Heart rate variability(HRV)that can reflect the dynamic balance between the sympathetic nervous and parasympathetic nervous of human autonomic nervous system(ANS)has attracted considerable attention.However,traditiona...Heart rate variability(HRV)that can reflect the dynamic balance between the sympathetic nervous and parasympathetic nervous of human autonomic nervous system(ANS)has attracted considerable attention.However,traditional electrocardiogram(ECG)devices for HRV analysis are bulky,and hard wires are needed to attach measuring electrodes to the chest,resulting in the poor wearable experience during the long-term measurement.Compared with that,wearable electronics enabling continuously cardiac signals monitoring and HRV assessment provide a desirable and promising approach for helping subjects determine sleeping issues,cardiovascular diseases,or other threats to physical and mental well-being.Until now,significant progress and advances have been achieved in wearable electronics for HRV monitoring and applications for predicting human physical and mental well-being.In this review,the latest progress in the integration of wearable electronics and HRV analysis as well as practical applications in assessment of human physical and mental health are included.The commonly used methods and physiological signals for HRV analysis are briefly summarized.Furthermore,we highlighted the research on wearable electronics concerning HRV assessment and diverse applications such as stress estimation,drowsiness detection,etc.Lastly,the current limitations of the integrated wearable HRV system are concluded,and possible solutions in such a research direction are outlined.展开更多
Ultra-thin crystalline silicon stands as a cornerstone material in the foundation of modern micro and nano electronics.Despite the proliferation of various materials including oxide-based,polymer-based,carbon-based,an...Ultra-thin crystalline silicon stands as a cornerstone material in the foundation of modern micro and nano electronics.Despite the proliferation of various materials including oxide-based,polymer-based,carbon-based,and two-dimensional(2D)materials,crystal silicon continues to maintain its stronghold,owing to its superior functionality,scalability,stability,reliability,and uniformity.Nonetheless,the inherent rigidity of the bulk silicon leads to incompatibility with soft tissues,hindering the utilization amid biomedical applications.Because of such issues,decades of research have enabled successful utilization of various techniques to precisely control the thickness and morphology of silicon layers at the scale of several nanometres.This review provides a comprehensive exploration on the features of ultra-thin single crystalline silicon as a semiconducting material,and its role especially among the frontier of advanced bioelectronics.Key processes that enable the transition of rigid silicon to flexible form factors are exhibited,in accordance with their chronological sequence.The inspected stages span both prior and subsequent to transferring the silicon membrane,categorized respectively as on-wafer manufacturing and rigid-to-soft integration.Extensive guidelines to unlock the full potential of flexible electronics are provided through ordered analysis of each manufacturing procedure,the latest findings of biomedical applications,along with practical perspectives for researchers and manufacturers.展开更多
ICSED (Improved Cluster Shade Edge Detection) algorithm and other various methods to accurately and efficiently detect edges on satellite data are presented. Error rate criterion is used to statistically evaluate the ...ICSED (Improved Cluster Shade Edge Detection) algorithm and other various methods to accurately and efficiently detect edges on satellite data are presented. Error rate criterion is used to statistically evaluate the performances of these methods in detecting oceanic features for both noise free and noise contaminated AVHRR (Advanced Very High Resolution Radiometer) IR image with Kuroshio. Also, practical experiments in detecting the eddy of Kuroshio with these methods are carried out for comparison. Results show that the ICSED algorithm has more advantages than other methods in detecting mesoscale features of ocean. Finally, the effectiveness of window size of ICSED method to oceanic features detection is quantitatively discussed.展开更多
It is difficult to identify suspected cases of atypical patients with coronavirus disease 2019(COVID-19),and data on severe or critical patients are scanty.This retrospective study presents the clinical,laboratory,and...It is difficult to identify suspected cases of atypical patients with coronavirus disease 2019(COVID-19),and data on severe or critical patients are scanty.This retrospective study presents the clinical,laboratory,and radiological profiles,treatments,and outcomes of atypical COVID-19 patients without respiratory symptoms or fever at onset.The study examined ten atypical patients out of 909 severe or critical patients diagnosed with COVID-19 in Wuhan Union Hospital West Campus between 25 January 2020 and 10 February 2020.Data were obtained from the electronic medical records of severe or critical patients without respiratory symptoms or fever at onset.Outcomes were followed up to discharge or death.Among 943 COVID-19 patients,909(96.4%)were severe or critical type.Of the severe or critical patients,ten(1.1%)presented without respiratory symptoms or fever at admission.The median age of the ten participants was 63 years(interquartile range(IQR):57–72),and seven participants were men.The median time from symptom onset to admission was 14 d(IQR:7–20).Eight of the ten patients had chronic diseases.The patients had fatigue(n=5),headache or dizziness(n=4),diarrhea(n=5),anorexia(n=3),nausea or vomiting(n=3),and eye discomfort(n=1).Four patients were found to have lymphopenia.Imaging examination revealed that nine patients had bilateral pneumonia and one had unilateral pneumonia.Eventually,two patients died and eight were discharged.In the discharged patients,the median time from admission to discharge lasted 24 d(IQR:13–43).In summary,some severe or critical COVID-19 patients were found to have no respiratory symptoms or fever at onset.All such atypical cases should be identified and quarantined as early as possible,since they tend to have a prolonged hospital stay or fatal outcomes.Chest computed tomography(CT)scan and nucleic acid detection should be performed immediately on close contacts of COVID-19 patients to screen out those with atypical infections,even if the contacts present without respiratory symptoms or fever at onset.展开更多
