As the life expectancy of the world’s population increases,age-related diseases are emerging as one of the greatest problems facing modern society.The onset of dementia and neurodegenerative diseases is strictly depe...As the life expectancy of the world’s population increases,age-related diseases are emerging as one of the greatest problems facing modern society.The onset of dementia and neurodegenerative diseases is strictly dependent on aging as a major risk factor and has a profound impact on various aspects of the lives of individuals and their families.展开更多
Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and ...Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBL02 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July,while on the western slope,it was affected by the relative humidity in the previous June–August,the current May–July and the precipitation in the current May–July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.展开更多
Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% oforal malignancies and impairs appearance, pronunciation, swallowing, and flavor perception...Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% oforal malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases werereported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ),and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oralmucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involvesgenetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeuticinterventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCCand OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors,thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC.Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitatecomprehension and provide several prospective outlooks for the fields.展开更多
1|CURRENT UNDERSTANDING OF LNCRNAS Long non-coding RNAs(lncRNAs)are a class of regulatory RNA molecules that have captured the attention of researchers in recent years due to their diverse roles in development,physiol...1|CURRENT UNDERSTANDING OF LNCRNAS Long non-coding RNAs(lncRNAs)are a class of regulatory RNA molecules that have captured the attention of researchers in recent years due to their diverse roles in development,physiological and pathological processes.展开更多
This year marks the seventh anniversary of the launch of the Lancang-Mekong Cooperation(LMC)mechanism and the first year of the Five-Year Plan of Action on the Lancang-Mekong Cooperation(2023-2027).Theseventh LMC Fore...This year marks the seventh anniversary of the launch of the Lancang-Mekong Cooperation(LMC)mechanism and the first year of the Five-Year Plan of Action on the Lancang-Mekong Cooperation(2023-2027).Theseventh LMC Foreign Ministers’Meeting in July 2022 formally proposed jointly building the region into a pilot zone for the Global Security Initiative(GSI).Recently,China officially released the“The Global Security Initiative Concept Paper,”which again clearly stated that it supports“efforts to promote cooperation in non-traditional security areas under the framework of the LMC,striving to foster a pilot zone for the GSI.”In the future,the GSI will expand cooperation among Lancang-Mekong countries in new directions and with new momentum,at both conceptual and practical levels.展开更多
Anti-jamming solutions based on antenna arrays enhance the anti-jamming ability and the robustness of global navigation satellite system(GNSS)receiver remarkably.However,the performance of the receiver will deteriorat...Anti-jamming solutions based on antenna arrays enhance the anti-jamming ability and the robustness of global navigation satellite system(GNSS)receiver remarkably.However,the performance of the receiver will deteriorate significantly in the overloaded interferences scenario.We define the overloaded interferences scenario as where the number of interferences is more than or equal to the number of antenna arrays elements.In this paper,the effect mechanism of interferences with different incident directions is found by studying the anti-jamming performance of the adaptive space filter.The theoretical analysis and conclusions,which are first validated through numerical examples,reveal the relationships between the optimal weight vector and the eigenvectors of the input signal autocorrelation matrix,the relationships between the interference cancellation ratio(ICR),the signal to interference and noise power ratio(SINR)of the adaptive space filter output and the number of interferences,the eigenvalues of the input signal autocorrelation matrix.In addition,two simulation experiments are utilized to further corroborate the theoretical findings through soft anti-jamming receiver.The simulation results match well with the theoretical analysis results,thus validating the effect mechanism of overloaded interferences.The simulation results show that,for a four elements circular array,the performance difference is up to 19 dB with different incident directions of interferences.Anti-jamming performance evaluation and jamming deployment optimization can obtain more accurate and efficient results by using the conclusions.展开更多
The rock fracture characteristics and principal stress directions are crucial for prevention of geological disasters.In this study,we carried out biaxial compression tests on cubic granite samples of 100 mm in side le...The rock fracture characteristics and principal stress directions are crucial for prevention of geological disasters.In this study,we carried out biaxial compression tests on cubic granite samples of 100 mm in side length with different intermediate principal stress gradients in combination with acoustic emission(AE)technique.Results show that the fracture characteristics of granite samples change from‘sudden and aggregated’to‘continuous and dispersed’with the increase of the intermediate principal stress.The effect of increasing intermediate principal stress on AE amplitude is not significant,but it increases the proportions of high-frequency AE signals and shear cracks,which in turn increases the possibility of unstable rock failure.The difference of stress in different directions causes the anisotropy of rock fracture and thus leads to the obvious anisotropic characteristics of wave velocity variations.The anisotropy of wave velocity variations with stress difference is probable to identify the principal stress directions.The AE characteristics and the anisotropy of wave velocity variations of granite under two-dimensional stress are not only beneficial complements for rock fracture characteristic and principal stress direction identification,but also can provide a new analysis method for stability monitoring in practical rock engineering.展开更多
