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91.
Since the early conceptual and practical demonstrations in the late 1990s, photonic crystal fibers (PCFs) have attracted considerable interest by virtue of their promise to deliver a unique range of optical properties that are simply not possible in standard fiber types. Hollow-core photonic band gap fiber has the potential to overcome some of the fundamental limitations of solid fiber as they also provide a unique medium for a range of light. PCF also be used as a unique optical material to make sensors due to the air-holes that can be filled with different materials (liquid, gas or even solid) to alter the difference of refractive index (RI) in the two modes, has been used in various sensing search fields. The application of PCF on physical quantities is discussed, and the recent results on temperature, magnetic, strain and vibration are reviewed. These developments demonstrate that the enlarged complexity and decreased accuracy of sensors offered by PCF make it useful in a wide range of engineering monitoring applications. 相似文献
92.
FU Xianwei LIU Yang LIU Zhi DONG Ning ZHAO Tianyu ZHAO Dan LIAN Gang WANG Qilong CUI Deliang 《高等学校化学研究》2018,34(1):95-100
Although organic semiconductors have attracted extensive interest and been utilized to fabricate a variety of optoelectronic devices, their electrical transportation characteristics under high pressure have rarely been investigated. However, the weak intermolecular interaction of organic semiconductors endows them with a pre- ssure-sensitive crystal structure and electrical transportation performance, especially the latter. Herein, a new pre- ssure-sensitive transistor was fabricated from an organic semiconductor 1,1'-dibutyl-4,4'-bipyridinium diiodide. It was found that this transistor exhibited increasing resistance as the pressure gradually increased and that it eventually shut off under a pressure of 288 MPa. Such a characteristic makes this organic semiconductor a potential candidate for the use in the fabrication of pressure-sensitive switches and regulators. In addition, these results shed light on the electrical performance of flexible organic optoelectronic devices working under high pressure levels resulted from the bending force. 相似文献
93.
Tianyu Cao Peidong Song Yixiang Shi Ahmed F. Ghoniem Ningsheng Cai 《Proceedings of the Combustion Institute》2019,37(3):2841-2848
A novel system based on the indirect oxy-combustion of coal in a liquid Sb anode solid oxide fuel cell (SOFC) has been used to produce electricity for over 48?h. Pulverized anthracite was fed to the liquid-antimony-anode of the fuel cell, and a peak power density of 47?mW cm?2 was reached at 1023?K and 35?mW cm?2 at 973?K. The fuel cell was prepared using a porous stainless-steel tube as a support for an LSM cathode, antimony oxide (Sb2O3)/yittria stabilized zirconia (YSZ, Y0.08Z0.92O1.96) composite electrolyte (membrane), while liquid antimony acted as the anode. Liquid antimony/antimony oxide served as the intermediate medium for coal oxidation producing mainly carbon dioxide, which evolved as a separate gas stream. The fuel cell will facilitate carbon capture process, and simultaneously convert the chemical energy of coal directly to electricity. The experiment showed that while the fabricated electrolyte was porous, it became dense during the actual operation, preventing nitrogen leakage into the Sb/C side and producing reasonable open circuit voltage. Analysis of the experimental EIS data illustrates that the Ohmic resistance was the primary loss mechanism in the system. It further suggests approaches to improve the design. Continuous operation of this coal fueled oxy-combustion/fuel cell system achieved an overall efficiency of 28.2% despite of its tiny scale. Simple technologies can be employed to scale up this system at relatively low cost of fabrication and materials. 相似文献
94.
Jiming Hu Tianyu Wang Damien Moigno Minawaer Wumaier Wolfgang Kiefer Jungang Mao Qiaofeng Wu Fei Niu Yinghong Gu Qingqi Chen Jinshi Ma Haitao Feng 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2001,57(14):2737-2743
The Fourier-transform Raman (FT-Raman), infrared (FT-IR), and UV-visible absorption spectra of four dipyrrinones and two mesobilirubins have been investigated in the solid state and in CH2Cl2 solutions. A detailed spectral analysis, assignment and discussion of these spectra are presented. The bands at 1735-1738, 1691-1707 and 1359-1377 cm(-1) which were assigned to the stretching vibrations of the C-O-C and C-O-H and symmetric deformation of C-H bonds, respectively, can act as a marker to distinguish the compounds of this class. The striking differences between the spectra of the compounds suggest that mesobilirubin XIIIalpha is tending to adopt as ridge-tile conformation, rather than linear conformation. 相似文献
95.
96.
通过原位共沉淀法可控制备了系列直接Z型MIL-100(Fe)/Bi OBr异质结。使用粉末X射线衍射(PXRD)、傅里叶红外变换(FTIR)光谱、紫外可见漫反射光谱(UV-Vis DRS)、扫描电镜(SEM)、高倍透射电镜(HRTEM)以及X射线光电子能谱(XPS)对MIL-100(Fe)/Bi OBr异质结晶体结构、微观形貌、光学性能、化学组成进行表征。以低功率发光二级管可见光为光源,探究了MIL-100(Fe)/Bi OBr异质结光芬顿降解磺胺甲恶唑(SMX)性能。最佳反应体系MB-7/Vis/H2O2(MB-7是MIL-100(Fe)质量为Bi OBr质量的70%时制备的样品)在光源照射70 min后可降解99.8%SMX(5 mg·L-1)。同时,还考察了H2O2浓度、催化剂投加量、p H值以及无机阴离子对MB-7/Vis/H2O2降解SMX影响。MB-7/Vis/H2O2能够在经过... 相似文献
97.
