优化结构有序建设积极促进橡胶工业全面协调和可持续发展

改革开放以来,我国橡胶工业的发展速度是前所未有的,其间有许多成功的经验,特别是入世后,在上世纪末全行业整体亏损的不利情况下,大家认识一致,认真对待,风雨同舟,趋利避害,经受住了考验,不仅行业经济全面复苏,而且取得新的发展。当前,全行业面对的是新一轮的竞争,而且更为激烈     

我的台湾工艺之旅

两期"台湾工艺之旅"圆满结束。对于文化艺术,无论是走马观花还是深度阅读,各人经历不同感悟也会不一样。你心目中的台湾,是什么样子呢?8天的旅程,累,却幸福着。忘不了,太鲁阁天然大理石岩的鬼斧神工,忘不了,清晨日月潭散发的柔美光辉,忘不了,黄安福大师表演玻璃技艺洒下的滴滴汗珠,忘不了,粘碧华大师的艺术之家和她亲切的笑容,忘不了,汉声巷黄永松老师挥手作别时眼里的殷殷期盼,忘不了,台北世界设计展上将书法创意延伸的"妙法自然"忘不了,中华手工电台带给我们的欢声和笑语,忘不了……黄永松老师说,这一代人需要觉醒,但觉醒的方向不要错,要回到文化的母土。或许你已留意到,     

半隐于郊 艺术之调

柳林小径深处,一扇木门掩映的白色建筑,即是王功新林天苗夫妇在宋庄的别墅。从大门进来,前方是白色的月亮门,像一道影壁墙,遮蔽外人的视线,经过一片水竹摇曳的甬道,才入院子。院内,三层小楼房顶上两层主体分别向两侧挑空,蜿蜒的池塘从花园延伸至室内,隔着一面大大的落地玻璃墙,恍惚间分不清哪里是室内,哪里是室外。更不可思议的是,池塘中间竟然是空的,下面就是那个巨大的工作室,鱼儿游过,涟漪荡漾开来,总担心这水会不会溢出……     

捕鸟蛛

凶悍的捕鸟蛛,已经抓住一只小鸟,正分泌毒液将猎物毒死,刚孵化的小鸟心有不甘,瞪大眼睛,却对身体的麻痹无可奈何,捕鸟蛛得意洋洋,八只毛茸茸的爪子渐渐放松,似乎要开始安心享用猎物。凶狠的捕杀场面,被作者处理得惟妙惟肖,全身长毛的蜘蛛、绝望的小鸟,让观者毛骨悚然。那么,请您猜猜看,这幅捕鸟蛛猎杀图,是用什么材质做成的呢?     

绽放你最灿烂的笑容

秋至过后,几场不经意的细雨飘来,将炎热一点点打退,正如人们所言"一场秋雨一场凉"。如果说春天把嫩绿给了三月,夏天把翠绿给了七月,冬天把洁白给了十二月,那么秋天,就把金色给了十月。十月,是花开飘香的季节。菊花开了,红的、黄的、白的,朵朵怒放着,风情万种、婀娜多姿;桂花开了,偶尔外出,惊奇的发现满枝的桂花把树木装扮的耀眼夺目,一阵微风吹过,阵阵清新淡雅香气飘来,沁人心脾。工作一天的烦躁情绪,在这别样的景象下瞬间被一扫而光。     

尾矿干式堆存在磷矿山选矿厂中的应用

0 引言 尾矿设施具有保护环境,充分利用水资源和保护矿产资源的作用,是矿山生产不可缺少的设施,但投资巨大,基建投资占矿山总投资的10%以上,占选矿厂投资的20%左右,有的几乎与选矿厂的投资一样多,甚至超过选矿厂.尾矿设施的运行成本也较高,有些矿山尾矿设施运行成本占选矿厂生产成本的30%以上.近年来,由于征购土地和搬迁农户的费用越来越高,因此建设尾矿设施的费用也越来越高.此外,尾矿库还是矿山生产的最大的危险源之一,一旦尾矿库失事,将给工农业生产及下游人民生命财产造成巨大损失.而若采用干式堆存尾矿,则可较大地缓解以上矛盾,因干式堆存的尾矿只含有11%～15%的水分,且可依地形而堆存,大大减少了占地面积,且不易垮落.贵州某一选矿厂利用脱水设备实现了尾矿的干式堆存,情况介绍如下.     