In this paper,we consider the practical prescribed-time performance guaranteed tracking control problem for a class of uncertain strict-feedback systems subject to unknown control direction.Due to the existence of unk...In this paper,we consider the practical prescribed-time performance guaranteed tracking control problem for a class of uncertain strict-feedback systems subject to unknown control direction.Due to the existence of unknown nonlinearities and uncertainties,it is challenging to design a controller that can ensure the stability of closed-loop system within a predetermined finite time while maintaining the specified transient performance.The underlying problem becomes further complex as the control directions are unknown.To deal with the above problems,a special translation function as well as Nussbaum type function are introduced in the prescribed performance control(PPC)framework.Finally,a PPC as well as preset finite time tracking control scheme is designed,and its effectiveness is confirmed by both theoretical analysis and numerical simulation.展开更多
Cloud microphysical processes occur at the smallest end of scales among cloud-related processes and thus must be parameterized not only in large-scale global circulation models(GCMs)but also in various higher-resoluti...Cloud microphysical processes occur at the smallest end of scales among cloud-related processes and thus must be parameterized not only in large-scale global circulation models(GCMs)but also in various higher-resolution limited-area models such as cloud-resolving models(CRMs)and large-eddy simulation(LES)models.Instead of giving a comprehensive review of existing microphysical parameterizations that have been developed over the years,this study concentrates purposely on several topics that we believe are understudied but hold great potential for further advancing bulk microphysics parameterizations:multi-moment bulk microphysics parameterizations and the role of the spectral shape of hydrometeor size distributions;discrete vs“continuous”representation of hydrometeor types;turbulence-microphysics interactions including turbulent entrainment-mixing processes and stochastic condensation;theoretical foundations for the mathematical expressions used to describe hydrometeor size distributions and hydrometeor morphology;and approaches for developing bulk microphysics parameterizations.Also presented are the spectral bin scheme and particle-based scheme(especially,super-droplet method)for representing explicit microphysics.Their advantages and disadvantages are elucidated for constructing cloud models with detailed microphysics that are essential to developing processes understanding and bulk microphysics parameterizations.Particle-resolved direct numerical simulation(DNS)models are described as an emerging technique to investigate turbulence-microphysics interactions at the most fundamental level by tracking individual particles and resolving the smallest turbulent eddies in turbulent clouds.Outstanding challenges and future research directions are explored as well.展开更多
Pterygium,a common ocular surface disorder,has a complex pathophysiology that may mimic tumorigenesis.There is altered expression of cell cycle/proliferation-related factors in pterygium tissues.Therefore,similar to c...Pterygium,a common ocular surface disorder,has a complex pathophysiology that may mimic tumorigenesis.There is altered expression of cell cycle/proliferation-related factors in pterygium tissues.Therefore,similar to cancer treatments,the management of pterygium ought to be multifactorial based on the patient’s condition.Current therapeutic methods for pterygium are focused on surgical resection in conjunction with antimetabolite use,in addition tissue graft is usually performed in the context of the avoidance of bare sclera.However,future directions in the management of pterygia will likely focus on genetic approaches.This perspective views the pathogenesis of pterygium,its existing therapies as well as current and future challenges in its treatment.展开更多
As a promising renewable energy,offshore wind energy currently is gaining more attention,by which the economic and efficient operation of floating wind turbine systems is a potential research direction.This study is p...As a promising renewable energy,offshore wind energy currently is gaining more attention,by which the economic and efficient operation of floating wind turbine systems is a potential research direction.This study is primarily devoted to the analysis of dynamic response of the NREL-5 MW reference wind turbine supported by an OC3-Hywind SPAR-type platform using a recompiled code which combines FAST with WAMIT.To verify the reliability of the recompiled code,the free decay motions of a floating wind turbine system in still water are examined with satisfactory results.After that,thirteen scenarios with different angles between wind and wave from 0°to 90°are investigated.The dynamic responses of the turbine system in various degrees of freedom(DOFs)for different incident wind/wave directions are presented in both time and frequency domains via the fast Fourier transform.展开更多
