Li J.-S.,China Jiliang University
Optics Express | Year: 2017
We present a terahertz wave switch utilizing Kretschmann configuration which consists of high-refractive-index prism-liquid crystal-periodically grooved metal grating. The switching mechanism of the terahertz switch is based on spoof surface plasmon polariton (SSPP) excitation in the attenuated total reflection regime by changing the liquid crystal refractive index. The results highlighted the fact that the feasibility to “tune” the attenuated total reflection terahertz wave intensity by using the external applied bias voltage. The extinction ratio of the terahertz switch reaches 31.48dB. The terahertz switch has good control ability and flexibility, and can be used in potential terahertz free space device systems. © 2017 Optical Society of America.
Du Y.,China Jiliang University |
Xue J.,Zhejiang Sci-Tech University
Current Pharmaceutical Design | Year: 2016
Active pharmaceutical ingredients (APIs) can exist in various types of crystalline forms including polymorphs and cocrystals. These multiple crystalline forms of APIs have district physical and physicochemical characteristics. Vibrational spectroscopic techniques used in solid-state pharmaceutical analysis include mid-infrared, Raman and terahertz spectroscopy. In this review, we will focus on the recent vibrational spectroscopic investigation on the polymorphism and cocrystallization of APIs in pharmaceutical fields. The distinctive spectral and structural information of pharmaceutical polymorphs and cocrystals could be obtained based on these vibrational spectroscopic techniques. © 2016 Bentham Science Publishers.
Albert J.,Carleton University |
Shao L.-Y.,China Jiliang University |
Caucheteur C.,University of Mons
Laser and Photonics Reviews | Year: 2013
Optical fiber gratings have developed into a mature technology with a wide range of applications in various areas, including physical sensing for temperature, strain, acoustic waves and pressure. All of these applications rely on the perturbation of the period or refractive index of a grating inscribed in the fiber core as a transducing mechanism between a quantity to be measured and the optical spectral response of the fiber grating. This paper presents a relatively recent variant of the fiber grating concept, whereby a small tilt of the grating fringes causes coupling of the optical power from the core mode into a multitude of cladding modes, each with its own wavevector and mode field shape. The main consequence of doing so is that the differential response of the modes can then be used to multiply the sensing modalities available for a single fiber grating and also to increase the sensor resolution by taking advantage of the large amount of data available. In particular, the temperature cross-sensitivity and power source fluctuation noise inherent in all fiber grating designs can be completely eliminated by referencing all the spectral measurements to the wavelength and power level of the core mode back-reflection. The mode resonances have a quality factor of 105, and they can be observed in reflection or transmission. A thorough review of experimental and theoretical results will show that tilted fiber Bragg gratings can be used for high resolution refractometry, surface plasmon resonance applications, and multiparameter physical sensing (strain, vibration, curvature, and temperature). © 2012 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Chen D.,Tsinghua University |
Chen D.,China Jiliang University |
Feng H.,Tsinghua University |
Li J.,Tsinghua University
Chemical Reviews | Year: 2012
Graphene, which consists of a one-atom-thick planar sheet comprising an sp-bonded carbon structure with exceptionally high crystal and electronic quality, is a novel material that has emerged as a rapidly rising star in the field of material science. Facile electron transfer between graphene and redox species opens up opportunities for sensing strategies based on direct electron transfer rather than mediation. It is not surprising, therefore, that graphene has recently attracted great attention worldwide from the electrochemical community. Despite its short history, this 2D material has already revealed potential applications in electrochemistry, and remarkably rapid progress in this area has already been made. The oxygen functional groups have been identified as mostly in the form of hydroxyl and epoxy groups on the basal plane, with smaller amounts of carboxy, carbonyl, phenol, lactone, and quinone at the sheet edges.
