期刊文献+
共找到5,730篇文章
< 1 2 250 >
每页显示 20 50 100
Practice patterns among ophthalmic surgeons in treating concomitant oculoplastic conditions in preoperative period:A questionnaire-based study
1
作者 Bijnya Birajita Panda Chitaranjan Mishra +3 位作者 Bhagabat Nayak Avik Kumar Roy Logesh Balakrishnan Priyadarshini Mishra 《World Journal of Clinical Cases》 SCIE 2025年第1期29-37,共9页
BACKGROUND Addressing oculoplastic conditions in the preoperative period ensures both the safety and functional success of any ophthalmic procedure.Some oculoplastic conditions,like nasolacrimal duct obstruction,have ... BACKGROUND Addressing oculoplastic conditions in the preoperative period ensures both the safety and functional success of any ophthalmic procedure.Some oculoplastic conditions,like nasolacrimal duct obstruction,have been extensively studied,whereas others,like eyelid malposition and thyroid eye disease,have received minimal or no research.AIM To investigate the current practice patterns among ophthalmologists while treating concomitant oculoplastic conditions before any subspecialty ophthalmic intervention.METHODS A cross-sectional survey was disseminated among ophthalmologists all over India.The survey included questions related to pre-operative evaluation,anaesthetic and surgical techniques preferred,post-operative care,the use of adjunctive therapies,and patient follow-up patterns.RESULTS A total of 180 ophthalmologists responded to the survey.Most practitioners(89%)felt that the ROPLAS test was sufficient during pre-operative evaluation before any subspecialty surgery was advised.The most common surgical techniques employed were lacrimal drainage procedures(Dacryocystorhinostomy)(63.3%),eyelid malposition repair(36.9%),and ptosis repair(58.7%).Post-operatively,47.7%of respondents emphasized that at least a 4-week gap should be maintained after lacrimal drainage procedures and eyelid surgeries.Sixty-seven percent of ophthalmologists felt that topical anaesthetic procedures should be preferred while performing ocular surgeries in thyroid eye disease patients.CONCLUSION Approximately 50%of ophthalmologists handle prevalent oculoplastic issues themselves,seeking the expertise of an oculoplastic surgeon under particular conditions.Many ophthalmologists still favor using ROPLAS as a preliminary screening method before proceeding with cataract surgery.Eyelid conditions and thyroid eye disease are not as commonly addressed before subspecialty procedures compared to issues like nasolacrimal duct obstruction and periocular infections. 展开更多
关键词 Oculoplasty Ophthalmic plastic surgery Nasolacrimal duct obstruction Practice patterns SURVEY
在线阅读 下载PDF
Optimization of production well patterns for natural gas hydrate reservoir: Referring to the results from production tests and numerical simulations
2
作者 Lang-feng Mu Hao-tian Liu +2 位作者 Chi Zhang Yi Zhang Hai-long Lu 《China Geology》 2025年第1期39-57,共19页
Natural gas hydrate is a clean energy source with substantial resource potential.In contrast to conventional oil and gas,natural gas hydrate exists as a multi-phase system consisting of solids,liquids,and gases,which ... Natural gas hydrate is a clean energy source with substantial resource potential.In contrast to conventional oil and gas,natural gas hydrate exists as a multi-phase system consisting of solids,liquids,and gases,which presents unique challenges and complicates the mechanisms of seepage and exploitation.Both domestic and international natural gas hydrate production tests typically employ a single-well production model.Although this approach has seen some success,it continues to be hindered by low production rates and short production cycles.Therefore,there is an urgent need to explore a new well network to significantly increase the production of a single well.This paper provides a comprehensive review of the latest advancements in natural gas hydrate research,including both laboratory studies and field tests.It further examines the gas production processes and development outcomes for single wells,dual wells,multi-branch wells,and multi-well systems under conditions of depressurization,thermal injection,and CO_(2) replacement.On this basis,well types and well networks suitable for commercial exploitation of natural gas hydrate were explored,and the technical direction of natural gas hydrate development was proposed.The study shows that fully exploiting the flexibility of complex structural wells and designing a well network compatible with the reservoir is the key to improving production from a single well.Moreover,multi-well joint exploitation is identified as an effective strategy for achieving large-scale,efficient development of natural gas hydrate. 展开更多
关键词 Gas Hydrate Production DEPRESSURIZATION Heat Injection REPLACEMENT Multi-Branch Well Well patterns Hydrate exploration engineering
在线阅读 下载PDF
Research on the Evolution of the Spatiotemporal Patterns and Influencing Factors of China’s Agricultural Green Resilience
3
作者 Chen Yihui Li Minjie 《Contemporary Social Sciences》 2025年第1期15-30,共16页
