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1.
采用D113离子交换树脂与Ni2 、Fe2 交换后形成含金属的Fe-Ni/D113前驱体,经热解制备碳包裹纳米FeNi合金粒子。TG分析表明,Fe-Ni/D113的热稳定性要强于D113。XRD、TEM测试结果表明,在400、500、600和700℃热解Fe-Ni/D113均可获得碳包裹纳米FeNi合金粒子,而且纳米FeNi合金粒子的粒径随热解温度的升高而增大。室温磁性能测试结果表明,400℃热解产物具有超顺磁特性,500、600和700℃热解产物的矫顽力Hc均远大于相应的块体金属,并与产物中纳米FeNi合金粒子的尺寸有关;所有热解产物比饱和磁化强度Ms小于相应的块体材料,并随其中纳米合金粒子尺寸的增大而增加。 相似文献
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功能化磁性纳米粒子因其独特的理化性质,在乳状液制备与破乳领域的应用受到广泛关注。本文归纳了功能化磁性纳米粒子的制备方法、合成结构与特征性质,阐述了其在乳状液制备及破乳中的应用过程,重点分析了磁性纳米粒子在溶液中良好分散、稳定吸附于油水界面排布为膜结构的作用行为,尤其是磁性纳米粒子的磁响应特征对乳状液中界面性质、液滴形貌及运动状态的影响,并进一步总结出其表面性质及作用行为对稳定乳状液或使乳状液破乳的规律。针对磁性纳米粒子对乳状液稳定性影响规律的探究可为其在应用领域提供理论支持。最后本文就功能化磁性纳米粒子研究中亟待解决的新问题作出展望。 相似文献
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采用脉冲激光轰击浸于流动乙醇中转动的FeNi合金固体靶连续制备得到纳米FeNi乙醇溶胶及其纳米合金. 能谱扫描测得纳米FeNi合金粒子Fe与Ni元素重量比约为66︰34; TEM观察纳米FeNi粒子初始粒径约为1~5 nm, 并随放置时间延长聚集长大; XRD显示纳米FeNi合金基本为非晶态; 荧光光谱发现纳米FeNi合金溶胶在311.00 nm处有一强的激发峰以及在273.00和347.00 nm处的二个弱激发峰, 以311.00 nm作为激发波长得到位于418.00 nm处的一强荧光光谱峰; UV-vis表明纳米FeNi合金溶胶在230.00 nm左右有一个含有一组可分辨的9个细峰的强吸收峰和一个位于275.00 nm处的弱激子吸收峰; FT-IR发现纳米FeNi/乙醇溶胶中乙醇缔合态羟基的伸缩振动吸收峰(υO-H)明显蓝移, 并且证实获得的纳米FeNi合金粒子表面在制备过程中为乙醇裂解产生的碳氢有机基团所修饰. 相似文献
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石墨炔纳米材料的制备与应用是石墨炔材料研究的重要方向, 通过对其纳米结构进行设计与优化, 可以提高石墨炔材料及其杂化结构的性能, 拓展其在能源储存与转换领域的应用. 本综述介绍了不同形貌和结构的石墨炔基纳米材料, 如纳米墙、 纳米片、 纳米薄膜等结构. 阐述了不同结构特征的石墨炔基纳米材料在电化学储能器件以及电化学能源催化中的应用, 同时也探讨了石墨炔不同纳米形貌和结构在能源应用领域快速发展的机遇及所面临的挑战. 相似文献
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由于纳米材料具有的独特物理效应,使纳米材料的荧光性能与纳米颗粒的结构、尺寸和形貌等微观特征密切相关,成为当前研究的热点领域.本论文以纳米荧光材料的可控制备技术作为研究重点,结合当前的应用发展趋势,从几个不同的角度制备了几种具有不同微观结构特征的新型纳米荧光及其复合材料,探索了一些新的方法和新的材料,并对其性能进行了表征,主要工作成果如下: 相似文献
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锂离子电池纳米正极材料 总被引:4,自引:0,他引:4
综述了锂离子电池纳米正极材料的研究进展,阐述了这种材料用于锂离子电池的优势和存在的问题,把纳米正极材料分为过渡金属嵌锂化合物、金属氧化物和金属硫化物和其它纳米正极材料。归纳了不同纳米正极材料的主要制备方法,探讨了材料的制备方法与其结构、形貌和电化学性能之间的关系,展望了纳米正极材料用于锂离子电池的未来前景。 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
18.
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL. 相似文献
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A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions. 相似文献