For permanent magnet synchronous machine(PMSM),the machine model is critical to predict the operating states for motor control,which,however,can be greatly affected by system nonlinearities.Hence,this paper investigat...For permanent magnet synchronous machine(PMSM),the machine model is critical to predict the operating states for motor control,which,however,can be greatly affected by system nonlinearities.Hence,this paper investigates accurate machine modeling for control and parameter estimation.In the proposed approach,the PMSM model with saturated inductances is used as the base model,and this paper investigates modeling and compensation of the offsets to the base model due to system nonlinearities such as saturation and core loss effects for accurate machine modeling and voltage prediction.Specifically,the offsets to the base model are modeled using nonlinear functions with variable coefficients to compensate saturation and core loss effect,which can achieve better accuracy without changing the model structure.A differential estimation model is derived to estimate the model coefficients from a small amount of measurements with simplified procedure.Moreover,the model offset calculation is both computation and memory efficient with simplified implementation.The contribution is to improve the machine model accuracy and achieve precise voltage prediction for practical applications.Experiments,comparisons and the application to temperature estimation are conducted on a test interior PMSM to validate the proposed approach.展开更多
Tomato is a common food on the human table. Up to now, the research on the growth and development model of tomato has been about 50 years. There are many researches on the main nutrients of tomato, such as carbon and ...Tomato is a common food on the human table. Up to now, the research on the growth and development model of tomato has been about 50 years. There are many researches on the main nutrients of tomato, such as carbon and nitrogen, but few on the trace element zinc. In this paper, taking plant nutrient C, N and Z<sub>n</sub> as variables, the differential equation model of C, N and Z<sub>n</sub> in tomato growth and development was established. According to the research of tomato as a whole and divided into root and leaf, the one-compartment and two-compartment models of tomato growth and development were established. The model was analyzed by Matlab program, and the existing experimental data was used to test the numerical simulation results, which proves that the model conforms to the facts.展开更多
The purpose of this study is to present an application of a novel enhancement technique for enhancing medical images generated from X-rays. The method presented in this study is based on a nonlinear partial differenti...The purpose of this study is to present an application of a novel enhancement technique for enhancing medical images generated from X-rays. The method presented in this study is based on a nonlinear partial differential equation （PDE） model, Kramer＇s PDE model. The usefulness of this method is investigated by experimental results. We apply this method to a medical X-ray image. For comparison, the X-ray image is also processed using classic Perona-Malik PDE model and Catte PDE model. Although the Perona-Malik model and Catte PDE model could also enhance the image, the quality of the enhanced images is considerably inferior compared with the enhanced image using Kramer＇s PDE model. The study suggests that the Kramer＇s PDE model is capable of enhancing medical X-ray images, which will make the X-ray images more reliable.展开更多
Objective To explore the clinical characteristics and methods for syndrome differentiation prediction,as well as to construct a predictive model for Qi deficiency and blood stasis syndrome in patients with acute ische...Objective To explore the clinical characteristics and methods for syndrome differentiation prediction,as well as to construct a predictive model for Qi deficiency and blood stasis syndrome in patients with acute ischemic stroke(AIS).Methods This study employed a retrospective case-control design to analyze patients with AIS who received inpatient treatment at the Neurology Department of The First Hospital of Hunan University of Chinese Medicine from January 1,2013 to December 31,2022.AIS patients meeting the diagnostic criteria for Qi deficiency and blood stasis syndrome were stratified into case group,while those without Qi deficiency and blood stasis syndrome were stratified into control group.The demographic characteristics(age and gender),clinical parameters[time from onset to admission,National Institutes of Health Stroke Scale(NIHSS)score,and blood pressure],past medical history,traditional Chinese medicine(TCM)diagnostic characteristics(tongue and pulse),neurological symptoms and signs,imaging findings[magnetic resonance imaging-diffusion weighted imaging(MRI-DWI)],and biochemical indicators of the two groups were collected and compared.The indicators with statistical difference(P<0.05)in univariate analysis were included in multivariate logistic regression analysis to evaluate their predictive value for the diagnosis of Qi deficiency and blood stasis syndrome,and the predictive model was constructed by receiver operating characteristic(ROC)curve analysis.Results The study included 1035 AIS patients,with 404 cases in case group and 631 cases in control group.Compared with control group,patients in case group were significantly older,had extended onset-to-admission time,lower diastolic blood pressure,and lower NIHSS scores(P<0.05).Case group showed lower incidence of hypertension history(P<0.05).Regarding tongue and pulse characteristics,pale and dark tongue colors,white tongue coating,fine pulse,astringent pulse,and sinking pulse were more common in case group.Imaging examinations demonstrated higher proportions of centrum semiovale infarction,cerebral atrophy,and vertebral artery stenosis in case group(P<0.05).Among biochemical indicators,case group showed higher proportions of elevated fasting blood glucose and glycated hemoglobin(HbA1c),while lower proportions of elevated white blood cell count,reduced hemoglobin,and reduced