走在路上

<正>冬至已过,最近天气渐渐凉了,下班的路上每天必须走过一座高架桥,沿着楼梯爬上去,冷风吹过来,瞬间清醒,连一整天工作的疲惫也消失的无影无踪了。搬家过去的前几天,上下班从高架桥上爬上爬下,左手拎着饭盒,右手拎着刚从菜市场买的菜,炎热的盛夏令人无比烦躁,心想明明直线距离很短的,走个高架桥就绕好多路,可偏偏也没别的小道走,于是每天就当做锻炼身体,慢慢适应了上下班的节奏。     

班级管理浅谈

管理是一门科学,更是一门艺术,班级足学校最基本单位.从某种意义上讲,班级管理工作的好坏,直接反映了一个学校的管理水平,如何使班级管理的科学性艺术性有机地统一起来,是我们每一位教师尤其是班主任老师值得深思的重大课题.我们必须清楚地认识到学生是班级的主体,班级管理必须认他们为中心来展开,民主化,科学化,人性化的班级管理是促进学生团结,锻炼学生能力,融洽师生关系的重要前提.只有这样,我们才能更好地促进学生全面发展,才能说是对学生、家长及社会负责,下面我就班级管理的民主化,科学化,人性化方面谈谈自己的一些看法与认识.     

浅谈王步青花艺术风格

在我国陶瓷美术发展史上,凡有所成就,有所作为的陶瓷美术家,不论哪个时代,哪个艺术院派,都离不开继承传统,吸取精华,并通过自己的长期实践,不断创新,才形成自己独有的艺术风格.景德镇陶瓷美术家王步先生创作的青花作品,以其笔简意骇,博大精深,水色莹澈,淋漓尽致的风格,为人们所称赞.本文试就他的艺术风格归纳为三个方面来简略论述.     

3000算盘指间拨

正入花甲之年的葛新华,20年默默收藏3000多把老算盘,为的是让人们在被键盘和鼠标声占满的今天,还能记得算珠拨动的旋律。"打主意,秋千格。"打一物品是什么?在没有计算器和电脑的年岁,这个几乎存在每家每户的老物件,如今已经慢慢淡出了人们的视野。曾几何时,珠算课是小学里必修的课程,儿时背着算盘上学堂,算珠在背后摇得"噼里啪啦"响;账房里的老先生记账算数,加减乘除,样样离不开打算盘。然而,当算盘逐渐远去时,有一个人,仍然守护着算盘拨动的记忆,经历长长20个年头,默默收集3000多把老算盘,他最欣慰的,是成立了自己独具特色的家庭式收藏馆,他就是葛新华。这位热爱算盘如痴,喜爱"精打细算"的老者年纪60岁,在他的收藏馆里,可以看到琳琅满目的算盘世界。墙上歪歪斜斜不规则地挂着许多算盘,     

Effect of the mechanical failure of catalyst pellets on the pressure drop of a reactor

The effect of the mechanical failure of catalyst pellets on the pressure drop across a laboratory-scale catalyst packing has been examined by experiment. Results reveal that, along with the mechanical failure of the pellets, there exists a point of maximum curvature around which the slope of pressure drop increases rapidly. This rapid increase is attributed to a mutation of the packing structure, occurring as the amount of failed pellets reaches a certain critical value. The secondary breakage of the pellets contributes much to the mutation of the packing and to the pressure drop. It has been observed that a trilobite catalyst is more susceptible to a mechanical stress than a cylindrical catalyst, and that a catalyst with a smaller diameter is much easier to result in an increase in the pressure drop. The measurement of the pressure drop across a laboratory-scale catalyst packing as the failure of pellets under a mechanical stress has a satisfactory reproducibility, and has a close meaning to the mechanical reliability of a fixed bed converter, and hence is recommended as a method for catalyst assessment. The multi-scale and multi-disciplinary nature of catalyst mechanical reliability is also discussed.     

