期刊文献+
共找到22,720篇文章
< 1 2 250 >
每页显示 20 50 100
Pelvic floor dysfunction in patients with gestational diabetes mellitus 被引量:2
1
作者 Mustafa Arslan Ramazan Kozan 《World Journal of Diabetes》 2025年第2期1-4,共4页
In this editorial,we comment on an article by Wang et al.Recent literature shows an increase in research on pelvic organ prolapse(POP).Although the true incidence of POP remains uncertain,its impact on quality of life... In this editorial,we comment on an article by Wang et al.Recent literature shows an increase in research on pelvic organ prolapse(POP).Although the true incidence of POP remains uncertain,its impact on quality of life is substantial.Anatomical studies report high incidence rates,surpassing those observed in symptom-based surveys.Weakness of the endopelvic fascia is a primary anatomical risk factor for POP.Additionally,gestational diabetes mellitus(GDM)has emerged as a growing concern,as poor glycemic control increases complications for both mother and fetus.GDM and POP are interconnected,with factors like maternal obesity,macrosomia,and hormonal changes exacerbating pelvic floor dysfunction.Modifiable risk factors,such as obesity and chronic hyperglycemia,along with multiparity,instrumental deliveries,and obstetric trauma,further increase susceptibility.For patients with GDM,gynecological exams,Pelvic Organ Prolapse Quantification staging,and pelvic floor ultrasonography are valuable diagnostics,with proctological exams and magnetic resonance defecography aiding in multi-compartment prolapse diagnoses.Imaging,though uncomfortable during pregnancy,is safe in the early postpartum period.This editorial emphasizes the need for further research on the pathophysiology of GDM-related POP and offers recommendations for improving diagnosis and clinical management of patients with GDM. 展开更多
关键词 DEFECOGRAPHY Chronic hyperglycemia Gestational diabetes mellitus MULTIPARITY Pelvic floor ultrasonography Pelvic organ prolapse OBESITY
暂未订购
Sinicization and psychometric validation of the German Pelvic Floor Questionnaire for Pregnant and Postpartum Women
2
作者 ZHU Liping ZHOU Chengyu +2 位作者 LI Xuhong HOU Qiao YANG Shuo 《中南大学学报(医学版)》 北大核心 2025年第1期72-80,共9页
Objective:Pelvic floor dysfunction is common among pregnant and postpartum women and significantly impacts quality of life.This study aims to translate the German Pelvic Floor Questionnaire for Pregnant and Postpartum... Objective:Pelvic floor dysfunction is common among pregnant and postpartum women and significantly impacts quality of life.This study aims to translate the German Pelvic Floor Questionnaire for Pregnant and Postpartum Women into Chinese and to evaluate its reliability and validity in the Chinese population.Methods:The questionnaire was translated using the Brislin model.A cross-sectional study was conducted among pregnant and postpartum women to assess the content validity,construct validity,Cronbach’sαcoefficient,test-retest reliability,and split-half reliability of the Chinese version.Results:A total of 72 women were included,with 6.9% being pregnant and 93.1% postpartum;the age was(32.3±3.6)years.The Chinese version of the questionnaire contains 4 dimensions and 45 items.The content validity index of individual items ranged from 0.833 to 1.000,with a scale-level content validity index of 0.977 and intraclass correlation coefficients(ICCs)exceeding 0.90.The overall Cronbach’s α coefficient was 0.891,with subscale coefficients ranging from 0.732 to 0.884(all ICCs>0.70).The testretest reliability of the total scale was 0.833,and for the 4 dimensions,bladder,bowel,prolapse,and sexual function,the values were 0.776,0.579,0.732,and 0.645,respectively.The split-half reliability was 0.74.Conclusion:The Chinese version of the questionnaire demonstrated good reliability and validity,indicating its applicability in assessing pelvic floor dysfunction and associated risk factors during pregnancy and postpartum. 展开更多
关键词 pelvic floor dysfunction PREGNANCY postpartum women QUESTIONNAIRE RELIABILITY validity
暂未订购
Research on the design floor response spectrum of buildings by dynamic analysis
3
作者 Liu Rongheng Bai Wen +3 位作者 Dai Junwu Shao Zhipeng Jiang Tao Zhao Bingzhang 《Earthquake Engineering and Engineering Vibration》 2025年第2期413-436,共24页
The seismic design forces of nonstructural components(NSCs)in buildings are closely related to floor acceleration response amplification.To investigate the differences in acceleration responses of structures with diff... The seismic design forces of nonstructural components(NSCs)in buildings are closely related to floor acceleration response amplification.To investigate the differences in acceleration responses of structures with different structural types,fundamental periods,and seismic design levels,56 reinforced concrete and steel structures with fundamental periods ranging from 0.37 s to 5.68 s were selected.For each structure,100 sets of earthquake motions were used as inputs for elastic time history analysis.Based on the resulting 26,500 sets of floor acceleration response data,the amplification rules of peak floor acceleration/peak ground acceleration(PFA/PGA)along the height of various structures and the corresponding floor response spectrum characteristics were studied.The nonlinear changes of PFA/PGA along the height of long period structures were compared with the codes of different countries.Moreover,more suitable prediction equations were proposed based on the structural characteristics.Finally,to solve the issue that existing research still cannot accurately reflect the acceleration amplification coefficient of NSCs with different dynamic characteristics in main structures with different periods,a normalized floor response spectrum is proposed that can simultaneously consider the effects of input ground motion characteristics and the main structure,which can be better used in the seismic design of NSCs. 展开更多
关键词 floor acceleration amplification factor nonstructural components component amplification factor seismic design floor response spectrum
在线阅读 下载PDF
What's on Each Floor?