high-density lipoprotein cholesterol(HDL-C)(P<0.05).Multivariate logistic regression analysis identified significant predictors for Qi deficiency and blood stasis syndrome including:fine pulse[odds ratio(OR)=4.38],astringent pulse(OR=3.67),superficial sensory abnormalities(OR=1.86),centrum semiovale infarction(OR=1.57),cerebral atrophy(OR=1.55),vertebral artery stenosis(OR=1.62),and elevated HbA1c(OR=3.52).The ROC curve analysis of the comprehensive prediction model yielded an area under the curve(AUC)of 0.878[95%confidence interval(CI)=0.855-0.900].Conclusion This study finds out that Qi deficiency and blood stasis syndrome represents one of the primary types of AIS.Fine pulse,astringent pulse,superficial sensory abnormalities,centrum semiovale infarction,cerebral atrophy,vertebral artery stenosis,elevated blood glucose,elevated HbA1c,pale and dark tongue colors,and white tongue coating are key objective diagnostic indicators for the syndrome differentiation of AIS with Qi deficiency and blood stasis syndrome.Based on these indicators,a syndrome differentiation prediction model has been developed,offering a more objective basis for clinical diagnosis,and help to rapidly identify this syndrome in clinical practice and reduce misdiagnosis and missed diagnosis.展开更多
With high spatial resolution,on-demand-flying ability,and the capacity for obtaining threedimensional measurements,unmanned aerial vehicle(UAV)photogrammetry is widely used for detailed investigations of single landsl...With high spatial resolution,on-demand-flying ability,and the capacity for obtaining threedimensional measurements,unmanned aerial vehicle(UAV)photogrammetry is widely used for detailed investigations of single landslides,but its effectiveness for landslide detection and monitoring in a large area needs to be investigated.The Heifangtai terrace in the Loess Plateau of China is a loess terrace that is extremely susceptible to irrigation-induced loess landslides.This paper used UAV-based photogrammetry for a series of highresolution images spanning over 30 months for landslide detection and monitoring of the terrace with an area of 32 km^2.Dense and evenly distributed ground control points were established and measured to ensure the high accuracy of the photogrammetry results.The structure-from-motion(Sf M)technique was used to convert overlapping images into orthographic images,3D point clouds,digital surface models(DSMs)and mesh models.Using multitemporal differential mesh models,landslide vertical movements and potential landslides were detected and monitored.The results indicate that a combination of UAV-based orthophotos and differential mesh models can be used for flexible and accurate detection and monitoring of potential loess landslides in a large area.展开更多
The character of the deformation zone on pair cross rolls is different from that of the regular 4-high mill. Considering comprehensive influences of normal stress and shear stress in rolling direction, width direction...The character of the deformation zone on pair cross rolls is different from that of the regular 4-high mill. Considering comprehensive influences of normal stress and shear stress in rolling direction, width direction and thickness direction, the rolling force calculation model of the PC （pair crossed） hot strip mill is built. Taking the entry stress and the exit stress of strip as the boundary conditions, the longitudinal and transverse distribution of rolling force is worked out by the differential method. Then the total rolling force is calculated, and calculated results are verified by experimental data.展开更多
Under China's innovation-driven development strategy, venture capital has become an important driving force in urban agglomeration integration and collaborative innovation. This paper uses social network analysis ...Under China's innovation-driven development strategy, venture capital has become an important driving force in urban agglomeration integration and collaborative innovation. This paper uses social network analysis to analyze spatiotemporal differences of venture capital in the Beijing-Tianjin-Hebei urban agglomeration for the period 2005–2015. A gravity model and panel data regression model are used to reveal the influencing factors on spatiotemporal differences in venture capital in the region. This study finds that there is a certain cyclical fluctuation and uneven differentiation in the venture capital network in the Beijing-Tianjin-Hebei urban agglomeration in terms of total investment, and that the three centers of venture capital(Beijing, Shijiazhuang and Tangshan) have a stimulatory effect on surrounding cities; flows of venture capital between cities display certain networking rules, but they are slow to develop and strongly centripetal; there is a strong positive correlation between levels of information infrastructure development and economic development and venture capital investment; and places with relatively underdeveloped financial environments and service industries are less able to apply the fruits of innovation and entrepreneurship and to attract funds. This study can act as a reference for the Beijing-Tianjin-Hebei urban agglomeration in building a world-class super urban agglomeration with the best innovation capabilities in China.展开更多
Precise control of a magnetically suspended double-gimbal control moment gyroscope （MSDGCMG） is of vital importance and challenge to the attitude positioning of spacecraft owing to its multivariable, nonlinear and s...Precise control of a magnetically suspended double-gimbal control moment gyroscope （MSDGCMG） is of vital importance and challenge to the attitude positioning of spacecraft owing to its multivariable, nonlinear and strong coupled properties. This paper proposes a novel linearization and decoupling method based on differential geometry theory and combines it with the internal model controller （IMC） to guarantee the system robustness to the external disturbance and parameter uncertainty. Furthermore, by introducing the dynamic compensation for the inner-gimbal rate-servo system and the magnetically suspended rotor （MSR） system only, we can eliminate the influence of the unmodeled dynamics to the decoupling control accuracy as well as save costs and inhibit noises effectively. The simulation results verify the nice decoupling and robustness performance of the system using the proposed method.展开更多
