bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improvement of N-type carbon nanotube field effect transistor performance using the combination of yttrium diffusion layer in HfO2 dielectrics and metal contacts
Authors: Hou Zhenfei , Niu Gang , Li Jie , Wu Shengli 
Published: October 2024

Abstract
In this paper, we obtained n-type top-gate carbon nanotube (CNT) thin film field effect transistors (FET) with source/drain extensions structure through dielectrics optimization strategy, combining the yttrium layer with HfO2 dielectric argon annealing process, and metal contacts. The mechanism for enhanced n-type conduction was explained as being due to the vertical diffusion of yttrium to the HfO2 dielectric during argon annealing. This diffusion causes a bending of the energy band, which results in more positive fixed charges, and a reduction in the electron injection barrier between the low work function source/drain Cr electrode and CNT thin film. The optimized technology has great prospects for the low cost, large scale and high performance n-type CNT thin film FET to be used in integrated electronic devices.
Observation of nonthermal electrons further acceleration and long-lasting associated with magnetic reconnection and turbulence bursting in tokamak plasma
Authors: Mai Chaowei , Xu Liqing , Lin Shiyao , Hu Liqun , Chen Yiping , Zhou Tianfu , Feng Xi , Liu Adi , Luo Zhengping , Chao Yan , Quan Haipeng , Zhang Yubo 
Published: October 2024

Abstract
Vital to magnetized plasma performance, the acceleration of nonthermal electrons significantly influences the current drive of radio frequency (RF) waves in plasma. In Experimental Advanced Superconducting Tokamak (EAST), we observed nonthermal electrons initially <215 keV in energy, being locally accelerated to 600 keV within 100 milliseconds, which corresponds to the total growth time of the magnetic island. Surprisingly, these fast electrons (FEs) lasted for 1.4 s, several times longer than the estimated relaxation time of 0.26 s, and exceeded 1/10 of the discharge length. Turbulence generation at island’s X point is attributed to the unexpected confinement and repopulation of FEs. This phenomenon may have positive implications for the steady-state long pulse H mode operation in EAST, especially regarding non-inductive current sustainment. For future RF electron heating-dominant devices, the mechanisms elucidated in this study have immediate implications for optimizing RF current drive efficiency.
Full-waveform ultrasonic imaging for bone
Authors: Xu Lexiu , Li Yifang , Shi Qinzhen , Zhang Yunyun , Ta Dean 
Published: October 2024

Abstract
This paper suggests a full-waveform ultrasonic imaging strategy for bone. A novel forward wavefield propagation is performed in the frequency-domain. To improve the efficiency of full-waveform inversion bone imaging, all relative computations are also conducted in the frequency-domain. Additionally, a conjugate gradient algorithm is employed in the inversion procedure to accelerate the reconstruction of the bone acoustic velocity. Eventually, numerical experiments on different bone models are carried out to demonstrate the effectiveness of explored imaging strategy.
Sound speed imaging of cortical bone and soft tissue based on frequency-domain ultrasound waveform tomography
Authors: Zhou Chenchen , Xu Kailiang 
Published: October 2024

Abstract
As one of the ultrasound computed tomography (UCT) algorithms, full-waveform inversion (FWI) can recover clear and detailed internal structures of bones by iteratively minimizing the misfit between observed and numerical data. However, time domain full-waveform inversion (TDFWI) often lacks sufficient low-frequency information, and the computation of full-time data imposes a significant computational burden. Besides, there are few studies on whole-medium reconstruction that jointly invert the bone and surrounding soft tissues. In this study, an FWI-based frequency-domain UCT (FD-UCT) is utilized for simultaneously imaging the sound speed of bones and soft tissues, which facilitates the inversion efficiency while ensuring the existence of low-frequency information. Simulated studies show that the FD-UCT can both reconstruct bones with large acoustic impedance and distinguish subtle impedance differences within soft tissues to reveal lesions.
In vitro experimental study on interventional ultrasound-mediated microbubble cavitation lithotripsy
Authors: Zhou Honglei , Wang Muyao , Chen Junjian , Zheng Xianhua , Chen Yiju , Wang Zhiyong 
Published: October 2024

