期刊文献+
共找到2,880篇文章
< 1 2 144 >
每页显示 20 50 100
Biopsychosocial health status of Indonesian student nurses on the new normal Jakarta Indonesia
1
作者 Eka Rokhmiati Wahyu Purnamasari Arby James Abonalla +3 位作者 Marcos Ochoa Mary Ann Nery Mark Santos Esteve Adrian Estiva 《Frontiers of Nursing》 2026年第1期115-120,共6页
Nursing education in Indonesia experienced a number of changes during the new normal.The biopsychosocial health status reveals how students can complete their studies well at nursing school in the new normal.A quantit... Nursing education in Indonesia experienced a number of changes during the new normal.The biopsychosocial health status reveals how students can complete their studies well at nursing school in the new normal.A quantitative,descriptive correlational study sampled 368 student nurses from2 universities.This study used a biopsychosocial questionnaire,which included biological,physiological,and social dimensions.In this study,there was no significant demographic student nurse relationship with the biological,psychological,and social dimensions of health,at P-value 0.05(Age P=0.70,P=0.27,P=0.93)sex(P=1,P=0.919,P=0.5),as well as grade level(P=0.9,P=0.37,P=0.64).Student nurses were dynamic,such as process input,resulting in coping adaptation and the ability to care for themselves.There was a relationship between both universities with a psychological dimension and a P-value of 0.049.In terms of Generation Z technology,both universities played a role.Lifestyle influences can lead to intense feelings of isolation and loneliness in some teens,including self-negativity,fear of missing out on information,and shame about not meeting appropriate standards for social media.The influence of an unhealthy lifestyle impacts stress and anxiety.The student nurses assigned considered themselves to be“healthy”in terms of their biopsychosocial health status.Student nurses continued to develop in their biopsychosocial health by utilizing different coping strategies to adapt and adjust to their environment in their school of nursing. 展开更多
关键词 biopsychosocial health new normal nursing school student nurses biological psychological social
在线阅读 下载PDF
Hybrid Pythagorean Fuzzy Decision-Making Framework for Sustainable Urban Planning under Uncertainty
2
作者 Sana Shahab Vladimir Simic +2 位作者 Ashit Kumar Dutta Mohd Anjum Dragan Pamucar 《Computer Modeling in Engineering & Sciences》 2026年第1期892-925,共34页
Environmental problems are intensifying due to the rapid growth of the population,industry,and urban infrastructure.This expansion has resulted in increased air and water pollution,intensified urban heat island effect... Environmental problems are intensifying due to the rapid growth of the population,industry,and urban infrastructure.This expansion has resulted in increased air and water pollution,intensified urban heat island effects,and greater runoff from parks and other green spaces.Addressing these challenges requires prioritizing green infrastructure and other sustainable urban development strategies.This study introduces a novel Integrated Decision Support System that combines Pythagorean Fuzzy Sets with the Advanced Alternative Ranking Order Method allowing for Two-Step Normalization(AAROM-TN),enhanced by a dual weighting strategy.The weighting approach integrates the Criteria Importance Through Intercriteria Correlation(CRITIC)method with the Criteria Importance through Means and Standard Deviation(CIMAS)technique.The originality of the proposed framework lies in its ability to objectively quantify criteria importance using CRITIC,incorporate decision-makers’preferences through CIMAS,and capture the uncertainty and hesitation inherent in human judgment via Pythagorean Fuzzy Sets.A case study evaluating green infrastructure alternatives in metropolitan regions demonstrates the applicability and effectiveness of the framework.A sensitivity analysis is conducted to examine how variations in criteria weights affect the rankings and to evaluate the robustness of the results.Furthermore,a comparative analysis highlights the practical and financial implications of each alternative by assessing their respective strengths and weaknesses. 展开更多
关键词 Sustainable urban planning criterion importance assessment two-step normalization environmental impact decision-making