This paper created an evaluation index system for agricultural green resilience,consisting of five dimensions:resistibility,recoverability,adaptability,innovatability,and reconstructability.We used the entropy method ... This paper created an evaluation index system for agricultural green resilience,consisting of five dimensions:resistibility,recoverability,adaptability,innovatability,and reconstructability.We used the entropy method to measure the agricultural green resilience levels of 30 provinces(municipalities/autonomous regions)in China from 2007 to 2021 and employed spatial Markov chains and geographic detectors to reveal the dynamics and evolution of the patterns and influencing factors of the agricultural green resilience.The study shows that the level of agricultural green resilience in China displayed a slight upward trend from 2007 to 2021,but the overall level remained low.Spatially,a distribution pattern of“eastern China>central China>northeastern China>western China”was observed.The transfer process for agricultural green resilience exhibited a“path dependence”characteristic that maintained its initial state,while it also showed a“trickle-down effect.”This means that the regions adjacent to provinces(municipalities/autonomous regions)with higher levels of agricultural green resilience tend to have an increased probability of an upward movement in their ranking.However,such movements are not leapfrogging and only occur at the adjacent levels.The spatial differentiations in the agricultural green resilience levels are primarily driven by the technological innovation capacity and market maturity,with interactions between these factors exhibiting both dual-factor enhancements and nonlinear enhancements.Accordingly,efforts should be made to strengthen support for the less-developed regions,increase research and development investment in the agricultural sector,and improve the market systems for agricultural products to enhance agricultural green resilience. 展开更多
关键词 AGRICULTURE green resilience spatiotemporal patterns spatial Markov chains geographic detector
在线阅读 下载PDF
Social Media Data Analysis:A Causal Inference Based Study of User Behavior Patterns
4
作者 Liangkeyi SUN 《计算社会科学》 2025年第1期37-53,共17页
This study aims to conduct an in-depth analysis of social media data using causal inference methods to explore the underlying mechanisms driving user behavior patterns.By leveraging large-scale social media datasets,t... This study aims to conduct an in-depth analysis of social media data using causal inference methods to explore the underlying mechanisms driving user behavior patterns.By leveraging large-scale social media datasets,this research develops a systematic analytical framework that integrates techniques such as propensity score matching,regression analysis,and regression discontinuity design to identify the causal effects of content characteristics,user attributes,and social network structures on user interactions,including clicks,shares,comments,and likes.The empirical findings indicate that factors such as sentiment,topical relevance,and network centrality have significant causal impacts on user behavior,with notable differences observed among various user groups.This study not only enriches the theoretical understanding of social media data analysis but also provides data-driven decision support and practical guidance for fields such as digital marketing,public opinion management,and digital governance. 展开更多
关键词 Social Media Data Causal Inference User Behavior patterns Propensity Score Matching DISCONTINUITY Data Preprocessing
在线阅读 下载PDF
Altitudinal patterns of plant diversity, cover, and life forms in a warm arid mountain: Insights from Sierra de Velasco, Argentina
5
作者 Sofia V.LIZARRAGA Omar VARELA Julieta CARILLA 《Journal of Mountain Science》 2025年第3期873-887,共15页
Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored varia... Mountains are important reservoirs of biodiversity and endemism on a global scale, but little is known about the altitudinal configuration of this diversity and its driving factors in arid mountains. We explored variations in composition, diversity, cover,and life forms of vascular plants along a complete altitudinal gradient(1300-4000 m a.s.l) in Sierra de Velasco, an arid mountain in northwestern Argentina.We evaluated the influence of environmental variables on plant diversity and cover. Field sampling was conducted in the northern sector of the Sa. de Velasco,on the western slope in eight 50 m wide altitudinal bands at 400 m elevation intervals. We used rectangular plots(20 × 4 m;n:10/altitudinal band) to register the vascular plants of all the growth forms, and linear transects(20 m long.;n:30/altitudinal band) to quantify the vegetation cover using the point intercept method. Diversity was calculated using hill numbers.Data analysis included non-metric multidimensional scaling(NMDS), indicator species analysis,generalized linear models(GLMs), and variance partitioning analysis. A total of 232 species from 51families and 158 genera were registered. Species composition showed greater similarity at intermediate elevations. Plant diversity and cover exhibited a unimodal distribution, peaking at intermediate elevations(2100-2500 m). In contrast, life forms' distribution showed divergent patterns. Therophytes and succulents predominated at low altitudes,phanerophytes and hemicryptophytes at medium altitudes, and chamaephytes and geophytes at high altitudes. The altitudinal patterns of plant diversity and cover were primarily driven by climatic factors.Conservation efforts in the Sierra de Velasco should focus on the middle and upper zones due to their high biodiversity and vulnerability to climate change. 展开更多
关键词 Elevation gradient Plant diversity Life forms Arid mountains Diversity pattern Climatic drivers
