As an advanced 4^(th) generation synchrotron radiation facility,the Shenzhen Innovation Light-source Facility(SILF)storage ring is based on multi-bend achromat(MBA)lattices,enabling one to two orders of magnitude redu...As an advanced 4^(th) generation synchrotron radiation facility,the Shenzhen Innovation Light-source Facility(SILF)storage ring is based on multi-bend achromat(MBA)lattices,enabling one to two orders of magnitude reduction in beam emittance compared to the 3^(rd) generation storage ring.This significantly enhance the radiation brightness and coherence.The multipole magnets of many types for SILF storage ring are under preliminary design,which require high integral field homogeneity.As a result,a dedicated pole tip optimization procedure with high efficiency is developed for quadrupole and sextupole magnets with Opera-2D^(■)python script.The procedure considers also the 3D field effect which makes the optimization more straightforward.In this paper,the design of the quadrupole and sextupole magnets for SILF storage ring is first presented,followed by a detailed description of the implemented pole shape optimization method.展开更多
BACKGROUND Sleeve fracture of the patella is an unusual fracture,almost unique to children.The majority of sleeve fractures involve the inferior patellar pole.However,sleeve fractures of the superior pole of the patel...BACKGROUND Sleeve fracture of the patella is an unusual fracture,almost unique to children.The majority of sleeve fractures involve the inferior patellar pole.However,sleeve fractures of the superior pole of the patella are extremely rare in adults.CASE SUMMARY An 18-year-old male patient fell while running in the morning.The patient had tenderness to palpation at the superior pole of the patella,with a palpable gap over the upper part of the patella in both knees.We applied two 4.5-mm suture anchors with the Krackow stitch to repair the sleeve fracture,augmented by autogenous gracilis through performing the figure-of-eight technique.The patient regained approximately the full range of motion of the knee joint without any quadriceps weakness and a normal gait 6 weeks after surgery.CONCLUSION Sleeve fractures of the superior pole of the patella are extremely rare in adults,especially bilateral sleeve fractures.Suture anchors,augmented by autogenous gracilis,provided secure fixation and achieved excellent results in this rare injury.展开更多
Conventional approaches for obtaining the second and third harmonics typically employ several nonlinear crystals to generate them,which is restricted in application due to the complexity of the optical path and the bu...Conventional approaches for obtaining the second and third harmonics typically employ several nonlinear crystals to generate them,which is restricted in application due to the complexity of the optical path and the bulkiness of the device.In this work,we present a comprehensive theoretical and numerical investigation of the simultaneous generation and competition between the second harmonic waves(SHW)and the third harmonic waves(THW)in a single nonlinear crystal.Through analyzing both small-signal and large-signal regimes,we reveal the complex coupling mechanisms between SHW and THW generation processes.Using periodically poled lithium niobate as an example,we demonstrate that the relative conversion efficiencies between SHW and THW can be freely adjusted by controlling the input fundamental wave power.This work provides new insights for designing efficient frequency converters capable of generating both SHW and THW outputs with controllable intensity ratios.展开更多
Due to its broken out-of-plane symmetry,z-cut periodically poled lithium niobate(PPLN)has exhibited ultrahigh second-order optical nonlinearity.Precise quantification of the domain structure of z-cut PPLN plays a crit...Due to its broken out-of-plane symmetry,z-cut periodically poled lithium niobate(PPLN)has exhibited ultrahigh second-order optical nonlinearity.Precise quantification of the domain structure of z-cut PPLN plays a critical role during poling fabrication.To enhance the imaging detection efficiency of the domain structure in z-cut PPLN,we have developed a second-harmonic generation microscope system specifically designed to produce a longitudinal electric field in foci for the imaging domain inversion.We demonstrated that imaging using a longitudinal electric field can achieve a contrast ratio enhancement by a factor of 1.77,showing high imaging efficiency and making the proposed method suitable for in situ monitoring of the z-cut PPLN poling process.展开更多
The development of artificial intelligence(AI)technologies creates a great chance for the iteration of railway monitoring.This paper proposes a comprehensive method for railway utility pole detection.The framework of ...The development of artificial intelligence(AI)technologies creates a great chance for the iteration of railway monitoring.This paper proposes a comprehensive method for railway utility pole detection.The framework of this paper on railway systems consists of two parts:point cloud preprocessing and railway utility pole detection.Thismethod overcomes the challenges of dynamic environment adaptability,reliance on lighting conditions,sensitivity to weather and environmental conditions,and visual occlusion issues present in 2D images and videos,which utilize mobile LiDAR(Laser Radar)acquisition devices to obtain point cloud data.Due to factors such as acquisition equipment and environmental conditions,there is a significant amount of noise interference in the point cloud data,affecting subsequent detection tasks.We designed a Dual-Region Adaptive Point Cloud Preprocessing method,which divides the railway point cloud data into track and non-track regions.The track region undergoes projection dimensionality reduction,with the projected results being unique and subsequently subjected to 2D density clustering,greatly reducing data computation volume.The non-track region undergoes PCA-based dimensionality reduction and clustering operations to achieve preprocessing of large-scale point cloud scenes.Finally,the preprocessed results are used for training,achieving higher accuracy in utility pole detection and data communication.Experimental results show that our proposed preprocessing method not only improves efficiency but also enhances detection accuracy.展开更多
