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Equivalent Conditions of Complete Convergence for Weighted Sums of Sequences of i.i.d.Random Variables under Sublinear Expectations
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作者 XU Mingzhou CHENG Kun 《应用概率统计》 北大核心 2025年第3期339-352,共14页
The complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space is studied.By moment inequality and truncation methods,we establish the... The complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space is studied.By moment inequality and truncation methods,we establish the equivalent conditions of complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space.The results complement the corresponding results in probability space to those for sequences of independent,identically distributed random variables under sublinear expectation space. 展开更多
关键词 complete convergence weighted sums i.i.d.random variables sublinear expectation
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Detection and characterization of regulatory elements using probabilistic conditional random field and hidden Markov models 被引量:3
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作者 Hongyan Wang Xiaobo Zhou 《Chinese Journal of Cancer》 SCIE CAS CSCD 2013年第4期186-194,共9页
By altering the electrostatic charge of histones or providing binding sites to protein recognition molecules, Chromatin marks have been proposed to regulate gene expression, a property that has motivated researchers t... By altering the electrostatic charge of histones or providing binding sites to protein recognition molecules, Chromatin marks have been proposed to regulate gene expression, a property that has motivated researchers to link these marks to cis-regulatory elements. With the help of next generation sequencing technologies, we can now correlate one specific chromatin mark with regulatory elements (e.g. enhancers or promoters) and also build tools, such as hidden Markov models, to gain insight into mark combinations. However, hidden Markov models have limitation for their character of generative models and assume that a current observation depends only on a current hidden state in the chain. Here, we employed two graphical probabilistic models, namely the linear conditional random field model and multivariate hidden Markov model, to mark gene regions with different states based on recurrent and spatially coherent character of these eight marks. Both models revealed chromatin states that may correspond to enhancers and promoters, transcribed regions, transcriptional elongation, and low-signal regions. We also found that the linear conditional random field model was more effective than the hidden Markov model in recognizing regulatory elements, such as promoter-, enhancer-, and transcriptional elongation-associated regions, which gives us a better choice. 展开更多
关键词 Epigenetics HISTONE modification CONDITIONAL random field REGULATORY elements
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Rock-soil slope stability analysis by two-phase random media and finite elements 被引量:10
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作者 Yong Liu Huawen Xiao +2 位作者 Kai Yao Jun Hu Hong Wei 《Geoscience Frontiers》 SCIE CAS CSCD 2018年第6期1649-1655,共7页
