期刊文献+
共找到2,292篇文章
< 1 2 115 >
每页显示 20 50 100
Influence of Low Temperature Dyeing Accelerant on Acrylic Fiber Dyed with Cationic Dyes
1
作者 郑今欢 杜旭宜 刘超 《Journal of Donghua University(English Edition)》 EI CAS 2011年第4期358-361,共4页
The dyeing behavior of cationic dyes to acrylic fiber with self-made low temperature dyeing accelerant was investigated in this study. Compared with conventional dyeing, the acrylic yarn was dyed with Cationic Turquoi... The dyeing behavior of cationic dyes to acrylic fiber with self-made low temperature dyeing accelerant was investigated in this study. Compared with conventional dyeing, the acrylic yarn was dyed with Cationic Turquoise Blue X-GB at 85℃ in the presence of accelerant and absence of accelerant, respectively. The influence of low temperature dyeing aceelerant on the dyeing mechanism of acrylic fiber dyed with cationic dye was analyzed through kinetics and thermodynamics study. The results show that adding dyeing accelerant ran heighten the equilibrium dye-uptake, dyeing rate constants, diffusion coefficients, and shorten half-dyeing time for acrylic fiber dyed with cationic dyes. Furthermore, the partition coefficient, the standard affinity, and the dye saturation value also increased in the dyeing at 85℃. 展开更多
关键词 acrylic fiber dyeing kinetics dyeing thermodynamics adsorption isotherms low temperature dyeing accelerant
在线阅读 下载PDF
Effect of Accelerant Additives in Concrete with Limestone Aggregate in Warm Weather
2
作者 Romel G. Solís Diego R. Hay Jesus Nicolás Zaragoza 《Journal of Building Construction and Planning Research》 2022年第4期140-154,共15页
Additives are chemical compounds that are added to concrete during its manufacture to modify one or more of its properties. The first additive used in modern concrete was the accelerator, intended to shorten the time ... Additives are chemical compounds that are added to concrete during its manufacture to modify one or more of its properties. The first additive used in modern concrete was the accelerator, intended to shorten the time during which the material is not capable of supporting stress. Traditionally, accelerators have been made from calcium chloride, but today the trend is to use chloride-free additives to prevent reinforcing steel from corroding and thereby make constructions durable. The objective of this study was to evaluate the effects on the concrete of two types of accelerating admixture, using limestone aggregates, under warm sub-humid climate conditions. The applied methodology consisted of the measurement in the laboratory of some of the main properties of concrete in fresh and hardened states, in samples manufactured both with and without accelerators. The results showed that the accelerator without chloride was less effective than the one based on calcium chloride and that without doses of the accelerator, the effectiveness documented by the manufacturers was achieved. 展开更多
关键词 CONCRETE Additives ACCELERATORS Limestone Aggregates Durability
在线阅读 下载PDF
Macrophage ATF6 accelerates corticotomy-assisted orthodontic tooth movement through promoting Tnfαtranscription 被引量:2
3
作者 Zhichun Jin Hao Xu +8 位作者 Weiye Zhao Kejia Zhang Shengnan Wu Chuanjun Shu Linlin Zhu Yan Wang Lin Wang Hanwen Zhang Bin Yan 《International Journal of Oral Science》 2025年第2期285-299,共15页
Corticotomy is a clinical procedure to accelerate orthodontic tooth movement characterized by the regional acceleratory phenomenon(RAP).Despite its therapeutic effects,the surgical risk and unclear mechanism hamper th... Corticotomy is a clinical procedure to accelerate orthodontic tooth movement characterized by the regional acceleratory phenomenon(RAP).Despite its therapeutic effects,the surgical risk and unclear mechanism hamper the clinical application.Numerous evidences support macrophages as the key immune cells during bone remodeling.Our study discovered that the monocyte-derived macrophages primarily exhibited a pro-inflammatory phenotype that dominated bone remodeling in corticotomy by CX3CR1CreERT2;R26GFP lineage tracing system.Fluorescence staining,flow cytometry analysis,and western blot determined the significantly enhanced expression of binding immunoglobulin protein(BiP)and emphasized the activation of sensor activating transcription factor 6(ATF6)in macrophages.Then,we verified that macrophage specific ATF6 deletion(ATF6f/f;CX3CR1CreERT2 mice)decreased the proportion of pro-inflammatory macrophages and therefore blocked the acceleration effect of corticotomy.In contrast,macrophage ATF6 overexpression exaggerated the acceleration of orthodontic tooth movement.In vitro experiments also proved that higher proportion of pro-inflammatory macrophages was positively correlated with higher expression of ATF6.At the mechanism level,RNA-seq and CUT&Tag analysis demonstrated that ATF6 modulated the macrophage-orchestrated inflammation through interacting with Tnfαpromotor and augmenting its transcription.Additionally,molecular docking simulation and dual-luciferase reporter system indicated the possible binding sites outside of the traditional endoplasmic reticulum-stress response element(ERSE).Taken together,ATF6 may aggravate orthodontic bone remodeling by promoting Tnfαtranscription in macrophages,suggesting that ATF6 may represent a promising therapeutic target for non-invasive accelerated orthodontics. 展开更多
