Tribological Behavior of Ti<Subscript>3</Subscript>SiC<Subscript>2</Subscript> Sliding Against Ni-based Alloys at Elevated Temperatures

Understanding the mechanism of “rubbing” noise and low-amplitude friction exited vibration generation in steady sliding can be helped by models describing the contact interactions. In the current article, we consider a simple microscopic contact model for surfaces in sliding, which is based on the adhesion theory of friction. In the proposed model, we consider that the formation and shearing of a junction contributes to a small change in the real contact area. The model incorporates random size and random spacing between junctions. We investigate the dependence of the instantaneous real contact area on the average size and number of junctions. We find that from the viewpoint of vibration reduction, it is advantageous if the real contact area needed to support the given load is obtained as a sum of many small-sized micro-contacts, instead of few large-sized micro-contacts. The above result is in agreement with experimentally observed reduction of vibrations of a hard-disk slider after texturing.     

可扩展的MRML在CBIR系统中的应用

基于内容的图像检索系统一直缺乏一个通用的通信协议和机制，使得组件复用难以实现，多媒体检索标记语言MRML的出现解决了这一问题，文章设计了一个基于MRML的CBIR系统，同时为了满足可视化查询需要对MRML进行了扩展，最后给出一个具体应用实例。     

堆石坝土石方调配与道路运输强度的联合优化模型

针对堆石坝土石方调配系统的特点,考虑堆石坝施工过程中的主要影响因素的综合协调,将料源平衡子系统和道路运输子系统纳入统一的模型体系,建立堆石坝土石方调配系统多目标联合优化模型,进行土石方调配与道路运输强度的综合优化,并用计算实例验证了该模型是经济可行的.     

基于内容的图像检索中的一种多维索引算法

由于图像信息越来越丰富,因此,基于内容的图像检索成为一个重要研究课题。在基于内容的图像检索中,需要解决的关键问题之一就是如何快速、有效地搜索。该文提出了一种与特征维数相关性极小的多维索引方法,从而提高了检索效率。该方法尤其适合于用户对查准率要求不高的情况下相关图像的查询。     

Friction reduction and antiwear properties of the complex of lanthanum and a phosphate

A complex of lanthanum and di-(2-ethyl hexyl) phosphate (DEHP) was prepared by an extractive method. The friction and wear behaviour of this complex (called LaDEHP) as an oil additive was evaluated using a four-ball wear tester. For comparison, the friction reduction and antiwear properties of DEHP as an oil additive were also investigated. The chemical composition of the boundary film formed after wear tests was examined using X-ray photoelectron spectrometry (XPS). Four-ball tests showed that the prepared LaDEHP was effective in reducing friction and wear as well as in increasing load-carrying capacity. XPS analyses indicate the formation of iron phosphate and lanthanum oxide in the boundary films.     

原油集输工艺流程的(火用)分析评价

不同原油集输工艺流程的能耗有很大差异.本文采用(火用)分析方法对掺热油和掺热水两种集输流程进行了评价,得出的结论是掺热油流程优于掺热水流程,对集输站子系统来说,结论则相反.     

小合成氨碳丙脱碳系统的清洗

我国采用碳酸丙烯脂脱除变换气中二氧化碳的小合成氨装置中,脱碳系统的主要设备内极易沉积硫垢,这种结垢是由碳丙工艺所决定,因而不可避免．硫垢影响设备的运行,但由于硫垢与水垢性能相差极大,通常的机械清洗与化学清洗很难奏效．通过５ 套小合成氨碳丙脱碳设备的清洗证明：ＨＦ－ ００２ 络合清洗法是这类硫垢的有效清除方法．     

青海混合原油综合评价Ⅰ.常规评价

对青海混合原油进行了综合评价,分析了原油和各个馏分的性质。结果表明,该混合原油的相对密度指数大、凝固点高、含蜡量多、特性因数大、硫含量低,系低硫石蜡基原油。实沸点蒸馏及窄馏分性质分析表明,该混合原油初馏点〈30℃,初馏点至200℃直馏汽油收率13．91％,140℃～240℃喷气燃料馏分收率10．61％,200℃～300℃轻柴油馏分收率14．39％,300℃～350℃柴油馏分收率10．83％,350℃前馏分收率合计39．13％,中性油原料占原油42．33％,500℃前馏分总拔出率70．63％,且混合原油灰分含量低,重金属含量不高,氮含量较低,适宜生产燃料和润滑油型炼厂加工。     

日用粗陶器的制造与发展前景

0前言陶瓷广义的概念可分为三类,即陶器、瓷器和介于两者之间的炻器(精陶)。陶器烧结不充分、致密度差、气孔多;瓷器内部结构比较致密、断面呈烧结状。它们都以粘土为主要原料,故统称为陶瓷。日用粗陶和日用细陶(如紫砂陶、美术陶、彩陶)是陶器中的两个门类,日用粗陶广泛应用于     

Effect of Strength and Microstructure on Stress Corrosion Cracking Behavior and Mechanism of X80 Pipeline Steel in High pH Carbonate/Bicarbonate Solution

The stress corrosion cracking (SCC) behaviors and mechanisms of X80 pipeline steels with different strength and microstructure in high pH carbonate/bicarbonate solution were investigated by slow strain rate testing and electrochemical test. The results showed that the cracking mode of low strength X80 steel composed of bulky polygonal ferrite and granular bainite in high pH solution was intergranular (IGSCC), and the SCC mechanism was anodic dissolution (AD). While the mixed cracking mode of high strength X80 steel consisted of fine acicular ferrite and granular bainite was intergranular (IGSCC) in the early stage, and transgranular (TGSCC) in the later stage. The decrease of pH value of crack tip was probably the key reason for the occurrence of TGSCC. The SCC mechanism may be a mixed mode of AD and hydrogen embrittlement (HE), and the HE mechanism may play a significant role in the deep crack propagation at the later stage. The cracking modes and SCC mechanisms of the two X80 steels were associated with its microstructure and strength.