Double-shaft-driven needle punching machine is a specialized equipment designed for processing C/C crucible preforms.Its main needle punching module is operated by two sets of reciprocating crank-slider mechanisms.The...Double-shaft-driven needle punching machine is a specialized equipment designed for processing C/C crucible preforms.Its main needle punching module is operated by two sets of reciprocating crank-slider mechanisms.The intense vibration during needle punching not only generates huge noise,but also substantially reduces the quality of the preform.It is imperative to perform a dynamic analysis and optimization of the entire needle punching machine.In this paper,the three-dimensional(3D)model of the entire double-shaft-driven needle punching machine for C/C crucible preforms is established.Based on the modal analysis theory,the modal characteristics of the needle punching machine under various operating conditions are analyzed and its natural frequencies and vibration modes are determined.The harmonic response analysis is then employed to obtain the amplitude of the needle plate at different frequencies,and the structural weak points of the needle punching machine are identified and improved.The feasibility of the optimized scheme is subsequently reevaluated and verified.The results indicate that the first six natural frequencies of the machine increase,and the maximum amplitude of the needle plate decreases by 70.3%.The enhanced dynamic characteristics of the machine significantly improve its performance,enabling more efficient needle punching of C/C crucible preforms.展开更多
Leveraging big data signal processing offers a pathway to the development of artificial intelligencedriven equipment.The analysis of fluid flow signals and the characterization of fluid flow behavior are of critical i...Leveraging big data signal processing offers a pathway to the development of artificial intelligencedriven equipment.The analysis of fluid flow signals and the characterization of fluid flow behavior are of critical in two-phase flow studies.Significant research efforts have focused on discerning flow regimes using various signal analysis methods.In this review,recent advances in time series signals analysis algorithms for stirred tank reactors have been summarized,and the detailed methodologies are categorized into the frequency domain methods,time-frequency domain methods,and state space methods.The strengths,limitations,and notable findings of each algorithm are highlighted.Additionally,the interrelationships between these methodologies have also been discussed,as well as the present progress achieved in various applications.Future research directions and challenges are also predicted to provide an overview of current research trends in data mining of time series for analyzing flow regimes and chaotic signals.This review offers a comprehensive summary for extracting and characterizing fluid flow behavior and serves as a theoretical reference for optimizing the characterization of chaotic signals in future research endeavors.展开更多
The study of capture mechanisms with high capture adaptability is the key to improving the efficiency of autonomous underwater vehicle(AUV)retrieval and release.This study aims to develop a capture mechanism for the l...The study of capture mechanisms with high capture adaptability is the key to improving the efficiency of autonomous underwater vehicle(AUV)retrieval and release.This study aims to develop a capture mechanism for the launch and recovery of AUV and elucidate its kinematic characteristics.Initially,based on the principles of deployment and retraction for AUV capture movements,a design scheme for a novel foldable and deployable capture mechanism is proposed.Subsequently,a detailed analysis of the Degrees of Freedom(DoFs)for enveloping and grasping movements is conducted according to screw theory.Additionally,the structural design of the actuation units for the capture mechanism is thoroughly discussed.Motion screw topology diagram is utilized to construct the kinematic model.On this basis,kinematic simulation verification of the capture mechanism is performed.The theoretical analysis revealed that the DoF for enveloping and grasping movements are 6 and 2,respectively.By appropriately configuring the actuation mechanism,enveloping and grasping movements can be achieved with a single actuation.The displacement and velocity curves of the capture mechanism were smooth,with no interference occurring.Vibration test results validate the reliability of the capture mechanism.The research work provides a valuable reference for the development of novel capture equipment for AUVs.展开更多
This study investigates the wind field structure and thermodynamic characteristics in the peripheral region of Tropical Storm Sinlaku(2020) through an integrated analysis of airborne dropsonde data, ERA5 reanalysis da...This study investigates the wind field structure and thermodynamic characteristics in the peripheral region of Tropical Storm Sinlaku(2020) through an integrated analysis of airborne dropsonde data, ERA5 reanalysis data, and China Meteorological Administration(CMA) best track dataset. The results indicate that the structure of the wind field varies with altitude, and dropsonde observations capture key features consistent with the dissipating stage of the tropical cyclone.Southwesterly winds are predominant in the middle and lower troposphere(500–975 hPa), which constitute the primary outflow layer and exhibits cyclonic motion. The tangential wind reaches its maximum speed(>17 m s^(–1)) at an altitude of3–4 km in the middle troposphere, coinciding with the region of the strongest cyclonic motion. Within the same group, as the dropsonde moves closer to the tropical storm center, the intensity of the cyclonic motion in the middle troposphere intensifies. In addition, the southeasterly winds dominate in the upper troposphere, which, along with the near-surface area,constitute the inflow layers. When the dropsonde is closer to the tropical storm center, the top of the near-surface inflow layer is observed at a lower altitude. Horizontal temperature gradients at different positions are relatively weak, but the vertical temperature lapse rate exhibits localized changes at different heights. The typhoon′s peripheral cloud system exists in an atmospheric environment characterized by instability in the lower levels and relative stability in the middle to upper levels.展开更多
Objective:To analyse the clinical characteristics of Mycoplasma pneumoniae pneumonia(MPP)in children under two years of age.Methods:A retrospective analysis was conducted on 112 paediatric cases of MPP admitted to our...Objective:To analyse the clinical characteristics of Mycoplasma pneumoniae pneumonia(MPP)in children under two years of age.Methods:A retrospective analysis was conducted on 112 paediatric cases of MPP admitted to our hospital between January 2022 and December 2023.Clinical data including symptoms,signs,imaging findings,and prognosis were collected.Results:Analysis of clinical symptom distribution revealed coughing in 100.0%of cases,comprising both paroxysmal dry cough and productive cough.Fever was present in 61.61%of cases,with additional manifestations including wheezing,vomiting,diarrhoea,and respiratory distress.Pulmonary rales were the most prevalent finding at 75.89%,alongside other signs such as diminished breath sounds.Imaging analysis of all 112 pneumonia cases revealed bronchopneumonia accounted for 70.54%of cases,representing a relatively high proportion.Treatment involved macrolide antibiotics,including azithromycin,with bronchodilators and corticosteroids added for significant wheezing.The overall treatment efficacy rate was 90.18%.Conclusion:Analysis of Mycoplasma pneumoniae characteristics in children under 2 years indicates that MPP in infants and young children under 2 presents with mild symptoms,pronounced signs,and relatively mild overall inflammation,resulting in a comparatively high overall cure rate.展开更多