The binary solid-liquid equilibrium of Dimethyl Terephthalate （DMT）, Dimethyl lsophthalate （DMI） and Dimeth- yl Phthalate （DMP） was investigated by experiment and differential scanning calorimetry （DSC）. The r...The binary solid-liquid equilibrium of Dimethyl Terephthalate （DMT）, Dimethyl lsophthalate （DMI） and Dimeth- yl Phthalate （DMP） was investigated by experiment and differential scanning calorimetry （DSC）. The result demonstrated DMT/DMI and DMT/DMP systems are eutectic while DMI/DMP is a solid-solution system. The eutectic temperature of DMT/DMI system is 336.7 K and that of DMT/DMP is 271.1 K. Furthermore, a classical solid-liquid phase equilibrium model was used to fit the experimental data of the eutectic systems of DMT/DMI and DMT/ DMP and the theoretical model could describe the eutectic solid-liquid phase diagrams properly.展开更多
The propagation of shear-horizontal(SH)waves in the periodic layered nanocomposite is investigated by using both the nonlocal integral model and the nonlocal differential model with the interface effect.Based on the t...The propagation of shear-horizontal(SH)waves in the periodic layered nanocomposite is investigated by using both the nonlocal integral model and the nonlocal differential model with the interface effect.Based on the transfer matrix method and the Bloch theory,the band structures for SH waves with both vertical and oblique incidences to the structure are obtained.It is found that by choosing appropriate interface parameters,the dispersion curves predicted by the nonlocal differential model with the interface effect can be tuned to be the same as those based on the nonlocal integral model.Thus,by propagating the SH waves vertically and obliquely to the periodic layered nanostructure,we could invert,respectively,the interface mass density and the interface shear modulus,by matching the dispersion curves.Examples are further shown on how to determine the interface mass density and the interface shear modulus in theory.展开更多
The aim of these investigations is to find the numerical performances of the delay differential two-prey and one-predator system.The delay differential models are very significant and always difficult to solve the dyn...The aim of these investigations is to find the numerical performances of the delay differential two-prey and one-predator system.The delay differential models are very significant and always difficult to solve the dynamical kind of ecological nonlinear two-prey and one-predator system.Therefore,a stochastic numerical paradigm based artificial neural network(ANN)along with the Levenberg-Marquardt backpropagation(L-MB)neural networks(NNs),i.e.,L-MBNNs is proposed to solve the dynamical twoprey and one-predator model.Three different cases based on the dynamical two-prey and one-predator system have been discussed to check the correctness of the L-MBNNs.The statistic measures of these outcomes of the dynamical two-prey and one-predator model are chosen as 13%for testing,12%for authorization and 75%for training.The exactness of the proposed results of L-MBNNs approach for solving the dynamical two-prey and onepredator model is observed with the comparison of the Runge-Kutta method with absolute error ranges between 10−05 to 10−07.To check the validation,constancy,validity,exactness,competence of the L-MBNNs,the obtained state transitions(STs),regression actions,correlation presentations,MSE and error histograms(EHs)are also provided.展开更多
A 3-craft formation configuration is proposed to perform the digital elevation model （DEM） for the distributed spacebome interferometric synthetic aperture radar （InSAR）, and it is optimized by the modified ant co...A 3-craft formation configuration is proposed to perform the digital elevation model （DEM） for the distributed spacebome interferometric synthetic aperture radar （InSAR）, and it is optimized by the modified ant colony algorithm to have the best compatibility with J2 invariant orbits created by differential correction algorithm. The configuration has succeeded in assigning the across-track baseline to vary periodically and with its mean value equal to the optimal baseline determined by the relative height measurement accuracy. The required relationship between crafts＇ magnitudes and phases is formulated for the general case of interferometry measure from non-orthographic and non-lateral view. The J2 invariant configurations created by differential correction algorithm are employed to investigate their compatibility with the required configuration. The colony algorithm is applied to search the optimal configuration holding the near-constant across-track baseline under the J2 perturbation, and the absolute height measurement accuracy is preferable as expected.展开更多
For some infectious diseases such as mumps,HBV,there is evidence showing that vaccinated individuals always lose their immunity at different rates depending on the inoculation time.In this paper,we propose an age-stru...For some infectious diseases such as mumps,HBV,there is evidence showing that vaccinated individuals always lose their immunity at different rates depending on the inoculation time.In this paper,we propose an age-structured epidemic model using a step function to describe the rate at which vaccinated individuals lose immunity and reduce the age-structured epidemic model to the delay differential model.For the age-structured model,we consider the positivity,boundedness,and compactness of the semiflow and study global stability of equilibria by constructing appropriate Lyapunov functionals.Moreover,for the reduced delay differential equation model,we study the existence of the endemic equilibrium and prove the global stability of equilibria.Finally,some numerical simulations are provided to support our theoretical results and a brief discussion is given.展开更多
