This essay is a research report, which is based on results of grammatical error analysis and interviews with linguistic teachers. These researches are conducted in four language streams, namely, Chinese, Spanish, Kore...This essay is a research report, which is based on results of grammatical error analysis and interviews with linguistic teachers. These researches are conducted in four language streams, namely, Chinese, Spanish, Korean and Japanese. It will talk about problems identified in all these four language streams, with Chinese as the focus. Although according to various definitions, translation competence includes several parts, which are all required for a professional translator; this essay covers mainly the linguistic competence with tense and aspect issue as the main point. Meanwhile, some major causes of mistakes will be identified, such as interference of mother tongue, lack of second language proficiency. In the end, some possible ways for improvement are presented for reaching what are needed for a professional translator.展开更多
The aim of the paper is to give a general comparison about the structural composition of the AUX in English and Chinese mainly from the perspective of tense-aspect.Based on the basic construction of English AUX system...The aim of the paper is to give a general comparison about the structural composition of the AUX in English and Chinese mainly from the perspective of tense-aspect.Based on the basic construction of English AUX system,which includes such elements as Tense,Modal,Perfect aspect,Progressive aspect and Passive,the paper focuses on comparing the syntactic characteristics of tense element in the two languages.The final part of the paper briefly summarized predicted learning problems that Chinese learners of English as well as English learners of Chinese would have in learning English and Chinese respectively.展开更多
It is well known that coarse-grained super-elastic NiTi shape memory alloys(SMAs)exhibit localized rather than homogeneous martensite transformation(MT),which,however,can be strongly influenced by either internal size...It is well known that coarse-grained super-elastic NiTi shape memory alloys(SMAs)exhibit localized rather than homogeneous martensite transformation(MT),which,however,can be strongly influenced by either internal size(grain size,GS)or the external size(geometric size).The coupled effect of GS and geometric size on the functional properties has not been clearly understood yet.In this work,the super-elasticity,one-way,and stress-assisted two-way shape memory effects of the polycrystalline NiTi SMAs with different aspect ratios(length/width for the gauge section)and different GSs are investigated based on the phase field method.The coupled effect of the aspect ratio and GS on the functional properties is adequately revealed.The simulated results indicate that when the aspect ratio is lower than about 4:1,the stress biaxiality and stress heterogeneity in the gauge section of the sample become more and more obvious with decreasing the aspect ratio,which can significantly influence the microstructure evolution in the process involving external stress.Therefore,the corresponding functional property is strongly dependent on the aspect ratio.With decreasing the GS and the aspect ratio(to be lower than 4:1),both the aspect ratio and GS can affect the MT or martensite reorientation in each grain and the interaction among grains.Thus,due to the strong internal constraint(i.e.,the constraint of grain boundary)and the external constraint(i.e.,the constraint of geometric boundary),the capabilities of the functional properties of NiTi SMAs are gradually weakened and highly dependent on these two factors.展开更多
Mesqan is a South Ethio-Semitic tongue which is mainly worn in day-to-day message by a people of 179,737 communities in the Gurage Zone,Ethiopia,whose linguistic skin was not well expressed.The inner aspire of this pa...Mesqan is a South Ethio-Semitic tongue which is mainly worn in day-to-day message by a people of 179,737 communities in the Gurage Zone,Ethiopia,whose linguistic skin was not well expressed.The inner aspire of this paper is to offer a complete account of tense,aspect,mood and aktionsart structures of the Mesqan tongue.The paper is expressive in character,as the lessons are mostly worried with telling what is really being in the tongue,and mostly rely on main linguistic facts.The linguistic facts,i.e.the elicited grammatical facts regarding tense,aspect,mood and aktionsart,were composed from local speakers of the tongue during 12 months of fieldwork mannered among 2011 and 2012 in four Mesqan villages and in Butajira,the managerial hub of the Mesqan Woreda.The perfective aspect in the tongue emphasizes the endpoint of the oral state with dynamic verbs,but the imperfective aspect relates with the lexical semantics of the verb,which can be practical when their purposes with stative and dynamic verbs are evaluated.Concerning tense,the past and the non-past tense in the tongue are distinguished by assisting verbs and a verb in the imperfective aspect is able to happen with states in the past and in the non-past,i.e.present or future.Future time can also be uttered by an anticipated act throughout the grouping of the future.In addition,an action happening in the past and still around in the tongue is marked by a zero morpheme in the present perfect.Concerning mood,the language has agent-oriented moods that are articulated by verb inflection,and speaker-oriented moods that are articulated by a periphrastic structure.Regarding aktionsart that denotes a specific phase in a verbal condition,like period,regularity,etc.Mesqan has two aktionsarten which are noticeable by periphrastic structures,that is the progressive and the prospective.展开更多