在线阅读 下载PDF
Local Characterizations of Results on the Normal Index of Subgroups in Finite Groups
3
作者 Yubo LV Yangming LI Xiaoxia DONG 《Journal of Mathematical Research with Applications》 2026年第1期33-39,共7页
Let G be a finite group and H a subgroup of G.The normal index of H in G is defined as the order of K/H_(G),where K is a normal supplement of H in G such that|K|is minimal and H_(G)≤K■G.Let p be a prime which divide... Let G be a finite group and H a subgroup of G.The normal index of H in G is defined as the order of K/H_(G),where K is a normal supplement of H in G such that|K|is minimal and H_(G)≤K■G.Let p be a prime which divides the order of a group G.In this paper,some characterizations of G being p-solvable or p-supersolvable were obtained by analyzing the normal index of certain subgroups of G.These results can be viewed as local version of recent results in the literature. 展开更多
关键词 p-solvable group p-supersolvable group normal index maximal subgroup 2-maximal subgroup
原文传递
Steady-state fretting response governed by periodic stress variations induced by oblique excitation
4
作者 Shenghao Lu Huan Wang Shaoze Yan 《Chinese Physics B》 2026年第1期535-547,共13页
This study investigates the mechanisms of friction-induced vibration under periodic variations in stress distribution using an improved fretting friction model.A fretting friction test system integrated with a total r... This study investigates the mechanisms of friction-induced vibration under periodic variations in stress distribution using an improved fretting friction model.A fretting friction test system integrated with a total reflection method was developed to analyze interfacial contact behavior under dynamic loading conditions.An improved fretting friction model was established,incorporating three critical nonlinear parameters:the hysteretic friction coefficient,tangential stiffness fluctuations,and stress distribution.Through systematic validation,the model demonstrates high-fidelity replication of experimental steady-state amplitude-frequency responses.Key findings reveal that non-uniform stress distribution governs irregularities in the vibration response,and increased uniformity intensifies stick-slip instabilities.Near the stick-slip transition threshold,distinct vibration anomalies emerge due to the coupled effects of stress heterogeneity,friction hysteresis,and stiffness variations during state transitions.Furthermore,the magnitude of the normal contact force systematically alters the dominant interfacial contact mechanism.The different interfacial contact states at various frequencies lead to distinct steady-state responses.This shift elevates resonance frequencies and amplifies higher-order resonant peaks.The fretting friction model provides a predictive framework for vibration control under dynamic interfacial loading. 展开更多
关键词 total reflection method stress distribution the fretting friction model normal force STICK-SLIP
原文传递
POHOZAEV MINIMIZERS FOR FRACTIONAL CHOQUARD EQUATIONS WITH MASS-SUPERCRITICAL NONLINEARITY
5
作者 Liju WU Jiankang XIA 《Acta Mathematica Scientia》 2026年第1期164-188,共25页
We investigate the constrained fractional Choquard equation■where m>0,N>2s with s∈(0,1)being the order of the fractional Laplacian operator and I_(α)forα∈(0,N)denotes the Riesz potential.The parameterμ∈ℝa... We investigate the constrained fractional Choquard equation■where m>0,N>2s with s∈(0,1)being the order of the fractional Laplacian operator and I_(α)forα∈(0,N)denotes the Riesz potential.The parameterμ∈ℝappears as a Lagrange multiplier.By imposing general mass-supercritical conditions on F,we confirm the existence of normalized solutions that characterize the global minimizer on the Pohozaev manifold.Our proof does not depend on the assumption that all weak solutions satisfy the Pohozaev identity,a challenge that remains unsolved for this doubly nonlocal equation. 展开更多
关键词 nonlinear fractional Choquard equation double nonlocality super-critical mass normalized solutions Pohozaev minimizer
在线阅读 下载PDF
Boundary effects on modal shape in deep ocean via non-integer order parabolic cylinder functions
6
作者 Jian-Kang Zhan Sheng-Chun Piao Li-Jia Gong 《Chinese Physics B》 2026年第2期469-474,共6页
