Schizophrenia(SZ)stands as a severe psychiatric disorder.This study applied diffusion tensor imaging(DTI)data in conjunction with graph neural networks to distinguish SZ patients from normal controls(NCs)and showcases...Schizophrenia(SZ)stands as a severe psychiatric disorder.This study applied diffusion tensor imaging(DTI)data in conjunction with graph neural networks to distinguish SZ patients from normal controls(NCs)and showcases the superior performance of a graph neural network integrating combined fractional anisotropy and fiber number brain network features,achieving an accuracy of 73.79%in distinguishing SZ patients from NCs.Beyond mere discrimination,our study delved deeper into the advantages of utilizing white matter brain network features for identifying SZ patients through interpretable model analysis and gene expression analysis.These analyses uncovered intricate interrelationships between brain imaging markers and genetic biomarkers,providing novel insights into the neuropathological basis of SZ.In summary,our findings underscore the potential of graph neural networks applied to multimodal DTI data for enhancing SZ detection through an integrated analysis of neuroimaging and genetic features.展开更多
The rich club,as a community of highly interconnected nodes,serves as the topological center of the network.However,the similarities and differences in how the rich club supports functional integration and segregation...The rich club,as a community of highly interconnected nodes,serves as the topological center of the network.However,the similarities and differences in how the rich club supports functional integration and segregation in the brain across different species remain unknown.In this study,we first detected and validated the rich club in the structural networks of mouse,monkey,and human brains using neuronal tracing or diffusion magnetic resonance imaging data.Further,we assessed the role of rich clubs in functional integration,segregation,and balance using quantitative metrics.Our results indicate that the presence of a rich club facilitates whole-brain functional integration in all three species,with the functional networks of higher species exhibiting greater integration.These findings are expected to help to understand the relationship between brain structure and function from the perspective of brain evolution.展开更多
With the development of urban infrastructure,it is inevitable that shield tunnels will undercross intercity railways.However,the safe operation of intercity railways requires strict subgrade deformation.On the basis o...With the development of urban infrastructure,it is inevitable that shield tunnels will undercross intercity railways.However,the safe operation of intercity railways requires strict subgrade deformation.On the basis of the engineering background of the Lianghu Tunnel in Wuhan,the three-dimensional centrifuge test and numerical back analysis were used to study the development of subgrade surface settlement during shield tunneling.A three-dimensional numerical model with the same size as the prototype was subsequently established to further study the settlement development and torsion behavior of the subgrade during tunnel excavation.The results show that the maximum settlement point of the transverse settlement trough gradually moves to the tunnel axis during tunnel excavation and that the entire subgrade experiences torsional deformation.Moreover,the effect of the intersection angle between the axes of the tunnel and the subgrade on the surface settlement of the subgrade was further studied.The results show that the intersection angle has no effect on the maximum settlement,but the width of the settlement trough increases gradually with increasing angle.Finally,on the basis of the soil arching effect caused by tunnel excavation,the subgrade settlement during tunnel excavation is reduced by reinforcing the soil in different zones of soil arching.The results show that the settlement of the subgrade caused by the shield tunnel can be effectively controlled by adding reinforcement directly to the top of the tunnel,and the maximum settlement of the subgrade surface is reduced from 24.41 mm to 9.47 mm,a reduction of approximately 61.2%.展开更多
