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The burden of upper motor neuron involvement is correlated with the bilateral limb involvement interval in patients with amyotrophic lateral sclerosis:a retrospective observational study
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作者 Jieying Wu Shan Ye +2 位作者 Xiangyi Liu Yingsheng Xu Dongsheng Fan 《Neural Regeneration Research》 SCIE CAS 2025年第5期1505-1512,共8页
Amyotrophic lateral sclerosis is a rare neurodegenerative disease characterized by the involvement of both upper and lower motor neurons.Early bilateral limb involvement significantly affects patients'daily lives ... Amyotrophic lateral sclerosis is a rare neurodegenerative disease characterized by the involvement of both upper and lower motor neurons.Early bilateral limb involvement significantly affects patients'daily lives and may lead them to be confined to bed.However,the effect of upper and lower motor neuron impairment and other risk factors on bilateral limb involvement is unclear.To address this issue,we retrospectively collected data from 586 amyotrophic lateral sclerosis patients with limb onset diagnosed at Peking University Third Hospital between January 2020 and May 2022.A univariate analysis revealed no significant differences in the time intervals of spread in different directions between individuals with upper motor neuron-dominant amyotrophic lateral sclerosis and those with classic amyotrophic lateral sclerosis.We used causal directed acyclic graphs for risk factor determination and Cox proportional hazards models to investigate the association between the duration of bilateral limb involvement and clinical baseline characteristics in amyotrophic lateral sclerosis patients.Multiple factor analyses revealed that higher upper motor neuron scores(hazard ratio[HR]=1.05,95%confidence interval[CI]=1.01–1.09,P=0.018),onset in the left limb(HR=0.72,95%CI=0.58–0.89,P=0.002),and a horizontal pattern of progression(HR=0.46,95%CI=0.37–0.58,P<0.001)were risk factors for a shorter interval until bilateral limb involvement.The results demonstrated that a greater degree of upper motor neuron involvement might cause contralateral limb involvement to progress more quickly in limb-onset amyotrophic lateral sclerosis patients.These findings may improve the management of amyotrophic lateral sclerosis patients with limb onset and the prediction of patient prognosis. 展开更多
关键词 amyotrophic lateral sclerosis bilateral limb involvement Cox proportional hazards regression model horizontal spread restricted cubic spline analysis time interval upper motor neuron vertical spread
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How the Brain Process Stimulus-Response Conflict? New Insights from Lateralized Readiness Potentials Scalp Topography and Reaction Times
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作者 Marc E. Lavoie Johannes E. A. Stauder 《Journal of Behavioral and Brain Science》 2013年第1期150-155,共6页