BACKGROUND Hepatitis B virus(HBV)infection is a leading cause of global hepatocellular carcinoma(HCC).Conventional biomarkers such as alpha-fetoprotein(AFP)demonstrate suboptimal sensitivity and specificity.Emerging e...BACKGROUND Hepatitis B virus(HBV)infection is a leading cause of global hepatocellular carcinoma(HCC).Conventional biomarkers such as alpha-fetoprotein(AFP)demonstrate suboptimal sensitivity and specificity.Emerging evidence suggests that serum extra spindle pole bodies like 1(ESPL1)protein and p53 antibody may improve diagnostic accuracy.AIM To assess and compare the diagnostic performance of serum ESPL1 protein and p53 antibody in HBV-related HCC(HBV-HCC).METHODS This case-control study from the First Affiliated Hospital of Guangxi Medical University enrolled 30 patients with chronic hepatitis B(CHB),30 with HBV-related liver cirrhosis(HBV-LC),55 with HBV-HCC,and 30 healthy controls.Serum ESPL1 protein and p53 antibody levels were quantified via ELISA.Diagnostic performance was evaluated using receiver operating characteristic(ROC)curve analysis,including sensitivity,specificity,and correlation with AFP.RESULTS Serum ESPL1 protein levels progressively increased across disease stages(CHB:89.9 ng/L;HBV-LC:188.83 ng/L;HBV-HCC:317.63 ng/L),with a significantly higher area under the ROC curve(AUC=0.917)than either p53 antibody(AUC=0.725)or AFP(AUC=0.678).p53 antibody levels were significantly elevated only in the HBVHCC group.ESPL1 demonstrated superior sensitivity and concordance with histopathological findings.A significant correlation between ESPL1 and p53 antibody levels was observed exclusively in the HBV-HCC group(r=0.320,P=0.017),suggesting potential interplay in malignant transformation.CONCLUSION Serum ESPL1 protein,a promising biomarker for early HBV-HCC detection,outperforms p53 antibody in diagnostic reliability.Higher ESPL1 levels correlate with increased HCC risk in chronic HBV patients.展开更多
With the continuous upgrading of traditional manufacturing industries and the rapid rise of emerging technology fields,the performance requirements for the permanent magnet synchronous motors(PMSMs)have become higher ...With the continuous upgrading of traditional manufacturing industries and the rapid rise of emerging technology fields,the performance requirements for the permanent magnet synchronous motors(PMSMs)have become higher and higher.The importance of fast and accurate electromagnetic thermal coupling analysis of such motors becomes more and more prominent.In view of this,the surfacemounted PMSM(SPMSM)equipped with unequally thick magnetic poles is taken as the main object and its electromagnetic thermal coupling analytical model(ETc AM)is investigated.First,the electromagnetic analytical model(EAM)is studied based on the modified subdomain method.It realizes the fast calculation of key electromagnetic characteristics.Subsequently,the 3D thermal analytical model(TAM)is developed by combining the EAM,the lumped parameter thermal network method(LPTNM),and the partial differential equation of heat flux.It realizes the fast calculation of key thermal characteristics in 3D space.Further,the information transfer channel between EAM and TAM is built with reference to the intrinsic connection between electromagnetic field and temperature field.Thereby,the novel ETcAM is proposed to realize the fast and accurate prediction of electromagnetic and temperature fields.Besides,ETcAM has a lot to commend it.One is that it well accounts for the complex structure,saturation,and heat exchange behavior.Second,it saves a lot of computer resources.It offers boundless possibilities for initial design,scheme evaluation,and optimization of motors.Finally,the validity,accuracy,and practicality of this study are verified by simulation and experiment.展开更多
To understand the spatio-temporal variability of precipitation(P)in the Third Pole region(centered on the Tibetan Plateau-TP),it is necessary to quantify the interannual periodicity of P and its relationship with larg...To understand the spatio-temporal variability of precipitation(P)in the Third Pole region(centered on the Tibetan Plateau-TP),it is necessary to quantify the interannual periodicity of P and its relationship with large-scale circulations.In this study,Morlet wavelet transform was used to detect significant(p<0.05)periodic characteristics in P data from meteorological stations in four climate domains in the Third Pole,and to reveal the major large-scale circulations that triggered the variability of periodic P,in addition to bringing large amounts of water vapour.The wavelet transform results were as follows.