100米燃气中型电瓷轻体隧道窑设计及运行控制

自控中型电瓷轻体隧道窑的结构设计是在传统隧道窑的基础上进行创新而发展起来的。但它摆脱了传统隧道窑的复杂而严谨的结构模式。采用新工艺,新材料多功能的高温耐火绝热轻型材料的复合体高温轻型碳化硅窑具。使窑体结构简化,窑体轻而薄的复合体。大大地增强了隔热性能。但它仍然沿用传统隧道窑的多道气幕,特别是气氛气幕的结构形式。开拓创新。完善了边续式窑炉的先进性和科学性。显著的成效是节约能源。降低消耗。     

玻艺之花盛开在上海玻璃博物馆—中国美院玻璃艺术展

“道可道,非常道。名可名,非常名。无名天地之始。有名万物之母。故常无欲以观其妙。常有欲以观其徼。此两者同出而异名,同谓之玄。玄之又玄,众妙之门。”玻璃艺术的材料特质似乎正是东方哲学的物化显影,将形而上学的形与心固化为可触摸的感动。“随心造化”是“丹士”的精神内视,将万千幻像显现为不可思议的再现。把思想的晶体放入高温中熔...     

浙江水泥业遭遇成长烦恼

通过新型干法生产线建设的推进。机立窑落后生产能力的淘汰，浙江水泥工业摆脱了工艺的因陋就简、规模的简单叠加和质量的临界控制，行业面貌发生了翻天覆地的变化。2004年底，形成新型干法水泥生产能力5000万吨以上，产能约占水泥总量的70％，在国内新型干法水泥的生产能力最大、比例最高。1～10月全省水泥产量6464万吨。同比增长9．61％；水泥工业总产值180．96亿元。同比增长47．37％。但是，水泥工业是一个资源依赖型、资本密集型、投资相伴型的产业。外部环境的关联影响很大。同时，水泥工业又是一个多种工艺业态并存、市场高度竞争的行业。内部秩序的整理任务很重。伴随行业的快速发展，有关浙江水泥业发展的讨论始终没有停息过。围绕着宏观经济与产业发展，围绕着资源禀赋与经济条件，围绕着结构转换模式与市场转化能力。仁者见仁。智者见智。今天．先行的浙江水泥业正遭遇着成长带来的烦恼。     

跨国公司收购中国化工资产愈演愈烈

作为全球增长最快的市场，中国一直是众多跨国公司投资的重点。与组建全资子公司相比。对中国化工资产进行收购和重组。是跨国公司进入中国市场更直接更便捷的方式。今年以来。跨国公司在中国的这种收购重组活动愈演愈烈。     

北京的声音

<正>或许,这些曾经的声音,都已归还给了大历史,无声地滋养着北京的静。客居京城两年,印象最深刻的是北京的静。北京的静,当然不是荒凉的静。这个城市,人口数以千万,商圈喧哗。然而,所有的声息都如同碎片,顺着风,搅起一些,还没听真切,它们就低下来,着地了。北京的静,和城市地理相关。三面雄关,指缝间漏下一个平原。北方苦寒,日短夜长,并不适合欢饮达旦。历史也为北京人留下了惯看秋月春风的稳健。     

首批商家进城华南城商机无限

2004年12月6日。阳光灿烂。暖意融融。位于深圳平湖物流基地的华南城彩旗飘扬、锣鼓喧天、人潮涌动。华南城举行了规模盛大的首批商家进城仪式。这是一个特殊的日子．是一直关心、支持华南城建设的人们盼望己久的日子。这一天不仅是华南城商家们的大喜日子，也是整个珠三角制造企业的大喜日子。从这一天起，一个充满商机的世界级工业原料展示交易中心向世人敞开了大门。云集华南城的五千多名海内外嘉宾、媒体记者、华南城商家与现场观众共同见证了这激动人心的历史性一幕。     

爱的礼物

<正>情人节,一个关于爱与浪漫的节日。在这一天。男女之间,互送礼物,用以表达爱意。牵手的男女,在经过相遇的忐忑、相恋的甜蜜、别离的伤感和相思的断肠,最后携手一生。在这一刻,情人之间,传递爱情,回首爱情,享受爱情。掬一捧清泉,洒一路花香,携祝福赠人间美眷。     

野外花卉摄影

Mark Hamblin将在这里分享在百花齐放的季节里,拍摄野外盛开花朵时的方法和注意事项。专家建议3条方法提升野花拍摄技巧。选择镜头首先要选择合适的镜头。使用广角镜头更容易表现野花与其所处的整体环境。使用长焦镜头拍摄则可以只突出一朵花,避开杂乱的环境。若想拍摄更近距离或花朵的局部细节,就要使用微距镜头了。     