The shale gas resources in China have great potential and the geological resources of shale gas is over 100×10^(12)m^(3),which includes about 20×10^(12)m^(3) of recoverable resources.Organic-rich shales can ...The shale gas resources in China have great potential and the geological resources of shale gas is over 100×10^(12)m^(3),which includes about 20×10^(12)m^(3) of recoverable resources.Organic-rich shales can be divided into three types according to their sedimentary environments,namely marine,marine-continental transitional,and continental shales,which are distributed in 13 stratigraphic systems from the Mesoproterozoic to the Cenozoic.The Sichuan Basin and its surrounding areas have the highest geological resources of shale gas,and the commercial development of shale gas has been achieved in the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in these areas,with a shale gas production of up to 20×10^(9)m^(3) in 2020.China has seen rapid shale gas exploration and development over the last five years,successively achieving breakthroughs and important findings in many areas and strata.The details are as follows.(1)Large-scale development of middle-shallow shale gas(burial depth:less than 3500 m)has been realized,with the productivity having rapidly increased;(2)breakthroughs have been constantly made in the development of deep shale gas(burial depth:3500-4500 m),and the ultradeep shale gas(burial depth:greater than 4500 m)is under testing;(3)breakthroughs have been made in the development of normal-pressure shale gas,and the assessment of the shale gas in complex tectonic areas is being accelerated;(4)shale gas has been frequently discovered in new areas and new strata,exhibiting a great prospect.Based on the exploration and development practice,three aspects of consensus have been gradually reached on the research progress in the geological theories of shale gas achieved in China.(1)in terms of deep-water fine-grained sediments,organic-rich shales are the base for the formation of shale gas;(2)in terms of high-quality reservoirs,the development of micro-nano organic matter-hosted pores serves as the core of shale gas accumulation;(3)in terms of preservation conditions,weak structural transformation,a moderate degree of thermal evolution,and a high pressure coefficient are the key to shale gas enrichment.As a type of important low-carbon fossil energy,shale gas will play an increasingly important role in achieving the strategic goals of peak carbon dioxide emissions and carbon neutrality.Based on the in-depth study of shale gas geological conditions and current exploration progress,three important directions for shale gas exploration in China in the next five years are put forward.展开更多
Mg-5Li-1Al-0.5Y alloy was rolled with different directions.The microstructure,mechanical properties and texture of the specimens were investigated with optical microscope,tensile tester and X-ray diffraction.The resul...Mg-5Li-1Al-0.5Y alloy was rolled with different directions.The microstructure,mechanical properties and texture of the specimens were investigated with optical microscope,tensile tester and X-ray diffraction.The results show that changing rolling directions can refine the grain size of as-rolled alloys.Meanwhile,rolling directions have an obvious influence on the mechanical properties and texture of Mg-5Li-1Al-0.5Y alloy,thus affecting the anisotropy of the alloy.The sheet,of which the RD(rolling direction)and ND(normal direction)are both changed between two passes,possesses the smallest anisotropy.From the texture results,changing rolling directions reduces the maximum pole density,making the highest point distribution region excursion and the highest point distributes more scatteredly.展开更多
Electricity theft is one of the major issues in developing countries which is affecting their economy badly.Especially with the introduction of emerging technologies,this issue became more complicated.Though many new ...Electricity theft is one of the major issues in developing countries which is affecting their economy badly.Especially with the introduction of emerging technologies,this issue became more complicated.Though many new energy theft detection(ETD)techniques have been proposed by utilising different data mining(DM)techniques,state&network(S&N)based techniques,and game theory(GT)techniques.Here,a detailed survey is presented where many state-of-the-art ETD techniques are studied and analysed for their strengths and limitations.Three levels of taxonomy are presented to classify state-of-the-art ETD techniques.Different types and ways of energy theft and their consequences are studied and summarised and different parameters to benchmark the performance of proposed techniques are extracted from literature.The challenges of different ETD techniques and their mitigation are suggested for future work.It is observed that the literature on ETD lacks knowledge management techniques that can be more effective,not only for ETD but also for theft tracking.This can help in the prevention of energy theft,in the future,as well as for ETD.展开更多
