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About One-Dimensional Conservative Systems with Position Depending Mass 被引量:2
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作者 Gustavo López Velázquez Carlos Rodrigo Martínez Prieto 《Journal of Modern Physics》 2014年第9期900-907,共8页
For a one-dimensional conservative system with position depending mass, one deduces consistently a constant of motion, a Lagrangian, and a Hamiltonian for the nonrelativistic case. With these functions, one shows the ... For a one-dimensional conservative system with position depending mass, one deduces consistently a constant of motion, a Lagrangian, and a Hamiltonian for the nonrelativistic case. With these functions, one shows the trajectories on the spaces (x,v) and (x,p) for a linear position depending mass. For the relativistic case, the Lagrangian and Hamiltonian cannot be given explicitly in general. However, we study the particular system with constant force and mass linear dependence on the position where the Lagrangian can be found explicitly, but the Hamiltonian remains implicit in the constant of motion. 展开更多
关键词 MASS VARIABLE Systems CONSERVATIVE System POSITION depending MASS
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Size Depending Separation of HAP:Eu Nanoparticles in Dispersed Sol
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作者 I W Bauer 李世普 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2005年第B12期198-200,共3页
The panicle size has a strong impact on the interactions between nanoparticles and cells. However, the synthesis process of nanoparticles limits the range of achievable average panicle sizes. When biocompatible hydrox... The panicle size has a strong impact on the interactions between nanoparticles and cells. However, the synthesis process of nanoparticles limits the range of achievable average panicle sizes. When biocompatible hydroxyapatite nanoparticles (HAP) are doped with the luminescent rare earth elemeat Europium (Eu), the panicle size becomes larger compared to pure HAP. Hence, a panicle size reduction is necessary to achieve similar experimental conditions when stbstituting pure HAP with luminescent HAP : Eu nanoparticles to investigate particlecell-interactions in cell culture experiments. While the sedimentation process of particles in liquids and gels has been well described in literature, the separation of particles in dispersed colloids has not been studied, yet. In this study, the size depending separation and particle size redaction of a homogeneous dispersed nanoparticle sol by gravity and centrifugation were investigated. As the results showed, shorter time of centrifugation at higher speed can reduce the average particle size compared to the decline of the panicle concentation in the upper sol layer most efficiently. This ceatrifugation method has some similarity to the overspeeding technique which is commonly used to lower the transient time to reach the equilibrium of sedimentation. 展开更多
关键词 NANOPARTICLES size depending separation CENTRIFUGE hydroxyapatite EUROPIUM
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Reaction Subdiffusion with Random Waiting Time Depending on the Preceding Jump Length
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作者 Hong Zhang Guo-Hua Li 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第9期19-23,共5页
To describe the energy-dependent characteristics of the reaction-subdiffusion process, we analyze the simple reaction A--→B under subdiffsion with waiting time depending on the preceding jump length, and derive the c... To describe the energy-dependent characteristics of the reaction-subdiffusion process, we analyze the simple reaction A--→B under subdiffsion with waiting time depending on the preceding jump length, and derive the corresponding master equations in the Fourier Laplace space for the distribution of A and B particles in a continuous time random walk scheme. Moreover, the generalizations of the reaction-diffusion equation for the Gaussian jump length with the probability density function of waiting time being quadratically dependent on the preceding jump length are obtained by applying the derived master equations. 展开更多
关键词 RDE Reaction Subdiffusion with Random Waiting Time depending on the Preceding Jump Length LENGTH
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Analytical Approximation to the Dynamics of a Binary Stars System with Time Depending Mass Variation
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作者 Gustavo V. López Elkin L. López 《Journal of Applied Mathematics and Physics》 2018年第3期613-619,共7页