4
作者 Maria Chiu 《空中英语教室(初级版.大家说英语)》 2025年第6期34-35,54,共3页
Conversation A(in a department store)Sara:Department store directories are helpful.Sam:They are.Today,I have to buy new furniture and bedding for my apartment.They're on the sixth floor.
关键词 BEDDING FURNITURE department store store directories floor
原文传递
Individualized pelvic floor rehabilitation training on psychological and functional recovery in postpartum women with generalized anxiety disorder
5
作者 Cong-Ying Zhao Shu-Qing Han +1 位作者 Xian-Chai Peng Zhen-Hong Liu 《World Journal of Psychiatry》 2025年第6期118-127,共10页
BACKGROUND Postpartum women are at an increased risk of generalized anxiety disorder(GAD),which can negatively affect both mental health and physical recovery.Pelvic floor dysfunction,common in this population,can exa... BACKGROUND Postpartum women are at an increased risk of generalized anxiety disorder(GAD),which can negatively affect both mental health and physical recovery.Pelvic floor dysfunction,common in this population,can exacerbate psychological distress.Although pelvic floor rehabilitation is effective in physical recovery,its potential to improve psychological outcomes,especially in women with GAD,remains underexplored.AIM To evaluate the effectiveness of an individualized pelvic floor rehabilitation program in improving anxiety,pelvic floor function,and quality of life in postpartum women with GAD.METHODS A retrospective study was performed to analyze 80 postpartum women with GAD who completed a 12-week individualized pelvic floor rehabilitation program(January 2020-December 2024),combining supervised pelvic floor muscle training and psychological support.Primary outcomes were changes in GAD-7 and Hamilton anxiety rating scale(HAM-A)scores and pelvic floor function measured by surface electromyography(sEMG).Secondary outcomes included World Health Organization quality of life-BREF,pelvic floor symptom severity,and impact on daily activities(pelvic floor impact questionnaire).Assessments were conducted at baseline and 6 and 12 weeks during the intervention period.RESULTS Significant improvements were observed in anxiety measures,with mean GAD-7 scores decreasing from 14.8±3.2 at baseline to 8.2±2.9 at week 12(P<0.001)and HAM-A scores decreasing from 22.6±4.5 to 12.4±3.8(P<0.001).Pelvic floor function showed substantial enhancement,with sEMG amplitude increasing from 22.4±5.6μV to 35.9±6.8μV(P<0.001).Quality of life improved across all domains,with the most significant improvements in psychological(28.5%increase)and physical health(25.8%increase).Program adherence was 91.5%for the supervised sessions,and no serious adverse events were reported.CONCLUSION Individualized pelvic floor rehabilitation training effectively improves both psychological and functional outcomes in postpartum women with GAD.The high adherence and significant outcomes make this integrated approach feasible and effective. 展开更多
关键词 Generalized anxiety disorder Pelvic floor rehabilitation Postpartum care Physical therapy Mental health
暂未订购
Fault-Induced Floor Water Inrush in Confined Aquifers under Mining Stress: Mechanisms and Prevention Technologies—A State-of-the-Art Review
6
作者 Zhengzheng Cao Fangxu Guo +5 位作者 Wenqiang Wang Feng Du Zhenhua Li Shuaiyang Zhang Qixuan Wang Yongzhi Zhai 《Fluid Dynamics & Materials Processing》 2025年第10期2419-2442,共24页
With the depletion of shallow mineral resources,mining operations are extending to greater depths and larger scales,increasing the risk of water inrush disasters,particularly from confined aquifers intersected by faul... With the depletion of shallow mineral resources,mining operations are extending to greater depths and larger scales,increasing the risk of water inrush disasters,particularly from confined aquifers intersected by faults.This paper reviews the current state of research on fault-induced water inrushes in mining faces,examining the damage characteristics and permeability of fractured floor rock,the mechanical behavior of faults under mining stress,and the mechanisms driving water inrush.Advances in prevention technologies,risk assessment,and prediction methods are also summarized.Research shows that damage evolution in fractured floor rock,coupled with