This paper mainly discusses verbal aspects and their syntactic markers in Lhasa Tibetan. Since aspects in Tibetan always share markers with other important categories called evidentiality and egocentricity, the former...This paper mainly discusses verbal aspects and their syntactic markers in Lhasa Tibetan. Since aspects in Tibetan always share markers with other important categories called evidentiality and egocentricity, the former of which assesses the evidence of speaker's statement and the latter denotes behavioral characteristics of a speaker'sego-centricity, this paper simultaneously describes all three types: aspect, evidentiality and egocentricity. There are nine types of verb aspects in Lhasa Tibetan, namely: Prospective, Imminent, Premediated, Realis, Durative, Resultative, Merely-past, Perfect, and Contextual aspects. There are four types of evidentialities, namely, Self-knowledge, Knowing-by-sight, Knowing-by-newly-found-information and Knowing-by-inference evidentialities. Categories of egocentricity demonstrate whether an action is towards the Self or the Other, whether the speaker gains or loses, and so on. Additionally, this essay also discusses the interactive relationship between syntactical verb aspects and personal pronouns, intentionality, modality, as well as temporal-spatial cognition.展开更多
The core issue concerning the usage of tense and aspect is seen as significantly important(Michaelis,1994;Swales and Feak,2000),especially in English writing in college.This study identifies the erroneous use of tense...The core issue concerning the usage of tense and aspect is seen as significantly important(Michaelis,1994;Swales and Feak,2000),especially in English writing in college.This study identifies the erroneous use of tense and aspect in liberal arts students' writing in comparison with that of engineering students' to examine their application ability in writing and identify areas of English learning in need of intensive instruction.This paper displays the frequency rates of errors about two English tenses(the present and the past),two aspects(the progressive and the perfect)based on an online writing corpus of students in two majors,which leads to the result that students in both majors are more likely to make mistakes in the present time and perfect aspect,liberal arts students less influenced.In addition,engineering students writing score seems to be more related to their grammatical errors than that of liberal arts students.To improve their writings,practical teaching strategies such as being aware of cross-lingual influence,practicing grammar on context level,personalized instructions,are also provided.展开更多
Driver distraction is a leading cause of traffic accidents,with fatigue being a significant contributor.This paper introduces a novel method for detecting driver distraction by analyzing facial features using machine ...Driver distraction is a leading cause of traffic accidents,with fatigue being a significant contributor.This paper introduces a novel method for detecting driver distraction by analyzing facial features using machine deep learning and 68 face model.The proposed system assesses driver tiredness by measuring the distance between key facial landmarks,such as the distance between the eyes and the angle of the mouth,to evaluate signs of drowsiness or disengagement.Real-time video feed analysis allows for continuous monitoring of the driver’s face,enabling the system to detect behavioral cues associated with distraction,such as eye closures or changes in facial expressions.The effectiveness of this method is demonstrated through a series of experiments on a dataset of driver videos,which proves that the approach can accurately assess tiredness and distraction levels under various driving conditions.By focusing on facial landmarks,the system is computationally efficient and capable of operating in real-time,making it a practical solution for in-vehicle safety systems.This paper discusses the system’s performance,limitations,and potential for future enhancements,including integration with other in-vehicle technologies to provide comprehensive driver monitoring.展开更多
One of the main causes of cancer-related morbidity and mortality globally is hepatocellular carcinoma(HCC).At every stage of the disease,HCC may now be treated using a variety of therapy techniques.Nevertheless,despit...One of the main causes of cancer-related morbidity and mortality globally is hepatocellular carcinoma(HCC).At every stage of the disease,HCC may now be treated using a variety of therapy techniques.Nevertheless,despite the abundance of effective therapeutic choices,the prognosis for patients with HCC is still typically dismal.Prognostic indicators are crucial when assessing prognosis and tracking tumor metastases or recurrence.There are many prognostic markers in HCC.We mainly focused on newly reported prognostic markers such as MEX3A,apolipoprotein B,alpha-fetoprotein,circulating tumor cells,SAMD13,Agrin,and Glypican-3 in the pathogenesis of HCC.Further,we highlighted how these prognostic markers correlated to clinical parameters such as tumor node metastasis,tumor diameter,differentiation,hepatocirrhosis,vascular invasion,and others in HCC.Therefore,identifying specific prognostic biomarkers of HCC helps to provide a great opportunity to improve the prognosis in patients with HCC and provide therapeutic targets.展开更多