We study the classical dynamics of binary stars when there is an interchange of mass between them. Assuming that one of the stars is more massive than others, the dynamics of the lighter one is analyzed as a function ... We study the classical dynamics of binary stars when there is an interchange of mass between them. Assuming that one of the stars is more massive than others, the dynamics of the lighter one is analyzed as a function of its time depending mass variation. Within our approximations and models for mass transference, we obtain a general result which establishes that if the lightest star looses mass, its period increases. If the lightest star wins mass, its period decreases. 展开更多
关键词 BINARY STARS TIME depending MASS PERIOD of BINARY STARS
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THE INTEGRAL AS A FUNCTlON OF THE UPPER LIMIT AND DEPENDING ON A PARAMETER TO SOLVE DRAWING THROUGH IDLING ROLLS
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作者 赵德文 赵志业 张强 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1994年第1期93-100,共8页
The relocity and sirain-rate .field which are different from Avilzur's have beenestablished in Caitesian coordinates. Using the integral as a function of the upper limitand integration depending on a parameler, an... The relocity and sirain-rate .field which are different from Avilzur's have beenestablished in Caitesian coordinates. Using the integral as a function of the upper limitand integration depending on a parameler, an analylical upper-bound solution todrawing stress through idling rolls has been obtained in this paper. 展开更多
关键词 drawing through idling rolls integral as a function of theupper limit. integration depending on a parameter analyticalsolution
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One Dimensional Conservative System with Quadratic Dissipation and Position Depending Mass
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作者 Gustavo V. López Erick S. Madrigal 《Journal of Modern Physics》 2022年第2期127-137,共11页
Forl a 1-D conservative system with a position depending mass within a dissipative medium, its effect on the body is to exert a force depending on the squared of its velocity, a constant of motion, Lagrangian, general... Forl a 1-D conservative system with a position depending mass within a dissipative medium, its effect on the body is to exert a force depending on the squared of its velocity, a constant of motion, Lagrangian, generalized linear momentum, and Hamiltonian are obtained. We apply these new results to the harmonic oscillator and pendulum under the characteristics mentioned about, obtaining their constant of motion, Lagrangian and Hamiltonian for the case when the body is increasing its mass. 展开更多
关键词 DISSIPATION Position Mass depending Constant of Motion HAMILTONIAN
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Depending on a Diaspora
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作者 Aggrey Mutambo 《ChinAfrica》 2013年第9期32-33,共2页
Somalia's rebirth relies greatly on the return of its many refugees MOGADISHU is on the mend and on the rise.A booming construction industry is building high-rise blocks that compete for skyline dominance,shops are o... Somalia's rebirth relies greatly on the return of its many refugees MOGADISHU is on the mend and on the rise.A booming construction industry is building high-rise blocks that compete for skyline dominance,shops are opening up at a much faster rate than two years earlier and airlines are launching routes to what has hitherto been considered the world's most dangerous city. Despite a rise in the number of ambushes,assassinations and suicide bombings in the city in August,a sign that Somali militant group Al-Shabaab has renewed its campaign to bring instability to the nation's capital,a sense of optimism still abounds as the country slowly makes its way back into the international arena.The United Kingdom has reopened its embassy after a 22-year closure. 展开更多
关键词 depending on a Diaspora
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Electrical and dielectric characterization of Au/ZnO/n-Si device depending frequency and voltage
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作者 I Orak A Kocyigit S Ahndal 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第2期477-483,共7页
Au/Zn O/n-type Si device is obtained using atomic layer deposition(ALD) for Zn O layer, and some main electrical parameters are investigated, such as surface/interface state(Nss), barrier height(Φb), series res... Au/Zn O/n-type Si device is obtained using atomic layer deposition(ALD) for Zn O layer, and some main electrical parameters are investigated, such as surface/interface state(Nss), barrier height(Φb), series resistance(Rs), donor concentration(Nd), and dielectric characterization depending on frequency or voltage. These parameters are acquired by use of impedance spectroscopy measurements at frequencies ranging from 10 k Hz to 1 MHz and the direct current(DC) bias voltages in a range from-2 V to +2 V at room temperature