The natural visibility graph method has been widely used in physiological signal analysis,but it fails to accurately handle signals with data points below the baseline.Such signals are common across various physiologi...The natural visibility graph method has been widely used in physiological signal analysis,but it fails to accurately handle signals with data points below the baseline.Such signals are common across various physiological measurements,including electroencephalograph(EEG)and functional magnetic resonance imaging(fMRI),and are crucial for insights into physiological phenomena.This study introduces a novel method,the baseline perspective visibility graph(BPVG),which can analyze time series by accurately capturing connectivity across data points both above and below the baseline.We present the BPVG construction process and validate its performance using simulated signals.Results demonstrate that BPVG accurately translates periodic,random,and fractal signals into regular,random,and scale-free networks respectively,exhibiting diverse degree distribution traits.Furthermore,we apply BPVG to classify Alzheimer’s disease(AD)patients from healthy controls using EEG data and identify non-demented adults at varying dementia risk using resting-state fMRI(rs-fMRI)data.Utilizing degree distribution entropy derived from BPVG networks,our results exceed the best accuracy benchmark(77.01%)in EEG analysis,especially at channels F4(78.46%)and O1(81.54%).Additionally,our rs-fMRI analysis achieves a statistically significant classification accuracy of 76.74%.These findings highlight the effectiveness of BPVG in distinguishing various time series types and its practical utility in EEG and rs-fMRI analysis for early AD detection and dementia risk assessment.In conclusion,BPVG’s validation across both simulated and real data confirms its capability to capture comprehensive information from time series,irrespective of baseline constraints,providing a novel method for studying neural physiological signals.展开更多
A variety of electromagnetic wave absorption materials(EMWAs)have been reported,but the integration of powder materials and multifunctional devices should be investigated in-depth to adapt to practical demands.Herein,...A variety of electromagnetic wave absorption materials(EMWAs)have been reported,but the integration of powder materials and multifunctional devices should be investigated in-depth to adapt to practical demands.Herein,carbon-coated cobalt composites were prepared by adsorbing magnetic metal cations into an anionic crystalline framework through an electrostatic encapsulate process.Excellent reflection loss(RL_(min))of-40.49 d B and effective absorption bandwidth(EAB)of 5.36 GHz(RL<-10 d B,10.4-15.76 GHz)was achieved with an optimal radar cross section(RCS)reduction of 34.9 dB·m^(2) for the sample tested.For commercial applications,Co@CN-4 was integrated into sodium carboxymethyl cellulose(CMC)aerogel to create an ultra-lightweight composite aerogel that is compressive resistant and heat-holding while also having photothermal conversion capabilities.The hydrophobic modification makes it more widely useful.This study provides a new strategy for EWAMs to integrate versatility and improve their application prospects.展开更多
When new information enters the brain,a human's prior knowledge of the world can change rapidly through a process referred to as"knowledge assembly".Recently,Nelli et al.investigated the neural correlate...When new information enters the brain,a human's prior knowledge of the world can change rapidly through a process referred to as"knowledge assembly".Recently,Nelli et al.investigated the neural correlates of knowledge assembly in the human brain using functional MRI.Further,inspired by the neural mechanism,the authors developed an artificial neural network algorithm to permit rapid knowledge assembly,improving the flexibility of the system[1].Once again,this research demonstrates that studying how the brain works can lead to better computational algorithms.展开更多
The functional brain network using blood-oxygen-level-dependent（BOLD） functional magnetic resonance imaging（fMRI） has revealed the potentials for probing brain architecture,as well as for identifying clinical biom...The functional brain network using blood-oxygen-level-dependent（BOLD） functional magnetic resonance imaging（fMRI） has revealed the potentials for probing brain architecture,as well as for identifying clinical biomarkers for brain diseases.In the general context of Brainnetome,this review focuses on the development of approaches for modeling and analyzing functional brain networks with BOLD fMRI.The prospects for these approaches are also discussed.展开更多
Neuroimaging has opened new opportunities to study the neural correlates of consciousness, and provided additional information concerning diagnosis, prognosis, and therapeutic interventions in patients with disorders ...Neuroimaging has opened new opportunities to study the neural correlates of consciousness, and provided additional information concerning diagnosis, prognosis, and therapeutic interventions in patients with disorders of consciousness. Here, we aim to review neuroimaging studies in chronic disorders of consciousness from the viewpoint of the brain network, focusing on positron emission tomogra- phy, functional MRI, functional near-infrared spectroscopy, electrophysiology, and diffusion MRI. To accelerate basic research on disorders of consciousness and provide a panoramic view of unconsciousness, we propose that it is urgent to integrate different techniques at various spatiotemporal scales, and to merge fragmented findings into a uniform ＂Brainnetome＂ （Brain-net-ome） research framework.展开更多
