Strong Magnetic Field Annealing for Improved Phthalocyanine Organic Thin-Film Transistors

Thin-film microstructure, morphology, and polymorphism can be controlled and optimized to improve the performance of carbon-based electronics. Thermal or solvent vapor annealing are common post-deposition processing techniques; however, it can be difficult to control or destructive to the active layer or substrates. Here, the use of a static, strong magnetic field (SMF) as a non-destructive process for the improvement of phthalocyanine (Pc) thin-film microstructure, increasing organic thin-film transistor (OTFTs) mobility by twofold, is demonstrated. Grazing incident wide-angle X-ray scattering (GIWAXS), X-ray diffraction (XRD), and atomic force microscopy (AFM) elucidate the effect of SMF on both para- and diamagnetic Pc thin-films when subjected to a magnetic field. A SMF is found to increase the concentration of oxygen-induced radical species within the Pc thin-film, lending a paramagnetic character to ordinarily diamagnetic metal-free Pc and resulting in magnetic field induced changes to its thin-film microstructures. In a nitrogen environment, without competing degradation effects of molecular oxygen, SMF processing is found to favorably improve charge transport characteristics and increase OTFT mobility. Thus, post-deposition thin-film annealing with a magnetic field is presented as an alternative and promising technique for future thin-film engineering applications.     

An x-Ray Time-Analyzing Electron-Optical Converter with Improved Design and Operating Parameters

A new x-ray electron-optical converter with an Au or CsJ photocathode is described. The instrument has improved time resolution and improved image brightness. The slit width in the accelerating electrode can be chosen to be 50–100 m. A working diagram of the converter is given.     

用(火用)分析法确定风机盘管机组性能的评价指标

在分析已有风机盘管机组性能评价指标的基础上,利用热力学第二定律和(火用)分析的方法,提出了一种新的风机盘管机组性能的评价指标.该指标简单实用,可以较合理地评价风机盘管机组的性能.     

A New Device for Measurements of Pulses or High-Frequency Currents

Resistors are frequently used for measuring waveforms and magnitudes of pulse currents, assuming that the effect of residual inductance of the resistors is very small. However, when the very high-frequency components of the current must be taken into account, the effect of the residual inductance cannot be neglected. In this paper, a new current measuring device with a resistor of a special type is described. It is so constructed that the effect of residual inductance does not appear in the observing circuit of the device. Consequently, the voltage observed becomes exactly the product of the resistance of the device and the current to be measured, flowing through the device. As the effect of the residual inductance of the device does not appear in the observing circuit, the resistance of the device can be made very low, consequently, the circuit condition will be practically undisturbed by the connection of the device.     

新型发射药包装物设计与性能研究

目的为解决当前发射药包装物存在的结构复杂、自重大、难以适应包装工艺自动化的突出问题,提高对发射药包装、贮存、运输、使用过程的适应性,设计一种结构合理、防护可靠的新型发射药包装物。方法根据发射药包装物技术要求,进行包装物材料选用和结构设计,通过性能研究,全面考核新型发射药包装物的相容性、防静电性能、老化性能、力学性能、密封性能、环境适应性、防拆封功能等。结果实验结果表明,设计和研制的新型发射药包装物与内装典型发射药相容性良好;表面电阻率为1.37×106～7.23×108Ω;在25℃贮存条件下,平均热老化寿命为17.51年;新型发射药包装物配质量为45kg,堆码3层,未出现倒垛、变形及破损现象;包装物经高温、低温、温度冲击后无变形、失效、永久硬化,且表面无裂解;密封性良好,可有效防止非正常拆封。结论该新型发射药包装物可实现对现有包装物的替代,可在火炸药行业推广应用。     

Selecting a Standard Thermal Converter for Checking Working Noble-Metal Ones

A method is considered for comparing electrodes one by one during checks on technical thermocouples of types TPP 10 and TPR by means of third-class standard thermal converters. It is shown that there are advantages in that method on checking such thermal converters.     

A New Thin-Film Permeameter for Measuring All Components of a Permeability Tensor

We describe a new permeameter to evaluate all components of a permeability tensor. The permeameter consists of a shorted microstrip line and a revolving coil, which can operate well up to 300 MHz. All mu_ij ^r (i, j = x, y, and z) of a relative permeability tensor of a magnetic thin film were evaluated by the permeameter. The measurements show that the sample has large off-diagonal components compared with diagonal ones, indicating that the examination of such off-diagonal components by the permeameter can be used to design new devices with high accuracy.     

