汽车车内噪声声音品质的测试与评价

研究车内噪声客观物理特征与人的主观感受之间的影响关系。通过对3种车型在不同行驶速度下的噪声进行实时录制,并在测试室采用成对比较的方法进行主观评价,同时提取其心理学评价指标,对车辆噪声的烦恼度影响因素进行了试验和分析。采用多元回归分析的方法分析心理学评价指标与主观烦恼度之间的关系。通过心理声学评价指标的线性组合得到的总评估值与主观评估值之间有很高的相关性,能很好地解释主观评估值,采用心理声学评价指标的线性组合对车辆声音品质进行主观评价是可行的。     

平板类零件平面度平行度的测量

本文以阀板为例介绍了一种平板类零件平面度平行度的测量方法，着重介绍了其测量原理以及相适应的机械测量装置。本测量系统可一次装夹同时测量出平板类零件的两个平面度参数和两平面互为基准的平行度参数，具有被测参数测量值显示、超差警示、测量结果显示等功能。     

基于卷积神经网络的内燃机声品质评价方法研究

为解决内燃机声品质评价中人工效率低、成本高的问题,引入卷积神经网络(convolutional neural network,CNN)模型和声谱分析方法构建了CNN声品质预测模型;同时模型中设计了带通滤波器,可对噪声样本进行自动特征提取,并以此为输入数据,利用自适应时刻估计(adaptive moment estimation,Adam)算法优化网络中各层权重,并将模型用于声品质评价。为证明CNN模型预测的性能,构建了基于心理声学参量的后向传播算法(back propagation,BP)声品质评价模型,并用于对照试验,在样本标签值(人工评价值)处理时,分析了客观评价心理声学参数与评分值的相关性,选取与人工评价结果相关度最大的4个心理声学参量作为BP模型的输入值进行预测。试验结果表明,基于CNN的声品质评价模型能更精确地预测内燃机声品质,并且在CNN预测模型中基于听觉谱的输入评价值比基于时域的短时平均能量、频域的频谱通量输入评价值精度更高。     

关于选装曲轴滑动轴承的几个问题

介绍了选装曲轴滑动轴承时，主轴承座孔同轴度、连杆轴承座孔圆度和轴承过盈量的控制方法，高锡铝合金的使用等问题。     

热电偶测量不确定度分析及应用

本文简述了热电偶的测温原理，重点对二等标准热电偶的测量不确定度进行了分析，并介绍了热电偶的特性及实际应用中的问题。     

锅炉管内壁氧化皮厚度测量影响因素分析

本文针对锅炉管内壁氧化皮厚度的超声波测量，研究了超声波在氧化皮中的传播速度、氧化皮分层、剥落、氧化皮与金属基体间隙等因素对测量准确性的影响规律，同时给出了典型情况下的测量波形。研究结果对氧化皮厚度超声波测量仪器的使用，提高测量准确性具有指导及参考意义。     

考虑支承柔度的轮系振动计算

本文介绍了计算轮系振动的一个方法,可供设计阶段预计轮系振动的静、动频谱,方法简便,适用于自由叶片-叶轮系统和整圈松拉金叶片-叶轮系统等周期对称结构。在计算中考虑了叶根支承柔度、轮孔支承柔度及叶片剪切变形、转动惯量的影响,并介绍了柔度系数的确定方法.     

电站主设备可靠性定量设计技术的研究

提出了电站主设备可靠性定量设计的方法，介绍了收集现场使用可靠性数据，建立可靠性数据库，分析可靠性薄弱环节和严重的失效模式，确定设计量的分布参数等可靠性设计的基础工作，使用概率设计法和历史数据统计分析法确定关键零件和普通零件的可靠度和可用度；给出了电站主设备的零件，子系统和系统的可靠度，可用度的计算公式和应用于汽轮机产品上的实例，图1参10。     

气缸磨损的测量与搪缸工艺研究

介绍了气缸磨损程度的两个测量指标—椭圆度和不柱度以及测量方法;重点从选择修理尺寸、确定搪削量和搪削次数、气缸的定心法和搪缸的切削等几个方面研究了气缸搪缸的工艺。     

一级热塔制造工艺技术研究

如何保证超长容器的“三度”，即直线度、垂直度和平行度，是制造大型塔器的关键问题。本文根据我公司近期制造的几台大型塔器，着重介绍了大型、薄壁、大长径比塔器设备的制造工艺以及一些关键工序的保证措施。     

Performance analysis and parametric study of a solid oxide fuel cell fueled by carbon monoxide

A theoretical model of the solid oxide fuel cell (SOFC) fueled by carbon monoxide is adopted and validated, in which the activation overpotential, concentration overpotential, and ohmic overpotential are regarded as the main sources of voltage losses. Based on the thermodynamic-electrochemical analysis, mathematical expressions of some performance parameters such as the cell potential, power output, efficiency, and entropy production rate are derived. The effects of microstructure parameters such as the electrode porosity, tortuosity, pore size, grain size, etc. on the electrochemical performance characteristics of the SOFC are revealed. Moreover, the effects of some operation conditions such as the current density, anode inlet gas molar fraction, operating temperature, and operating pressure on some important performance parameters of the SOFC are also discussed. It is found that there exist some optimal values of microstructure parameters and operating conditions at which the better performance can be expected. The results obtained in the paper may provide some theoretical guidance for the design and operation of practical SOFCs fueled by coal-derived gases.     