This study investigates the effects of ocean boundaries on modal shapes in very-low-frequency(VLF,1–10 Hz)sound propagation through the deep ocean.Utilizing a normal mode solution formulated in terms of parabolic cyl... This study investigates the effects of ocean boundaries on modal shapes in very-low-frequency(VLF,1–10 Hz)sound propagation through the deep ocean.Utilizing a normal mode solution formulated in terms of parabolic cylinder functions(PCF),we demonstrate that boundary interactions induce a phase change reduction below-πat frequencies of several hertz.This reduction,in turn,forces a key transition in the solution,shifting the order of the PCF from integer to non-integer values.Analysis of the characteristic shape of the PCF versus its order reveals that these boundary-influenced modes exhibit an energy shift toward deeper regions and a weakened axial convergence of the underwater sound field. 展开更多
关键词 very-low-frequency sound propagation normal modes parabolic cylinder function
原文传递
Melnikov-type Vectors and Principal Normals 被引量:2
7
作者 朱德明 《Science China Mathematics》 SCIE 1994年第7期814-822,共9页
The exponential dichotomy and the theory of transversality are used to give the condition and its geometric significance for the persistence of a singular orbit with higher degeneracy under small autonomous perturbati... The exponential dichotomy and the theory of transversality are used to give the condition and its geometric significance for the persistence of a singular orbit with higher degeneracy under small autonomous perturbations. Examples of the uniquely persisting singular orbits situated on a 2-dimensional cylinder (resp. torus) consisting of heteroclinic (resp. homoclinic) orbits are also given. 展开更多
关键词 HETEROCLINIC orbit EXPONENTIAL DICHOTOMY TRANSVERSITY principal normal.
原文传递
An Improved Algorithm for k-Nearest-Neighbor Finding and Surface Normals Estimation
8
作者 赵灿 孟祥林 《Tsinghua Science and Technology》 SCIE EI CAS 2009年第S1期77-81,共5页
This paper is to improve the speed of k-nearest-neighbor search and put forward algorithms related to tangent plane estimation based on existing methods. Starting from the points cloud, the algorithm segments the whol... This paper is to improve the speed of k-nearest-neighbor search and put forward algorithms related to tangent plane estimation based on existing methods. Starting from the points cloud, the algorithm segments the whole data into many different small cubes in space, and the size of cube is related to the density of the points cloud. Considering the position of the point in the cube, the algorithm enlarges the area around the given point step by step until the k-nearest-neighbor is accomplished. The neighbor’s least-squares tangent plane is estimated. In order to orient the planes, the k-nearest-neighbor is introduced into the problem of seeking the minimum spanning trees instead of searching the whole data. The research proved that the algorithms put forward in this paper were effective in processing data in short time and with high precision. The theory was useful for the practical application in reverse engineering and other areas related. Solution for finding k-nearest-neighbor problem, which still costs much time in present, was provided, and a propagation algorithm for orienting the planes was also discussed. The algorithm chose the orientation among the k-nearest-neighbor of the current point. 展开更多
关键词 reverse engineering points cloud normal vector LEAST-SQUARES minimum spanning tree
原文传递
The local classifications of the ruled surfaces of normals and binormals of a regular space curve
9
作者 Jian-fei XIONG 《Science China Mathematics》 SCIE 2007年第4期533-548,共16页
The ruled surfaces of normals and binormals of a space curve is locally classified under the left-right action according to the types of the curve.In order to do this some useful results are obtained on the relationsh... The ruled surfaces of normals and binormals of a space curve is locally classified under the left-right action according to the types of the curve.In order to do this some useful results are obtained on the relationship of the powers of terms in the Taylor series of an invertible function and its inverse. 展开更多
关键词 local classification left-right equivalence orthogonal-right equivalence ruled surface normal and binormal
原文传递