(1)Significant quasiperiodicity varied from 2 to 11 years.The high-frequency variability mode(2 to 6 years quasi-periods)was universal,and the low-frequency variability mode(7 to 11 years quasi-periods)was rare,occurring mainly in the westerlies and Indian monsoon domains.(2)The majority of periods were base periods(53%),followed by two-base periods.Almost all stations in the Third Pole(95%)showed one or two periods.(3)Periodicity was widely detected in the majority of years(84%).(4)The power spectra of P in the four domains were dominated by statistically significant high-frequency oscillations(ie.,with short periodicity).(5)Large-scale circulations directly and indirectly influenced the periodic P variability in the different domains.The mode of P variability in the different domains was influenced by interactions between large-scale circulation features and not only by the dominant circulation and its control of water vapour transport.The results of this study will contribute to better understanding of the causal mechanisms associated with P variability,which is important for hydrological science and waterresourcemanagement.展开更多
Planar arrays of tree diagrams were introduced as a generalization of Feynman diagrams that enable the computation of biadjoint amplitudes m_(n)(^(k))for k>2.In this follow-up work,we investigate the poles of m_(n)...Planar arrays of tree diagrams were introduced as a generalization of Feynman diagrams that enable the computation of biadjoint amplitudes m_(n)(^(k))for k>2.In this follow-up work,we investigate the poles of m_(n)(^(k))from the perspective of such arrays.For general k,we characterize the underlying polytope as a Flag Complex and propose a computation of the amplitude-based solely on the knowledge of the poles,whose number is drastically less than the number of the full arrays.As an example,we first provide all the poles for the cases(k,n)=(3,7),(3,8),(3,9),(3,10),(4,8)and(4,9)in terms of their planar arrays of degenerate Feynman diagrams.We then implement simple compatibility criteria together with an addition operation between arrays and recover the full collections/arrays for such cases.Along the way,we implement hard and soft kinematical limits,which provide a map between the poles in kinematic space and their combinatoric arrays.We use the operation to give a proof of a previously conjectured combinatorial duality for arrays in(k,n)and(n-k,n).We also outline the relation to boundary maps of the hypersimplex Δ_(k,n) and rays in the tropical Grassmannian Tr(k,n).展开更多
Nowadays,there is considerable research interest in proposing modern permanent magnet(PM)electric machine structures for applications such as electric vehicles.Several radial and axial topologies with different arrang...Nowadays,there is considerable research interest in proposing modern permanent magnet(PM)electric machine structures for applications such as electric vehicles.Several radial and axial topologies with different arrangements of PM in the stator and rotor have been introduced for PM Vernier motors(PMVM)with the aim of increasing the performance characteristics such as power factor,efficiency,rotational torque torque density and wider constant torque-speed region.Meanwhile,the spoke PM arrangement has provided higher torque density than the surface and V-shaped arrangement.But in contrast,the V-shaped arrangement has a more sinusoidal flux and less cogging torque.In this paper,a 620 W,12-slot 16-pole Vernier PM motor with a fractional slot arrangement.Consequent K-shaped pole is introduced,which has the advantages of spoke and V-shaped magnetic arrangements.After presenting and confirming the concept of the proposed structure based on functional comparison with conventional structures,an analytical modeling based on the harmonic analysis method is introduced to accurately predict the performance of the machine,and finally the proposed structure is prototyped and the experimental results are simulated and modeling are compared.展开更多
Previous studies done elsewhere have shown that Eucalyptus poles treated with chromated copper arsenate (CCA) can last over 30 years. Kenya is exceptional because in some eco-regions, the Eucalyptus poles’ life span ...Previous studies done elsewhere have shown that Eucalyptus poles treated with chromated copper arsenate (CCA) can last over 30 years. Kenya is exceptional because in some eco-regions, the Eucalyptus poles’ life span has greatly reduced to 5 years. The current study was designed to evaluate wood deteriorating agents of CCA-treated Eucalyptus poles and variability in four eco-regions of Kenya, namely, dryland, coastal, highland and humid lake. A total of 360 Eucalyptus pole samples were used for this experiment. Three CCA treatments were used to treat transmission poles at 20 kg/cm3 fencing posts samples at 6 kg/cm3, and a control group. Results indicated that termites and wood-decay fungi attacks caused wood deterioration in the four eco-regions. The proportion of power transmission pole degradation by wood deteriorating agents varied across eco-regions, between treatments and control and between time after treatments. Dryland eco-regions had the highest termite-related degradation (41.82%) while wood-decay fungi attack was highest in the highland eco-regions (9.20%). Samples treated with 6 kg/cm3 recorded the lowest level of wood deterioration, manifested by minimal superficial termite and wood-decay fungi attack. Samples treated with 20 kg/cm3 were characterized by moderate termite and wood-decay fungi attacks observed around the heartwood region, unlike sapwood. This study concluded that the deterioration of Eucalyptus CCA-treated poles is a question of climatic variability and hence, to increase the poles’ lifespan, CCA treatment should be tailored according to the characteristics of the ecoregion of use. Further investigations will inform the diversity of termites and decay-fungi across different eco-regions.展开更多