Modeling, simulation, and prediction of global energy indices remain veritable tools for econometric, engineering, analysis, and prediction of energy indices. Thus, this paper differentially modeled, simulated, and no...Modeling, simulation, and prediction of global energy indices remain veritable tools for econometric, engineering, analysis, and prediction of energy indices. Thus, this paper differentially modeled, simulated, and non-differentially predicated the global energy indices. The state-of-the-art of the research includes normalization of energy indices, generation of differential rate terms, and regression of rate terms against energy indices to generate coefficients and unexplained terms. On imposition of initial conditions, the solution to the system of linear differential equations was realized in a Matlab environment. There was a strong agreement between the simulated and the field data. The exact solutions are ideal for interpolative prediction of historic data. Furthermore, the simulated data were upgraded for extrapolative prediction of energy indices by introducing an innovative model, which is the synergy of deflated and inflated prediction factors. The innovative model yielded a trendy prediction data for energy consumption, gross domestic product, carbon dioxide emission and human development index. However, the oil price was untrendy, which could be attributed to odd circumstances. Moreover, the sensitivity of the differential rate terms was instrumental in discovering the overwhelming effect of independent indices on the dependent index. Clearly, this paper has accomplished interpolative and extrapolative prediction of energy indices and equally recommends for further investigation of the untrendy nature of oil price.展开更多
This paper present a formal teletraffic model for service diferentiation in optical packet switched networks by utilizing the wavelength domain.Expressions for the time congestion are derived.Simulation results are al...This paper present a formal teletraffic model for service diferentiation in optical packet switched networks by utilizing the wavelength domain.Expressions for the time congestion are derived.Simulation results are also reported.展开更多
Dietary factors play a crucial role in irritable bowel syndrome(IBS)pathogenesis.Therefore,the dietary contraindications for patients with IBS require further supplementation.Recent investigations have revealed that g...Dietary factors play a crucial role in irritable bowel syndrome(IBS)pathogenesis.Therefore,the dietary contraindications for patients with IBS require further supplementation.Recent investigations have revealed that ginger consumption may pose a risk of aggravating the symptoms and incidence of IBS;however,the specific mechanism remains unknown.In this study,we developed experimental IBS and intestinal organoid differentiation screening models to elucidate the mechanisms underlying the gingermediated exacerbation of IBS symptoms.Subsequently,we used a knockout approach combined with click chemistry as well as virus infection to identify the toxic components of ginger and the target mechanism.Our results showed that a daily intake of 90 to 300 mg/kg ginger(equivalent to a human daily dose of O.6 to 2 g per person)may pose a risk of exacerbating IBS symptoms.Furthermore,a component derived from 6-gingerol(ginger's main ingredient)through in vivo gastric acid and heat processing inhibited the formation of the elF3 transcription initiation complex by covalently binding to the Cys^(58)site of elF3A,a key factor regulating intestinal crypt stem celldifferentiation,further reducing the goblet cellnumber and related mucus layer thickness and increasing lipopolysaccharide infiltration and low-grade inflammation in the ileum crypts,thereby exacerbating the symptoms of IBS in mice.Our study suggests that dietary ginger aggravates IBS and provides safety evaluation methods for the proper use of foods in specific populations.展开更多
Driven by advancements in artificial intelligence,end-to-end learning has become a key method for system optimization in various fields,including communications.However,applying learning algorithms such as backpropaga...Driven by advancements in artificial intelligence,end-to-end learning has become a key method for system optimization in various fields,including communications.However,applying learning algorithms such as backpropagation directly to communication systems is challenging due to their non-differentiable nature.Existing methods typically require developing a precise differentiable digital model of the physical system,which is computationally complex and can cause significant performance loss after deployment.In response,we propose a novel end-to-end learning framework called physics-guided learning.展开更多
This paper presents numerical and experimental results of the flow in the tipclearance region of the guide vane row in hydraulic turbine. The 3-D Navier-Stokes equations wereemployed to model the flow in end clearance...This paper presents numerical and experimental results of the flow in the tipclearance region of the guide vane row in hydraulic turbine. The 3-D Navier-Stokes equations wereemployed to model the flow in end clearance region of guide vane cascade, the Reynolds stressdifferential model was used for turbulence closure, and the body-fitted curvilinear coordinates andthe SIMPLE! algorithm were adopted. The governing equations were discretized with the non-staggeredgrids by means of the finite volume method. Detailed comparison of hydrodynamical characteristics ofguide vane in hydraulic turbine with or without tip gap was made. Special attention was paid to theinfluence of leakage flow on the main flow and to the movement of tip leakage flow in the end guidevane. The position and strength of the roll-vortex on the sides of guide vane in were determined.The numerical solutions agree with the experimental results obtained by particle image ve-locimetry.The results help to clarify the loss, wear and cavi-tation erosion between the guide vane andrings, especially for those used in the Yellow River which has a high sediment content.展开更多