基于改进YOLOv7的交通信号灯检测 被引量:1
10
作者 郑岚月 张玉洁 《系统仿真学报》 北大核心 2025年第4期993-1007,共15页
针对通用物体检测算法在信号灯检测方面存在着识别精度较低的问题,提出一种专门针对交通信号灯检测任务的改进的YOLOv7算法。去掉20×20检测尺度,添加160×160的检测尺度,在使模型轻量化的同时增加浅层特征;结合BiFormer中提出... 针对通用物体检测算法在信号灯检测方面存在着识别精度较低的问题,提出一种专门针对交通信号灯检测任务的改进的YOLOv7算法。去掉20×20检测尺度,添加160×160的检测尺度,在使模型轻量化的同时增加浅层特征;结合BiFormer中提出的BRA(bi-level routing attention)与坐标轴注意力,针对交通信号灯位置特点提出了ABRA(axially-guided BRA);针对IoU指标对物体尺寸敏感的问题,引入NWD(normalized wasserstein distance)度量,改进物体定位损失与置信度损失。实验结果表明:改进YOLOv7算法的mAP值达到了97.7%,比原始YOLOv7提高了11.4%,检测速度提升了90帧/s,计算复杂度降低了4.5%。 展开更多
关键词 交通信号灯检测 注意力机制 BiFormer NWD(normalized wasserstein distance) YOLOv7
原文传递
Effects of feature selection and normalization on network intrusion detection 被引量:3
11
作者 Mubarak Albarka Umar Zhanfang Chen +1 位作者 Khaled Shuaib Yan Liu 《Data Science and Management》 2025年第1期23-39,共17页
The rapid rise of cyberattacks and the gradual failure of traditional defense systems and approaches led to using artificial intelligence(AI)techniques(such as machine learning(ML)and deep learning(DL))to build more e... The rapid rise of cyberattacks and the gradual failure of traditional defense systems and approaches led to using artificial intelligence(AI)techniques(such as machine learning(ML)and deep learning(DL))to build more efficient and reliable intrusion detection systems(IDSs).However,the advent of larger IDS datasets has negatively impacted the performance and computational complexity of AI-based IDSs.Many researchers used data preprocessing techniques such as feature selection and normalization to overcome such issues.While most of these researchers reported the success of these preprocessing techniques on a shallow level,very few studies have been performed on their effects on a wider scale.Furthermore,the performance of an IDS model is subject to not only the utilized preprocessing techniques but also the dataset and the ML/DL algorithm used,which most of the existing studies give little emphasis on.Thus,this study provides an in-depth analysis of feature selection and normalization effects on IDS models built using three IDS datasets:NSL-KDD,UNSW-NB15,and CSE–CIC–IDS2018,and various AI algorithms.A wrapper-based approach,which tends to give superior performance,and min-max normalization methods were used for feature selection and normalization,respectively.Numerous IDS models were implemented using the full and feature-selected copies of the datasets with and without normalization.The models were evaluated using popular evaluation metrics in IDS modeling,intra-and inter-model comparisons were performed between models and with state-of-the-art works.Random forest(RF)models performed better on NSL-KDD and UNSW-NB15 datasets with accuracies of 99.86%and 96.01%,respectively,whereas artificial neural network(ANN)achieved the best accuracy of 95.43%on the CSE–CIC–IDS2018 dataset.The RF models also achieved an excellent performance compared to recent works.The results show that normalization and feature selection positively affect IDS modeling.Furthermore,while feature selection benefits simpler algorithms(such as RF),normalization is more useful for complex algorithms like ANNs and deep neural networks(DNNs),and algorithms such as Naive Bayes are unsuitable for IDS modeling.The study also found that the UNSW-NB15 and CSE–CIC–IDS2018 datasets are more complex and more suitable for building and evaluating modern-day IDS than the NSL-KDD dataset.Our findings suggest that prioritizing robust algorithms like RF,alongside complex models such as ANN and DNN,can significantly enhance IDS performance.These insights provide valuable guidance for managers to develop more effective security measures by focusing on high detection rates and low false alert rates. 展开更多
关键词 CYBERSECURITY Intrusion detection system Machine learning Deep learning Feature selection NORMALIZATION
在线阅读 下载PDF
Immune checkpoint blockade for cancer therapy: current progress and perspectives 被引量:2
12
作者 Hongying YE Weijie LIAO +2 位作者 Jiongli PAN Yin SHI Qingqing WANG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 2025年第3期203-226,共24页