To investigate the strong random nature of the geometric interfaces between soil and rock, a rock-soil slope is considered as a two-phase random medium. A nonlinear translation of a Gaussian field is utilized to simul... To investigate the strong random nature of the geometric interfaces between soil and rock, a rock-soil slope is considered as a two-phase random medium. A nonlinear translation of a Gaussian field is utilized to simulate the two-phase random media, such that the soil(or rock) volume fraction and the inclination of the soil layer can be examined. The finite element method with random media incorporated as the material properties is used to determine the factor of safety of the rock-soil slope. Monte-Carlo simulations are used to estimate the statistical characteristics of the factor of safety. The failure mode of the rock-soil slope is examined by observing the maximum principal plastic strain at incipient slope failure. It is found that the critical surface of a rock-soil slope is fairly irregular, and it significantly differs from that of a pure soil slope. The factor of safety is sensitive to the soil volume faction, but it is predictable. The average factor of safety could be well predicted by the weighted harmonic average between the strength of soil and rock; the prediction model is practical and simple. Parametric studies on the inclination of the soil layer demonstrate that the most instable scenario occurs when the slope angle is consistent with the inclination of the soil layer. 展开更多
关键词 SLOPES stability Numerical computation STATISTICAL analysis FINITE-ELEMENT modelling random FIELDS Monte-Carlo simulations
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DISTRIBUTION OF RANDOM ELEMENTS SUBJECTED TO A FLEXIBLE BOUNDARY CONDITION
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作者 陈汉栋 乔宇 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第3期313-316,共4页
The probability distribution function of n random elements subjected to the flexible boundary condition is derived. The probability density is a descending curve and converges to a delta function as n tends to infinit... The probability distribution function of n random elements subjected to the flexible boundary condition is derived. The probability density is a descending curve and converges to a delta function as n tends to infinity. The distribution of the minimum value is discussed in context of ordered statistics. 展开更多
关键词 flexible boundary condition constrained random elements probability density ordered statistics
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CONVERGENCE RATES IN THE LAW OF LARGE NUMBERS FOR B-VALUED RANDOM ELEMENTS
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作者 梁汉营 王丽 《Acta Mathematica Scientia》 SCIE CSCD 2001年第2期229-236,共8页
The author discusses necessary and sufficient conditions of the complete con- vergence for sums of B-valued independent but not necessarily identically distributed r.v.'s in Banach space of type p, and obtains cha... The author discusses necessary and sufficient conditions of the complete con- vergence for sums of B-valued independent but not necessarily identically distributed r.v.'s in Banach space of type p, and obtains characterization of Banach space of type p in terms of the complete convergence. A series of classical results on iid real valued r.v.'s are ex- tended. As application authors give the analogous results for randomly indexed sums. 展开更多
关键词 Convergence rate random element Banach space of type p slowly varying function
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Psychological effects of virtual reality intervention on breast cancer patients with different personalities: A randomized controlled trial 被引量:6
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作者 Shanshan Wu Guodu Liu +9 位作者 Jie Yang Xinxin Xie Mei-E Wu Lili Wang Yanhui Zhang Jinmei Chen Xiaowei Wang Wanjiao Li Yihong Qiu Jie Chen 《International Journal of Nursing Sciences》 2025年第2期107-114,共8页