Aqueous Zn-ion batteries(ZIBs)featuring safety,affordability and high energy density may provide a promising solution to the demand for better energy storage devices.ZIBs with high electrochemical performances rely on...Aqueous Zn-ion batteries(ZIBs)featuring safety,affordability and high energy density may provide a promising solution to the demand for better energy storage devices.ZIBs with high electrochemical performances rely on a stable and reversible Zn metal negative electrode.The side reactions such as the hydrogen evolution reaction(HER)at the anode-electrolyte interface are responsible for the low reversibility,and uneven Zn deposition/dissolution gives rise to the instability of Zn anode.Here,a facile and scalable method of regulating electrolytes has been proposed by Chao and his co-works through adding a lowcost,safe and environmentally-friendly electrolyte additive:glucose.Theoretical calculations and experimental studies reveal that the glucose not only suppresses side reactions by modulating the solvated shell of Zn^(2+)but also homogenizes Zn deposition/dissolution through forming a special local absorption interface.This bi-functional electrolyte additive endows the Zn anode with both high reversibility and stability,which efficiently improves the performances of ZIBs.This work explores a promising electrolyte strategy for realizing the large-scale application of ZIBs.展开更多
Due to the large differences in physico-mechanical pro perties of composite strata,jamming,head sinking and other serious consequences occur frequently during tunnel boring machine(TBM)excavation.To analyse the stabil...Due to the large differences in physico-mechanical pro perties of composite strata,jamming,head sinking and other serious consequences occur frequently during tunnel boring machine(TBM)excavation.To analyse the stability of surrounding rocks in composite strata under the disturbance of TBM excavation,a geomechanical model test was carried out based on the Lanzhou water supply project.The evolution patterns and distribution characteristics of the strain,stress,and tunnel deformation and fracturing were analysed.The results showed that during TBM excavation in the horizontal composite formations(with upper soft and lower hard layers and with upper hard and lower soft layers),a significant difference in response to the surrounding rocks can be observed.As the strength ratio of the surrounding rocks decreases,the ratio of the maximum strain of the hard rock mass to that of the relatively soft rock mass gradually decreases.The radial stress of the relatively soft rock mass is smaller than that of the hard rock mass in both types of composite strata,indicating that the weak rock mass in the composite formation results in the difference in the mechanical behaviours of the surrounding rocks.The displacement field of the surrounding rocks obtained by the digital speckle correlation method(DSCM)and the macro-fracture morphology after tunnel excavation visually reflected the deformation difference of the composite rock mass.Finally,some suggestions and measures were provided for TBM excavation in composite strata,such as advance geological forecasting and effective monitoring of weak rock masses.展开更多
Background:Oral cancer is a common type of head and neck cancers.Knowing its epidemiologic characteristics is crucial to preventing,diagnosing,and treating this cancer.This study aimed to explore the epidemiologic cha...Background:Oral cancer is a common type of head and neck cancers.Knowing its epidemiologic characteristics is crucial to preventing,diagnosing,and treating this cancer.This study aimed to explore the epidemiologic characteristics of oral cancer in South China.Methods:We retrospectively analyzed data from 4097 oral cancer patients treated at the Sun Yat-sen University Cancer Center between 1960 and 2013.We compared the age of onset,sex ratio,pathologic type,and primary tumor location among three subcultural areas(Guangfu,Hakka,and Chaoshan) and between an economically developed region and a less-developed one in Guangdong.Results:Overall,oral cancer had a male-to-female ratio of approximately 2:1,and this ratio decreased over time.Oral cancer occurred mostly in patients of 45-64 years old(54.5%),and the percentage of older patients gradually increased over time.The most common tumor location was the tongue.Squamous cell carcinoma was the predominant pathologic type.The percentage of blood type O in oral cancer patients was lower than that in the healthy population.The male-to-female ratio in the Chaoshan area was higher than that in the Guangfu and Hakka areas,whereas the age of disease onset in Guangfu was higher than that in Hakka and Chaoshan.The male-to-female ratio was lower and the age of disease onset was higher in the economically developed region than in the less-developed region.Conclusion:The incidence of oral cancer in South China presents typical characteristics to which doctors should pay attention when diagnosing and treating oral cancer patients.展开更多
