含硫成分等关键因素对排放的影响程度。     

The permeability of non-crimp stitched fabrics

Non-crimp stitched fabrics are becoming increasingly popular as reinforcing materials in high-performance composites due to their high mechanical properties. Hence, it is of interest to investigate the processability of this type of fabrics. Focus is here set on the permeability of the fabrics. The methods of this investigation are: (i) a theoretical analysis; (ii) microscopic studies of the geometry of the fabrics and (iii) measurements of the permeability. From the experiments, it is found that only small variations of the geometry change the permeability up to three times. Furthermore, the simple model proposed works surprisingly well in certain cases, while in others it fails to predict the permeability. From the experimental results and a comparison between the model and the experiments, some guidelines are presented how to design a high-permeable fabric.     

基于航迹矢量分级聚类的雷达与电子支援措施抗差关联算法

针对同平台雷达与电子支援措施(ESM)存在系统误差、上报目标不完全一致等复杂场景下航迹关联鲁棒性和有效性问题,该文提出一种基于航迹矢量分级聚类的雷达与ESM航迹抗差关联算法。首先推导修正极坐标系(MPC)下目标等价测量方程,基于等价测量的近似展开得到目标状态估计分解方程,利用真实状态对消的方法得到航迹矢量,基于高斯随机矢量的统计特性,采用航迹矢量分级聚类的方法提取同源航迹。最后通过实验仿真验证,所提算法在不同系统误差、目标分布密度、检测概率等环境下具有较好的关联效果和鲁棒性。     

Comparative Study of the Leak Characteristics of Two Ceramic/Glass Composite Seals for Solid Oxide Fuel Cells

Solid oxide fuel cells (SOFCs) have the potential to play a significant role in a future clean energy economy. However, SOFCs still face major obstacles before they can be commercialized, with efficient sealing being among the most prominent. The present research focuses on the comparative study of microstructure, crystal phase evolution, and leak rates, for two ceramic/glass seals used in an SOFC. The leak test apparatus is a controlled facility designed to incorporate different mechanical loading, stack configurations, and thermal cycles. Simultaneous leak testing with an acoustic emission (AE) sensor was also used to identify any micro‐damage in seals. A two‐level factorial design was applied to the first sealing composition to identify the main and the interactive factors for leak rates. MINITAB^® was also used to determine a linear regression‐based leak rate model. The second seal formulation employed a more stable glass which led to reduced leak rates. Additional factors in a two‐level factorial design were investigated for the second seal formulation. Based on multiple experiments with different stack components, it was determined that the number of interfaces is most critical for leak rate, showing that even in the presence of thermal cycling, leakage is an interfacial dominated phenomenon.     

Performance evaluation of radiant baseboards (skirtings) for room heating – An analytical and experimental approach

The aim of this study was to investigate the thermal performance of the hydronic radiant baseboards currently used for space heating in built environments. The presently available equations for determination of heat outputs from these room heaters are valid for a certain height at a specific temperature range. This limitation needed to be addressed as radiant baseboards may be both energy and cost efficient option for space heating in the future. The main goal of this study was therefore to design an equation valid for all baseboard heights (100–200 mm) and excess temperatures (9–60 °C) usually used in built environments.The proposed equation was created by curve fitting using the standard method of least squares together with data from previous laboratory measurements. It was shown that the predictions by the proposed equation were in close agreement with reported experimental data. Besides, it was also revealed that the mean heat transfer coefficient of the investigated radiant baseboards was about 50% higher than the mean heat transfer coefficient of five conventional panel radiators of different types.The proposed equation can easily be used or programed in energy simulation codes. Hopefully this will help engineers to quantify more accurately the energy consumption for space heating in buildings served by radiant baseboards.     

Determination of moisture content of in-shell peanuts by parallel-plate impedance measurements in cylindrical sample holder

This paper describes a method to determine the moisture content of in-shell peanuts with a parallel-plate electrode system fitted inside a cylinder by using impedance measurements made on the system. Two parallel-plate electrodes were mounted inside a cylinder, made of acrylic material, and the space between the plates was filled with in-shell peanuts (80–100 g). The impedance measurements were made on the parallel-plate system at 1 and 9 MHz, and the average moisture content (MC) of the peanut pods (in-shell peanuts) was determined from a semi-empirical equation. The calculated MC values were compared with standard oven-determined values and were within 1% of the standard oven values for 90% of the samples tested in the moisture range between 6% and 19%. Two parallel-plate sensors with different plate separations and peanuts from the 2004 and 2005 harvests, were used in these measurements. The method, being rapid and nondestructive, is suitable for the development of a practical instrument for measurement of moisture content in in-shell peanuts.

循环流化床锅炉的磨损分析与对策

分析了循环流化床锅炉炉膛水冷壁、旋风分离器等不同部位产生磨损的原因。通过对燃料特性、运行参数等影响磨损主要原因的分析,提出了锅炉结构设计、防磨材料的选用和表面处理等要求,也提出了预防和减小磨损的技术措施。     

钍射气220^Rn测量方法综述

介绍并分析了钍射气220^Rn的几种主要测量方法,包括双滤膜法、闪烁室法、固体核径迹法、主动式活性炭吸附法和半导体探测法,阐述了220^Rn测量仪的刻度方法.     

Comparison of PIV and PDA droplet velocity measurement techniques on two high-pressure water mist nozzles

The need for reliable measurement of droplet velocities and droplet size has increased with the more widespread use of water mist systems. Two optical measuring techniques have been investigated, Particle Image Velocimetry (PIV) and phase Doppler anemometry (PDA). Measurements have been performed on two high-pressure nozzles, a hollow cone nozzle and a full cone nozzle. Both methods performed well close to the nozzle and further away from the nozzle. In the intermediate region the results obtained with PIV are biased against the larger droplets. The two methods complement each other, PIV giving the instantaneous velocity field and PDA giving both the droplet velocity and droplet size at a point. The measurement indicates that higher throw length can be archived with a full cone nozzle compared to the hollow cone nozzle, if both nozzles have the same cone angle and flow rate.