fluid-solid interactions,provides the primary pathways for water inrush.Stress-seepage coupling in porous media plays a decisive role in determining inrush potential.Mining-induced stress redistribution can activate faults,with parameters such as dip angle and internal friction angle controlling stress evolution and slip.Critical triggers include the hydraulic connectivity among faults,aquifers,and mining-induced fracture networks,followed by hydraulic erosion.A multi-pronged prevention framework has been developed,integrating precise fault detection,targeted grouting for water sealing,drainage to reduce water pressure,optimized waterproof coal pillar design,and dynamic risk assessment and prediction.However,gaps remain in understanding multi-physical field coupling under deep mining conditions,establishing quantitative criteria for fault activation-induced water inrush,and refining control technologies.Future work should focus on multi-scale numerical simulations,advanced active control measures,and intelligent,integrated prevention systems to clarify the mechanisms of fault-induced water inrush and enhance theoretical and technical support for mine safety. 展开更多
关键词 Water inrush mechanisms FAULTS floor strata damage and failure prevention and control technologies
在线阅读 下载PDF
Predicting floor heave risk in road tunnels with machine learning
7
作者 Xuefeng Ou Ye Zhou +5 位作者 Yong Kong Tongming Qu Shiquan Xu Wei Liao Cong Tang Xuemin Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第10期6428-6438,共11页
Floor heave is a common defect in mountainous tunnels.It is critical but challenging to predict the risk of floor heave,as traditional methods often fail to characterize this phenomenon effectively.This study proposes... Floor heave is a common defect in mountainous tunnels.It is critical but challenging to predict the risk of floor heave,as traditional methods often fail to characterize this phenomenon effectively.This study proposes a data-driven approach utilizing a support vector machine(SVM)optimized by the sparrow search algorithm(SSA)to address the issue.The model was developed and validated using a dataset collected from 100 tunnels.Shapley value analysis was conducted to identify the key features influencing floor heave defects.Moreover,a committee-based uncertainty quantification method is presented to evaluate the reliability of each prediction.The results show that:(1)Data feature engineering and SSA play pivotal roles in expediting the convergence of the SVM model.(2)Groundwater and high in situ stress are key factors contributing to tunnel floor heave.(3)In comparison to backpropagation(BP)neural networks,the SSA-SVM demonstrates superior robustness in handling imperfect and limited data.(4)The committee-based uncertainty quantification method is proven effective to evaluate the trustworthiness of each prediction.This data-driven surrogate model offers an effective strategy for understanding the factors that impact tunnel floor defects and accurately predicting tunnel floor heave deformation. 展开更多
关键词 floor heave Support vector machine(SVM) Sparrow search algorithm(SSA) Shapley value Uncertainty quantification
在线阅读 下载PDF
Numerical and Experimental Study of Thermal Storage Energy in a Building with Various Pipeline Design under Floor—Case Study
8
作者 Rafah H.Zaidan Najim A.Jasim 《Frontiers in Heat and Mass Transfer》 2025年第5期1595-1620,共26页
This paper presents a comprehensive experimental and numerical investigation of radiant floor heating(RFH)systems integrated with phase changematerial(PCM)-based thermal energy storage(TES).The study compares two unde... This paper presents a comprehensive experimental and numerical investigation of radiant floor heating(RFH)systems integrated with phase changematerial(PCM)-based thermal energy storage(TES).The study compares two underfloor pipe configurations:double serpentine and spiral.It also looks at how well a paraffin wax PCM system works with compact heat exchanger-type TES units during winter in Iraq.Key performance indicators including discharge temperature,heat transfer rate,liquid fraction evolution,and temperature uniformity were assessed through in situ experimental measurements and ANSYS fluent simulations.Results