朋友

正像往年新年一样,收到了许许多多同事、同仁、朋友、合作者的祝福短信和贺卡。短信的词汇或长或短,或转发或原创,斑斓多彩,丰富感人,让人温暖兴奋,看不释眼;贺卡或豪华或简朴,或来自遥远的异地,或来自咫尺的近邻,让人感到其中的牵挂、祝福,爱不释手。不论老友新朋,见字如人,回味绵长。我越来越觉得,看短信比看春晚更热切,更有意义,更令人慰藉。特别是在寒冷的冬天里,在全球的危机     

闪出耀眼星光 自制闪光环

我喜欢人像,喜欢拍人像,喜欢拍出与众不同,风格迥异的人像。当我乐此不疲的更换着各种焦段的镜头时,我发现无论是广角镜头,长焦镜头,鱼眼镜头还是微距镜头,都再也满足不了我追求新、奇、特的信念。后来,闪光灯带给我的新乐趣,各种不同的光型,不同的照度和不同的光位,都曾给我拍摄的人像增添了很多的情趣。在不断的创新变化中,我     

乡村演员

正这组照片是我今年拍摄于河南浚县的正月庙会。我所拍摄的乡村演员其实应加上"临时"二字,他(她)们的化妆造型跟专业剧团相比是粗糙的,是没有经过打磨的,但他(她)们就像自家地里的庄稼一样,是原生态的,是新鲜和真诚的,是接地气的,在我国广袤的农村世世代代地传承至今。平时他们的身份就是实实在在的农民,下田种地,外出打工,但毎逢过年过节,他们就穿上龙袍戏袍,化上彩妆,一个个化身成神话、传说、戏曲中的各式人物,一展英姿,此时的他们忘却了平日的劳苦,置身于节日欢乐的人群中,此时的他们是幸福快乐的。     

论管理中的“大事”与“小事”

东汉的薛勤说,一屋不扫,何以扫天下?这是朴素的管理思想,它蕴含的道理是,欲善其大事,必先把小事做扎实,即所谓千里之行始于足下,九层之台起于垒土。在管理领域,任何大事业的完成,最终都要落到一个个具体的小事的处理上,管理无大事,这话是有一定道理的。当然这并不意味着,从此只为一屋一院所困,把自己的大部分时间都花在它上面,而没了成就大事业的远大理想,这样根本谈不上扫天下了!而与薛勤同时代的陈蕃却持有大丈夫处世,当扫除天下,安事一屋的观点,这只不过是他胸怀大志而已,如果真有扫天下的魄力,我们认为他实现这个理想也要从点滴做起、从日常小事做起。     

古墨有河 水磨情长

云南省临沧市凤庆县古墨村1820米的海拔本不算高,却因流浪河的仙风道骨,有一种立于天边的世外桃源之感。无名的野花,在日月轮回中纤尘不染。缥缈的炊烟,是村庄生动的呼吸。善良的村民,在每一个岔路口写一块小石牌,告诉你归来与离去的正确路径。半山腰系着绸缎一样的雾,变幻成各种形态。最好是逆流而上,树林越来越密,风景越来越美,任何一座桥边,都可以停下来,在草甸上支起帐篷,听风,想心事。     

食品安全与消费·白酒篇

中国白酒与法国的白兰地,俄罗斯的伏特加,英格兰的威士忌,起源于西印度地区的朗姆酒与荷兰的金酒并称为世界六大蒸馏酒,但中国的酿酒和中国的白酒历史最久远,是世界蒸馏酒的鼻祖。就蒸馏技术而言,中国早在秦汉时期,随着炼丹技术的不断发展,经过长期地摸索,炼丹术积累了不少物质分离、提炼的方法,创造了包括蒸馏器具在内的种种设备,因此中国是世界上第一个发明蒸馏技术和蒸馏酒的国家。最接近现代白酒生产和口味的酿酒工艺出现在元代,明代医学家李时珍的《本草纲目》中记载道:"烧酒非古法也,自元代始创其法,其法用浓酒和糟入甑,蒸令汽上,用器承取滴露,凡酸败之酒,皆可蒸烧。近时惟以糯米或粳米,或黍或秫,或大麦,蒸熟,和曲酿瓮中七日,以甑蒸取,其清如水,味极浓洌,盖酒露也。"在这里需要注意的是,在记述元代以前的蒸馏方法时,都是以酿造酒为原料的液态蒸馏,而李时珍所描述的"用浓酒和糟入甑,蒸令     