Stimulus-Response Compatibility (SRC) refers to the fact that some tasks are performed easier and better than others because of the way stimuli and responses are paired with each other. To assess the brain responses t... Stimulus-Response Compatibility (SRC) refers to the fact that some tasks are performed easier and better than others because of the way stimuli and responses are paired with each other. To assess the brain responses to stimulus-response conflicts, we investigated the behavioral (accuracy and Reaction Times: RTs) as well as the physiological response (Lateralized Readiness Potentials: LRP) modulations in a positional blocked and a conditional mixed design in twelve university students. Results revealed that the performance was less accurate and the RTs, as well as the LRP onset, were delayed under the mixed conditional design. A greater compatibility effect was also noted on accuracy, RTs and LRP onset latency in the mixed design. Consistent with these findings, smaller peak activation at fronto-central areas suggests that more selective inhibition is needed in a mixed design context. Despite a smaller activation, the topographical distribution is similar in both designs. These results indicate that the translation time between stimulus- and response codes are greater under the mixed instruction, while the similar LRP topography suggests that common neural structures underlie LRPs in response to both type of designs. 展开更多
关键词 lateralized READINESS POTENTIALS Mixed-Blocked Designs STIMULUS Response-Compatibility Reaction times
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基于多交叉置换扩增和纳米生物传感技术快速检测肺炎支原体方法的建立
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作者 肖飞 郑宝英 +8 位作者 徐文健 伏瑾 黄小兰 孙春荣 贾楠 张裕 许峥 周娟 王毅 《遵义医科大学学报》 2024年第5期513-521,共9页
目的建立一种简单、灵敏、快速的肺炎支原体(MP)检测方法,并对其应用性进行验证和评价。方法利用多交叉置换扩增(MCDA)技术对肺炎支原体特异基因CARDS毒素基因进行扩增,利用侧流免疫层析生物传感(LFB)技术读取扩增结果,命名该方法为MP-M... 目的建立一种简单、灵敏、快速的肺炎支原体(MP)检测方法,并对其应用性进行验证和评价。方法利用多交叉置换扩增(MCDA)技术对肺炎支原体特异基因CARDS毒素基因进行扩增,利用侧流免疫层析生物传感(LFB)技术读取扩增结果,命名该方法为MP-MCDA-LFB。分析扩增反应在60~67℃(间隔1℃)的扩增效率,筛选最适反应温度;分析分别扩增10、20、30、40 min时能够检测到的最低核酸浓度,筛选最佳反应时间。利用10倍系列稀释的肺炎支原体核酸分析MP-MCDA-LFB方法的灵敏度和检测限,利用35株非肺炎支原体菌株分析MP-MCDA-LFB方法的特异性。利用MP-MCDA-LFB方法检测80份疑似MP感染的临床样本,并与RT-PCR法检测结果进行比较,分析MP-MCDA-LFB方法的临床应用性。结果MP-MCDA-LFB能够实现对肺炎支原体CARDS毒素基因的快速检测。其最佳反应温度为63℃,最短反应时间为40 min,整个检测过程可在1 h内。MP-MCDA-LFB方法具有较高的灵敏度和特异性,其检测限低至45 ng/L,与其他临床表现相似的病原体无交叉反应,特异性为100%。MP-MCDA-LFB方法从80份临床样本中检出45份阳性样本(56.3%),检出率与RT-PCR方法一致。结论本研究建立的以CARDS毒素基因为靶标的MP-MCDA-LFB检测方法具有简单、快速、灵敏度高、特异性强的优点,在基层医疗机构和现场检测具有较好的应用潜力。 展开更多
关键词 肺炎支原体 多交叉置换扩增技术 侧流免疫层析生物传感技术 CARDS毒素基因 RT-PCR
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基于时程分析法的中美隔震设计对比研究
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作者 张蜀泸 张志军 +1 位作者 李嘉琪 罗秀 《四川建筑科学研究》 2024年第2期16-24,共9页
介绍了中国《建筑隔震设计标准》(GB/T 51408—2021)(以下简称《隔标》)和美国Minimum design loads and associated criteria for buildings and other structures(ASCE 7-16)隔震设计的相关要求,并针对基于《建筑抗震设计规范》(GB 50... 介绍了中国《建筑隔震设计标准》(GB/T 51408—2021)(以下简称《隔标》)和美国Minimum design loads and associated criteria for buildings and other structures(ASCE 7-16)隔震设计的相关要求,并针对基于《建筑抗震设计规范》(GB 50011—2010)(2016年版)(以下简称《抗规》)设计的某9度区近场隔震结构,进行了两国规范的设计对比。按《抗规》设计的隔震结构,仍然能满足《隔标》的设计要求。ASCE 7-16对于隔震支座考虑了老化和环境、测试、制造等因素引起的性能参数变化,并按隔震支座的上限及下限属性进行了结构设计。基于相同地震概率水准(50年超越概率2%)的设计对比研究表明,ASCE 7-16的等效侧力法计算值高于《隔标》,按ASCE 7-16要求选择的地震波反应谱明显高于《隔标》,其时程分析结果也大于中国规范,对隔震支座的性能要求更高。 展开更多
关键词 隔震设计 上、下限属性 时程分析法 等效侧力法
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基于RPA的病原体快速诊断策略
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作者 许淑莹 王冬梅 欧阳松应 《福建师范大学学报(自然科学版)》 CAS 北大核心 2024年第1期34-44,共11页