demonstrate that the spiral design provides slightly more uniform temperature distribution on the tile surface at an inlet water temperature of 55℃,with an average difference of approximately 0.5%,the serpentine layout exhibits higher slab temperature distribution by about 0.66%.Notably,the serpentine configuration shows superior thermal homogeneity and heat distribution,with a 15.05%increase in heat gain at a 55℃ inlet temperature compared to the spiral design.The performance gap between the two layouts narrows as the inlet temperature increases from 50℃ in 5℃ increments by approximately 4.1%,3.7%,and 1.7%,respectively.Higher inlet temperatures also improve PCM discharging and charging rates,improving energy storage utilization.The findings provide significant design guidelines for sustainable heating systems for cold climates. 展开更多
关键词 Radiant floor heating systems phase change materials(PCM) paraffin wax thermal energy storage experimental invistagation numerical thermal energy
在线阅读 下载PDF
Botulinum toxin type A injection combined with biofeedback in the treatment of spastic pelvic floor syndrome 被引量:4
9
作者 Fei-Fei Sun Yong-Qiang Chen +1 位作者 Zong-Lin Jiang Lin Ma 《World Journal of Clinical Cases》 SCIE 2024年第22期4905-4912,共8页
BACKGROUND Spastic pelvic floor syndrome(SPFS)is a refractory pelvic floor disease characterized by abnormal(uncoordinated)contractions of the external anal sphincter and puborectalis muscle during defecation,resultin... BACKGROUND Spastic pelvic floor syndrome(SPFS)is a refractory pelvic floor disease characterized by abnormal(uncoordinated)contractions of the external anal sphincter and puborectalis muscle during defecation,resulting in rectal emptation and obstructive constipation.The clinical manifestations of SPFS are mainly characterized by difficult defecation,often accompanied by a sense of anal blockage and drooping.Manual defecation is usually needed during defecation.From physical examination,it is commonly observed that the patient's anal muscle tension is high,and it is difficult or even impossible to enter with his fingers.AIM To investigate the characteristics of anorectal pressure and botulinum toxin A injection combined with biofeedback in treating pelvic floor muscle spasm syndrome.METHODS Retrospective analysis of 50 patients diagnosed with pelvic floor spasm syndrome.All patients underwent pelvic floor surface electromyography assessment,anorectal dynamics examination,botulinum toxin type A injection 100 U intramuscular injection,and two cycles of biofeedback therapy.RESULTS After the botulinum toxin A injection combined with two cycles of biofeedback therapy,the patient's postoperative resting and systolic blood pressure were significantly lower than before surgery(P<0.05).Moreover,the electromyography index of the patients in the resting stage and post-resting stages was significantly lower than before surgery(P<0.05).CONCLUSION Botulinum toxin A injection combined with biofeedback can significantly reduce pelvic floor muscle tension in treating pelvic floor muscle spasm syndrome.Anorectal manometry is an effective method to evaluate the efficacy of treatment objectively.However,randomized controlled trials are needed. 展开更多
关键词 Spastic pelvic floor syndrome Botulinum toxin A BIOFEEDBACK Anorectal pressure measurement Agachan constipation score
暂未订购
Curative effect of hydrogen peroxide combined with silver ion disinfection on pelvic floor dysfunction 被引量:1
10
作者 Wei Zhou Hua Guo 《World Journal of Clinical Cases》 SCIE 2024年第21期4508-4517,共10页
BACKGROUND Pelvic floor dysfunction(PFD)is related to muscle fiber tearing during childbirth,negatively impacting postpartum quality of life of parturient.Appropriate and effective intervention is necessary to promote... BACKGROUND Pelvic floor dysfunction(PFD)is related to muscle fiber tearing during childbirth,negatively impacting postpartum quality of life of parturient.Appropriate and effective intervention is necessary to promote PFD recovery.AIM To analyze the use of hydrogen peroxide and silver ion disinfection for vaginal electrodes in conjunction with comprehensive rehabilitation therapy for postpartum women with PFD.METHODS A total of 59 women with PFD who were