关键词 MACROPHAGES ATF accelerate orthodontic tooth movement regional acceleratory phenomenon rap despite bone remodeling bone remodelingour immune cells CORTICOTOMY
暂未订购
Classification of superconducting radio-frequency cavity faults of CAFE2 using machine learning 被引量:1
4
作者 Li-Juan Yang Jia-Yi Peng +16 位作者 Feng Qiu Yuan He Jin-Ying Ma Zong-Heng Xue Tian-Cai Jiang Zheng-Long Zhu Qi Chen Cheng-Ye Xu Jing-Wei Yu Zhen Ma Di-Di Luo Zi-Qin Yang Zheng Gao Lie-Peng Sun Zhou-Li Zhang Gui-Rong Huang Zhi-Jun Wang 《Nuclear Science and Techniques》 2025年第6期37-55,共19页
Superconducting radio-frequency(SRF)cavities are the core components of SRF linear accelerators,making their stable operation considerably important.However,the operational experience from different accelerator labora... Superconducting radio-frequency(SRF)cavities are the core components of SRF linear accelerators,making their stable operation considerably important.However,the operational experience from different accelerator laboratories has revealed that SRF faults are the leading cause of short machine downtime trips.When a cavity fault occurs,system experts analyze the time-series data recorded by low-level RF systems and identify the fault type.However,this requires expertise and intuition,posing a major challenge for control-room operators.Here,we propose an expert feature-based machine learning model for automating SRF cavity fault recognition.The main challenge in converting the"expert reasoning"process for SRF faults into a"model inference"process lies in feature extraction,which is attributed to the associated multidimensional and complex time-series waveforms.Existing autoregression-based feature-extraction methods require the signal to be stable and autocorrelated,resulting in difficulty in capturing the abrupt features that exist in several SRF failure patterns.To address these issues,we introduce expertise into the classification model through reasonable feature engineering.We demonstrate the feasibility of this method using the SRF cavity of the China accelerator facility for superheavy elements(CAFE2).Although specific faults in SRF cavities may vary across different accelerators,similarities exist in the RF signals.Therefore,this study provides valuable guidance for fault analysis of the entire SRF community. 展开更多
关键词 Superconducting radio-frequency cavity Fault recognition Machine learning Feature engineering Particle accelerator
在线阅读 下载PDF
MG-SLAM: RGB-D SLAM Based on Semantic Segmentation for Dynamic Environment in the Internet of Vehicles 被引量:1
5
作者 Fengju Zhang Kai Zhu 《Computers, Materials & Continua》 2025年第2期2353-2372,共20页
The Internet of Vehicles (IoV) has become an important direction in the field of intelligent transportation, in which vehicle positioning is a crucial part. SLAM (Simultaneous Localization and Mapping) technology play... The Internet of Vehicles (IoV) has become an important direction in the field of intelligent transportation, in which vehicle positioning is a crucial part. SLAM (Simultaneous Localization and Mapping) technology plays a crucial role in vehicle localization and navigation. Traditional Simultaneous Localization and Mapping (SLAM) systems are designed for use in static environments, and they can result in poor performance in terms of accuracy and robustness when used in dynamic environments where objects are in constant movement. To address this issue, a new real-time visual SLAM system called MG-SLAM has been developed. Based on ORB-SLAM2, MG-SLAM incorporates a dynamic target detection process that enables the detection of both known and unknown moving objects. In this process, a separate semantic segmentation thread is required to segment dynamic target instances, and the Mask R-CNN algorithm is applied on the Graphics Processing Unit (GPU) to accelerate segmentation. To reduce computational cost, only key frames are segmented to identify known dynamic objects. Additionally, a multi-view geometry method is adopted to detect unknown moving objects. The results demonstrate that MG-SLAM achieves higher precision, with an improvement from 0.2730 m to 0.0135 m in precision. Moreover, the processing time required by MG-SLAM is significantly reduced compared to other dynamic scene SLAM algorithms, which illustrates its efficacy in locating objects in dynamic scenes. 展开更多