工具厂电镀车间清洁生产审核总结

为了促进工具厂的清洁生产,提高镍和铬的利用率,有效利用电镀废水,工具厂开展了清洁生产审核.审核过程中,在镀镍槽后增设2个静止的回收清洗槽,每生产班次都对挂具刷绝缘漆,通过镍的物流实测验证,镍的利用率从70%提高到87%.在镀铬槽后增设3个静止的回收清洗槽,并且使用稀土镀装饰铬,铬酐浓度为150～180g/L,并且添加抑雾剂F-53,通过铬的物流实测验证,发现铬的利用率从15%提高到43%.考虑工具厂各生产车间的用水要求,在全厂范围对电镀废水进行合理调配,电镀车间外排的废水被蒸发,实现电镀废水零排放,为电镀行业的清洁生产提供一种新思路.     

工地奏鸣曲

<正>一张张纯朴憨厚的笑脸,一个个高大魁梧的背影,逢山开路,遇水架桥,使高峡出平湖,让天堑变通途。在我工作的工地上,有太多这样可爱的人,虽然很多人都不知道他们的姓名,然而却是他们平凡而朴实的背影,使祖国的面貌发生了翻天覆地的变化,我们的生活也更加方便美好。十几年的工作生涯,让我走遍了     

孩童世界

成长的岁月像流水,匆匆而来,匆匆而去。那时的他们,刚入学。心怀对新环境的恐惧和对父母家人的依恋,每天上午到园必有一哭,我哭,你哭,他哭,大家相互感染;也有胆大不哭在一旁看热闹的。每每这时,纠心的是家长,忙碌的是老师,左手抱一个,右手抱一个,身边还得靠两个,哄完这个亲那个……     

莫让期房变“欺房”

如今各式各样的房展会上楼盘五花八门,且多为期房。虽说期房看不见摸不着,然而,期房往往略低于现房的价格,开发商天花乱坠的广告吹嘘成了期房吸引消费者的法宝。但是“货不对板”的隐患也往往就在此时埋下了。期房并非一无是处,其远低于现房的价格,可以令您以较小的投入尽快实现安居之梦。因此,消费者选购期房的时候一定要睁大眼睛,悉心挑选,避免日后“期房变欺房”的困境。盯准实力派开发商。实力派开发商经验丰富,资金雄厚,十分注重树立与维护自身的品牌形象,因此,实力派开发商的产品通常都是过硬的,且炒作有度。如天鸿集团开发的北京回龙…     

陶瓷的润滑问题

本文阐述了并分析了陶瓷材料的摩擦磨损、润滑研究现状，由于陶瓷的化学惰性，传统的润滑剂，添加剂在陶瓷表面的吸附力较弱，且很难在边界润滑下与表面发生摩擦化学反应形成极压润滑膜，传统润滑剂对陶瓷铁润滑效果与润滑金属相比要差科多，尽管在干摩时陶瓷材料磨损率比金属小得多，但仍比实际应用时要求的磨损率高必个量级。     

Talc functionality as lubricant: texture, mean diameter, and specific surface area influence

Talc is widely used as a glidant (flow regulator) for powders. This study highlights the characteristics that confer to talcs new end use properties in improving the lubrication function during compression. We studied the contribution of texture, mean diameter (D50), and specific surface area on the residual die pressure, the ejection pressure, the lubrication index, and the tablet hardness. Different textures were studied: microcrystalline, macrocrystalline, and moderately macrocrystalline talc grade. The compression parameters were improved according to the texture. D50 varies from 0.62 to 15 µm. As D50 decreases, the lubrication performance is improved. Finally, the specific surface area of talcs was studied. This last characteristic of talcs was shown as the most relevant parameter in determining lubrication ability.     