The effect of the annealing time and annealing temperature on Ni/Ge/Au electrode contacts deposited on the n-type InP contact layer has been studied using a circular transmission line model. The minimum specific conta...The effect of the annealing time and annealing temperature on Ni/Ge/Au electrode contacts deposited on the n-type InP contact layer has been studied using a circular transmission line model. The minimum specific contact resistance of 3.210 7 cm2was achieved on the low-doped n-type InP contact layer with a 40 s anneal at 425 ℃. In order to improve the ohmic contact and reduce the difficulty in the fabrication of the high doped InP epi-layer, the doping concentration in the InP contact layer was chosen to be 51018cm 3in the fabrication of transferred electronic devices. Excellent differential negative resistance properties were obtained by an electron beam evaporating the Ni/Ge/Au/Ge/Ni/Au composite electrode on an InP epi-layer with a 60 s anneal at 380 ℃.展开更多
基金supported by in part by the National Natural Science Foundation of China(52105079,62103455)the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2023SP241)。
文摘For permanent magnet synchronous machine(PMSM),the machine model is critical to predict the operating states for motor control,which,however,can be greatly affected by system nonlinearities.Hence,this paper investigates accurate machine modeling for control and parameter estimation.In the proposed approach,the PMSM model with saturated inductances is used as the base model,and this paper investigates modeling and compensation of the offsets to the base model due to system nonlinearities such as saturation and core loss effects for accurate machine modeling and voltage prediction.Specifically,the offsets to the base model are modeled using nonlinear functions with variable coefficients to compensate saturation and core loss effect,which can achieve better accuracy without changing the model structure.A differential estimation model is derived to estimate the model coefficients from a small amount of measurements with simplified procedure.Moreover,the model offset calculation is both computation and memory efficient with simplified implementation.The contribution is to improve the machine model accuracy and achieve precise voltage prediction for practical applications.Experiments,comparisons and the application to temperature estimation are conducted on a test interior PMSM to validate the proposed approach.
文摘Tomato is a common food on the human table. Up to now, the research on the growth and development model of tomato has been about 50 years. There are many researches on the main nutrients of tomato, such as carbon and nitrogen, but few on the trace element zinc. In this paper, taking plant nutrient C, N and Z<sub>n</sub> as variables, the differential equation model of C, N and Z<sub>n</sub> in tomato growth and development was established. According to the research of tomato as a whole and divided into root and leaf, the one-compartment and two-compartment models of tomato growth and development were established. The model was analyzed by Matlab program, and the existing experimental data was used to test the numerical simulation results, which proves that the model conforms to the facts.
文摘The purpose of this study is to present an application of a novel enhancement technique for enhancing medical images generated from X-rays. The method presented in this study is based on a nonlinear partial differential equation （PDE） model, Kramer＇s PDE model. The usefulness of this method is investigated by experimental results. We apply this method to a medical X-ray image. For comparison, the X-ray image is also processed using classic Perona-Malik PDE model and Catte PDE model. Although the Perona-Malik model and Catte PDE model could also enhance the image, the quality of the enhanced images is considerably inferior compared with the enhanced image using Kramer＇s PDE model. The study suggests that the Kramer＇s PDE model is capable of enhancing medical X-ray images, which will make the X-ray images more reliable.
基金National Natural Science Foundation of China(U22A20377)Natural Science Foundation of Hunan Province of China(23C0168).
文摘Objective To explore the clinical characteristics and methods for syndrome differentiation prediction,as well as to construct a predictive model for Qi deficiency and blood stasis syndrome in patients with acute ischemic stroke(AIS).Methods This study employed a retrospective case-control design to analyze patients with AIS who received inpatient treatment at the Neurology Department of The First Hospital of Hunan University of Chinese Medicine from January 1,2013 to December 31,2022.AIS patients meeting the diagnostic criteria for Qi deficiency and blood stasis syndrome were stratified into case group,while those without Qi deficiency and blood stasis syndrome were stratified into control group.The demographic characteristics(age and gender),clinical parameters[time from onset to admission,National Institutes of Health Stroke Scale(NIHSS)score,and blood pressure],past medical history,traditional Chinese medicine(TCM)diagnostic characteristics(tongue and pulse),neurological symptoms and signs,imaging findings[magnetic resonance imaging-diffusion weighted imaging(MRI-DWI)],and biochemical indicators of the two groups were collected and compared.The indicators with statistical difference(P<0.05)in univariate analysis were included in multivariate logistic regression analysis to evaluate their predictive value for the diagnosis of Qi deficiency and blood stasis syndrome,and the predictive model was constructed by receiver operating characteristic(ROC)curve analysis.Results The study included 1035 AIS patients,with 404 cases in case group and 631 cases in control group.Compared with control group,patients in case group were significantly older,had extended onset-to-admission time,lower diastolic blood pressure,and lower NIHSS scores(P<0.05).Case group showed lower incidence of hypertension history(P<0.05).Regarding tongue and pulse characteristics,pale and dark tongue colors,white tongue coating,fine pulse,astringent pulse,and sinking pulse were more common in case group.Imaging examinations demonstrated higher proportions of centrum semiovale infarction,cerebral atrophy,and vertebral artery stenosis in case group(P<0.05).Among