在线阅读 下载PDF
Latitudinal patterns of tree β-diversity and relevant ecological processes vary across spatial extents in forests of southeastern China
6
作者 Maochou Liu Wenxiang Wu +5 位作者 Ke Wang Xinshuai Ren Xueqin Zhang Lei Wang Jing Geng Bo Yang 《Plant Diversity》 2025年第1期89-97,共9页
Latitudinal patterns of treeβ-diversity reveal important insights into the biogeographical processes that influence forest ecosystems.Although previous studies have extensively documentedβ-diversity within relativel... Latitudinal patterns of treeβ-diversity reveal important insights into the biogeographical processes that influence forest ecosystems.Although previous studies have extensively documentedβ-diversity within relatively small spatial extents,the potential drivers ofβ-diversity along latitudinal gradients are still not well understood at larger spatial extents.In this study,we determined whether treeβ-diversity is correlated with latitude in forests of southeastern China,and if so,what ecological processes contribute to these patterns of treeβ-diversity.We specifically aimed to disentangle the relative contributions from interspecific aggregation and environmental filtering across various spatial extents.We delineated regional communities comprising multiple nearby national forest inventory(NFI)plots around random focal plots.The number of NFI plots in a regional community served as a surrogate for spatial extent.We also used a null model to simulate randomly assembled communities and quantify the deviation(β-deviation)between observed and expectedβ-diversity.We found thatβ-diversity decreased along a latitudinal gradient and that this pattern was clearer at larger spatial extents.In addition,latitudinal patterns ofβ-deviation were explained by the degree of species spatial aggregation.We also identified environmental factors that driveβ-deviation in these forests,including precipitation,seasonality,and temperature variation.At larger spatial extents,these environmental variables explained up to 84%of theβ-deviation.Our results reinforce that ecological processes are scale-dependent and collectively contribute to theβ-gradient in subtropical forests.We recommend that conservation efforts maintain diverse forests and heterogeneous environments at multiple spatial extents to mitigate the adverse effects of climate change. 展开更多
关键词 Environmental filtering Latitudinal pattern Forest beta diversity Spatial extent Species spatial aggregation Regional community
在线阅读 下载PDF
Territorial Ecological Restoration with a High-carbon Storage Focus in the Beibu Gulf Urban Agglomeration of China:Insights from Carbon Metabolism Spatial Security Patterns
7
作者 QIN Menglin LIU Yuting +5 位作者 TAN Qianxi ZHU Ziming WU Xinyu JIANG Hongbo LI Hang SHI Qianqian 《Chinese Geographical Science》 2025年第1期73-91,共19页
This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking an... This study focuses on urgent research on restoring and enhancing carbon storage capacity in the Beibu Gulf Urban Agglomer-ation of China,a key area in the‘Belt and Road’Initiative,which aligns with carbon peaking and neutrality goals.This research ana-lyzes the spatial characteristics of carbon metabolism from 2000 to 2020 and uses models to identify stable carbon sink areas,positive carbon flow corridors,and carbon sequestration nodes.The goal is to construct a carbon metabolism spatial security pattern(CMSSP)and propose territorial ecological restoration strategies under different development demand scenarios.The results show the following:1)in 2020,the study area’s carbon sink decreased by 8.29×10^(4) t C/yr compared with that in 2010 and by 10.83×10^(4) t C/yr compared with that in 2000.High-carbon sinks were found mainly in mountainous areas,whereas low-carbon sinks are concentrated in urban con-struction land,rural residential areas,and land margins.2)From 2000 to 2020,the spatial security pattern of carbon metabolism tended to be‘high in the middle of the east and west and low in the gulf.’In 2000,2010,and 2020,16 stable carbon sinks were identified.The carbon energy flow density in Guangxi was greater than that in Guangdong and Hainan,with positive carbon flow corridors located primarily in Guangxi and Guangdong.The number of carbon sequestration nodes remained stable at approximately 15,mainly in Guangxi and Hainan.3)Scenario simulations revealed that under the Nature-based mild restoration scenario,the carbon sink rate will reach 611.85×10^(4) t C/yr by 2030 and increase to 612.45×10^(4) t C/yr by 2060,with stable carbon sinks increasing to 18.In the restora-tion scenario based on Anti-globalization,the carbon sink will decrease from 610.24×10^(4) t C/yr in 2030 to 605.19×10^(4) t C/yr in 2060,with the disappearance of some positive carbon flow corridors and stable carbon sinks.Under the Human-based sustainable restoration scenario,the carbon sink area will decrease from 607.00×10^(4) t C/yr in 2030 to 596.39×10^(4) t C/yr in 2060,with carbon sink areas frag-menting and positive carbon flow corridors becoming less dense.4)On the basis of the current and predicted CMSSPs,this study ex-plores spatial ecological restoration strategies for high-carbon storage areas in bay urban agglomerations at four levels:the land control region,urban agglomeration structure system,carbon sink structure and bay structure control region. 展开更多