Utilizing aircraft sounding data collected from the Surface Heat Budget of the Arctic Ocean (SHEBA, 1998) campaign, the authors evaluated commonly-used profile methods for Arctic ABL height estimation by validating ag...Utilizing aircraft sounding data collected from the Surface Heat Budget of the Arctic Ocean (SHEBA, 1998) campaign, the authors evaluated commonly-used profile methods for Arctic ABL height estimation by validating against the'true'ABL height from aircraft sounding profiles, where ABL height is defined as the top of the layer with significant turbulence. Furthermore, the best performing method was used to estimate ABL height from the one-year GPS soundings obtained during SHEBA (October 1997-October 1998). It was found that the temperature gradient method produces a reliable estimate of ABL height. Additionally, the authors determined optimal threshold values of temperature gradient for stable boundary layer (SBL) and convective boundary layer (CBL) to be 6.5 K/100 m and 1.0 K/100 m, respectively. The maximum ABL height during the year was 1150 m occurred in May. Median values of Arctic ABL height in May, June, July, and August were 400 m, 430 m, 180 m, and 320 m, respectively. Arctic ABL heights are clearly higher in the spring than in the summer.展开更多
A high microwave performance enhancement-mode(E-mode)In_(0.4)Ga_(0.6)As channel metal-oxide-semiconductor field-effect transistor(MOSFET)with a Si-doped In_(0.49)Ga0.51P interfacial layer is fabricated.A 0.8-μm-gate-...A high microwave performance enhancement-mode(E-mode)In_(0.4)Ga_(0.6)As channel metal-oxide-semiconductor field-effect transistor(MOSFET)with a Si-doped In_(0.49)Ga0.51P interfacial layer is fabricated.A 0.8-μm-gate-length In_(0.4)Ga_(0.6)As MOSFET with a 5-nm Al_(2)O_(3) dielectric layer provides a current gain cutoff frequency of 16.7 GHz and a maximum oscillation frequency of 52 GHz.A semi-empirical small-signal-parameter extraction technique accounting for the low frequency anomaly of this MOSFET device is described,which is based on on-wafer S-parameter measurements.Excellent agreement between measured and simulated scattering parameters as well as the physically realistic circuit elements demonstrates the validity of this approach.展开更多
Inverse lithography technology(ILT)is intended to achieve optimal mask design to print a lithography target for a given lithography process.Full chip implementation of rigorous inverse lithography remains a challengin...Inverse lithography technology(ILT)is intended to achieve optimal mask design to print a lithography target for a given lithography process.Full chip implementation of rigorous inverse lithography remains a challenging task because of enormous computational resource requirements and long computational time.To achieve full chip ILT solution,attempts have been made by using machine learning techniques based on deep convolution neural network(DCNN).The reported input for such DCNN is the rasterized images of the lithography target;such pure geometrical input requires DCNN to possess considerable number of layers to learn the optical properties of the mask,the nonlinear imaging process,and the rigorous ILT algorithm as well.To alleviate the difficulties,we have proposed the physics based optimal feature vector design for machine learning ILT in our early report.Although physics based feature vector followed by feedforward neural network can provide the solution to machine learning ILT,the feature vector is long and it can consume considerable amount of memory resource in practical implementation.To improve the resource efficiency,we proposed a hybrid approach in this study by combining first few physics based feature maps with a specially designed DCNN structure to learn the rigorous ILT algorithm.Our results show that this approach can make machine learning ILT easy,fast and more accurate.展开更多
The rapid advancement of artificial intelligence(AI)has significantly impacted photonics,creating a symbiotic relationship that accelerates the development and applications of both fields.From the perspective of AI ai...The rapid advancement of artificial intelligence(AI)has significantly impacted photonics,creating a symbiotic relationship that accelerates the development and applications of both fields.From the perspective of AI aiding photonics,deep-learning methods and various intelligent algorithms have been developed for designing complex photonic structures,where traditional design approaches fall short.AI’s capability to process and analyze large data sets has enabled the discovery of novel materials,such as for photovoltaics,leading to enhanced light absorption and efficiency.AI is also significantly transforming the field of optical imaging with improved performance.In addition,AI-driven techniques have revolutionized optical communication systems by optimizing signal processing and enhancing the bandwidth and reliability of data transmission.Conversely,the contribution of photonics to AI is equally profound.Photonic technologies