Based on Zak＇s stress function, the eigen-equation of stress singularity ofbi-materials with a V-notch was obtained. A new definition of stress intensity factor for a perpendicular interfacial V-notch of bi-material ...Based on Zak＇s stress function, the eigen-equation of stress singularity ofbi-materials with a V-notch was obtained. A new definition of stress intensity factor for a perpendicular interfacial V-notch of bi-material was put forward. The effects of shear modulus and Poisson＇s ratio of the matrix material and attaching material on eigen-values were analyzed. A generalized expression for calculating/（i of the perpendicular V-notch of bi-materials was obtained by means of stress extrapolation. Effects of notch depth, notch angle and Poisson＇s ratio of materials on the singular stress field near the tip of the V-notch were analyzed systematically with numerical simulations. As an example, a finite plate with double edge notches under uniaxial uniform tension was calculated by the method presented and the influence of the notch angle and Poisson＇s ratio on the stress singularity near the tip of notch was obtained.展开更多
We investigate (2+1)-dimensional generalized modified dispersive water wave (GMDWW) equation by utilizing the bifurcation theory of dynamical systems. We give the phase portraits and bifurcation analysis of the plane ...We investigate (2+1)-dimensional generalized modified dispersive water wave (GMDWW) equation by utilizing the bifurcation theory of dynamical systems. We give the phase portraits and bifurcation analysis of the plane system corresponding to the GMDWW equation. By using the special orbits in the phase portraits, we analyze the existence of the traveling wave solutions. When some parameter takes special values, we obtain abundant exact kink wave solutions, singular wave solutions, periodic wave solutions, periodic singular wave solutions, and solitary wave solutions for the GMDWW equation.展开更多
基金supported by the National Natural Science Foundation of China(62276049,61701078,61872068,and 62006038)the Natural Science Foundation of Sichuan Province(2025ZNSFSC0487)+3 种基金the Science and Technology Innovation 2030-Brain Science and Brain-Inspired Intelligence Project(2021ZD0200200)the National Key R&D Program of China(2023YFE0118600)Sichuan Province Science and Technology Support Program(2019YJ0193,2021YFG0126,2021YFG0366,and 2022YFS0180)Medico-Engineering Cooperation Funds from the University of Electronic Science and Technology of China(ZYGX2021YGLH014).
文摘Schizophrenia(SZ)stands as a severe psychiatric disorder.This study applied diffusion tensor imaging(DTI)data in conjunction with graph neural networks to distinguish SZ patients from normal controls(NCs)and showcases the superior performance of a graph neural network integrating combined fractional anisotropy and fiber number brain network features,achieving an accuracy of 73.79%in distinguishing SZ patients from NCs.Beyond mere discrimination,our study delved deeper into the advantages of utilizing white matter brain network features for identifying SZ patients through interpretable model analysis and gene expression analysis.These analyses uncovered intricate interrelationships between brain imaging markers and genetic biomarkers,providing novel insights into the neuropathological basis of SZ.In summary,our findings underscore the potential of graph neural networks applied to multimodal DTI data for enhancing SZ detection through an integrated analysis of neuroimaging and genetic features.
基金supported by STI2030-Major Projects(2021ZD0200200)the National Natural Science Foundation of China(62327805 and 82151307)+1 种基金the Equipment Development Project of the Chinese Academy of Sciences(YJKYYQ20190040)the Science and Technology Innovation Program of Hunan Province(2024RC4028).
文摘The rich club,as a community of highly interconnected nodes,serves as the topological center of the network.However,the similarities and differences in how the rich club supports functional integration and segregation in the brain across different species remain unknown.In this study,we first detected and validated the rich club in the structural networks of mouse,monkey,and human brains using neuronal tracing or diffusion magnetic resonance imaging data.Further,we assessed the role of rich clubs in functional integration,segregation,and balance using quantitative metrics.Our results indicate that the presence of a rich club facilitates whole-brain functional integration in all three species,with the functional networks of higher species exhibiting greater integration.These findings are expected to help to understand the relationship between brain structure and function from the perspective of brain evolution.
基金funding support from the National Natural Science Foundation of China(Grant Nos.52208355and 52378308)Shenzhen University's 2035 Program for Excellent Research(Grant No.00000219).
