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16篇 您的检索式:作者名="Xiqi Zhang"
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1Towards 6G wireless communication networks:vision,enabling technologies,and new paradigm shifts显示文摘The fifth generation(5G)wireless communication networks are being deployed worldwide from 2020 and more capabilities are in the process of being standardized,such as mass connectivity,ultra-reliability,and guaranteed low latency.However,5G will not meet all requirements of the future in 2030 and beyond,and sixth generation(6G)wireless communication networks are expected to provide global coverage,enhanced spectral/energy/cost efficiency,better intelligence level and security,etc.To meet these requirements,6G networks will rely on new enabling technologies,i.e.,air interface and transmission technologies and novel network architecture,such as waveform design,multiple access,channel coding schemes,multi-antenna technologies,network slicing,cell-free architecture,and cloud/fog/edge computing.Our vision on 6G is that it will have four new paradigm shifts.First,to satisfy the requirement of global coverage,6G will not be limited to terrestrial communication networks,which will need to be complemented with non-terrestrial networks such as satellite and unmanned aerial vehicle(UAV)communication networks,thus achieving a space-airground-sea integrated communication network.Second,all spectra will be fully explored to further increase data rates and connection density,including the sub-6GHz,millimeter wave(mmWave),terahertz(THz),and optical frequency bands.Third,facing the big datasets generated by the use of extremely heterogeneous networks,diverse communication scenarios,large numbers of antennas,wide bandwidths,and new service requirements,6G networks will enable a new range of smart applications with the aid of artificial intelligence(AI)and big data technologies.Fourth,network security will have to be strengthened when developing 6G networks.This article provides a comprehensive survey of recent advances and future trends in these four aspects.Clearly,6G with additional technical requirements beyond those of 5G will enable faster and further communications to the extent that the boundary between physical and cyber worlds disappears.Xiaohu YOU Cheng-Xiang WANG Jie HUANG Xiqi GAO Zaichen ZHANG Mao WANG Yongming HUANG Chuan ZHANG Yanxiang JIANG Jiaheng WANG Min ZHU Bin SHENG Dongming WANG Zhiwen PAN Pengcheng ZHU Yang YANG Zening LIU Ping ZHANG Xiaofeng TAO Shaoqian LI Zhi CHEN Xinying MA Chih-Lin I Shuangfeng HAN Ke LI Chengkang PAN Zhimin ZHENG Lajos HANZO Xuemin(Sherman)SHEN Yingjie Jay GUO Zhiguo DING Harald HAAS Wen TONG Peiying ZHU Ganghua YANG Jun WANG Erik GLARSSON Hien Quoc NGO Wei HONG Haiming WANG Debin HOU Jixin CHEN Zhe CHEN Zhangcheng HAO Geoffrey Ye LI Rahim TAFAZOLLI Yue GAO HVincent POOR Gerhard P.FETTWEIS Ying-Chang LIANG 2021Science China(Information Sciences)2021,64,1:122
2An overview of transmission theory and techniques of large-scale antenna systems for 5G wireless communications显示文摘To meet the future demand for huge traffic volume of wireless data service, the research on the fifth generation(5G) mobile communication systems has been undertaken in recent years. It is expected that the spectral and energy efficiencies in 5G mobile communication systems should be ten-fold higher than the ones in the fourth generation(4G) mobile communication systems. Therefore, it is important to further exploit the potential of spatial multiplexing of multiple antennas. In the last twenty years, multiple-input multiple-output(MIMO) antenna techniques have been considered as the key techniques to increase the capacity of wireless communication systems. When a large-scale antenna array(which is also called massive MIMO) is equipped in a base-station, or a large number of distributed antennas(which is also called large-scale distributed MIMO)are deployed, the spectral and energy efficiencies can be further improved by using spatial domain multiple access. This paper provides an overview of massive MIMO and large-scale distributed MIMO systems, including spectral efficiency analysis, channel state information(CSI) acquisition, wireless transmission technology, and resource allocation.Dongming WANG Yu ZHANG Hao WEI Xiaohu YOU Xiqi GAO Jiangzhou WANG 2016Science China(Information Sciences)2016,59,8:21
