排序方式: 共有35条查询结果,搜索用时 15 毫秒
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采用溶剂热法制备出具有尺寸可调、分散性好、亲水性和超顺磁性的亚微米Fe3O4磁球,并考察了不同表面活性剂、反应时间和反应温度的影响。分别采用XRD、FE-SEM、FTIR、超导量子干涉仪(SQUID)对其结构、形貌、表面性质及磁性进行了表征。结果表明,产物为立方结构、具有单分散性的Fe3O4亚微米球,粒径在140~360nm可调。所得Fe3O4亚微米球在室温条件下的磁滞回线表现出超顺磁性,矫顽力为零。不同表面活性剂对粒径大小和磁饱和强度有一定的影响,但对其形貌和晶相结构无影响。随着反应时间的延长和反应温度的提高,颗粒粒径有逐渐减小的趋势。 相似文献
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通过水热合成法,合成了4,4′-联吡啶多钼酸盐((4,4′-bipyridine)Mo7O22·H2O)单晶超分子化合物.通过元素分析、热重-差热分析(TG-DTA)、粉末X射线衍射(XRD)、单晶X射线衍射、傅里叶变换红外(FTIR)光谱、紫外-可见漫反射光谱(UV-VisDRS)和电子自旋共振(ESR)技术对其组成、热稳定性、结构、光谱和电子特性进行了表征.实验结果表明:该超分子化合物的分子式为C10H12Mo7N2O23,在空气中320℃以下不分解.属于单斜晶系(空间群为P2/n),晶胞参数为a=1.22561(19)nm,b=0.55222(9)nm,c=1.8385(3)nm,β=103.221(2)°,V=1.2113(3)nm3,Z=2和Dc=3.289g·cm-3.基于F2的最终统计:GOF=0.982,R1=0.0228和wR2=0.0557(I2σ(I)).该单晶超分子化合物由质子化的4,4′-联吡啶阳离子和多金属钼酸盐阴离子[Mo7O22]2-及结晶水组成.它们通过氢键、静电引力和分子间作用力结合在一起的,并构成二维网络结构.样品在光照或加热条件下具有光致变色和热致变色性质.XRD和FTIR证明,变色前后,样品的结构除轻微的畸变外几乎没有变化;而ESR结果表明,光致变色与热致变色的机理可能存在差别.该光致和热致变色的超分子化合物能够为变色机理研究提供参考模型,并在传感器和光敏材料等领域具有潜在应用. 相似文献
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Cheng G Zhang JL Liu YL Sun DH Ni JZ 《Chemical communications (Cambridge, England)》2011,47(20):5732-5734
Fe(3)O(4)@SiO(2)@CeO(2) microspheres with magnetic core and mesoporous shell were synthesized, and the multifunctional materials were utilized to capture phosphopeptides and catalyze the dephosphorylation simultaneously, thereby labeling the phosphopeptides for rapid identification. 相似文献
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De-Hui Guan Xiao-Xue Wang Ma-Lin Li Fei Li Li-Jun Zheng Prof. Xiao-Lei Huang Prof. Ji-Jing Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(44):19686-19692
A photoinduced flexible Li-CO2 battery with well-designed, hierarchical porous, and free-standing In2S3@CNT/SS (ICS) as a bifunctional photoelectrode to accelerate both the CO2 reduction and evolution reactions (CDRR and CDER) is presented. The photoinduced Li-CO2 battery achieved a record-high discharge voltage of 3.14 V, surpassing the thermodynamic limit of 2.80 V, and an ultra-low charge voltage of 3.20 V, achieving a round trip efficiency of 98.1 %, which is the highest value ever reported (<80 %) so far. These excellent properties can be ascribed to the hierarchical porous and free-standing structure of ICS, as well as the key role of photogenerated electrons and holes during discharging and charging processes. A mechanism is proposed for pre-activating CO2 by reducing In3+ to In+ under light illumination. The mechanism of the bifunctional light-assisted process provides insight into photoinduced Li-CO2 batteries and contributes to resolving the major setbacks of the system. 相似文献
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Shao-Ming Chi Yu-Fei Wang Xin Gan De-Hui Wang Wen-Fu Fu 《Central European Journal of Chemistry》2009,7(4):923-928
A new ligand napaa (napaa = 7-acetamido-4-methyl-1,8-naphthyridin-2-carbaldehyde azine) and its two dinuclear copper(I) complexes,
Cu2(napaa)(dppe)2(ClO4)2 (1) and Cu2(napaa)(PPh3)4(BF4)2 (2) (dppe = 1,2-bis(diphenylphosphino)ethane) and PPh3 = triphenylphosphine) were synthesized and characterized, and the structure of 1 was determined by X-ray crystal analysis. Each copper atom in 1 has a distorted tetrahedral geometry in which the metal center is associated to napaa and dppe ligands displaying chelating