are used. The main electrical parameters and dielectric parameters,such as dielectric constant(ε"), dielectric loss(ε"), loss tangent(tan δ), the real and imaginary parts of electric modulus(M and M), and alternating current(AC) electrical conductivity(σ) are affected by changing voltage and frequency. The characterizations show that some main electrical parameters usually decrease with increasing frequency because charge carriers at surface states have not enough time to fallow an external AC signal at high frequencies, and all dielectric parameters strongly depend on the voltage and frequency especially in the depletion and accumulation regions. Consequently, it can be concluded that interfacial polarization and interface charges can easily follow AC signal at low frequencies. 展开更多
关键词 Au/ZnO/n–Si device dielectric properties polarization process frequency and voltage dependence
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Assessing ground stability of a vertical backfilled stope considering creep behaviors of surrounding rocks 被引量:2
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作者 Ruofan Wang Lang Liu +4 位作者 Mengbo Zhu Huafu Qiu Bingbing Tu Huisheng Qu Hao Cui 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第1期187-199,共13页
Backfill is often employed in mining operations for ground support,with its positive impact on ground stability acknowledged in many underground mines.However,existing studies have predominantly focused only on the st... Backfill is often employed in mining operations for ground support,with its positive impact on ground stability acknowledged in many underground mines.However,existing studies have predominantly focused only on the stress development within the backfill material,leaving the influence of stope backfilling on stress distribution in surrounding rock mass and ground stability largely unexplored.Therefore,this paper presents numerical models in FLAC3D to investigate,for the first time,the time-dependent stress redistribution around a vertical backfilled stope and its implications on ground stability,considering the creep of surrounding rock mass.Using the Soft Soil constitutive model,the compressibility of backfill under large pressure was captured.It is found that the creep deformation of rock mass exercises compression on backfill and results in a less void ratio and increased modulus for fill material.The compacted backfill conversely influenced the stress distribution and ground stability of rock mass which was a combined effect of wall creep and compressibility of backfill.With the increase of time or/and creep deformation,the minimum principal stress in the rocks surrounding the backfilled stope increased towards the pre-mining stress state,while the deviatoric stress reduces leading to an increased factor of safety and improved ground stability.This improvement effect of backfill on ground stability increased with the increase of mine depth and stope height,while it is also more pronounced for the narrow stope,the backfill with a smaller compression index,and the soft rocks with a smaller viscosity coefficient.Furthermore,the results emphasize the importance of minimizing empty time and backfilling extracted stope as soon as possible for ground control.Reduction of filling gap height enhances the local stability around the roof of stope. 展开更多
关键词 Ground stability Time dependency CREEP Surrounding rocks Backfilled stope
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Two-Phase Software Fault Localization Based on Relational Graph Convolutional Neural Networks 被引量:1
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作者 Xin Fan Zhenlei Fu +2 位作者 Jian Shu Zuxiong Shen Yun Ge 《Computers, Materials & Continua》 2025年第2期2583-2607,共25页
Spectrum-based fault localization (SBFL) generates a ranked list of suspicious elements by using the program execution spectrum, but the excessive number of elements ranked in parallel results in low localization accu... Spectrum-based fault localization (SBFL) generates a ranked list of suspicious elements by using the program execution spectrum, but the excessive number of elements ranked in parallel results in low localization accuracy. Most researchers consider intra-class dependencies to improve localization accuracy. However, some studies show that inter-class method call type faults account for more than 20%, which means such methods still have certain limitations. To solve the above problems, this paper proposes a two-phase software fault localization based on relational graph convolutional neural networks (Two-RGCNFL). Firstly, in Phase 1, the method call dependence graph (MCDG) of the program is constructed, the intra-class and inter-class dependencies in MCDG are extracted by using the relational graph convolutional neural network, and