biochemical indicators,case group showed higher proportions of elevated fasting blood glucose and glycated hemoglobin(HbA1c),while lower proportions of elevated white blood cell count,reduced hemoglobin,and reduced high-density lipoprotein cholesterol(HDL-C)(P<0.05).Multivariate logistic regression analysis identified significant predictors for Qi deficiency and blood stasis syndrome including:fine pulse[odds ratio(OR)=4.38],astringent pulse(OR=3.67),superficial sensory abnormalities(OR=1.86),centrum semiovale infarction(OR=1.57),cerebral atrophy(OR=1.55),vertebral artery stenosis(OR=1.62),and elevated HbA1c(OR=3.52).The ROC curve analysis of the comprehensive prediction model yielded an area under the curve(AUC)of 0.878[95%confidence interval(CI)=0.855-0.900].Conclusion This study finds out that Qi deficiency and blood stasis syndrome represents one of the primary types of AIS.Fine pulse,astringent pulse,superficial sensory abnormalities,centrum semiovale infarction,cerebral atrophy,vertebral artery stenosis,elevated blood glucose,elevated HbA1c,pale and dark tongue colors,and white tongue coating are key objective diagnostic indicators for the syndrome differentiation of AIS with Qi deficiency and blood stasis syndrome.Based on these indicators,a syndrome differentiation prediction model has been developed,offering a more objective basis for clinical diagnosis,and help to rapidly identify this syndrome in clinical practice and reduce misdiagnosis and missed diagnosis.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.41521002,41941019,41630640)the Major R&D projects of Sichuan Science and Technology Plan(Grant No.2018SZ0339)the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project(Grant No.SKLGP2014Z004)。
文摘With high spatial resolution,on-demand-flying ability,and the capacity for obtaining threedimensional measurements,unmanned aerial vehicle(UAV)photogrammetry is widely used for detailed investigations of single landslides,but its effectiveness for landslide detection and monitoring in a large area needs to be investigated.The Heifangtai terrace in the Loess Plateau of China is a loess terrace that is extremely susceptible to irrigation-induced loess landslides.This paper used UAV-based photogrammetry for a series of highresolution images spanning over 30 months for landslide detection and monitoring of the terrace with an area of 32 km^2.Dense and evenly distributed ground control points were established and measured to ensure the high accuracy of the photogrammetry results.The structure-from-motion(Sf M)technique was used to convert overlapping images into orthographic images,3D point clouds,digital surface models(DSMs)and mesh models.Using multitemporal differential mesh models,landslide vertical movements and potential landslides were detected and monitored.The results indicate that a combination of UAV-based orthophotos and differential mesh models can be used for flexible and accurate detection and monitoring of potential loess landslides in a large area.
基金Item Sponsored by ("863"Program) of China National High Technology Research and Development Program(2009AA04Z143)
文摘The character of the deformation zone on pair cross rolls is different from that of the regular 4-high mill. Considering comprehensive influences of normal stress and shear stress in rolling direction, width direction and thickness direction, the rolling force calculation model of the PC （pair crossed） hot strip mill is built. Taking the entry stress and the exit stress of strip as the boundary conditions, the longitudinal and transverse distribution of rolling force is worked out by the differential method. Then the total rolling force is calculated, and calculated results are verified by experimental data.
基金Major Program of the National Natural Science Foundation of China,No.41590842
文摘Under China's innovation-driven development strategy, venture capital has become an important driving force in urban agglomeration integration and collaborative innovation. This paper uses social network analysis to analyze spatiotemporal differences of venture capital in the Beijing-Tianjin-Hebei urban agglomeration for the period 2005–2015. A gravity model and panel data regression model are used to reveal the influencing factors on spatiotemporal differences in venture capital in the region. This study finds that there is a certain cyclical fluctuation and uneven differentiation in the venture capital network in the Beijing-Tianjin-Hebei urban agglomeration in terms of total investment, and that the three centers of venture capital(Beijing, Shijiazhuang and Tangshan) have a stimulatory effect on surrounding cities; flows of venture capital between cities display certain networking rules, but they are slow to develop and strongly centripetal; there is a strong positive correlation between levels of information infrastructure development and economic development and venture capital investment; and places with relatively underdeveloped financial environments and service industries are less able to apply the fruits of innovation and entrepreneurship and to attract funds. This study can act as a reference for the Beijing-Tianjin-Hebei urban agglomeration in building a world-class super urban agglomeration with the best innovation capabilities in China.
文摘Precise control of a magnetically suspended double-gimbal control moment gyroscope （MSDGCMG） is of vital importance and challenge to the attitude positioning of spacecraft owing to its multivariable, nonlinear and strong coupled properties. This paper proposes a novel linearization and decoupling method based on differential geometry theory and combines it with the internal model controller （IMC） to guarantee the system robustness to the external disturbance and parameter uncertainty. Furthermore, by introducing the dynamic compensation for the inner-gimbal rate-servo system and the magnetically suspended rotor （MSR） system only, we can eliminate the influence of the unmodeled dynamics to the decoupling control accuracy as well as save costs and inhibit noises effectively. The simulation results verify the nice decoupling and robustness performance of the system using the proposed method.
