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121.
A universal and straightforward method for the preparation of polymer brushes via the formation of Si-C bond on silicon substrates through the UV-induced photopolymerization is demonstrated. 相似文献
122.
Yuan-Guo Wu Xing-Bao Zhu Wei-Hua Wan Zi-Ning Man Yu Wang Zhe Lü 《Advanced functional materials》2021,31(49):2105664
Modern technology constantly requires smaller, more efficient lithium–oxygen batteries (LOBs). To meet this need, a chemical vapor deposition (CVD) method is used to create an innovative cathode design with both a hierarchical porous nanostructure and a 3D flexible macroscopical morphology. This method employs architectural optimization to further improve cathodic ORR and OER performance via heteroatom doping, surface-sprouted carbon nanofibers (CNFs) grafting, and boundary exposing. The cathode consists of a 3D hierarchical porous graphene foam (PGF), along with RuO2 nanoparticles impregnated and nitrogen doped CNFs (RuO2@NCNFs), where the PGF serves as a structural support and cathodic current collector, and the RuO2@NCNFs work as a superior bi-functional catalyst. The cathode delivers an outstanding discharge capacity of 8440 mAh gcathode−1 while maintaining a recharge plateau at ≈4.0 V, and can cycle for over 700 rounds without obvious degeneration under a fixed capacity. Notably, this free-standing cathode can be directly used in LOBs without the need for additional substrates or current collectors. Therefore, the current densities and capacities herein are calculated based on the total weight of the cathodes. These results demonstrate the RuO2@NCNFs-PGF cathode's remarkable potential for LOB applications, and this rational cathodic structure may be extended to other highly efficient catalyst applications. 相似文献
123.
基于数值仿真计算和微波网络理论,提出了一种多层介质中频率选择表面(FSS)等效电路的分析方法.该方法物理过程直观,计算量小,适用于二维任意形状FSS等效电路的精确求解.以方形贴片型FSS为例验证了等效电路模型的准确性,并分析了多层介质对其等效电路参数的影响规律.最后,基于滤波器理论与FSS等效电路模型设计了双层带通型FSS,计算结果表明全波仿真结果与理论计算结果基本一致,为多层FSS的综合设计提供了一种精确设计方法. 相似文献
124.
A Patterned Graphene/ZnO UV Sensor Driven by Integrated Asymmetric Micro‐Supercapacitors on a Liquid Metal Patterned Foldable Paper 下载免费PDF全文
Junyeong Yun Yein Lim Hanchan Lee Geumbee Lee Heun Park Soo Yeong Hong Sang Woo Jin Yong Hui Lee Sang‐Soo Lee Jeong Sook Ha 《Advanced functional materials》2017,27(30)
A foldable array of patterned graphene/ZnO nanoparticle UV sensor and asymmetric micro‐supercapacitors (AMSCs) integrated on a paper substrate with patterned liquid metal interconnections is reported. The resistor type UV sensor based on graphene/ZnO nanoparticles is patterned to be driven by the stored energy of the integrated AMSCs. The AMSC consists of MnO2 nanoball deposited multiwalled carbon nanotubes (MWNTs) and V2O5 wrapped MWNTs as positive and negative electrodes, respectively. As an electrolyte, propylene carbonate‐poly(methyl methacrylate)‐LiClO4, an organic solvent‐based gel, is used. The UV sensor and AMSCs can be easily integrated on a liquid metal, Galinstan, patterned, waterproof mineral paper and show a mechanically stable UV sensing, regardless of repetitive folding cycles. This work demonstrates a novel foldable nanomaterial based sensor system driven by integrated energy storage devices, applicable to future wearable and portable electronics. 相似文献
125.
Ali Reza MahjoubMohammad Zaman Kassaee 《Tetrahedron letters》2003,44(24):4555-4557
Tetramethylammonium fluorochromate(VI), (CH3)4N+CrO3F− (TMAFC), was prepared and used for quantitative oxidation of several organic substrates. This new compound is more efficient and has certain advantages over similar oxidizing agents in terms of the amount of oxidant and solvent required, short reaction times and high yields. 相似文献
126.