Objectives:To explore the efficacy and safety of virtual reality(VR)in relieving negative emotions in patients with breast cancer with different personalities.Methods:A randomized controlled trial was conducted.Betwee... Objectives:To explore the efficacy and safety of virtual reality(VR)in relieving negative emotions in patients with breast cancer with different personalities.Methods:A randomized controlled trial was conducted.Between April 2023 and October 2023,we enrolled patients with breast cancer treated in the Department of Breast Cancer and Oncology at Sun Yat-Sen Memorial Hospital,Sun Yat-Sen University,Guangdong Province.The patients were randomly divided into an intervention group(n=118)and a control group(n=119)using block randomization.The intervention group received the VR intervention 3-5 times over 5±2 weeks using natural landscapes with music or relaxation guidance,and the duration of each VR intervention was 15±3 min.The control group received routine nursing care,including disease education and psychological counseling.Patients were assessed using the Type D Scale,Positive and Negative Affect Scale,and Distress Thermometer,and adverse events during the intervention were recorded.Results:Overall,85 patients completed the study(44 in the intervention group and 41 in the control group).Patients with Type D personalities showed more negative emotions[25.0(21.5,27.5)vs.19.0(16.0,24.0),P=0.001]and distressed attitudes[4.0(2.0,5.0)vs.3.0(1.0,4.0),P=0.020]with fewer positive emotions(27.2±5.6 vs.31.0±5.9,P=0.014)than those with non-Type D personalities.Total population analysis revealed no significant differences between the groups.However,in the subgroup analysis,patients with Type D personalities in the intervention group showed greater relief from negative emotions than those in the control group[median difference,-5.0(-9.0,-2.5)vs.-2.0(-4.0,2.0),P=0.046].No significant differences were found between groups of patients with non-Type D personality traits.The proportion of adverse events was not significantly different between groups(P=0.110).Conclusions:Breast cancer patients with Type D personalities suffer more severe negative emotions and distress,and more attention should be paid to them.VR intervention significantly and safely reduced negative emotions in patients with Type D personalities. 展开更多
关键词 Breast neoplasms Rehabilitation research randomized controlled trial Type D personality Virtual reality
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Effects of spatial heterogeneity on pseudo-static stability of coal mine overburden dump slope,using random limit equilibrium and random finite element methods:A comparative study
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作者 Madhumita Mohanty Rajib Sarkar Sarat Kumar Das 《Earthquake Engineering and Engineering Vibration》 2025年第1期83-99,共17页
Sudden and unforeseen seismic failures of coal mine overburden(OB)dump slopes interrupt mining operations,cause loss of lives and delay the production of coal.Consideration of the spatial heterogeneity of OB dump mate... Sudden and unforeseen seismic failures of coal mine overburden(OB)dump slopes interrupt mining operations,cause loss of lives and delay the production of coal.Consideration of the spatial heterogeneity of OB dump materials is imperative for an adequate evaluation of the seismic stability of OB dump slopes.In this study,pseudo-static seismic stability analyses are carried out for an OB dump slope by considering the material parameters obtained from an insitu field investigation.Spatial heterogeneity is simulated through use of the random finite element method(RFEM)and the random limit equilibrium method(RLEM)and a comparative study is presented.Combinations of horizontal and vertical spatial correlation lengths were considered