admitted to the hospital from May 2019 to July 2022 were divided into two groups:Control group(n=27)received comprehensive rehabilitation therapy and observation group(n=32)received intervention with pelvic floor biostimulation feedback instrument in addition to comprehensive rehabilitation therapy.The vaginal electrodes were disinfected with hydrogen peroxide and silver ion before treatment.Intervention for both groups was started 6 weeks postpartum,and rehabilitation lasted for 3 months.Pelvic floor muscle voltage,pelvic floor muscle strength,vaginal muscle voltage,vaginal muscle tone,pelvic floor function,quality of life,and incidence of postpartum PFD were compared between the two groups.RESULTS Before comprehensive rehabilitation treatment,basic data and pelvic floor function were not significantly different between the two groups.After treatment,the observation group showed significant improvements in the maximum voltage and average voltage of pelvic floor muscles,contraction time of type I and type II fibers,pelvic floor muscle strength,vaginal muscle tone,vaginal muscle voltage,and quality of life(GQOLI-74 reports),compared with the control group.The observation group had lower scores on the pelvic floor distress inventory(PFDI-20)and a lower incidence of postpartum PFD,indicating the effectiveness of the pelvic floor biostimulation feedback instrument in promoting the recovery of maternal pelvic floor function.CONCLUSION The combination of the pelvic floor biostimulation feedback instrument and comprehensive rehabilitation nursing can improve pelvic floor muscle strength,promote the recovery of vaginal muscle tone,and improve pelvic floor function and quality of life.The use of hydrogen peroxide and silver ion disinfectant demonstrated favorable antibacterial efficacy and is worthy of clinical application. 展开更多
关键词 Pelvic floor biostimulation feedback instrument Comprehensive rehabilitation therapy Postpartum pelvic floor dysfunction Vaginal electrode Disinfection with hydrogen peroxide and silver ion Nanocolloidal silver
暂未订购
Prediction of Sound Transmission Loss of Vehicle Floor System Based on 1D-Convolutional Neural Networks 被引量:1
11
作者 Cheng Peng Siwei Cheng +3 位作者 Min Sun Chao Ren Jun Song Haibo Huang 《Sound & Vibration》 EI 2024年第1期25-46,共22页
The Noise,Vibration,and Harshness(NVH)experience during driving is significantly influenced by the sound insulation performance of the car floor acoustic package.As such,accurate and efficient predictions of its sound... The Noise,Vibration,and Harshness(NVH)experience during driving is significantly influenced by the sound insulation performance of the car floor acoustic package.As such,accurate and efficient predictions of its sound insulation performance are crucial for optimizing related noise reduction designs.However,the complex acoustic transmission mechanisms and difficulties in characterizing the sound absorption and insulation properties of the floor acoustic package pose significant challenges to traditional Computer-Aided Engineering(CAE)methods,leading to low modeling efficiency and prediction accuracy.To address these limitations,a hierarchical multiobjective decomposition system for predicting the sound insulation performance of the floor acoustic package has been developed based on an analysis of the noise transmission path.This approach involves introducing a 1D-Convolutional Neural Network(1D-CNN)model for predicting the sound insulation performance of the floor acoustic package,thereby avoiding the limitations of conventional CAE approaches that rely solely on“data-driven”methods.The proposed method was applied and tested using specific vehicle models,and the results demonstrated the effectiveness and superiority of the proposed approach relative to those obtained using 2D-CNN and Support Vector Regression(SVR)models. 展开更多
关键词 Noise vibration and harshness car floor acoustic package sound transmission loss PREDICTION convolutional neural networks
在线阅读 下载PDF
Restraint effect of partition wall on the tunnel floor heave in layered rock mass
12
作者 YANG Yunyun HUANG Da +2 位作者 ZHONG Zhu LIU Yang PENG Jianbing 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2462-2479,共18页