Dysfunction of anti-tumor immune responses is crucial for cancer progression. Immune checkpoint blockade(ICB), which can potentiate T cell responses, is an effective strategy for the normalization of host anti-tumor i... Dysfunction of anti-tumor immune responses is crucial for cancer progression. Immune checkpoint blockade(ICB), which can potentiate T cell responses, is an effective strategy for the normalization of host anti-tumor immunity. In recent years, immune checkpoints, expressed on both tumor cells and immune cells, have been identified;some of them have exhibited potential druggability and have been approved by the US Food and Drug Administration(FDA) for clinical treatment. However, limited responses and immune-related adverse events(ir AEs) cannot be ignored. This review outlines the development and applications of ICBs, potential strategies for overcoming resistance, and future directions for ICB-based cancer immunotherapy. 展开更多
关键词 Immune checkpoint blockade Cancer immunotherapy Tumor immune evasion Immune normalization
原文传递
Energy transfer in dynamic fragmentation of rock-like spheres:Insights from impact experiments 被引量:1
13
作者 Jian Huang Yuan Yuan +3 位作者 Da Huang Tan Zeng Pusheng Zhang Xiang Huang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第10期6439-6454,共16页
Rockfall represents a significant geological hazard in mountainous regions,characterized by a sudden and unpredictable feature.The process of dynamic fragmentation and energy conversion in a rockfall event remains com... Rockfall represents a significant geological hazard in mountainous regions,characterized by a sudden and unpredictable feature.The process of dynamic fragmentation and energy conversion in a rockfall event remains complex and not fully understood.This study aims to gain a further understanding of the energy transfer mechanism during rockfall impact and fragmentation by impact tests using a variety of rock-like sphere specimens.The experiments mainly focus on the quantitative correlation between fragmentation degree and influence factors,i.e.impact angle and velocity on steel and granite slabs.The analysis focuses on the energy distribution characteristics,energy dissipation mechanisms,and the energy conversion rate of the fragments during impact and fragmentation.The results show that there is a significant correlation between the energy conversion rate and the fragmentation degree.In normal impact tests,elasto-plastic deformation energy and fracture energy are found to be two primary categories of energy dissipation.The proportion of total kinetic energy after impact is inversely proportional to the initial energy.A comparative analysis between normal and inclined slab impact tests reveals that the impact angle significantly influences the energy conversion rate,which controls the fragmentation degree as well.In addition,the fragmentation degree is inversely proportional to the restitution coefficient.These findings contribute to a better understanding of the energy conversion mechanism during rockfall impact and fragmentation,providing valuable insight for the development of effective strategies to mitigate such rockfall hazards. 展开更多
关键词 ROCKFALL Normal impact Energy conversion Fragmentation degree
在线阅读 下载PDF
Fluid therapy in acute pancreatitis comparing balanced solutions and normal saline:A systematic review,meta-analysis and trial sequential analysis 被引量:1
14
作者 Lin Gao Hsiang-Wei Wang +4 位作者 Zi-Rui Liu Yi-Zhen Xu Lu Ke Wei-Qin Li John A Windsor 《Hepatobiliary & Pancreatic Diseases International》 2025年第4期371-380,共10页
Background:Isotonic crystalloids are recommended as the first choice for fluid therapy in acute pan-creatitis(AP),with normal saline(NS)and lactate Ringer’s(LR)used most often.Evidence based recom-mendations on the t... Background:Isotonic crystalloids are recommended as the first choice for fluid therapy in acute pan-creatitis(AP),with normal saline(NS)and lactate Ringer’s(LR)used most often.Evidence based recom-mendations on the type of fluid are conflicting and generally come from small single-center randomized controlled trials(RCTs).We therefore conducted a systematic review and meta-analysis to compare the effect of balanced solutions(BS)versus NS on patient-centered clinical outcomes in AP.Methods:From four databases searched up to October 2024,we included only RCTs of adult patients with AP that compared the use of BS(including LR,acetate Ringer’s,etc.)with NS.The primary out-come was the disease