Abstract
Ultrasound-mediated microbubble cavitation lithotripsy as a new minimally invasive approach has received great attention for the treatment of urinary stones. However, the attenuation of ultrasonic waves in human tissues and stone displacement during lithotripsy are two key issues limiting the development of this technology. In this paper, a method of interventional ultrasound-mediated microbubble cavitation lithotripsy is proposed, which can realize the in-situ delivery of ultrasonic waves and microbubbles. A piezoelectric ultrasound transducer with the center frequency of 461 kHz and output peak to peak acoustic pressures of 3.2 MPa is fabricated, and microbubbles with the concentration of 1.33×109/ml are synthesized. An extracorporeal experiment platform is built and in vitro tests of ultrasound mediated microbubble cavitation lithotripsy are conducted by using microbubbles with different concentrations and water. The results show that the proposed interventional ultrasound-mediated microbubble cavitation lithotripsy is an efficient method for the fragmentation of ureteral stones. The maximum mass reduction of the stone is 9.4 mg within 30 minutes of treatment under the combined action of ultrasound with the peak-negative pressure of 1.6 MPa and center frequency of 461 kHz and microbubbles with the concentration of 3.325×107/ml. The research results will provide a technical basis for further optimization of subsequent tentative schemes, in vivo experiments with animals and future clinical applications.
Wave mode variation of multi-wavelength photoacoustic guided waves in cortical bone
Authors: Chen Honglei , Li Ying , Tran Tho Nht , Sun Shuxin , Xu Kailiang 
Published: October 2024

Abstract
Photoacoustic guided waves (PAGWs), excited based on the optical-thermo-mechanical coupling mechanism, have the potential to non-invasion assess the optical properties which associates tissue composition of bones. This study investigates the wave mode variation of PAGWs with the optical transmissivity in a 2mm-thick cortical bone plate. Multi-wavelength PAGWs were generated by lasers of different wavelength with a tunable pulsed laser system; Two piezoelectric transducers with the centre frequency of 500 kHz, symmetrically sticked on the bone surfaces, were used to acquire the signals. The symmetric (S) mode and anti-symmetric (A) mode were extracted by adding and subtracting the signals received by different transducers, respectively. The relative amplitude ratio of A mode and S mode was found to have an inverse relationship with the optical transmissivity of the bone. For the 750 nm laser with high transmissivity, the waves are mainly S mode; the relative amplitude of A mode wave increases with the laser wavelength. The amplitude ratio of A- and S- modes is in exponential attenuation with the transmissivity. The research results suggest that the wave mode variation in signal amplitude is suitable for evaluating the optical properties of bones, which is benefit for the development of quantitative ultrasound assessment of long cortical bone.
Improved subarray coherence factor beamformer for ultrasound plane-wave imaging
Authors: Guan Huchang , Jiang Chen , Xu Kailiang , Ta Dean 
Published: October 2024

Abstract
Coherent plane-wave compounding (CPWC) has gained significant traction in medical ultrasound imaging. The coherence factor (CF) weighting algorithm, a classical adaptive beamforming strategy, aims to enhance the CPWC imaging lateral resolution, but it also noticeably compromises the speckle patterns, particularly.at a low signal-to-noise ratio (SNR). Delay multiply and sum (DMAS) has been proposed to reduce side lobes. However, the reconstructed image quality with DMAS is limited in terms of resolution and speckle level. In the present study, an improved subarray coherence factor (ISCF) algorithm is introduced by combining CF with DMAS strategies, aiming to improve the contrast and resolution while preserving the speckle level. The performance of the proposed algorithm is evaluated using simulation and phantom datasets. Results indicate that the resolution and the contrast of ISCF can be improved by 41.6% and 79.4%, respectively; compared with delay and sum (DAS) algorithm. Additionally, the resolution and the speckle level of ISCF can be improved by 10.6% and 35.7% compared with CF algorithm, respectively. The proposed ISCF algorithm outperforms CF in terms of resolution, contrast, and speckle preservation.
Hadamard Coded Multiplane Wave based Ultrafast Doppler for Rat Brain Imaging
Authors: Yan Shaoyuan , Fu Yapeng , Xu Kailiang 
Published: October 2024