Flow characteristics around a wall-mounted square cylinder have been numerically simulated at aspect ratios (AR) ranging from 4 to 7 at Re =10 000. Four turbulence models have been compared in terms of drag coefficien...Flow characteristics around a wall-mounted square cylinder have been numerically simulated at aspect ratios (AR) ranging from 4 to 7 at Re =10 000. Four turbulence models have been compared in terms of drag coefficient (C_D). The closest result has been provided by two turbulence models, namely, k-ε Realizable and k ?ω Shear Stress Transport (SST). Hence, these models were utilized to present the flow patterns of pressure distributions, turbulent kinetic energy values, velocity magnitude values with streamlines, streamwise velocity components, crossstream velocity components and spanwise velocity components on different planes. Flow stagnation has been attained in front of the cylinder. Pressure values peaked for the upstream region. Over the cylinders, the tip vortex structure was dominant owing to the influence of the free end. Flow separation from the top front edge of the body has been obtained. The dividing streamline affected by the flow separation was highly effective in the wake region and moved nearer to the body when the aspect ratio was decreased;the reason was the wake shrinkage owing to the decreasing aspect ratio. Upwash and downwash have been seen in the cylinder wake. These two models presented similar flow patterns and drag coefficients. These drag coefficients are in good agreement with those in previous studies.展开更多
Streamlined box girders serve as a prevalent choice for the primary structural elements in large-span suspension bridge designs.With the increase in traffic demands,the design of such girders is evolving towards wider...Streamlined box girders serve as a prevalent choice for the primary structural elements in large-span suspension bridge designs.With the increase in traffic demands,the design of such girders is evolving towards wider bridge decks and larger aspect ratios(B/D).To obtain more effective and aerodynamic design shapes for streamlined box girders,it is essential to investigate the impact of B/D on their aerodynamic performance.Accordingly,in this study we investigate the buffeting responses of large-span suspension bridges using girders of varying aspect ratios(B/D of 7.5,9.3,and 12.7).First,the aerodynamic coefficients of these girders are estimated using computational fluid dynamics(CFD)simulations.Subsequently,spatial finite element(FE)models of three long-span suspension bridges with different girders(B/D of 7.5,9.3,and 12.7)are established in Ansys software,and the dynamic characteristics of these bridges are obtained.Then,the time-domain buffeting analysis is performed by simulating the fluctuating wind fields acting on the bridge through the spectral representation method.Ultimately,the buffeting responses are computed using Ansys software,and the impact of B/D on these responses is assessed.The results reveal that the root mean square(RMS)values of the main girder’s buffeting displacement are highest at the midspan position and are lowest at the ends of the bridge.A decrease in B/D of the main girder leads to a more severe buffeting response because both the range and the effective value of the displacement increase with the decreasing B/D.Comparing the buffeting displacements in three directions,B/D plays a significant role in the vertical buffeting displacement,moderately impacts the torsional displacement,and has the least effect on the lateral displacement.The findings of this study may help wind resistance analysis and design optimization for bridges.展开更多
A two-dimensional large eddy simulation numerical model is proposed to study the transient vortex flow and pressure oscillation of a large-aspect-ratio solid rocket motor.The numerical model is validated through exper...A two-dimensional large eddy simulation numerical model is proposed to study the transient vortex flow and pressure oscillation of a large-aspect-ratio solid rocket motor.The numerical model is validated through experimental data,finite element analysis and cumulative error analysis.The numerical simulations are executed to obtain the characteristics of the vortex-acoustic and pressure oscillation.The results show that the burning surface regression decreases the motor aspect ratio,increasing the corresponding natural frequency from 260 Hz to 293 Hz.The pressure oscillation phenomenon is formed due to the vortex-acoustic coupling.Decreasing the corner vortex shedding intensity shows negative effects on the dimensionless amplitude of the pressure oscillation.The head cavity without the injection can decrease the vortex-acoustic coupling level at the acoustic pressure antinode.The modified motor with head cavity can obtain a lower dimensionless oscillating pressure amplitude 0.00149 in comparison with 0.00895 of the original motor.The aspect ratio and volume of the head cavity without the injection have great effects on the pressure oscillation suppression,particularly at the low aspect ratio or large volume.The reason is that the mass in the region around the acoustic pressure antinode is extracted centrally,reducing the energy contribution to the acoustic system.With the volume increasing,the acoustic energy capacity increases.展开更多
