Advances in Tongue Diagnosis Objectification of Traditional Chinese Medicine

Tongue diagnosis is a non-invasive,efficient,and accurate method for determining a person’s physical condition,and plays an essential role in disease diagnosis and health management.However,tongue diagnosis is easily influenced by the subjective experience of the practitioner and the light environment.In addition,tongue diagnosis lacks clear quantitative indicators and objective records.This all limits the transmission and development of tongue diagnosis.Therefore,the acquisition and analysis of tongue information using image equipment,image processing and computer vision have become a hot research topic for the objectification of tongue diagnosis.This paper reviews the research progress of tongue diagnosis objectification in Traditional Chinese medicine.The tongue image acquisition,color correction,segmentation,feature extraction and analysis,and disease prediction included in the study of tongue diagnosis objectification are reviewed.The shortcomings of current automated tongue diagnosis systems and future research ideas are also summarized to provide a reference for further development of tongue diagnosis objectification.

Fully sprayed MXene-based high-performance flexible piezoresistive sensor for image recognition

High-performance flexible pressure sensors provide comprehensive tactile perception and are applied in human activity monitoring,soft robotics,medical treatment,and human-computer interface.However,these flexible pressure sensors require extensive nano-architectural design and complicated manufacturing and are timeconsuming.Herein,a highly sensitive,flexible piezoresistive tactile sensor is designed and fabricated,consisting of three main parts:the randomly distributed microstructure on T-ZnOw/PDMS film as a top substrate,multilayer Ti_(3)C_(2)-MXene film as an intermediate conductive filler,and the few-layer Ti_(3)C_(2)-MXene nanosheetbased interdigital electrodes as the bottom substrate.The MXene-based piezoresistive sensor with randomly distributed microstructure exhibits a high sensitivity over a broad pressure range(less than 10 kPa for 175 kPa^(-1))and possesses an out-standing permanence of up to 5000 cycles.Moreover,a 16-pixel sensor array is designed,and its potential applications in visualizing pressure distribution and an example of tactile feedback are demonstrated.This fully sprayed MXene-based pressure sensor,with high sensitivity and excellent durability,can be widely used in,electronic skin,intelligent robots,and many other emerging technologies.

A Novel Method for Heightening Sensitivity of Prism Coupler-Based SPR Sensor

We present a novel method for heightening the sensitivity of a prism coupler-based surface plasmon resonance(SPR)sensor.The method is based on the total reflection prism made of BK7 glass combined with the Kretschmann geometry of theattenuated total reflection(ATR)method.Compared to the conventional methods of prism coupler-based SPR,the novel method provides higher sensitivity to the measurement system.Theoretical simulations show that the detection sensitivity to the refractive index(RI)of the sensor based on the novel approach has a strong dependence on the thickness of the metal layer.The RI resolution of the sensor is predicted to be 8×10^(-7)refractive index units(RIU)under the condition of optimum metal film thickness.This novel method can leave out a precision angle rotation device in the angle modulation and it is unnecessary to adjust the acceptance angle of the light detector.The principal advantage of this method over other methods of light intensity modulation based on prism coupler-based SPR is high sensitivity,expediency to measure and application of long distances.

Adsorption of Methyl Orange on Magnetically Separable Mesoporous Titania Nanocomposite

The adsorption of mesoporous Fe3O4–SiO2–TiO2(MFST), which can be separated easily from solution by a magnet, for the removal of methyl orange(MO) was investigated. The nitrogen adsorption–desorption measurement shows successful synthesis of MFST with an average pore size of 3.8 nm and a large specific surface area of55 m2·g-1. About 95% adsorption percentage of MO is achieved with an initial concentration of 10 mg·L-1in the dark and the MFST exhibits superior adsorption ability under acid conditions. The adsorption data fit well with the pseudo-second order model for adsorption. After 4 cycles, the adsorption rate for MO remains 74% in the dark and the MFST can be recovered in a magnetic field with a recovery of about 80 %(by mass). It demonstrates that the samples have significant value on applications of wastewater treatment.