关键词 Visual SLAM dynamic scene semantic segmentation GPU acceleration key segmentation frame
在线阅读 下载PDF
Microbial-Enhanced Steel Slag Fixation of CO_(2)from Cement Kiln Flue Gas for the Production of Supplementary Cementitious Material 被引量:1
6
作者 Chunxiang Qian Yijin Fan +2 位作者 Yafeng Rui Xiao Zhang Yangfan Xu 《Engineering》 2025年第7期136-149,共14页
The production of cement and concrete using carbonated steel slag as a supplementary cementitious material achieves the dual benefits of efficient steel slag utilization and CO_(2)fixation.In this study,a combination ... The production of cement and concrete using carbonated steel slag as a supplementary cementitious material achieves the dual benefits of efficient steel slag utilization and CO_(2)fixation.In this study,a combination of microbial technology and a rotary kiln process was employed to expedite the carbonation of steel slag for fixation from cement kiln flue gas.This approach resulted in a significant increase in the CO_(2)-fixation rate,with a CO_(2)-fixation ratio of approximately 10%achieved within 1 h and consistent performance across different seasons throughout the year.Investigation revealed that both the CO_(2)-fixation ratio and the particle fineness are pivotal for increasing the soundness and reactivity of steel slag.When the CO_(2)-fixation ratio exceeds 8%and the specific surface area is at least 300 m2∙kg−1,the soundness issue of steel slag can be effectively addressed,facilitating the safe utilization of steel slag.Residual microbes present in the carbonated steel slag powder act as nucleating sites,increasing the hydration rate of the silicate phases in Portland cement to form more hydration products.Microbial regulation results in the biogenic calcium carbonate having smaller crystal sizes,which facilitates the formation of monocarboaluminate to increase the strength of hardened cement paste.At the same CO_(2)-fixation ratio,microbial mineralized steel slag powder exhibits greater hydration activity than carbonated steel slag powder.With a CO_(2)-fixation ratio of 10%and a specific surface area of 600 m^(2)∙kg^(−1),replacing 30%of cement clinker with microbial mineralized steel slag powder yields an activity index of 87.7%.This study provides a sustainable solution for reducing carbon emissions and safely and efficiently utilizing steel slag in the construction materials sector,while expanding the application scope of microbial technology. 展开更多
关键词 Steel slag Microbial mineralization Accelerated carbonation Green construction materials
在线阅读 下载PDF
Currents from relativistic laser-plasma interaction as a novel metrology for the system stability of high-repetition-rate laser secondary sources 被引量:1
7
作者 Michael Ehret Iuliana-Mariana Vladisavlevici +16 位作者 Philip Wykeham Bradford Jakub Cikhardt Evgeny Filippov Jose Luis Henares Rubén Hernández Martín Diego de Luis JoséAntonio Pérez-Hernández Pablo Vicente Tomas Burian Enrique García-García Juan Hernández Cruz Mendez Marta Olivar Ruíz Óscar Varela Maria Dolores Rodríguez Frías João Jorge Santos Giancarlo Gatti 《Matter and Radiation at Extremes》 2025年第2期24-34,共11页
This work demonstrates experimentally the close relation between return currents from relativistic laser-driven target polarization and the quality of the relativistic laser–plasma interaction for laser-driven second... This work demonstrates experimentally the close relation between return currents from relativistic laser-driven target polarization and the quality of the relativistic laser–plasma interaction for laser-driven secondary sources,taking as an example ion acceleration by target normal sheath acceleration.The Pearson linear correlation of maximum return current amplitude and proton spectrum cutoff energy is found to be in the range from~0.70 to 0.94.kA-scale return currents rise in all interaction schemes where targets of any kind are charged by escaping laser-accelerated relativistic electrons.Their precise measurement is demonstrated using an inductive scheme that allows operation at high repetition rates.Thus,return currents can be used as a metrological online tool for the optimization of many laser-driven secondary sources and for diagnosing their stability.In particular,in two parametric studies of laser-driven ion acceleration,we carry out a noninvasive online measurement of return currents in a tape target system irradiated by the 1 PW VEGA-3 laser at Centro de Láseres Pulsados:first the size of the irradiated area is varied at best compression of the laser pulse;second,the pulse duration is varied by means of induced group delay dispersion at best focus.This work paves the way to the development of feedback systems that operate at the high repetition rates of PW-class lasers. 展开更多