offer unparalleled advantages in the development of AI hardware,providing solutions to overcome the bottlenecks of electronic systems.The implementation of photonic neural networks,leveraging the high speed and parallelism of optical computing,demonstrates significant improvements in the processing speed and energy efficiency of AI computations.Furthermore,advancements in optical sensors and imaging technologies not only enrich AI applications with high-quality data but also expand the capabilities of AI in fields such as autonomous vehicles and medical imaging.We provide comprehensive knowledge and a detailed analysis of the current state of the art,addressing both challenges and opportunities at the intersection of AI and photonics.The multifaceted interactions between AI and photonics will be explored,illustrating how AI has become an indispensable tool in the development of photonics and how photonics,in turn,facilitates advancements in AI.Through a collection of case studies and examples,we underscore the potential of this interdisciplinary approach to drive innovation,proposing challenges and future research directions that could further harness the synergies between AI and photonics for scientific and technological breakthroughs.展开更多
Electrocaloric(EC)refrigeration,which employs ferroelectric(FE)ceramics as a working medium,is regarded as a promising green refrigeration technology that could potentially replace vapor-compression refrigeration.One ...Electrocaloric(EC)refrigeration,which employs ferroelectric(FE)ceramics as a working medium,is regarded as a promising green refrigeration technology that could potentially replace vapor-compression refrigeration.One of the principal considerations in EC application is the capacity to attain high EC strength near room temperature.In this work,we investigated the EC effect in Sm/Mn co-doped BaTiO_(3)[(Ba_(1-1.5x)Sm_(x))(Ti_(0.99)Mn_(0.01))O_(3)]ceramics.As the smallest trivalent ion that can totally occupy the A site,Sm^(3+)is not only capable of shifting the Curie temperature but also of optimizing the EC effect.Furthermore,the introduction of the Mn element into the matrix results in the formation of defect dipoles,which also serves to enhance the EC performance.Therefore,large EC strengths of △T/△E=0.49Kmm kV^(-1)(@51℃),0.34Kmm kV^(-1)(@39℃)and 0.21Kmm kV^(-1)(@30℃)were,respectively,achieved in x=0.05-0.07 ceramics,demonstrating the potential for future refrigeration applications.展开更多
Cavity magnomechanics,exhibiting remarkable experimental tunability,rich magnonic nonlinearities,and compatibility with various quantum systems,has witnessed considerable advances in recent years.However,the potential...Cavity magnomechanics,exhibiting remarkable experimental tunability,rich magnonic nonlinearities,and compatibility with various quantum systems,has witnessed considerable advances in recent years.However,the potential benefits of using cavity magnomechanical(CMM)systems in further improving the performance of quantum-enhanced sensing for weak forces remain largely unexplored.Here we show that,by squeezing the magnons,the performance of a quantum CMM sensor can be significantly enhanced beyond the standard quantum limit(SQL).We find that,for comparable parameters,two orders of magnitude enhancement in the force sensitivity can be achieved in comparison with the case without magnon squeezing.Moreover,we obtain the optimal parameter regimes of homodyne angle for minimizing the added quantum noise.Our findings provide a promising approach for highly tunable and compatible quantum force sensing using hybrid CMM devices,with potential applications ranging from quantum precision measurements to quantum information processing.展开更多
Ferroelectric phase transition has been identified as a promising avenue for designing high-performanceelectrocaloric materials for zero-emission and solid-state refrigeration. However, extensive research has been lim...Ferroelectric phase transition has been identified as a promising avenue for designing high-performanceelectrocaloric materials for zero-emission and solid-state refrigeration. However, extensive research has been limited todeveloping ferroelectric materials with large electrocaloric effects near room temperature, preventing them from meetingdiverse refrigeration requirements. In this study, by leveraging the room-temperature phase diagram of the (PbLa)(ZrTi)O_(3)solution, we prepared a series of Pb_(0.775)La_(0.15)Zr_(x)Ti_(1−x)O_(3) bulk ceramics spanning the ferroelectric and relaxor ferroelectricphase regions. This enabled the attainment of various phase transition features and temperatures. Finally, largeelectrocaloric effects, coupled with adjustable operation temperatures ranging from 150 to −45℃, are successfullyachieved through manipulation of the Zr/Ti ratio. This comprehensive range of operation temperatures effectively addressesdiverse refrigeration application requirements, ranging from industrial equipment to freezer cabinets. This work not onlyunderscores the expansion of the electrocaloric refrigeration application domain but also proposes a material designstrategy tailored to meet these evolving demands.展开更多
A robust optimal framework is designed herein to mitigate the oscillatory dynamics in a doubly fed induction generator(DFIG)even in the presence of network disturbances and input variation.To address uncertain dynamic...A robust optimal framework is designed herein to mitigate the oscillatory dynamics in a doubly fed induction generator(DFIG)even in the presence of network disturbances and input variation.To address uncertain dynamics,herein,a novel transformation formula is developed for a wind energy conversion system.An unscented Kalman filter is applied to estimate the un-measured internal states of the wind energy conversion system using terminal measurements.The detailed convergence and stability analyses of the presented framework are investigated to validate its effectiveness.Additionally,comparative modal analyses are carried out to demonstrate the improvement in the damping of critical low-frequency oscillatory modes using the presented framework.The simulation results demonstrate satisfactory performance under various operating scenarios,such as increasing and decreasing wind speed and varying the terminal voltage.The comparative performance is demonstrated to validate the effectiveness of the presented framework over that of the state-of-the-art frameworks.展开更多