Wireless contactless pressure measurement of an LC passive pressure sensor with a novel antenna for high-temperature applications

In this paper, a novel antenna is proposed for high-temperature testing, which can make the high-temperature pressure characteristics of a wireless passive ceramic pressure sensor demonstrated at up to a temperature of 600℃. The design parameters of the antenna are similar to those of the sensor, which will increase the coupling strength between the sensor and testing antenna. The antenna is fabricated in thick film integrated technology, and the properties of the alumina ceramic and silver ensure the feasibility of the antenna in high-temperature environments. The sensor, coupled with the ceramic antenna, is investigated using a high-temperature pressure testing platform. The experimental measurement results show that the pressure signal in a harsh environment can be detected by the frequency diversity of the sensor.

A method of line spectrum extraction based on target radiated spectrum feature and its post-processing

To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum that the high intense and stable line spectrum is superimposed on the wide continuous spectrum.This method modifies the traditional beam forming algorithm by calculating and fusing the beam forming results at multi-frequency band and multi-azimuth interval,showing an excellent way to extract the line spectrum when the interference and the target are not in the same azimuth interval simultaneously.Statistical efficiency of the estimated azimuth variance and corresponding power of the line spectrum band depends on the line spectra ratio(LSR)of the line spectrum.The change laws of the output signal to noise ratio(SNR)with the LSR,the input SNR,the integration time and the filtering bandwidth of different algorithms bring the selection principle of the critical LSR.As the basis,the detection gain of wideband energy integration and the narrowband line spectrum algorithm are theoretically analyzed.The simulation detection gain demonstrates a good match with the theoretical model.The application conditions of all methods are verified by the receiver operating characteristic(ROC)curve and experimental data from Qiandao Lake.In fact,combining the two methods for target detection reduces the missed detection rate.The proposed post-processing method in2-dimension with the Kalman filter in the time dimension and the background equalization algorithm in the azimuth dimension makes use of the strong correlation between adjacent frames,could further remove background fluctuation and improve the display effect.

Analysis and compensation of low frequency characteristics of sensors for vibration testing

In view of the influence and harm of low frequency vibration environment on the structure of spaceflight products,a low frequency dynamic study method for piezoelectric sensor based on the dynamic system of sinusoidal pressure is proposed.This method uses a sinusoidal pressure dynamic system with two-way dual channel import and export synchronization technology to study the low frequency characteristics of a piezoelectric sensor of PCB company,and its lower cut-off frequency is 0.26 Hz.It is also studied that when the frequency of the measured vibration or shock signal is 1-200 kHz,the error range of signal positive pressure action time is 4.87%-0.03%.The dynamic compensation for the low frequency of the vibration sensor is carried out,and the compensation effect is good.

An improved crossbar array of memristor

This paper conducts an analysis of HP model of a memristor and memory cells of a differential type memristor,formsa classic array of the memristor using the HP model,and does the stimulation of its storage capacity.Based on differential typememristor cells,this paper proposes an improved crossbar array of the memristor,which can be applied in image storage.Bymeans of theoretical analysis and stimulation,this improved crossbar array of memristor has been proved to have bettergrayscale image storage capacity,and its peak signal-to-noise ratio(PSNR)has been improved by about30%.

Acoustic multipolar local effects of metamaterial with annular columnar structures

Research of the acoustic local effect of metamaterial is widely used in the fields of environmental science,military industry and biomedicine.In this paper,the metamaterial is designed by annular columnar structures.The acoustic local effect in slender columnar structure with two layers of rings in air is investigated.Results prove that when the plane acoustic wave is incident into the model,complex interference and diffraction occur.And at different frequencies,multipolar acoustic local effect existes and cycle distribution phenomenon is observed.It is noteworthy that this phenomenon has very weak relatedness with the materials and acoustic parameters of the model.The research of this metamaterial design in this paper has definite reference significance in the acoustic communication and amplification of the acoustic signal detection.