A Study on Coupled Thermo-Elasto-Plastic-Damage Dissipative Phenomena: Models and Application to Some Innovative Materials

This is a review paper on some irreversible thermodynamics-based constitutive models capable of capturing complex dissipative physical bahaviour in multifunctional innovative materials. The thermomechanical response of such materials accounts for two basic sources of material nonlinearity, plasticity and damage, which may result in various failure mechanisms. A number of couplings, such as thermo-elastic-damage, elastic-plastic hardening, plastic-damage hardening, thermo-elastic-plastic-damage, etc., are discussed. Various material symmetry classes, including anisotropy, orthotropy, transverse isotropy, are referred to some innovative materials, such as composite materials, functionally graded structures, thermal or wear resistant coatings, etc. Examples of implementation of chosen models for simulation of some initial boundary problems are presented.     

环形集箱制造工艺分析与探讨

上海锅炉厂有限公司近期制造的 2台CFB锅炉旋风筒环形集箱制造中出现的问题 ,如 :环形集箱本体弯制圆度及平面平整度控制问题 ;焊接变形控制问题 ;水压试验余量问题以及在最近制造的出口美国517t/hCFB锅炉中出现的大直径环形集箱装配场地问题等 ,介绍在该台 517t/hCFB锅炉制造中采取的一些针对性措施 ,并对环形集箱制造工艺进行一些分析、探讨和总结     

供暖系统规划设计中的几点节能分析

本文利用分析的原理,从节能的角度,对供暖系统在供暖方式、介质参数、供暖设备及管网调节方式等一系列问题进行了简要分析与比较,并提出了一些供暖系统的节能途径和措施。     

Unified cycle model of a class of internal combustion engines and their optimum performance characteristics

The unified cycle model of a class of internal combustion engines is presented, in which the influence of the multi-irreversibilities mainly resulting from the adiabatic processes, finite-time processes and heat leak loss through the cylinder wall on the performance of the cycle are taken into account. Based on the thermodynamic analysis method, the mathematical expressions of the power output and efficiency of the cycle are calculated and some important characteristic curves are given. The influence of the various design parameters such as the high-low pressure ratio, the high-low temperature ratio, the compression and expansion isentropic efficiencies etc. on the performance of the cycle is analyzed. The optimum criteria of some important parameters such as the power output, efficiency and pressure ratio are derived. The results obtained from this unified cycle model are very general and useful, from which the optimal performance of the Atkinson, Otto, Diesel, Dual and Miller heat engines and some new heat engines can be directly derived.     

a－Si：H薄膜的表面缺陷研究

ａ－Ｓｉ：Ｈ薄膜的缺陷会给以该材料制作的半导体器件，如太阳电池、激光唱盘、光导鼓、ＴＦＴ等造成疵点，降低器件的质量和成品率；而对微波功率器件，这些缺陷则是致命的危害。本文讨论表面上由细微颗粒造成的各种缺陷。揭示这些缺陷的微结构形貌，对其形成的原因进行理论分析，并就如何消除这些缺陷，制备光洁如镜的ａ－Ｓｉ：Ｈ薄膜进行讨论。     

Are biofuels a feasible option?

Recently a number of objections have been raised against the use of ethanol produced from agricultural products such as maize, sugarcane, wheat or sugar beets as a replacement for gasoline, despite some of their advantages such as being cleaner and to some extent renewable. We address these objections in this paper. Topics discussed include the “corn connection” (which was theorized to be a cause of deforestation in the Amazonia), the rise of food prices due to ethanol production and the real possibilities of ethanol in reducing greenhouse gas emissions. It has been shown that such concerns are grossly exaggerated and that ethanol from sugarcane, as produced in Brazil, is the preferred option for the production of fuel not only in terms of cost but also as a favourable energy balance. Finally, the possibility of expanding ethanol production to other sugar-producing countries is also discussed.     

我国新能源汽车产业发展及其困境摆脱

我国新能源汽车产业仍面临着许多的问题:核心技术缺乏竞争力,关键技术瓶颈凸显;基础配套设施不够完善;价格普遍偏高,市场推广有难度;等等.因此,需坚持传统汽车和新能源汽车"两条腿走路"的方针;加快核心部件的技术研发力度;促进新能源整车和零部件协调发展;尽快建立统一的技术标准;完善与新能源汽车发展相适应的基础配套设施;等等.     

国产300MW机组振动问题分析及治理

国内三大动力集团公司生产的300MW机组在运行过程中存在一些较为普遍的振动问题,如过发电机/励磁机临界区域振动大、4号轴承振动偏大、大负荷下高中压转子轴承突发性振动等,严重影响机组的安全可靠运行。阐述了国产300MW机组的振动特征,分析振动原因,并总结处理过程,给出现场振动治理的措施。     

Simultaneous determination of absolute and relative permeabilities

Data from core analyses, such as residual oil saturation and relative permeabilities, are of great importance for proper exploitation of the petroleum resources. Such quantities are typically determined through interpretation of data acquired during some flooding experiment. In such determinations, the absolute permeabilities are typically represented by a single average value, i.e., the core is assumed homogeneous and isotropic. Recent studies, however, show that the validity of such assumptions can be questioned. When using such assumptions analyzing flooding data, the derived relative permeabilities will depend on the actual core sample heterogeneity, i.e., the variation and distribution of the absolute permeability in the core. A better option would therefore be to determine the absolute and relative permeabilities simultaneously from the data, thereby accounting for heterogeneity effects. In this paper we describe and test a method for such determinations, and discuss some results.