文摘With the development of urban infrastructure,it is inevitable that shield tunnels will undercross intercity railways.However,the safe operation of intercity railways requires strict subgrade deformation.On the basis of the engineering background of the Lianghu Tunnel in Wuhan,the three-dimensional centrifuge test and numerical back analysis were used to study the development of subgrade surface settlement during shield tunneling.A three-dimensional numerical model with the same size as the prototype was subsequently established to further study the settlement development and torsion behavior of the subgrade during tunnel excavation.The results show that the maximum settlement point of the transverse settlement trough gradually moves to the tunnel axis during tunnel excavation and that the entire subgrade experiences torsional deformation.Moreover,the effect of the intersection angle between the axes of the tunnel and the subgrade on the surface settlement of the subgrade was further studied.The results show that the intersection angle has no effect on the maximum settlement,but the width of the settlement trough increases gradually with increasing angle.Finally,on the basis of the soil arching effect caused by tunnel excavation,the subgrade settlement during tunnel excavation is reduced by reinforcing the soil in different zones of soil arching.The results show that the settlement of the subgrade caused by the shield tunnel can be effectively controlled by adding reinforcement directly to the top of the tunnel,and the maximum settlement of the subgrade surface is reduced from 24.41 mm to 9.47 mm,a reduction of approximately 61.2%.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFF1204803)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20190736)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.NJ2024029)the National Natural Science Foundation of China(Grant Nos.81701346 and 62201265).
文摘The natural visibility graph method has been widely used in physiological signal analysis,but it fails to accurately handle signals with data points below the baseline.Such signals are common across various physiological measurements,including electroencephalograph(EEG)and functional magnetic resonance imaging(fMRI),and are crucial for insights into physiological phenomena.This study introduces a novel method,the baseline perspective visibility graph(BPVG),which can analyze time series by accurately capturing connectivity across data points both above and below the baseline.We present the BPVG construction process and validate its performance using simulated signals.Results demonstrate that BPVG accurately translates periodic,random,and fractal signals into regular,random,and scale-free networks respectively,exhibiting diverse degree distribution traits.Furthermore,we apply BPVG to classify Alzheimer’s disease(AD)patients from healthy controls using EEG data and identify non-demented adults at varying dementia risk using resting-state fMRI(rs-fMRI)data.Utilizing degree distribution entropy derived from BPVG networks,our results exceed the best accuracy benchmark(77.01%)in EEG analysis,especially at channels F4(78.46%)and O1(81.54%).Additionally,our rs-fMRI analysis achieves a statistically significant classification accuracy of 76.74%.These findings highlight the effectiveness of BPVG in distinguishing various time series types and its practical utility in EEG and rs-fMRI analysis for early AD detection and dementia risk assessment.In conclusion,BPVG’s validation across both simulated and real data confirms its capability to capture comprehensive information from time series,irrespective of baseline constraints,providing a novel method for studying neural physiological signals.
基金financially supported by the National Natural Science Foundation of China(Nos.22001156 and 22301239)the Youth Talent Fund of University Association for Science and Technology in Shaanxi,China(No.20210602)+4 种基金International Cooperation Key Project of Science and Technology Department of Shaanxi,China(No.2022KWZ-06)the research project of Science and Technology Department of Shaanxi Province(No.2021JQ-533)the Research Program of the Shaanxi Provincial Department of Education(No.23JK0596)the open Foundation of Xi’an Key Laboratory of Functional Supramolecular Structure and Materials(No.CFZKFKT23003)Shaanxi Provincial Department of Education service local special project,industrialization cultivation project(No.23JC007)。
文摘A variety of electromagnetic wave absorption materials(EMWAs)have been reported,but the integration of powder materials and multifunctional devices should be investigated in-depth to adapt to practical demands.Herein,carbon-coated cobalt composites were prepared by adsorbing magnetic metal cations into an anionic crystalline framework through an electrostatic encapsulate process.Excellent reflection loss(RL_(min))of-40.49 d B and effective absorption bandwidth(EAB)of 5.36 GHz(RL<-10 d B,10.4-15.76 GHz)was achieved with an optimal radar cross section(RCS)reduction of 34.9 dB·m^(2) for the sample tested.For commercial applications,Co@CN-4 was integrated into sodium carboxymethyl cellulose(CMC)aerogel to create an ultra-lightweight composite aerogel that is compressive resistant and heat-holding while also having photothermal conversion capabilities.The hydrophobic modification makes it more widely useful.This study provides a new strategy for EWAMs to integrate versatility and improve their application prospects.