Extensive urban areas worldwide face significant landslide hazards, impacting inhabitants, buildings, and critical infrastructures alike. In the case of slow-moving deep-seated landslides involving huge areas and char...Extensive urban areas worldwide face significant landslide hazards, impacting inhabitants, buildings, and critical infrastructures alike. In the case of slow-moving deep-seated landslides involving huge areas and characterized by complex patterns, when the cost of repairing infrastructures, relocating communities, and restoring cultural sites might be such that it is unsustainable for the community, the exposed structures require significant effort for their surveillance and protection, which can be supported by the development of innovative monitoring systems. For this purpose, a smart extenso-inclinometer, realized by equipping a conventional inclinometer tube with distributed strain and temperature transducers based on optical fiber sensing technology, is presented. In situ monitoring of the active deep-seated San Nicola landslide in Centola (Campania, southern Italy) demonstrated its ability to capture the main features of movements and reconstruct a tridimensional evolution of the landslide pattern, even when the entity of both vertical and horizontal soil strain components is comparable. Although further tests are needed to definitively ascertain the extensometer function of the new device, by interpreting the strain profiles of the landslide body and identifying the achievement of predetermined thresholds, this system could provide a warning of the trigger of a landslide event. The use of the smart extenso-inclinometer within an early warning system for slow-moving landslides holds immense potential for reducing the impact of landslide events.展开更多
Rechargeable magnesium batteries(RMBs)are a cutting-edge energy storage solution,with several advantages over the state-of-art lithiumion batteries(LIBs).The use of magnesium(Mg)metal as an anode material provides a m...Rechargeable magnesium batteries(RMBs)are a cutting-edge energy storage solution,with several advantages over the state-of-art lithiumion batteries(LIBs).The use of magnesium(Mg)metal as an anode material provides a much higher gravimetric capacity compared to graphite,which is currently used as the anode material in LIBs.Despite the significant advances in electrolyte,the development of cathode material is limited to materials that operate at low average discharge voltage(<1.0 V vs.Mg/Mg^(2+)),and developing high voltage cathodes remains challenging.Only a few materials have been shown to intercalate Mg^(2+)ions reversibly at high voltage.This review focuses on the structural aspects of cathode material that can operate at high voltage,including the Mg^(2+)intercalation mechanism in relation to its electrochemical properties.The materials are categorized into transition metal oxides and polyanions and subcategorized by the intrinsic Mg^(2+)diffusion path.This review also provides insights into the future development of each material,aiming to stimulate and guide researchers working in this field towards further advancements in high voltage cathodes.展开更多
Aspect-oriented sentiment analysis is a meticulous sentiment analysis task that aims to analyse the sentiment polarity of specific aspects. Most of the current research builds graph convolutional networks based on dep...Aspect-oriented sentiment analysis is a meticulous sentiment analysis task that aims to analyse the sentiment polarity of specific aspects. Most of the current research builds graph convolutional networks based on dependent syntactic trees, which improves the classification performance of the models to some extent. However, the technical limitations of dependent syntactic trees can introduce considerable noise into the model. Meanwhile, it is difficult for a single graph convolutional network to aggregate both semantic and syntactic structural information of nodes, which affects the final sentence classification. To cope with the above problems, this paper proposes a bi-channel graph convolutional network model. The model introduces a phrase structure tree and transforms it into a hierarchical phrase matrix. The adjacency matrix of the dependent syntactic tree and the hierarchical phrase matrix are combined as the initial matrix of the graph convolutional network to enhance the syntactic information. The semantic information feature representations of the sentences are obtained by the graph convolutional network with a multi-head attention mechanism and fused to achieve complementary learning of dual-channel features. Experimental results show that the model performs well and improves the accuracy of sentiment classification on three public benchmark datasets, namely Rest14, Lap14 and Twitter.展开更多
This paper aims at examining the perception of English tense and lax vowel contrasts by testing an identification task of CVC syllables with different manipulated durations in Chinese learners of English.This can prov...This paper aims at examining the perception of English tense and lax vowel contrasts by testing an identification task of CVC syllables with different manipulated durations in Chinese learners of English.This can provide some empirical evidence for English as a second language teachers in teaching second language pronunciation.展开更多