3Therapeutic effect of electroacupuncture,massage,and blocking therapy on external humeral epicondylitis显示文摘OBJECTIVE:To compare two therapeutic methods:electroacupuncture + massage + blocking therapy,and blocking therapy alone in the treatment of external humeral epicondylitis.METHODS:Eighty-six patients were randomized into two groups with 43 in each. The treatment group received electroacupuncture + massage +blocking therapy, while the control group received blocking therapy only. A course of electroacupuncture treatment included therapy once a day for 10days. There were 10 treatments in a massage course and massage was given once a day, with a1-week interval given before the next course. A course of blocking treatment included therapy once a week, for twototaltreatments,andgenerallyno more than three times. The therapeutic effects were evaluated with the visual analog scale(VAS),grip strength index(GSI) score, and Mayo elbow performance score(MEPS) before treatment and at0, 6, 12, and 24 months after treatment to observe thetotaleffectiverate.RESULTS: In the treatment and control groups before treatment and at 0, 6, 12, and 24 months after treatment, the VAS scores were: 6.5±1.9 and 6.4±1.6; 4.6±1.3 and 4.6±1.7; 4.8±1.3 and 4.8±1.2; 4.6±1.2 and 6.6±1.6; and 6.5±1.6 and 6.5±1.3, respectively. The GSI scores were 63±8 and 63±8; 84±6and82±7;82±7and82±6;84±6and62±8;and64±6 and 64±7, respectively.The MEPS of both groups were65±7and66±8;85±6and84±7;84±5and84±7;80±7and66±6;and65±6and65±7,respectively.The total effective rates of the treatment and control groups at 0, 6, 12, and 24 months after treatment were 87.5% and 85.0%; 85.0% and 82.5%;80.0% and 12.5%; and 2.5% and 5.0%, respectively.Compared with the treatment group, the control group had greater joint function, better the rapeutic effect, and lower pain intensity(P<0.01), indicating a high recurrence rate in the 12th month after treatment.There were no differences inVAS, GSI, or MEPS at 0, 6, and 24 months after treatment(P>0.05)betweenthetwogroups.CONCLUSION: We found that both methods were effective for external humeral epicondylitis. After 6months of treatment,the effects were good in both groups. However, in the 12th month, the control group had a relatively severe relapse. After 24months, both groups relapsed. The effect of electroacupuncture, massage, and blocking therapy used in combination lasted longer, delaying the recurrence of the disease.Xinjian Li Kun Zhou Enming Zhang Zhen xiQi Weiqing Sun Liangfu Xu Jianfeng Xu Youzhi Cai Ronghui Wang 2014Journal of Traditional Chinese Medicine2014,34,3:6
4Quantum-confined ion superfluid in nerve signal transmission显示文摘We propose a process of quantum-confined ion superfluid (QISF),which is enthalpy-driven confined ordered fluid,to explain the transmission of nerve signals.The ultrafast Na^+ and K^+ ions transportation through all sodium-potassium pump nanochannels simultaneously in the membrane is without energy loss,and leads to QISF wave along the neuronal axon,which acts as an information medium in the ultrafast nerve signal transmission.The QISF process will not only provide a new view point for a reasonable explanation of ultrafast signal transmission in the nerves and brain,but also challenge the theory of matter wave for ions,molecules and particles.Xiqi Zhang Lei Jiang 2019Nano Research2019,12,6:6
5Resource allocation for pilot-assisted massive MIMO transmission显示文摘This paper is on the resource allocation problem for pilot-assisted multi-user massive multipleinput-multiple-output(MIMO) uplink with linear minimum mean-squared error(MMSE) channel estimation and detection. We utilize the angular domain channel representation for uniform linear antenna arrays, and adopt its equivalent independent and nonidentical distributed channel model. For a given coherence interval and total energy budget, we study the joint optimization of the training length and the training power to maximize the achievable sum-rate. For tractable analysis and low-complexity solution, a tight approximation on the achievable sum-rate is derived first. Then the training length optimization for fixed training power and the training power optimization for fixed training length with respect to the approximate sum-rate maximization are both shown to be concave. An alternative optimization that solves the training length and power iteratively is proposed for the joint resource allocation. In addition, for the special case that the training and data transmission powers are equal, we derive the optimal training lengths for both high and low signal-to-noiseratio(SNR) regions. Numerical results show the tightness of the derived sum-rate approximation and also the significant performance advantage of the proposed resource allocation.Yun XUE Jun ZHANG Xiqi GAO 2017Science China(Information Sciences)2017,60,4:4