The presence of horizontal layered rocks in tunnel engineering significantly impacts the stability and strength of the surrounding rock mass,leading to floor heave in the tunnel.This study focused on preparing layered... The presence of horizontal layered rocks in tunnel engineering significantly impacts the stability and strength of the surrounding rock mass,leading to floor heave in the tunnel.This study focused on preparing layered specimens of rock-like material with varying thickness to investigate the failure behaviors of tunnel floors.The results indicate that thin-layered rock mass exhibits weak interlayer bonding,causing rock layers near the surface to buckle and break upwards when subjected to horizontal squeezing.With an increase in the layer thickness,a transition in failure mode occurs from upward buckling to shear failure along the plane,leading to a noticeable reduction in floor heave deformation.The primary cause of significant deformation in floor heave is upward buckling failure.To address this issue,the study proposes the installation of a partition wall in the middle of the floor to mitigate heave deformation of the rock layers.The results demonstrate that the partition wall has a considerable stabilizing effect on the floor,reducing the zone of buckling failure and minimizing floor heave deformation.It is crucial for the partition wall to be sufficiently high to prevent buckling failure and ensure stability.Through simulation calculations on an engineering example,it is confirmed that implementing a partition wall can effectively reduce floor heave and enhance the stability of tunnel floor. 展开更多
关键词 Layered rock floor heave Horizontal compression test Failure behavior Partition wall
原文传递
A clinical trial on pelvic floor sensory testing in women with and without stress urinary incontinence
13
作者 ZHANG Xiulan ZHOU Chengyu +5 位作者 YAN Wenguang LI Xuhong WANG Zhaojun ZHOU Yanhua XIE Fen FAN Shuai 《中南大学学报(医学版)》 CSCD 北大核心 2024年第12期1919-1926,共8页
Objective:Pelvic floor sensory training is commonly used in clinical practice for the treatment of stress urinary incontinence(SUI);however,there is a lack of comparative studies evaluating pelvic floor sensation betw... Objective:Pelvic floor sensory training is commonly used in clinical practice for the treatment of stress urinary incontinence(SUI);however,there is a lack of comparative studies evaluating pelvic floor sensation between women with SUI and healthy controls.Additionally,normative data for two-point discrimination thresholds in the female pelvic floor region remain scarce.This study aims to compare the results of 4 sensory tests in the pelvic floor region between women with mild SUI and healthy women,in order to provide reference values for two-point discrimination thresholds in this area.Methods:From April 1 to October 30,2023,108 healthy women[(32.5±3.6)years]and 90 women with mild SUI[(32.9±3.3)years]were recruited from the Third Xiangya Hospital,Central South University.Participants underwent 4 sensory tests in the pelvic floor region:Two-dot discrimination,weight perception,shape recognition,and 9-grid localization.The results were compared between the 2 groups.Results:Compared with healthy women,those with mild SUI had lower sensitivity and higher thresholds in 2-dot discrimination tests in the pelvic floor region(all P<0.001).No significant differences were found between groups in weight perception,shape recognition,or grid localization tests(P>0.05).Conclusion:Women with mild stress urinary incontinence have impaired two-point discrimination ability in the pelvic floor region. 展开更多
关键词 stress urinary incontinence pelvic floor sensation two-point discrimination test mode of delivery pelvic floor rehabilitation
暂未订购
我国不同类别煤层底板水害致灾机理与防控远景导向 被引量:10
14
作者 曾一凡 朱慧聪 +9 位作者 武强 王厚柱 傅先杰 王铁记 王玺瑞 樊九林 胡荣杰 才向军 阚雪冬 高生保 《煤炭学报》 北大核心 2025年第2期1073-1099,共27页