文摘This essay is a research report, which is based on results of grammatical error analysis and interviews with linguistic teachers. These researches are conducted in four language streams, namely, Chinese, Spanish, Korean and Japanese. It will talk about problems identified in all these four language streams, with Chinese as the focus. Although according to various definitions, translation competence includes several parts, which are all required for a professional translator; this essay covers mainly the linguistic competence with tense and aspect issue as the main point. Meanwhile, some major causes of mistakes will be identified, such as interference of mother tongue, lack of second language proficiency. In the end, some possible ways for improvement are presented for reaching what are needed for a professional translator.
文摘The aim of the paper is to give a general comparison about the structural composition of the AUX in English and Chinese mainly from the perspective of tense-aspect.Based on the basic construction of English AUX system,which includes such elements as Tense,Modal,Perfect aspect,Progressive aspect and Passive,the paper focuses on comparing the syntactic characteristics of tense element in the two languages.The final part of the paper briefly summarized predicted learning problems that Chinese learners of English as well as English learners of Chinese would have in learning English and Chinese respectively.
基金supported by the National Natural Science Foundation of China (Grant Nos.12202294 and 12022208)the Project funded by China Postdoctoral Science Foundation (Grant No.2022M712243)the Fundamental Research Funds for the Central Universities (Grant No.2023SCU12098).
文摘It is well known that coarse-grained super-elastic NiTi shape memory alloys(SMAs)exhibit localized rather than homogeneous martensite transformation(MT),which,however,can be strongly influenced by either internal size(grain size,GS)or the external size(geometric size).The coupled effect of GS and geometric size on the functional properties has not been clearly understood yet.In this work,the super-elasticity,one-way,and stress-assisted two-way shape memory effects of the polycrystalline NiTi SMAs with different aspect ratios(length/width for the gauge section)and different GSs are investigated based on the phase field method.The coupled effect of the aspect ratio and GS on the functional properties is adequately revealed.The simulated results indicate that when the aspect ratio is lower than about 4:1,the stress biaxiality and stress heterogeneity in the gauge section of the sample become more and more obvious with decreasing the aspect ratio,which can significantly influence the microstructure evolution in the process involving external stress.Therefore,the corresponding functional property is strongly dependent on the aspect ratio.With decreasing the GS and the aspect ratio(to be lower than 4:1),both the aspect ratio and GS can affect the MT or martensite reorientation in each grain and the interaction among grains.Thus,due to the strong internal constraint(i.e.,the constraint of grain boundary)and the external constraint(i.e.,the constraint of geometric boundary),the capabilities of the functional properties of NiTi SMAs are gradually weakened and highly dependent on these two factors.
文摘Mesqan is a South Ethio-Semitic tongue which is mainly worn in day-to-day message by a people of 179,737 communities in the Gurage Zone,Ethiopia,whose linguistic skin was not well expressed.The inner aspire of this paper is to offer a complete account of tense,aspect,mood and aktionsart structures of the Mesqan tongue.The paper is expressive in character,as the lessons are mostly worried with telling what is really being in the tongue,and mostly rely on main linguistic facts.The linguistic facts,i.e.the elicited grammatical facts regarding tense,aspect,mood and aktionsart,were composed from local speakers of the tongue during 12 months of fieldwork mannered among 2011 and 2012 in four Mesqan villages and in Butajira,the managerial hub of the Mesqan Woreda.The perfective aspect in the tongue emphasizes the endpoint of the oral state with dynamic verbs,but the imperfective aspect relates with the lexical semantics of the verb,which can be practical when their purposes with stative and dynamic verbs are evaluated.Concerning tense,the past and the non-past tense in the tongue are distinguished by assisting verbs and a verb in the imperfective aspect is able to happen with states in the past and in the non-past,i.e.present or future.Future time can also be uttered by an anticipated act throughout the grouping of the future.In addition,an action happening in the past and still around in the tongue is marked by a zero morpheme in the present perfect.Concerning mood,the language has agent-oriented moods that are articulated by verb inflection,and speaker-oriented moods that are articulated by a periphrastic structure.Regarding aktionsart that denotes a specific phase in a verbal condition,like period,regularity,etc.Mesqan has two aktionsarten which are noticeable by periphrastic structures,that is the progressive and the prospective.