Abstract
This study explores the application of Hadamard multiplane-wave coding in ultrafast power and color Doppler imaging for enhanced visualization of rat brain vasculature. By implementing an 8-order Hadamard matrix, an approximate 10 dB improvement in signal-to-noise ratio was significantly achieved, particularly in deep brain regions and the hippocampus. The enhanced imaging technique, compared to classical plane wave coherent compounding, demonstrates its potential for applications requiring deep penetration and high sensitivity to small blood flow without compromising the ultrafast frame rate.
A Study of Mechanical Scanning High-frequency Ultrasonic Color Flow Imaging
Authors: Heng Jiaming , Wang Qing , Li Chengxi , Chu Tianxiang , Gao Feng , Jian Xiaohua 
Published: October 2024

Abstract
High-frequency Ultrasonic imaging can promote high-resolution images and detailed diagnostic information, which has great clinical application prospects. However, due to the difficulty and high cost of high-frequency multi-channel ultrasound systems and multi-array element transducers, it is not conducive to popularization. Mechanical scanning high-frequency ultrasound imaging system is an alternative and low-cost method. However, current mechanical scanning systems cannot perform ultrasound flow imaging, and hemodynamic information is clinically important. Therefore, an improved high-frequency, miniaturized mechanical scanning system for color flow imaging was designed and developed. The system uses a crank linkage structure to drive a miniature transducer with a center frequency of 12 MHz for reciprocating scanning imaging within a range of 15 mm. By optimizing the clutter filter and dynamic domain flow imaging process, two methods are realized: real-time rapid ultrasound imaging and highly sensitive ultrasound flow imaging. The two optimized methods used power Doppler and color flow Doppler for flow phantom imaging, and the final measured blood flow error was less than 5%, which indicates that the mechanical scanning high-frequency ultrasonic color flow imaging system has a good application prospect.
Ultrasonic visualization of destruction processes in nonwoven polymeric matrix for regenerative medicine
Authors: Morokov E , Tubaeva P , Zykova A 
Published: October 2024

Abstract
The paper depicts the tensile behaviour of a random oriented nonwoven polymer matrix based on poly-3-hydroxybutyrate. The process of alignment, orientation and stretching of polymer fibers in a water filled condition mimicked presence in a living organism was revealed using acoustic microscopy. To describe the micromechanics of electrospun mats the mechanism of ultrasound contrast of small-sized single cylindrical scatterer was described.
An integrated dual-frequency IVUS system with interleaved sampling and parallel signal processing based on FPGA
Authors: Xiao Xin , Can Yu , Wang Zhuochen 
Published: October 2024

Abstract
Due to the lack of high voltage and low frequency pulse transmission channels, commercial high frequency IVUS imaging system cannot meet the hardware requirements of ultrasound angiography. Therefore, it is of great research significance to develop a dual-frequency IVUS rotary imaging system with high integration, high sampling rate and sampling accuracy. In this work, an integrated dual-frequency IVUS system with interleaved sampling and parallel signal processing based on FPGA was developed. The central frequency of low-frequency channel is up to 10MHz, and the peak voltage range is 80-200V. The central frequency of the high-frequency channel is up to 60MHz, and the voltage peak-to-peak range is 40-80V. The acquisition channel is 500MHz and 12bit, which is realized by interleaved sampling of two ADC. The motor controlled ultrasonic transducer acquires 400-800 lines per turn, and eventually form a 360-degree IVUS hybrid imaging successfully.
The Feasibility Study of Bone Fracture Assessment Based on Photoacoustic Time-of-Flight Method
Authors: Fang Yousong , Feng Ting , Ni Chenyin , Liu Chengcheng , Cheng Qian 
Published: October 2024

Abstract
Photoacoustic imaging (PAI) technology combines the advantages of acoustic resolution and optical contrast imaging within deep tissue. The commonly clinically used bone fracture detection and evaluation method is X-ray based imaging techniques. In order to study the feasibility of human radius fractures detection in non-radiation and non-invasive way, this study combined the time-of-flight (TOF) method commonly used in industrial nondestructive testing with photoacoustic technology for the detection and location of bone fractures. Firstly, the bone fracture information carried by PA signal was studied by simulating the bone models with different locations of bone fractures. The finite difference time domain (FDTD) method was used to simulate the propagation process of photoacoustic signal in bone tissue. Secondly, the PATOF diagrams formed by PA signals at different locations is obtained by using laser fixed and ultrasonic detector motion detection method. Finally, the PATOF diagrams are further analyzed and quantified. The results show that the photoacoustic bone detection method based on TOF method can effectively locate the fracture location. This study confirms the feasibility of combining PAI technique with TOF method to detect bone fractures, which indicates that PAI technique has great application prospect in bone detection field.
Multi-focus Image Fusion via Blind Deconvolution and Registration based on Photoacoustic Microscopy
Authors: Li Hang , Ma Haigang , Zuo Chao , Feng Ting 
Published: October 2024