Aiming at the problem of high temperature and even demagnetization failure of permanent magnet (PM) due to PM eddy current loss in PM synchronous high-speed motors, this paper proposes a technique to lessen PM eddy cu...Aiming at the problem of high temperature and even demagnetization failure of permanent magnet (PM) due to PM eddy current loss in PM synchronous high-speed motors, this paper proposes a technique to lessen PM eddy current loss by cutting the angle of PM poles to change the shape of PM structure. Firstly, an analysis is conducted on the mechanism of PM synchronous high-speed motor eddy current loss production, the theoretical analytical model of PM eddy current loss is deduced, and it is theoretically proved that the magnetic pole shaving angle can reduce PM eddy current loss. Then, a 25 KW surface-type PM synchronous high-speed motor as an object, using two-dimensional time-step finite element method (FEM) to model and analyze PM eddy current loss. The results show that the smaller the PM pole shaving angle, the less its eddy current loss will be, it is possible to minimize the pole shaving angle of eddy current loss by 9.8% compared to the unshaved angle. Finally, the temperature field of the PM is calculated using a finite element method, and the outcomes demonstrate that the maximum temperature of the PM with a magnetic pole shaving angle can be reduced by about 5% compared with the unshaved angle.展开更多
The Head-Related Transfer Function(HRTF)describes the effects of sound reflection and scattering caused by the environment and the human body when sound signals are transmitted from a source to the human ear.It contai...The Head-Related Transfer Function(HRTF)describes the effects of sound reflection and scattering caused by the environment and the human body when sound signals are transmitted from a source to the human ear.It contains a significant amount of auditory cue information used for sound localization.Consequently,HRTF renders 3D audio accurately in numerous immersive multimedia applications.Because HRTF is high-dimensional,complex,and nonlinear,it is a relatively large and intricate dataset,typically consisting of hundreds of thousands of samples.Storing HRTF requires a significant amount of storage space in practical applications.Based on this,high-dimensional,complex,and nonlinear HRTFs need to be compressed and reconstructed.In this study,inspired by the conventional common-pole/zero model,we propose a method for representing HRTF based on the common-pole/zero model and principal component analysis(PCA).Our method utilizes human auditory features and extends the traditional Common-Acoustical-Pole/Zero(CAPZ)method to estimate the common pole and zero coefficients across multiple subjects.Subsequently,the zero coefficients are compressed using the PCA procedure.Experimental results on the CIPIC database show that the compression ratio can reach 9.5%when the average spectral distortion is less than 2 dB.展开更多
Analyzing from the perspective of physics mechanics,the pole vault is a project which transforms kinetic energy into elastic potential energy.The magnitude of kinetic energy depends on the vaulter’s approaching speed...Analyzing from the perspective of physics mechanics,the pole vault is a project which transforms kinetic energy into elastic potential energy.The magnitude of kinetic energy depends on the vaulter’s approaching speed,while the magnitude of elastic potential energy depends on height.Therefore,the run-up speed determines the vaulter’s performance in pole vault to a certain extent.the horizontal speed of the pole-holding approach phase transitioning into vertical upward speed plays a crucial role in executing pole vault techniques,and the model of approaching speed establishes a theoretical foundation for vaulters to break through the pole limitation.In terms of specialized technical assistance in speed training,short-distance speed exercises are used in the approaching phase;in the swinging phase,gymnastic rings,single bar and suspension rope exercises are employed for suspension;in the stretch phase,trampoline exercises play a important role in rotation phase,etc.展开更多
The present work deals with reducing greenhouse gas emissions through improving the life span of wooden power electric poles of Eucalyptus saligna. Indeed, in Sub-Saharan African countries, Cameroon in particular, mos...The present work deals with reducing greenhouse gas emissions through improving the life span of wooden power electric poles of Eucalyptus saligna. Indeed, in Sub-Saharan African countries, Cameroon in particular, most of the power line networks are made of wooden supports and according to the Cameroon energy distribution company, wooden poles represent 32% of the causes of death linked to the state of the network. The company’s 2019 annual report indicates that 40,000 wooden poles were in critical condition and should be replaced. A significant number of mechanical failures affecting these supports have been observed. For example, on the HVA/LV power line “D17 Nko- abang” in Yaoundé in Cameroon, less than three years old, 10 (ten) cases of poles falling and/or breaking, due to their mechanical loading, were observed over a period of fewer than nine