Chen D.,Tsinghua University |
Chen D.,China Jiliang University |
Tang L.,Tsinghua University |
Li J.,Tsinghua University
Chemical Society Reviews | Year: 2010
Graphene, as the fundamental 2D carbon structure with exceptionally high crystal and electronic quality, has emerged as a rapidly rising star in the field of material science. Its sudden discovery in 2004 led to an explosion of interest in the study of graphene with respect to its unique physical, chemical, and mechanical properties, opening up a new research area for materials science and condensed-matter physics, and aiming for wide-ranging and diversified technological applications. In this critical review, we will describe recent advances in the development of graphene-based materials from the standpoint of electrochemistry. To begin with, electron transfer properties of graphene will be discussed, involving its unusual electronic structure, extraordinary electronic properties and fascinating electron transport. The next major section deals with the exciting progress related to graphene-based materials in electrochemistry since 2004, including electrochemical sensing, electrochemiluminescence, electrocatalysis, electrochemical energy conversion and FET devices. Finally, prospects and further developments in this exciting field of graphene-based materials are also suggested (224 references). © 2010 The Royal Society of Chemistry.
Li J.,China Jiliang University
Optics Communications | Year: 2010
We designed a narrow bandpass terahertz wave filter using photonic crystals with a line defect. An inserted linear defect in one-dimensional photonic crystal structures for a channeled filtering in the terahertz range are studied and designed theoretically. By using transfer matrix method, we examined the transmittance spectra for the proposed terahertz wave filter has a 3 dB transmission loss bandwidth of 20 MHz ranging from 0.29998 THz to 0.30001 THz. The simulated results show that a very narrow transmission band and high transmission (higher than 99.99%) centered at λ0, and very sharp edges can be achieved. © 2010 Elsevier B.V. All rights reserved.
China Jiliang University | Date: 2012-04-27
A siphon drainage type rainfall remote measurement device with self-compensation function is provided. The bottom existence of a rain collection barrel (2) is connected via a flexible tube (14) to the bottom of a rainfall measuring tube (13) to which a siphon (5) is attached. The tube (13) and a measurement instrument (6) are installed on a holding frame (9). The instrument (6) is connected to a pressure sensor (12) and an accumulator (11) at the bottom of the tube (13). The whole device is fixed in an outer barrel (1). According to the pressure of the bottom of the tube (13), the sensor (12) measures the height of the water level in the tube (13) which is directly proportional to the rainfall. The sensor (12) signal processed by the instrument (6) is transformed into the rainfall, processed by a compensation algorithm and sent by GSM or GPRS.
China Jiliang University | Date: 2014-09-24
This invention discloses a parallel spiral transmission line structure sensing cable for rock and soil deformation distributed measurement. A circular cross-section silicone rubber is tightly wounded by two insulated wires. The two insulated wires make the spiral cable. Out of the spiral cable is the silicone rubber pipe). They constitute a sensing cable. A termination matching impedance ZL is connected to one end of the two wires. TDR measurement instrument is connected to the other end of the two wires. This invention implements a distributed positioning and measuring rock and sail deformation. It solves the dilemma of measuring at unchanged and the changed is not measured in the landslides, ground subsidence and other geotechnical deformation monitoring. It provides good tool for distributed deformation measurement.
China Jiliang University | Date: 2012-09-19
A method and apparatus for remote siphon drainage type rainfull measurement with self-compensation function are provided. The exit in the bottom of the water butt (2) is connected to the bottom of the rainfall measuring tube (13) by the water hose (14). The siphon (5) is in the wall of the rainfall measuring tube (13). The rainfall measuring tube (13) and measuring device (6) are installed on the support bracket (9). The measuring device (6) is connected with the pressure sensor (12) installed in the bottom of rainfall measuring tube (13) and battery (11). The whole apparatus is installed in the outer barrel (1). According to the pressure of the bottom of the rainfall measuring tube (13), pressure sensor (12) can measure the height of the water level of the rainfall measuring tube (13). The height of the water level is in proportional to the rainfall. The signal of the pressure sensor (12) is processed by the measuring device (6), converted into rainfall, then processed by compensation algorithm and at last sent via GSM or GPRS.
China Jiliang University | Date: 2012-11-13
This present disclosure provides a sensing cable of parallel spiral transmission line structure for distributed sensing and measuring of rock-soil mass deformation. A circular cross-section of a silicone strip is tightly wounded by two mutually-insulated wires. The two mutually-insulated wires form the spiral cable. The two mutually-insulated wires are wrapped around and covered by a silicone shroud. They constitute a sensing cable. A termination matching impedance is connected to one end of each of the two mutually-insulated wires. A time domain reflectometry measurement instrument is connected to the other end of the two mutually-insulated wires. The present disclosure implements a distributed positioning and measurement of rock-soil mass deformation.