Background To explore the clinical,radiological,and surgical characteristics of anterior perforated substance(APS)gliomas.Methods Twenty patients with APS glioma who were treated with surgery between March 2019 and Ja...Background To explore the clinical,radiological,and surgical characteristics of anterior perforated substance(APS)gliomas.Methods Twenty patients with APS glioma who were treated with surgery between March 2019 and January 2022 from Tiantan hospital were retrospectively reviewed.The clinical,histological and radiological data were collected.Results Twenty patients,including 7 males(55%)and 13 females(45%),with a mean age at diagnosis of 37.9 years(range,28-53 years)underwent operative intervention for APS.Headaches and dizziness were the most common preoperative symptoms in the majority patients(14,70%).Based on radiological features of MRI,the APS was classified into two subtypes,type A and type B.Seven patients(40%)in type A indicated a clear tumor margin,while 13 patients(60%)in type B showed an ill-defined margin.The surgical approach including frontal,temporal,and coronal frontal incisions for type A and type B tumors,respectively.Three patients in type A received total resection,while one patient in type B were total resected.Pathologically,12 cases(60%,12/20)were diagnosed as astrocytoma and 8 cases(20%,8/20)were oligodendroglioma.Meanwhile,17 cases(85%,17/20)had MGMT promotor methylation.Conclusion In this study,we performed the first systematic research of patients with APS glioma.Most of patients with APS presented headaches and dizziness symptoms.The APS glioma was further divided into two major radiological subtypes with relevant different surgical approaches.The APS glioma in type A were more likely to receive total resection.展开更多
This paper investigates the coupling characteristics of motion and heat transfer between airflow and ice crystals in a single-stage compressor.The motion and phase transition process of ice crystal particles were mode...This paper investigates the coupling characteristics of motion and heat transfer between airflow and ice crystals in a single-stage compressor.The motion and phase transition process of ice crystal particles were modeled using the Eulerian trajectory method and validated.The heat and mass transfer processes between airflows in compressor and ice crystals were simulated and analyzed.The melting ratio,catching efficiency,and sticking efficiency of ice crystals were obtained,as well as variations in temperature and humidity ratio in the airflow due to ice crystal phase change.The results show that the ice crystals sticking to blades in the single-stage compressor account for 10.35%of the impact mass flow rate.Additionally,the presence of ice crystals causes a 0.466 K decrease in the airflow temperature and a 0.114 g/kg(a)increase in the humidity ratio.The theoretical model and calculation method provide strong support for future ice crystal icing simulations and engine operation research.展开更多
In the applications such as food production,the environmental temperature should be measured continuously dur-ing the entire process,which requires an ultra-low-power temperature sensor for long-termly monitoring.Conv...In the applications such as food production,the environmental temperature should be measured continuously dur-ing the entire process,which requires an ultra-low-power temperature sensor for long-termly monitoring.Conventional tempera-ture sensors trade the measurement accuracy with power consumption.In this work,we present a battery-free wireless tempera-ture sensing chip for long-termly monitoring during food production.A calibrated oscillator-based CMOS temperature sensor is proposed instead of the ADC-based power-hungry circuits in conventional works.In addition,the sensor chip can harvest the power transferred by a remote reader to eliminate the use of battery.Meanwhile,the system conducts wireless bidirectional communication between the sensor chip and reader.In this way,the temperature sensor can realize both a high precision and battery-free operation.The temperature sensing chip is fabricated in 55 nm CMOS process,and the reader chip is imple-mented in 65 nm CMOS technology.Experimental results show that the temperature measurement error achieves±1.6℃ from 25 to 50℃,with battery-free readout by a remote reader.展开更多
Molecular dynamics simulations are carried out for describing growth of Pd and PdO nanoclusters using the ReaxFF force field. The resulting nanocluster structures are successfully compared to those of nanoclusters exp...Molecular dynamics simulations are carried out for describing growth of Pd and PdO nanoclusters using the ReaxFF force field. The resulting nanocluster structures are successfully compared to those of nanoclusters experimentally grown in a gas aggregation source. The PdO structure is quasi-crystalline as revealed by high resolution transmission microscope analysis for experimental PdO nanoclusters. The role of the nanocluster temperature in the molecular dynamics simulated growth is highlighted.展开更多
基金supported in part by National Science and Technology Major Project from the Minister of Science and Technology of China(2018AAA0103100).