基金supported by STI2030-Major Projects 2021ZD0200201the Scientific Research and Equipment Development Project of the Chinese Academy of Sciences(YJKYYQ20190040)。
文摘When new information enters the brain,a human's prior knowledge of the world can change rapidly through a process referred to as"knowledge assembly".Recently,Nelli et al.investigated the neural correlates of knowledge assembly in the human brain using functional MRI.Further,inspired by the neural mechanism,the authors developed an artificial neural network algorithm to permit rapid knowledge assembly,improving the flexibility of the system[1].Once again,this research demonstrates that studying how the brain works can lead to better computational algorithms.
基金supported by the National Basic Research Development Program(973) of China(2011CB707800)the National Natural Science Foundation of China(91132301 and 81101040)
文摘The functional brain network using blood-oxygen-level-dependent（BOLD） functional magnetic resonance imaging（fMRI） has revealed the potentials for probing brain architecture,as well as for identifying clinical biomarkers for brain diseases.In the general context of Brainnetome,this review focuses on the development of approaches for modeling and analyzing functional brain networks with BOLD fMRI.The prospects for these approaches are also discussed.
基金supported by the National Natural Science Foundation of China(81471380,31771076,81501550,91432302,31620103905,and 81501179)the Science Frontier Program of the Chinese Academy of Sciences(QYZDJSSW-SMC019)+4 种基金National Key R&D Program of China(2017YFA0105203,2017YFB1002502)Beijing Municipal Science and Technology Commission(Z161100000216152,Z161100000216139,Z171100000117002,and Z161100000516165)the Shenzhen Peacock Plan(KQTD2015033016104926)the Guangdong Pearl River Talents Plan(2016ZT06S220)Youth Innovation Promotion Association,CAS,China
文摘Neuroimaging has opened new opportunities to study the neural correlates of consciousness, and provided additional information concerning diagnosis, prognosis, and therapeutic interventions in patients with disorders of consciousness. Here, we aim to review neuroimaging studies in chronic disorders of consciousness from the viewpoint of the brain network, focusing on positron emission tomogra- phy, functional MRI, functional near-infrared spectroscopy, electrophysiology, and diffusion MRI. To accelerate basic research on disorders of consciousness and provide a panoramic view of unconsciousness, we propose that it is urgent to integrate different techniques at various spatiotemporal scales, and to merge fragmented findings into a uniform ＂Brainnetome＂ （Brain-net-ome） research framework.
基金This study was financially supported by the National Natural Science Foundation of China(No.22075115)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(No.19KJA430020)Jiangsu Qing Lan Project(2020)。
文摘Aqueous Zn-ion batteries(ZIBs)featuring safety,affordability and high energy density may provide a promising solution to the demand for better energy storage devices.ZIBs with high electrochemical performances rely on a stable and reversible Zn metal negative electrode.The side reactions such as the hydrogen evolution reaction(HER)at the anode-electrolyte interface are responsible for the low reversibility,and uneven Zn deposition/dissolution gives rise to the instability of Zn anode.Here,a facile and scalable method of regulating electrolytes has been proposed by Chao and his co-works through adding a lowcost,safe and environmentally-friendly electrolyte additive:glucose.Theoretical calculations and experimental studies reveal that the glucose not only suppresses side reactions by modulating the solvated shell of Zn^(2+)but also homogenizes Zn deposition/dissolution through forming a special local absorption interface.This bi-functional electrolyte additive endows the Zn anode with both high reversibility and stability,which efficiently improves the performances of ZIBs.This work explores a promising electrolyte strategy for realizing the large-scale application of ZIBs.