In the area of pattern recognition and machine learning,features play a key role in prediction.The famous applications of features are medical imaging,image classification,and name a few more.With the exponential grow...In the area of pattern recognition and machine learning,features play a key role in prediction.The famous applications of features are medical imaging,image classification,and name a few more.With the exponential growth of information investments in medical data repositories and health service provision,medical institutions are collecting large volumes of data.These data repositories contain details information essential to support medical diagnostic decisions and also improve patient care quality.On the other hand,this growth also made it difficult to comprehend and utilize data for various purposes.The results of imaging data can become biased because of extraneous features present in larger datasets.Feature selection gives a chance to decrease the number of components in such large datasets.Through selection techniques,ousting the unimportant features and selecting a subset of components that produces prevalent characterization precision.The correct decision to find a good attribute produces a precise grouping model,which enhances learning pace and forecast control.This paper presents a review of feature selection techniques and attributes selection measures for medical imaging.This review is meant to describe feature selection techniques in a medical domainwith their pros and cons and to signify its application in imaging data and data mining algorithms.The review reveals the shortcomings of the existing feature and attributes selection techniques to multi-sourced data.Moreover,this review provides the importance of feature selection for correct classification of medical infections.In the end,critical analysis and future directions are provided.展开更多
Age related macular degeneration(AMD)is a complex progressive neurodegenerative disease causing blindness in 30–35 million people worldwide.It affects the macula region of the retina leading to severe vision loss and...Age related macular degeneration(AMD)is a complex progressive neurodegenerative disease causing blindness in 30–35 million people worldwide.It affects the macula region of the retina leading to severe vision loss and legal blindness in individuals>50 years of age(Wong et al.,2014).The precise aetiology of AMD is unknown but smoking,age and genetic factors are major risk factors for AMD predisposition(Ding et al.,2009).展开更多
As this special volume indicates,we have multiple modalities and approaches for thinking about anxiety and its therapeutics.Our treatment approaches and understandings vary from the psychological and cognitive to the ...As this special volume indicates,we have multiple modalities and approaches for thinking about anxiety and its therapeutics.Our treatment approaches and understandings vary from the psychological and cognitive to the biological and pharmacological.We also assert that the underlying neurobiology,mechanisms and evolutionary psychology of anxiety are the best understood of any form of psychiatric disorder.Yet while most patients who suffer anxiety disorders can be helped,few are cured.Furthermore,while anxiety research is robust,as evidenced in this issue,the therapies and therapeutic outcomes of today look very much the same as 30 years ago.The most dramatically and acutely effective of pharmacological anxiolytic treatments are limited by challenges of tachyphylaxis,diversion and abuse,and withdrawal syndromes when discontinued.展开更多
All synthetic and natural estrogen receptor agonists,including the most potent physiological molecule estrogen or estradiol(E2),work typically via activation of nuclear estrogen receptor alpha(ERα)and estrogen recept...All synthetic and natural estrogen receptor agonists,including the most potent physiological molecule estrogen or estradiol(E2),work typically via activation of nuclear estrogen receptor alpha(ERα)and estrogen receptor beta(ERβ).Both ERαand ERβmodulate the expression of a variety of genes in the cells.Neurons and glial cells express ERαand ERβ.Many studies so far from our and other展开更多
On the basis of the wave energy balance equation, the response model of mean directions of locally wind-generated waves in slowly turning wind fields has been derived. The results show that in a homogeneous field, the...On the basis of the wave energy balance equation, the response model of mean directions of locally wind-generated waves in slowly turning wind fields has been derived. The results show that in a homogeneous field, the time scale of the response is not only related to the rate of wave growth, but also to the directional energy distribution and the angle between the wind direction and the mean wave direction. Furthermore, the law of change in the mean wave direction has been derived. The numerical computations show that the response of wave directions to slowly turning wind directions can be treated as the superposition of the responses of wave directions to a series of sudden small-angle changes of wind directions and the turning rate of the mean wave direction depends on the turning rate and the total turning angles of the wind direction. The response of wave directions is in agreement with the response for a sudden change of wind directions if the change in wind directions is very fast. Based on the展开更多
The electrostatic potential of carbene and nitrene,have been calculated by ABINITIO method with 6-31G** basis set,there are positive potential regions in the directionsof vacant P orbitals,and negative regions in the ...The electrostatic potential of carbene and nitrene,have been calculated by ABINITIO method with 6-31G** basis set,there are positive potential regions in the directionsof vacant P orbitals,and negative regions in the directions of lone-pair electrons.Therefore,atoms in these molecules have different electric properties in differentdirections.The idea of electrophilic and nucleophilic directions of an atom in moleculesshould be introduced.展开更多
基金funded by U.S.Air Force Office of Scientific Research,No.FA9550-21-1-0096FONDAP program,No.15150012+1 种基金Department of Defense grant,Nos.W81XWH2110960,ANID/FONDEF ID1ID22I10120,and ANID/NAM22I0057Swiss Consolidation Grant-The Leading House for the Latin American Region(all to CH)。
文摘As the life expectancy of the world’s population increases,age-related diseases are emerging as one of the greatest problems facing modern society.The onset of dementia and neurodegenerative diseases is strictly dependent on aging as a major risk factor and has a profound impact on various aspects of the lives of individuals and their families.