我国成煤条件苛刻,赋煤环境复杂多变,资源呈全域性跨多地质类型、点散式分布,导致回采共(伴)生地质灾害频现。同时,伴随煤炭资源开发布局优化调控,煤层底板水害负面导向性越趋显著,高承压水水力驱动及强敏感性缺陷构造活化的协同作用导... 我国成煤条件苛刻,赋煤环境复杂多变,资源呈全域性跨多地质类型、点散式分布,导致回采共(伴)生地质灾害频现。同时,伴随煤炭资源开发布局优化调控,煤层底板水害负面导向性越趋显著,高承压水水力驱动及强敏感性缺陷构造活化的协同作用导致煤层底板水害宏观动力学表象威胁性显著提升,成为我国煤炭资源高质量转型发展的内生阻力。为全方位掌握我国煤层底板水害发展形势,探讨未来基于新技术开展防控作业的重点攻关方向,从时间、空间、突水量等多维视角下全方位展示了近年来我国煤层底板水害动态演变趋势,对类型进行了“总−分”式细划,并通过建立地质力学模型探讨了我国煤层底板水害力学互馈响应机制,基于灾害宏观表象等揭示了其内生致灾机理,指出了防控技术理念的新发展路径和远景导向。研究发现:统计分析了我国煤层底板水害多维视角下的演变规律和特征,探讨建立了我国煤层底板水害主体架构,依据事故核心致因体系及宏观致灾表象等将煤层底板水害划分为岩溶陷落柱突水、断层活化突水及裂隙导升(复合)灰岩水突涌3大类,进一步细化为全路径贯通增量导升型突水(岩溶陷落柱)、贯穿煤层型突水(断层)、单层随采卸荷直接型突水(裂隙)等12个子类,并针对性的独立分析了3个大类煤层底板水害地理空间分布规律;分析了地应力和承压水水压对岩溶陷落柱突水过程承压水导升路径异化发育作用机制,提出了覆岩顶板动/静载扰动诱发底板岩溶陷落柱突水模式,阐明了其力学启动条件及致灾机理;建立了煤层底板断层宏细观地质力学构造概化模型,基于诱发断层活化突水的核心致灾诱因识别并建立了不同类别煤层底板断层活化突水力学判据;以裂隙为基础单元,“由1至n”式建立了单一层位和复合层位承压含水层诱发裂隙型导升(复合)灰岩水突涌的临界判别条件,揭示了该类型底板水害全过程致灾机理;在总结现行煤层底板水害探查、预测及控制技术理念基础上,结合前沿发展方向,指出并建议在煤层底板本底地质基因的全生命周期采动诱变特征三维动态重构、适用于时空分异动态地质环境的煤层底板突水预测预报理念升级、低扰动强干预的随采随治保/控水互馈注浆治理技术应用、修复后地质生态系统长效监控诊断诊疗平台建立等方面展开攻关,构建煤层底板水害全时空防控大体系,紧跟新质生产力大背景下全煤行业新业态发展步伐。 展开更多
关键词 矿井水防治 底板水害 岩溶陷落柱 断层 致灾机理
在线阅读 下载PDF
松辽盆地齐家—古龙凹陷青山口组油层顶底板封闭性及对页岩油的保存作用 被引量:3
15
作者 李军辉 刘伟 +4 位作者 苏杨鑫 曾旭 付秀丽 关铭 李书现 《天然气地球科学》 北大核心 2025年第2期209-220,共12页
保存条件对于页岩油气滞留聚集至关重要,是保障页岩地层蓄积充足能量和油气有效流动的关键。顶底板封闭性优劣直接影响着页岩气的富集和空间分布,但对页岩油层是否同样重要仍不清楚。以古龙页岩油作为研究对象,在顶底板矿物岩石学、致... 保存条件对于页岩油气滞留聚集至关重要,是保障页岩地层蓄积充足能量和油气有效流动的关键。顶底板封闭性优劣直接影响着页岩气的富集和空间分布,但对页岩油层是否同样重要仍不清楚。以古龙页岩油作为研究对象,在顶底板矿物岩石学、致密化过程、物性及孔隙结构等分析基础上,结合突破压力测试和测井预测结果,探讨古龙页岩油顶底板封闭能力。结果显示:顶板主要为深湖—半深湖相泥页岩,渗透率更低、孔隙主体孔径更小、突破压力更高,平面上高值区主要分布在凹陷中部和南部地区,低值区与上覆高台子油藏储量区有较好的一致性;底板沉积三角洲相或浅湖相砂岩、粉砂岩和泥岩,孔、渗略高于顶板、孔隙主体孔径为介孔—大孔、突破压力更小,平面上高值区主要分布在凹陷中部地区,低值区与下覆扶余油藏储量区有较好的匹配性。古龙页岩油层顶底板突破压力高,具有较强封闭能力,突破压力高值分布区对应于页岩油高产区。优质顶底板是富含轻质组分古龙页岩油原位滞留富集的关键因素之一,研究成果可望为古龙页岩油的选区定井提供科学指导。 展开更多
关键词 古龙页岩油 顶底板 岩相 突破压力 保存条件
原文传递
Mechanism of rockburst induced by the microseismic event in the floor strata of high tectonic stress zones:A case study
16
作者 Songwei Wang Anye Cao +5 位作者 Changbin Wang Wenhao Guo Chengchun Xue Jian-gang Liu Xuesong Wu Gangsheng Shi 《International Journal of Coal Science & Technology》 CSCD 2024年第6期1-15,共15页
With the increase of mining scope,rockburst occurs frequently,but its generation mechanism has not been understood comprehensively.Based on a rockburst in the coal pillar area of high tectonic stress zones(HTSZs),this... With the increase of mining scope,rockburst occurs frequently,but its generation mechanism has not been understood comprehensively.Based on a rockburst in the coal pillar area of high tectonic stress zones(HTSZs),this study analyzed the distribution characteristics of large-energy microseismic(MS)events by using data statistics.The mechanical cause of the MS event that induced the rockburst was revealed by means of seismic moment tensor inversion.On this basis,by using numerical simulation,this study explored the distribution characteristics of static load in rockburst area and the effect of dynamic load in the floor,and then proposed the rockburst mechanism.The results show that under the squeezing action,the floor strata in HTSZs implode and transmit energy outward in the form of stress waves.This causes the cumulative damage and stress of the coal body in the fast track of coal pillar area increase in a short time.Since the coal in this area has already been in the critical stress state,small stress changes may lead to coal failure and rockburst.In this case of rockburst,the high static load of coal is the main force source,and the dynamic load plays a role in increasing coal body damage and inducing rockburst.Combined with seismic moment tensor inversion and numerical simulation,this paper proposes a rockburst research scheme,which makes the simulation of dynamic load more reasonable.The results provide the theoretical basis for rockburst control under similar conditions. 展开更多
关键词 High tectonic stress floor seismic source Microseismic monitoring Mechanism of rockburst
在线阅读 下载PDF
Digital Twin of the Female Pelvic Floor
17
作者 Vladimir Egorov 《Open Journal of Obstetrics and Gynecology》 2024年第11期1687-1694,共8页
