耐烧碱蚀合金铸铁的研发

本课题针对制烧碱工业中设备的腐蚀问题,研制出不同稀土含量、不同镍含量的稀土Ni-Cr-Cu合金铸铁,采用光学显微镜观察材料的显微组织;用失重法测定各合金铸铁在动态、高浓度下的碱腐蚀速率;采用S-3400N型扫描电镜观察,对其耐碱腐蚀性能进行评价进而讨论稀土Ni-Cr-Cu合金铸铁在烧碱液中的耐碱腐蚀机理。结果表明:随着镍含量的增加,合金铸铁的耐蚀性能增加;适量稀土元素可以改善铸铁中石墨和碳化物的形态、分布,使石墨球化、碳化物弥散分布。     

激光表面强化处理高NiCr无限冷硬铸铁轧辊材料研究

利用大功率CO-2激光机床对高NiCr无限冷硬铸铁轧辊材料进行激光表面强化处理试验,经过多次调整和优化激光表面强化处理试验工艺,完成高NiCr无限冷硬铸铁轧辊材料的激光表面强化处理试验.经过检验,高NiCr无限冷硬铸铁轧辊材料的激光强化区域没有裂纹,其硬度和金相组织均有所改善,强化效果较明显.     

脆性材料单轴压缩力学特性的加载速率效应

利用电子材料试验机及岩石三轴试验机对铸铁、煤、砂岩3种脆性材料进行了不同加载速率下的单轴压缩试验,得到了它们的应力-应变曲线及抗压强度与压缩率随加载速率的变化曲线。研究结果表明:①3种脆性材料的抗压强度随加载速率的变化趋势各不相同。随着加载速率的增加,铸铁的抗压强度先减小后增加,煤样的抗压强度先增加后减小,而砂岩的抗压强度则持续减小。②随着加载速率的增加,铸铁、煤的抗压强度与各自的压缩率有相同的变化趋势。③铸铁的抗压强度是煤样的近15倍,而煤样的最大压缩率是铸铁的近28倍。     

稀土对镁质胶凝材料性能的影响

通过在氧化镁和氯化镁溶液中掺加稀土盐,研究稀土对镁质胶凝材料性能的影响.实验发现稀土盐可以延缓镁质胶凝材料的结晶固化过程,通过抗折强度测试机和抗压强度测试机测试表明:随着稀土盐含量的增加,得到的稀土改性镁质胶凝材料抗压强度和抗折强度均随混合稀土氯化物含量的增加先增加后减少.这些变化可能与稀土改性镁质胶凝材料的结晶固化有关.     

铸铁遗传性机理的分析

分析铸铁遗传性因素,找出灰口铸铁件生产中出现白口铸铁件的原因,从而采取简捷的措施,将若干白口铸件和废轧辊掺入炉料中,产出了合格铸件。     

低铬白口铸铁磨球质量的影响因素

叙述了磨球的服役条件及对材料的要求;分析稀土低铬白口铸铁磨球破碎率高的主要原因是：碳化物呈连续网状分析和铸造缺陷;讨论了低铬白口铸铁磨球的生产工艺及质量控制。     

带锈铸铁脱盐缓蚀后的耐蚀性能研究

在加入钼酸盐与硅酸盐复合缓蚀剂的碱性脱盐溶液中,对带锈铸铁进行脱盐缓蚀处理,对带锈铸铁处理前后的耐蚀性能进行了测试评价,并运用扫描电子显微镜和傅里叶变换红外光谱仪对锈层形貌结构进行了分析。结果表明,在该体系中脱盐缓蚀处理后,铸铁的腐蚀速度下降至5%以下,脱盐缓蚀改善了锈层结构,锈层主要组成由不稳定锈γ-FeOOH向稳定的α-FeOOH转变,锈层结合紧密,铸铁的耐蚀性能提高。     

重轨轧辊技术参数的优化

通过对BD1轧机轧辊孔型参数和孔型配置的优化、对BD2轧机轧辊的材质的优选、对万能轧机采取增大轧辊直径等措施,提高了轧辊使用寿命,降低了轧辊消耗,取得了显著的经济效益,产品质量也得到了有效控制。     

CSP轧辊预热温度场分析

针对一种CSP轧辊预热装置,利用有限元模拟了在不同预热条件下轧辊的升温过程,确定了最佳预热条件和轧辊预热装置的设计参数。通过分析发现,提高热流气体温度和喷气速度可以有效提高轧辊的温度,适宜的保温时间可有效降低轧辊表面与芯部的温度差,预热过程的模拟计算分析为轧辊预热装置设计提供了理论依据。     

超高铬铸铁成分对性能的影响

高铬铸铁（含铬〉12％）是优良的抗磨材料。在高铬铸铁的研究中，一般集中在Cr15，Cr20等高铬铸铁上。文章分析了高铬铸铁的重要组成部分超高铬铸铁（铬含量〉20％）随着Cr含量的提高及各种合金元素的加入，对研究组织的变化性能的影响。     

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?     

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.     

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…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.