coordination modes and the naphthyridine rings of napaa are almost coplanar. The two complexes exhibit similar electronic
absorption spectra with λmax at about 366 nm, which can be tentatively assigned to metal-to-ligand charge-transfer (MLCT) transition. The assignment was
further supported by density functional theory (DFT) calculations.
相似文献
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New generating function formulae of even- and odd-Hermite polynomials obtained and applied in the context of quantum optics
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By combining the operator Hermite polynomial method and the technique of integration within an ordered product of operators, for the first time we derive the generating function of even- and odd-Hermite polynomials which will be useful in constructing new optical field states. We then show that the squeezed state and photon-added squeezed state can be expressed by even- and odd-Hermite polynomials. 相似文献
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De-Hui Tuo Chao Chen Huapeng Ruan Prof. Dr. Qi-Qiang Wang Dr. Yu-Fei Ao Prof. Dr. Xinping Wang Prof. Dr. De-Xian Wang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(33):14144-14147
Radical pimers are the simplest and most important models for studying charge-transfer processes and provide deep insight into π-stacked organic materials. Notably, radical pimer systems with magnetic bi- or multistability may have important applications in switchable materials, thermal sensors, and information-storage media. However, no such systems have been reported. Herein, we describe a new pimer consisting of neutral N-(n-propyl) benzene triimide ([BTI-3C]) and its anionic radical ([BTI-3C]−.) that exhibits rare magnetic multistability. The crystalline pimer was readily synthesized by reduction of BTI-3C with cobaltocene (CoCp2). The transition occurred with a thermal hysteresis loop that was 27 K wide in the range of 170–220 K, accompanied by a smaller loop with a width of 25 K at 220–242 K. The magnetic multistability was attributed to slippage of the π-stacked BTI structures and entropy-driven conformational isomerization of the side propyl chains in the crystalline state during temperature variation. 相似文献
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De-Hui Han 《European Polymer Journal》2006,42(3):507-515
The amphiphilic π-shaped copolymers with narrow molecular weight distribution (Mw/Mn = 1.04-1.09) based on polystyrene (PSt) and poly(ethylene glycol) have been synthesized successfully. The reversible addition-fragmentation transfer (RAFT) polymerization of St in the presence of dibenzyl trithiocarbonate and N,N′-azobis(isobutyronitrile) (AIBN) yielded macro RAFT agent PSt-SC(S)S-PSt, subsequent reaction with excess maleic anhydride (MAh) at 80 °C in tetrahydrofuran afforded the PSt-MAh-SC(S)S-MAh-PSt. It was used as RAFT agent in the RAFT polymerization of St, and finally the amphiphilic π-shaped copolymers were obtained by the reaction of MAh with hydroxyl-terminated poly(ethylene glycol methyl ether) at 90 °C for 48 h. Their structures were confirmed by FT-IR and 1H NMR spectra, and their molecular weight and molecular weight distribution were measured by gel permeation chromatography. 相似文献