the classifier is used to identify the faulty methods. Then, the GraphSMOTE algorithm is improved to alleviate the impact of class imbalance on classification accuracy. Aiming at the problem of parallel ranking of element suspicious values in traditional SBFL technology, in Phase 2, Doc2Vec is used to learn static features, while spectrum information serves as dynamic features. A RankNet model based on siamese multi-layer perceptron is constructed to score and rank statements in the faulty method. This work conducts experiments on 5 real projects of Defects4J benchmark. Experimental results show that, compared with the traditional SBFL technique and two baseline methods, our approach improves the Top-1 accuracy by 262.86%, 29.59% and 53.01%, respectively, which verifies the effectiveness of Two-RGCNFL. Furthermore, this work verifies the importance of inter-class dependencies through ablation experiments. 展开更多
关键词 Software fault localization graph neural network RankNet inter-class dependency class imbalance
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A hierarchical blockchain-enabled distributed federated learning system with model contribution based rewarding 被引量:1
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作者 Haibo Wang Hongwei Gao +2 位作者 Teng Ma Chong Li Tao Jing 《Digital Communications and Networks》 2025年第1期35-42,共8页
Distributed Federated Learning(DFL)technology enables participants to cooperatively train a shared model while preserving the privacy of their local datasets,making it a desirable solution for decentralized and privac... Distributed Federated Learning(DFL)technology enables participants to cooperatively train a shared model while preserving the privacy of their local datasets,making it a desirable solution for decentralized and privacy-preserving Web3 scenarios.However,DFL faces incentive and security challenges in the decentralized framework.To address these issues,this paper presents a Hierarchical Blockchain-enabled DFL(HBDFL)system,which provides a generic solution framework for the DFL-related applications.The proposed system consists of four major components,including a model contribution-based reward mechanism,a Proof of Elapsed Time and Accuracy(PoETA)consensus algorithm,a Distributed Reputation-based Verification Mechanism(DRTM)and an Accuracy-Dependent Throughput Management(ADTM)mechanism.The model contribution-based rewarding mechanism incentivizes network nodes to train models with their local datasets,while the PoETA consensus algorithm optimizes the tradeoff between the shared model accuracy and system throughput.The DRTM improves the system efficiency in consensus,and the ADTM mechanism guarantees that the throughput performance remains within a predefined range while improving the shared model accuracy.The performance of the proposed HBDFL system is evaluated by numerical simulations,with the results showing that the system improves the accuracy of the shared model while maintaining high throughput and ensuring security. 展开更多
关键词 Blockchain Federated learning Consensus scheme Accuracy dependent throughput management
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Complete f-Moment Convergence for Sung’s Type Weighted Sums of Negatively Superadditive Dependent Random Variables
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作者 HU Xueping WANG Liuliu +1 位作者 HU Ke XU Zhonghao 《应用概率统计》 北大核心 2025年第4期585-601,共17页
In this paper,by utilizing the Marcinkiewicz-Zygmund inequality and Rosenthal-type inequality of negatively superadditive dependent(NSD)random arrays and truncated method,we investigate the complete f-moment convergen... In this paper,by utilizing the Marcinkiewicz-Zygmund inequality and Rosenthal-type inequality of negatively superadditive dependent(NSD)random arrays and truncated method,we investigate the complete f-moment convergence of NSD random variables.We establish and improve a general result on the complete f-moment convergence for Sung’s type randomly weighted sums of NSD random variables under some general assumptions.As an application,we show the complete consistency for the randomly weighted estimator in a nonparametric regression model based on NSD errors. 展开更多
关键词 Marcinkiewicz-Zygmund inequality Rosenthal-type inequality Sung’s type randomly weighted sums negatively superadditive dependent random variables complete f-moment convergence
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Design and Research of the Recliner for the Elderly
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作者 Libin Zhou Ya Wang +1 位作者 Baoming Dai Tijin Gui 《Journal of Architectural Research and Development》 2025年第3期125-135,共11页