Error modeling and analysis of inclinometer based on digital accelerometer

Measuring accuracy of inclinometer based on accelerometer is mainly influenced by the adopted accelerometer sensor.To improve the measuring accuracy of the inclinometer,the structure of the measuring system is given and measuring principle is analyzed,and the error model is established in this paper.Furthermore,the model is verified by simulation and experiment,which not only gives the smallest errors of the measured pitch and roll,but also lays foundation for sensor selection,error analysis and error compensation.The results show that the error model is of practical value.

Analysis of errors induced by λ/4 wave plate in fiber-optic current sensor system

1/4λ wave plate is a key element in the fiber-optic current sensor system. When a retardation error or an orientation error of birefringence axes of 1/4λ wave plate with respect to the hi-bi fiber axes occurs in the 1/4λ wave plate, the sensor system will output a wrong result of the measured current. The contributions of these two errors to the final result of the whole system were studied and the errors functions were deduced by establishing the measurement function of the current sensor system with Jones matrixes of the optical elements. The results show that that the greater the orientation error or the retardation error, the larger the final error, and that these two errors cannot be compensated each other.

Pressure effect study on the Ⅰ-Ⅴ property of the GaAs-based resonant tunnelling structure by photoluminescence measurement

This paper discusses the I-V property of the GaAs-based resonant tunnelling structure （RTS） under external uniaxial pressure by photoluminescence studies. Compressive pressure parallel to the [110] direction, whose value is determined by Hooke＇s law, is imposed on the sample by a helix micrometer. With the increase of the applied external uniaxial compressive pressure, the blue shift and splitting of the luminescence peaks were observed, which have some influence on the I-V curve of RTS from the point of view of the energy gap, and the splitting became more apparent with applied pressure. Full width at half maximum broadening could also be observed.

Temperature dependence of biaxial strain and its influence on phonon and band gap of GaN thin film

Hexagonal GaN epilayer grown on sapphire substrate by metal organic chemical vapour deposition （MOCVD） is studied using Raman scattering and photoluminescence in a temperature range from 100K to 873 K. The model of strain （stress） induced by the different lattice parameters and thermal coefficients of epilayer and substrate as a function of temperature is set up. The frequency and the linewidth of E2^high mode in a GaN layer are modelled by a theory with considering the thermal expansion of the lattice, a symmetric decay of the optical phonons, and the strain （stress） in the layer. The temperature-dependent energy shift of free exeiton A is determined by using Varshni empirical relation, and the effect of strain （stress） is also investigated. We find that the strain in the film leads to a decreasing shift of the phonon frequency and an about 10meV-inereasing shift of the energy in a temperature range from 100 K to 823 K.

A Novel Silicon Etching Method Using Vapor of Tetramethylammonium Hydroxide Solution

Silicon bulk etching is an important part of micro-electro-mechanical system(MEMS) technology. In this work, a novel etching method is proposed based on the vapor from tetramethylammonium hydroxide(TMAH) solution heated up to boiling point. The monocrystalline silicon wafer is positioned over the solution surface and can be anisotropically etched by the produced vapor. This etching method does not rely on the expensive vacuum equipment used in dry etching. Meanwhile, it presents several advantages like low roughness, high etching rate and high uniformity compared with the conventional wet etching methods. The etching rate and roughness can reach 2.13 μm/min and 1.02 nm, respectively. Furthermore,the diaphragm structure and Al-based pattern on the non-etched side of wafer can maintain intact without any damage during the back-cavity fabrication. Finally, an etching mechanism has been proposed to illustrate the observed experimental phenomenon. It is suggested that there is a water thin film on the etched surface during the solution evaporation. It is in this water layer that the ionization and etching reaction of TMAH proceed, facilitating the desorption of hydrogen bubble and the enhancement of molecular exchange rate. This new etching method is of great significance in the low-cost and high-quality micro-electromechanical system industrial fabrication.