关键词 carbon metabolism spatial security pattern(CMSSP) territorial ecological restoration carbon sink carbon storage capacity Beibu Gulf Urban Agglomeration China
在线阅读 下载PDF
Acute effect of foot strike patterns on in vivo tibiotalar and subtalar joint kinematics during barefoot running 被引量:2
8
作者 Dongqiang Ye Lu Li +4 位作者 Shen Zhang Songlin Xiao Xiaole Sun Shaobai Wang Weijie Fu 《Journal of Sport and Health Science》 SCIE CSCD 2024年第1期108-117,共10页
Background:Foot kinematics,such as excessive eversion and malalignment of the hindfoot,are believed to be associated with running-related injuries.The maj ority of studies to date show that different foot strike patte... Background:Foot kinematics,such as excessive eversion and malalignment of the hindfoot,are believed to be associated with running-related injuries.The maj ority of studies to date show that different foot strike patterns influence these specific foot and ankle kinematics.However,technical deficiencies in traditional motion capture approaches limit knowledge of in vivo joint kinematics with respect to rearfoot and forefoot strike patterns(RFS and FFS,respectively).This study uses a high-speed dual fluoroscopic imaging system(DFIS)to determine the effects of different foot strike patterns on 3D in vivo tibiotalar and subtalar joints kinematics.Methods:Fifteen healthy male recreational runners underwent foot computed tomography scanning for the construction of 3-dimensional models.A high-speed DFIS(100 Hz)was used to collect 6 degrees of freedom kinematics for participants’tibiotalar and subtalar joints when they adopted RFS and FFS in barefoot condition.Results:Compared with RFS,FFS exhibited greater internal rotation at 0%-20%of the stance phase in the tibiotalar joint.The peak internal rotation angle of the tibiotalar joint under FFS was greater than under RFS(p<0.001,Cohen’s d=0.92).RFS showed more dorsiflexion at 0%-20%of the stance phase in the tibiotalar joint than FFS.RFS also presented a larger anterior translation(p<0.001,Cohen’s d=1.28)in the subtalar joint at i nitial contact than FFS.Conclusion:Running with acute barefoot FFS increases the internal rotation of the tibiotalar joint in the early stance.The use of high-speed DFIS to quantify the movement of the tibiotalar and subtalar joint was critical to revealing the effects of RF S and FFS during running. 展开更多
关键词 Foot strike patterns High-speed dual fluoroscopic imaging system In vivo kinematics Running
在线阅读 下载PDF
Venous Doppler flow patterns,venous congestion,heart disease and renal dysfunction:A complex liaison 被引量:1
9
作者 Alessio Di Maria Rossella Siligato +1 位作者 Marta Bondanelli Fabio Fabbian 《World Journal of Cardiology》 2024年第1期5-9,共5页
The World Journal of Cardiology published an article written by Kuwahara et al that we take the pleasure to comment on.We focused our attention on venous congestion.In intensive care settings,it is now widely accepted... The World Journal of Cardiology published an article written by Kuwahara et al that we take the pleasure to comment on.We focused our attention on venous congestion.In intensive care settings,it is now widely accepted that venous congestion is an important clinical feature worthy of investigation.Evaluating venous Doppler profile abnormalities at multiple sites could suggest adequate treatment and monitor its efficacy.Renal dysfunction could trigger or worsen fluid overload in heart disease,and cardio-renal syndrome is a well-characterized spectrum of disorders describing the complex interactions between heart and kidney diseases.Fluid overload and venous congestion,including renal venous hypertension,are major determinants of acute and chronic renal dysfunction arising in heart disease.Organ congestion from venous hypertension could be involved in the development of organ injury in several clinical situations,such as critical diseases,congestive heart failure,and chronic kidney disease.Ultrasonography and abnormal Doppler flow patterns diagnose clinically significant systemic venous congestion.Cardiologists and nephrologists might use this valuable,noninvasive,bedside diagnostic tool to establish fluid status and guide clinical choices. 展开更多
关键词 Cardio-renal syndrome Fluid overload Venous congestion Acute kidney injury ULTRASOUND Doppler flow patterns
在线阅读 下载PDF
How elevation and soil properties affect plant distribution patterns and species diversity in the Mediterranean mountain ecosystem of Al-Jabal Al- Akhdar, Libya
10
作者 ABD EL-GHANI Monier AL BORKI Abd El-Nasser 《Journal of Mountain Science》 SCIE CSCD 2024年第11期3683-3701,共19页
The objectives of this study were to assess distribution patterns of plant species richness,plant diversity and vegetation structure in relation to environmental factors along elevation gradient in Al-Jabal Al-Akhdar,... The objectives of this study were to assess distribution patterns of plant species richness,plant diversity and vegetation structure in relation to environmental factors along elevation gradient in Al-Jabal Al-Akhdar,Libya.For each species,its growth form,chorological affinities,degree of occurrence,endemism status and originality were provided.A total of 534 taxa were generated from 70 families of the flowering plants,and 3 of the non-flowering plants were identified.The native flora of the study area was counted for 80.2%of the total indigenous taxa(465).The hump-shaped pattern of plant species richness was obtained,with the highest species richness at the mid-elevations,and both ends of the gradient have the