塑料制品产业发展及聚烯烃材料市场需求浅析

我国塑料工业经过多年的发展。已成为与钢材、水泥、木材并列的重要基础材料产业。目前。塑料制品的应用领域广泛分布于农业、工业、交通、能源等传统产业。并越来越多的被应用于电子、信息、宇航、海洋开发等高新技术领域。近年来。我国塑料工业增长速度高于国民经济增长速度。达到10％以上，目前是世界塑料制品大国。而广东省更是在近二十年的时间内发展成为华南地区乃至中国最大的塑料制品省份。     

权威人士热评"加息"

自去年下半年以来。关于中国加息的传闻时起时落．每一次都牵动着海内外市场的神经。然而。今年2004年10月29日中国人民银行宣布利塞调整的消息传来，仍然令市场为之震动。加息之后，各方人士观点见诸媒体报端。现本刊整理部分权威人士的观点看法．以飨读者。     

稀土氧化物对氮化铝瓷介电性能的影响(英文)

研究了添加Nd2O3和Er2O3对氮化铝陶瓷烧结性能、介电性能和显微结构的影响。结果表明:在氮化铝瓷中添加Nd2O3和Er2O3,有利于降低氮化铝陶瓷烧结温度,提高致密性,并且介电性能能够得到显著改善。添加3%(质量分数)Er2O3的AlN陶瓷的相对密度达98.8%,介电损耗为1.3×10-4,是纯AlN陶瓷的5%。其显微结构分析表明,氮化铝晶粒尺寸更均匀,并且其晶格参数更接近理论值,晶界相较少,从而使得其介电性能得到较大改善。     

Composition and Properties of Hot-Pressed SiC-AIN Solid Solutions

High-density SiC-AIN compositions were fabricated from powder mixtures by hot-pressing in the 1700° to 2300°C temperature range. At 2100°C, a 2H solid solution was found from =35 to 100 wt% AlN. The single-phase solid solution samples had steep composition gradients of >10%/μm within the grains. Lattice parameters closely followed Vegard's law. For compositions with <35% AIN, multiphase assemblages were found. Increasing grain size was observed for increasing firing temperature for SiC and AIN. Grain size of the solid solutions was significantly smaller than for SiC or AIN fired to the same temperature. Microhardness values decreased linearly in the solid solution region with increasing AIN content. Flexural strengths of SiC and AIN decreased with increasing firing temperature and increasing grain size. The strengths of SiC, AIN, and the solid solutions were low for materials hot-pressed at 2100°C.     

Si3N4／Al反应烧结制备AIN／Al复合材料

研究了采用Si，N4与Al的混合粉，经压制、烧结制备AIN／Al-Si复合材料的技术方法。试验结果表明：AIN的反应生成机制属于一种连续渐进式反应形成过程，即于高温下液相Al中的Al原予渗入Si3N4的晶体点阵取代Si原予而逐渐使之向AIN晶体点阵转化的过程。被取代的Si原予从固相Si3N4中析出，扩散溶入液相Al中，冷却后形成Al-Si舍金固溶体，一般呈网状分布于AIN晶体相的周围。新生成的AIN与Al-Si合金相之间表现出很好的界面亲和性。     

氮化铝陶瓷低温真空热压烧结研究

以自蔓延高温合成的AIN粉体为原料,Y2O3、Dy2O3、La2O3为添加剂,采用真空热压烧结工艺,实现了含有添加剂的AIN陶瓷体的低温烧结;研究了烧结温度对AIN烧结性能的影响。用XRD、SEM对AIN高压烧结体进行了表征。研究表明：粉体粒径、烧结工艺、烧结助剂对AIN陶瓷低温烧结真空热压烧结性能有很大影响;含烧结助剂的真空热压烧结能够有效降低AIN陶瓷的烧结温度并缩短烧结时间,使烧结体的结构致密。烧结温度1550℃条件下,真空热压烧结90min时,得到的AIN陶瓷的致密度最高。     

Simultaneous Chemical Vapor Deposition of Boron Nitride and Aluminum Nitride

Two chemically different phases, hexagonal BN and AIN, were simultaneously produced by chemical vapor deposition (CVD) using an impinging jet reactor and the BCl₃─AlCl₃─NH₃─Ar reagent system. The microstructure of the BN + AIN composite coatings was strongly dependent on temperature, pressure, and BCl₃ and AlCl₃ concentrations. The growth characteristics of BN and AIN in the codeposition system were similar to those expected from the single-phase deposition processes (i.e., BN-CVD and AIN-CVD), except the growth of AIN whiskers was accentuated, and competition between BN and AIN deposition in the composites was suspected to be the cause of less-crystalline deposits. In both BN + AIN-CVD and AIN-CVD, the growth of AIN whiskers became more apparent with increasing pressure or temperature. The codeposition behavior observed experimentally was compared with thermodynamic predictions.     