基金the National Natural Science Foundation of China(No.4207741741671042)。
文摘Global warming will affect growth strategies and how trees will adapt.To compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu Mountains.Correlation analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–July.The difference of the climate response to slopes was small but not negligible.Radial growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBL02 site was affected by maximum temperatures.With regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July,while on the western slope,it was affected by the relative humidity in the previous June–August,the current May–July and the precipitation in the current May–July.With the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature range.These results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.
基金supported by the National Key Research and Development Project of China (2020YFA0509400)Guangdong Basic and Applied Basic Research Foundation(2019B030302012)+1 种基金National Natural Science Foundation of China (81821002, 82130082)1·3·5 project for disciplines of excellence (ZYGD22007,ZYGC21004)
文摘Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% oforal malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases werereported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ),and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oralmucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involvesgenetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeuticinterventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCCand OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors,thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC.Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitatecomprehension and provide several prospective outlooks for the fields.
基金National Natural Science Foundation of ChinaGrant/Award Number:31970598 and 32170557+3 种基金Anhui Provincial Key Research and Development ProjectGrant/Award Number:2022e07020020Research Funds of Centre for Leading Medicine and Advanced Technologies of IHMGrant/Award Number:2023IHM01030。
文摘1|CURRENT UNDERSTANDING OF LNCRNAS Long non-coding RNAs(lncRNAs)are a class of regulatory RNA molecules that have captured the attention of researchers in recent years due to their diverse roles in development,physiological and pathological processes.
文摘This year marks the seventh anniversary of the launch of the Lancang-Mekong Cooperation(LMC)mechanism and the first year of the Five-Year Plan of Action on the Lancang-Mekong Cooperation(2023-2027).Theseventh LMC Foreign Ministers’Meeting in July 2022 formally proposed jointly building the region into a pilot zone for the Global Security Initiative(GSI).Recently,China officially released the“The Global Security Initiative Concept Paper,”which again clearly stated that it supports“efforts to promote cooperation in non-traditional security areas under the framework of the LMC,striving to foster a pilot zone for the GSI.”In the future,the GSI will expand cooperation among Lancang-Mekong countries in new directions and with new momentum,at both conceptual and practical levels.
基金supported by the National Natural Science Foundation of China(62003354).
文摘Anti-jamming solutions based on antenna arrays enhance the anti-jamming ability and the robustness of global navigation satellite system(GNSS)receiver remarkably.However,the performance of the receiver will deteriorate significantly in the overloaded interferences scenario.We define the overloaded interferences scenario as where the number of interferences is more than or equal to the number of antenna arrays elements.In this paper,the effect mechanism of interferences with different incident directions is found by studying the anti-jamming performance of the adaptive space filter.The theoretical analysis and conclusions,which are first validated through numerical examples,reveal the relationships between the optimal weight vector and the eigenvectors of the input signal autocorrelation matrix,the relationships between the interference cancellation ratio(ICR),the signal to interference and noise power ratio(SINR)of the adaptive space filter output and the number of interferences,the eigenvalues of the input signal autocorrelation matrix.In addition,two simulation experiments are utilized to further corroborate the theoretical findings through soft anti-jamming receiver.The simulation results match well with the theoretical analysis results,thus validating the effect mechanism of overloaded interferences.The simulation results show that,for a four elements circular array,the performance difference is up to 19 dB with different incident directions of interferences.Anti-jamming performance evaluation and jamming deployment optimization can obtain more accurate and efficient results by using the conclusions.
基金This work was financially supported by the National Key Research and Development Program of China(Grant No.2021YFC2900500)the International(Regional)Cooperation and Exchange Program of National Natural Science Foundation of China(Grant No.52161135301)the Special Fund for Basic Scientific Research Operations in Universities(Grant No.2282020cxqd055).
文摘The rock fracture characteristics and principal stress directions are crucial for prevention of geological disasters.In this study,we carried out biaxial compression tests on cubic granite samples of 100 mm in side length with different intermediate principal stress gradients in combination with acoustic emission(AE)technique.Results show that the fracture characteristics of granite samples change from‘sudden and aggregated’to‘continuous and dispersed’with the increase of the intermediate principal stress.The effect of increasing intermediate principal stress on AE amplitude is not significant,but it increases the proportions of high-frequency AE signals and shear cracks,which in turn increases the possibility of unstable rock failure.The difference of stress in different directions causes the anisotropy of rock fracture and thus leads to the obvious anisotropic characteristics of wave velocity variations.The anisotropy of wave velocity variations with stress difference is probable to identify the principal stress directions.The AE characteristics and the anisotropy of wave velocity variations of granite under two-dimensional stress are not only beneficial complements for rock fracture characteristic and principal stress direction identification,but also can provide a new analysis method for stability monitoring in practical rock engineering.