for simulating isotropic and anisotropic random fields within the OB dump slope.Seismic performances of the slope have been reported through the probability of failure and reliability index.It was observed that the RLEM approach overestimates failure probability(P_(f))by considering seismic stability with spatial heterogeneity.The P_(f)was observed to increase with an increase in the coefficient of variation of friction angle of the dump materials.Further,it was inferred that the RLEM approach may not be adequately applicable for assessing the seismic stability of an OB dump slope for a horizontal seismic coefficient that is more than or equal to 0.1. 展开更多
关键词 coal mine overburden dump slope random limit equilibrium method random finite element method seismic slope stability spatial heterogeneity
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Analysis of key therapeutic elements in acupuncture therapy and placebo acupuncture controls
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作者 Jian-fei NIU Guan-qun WANG +3 位作者 Xiao-long XIE Shuo DU Bi-hui PENG Ji-ping ZHAO 《World Journal of Acupuncture-Moxibustion》 2025年第2期145-151,共7页
Identifying key acupuncture elements is essential for optimizing sham acupuncture controls.Based on the characteristics and current state of acupuncture therapy,this paper categorizes key acupuncture elements into typ... Identifying key acupuncture elements is essential for optimizing sham acupuncture controls.Based on the characteristics and current state of acupuncture therapy,this paper categorizes key acupuncture elements into types and contents.Taking the former as a clue,it examines the current understanding of key acupuncture elements and underscores the need for further refinement to ensure that sham acupuncture controls more closely approximate physiological inertness.Additionally,it explores strategies and methodologies for advancing the understanding of key acupuncture elements from both the type and content perspectives.Key acupuncture elements should expand the number of included element types.Elements such as acupuncture needles,point selection,point combination,needle insertion,needle manipulation,and needle withdrawal should all be included,and they should be reported in a standardized manner in the trials.Regarding element content,improvements should be made in three key areas to enhance selection accuracy:1.Strengthening the comprehensiveness of relevant theoretical frameworks.2.Emphasizing the role of Traditional Chinese Medicine(TCM)diagnosis and acupoint palpation methods in trial application and reporting.3.Continuously investigating the mechanisms underlying both the specific efficacy and the placebo efficacy of acupuncture. 展开更多
关键词 Key acupuncture elements Placebo acupuncture Sham acupuncture Explanatory randomized controlled trials
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Randomly generating realistic calcareous sand for directional seepage simulation using deep convolutional generative adversarial networks
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作者 Dou Chen Wei Zhang +4 位作者 Chenghao Li Linjian Ma Xiaoqing Shi Haiyang Li Honghu Zhu 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第11期7297-7312,共16页