advances from AP to moderately severe and severe AP(MSAP/SAP).Trial sequential analyses(TSA)were conducted to control for type-I and type-II errors and Grading of Recommendations Assessment,Development,and Evaluation(GRADE)was used to assess the quality of evidence.Results:Six RCTs were identified and included,involving 260 patients treated with BS and 298 patients with NS.Patients who received the BS had less MSAP/SAP[odds ratio(OR)=0.50,95%confidence in-terval(CI):0.29 to 0.85,P=0.01,I^(2)=0%;5 studies,299 patients],reduced the need of ICU admission(OR=0.60,95%CI:0.39 to 0.93,P=0.02,I^(2)=0%;5 studies,507 patients)and shorter length of hospital stay[mean difference(MD)=-0.88,95%CI:-1.48 to-0.28,P=0.004,I^(2)=0%;6 studies,558 patients;confirmed by TSA with high certainty]compared with those who received NS.The evidence for most of the clinical outcomes was rated as moderate to low due to the risk of bias,imprecision and inconsistency.Conclusions:BS,compared with NS,was associated with improved clinical outcomes in patients with AP.However,given the moderate to low quality of evidence for most of the outcomes assessed,further trials are warranted. 展开更多
关键词 Acute pancreatitis Fluid therapy Normal saline Balanced solution Systematic review
暂未订购
Large deformation mechanism and“stress relief-support reinforcement”synergetic control method of soft rock roadway in footwall of deep normal fault 被引量:1
15
作者 PEI Hong-xi LIU Xue-sheng +5 位作者 FAN De-yuan TAN Yun-liang LI Xue-bin GAO Yu-dong SHI Zhi-han ZHANG Yu 《Journal of Central South University》 2025年第10期3945-3967,共23页
The surrounding rock of the soft rock roadway is seriously deformed and damaged under the superposition of mining stress and fault tectonic stress.In this paper,taking the No.232206 intake roadway in Meihuajing Coal M... The surrounding rock of the soft rock roadway is seriously deformed and damaged under the superposition of mining stress and fault tectonic stress.In this paper,taking the No.232206 intake roadway in Meihuajing Coal Mine as the engineering background,the deformation and failure law of the surrounding rock of the roadway in different fault protection pillar widths were obtained by numerical simulation method.On this basis,the mechanical model of the roadway under the action of hanging wall overburden migration and fault slip in normal faults was established,and the energy-driven mechanism of large deformation of the surrounding rock of the roadway was revealed.The ratio T of the energy applying on anchoring surrounding rock to the resistant energy of the anchored surrounding rock was defined as the criterion for the deformation of the roadway.Finally,it was calculated according to the actual working conditions on site,and the control method of“stress relief-support reinforcement”was used to support the roadway with the risk of large deformation.The on-site monitoring results show that the control effect of the surrounding rock of the roadway is obvious. 展开更多
关键词 normal fault large deformation mechanism pillar widths ENERGY synergetic control method
在线阅读 下载PDF
Revisiting the normal stiffness–permeability relations for shale fractures under true triaxial stress 被引量:1
16
作者 Fudong Li Derek Elsworth +6 位作者 Xia-Ting Feng Tianyu Chen Jun Zhao Yingchun Li Jianyu Zhang Qiong Wu Guanglei Cui 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第8期5001-5017,共17页
Understanding the relationship between normal stiffness and permeability in rock fractures under high and true-triaxial in situ stress conditions is critical to assess hydro-mechanical coupling in the Earth's crus... Understanding the relationship between normal stiffness and permeability in rock fractures under high and true-triaxial in situ stress conditions is critical to assess hydro-mechanical coupling in the Earth's crust.Previous data on stiffness–permeability relations are measured under uniaxial stress states as well as under normal stress.However,many projects involve faulted formations with complex three-dimensional(3D)stress states or significant changes to the original stress state.We rectified this by following the permeability evolution using a true-triaxial stress-permeability apparatus as well as independently applying a spectrum of triaxial stresses from low to high.The