基金supported in part by the National Key Research and Development Program of China under grant(No.2022YFB4701400/4701401)by the National Natural Science Foundation of China under grant(No.61991400,No.61991403,No.62250710167,No.61860206008,No.61933012,No.62273064,No.62203078)+2 种基金in part by the National Key Research and Development Program of China under grant(No.2021ZD0201300)in part by the Innovation Support Program for International Students Returning to China under grant(No.cx2022016)in part by the Chongqing Medical Scientific Research Project under grant(No.2022DBXM001).
文摘In this paper,we consider the practical prescribed-time performance guaranteed tracking control problem for a class of uncertain strict-feedback systems subject to unknown control direction.Due to the existence of unknown nonlinearities and uncertainties,it is challenging to design a controller that can ensure the stability of closed-loop system within a predetermined finite time while maintaining the specified transient performance.The underlying problem becomes further complex as the control directions are unknown.To deal with the above problems,a special translation function as well as Nussbaum type function are introduced in the prescribed performance control(PPC)framework.Finally,a PPC as well as preset finite time tracking control scheme is designed,and its effectiveness is confirmed by both theoretical analysis and numerical simulation.
基金supported by the US Department of Energy(DOE)’s Office of Science Atmospheric Systems Research(ASR)Programthe Office of Energy Efficiency and Renewable Energy(EERE)Solar Energy Technologies Office(SETO)award(33504)+3 种基金the Brookhaven National Laboratory(BNL)’s Laboratory Directed Research&Development Program(LDRD)(22-065)The Brookhaven National Laboratory is operated by the Brookhaven Science Associates,LLC(BSA),for the US Department of Energy under Contract No.DESC0012704supported by JSPS KAKENHI Grant No.26286089MEXT KAKENHI Grant No.18H04448。
文摘Cloud microphysical processes occur at the smallest end of scales among cloud-related processes and thus must be parameterized not only in large-scale global circulation models(GCMs)but also in various higher-resolution limited-area models such as cloud-resolving models(CRMs)and large-eddy simulation(LES)models.Instead of giving a comprehensive review of existing microphysical parameterizations that have been developed over the years,this study concentrates purposely on several topics that we believe are understudied but hold great potential for further advancing bulk microphysics parameterizations:multi-moment bulk microphysics parameterizations and the role of the spectral shape of hydrometeor size distributions;discrete vs“continuous”representation of hydrometeor types;turbulence-microphysics interactions including turbulent entrainment-mixing processes and stochastic condensation;theoretical foundations for the mathematical expressions used to describe hydrometeor size distributions and hydrometeor morphology;and approaches for developing bulk microphysics parameterizations.Also presented are the spectral bin scheme and particle-based scheme(especially,super-droplet method)for representing explicit microphysics.Their advantages and disadvantages are elucidated for constructing cloud models with detailed microphysics that are essential to developing processes understanding and bulk microphysics parameterizations.Particle-resolved direct numerical simulation(DNS)models are described as an emerging technique to investigate turbulence-microphysics interactions at the most fundamental level by tracking individual particles and resolving the smallest turbulent eddies in turbulent clouds.Outstanding challenges and future research directions are explored as well.
文摘Pterygium,a common ocular surface disorder,has a complex pathophysiology that may mimic tumorigenesis.There is altered expression of cell cycle/proliferation-related factors in pterygium tissues.Therefore,similar to cancer treatments,the management of pterygium ought to be multifactorial based on the patient’s condition.Current therapeutic methods for pterygium are focused on surgical resection in conjunction with antimetabolite use,in addition tissue graft is usually performed in the context of the avoidance of bare sclera.However,future directions in the management of pterygia will likely focus on genetic approaches.This perspective views the pathogenesis of pterygium,its existing therapies as well as current and future challenges in its treatment.
