连续冲击与振动试验：—用振动台进行连续冲击试验的试验方法探讨

运输包装件连续冲击试验的目的是模拟包装件在 颠簸的路面上运输时的状况。但目前的连续冲击试验机 在试验样品质量较大的情况下无法满足试验的要求。为 此，我们设计了用振动台进行连续冲击试验的方法，并通 过试验对这种方法加以验证。     

冷藏运输条件仿真试验台的设计与测试

设计、建立了冷藏运输条件仿真试验台。试验台由两部分组成：一是外部环境模拟，可模拟各种温度、湿度以及速度环境，通过无级调节，多种组合，可模拟冷藏运输单元所能遇到的主要外部条件。二是冷藏运输单元模拟，以20英尺冷藏集装箱为基础，对风口位置、大小，出风方向、风量等进行调节，还能对箱内温度、湿度、气体成分进行组合调节，对多温空间、各种货物不同装载模式进行试验。试验台配备高精度的检测、控制设备。对试验台气密性、漏热率等性能指标进行了全面检测，所有参数达到设计要求，为冷藏运输设备的优化设计、食品运输安全等方面研究提供基础。     

燃料运输容器跌落姿态分析技术

目的总结燃料运输容器跌落分析流程,设计合理的姿态分析方案,通过分析使燃料运输容器设计满足GB 11806规定的跌落试验要求。方法使用动力有限元方法对新燃料运输容器进行多姿态多工况的跌落分析,并根据试验结果对分析结果进行验证,将分析和试验经验总结成完整的分析流程。结果通过分析,新燃料运输容器在正常运输条件下的最不利跌落姿态为9°小角度跌落,该工况下容器外壳最大变形量为49 mm。事故运输条件下最不利跌落姿态为正向垂直跌落,燃料组件最大冲击力为1.78 MN。结合分析和试验结果总结了容器最不利跌落姿态的分析流程和技术要点。结论结合分析和试验结果,得到了新燃料运输容器各跌落试验的最不利跌落姿态,并总结了燃料运输容器跌落分析的通用流程。     

汽轮机导板断裂的焊接修复

由于运输不慎,将一台汽轮机的后导板折断.通过对其材质的焊接性能分析,先用试板进行焊接试验,确定了合理的焊接工艺措施,保证了后导板断裂处的焊接修复质量.     

车载机柜隔振系统道路试验

为分析车载机柜由于道路运输振动对物资产生的影响,在机柜和车厢之间安装钢丝绳隔振器,对运输物资垂向隔振效果进行测试。对机柜进行三种不同路面的道路运输试验。通过对试验数据进行研究分析发现,钢丝绳隔振器在机柜道路运输过程中具有明显的隔振效果。     

运输包装件振动试验系统研究

在流通环境振动分析的基础上，进行了运输包装件各种振动试验的特点比较，并对随机振动试验系统的方案和实施过程等做了一定的研究，为运输包装件的优化设计打好了基础。     

GB/T 21145—2023《运输用制冷机组》标准解读

随着冷链物流技术的发展，运输用制冷机组的运行工况范围和运行条件有了很大的拓展。新版GB/T 21145《运输用制冷机组》标准完善了运输用制冷机组的分类体系、技术要求和试验方法，为机组研发和质量评定提供统一的评价要求和试验方法，推进运输用制冷机组产业的技术进步。详细论述了新版标准的制订背景、适用范围，运输用制冷机组的考核工况条件、启动运行及最大负荷连续运行的技术要求和试验方法、多温区机组的制冷量试验方法、替代制冷剂的相关要求等，以期能够指导相关人员更好地使用和执行新版标准。     

弹药运输环境振动特性研究

通过对勤务环境中的力学环境进行分析，列出了几种常用运输工具的力学诱导环境和装卸跌落环境条件，研究了复杂勤务环境中上千种环境因素随机组合条件下的力学环境筛选简化方法．运输环境分别按环境严酷程度分成不同的类别，将引信按其解脱保险的难易分成不同的类别建立组合化简条件；建立了运输车辆受迫振动数学模型，通过试验测定了卡车运输环境中，不同路面不同方向最大加速度值，代表了这一类型车辆的运输环境条件用来指导弹药勤务工作。     

