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
Bismuth sodium titanate-based(Bi_(0.5)Na_(0.5)TiO_(3),BNT)leadfree piezoelectric ceramics exhibit significant potential for precision actuation because of their large electrostrain.However,the inherent trade-off betwe...Bismuth sodium titanate-based(Bi_(0.5)Na_(0.5)TiO_(3),BNT)leadfree piezoelectric ceramics exhibit significant potential for precision actuation because of their large electrostrain.However,the inherent trade-off between high electrostrain performance and temperature stability hinders their practical application.This study addresses this challenge by developing a series of Bi_(0.47)Na_(0.47)Ba_(0.06)Ti_(1−x)Hf_(x)O_(3)(BNBT-100xH)ceramics via a B-site Hf^(4+)doping strategy enabling synergistic regulation of the phase boundary and domain state.The optimized BNBT-3H composition(x=0.03)features a morphotropic phase boundary(MPB)comprising coexisting rhombohedral(R3c,51%)and tetragonal(P4bm,49%)phases,alongside a unique coexistence domain structure of ferroelectric macrodomains and relaxor nanodomains(~100 nm).This microstructural design achieves an ultrahigh bipolar electrostrain of up to 0.6%(d_(33)^(*)=500 pm/V),along with an ultralow temperature fluctuation of only 16.7%over a wide temperature range of 25–150℃.Notably,the electrostrain at 150℃decreases by only 4%compared with that at room temperature,demonstrating excellent thermal stability and overall performance superior to those of other lead-free systems.Through multiscale characterization,the origin of the high electrostrain is confirmed to stem from an electric field-induced reversible relaxor–ferroelectric phase transition,facilitated by the flattened energy landscape at the critical rhombohedral–tetragonal phase boundary.Simultaneously,the exceptional thermal stability arises from the thermal-electric driven dynamic equilibrium within the multiphase nanodomain structure.This work not only provides a high-performance material candidate for broad-temperature-range precision actuators but also offers novel insights into optimizing functional ceramics through precise microstructure control.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
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
Dengue is still a substantial vector-borne viral disease threat and burden of public health importance worldwide.This situation is complicated by dengue virus unprecedented resurgence and persistence of varied serotyp...Dengue is still a substantial vector-borne viral disease threat and burden of public health importance worldwide.This situation is complicated by dengue virus unprecedented resurgence and persistence of varied serotypes in endemic-prone areas,and man-made and natural activities consequences that promote vector emergence,transmission dynamics and spread across the Asia-Pacific region.There is an urgent need to strengthen operational and contextual surveillance-response research in improving early detection of active reservoir detection,novel drug in case management and quality evidence-based response including the deployment of dengue mass vaccination.Moreover,sustained mapping and watching of dengue risk factors or determinants,performance and outcome indicators of control or elimination programs effectiveness in defining minimum effective data towards community knowledge-based decision-making policy and effective response packages is imperative.Moreover,implementation of a robust,integrated dengue early warning surveillance,monitoring and response systems metrics is required for evidence-based,timely and cost-effective contextual mitigation strategies,and innovative interventions.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
The yam Dioscorea alata L.is widely cultivated globally.Purple-fleshed varieties of this important crop have enhanced market value due to their high anthocyanin contents,but how anthocyanin biosynthesis in D.alata tub...The yam Dioscorea alata L.is widely cultivated globally.Purple-fleshed varieties of this important crop have enhanced market value due to their high anthocyanin contents,but how anthocyanin biosynthesis in D.alata tubers is regulated remains poorly understood.In this study,we identified and functionally validated key transcription factors that regulate anthocyanin biosynthesis based on a comparative transcriptome and metabolome analysis of three D.alata cultivars with different colored tubers(dark purple,light purple,and white).The anthocyanin glycoside cyanidin-3-O-(2′′-O-glucosyl)glucoside was abundant during early tuber development,and we determined that its accumulation is regulated in opposite manners by two R2R3-MYB transcription factors:DaMYB75 and DaMYB56.Yeast two-hybrid and bimolecular fluorescence complementation assays in Nicotiana benthamiana and co-expression assays in D.alata demonstrated that DaMYB75 promotes anthocyanin biosynthesis by specifically activating the promoter of the late anthocyanin biosynthesis gene DaANS and enhancing its expression through an interaction with DabHLH72.By contrast,DaMYB56 is a negative regulator of anthocyanin biosynthesis that binds to the DaANS promoter together with DabHLH72.Furthermore,the methylation levels of the DaMYB75 promoter were significantly lower in purple tubers than in white tubers.These findings shed light on the regulation of anthocyanin biosynthesis by MYBs and provide the basis for genetically improving anthocyanin content in D.alata.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 Natural Science Foundation of China(Nos.52402149 and 12174210)the Natural Science Foundation of Shandong Province(Nos.ZR2022QE078 and ZR2021ME235)+2 种基金the Basic Research Project of Qilu Univ.of Tech.(Nos.2024RCKY020,2023PX012,and 2023RCKY120)Li also acknowledges the Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices(No.EFMD2022013M)the Major Innovation Project of Qilu University of Technology(Shandong Academy of Sciences)(No.2025ZDZX03).