lowest.The annuals(300 species,56.2%)and non-succulent perennial herbs(165 species,30.9%)were the most dominant growth forms of the total species composition.Along the elevation gradient,Asteraceae,Fabaceae,Poaceae,Lamiaceae and Apiaceae were the dominant families with the highest numbers of species.This investigation recorded 31 endemic taxa,comprising 25 dicots and 6 monocots,primarily of Mediterranean origin,with most belonging to the Asteraceae and Lamiaceae families.Mediterranean chorotype was the dominant,whether pure(mono-),or combined with one(bi-and pluri-regional)or more(pluri-regional).Application of cluster analysis on the vegetation data yielded four cluster groups;each was linked to an elevation level.It emphasized the importance of establishing conservation strategies to minimize human disturbance and safeguard relic habitats of Juniperus phoenicea L.at its southern distribution limits in Africa,underlining the proactive management required for species preservation.The application of Redundancy Analysis revealed that Shannon diversity index(H'),pH and Fe were the determinant soil factor in the mid-elevation levels(L2 and L3)whereas altitude,fine sand,HCO3,OM,and soil contents of Na,SO4 and Cl for the extreme levels(L1 and L4). 展开更多
关键词 Altitudinal gradient Distribution patterns Floristic diversity Growth forms Libya Soil structure Vegetation analysis
在线阅读 下载PDF
The impact of short-term changes in sleeping and eating patterns on glucometabolic health and gut microbiota in healthy young adults: a proof-of-concept controlled feeding study
11
作者 Jiehua Chen Ruijie Zhang +15 位作者 Chao Zhou Louise Weiwei Lu Dana Feng Haiqiao Zou Ran Gao Xinying Zhang Peiyi Chen Jiayue Zhu Haoxie Xu Nina Zeng Cijuan Zhang Bin Liu Mingfu Wang Qian Ge Caiqun Ouyang Feng Chen 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第6期3553-3569,共17页
Epidemiological studies showed that night workers are at higher risk of developing chronic metabolic diseases.However,no study has investigated the changes in circadian rhythms caused by a combined effect of sleep and... Epidemiological studies showed that night workers are at higher risk of developing chronic metabolic diseases.However,no study has investigated the changes in circadian rhythms caused by a combined effect of sleep and diet in a real-life setting on cardiometabolic health,gut microbiota,and psychological status in healthy people.A 4-week step-wise misaligned-realigned controlled-feeding trial with a 2×2 factorial design(sleep and diet)was conducted on healthy young adults.At first,subjects experienced a one-week circadian rhythm misalignment with a high-fat fast-food diet,extended eating window,and delayed sleep schedules,then gradually transited to a complete circadian rhythm realignment with a high-fiber balanced diet,8-h timerestricted eating,and normal sleep schedules.Circadian rhythm misalignment led to significantly higher levels of fasting glucose and homeostatic model assessment for insulin resistance(HOMA-IR)of subjects compared to baseline and failed to recover to the baseline level in circadian rhythm realignments.Notably,the incremental area under the curve(iAUC)of postprandial glucose decreased with circadian rhythm adjustments as compared to that in circadian rhythm misalignment,suggesting circadian rhythm realignment by sleep or/and diet could partly restore glucose metabolism impaired by a short-term circadian rhythm misalignment.However,circadian rhythm changes did not result in overall perturbations of gut microbiota diversities. 展开更多
关键词 Circadian rhythm Glucose metabolism Gut microbiota Dietary patterns Sleep schedule Psychological status
在线阅读 下载PDF
Three-dimensional numerical analysis of plant-soil hydraulic interactions on pore water pressure of vegetated slope under different rainfall patterns
12
作者 Haowen Guo Charles Wang Wai Ng Qi Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第9期3696-3706,共11页
Understanding the pore water pressure distribution in unsaturated soil is crucial in predicting shallow landslides triggered by rainfall,mainly when dealing with different temporal patterns of rainfall intensity.Howev... Understanding the pore water pressure distribution in unsaturated soil is crucial in predicting shallow landslides triggered by rainfall,mainly when dealing with different temporal patterns of rainfall intensity.However,the hydrological response of vegetated slopes,especially three-dimensional(3D)slopes covered with shrubs,under different rainfall patterns remains unclear and requires further investigation.To address this issue,this study adopts a novel 3D numerical model for simulating hydraulic interactions between the root system of the shrub and the surrounding soil.Three series of numerical parametric studies are conducted to investigate the influences of slope inclination,rainfall pattern and rainfall duration.Four rainfall patterns(advanced,bimodal,delayed,and uniform)and two rainfall durations(4-h intense and 168-h mild rainfall)are considered to study the hydrological response of the slope.The computed results show that 17%higher transpiration-induced suction is found for a steeper slope,which remains even after a short,intense rainfall with a 100-year return period.The extreme rainfalls with advanced(PA),bimodal(PB)and uniform(PU)rainfall patterns need to be considered for the short rainfall duration(4 h),while the delayed(PD)and uniform(PU)rainfall patterns are highly recommended for long rainfall durations(168 h).The presence of plants can improve slope stability markedly under extreme rainfall with a short duration(4 h).For the long duration(168 h),the benefit of the plant in preserving pore-water pressure(PWP)and slope stability may not be sufficient. 展开更多
