路面激励引起的车内噪声仿真分析研究

使用ADAMs、Nastran与sysnoise软件,采用多体系统动力学理论,有限元理论和边界元理论相结合的方法对由于路面不平激励引起的车内低频噪声特性进行了仿真分析.还探讨了座椅特性对车内噪声的影响,并对不同车速下的车内噪声特性进行了比较.     

钢弹簧浮置板轨道对车内噪声影响的实测与分析

在列车经过钢弹簧浮置板地段时,车内产生中低频噪声,影响着人们乘车环境舒适性。通过对不同钢弹簧浮置板轨道地段车内噪声的对比测试,分析钢弹簧浮置板轨道对车内噪声的影响,结果表明采用高阻尼钢弹簧浮置板轨道可有效降低车内噪声。     

微型客车车内气流速度场的三维数值模拟

采用UG建立微型客车车内结构的几何模型,运用ANSYSIECM10.0划分网格,以微型客车空调车内流动的空气气流为研究对象,应用标准K-ε湍流计算模型,通过Fluent软件分析前、顶蒸发器不同的送风角度车内的速度场的分布特征,为设计微型客车车内均匀气流场提供参考依据.     

新能源电动汽车稳态工况车内声品质客观评价特征提取

车内噪声是影响新能源电动汽车整体品质的重要因素。为更准确预测电动汽车车内噪声的声品质，以12辆国内典型的电动汽车车内驾驶侧噪声为输入，使用基于核函数的主成分分析方法，对比不同核函数及核函数的参数对特征提取准确性的影响，通过对控制变量取优的方式确定使用高斯径向基核函数提取电动汽车车内声品质客观评价特征，并成功将8维特征降低至4维，得到影响电动汽车车内声品质的4个主要客观参量依次为语音清晰度、A计权声压级、粗糙度、音调度。     

乘用车内甲醛、TVOC的浓度检测

选择了11辆不同品牌与使用时间的乘用车,测定车内空气中甲醛、总挥发性有机化合物(TVOC)的浓度,并依据相关国家标准限定值对检测结果进行分析,发现车内TVOC浓度超出限定值程度远高于甲醛,同时评估了开启车门通风以及使用车内空调对两者浓度变化的影响。     

冷藏车开门时车内温湿度变化实验研究

配送过程中冷藏车开门时的热质交换会引起车内空气温湿度的剧烈变化,这使得食品的品质难以得到保证.针对目前冷藏车开门卸货时存在的一些问题,进行了对比实验,对不同条件下的车内温度、相对湿度变化进行了分析,得出在开门时长一定的情况下车厢内外空气温差是影响车内温升的主要因素,采用PVC门帘可以有效地抑制车内温度升高,一定程度上保证食品安全.     

车内噪声烦恼度的声品质分析

以4种类型轿车在不同车速下匀速行驶时不同位置点采集到的车内噪声样本为评价对象,采用等级评分法对车内噪声声品质烦恼度进行主观评价试验,分析计算各噪声样本的心理声学客观参数;通过相关分析和多元线性回归分析,建立匀速车内噪声主观评价烦恼度与心理声学客观参数间的数学模型。研究结果表明,在良好路面和匀速工况下车内声品质烦恼度主要受低沉度和音调度两个心理声学客观参数影响。     

自行式C型旅居车餐厨空间人机工程设计

目的 随着自驾旅行的日趋流行,一种集成会客、起居、餐厨、卫浴等功能的旅居车出现在汽车市场,满足了旅行者车内生活的基本需要.其中餐厨空间是旅居车内部生活空间的重要组成部分,食物烹饪加工和存放是餐厨空间的基本功能.针对某型自行式C型旅居车餐厨空间的人机设计缺陷,对其设施布局、使用方式进行人机工程学改良设计.方法 首先通过分析中国成年人体标准尺寸确定用户在餐厨空间操作的舒适范围,并结合旅居车内可用空间尺寸来对车内餐厨空间的人机设备进行布局并设计方案,为自行式C型旅居车提供一款餐厨空间方案,其次采用人机工程软件Siemens Jack验证设计方案的可行性.结论 通过对设计方案的分析与验证,从使用舒适性及便利性的方向为旅居车餐厨空间的造型设计和研发提供有效的建议.     