6Validation of the simplified criteria for diagnosis of autoimmune hepatitis in Chinese patients显示文摘Dekai Qiu Qixia Wang Hui Wang Qing Xie Guoqing Zang Hong Jiang Chuantao Tu Jinsheng Guo Shuncai Zhang Jianshe Wang Yi Lu Ying Han Lei Shen Xiaoyu Chen Xiqi Hu Xiaojin Wang Chengwei Chen Qingchun Fu Xiong Ma 2010Journal of Hepatology2010,,:2
7TIME-DOMAIN INTERPOLATION ON GRAPHICS PROCESSING UNIT显示文摘The signal processing speed of spectral domain optical coherence tomography(SD-OCT)has become a bottleneck in a lot of medical applications.Recently,a time-domain interpolation method was proposed.This method can get better signal-to-noise ratio(SNR)but much-reduced signal processing time in SD-OCT data processing as compared with the commonly used zeropadding interpolation method.Additionally,the resampled data can be obtained by a few data and coefficients in the cutoff window.Thus,a lot of interpolations can be performed simultaneously.So,this interpolation method is suitable for parallel computing.By using graphics processing unit(GPU)and the compute unified device architecture(CUDA)program model,time-domain interpolation can be accelerated significantly.The computing capability can be achieved more than 250,000 A-lines,200,000 A-lines,and 160,000 A-lines in a second for 2,048 pixel OCT when the cutoff length is L=11,L=21,and L=31,respectively.A frame SD-OCT data(400A-lines×2,048 pixel per line)is acquired and processed on GPU in real time.The results show that signal processing time of SD-OCT can befinished in 6.223 ms when the cutoff length L=21,which is much faster than that on central processing unit(CPU).Real-time signal processing of acquired data can be realized.XIQI LI GUOHUA SHI YUDONG ZHANG 2011Journal of Innovative Optical Health Sciences2011,4,1:1
8Driving Force of Molecular/Ionic Superfluid Formation显示文摘Ordered-and high-flux flow of molecules and ions in biological channels is considered as a quantumconfined superfluid,which is highly important in chemical reactions and bioinformation transmission.However,the driving forces for these ordered arrangements of molecules and ions in confined spaces have not been discussed.Herein,we demonstrate that the driving force of molecular/ionic superfluid formation is the attraction-repulsion balance of particles under the effect of interfacial confinement.Xiqi Zhang Bo Song Lei Jiang 2021CCS Chemistry2021,3,8:0
9Non-Ischemic, Non-Hypoxic Myocardial Injury, and Long-Term Mortality in Patients with Coronavirus Disease 2019: A Retrospective Cohort Study显示文摘Objective:Cardiac damage is commonly reported in patients with coronavirus disease 2019(COVID-19)but its prevalence and impact on the long-term survival of patients remain uncertain.This study aimed to explore the prevalence of myocardial injury and assess its prognostic value in patients with COVID-19.Methods:A single-center,retrospective cohort study was performed at the Affiliated Hospital of Jianghan University.Data from 766 patients with confirmed COVID-19 who were hospitalized from December 27,2019 to April 25,2020 were collected.Demographic,clinical,laboratory,electrocardiogram,treatment data and all-cause mortality during follow-up were collected and analyzed.Results:Of the 766 patients with moderate to critically ill COVID-19,86(11.2%)died after a mean follow-up of 72.8 days.Myocardial injury occurred in 94(12.3%)patients.The mortality rate was 64.9%(61/94)and 3.7%(25/672)in patients with and without myocardial injury,respectively.Cox regression showed that myocardial injury was an independent risk factor for mortality(hazard ratio:8.76,95%confidence interval:4.76–16.11,P<0.001).Of the 90 patients with myocardial injury with electrocardiogram results,sinus tachycardia was present in 29,bundle branch block in 26,low voltage in 10,and abnormal T-wave in 53.Conclusions:COVID-19 not only involves pneumonia but also cardiac damage.Myocardial injury is a common complication and an independent risk factor for mortality in COVID-19 patients.Fajiu Li Xijie Zhu Ziyang Zhu Yinjian Yang Zhuang Tian Duolao Wang Shi Chen Xiaoyan Gao Yalin Xu Bo Zhang Wei Yu Min Liu Xiqi Xu Chenghong Li Shuyang Zhang 2022Cardiology Discovery2022,2,2:0
10Acceleration of optical coherence tomography signal processing by multi-graphics processing units显示文摘A multi-GPU system designed for high-speed,real-time signal processing of optical coherencetomography(OCT)is described herein.For the OCT data sampled in linear wave numbers,themaximum procesing rates reached 2.95 MHz for 1024-OCT and 1.96 MHz for 2048-OCT.Data sampled using linear wavelengths were re-sampled using a time-domain interpolation method and zero-padding interpolation method to improve image quality.The maximum processing rates for1024-OCT reached 2.16 MHz for the time-domain method and 1.26 MHz for the zero-paddingmethod.The maximum processing rates for 2048-0CT reached_1.58 MHz,and 0.68 MHz,respectively.This method is capable of high-speed,real-time processing for O CT systems.Xiqi Li Guohua Shi Ping Huang Yudong Zhang 2014Journal of Innovative Optical Health Sciences2014,7,3:0