Kopaczyñska M Wang T Schulz A Dudic M Casnati A Sansone F Ungaro R Fuhrhop JH 《Langmuir : the ACS journal of surfaces and colloids》2005,21(18):8460-8465
A water soluble calixarene[4]arene 1 with four guanidinium substituents on the upper rim and propyl groups below was anchored in the propylamino coating of smooth silica particles, and a tricarboxylate-tripod porphyrin 2 of 2 nm height was attached to these cationic islands. The molecular complex with a height of 3 nm was unequivocally detected on the particles' surface by atomic force microscopy in the tapping mode. Although deposits of 1 (height: 1 nm) and 2 (height: 2 nm) were also evident on the smooth silica particles, 3 nm seems to be the minimal height to identify single objects. The soft surface of the particles not only allowed tight attachment of molecular edge amphiphiles by the hydrophobic effect but also immobilized the particles on the mica surface by amine-silicate interactions. 相似文献
98.
Li G Bhosale SV Wang T Hackbarth S Roeder B Siggel U Fuhrhop JH 《Journal of the American Chemical Society》2003,125(35):10693-10702
Smooth and nonswelling spherical silica particles with a diameter of 100 nm and an aminopropyl coating are soluble in water at pH 11, coagulate quickly at pH 3, and redissolve at pH 9. Electron microscopy as well as visible spectra of covalently attached porphyrins indicate the aggregation state of the particles. Long-chain alpha,omega-dicarboxylic acids with a terminal oligoethyleneglycol (=OEG)-amide group were attached in a second self-assembly step to the remaining amine groups around the porphyrins. Form-stable 2-nm wells were thus obtained and were characterized by fluorescence quenching experiments using the bottom porphyrin as a target. The one-dimensional diffusion of fitting quencher molecules along the 2-nm pathway took several minutes. Porphyrins with a diameter above 2 nm could not enter the form-stable gaps at all. Added tyrosine stuck irreversibly to the walls of the nanowells and prevented the entrance of quencher molecules, the OEG-headgroups fixated 2,6-diaminoanthraquinone. A ring of methylammonium groups was then fixed at the walls of the wells at a distance of 5 or 10 A with respect to the bottom porphyrin. 2,6-Disulfonatoanthraquinone was attached only loosely to this ring, but the exactly fitting manganese(III) meso-(tetraphenyl-4-sulfonato)porphyrinate (Mn(III) TPPS) was tightly bound. Transient fluorescence experiments showed a fast decay time of 0.2 ns for the bottom porphyrin, when the Mn(III) TPPS was fixated at a distance of 5 A. Two different dyes have thus been immobilized at a defined subnanometer distance in an aqueous medium. 相似文献
99.
Dr. Md Mokhlesur Rahman Irin Sultana Dr. Tianyu Yang Dr. Zhiqiang Chen Dr. Neeraj Sharma Dr. Alexey M. Glushenkov Prof. Ying Chen 《Angewandte Chemie (International ed. in English)》2016,55(52):16059-16063
A simple, cost‐effective, and easily scalable molten salt method for the preparation of Li2GeO3 as a new type of high‐performance anode for lithium‐ion batteries is reported. The Li2GeO3 exhibits a unique porous architecture consisting of micrometer‐sized clusters (secondary particles) composed of numerous nanoparticles (primary particles) and can be used directly without further carbon coating which is a common exercise for most electrode materials. The new anode displays superior cycling stability with a retained charge capacity of 725 mAh g?1 after 300 cycles at 50 mA g?1. The electrode also offers excellent rate capability with a capacity recovery of 810 mAh g?1 (94 % retention) after 35 cycles of ascending steps of current in the range of 25–800 mA g?1 and finally back to 25 mA g?1. This work emphasizes the importance of exploring new electrode materials without carbon coating as carbon‐coated materials demonstrate several drawbacks in full devices. Therefore, this study provides a method and a new type of anode with high reversibility and long cycle stability. 相似文献
100.
Xinxin Wang Xu Ding Yucheng Jin Dongdong Qi Hailong Wang Yuesheng Han Tianyu Wang Jianzhuang Jiang 《Angewandte Chemie (International ed. in English)》2023,62(18):e202302808
Rational regulation of electronic structures and functionalities of framework materials still remains challenging. Herein, reaction of 4,4′,4′′-nitrilo-tribenzhydrazide with tris(μ2-4-carboxaldehyde-pyrazolato-N,N′)-tricopper (Cu3Py3) generates the crystalline copper organic framework USTB-11(Cu). Post-modification with divalent nickel ions affords the heterometallic framework USTB-11(Cu,Ni). Powder X-ray diffraction and theoretical simulations reveal their two-dimensional hexagonal structure geometry. A series of advanced spectroscopic techniques disclose the mixed CuI/CuII state nature of Cu3Py3 in USTB-11(Cu,Ni) with a uniform bistable Cu34+(CuI2CuII) : Cu35+(CuICuII2) (ca. 1 : 3) oxidation state, resulting in a significantly improved formation efficiency of the charge-separation state. This endows the Ni sites with enhanced activity and USTB-11(Cu,Ni) with outstanding photocatalytic CO2 to CO performance with a conversion rate of 22 130 μmol g−1 h−1 and selectivity of 98 %. 相似文献