Digital twin technology, originally developed for intricate physical systems, holds great potential in women’s healthcare, particularly in the management of pelvic floor disorders. This paper delves into the developm... Digital twin technology, originally developed for intricate physical systems, holds great potential in women’s healthcare, particularly in the management of pelvic floor disorders. This paper delves into the development of a digital twin specifically for the female pelvic floor, which can amalgamate various data sources such as imaging, biomechanical assessments, and patient-reported outcomes to offer personalized diagnostic and therapeutic insights. Through the utilization of 3D modeling and machine learning, the digital twin may facilitate precise visualization, prediction, and individualized treatment planning. Nevertheless, it is crucial to address the ethical and practical challenges related to data privacy and ensuring fair access. As this technology progresses, it has the potential to revolutionize gynecological and obstetric care by enhancing diagnostics, customizing treatments, and increasing patient involvement. 展开更多
关键词 Digital Twin Female Pelvic floor INCONTINENCE PROLAPSE Pelvic Pain Endometriosis ADENOMYOSIS Uterine Fibroids Maternal Injury during Childbirth Spontaneous Preterm Birth
在线阅读 下载PDF
曲线隅撑和柱端滑移摩擦节点单层钢框架的抗震性能研究 被引量:1
18
作者 李成玉 杨草原 +1 位作者 贾良玖 陈焰周 《工程力学》 北大核心 2025年第3期113-127,共15页
基于损伤控制概念,提出了一种配置曲线隅撑和柱端滑移摩擦连接的新型梁贯通式分层装配式钢框架体系。在地震作用中,曲线隅撑作为结构的第一道“保险丝”,先发生塑性变形,柱端滑移摩擦连接作为结构的第二道“保险丝”,既可避免梁柱等主... 基于损伤控制概念,提出了一种配置曲线隅撑和柱端滑移摩擦连接的新型梁贯通式分层装配式钢框架体系。在地震作用中,曲线隅撑作为结构的第一道“保险丝”,先发生塑性变形,柱端滑移摩擦连接作为结构的第二道“保险丝”,既可避免梁柱等主要构件出现塑性损伤,又能实现结构在地震作用下损伤时序的“稳定、渐进、可控”。设计并制作了2个1/2缩尺的单层钢框架试件,其中第一个试件的柱脚为盖板式滑移摩擦节点(CPSFJ),柱顶为L形连接件滑移摩擦节点(LCSFJ);第二个试件柱顶在第一个试件的基础上配置了曲线隅撑。对两个试件进行了拟静力循环加载试验。结果表明,柱端滑移摩擦节点能有效降低主体结构的塑性损伤,实现框架结构的低损伤;曲线隅撑的钢框架试件较未配置隅撑的钢框架具有更高的初始刚度、承载能力和更优的耗能能力,加载过程中隅撑先于节点转动进入塑性,塑性损伤主要集中在曲线隅撑、CPSFJ盖板和LCSFJ连接件上,梁柱等主要构件均未发生损伤,设置这些节点的框架能够在震后快速修复。 展开更多
关键词 分层装配 损伤控制 滑移摩擦节点 曲线隅撑 损伤时序 抗震性能
在线阅读 下载PDF
Basic Characteristics of an Appropriate Waste Fillers for Solvent Free and Water-Borne Industrial Polymer Floors and Their Utilization
19
作者 Jana Kosikova 《Journal of Civil Engineering and Architecture》 2024年第3期141-147,共7页
Recently the manufacture of epoxy coating and flooring materials begun to be under strong pressure to use more environmentally friendly raw materials in its composition.First tendency to reduce of solvents and diluent... Recently the manufacture of epoxy coating and flooring materials begun to be under strong pressure to use more environmentally friendly raw materials in its composition.First tendency to reduce of solvents and diluents contained in the materials appeared at the end of 90´s.This situation was supported by the Council of Europe in 2004 to reduce VOC emissions to zero till 2020.Solvent materials were thus largely replaced by solvent free materials from which the volatile substances are not released into the air.But pressure continued to increase,and over the past decade began to take centre stage water-based epoxy.On the Czech market solvent based material is still occasionally used,but predominant are solvent free materials.There are no commonly used materials containing wastes as fillers in new water-borne and solvent-free epoxy materials.Characteristics identification of the waste material as a potential filler is a set of properties that determine the limits of secondary raw materials or waste as a filler.This paper describes the basic characteristics which must be selected to meet the requirements,to affect negatively the workability,sedimentation,properties and behavior of the final floor system.Some materials must comply with special requirements,such as resistance to chemicals,etc.Next part of paper talks about utilization of polymer floors and their mechanical properties. 展开更多
关键词 Industrial polymer flooring materials waster fillers building materials
在线阅读 下载PDF
深井切顶留巷底鼓机制及其防控 被引量:1
20
作者 华心祝 李琛 +3 位作者 刘啸 杨朋 陈登红 祁亚宝 《岩土力学》 北大核心 2025年第3期955-968,共14页
沿空切顶巷道所处应力环境复杂、留巷服务期长,一次采动及留巷期间底鼓问题突出。以淮南丁集煤矿1462(1)轨顺切顶留巷条件为工程研究背景,建立离散元数值计算模型,分析得到一次采动至留巷稳定阶段底板非对称变形特征及其受力状态。构建... 沿空切顶巷道所处应力环境复杂、留巷服务期长,一次采动及留巷期间底鼓问题突出。以淮南丁集煤矿1462(1)轨顺切顶留巷条件为工程研究背景,建立离散元数值计算模型,分析得到一次采动至留巷稳定阶段底板非对称变形特征及其受力状态。构建一次采动至留巷稳定阶段两端固支二次超静定底板梁力学模型,并引入等效载荷概念求解得到了各分布力作用下底板挠度数学表达式,运用叠加原理推导出切顶留巷底板变形表达式。结合留巷条件,求得该巷道平均底鼓量为0.74 m,最大底鼓量为0.77 m,最大鼓起位置偏向采空区侧,距巷中1.15 m,计算结果与现场实测和数值计算结果较为吻合。依据所求得的底板变形表达式,分析了留巷底鼓影响因素,底鼓量与底板刚度的增加呈负指数减小,底板刚度在5~13 MN·m^(2)之间内变化时,巷道底鼓对其变化较为敏感;与底板载荷、支架载荷、煤帮载荷及应力集中系数λ均呈线性正相关,增长率分别为0.0826、0.0349、0.0272 m/MPa和0.007 m。基于对留巷底板受力变形及其影响因素的分析,提出了“顶底互控、帮角加固、底板强化”的防控对策。工程实践表明,相较于留巷初期底板变形得以有效控制,底鼓降幅明显,所留巷道能够满足复用要求。 展开更多
关键词 底鼓机制 沿空留巷 切顶卸压 底鼓防控
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部