重组酶聚合酶扩增(recombinase enzyme polymerase amplification,RPA)检测技术是2006年出现的一种等温核酸扩增检测技术。RPA所需引物设计简单,反应时间短,在37~42℃下仅需15~20 min即可达到病原体检测水平,搭配便捷装置即可实现核酸检... 重组酶聚合酶扩增(recombinase enzyme polymerase amplification,RPA)检测技术是2006年出现的一种等温核酸扩增检测技术。RPA所需引物设计简单,反应时间短,在37~42℃下仅需15~20 min即可达到病原体检测水平,搭配便捷装置即可实现核酸检测,近些年得到快速发展。重点介绍了RPA反应产物检测的相关策略,并对RPA在致病菌、病毒以及寄生虫上的快速诊断应用研究进行述评。 展开更多
关键词 等温扩增 重组酶聚合酶扩增 侧向流动 实时荧光检测 病原体检测
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基于预瞄时间自调整控制智能车辆横向轨迹跟踪研究
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作者 郭子奇 张昕 +1 位作者 马昕池 张宏远 《车辆与动力技术》 2024年第2期34-39,共6页
提出了一种基于预瞄时间自调整控制的四轮转向(4ws)智能车辆横向轨迹跟踪算法.针对轨迹跟踪精度问题,建立了预瞄时间自调整控制驾驶员模型,调整预瞄时间,采用滑模控制对前轮进行控制.针对跟踪过程中行驶稳定性较差等问题,后轮转向采用... 提出了一种基于预瞄时间自调整控制的四轮转向(4ws)智能车辆横向轨迹跟踪算法.针对轨迹跟踪精度问题,建立了预瞄时间自调整控制驾驶员模型,调整预瞄时间,采用滑模控制对前轮进行控制.针对跟踪过程中行驶稳定性较差等问题,后轮转向采用横摆角速度反馈控制策略.在Carsim与Simulink联合仿真平台下进行单移线工况下的仿真,仿真结果表明:预瞄时间自调整控制在低速时的跟踪精度比固定预瞄时间控制提升55%,高速时提升5%.后轮转向采用横摆角速度反馈控制的质心侧偏角比采用前馈控制在低速时减小了21%,高速时减少了54%,验证了所提出的控制算法,提高了转向过程中的行驶稳定性和横向轨迹跟踪能力. 展开更多
关键词 四轮转向 预瞄时间自调整 反馈控制 横向轨迹跟踪
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高血压脑出血患者应用经侧裂显微手术治疗的效果
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作者 丁涛 谢民 《中国卫生标准管理》 2024年第11期70-73,共4页
目的对比高血压脑出血患者实施经侧裂显微手术与小骨窗开颅手术的效果。方法选取2022年8月—2023年8月兰州大学第一医院神经外科诊治的50例高血压脑出血患者,随机数字表法分为2组,各25例。参照组实施小骨窗开颅手术治疗,试验组实施经侧... 目的对比高血压脑出血患者实施经侧裂显微手术与小骨窗开颅手术的效果。方法选取2022年8月—2023年8月兰州大学第一医院神经外科诊治的50例高血压脑出血患者,随机数字表法分为2组,各25例。参照组实施小骨窗开颅手术治疗,试验组实施经侧裂显微手术治疗。比较2组患者的手术指标、临床疗效及术后并发症发生情况。结果试验组患者手术时间(92.41±8.57)min、术后苏醒时间(6.34±1.25)h及住院时间(12.86±1.74)d,均短于参照组(124.65±12.39)min、(8.72±1.87)h、(16.25±2.38)d(P<0.05)。试验组手术造成的出血量为(80.34±6.57)mL,低于参照组的(152.85±10.84)mL(P<0.05)。试验组手术总有效率(100%)优于参照组(84.00%)(P<0.05)。试验组术后并发症发生率(4.00%)低于参照组(28.00%)(P<0.05)。结论经侧裂显微手术用于治疗高血压脑出血取得的临床疗效相比于小骨窗开颅手术更显著,可降低手术出血量,缩短手术时间,术后并发症相对较少。 展开更多
关键词 高血压脑出血 经侧裂显微手术 小骨窗开颅手术 临床疗效 并发症 苏醒时间
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预制T梁架设阶段横向温度梯度作用侧向变形研究
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作者 郭宝君 陈鹏 +2 位作者 贺君 武楠蕾 张飞宇 《世界桥梁》 北大核心 2024年第2期74-80,共7页
为控制大跨预制混凝土T梁架设阶段由横向温差导致的侧向失稳,以标准截面预制混凝土T梁为背景,对架设阶段横向温度梯度作用下的T梁侧向变形进行研究。建立截面热传递理论模型,通过热传递有限元分析得到主梁温度时程与分布,并与实测结果... 为控制大跨预制混凝土T梁架设阶段由横向温差导致的侧向失稳,以标准截面预制混凝土T梁为背景,对架设阶段横向温度梯度作用下的T梁侧向变形进行研究。建立截面热传递理论模型,通过热传递有限元分析得到主梁温度时程与分布,并与实测结果对比以验证有限元分析准确性,分析极端环境条件下(最高气温、最低气温、最大温差和最强太阳辐射)截面横向温度梯度分布,提出横向温度梯度多线性分布模式和预制混凝土T梁在横向温度梯度作用下的侧向变形简化分析方法。结果表明:热传递有限元分析计算结果与实测结果吻合;混凝土T梁顶、底板温差明显,且均产生较大的横向温度梯度;顶、底板及腹板的最高温度均出现在太阳直射边缘,最低温度出现在横向中心位置附近;采用简化分析方法计算预制混凝土T梁在横向温度梯度作用下的侧向变形,并得到不同标准截面梁在极端横向温度梯度下的侧向变形与跨径的关系,可为预制混凝土T梁架设时侧向变形控制提供参考。 展开更多
关键词 预制混凝土T梁 侧向变形 横向温度梯度 架设阶段 热传递分析 温度时程曲线 有限元数值模拟
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Lateral load pattern in pushover analysis 被引量:9
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作者 孙景江 Tetsuro Ono +1 位作者 赵衍刚 王威 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2003年第1期99-108,共10页