基金This study is sponsored by the National Natural Science foundation of China (Number 60173024,60473135). We thank Professors Sun Tianxin, J. L. Randy, J. A. Matisoff and Gu Yang for theirconstructive comments.
文摘This paper mainly discusses verbal aspects and their syntactic markers in Lhasa Tibetan. Since aspects in Tibetan always share markers with other important categories called evidentiality and egocentricity, the former of which assesses the evidence of speaker's statement and the latter denotes behavioral characteristics of a speaker'sego-centricity, this paper simultaneously describes all three types: aspect, evidentiality and egocentricity. There are nine types of verb aspects in Lhasa Tibetan, namely: Prospective, Imminent, Premediated, Realis, Durative, Resultative, Merely-past, Perfect, and Contextual aspects. There are four types of evidentialities, namely, Self-knowledge, Knowing-by-sight, Knowing-by-newly-found-information and Knowing-by-inference evidentialities. Categories of egocentricity demonstrate whether an action is towards the Self or the Other, whether the speaker gains or loses, and so on. Additionally, this essay also discusses the interactive relationship between syntactical verb aspects and personal pronouns, intentionality, modality, as well as temporal-spatial cognition.
文摘The core issue concerning the usage of tense and aspect is seen as significantly important(Michaelis,1994;Swales and Feak,2000),especially in English writing in college.This study identifies the erroneous use of tense and aspect in liberal arts students' writing in comparison with that of engineering students' to examine their application ability in writing and identify areas of English learning in need of intensive instruction.This paper displays the frequency rates of errors about two English tenses(the present and the past),two aspects(the progressive and the perfect)based on an online writing corpus of students in two majors,which leads to the result that students in both majors are more likely to make mistakes in the present time and perfect aspect,liberal arts students less influenced.In addition,engineering students writing score seems to be more related to their grammatical errors than that of liberal arts students.To improve their writings,practical teaching strategies such as being aware of cross-lingual influence,practicing grammar on context level,personalized instructions,are also provided.
文摘Driver distraction is a leading cause of traffic accidents,with fatigue being a significant contributor.This paper introduces a novel method for detecting driver distraction by analyzing facial features using machine deep learning and 68 face model.The proposed system assesses driver tiredness by measuring the distance between key facial landmarks,such as the distance between the eyes and the angle of the mouth,to evaluate signs of drowsiness or disengagement.Real-time video feed analysis allows for continuous monitoring of the driver’s face,enabling the system to detect behavioral cues associated with distraction,such as eye closures or changes in facial expressions.The effectiveness of this method is demonstrated through a series of experiments on a dataset of driver videos,which proves that the approach can accurately assess tiredness and distraction levels under various driving conditions.By focusing on facial landmarks,the system is computationally efficient and capable of operating in real-time,making it a practical solution for in-vehicle safety systems.This paper discusses the system’s performance,limitations,and potential for future enhancements,including integration with other in-vehicle technologies to provide comprehensive driver monitoring.
文摘One of the main causes of cancer-related morbidity and mortality globally is hepatocellular carcinoma(HCC).At every stage of the disease,HCC may now be treated using a variety of therapy techniques.Nevertheless,despite the abundance of effective therapeutic choices,the prognosis for patients with HCC is still typically dismal.Prognostic indicators are crucial when assessing prognosis and tracking tumor metastases or recurrence.There are many prognostic markers in HCC.We mainly focused on newly reported prognostic markers such as MEX3A,apolipoprotein B,alpha-fetoprotein,circulating tumor cells,SAMD13,Agrin,and Glypican-3 in the pathogenesis of HCC.Further,we highlighted how these prognostic markers correlated to clinical parameters such as tumor node metastasis,tumor diameter,differentiation,hepatocirrhosis,vascular invasion,and others in HCC.Therefore,identifying specific prognostic biomarkers of HCC helps to provide a great opportunity to improve the prognosis in patients with HCC and provide therapeutic targets.