Chairs are the most common furniture in household environments,and reclining chairs specifically cater to the functional needs of the elderly.With the gradually increasing aging population,our preliminary research has... Chairs are the most common furniture in household environments,and reclining chairs specifically cater to the functional needs of the elderly.With the gradually increasing aging population,our preliminary research has revealed that current reclining chair designs often fail to align with the physical dimensions and needs of older adults.Many designs appear to prioritize technology over usability,resulting in a homogenous product landscape.Using statistical analysis and the weighted average method,an elderly-friendly reclining chair that considers height,depth,and width is designed.The final design aims to meet the psychological and physiological needs of self-care,semi-dependent,and fully dependent elderly individuals.Adhering to the“people-oriented”design philosophy and targeting“convenience and efficiency,”our ultimate goal is to create a reclining chair that helps the elderly lie down,stand up,and sit down with dignity.This innovative approach offers a new perspective for the market of aging-friendly furniture. 展开更多
关键词 Reclining chair SELF-CARE Semi-dependent Fully dependent Aging-friendly
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Contrastive learning for nested Chinese Named Entity Recognition via template words
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作者 Yuke Wang Qiao Liu +3 位作者 Tingting Dai Junjie Lang Ling Lu Yinong Chen 《CAAI Transactions on Intelligence Technology》 2025年第2期450-459,共10页
Existing Chinese named entity recognition(NER)research utilises 1D lexicon-based sequence labelling frameworks,which can only recognise flat entities.While lexicons serve as prior knowledge and enhance semantic inform... Existing Chinese named entity recognition(NER)research utilises 1D lexicon-based sequence labelling frameworks,which can only recognise flat entities.While lexicons serve as prior knowledge and enhance semantic information,they also pose completeness and resource requirements limitations.This paper proposes a template-based classification(TC)model to avoid lexicon issues and to identify nested entities.Template-based classification provides a template word for each entity type,which utilises contrastive learning to integrate the common characteristics among entities with the same category.Contrastive learning makes template words the centre points of their category in the vector space,thus improving generalisation ability.Additionally,TC presents a 2D tablefilling label scheme that classifies entities based on the attention distribution of template words.The proposed novel decoder algorithm enables TC recognition of both flat and nested entities simultaneously.Experimental results show that TC achieves the state-ofthe-art performance on five Chinese datasets. 展开更多
关键词 Chinese NER classification GENERALIZATION syntactic dependency TEMPLATE
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Embracing Internal States:A Review of Optimization of Repetitive Transcranial Magnetic Stimulation for Treating Depression
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作者 Tingting Wu Qiuxuan Yu +4 位作者 Ximei Zhu Yinjiao Li Mingyue Zhang Jiahui Deng Lin Lu 《Neuroscience Bulletin》 2025年第5期866-880,共15页
Repetitive transcranial magnetic stimulation(rTMS)is a rapid and effective therapy for major depressive disorder;however,there is significant variability in therapeutic outcomes both within and across individuals,with... Repetitive transcranial magnetic stimulation(rTMS)is a rapid and effective therapy for major depressive disorder;however,there is significant variability in therapeutic outcomes both within and across individuals,with approximately 50% of patients showing no response to rTMS treatment.Many studies have personalized the stimulation parameters of rTMS(e.g.,location and intensity of stimulation)according to the anatomical and functional structure of the brain.In addition to these parameters,the internal states of the individual,such as circadian rhythm,behavior/cognition,neural oscillation,and neuroplasticity,also contribute to the variation in rTMS effects.In this review,we summarize the current literature on the interaction between rTMS and internal states.We propose two possible methods,multimodal treatment,and adaptive closed-loop treatment,to integrate patients'internal states to achieve better rTMS treatment for depression. 展开更多
关键词 DEPRESSION RTMS State dependency Personalized medicine Circadian rhythm
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Study on the Long-Term Cognitive Effects of Excessive LLM Use Among Students and General Users
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作者 Bingzhi Li 《Journal of Contemporary Educational Research》 2025年第10期203-214,共12页