Theory of yield of cohesive powders

In many problems in process technology, the influence of the adhesion forces on the mechanics of fine powders plays a considerable role. The existing knowledge is characterized by intensive experimental and theoretical investigations into the mechanism of adhesion for single particle contacts without consolidation by external forces. On the other hand, the mechanical behaviour of cohesive powders has been investigated mainly on the basis of continuum mechanics.For science and technology, it is useful to combine the particles approach and the continuum approach in order to provide a better understanding of the mechanical properties of cohesive powders. A theoretical model has therefore been developed which takes into account the forces acting in interparticle contacts. The theory especially considers the increase in the adhesion forces transmitted in interparticle contacts with increasing consolidation. Contrary to the commonly used phenomenological view, this theory yields a physically based understanding of the effective yield locus for steady-state flow which is reduced to material properties of the solid particles and is therefore shown to be an invariant of a respective powder.The opinion found in the literature that a single yield locus uniquely belongs to one consolidation locus is shown to be not valid. The microstructural view of a cohesive powder is able to show that, contrary to the continuum mechanical view, in the general case a cohesive powder is mechanically anisotropic due to its loading history.     

过碳酸钠洗涤性能和稳定性能影响因素的研究

过碳酸钠 (PC)是一种碳酸钠与过氧化氢的络合物 ,其特点是对环境无污染。作者以洗涤剂中含有过碳酸钠为前提 ,从洗涤剂最常见的原料对PC的活性与稳定性能的影响方面进行了研究 ,通过实验证明Na2 CO3 、Na2 SO4 、十二烷基苯磺酸钠 (LAS)、三聚磷酸钠 (STPP)、MgSO4 、Na2 SiO3 、四乙酰乙二胺 (TAED)对PC的活性和稳定性都有影响。发现Na2 CO3 对过碳酸钠漂白的促进作用在过碳酸钠质量浓度低的时候尤其明显 ;随着Na2 SO4 、LAS用量的增加 ,白度值上升 ,在达到一定值后白度下降 ;而STPP恰恰相反 ,质量浓度增大 ,白度增大 ,当STPP质量浓度达到一定值时 ,作用反而更显著 ;MgSO4 很敏感 ,在窄区间有一峰值 ;Na2 SiO3 的用量在 2 5 %以内时 ,白度升高的趋势很强 ;TAED对PC起活化作用且和温度有关。最后设计出一个配方与标准粉比较去污比值是 2 2 1。     

Calculation of the ignition sensitivity of dust clouds of varying size distributions

For a cloud of flammable dust in air to ignite, the temperature of the air must be a specific value that depends upon properties of the dust material and of the dust cloud.First, a theoretical treatment is used to explain variations in experimental ignition temperatures in terms of particle size. The theory modifies Cassel and Liebman's method to take account of residence time of dust in experimental furnaces or in hot air. It is shown that it is possible for the ignition temperature of mono-sized coal particles (about 50 μm diameter) to be minimal under a limited residence time.The theory is extended to deal with dust clouds with a distribution in particle size. It is shown that there exists a range of size distributions for which the possibility of ignition is at a maximum. The calculated results are presented in the form of Rosin—Rammler charts indicating the distribution most sensitive to ignition.     

注塑机拉杆三角螺纹端卸载槽的多目标优化

针对注塑机拉杆三角螺纹在近卸载槽处发生早期断裂的问题，在用ANSYS软件对近卸载槽处三角螺纹进行有限元分析的基础上，就拉杆三角螺纹端卸载槽的几何特性建立参数优化模型，以控制三角螺纹在近卸载槽附近的最大应力、卸载槽的最大应力以及卸载槽加工量最小化为统一的目标函数。通过对拉杆在单向拉伸力作用下的多目标优化，可使拉杆三角螺纹牙根在卸载槽处的最大应力降低55％，在偏载作用下，其最大应力降低21．4％。在单向拉伸力作用下，拉杆卸载槽的最大应力比平均单向拉伸应力提高26．5％，使卸载槽能够较好地发挥其卸载的作用。     