Sandy cobble soil exhibits pronounced heterogeneity.The assessment of the uncertainty surrounding its properties is crucial for the analysis of settlement characteristics resulting from volume loss during shield tunne...Sandy cobble soil exhibits pronounced heterogeneity.The assessment of the uncertainty surrounding its properties is crucial for the analysis of settlement characteristics resulting from volume loss during shield tunnelling.In this study,a series of probabilistic analyses of surface and subsurface settlements was conducted considering the spatial variability of the friction angle and reference stiffness modulus,under different volumetric block proportions(Pv)and tunnel volume loss rates(ηt).The non-intrusive random finite difference method was used to investigate the probabilistic characteristics of maximum surface settlement,width of subsurface settlement trough,maximum subsurface settlement,and subsurface soil volume loss rate through Monte Carlo simulations.Additionally,a comparison between stochastic and deterministic analysis results is presented to underscore the significance of probabilistic analysis.Parametric analyses were subsequently conducted to investigate the impacts of the key input parameters in random fields on the settlement characteristics.The results indicate that scenarios with higher Pv or greaterηt result in a higher dispersion of stochastic analysis results.Neglecting the spatial variability of soil properties and relying solely on the mean values of material parameters for deterministic analysis may result in an underestimation of surface and subsurface settlements.From a probabilistic perspective,deterministic analysis alone may prove inadequate in accurately capturing the volumetric deformation mode of the soil above the tunnel crown,potentially affecting the prediction of subsurface settlement.展开更多
Radial rotating oscillating heat pipes(R-OHPs)have excellent thermal performance and great potential for application in the thermal management of rotatory machinery.However,the heat transport behavior and temperature ...Radial rotating oscillating heat pipes(R-OHPs)have excellent thermal performance and great potential for application in the thermal management of rotatory machinery.However,the heat transport behavior and temperature characteristics of R-OHPs are complex,and their understanding is still limited,hence necessitating further research.In this study,thanks to an experimental investigation involving a copper R-OHP running with acetone and water,its thermal performance is evaluated,and then the temperature characteristics are analyzed by nonlinear dynamic analysis.The study reveals that the effective heat transfer coefficient of R-OHPs undergoes a notable increase with rising rotational speed,exhibiting a peak at a threshold speed value.Such a peak is present irrespectively of the working fluid,and,after exceeding the threshold,higher rotational speeds lead to a lower thermal performance.Based on nonlinear dynamic analysis,the power spectrum density of the evaporator temperature indicates a lack of dominant frequency in temperature signals,suggesting a complex behavior characterized by random oscillations of vapor slugs and liquid plugs.In order to better understand how strong the chaotic behavior is,an autocorrelation analysis was carried out,the OHP at static state has a stronger chaos than R-OHPs.The correlation dimension analysis of the evaporator temperature provides values ranging from 1.2 to 1.6,which together with the Lyapunov exponent calculations,further support an evident chaotic nature of R-OHPs.展开更多
BACKGROUND Primary gastrointestinal diffuse large B-cell lymphoma(PGI-DLBCL),the most prevalent extranodal non-Hodgkin lymphoma,poses significant diagnostic and therapeutic challenges due to its non-specific symptoms ...BACKGROUND Primary gastrointestinal diffuse large B-cell lymphoma(PGI-DLBCL),the most prevalent extranodal non-Hodgkin lymphoma,poses significant diagnostic and therapeutic challenges due to its non-specific symptoms and poor prognosis.AIM To develop and validate a risk model for the early identification of PGI-DLBCL using Least Absolute Shrinkage and Selection-Cox regression,with the aim of guiding clinical decision-making.METHODS The clinical data of patients diagnosed with PGI-DLBCL at the Tumor Hospital Affiliated to Xinjiang Medical University were analyzed retrospectively from January 2010 to April 2022.RESULTS A total of 319 patients with PGI-DLBCL were included and divided into training(n=223)and validation(n=96)cohorts.The median age was 55 years,with 48.9%male and 51.1%female patients.Key clinical features included Eastern Cooperative Oncology Group performance status≥2(40.8%),advanced-stage disease(stage IV:27.6%),extranodal involvement≥2 sites(47%),tumor>5 cm(46.1%),elevated beta-2 microglobulin(50.5%),elevated lactate dehydrogenase(27%),high International Prognostic Index(3-5:69.9%),non-germinal center B-cell-like subtype(59.9%),and B symptoms(55.8%).Immunohistochemical analysis showed frequent expression of CD10(51.1%),B-cell lymphoma 6(53.3%),multiple myeloma oncogene 1(40.1%),Bcell lymphoma 2(49.2%),myelocytomatosis viral oncogene homolog(48.3%),Ki-67(67.1%),and CD5(42.6%);Epstein-Barr virus-encoded RNA was positive in 3.1%.Based on Least Absolute Shrinkage and Selection regression and subsequent univariate and multivariate Cox regression analyses,extranodal sites≥2,B symptoms,mixed lesion type,and negative multiple myeloma oncogene 1 expression were identified as independent risk factors for PGI-DLBCL.The risk model stratified patients into high-and low-risk groups with significantly different overall survival(P<0.05).Area under the curve values for 1-,3-,and 5-year overall survival were 0.625,0.663,and 0.723 in the training cohort,with consistent performance in the validation cohort.Decision curve analysis indicated favorable clinical utility.CONCLUSION PGI-DLBCL in our cohort showed distinctive clinical features and a predominance of the non-germinal center Bcell-like subtype.Decision curve analysis confirmed the clinical applicability of our prognostic model.Although molecular biomarkers will be needed to improve predictive precision,our model offers a practical tool for early risk identification and individualized management in clinical practice.展开更多