沥青砼路面施工质量控制要点

文章分别从施工准备工作，沥青的拌和及其运输，铺筑试验路段的质量控制，沥青砼路面摊铺的质量控制和沥青砼路面摊铺的质量控制分别作了详细的介绍。     

矿车连接装置拉力试验机在龙固煤矿应用

矿车连接装置拉力试验是安全质量标准化要求矿井必须履行的法定义务，是技术性较强的矿井运输车辆安全性能检测项目。试验时最大静载荷的确认，试验方法的选择对试验结果的影响是至关重要的。从矿车拉力试验的必要性入手，对比分析了矿车拉力试验时可取的方法及其优缺点。针对矿车拉力试验机结构组成，论述了拉力试验机工作的依据与方法．以期为煤炭企业在矿车拉力试验工作过程中进行静载拉力整定提供参考。     

Numerical Model of the Microwave Properties of Superconducting Resonators and Transmission Lines

We propose a model for microwave power transmission in superconducting lines and resonators. The correct current density incorporating the critical current density is used. A numerical self-consistent method is suggested to calculate different transport quantities, such as the surface resistance and the quality factor as function of both temperature and magnetic field. The effect of the strength of pinning on the transport properties is studied, as well. Some of these results are compared with experiment.     

Supersolidity and Superfluidity of Grain Boundaries

We have looked for dc mass transport through solid ⁴He in a simple experiment with two communicating vessels filled with solid ⁴He in equilibrium with liquid ⁴He. Through good quality crystals, we have observed no mass transport, in contradiction with the hypothesis of a Bose–Einstein condensation of vacancies. Through crystals containing grain boundaries, we have found superfluid flow along these grain boundaries. We discuss these results in the context of other experiments on supersolidity.     

DNA分子材料电子输运研究进展

由于DNA分子在纳米电子学、分子电子学中具有广泛的潜在应用,对DNA分子中电子输运特性的研究备受关注.然而,目前对DNA分子电子输运特性的研究还未形成统一认识.阐述了DNA分子中的电子输运理论、实验研究进展.实验方面,DNA分子呈现出绝缘体、半导体、导体的各种可能结果都有报道;理论方面,主要形成了2种方法,一种是第一原理计算,另一种是基于哈密顿量模型的计算.     

新型危险品防爆运输箱设计及抗爆试验研究

分析和研究了目前装备使用的危险品防爆运输箱所存在的问题;采用层状复合工艺,制备了UHM-WPE-PUF复合材料,运用所设计的UHMWPE-PUF复合材料,设计和制作了一种新型危险品防爆运输箱,并进行了爆炸破坏性试验。研究表明:UHMWPE-PUF复合材料可以充分发挥UHMWPE材料的高强度、高模量特点以及PUF材料较高的吸能特性,运用该复合材料所制作的新型危险品防爆运输箱具有质量小、抗爆能力强等特点,适用于危险品的运输储存。     

Superconducting current stability in composite superconductors

The maximum transport current in multifilament composite superconductors has been studied. The experimentally obtained values of transport current exceed the normal phase minimum propagation current substantially. The current-voltage characteristics of the investigated samples have been studied. It is shown that the relatively high value of the maximum transport current is attributed, under the given experimental conditions, to the behaviour of the current-voltage characteristic in the region of low values of the electric field. The theory and experiment are in good agreement.     