relationship between permeability and fracture normal stiffness was quantified using constraints based on the principle of virtual work.The impacts of fracture-lateral and fracture-normal stresses on permeability and normal stiffness evolution were measured.It was found that permeability decreases with increasing fracture-lateral and fracture-normal stresses as a result of Poisson confinement,independent of the orientation of the fracture relative to the stresses.The lateral stresses dominated the evolution of normal stiffness at lower normal stresses(σ_(3)=10 MPa)and played a supplementary role at higher normal stresses(σ_(3)>10 MPa).Moreover,correlations between the evolution of permeability and normal stiffness were extended beyond the low-stiffness,high-permeability region to the high-stiffness,low-permeability region under high fracture-lateral stresses(10–80 MPa)with fracture-normal stress(10–50 MPa)conditions.Again,high lateral stresses further confined the fracture and therefore reduced permeability and increased normal stiffness,which exceeded the previous reported stiffness under no lateral stress conditions.This process enabled us to identify a fundamental change in the flow regime from multi-channel to isolated channelized flow.These results provide important characterizations of fracture permeability in the deep crust,including recovery from deep shale-gas reservoirs. 展开更多
关键词 Fracture permeability Deformation Fracture normal stiffness True-triaxial stress Principle of virtual work
在线阅读 下载PDF
Shear behaviors of intermittent joints subjected to shearing cycles under constant normal stiffness conditions:Effects of loading parameters 被引量:1
17
作者 Bin Wang Yujing Jiang +1 位作者 Qiangyong Zhang Hongbin Chen 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第5期2695-2712,共18页
A conceptual model of intermittent joints is introduced to the cyclic shear test in the laboratory to explore the effects of loading parameters on its shear behavior under cyclic shear loading.The results show that th... A conceptual model of intermittent joints is introduced to the cyclic shear test in the laboratory to explore the effects of loading parameters on its shear behavior under cyclic shear loading.The results show that the loading parameters(initial normal stress,normal stiffness,and shear velocity)determine propagation paths of the wing and secondary cracks in rock bridges during the initial shear cycle,creating different morphologies of macroscopic step-path rupture surfaces and asperities on them.The differences in stress state and rupture surface induce different cyclic shear responses.It shows that high initial normal stress accelerates asperity degradation,raises shear resistance,and promotes compression of intermittent joints.In addition,high normal stiffness provides higher normal stress and shear resistance during the initial cycles and inhibits the dilation and compression of intermittent joints.High shear velocity results in a higher shear resistance,greater dilation,and greater compression.Finally,shear strength is most sensitive to initial normal stress,followed by shear velocity and normal stiffness.Moreover,average dilation angle is most sensitive to initial normal stress,followed by normal stiffness and shear velocity.During the shear cycles,frictional coefficient is affected by asperity degradation,backfilling of rock debris,and frictional area,exhibiting a non-monotonic behavior. 展开更多
关键词 Intermittent joint Cyclic shear Loading parameter Constant normal stiffness(CNS)
在线阅读 下载PDF
Source apportionment of PM_(2.5) using dispersion normalized positive matrix factorization(DN-PMF)in Beijing and Baoding,China 被引量:1
18
作者 Ilhan Ryoo Taeyeon Kim +6 位作者 Jiwon Ryu Yeonseung Cheong Kwang-joo Moon Kwon-ho Jeon Philip K.Hopke Seung-Muk Yi Jieun Park 《Journal of Environmental Sciences》 2025年第9期395-408,共14页