Abstract
Optical resolution photoacoustic microscopy (OR-PAM), which can present the microstructure of biological tissues is useful in the disease diagnosis. However, conventional OR-PAM can only obtain images with high resolution in a narrow range of depths around the focal plane. In this study, we proposed a multi-focus photoacoustic image fusion method based on the blind deconvolution. This method is divided into two steps. First, we used the method of blind deconvolution to obtain an approximate point spread function (PSF) for each photoacoustic images obtained from multiple layers, and then got the corresponding deblurred photoacoustic images. Second, we used the method of multi-focus images registration and fusion to accurately align the multi-focus photoacoustic images and effectively fuse the features of different images. Finally, the proposed method was applied to process the photoacoustic images obtained from photoacoustic imaging experiments on ants with irregular morphology using fast controllable confocal focus PAM (FC-PAM). The results show that our method improves the quality of photoacoustic images, and can quickly obtain multi-focus fused photoacoustic images with high resolution. It indicates that the proposed multi-focus photoacoustic image fusion method based on FC-PAM has great potential in fast imaging of living biological tissues at multiple imaging depths.
Feasibility of Prostatitis Evaluation Based on Photoacoustic Microscopy
Authors: Wang Chong , Li Ying , Li Boyi , Zhu Yunkai , Chen Yaqing 
Published: October 2024

Abstract
This study aims to investigate the feasibility of using photoacoustic microscopy for the diagnosis of prostatitis. We induced inflammation in rats to establish a model of prostatitis using Freund’s Complete Adjuvant (FCA). Prostate tissues from both the model and control groups were extracted and processed into histological sections. We explored the photoacoustic microscopy imaging results of unstained sections, consistent with the histological detection results using HE staining. Inflammation was found to enhance the photoacoustic signals. Subsequently, we conducted photoacoustic microscopy imaging on all samples, and the detection results were nearly consistent with the diagnoses made by medical professionals. Finally, we quantified the collected photoacoustic signals to classify the severity of prostatitis.
Super-resolution based on frequency dependence of echo phase rotation in 3D ultrasound imaging by spatially encoded transmit/receive
Authors: Syaryadhi M , Zheng J , Tagawa N , Yang M 
Published: October 2024

Abstract
Currently, we are investigating the ultrasound imaging of a single transmitter/receiver system for a puncture microscopy application. The proposed model, consisting of an encoding mask layer with irregular thickness attached to the surface of the transducer, was carried out by a finite element method simulator. To increase the number of measurements, the device was rotated for several rotations. The image for each rotation was constructed separately by numerically solving the linear equation of the image model. In this paper, we introduce a super resolution method (SCM) based on an eigenvalue analysis in order to improve the poor resolution. It was assigned as weights and multiplied by the current image. The simple averaging and coherence factor were applied to compound over a number of rotations to obtain the final image. The results show that the image has a better image resolution and also suppresses the unwanted signals as well.
Estimation method of the Homodyned K-distribution based on the Improved Shuffled Frog Leaping Algorithm for ultrasound tissue characterization
Authors: Wu Keyan , Zeng Xiuhua , Zhao ChuanLiang , Xu Xinggui , Jiang Rong , Wang Kun 
Published: October 2024