Co-carbonization of solvent fractions of hydrogenated and alkylated SRC pitches in studies of formation of needle-cokes

The optical texture of cokes from two SRC pitches of different coking properties, from co-carbonizations of these materials and of hydrogenated and alkylated products has been studied. The objective, relative to formation of needle-cokes, is to correlate the optical texture of cokes with the chemical structure of the pitch materials using both benzene-soluble (BS) and insoluble (BI) fractions of the pitches. Hydrogenation improved the compatibility of the BS fraction of the inferior SRC pitch (No. 2) with the BI fractions of the two pitches (non-hydrogenated) using a ratio of only 1 to 9. Before hydrogenation, a ratio of BS to BI of 8 to 2 did not give a needle-coke. In contrast, alkylation destroyed the compatibility of the BS fraction of the superior SRC pitch (No. 1) with the BI fraction (non-alkylated) using a ratio of 6 to 4, and which gave a needle-coke before alkylation. Hydrogenation of the alkylated material restored the compatability. The relevance of these studies to industrial carbonization processes is discussed in terms of chemical treatment and the hydrogen economy.     

A Self-Delamination Method of Measuring the Surface Energy of Adhesion of Coatings

A self-delamination technique is presented to assess the surface energy of adhesion of coatings. By measuring the debond area resulting from a circular hole cut in a film adhered onto a substrate, the surface energy may be determined if the tensile modulus, Poisson's ratio and residual stress level of the film are known. This method is useful for coating thicknesses greater than a critical thickness for self-peeling. Using this technique, the surface energy for a polyimide film (cured up to 220°C) on a glass plate was determined to 3.2 Nm^-1.     

The determination of the coefficient of dynamic friction of organic powder compacts on steel

A practical experimental model system has been successfully used to study the frictional response of organic powder compacts sliding across a polished steel plate, representative of the die bore of a production compaction system. This system offers a controlled approach to the study of frictional phenomena occurring during compaction and facilitates a more detailed investigation into the fundamental mechanisms of friction than a simple resolution of forces within a punch and die apparatus.For acetylsalicyclic acid sliding on steel, the dynamic friction coefficient was found to be dependent on the displacement and, to a lesser extent, the initial normal load, whereas for PTFE on steel, the dynamic friction coefficient was independent of displacement and load and estimated at 0.09. Thus, soft organic materials exhibit very different frictional characteristics to those of brittle materials. These differences reflect the differing importance and magnitude of the three frictional components, adhesion, shear and ploughing.     

Principles of Isotachophoresis and Dynamics of the Isotachophoretic Separation of Two Components

Abstract

This paper reviews the principles of isotachophoresis, a separation method in which a migrating steady-state zone structure is established through electrical transport. Prior to attaining steady state, a moving transient system of homogeneous zones is gradually reduced to consecutive sample zones of constant length, where all boundaries migrate with equal velocity. The separation process of a pair of sample components is discussed to illustrate the dynamics of this unique electrophoretic method. Solutions in terms of separation time, separation rate, and separation distance are given. Furthermore, techniques for the enhancement of the maximum sample load of a column are discussed. The features of isotachophoresis are presented to illustrate the advantages of multichannel zone detection in an isotachophoretic instrument.     

Experimental validation of a theoretical analysis of the range of operation of catalyst poisons

A formula to calculate theminimum quantity of material necessary to poison or promote a supported metal catalyst, based on theoretical criteria of poisoning range, has recently been proposed (R.W. Joyner and J.B. Pendry, Catal. Lett. 1 (1988) 1). This paper reports experimental tests of this formula for chlorine, sulphur and iodine poisoning of a Pd/C catalyst for the hydrogenation of cyclohexene. For chlorine and sulphur a significant excess of poison is required compared to the estimate, while the results for iodine are in excellent agreement with the calculation. The theory is also compared with a number of literature studies of sulphur poisoning and appears to have wide validity.