蒸氨塔的钛衬环及与钛筒体焊接和防变形措施

本文着重讨论蒸氨塔钛衬环的焊接，钛衬环与钛筒体的焊接，以及焊接过程中的气体保护措施和防变形的措施，保证了产品制造质量，获得了理想的焊接效果。     

带加劲环地面式钢衬钢筋混凝土管道取消伸缩节研究

以某水电站带加劲环地面式钢衬钢筋混凝土管道为例,建立三维有限元模型,在分析其承载特性的基础上,论证了取消伸缩节的可行性。结果表明,在正常运行工况下,钢管以环向受拉为主;考虑温度变化后,环向应力基本不变,而轴向拉应力在温升作用下减小,在温降作用下增大;设伸缩节后,伸缩节附近钢管轴向应力的减小使其等效应力反而增大,且由于加劲环的约束和钢管与混凝土之间的摩擦作用,钢管并不随温度变化而自由伸缩,伸缩节起不到减小温度应力和适应不均匀沉降的作用,因此对于带加劲环的地面式钢衬钢筋混凝土管道建议不设伸缩节。     

精密衬环自动检测的测量原理及误差分析

对精密衬环的技术要求进行了介绍,对精密衬环厚度及平行度自动检测分选机的基本功能进行了描述,在此基础上介绍了厚度和平行度的测量原理,并对自动检测分选机的各项误差进行了分析,分别分析出其中的系统误差和随机误差,同时,说明了消除或减小各类误差的方法,从而为测量精度的提高提供了途径。     

哈斯汀不锈钢衬簧的特征分析

1 前言 钢带组合油环,由于具有高贴合性,控油性能佳,安装使用方便等特点,已越来越为国内的汽车制造厂及汽车零部件供应商所认同和接受。特别是它的主要构件——衬簧,在高温状态下弹力稳定,回油性能好,摩擦功损耗小,使用寿命长,因而深受广大用户的青睐。安庆活塞环厂几年前从世界著名的活塞环制造公司——美国哈斯汀公司率先全套引进了一条最先进的钢带组合油环生产线,且从国外购买优质的不锈钢带用于生产,产品达到了与哈斯汀公司同等的质量标准,产品为一汽,天津夏利等汽车制造公司配套,笔者作为一名在哈斯汀生产线上从事技术工作的现场管理人员就不锈钢内衬簧的品质特征做简要的分析,并与国内普通的内衬簧相比较,从而使广大的活塞环用户更全面地了解哈斯汀波型衬簧。     

滑动轴承—厚壁多层滑动轴承的轴承金属铸造

没有规定的细节可合理的选择或按有关尺寸标准的规定。 1、应用范围 本标准旨在帮助设计者得到在轴承背上带槽和不带槽的滑动轴承金属衬的有效设计。 本标准适用于普通机械和电动机械的齿轮和发动机结构的薄壁整体式和剖分式滑动轴承。轴承的金属衬为如DIN ISO4381规定的铅锡铸造合金或其它合适的轴承金属。 2、轴承衬背 轴承衬背通常设计为衬套,壳体,环或衬垫。 2.1 材料 根据设计要求,考虑到轴承尺寸,轴承负荷和加工设备,轴承背选材可考虑DIN ISO280,例如:用钢,按DIN 17100,DIN 17155和DIN 17210;用铸钢,按DIN 1681;用铜锡和铜锡锌铸造合金（铸造锡青铜和锡锌青铜）,按DIN 1705;用铜铅锡铸造合金（铸     

钢衬壁厚对抽蓄电站围岩内水压力分担率的影响

根据实际工程需要,采用FLAC3D数值模拟软件通过改变钢衬壁厚,分析了不同设计内水压力组合条件下,钢衬、混凝土垫层和围岩的位移和变形特征及钢衬环向拉应力,研究了引水钢衬壁厚对围岩内水压力分担率的影响。结果表明,随着壁厚增大,虽可相应减少钢衬径向位移和环向拉应力,但减幅小,效果不显著;随着壁厚变小,钢衬径向位移变大,根据变形协调,有助于荷载传递,提高了围岩分担率,有利于"钢衬-垫层-围岩"联合承载;在满足抗外压稳定验算、焊接工艺和施工安装前提下,壁厚可较大幅减小。研究成果不仅有利于减少不必要的投资,还有利于降低硐室钢衬运输安装等施工难度,可供类似工程设计参考。     

一起典型筒体带衬环封闭环焊缝疑似缺陷分析

小直径圆筒型容器最后一道封闭环焊缝，焊接过程中通常采用带衬环的氩孤焊打底，手弧焊盖面的焊接工艺，经常在该环焊缝X光探伤底片上发现在简体内侧焊缝根部有一条断续或连续的黑线，该线看似平淡，无未焊透的典型症状，线呈一定的宽度，黑度基本均匀，给缺陷评定带来一定的难度。为弄清该影象的成因，我们就一起具体事例详细加以分析。     