months, causing an average service stoppage for more than 11 hours and affecting an average of 3280 customers. These incidents lead to questions about how the supports are dimensioned and what load capacities they are designed to support. The aim of this work is, therefore, to suggest a method of dimensioning wooden poles hence reducing green- house gas emissions due to the deforestation by reducing the number of woo- den poles at risk to be replaced on Cameroon’s electricity distribution network. And more specifically, to reduce the number of mechanical failures affecting the wooden supports observed by analyzing the current wooden supports with their loads and to make proposals for improving the actual dimensioning me- thods. From the study carried out, it appears that 449 out of 845 supports, i.e., 53% needed to be replaced or monitored because they support the nominal forces ranging from 85% to 150% of their admissible limit and proposals have been made to improve their dimensioning.展开更多
文摘As an advanced 4^(th) generation synchrotron radiation facility,the Shenzhen Innovation Light-source Facility(SILF)storage ring is based on multi-bend achromat(MBA)lattices,enabling one to two orders of magnitude reduction in beam emittance compared to the 3^(rd) generation storage ring.This significantly enhance the radiation brightness and coherence.The multipole magnets of many types for SILF storage ring are under preliminary design,which require high integral field homogeneity.As a result,a dedicated pole tip optimization procedure with high efficiency is developed for quadrupole and sextupole magnets with Opera-2D^(■)python script.The procedure considers also the 3D field effect which makes the optimization more straightforward.In this paper,the design of the quadrupole and sextupole magnets for SILF storage ring is first presented,followed by a detailed description of the implemented pole shape optimization method.
文摘BACKGROUND Sleeve fracture of the patella is an unusual fracture,almost unique to children.The majority of sleeve fractures involve the inferior patellar pole.However,sleeve fractures of the superior pole of the patella are extremely rare in adults.CASE SUMMARY An 18-year-old male patient fell while running in the morning.The patient had tenderness to palpation at the superior pole of the patella,with a palpable gap over the upper part of the patella in both knees.We applied two 4.5-mm suture anchors with the Krackow stitch to repair the sleeve fracture,augmented by autogenous gracilis through performing the figure-of-eight technique.The patient regained approximately the full range of motion of the knee joint without any quadriceps weakness and a normal gait 6 weeks after surgery.CONCLUSION Sleeve fractures of the superior pole of the patella are extremely rare in adults,especially bilateral sleeve fractures.Suture anchors,augmented by autogenous gracilis,provided secure fixation and achieved excellent results in this rare injury.
基金supported by the Science and Technology Project of Guangdong Province,China(Grant No.2020B010190001)the National Natural Science Foundation of China(Grant No.12434016)+1 种基金the National Key Research and Development Program of China(Grant No.2023YFA1406900)the Fund of the National Postdoctoral Researcher Program(Grant No.GZB20240785).
文摘Conventional approaches for obtaining the second and third harmonics typically employ several nonlinear crystals to generate them,which is restricted in application due to the complexity of the optical path and the bulkiness of the device.In this work,we present a comprehensive theoretical and numerical investigation of the simultaneous generation and competition between the second harmonic waves(SHW)and the third harmonic waves(THW)in a single nonlinear crystal.Through analyzing both small-signal and large-signal regimes,we reveal the complex coupling mechanisms between SHW and THW generation processes.Using periodically poled lithium niobate as an example,we demonstrate that the relative conversion efficiencies between SHW and THW can be freely adjusted by controlling the input fundamental wave power.This work provides new insights for designing efficient frequency converters capable of generating both SHW and THW outputs with controllable intensity ratios.
基金supported by the National Key Research and Development Program of China(Grant Nos.2022YFC3401100 and 2022YFF0712500)the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030009)+2 种基金the National Natural Science Foundation of China(Grant Nos.12204017,12004012,12004013,12041602,91750203,91850111,and 92150301)the China Postdoctoral Science Foundation(Grant No.2020M680220 and 2020M680230)the Clinical Medicine Plus X-Young Scholars Project,Peking University,Fundamental Research Funds for the Central Universities.
文摘Due to its broken out-of-plane symmetry,z-cut periodically poled lithium niobate(PPLN)has exhibited ultrahigh second-order optical nonlinearity.Precise quantification of the domain structure of z-cut PPLN plays a critical role during poling fabrication.To enhance the imaging detection efficiency of the domain structure in z-cut PPLN,we have developed a second-harmonic generation microscope system specifically designed to produce a longitudinal electric field in foci for the imaging domain inversion.We demonstrated that imaging using a longitudinal electric field can achieve a contrast ratio enhancement by a factor of 1.77,showing high imaging efficiency and making the proposed method suitable for in situ monitoring of the z-cut PPLN poling process.