Stabilization of Cubic Zirconia by Aluminum Nitride

Cubic ZrO₂ is stabilized at room temperature by the addition of AIN. The percentage of c-ZrO₂ in the mixture of c-ZrO₂ and m-ZrO₂ increases linearly with the addition of up to 20 mol% AIN and decreases thereafter. Stabilization becomes complete at 50 mol% AIN. The lattice spacing of the cubic phase gradually expands up to 20 mol% AIN. A displacement reaction ZrO₂+ AIN → ZrN+Al₂O₃ occurs above 20 mol% AIN and is completed at 50 mol% AIN.     

EELS Study of Oxygen Diffusion in Aluminum Nitride

The oxygen/nitrogen interdiffusion in AIN ceramics was investigated by electron energy-loss spectroscopy (EELS) in combination with transmission electron microscopy (TEM). AL₂O₃/AIN diffusion couples were prepared by oxidation of an AIN ceramic. The samples were annealed for different times in the temperature range from 1500° to 1900°C. The diffusion couples were encapsulated in a tantalum ampoule to guarantee an inert atmosphere. Oxygen concentration profiles across the oxide/nitride interface were measured by EELS. The oxygen/nitrogen interdiffusion coefficient in AIN is given by D = 1.5_–1.2^+6.0× 10^–8 exp[–240 ± 40 (kJ/mol)/( RT )] (cm²/s). The magnitude and temperature dependence of the N/O interdiffusion is comparable to diffusion coefficients reported in the literature for other non-oxide ceramic materials. At standard AIN sintering conditions the O/N interdiffusion is so slow that it cannot provide an effective means for oxygen removal from the AIN grains.     

Formation of β-SiAION as an Intermediate Oxidation Product of SiC–AIN Ceramics

The oxidation mechanisms in SiC-AlN solid solutions, exposed at 1370°C for 200 h in air, have been investigated by scanning electron microscopy (SEM), analytical and high-resolution electron microscopy (HREM), and X-ray diffraction techniques. Five hot-pressed compositions, including pure SiC and pure AIN, were examined. Assuming parabolic rate behavior, the values of the parabolic rate constants based on oxide layer thickness increased by over 2 orders of magnitude by increasing AIN contents from 0% to 62%. A continuous amorphous phase containing cristobalite and mullite crystallites was present at the oxide layer in 13% AIN and 27% AIN samples. Two reaction layers were found in the oxidized SiC–62% AIN solid solution. The inner layer consisted of a mixture of β-SiAION and graphite phases, while the outer layer consisted of mullite as a major phase and cristobalite as a minor phase. The oxidation proceeded in two stages: a partial oxidation of SiC–AIN to β-SiAION and carbon (graphite), and a final oxidation of β-SiAION to mullite + SiO₂.     

Effect of Milling Treatment on the Particle Size in the Preparation of AIN Powder from Aluminum Polynuclear Complexes

Aluminum nitride powder was synthesized from aluminum polynuclear complexes. Basic aluminum chloride (BAC) provided the aluminum polynuclear complexes. The effect of the milling treatment for the precursor made from basic aluminum chloride and glucose on the particle size was investigated. BAC and glucose were dissolved in water and mixed homogeneously. AIN powder was obtained by calcining under a nitrogen gas flow after drying, milling by vibration mill, and precalcining at 800°C. Then excess carbon was removed by firing in air. It was found that the milling treatment affected the particle size of AIN powder and nitridation mechanism. Without the milling treatment, AIN powder was synthesized directly from the γ-alumina of an intermediate product. In using a milled precursor, however, α-alumina was formed during the calcining, and the particle size of the AIN powder obtained was about five times larger than that of AIN powder synthesized from a raw precursor. The formation of α-alumina phase began at the rather low temperature of 800°C. These results suggest that the mechanochemical effects added by the milling promotes the formation of α-alumina during calcining, and the α-alumina phase formed accelerates the particle growth. AIN powders obtained were very uniform. The oxygen content and the surface area of AIN powders synthesized from the raw and milled precursors were 2.9 wt% and 17.5 m²/g, and 1.1 wt% and 3.6 m²/g, respectively.     

Preparation of Dispersed Phase Ceramic Boron Nitride and Aluminum Nitride Composite Coatings by Chemical Vapor Deposition

Dispersed phase ceramic composite coatings containing BN and AIN were prepared by chemical vapor deposition. The BN + AIN coatings were deposited on Al₂O₃ from the BCI₃–AICI₃-NH₃ reagent system in the temperature range of 700° to 1200°C. Also, single-phase BN and AIN coatings were prepared for comparison purposes. The composite coatings consisted of very small BN and AIN regions which were either crystalline or amorphous, depending on deposition temperature and reagent concentrations. For example, a composite containing AlN whiskers of less than 100-nm diameter in a matrix of turbostratic BN of 2-nm grain size was deposited at 1100°C and 20 kPa.