The issues of seepage in calcareous sand foundations and backfillshave a potentially detrimental effect on the stability and safety of superstructures.Simplifying calcareous sand grains as spheres or ellipsoids in num... The issues of seepage in calcareous sand foundations and backfillshave a potentially detrimental effect on the stability and safety of superstructures.Simplifying calcareous sand grains as spheres or ellipsoids in numerical simulations may lead to significantinaccuracies.In this paper,we present a novel intelligence framework based on a deep convolutional generative adversarial network(DCGAN).A DCGAN model was trained using a training dataset comprising 11,625 real particles for the random generation of three-dimensional calcareous sand particles.Subsequently,3800 realistic calcareous sand particles with intra-particle voids were generated.Generative fidelityand validity of the DCGAN model were well verifiedby the consistency of the statistical values of nine morphological parameters of both the training dataset and the generated dataset.Digital calcareous sand columns were obtained through gravitational deposition simulation of the generated particles.Directional seepage simulations were conducted,and the vertical permeability values of the sand columns were found to be in accordance with the objective law.The results demonstrate the potential of the proposed framework for stochastic modeling and multi-scale simulation of the seepage behaviors in calcareous sand foundations and backfills. 展开更多
关键词 Calcareous sand random generation Generative adversarial networks Discrete element modeling Signed distance field Vertical permeability
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Seismic dip estimation based on the twodimensional Hilbert transform and its application in random noise attenuation 被引量:8
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作者 刘财 陈常乐 +3 位作者 王典 刘洋 王世煜 张亮 《Applied Geophysics》 SCIE CSCD 2015年第1期55-63,121,共10页
In seismic data processing, random noise seriously affects the seismic data quality and subsequently the interpretation. This study aims to increase the signal-to-noise ratio by suppressing random noise and improve th... In seismic data processing, random noise seriously affects the seismic data quality and subsequently the interpretation. This study aims to increase the signal-to-noise ratio by suppressing random noise and improve the accuracy of seismic data interpretation without losing useful information. Hence, we propose a structure-oriented polynomial fitting filter. At the core of structure-oriented filtering is the characterization of the structural trend and the realization of nonstationary filtering. First, we analyze the relation of the frequency response between two-dimensional(2D) derivatives and the 2D Hilbert transform. Then, we derive the noniterative seismic local dip operator using the 2D Hilbert transform to obtain the structural trend. Second, we select polynomial fitting as the nonstationary filtering method and expand the application range of the nonstationary polynomial fitting. Finally, we apply variableamplitude polynomial fitting along the direction of the dip to improve the adaptive structureoriented filtering. Model and field seismic data show that the proposed method suppresses the seismic noise while protecting structural information. 展开更多
关键词 Two-dimensional Hilbert transform random noise attenuation structure protection nonstationary polynomial fitting local seismic d
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木勺毛坯捆抓取柔性夹持器结构优化
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作者 张加成 张森 +2 位作者 刘玉童 黄辉 赵辉 《森林工程》 北大核心 2026年第1期140-150,共11页
针对木勺模压工艺中人工浸水效率低、木勺毛坯易损的问题,设计一种面向木勺毛坯捆抓取的自适应柔性夹持器。结合有限元分析软件,开展优化试验方案的设计。提出基于超参数优化的贝叶斯优化算法(Bayesian optimization,BO)-随机森林(rando... 针对木勺模压工艺中人工浸水效率低、木勺毛坯易损的问题,设计一种面向木勺毛坯捆抓取的自适应柔性夹持器。结合有限元分析软件,开展优化试验方案的设计。提出基于超参数优化的贝叶斯优化算法(Bayesian optimization,BO)-随机森林(random forest,RF)方法(BO-RF),构建柔性夹持器应变能的回归预测模型,并运用可解释性机器学习方法(SHapley Additive exPlanations,SHAP)从全局和单个样本层面对模型进行可解释性分析。基于该预测模型,以最大上表面应变能和最小整体应变能为优化目标,应用遗传算法开展柔性夹持器的优化设计,并计算基于BO-RF模型的多目标帕累托(Pareto)前沿。仿真结果验证所提建模与优化方法的有效性和可行性。 展开更多