文摘As a promising renewable energy,offshore wind energy currently is gaining more attention,by which the economic and efficient operation of floating wind turbine systems is a potential research direction.This study is primarily devoted to the analysis of dynamic response of the NREL-5 MW reference wind turbine supported by an OC3-Hywind SPAR-type platform using a recompiled code which combines FAST with WAMIT.To verify the reliability of the recompiled code,the free decay motions of a floating wind turbine system in still water are examined with satisfactory results.After that,thirteen scenarios with different angles between wind and wave from 0°to 90°are investigated.The dynamic responses of the turbine system in various degrees of freedom(DOFs)for different incident wind/wave directions are presented in both time and frequency domains via the fast Fourier transform.
基金supported by a project of shale gas in Southern China(DD20190561)initiated by the China Geological Surveythe project for High-level Innovative Talents in Science and Technology,Ministry of Natural Resources(12110600000018003918)。
文摘The shale gas resources in China have great potential and the geological resources of shale gas is over 100×10^(12)m^(3),which includes about 20×10^(12)m^(3) of recoverable resources.Organic-rich shales can be divided into three types according to their sedimentary environments,namely marine,marine-continental transitional,and continental shales,which are distributed in 13 stratigraphic systems from the Mesoproterozoic to the Cenozoic.The Sichuan Basin and its surrounding areas have the highest geological resources of shale gas,and the commercial development of shale gas has been achieved in the Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in these areas,with a shale gas production of up to 20×10^(9)m^(3) in 2020.China has seen rapid shale gas exploration and development over the last five years,successively achieving breakthroughs and important findings in many areas and strata.The details are as follows.(1)Large-scale development of middle-shallow shale gas(burial depth:less than 3500 m)has been realized,with the productivity having rapidly increased;(2)breakthroughs have been constantly made in the development of deep shale gas(burial depth:3500-4500 m),and the ultradeep shale gas(burial depth:greater than 4500 m)is under testing;(3)breakthroughs have been made in the development of normal-pressure shale gas,and the assessment of the shale gas in complex tectonic areas is being accelerated;(4)shale gas has been frequently discovered in new areas and new strata,exhibiting a great prospect.Based on the exploration and development practice,three aspects of consensus have been gradually reached on the research progress in the geological theories of shale gas achieved in China.(1)in terms of deep-water fine-grained sediments,organic-rich shales are the base for the formation of shale gas;(2)in terms of high-quality reservoirs,the development of micro-nano organic matter-hosted pores serves as the core of shale gas accumulation;(3)in terms of preservation conditions,weak structural transformation,a moderate degree of thermal evolution,and a high pressure coefficient are the key to shale gas enrichment.As a type of important low-carbon fossil energy,shale gas will play an increasingly important role in achieving the strategic goals of peak carbon dioxide emissions and carbon neutrality.Based on the in-depth study of shale gas geological conditions and current exploration progress,three important directions for shale gas exploration in China in the next five years are put forward.
基金This work was supported by the Heilongjiang Province Youth Skeleton Program(1252G018)Research Fund for the Doctoral Program of Higher Education(20132304110006)+3 种基金Project of Science and Technology of Heilongjiang Province Education Department(12511068)Fundamental Research Funds for the Central Universities(HEUCF20151006)Heilongjiang Province Natural Science Foundation(E201420)Harbin City Application Technology Research and Devolopment Project(2015AE005).
文摘Mg-5Li-1Al-0.5Y alloy was rolled with different directions.The microstructure,mechanical properties and texture of the specimens were investigated with optical microscope,tensile tester and X-ray diffraction.The results show that changing rolling directions can refine the grain size of as-rolled alloys.Meanwhile,rolling directions have an obvious influence on the mechanical properties and texture of Mg-5Li-1Al-0.5Y alloy,thus affecting the anisotropy of the alloy.The sheet,of which the RD(rolling direction)and ND(normal direction)are both changed between two passes,possesses the smallest anisotropy.From the texture results,changing rolling directions reduces the maximum pole density,making the highest point distribution region excursion and the highest point distributes more scatteredly.
基金supported by the European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sk?odowska-Curie Grant Agreement(801522)Science Foundation Ireland and co-funded by the European Regional Development Fund through the ADAPT Centre for Digital Content Technology(13/RC/2106_P2)。
文摘Electricity theft is one of the major issues in developing countries which is affecting their economy badly.Especially with the introduction of emerging technologies,this issue became more complicated.Though many new energy theft detection(ETD)techniques have been proposed by utilising different data mining(DM)techniques,state&network(S&N)based techniques,and game theory(GT)techniques.Here,a detailed survey is presented where many state-of-the-art ETD techniques are studied and analysed for their strengths and limitations.Three levels of taxonomy are presented to classify state-of-the-art ETD techniques.Different types and ways of energy theft and their consequences are studied and summarised and different parameters to benchmark the performance of proposed techniques are extracted from literature.The challenges of different ETD techniques and their mitigation are suggested for future work.It is observed that the literature on ETD lacks knowledge management techniques that can be more effective,not only for ETD but also for theft tracking.This can help in the prevention of energy theft,in the future,as well as for ETD.