文摘Heart rate variability(HRV)that can reflect the dynamic balance between the sympathetic nervous and parasympathetic nervous of human autonomic nervous system(ANS)has attracted considerable attention.However,traditional electrocardiogram(ECG)devices for HRV analysis are bulky,and hard wires are needed to attach measuring electrodes to the chest,resulting in the poor wearable experience during the long-term measurement.Compared with that,wearable electronics enabling continuously cardiac signals monitoring and HRV assessment provide a desirable and promising approach for helping subjects determine sleeping issues,cardiovascular diseases,or other threats to physical and mental well-being.Until now,significant progress and advances have been achieved in wearable electronics for HRV monitoring and applications for predicting human physical and mental well-being.In this review,the latest progress in the integration of wearable electronics and HRV analysis as well as practical applications in assessment of human physical and mental health are included.The commonly used methods and physiological signals for HRV analysis are briefly summarized.Furthermore,we highlighted the research on wearable electronics concerning HRV assessment and diverse applications such as stress estimation,drowsiness detection,etc.Lastly,the current limitations of the integrated wearable HRV system are concluded,and possible solutions in such a research direction are outlined.
基金support received from National Research Foundation of Korea (NRF) Grant funded by the Korea government (MSIT)(RS-2024-00353768)the National Research Foundation of Korea (NRF) Grant funded by the Korea government (MSIT)(RS-2025-02217919)+1 种基金funded by the Yonsei Fellowshipfunded by Lee Youn Jae and the KIST Institutional Program Project No.2E31603-22-140 (KJY).
文摘Ultra-thin crystalline silicon stands as a cornerstone material in the foundation of modern micro and nano electronics.Despite the proliferation of various materials including oxide-based,polymer-based,carbon-based,and two-dimensional(2D)materials,crystal silicon continues to maintain its stronghold,owing to its superior functionality,scalability,stability,reliability,and uniformity.Nonetheless,the inherent rigidity of the bulk silicon leads to incompatibility with soft tissues,hindering the utilization amid biomedical applications.Because of such issues,decades of research have enabled successful utilization of various techniques to precisely control the thickness and morphology of silicon layers at the scale of several nanometres.This review provides a comprehensive exploration on the features of ultra-thin single crystalline silicon as a semiconducting material,and its role especially among the frontier of advanced bioelectronics.Key processes that enable the transition of rigid silicon to flexible form factors are exhibited,in accordance with their chronological sequence.The inspected stages span both prior and subsequent to transferring the silicon membrane,categorized respectively as on-wafer manufacturing and rigid-to-soft integration.Extensive guidelines to unlock the full potential of flexible electronics are provided through ordered analysis of each manufacturing procedure,the latest findings of biomedical applications,along with practical perspectives for researchers and manufacturers.
文摘ICSED (Improved Cluster Shade Edge Detection) algorithm and other various methods to accurately and efficiently detect edges on satellite data are presented. Error rate criterion is used to statistically evaluate the performances of these methods in detecting oceanic features for both noise free and noise contaminated AVHRR (Advanced Very High Resolution Radiometer) IR image with Kuroshio. Also, practical experiments in detecting the eddy of Kuroshio with these methods are carried out for comparison. Results show that the ICSED algorithm has more advantages than other methods in detecting mesoscale features of ocean. Finally, the effectiveness of window size of ICSED method to oceanic features detection is quantitatively discussed.
基金This research was supported by the National Natural Science Foundation of China(82041018,81770096,81700091,and 81800094)the National Science and Technology Major Project of the Ministry of Science and Technology of China(2019ZX09301001)+1 种基金the National Key Research and Development Program of the Ministry of Science and Technology of China(2020YFC0844300)the Fundamental Research Funds for the Central Universities(China)(2020kfyXGYJ011).
文摘It is difficult to identify suspected cases of atypical patients with coronavirus disease 2019(COVID-19),and data on severe or critical patients are scanty.This retrospective study presents the clinical,laboratory,and radiological profiles,treatments,and outcomes of atypical COVID-19 patients without respiratory symptoms or fever at onset.The study examined ten atypical patients out of 909 severe or critical patients diagnosed with COVID-19 in Wuhan Union Hospital West Campus between 25 January 2020 and 10 February 2020.Data were obtained from the electronic medical records of severe or critical patients without respiratory symptoms or fever at onset.Outcomes were followed up to discharge or death.Among 943 COVID-19 patients,909(96.4%)were severe or critical type.Of the severe or critical patients,ten(1.1%)presented without respiratory symptoms or fever at admission.The median age of the ten participants was 63 years(interquartile range(IQR):57–72),and seven participants were men.The median time from symptom onset to admission was 14 d(IQR:7–20).Eight of the ten patients had chronic diseases.The patients had fatigue(n=5),headache or dizziness(n=4),diarrhea(n=5),anorexia(n=3),nausea or vomiting(n=3),and eye discomfort(n=1).Four patients were found to have lymphopenia.Imaging examination revealed that nine patients had bilateral pneumonia and one had unilateral pneumonia.Eventually,two patients died and eight were discharged.In the discharged patients,the median time from admission to discharge lasted 24 d(IQR:13–43).In summary,some severe or critical COVID-19 patients were found to have no respiratory symptoms or fever at onset.All such atypical cases should be identified and quarantined as early as possible,since they tend to have a prolonged hospital stay or fatal outcomes.Chest computed tomography(CT)scan and nucleic acid detection should be performed immediately on close contacts of COVID-19 patients to screen out those with atypical infections,even if the contacts present without respiratory symptoms or fever at onset.