关键词 Root-soil interactions Rainfall patterns Slope stability Three-dimensional(3D)
在线阅读 下载PDF
A Non-Stationary Beam-Enabled Stochastic Channel Model and Characterization over Non-Reciprocal Beam Patterns
13
作者 Zhang Jiachi Liu Liu +3 位作者 Tan Zhenhui Wang Kai Li Lu Zhou Tao 《China Communications》 SCIE CSCD 2024年第10期43-58,共16页
The multiple-input multiple-output(MIMO)-enabled beamforming technology offers great data rate and channel quality for next-generation communication.In this paper,we propose a beam channel model and enable it with tim... The multiple-input multiple-output(MIMO)-enabled beamforming technology offers great data rate and channel quality for next-generation communication.In this paper,we propose a beam channel model and enable it with time-varying simulation capability by adopting the stochastic geometry theory.First,clusters are generated located within transceivers'beam ranges based on the Mate?rn hardcore Poisson cluster process.The line-of-sight,singlebounce,and double-bounce components are calculated when generating the complex channel impulse response.Furthermore,we elaborate on the expressions of channel links based on the propagation-graph theory.A birth-death process consisting of the effects of beams and cluster velocities is also formulated.Numerical simulation results prove that the proposed model can capture the channel non-stationarity.Besides,the non-reciprocal beam patterns yield severe channel dispersion compared to the reciprocal patterns. 展开更多
关键词 beam channel model channel non-stationarity non-reciprocal beam patterns stochastic geometry
在线阅读 下载PDF
Spatial patterns of the Brusselator model with asymmetric Lévy diffusion
14
作者 Hongwei Yin Shangtao Yang +2 位作者 Xiaoqing Wen Haohua Wang Shufen Yang 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第11期129-136,共8页
The formation of spatial patterns is an important issue in reaction–diffusion systems.Previous studies have mainly focused on the spatial patterns in reaction–diffusion models equipped with symmetric diffusion(such ... The formation of spatial patterns is an important issue in reaction–diffusion systems.Previous studies have mainly focused on the spatial patterns in reaction–diffusion models equipped with symmetric diffusion(such as normal or fractional Laplace diffusion),namely,assuming that spatial environments of the systems are homogeneous.However,the complexity and heterogeneity of spatial environments of biochemical reactions in vivo can lead to asymmetric diffusion of reactants.Naturally,there arises an open question of how the asymmetric diffusion affects dynamical behaviors of biochemical reaction systems.To answer this,we build a general asymmetric L´evy diffusion model based on the theory of a continuous time random walk.In addition,we investigate the two-species Brusselator model with asymmetric L´evy diffusion,and obtain a general condition for the formation of Turing and wave patterns.More interestingly,we find that even though the Brusselator model with symmetric diffusion cannot produce steady spatial patterns for some parameters,the asymmetry of L´evy diffusion for this model can produce wave patterns.This is different from the previous result that wave instability requires at least a three-species model.In addition,the asymmetry of L´evy diffusion can significantly affect the amplitude and frequency of the spatial patterns.Our results enrich our knowledge of the mechanisms of pattern formation. 展开更多
关键词 asymmetric Lévy diffusion Turing and wave patterns Brusselator model
在线阅读 下载PDF
Smartphone use patterns and the impact on accommodation and convergence system of the eyes among Malaysian teenagers
15
作者 Thilageswary Chellapan Norlaila Mat Daud Sumithira Narayanasamy 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第11期2093-2099,共7页
AIM:To determine the smartphone use patterns and effects of smartphone use on accommodation and convergence system of the eyes among Malaysian teenagers.METHODS:A total of 62 participants aged between 13 and 17y were ... AIM:To determine the smartphone use patterns and effects of smartphone use on accommodation and convergence system of the eyes among Malaysian teenagers.METHODS:A total of 62 participants aged between 13 and 17y were involved.A self-administered questionnaires containing 12 items was used to evaluate the smartphone usage patterns.This was followed by an eye examination,involving a battery of accommodation and convergence assessments before and after the smartphone use.The data analysis comprised descriptive statistics,paired t-test,and correlation coefficients.RESULTS:The use of smartphones is at a high level and at an optimal distance daily,with more than 6h a day watching video films,games,and completing school projects.Majority of the participants not reported eye strain factors and eye prescription changes with the use of digital devices.The use of a smartphone continuously for 30min was found to significantly decrease amplitude of accommodation,accommodative facility,and positive relative accommodation(P<0.001).Meanwhile,the lag of accommodation parameters and negative relative accommodation increased with the use of smartphones significantly(P<0.001).The near point of convergence(NPC)and distance and near negative fusional vergence decreased significantly(P<0.001).The NPC parameter was found to have a weak negative association with the frequency of smartphone use(R=-0.276,P<0.05).CONCLUSION:Frequent and continuous use of smartphones have increased visual stress and resulted in weakness of accommodation and vergence functions.Therefore,frequent break is mandatory when using a smartphone and appropriate visual hygiene,the 20-20-20 rule(every 20min,view something 20 feet away for 20s)are required during smartphone use to maintain visual function. 展开更多