The seismic capacity curves of three types of buildings including frame,frame-shear wall and shear wall ob- tained by pushover analysis under different lateral load patterns are compared with those from nonlinear time... The seismic capacity curves of three types of buildings including frame,frame-shear wall and shear wall ob- tained by pushover analysis under different lateral load patterns are compared with those from nonlinear time history analy- sis.Based on the numerical results obtained a two-phase load pattern:an inverted triangle(first mode)load pattern until the base shear force reaches β times its maximum value,V_(max)followed by a(x/H)~α form,here β and α being some coeffi- cients depending on the type of the structures considered,is proposed in the paper,which can provide excellent approxima- tion of the seismic capacity curve for low-to-mid-rise shear type buildings.Furthermore,it is shown both the two-phase load pattern proposed and the invariant uniform pattern can be used for low-to-mid-rise shear-bending type and low-rise bending type of buildings.No suitable load patterns have been found for high-rise buildings. 展开更多
关键词 pushover analysis performance-based seismic design lateral load pattern nonlinear time history analysis
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Stabilization of Uncertain Systems With Markovian Modes of Time Delay and Quantization Density 被引量:4
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作者 Jufeng Wang Chunfeng Liu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2018年第2期463-470,共8页
This work studies the stabilization of a class of control systems that use communication networks as signal transmission medium. The lateral motion of independently actuated four-wheel vehicle is modeled as an uncerta... This work studies the stabilization of a class of control systems that use communication networks as signal transmission medium. The lateral motion of independently actuated four-wheel vehicle is modeled as an uncertain-linear system. Time delay and quantization density are modeled as Markov chains.The networked control systems(NCSs) with plants being lateral motion are first transformed to switched linear systems with uncertain parameters. Sufficient and necessary conditions for the stochastic stability of closed-loop networked control systems are then established. By solving the matrix inequalities, this work presents an output-feedback controller that depends on the modes of time delay and quantization density. The controller performance is illustrated via a vehicular lateral motion system. 展开更多
关键词 Networked control system(NCS) QUANTIZATION STABILIZATION time delay vehicle lateral motion
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Proximal-distal motor unit number estimationdynamic changes in patients with amyotrophic lateral sclerosis A one-year follow-up
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作者 Sartucci Ferdinando Moscato Gianluca +5 位作者 Rossi Chiara Caleo Matteo Bocci Tommaso Murri Luigi Giannini Fabio Rossi Alessandro 《Neural Regeneration Research》 SCIE CAS CSCD 2010年第8期597-601,共5页
BACKGROUND:Amyotrophic lateral sclerosis (ALS) is the most common of all the motor neuron diseases and the absence of a biologic marker has made both diagnosis and tracking evolution of the disease difficult, Elect... BACKGROUND:Amyotrophic lateral sclerosis (ALS) is the most common of all the motor neuron diseases and the absence of a biologic marker has made both diagnosis and tracking evolution of the disease difficult, Electrodiagnostic tests play a fundamental role in quantifying pathological changes in the motor unit pool.OBJECTIVE:We assessed distal-proximal Motor Unit (MU) loss and changes using the method of motor unit number estimation (MUNE).DESIGN, TIME AND SETTING:A case-control study was performed at the Department of Neuroscience, Pisa University Medical School, Italy from December 1999 to November 2009. PARTICIPANTS:A total of 50 ALS patients were recruited, 30 males:mean age (59.6 ± 13.3) years; 20 females:mean age (63.9 ± 11.7) years; range (30-82) years; all patients had probable or definite ALS. Thirty healthy volunteers were recruited from department staffs, including 20 males and 10 females; mean age (57.7 ± 13.8) years served as controls.METHODS:MUNE was performed for both the biceps brachii and abductor digiti minimi muscles of the same side. The technique used relayed substantially on manual incremental stimulation of the motor nerve, known as the McComas technique (50 ms sweep duration, a gain of 2 mV/Div for M wave, 0.5 mV/Div for each step; filters 10-20 kHz).MAIN OUTCOME MEASURES:MUNE results were measured.RESULTS:Functioning MU numbers, measured by MUNE, decreased in the biceps brachii and abductor digiti minimi muscles over the entire one-year follow-up period (one assessment every three months) compared with baseline determination, the rate of MU decrease was similar in both muscles, but steeper distally.CONCLUSION:MUNE is a feasible method for ALS patients both proximally and distally to track changes over time in muscle MUs during the disease's evolution. 展开更多
关键词 motor unit number estimation amyotrophic lateral sclerosis motor neuron disease time changes DENERVATION REINNERVATION
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Changes in somatosensory evoked potentials elicited by stimulation of upper-limb and lower-limb nerves in amyotrophic lateral sclerosis patients
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作者 Ying Zheng Zhaohuan Zhang Weihua Wu Zhongxin Zhao 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第26期2018-2021,共4页
This study observed the changes in somatosensory evoked potentials between patients with amyotrophic lateral sclerosis (ALS) and healthy controls to evaluate the function of the central deep somatosensory pathway. I... This study observed the changes in somatosensory evoked potentials between patients with amyotrophic lateral sclerosis (ALS) and healthy controls to evaluate the function of the central deep somatosensory pathway. In patients with ALS, 28 patients (54%) showed an abnormality in somatosensory evoked potentials. All had abnormal lower limb somatosensory evoked potentials. Compared with healthy controls, the abnormality in somatosensory evoked potential was characterized by prolonged N20, P2, N2 latency and central conduction time, with or without a decrease in wave amplitude or disappearance of waveform. Results showed marked alterations in the somatosensory evoked potential in cortical components of the upper and lower limb in 54% of patients with ALS, and confirmed that patients with ALS may also have a defective deep somatosensory pathway, particularly an abnormal central deep somatosensory pathway. 展开更多
关键词 amyotrophic lateral sclerosis somatosensory evoked potential central conduction time neural regeneration