基于心理声学响度分析的高速列车车内噪声评价

测试不同运行速度下高速列车车厢内部噪声,并进行噪声的频谱分析。根据噪声强度主观感觉的心理声学理论,分析使用A计权和响度来评价车内噪声环境的不同,指出响度能更准确地评价车内噪声。并在此基础上提出车内降噪的频率范围。     

基于单片机与手机控制的公共交通工具内部空间的复合式消杀装置研究

结合当下公交汽车运行需要对车内进行消毒的实际需求以及疫情防控常态化对公交系统车内环境提出的新要求,该文设计了基于单片机与手机控制的车内复合式消杀装置。该装置使用消毒液喷洒模块和臭氧消毒模块复合的方式完成对公交车内重点位置与车厢环境的自动化消毒与杀菌。同时,采用手机App通过蓝牙模块连接设备以及单片机内置程序控制设备的联合控制模式,实现操作人员对消杀设备的智能化操控。     

Influence of ozone concentration and temperature on ultra-fine particle and gaseous volatile organic compound formations generated during the ozone-initiated reactions with emitted terpenes from a car air freshener

Experiments were conducted to identify the emissions from the car air freshener and to identify the formation of ultra-fine particles and secondary gaseous compounds during the ozone-initiated oxidations with emitted volatile organic compounds (VOCs). The identified primary constituents emitted from the car air freshener in this study were alpha-pinene, beta-pinene, p-cymene, and limonene. Formation of ultra-fine particles (4.4-160nm) was observed when ozone was injected into the chamber containing emitted monoterpenes from the air freshener. Particle number concentrations, particle mass concentrations, and surface concentrations were measured in time dependent experiments to describe the particle formation and growth within the chamber. The irritating secondary gaseous products formed during the ozone-initiated reactions include formaldehyde, acetaldehyde, acrolein, acetone, and propionaldehyde. Ozone concentration (50 and 100ppb) and temperature (30 and 40 degrees C) significantly affect the formation of particles and gaseous products during the ozone-initiated reactions. The results obtained in this study provided an insight on the potential exposure of particles and irritating secondary products formed during the ozone-initiated reaction to passengers in confined spaces.     

Children at risk: predictors of car safety seat misuse in Ontario

When used correctly, child safety seats can reduce the risk of death and serious injury by 54% in toddlers and 71% in infants [National Highway Traffic Safety Administration (NHTSA), 2001. Traffic Safety Facts 2001. Children (DOT HS 809 471), U.S. Department of Transportation, Washington, DC]. The purpose of this study was to identify factors that predict correct use of car safety seats. The study was conducted in a large urban area in Southwestern Ontario and a small urban and rural area in Northern Ontario. Participants were 1263 caregivers who completed a self-report survey on their knowledge and use of car safety seats for their children (N=2199). Logistic regression analysis revealed that female caregivers, caregivers with higher levels of education, and caregivers who reported that finding information about the correct use of child safety seats was "difficult" were more likely to report correctly using car safety seats. The results also showed that children aged 7 months to 8 years old had substantially lower odds of being in the correct car safety seat compared to children aged 6 months or younger, or children aged 9 years or older. The high risk nature of misuse of child seats for infants and younger children may be an important cue to action for health professionals to develop comprehensive prevention strategies.     

PARTICULATE CONCENTRATION IN AUTOMOBILE PASSENGER COMPARTMENTS

An experimental study of the dust concentration in automobile passenger compartments was conducted to understand how driving conditions and a vehicle's ventilation system can affect cabin air quality. The results of this study are essential for designing appropriate cabin air filters and developing proper test procedures.

The particle size distribution of atmospheric contaminants entering the vehicle's passenger compartment through air registers and in the occupants' breathing zone was measured using an optical particle counter. The concentration and size distribution of aerosol in the cabin was found to be dependent on traffic conditions, road surface, environmental conditions (e.g., weather) and ventilation mode. In all cases over 90% of the particles were smaller than 1 µm. The vehicle's HVAC system (evaporator core) reduces the concentration of aerosol entering the car interior, especially larger particles. Commercial vehicle ventilation filters decrease particle concentrations in a driver's breathing zone for all particle sizes. However, the reduction in the submicron particle range is not sufficient to substantially improve air quality in the passenger cabin.     

Keeping baby safe: A randomized trial of a parent training program for infant and toddler motor vehicle injury prevention

Motor vehicle crashes are responsible for much death and disability among infants and toddlers. This study evaluated Keeping Baby Safe In and Around the Car, a multimedia DVD designed to improve knowledge about car seat installation among parents of infants and toddlers. The randomized controlled trial was conducted with 195 parents of children aged 0–24 months. Effective car seat use was evaluated via a written knowledge quiz and car seat simulation. Results from analyses of covariance models show that posttest scores for the intervention condition were significantly higher than those of the control condition on both knowledge and car seat simulation measures. The results, consistent across outcome measures and regardless of child age, suggest that viewing the Keeping Baby Safe In and Around the Car DVD resulted in significant gains in parents’ car seat knowledge and their ability to discriminate the critical elements of correct car seat installation. Dissemination of engaging multimedia DVDs such as this program might reduce motor vehicle crash-related injuries to infants and toddlers.     