文摘The development of artificial intelligence(AI)technologies creates a great chance for the iteration of railway monitoring.This paper proposes a comprehensive method for railway utility pole detection.The framework of this paper on railway systems consists of two parts:point cloud preprocessing and railway utility pole detection.Thismethod overcomes the challenges of dynamic environment adaptability,reliance on lighting conditions,sensitivity to weather and environmental conditions,and visual occlusion issues present in 2D images and videos,which utilize mobile LiDAR(Laser Radar)acquisition devices to obtain point cloud data.Due to factors such as acquisition equipment and environmental conditions,there is a significant amount of noise interference in the point cloud data,affecting subsequent detection tasks.We designed a Dual-Region Adaptive Point Cloud Preprocessing method,which divides the railway point cloud data into track and non-track regions.The track region undergoes projection dimensionality reduction,with the projected results being unique and subsequently subjected to 2D density clustering,greatly reducing data computation volume.The non-track region undergoes PCA-based dimensionality reduction and clustering operations to achieve preprocessing of large-scale point cloud scenes.Finally,the preprocessed results are used for training,achieving higher accuracy in utility pole detection and data communication.Experimental results show that our proposed preprocessing method not only improves efficiency but also enhances detection accuracy.
基金Supported by National Natural Science Foundation of China,No.81960115,No.82160123 and No.82260124Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor(Guangxi Medical University),Ministry of Education,No.GKEZZ202107+1 种基金Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor,No.GKE-ZZ202218Guangxi Science and Technology Program,No.AD25069077.
文摘BACKGROUND Hepatitis B virus(HBV)infection is a leading cause of global hepatocellular carcinoma(HCC).Conventional biomarkers such as alpha-fetoprotein(AFP)demonstrate suboptimal sensitivity and specificity.Emerging evidence suggests that serum extra spindle pole bodies like 1(ESPL1)protein and p53 antibody may improve diagnostic accuracy.AIM To assess and compare the diagnostic performance of serum ESPL1 protein and p53 antibody in HBV-related HCC(HBV-HCC).METHODS This case-control study from the First Affiliated Hospital of Guangxi Medical University enrolled 30 patients with chronic hepatitis B(CHB),30 with HBV-related liver cirrhosis(HBV-LC),55 with HBV-HCC,and 30 healthy controls.Serum ESPL1 protein and p53 antibody levels were quantified via ELISA.Diagnostic performance was evaluated using receiver operating characteristic(ROC)curve analysis,including sensitivity,specificity,and correlation with AFP.RESULTS Serum ESPL1 protein levels progressively increased across disease stages(CHB:89.9 ng/L;HBV-LC:188.83 ng/L;HBV-HCC:317.63 ng/L),with a significantly higher area under the ROC curve(AUC=0.917)than either p53 antibody(AUC=0.725)or AFP(AUC=0.678).p53 antibody levels were significantly elevated only in the HBVHCC group.ESPL1 demonstrated superior sensitivity and concordance with histopathological findings.A significant correlation between ESPL1 and p53 antibody levels was observed exclusively in the HBV-HCC group(r=0.320,P=0.017),suggesting potential interplay in malignant transformation.CONCLUSION Serum ESPL1 protein,a promising biomarker for early HBV-HCC detection,outperforms p53 antibody in diagnostic reliability.Higher ESPL1 levels correlate with increased HCC risk in chronic HBV patients.
基金supported by the Project of National Natural Science Foundation of China under Grant 52077122。
文摘With the continuous upgrading of traditional manufacturing industries and the rapid rise of emerging technology fields,the performance requirements for the permanent magnet synchronous motors(PMSMs)have become higher and higher.The importance of fast and accurate electromagnetic thermal coupling analysis of such motors becomes more and more prominent.In view of this,the surfacemounted PMSM(SPMSM)equipped with unequally thick magnetic poles is taken as the main object and its electromagnetic thermal coupling analytical model(ETc AM)is investigated.First,the electromagnetic analytical model(EAM)is studied based on the modified subdomain method.It realizes the fast calculation of key electromagnetic characteristics.Subsequently,the 3D thermal analytical model(TAM)is developed by combining the EAM,the lumped parameter thermal network method(LPTNM),and the partial differential equation of heat flux.It realizes the fast calculation of key thermal characteristics in 3D space.Further,the information transfer channel between EAM and TAM is built with reference to the intrinsic connection between electromagnetic field and temperature field.Thereby,the novel ETcAM is proposed to realize the fast and accurate prediction of electromagnetic and temperature fields.Besides,ETcAM has a lot to commend it.One is that it well accounts for the complex structure,saturation,and heat exchange behavior.Second,it saves a lot of computer resources.It offers boundless possibilities for initial design,scheme evaluation,and optimization of motors.Finally,the validity,accuracy,and practicality of this study are verified by simulation and experiment.