文摘The binary solid-liquid equilibrium of Dimethyl Terephthalate （DMT）, Dimethyl lsophthalate （DMI） and Dimeth- yl Phthalate （DMP） was investigated by experiment and differential scanning calorimetry （DSC）. The result demonstrated DMT/DMI and DMT/DMP systems are eutectic while DMI/DMP is a solid-solution system. The eutectic temperature of DMT/DMI system is 336.7 K and that of DMT/DMP is 271.1 K. Furthermore, a classical solid-liquid phase equilibrium model was used to fit the experimental data of the eutectic systems of DMT/DMI and DMT/ DMP and the theoretical model could describe the eutectic solid-liquid phase diagrams properly.
基金Project supported by the National Natural Science Foundation of China(Nos.11472182 and 11272222)the China Scholarship Council(No.201907090051)。
文摘The propagation of shear-horizontal(SH)waves in the periodic layered nanocomposite is investigated by using both the nonlocal integral model and the nonlocal differential model with the interface effect.Based on the transfer matrix method and the Bloch theory,the band structures for SH waves with both vertical and oblique incidences to the structure are obtained.It is found that by choosing appropriate interface parameters,the dispersion curves predicted by the nonlocal differential model with the interface effect can be tuned to be the same as those based on the nonlocal integral model.Thus,by propagating the SH waves vertically and obliquely to the periodic layered nanostructure,we could invert,respectively,the interface mass density and the interface shear modulus,by matching the dispersion curves.Examples are further shown on how to determine the interface mass density and the interface shear modulus in theory.
基金This research received funding support from the NSRF via the Program Management Unit for Human Resources&Institutional Development,Research and Innovation(grant number B05F640088).
文摘The aim of these investigations is to find the numerical performances of the delay differential two-prey and one-predator system.The delay differential models are very significant and always difficult to solve the dynamical kind of ecological nonlinear two-prey and one-predator system.Therefore,a stochastic numerical paradigm based artificial neural network(ANN)along with the Levenberg-Marquardt backpropagation(L-MB)neural networks(NNs),i.e.,L-MBNNs is proposed to solve the dynamical twoprey and one-predator model.Three different cases based on the dynamical two-prey and one-predator system have been discussed to check the correctness of the L-MBNNs.The statistic measures of these outcomes of the dynamical two-prey and one-predator model are chosen as 13%for testing,12%for authorization and 75%for training.The exactness of the proposed results of L-MBNNs approach for solving the dynamical two-prey and onepredator model is observed with the comparison of the Runge-Kutta method with absolute error ranges between 10−05 to 10−07.To check the validation,constancy,validity,exactness,competence of the L-MBNNs,the obtained state transitions(STs),regression actions,correlation presentations,MSE and error histograms(EHs)are also provided.
基金supported by the National Natural Science Foundation of China (10702003)
文摘A 3-craft formation configuration is proposed to perform the digital elevation model （DEM） for the distributed spacebome interferometric synthetic aperture radar （InSAR）, and it is optimized by the modified ant colony algorithm to have the best compatibility with J2 invariant orbits created by differential correction algorithm. The configuration has succeeded in assigning the across-track baseline to vary periodically and with its mean value equal to the optimal baseline determined by the relative height measurement accuracy. The required relationship between crafts＇ magnitudes and phases is formulated for the general case of interferometry measure from non-orthographic and non-lateral view. The J2 invariant configurations created by differential correction algorithm are employed to investigate their compatibility with the required configuration. The colony algorithm is applied to search the optimal configuration holding the near-constant across-track baseline under the J2 perturbation, and the absolute height measurement accuracy is preferable as expected.
基金supported by The National Natural Science Foundation of China[12026236,12026222,12061079,11601293,12071418]Science and Technology Activities Priority Program for Overseas Researchers in Shanxi Province[20210049]The Natural Science Foundation of Shanxi Province[201901D211160,201901D211461,201901D111295]。
文摘For some infectious diseases such as mumps,HBV,there is evidence showing that vaccinated individuals always lose their immunity at different rates depending on the inoculation time.In this paper,we propose an age-structured epidemic model using a step function to describe the rate at which vaccinated individuals lose immunity and reduce the age-structured epidemic model to the delay differential model.For the age-structured model,we consider the positivity,boundedness,and compactness of the semiflow and study global stability of equilibria by constructing appropriate Lyapunov functionals.Moreover,for the reduced delay differential equation model,we study the existence of the endemic equilibrium and prove the global stability of equilibria.Finally,some numerical simulations are provided to support our theoretical results and a brief discussion is given.
文摘Modeling, simulation, and prediction of global energy indices remain veritable tools for econometric, engineering, analysis, and prediction of energy indices. Thus, this paper differentially modeled, simulated, and non-differentially predicated the global energy indices. The state-of-the-art of the research includes normalization of energy indices, generation of differential rate terms, and regression of rate terms against energy indices to generate coefficients and unexplained terms. On imposition of initial conditions, the solution to the system of linear differential equations was realized in a Matlab environment. There was a strong agreement between the simulated and the field data. The exact solutions are ideal for interpolative prediction of historic data. Furthermore, the simulated data were upgraded for extrapolative prediction of energy indices by introducing an innovative model, which is the synergy of deflated and inflated prediction factors. The innovative model yielded a trendy prediction data for energy consumption, gross domestic product, carbon dioxide emission and human development index. However, the oil price was untrendy, which could be attributed to odd circumstances. Moreover, the sensitivity of the differential rate terms was instrumental in discovering the overwhelming effect of independent indices on the dependent index. Clearly, this paper has accomplished interpolative and extrapolative prediction of energy indices and equally recommends for further investigation of the untrendy nature of oil price.