Common bean(Phaseolus vulgaris L.)is a vital source of protein and essential nutrients for human consumption and plays a key role in sustainable agriculture due to its nitrogen-fixing ability(Nadeem et al.,2021).Kidne...Common bean(Phaseolus vulgaris L.)is a vital source of protein and essential nutrients for human consumption and plays a key role in sustainable agriculture due to its nitrogen-fixing ability(Nadeem et al.,2021).Kidney beans,a subcategory of dry common beans,are highly valued for their rich protein,dietary fiber,low fat content,and various trace elements(Garcia-Cordero et al.,2021).Despite the release of several de novo genome assemblies(Goodstein et al.,2012;Schmutz et al.,2014;Vlasova et al.,2016;Cortinovis et al.,2024),existing common bean genomes remain incomplete,particularly in complex regions such as centromeres and telomeres,limiting a comprehensive understanding of the genomic landscape.展开更多
Based on the monthly precipitation data from 43 stations in North China from 1979 to 2008,the variation characteristics of precipitation in North China in recent 30 years were analyzed by means of empirical orthogonal...Based on the monthly precipitation data from 43 stations in North China from 1979 to 2008,the variation characteristics of precipitation in North China in recent 30 years were analyzed by means of empirical orthogonal function(EOF)decomposition,Morlet wavelet transform and Mann-Kendall test.The results showed that the spatial distribution of annual and seasonal precipitation was basically identical in North China,while the annual and summer precipitation from the middle of 1980s to the middle of 1990s were obviously more than these in other periods,and there was great annual variation in spring precipitation in 1990s,while autumn precipitation was higher from 1980s to 1990s and then went down after the beginning of 21st century,which was opposite to winter precipitation,namely there was more winter precipitation from 1980s to 1990s and fewer winter precipitation after the beginning of 21st century.In addition,the annual and summer precipitation changed abruptly in 1997,and there was no obvious change in spring precipitation and autumn precipitation,while winter precipitation had an abrupt change in 2000.Meanwhile,wavelet analysis revealed that the variation period of annual and seasonal precipitation was 3-4 years.展开更多
The characteristics of the temperature variation in Baoji City were analyzed with the temperature data from 1952 to 2003.The results showed that the value of annual average temperature and seasonal average temperature...The characteristics of the temperature variation in Baoji City were analyzed with the temperature data from 1952 to 2003.The results showed that the value of annual average temperature and seasonal average temperature wavily rose before 1980 and obviously ascended after 1980.During the period of last 52 years,there was a process of ascent-descent-ascent in summer seasonal temperature variation.While in autumn and winter,the temperature decreased at first and then increased.The steady ascent of the temperature in summer season had a great contribution to the increment of its average temperature.The type of the variation trend in the average temperature in Baoji in recent 52 years was verified according to the results.展开更多
Based on meteorology and environment monitoring data in January,2008 in Liaoning central region,a typical haze weather process was analyzed.The results showed that haze was formed due to the stable weather condition i...Based on meteorology and environment monitoring data in January,2008 in Liaoning central region,a typical haze weather process was analyzed.The results showed that haze was formed due to the stable weather condition in the earth surface and upper air layer in Liaoning central region.Especially because that the weakening of atmospheric dispersion ability in the urban boundary layer that was 500 m under earth surface,caused the pollutant in the air can not disperse.Thus,it resulted in the deterioration of air quality,increase of concentration of particulate mass,and declination of visibility.And in the end,haze formed.展开更多
According to the Chapman multi-scale rock physical model, the seismic response characteristics vary for different fluid-saturated reservoirs. For class I AVO reservoirs and gas-saturation, the seismic response is a hi...According to the Chapman multi-scale rock physical model, the seismic response characteristics vary for different fluid-saturated reservoirs. For class I AVO reservoirs and gas-saturation, the seismic response is a high-frequency bright spot as the amplitude energy shifts. However, it is a low-frequency shadow for the Class III AVO reservoirs saturated with hydrocarbons. In this paper, we verified the high-frequency bright spot results of Chapman for the Class I AVO response using the frequency-dependent analysis of a physical model dataset. The physical model is designed as inter-bedded thin sand and shale based on real field geology parameters. We observed two datasets using fixed offset and 2D geometry with different fluid- saturated conditions. Spectral and time-frequency analyses methods are applied to the seismic datasets to describe the response characteristics for gas-, water-, and oil-saturation. The results of physical model dataset processing and analysis indicate that reflection wave tuning and fluid-related dispersion are the main seismic response characteristic mechanisms. Additionally, the gas saturation model can be distinguished from water and oil saturation for Class I AVO utilizing the frequency-dependent abnormal characteristic. The frequency-dependent characteristic analysis of the physical model dataset verified the different spectral response characteristics corresponding to the different fluid-saturated models. Therefore, by careful analysis of real field seismic data, we can obtain the abnormal spectral characteristics induced by the fluid variation and implement fluid detection using seismic data directly.展开更多
[Objective] To provide a theoretical basis for high-yield breeding of broom sorghum.[Method] Using 11 kinds of broom sorghum collected at home as research objects, the differences in morphological characteristics of b...[Objective] To provide a theoretical basis for high-yield breeding of broom sorghum.[Method] Using 11 kinds of broom sorghum collected at home as research objects, the differences in morphological characteristics of broom sorghum were compared through the survey of some indicators, such as plant height, tillering, inflorescence, stem node, stem-leaf ratio, yield, and so on. [Result] The 11 kinds of broom sorghum were different in morphological characteristics with large amplitude of plant height; zygl-1, zygl-6, zygl-8 and zygl-9 were appropriate for fixed broom type; zygl-9 had the highest integrated production. [Condusion] The study laid the foundation for further exploring breeding, cultivation and promotion of broom sorghum.展开更多
[ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices （body length, body weight, forelimb length, hindlimb length） of eight geogra...[ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices （body length, body weight, forelimb length, hindlimb length） of eight geographical populations of R.dybowskii which naturally distribute in Changhai Mountain and Xiaoxing＇an Mountain were measured. Measure results were variance analyzed and cluster analyzed. [Result] Variance analysis showed： the genetic branching among the Dongfanghong male population（ belongs to Wandashan） and Xiaoxing＇an Mountain male population and Changbai Mountain male population were significantly different （P〈0.05） ; the genetic branching between the Hebei female population （belongs to Xiaoxing＇an Mountain） and Changbai Mountain female population was significantly different （P〈0.05 ）. Cluster analysis showed ： male R.dybowskii can be divided into three groups ： the first group included Quanyang, Tianbei, Chaoyang and Ddkouqin, the second group included Tieli and Anshan, the third group included Dongfanghong; and the female R. dybowskii can be divided into three groups ： the first group included Quanyang and Chaoyang, the second group included Tianbei and Dakouqin, the third group included Hebei. [Condusion] The paper deduced that the Sanjiang Plain was the geographical origin center ofR. dybowskii which radiated to Changbai Mountain and Xiaoxing＇an Mountain along the adverse current of Songhua River basin, therefore, the current distribution pattern of R. dybowskii was formed.展开更多