铁路货运装备新型外包保温加热系统综合性能研究

目的 提出一种新型外包保温加热系统,并检测其综合性能。方法 将冷链物流作为切入点,提出一种新型保温加热系统,结合传热学基础理论,从物理性能分析、工艺性能实践、综合性能检测、应用性能验证等不同角度,详细阐述新型保温系统的综合性能。结果 新型外包保温绝热材料达到热动平衡后,漏热率与温差关系曲线相对稳定,无大的波动点;同时与之相搭配的新型加热系统柴油消耗量由19.3 L/h降低至17.2 L/h,平均加热时长减少了1 h。结论 新型外包保温加热系统的加热效率得到了很大的提升,并且进一步减少了热能损失,同时加快了装卸效率。     

Design of a New Method for Obtaining Thermal Insulation Blocks from Hydrosilicate

Journal of Engineering Physics and Thermophysics - Design of thermal insulation from porous materials based on hydrosilicates is a promising area of researches. In this paper, the formation of...     

Analytic Thermal Modeling for dc-to-Midrange Modulation Frequency Responses of Thin-Film High- T c Superconductive Edge-Transition Bolometers

Thin-film superconductive edge-transition bolometers are modeled with a one-dimensional analytic thermal model with joule heating, film and substrate materials, and the physical interface effects taken into consideration. The results from the model agree well with the experimental results of samples made of large-meander-line Yba(2)Cu(3)O(7-x) films on crystalline SrTiO(3), LaAlO(3), and MgO substrates up to 100 kHz, the limits of the experimental setup. Compared with the results of the SrTiO(3) substrate samples, the results from the model of the LaAlO(3) and the MgO substrate samples deviate slightly from the measured values at very low modulation frequencies (below ~10 Hz). The deviation increases for higher thermal-conductive substrate materials. When the model was used, the substrate absorption and the thermal parameters of the devices could also be investigated.     

冷天花冷却顶板热工性能分析

研究表明,冷天人空调方式具有舒适性好、节约能源等特点。在国外已经有了比较普遍的应用。本结合我国的材料条件、加工能力等具体情况,在对冷却顶板热工性能理论分析的基础上,对冷天花冷却顶板进行了热工实验研究和对实验结果进行正交分析。研究结果表明,在影响冷却顶板传热性能的多种因素中,冷却顶板内部的冷媒管管间距、冷却顶板的板面材料导热性能等与冷却顶板传热（冷）量有显的相关性,而冷媒管管径、冷却顶板的厚度与     

高频动态校准系统的自校准模板设计方法研究

本文对数据采集系统的内装式自校准模板的设计、开发进行了研究.自校准模板采用ARM9和高速、高准确度DAC发生动态校准信号,高稳定度电压基准发生静态校准信号.模板上的高精密12档衰减器实现了对信号幅值的设置,可程控8档截频滤波器根据动态校准信号的频率对DAC产生的动态模拟信号进行滤波.论述了自校准模板静态电压基准电路、衰减器及数模转换电路的设计.采用ARM9和C语言开发了完善的通信模块、参数设置模块、功能实现模块及上位机与模板的通信协议模块等.通过设计、制作和调试,实现了幅值满度为+10V及频率为100 kHz动态校准信号的发生.     

基于改进差分进化算法的热电池装配机器人优化设计

目的 为了实现异形热电池组的智能化装配和解决装配过程中存在装配精度不高的问题,设计了一种装配机器人,并仿真验证该机器人是否能够满足异形热电池组的装配精度需求。方法 采用改进D-H参数法构建运动学模型,通过正运动学分析机器人末端轨迹。采用改进DE算法进行逆运动学求解,并通过仿真实验分析运动学求解结果。结果 求得平均位置误差为1.4×10–4 mm,平均姿态误差为2.4×10–4度,平均解迭代次数为219.857,各构件最大角速度不应超过3.5 rad/s。结论 设计的装配机器人能够满足异形热电池组装配精度要求,运动学求解精度提高2个数量级,效率提高72.5%。     

A New Resistance-to-Frequency Converter for Temperature Measurements in Calorimeters

A circuit is described for the measurement of the temperature difference between input and output heat exchangers by means of resistance thermometers. Two thermometer resistors form part of a resistance-to-frequency converter, the frequency being proportional to their difference in resistance value. The frequency is also dependent on a few additional resistors and a capacitor. Drifts and offsets of amplifiers are eliminated to a first order. No stabilized voltages are used. The circuit was developed as part of a simple and reliable calorimeter for domestic uses.     