基金supported by the China Meteorological Administration under Grant GYHY201006024the Chinese Academy of Sciences Strategic Priority Research Program under Grant XDA05110104spon-sorship of National Science Foundation
文摘Utilizing aircraft sounding data collected from the Surface Heat Budget of the Arctic Ocean (SHEBA, 1998) campaign, the authors evaluated commonly-used profile methods for Arctic ABL height estimation by validating against the'true'ABL height from aircraft sounding profiles, where ABL height is defined as the top of the layer with significant turbulence. Furthermore, the best performing method was used to estimate ABL height from the one-year GPS soundings obtained during SHEBA (October 1997-October 1998). It was found that the temperature gradient method produces a reliable estimate of ABL height. Additionally, the authors determined optimal threshold values of temperature gradient for stable boundary layer (SBL) and convective boundary layer (CBL) to be 6.5 K/100 m and 1.0 K/100 m, respectively. The maximum ABL height during the year was 1150 m occurred in May. Median values of Arctic ABL height in May, June, July, and August were 400 m, 430 m, 180 m, and 320 m, respectively. Arctic ABL heights are clearly higher in the spring than in the summer.
基金Supported by the National Basic Research Program of China under Grant Nos 2011CBA00605 and 2010CB327501the National Science&Technology Major Project under Grant No 2011ZX02708-003One Hundred Talents Program of Chinese Academy of Sciences,and the Scientific Research Foundation for the Returned Overseas Chinese Scholars,the Ministry of Education of China.
文摘A high microwave performance enhancement-mode(E-mode)In_(0.4)Ga_(0.6)As channel metal-oxide-semiconductor field-effect transistor(MOSFET)with a Si-doped In_(0.49)Ga0.51P interfacial layer is fabricated.A 0.8-μm-gate-length In_(0.4)Ga_(0.6)As MOSFET with a 5-nm Al_(2)O_(3) dielectric layer provides a current gain cutoff frequency of 16.7 GHz and a maximum oscillation frequency of 52 GHz.A semi-empirical small-signal-parameter extraction technique accounting for the low frequency anomaly of this MOSFET device is described,which is based on on-wafer S-parameter measurements.Excellent agreement between measured and simulated scattering parameters as well as the physically realistic circuit elements demonstrates the validity of this approach.
文摘Inverse lithography technology(ILT)is intended to achieve optimal mask design to print a lithography target for a given lithography process.Full chip implementation of rigorous inverse lithography remains a challenging task because of enormous computational resource requirements and long computational time.To achieve full chip ILT solution,attempts have been made by using machine learning techniques based on deep convolution neural network(DCNN).The reported input for such DCNN is the rasterized images of the lithography target;such pure geometrical input requires DCNN to possess considerable number of layers to learn the optical properties of the mask,the nonlinear imaging process,and the rigorous ILT algorithm as well.To alleviate the difficulties,we have proposed the physics based optimal feature vector design for machine learning ILT in our early report.Although physics based feature vector followed by feedforward neural network can provide the solution to machine learning ILT,the feature vector is long and it can consume considerable amount of memory resource in practical implementation.To improve the resource efficiency,we proposed a hybrid approach in this study by combining first few physics based feature maps with a specially designed DCNN structure to learn the rigorous ILT algorithm.Our results show that this approach can make machine learning ILT easy,fast and more accurate.
基金supported by the National Science and Technology Major Project(Grant No.2021ZD0109904)the National Natural Science Foundation of China(Grant Nos.T2325022,U23A2074,12274031,62135004,and 62305307)+1 种基金the Beijing Institute of Technology Science and Technology Innovation Plan(Grant No.2022CX01006)the Key R&D Program of Zhejiang(Grant No.2024SSYS0014).
文摘The rapid advancement of artificial intelligence(AI)has significantly impacted photonics,creating a symbiotic relationship that accelerates the development and applications of both fields.From the perspective of AI aiding photonics,deep-learning methods and various intelligent algorithms have been developed for designing complex photonic structures,where traditional design approaches fall short.AI’s capability to process and analyze large data sets has enabled the discovery of novel materials,such as for photovoltaics,leading to enhanced light absorption and efficiency.AI is also significantly transforming the field of optical imaging with improved performance.In addition,AI-driven techniques have revolutionized optical communication systems by optimizing signal processing and enhancing the bandwidth and reliability of data transmission.Conversely,the contribution of photonics to AI is equally profound.Photonic technologies offer unparalleled advantages in the development of AI hardware,providing solutions to overcome the bottlenecks of electronic systems.The implementation of photonic neural networks,leveraging the high speed and parallelism of optical computing,demonstrates significant improvements in the processing speed and energy efficiency of AI computations.Furthermore,advancements in optical sensors and imaging technologies not only enrich AI applications with high-quality data but also expand the capabilities of AI in fields such as autonomous vehicles and medical imaging.We provide comprehensive knowledge and a detailed analysis of the current state of the art,addressing both challenges and opportunities at the intersection of AI and photonics.The multifaceted interactions between AI and photonics will be explored,illustrating how AI has become an indispensable tool in the development of photonics and how photonics,in turn,facilitates advancements in AI.Through a collection of case studies and examples,we underscore the potential of this interdisciplinary approach to drive innovation,proposing challenges and future research directions that could further harness the synergies between AI and photonics for scientific and technological breakthroughs.