Robinia pseudoacacia stands act as a typical ecological protection forest in hilly semi-arid area of China. Two fields of surface runoff were separately set up in R. pseudoacacia stand and its clearcut area in the wes...Robinia pseudoacacia stands act as a typical ecological protection forest in hilly semi-arid area of China. Two fields of surface runoff were separately set up in R. pseudoacacia stand and its clearcut area in the western Liaoning Province (1850-12225 E, 4024-4234 N) for measuring the characteristics of runoff and sediment as well as soil moisture dynamics. Contractive analysis of the two land types showed that there existed a significant difference in volumes of runoff and sediment between the sites of R. pseudoacacia stand and its clearcut area. The runoff volume and sediment volume in clearcut area were much bigger than those in R. pseudoacacia stand, with an increase amount of 40%-177% for runoff and 180%-400% for sediment. Hydrograph of surface runoff of typical rainfall showed that the peak value of runoff in R. pseudoacacia stand was decreased by 1.0-2.5?0-3m3s-1 compared with that in its clearcut area, and the occurring time of peak value of runoff in R. pseudoacacia stand was 10-20 min later than that in its clearcut area. Harmonic analysis of soil moisture dynamics indicated that the soil moisture in R. pseudoacacia stand was 2.3 % higher than that in clearcut area, and the soil moisture both in R. pseudoacacia stand and its clearcut area could be divided into dry season and humid season and varied periodically with annual rainfall precipitation. It was concluded that R. pseudoacacia stand plays a very important role in storing water, increasing soil moisture, and reducing surface runoff and soil erosion.展开更多
We propose an electronic model in Spice, instead of traditional mathematical analysis, for analyzing the performance of ferroelectric liquid crystal （FLC） under various working conditions. Using this equivalent circ...We propose an electronic model in Spice, instead of traditional mathematical analysis, for analyzing the performance of ferroelectric liquid crystal （FLC） under various working conditions. Using this equivalent circuit model,it is easy to simulate and analyze the behavior of an FLC layer in three different typical parameters,including temperature, input light wavelength, and the frequency of driving voltage. We conclude that the response velocity drops as the wavelength increases in the range of visible light, and for the parameter of temperature, the velocity reaches its lowest value when the temperature reaches a certain degree,meanwhile,the frequency of driving voltage exerts important effects on the response velocity only when the frequency is beyond a critical value. Excellent agreement is achieved between simulation and experimental results.展开更多
Seismic texture attributes are closely related to seismic facies and reservoir characteristics and are thus widely used in seismic data interpretation.However,information is mislaid in the stacking process when tradit...Seismic texture attributes are closely related to seismic facies and reservoir characteristics and are thus widely used in seismic data interpretation.However,information is mislaid in the stacking process when traditional texture attributes are extracted from poststack data,which is detrimental to complex reservoir description.In this study,pre-stack texture attributes are introduced,these attributes can not only capable of precisely depicting the lateral continuity of waveforms between different reflection points but also reflect amplitude versus offset,anisotropy,and heterogeneity in the medium.Due to its strong ability to represent stratigraphies,a pre-stack-data-based seismic facies analysis method is proposed using the selforganizing map algorithm.This method is tested on wide azimuth seismic data from China,and the advantages of pre-stack texture attributes in the description of stratum lateral changes are verified,in addition to the method＇s ability to reveal anisotropy and heterogeneity characteristics.The pre-stack texture classification results effectively distinguish different seismic reflection patterns,thereby providing reliable evidence for use in seismic facies analysis.展开更多
Based on acid rain data from ten monitoring sites in Guangxi from 2003 to 2009,the temporal and spatial distribution characteristic of acid rain in Guangxi were analyzed by means of empirical orthogonal function resol...Based on acid rain data from ten monitoring sites in Guangxi from 2003 to 2009,the temporal and spatial distribution characteristic of acid rain in Guangxi were analyzed by means of empirical orthogonal function resolution(EOF).The results showed that there was fluctuating change of acid rain frequency in Guangxi,and acid rain pollution became severer in 2004-2008;acid rain frequency changed conformably in the whole region and it was obviously higher in eastern and northwestern Guangxi,while acid rain pollution became severe in western Guangxi;acid rain frequency varied out of phase between northeastern and southwestern Guangxi in an individual year.展开更多
基金Open Project of Shanghai Key Laboratory of Lightweight Composite,China(No.2232021A4-04)。
文摘Double-shaft-driven needle punching machine is a specialized equipment designed for processing C/C crucible preforms.Its main needle punching module is operated by two sets of reciprocating crank-slider mechanisms.The intense vibration during needle punching not only generates huge noise,but also substantially reduces the quality of the preform.It is imperative to perform a dynamic analysis and optimization of the entire needle punching machine.In this paper,the three-dimensional(3D)model of the entire double-shaft-driven needle punching machine for C/C crucible preforms is established.Based on the modal analysis theory,the modal characteristics of the needle punching machine under various operating conditions are analyzed and its natural frequencies and vibration modes are determined.The harmonic response analysis is then employed to obtain the amplitude of the needle plate at different frequencies,and the structural weak points of the needle punching machine are identified and improved.The feasibility of the optimized scheme is subsequently reevaluated and verified.The results indicate that the first six natural frequencies of the machine increase,and the maximum amplitude of the needle plate decreases by 70.3%.The enhanced dynamic characteristics of the machine significantly improve its performance,enabling more efficient needle punching of C/C crucible preforms.