关键词 柔性夹持器 木勺毛坯捆 有限元分析 BO-RF随机森林 SHAP分析 遗传算法 多目标优化 应变能
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FORS-D分析软件“Random_fold_scan”和不同碱基随机打乱算法对FORS-D分析的影响
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作者 徐顺高 魏继福 张驰宇 《江苏大学学报(医学版)》 CAS 2007年第6期461-466,470,共7页
目的:开发FORS-D分析软件,并比较不同碱基随机打乱算法对FORS-D分析的影响。方法:根据单、双、三碱基及密码子随机打乱算法,用ActivePerl-5.8.8.820编写"Random_fold_scan"软件,它通过系统命令调用RNA-structure4.2来计算FOR... 目的:开发FORS-D分析软件,并比较不同碱基随机打乱算法对FORS-D分析的影响。方法:根据单、双、三碱基及密码子随机打乱算法,用ActivePerl-5.8.8.820编写"Random_fold_scan"软件,它通过系统命令调用RNA-structure4.2来计算FORS-D值。用4种碱基随机打乱算法分别计算来自不同物种的12个mRNA序列,并且比较它们对FORS-D值的影响。结果:4种随机打乱策略不影响核酸序列的FORS-D分布趋势,但是单碱基打乱算法可以获得比其他3种算法更低的FORS-D值。比较4种打乱算法获得的FORS-D值的Z-score分布,发现单碱基打乱产生的FORS-D值显著小于0的比例最高,相反,FORS-D值显著大于0的比例最低。结论:单碱基随机打乱算法能够彻底破坏原始核酸的序列信息,在概念和理论上能够真正反映FORS-D的生物学涵义。这表明FORS-D分析中单碱基打乱足以给出准确、可靠的数据信息。此外,我们开发了软件"Random_fold_scan"用于FORS-D分析。 展开更多
关键词 FORS-D分析 Z-SCORE 单碱基随机打乱 双碱基随机打乱
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基于孟德尔随机化分析11种微量元素和22种饮食与妊娠剧吐的因果关系
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作者 阮晓川 邓米娜 阮云瑶 《护理研究》 北大核心 2026年第1期35-45,共11页
目的:采用孟德尔随机化方法研究钙、铁、锌、硒、镁、铜、维生素A、维生素C、维生素D、维生素E、胡萝卜素11种微量元素以及饮酒、牛肉摄入量、面包摄入量、谷物摄入量、奶酪摄入量、咖啡摄入量、熟蔬菜摄入量、干果摄入量、新鲜水果摄... 目的:采用孟德尔随机化方法研究钙、铁、锌、硒、镁、铜、维生素A、维生素C、维生素D、维生素E、胡萝卜素11种微量元素以及饮酒、牛肉摄入量、面包摄入量、谷物摄入量、奶酪摄入量、咖啡摄入量、熟蔬菜摄入量、干果摄入量、新鲜水果摄入量、羊肉摄入量、非油性鱼类摄入量、油性鱼类摄入量、猪肉摄入量、家禽摄入量、加工肉类摄入量、生蔬菜摄入量、添加到食物中的盐、茶摄入量、热饮、碳酸饮料摄入量、大蒜摄入量、韭菜摄入量22种常见饮食食物与妊娠剧吐的因果关系。方法:利用全基因组关联研究汇总数据(Genome-Wide Association Studies,GWAS),以单核苷酸多态性作为工具变量,利用逆方差加权、加权模式、MR Egger、加权中位数的方法进行分析。采用Cochrane′s Q检验识别结果的异质性,MR Egger截距检验及“留一法”检验等方法评估11种微量元素以及22种饮食和妊娠剧吐关联的稳健性。结果:补充维生素D可以降低妊娠剧吐发病风险[OR=0.48,95%CI(0.30,0.75)],未发现其余10种微量元素以及22种食物对妊娠剧吐发病风险的影响(P>0.05);且不存在水平多效性和异质性(P>0.05),提示结果稳健性。结论:维生素D可以降低妊娠剧吐发病风险,暂未发现其余10种微量元素以及22种饮食对降低或增加妊娠剧吐风险的影响。 展开更多
关键词 微量元素 饮食 妊娠 妊娠剧吐 孟德尔随机化 因果推断
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D-松醇缓解脑缺血/再灌注模型大鼠的脑损伤
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作者 徐伯鑫 山媛 杨云鹏 《基础医学与临床》 2026年第3期359-366,共8页
目的探究D-松醇(DP)对脑缺血/再灌注损伤(CI/RI)模型大鼠的治疗作用。方法将大鼠随机分为6组(n=12):假手术组(sham)、模型组(model,改良Longa线栓法建立的CI/RI大鼠模型)、低(L-DP组)、中(M-DP组)和高剂量DP组(H-DP组)(分别灌胃10/20/40... 目的探究D-松醇(DP)对脑缺血/再灌注损伤(CI/RI)模型大鼠的治疗作用。方法将大鼠随机分为6组(n=12):假手术组(sham)、模型组(model,改良Longa线栓法建立的CI/RI大鼠模型)、低(L-DP组)、中(M-DP组)和高剂量DP组(H-DP组)(分别灌胃10/20/40 mg/kg的DP),以及H-DP+抑制剂组(inhibitor,灌胃40 mg/kg的DP及腹腔注射30 mg/kg Nrf2抑制剂ML385)。用双盲法进行Zea Longa评分,TTC染色评价脑梗死体积,苏木精-伊红(HE)和尼氏染色观察神经元形态,TUNEL染色标记凋亡细胞。按试剂盒说明检测脑组织SOD活性以及GSH、MDA、TNF-α、IL-1β和IL-6含量。用可见分光光度法检测脑组织匀浆中的Fe^(2+)含量。RT-qPCR检测脑组织血红素加氧酶-1(HO-1)、醌氧化还原酶-1(NQO1)、谷胱甘肽过氧化物酶4(GPX4)mRNA水平。Western blot检测脑组织Nrf2(细胞核)、Keap1、HO-1、NQO-1和GPX4蛋白表达水平。结果与假手术组比较,模型组大鼠出现明显脑损伤,神经功能评分、脑梗死体积和TUNEL+细胞比例升高(P<0.05);GSH含量和SOD活性降低(P<0.05),MDA、TNF-α、IL-1β、IL-6和Fe^(2+)水平升高(P<0.05);GPX4、Nrf2(细胞核)及HO-1和NQO-1蛋白水平降低(P<0.05),Keap1蛋白水平升高(P<0.05)。与模型组比较,L/M/H-DP组大鼠脑损伤明显减轻,神经功能评分、脑梗死体积和TUNEL+细胞比例均降低(P<0.05);GSH含量和SOD活性升高(P<0.05),MDA、TNF-α、IL-1β、IL-6和Fe^(2+)水平均降低(P<0.05);GPX4、Nrf2(细胞核)及HO-1和NQO-1蛋白水平升高(P<0.05),Keap1蛋白水平降低(P<0.05)。与H-DP组比较,抑制剂组大鼠脑损伤加重,神经功能评分、脑梗死体积和TUNEL+细胞比例均升高(P<0.05);GSH含量和SOD活性降低(P<0.05),MDA、TNF-α、IL-1β、IL-6和Fe^(2+)水平均升高(P<0.05);GPX4、Nrf2(细胞核)及HO-1和NQO-1蛋白水平降低(P<0.05),Keap1蛋白水平升高(P<0.05)。结论D-松醇通过抗氧化、抗感染、抗凋亡及抑制铁死亡缓解CI/RI大鼠的脑损伤。 展开更多
关键词 脑缺血/再灌注损伤 D-松醇 核因子E2相关因子2 抗氧化反应元件 氧化应激 铁死亡
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A Hybrid Experimental-Numerical Framework for Identifying Viscoelastic Parameters of 3D-Printed Polyurethane Samples:Cyclic Tests,Creep/Relaxation and Inverse Finite Element Analysis
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作者 Nikita Golovkin Olesya Nikulenkova +4 位作者 Vsevolod Pobezhimov Alexander Nesmelov Sergei Chvalun Fedor Sorokin Arthur Krupnin 《Computers, Materials & Continua》 2026年第3期519-536,共18页