基金supported by the Sichuan Science and Technology Program(No.2023NSFSC0975)National Natural Science Foundation of China(Nos.52302134 and 52302135)+1 种基金Scientific Research Foundation of Chengdu University of Information Technology(No.KYTZ202246)open research fund of the Sichuan Province Key Laboratory of Information Materials and Devices Application(No.2023XXCL003).
文摘Electrocaloric(EC)refrigeration,which employs ferroelectric(FE)ceramics as a working medium,is regarded as a promising green refrigeration technology that could potentially replace vapor-compression refrigeration.One of the principal considerations in EC application is the capacity to attain high EC strength near room temperature.In this work,we investigated the EC effect in Sm/Mn co-doped BaTiO_(3)[(Ba_(1-1.5x)Sm_(x))(Ti_(0.99)Mn_(0.01))O_(3)]ceramics.As the smallest trivalent ion that can totally occupy the A site,Sm^(3+)is not only capable of shifting the Curie temperature but also of optimizing the EC effect.Furthermore,the introduction of the Mn element into the matrix results in the formation of defect dipoles,which also serves to enhance the EC performance.Therefore,large EC strengths of △T/△E=0.49Kmm kV^(-1)(@51℃),0.34Kmm kV^(-1)(@39℃)and 0.21Kmm kV^(-1)(@30℃)were,respectively,achieved in x=0.05-0.07 ceramics,demonstrating the potential for future refrigeration applications.
基金supported by the National Natural Science Foundation of China(Grant No.11935006)supported by the National Natural Science Foundation of China(Grant No.12205054)+7 种基金the Science and Technology Innovation Program of Hunan Province(Grant No.2020RC4047)National Key R&D Program of China(Grant No.2024YFE0102400)Hunan Provincial Major Scitech Program(Grant No.2023ZJ1010)Ph.D.Research Foundation(BSJJ202122)supported by the Japan Society for the Promotion of Science(JSPS)Postdoctoral Fellowships for Research in Japan(No.P22018)Nippon Telegraph and Telephone Corporation(NTT)Research,the Japan Science and Technology Agency(JST)(via the Quantum Leap Flagship Program(Q-LEAP),and the Moonshot R&D(Grant No.JPMJMS2061))the Asian Office of Aerospace Research and Development(AOARD)(Grant No.FA2386-20-1-4069)the Office of Naval Research(ONR)Global(Grant No.N62909-23-1-2074)。
文摘Cavity magnomechanics,exhibiting remarkable experimental tunability,rich magnonic nonlinearities,and compatibility with various quantum systems,has witnessed considerable advances in recent years.However,the potential benefits of using cavity magnomechanical(CMM)systems in further improving the performance of quantum-enhanced sensing for weak forces remain largely unexplored.Here we show that,by squeezing the magnons,the performance of a quantum CMM sensor can be significantly enhanced beyond the standard quantum limit(SQL).We find that,for comparable parameters,two orders of magnitude enhancement in the force sensitivity can be achieved in comparison with the case without magnon squeezing.Moreover,we obtain the optimal parameter regimes of homodyne angle for minimizing the added quantum noise.Our findings provide a promising approach for highly tunable and compatible quantum force sensing using hybrid CMM devices,with potential applications ranging from quantum precision measurements to quantum information processing.
基金supported by the National Natural Science Foundation of China(Nos.52302134 and 52173217)the Sichuan Science and Technology Program(No.2023NSFSC0975)+1 种基金the Scientific Research Foundation of Chengdu University of Information Technology(No.KYTZ202246)the open research fund of the Sichuan Province Key Laboratory of Information Materials and Devices Application(No.2023XXCL003).
文摘Ferroelectric phase transition has been identified as a promising avenue for designing high-performanceelectrocaloric materials for zero-emission and solid-state refrigeration. However, extensive research has been limited todeveloping ferroelectric materials with large electrocaloric effects near room temperature, preventing them from meetingdiverse refrigeration requirements. In this study, by leveraging the room-temperature phase diagram of the (PbLa)(ZrTi)O_(3)solution, we prepared a series of Pb_(0.775)La_(0.15)Zr_(x)Ti_(1−x)O_(3) bulk ceramics spanning the ferroelectric and relaxor ferroelectricphase regions. This enabled the attainment of various phase transition features and temperatures. Finally, largeelectrocaloric effects, coupled with adjustable operation temperatures ranging from 150 to −45℃, are successfullyachieved through manipulation of the Zr/Ti ratio. This comprehensive range of operation temperatures effectively addressesdiverse refrigeration application requirements, ranging from industrial equipment to freezer cabinets. This work not onlyunderscores the expansion of the electrocaloric refrigeration application domain but also proposes a material designstrategy tailored to meet these evolving demands.