关键词 relativistic laser plasma interaction pearson linear correlation proton spectrum cutoff energy interaction schemes ion acceleration target normal sheath accelerationthe return current return currents
在线阅读 下载PDF
Predicting peak ground acceleration using the ConvMixer network 被引量:1
8
作者 Mona Mohammed Omar M Saad +1 位作者 Arabi Keshk Hatem M Ahmed 《Earthquake Science》 2025年第2期126-135,共10页
The level of ground shaking,as determined by the peak ground acceleration(PGA),can be used to analyze seismic hazard at a certain location and is crucial for constructing earthquake-resistant structures.Predicting the... The level of ground shaking,as determined by the peak ground acceleration(PGA),can be used to analyze seismic hazard at a certain location and is crucial for constructing earthquake-resistant structures.Predicting the PGA immediately after an earthquake occurs allows for the issuing of a warning by an earthquake early warning system.In this study,we propose a deep learning model,ConvMixer,to predict the PGA recorded by weak-motion velocity seismometers in Japan.We use 5-s threecomponent seismograms,from 2 s before until 3 s after the P-wave arrival time of the earthquake.Our dataset comprised more than 50,000 single-station waveforms recorded by 10 seismic stations in the K-NET,Kiki-NET,and Hi-Net networks between 2004 and 2023.The proposed ConvMixer is a patch-based model that extracts global features from input seismic data and predicts the PGA of an earthquake by combining depth and pointwise convolutions.The proposed ConvMixer network had a mean absolute error of 2.143 when applied to the test set and outperformed benchmark deep learning models.In addition,the proposed ConvMixer demonstrated the ability to predict the PGA at the corresponding station site based on 1-second waveforms obtained immediately after the arrival time of the P-wave. 展开更多
关键词 peak ground acceleration(PGA) earthquake early warning system(EEWS) deep learning(DL)
在线阅读 下载PDF
Preheating detoxification of flaxseed and its impact on the quality of flaxseed
9
作者 ZHOU Junzhuo CHU Pengfei +5 位作者 DONG Guimei PEI Xuechen HUANG Jiaqian ZHENG Rui YIN Fawen ZHOU Dayong 《中国油脂》 北大核心 2025年第6期11-22,30,共13页
Aiming to provide a theoretical basis for possible uses of flaxseed as a food supplement and functional ingredient, the heat treatment of flaxseed was carried out using steaming, roasting, and microwave methods to inv... Aiming to provide a theoretical basis for possible uses of flaxseed as a food supplement and functional ingredient, the heat treatment of flaxseed was carried out using steaming, roasting, and microwave methods to investigate the detoxification effects of these three pretreatment methods on flaxseed, as well as the impact of the three methods on the quality of flaxseed. The results showed that all three pretreatment methods had better detoxification effects on flaxseed, in which, microwave treatment was the most effective method. After 5 min of microwave treatment, the hydrogen cyanide(HCN) content in flaxseed decreased from(94.65±1.68) mg/kg to(7.80±0.57) mg/kg. All three pretreatment methods significantly reduced the water content in flaxseed but had a weaker effect on protein, fat, and ash contents. After pretreatment by the three methods, the polyphenol content, peroxide value(POV), and a*value of flaxseed increased significantly, thiobarbituric acid reactive substances(TBARS) increased, while polyunsaturated fatty acids(PUFA) content, amino acid content, and L*, W*, and b*values decreased, with varying degrees of wrinkles and cracks appearing on the surface of flaxseed, and the overall signal pattern of FTIR spectra did not change much. During the 40℃ accelerated storage process, the quality of flaxseed treated by all three preheating methods generally declined, and correlation analysis revealed that color change was a good indicator of quality changes in flaxseed. Notably, all three pretreatment methods extended the shelf-life of flaxseed. Compared with steaming(120℃ for 20 min) and roasting(100℃ for 40 min), microwave(560 W for 4 min) is recommended to remove cyanogenic glycosides and improve the stability and quality characteristics of flaxseed. 展开更多
关键词 FLAXSEED DETOXIFICATION POLYPHENOL COLOR stability ACCELERATED storage
在线阅读 下载PDF
Design of a compact beam transport system for laser-driven proton therapy
10
作者 Yangfan LI Xiaofei SHEN +1 位作者 Yilin YAO Bin QIAO 《Plasma Science and Technology》 2025年第1期1-6,共6页