Talc Functionality as Lubricant: Texture,Mean Diameter,and Specific Surface Area Influence

Abstract

Talc is widely used as a glidant (flow regulator) for powders. This study highlights the characteristics that confer to talcs new end use properties in improving the lubrication function during compression. We studied the contribution of texture, mean diameter (D50), and specific surface area on the residual die pressure, the ejection pressure, the lubrication index, and the tablet hardness. Different textures were studied: microcrystalline, macrocrystalline, and moderately macrocrystalline talc grade. The compression parameters were improved according to the texture. D50 varies from 0.62 to 15 µm. As D50 decreases, the lubrication performance is improved. Finally, the specific surface area of talcs was studied. This last characteristic of talcs was shown as the most relevant parameter in determining lubrication ability.     

Seizure resistance of leaded aluminium bearing alloys

Abstract

The antifriction and antiseizure characteristics of a number of aluminium bearing alloys varying in lead content from 10 to 50 wt-% have been studied under different lubrication conditions using a bearing test machine designed for the investigation. With continuous oil lubrication, bearings of all the leaded alloys are able to run without seizure up to the regimes of boundary and mixed lubrication, whereas the base alloys seize under conditions in which the leaded alloys are under hydrodynamic lubrication. The load at which bearing seizure takes place is primarily determined by the frictional state of the bearing. In general, the addition of lead to aluminium alloys is found to reduce interface friction and to improve their ability to resist seizure only for concentrations in the range 10–25 wt-%. Lead–containing aluminium alloys also show a capacity to absorb and to store a lubricating oil and to use it to diminish friction in the event of failure of the oil supply.

MST/121     

颗粒流润滑剪切膨胀的力学机制研究

颗粒流润滑是可用于苛刻环境下的新型润滑方法,颗粒流的剪切膨胀特性是全面建立颗粒流润滑理论亟需解决的关键问题。该文基于离散单元法建立了颗粒流润滑的分析模型,研究了润滑启动阶段剪切膨胀现象的变化规律,剪切膨胀的速度适应机制和压力适应机制,并在总结剪切速度和压力载荷对剪切膨胀影响的基础上分析得出了剪切膨胀现象的力学机制。研究结果表明:润滑启动阶段,颗粒润滑系统的剪胀率随时步的变化服从二次多项式规律;颗粒润滑系统的剪切膨胀幅度随剪切速度,压力载荷的增大均呈现逐步递减的变化趋势;颗粒润滑系统的剪切膨胀特性与颗粒润滑介质间细观力链的波动密切相关,当细观力链的波动幅度变大时,颗粒润滑系统剪切膨胀的变化幅度亦增大,反之则减小。颗粒润滑介质间的接触力分布按幂函数规律变化,且颗粒润滑介质间力链的强度随着剪胀率绝对值的增大而变强。     

润滑状态下线接触滑动粗糙界面的动摩擦特性研究

滑动粗糙界面的摩擦润滑特性对界面的润滑设计和润滑状态预测具有重要的理论和实际意义。本文通过建立不同润滑状态下的滑动粗糙界面模型,基于界面的法向载荷由润滑油膜和粗糙体共同承担的载荷分配思想,采用Greenwood-Williamson统计模型描述粗糙表面形貌,考虑界面润滑的时变效应和润滑油的粘-压特性,建立了线接触滑动粗糙界面的油膜厚度方程和粗糙体接触压力方程,获得了整个润滑区的润滑油膜载荷比例因子、油膜厚度和摩擦系数随滑动速度的变化关系,推导了界面由混合润滑过渡为液压润滑的临界速度关系表达式,分析了滑动粗糙界面的润滑承载机理,获得了界面油膜厚度、摩擦系数和临界速度随界面形貌参数、法向载荷、润滑油属性参数的变化规律,为机械结构的界面润滑设计、润滑状态预测和润滑优化提供理论和实验参考。     