127.
S. Dakshina Murthy I. B. Bhat B. Johs S. Pittal P. He 《Journal of Electronic Materials》1995,24(5):445-449
A multi-wavelengthinsitu spectroscopic ellipsometer system is described. The hardware can acquire accurate ellipsometric data at 44 wavelengths in
less than one second, is simple and compact, and is well suited forin-situ monitoring of chemical vapor deposition. The software used for data analysis is capable of determining the growth rate and
composition of the growing layer in real time. These tools were used to study the organometallic chemical vapor deposition
of CdTe, HgTe, and HgCdTe on GaAs. We could obtain the dielectric constants of these materials at the growth temperature and
also the growth rate and composition of the layers in real time. Feedback control of CdTe growth was performed by connecting
an analog control voltage line from the data acquisition/ analysis computer to the dimethylcadmium mass flow controller. Using
dielectric constants of HgCdTe for two different compositions at the growth temperature, composition control of HgCdTe was
attempted in a similar manner. 相似文献
128.
用MOCVD技术在高阻6H-SiC衬底上研制出了具有高迁移率GaN沟道层的AlGaN/AlN/GaN高电子迁移率晶体管(HEMT)结构材料,其室温和80K时二维电子气迁移率分别为1944和11588cm2/(V·s),相应二维电子气浓度为1.03×1013cm-2;三晶X射线衍射和原子力显微镜分析表明该材料具有良好的晶体质量和表面形貌,10μm×10μm样品的表面粗糙度为0.27nm.用此材料研制出了栅长为0.8μm,栅宽为1.2mm的HEMT器件,最大漏极饱和电流密度和非本征跨导分别为957mA/mm和267mS/mm. 相似文献
129.
Ferroelectric BaTiO3 thin films were deposited on single crystal Si substrates by radio-frequency magnetron sputtering. Bilayer structures of
BaTiO3 thin films, either amorphous on polycrystalline (A/P) or polycrystalline on microcrystalline (P/M), were utilized to reduce
the leakage current and to enhance the dielectric constant of the films compared to single polycrystalline and amorphous layer
structures, respectively. Relatively lower charge density, determined by the capacitance-voltage measurement on the capacitors
with a configuration of Au/ BaTiO/p-Si/Al, was detected for the BaTiO3 thin film with a structure of P/M. The current-voltage characteristics of the Al/SiO2(~1.8 nm)/p-Si/Al diodes fabricated on the Si after removing BaTiO3 layers gave direct evidence of the preservation of the Si surface crystal by using a P/M instead of a A/P structure. This
was further confirmed by the Auger electron spectroscopy analysis on the samples. 相似文献
130.
Gerd Grau Rungrot Kitsomboonloha Sarah L. Swisher Hongki Kang Vivek Subramanian 《Advanced functional materials》2014,24(32):5067-5074
The integration of fully printed transistors on low cost paper substrates compatible with roll‐to‐roll processes is demonstrated here. Printed electronics promises to enable a range of technologies on paper including printed sensors, RF tags, and displays. However, progress has been slow due to the paper roughness and ink absorption. This is solved here by employing gravure printing to print local smoothing pads that also act as an absorption barrier. This innovative local smoothing process retains desirable paper properties such as foldability, breathability, and biodegradability outside of electronically active areas. Atomic force microscopy measurements show significant improvements in roughness. The polymer ink and printing parameters are optimized to minimize ink absorption and printing artifacts when printing the smoothing layer. Organic thin film transistors (OTFT) are fabricated on top of this locally smoothed paper. OTFTs exhibit performance on par with previously reported printed transistors on plastic utilizing the same materials system (pBTTT semiconductor, poly‐4‐vinylphenol dielectric). OTFTs deliver saturation mobility approaching 0.1 cm2V–1s–1 and on‐off‐ratio of 3.2 × 104. This attests to the quality of the local smoothing, and points to a promising path for realizing electronics on paper. 相似文献