We put forward a new design of a compact beam transport system for intense laser-driven proton therapy,where instead of using conventional pulsed solenoids,our design relies on a helical coil irradiated by a nanosecon... We put forward a new design of a compact beam transport system for intense laser-driven proton therapy,where instead of using conventional pulsed solenoids,our design relies on a helical coil irradiated by a nanosecond laser pulse to generate strong magnetic fields for focusing protons.A pair of dipole magnets and apertures are employed to further filter protons with large divergences and low energies.Our numerical studies combine particle-in-cell simulations for laser-plasma interaction to generate high-energy monoenergetic proton beams,finite element analysis for evaluating the magnetic field distribution inside the coil,and MonteCarlo simulations for beam transport and energy deposition.Our results show that with this design,a spread-out Bragg peak in a range of several centimeters to a deep-seated tumor with a dose of approximately 16.5 cGy and fluctuation around 2% can be achieved.The instantaneous dose rate reaches up to 10^(9)Gy/s,holding the potential for future FLASH radiotherapy research. 展开更多
关键词 intense laser-plasma interaction laser-driven ion acceleration laser-driven proton acceleration PARTICLE-IN-CELL proton radiotherapy
在线阅读 下载PDF
Physics opportunities of the nuclear excitation by electron capture process
11
作者 Yi Yang Han-Xu Zhang +5 位作者 Yuan-Bin Wu Song Guo Xu Wang Chang-Bo Fu Yang Sun Yu-Gang Ma 《Nuclear Science and Techniques》 2025年第8期1-17,共17页
Nuclear excitation by electron capture(NEEC)is a fundamental process in nuclear physics.Despite its theoretical framework established nearly half a century ago,the experimental confirmation of NEEC remains elusive bec... Nuclear excitation by electron capture(NEEC)is a fundamental process in nuclear physics.Despite its theoretical framework established nearly half a century ago,the experimental confirmation of NEEC remains elusive because of significant technical challenges.A notable effort to validate NEEC experimentally involved the enhanced ^(93m)Mo isomer-depletion experiment,which was ultimately hindered by substantial noise interference.This mini-review provides a brief historical overview of NEEC studies and explores the role of NEEC processes in astrophysical environments and laser-induced plasmas.Several platforms have been proposed to facilitate the observation of NEEC,including traditional cooling-storage rings,ion accelerators,and electron beam ion traps.These approaches aim to enhance the nuclear excitation rate,thereby improving the signal-to-noise ratio.In addition,the employment of exotic vortex beams is discussed as a potential methodological approach to address these challenges. 展开更多
关键词 NEEC ISOMER PLASMAS ACCELERATOR
在线阅读 下载PDF
Automatic phase-setting via time-of-flight alignment and phase calibration on a superconducting hadron linac
12
作者 Chi Feng Jonathan CWong +4 位作者 Zhi-Jun Wang Zhong-Yi Li Wang-Sheng Wang Wei-Long Chen Yuan He 《Nuclear Science and Techniques》 2025年第7期167-178,共12页
Automatic phase-setting is essential for modern linacs which have increasingly stringent time demands for beam tune-up and fault compensation.A key challenge in automatic phase-setting is obtaining an accurate knowled... Automatic phase-setting is essential for modern linacs which have increasingly stringent time demands for beam tune-up and fault compensation.A key challenge in automatic phase-setting is obtaining an accurate knowledge of the position and phase offsets of all cavities.This study proposes a beam-based method that employs time-of-flight experiments for simultaneous alignment and phase calibration of a superconducting hadron linac.The proposed method is verified using the CAFE2 accelerator at the Institute of Modern Physics,where offset measurements enable rapid tune-up via automatic phase-setting,and the output beam energies closely match the predicted values.The proposed method is able to address longitudinal position shifts within cryomodules due to cool-down,readily applicable to superconducting hadron linacs,and expected to be employed in the upcoming commissioning of CiADS and HIAF. 展开更多
关键词 Linear accelerators Beam position monitor Heavy ion accelerators
在线阅读 下载PDF
Enhancing clinical and public health interpretation of accelerometer-assessed physical activity with age-referenced values based on UK Biobank data
13
作者 Alex V.Rowlands Andrew P.Kingsnorth +10 位作者 Bjørge H.Hansen Stuart J.Fairclough Lynne M.Boddy Benjamin D.Maylor Henrik R.Eckmann Borja del Pozo Cruz Nathan P.Dawkins Cameron Razieh Kamlesh Khunti Francesco Zaccardi Tom Yates 《Journal of Sport and Health Science》 2025年第1期27-37,共11页