基金the National Natural Science Foundation of China(22078030)the National Key Research and Development Project(2019YFC1905802,2022YFB3504305)+1 种基金the Joint Funds of the National Natural Science Foundation of China(U1802255,CSTB2022NSCQ-LZX0014)the Key Project of Independent Research Project of State Key Laboratory of Coal Mine Disaster Dynamics and Control(2011DA105287-zd201902).
文摘Leveraging big data signal processing offers a pathway to the development of artificial intelligencedriven equipment.The analysis of fluid flow signals and the characterization of fluid flow behavior are of critical in two-phase flow studies.Significant research efforts have focused on discerning flow regimes using various signal analysis methods.In this review,recent advances in time series signals analysis algorithms for stirred tank reactors have been summarized,and the detailed methodologies are categorized into the frequency domain methods,time-frequency domain methods,and state space methods.The strengths,limitations,and notable findings of each algorithm are highlighted.Additionally,the interrelationships between these methodologies have also been discussed,as well as the present progress achieved in various applications.Future research directions and challenges are also predicted to provide an overview of current research trends in data mining of time series for analyzing flow regimes and chaotic signals.This review offers a comprehensive summary for extracting and characterizing fluid flow behavior and serves as a theoretical reference for optimizing the characterization of chaotic signals in future research endeavors.
基金Supported by Jiangsu Provincial Natural Science Foundation(Grant No.BK20220649)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.23KJB460010)+2 种基金Provincial Key Laboratory of High-end Deepsea Machinery Equipment(Grant Nos.SYH2024003 and SYH2025001)the Jiangsu Provincial Key R&D Project(Grant No.BE2022062)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.SJCX25_2526).
文摘The study of capture mechanisms with high capture adaptability is the key to improving the efficiency of autonomous underwater vehicle(AUV)retrieval and release.This study aims to develop a capture mechanism for the launch and recovery of AUV and elucidate its kinematic characteristics.Initially,based on the principles of deployment and retraction for AUV capture movements,a design scheme for a novel foldable and deployable capture mechanism is proposed.Subsequently,a detailed analysis of the Degrees of Freedom(DoFs)for enveloping and grasping movements is conducted according to screw theory.Additionally,the structural design of the actuation units for the capture mechanism is thoroughly discussed.Motion screw topology diagram is utilized to construct the kinematic model.On this basis,kinematic simulation verification of the capture mechanism is performed.The theoretical analysis revealed that the DoF for enveloping and grasping movements are 6 and 2,respectively.By appropriately configuring the actuation mechanism,enveloping and grasping movements can be achieved with a single actuation.The displacement and velocity curves of the capture mechanism were smooth,with no interference occurring.Vibration test results validate the reliability of the capture mechanism.The research work provides a valuable reference for the development of novel capture equipment for AUVs.
基金China Meteorological Administration Innovation Development Special Project (CXFZ2025J064)National Natural Science Foundation of China (U2442214)。
文摘This study investigates the wind field structure and thermodynamic characteristics in the peripheral region of Tropical Storm Sinlaku(2020) through an integrated analysis of airborne dropsonde data, ERA5 reanalysis data, and China Meteorological Administration(CMA) best track dataset. The results indicate that the structure of the wind field varies with altitude, and dropsonde observations capture key features consistent with the dissipating stage of the tropical cyclone.Southwesterly winds are predominant in the middle and lower troposphere(500–975 hPa), which constitute the primary outflow layer and exhibits cyclonic motion. The tangential wind reaches its maximum speed(>17 m s^(–1)) at an altitude of3–4 km in the middle troposphere, coinciding with the region of the strongest cyclonic motion. Within the same group, as the dropsonde moves closer to the tropical storm center, the intensity of the cyclonic motion in the middle troposphere intensifies. In addition, the southeasterly winds dominate in the upper troposphere, which, along with the near-surface area,constitute the inflow layers. When the dropsonde is closer to the tropical storm center, the top of the near-surface inflow layer is observed at a lower altitude. Horizontal temperature gradients at different positions are relatively weak, but the vertical temperature lapse rate exhibits localized changes at different heights. The typhoon′s peripheral cloud system exists in an atmospheric environment characterized by instability in the lower levels and relative stability in the middle to upper levels.
文摘Objective:To analyse the clinical characteristics of Mycoplasma pneumoniae pneumonia(MPP)in children under two years of age.Methods:A retrospective analysis was conducted on 112 paediatric cases of MPP admitted to our hospital between January 2022 and December 2023.Clinical data including symptoms,signs,imaging findings,and prognosis were collected.Results:Analysis of clinical symptom distribution revealed coughing in 100.0%of cases,comprising both paroxysmal dry cough and productive cough.Fever was present in 61.61%of cases,with additional manifestations including wheezing,vomiting,diarrhoea,and respiratory distress.Pulmonary rales were the most prevalent finding at 75.89%,alongside other signs such as diminished breath sounds.Imaging analysis of all 112 pneumonia cases revealed bronchopneumonia accounted for 70.54%of cases,representing a relatively high proportion.Treatment involved macrolide antibiotics,including azithromycin,with bronchodilators and corticosteroids added for significant wheezing.The overall treatment efficacy rate was 90.18%.Conclusion:Analysis of Mycoplasma pneumoniae characteristics in children under 2 years indicates that MPP in infants and young children under 2 presents with mild symptoms,pronounced signs,and relatively mild overall inflammation,resulting in a comparatively high overall cure rate.