抗事故包装箱热防护结构的设计及其性能分析

对抗事故包装箱的火灾环境条件进行了研究 ,初步确定了抗事故包装箱的设计模型 ,提出了一种可用于分析评价抗事故包装箱防火 (或高温 )性能的理论模型 ,并对影响结构热响应的几个关键因素进行了有限元数值模拟     

Optimization Technique for Design of Automotive Air Filter Housings with Improved Fluid Dynamic Performance and Filtration

A filter housing design technique has been developed that computes the housing geometry required to provide a user-specified velocity distribution through the filter. Appropriate control of the flow field across the filter can improve filter efficiency. Two-dimensional computational designs have been performed specifying a uniform velocity distribution through the filter. This distribution corresponds to a uniform, constant pressure drop across the filter from the upstream to the downstream side. A computational optimization method is used to minimize the variation in the pressure drop along the filter by changing the geometry of the upper wall. Computational fluid dynamics (CFD) calculations of the viscous laminar flow upstream and downstream of the filter are performed using two-dimensional Navier-Stokes equations. As the upper wall profile is numerically changed, the CFD solution for the computations is repeated and the pressure drop variation is reevaluated until an optimum configuration is achieved. The optimization results have produced a pressure distribution that is very close to the specified uniform distribution. Experimental verifications were performed using a laser Doppler anemometer to measure the velocity distribution just upstream of the filter and a pressure transducer to measure pressure drops across the filter. The velocity distribution in this (optimized) housing is more uniform than other housing models having the same fundamental rectangular geometry.     

基于新型防热机理的防热材料的设计与试验验证

传统的防热材料大多是依靠材料自身的高熔点"忍受"热流或依靠缓慢烧蚀来被动地延长寿命的,这些材料因其密度大或耐氧化不足等问题已经不能满足飞行器设计者的期望,突破传统的被动式防热的思路从防热机理的源头上探索新的思路或许可以找到可行的技术途径。作者设计了一个新的材料体系——耗散防热材料,即在石墨中加入还原性金属,在烧蚀过程中还原性金属耗散热量,同时耗散外界的氧,自发生成氧化物陶瓷膜。新的材料设计的思想是"利用"热流而不是单纯"忍受"热流,初步试验验证表明,在廉价的石墨渗入耗散剂——铝制备的耗散防热材料,在2 900℃,4 MW/m2热焓值烧蚀下,线烧蚀率仅为传统C/C的1/10。其耗散防热原理包含了以往的汇热防热、辐射防热、烧蚀防热、发汗防热等防热形式,增加了相变反应防热,是一种新的防热原理,这种高效能、低成本的材料预计具有很好的应用前景,也将推动非平衡条件下的金属化学基础理论突破。本材料研究的科学问题,涉及高温、高压、高速气流冲刷等非平衡状态的化学反应问题、金属流动问题等,这些问题的研究必将推动材料科学与传热学、流体力学、燃烧化学、气动力学等学科的交叉互动和新的发展。     

冰激凌PLA保温包装结构设计及其保温性能研究

为了使冰激凌在“最后一公里”配送时始终处于合理的温度范围内,设计了一种基于3D打印技术的保温包装杯。分析了不同容器壁厚、不同外界温湿度对保温杯保温性能的影响,同时建立了关于外界温度-厚度-保温时间的三维曲面模型及曲面方程,并对3种不同温度和厚度的包装模型进行了验证。结果表明:30mm的容器壁厚足以使冰激凌的保温时间达到配送要求的60min;当外界温湿度为23℃/50%RH,30℃/85%RH时,3个测试点的保温时间均能满足最低配送要求,当外界温湿度为40℃/90%RH时,只有中心点的保温时间达到配送要求;理论值与试验值的误差在±10%,该曲面方程具有一定的参考价值。     

An Improved Empirical Correlation for the Thermal Conductivity of Propane

New experimental data on the thermal conductivity of propane have been reported since the wide-range correlations proposed by Holland et al. and by Younglove and Ely. These new experimental data, covering a temperature range of 110 to 700 K and a pressure range of 0.1 to 70 MPa, are used together with the previously available data to develop an improved empirical equation for the thermal conductivity of gaseous and liquid propane. The quality of the new data is such that the thermal-conductivity correlation for propane is estimated to have an uncertainty of about ±5% at a 95% confidence level, with the exception of state points near the critical point, where the uncertainty of the correlation increases to ±10%.