Artificial intelligence,especially large language models(LLMs),is reshaping how we learn,communicate,and create.These systems provide students and professionals immediate access to fluent,context-aware language that c... Artificial intelligence,especially large language models(LLMs),is reshaping how we learn,communicate,and create.These systems provide students and professionals immediate access to fluent,context-aware language that can support learning,increase productivity,and spark creativity.But what happens when their use becomes excessive?This paper explores the potential long-term consequences of over-relying on LLMs-particularly memory,critical thinking,creativity,and motivation.Drawing on research in cognitive psychology,education,neuroscience,and media studies,it argues that LLMs are best understood as cognitive prostheses:incredibly valuable when used wisely,but risky when they replace rather than support human imagination. 展开更多
关键词 Artificial intelligence Large language models COGNITION CREATIVITY DEPENDENCY Education
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Exploring the multiplicity dependence of the flavor hierarchy for hadron production in high-energy pp collisions
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作者 Ao-Gui Zhang Xin-Ye Peng Liang Zheng 《Nuclear Science and Techniques》 2025年第8期126-137,共12页
In this study,we performed a systematic analysis of the multiplicity dependence of hadron production at mid-rapidity(|y|<0.5),ranging from the light to the charm sector in proton-proton(pp)collisions at√s=13 TeV.T... In this study,we performed a systematic analysis of the multiplicity dependence of hadron production at mid-rapidity(|y|<0.5),ranging from the light to the charm sector in proton-proton(pp)collisions at√s=13 TeV.This study used a multi-phase transport(AMPT)model coupled with PYTHIA8 initial conditions.We investigated the baryon-to-meson and the strange-to-non-strange meson ratios varying with the charged particle density.By tuning the coalescence parameters,the AMPT model provides a reasonable description of the experimental data for the inclusive production of both light and charm hadrons,comparable to the string fragmentation model calculations with color reconnection effects.Additionally,we analyzed the relative production of hadrons by examining the self-normalized particle ratios as a function of the charged hadron density.Our findings suggest that parton evolution effects and the coalescence hadronization process in the AMPT model result in a strong flavor hierarchy in the multiplicity dependence of the baryon-to-meson ratio.Furthermore,our investigation of the p_(T) differential double ratio of the baryon-to-meson fraction between high-and low-multiplicity events revealed distinct modifications to the flavor associated baryon-to-meson ratio p_(T) shape in high-multiplicity events when comparing the coalescence hadronization model to the color reconnection model.These observations highlight the importance of understanding the hadronization process in high-energy pp collisions through comprehensive multiplicity-dependent multi-flavor analysis. 展开更多
关键词 Heavy flavor Multiplicity dependence Small system AMPT
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Role of feature importance in geomechanical classification of rock slopes
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作者 Ashutosh Kainthola Vishnu Himanshu Ratnam Pandey +1 位作者 Gaurav Kushwaha Vikas Yadav 《Deep Resources Engineering》 2025年第1期9-24,共16页
Rock slope along motorways in the Higher Himalayan terrains are prone to various types of failure.In order to effectively mitigate these failures,a thorough assessment of rock mass behavior is entailed.The present res... Rock slope along motorways in the Higher Himalayan terrains are prone to various types of failure.In order to effectively mitigate these failures,a thorough assessment of rock mass behavior is entailed.The present research employs and compares widely practiced geo-mechanical classification schemes viz.,RQD,RMR,SMR,Q-slope,and GSI.A 23 km road cut section,along Sangla to Chitkul route,in Higher Himalayan region(India)has been taken up for this work.Total of 18 locations were selected,and their slope and rockmass properties were examined.Afterwards,the most influencing parameters in RMR,SMR,and Q-Slope were evaluated through a machine learning algorithm,i.e.,Random Forest.For RMRbasic,about 83%of rock-slopes were designated in good condition and rest were of Fair quality.Evaluation of slope mass rating along all 18-locations highlighted eight-sites as partially unstable,six-sites as partially stable.Remaining four locations varied between,Very Bad to Bad slope-conditions,necessitating the installation of mechanical supports and redesign of slopes.For SMR classification,feature importance analysis revealed the predominance of F3 variable,RQD and intact rock strength.Q-Slope approach was incorporated to identify the most stable steepest angle of the examined locations.For Q-Slope rating,Jn and RQD were found to have the most influence in classification of the slopes.Three zones on the basis of GSI-scores have been identified in the study area,i.e.,A(6595),B(4555),and C(2535).This study highlights the application of multiple geomechanical classification schemes,demonstrating how each approach can complement the others. 展开更多