文摘In the area of pattern recognition and machine learning,features play a key role in prediction.The famous applications of features are medical imaging,image classification,and name a few more.With the exponential growth of information investments in medical data repositories and health service provision,medical institutions are collecting large volumes of data.These data repositories contain details information essential to support medical diagnostic decisions and also improve patient care quality.On the other hand,this growth also made it difficult to comprehend and utilize data for various purposes.The results of imaging data can become biased because of extraneous features present in larger datasets.Feature selection gives a chance to decrease the number of components in such large datasets.Through selection techniques,ousting the unimportant features and selecting a subset of components that produces prevalent characterization precision.The correct decision to find a good attribute produces a precise grouping model,which enhances learning pace and forecast control.This paper presents a review of feature selection techniques and attributes selection measures for medical imaging.This review is meant to describe feature selection techniques in a medical domainwith their pros and cons and to signify its application in imaging data and data mining algorithms.The review reveals the shortcomings of the existing feature and attributes selection techniques to multi-sourced data.Moreover,this review provides the importance of feature selection for correct classification of medical infections.In the end,critical analysis and future directions are provided.
基金funding from the National Health and Medical Research Council of Australia (NHMRC) project grant 1008979Senior Research Fellowship 1028444 (PNB)+1 种基金Melbourne International research ScholarshipMelbourne International fee remission scholarship from the University of Melbourne Australia
文摘Age related macular degeneration(AMD)is a complex progressive neurodegenerative disease causing blindness in 30–35 million people worldwide.It affects the macula region of the retina leading to severe vision loss and legal blindness in individuals>50 years of age(Wong et al.,2014).The precise aetiology of AMD is unknown but smoking,age and genetic factors are major risk factors for AMD predisposition(Ding et al.,2009).
文摘As this special volume indicates,we have multiple modalities and approaches for thinking about anxiety and its therapeutics.Our treatment approaches and understandings vary from the psychological and cognitive to the biological and pharmacological.We also assert that the underlying neurobiology,mechanisms and evolutionary psychology of anxiety are the best understood of any form of psychiatric disorder.Yet while most patients who suffer anxiety disorders can be helped,few are cured.Furthermore,while anxiety research is robust,as evidenced in this issue,the therapies and therapeutic outcomes of today look very much the same as 30 years ago.The most dramatically and acutely effective of pharmacological anxiolytic treatments are limited by challenges of tachyphylaxis,diversion and abuse,and withdrawal syndromes when discontinued.
基金supported in part by the grants from the South Carolina Spinal Cord Injury Research Fund(SC SCIRF-2015-I-01,Columbia,SC,USA)the United Soybean Board(USB,Chesterfield,MO,USA)to SKR
文摘All synthetic and natural estrogen receptor agonists,including the most potent physiological molecule estrogen or estradiol(E2),work typically via activation of nuclear estrogen receptor alpha(ERα)and estrogen receptor beta(ERβ).Both ERαand ERβmodulate the expression of a variety of genes in the cells.Neurons and glial cells express ERαand ERβ.Many studies so far from our and other
文摘On the basis of the wave energy balance equation, the response model of mean directions of locally wind-generated waves in slowly turning wind fields has been derived. The results show that in a homogeneous field, the time scale of the response is not only related to the rate of wave growth, but also to the directional energy distribution and the angle between the wind direction and the mean wave direction. Furthermore, the law of change in the mean wave direction has been derived. The numerical computations show that the response of wave directions to slowly turning wind directions can be treated as the superposition of the responses of wave directions to a series of sudden small-angle changes of wind directions and the turning rate of the mean wave direction depends on the turning rate and the total turning angles of the wind direction. The response of wave directions is in agreement with the response for a sudden change of wind directions if the change in wind directions is very fast. Based on the
基金This work is supported by Scientific Fund of the Chinese Academy of Science.
文摘The electrostatic potential of carbene and nitrene,have been calculated by ABINITIO method with 6-31G** basis set,there are positive potential regions in the directionsof vacant P orbitals,and negative regions in the directions of lone-pair electrons.Therefore,atoms in these molecules have different electric properties in differentdirections.The idea of electrophilic and nucleophilic directions of an atom in moleculesshould be introduced.