关键词 smartphone use patterns accommodation and convergence visual function visual stress
在线阅读 下载PDF
Maternal dietary patterns associated with bone density in Chinese lactating women and infants at 6 months postpartum:a prospective study using data from 2018-2019
16
作者 Yalin Zhou Xiaoyu Zhu +7 位作者 Ying Lü Runlong Zhao Hanxu Shi Wanyun Ye Zhang Wen Rui Li Hanming Huang Yajun Xu 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第5期2668-2676,共9页
This cohort study was designed to explore the relationship between maternal dietary patterns(DPs)and bone health in Chinese lactating mothers and infants.We recruited 150 lactating women at 1-month postpartum.The esti... This cohort study was designed to explore the relationship between maternal dietary patterns(DPs)and bone health in Chinese lactating mothers and infants.We recruited 150 lactating women at 1-month postpartum.The estimated bone mineral density(eBMD)of subjects’calcanei and the information on dietary intake were collected.After 5-month follow-up,the eBMD of mothers and their infants were measured again.Factor analysis was applied to determine maternal DPs.General linear models were used to evaluate the association between maternal DPs and maternal eBMD loss or infants’eBMD.With all potential covariates adjusted,Factor 2(high intake of whole grains,tubers,mixed beans,soybeans and soybean products,seaweeds,and nuts)showed a positive association with the changes of maternal eBMD(β=0.16,95%CI:0.005,0.310).Factor 3(high intake of soft drinks,fried foods,and puffed foods)was inversely correlated with the changes of maternal eBMD(β=-0.22,95%CI:-0.44,0.00).The changes of maternal eBMD were positively associated with 6-month infants’eBMD(β=0.34,95%CI:0.017,0.652).In conclusion,Factor 2 might contribute to the maintenance of eBMD in lactating women,while Factor 3 could exacerbate maternal eBMD loss.Additionally,the changes of maternal eBMD presented a positive correlation with 6-month infants’eBMD. 展开更多
关键词 Dietary patterns Estimated bone mineral density Lactating women
在线阅读 下载PDF
Comparative Analysis of Metro Passengers’Mobility Patterns and Jobs-housing Balance of Metropolitan
17
作者 HUANG Yiman ZHANG Anshu +1 位作者 SU Yuezhu SHI Wenzhong 《Journal of Geodesy and Geoinformation Science》 CSCD 2024年第2期1-17,共17页
The advent of the big data era has provided many types of transportation datasets,such as metro smart card data,for studying residents’mobility and understanding how their mobility has been shaped and is shaping the ... The advent of the big data era has provided many types of transportation datasets,such as metro smart card data,for studying residents’mobility and understanding how their mobility has been shaped and is shaping the urban space.In this paper,we use metro smart card data from two Chinese metropolises,Shanghai and Shenzhen.Five metro mobility indicators are introduced,and association rules are established to explore the mobility patterns.The proportion of people entering and exiting the station is used to measure the jobs-housing balance.It is found that the average travel distance and duration of Shanghai passengers are higher than those of Shenzhen,and the proportion of metro commuters in Shanghai is higher than that of Shenzhen.The jobs-housing spatial relationship in Shenzhen based on metro travel is more balanced than that in Shanghai.The fundamental reason for the differences between the two cities is the difference in urban morphology.Compared with the monocentric structure of Shanghai,the polycentric structure of Shenzhen results in more scattered travel hotspots and more diverse travel routes,which helps Shenzhen to have a better jobs-housing balance.This paper fills a gap in comparative research among Chinese cities based on transportation big data analysis.The results provide support for planning metro routes,adjusting urban structure and land use to form a more reasonable metro network,and balancing the jobs-housing spatial relationship. 展开更多
关键词 metro smart card data mobility patterns association rules jobs-housing balance
在线阅读 下载PDF
Correlation between self-efficacy,parental parenting patterns,and severe depression in adolescents
18
作者 Bin-Feng Zhang Xiao-Yu Zhang 《World Journal of Psychiatry》 SCIE 2024年第12期1827-1835,共9页