关键词 SMR Q-slope GSI Feature importance Partial dependence Economic Mitigations
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Research on the mental health of heroin addicts
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作者 Jiuxue Li Caihua Yang +2 位作者 Ran Tian Yanzhen Xie Min Mo 《Journal of Translational Neuroscience》 2025年第1期8-13,共6页
Heroin dependence is a serious substance use disorder that not only causes great harm to physical health but also significantly affects mental health.Addicts often experience a variety of psychological problems,such a... Heroin dependence is a serious substance use disorder that not only causes great harm to physical health but also significantly affects mental health.Addicts often experience a variety of psychological problems,such as depression,anxiety,personality disorders,and cognitive impairment.In recent years the mechanisms and intervention methods related to mental health problems in heroin addicts have received widespread research attention.This article reviews the current research into mental health problems in heroin addicts in order to provide a theoretical basis for optimizing drug addiction intervention strategies. 展开更多
关键词 heroin dependence mental health DEPRESSION ANXIETY personality disorders cognitive function
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Moving away from home:Early life movements and space use in juvenile Montagu's Harriers(Circus pygargus)from central Italy
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作者 Giampiero Sammuri Guido Alari Esposito +4 位作者 Giuseppe Anselmi Francesco Pezzo Vincenzo Rizzo Pinna Andrea Sforzi Flavio Monti 《Avian Research》 2025年第2期251-263,共13页
Assessing individual differences and variability in animal movement patterns is essential to improve our understanding of the evolution and ontogeny of migratory strategies.In long-distance migratory species,fledged j... Assessing individual differences and variability in animal movement patterns is essential to improve our understanding of the evolution and ontogeny of migratory strategies.In long-distance migratory species,fledged juveniles often rely on an extremely restricted time span to learn the essential skills for survival and to prepare for migration,possibly the most risky phase of their lives.Collecting detailed information on the dynamics of the movements during the crucial pre-migratory phase is hence essential to understand the solutions developed by migratory species in different environmental contexts.Here,we used high-resolution GPS/GSM transmitters to collect information on the movement ecology of seven juvenile Montagu's Harriers(Circus pygargus)born in central Italy,investigating their early life stages,namely the post-fledging dependence period(PFDP)and the pre-migratory phase(PMP),until autumn migration.After fledging,individuals showed high variability(both in space and time)in home range size,daily distances covered(6.88±11.44 km/day),distance from the nest(1.45±2.8 km)and PFDP length(23.3±5.3 days).Residence time at the natal site significantly decreased,while time interval between revists in the natal area significantly increased,as the PFDP progressed.During the PMP,explored areas and distance from the nest(max value up to 320.8 km)varied among individuals,despite daily distances covered(27±40 km/day)and time allocation between traveling(60.7%)and foraging(39.3%)were similar across individuals.The PMP lasted 38±14 days.Land cover composition of foraging locations was mostly represented by agricultural lands(~78.2%),though habitat use differed among individuals.More than 76%of such locations were outside protected areas.This individual-based tracking study represents a novel approach that improves previous knowledge based on field studies on the early life stages of the Montagu's Harrier.High inter-individual variability in movement patterns,broad-range exploratory movements and foraging locations outside the protected area network make the application of standard conservation measures difficult,raising concerns about the long-term preservation of this vulnerable migratory species in Italy. 展开更多
关键词 Dispersal Habitat use Migration Post-fledging dependence period Protected areas RAPTOR
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