Analysis of Bus Ride Comfort Using Smartphone Sensor Data

Passenger comfort is an important indicator that is often used to measure the quality of public transport services. It may also be a crucial factor in the passenger’s choice of transport mode. The typical method of assessing passenger comfort is through a passenger interview survey which can be tedious. This study aims to investigate the relationship between bus ride comfort based on ride smoothness and the vehicle’s motion detected by the smartphone sensors. An experiment was carried out on a bus fixed route within the University campus where comfort levels were rated on a 3-point scale and recorded at 5-second intervals. The kinematic motion characteristics obtained includes tri-axial linear accelerations, tri-axial rotational velocities, tri-axial inclinations and the latitude and longitude position of the vehicle and the updated speed. The data acquired were statistically analyzed using the Classification & Regression Tree method to correlate ride comfort with the best set of kinematic data. The results indicated that these kinematic changes captured in the smartphone can reflect the passenger ride comfort with an accuracy of about 90%. The work demonstrates that it is possible to make use of larger and readily available kinematic data to assess passenger comfort. This understanding also suggests the possibility of measuring driver behavior and performance.     

Generalized free-space diffuse photon transport model based on the influence analysis of a camera lens diaphragm

The camera lens diaphragm is an important component in a noncontact optical imaging system and has a crucial influence on the images registered on the CCD camera. However, this influence has not been taken into account in the existing free-space photon transport models. To model the photon transport process more accurately, a generalized free-space photon transport model is proposed. It combines Lambertian source theory with analysis of the influence of the camera lens diaphragm to simulate photon transport process in free space. In addition, the radiance theorem is also adopted to establish the energy relationship between the virtual detector and the CCD camera. The accuracy and feasibility of the proposed model is validated with a Monte-Carlo-based free-space photon transport model and physical phantom experiment. A comparison study with our previous hybrid radiosity-radiance theorem based model demonstrates the improvement performance and potential of the proposed model for simulating photon transport process in free space.     

航空运输集装托盘脱胶监测成像方法

目的为了提高航空运输集装托盘使用的安全性与经济性,实现航空运输集装托盘脱胶的在线监测。方法研究一种基于优化损伤概率成像的航空运输集装托盘脱胶监测方法,该方法首先将监测区域划分为一个个矩形子区域,然后判别航空运输集装托盘脱胶发生的子区域,其次使用损伤概率成像方法对脱胶进行定位,最后结合脱胶发生的子区域计算出航空运输集装托盘脱胶的位置坐标。结果依据航空运输集装托盘的生产工艺自制了一块试件对该方法进行实验验证,定位距离误差不大于2 cm。结论基于优化损伤概率成像的航空运输集装托盘脱胶监测方法可对航空运输集装托盘脱胶进行不依赖信号传播速度的成像定位。     

Application of Time-Domain Reflectometry for Measurement of Moisture Profiles in a Drying Experiment

The time-domain reflectometry (TDR) method is used for the measurement of moisture profiles in calcium silicate during a drying experiment. The specimens are saturated at first by water, and their lateral sides and one of the face sides are water- and vapor-proof insulated to ensure one-dimensional (1-D) water transport. Then, the drying process is started in an environment with a relative humidity of 20%. Moisture profiles are measured at specified time intervals using the TDR method. The experiment is stopped when the moisture content along the whole length of the sample is lower than the maximum hygroscopic moisture content. The obtained results can be used for the determination of moisture diffusivity in the drying phase of moisture transport.     

Effects of cushioning materials on the firmness of Huanghua pears (Pyrus pyrifolia Nakai cv. Huanghua) during distribution and storage

The type and quality of cushioning materials could significantly affect the vibration intensity and physical quality of fruits during transport. In the current paper, we evaluated the different cushioning materials (paper‐wrap materials, foam‐net packages) for their protective effect on the vibration levels, number of bruises and mechanical damage to Huanghua pears (Pyrus pyrifolia Nakai cv. Huanghua) during transport. Changes in pear firmness, hydrolase activity and cell wall constituents were examined in fruits stored for up to 36 days after transport. Our data suggested that the choice of cushioning material significantly reduced the vibration intensity in transit, affecting the physical quality of fruits and their subsequent commercialization, and that foam‐net packages provided a greater protective effect than paper‐wrap packages. Copyright © 2007 John Wiley & Sons, Ltd.