基金supported by the Natural Science Foundation of Beijing Municipality(No.8222004),Chinathe National Natural Science Foundation of China(No.51978019)+3 种基金the Natural Science Foundation of Henan Province(No.252300420445),Chinathe Doctoral Research Initiation Fund of Henan University of Science and Technology(No.4007/13480062),Chinathe Henan Postdoctoral Foundation(No.13554005),Chinathe Joint Fund of Science and Technology R&D Program of Henan Province(No.232103810082),China。
文摘Sandy cobble soil exhibits pronounced heterogeneity.The assessment of the uncertainty surrounding its properties is crucial for the analysis of settlement characteristics resulting from volume loss during shield tunnelling.In this study,a series of probabilistic analyses of surface and subsurface settlements was conducted considering the spatial variability of the friction angle and reference stiffness modulus,under different volumetric block proportions(Pv)and tunnel volume loss rates(ηt).The non-intrusive random finite difference method was used to investigate the probabilistic characteristics of maximum surface settlement,width of subsurface settlement trough,maximum subsurface settlement,and subsurface soil volume loss rate through Monte Carlo simulations.Additionally,a comparison between stochastic and deterministic analysis results is presented to underscore the significance of probabilistic analysis.Parametric analyses were subsequently conducted to investigate the impacts of the key input parameters in random fields on the settlement characteristics.The results indicate that scenarios with higher Pv or greaterηt result in a higher dispersion of stochastic analysis results.Neglecting the spatial variability of soil properties and relying solely on the mean values of material parameters for deterministic analysis may result in an underestimation of surface and subsurface settlements.From a probabilistic perspective,deterministic analysis alone may prove inadequate in accurately capturing the volumetric deformation mode of the soil above the tunnel crown,potentially affecting the prediction of subsurface settlement.
基金Supported by National Natural Science Foundation of China(Grant No.52205476)Jiangsu Provincial Natural Science Foundation(Grant No.BK20242040)+2 种基金Fundamental Research Funds for the Central Universities(Grant No.NG2024008)the Youth Talent Support Project of CASTthe Fund of Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology(Grant No.1005-ZAA20003-14)。
文摘Radial rotating oscillating heat pipes(R-OHPs)have excellent thermal performance and great potential for application in the thermal management of rotatory machinery.However,the heat transport behavior and temperature characteristics of R-OHPs are complex,and their understanding is still limited,hence necessitating further research.In this study,thanks to an experimental investigation involving a copper R-OHP running with acetone and water,its thermal performance is evaluated,and then the temperature characteristics are analyzed by nonlinear dynamic analysis.The study reveals that the effective heat transfer coefficient of R-OHPs undergoes a notable increase with rising rotational speed,exhibiting a peak at a threshold speed value.Such a peak is present irrespectively of the working fluid,and,after exceeding the threshold,higher rotational speeds lead to a lower thermal performance.Based on nonlinear dynamic analysis,the power spectrum density of the evaporator temperature indicates a lack of dominant frequency in temperature signals,suggesting a complex behavior characterized by random oscillations of vapor slugs and liquid plugs.In order to better understand how strong the chaotic behavior is,an autocorrelation analysis was carried out,the OHP at static state has a stronger chaos than R-OHPs.The correlation dimension analysis of the evaporator temperature provides values ranging from 1.2 to 1.6,which together with the Lyapunov exponent calculations,further support an evident chaotic nature of R-OHPs.
基金Supported by the Natural Science Foundation of Xinjiang Uygur Autonomous Region,No.2022D01D21“Tianshan Talents”Cultivation Program of Xinjiang Uygur Autonomous Region,No.2024TSYCLJ0025National Natural Science Foundation of China,No.82360037.
文摘BACKGROUND Primary gastrointestinal diffuse large B-cell lymphoma(PGI-DLBCL),the most prevalent extranodal non-Hodgkin lymphoma,poses significant diagnostic and therapeutic challenges due to its non-specific symptoms and poor prognosis.AIM To develop and validate a risk model for the early identification of PGI-DLBCL using Least Absolute Shrinkage and Selection-Cox regression,with the aim of guiding clinical decision-making.METHODS The clinical data of patients diagnosed with PGI-DLBCL at the Tumor Hospital Affiliated to Xinjiang Medical University were analyzed retrospectively from January 2010 to April 2022.RESULTS A total of 319 patients with PGI-DLBCL were included and divided into training(n=223)and validation(n=96)cohorts.The median age was 55 years,with 48.9%male and 51.1%female patients.Key clinical features included Eastern Cooperative Oncology Group performance status≥2(40.8%),advanced-stage disease(stage IV:27.6%),extranodal involvement≥2 sites(47%),tumor>5 cm(46.1%),elevated beta-2 microglobulin(50.5%),elevated lactate dehydrogenase(27%),high International Prognostic Index(3-5:69.9%),non-germinal center B-cell-like subtype(59.9%),and B symptoms(55.8%).Immunohistochemical analysis showed frequent expression of CD10(51.1%),B-cell lymphoma 6(53.3%),multiple myeloma oncogene 1(40.1%),Bcell lymphoma 2(49.2%),myelocytomatosis viral oncogene homolog(48.3%),Ki-67(67.1%),and CD5(42.6%);Epstein-Barr virus-encoded RNA was positive in 3.1%.Based on Least Absolute Shrinkage and Selection regression and subsequent univariate and multivariate Cox regression analyses,extranodal sites≥2,B symptoms,mixed lesion type,and negative multiple myeloma oncogene 1 expression were identified as independent risk factors for PGI-DLBCL.The risk model stratified patients into high-and low-risk groups with significantly different overall survival(P<0.05).Area under the curve values for 1-,3-,and 5-year overall survival were 0.625,0.663,and 0.723 in the training cohort,with consistent performance in the validation cohort.Decision curve analysis indicated favorable clinical utility.CONCLUSION PGI-DLBCL in our cohort showed distinctive clinical features and a predominance of the non-germinal center Bcell-like subtype.Decision curve analysis confirmed the clinical applicability of our prognostic model.Although molecular biomarkers will be needed to improve predictive precision,our model offers a practical tool for early risk identification and individualized management in clinical practice.