Fine particulatematter(PM_(2.5))samples were collected in two neighboring cities,Beijing and Baoding,China.High-concentration events of PM_(2.5) in which the average mass concentration exceeded 75μg/m^(3) were freque... Fine particulatematter(PM_(2.5))samples were collected in two neighboring cities,Beijing and Baoding,China.High-concentration events of PM_(2.5) in which the average mass concentration exceeded 75μg/m^(3) were frequently observed during the heating season.Dispersion Normalized Positive Matrix Factorization was applied for the source apportionment of PM_(2.5) as minimize the dilution effects of meteorology and better reflect the source strengths in these two cities.Secondary nitrate had the highest contribution for Beijing(37.3%),and residential heating/biomass burning was the largest for Baoding(27.1%).Secondary nitrate,mobile,biomass burning,district heating,oil combustion,aged sea salt sources showed significant differences between the heating and non-heating seasons in Beijing for same period(2019.01.10–2019.08.22)(Mann-Whitney Rank Sum Test P<0.05).In case of Baoding,soil,residential heating/biomass burning,incinerator,coal combustion,oil combustion sources showed significant differences.The results of Pearson correlation analysis for the common sources between the two cities showed that long-range transported sources and some sources with seasonal patterns such as oil combustion and soil had high correlation coefficients.Conditional Bivariate Probability Function(CBPF)was used to identify the inflow directions for the sources,and joint-PSCF(Potential Source Contribution Function)was performed to determine the common potential source areas for sources affecting both cities.These models facilitated a more precise verification of city-specific influences on PM_(2.5) sources.The results of this study will aid in prioritizing air pollution mitigation strategies during the heating season and strengthening air quality management to reduce the impact of downwind neighboring cities. 展开更多
关键词 Source apportionment Dispersion normalized positive matrix factorization Adjacent cities Inter-city impact Source location Heating season Air quality management
原文传递
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
19
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
Expert consensus on early orthodontic treatment of class Ⅲ malocclusion 被引量:1
20
作者 Xin Zhou Si Chen +30 位作者 Chenchen Zhou Zuolin Jin Hong He Yuxing Bai Weiran Li Jun Wang Min Hu Yang Cao Yuehua Liu Bin Yan Jiejun Shi Jie Guo Zhihua Li Wensheng Ma Yi Liu Huang Li Yanqin Lu Liling Ren Rui Zou Linyu Xu Jiangtian Hu Xiuping Wu Shuxia Cui Lulu Xu Xudong Wang Songsong Zhu Li Hu Qingming Tang Jinlin Song Bing Fang Lili Chen 《International Journal of Oral Science》 2025年第3期328-340,共13页
The prevalence of Class Ⅲ malocclusion varies among different countries and regions. The populations from Southeast Asian countries (Chinese and Malaysian) showed the highest prevalence rate of 15.8%, which can serio... The prevalence of Class Ⅲ malocclusion varies among different countries and regions. The populations from Southeast Asian countries (Chinese and Malaysian) showed the highest prevalence rate of 15.8%, which can seriously affect oral function, facial appearance, and mental health. As anterior crossbite tends to worsen with growth, early orthodontic treatment can harness growth potential to normalize maxillofacial development or reduce skeletal malformation severity, thereby reducing the difficulty and shortening the treatment cycle of later-stage treatment. This is beneficial for the physical and mental growth of children. Therefore,early orthodontic treatment for Class Ⅲ malocclusion is particularly important. Determining the optimal timing for early orthodontic treatment requires a comprehensive assessment of clinical manifestations, dental age, and skeletal age, and can lead to better results with less effort. Currently, standardized treatment guidelines for early orthodontic treatment of Class Ⅲ malocclusion are lacking. This review provides a comprehensive summary of the etiology, clinical manifestations, classification, and early orthodontic techniques for Class Ⅲ malocclusion, along with systematic discussions on selecting early treatment plans. The purpose of this expert consensus is to standardize clinical practices and improve the treatment outcomes of Class Ⅲ malocclusion through early orthodontic treatment. 展开更多
关键词 reducing difficulty shortening trea normalize maxillofacial development Early orthodontic treatment Southeast Asian countries ClassⅢmalocclusion orthodontic treatment Prevalence reduce skeletal malformation severitythereby
暂未订购
上一页 1 2 144 下一页 到第
使用帮助 返回顶部