基金supported by the National Natural Science Foundation of China(Grant No.41941018)the National Program on Key Basic Research of China(973 Program)(Grant No.2014CB046902)The partial support from the Hubei Province Natural Science Foundation Innovation Group(Grant No.2018CFA013)。
文摘Due to the large differences in physico-mechanical pro perties of composite strata,jamming,head sinking and other serious consequences occur frequently during tunnel boring machine(TBM)excavation.To analyse the stability of surrounding rocks in composite strata under the disturbance of TBM excavation,a geomechanical model test was carried out based on the Lanzhou water supply project.The evolution patterns and distribution characteristics of the strain,stress,and tunnel deformation and fracturing were analysed.The results showed that during TBM excavation in the horizontal composite formations(with upper soft and lower hard layers and with upper hard and lower soft layers),a significant difference in response to the surrounding rocks can be observed.As the strength ratio of the surrounding rocks decreases,the ratio of the maximum strain of the hard rock mass to that of the relatively soft rock mass gradually decreases.The radial stress of the relatively soft rock mass is smaller than that of the hard rock mass in both types of composite strata,indicating that the weak rock mass in the composite formation results in the difference in the mechanical behaviours of the surrounding rocks.The displacement field of the surrounding rocks obtained by the digital speckle correlation method(DSCM)and the macro-fracture morphology after tunnel excavation visually reflected the deformation difference of the composite rock mass.Finally,some suggestions and measures were provided for TBM excavation in composite strata,such as advance geological forecasting and effective monitoring of weak rock masses.
基金supported by grants from the National Natural Science Foundation of China(No.81172568)
文摘Background:Oral cancer is a common type of head and neck cancers.Knowing its epidemiologic characteristics is crucial to preventing,diagnosing,and treating this cancer.This study aimed to explore the epidemiologic characteristics of oral cancer in South China.Methods:We retrospectively analyzed data from 4097 oral cancer patients treated at the Sun Yat-sen University Cancer Center between 1960 and 2013.We compared the age of onset,sex ratio,pathologic type,and primary tumor location among three subcultural areas(Guangfu,Hakka,and Chaoshan) and between an economically developed region and a less-developed one in Guangdong.Results:Overall,oral cancer had a male-to-female ratio of approximately 2:1,and this ratio decreased over time.Oral cancer occurred mostly in patients of 45-64 years old(54.5%),and the percentage of older patients gradually increased over time.The most common tumor location was the tongue.Squamous cell carcinoma was the predominant pathologic type.The percentage of blood type O in oral cancer patients was lower than that in the healthy population.The male-to-female ratio in the Chaoshan area was higher than that in the Guangfu and Hakka areas,whereas the age of disease onset in Guangfu was higher than that in Hakka and Chaoshan.The male-to-female ratio was lower and the age of disease onset was higher in the economically developed region than in the less-developed region.Conclusion:The incidence of oral cancer in South China presents typical characteristics to which doctors should pay attention when diagnosing and treating oral cancer patients.
基金supported by the Ministry of Education of China(No.208152)Gansu Natural Science Foundation(No.3ZS061-A52-47).
文摘Based on Zak＇s stress function, the eigen-equation of stress singularity ofbi-materials with a V-notch was obtained. A new definition of stress intensity factor for a perpendicular interfacial V-notch of bi-material was put forward. The effects of shear modulus and Poisson＇s ratio of the matrix material and attaching material on eigen-values were analyzed. A generalized expression for calculating/（i of the perpendicular V-notch of bi-materials was obtained by means of stress extrapolation. Effects of notch depth, notch angle and Poisson＇s ratio of materials on the singular stress field near the tip of the V-notch were analyzed systematically with numerical simulations. As an example, a finite plate with double edge notches under uniaxial uniform tension was calculated by the method presented and the influence of the notch angle and Poisson＇s ratio on the stress singularity near the tip of notch was obtained.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 11361069 and 11775146).
文摘We investigate (2+1)-dimensional generalized modified dispersive water wave (GMDWW) equation by utilizing the bifurcation theory of dynamical systems. We give the phase portraits and bifurcation analysis of the plane system corresponding to the GMDWW equation. By using the special orbits in the phase portraits, we analyze the existence of the traveling wave solutions. When some parameter takes special values, we obtain abundant exact kink wave solutions, singular wave solutions, periodic wave solutions, periodic singular wave solutions, and solitary wave solutions for the GMDWW equation.