基金supported by the National Natural Science Foundation of China(32241045,32241046,32241038)the Major Special Science and Technology Projects in Shanxi Province(202101140601027)+3 种基金Shanxi Provincial Agricultural Key Technologies Breakthrough Project(NYGG01)Doctoral Research Starting Project at Shanxi Agricultural University(2024BQ77)the National Key Research and Development Program of China(2023YFD1202705/2023YFD120270503,2023YFD1202703/2023YFD1202703-4)Shanxi HouJi Laboratory Self-proposed Research Project(202304010930003/202304010930003-03).
文摘Common bean(Phaseolus vulgaris L.)is a vital source of protein and essential nutrients for human consumption and plays a key role in sustainable agriculture due to its nitrogen-fixing ability(Nadeem et al.,2021).Kidney beans,a subcategory of dry common beans,are highly valued for their rich protein,dietary fiber,low fat content,and various trace elements(Garcia-Cordero et al.,2021).Despite the release of several de novo genome assemblies(Goodstein et al.,2012;Schmutz et al.,2014;Vlasova et al.,2016;Cortinovis et al.,2024),existing common bean genomes remain incomplete,particularly in complex regions such as centromeres and telomeres,limiting a comprehensive understanding of the genomic landscape.
基金Supported by National Key Technology R&D Program(2007BAC-29B02)
文摘Based on the monthly precipitation data from 43 stations in North China from 1979 to 2008,the variation characteristics of precipitation in North China in recent 30 years were analyzed by means of empirical orthogonal function(EOF)decomposition,Morlet wavelet transform and Mann-Kendall test.The results showed that the spatial distribution of annual and seasonal precipitation was basically identical in North China,while the annual and summer precipitation from the middle of 1980s to the middle of 1990s were obviously more than these in other periods,and there was great annual variation in spring precipitation in 1990s,while autumn precipitation was higher from 1980s to 1990s and then went down after the beginning of 21st century,which was opposite to winter precipitation,namely there was more winter precipitation from 1980s to 1990s and fewer winter precipitation after the beginning of 21st century.In addition,the annual and summer precipitation changed abruptly in 1997,and there was no obvious change in spring precipitation and autumn precipitation,while winter precipitation had an abrupt change in 2000.Meanwhile,wavelet analysis revealed that the variation period of annual and seasonal precipitation was 3-4 years.
基金Supported by Fund of Teacher Education Innovation Platform in Southwest University
文摘The characteristics of the temperature variation in Baoji City were analyzed with the temperature data from 1952 to 2003.The results showed that the value of annual average temperature and seasonal average temperature wavily rose before 1980 and obviously ascended after 1980.During the period of last 52 years,there was a process of ascent-descent-ascent in summer seasonal temperature variation.While in autumn and winter,the temperature decreased at first and then increased.The steady ascent of the temperature in summer season had a great contribution to the increment of its average temperature.The type of the variation trend in the average temperature in Baoji in recent 52 years was verified according to the results.
基金Supported by Liaoning Meteorology Bureau Scientific Research Fund (200808)China Meterological Administration Shenyang Atmospheric Science Research Bureau Scieatific Resarch Fund ProgramScientific Research Special Fund for Public Welfare Industry in 2008 (GYHY20080620)
文摘Based on meteorology and environment monitoring data in January,2008 in Liaoning central region,a typical haze weather process was analyzed.The results showed that haze was formed due to the stable weather condition in the earth surface and upper air layer in Liaoning central region.Especially because that the weakening of atmospheric dispersion ability in the urban boundary layer that was 500 m under earth surface,caused the pollutant in the air can not disperse.Thus,it resulted in the deterioration of air quality,increase of concentration of particulate mass,and declination of visibility.And in the end,haze formed.
基金supported by the National Science and Technology Major Project (No. 2011ZX05019-008)the National Natural Science Foundation of China (No. 41074080)+1 种基金the Science Foundation of China University of Petroleum, Beijing (No. KYJJ2012-05-11)supported by the CNPC international collaboration program through the Edinburgh Anisotropy Project (EAP) of the British Geological Survey (BGS) and the CNPC Key Geophysical Laboratory at the China University of Petroleum and CNPC geophysical prospecting projects for new method and technique research
文摘According to the Chapman multi-scale rock physical model, the seismic response characteristics vary for different fluid-saturated reservoirs. For class I AVO reservoirs and gas-saturation, the seismic response is a high-frequency bright spot as the amplitude energy shifts. However, it is a low-frequency shadow for the Class III AVO reservoirs saturated with hydrocarbons. In this paper, we verified the high-frequency bright spot results of Chapman for the Class I AVO response using the frequency-dependent analysis of a physical model dataset. The physical model is designed as inter-bedded thin sand and shale based on real field geology parameters. We observed two datasets using fixed offset and 2D geometry with different fluid- saturated conditions. Spectral and time-frequency analyses methods are applied to the seismic datasets to describe the response characteristics for gas-, water-, and oil-saturation. The results of physical model dataset processing and analysis indicate that reflection wave tuning and fluid-related dispersion are the main seismic response characteristic mechanisms. Additionally, the gas saturation model can be distinguished from water and oil saturation for Class I AVO utilizing the frequency-dependent abnormal characteristic. The frequency-dependent characteristic analysis of the physical model dataset verified the different spectral response characteristics corresponding to the different fluid-saturated models. Therefore, by careful analysis of real field seismic data, we can obtain the abnormal spectral characteristics induced by the fluid variation and implement fluid detection using seismic data directly.