Abstract
Aiming at promoting the accuracy of the integral value of the probability distribution function (PDF) of Homodyned K-distribution (HK), a new maximum likelihood estimation method for HK distribution parameters is proposed by using the improved shuffled frog leaping algorithm (ADM-SFLA) and Newton-Raphson iterative algorithm (NR). To improve the accuracy of the global search of the traditional SFLA, two variation factors of Gauss and Cauchy are first used to find the global optimal solution in a convergence state. Secondly, to obtain the integral node with optimal segmentation, the ADM-SFLA is used to perform the non-equidistant adaptive segmentation of the integral interval. Then, the PDF of the HK distribution is calculated between each numerical integration cell based on Simpson integral formula. Subsequently, the integral value of the PDF for HK distribution is obtained by summing the integration values from each numerical integration cell. Finally, the optimal estimation of HK distribution parameters is obtained based on NR algorithm. The performance of the proposed method is evaluated and compared through simulated data as well as the envelope signals obtained from the ultrasonic simulation model with different scattering components. The results show that the ADM-SFLA based method can improve the estimation accuracy of HK distribution parameters effectively.
Application of distributed acoustic sensing technology in deep shale gas exploration
Authors: Zhou Anfu , Cheng Xiaoyan , Xie Wei , Qiu Xunxi , Chen Yuanzhong , Wang Yu , Li Qifeng , Zhao Jilong , Tan Fengyu 
Published: October 2024

Abstract
In the past decade, the exploration and development of deep shale gas usually adopted geophone acquisition for vertical seismic profile (VSP) to improve the accuracy and resolution of seismic data. However, it’s very hard to use the 10-20m level spacing geophones to meet the resolution of 2-5m thin reservoir. Distributed acoustic sensing (DAS) technology has been widely used in the oil and gas field due to its advantages of high density and high efficiency acquisition, especially in vertical seismic profile and dynamic monitoring. We have acquired zero offset VSP by DAS and geophone for the first time in deep shale gas wells at home, and successfully overcome the coupling problem in open-hole sections. Vibrators are used as sources for multiple stacking to improve the signal-to-noise ratio (SNR) of DAS VSP. The records show DAS has significant advantages in frequency, SNR and wavelet consistency. After data processing, the layer velocity characteristics of DAS VSP are more obvious. DAS VSP corridor stack has a high degree of consistency with the synthetic record and seismic profile, and the resolution of the reservoir was higher than geophone.
Shear wave measurement in slow formations for eccentric monopole acoustic logging while drilling
Authors: Ji Y J , Wang H 
Published: October 2024

Abstract
The use of a logging-while-drilling (LWD) monopole tool to directly measure shear (S) wave velocity in slow formations has been proven feasible under certain conditions. However, S-wave signals received in the borehole are fairly weak, which limits the application range of this measurement method. To find ways to enhance shear waves, we first explore factors sensitive to the S-wave excitation. Simulation results indicate that four parameters including the receiver-source distance, the radial distance from receiver to borehole wall, the formation S-wave velocity and source frequency, primarily influence the S-wave excitation. Shear waves can be enhanced by judiciously optimizing these parameters during tool design. We also investigate borehole wavefields with an eccentric LWD tool in both commonly slow and ultra-slow formations. Results reveal that tool eccentricity can amplify shear waves and improve its measurement accuracy, provided that waveforms received in the direction of tool movement are used. We successfully extracted the S-wave velocity of an ultra-slow formation under conditions of large eccentricity, while similar actions originally failed with a centralized instrument.
Reflection and Transmission of Plane Waves at the Interface of Fluid and Porous Media with Seismoelectric Effect
Authors: Gao Wenyang , Zhang Yan , Zhao Zhiming , Cui Zhiwen 
Published: October 2024

Abstract
The relationship between energy flux reflection and transmission coefficient of seismoelectric plane waves in plane layered media and incident angle and frequency is studied. Pride equations is adopted to describe the coupling phenomenon between elastic waves and electromagnetic fields in subsurface fluid-saturated porous media. The Helmholtz decomposition is used to derive the energy flux expression for seismoelectric plane waves propagating in fluid-saturated porous media. It shows that the impermeable interface conditions have a great influence on the reflection and transmission coefficient of seismoelectirc waves. The transmission coefficient of slow longitudinal waves under impermeable interface is much smaller than that of permeable interface conditions Reflection coefficient of longitudinal wave, transmission coefficients of the fast longitudinal waves and transverse waves are all larger under impermeable interface conditions than that of permeable cases. And the reflection coefficient of electromagnetic wave under impermeable interface conditions is almost one order of magnitude smaller than that permeable case.