BACKGROUND Adolescence is a critical period marked by significant psychological changes.This study explores how self-efficacy and parental parenting styles may influence the risk of severe depression among teens.The h... BACKGROUND Adolescence is a critical period marked by significant psychological changes.This study explores how self-efficacy and parental parenting styles may influence the risk of severe depression among teens.The hypothesis is that higher self-efficacy and authoritative parenting patterns will be negatively correlated with severe depression in adolescents.AIM To investigate the correlation between self-efficacy,parenting patterns and major depression in adolescents,and to provide guidance for mental intervention.METHODS Using a cross-sectional survey design,the data were collected through a questionnaire survey.Patients with major depression and healthy adolescents in the hospital control group were selected as the study objects.The General Self-Efficacy Scale,the Parenting Style Evaluation Scale,and the Beck Depression Inventory were used as research instruments.Data input and statistical analysis were performed,including descriptive statistics,correlation analysis,through SPSS software.RESULTS The study found that depressed patients had significantly lower self-efficacy than healthy controls,and parenting style was significantly associated with depressive symptoms in terms of emotional warmth and understanding,punishment severity,and denial.Specifically,parental emotional warmth and understanding were significantly negatively associated with depressive symptoms,while parental punishment severity and denial were significantly positively associated with depressive symptoms.Self-efficacy showed a significant negative correlation with depressive symptoms,indicating that higher self-efficacy had lower depressive symptoms.CONCLUSION Adolescent major depressive disorder patient was significantly associated with their parenting style and selfefficacy.Higher self-efficacy is associated with decreased depressive symptoms,so improving adolescent selfefficacy and improving parenting style are important. 展开更多
关键词 Adolescent depression SELF-EFFICACY Parental parenting patterns Correlation analysis Psychological interventions
在线阅读 下载PDF
Disruption of sleep patterns among secondary school adolescents
19
作者 Zeki Sabah MUSIHB Hasan Saud Abdul HUSSEIN Alaa Mahdi Abd ALI 《Journal of Integrative Nursing》 2024年第3期145-149,共5页
Objectives:This study aims to assess sleep disorders among secondary school adolescents and explore the relationship between sociodemographic factors(age,gender,household income,and sleep duration)and the occurrence o... Objectives:This study aims to assess sleep disorders among secondary school adolescents and explore the relationship between sociodemographic factors(age,gender,household income,and sleep duration)and the occurrence of these disorders.Methods:A quantitative,descriptive,cross-sectional study,was conducted from November 20th,2022,to May 25th,2023,involving 200 secondary school students selected through convenience sampling.Data collection utilized a structured questionnaire divided into sociodemographic and sleep disorder sections.Validity was ensured by a panel of ten experts,and reliability was confirmed using Cronbach’s Alpha(0.77).Statistical analysis employed SPSS version 26.Results:Findings revealed that a majority of participants(70.5%)had low-level sleep disorders,followed by moderate disorders represented(29%).Significant associations were found between sleep disorders and gender(P=0.000),economic status for family(P=0.020),and nightly sleep duration(P=0.016).However,no significant relationship was observed between sleep disorders and family structure or age(P>0.05).Conclusions:The study highlights that most secondary school students experience mild sleep disorders,followed by moderate disorders.Notably,gender,income,and sleep duration showed significant correlations with sleep disorders. 展开更多
关键词 Disruption of sleep secondary school adolescents sleep patterns
在线阅读 下载PDF
The Role of Beliefs, Perception, and Behavioral Patterns in the Evolution of Psychophysical Disorders
20
作者 Ken Ware 《Journal of Behavioral and Brain Science》 2024年第11期297-309,共13页
In accounts of the development and progression of psychophysical disorders such as Hereditary Spastic Paraplegia (HSP) and Facioscapulohumeral Muscular Dystrophy (FSHD), the role of beliefs, perceptions, and behaviora... In accounts of the development and progression of psychophysical disorders such as Hereditary Spastic Paraplegia (HSP) and Facioscapulohumeral Muscular Dystrophy (FSHD), the role of beliefs, perceptions, and behavioral patterns has often been overlooked in favor of a genetically determinist paradigm. This paper explores the impact of NeuroPhysics Treatment (NPT) on patients with HSP and FSHD. Through a series of clinical case reports, I demonstrate how intensive four-day NPT sessions can lead to rapid restoration of lost functions, challenging the conventional view of these disorders. I hypothesize that, by modulating the patient’s perceptual and behavioral frameworks, NPT facilitates the emergence of healthier patterns, suggesting that environmental and psychological factors significantly influence the manifestation and management of these conditions. These findings indicate that the role of genetic inheritance may be overstated and that beliefs and perceptions could play a crucial role in the evolution of psychophysical disorders. The implications of this research extend beyond the traditional treatment paradigms, advocating for a more holistic approach that integrates the psychophysical dimensions of health and challenges the deterministic perspective of genetic inheritance. 展开更多
关键词 NeuroPhysics Treatment Emergence Psychophysical Conditions PERCEPTION BELIEFS Behavioral patterns INHERITANCE GENETICS
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部