11Enhancement of interfacial catalysis in a triphase reactor using oxygen nanocarriers显示文摘Multiphase catalysis is used in many industrial processes;however,the reaction rate can be restricted by the low accessibility of gaseous reactants to the catalysts in water,especially for oxygen-dependent biocatalytic reactions.Despite the fact that solubility and diffusion rates of oxygen in many liquids(such as perfluorocarbon)are much higher than in water,multiphase reactions with a second liquid phase are still difficult to conduct,because the interaction efficiency between immiscible phases is extremely low.Herein,we report an efficient triphase biocatalytic system using oil core-silica shell oxygen nanocarriers.Such design offers the biocatalytic system an extremely large water-solid-oil triphase interfacial area and a short path required for oxygen diffusion.Moreover,the silica shell stabilizes the oil nanodroplets in water and prevents their aggregation.Using oxygen-dependent oxidase enzymatic reaction as an example,we demonstrate this efficient biocatalytic system for the oxidation of glucose,choline,lactate,and sucrose by substituting their corresponding oxidase counterparts.A rate enhancement by a factor of 10-30 is observed when the oxygen nanocarriers are introduced into reaction system.This strategy offers the opportunity to enhance the efficiency of other gaseous reactants involved in multiphase catalytic reactions.Lu Zhou Liping Chen Zhenyao Ding Dandan Wang Hao Xie Weihai Ni Weixiang Ye Xiqi Zhang Lei Jiang Xinjian Feng 2021Nano Research2021,14,1:0
12Improved wavelet hierarchical threshold filter method for optical coherence tomography image de-noising显示文摘According to the speckle feature in Optical coherence tomography(OCT),images with speckleindicate not only noise but also signals,an improved wavelet hierarchical threshold filter(IWHTF)method is proposed.At first,a modified hierarchical threshold-selected algorithm isused to prevent signals from being removed by asssing suitable thresholds for different noiselevels,Then,an improved wavelet threshold function based on two traditional threshold fumnc.tions is proposed to trade-ff betwen speckle removing and sharpness degradation.The de-noising results of an OCT finger skin image shows that the IWHTF method obtains betterobjective evaluation metrics and visual image quality improvement,Whenαa=0.2,β=5.0 andK=1.2,the improved method can achieve 9.58 dB improvement in signal-to-noise ratio,withsharpnesdegraded by 3.81%.Jing Cao Pinghe Wang Bo Wu Guohua Shi Yan Zhang Xiqi Li Yudong Zhang Yong Liu 2018Journal of Innovative Optical Health Sciences2018,,3:0
13HIGH-SPEED SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY SIGNAL PROCESSING WITH TIME-DOMAIN INTERPOLATION USING GRAPHICS PROCESSING UNIT显示文摘Sensitivity and data processing speed are important in spectral domain Optical Coherence Tomography(SD-OCT)system.To get a higher sensitivity,zero-padding interpolation together with linear interpolation is commonly used to re-sample the interference data in SD-OCT,which limits the data processing speed.Recently,a time-domain interpolation for SD-OCT was proposed.By eliminating the huge Fast Fourier Transform Algorithm(FFT)operations,the operation number of the time-domain interpolation is much less than that of the zero-padding interpolation.In this paper,a numerical simulation is performed to evaluate the computational complexity and the interpolation accuracy.More than six times acceleration is obtained.At the same time,the normalized mean square error(NMSE)results show that the time-domain interpolation method with cut-offlength L?21 and L?31 can improve about 1.7 dB and 2.1 dB when the distance mismatch is 2.4mm than that of zero-padding interpolation method with padding times M?4,respectively.Furthermore,this method can be applied the parallel arithmetic processing because only the data in the cut-offwindow is processed.By using Graphics Processing Unit(GPU)with compute unified device architecture(CUDA)program model,a frame(400 A-lines2048 pixels12 bits)data can be processed in 6 ms and the processing capability can be achieved 164,000 line/s for 1024-OCT and 71,000 line/s for 2048-OCT when the cut-offlength is 21.Thus,a high-sensitivity and ultra-high data processing SD-OCT is realized.XIQI LI GUOHUA SHI LING WEI ZHIHUA DING YUDONG ZHANG 2011Journal of Innovative Optical Health Sciences2011,4,3:0
