氮化硅对石英陶瓷性能影响

研究了氮化硅加入物对石英陶瓷性能的影响。结果表明,氮化硅有助于石英陶瓷的烧结,而对烧结温度无影响。在1150℃-1200℃的温度范围内,添加0.5-1.5％的氮化硅不会引导石英玻璃的析晶。烧成在1150℃-1200℃温度范围内,石英陶瓷的强度、体积密度随氮化硅的添加量增大和烧结温度提高而增大,而石英陶瓷的显气孔率随氮化硅添加量的增大和烧结温度的升高而减小。     

深刻理解溶液析晶道理 熟练掌握溶液析晶计算

溶液析晶计算是有关溶解度知识的深化和提高,也是中考试题螅热点,更是同学们学习的难点．在解答这类试题时,只有明确了析晶道理,才能掌握其有关计算技能．笔者就拟对上述问题,分以下两个方面,做以全面分析,供同学们学习参考．     

“图示法”分析溶解度和析晶计算四例

溶解度和析晶计算不仅是初中化学的一个重点,也是一个难点,就是学生进入高中以后,对这方面计算仍有困难.在高三总复习时,我运用“图示法”分析有关溶解度和析晶计算题,收到了较好     

测试乳化炸药水相溶液析晶点的几点建议

本文从生产实践出发,阐述了析晶点测试过程中误差产生的原因,并提出了建议,从而进行调整与改进,以保证产品质量。     

非晶、纳米晶铁基合金的实验研究

用X射线衍射分析仪(XRD), 透射电子显微镜(TEM), 扫描电子显微镜(SEM)和X射线吸收精细结构分析仪(EXAFS)对机械合金化后的FeNiPB(Cu, Nb)混合粉末进行了分析研究. 研究结果表明: FeNiPB(Cu, Nb)混合粉末球磨20h后合金化, 球磨80h后FeNiPB(Cu, Nb)混合粉末中的Fe, Ni原子处于非晶环境中, 粉末的形态为棉絮状, 电子衍射为典型的非晶环. XRD, EXAFS, TEM的分析结果表明在该条件下, FeNiPB(Cu, Nb)混合粉末完全转变成了非晶. FeNiPB(Cu, Nb)非晶合金在520℃加热1h后产生纳米晶, 所以纳米晶铁基合金可通过FeNiPB(Cu, Nb)非晶合金部分晶化获得.     

晶化温度对合成二氧化锆介孔分子筛介观结构的影响

采用有机小分子三乙醇胺同时作为水解抑制剂和模板剂,丙醇锆作为前驱物,通过溶凝胶工艺合成了二氧化锆介孔分子筛.利用X射线粉末衍射、低温N2吸-脱附法等表征手段,考察了晶化温度对二氧化锆介孔分子筛介观结构的影响.     

菲利华:公司驶入成长快车道

菲利华(300395):公司始建于1966年,经过五十年的发展,现已发展成为国内外具有较大影响力和规模优势的石英材料及石英纤维制造企业,主营光通讯、半导体、航空航天等高新技术领域配套用高性能石英玻璃材料、石英纤维及制品.公司为国内首家获得国际主要半导体设备制造商认证的石英玻璃材料企业,是全球少数几家具有石英纤维批量产能的制造商之一,中国航空航天等国防军工领域唯一的石英纤维供应商.     

硼铝硅玻璃析晶及对耐火物融蚀机理研究

结石和气泡都是影响硼铝硅玻璃产品合格率的重要因素,有时甚至会成为制约生产的主要因素,尤其是液晶基板玻璃生产,因其对产品中存在缺陷要求极严,甚至目视无法观察到的极其微小的夹杂物都是不容许的.解决玻璃制品中发生气泡和结石的问题,历来都是玻璃生产和工艺研究中的重要课题,有非常显著的经济效益.本文试图通过对该玻璃的析晶及其对耐火物融蚀机理的研究,了解结石形成原因和发生源.研究减少结石的可能,从而达到提高产品质量和合格率的目的.     

硅酸锌结晶釉的原料及烧制工艺探究

以玻璃粉、长石、方解石、氧化锌为原料,制备硅酸锌结晶釉。通过调整配方中各组分的含量及改善烧成制度来制备具有良好析晶效果的结晶釉,并通过金相显微镜观察釉面晶花形态,采用X射线衍射仪分析晶相组成,探讨原料配比和保温温度对釉面析晶和坯釉适应性的影响。实验结果表明,硅酸锌结晶釉的氧化锌最佳含量为30%;玻璃粉含量在45%~52%之间变化时,釉面可获得不同形态的硅酸锌晶花。此外,烧成温度对釉面析晶也有重要影响,在1080℃保温1h,釉面析晶及品质最佳。     

基于衍射原理测量石英玻璃的热光系数

热光系数是描述热光效应的基本物理量之一。目前热光系数的常见测量方法是干涉法和光谱法，但均需复杂的实验设计和较高的仪器成本。为此，提出了一种基于衍射原理测量石英玻璃热光系数的方法，仅采用一台分光计即可实现石英玻璃热光系数的测量。通过测量石英光栅的第三级衍射光栅光谱随温度的漂移曲线，得到石英玻璃热光系数1.092×10^-5/K,与石英玻璃热光系数理论值1.0×10^-5/K非常接近。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

汉字倒说

汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

钱生钱!

我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…