Background Higher accelerometer-assessed volume and intensity of physical activity(PA)have been associated with a longer life expectancy but can be difficult to translate into recommended doses of PA.We aimed to:(a)im... Background Higher accelerometer-assessed volume and intensity of physical activity(PA)have been associated with a longer life expectancy but can be difficult to translate into recommended doses of PA.We aimed to:(a)improve interpretability by producing UK Biobank age-referenced centiles for PA volume and intensity;(b)inform public-health messaging by examining how adding recommended quantities of moderate and vigorous PA affect PA volume and intensity.Methods 92,480 UK Biobank participants aged 43-80 years with wrist-worn accelerometer data were included.Average acceleration and intensity gradient were derived as proxies for PA volume and intensity.We generated sex-specific centile curves using Generalized Additive Models for Location Scale and Shape(GAMLSS)and modeled the effect of adding moderate(walking)or vigorous(running)activity on the combined change in the volume and intensity centiles(change in PA profile).Results In men,volume was lower as age increased while intensity was lower after age 55;in women,both volume and intensity were lower as age increased.Adding 150 min of moderate PA weekly(5×30 min walking)increased the PA profile by 4 percentage points.Defining moderate PA as brisk walking approximately doubled the increase(9 percentage points)while 75 min of vigorous PA weekly(5×15 min running)trebled the increase(13 percentage points).Conclusion These UK Biobank reference centiles provide a benchmark for interpretation of accelerometer data.Application of our translational methods demonstrate that meeting PA guidelines through shorter duration vigorous activity is more beneficial to the PA profile(volume and intensity)than longer duration moderate activity. 展开更多
关键词 Physical activity recommendations Average acceleration Intensity gradient MODERATE Vigorous
在线阅读 下载PDF
Hydraulic conductivity of sand influenced by temperature and porosity in centrifugal tests
14
作者 Jianjian HE Xihao JIANG Yubing WANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 2025年第3期177-193,共17页
This study focused on the hydraulic conductivity of sand in centrifuge modeling.A self-designed temperature-controlled falling-head permeameter apparatus was used,and a series of falling-head seepage tests were perfor... This study focused on the hydraulic conductivity of sand in centrifuge modeling.A self-designed temperature-controlled falling-head permeameter apparatus was used,and a series of falling-head seepage tests were performed on sand samples with various porosities at different temperatures and centrifugal accelerations.The objectives were to qualitatively and quantitatively investigate the effects of temperature,porosity,and centrifugal acceleration on the hydraulic conductivity of sand and to study the applicability of the Kozeny-Carman equation for the centrifugal environment.Test results showed that in a similar temperature range and under the same porosity,the hydraulic conductivity of the sand is linearly correlated with centrifugal acceleration.When subjected to the same centrifugal acceleration and in a similar temperature range,the hydraulic conductivity of the sand exhibits an almost linear increase in relation to its porosity function(s^(3)/(1−s)^(2));the functional relationships between the hydraulic conductivity of the sand and temperature,centrifugal acceleration level,and porosity were established using two pathways.When the centrifugal acceleration is less than 50g,the Kozeny-Carman equation is effectively accurate in predicting the hydraulic conductivity of sand;however,when the centrifugal acceleration exceeds 50g,it is important to consider a significant error. 展开更多
关键词 Hydraulic conductivity of sand TEMPERATURE POROSITY Centrifugal acceleration Kozeny-Carman equation
原文传递
The EU’s Perception of Multipolarity and China-EU Multilateral Cooperation
15
作者 Jin Ling 《China International Studies》 2025年第2期102-132,共31页
As the accelerated changes on a scale unprecedented in a century are unfolding across the world,multipolarity of the international system is increasingly accepted as a fundamental trend.As a unique international actor... As the accelerated changes on a scale unprecedented in a century are unfolding across the world,multipolarity of the international system is increasingly accepted as a fundamental trend.As a unique international actor,the European Union,despite its initial strategic anxiety about multipolarity,has gradually come to terms with the growing reality of multipolarity and adjusted its foreign strategy to become one of the poles in the multipolar world. 展开更多