混凝土垫层对抽蓄电站引水系统围岩内水压力分担率的影响

基于FLAC~(3D)软件,通过对比分析工程实测数据、数值仿真和规范方法结果,研究引水系统回填混凝土标号改变对钢衬变形和围岩内水压力分担率的影响。结果表明,现行规范在计算钢衬环向应力时,未考虑混凝土垫层,可能导致计算应力值偏差,进而影响围岩内水压力分担率;垫层混凝土标号由C15增加到C25,虽可减小钢衬的径向位移和环向拉应力,提高围岩内水压力分担率,但效果不显著。     

几组新结构活塞环

我厂在吸收国外活塞环先进结构和先进工艺技术基础上,结合我国内燃机现状,在兄弟单位协助下,新试制了桶形面活塞环,整体铸铁镀铬油环和带螺旋弹簧胀圈镀铬油环。经过台架和大量田间试验证明:第一道采用桶形面镀铬压缩环,第二、三道采用含硼耐磨铸铁扭曲环,第四道采用整体铸铁镀铬油环或带螺旋弹簧胀圈镀铬油环,在正常使用条件下,其使用性能和寿命比原产品提高三倍以上,可达4000-5000小时。 新试制的产品分别简介如下:     

钢带组合油环的弹力设计和弹力控制

介绍弹力对钢带组合油环使用性能的影响，弹力设计基准和计算式。论述了弹力和波节距的关系，从而得出了弹力可以通过波节距的变化来调整，并介绍了三种结构形式衬环波节距调整工艺。     

An experimental investigation of sewage sludge gasification in near and super-critical water using a batch reactor

The gasification of sewage sludge in near and super-critical water was investigated in a batch reactor. Results showed that the formation of gaseous products could be intensively affected by temperature. In order to understand the effect of temperature on the development of reaction process and the formation of gaseous products better, the detailed characteristics of solid and liquid products were analyzed by SEM, N₂ adsorption–desorption technique, FTIR, TOC, Ammonia–nitrogen analysis and SPE-GC/MS. The changes in the yield distribution of products and the characteristics of solid and liquid products indicated that organic matters in sewage sludge were almost completely dissolved and hydrolyzed in water at 425 °C. The dissolution and hydrolysis products were gasified by reforming and other reactions. The polymerization and dehydrogenation also occurred in dissolution and hydrolysis products, and the Diels–Alder reaction mechanism could be used to explain the phenomenon.     

Thermal decomposition of energetic materials 14. Selective product distributions evidenced in rapid,real-time thermolysis of nitrate esters at various pressures

Rapid-scan infrared spectroscopy (10 scans s⁻¹) was used to characterize the gas products in real time that were generated by fast pyrolysis (50–250K s⁻¹) of nine molecular and homopolymeric nitrate esters. On the basis of concentration versus pressure plots of the initial gas products, these compounds cluster into three categories: (1) those for which the side-chain nitroxy products dominant, (2) those for which nitroxy and framework or backbone decomposition products compete, and (3) those for which backbone decomposition products are most prevalant. These classes qualitatively correlate with the carbon, nitrogen, and oxygen balance in the nitrate ester and may be related to the extent of decomposition reactions in the condensed phase. The products liberated by two copolymers of nitroxymethyl- and azidomethyloxetanes closely resemble the sum of the products from the constituent homopolymers.     

Bio-Liquefaction/Solubilization of Lignitic Humic Acids by White-Rot Fungus (Phanerochaete chrysosporium)

Humic acid samples obtained from lignite were liquefied/solubilized by using white-rot fungus, and chemical characterization of the products was investigated by FTIR and GC-MS techniques. Prior to the microbial treatment, raw lignite was oxidized with hydrogen peroxide and nitric acid separately, and then humic acids were extracted by alkali solution. The prepared humic acid samples were placed on the agar surface of the fungus and liquid products formed by microbial affects were collected. The products were analyzed and the chemical properties were compared. The results show that oxidation agent and oxidation degree affect composition of the liquid products formed by microbial attack.     

三轴电磁泄漏检测仪的研究与设计

对电子产品、家电和工业电器设备等电器产品工作时周围磁场进行测量,以便及时了解电器产品工作时的电磁辐射状况,提出了一种利用电磁耦合原理设计的基于三轴检测电器产品电磁泄漏强度的新方法,克服了传统单轴测量需要多次测量才能获得总磁场值问题,设计了三轴电磁泄漏检测仪实际测量电路,通过实际测量电路实验,验证了该测量电路的正确性,该检测仪器可以方便地检测出电器产品产生的30 kHz~2 kHz低频泄漏的磁场强度值。     

Influence of metal (Fe/Zn) modified ZSM-5 catalysts on product characteristics based on the bench-scale pyrolysis and Py-GC/MS of biomass