基金National Natural Science Foundation of China,No.42271141,No.42071129National Key Basic Research and Development Project,No.2022YFF1300902。
文摘To understand the spatio-temporal variability of precipitation(P)in the Third Pole region(centered on the Tibetan Plateau-TP),it is necessary to quantify the interannual periodicity of P and its relationship with large-scale circulations.In this study,Morlet wavelet transform was used to detect significant(p<0.05)periodic characteristics in P data from meteorological stations in four climate domains in the Third Pole,and to reveal the major large-scale circulations that triggered the variability of periodic P,in addition to bringing large amounts of water vapour.The wavelet transform results were as follows.(1)Significant quasiperiodicity varied from 2 to 11 years.The high-frequency variability mode(2 to 6 years quasi-periods)was universal,and the low-frequency variability mode(7 to 11 years quasi-periods)was rare,occurring mainly in the westerlies and Indian monsoon domains.(2)The majority of periods were base periods(53%),followed by two-base periods.Almost all stations in the Third Pole(95%)showed one or two periods.(3)Periodicity was widely detected in the majority of years(84%).(4)The power spectra of P in the four domains were dominated by statistically significant high-frequency oscillations(ie.,with short periodicity).(5)Large-scale circulations directly and indirectly influenced the periodic P variability in the different domains.The mode of P variability in the different domains was influenced by interactions between large-scale circulation features and not only by the dominant circulation and its control of water vapour transport.The results of this study will contribute to better understanding of the causal mechanisms associated with P variability,which is important for hydrological science and waterresourcemanagement.
基金supported in part by the Government of Canada through the Department of Innovation, Science and Economic Development Canadaby the Province of Ontario through the Ministry of Economic Development, Job Creation and Trade
文摘Planar arrays of tree diagrams were introduced as a generalization of Feynman diagrams that enable the computation of biadjoint amplitudes m_(n)(^(k))for k>2.In this follow-up work,we investigate the poles of m_(n)(^(k))from the perspective of such arrays.For general k,we characterize the underlying polytope as a Flag Complex and propose a computation of the amplitude-based solely on the knowledge of the poles,whose number is drastically less than the number of the full arrays.As an example,we first provide all the poles for the cases(k,n)=(3,7),(3,8),(3,9),(3,10),(4,8)and(4,9)in terms of their planar arrays of degenerate Feynman diagrams.We then implement simple compatibility criteria together with an addition operation between arrays and recover the full collections/arrays for such cases.Along the way,we implement hard and soft kinematical limits,which provide a map between the poles in kinematic space and their combinatoric arrays.We use the operation to give a proof of a previously conjectured combinatorial duality for arrays in(k,n)and(n-k,n).We also outline the relation to boundary maps of the hypersimplex Δ_(k,n) and rays in the tropical Grassmannian Tr(k,n).
文摘Nowadays,there is considerable research interest in proposing modern permanent magnet(PM)electric machine structures for applications such as electric vehicles.Several radial and axial topologies with different arrangements of PM in the stator and rotor have been introduced for PM Vernier motors(PMVM)with the aim of increasing the performance characteristics such as power factor,efficiency,rotational torque torque density and wider constant torque-speed region.Meanwhile,the spoke PM arrangement has provided higher torque density than the surface and V-shaped arrangement.But in contrast,the V-shaped arrangement has a more sinusoidal flux and less cogging torque.In this paper,a 620 W,12-slot 16-pole Vernier PM motor with a fractional slot arrangement.Consequent K-shaped pole is introduced,which has the advantages of spoke and V-shaped magnetic arrangements.After presenting and confirming the concept of the proposed structure based on functional comparison with conventional structures,an analytical modeling based on the harmonic analysis method is introduced to accurately predict the performance of the machine,and finally the proposed structure is prototyped and the experimental results are simulated and modeling are compared.
文摘Previous studies done elsewhere have shown that Eucalyptus poles treated with chromated copper arsenate (CCA) can last over 30 years. Kenya is exceptional because in some eco-regions, the Eucalyptus poles’ life span has greatly reduced to 5 years. The current study was designed to evaluate wood deteriorating agents of CCA-treated Eucalyptus poles and variability in four eco-regions of Kenya, namely, dryland, coastal, highland and humid lake. A total of 360 Eucalyptus pole samples were used for this experiment. Three CCA treatments were used to treat transmission poles at 20 kg/cm3 fencing posts samples at 6 kg/cm3, and a control group. Results indicated that termites and wood-decay fungi attacks caused wood deterioration in the four eco-regions. The proportion of power transmission pole degradation by wood deteriorating agents varied across eco-regions, between treatments and control and between time after treatments. Dryland eco-regions had the highest termite-related degradation (41.82%) while wood-decay fungi attack was highest in the highland eco-regions (9.20%). Samples treated with 6 kg/cm3 recorded the lowest level of wood deterioration, manifested by minimal superficial termite and wood-decay fungi attack. Samples treated with 20 kg/cm3 were characterized by moderate termite and wood-decay fungi attacks observed around the heartwood region, unlike sapwood. This study concluded that the deterioration of Eucalyptus CCA-treated poles is a question of climatic variability and hence, to increase the poles’ lifespan, CCA treatment should be tailored according to the characteristics of the ecoregion of use. Further investigations will inform the diversity of termites and decay-fungi across different eco-regions.