关键词 MULTIPOLARITY European Union strategic anxiety accelerated changes China EU cooperation international system
在线阅读 下载PDF
Enriching harmonic balance with non‐smooth Bernoulli bases for accelerated convergence of non-smooth periodic systems
16
作者 Yu Zhou Jianliang Huang Li Wang 《Theoretical & Applied Mechanics Letters》 2025年第1期57-68,共12页
The harmonic balance method(HBM)has been widely applied to get the periodic solution of nonlinear systems,however,its convergence rate as well as computation efficiency is dramatically degraded when the system is high... The harmonic balance method(HBM)has been widely applied to get the periodic solution of nonlinear systems,however,its convergence rate as well as computation efficiency is dramatically degraded when the system is highly non-smooth,e.g.,discontinuous.In order to accelerate the convergence,an enriched HBM is developed in this paper where the non-smooth Bernoulli bases are additionally introduced to enrich the conventional Fourier bases.The basic idea behind is that the convergence rate of the HB solution,as a truncated Fourier series,can be improved if the smoothness of the solution becomes finer.Along this line,using non-smooth Bernoulli bases can compensate the highly non-smooth part of the solution and then,the smoothness of the residual part for Fourier approximation is improved so as to achieve accelerated convergence.Numerical examples are conducted on systems with non-smooth restoring and/or external forces.The results confirm that the proposed enriched HBM indeed increases the convergence rate and the increase becomes more significant if more non-smooth bases are used. 展开更多
关键词 Harmonic balancemethod Non-smooth Bernoullibases Event-driven Gaussquadrature Non-smooth systems Accelerated convergence
在线阅读 下载PDF
Research on fall detection algorithm based on heterogeneous sensor data fusion
17
作者 CHEN Jing YAN Bowen +1 位作者 YE Xiaoxia ZHANG Hao 《High Technology Letters》 2025年第2期131-143,共13页
In order to solve the problems of limited performance of single and homogeneous sensors and high false alarm rate caused by environmental noise,heterogeneous sensor data fusion(HSDF),a fall detection framework based o... In order to solve the problems of limited performance of single and homogeneous sensors and high false alarm rate caused by environmental noise,heterogeneous sensor data fusion(HSDF),a fall detection framework based on heterogeneous sensor fusion of acceleration and audio signals,is proposed in this paper.By analyzing the heterogeneity of acceleration data and audio data,the framework uses Dempstershafer Theory(D-S Theory)to integrate the output of acceleration and audio data at decision level.Firstly,a normalized window interception algorithm——anomaly location window algorithm(ALW)is proposed by analyzing the fall process and the characteristics of acceleration changes based on acceleration data.Secondly,the one-dimensional residual convolutional network(1D-ReCNN)is designed for fall detection based on the audio data.Finally,it is verified that the HSDF framework has good advantages in terms of sensitivity and false alarm rate by the collection of volunteers’simulated fall data and free living data in real environment. 展开更多
关键词 fall detection ACCELERATION AUDIO decision fusion Dempstershafer Theory(DS Theory)
在线阅读 下载PDF
Hybrid modelling incorporating reaction and mechanistic data for accelerating the development of isooctanol oxidation
18
作者 Xin Zhou Ce Liu +9 位作者 Zhibo Zhang Xinrui Song Haiyan Luo Weitao Zhang Lianying Wu Hui Zhao Yibin Liu Xiaobo Chen Hao Yan Chaohe Yang 《Chinese Journal of Chemical Engineering》 2025年第4期166-183,共18页
Alcohol oxidation is a widely used green chemical reaction.The reaction process produces flammable and explosive hydrogen,so the design of the reactor must meet stringent safety requirements.Based on the limited exper... Alcohol oxidation is a widely used green chemical reaction.The reaction process produces flammable and explosive hydrogen,so the design of the reactor must meet stringent safety requirements.Based on the limited experimental data,utilizing the traditional numerical method of computational fluid dynamics(CFD)to simulate the gas-liquid two-phase flow reactor can mitigate the risk of danger under varying working conditions.However,the calculation process is highly time-consuming.Therefore,by integrating process simulation,computational fluid dynamics,and deep learning technologies,an intelligent hybrid chemical model based on machine learning was proposed to expedite CFD calculations,enhance the prediction of flow fields,conversion rates,and concentrations inside the reactor,and offer