In this study, sawdust was selected as the raw material for biomass pyrolysis to obtain organic products. The catalyst was modified with two elements (Fe and Zn). Through analysis of the catalytic products, we attempted to identify a pyrolysis catalyst that can improve the yield of aromatic hydrocarbon products. ZSM-5, modified with Fe and Zn, was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and Brunauer–Emmett–Teller (BET) measurements. Tube furnace and flash pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) were used to comprehensively investigate the characteristics of the products of biomass pyrolysis. The highest yield of phenols was obtained using the Fe-modified ZSM-5 catalyst, which was 18.30% higher than the yield obtained by the pure ZSM-5 catalyst. The lowest yield of acid products was obtained by single-metal-supported catalytic pyrolysis with Fe or Zn, which was 50.66% lower than the yield obtained by direct pyrolysis. During the pyrolysis of biomass using metal-modified catalysts, the production of aromatic hydrocarbons was greatly improved. Among them, compared with direct pyrolysis, the Fe-Zn co-modified ZSM-5 catalyst exhibited the weakest promotion of aromatic hydrocarbon formation, but there was still a 68.50% improvement. Although the co-modified catalyst did not show absolute advantages under the conditions used for this experiment, the improvements in the production of aromatics and phenolic products also showed its potential for improving bio-oil products. Under the action of Fe-modified catalysts, the most abundant components in the gas product were CO and CO₂, which reached levels as high as 53.45% and 15.34%, respectively, showing strong deoxidation capabilities. Therefore, Fe-modified ZSM-5 catalysts were found to better promote the formation of aromatic hydrocarbon products of biomass pyrolysis.     

Long-term reliability of amorphous silicon solar cells

The long-term reliability of amorphous silicon solar cells of 1988 products over more than ten years is estimated by a simulation method using the Weibull function with the experimental data of 1988 products exposed outdoors for five years and those of 1983 products exposed outdoors for ten years. The mathematical model is developed based on the accelerated tests and recovery tests in a laboratory for a short period of time. The simulation method is discussed. The decrease of the conversion efficiency of 1988 products after ten years of exposure is estimated to be 25% and 35% at best and worst, respectively. The newest products having initial conversion efficiency of over 13% in a small cell are expected to maintain an efficiency of about 10% at best over a decade.     

Study of orange peels dryings kinetics and development of a solar dryer by forced convection

The solar drier project aims at using solar energy as heat source, frequent in the area, for the drying of perishable products. Solar drier does not degrade any more the dried products with the manner of the products dried at the natural sun. The drying unit is composed mainly of a solar air collector and a drying chamber. The transformation of the solar radiation into heat is done thanks to the solar collector whose effectiveness is increased by the addition of suitable baffles in the mobile air vein. The efficiency of the collector reaches then 80%. The hot air on the outlet side of the collector arrives in the drying chamber where the heat transfer with the product to be dried is done by convection. The drying kinetics study shows that in addition to the dependence of the temperature and air velocity of drying, the rate of drying also depends on sectioning on the product to dry, and mainly, of the product surface in contact with the drying air. Thus, the moisture content in wet basis is reduced from 76 to 13% in one day. Then, we obtains dried products in a healthy way, and the so frequent sand wind in the area does not degrade any more the dried products quality at the manner of the products dried with the free air. The total efficiency of the drier reached 28%.     

Determination of drying times for regular multi-dimensional objects

Drying of multi-dimensional food products is investigated analytically. A simple method is developed for the determination of drying time of multi-dimensional products using drying parameters that are available from the literature or can be determined experimentally. In this respect, geometric shape factors for different regular multi-dimensional products are introduced. Drying time that can be calculated analyticaly for an infinite slab geometry is used to predict the drying times for other multi-dimensional products by means of the geometric shape factors. The present model is verified through comparison with experimental drying times of several food products in different shapes that are obtained from the literature. The comparison of the results obtained from the present model with the experimental data shows that the predictions are accurate within ±10% range, in general.     

竹木质素的NaOH-乙醇水溶液热降解及产物分析

本研究以NaOH-乙醇水溶液为溶剂体系对竹木质素进行热降解,主要考察了NaOH浓度、反应温度、反应时间、乙醇用量等条件对竹木质素降解转化为酚类化合物的影响。通过GC-MS及FT-IR对降解产物进行分析检测,得出最佳反应条件为：竹木质素5 g,NaOH浓度（基于乙醇水溶液）20 g/L,乙醇10 mL,反应时间2 h,反应温度240℃。在此条件下,降解产物中总的酚类化合物的相对峰面积为73.88%,残渣率为30.67%。竹木质素的降解主要产物是酚类化合物：苯酚（17.98%）、2-甲氧基苯酚（16.49%）及1,2-苯二酚（10.03%）。与现有文献相比,本文竹木质素在碱性乙醇溶剂体系中降解能够获得较高产量的酚类化合物,有望实现竹木质素的高值化利用。     

节电器和节能冰箱的测试分析

为了掌握非线性电路节能产品的实际节电性能和对电网电能质量的影响及其改进方向,选择市场上具有一定代表性的不同体制、不同区域企业所生产的节电器和节能冰箱作为切入点,采用科学的测试方法与手段,对其进行测试,并予以统计分析.对不同厂家生产的产品的实际耗电性能进行测试与对比,旨在对其相关特性给予客观的评估,以达到在关注真实的节能技术和节能产品的同时关注电网污染的治理目的.