石蜡相变储能模块的控温性能研究

目的 为了控制电子设备工作温度，研发一种相变储能模块，并研究其控温性能。方法 本文通过仿真对以32号石蜡、62号石蜡和质量分数为6%的膨胀石墨(EG)-62号石蜡为相变工质的储能模块进行研究，分析相变材料、翅片材料以及加热功率对相变储能模块控温性能的影响。结果 32号石蜡在900 s时接近完全融化，62号石蜡在2 000 s时才融化过半，膨胀石墨-石蜡复合材料在1 250 s就已经接近完全融化，填充62号石蜡的Al翅片模块的温升速率为0.035 ℃/s，Cu翅片模块的温升速率为0.03 ℃/s，相比未填充相变材料的模块温升速率分别降低了73.1%和70%。结论 具有不同物性参数的相变材料，在不同工况下其呈现的控温性能也各不相同，但是在较高功率工况下，熔点较低或导热系数较高的相变材料具有更好的控温性能。储能模块内部导热翅片对内部强化换热效果明显，翅片导热系数越高，越有利于模块的控温。     

高温盐浴炉直接测温的实践

高温盐浴炉是高速钢刀具的加热淬火炉。刀具的质量和使用寿命与热处理的控温、测温的准确性,有很密切的关系。一般采用如光学高温计、辐射高温计等间接式测温的方法均有不少缺陷,使刀具质量得不到保证。为此,我们于1975年采用了高温盐浴直接测温,经多年生产实践证明,这种测温方法与间接测温相比较,有较多的优点:(1) 测温和控温的精度较高。在显示仪表量程的范围内,经对综合误差的修正后,控温精度为±2℃。     

控温包装控温时间预测模型研究

目的建立控温包装控温时间预测模型,保护温度敏感产品在一定时间内不受外界温度变化的影响。方法以典型长方体产品的控温包装为研究对象,通过计算控温包装系统热阻及控温包装内蓄冷剂的吸热量,建立控温包装控温时间预测模型。同时,基于2种典型控温包装产品在296,308,318 K等3个温度环境中的储藏试验,进行理论与实验验证。结果实际控温时间比模型预测时间长,但偏差均小于10%。结论该理论模型能准确地预测控温包装控温时间,研究成果为控温包装设计提供了理论依据。     

工业铂电阻感温元件作精密测温的分度和计算方法

一、前言工业铂电阻广泛地用于工矿企业-200～500℃测温和控温,但是误差比较大。如果采用四引线双臂电桥来测量,对铂电阻的 R 0和α(或 W_(100))修正进行分度,以温度偏差内插法计算实际温度,即可实现精密测温。初步估计,此法与普通二次仪表测温法比较,可大大提高测量精度,适用于科研和工业试验现场及实验室精密测温,对于设备和仪器内部精密测温尤为优越。     

稀土铝酸锶对木基复合材料储热过程的影响及模拟

蓄热技术(thermal energy storage, TES)可有效改善建筑材料的热性能，用于TES的相变材料具有较高的储热量和良好的生物相容性，但导热系数低，传热效率不高。通过TES技术，以脱木素木材(delignified wood, DW)为载体，聚乙二醇(polyethylene glycol, PEG)为储热材料，稀土铝酸锶(SrO·Al₂O₃:Eu2+,Dy³⁺,SAED)为导热材料制备了不同SAED含量的新型木基复合材料，同时探究了SAED含量对木基复合材料热性能的影响，结合实际工艺建立了其储热过程的传热模型并进行求解。结果表明，40%SAED/PEG/DW的导热系数和升温速率相较于纯PEG/DW分别提高了57.14%和29.76%;建模求解纯PEG/DW,20%、30%和40%SAED/PEG/DW的储热过程，对比实际值和模拟预测值，其标准误差SE分别为1.35、1.92、1.73和1.35℃,预测误差PE分别为2.82%、-0.41%、-0.19%和-0.55%,模拟结果与实测结果吻合较好，可有效预...     

冷冻治疗头颈部恶性肿瘤28例观察

我院自1931年始,使用英国进口冷冻治疗仪,治疗了一批良恶性肿瘤,其中头颈部恶性肿瘤28例,现报道如下:一般资料一、冷冻仪及其参数;英国制造 Spembly Cryosurgery System Type DFS 30,具有自动控温指示表(50℃～-200℃)可调。冷冻时间随意控制,探头速冻后有迅速复温装置,配有微型电偶针对组织测温,压力可调,     

基于半导体制冷片的高精度控温电路系统设计

基于半导体制冷片(Thermo Electric Cooler,TEC)设计了一种高精度控温电路系统。本文详细介绍了TEC的选型方法,设计并实现了以单片机为核心的硬件电路,采用PID软件控制算法优化温控参数。在实验中,选择较大热负载紫铜块作为控温对象进行实验验证,实验结果表明:在室温23℃的情况下,紫铜块的控温范围为-10~40℃,控温精度高达0.01℃。     

MapleSim在振动仿真中的应用

目的利用MapleSim软件,探究数值-符号仿真应用于包装振动领域的可行性。方法首先,根据单自由度振动模型构建并验证理论状态下的单层负载振动模型;在此基础上提出可应用于随机振动的仿真模型,进一步研究仿真关键参数的计算方法;最后进行随机振动试验,将试验与仿真结果进行对比与分析。结果 PSD分析表明,不论中间还是角落位置,仿真PSD与实验PSD的变化趋势一致,但仿真PSD在低频(10~40 Hz)下会产生一定的误差,该误差对于角落振动的情况更为显著;Grms值的对比表明仿真误差小于10%。结论基于MapleSim的数值-符号仿真模型能够反映真实振动,该方法应用于随机振动具有可行性及可信度,但文中方法尚存在仿真误差,需进一步优化仿真关键参数的计算方法。     

新型红外额温计的研制

针对红外额温计在极端温度环境下的使用需求,笔者研制出基于红外热电堆传感器的具有较宽工作环境温度范围的高精度红外额温计。研制的额温计还匹配了蓝牙模块,以实时采集环境温度数据进行体温的计算补偿,从而实现不同环境中体温的精确测量。本研究还利用标准黑体辐射源校准装置对红外额温计进行了校准。结果表明,校准模式下研制的红外额温计在30℃～41℃测温范围内实验室误差≤0.2℃,测量重复性≤0.2℃,且实验室误差的不确定度为0.1℃(k=2)。研制的红外额温计将工作环境温度范围拓宽到0～40℃,可以实现不同环境中人体体温的精确测量。     

缓冲包装跌落仿真误差分析

目的研究Ansys/LS-DYNA DTM模块跌落仿真分析与经典缓冲包装设计方法之间的误差,并分析阻尼及摩擦因数对仿真结果的影响。方法基于经典缓冲包装设计方法,分别设计线弹性与双线性材料为缓冲材料的产品-衬垫系统;利用Ansys/LS-DYNA DTM模块对线弹性与双线性缓冲材料的产品-衬垫系统进行跌落分析,对比分析理论设计与仿真分析结果。结果对于线弹性材料与双线性缓冲材料的产品-衬垫系统,Ansys/LS-DYNA DTM模块跌落仿真分析与经典缓冲包装理论设计之间的误差均在5%以内。系统阻尼的增加导致所受最大冲击加速度减小;摩擦因数对所受最大冲击加速度影响较小;线性粘滞系数的增加导致所受最大冲击加速度增加。结论对于一般的工程应用,Ansys/LS-DYNA DTM模块跌落仿真分析方法与经典缓冲包装设计方法之间的误差在允许范围内。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.