文摘Aiming at the problem of high temperature and even demagnetization failure of permanent magnet (PM) due to PM eddy current loss in PM synchronous high-speed motors, this paper proposes a technique to lessen PM eddy current loss by cutting the angle of PM poles to change the shape of PM structure. Firstly, an analysis is conducted on the mechanism of PM synchronous high-speed motor eddy current loss production, the theoretical analytical model of PM eddy current loss is deduced, and it is theoretically proved that the magnetic pole shaving angle can reduce PM eddy current loss. Then, a 25 KW surface-type PM synchronous high-speed motor as an object, using two-dimensional time-step finite element method (FEM) to model and analyze PM eddy current loss. The results show that the smaller the PM pole shaving angle, the less its eddy current loss will be, it is possible to minimize the pole shaving angle of eddy current loss by 9.8% compared to the unshaved angle. Finally, the temperature field of the PM is calculated using a finite element method, and the outcomes demonstrate that the maximum temperature of the PM with a magnetic pole shaving angle can be reduced by about 5% compared with the unshaved angle.
文摘The Head-Related Transfer Function(HRTF)describes the effects of sound reflection and scattering caused by the environment and the human body when sound signals are transmitted from a source to the human ear.It contains a significant amount of auditory cue information used for sound localization.Consequently,HRTF renders 3D audio accurately in numerous immersive multimedia applications.Because HRTF is high-dimensional,complex,and nonlinear,it is a relatively large and intricate dataset,typically consisting of hundreds of thousands of samples.Storing HRTF requires a significant amount of storage space in practical applications.Based on this,high-dimensional,complex,and nonlinear HRTFs need to be compressed and reconstructed.In this study,inspired by the conventional common-pole/zero model,we propose a method for representing HRTF based on the common-pole/zero model and principal component analysis(PCA).Our method utilizes human auditory features and extends the traditional Common-Acoustical-Pole/Zero(CAPZ)method to estimate the common pole and zero coefficients across multiple subjects.Subsequently,the zero coefficients are compressed using the PCA procedure.Experimental results on the CIPIC database show that the compression ratio can reach 9.5%when the average spectral distortion is less than 2 dB.
文摘Analyzing from the perspective of physics mechanics,the pole vault is a project which transforms kinetic energy into elastic potential energy.The magnitude of kinetic energy depends on the vaulter’s approaching speed,while the magnitude of elastic potential energy depends on height.Therefore,the run-up speed determines the vaulter’s performance in pole vault to a certain extent.the horizontal speed of the pole-holding approach phase transitioning into vertical upward speed plays a crucial role in executing pole vault techniques,and the model of approaching speed establishes a theoretical foundation for vaulters to break through the pole limitation.In terms of specialized technical assistance in speed training,short-distance speed exercises are used in the approaching phase;in the swinging phase,gymnastic rings,single bar and suspension rope exercises are employed for suspension;in the stretch phase,trampoline exercises play a important role in rotation phase,etc.
文摘The present work deals with reducing greenhouse gas emissions through improving the life span of wooden power electric poles of Eucalyptus saligna. Indeed, in Sub-Saharan African countries, Cameroon in particular, most of the power line networks are made of wooden supports and according to the Cameroon energy distribution company, wooden poles represent 32% of the causes of death linked to the state of the network. The company’s 2019 annual report indicates that 40,000 wooden poles were in critical condition and should be replaced. A significant number of mechanical failures affecting these supports have been observed. For example, on the HVA/LV power line “D17 Nko- abang” in Yaoundé in Cameroon, less than three years old, 10 (ten) cases of poles falling and/or breaking, due to their mechanical loading, were observed over a period of fewer than nine months, causing an average service stoppage for more than 11 hours and affecting an average of 3280 customers. These incidents lead to questions about how the supports are dimensioned and what load capacities they are designed to support. The aim of this work is, therefore, to suggest a method of dimensioning wooden poles hence reducing green- house gas emissions due to the deforestation by reducing the number of woo- den poles at risk to be replaced on Cameroon’s electricity distribution network. And more specifically, to reduce the number of mechanical failures affecting the wooden supports observed by analyzing the current wooden supports with their loads and to make proposals for improving the actual dimensioning me- thods. From the study carried out, it appears that 449 out of 845 supports, i.e., 53% needed to be replaced or monitored because they support the nominal forces ranging from 85% to 150% of their admissible limit and proposals have been made to improve their dimensioning.