This study presents and verifies a hybrid methodology for reliable determination of parameters in structural rheological models(Zener,Burgers,and Maxwell)describing the viscoelastic behavior of polyurethane specimens ... This study presents and verifies a hybrid methodology for reliable determination of parameters in structural rheological models(Zener,Burgers,and Maxwell)describing the viscoelastic behavior of polyurethane specimens manufactured using extrusion-based 3D printing.Through comprehensive testing,including cyclic compression at strain rates ranging from 0.12 to 120 mm/min(0%-15%strain)and creep/relaxation experiments(10%-30%strain),the lumped parameters were independently determined using both analytical and numerical solutions of the models’differential equations,followed by cross-verification in additional experiments.Numerical solutions for creep and relaxation problems were obtained using finite element analysis,with the three-parameter Mooney-Rivlin model and Prony series employed to simulate elastic and viscous stress components,respectively.Energy dissipation per cycle was quantified during cyclic compression tests.The results demonstrate that all three models adequately describe material behavior within the 0%-15%strain range across various strain rates.Comparative analysis revealed the Burgers model’s superior performance in characterizing creep and stress relaxation at low strain levels.While Zener and Burgers model parameters from uniaxial compression showed limited applicability for energy dissipation calculations,the generalized Maxwell model effectively captured viscoelastic properties across different strain rates.Notably,parameters derived from creep tests provided a more universal assessment of dissipative properties due to optimization based on characteristic curve regions.Both parameter sets described polyurethane’s elastic-hysteretic behavior with approximately 20%error,proving significantly more accurate than the linear strain-time dependence hypothesis.Finite element analysis(FEA)complemented numerical modeling by demonstrating that while the generalized Maxwell model effectively describes initial rapid stress-strain changes,FEA provides superior characterization of steady-state processes.This computational approach yields more physically representative results compared to simplified analytical solutions,despite certain limitations in transient analysis. 展开更多
关键词 VISCOELASTICITY cyclic compression HYSTERESIS CREEP stress relaxation finite element method optimization 3D printing structural rheological models Prony series
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基于机器学习的元素录井宏观煤岩类型识别方法研究
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作者 蔡天 孙建孟 +2 位作者 孙红华 郑珊珊 刘粤蛟 《测井技术》 2026年第1期97-107,120,共12页
为解决传统测井方法识别宏观煤岩类型时易受井眼条件干扰、模型区域适应性差的问题,为煤层气储层评价与甜点预测提供可靠技术支撑,以鄂尔多斯盆地东部本溪组煤层为研究对象,采用元素录井数据与机器学习相结合的智能识别方法。通过密度... 为解决传统测井方法识别宏观煤岩类型时易受井眼条件干扰、模型区域适应性差的问题,为煤层气储层评价与甜点预测提供可靠技术支撑,以鄂尔多斯盆地东部本溪组煤层为研究对象,采用元素录井数据与机器学习相结合的智能识别方法。通过密度灰分反包络实现煤层精准识别,运用SMOTE算法均衡小样本数据集,结合主成分分析对Al、Ca、Fe等7种元素进行降维处理,对比随机森林、优化分布式梯度提升库(eXtreme Gradient Boosting,XGBoost)、支持向量机这3种机器学习模型并优选最优模型,开展盲井验证与含气量相关性分析。研究结果表明:①密度灰分反包络煤层识别准确率达82.9%,构建的工业组分计算模型相对误差均低于27%。②主成分分析提取的前3个主成分累计贡献率达83.3%,可有效表征原始元素信息。③XGBoost模型识别效果最优,测试集宏平均F_(1)值为0.92,盲井验证平均准确率达89.45%,对暗淡煤识别准确率达86%。④煤岩光亮程度与含气量呈正相关,光亮煤吸附能力最强,产能潜力更高。结论认为,融合元素录井与XGBoost模型的识别方法可有效降低环境干扰,提升宏观煤岩类型识别精度与模型鲁棒性,为优质煤层气储层预测、产能评价提供重要技术途径与理论依据。 展开更多
关键词 储层评价 煤层气 宏观煤岩类型 随机森林 XGBoost 支持向量机 元素录井 机器学习 SMOTE算法
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氘代氨气体杂质分析及成膜性能研究