文摘Flow characteristics around a wall-mounted square cylinder have been numerically simulated at aspect ratios (AR) ranging from 4 to 7 at Re =10 000. Four turbulence models have been compared in terms of drag coefficient (C_D). The closest result has been provided by two turbulence models, namely, k-ε Realizable and k ?ω Shear Stress Transport (SST). Hence, these models were utilized to present the flow patterns of pressure distributions, turbulent kinetic energy values, velocity magnitude values with streamlines, streamwise velocity components, crossstream velocity components and spanwise velocity components on different planes. Flow stagnation has been attained in front of the cylinder. Pressure values peaked for the upstream region. Over the cylinders, the tip vortex structure was dominant owing to the influence of the free end. Flow separation from the top front edge of the body has been obtained. The dividing streamline affected by the flow separation was highly effective in the wake region and moved nearer to the body when the aspect ratio was decreased;the reason was the wake shrinkage owing to the decreasing aspect ratio. Upwash and downwash have been seen in the cylinder wake. These two models presented similar flow patterns and drag coefficients. These drag coefficients are in good agreement with those in previous studies.
基金funded by the National Natural Science Foundation of China(Grant No.52108435)the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202404320)+1 种基金Chongqing Jiaotong University Postgraduate Research and Innovation Project(2024S0013)Chongqing Jiaotong University Undergraduate Innovation and Entrepreneurship Project(S202410618019).
文摘Streamlined box girders serve as a prevalent choice for the primary structural elements in large-span suspension bridge designs.With the increase in traffic demands,the design of such girders is evolving towards wider bridge decks and larger aspect ratios(B/D).To obtain more effective and aerodynamic design shapes for streamlined box girders,it is essential to investigate the impact of B/D on their aerodynamic performance.Accordingly,in this study we investigate the buffeting responses of large-span suspension bridges using girders of varying aspect ratios(B/D of 7.5,9.3,and 12.7).First,the aerodynamic coefficients of these girders are estimated using computational fluid dynamics(CFD)simulations.Subsequently,spatial finite element(FE)models of three long-span suspension bridges with different girders(B/D of 7.5,9.3,and 12.7)are established in Ansys software,and the dynamic characteristics of these bridges are obtained.Then,the time-domain buffeting analysis is performed by simulating the fluctuating wind fields acting on the bridge through the spectral representation method.Ultimately,the buffeting responses are computed using Ansys software,and the impact of B/D on these responses is assessed.The results reveal that the root mean square(RMS)values of the main girder’s buffeting displacement are highest at the midspan position and are lowest at the ends of the bridge.A decrease in B/D of the main girder leads to a more severe buffeting response because both the range and the effective value of the displacement increase with the decreasing B/D.Comparing the buffeting displacements in three directions,B/D plays a significant role in the vertical buffeting displacement,moderately impacts the torsional displacement,and has the least effect on the lateral displacement.The findings of this study may help wind resistance analysis and design optimization for bridges.
基金supported by the Natural Science Foundation of Hunan Province of China(No.2023JJ40672)the Innovation Science Fund Project of National University of Defense Technology,China(No.ZK2023-039)。
文摘A two-dimensional large eddy simulation numerical model is proposed to study the transient vortex flow and pressure oscillation of a large-aspect-ratio solid rocket motor.The numerical model is validated through experimental data,finite element analysis and cumulative error analysis.The numerical simulations are executed to obtain the characteristics of the vortex-acoustic and pressure oscillation.The results show that the burning surface regression decreases the motor aspect ratio,increasing the corresponding natural frequency from 260 Hz to 293 Hz.The pressure oscillation phenomenon is formed due to the vortex-acoustic coupling.Decreasing the corner vortex shedding intensity shows negative effects on the dimensionless amplitude of the pressure oscillation.The head cavity without the injection can decrease the vortex-acoustic coupling level at the acoustic pressure antinode.The modified motor with head cavity can obtain a lower dimensionless oscillating pressure amplitude 0.00149 in comparison with 0.00895 of the original motor.The aspect ratio and volume of the head cavity without the injection have great effects on the pressure oscillation suppression,particularly at the low aspect ratio or large volume.The reason is that the mass in the region around the acoustic pressure antinode is extracted centrally,reducing the energy contribution to the acoustic system.With the volume increasing,the acoustic energy capacity increases.