文摘Bismuth sodium titanate-based(Bi_(0.5)Na_(0.5)TiO_(3),BNT)leadfree piezoelectric ceramics exhibit significant potential for precision actuation because of their large electrostrain.However,the inherent trade-off between high electrostrain performance and temperature stability hinders their practical application.This study addresses this challenge by developing a series of Bi_(0.47)Na_(0.47)Ba_(0.06)Ti_(1−x)Hf_(x)O_(3)(BNBT-100xH)ceramics via a B-site Hf^(4+)doping strategy enabling synergistic regulation of the phase boundary and domain state.The optimized BNBT-3H composition(x=0.03)features a morphotropic phase boundary(MPB)comprising coexisting rhombohedral(R3c,51%)and tetragonal(P4bm,49%)phases,alongside a unique coexistence domain structure of ferroelectric macrodomains and relaxor nanodomains(~100 nm).This microstructural design achieves an ultrahigh bipolar electrostrain of up to 0.6%(d_(33)^(*)=500 pm/V),along with an ultralow temperature fluctuation of only 16.7%over a wide temperature range of 25–150℃.Notably,the electrostrain at 150℃decreases by only 4%compared with that at room temperature,demonstrating excellent thermal stability and overall performance superior to those of other lead-free systems.Through multiscale characterization,the origin of the high electrostrain is confirmed to stem from an electric field-induced reversible relaxor–ferroelectric phase transition,facilitated by the flattened energy landscape at the critical rhombohedral–tetragonal phase boundary.Simultaneously,the exceptional thermal stability arises from the thermal-electric driven dynamic equilibrium within the multiphase nanodomain structure.This work not only provides a high-performance material candidate for broad-temperature-range precision actuators but also offers novel insights into optimizing functional ceramics through precise microstructure control.
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.
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.
文摘Dengue is still a substantial vector-borne viral disease threat and burden of public health importance worldwide.This situation is complicated by dengue virus unprecedented resurgence and persistence of varied serotypes in endemic-prone areas,and man-made and natural activities consequences that promote vector emergence,transmission dynamics and spread across the Asia-Pacific region.There is an urgent need to strengthen operational and contextual surveillance-response research in improving early detection of active reservoir detection,novel drug in case management and quality evidence-based response including the deployment of dengue mass vaccination.Moreover,sustained mapping and watching of dengue risk factors or determinants,performance and outcome indicators of control or elimination programs effectiveness in defining minimum effective data towards community knowledge-based decision-making policy and effective response packages is imperative.Moreover,implementation of a robust,integrated dengue early warning surveillance,monitoring and response systems metrics is required for evidence-based,timely and cost-effective contextual mitigation strategies,and innovative interventions.
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 by the National Natural Science Foundation of China(32460767)Jiangxi Provincial Key Research and Development Program(20232BBF60007)Jiangxi Provincial Natural Science Foundation(20224BAB205024).
文摘The yam Dioscorea alata L.is widely cultivated globally.Purple-fleshed varieties of this important crop have enhanced market value due to their high anthocyanin contents,but how anthocyanin biosynthesis in D.alata tubers is regulated remains poorly understood.In this study,we identified and functionally validated key transcription factors that regulate anthocyanin biosynthesis based on a comparative transcriptome and metabolome analysis of three D.alata cultivars with different colored tubers(dark purple,light purple,and white).The anthocyanin glycoside cyanidin-3-O-(2′′-O-glucosyl)glucoside was abundant during early tuber development,and we determined that its accumulation is regulated in opposite manners by two R2R3-MYB transcription factors:DaMYB75 and DaMYB56.Yeast two-hybrid and bimolecular fluorescence complementation assays in Nicotiana benthamiana and co-expression assays in D.alata demonstrated that DaMYB75 promotes anthocyanin biosynthesis by specifically activating the promoter of the late anthocyanin biosynthesis gene DaANS and enhancing its expression through an interaction with DabHLH72.By contrast,DaMYB56 is a negative regulator of anthocyanin biosynthesis that binds to the DaANS promoter together with DabHLH72.Furthermore,the methylation levels of the DaMYB75 promoter were significantly lower in purple tubers than in white tubers.These findings shed light on the regulation of anthocyanin biosynthesis by MYBs and provide the basis for genetically improving anthocyanin content in D.alata.
