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目的:镍-二氧化钛核壳复合微球的制备及其光电性能研究.方法:采用水合肼还原乙酸镍制备了镍微球,通过对不同反应介质、反应时间、pH值以及表面活性剂的考察,以获得制备镍微球的最佳条件;再以镍微球为核心材料,制备了Ni-TiO2核壳复合材料.对其光吸收和光催化性能进行评价紫外可见光下.结果:在使用1,2-丙二醇为溶剂,以聚乙烯吡咯烷酮为表面活性剂,反应时间2h的条件下制备得到了分散性较好的镍微球.以镍微球为核心材料,在1,2-丙二醇中通过水解钛酸丁酯,T iO2成功负载于镍球表面,复合材料在紫外光和可见光下光催化降解率分别为78.6％ 和79.5％,其吸收波长范围可达550 nm左右,其复合微球的禁带宽度为2.23 eV.结论:复合微球具有比单一T iO2更广的光吸收范围,Ni-TiO2核壳复合材料在紫外光和可见光下都表现出更好的光催化性能. 相似文献
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《广东轻工职业技术学院学报》2017,(4)
电极材料是影响超级电容器性能的关键所在,目前已发现氧化镍作为超级电容器电极材料具有良好的电容性能,利用硫元素与氧元素同族的特点,研究硫化镍的电容性能。以碳布为基底,将六水合硝酸镍和六次甲基四胺混合溶液通过水热法制备氧化镍;然后利用硫代乙酰胺溶液水热硫化得到硫化镍,并通过循环伏安法、热场扫描电子显微镜、拉曼光谱分析法、X射线粉末晶体衍射等方法表征所制备硫化镍的电化学性能和形貌组成。 相似文献
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采用混合溶剂热法成功地制备了空心状3D-Bi2WO6分等级微球。通过X-多晶粉末衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)、紫外-可见漫反射(UV-Vis DRS)、比表面测试仪(BET)和光催化降解等手段对所合成材料的组成、结构、形貌、光学、比表面积以及光催化性能进行了表征。讨论了影响3D-Bi2WO6空心微球形成的因素和机理;在可见光照射下,空心状3D-Bi2WO6分等级微球210min内对罗丹明溶液(10-5mol/L,100 mL)的降解率达到了98%,并且性能稳定、易回收。 相似文献
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《陕西教育学院学报》2016,(9):146-149
采用溶胶-凝胶法以醋酸镍、氯化镍、硼酸和表面活性剂为主要原料,通过改变反应物的比例和种类、反应温度、反应时间以及表面活性剂的用量和种类等条件,制备出了片状、粒状和棒状三种不同形貌的微纳米硼酸镍。在此基础上,对新合成出来的微纳米硼酸镍进行了X射线的粉末衍射(XRD)、红外光谱(FT-IR)、扫描电子显微镜(SEM)等多种表征。 相似文献
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通过二水醋酸锌与吡啶200℃溶剂热反应24h制备出ZnO空心微球。采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对所制备样品进行了表征。ZnO空心微球形成机理主要遵循Ostwald老化机理。在室温下研究了ZnO空心微球的光催化性能。实验结果表明ZnO空心微球是光降解酸性大红的有效催化剂,其催化过程为准一级反应。 相似文献
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采用三嵌段共聚物P123为表面活性剂,四氢呋喃(THF)为溶剂,钛酸四丁酯(TBOT)为钛源,通过溶剂热策略制备出多级结构二氧化钛微球。利用浸渍还原法将Pt纳米粒子负载在二氧化钛微球上,得到Pt/TiO2催化剂。采用XRD、N2吸附脱附和TEM手段对催化剂进行表征,以糠醛加氢为模型反应考察了Pt/TiO2的催化性能。结果表明,合成的Pt/TiO2催化剂在糠醛加氢反应中表现出优异的活性,在30～80℃反应3 h,对糠醛加氢反应的转化率为82%,选择性为78.4%。Pt/TiO2催化剂循环使用过程中仍表现出较好的催化活性,因此研究TiO2微球载Pt催化剂对糠醛加氢生成糠醇具有一定价值。 相似文献
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《浙江大学学报(A卷英文版)》2020,(5)
目的:电动汽车和大规模储能的发展对锂离子电池的能量密度提出了更高的要求,但现有商业石墨负极容量难以满足要求。本文结合石墨烯高电导和高容量的优点以及中间相碳微球材料循环稳定性优良的优势,研究和报道一种容量高和循环性能好的石墨烯/中间相碳微球复合负极材料。方法:1.通过选择高电导率石墨烯和中间相碳微球,制备石墨烯和中间相碳微球复合负极材料。2.选用商业聚偏氟乙烯(PVDF)粘结剂,制备复合材料电极极片,测试和表征电极的形貌、电导以及半电池的充放电等电化学性能,并优化复合材料质量比。3.选择优化的复合负极材料(GMC(8:2)),研究其长循环性能。结论:中间相碳微球的球形结构能有效防止石墨烯的折叠团聚,从而发挥石墨烯的高电导性能。因此,石墨烯/中间相碳微球复合负极材料表现出了很好的倍率性能和循环性能,且其容量达到了421 mA·h/g以上,高于商业石墨的理论容量,具有潜在的应用前景。 相似文献
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《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
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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《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
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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
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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
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献