Mode characteristics of nested eccentric waveguides constructed by two cylindrical nanowires coated with graphene

A kind of nested eccentric waveguide constructed with two cylindrical nanowires coated with graphene was designed.The mode characteristics of this waveguide were studied using the multipole method. It was found that the three lowest modes(mode 0, mode 1 and mode 2) can be combined by the zero-order mode or/and the first-order modes of two single nanowires. Mode 0 has a higher figure of merit and the best performance among these modes within the parameter range of interest. The mode characteristics can be adjusted by changing the parameters of the waveguide. For example, the propagation length will be increased when the operating wavelength, the minimum spacing between the inner and outer cylinders, the inner cylinder radius and the Fermi energy are increased. However, when the outer cylinder radius, the dielectric constants of region Ⅰ, or the dielectric constants of region Ⅲ are increased, the opposite effect can be seen. These results are consistent with the results obtained using the finite element method(FEM). The waveguide structure designed in this paper is easy to fabricate and can be applied to the field of micro/nano sensing.

Simulation of fluctuation effect on dendrite growth by phase field method

The dendrite growth process was simulated with the phase field model coupling with the fluctuation.The effect of fluctuation intensity on the dendrite morphology and that of the thermal fluctuation together with the phase field fluctuation on the forming of side branches were investigated.The results indicate that with the decrease of thermal fluctuation amplitude,the furcation of dendrite tip also decreases,transverse dendrites become stronger,longitudinal dendrites become degenerated,Doublon structure disappears,and a quite symmetrical dendrite structure appears finally.Thermal fluctuation can result in the unsteadiness of dendrites side branches,and it is also the main reason for forming side branches.The phase field fluctuation has a little contribution to the side branches,and it is usually ignored in calculation.When the thermal fluctuation amplitude(F_u) is appropriate,the thermal noise can result in the side branches,but cannot change the steady behavior of the dendrites tip.

Enhancing the Robustness of the Microcavity Coupling System

A novel method to enhance the robustness of the microcavity coupling system(MCS)is presented by encapsulating and solidifying the MCS with a low refractive index(RI)curable UV polymer.The encapsulating process is illustrated in detail for a typical microsphere with a radius of R about 240μm.Three differences of the resonant characteristics before and after the package are observed and analyzed.The first two differences refer to the enhancement of the coupling strength and the shift of the resonant spectrum to the longer wavelength,which are both mainly because of the microsphere surrounding RI variation.Another difference is the quality factor(Q-factor)which decreases from 7.8×10^(7)to 8.7×10^(6)after the package due to the polymer absorption.Moreover,rotation testing experiments have been carried out to verify the robustness of the package MCS.Experimental results demonstrate that the packaged MCR has much better robust performance than the un-package sample.The enhancement of the robustness greatly promotes the microcavity research from fundamental investigations to application fields.

Withdrawal of Chinese Physics Letters 28 (2011) 107301 "High-Efficiency Graphene Photo Sensor Using a Transparent Electrode" by LIU Tao and HUANG Zheng

The authors withdraw the research paper“High-Efficiency Graphene Photo Sensor Using a Transparent Electrode”,which was published in Chinese Physics Letters 28(10),107301(2011),due to the major mistakes in management and experiment,which led to the authors adopting inappropriate data published without sufficient examination and permission processes.

Implementation of Adaptive Wavelet Thresholding Denoising Algorithm Based on DSP

By utilizing the capability of high-speed computing,powerful real-time processing of TMS320F2812 DSP,wavelet thresholding denoising algorithm is realized based on Digital Signal Processors.Based on the multi-resolution analysis of wavelet transformation,this paper proposes a new thresholding function,to some extent,to overcome the shortcomings of discontinuity in hard-thresholding function and bias in soft-thresholding function.The threshold value can be abtained adaptively according to the characteristics of wavelet coefficients of each layer by adopting adaptive threshold algorithm and then the noise is removed.The simulation results show that the improved thresholding function and the adaptive threshold algorithm have a good effect on denoising and meet the criteria of smoothness and similarity between the original signal and denoising signal.

Research on location of underground explosion center based on distributed testing system

Distributed testing system has strong applicability in the field of dynamic testing,which can centrally manage the testing equipment in different locations through the local area network,and meet the new requirements of the test.Based on the theory of seismic location,the location of underground explosion center was studied.The applicability of seismic location theory to the location of underground explosion center was verified by simulating the underground explosion with LS-DYNA simulation platform.Combined with distributed testing system theory and weighting method,the optimal distribution method of test points was summarized through data analysis.