文摘[Objective] To provide a theoretical basis for high-yield breeding of broom sorghum.[Method] Using 11 kinds of broom sorghum collected at home as research objects, the differences in morphological characteristics of broom sorghum were compared through the survey of some indicators, such as plant height, tillering, inflorescence, stem node, stem-leaf ratio, yield, and so on. [Result] The 11 kinds of broom sorghum were different in morphological characteristics with large amplitude of plant height; zygl-1, zygl-6, zygl-8 and zygl-9 were appropriate for fixed broom type; zygl-9 had the highest integrated production. [Condusion] The study laid the foundation for further exploring breeding, cultivation and promotion of broom sorghum.
文摘[ObJective] The research aimed to determine the geographic distribution map of system of Rana dybowskii. [Method] Four morphologic indices （body length, body weight, forelimb length, hindlimb length） of eight geographical populations of R.dybowskii which naturally distribute in Changhai Mountain and Xiaoxing＇an Mountain were measured. Measure results were variance analyzed and cluster analyzed. [Result] Variance analysis showed： the genetic branching among the Dongfanghong male population（ belongs to Wandashan） and Xiaoxing＇an Mountain male population and Changbai Mountain male population were significantly different （P〈0.05） ; the genetic branching between the Hebei female population （belongs to Xiaoxing＇an Mountain） and Changbai Mountain female population was significantly different （P〈0.05 ）. Cluster analysis showed ： male R.dybowskii can be divided into three groups ： the first group included Quanyang, Tianbei, Chaoyang and Ddkouqin, the second group included Tieli and Anshan, the third group included Dongfanghong; and the female R. dybowskii can be divided into three groups ： the first group included Quanyang and Chaoyang, the second group included Tianbei and Dakouqin, the third group included Hebei. [Condusion] The paper deduced that the Sanjiang Plain was the geographical origin center ofR. dybowskii which radiated to Changbai Mountain and Xiaoxing＇an Mountain along the adverse current of Songhua River basin, therefore, the current distribution pattern of R. dybowskii was formed.
基金This paper was supported by Chinese 863 Plan Water-Saving Agriculture (2002AA2Z4321),the Key Knowledge Innovation Project (SCXZY0103) and The Tenth-five Plan of Liaoning Province (2001212001).
文摘Robinia pseudoacacia stands act as a typical ecological protection forest in hilly semi-arid area of China. Two fields of surface runoff were separately set up in R. pseudoacacia stand and its clearcut area in the western Liaoning Province (1850-12225 E, 4024-4234 N) for measuring the characteristics of runoff and sediment as well as soil moisture dynamics. Contractive analysis of the two land types showed that there existed a significant difference in volumes of runoff and sediment between the sites of R. pseudoacacia stand and its clearcut area. The runoff volume and sediment volume in clearcut area were much bigger than those in R. pseudoacacia stand, with an increase amount of 40%-177% for runoff and 180%-400% for sediment. Hydrograph of surface runoff of typical rainfall showed that the peak value of runoff in R. pseudoacacia stand was decreased by 1.0-2.5?0-3m3s-1 compared with that in its clearcut area, and the occurring time of peak value of runoff in R. pseudoacacia stand was 10-20 min later than that in its clearcut area. Harmonic analysis of soil moisture dynamics indicated that the soil moisture in R. pseudoacacia stand was 2.3 % higher than that in clearcut area, and the soil moisture both in R. pseudoacacia stand and its clearcut area could be divided into dry season and humid season and varied periodically with annual rainfall precipitation. It was concluded that R. pseudoacacia stand plays a very important role in storing water, increasing soil moisture, and reducing surface runoff and soil erosion.
文摘We propose an electronic model in Spice, instead of traditional mathematical analysis, for analyzing the performance of ferroelectric liquid crystal （FLC） under various working conditions. Using this equivalent circuit model,it is easy to simulate and analyze the behavior of an FLC layer in three different typical parameters,including temperature, input light wavelength, and the frequency of driving voltage. We conclude that the response velocity drops as the wavelength increases in the range of visible light, and for the parameter of temperature, the velocity reaches its lowest value when the temperature reaches a certain degree,meanwhile,the frequency of driving voltage exerts important effects on the response velocity only when the frequency is beyond a critical value. Excellent agreement is achieved between simulation and experimental results.
基金supported by the Scientific Research Staring Foundation of University of Electronic Science and Technology of China(No.ZYGX2015KYQD049)
文摘Seismic texture attributes are closely related to seismic facies and reservoir characteristics and are thus widely used in seismic data interpretation.However,information is mislaid in the stacking process when traditional texture attributes are extracted from poststack data,which is detrimental to complex reservoir description.In this study,pre-stack texture attributes are introduced,these attributes can not only capable of precisely depicting the lateral continuity of waveforms between different reflection points but also reflect amplitude versus offset,anisotropy,and heterogeneity in the medium.Due to its strong ability to represent stratigraphies,a pre-stack-data-based seismic facies analysis method is proposed using the selforganizing map algorithm.This method is tested on wide azimuth seismic data from China,and the advantages of pre-stack texture attributes in the description of stratum lateral changes are verified,in addition to the method＇s ability to reveal anisotropy and heterogeneity characteristics.The pre-stack texture classification results effectively distinguish different seismic reflection patterns,thereby providing reliable evidence for use in seismic facies analysis.
基金Supported by Scientific Research and Technological Development Planning Project of Guangxi Province(10123009-9)~~
文摘Based on acid rain data from ten monitoring sites in Guangxi from 2003 to 2009,the temporal and spatial distribution characteristic of acid rain in Guangxi were analyzed by means of empirical orthogonal function resolution(EOF).The results showed that there was fluctuating change of acid rain frequency in Guangxi,and acid rain pollution became severer in 2004-2008;acid rain frequency changed conformably in the whole region and it was obviously higher in eastern and northwestern Guangxi,while acid rain pollution became severe in western Guangxi;acid rain frequency varied out of phase between northeastern and southwestern Guangxi in an individual year.