文摘This paper present a formal teletraffic model for service diferentiation in optical packet switched networks by utilizing the wavelength domain.Expressions for the time congestion are derived.Simulation results are also reported.
基金supported by the National Natural Science Foundation of China(grant numbers 82125037,8197-3498,82104508,and 81774283)Science Foundation for Distinguished Young Scholars of Jiangsu Province(BK20231528)+5 种基金the National Key Research and Development Program of China(2023YFC2308200)Key R&D Program of Jiangsu Province(grant number BE2022815)Jiangsu Provincial Medical Innovation Center(grant number CXZX202225)Young Elite Scientists Sponsorship Program of the China Association for Science and Technology(grant number 2021-QNRC2-B17)333 high-level talents project of Jiangsu Province for Y.Y.(BRA202202)Suzhou GuSu Medical Talent Project(GSWS2022100).
文摘Dietary factors play a crucial role in irritable bowel syndrome(IBS)pathogenesis.Therefore,the dietary contraindications for patients with IBS require further supplementation.Recent investigations have revealed that ginger consumption may pose a risk of aggravating the symptoms and incidence of IBS;however,the specific mechanism remains unknown.In this study,we developed experimental IBS and intestinal organoid differentiation screening models to elucidate the mechanisms underlying the gingermediated exacerbation of IBS symptoms.Subsequently,we used a knockout approach combined with click chemistry as well as virus infection to identify the toxic components of ginger and the target mechanism.Our results showed that a daily intake of 90 to 300 mg/kg ginger(equivalent to a human daily dose of O.6 to 2 g per person)may pose a risk of exacerbating IBS symptoms.Furthermore,a component derived from 6-gingerol(ginger's main ingredient)through in vivo gastric acid and heat processing inhibited the formation of the elF3 transcription initiation complex by covalently binding to the Cys^(58)site of elF3A,a key factor regulating intestinal crypt stem celldifferentiation,further reducing the goblet cellnumber and related mucus layer thickness and increasing lipopolysaccharide infiltration and low-grade inflammation in the ileum crypts,thereby exacerbating the symptoms of IBS in mice.Our study suggests that dietary ginger aggravates IBS and provides safety evaluation methods for the proper use of foods in specific populations.
基金RGC(ECS 24203724,YCRG C4004-24Y,YCRG C1002-22Y)NSFC(62405258)+2 种基金Innovation and Technology Fund(ITS/237/22)Innovation and TechnologyFund(ITS/226/21FP)NSFC/RGC Joint Research Scheme(N_CUHK444/22).
文摘Driven by advancements in artificial intelligence,end-to-end learning has become a key method for system optimization in various fields,including communications.However,applying learning algorithms such as backpropagation directly to communication systems is challenging due to their non-differentiable nature.Existing methods typically require developing a precise differentiable digital model of the physical system,which is computationally complex and can cause significant performance loss after deployment.In response,we propose a novel end-to-end learning framework called physics-guided learning.
文摘This paper presents numerical and experimental results of the flow in the tipclearance region of the guide vane row in hydraulic turbine. The 3-D Navier-Stokes equations wereemployed to model the flow in end clearance region of guide vane cascade, the Reynolds stressdifferential model was used for turbulence closure, and the body-fitted curvilinear coordinates andthe SIMPLE! algorithm were adopted. The governing equations were discretized with the non-staggeredgrids by means of the finite volume method. Detailed comparison of hydrodynamical characteristics ofguide vane in hydraulic turbine with or without tip gap was made. Special attention was paid to theinfluence of leakage flow on the main flow and to the movement of tip leakage flow in the end guidevane. The position and strength of the roll-vortex on the sides of guide vane in were determined.The numerical solutions agree with the experimental results obtained by particle image ve-locimetry.The results help to clarify the loss, wear and cavi-tation erosion between the guide vane andrings, especially for those used in the Yellow River which has a high sediment content.
基金Project supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(No.YYYJ1123)
文摘The effect of the annealing time and annealing temperature on Ni/Ge/Au electrode contacts deposited on the n-type InP contact layer has been studied using a circular transmission line model. The minimum specific contact resistance of 3.210 7 cm2was achieved on the low-doped n-type InP contact layer with a 40 s anneal at 425 ℃. In order to improve the ohmic contact and reduce the difficulty in the fabrication of the high doped InP epi-layer, the doping concentration in the InP contact layer was chosen to be 51018cm 3in the fabrication of transferred electronic devices. Excellent differential negative resistance properties were obtained by an electron beam evaporating the Ni/Ge/Au/Ge/Ni/Au composite electrode on an InP epi-layer with a 60 s anneal at 380 ℃.