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Lag time,high-risk histopathological features,metastasis,and survival interrelation in retinoblastoma:a perspective from lower-middle income country
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作者 Purjanto Tepo Utomo Datu Respatika +6 位作者 Bambang Ardianto Hanggoro Tri Rinonce Didik Setyo Heriyanto Banu Aji Dibyasakti Irene Titin Darajati Indra Tri Mahayana Agus Supartoto 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2022年第12期1994-2000,共7页
AIM:To investigate the impact of lag time to metastasis and survival rates among patients with retinoblastoma.METHODS:This retrospective study was conducted with 52 patients from the Department of Ophthalmology and th... AIM:To investigate the impact of lag time to metastasis and survival rates among patients with retinoblastoma.METHODS:This retrospective study was conducted with 52 patients from the Department of Ophthalmology and the Department of Pediatrics of Dr.Sardjito General Hospital,between 1^(st) January 2014 and 31^(st) December 2020.Lag time was defined as the time delay between the first sign of retinoblastoma to the diagnosis of retinoblastoma.The subjects with lag time>one year were included in the case group,while the subjects with lag time<one year were included in the control group.RESULTS:The lag time was significantly correlated with American Joint Committee on Cancer and Intraocular Classification of Retinoblastoma staging of retinoblastoma(P=0.005 and P=0.006,respectively).The lag time was also significantly correlated with both metastasis event[odds ratio(OR):5.06,95%Cl:1.56-16.44,P=0.006]and mortality(OR:4.54,95%Cl:1.37-15.07,P=0.011).The follow-up was continued for 32 subjects for 3y after initial diagnoses.Survival analysis revealed a significant difference among these two groups(P=0.021).Furthermore,lag time was significantly correlated with survival of retinoblastoma(r=-0.53,P=0.046).CONCLUSION:The study highlights the importance of lag time between the onset of first symptoms and the time of retinoblastoma diagnosis which significantly contribute to metastasis and mortality of patients with retinoblastoma.Examinations for the early detection of retinoblastoma should be performed for individuals at-risk to minimize lag time and improve the outcomes. 展开更多
关键词 RETINOBLASTOMA lag time METASTASIS SURVIVAL staging laterALITY
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Negative Phase Time Effectin Potential-Well Passing
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作者 Chun-fang Li Qi Wang 《Advances in Manufacturing》 2000年第3期210-213,共4页
The properties of phase time taken for particles to pass through a quantum potential well are investigated. It is found in a 1 dimensional quantum mechanical problem that the phase time is negative when the incident e... The properties of phase time taken for particles to pass through a quantum potential well are investigated. It is found in a 1 dimensional quantum mechanical problem that the phase time is negative when the incident energy and the thickness of potential well satisfy certain conditions. Similar results are also found in a 2 dimensional fully relativistic optical analog. It is shown that the expression of the la teral shift of transmitted optical waves is similar to that of the phase time in the 1 dimensional quantum mechanical problem. The phase time in the 2 dimensional optical problem is also shown to be negative under certain conditions. 展开更多
