退火温度对NZFO铁氧体薄膜磁性能的影响(英文)

采用化学溶液沉积法在Si(001)衬底上制备Ni0.7Zn0.3Fe2O4铁氧体薄膜,XRD谱表明样品具有单相的尖晶石结构;扫描电子显微镜结果表明样品平均颗粒尺寸随着退火温度的上升从10 nm增加到32 nm。NZFO铁氧体薄膜磁性能与退火温度有强烈的依赖关系,薄膜的矫顽力从退火温度为500℃时的25 Oe增加到900℃时的80 Oe,饱和磁化强度也由146emu/cm3增加到283 emu/cm3,这对于现代电子器件微型化有着非常重要的意义。     

锂离子电池正极材料LiNi0.8Co0.2O2的研制

采用热分析法对不同组成的LiOH-LiNO3二元体系进行研究,绘制了具有最低共熔点的该二元体系T-x相图。用该低共熔混合物为锂盐,与前驱体Ni0.8Co0.2(OH)2混合烧结制备出锂离子电池正极材料LiNi0.8Co0.2O2。     

静电纺丝法制备Co0.5Ni0.5Fe2O4纳米纤维及影响因素研究

采用静电纺丝技术制备了PVP/[Co(NO3)3+Ni(CH3COO)2+Fe(NO3)3]复合纤维,通过X射线衍射(XRD)、扫描电镜(SEM)和振动样品磁强计(VSM)对复合纤维及其焙烧产物进行了表征,较为系统地考察了制备参数,如PVP含量、醇/水比例、电场强度以及无机盐含量对复合纤维形貌和直径的影响,获得了最佳制备条件。将所得复合纤维在550℃焙烧2h可以制得单相尖晶石结构的晶态Co0.5Ni0.5Fe2O4纳米纤维,其平均直径约为80nm,在室温下具有良好的磁性,比饱和磁化强度和矫顽力分别为52.3A.m2/kg和81.0kA/m。     

烧结温度对Ni0.8Zn0.2Fe2O4铁氧体低频低磁通损耗的影响

NixZn1-xFe2O4铁氧体具有高频中低损耗的特点,通过提高Ni含量至0.8降低起始磁导率,增加截止频率,应用于更高频率。通过固相反应法合成了Ni0.8Zn0.2Fe2O4,并测定了铁氧体样品在低频低磁通密度下的损耗特性,讨论了烧结温度对损耗的影响。     

对靶磁控溅射Co/TiO_2薄膜制备和表征

为了研究稀磁半导体Co/TiO2薄膜的微观结构和磁性,进一步探讨制备工艺和测量方法对稀磁半导体薄膜材料的影响。通过高真空对靶直流磁控溅射装置和原位退火工艺制备了Co/TiO2薄膜样品,然后利用扫描探针显微镜、振动样品磁强计和X射线衍射仪对所制得的薄膜样品的磁性和微结构进行了研究,发现磁性金属Co的掺杂量对Co/TiO2薄膜的结构及磁性有重要影响。结果表明:样品的表面粗糙度和颗粒尺寸随磁性金属含量升高而增大;随着Co百分含量的升高,形成的薄膜样品Co/TiO2和Co金属混合结构会减小矫顽力;对于Co含量较低样品其磁滞回线的斜率在低温测量时得到的结果明显小于室温环境的结果,归因于受到了顺磁相的影响。由X射线衍射结果可知此时样品为锐钛矿结构。     

固相法制备镍锌铁氧体的研究

以NH_4HCO_3、FeCl_3·6H_2O、Zn(NO_3)_2·6H_2O和Ni(NO_3)_2·6H_2O为原料,在室温条件下,采用固相法合成了超细镍锌铁氧体。通过TGA/DSC、扫描电子显微镜(SEM)和X射线衍射仪(XRD)进行了分析和表征,结果表明:前驱体在800℃进行煅烧,合成了立方晶系的镍锌铁氧体超细粉体,粒子粒度较为均匀,粒晶在0.2-0.3μm之间,分散性较好。     

复合稳定剂对PVC脱氯化氢的影响

将硫醇甲基锡(DX-181)、硬脂酸锌(Zn St2)和双季戊四醇(Di-PE)按照一定比例制备了聚氯乙烯复合稳定剂,通过热稳定性实验研究了不同组分对PVC热稳定性的影响,利用SEM-EDS技术测定了样品老化过程中的表观形貌和微区化学组成.结果表明:在一定配比下,助剂Di-PE和稳定剂DX-181和Zn St2复合稳定剂不仅能显著提高PVC薄膜的耐热性,还能有效延缓Zn St2的"锌烧"作用;在老化过程中当有HCl气体释放时,样品表面会生成一定数量的微孔,且组成与PVC的稳定性、微孔大小和数量密切相关,复合稳定剂对PVC的耐热性的影响关键在于和氯化氢气体的反应或抑制HCl气体的释放.     

水杨醛缩邻苯二胺金属配合物的微波液-固相合成

在微波辐射条件下研究了水杨醛缩邻苯二胺席夫碱与其过渡金属——Cu(Ⅱ)、Zn(Ⅱ)、Ni(Ⅱ)、Co(Ⅱ)——配合物的液-固相合成反应．并对微波辐射条件下的液-固相配位反应条件进行了探索。     

衬底温度对Zn0.95Ca0.05O薄膜结构和光学性质的影响

利用磁控溅射法在玻璃基片上制备Zn0.95Ca0.05O薄膜,用X射线衍射(XRD)研究薄膜的结构特性,用LS920荧光光谱仪测量了样品薄膜的PL谱,探讨了衬底温度对薄膜结晶质量和光学性质的影响。研究发现,衬底温度对薄膜的质量影响较小,450℃时制备的薄膜结晶质量最好;不同衬底温度对发光峰强度有影响;薄膜在可见光区显示出较高的透过性,在350-400 nm范围内薄膜透过率骤然下降,在该范围内存在吸收边。     

纤维素降解过程中金属离子作用的研究

用微量量热法研究了7种金属离子及几种混合离子对纤维素酶降解纤维素反应的影响.实验结果表明,在pH=4.60,T=310K时,相同浓度的离子中Li+、Na+、K+、Ni2+、Zn2+、Co2+离子均表现出抑制作用,其中Li+抑制作用显著;Cu2+有明显的激活作用.当Li+、Na+、K+3种离子混合共同作用于反应时,表现出激活作用;当Ni2+、Cu2+、Zn2+3种离子,Co2+、Ni2+2种离子混合共同作用于反应时,表现出抑制作用.     

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,     

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…     

胡主席在印度,我却在中国

Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.     

STORIES

正A One day a pig went to the stable(马棚)to see his good friend,an oldhorse,and was going to stay there forthenight.Night came and it was time forsleep.The pig went into the straw heap(稻草堆)and lay comfortably.A longtime passed,but the horse was stillstanding there and did not move.Thepig asked the horse why he did not go tosleep."Standing like this is the begin-ning ofsleeping,"answered the horse.     

巧妙引语(英文)

正1.Any fool can count the seeds in an apple.Only God can count all the apples in one seed.2.Happy families are all alike;every unhappy family is unhappy in its own way.3.Memories are the key not to the past,but to the future.4.Sometimes in the dark you see what you want to see.5.There is a great difference between     

Information for Authors

正Scope and Policy The Journal of Chongqing University-English Edition(JCQU-E)is a peerreviewed journal publishing research articles in multiple disciplines of science and technology,covering civil and environmental engineering,chemical engineering,biotechnology,mechanical and electrical engineering,computer and data processing,mining,metallurgy,materials science,and interdisciplines thereof.