基金supported by Universita della Campania“L.Vanvitelli”,Program VALERE“VAnviteLli pEr la RicErca”(Grant No.516/2018)Italian Ministry of Economic Development#NOACRONYM Project,PoC MISE 2021.
文摘Extensive urban areas worldwide face significant landslide hazards, impacting inhabitants, buildings, and critical infrastructures alike. In the case of slow-moving deep-seated landslides involving huge areas and characterized by complex patterns, when the cost of repairing infrastructures, relocating communities, and restoring cultural sites might be such that it is unsustainable for the community, the exposed structures require significant effort for their surveillance and protection, which can be supported by the development of innovative monitoring systems. For this purpose, a smart extenso-inclinometer, realized by equipping a conventional inclinometer tube with distributed strain and temperature transducers based on optical fiber sensing technology, is presented. In situ monitoring of the active deep-seated San Nicola landslide in Centola (Campania, southern Italy) demonstrated its ability to capture the main features of movements and reconstruct a tridimensional evolution of the landslide pattern, even when the entity of both vertical and horizontal soil strain components is comparable. Although further tests are needed to definitively ascertain the extensometer function of the new device, by interpreting the strain profiles of the landslide body and identifying the achievement of predetermined thresholds, this system could provide a warning of the trigger of a landslide event. The use of the smart extenso-inclinometer within an early warning system for slow-moving landslides holds immense potential for reducing the impact of landslide events.
基金supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(RS-2024-00446825)by the Technology Innovation Program(RS-2024-00418815)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea).
文摘Rechargeable magnesium batteries(RMBs)are a cutting-edge energy storage solution,with several advantages over the state-of-art lithiumion batteries(LIBs).The use of magnesium(Mg)metal as an anode material provides a much higher gravimetric capacity compared to graphite,which is currently used as the anode material in LIBs.Despite the significant advances in electrolyte,the development of cathode material is limited to materials that operate at low average discharge voltage(<1.0 V vs.Mg/Mg^(2+)),and developing high voltage cathodes remains challenging.Only a few materials have been shown to intercalate Mg^(2+)ions reversibly at high voltage.This review focuses on the structural aspects of cathode material that can operate at high voltage,including the Mg^(2+)intercalation mechanism in relation to its electrochemical properties.The materials are categorized into transition metal oxides and polyanions and subcategorized by the intrinsic Mg^(2+)diffusion path.This review also provides insights into the future development of each material,aiming to stimulate and guide researchers working in this field towards further advancements in high voltage cathodes.
文摘Aspect-oriented sentiment analysis is a meticulous sentiment analysis task that aims to analyse the sentiment polarity of specific aspects. Most of the current research builds graph convolutional networks based on dependent syntactic trees, which improves the classification performance of the models to some extent. However, the technical limitations of dependent syntactic trees can introduce considerable noise into the model. Meanwhile, it is difficult for a single graph convolutional network to aggregate both semantic and syntactic structural information of nodes, which affects the final sentence classification. To cope with the above problems, this paper proposes a bi-channel graph convolutional network model. The model introduces a phrase structure tree and transforms it into a hierarchical phrase matrix. The adjacency matrix of the dependent syntactic tree and the hierarchical phrase matrix are combined as the initial matrix of the graph convolutional network to enhance the syntactic information. The semantic information feature representations of the sentences are obtained by the graph convolutional network with a multi-head attention mechanism and fused to achieve complementary learning of dual-channel features. Experimental results show that the model performs well and improves the accuracy of sentiment classification on three public benchmark datasets, namely Rest14, Lap14 and Twitter.
文摘This paper aims at examining the perception of English tense and lax vowel contrasts by testing an identification task of CVC syllables with different manipulated durations in Chinese learners of English.This can provide some empirical evidence for English as a second language teachers in teaching second language pronunciation.