基金supported in part by the National Natural Science Foundation of China(No.62103296)the UK Engineering and Physical Sciences Research Council(No.EP/T021713/1)the Shanxi Scholarship Council of China(No.2023-062).
文摘A robust optimal framework is designed herein to mitigate the oscillatory dynamics in a doubly fed induction generator(DFIG)even in the presence of network disturbances and input variation.To address uncertain dynamics,herein,a novel transformation formula is developed for a wind energy conversion system.An unscented Kalman filter is applied to estimate the un-measured internal states of the wind energy conversion system using terminal measurements.The detailed convergence and stability analyses of the presented framework are investigated to validate its effectiveness.Additionally,comparative modal analyses are carried out to demonstrate the improvement in the damping of critical low-frequency oscillatory modes using the presented framework.The simulation results demonstrate satisfactory performance under various operating scenarios,such as increasing and decreasing wind speed and varying the terminal voltage.The comparative performance is demonstrated to validate the effectiveness of the presented framework over that of the state-of-the-art frameworks.
基金funding by the National Natural Science Foundation of China(No.81772005,No.82102764)the collaborative innovative major special project supported by Beijing Municipal Science&Technology Commission(No.Z191100006619088)
文摘Background To explore the clinical,radiological,and surgical characteristics of anterior perforated substance(APS)gliomas.Methods Twenty patients with APS glioma who were treated with surgery between March 2019 and January 2022 from Tiantan hospital were retrospectively reviewed.The clinical,histological and radiological data were collected.Results Twenty patients,including 7 males(55%)and 13 females(45%),with a mean age at diagnosis of 37.9 years(range,28-53 years)underwent operative intervention for APS.Headaches and dizziness were the most common preoperative symptoms in the majority patients(14,70%).Based on radiological features of MRI,the APS was classified into two subtypes,type A and type B.Seven patients(40%)in type A indicated a clear tumor margin,while 13 patients(60%)in type B showed an ill-defined margin.The surgical approach including frontal,temporal,and coronal frontal incisions for type A and type B tumors,respectively.Three patients in type A received total resection,while one patient in type B were total resected.Pathologically,12 cases(60%,12/20)were diagnosed as astrocytoma and 8 cases(20%,8/20)were oligodendroglioma.Meanwhile,17 cases(85%,17/20)had MGMT promotor methylation.Conclusion In this study,we performed the first systematic research of patients with APS glioma.Most of patients with APS presented headaches and dizziness symptoms.The APS glioma was further divided into two major radiological subtypes with relevant different surgical approaches.The APS glioma in type A were more likely to receive total resection.
基金the Key Laboratory of Icing and Anti/De-icing of CARDC(IADL20210102)the National Natural Science Foundation of China(52272428)+1 种基金the Fundamental Research Funds for the Central Universities(YWF-22-L-732,YWF-23-SDHK-L-003)111 Center(B18002)for financial supports of this work.
文摘This paper investigates the coupling characteristics of motion and heat transfer between airflow and ice crystals in a single-stage compressor.The motion and phase transition process of ice crystal particles were modeled using the Eulerian trajectory method and validated.The heat and mass transfer processes between airflows in compressor and ice crystals were simulated and analyzed.The melting ratio,catching efficiency,and sticking efficiency of ice crystals were obtained,as well as variations in temperature and humidity ratio in the airflow due to ice crystal phase change.The results show that the ice crystals sticking to blades in the single-stage compressor account for 10.35%of the impact mass flow rate.Additionally,the presence of ice crystals causes a 0.466 K decrease in the airflow temperature and a 0.114 g/kg(a)increase in the humidity ratio.The theoretical model and calculation method provide strong support for future ice crystal icing simulations and engine operation research.
基金supported by the National Key R&D Program of China under Grant 2024YFE0203500Xiaomi Young Talents Program。
文摘In the applications such as food production,the environmental temperature should be measured continuously dur-ing the entire process,which requires an ultra-low-power temperature sensor for long-termly monitoring.Conventional tempera-ture sensors trade the measurement accuracy with power consumption.In this work,we present a battery-free wireless tempera-ture sensing chip for long-termly monitoring during food production.A calibrated oscillator-based CMOS temperature sensor is proposed instead of the ADC-based power-hungry circuits in conventional works.In addition,the sensor chip can harvest the power transferred by a remote reader to eliminate the use of battery.Meanwhile,the system conducts wireless bidirectional communication between the sensor chip and reader.In this way,the temperature sensor can realize both a high precision and battery-free operation.The temperature sensing chip is fabricated in 55 nm CMOS process,and the reader chip is imple-mented in 65 nm CMOS technology.Experimental results show that the temperature measurement error achieves±1.6℃ from 25 to 50℃,with battery-free readout by a remote reader.
文摘Molecular dynamics simulations are carried out for describing growth of Pd and PdO nanoclusters using the ReaxFF force field. The resulting nanocluster structures are successfully compared to those of nanoclusters experimentally grown in a gas aggregation source. The PdO structure is quasi-crystalline as revealed by high resolution transmission microscope analysis for experimental PdO nanoclusters. The role of the nanocluster temperature in the molecular dynamics simulated growth is highlighted.