交互体验式婴幼儿书籍设计

目的着眼于0—3岁交互体验式婴幼儿书籍设计的研究。方法对交互体验式婴幼儿书籍进行归纳,进而阐述了质感体验、场景体验、生活体验3种不同交互体验式书籍对婴幼儿成长的影响和作用。结论总结交互体验式书籍的艺术美感,提出开发交互体验式书籍设计对婴幼儿的成长有着至关重要的作用,使其在轻松愉悦的氛围中学习到知识。     

Online laser desorption-multiphoton postionization mass spectrometry of individual aerosol particles: molecular source indicators for particles emitted from different traffic-related and wood combustion sources

Direct inlet aerosol mass spectrometry plays an increasingly important role in applied and fundamental aerosol and nanoparticle research. Laser desorption/ionization (LDI) based techniques for single particle time-of-flight mass spectrometry (LDI-SP-TOFMS) are a promising approach in the chemical analysis of single aerosol particles, especially for the detection of inorganic species and distinction of particle classes. However, until now the detection of molecular organic compounds on a single particle basis has been difficult due to the high laser power densities which are required for the LDI process as well as due to the inherent matrix effects associated with this ionization technique. By the application of a two-step approach, where an IR desorption laser pulse is applied to perform a gentle desorption of organic material from the single particle surface and a second UV-laser performs the soft ionization of the desorbed species, this drawback of laser based single particles mass spectrometry can be overcome. The postionization of the desorbed molecules has been accomplished in this work by resonance enhanced multiphoton ionization (REMPI) using a KrF excimer laser (248 nm). REMPI allows an almost fragmentation free trace analysis of polycyclic aromatic hydrocarbons (PAHs) and their derivatives from individual single particles (laser desorption-REMPI postionization-single particle-time-of-flight mass spectrometry or LD-REMPI-SP-TOFMS). Crucial system parameters of the home-built aerosol mass spectrometer such as the power densities and the relative timing of both lasers were optimized with respect to the detectability of particle source specific organic signatures using well characterized standard particles. In a second step, the LD-REMPI-SP-TOFMS system was applied to analyze different real world aerosols (spruce wood combustion, gasoline car exhaust, beech wood combustion, and diesel car exhaust). It was possible to distinguish the particles from different sources by their molecular signature. Finally, exemplary ambient aerosol measurements have been carried out, which demonstrate the potential of the method for investigating urban aerosol and making contributions to source attribution studies.     

情感化设计在婴幼儿餐盘中的应用

目的将情感化设计的思维方法应用于婴幼儿餐盘设计中,设计一款能够打动人心的产品。方法婴幼儿餐盘的情感化设计主要体现在本能层面的好看和行为层面的好用上,在反思层面上对婴幼儿餐盘进行创意设计,旨在通过设计理念引导婴幼儿建立良好的行为习惯。结论情感化设计理念应用于婴幼儿产品具有重要意义,婴幼儿产品的设计不仅需要富有趣味的造型和安全易用的使用方式,而且还可以从反思层面探索更多新颖与有趣的形式。     

一种新型粉体分散装置的实验研究

为了获得高质量的粉体气溶胶,开发了一种依据浮动压差原理设计的新型粉体分散装置,同时利用该装置进行不同粒径滑石粉的分散实验,分析气溶胶生成质量,考察气体压力、气流量及粉体剩余量等因素时粉体输送量的影响。该分散装置采用锥体流化板结构使物料与空气充分混合,在空气中形成有效的粉体气溶胶,并通过流量控制装置控制气体压力和流量,从而控制粉体的输送速度和输送量。结果表明,该装置能够生成粒径在2μm左右的固体气溶胶,可以通过控制高压空气流量控制粉体输送量。     

我国与欧盟婴幼儿配方食品标准存在的差异分析

本文介绍了欧盟与我国婴幼儿配方食品标准状况,对比分析我国婴幼儿配方食品标准与欧盟标准间的差距,为改进和完善我国婴幼儿食品标准体系提供了参考。     

The effectiveness of an air cleaner in controlling droplet/aerosol particle dispersion emitted from a patient's mouth in the indoor environment of dental clinics

Dental healthcare workers (DHCWs) are at high risk of occupational exposure to droplets and aerosol particles emitted from patients'' mouths during treatment. We evaluated the effectiveness of an air cleaner in reducing droplet and aerosol contamination by positioning the device in four different locations in an actual dental clinic. We applied computational fluid dynamics (CFD) methods to solve the governing equations of airflow, energy and dispersion of different-sized airborne droplets/aerosol particles. In a dental clinic, we measured the supply air velocity and temperature of the ventilation system, the airflow rate and the particle removal efficiency of the air cleaner to determine the boundary conditions for the CFD simulations. Our results indicate that use of an air cleaner in a dental clinic may be an effective method for reducing DHCWs'' exposure to airborne droplets and aerosol particles. Further, we found that the probability of droplet/aerosol particle removal and the direction of airflow from the cleaner are both important control measures for droplet and aerosol contamination in a dental clinic. Thus, the distance between the air cleaner and droplet/aerosol particle source as well as the relative location of the air cleaner to both the source and the DHCW are important considerations for reducing DHCWs'' exposure to droplets/aerosol particles emitted from the patient''s mouth during treatments.