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1.
采用两种不同孔径的分子筛(5A、13X)制备分子筛增强顺丁橡胶复合材料.研究表明,分子筛的孔径、表面处理及填充量对橡胶基复合材料的硫化特性和力学性能均产生影响.分子筛孔径越大,对提高顺丁橡胶的硫化速率和界面粘结力效果越明显.改性后分子筛增强顺丁橡胶复合材料的拉伸性能和撕裂强度都得到提高.改性后的大孔径分子筛13X增强顺丁橡胶材料,能提高材料的耐老化性能.  相似文献   

2.
探索制备淀粉/茅草复合材料的制备工艺条件,以便开发新型的可降解复合材料。以淀粉为黏结剂、茅草颗粒为主要原料,水作为塑化剂,用热压成型的方法制备了淀粉/茅草复合材料;测试了复合材料的硬度、拉伸强度和扯断伸长率等力学性能;讨论了黏结剂用量、塑化剂-水的用量对复合材料力学性能的影响。淀粉含量为40%(干基)、水用量为25%(湿基)、热压温度120℃、热压时间10min时,制备的淀粉/茅草复合材料的拉伸强度和扯断伸长率最高,硬度稍低。  相似文献   

3.
探讨了ABS树脂的生产工艺和聚合原理,分析了橡胶含量、橡胶粒径、橡胶粒径分布对ABS冲击强度的影响,详细阐明了橡胶粒径的相关控制方法.研究结果表明,增加橡胶含量,ABS树脂的冲击性能增加;如果橡胶粒径小,则相应材料的冲击强度增强.  相似文献   

4.
对于快速成型中的光造型制作工艺,通过在光敏树脂中加入短纤维而制得复合材料.实验发现复合材料制作的样件的弹性模量和拉伸强度明显高于纯树脂固化样件,且其在后固化过程中的收缩量也比后者小.实验结果为光造型系统的制造提供最优的操作参数.  相似文献   

5.
以硫酸钙晶须(CSW)改性PA66材料,并测试CSW改性PA66复合材料的摩擦系数、拉伸强度和冲击强度.结果表明:随着CSW用量的增加,PA66复合材料的摩擦系数先减小后增大;拉伸强度和冲击强度都呈现出先增大后减小的趋势.改性PA66复合材料性能得到了提高.  相似文献   

6.
对于快速成型中的光造型制作工艺,通过在光敏树脂中加入短纤维而制得复合材料,实验发现复合材料制作的样件的弹性模量和拉伸强度明显高于纯树脂固化样件,且其在后固化过程中的收缩量也比后者小,实验结果为光造型系统的制造提供最优的操作参数。  相似文献   

7.
通过碱+马来酸酐(MA)和碱+偶联剂+MA对苎麻进行联合改性处理,采用真空辅助树脂传递模塑(VARTM)制备得到两种苎麻/环氧树脂(RF/EP)复合材料,分别是RF1/EP和RF2/EP,并对其进行力学性能测试.结果表明,与未经任何处理制得的RF0/EP复合材料对照,两种表面处理方法制得的复合材料树脂含量无明显变化,力学性能也有所降低.RF1/EP的拉伸强度和抗弯强度较RF0/EP分别降低了4.33%和17.13%;RF2/EP的拉伸强度和弯曲强度较RF0/EP分别降低了16.01%和22.45%.故工艺需要选择恰当的碱和马来酸酐溶液浓度,尽量减少纤维整体结构的变化,提升纤维与基体附着力,从而提升复合材料的力学性能.  相似文献   

8.
罗俊杰 《林区教学》2013,(12):93-94
硼酸镁晶须对金属、陶瓷及塑料等材料具有较强的机械增强作用,在交通运输等领域有较大的潜在应用价值。采用水热法制备出带状的硼酸镁纳米材料,产物的产量和纯度都比较高,形貌均匀,对进一步研究硼酸镁纳米材料的性质及应用具有一定的支撑作用。  相似文献   

9.
按一定比例加入助剂改性回收聚乙烯(PE)塑料,采用熔融共混的方法,按照一定的工艺配方将回收聚乙烯和助剂混合注塑成型,制备得到改性纳米复合材料;通过测试其力学性能,用扫描电镜(SEM)、X射线衍射(XRD)来表征其结构,找出性能理想的工艺配方.结果表明:当纳米氧化锌(Zn O)与聚乙烯辛烯共弹性体(POE)添加的质量之比为3∶2时,回收聚乙烯和填充剂、抗氧剂、增塑剂、增韧剂等助剂制备出复合材料的综合性能良好,所得复合材料的拉伸强度比回收聚乙烯提高了23.54%,弯曲强度提高了15.87%,其衍射峰的强度增加了50%,且峰变得尖细,其晶化程度较大.  相似文献   

10.
TiCp/ZM5镁基复合材料的组织和性能   总被引:2,自引:0,他引:2  
采用XD法制备TiCp/Al预制块.然后将其加入到Ar气保护的镁液中,通过机械搅拌制备TiCp/ZM5复合材料.对其显微组织和力学性能进行分析测试。实验结果表明:反应生成的TiC颗粒非常细小.粒径在1—3μm。加入5%TiC粒子后,TiCp/ZM5复合材料中的基体晶粒明显细化,Mg17Al12相变细小.加入10%的TiC粒子后,基体晶粒进一步细化,TiC粒子略有团聚。随着TiC粒子含量的增加.TiCp/ZM5复合材料的抗拉强度、屈服强度、硬度值提高,延伸率降低。  相似文献   

11.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

12.
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/  相似文献   

13.
《海外英语》2007,(5):10-11
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?  相似文献   

14.
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。  相似文献   

15.
《海外英语》2007,(4):36
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.  相似文献   

16.
王菲 《华章》2007,(12):273-273
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.  相似文献   

17.
裴水妹 《华章》2007,(11):196
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.  相似文献   

18.
19.
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…  相似文献   

20.
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  相似文献   

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