关键词 negative phase time negative lateral shift potential well quantum like dependence of phase on potential well thickness
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Quantitative evaluation of lateral sealing of extensional fault by an integral mathematical-geological model
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作者 LYU Yanfang HU Xinlei +5 位作者 JIN Fengming XIAO Dunqing LUO Jiazhi PU Xiugang JIANG Wenya DONG Xiongying 《Petroleum Exploration and Development》 CSCD 2021年第3期569-580,共12页
To evaluate the lateral sealing mechanism of extensional fault based on the pressure difference between fault and reservoir, an integral mathematical-geological model of diagenetic time on diagenetic pressure consider... To evaluate the lateral sealing mechanism of extensional fault based on the pressure difference between fault and reservoir, an integral mathematical-geological model of diagenetic time on diagenetic pressure considering the influence of diagenetic time on the diagenetic pressure and diagenetic degree of fault rock has been established to quantitatively calculate the lateral sealing ability of extensional fault. By calculating the time integral of the vertical stress and horizontal in-situ stress on the fault rock and surrounding rock, the burial depth of the surrounding rock with the same clay content and diagenesis degree as the target fault rock was worked out. In combination with the statistical correlation of clay content, burial depth and displacement pressure of rock in the study area, the displacement pressure of target fault rock was calculated quantitatively. The calculated displacement pressure was compared with that of the target reservoir to quantitatively evaluate lateral sealing state and ability of the extensional fault. The method presented in this work was used to evaluate the sealing of F_(1), F_(2) and F_(3) faults in No.1 structure of Nanpu Sag, and the results were compared with those from fault-reservoir displacement pressure differential methods without considering the diagenetic time and simple considering the diagenetic time. It is found that the results calculated by the integral mathematical-geological model are the closest to the actual underground situation, the errors between the hydrocarbon column height predicted by this method and the actual column height were 0–8 m only, proving that this model is more feasible and credible. 展开更多
关键词 lateral sealing of extensional fault integral mathematical–geological model diagenetic time diagenetic pressure Nanpu Sag
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冷弯薄壁型钢组合墙体简化计算模型研究 被引量:1
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作者 管宇 周绪红 +3 位作者 石宇 李松松 聂少锋 姚欣梅 《湖南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2023年第1期59-68,共10页
组合墙体作为冷弯薄壁型钢结构体系的主要承重和抗侧力构件,其受力性能对房屋整体结构抗震性能的影响应重点关注.基于此,建立冷弯薄壁型钢组合墙体简化计算模型,采用非线性对角弹簧模拟分析组合墙体的剪切变形,设置梁式杆件模拟分析组... 组合墙体作为冷弯薄壁型钢结构体系的主要承重和抗侧力构件,其受力性能对房屋整体结构抗震性能的影响应重点关注.基于此,建立冷弯薄壁型钢组合墙体简化计算模型,采用非线性对角弹簧模拟分析组合墙体的剪切变形,设置梁式杆件模拟分析组合墙体的弯曲变形,且墙体门窗洞口的影响也可在模型中体现.借鉴日本规范建议的墙体等代拉条法,推导出简化计算模型中对角弹簧轴向刚度的计算方法.结合组合墙体拟静力加载试验,验证了组合墙体简化计算模型的正确性,该模型满足基于弹性的设计要求,不适用于结构的弹塑性分析.最后,基于组合墙体的简化计算模型,参照振动台试验试件建立了3层冷弯薄壁型钢结构房屋的有限元模型,通过弹性动力时程分析验证了组合墙体简化计算模型的正确性,可为轻钢结构的抗震设计提供参考. 展开更多