梯度自润滑复合材料在不同滑动摩擦下的摩擦学特性

梯度自润滑复合材料是一种新型润滑材料,利用粉末冶金工艺设计和制备了该材料,考察了其在不同摩擦条件下的摩擦学特性,并对其摩擦磨损机理进行了分析和研究.结果表明:梯度自润滑复合材料随着复合固体润滑剂含量的增多,摩擦学性能明显改善,但润滑剂含量过高将导致材料表面硬度过低;该材料适用于高载倚下的润滑部件;脂润滑条件下,复合固体润滑剂与润滑脂结合在摩擦面上形成的膏状润滑膜使梯度自润滑复合材料的摩擦学性能显著改善;在脂润滑高载荷条件下,梯度自润滑复合材料的磨损主要发生在磨损初期,之后磨损极小,摩擦系数也趋于减小.     

Simplified MQL system for drilling AISI 304 SS using cryogenically treated drills

In machining operations, cutting fluids have been comprehensively used to improve the cutting tool life, but the issues related to manufacturing cost, environment and health call for reducing their use by possible methods. Minimum quantity lubrication (MQL) is a technique that overcomes these problems by spraying a small amount of cutting fluid (<100?ml/hr) as mist using compressed air. In this work, the basic MQL technique is used to achieve flow rates slightly higher (～880?ml/hr) than MQL using simple techniques like paint sprayer and compressor, which is more generally called reduced quantity lubrication (RQL). Another method to increase the tool life is by cryogenic treatment, which increases the hardness of the tool. Tungsten carbide drill bits were subjected to cryogenic treatment (?185 °C). Drilling studies were carried out on AISI 304 stainless steel (SS) using untreated and cryo-treated WC drill bits under RQL and conventional wet lubrication conditions. The tool wear on the treated WC drill bits with RQL was comparatively less than on the untreated ones with RQL and wet lubrication. These improvements were established through microhardness, SEM images, XRD, wear studies and surface roughness measurements comparisons.     

颗粒间摩擦对颗粒流润滑影响的力学机制

颗粒流润滑是一种可用于苛刻工况环境的新型润滑方式,颗粒间摩擦对颗粒流润滑影响的规律和特性是阐明颗粒流润滑理论的关键科学问题,也可以为极端工况环境下颗粒流润滑轴承的设计和参数选择提供技术支持。为了分析颗粒间摩擦对颗粒流润滑系统宏、微观特性以及下摩擦副与颗粒润滑介质间摩擦的影响规律,构建了颗粒流润滑离散元数值模型,并对该问题进行了分析和研究。研究结果表明:颗粒间摩擦对颗粒流润滑系统的减摩润滑特性具有显著影响,下摩擦副和颗粒润滑介质之间的平均摩擦系数会随着颗粒间摩擦的增大而增大;颗粒流润滑系统内的微观配位数和滑动率均随着颗粒间摩擦系数的减小而增大;颗粒润滑介质在摩擦副间隙的宏观流动行为具有明显的分层特性,且宏观流动速度随着颗粒间摩擦的增大而减小,进一步的分析结果表明:颗粒润滑介质的波动速度是直接反映其宏观流动速度快慢的关键性参数。     

Turning of Brasses Using Minimum Quantity of Lubricant (MQL) and Flooded Lubricant Conditions

A lot of effort is being carried out to reduce the use of lubricants in metal machining operations from the viewpoint of cost, ecology and human health issues. Minimal quantity lubrication (MQL) is now an established alternative to conventional flood lubricant system. This paper reports on the experimental work carried out during turning of brasses with different amounts of MQL. Turning with flood lubrication was also performed and a comparison is made. The various parameters studied include the feed, cutting power, specific cutting power, and surface roughness. The results of the study suggest that with proper selection of the MQL system, results similar to flood lubricant condition can be achieved.