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作者 桂娟 关子钧 李奥琦 《科学技术创新》 2026年第2期41-44,共4页
氘代氨的化学键比氨强度高,在高温环境下,氘代氨更加稳定且不易发生分解反应。这个特性可提高器件的效率和寿命。本文通过氦离子化气相色谱仪,研究了氘代氨气体中杂质气体理化性能测试。通过等离子体增强化学气相沉积生长成膜,研究PECV... 氘代氨的化学键比氨强度高,在高温环境下,氘代氨更加稳定且不易发生分解反应。这个特性可提高器件的效率和寿命。本文通过氦离子化气相色谱仪,研究了氘代氨气体中杂质气体理化性能测试。通过等离子体增强化学气相沉积生长成膜,研究PECVD工艺条件对氘代氨镀膜材料性能影响。 展开更多
关键词 氘代氨 等离子体增强化学气相沉积 杂质元素
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AI-assisted design of 3 D-printed prosthesis for integrated replacement of the hip,femur,and knee caused by osseous hydatidosis
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作者 Yanlong Han Haoyuan Lei +7 位作者 Ruozhen Jia Wei Zhao Habaxi Kaken Deli Wang Yongsheng Liu Zhen Tan Li Wang Changchun Zhou 《Bio-Design and Manufacturing》 2026年第1期94-99,I0017,共7页
Cases of widespread bone hydatid infection are relatively rare in clinical practice.In this study,we reported for the first time a validated integrated repair therapy for multiple bone tissues,including the hip,femur,... Cases of widespread bone hydatid infection are relatively rare in clinical practice.In this study,we reported for the first time a validated integrated repair therapy for multiple bone tissues,including the hip,femur,and knee,caused by echinococ cosis.Artificial intelligence(AI)was used to develop a targeted surgical plan and to design a personalized prosthesis.Finite element analysis(FEA)was used to optimize the mechanical effectiveness of a customized integrated replacement prosthesis and to model stress distribution in the surrounding bone.Three-dimensional(3 D)printing was used to fabricate a customized prosthesis.With the assistance of AI,FEA,and 3 D printing technology,a personalized surgical plan and customized prosthesis were successfully constructed based on the patient’s disease.This approach achieved a successful therapeutic effect,demonstrating that AI-assisted personalized medicine holds great promise for the future. 展开更多
关键词 develop targeted surgical plan optimize mechanical effectiveness AI assisted design D printed prosthesis design personalized prosthesisfinite element analysis fea bone tissuesincluding bone hydatid infection integrated repair therapy
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利用网络药理学和RWR方法揭示参麦注射液治疗结直肠癌潜在的分子作用机制
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作者 黎民钦 谭杰文 李勇 《现代检验医学杂志》 2026年第1期100-104,共5页
目的旨在利用网络药理学和重启随机游走(RWR)方法探究参麦注射液(SMI)作用于结直肠癌(CRC)的关键小分子化合物以及作用靶点。方法利用STRING数据库对SMI药物靶点基因和CRC相关基因进行蛋白质相互作用(PPI)网络的构建。以此靶点为seed基... 目的旨在利用网络药理学和重启随机游走(RWR)方法探究参麦注射液(SMI)作用于结直肠癌(CRC)的关键小分子化合物以及作用靶点。方法利用STRING数据库对SMI药物靶点基因和CRC相关基因进行蛋白质相互作用(PPI)网络的构建。以此靶点为seed基因,对PPI网络进行RWR分析。以RWR网络中亲和系数top50基因为基础,构建药物-有效成分-基因的相互作用网络,并对top50基因进行了基因本体论(GO)和京都基因与基因组百科全书(KEGG)富集分析。最后基于RSCB PDB数据库和Pub Chem数据库,使用Swiss Dock进行分子对接,使用Gromacs进行分子动力学模拟。结果GO和KEGG富集分析结果显示RWR网络中亲和系数top50基因显著富集在PI3K-Akt信号通路和活性跨膜转运蛋白活性等功能和通路上(P<0.05,q<0.05)。分子对接和分子动力学模拟验证了DNA拓扑异构酶Ⅱα(TopoismeruseⅡα)与麦冬黄烷酮D的稳定结合。结论基于网络药理学和RWR方法以及分子对接阐明了SMI治疗CRC的关键小分子化合物及其作用靶点,初步分析了SMI治疗CRC的分子机制,为SMI在CRC治疗中的应用提供了科学依据。 展开更多
关键词 网络药理学 参麦注射液 结直肠癌 DNA拓扑异构酶Ⅱα 麦冬黄烷酮D 重启随机游走
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基于随机振动仿真的空调室外机管路优化设计
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作者 刘煜 康玉勋 +1 位作者 夏凯 高辉 《环境技术》 2026年第1期68-74,共7页
针对某空调室外机管路在随机振动试验中出现的开裂问题,基于ANSYS Workbench仿真软件建立管路系统的模态与随机振动仿真模型,结合Miner线性累积损伤理论对管路结构进行损伤评估,评估结果与试验现象一致。基于随机振动仿真的方向变形结果... 针对某空调室外机管路在随机振动试验中出现的开裂问题,基于ANSYS Workbench仿真软件建立管路系统的模态与随机振动仿真模型,结合Miner线性累积损伤理论对管路结构进行损伤评估,评估结果与试验现象一致。基于随机振动仿真的方向变形结果,确定主导管路失效的关键固频,并以提升关键固频为目标制定优化方案。仿真结果表明,优化后管路的随机振动3σ(均值±3倍标准差)最大应力降低44%,损伤系数满足强度设计要求。最终通过测试,验证了方案的有效性。本文提出的仿真分析与优化方法可为空调随机振动下的管路设计优化提供参考。 展开更多
关键词 空调室外机 管路 随机振动 疲劳寿命 有限元仿真
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