关键词 冷弯薄壁型钢 组合墙体 计算模型 侧向变形 弹性动力时程分析
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低场核磁共振技术分析杏鲍菇在热风-微波联合干燥过程中的水分变化 被引量:3
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作者 唐小闲 蔡明君 +3 位作者 韦珍珍 任爱清 刘艳 劳琪珍 《粮食与油脂》 北大核心 2023年第8期90-94,共5页
利用低场核磁共振(LF-NMR)技术分析热风-微波联合干燥过程中杏鲍菇的横向弛豫时间(T2)反演图谱和核磁共振成像(MRI)图像,探究杏鲍菇在干燥过程中的水分状态及变化规律。结果表明:新鲜杏鲍菇片含自由水、半结合水和结合水3种状态水分,水... 利用低场核磁共振(LF-NMR)技术分析热风-微波联合干燥过程中杏鲍菇的横向弛豫时间(T2)反演图谱和核磁共振成像(MRI)图像,探究杏鲍菇在干燥过程中的水分状态及变化规律。结果表明:新鲜杏鲍菇片含自由水、半结合水和结合水3种状态水分,水分分布较均匀;在杏鲍菇片干燥过程中,热风干燥温度越高、微波功率越大,所需干燥时间越短,T23不断往左推移,自由水先被脱除,水分流动性不断减小,达到干燥终点时,只剩下结合水;3种状态水分之间存在互相转化和渗透现象,干燥改变了杏鲍菇内部水分的分布状态及水分含量。 展开更多
关键词 杏鲍菇 低场核磁共振 热风-微波联合干燥 横向弛豫时间
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Hydrodynamic behaviour of the lateral flow biological aerated filter
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作者 何强 王胤 +2 位作者 方俊华 张红津 许静 《Journal of Central South University of Technology》 EI 2006年第4期412-416,共5页
Pulsed signal experiment was carried out to determine the hydrodynamic behaviours of lateral flow biological aerated filter(LBAF). With the analysis of experimental results, LBAF is viewed as an approximate plug flow ... Pulsed signal experiment was carried out to determine the hydrodynamic behaviours of lateral flow biological aerated filter(LBAF). With the analysis of experimental results, LBAF is viewed as an approximate plug flow reactor, and hydraulic retention time distribution function was derived based on LBAF. The results show that flow rate and aeration strength are two critical factors which influence flow patterns in LBAF reactor. The hydrodynamic behaviour analysis of LBAF is the theoretical basis of future research on improving capacity factor and developing kinetic model for the reactor. 展开更多
关键词 侧向流动 废水处理 生物处理法 水力分析
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改良70°侧卧位用于达芬奇机器人辅助下肾部分切除手术的效果 被引量:1
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作者 侯晓敏 彭焕椽 +1 位作者 朱丽瑜 殷彬燕 《护理学杂志》 CSCD 北大核心 2023年第8期44-46,共3页
目的探讨改良70°侧卧位在达芬奇机器人辅助下肾部分切除手术中的应用效果。方法将216例达芬奇机器人辅助下肾部分切除手术患者按照手术时间分为传统组100例和改良组116例。在手术过程中,传统组患者背部纵轴平面与手术床纵轴平面呈9... 目的探讨改良70°侧卧位在达芬奇机器人辅助下肾部分切除手术中的应用效果。方法将216例达芬奇机器人辅助下肾部分切除手术患者按照手术时间分为传统组100例和改良组116例。在手术过程中,传统组患者背部纵轴平面与手术床纵轴平面呈90°角,改良组患者背部纵轴平面与手术床纵轴平面呈70°角。结果改良组体位安置时间、手术时间及肾动脉阻断时间显著短于传统组,患者舒适度和医生满意度显著优于传统组,且术中机械臂碰撞躯干例数显著少于传统组(均P<0.05);两组患者术中出血量及机器人二次泊位发生率差异无统计学意义(均P>0.05)。结论改良70°侧卧位用于达芬奇机器人辅助下肾部分切除手术可便捷手术操作,提高患者安全和舒适性,有利于护理质量提升。 展开更多
关键词 肾癌 机器人 肾部分切除术 改良体位 半侧卧位 手术体位 肾动脉阻断时间
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设置BRB的双柱式桥墩弹塑性地震反应分析
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作者 刘春城 杨爱全 邢爽 《振动.测试与诊断》 EI CSCD 北大核心 2023年第1期52-58,197,共8页
为研究防屈曲支撑(buckling-restrained brace,简称BRB)对双柱式桥墩抗震性能的影响,在双柱式桥墩间设置5种BRB布置方案以提高桥墩的抗侧刚度,并与原桥墩对比研究其抗震性能。首先,进行桥墩拟静力分析,通过与文献试验数据对比,验证数值... 为研究防屈曲支撑(buckling-restrained brace,简称BRB)对双柱式桥墩抗震性能的影响,在双柱式桥墩间设置5种BRB布置方案以提高桥墩的抗侧刚度,并与原桥墩对比研究其抗震性能。首先,进行桥墩拟静力分析,通过与文献试验数据对比,验证数值模拟方法的正确性;其次,开展桥墩的抗震性能研究,通过对6种模型在不同地震动(0.2g,0.4g,0.8g)作用下的非线性时程分析,得到桥墩的损伤、内力和变形计算结果。经对比研究,提出一种最佳的BRB布置方案。研究表明:双柱式桥墩设置BRB可以有效提高桥墩的抗侧刚度,减小桥墩在地震作用下的墩顶位移响应,降低桥墩的损伤,减少钢筋屈服和桥墩塑性铰区域,大幅减小墩底弯矩,但不同的BRB设置有时会导致墩底剪力有所增加。 展开更多
关键词 双柱式桥墩 防屈曲支撑 非线性时程分析 抗侧刚度 抗震性能
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