14High-Performance Photocathodic Bioanalysis Based on Core-Shell Structured Cu_(2)O@TiO_(2) Nanowire Arrays with Air–Liquid–Solid Joint Interfaces显示文摘Developing photoelectrochemical(PEC)bioassays based on the principle of a photocathodic measurement of enzymatic product H_(2)O_(2) is highly attractive because it can naturally avoid interfering signals arising from reductive species inherent to biofluids.However,fluctuant oxygen levels in the analyte solution can compromise the accuracy of photocathodic bioanalysis and restrict its application because oxygen reduction potential is similar to H_(2)O_(2).Herein,we addressed this restriction by constructing a triphase biophotocathode with air–liquid–solid joint interfaces by immobilizing an oxidase enzyme film on the tip part of superhydrophobic p-type semiconductor nanowire arrays.Such a triphase biophotocathode has a reaction zone with steady and air phasedependent oxygen concentration which stabilizes and increases the oxidase kinetics,and enables the photocathodic measurement principle in reliable PEC bioassay development with high selectivity,good accuracy,and a wide linear detection range.Moreover,the biophotocathode shows good stability during repeated testing under light illumination.This reliable PEC bioassay system has broad potential in the fields of disease diagnosis,medical research,and environmental monitoring.Zhaohong Wang Liping Chen Dandan Wang Zhenyao Ding Xiqi Zhang Xinjian Feng Lei Jiang 2022CCS Chemistry2022,4,3:0
15Integrin-Mimetic Mechanosensory Elastomer with Fluorescence Probe for Monitoring Chain Deformation in Situ显示文摘Mechanosensory elastomers attract intense interests in the academic and industrial fields.However,molecular insight of macroscopic properties remains a significant challenge.Herein,we build up a correlation between the microscopic and macroscopic level by designing a mechanosensory elastomer with aggregation-induced emission luminogens(AIEgens)that monitors chain deformation in situ.The key constituents are the mechanosensory units,which are dynamic dimers bonded by ureidopyrimidinone(UPy)groups and tetraphenylethylene(TPE)for the fluorescence signal output.The photoluminescence(PL)technique successfully monitors elastomer chain deformation under external forces.The PL intensity increases linearly at low elongation,in excellent agreement with Hooke’s law for ideal chains.Strong deviation from linear PL intensity is measured at high elongation,which can be theoretically described by the Langevin function.A correlation between the microscopic and the macroscopic level is then built.Chao Li Xiqi Zhang Longfei Luo Lei Jiang Longcheng Gao 2022CCS Chemistry2022,4,3:0
16Peptidomimetic-liganded gold nanoclusters for controlled iron delivery and synergistic suppression of tumor growth显示文摘A novel peptidomimetic-liganded gold nanocluster(CDp-AuNC)is proposed for the synergistic suppression of tumor growth.Taking advantages of the multi-capabilities offered by the surface ligands,including iron chelation,glutathione peroxidases-1(GPx-1)binding,and tumor cells recognition,CDp-AuNCs are able to function as the nanocarriers to deliver iron in a controlled manner for the ferroptosis therapy and as the inhibitors for GPx-1 to induce the apoptosis of tumor cells.The Fe2+@CDp-AuNC nanocomplexes are fabricated through a facile self-assembly method.The experimental data verify that the nanocomplexes are internalized specifically by tumor cells with high efficiency.The acidic microenvironment in endosomes triggers the collapse of the nanocomplexes and thereby releases Fe2+to induce ferroptosis and CDp-AuNCs to inhibit the enzyme activity of GPx-1.Benefiting from the H_(2)O_(2)-depleted pathway inhibition and ferroptosis acceleration,the intracellular reactive oxygen species(ROS)level could be enhanced significantly.As a consequence,the apoptosis/ferroptosis of 4T1 cells as well as the tumor elimination in vivo are observed after treatment with the Fe2+@CDp-AuNC nanocomplexes at a relatively low dose.The facile iron loading method,simple construction procedure,and outstanding tumor suppression performance,provide CDp-AuNCs great application promise.More importantly,the strategy of peptidomimetic ligands design provides a transferable approach to building multifunctional nanomaterials.Xiqi Ma Duo Cai Zhixiong Zhang Qi Dai Xinyu Li Biao Yu Baosheng Ge Shihai Liu Xiaojuan Wang Fang Huang 2023Nano Research2023,16,10:0
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