insights for designing and optimizing the reactor for the alcohol oxidation system.The results show that the hybrid model based on the long and short-term memory neural network achieves 99.8%accuracy in conversion rate prediction and 99.9%accuracy in product concentration prediction.Through validation,the hybrid model is accelerated by about 360 times compared with instrumental analysis in conversion rate prediction and about 45 times compared with CFD calculation in concentration distribution prediction.This hybrid model can quickly predict the conversion rate and product concentration distribution in the gas-liquid two-phase flow reactor and provide a model reference for fast prediction and accurate control in the actual chemical production process. 展开更多
关键词 Hybrid modelling Numerical simulation Deep learning Soft measurements Computational acceleration
在线阅读 下载PDF
Detonation product analysis and the paradoxical performance mechanism of TKX-50:High detonation velocity with low metal acceleration
19
作者 Kaiyuan Tan Yaqi Zhao +10 位作者 Qin Liu Lixiao Hao Yushi Wen Chunliang Ji Sha Yang Haoxu Wang Luchuan Jia Jiahui Liu Zhuoping Duan Yong Han Fenglei Huang 《Defence Technology(防务技术)》 2025年第4期255-266,共12页
This study investigates the paradoxical detonation behavior of TKX-50,a nitrogen-rich energetic material,exhibiting higher detonation velocities but lower metal acceleration ability compared to HMX.Through experimenta... This study investigates the paradoxical detonation behavior of TKX-50,a nitrogen-rich energetic material,exhibiting higher detonation velocities but lower metal acceleration ability compared to HMX.Through experimental measurements and theoretical calculations,we propose a novel three-factor competition mechanism to explain this phenomenon.TKX-50-based PBX formulations achieved detonation velocities up to 9100 m/s,surpassing HMX-based counterparts.However,cylinder expansion tests revealed a 15%reduction in metal acceleration ability.Thermochemical measurements showed lower detonation heat for TKX-50(4900 J/g)versus HMX(5645 J/g).Our mechanism involves:(1)compositional effects prevailing at high pressures;(2)Energy release becoming essential as pressure drops;(3)Pressure-dependent product composition evolution functioning at low pressure.VLW code calculations unveiled a"crossover"in Hugoniot curves,lending support to this mechanism.This study furnishes a new framework for comprehending the performance of nitrogen-rich energetic materials,with significant implications for the design and optimization of future high-energy density materials. 展开更多
关键词 TKX-50 Nitrogen-rich explosives Detonation velocity Metal acceleration Detonation product
在线阅读 下载PDF
Quantification of soil erosion in mountain catchment in the Himalaya using meteoric ^(10)Be as a tracer tool
20
作者 Arkaprabha SARKAR Vimal SINGH +2 位作者 Pankaj KUMAR Pavitra KUMAR Rajveer SHARMA 《Journal of Mountain Science》 2025年第8期2898-2915,共18页
Soil erosion is one of the major global hazards threatening the food security of the world population.Soil erosion can be a result of both natural and anthropogenic processes.Field monitoring and models(numerical and ... Soil erosion is one of the major global hazards threatening the food security of the world population.Soil erosion can be a result of both natural and anthropogenic processes.Field monitoring and models(numerical and physical)are commonly used to quantify soil erosion.However,field methods are time-consuming and the models inherently work with a level of uncertainty.Soil erosion studies in the Himalayas have been mostly carried out using modelling but there is a lack of sufficient field data to validate the results.We quantified soil erosion in a small catchment(Pranmati)in the Himalayas using the fallout meteoric^(10)Be nuclide for the first time.Based on the^(10)Be flux delivery rates determined from global circulation models(GCM),we calculated the rates of soil erosion at discrete points in the hilltop and mid-slope regions of hillslopes.The erosion rates vary between 17 mm kyr^(-1)to 68 mm kyr^(-1).These rates were determined in pristine areas that are unaffected by anthropogenic activities,thus,indicate the background erosion rates in the region.We established empirical relationships with estimated erosion rates and topographic parameters to assess the sediment dynamics in the hillslopes.It was observed that the sediment redistribution process operates differently in the mid-slope region compared to the hilltop region,due to increasing complexity of the active processes in the mid-slope region. 展开更多
关键词 Soil erosion Cosmogenic nuclide HIMALAYAS Meteoric 10Be Fallout nuclide Accelerator mass spectrometer
原文传递
上一页 1 2 115 下一页 到第
使用帮助 返回顶部