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A closed-form solution for a double infinite Euler-Bernoulli beam on a viscoelastic foundation subjected to harmonic line load

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Earthquake Engineering and Engineering Vibration 2019年第1期18卷 129-140页

作者： Li Bing cheng yongfeng Zhu Zhaoqing Zhang Fuyou Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education Southeast University China Electric Power Research Institute Institute of Engineering Safety and Disaster Prevention Hohai University

The dynamic response of a double infinite beam system connected by a viscoelastic foundation under the harmonic line load is studied. The double infinite beam system consists of two identical and parallel beams, and the two beams are infinite elastic homogeneous and isotropic. A viscoelastic layer connects the two beams continuously. To decouple the two coupled equations governing the response of the double infinite beam system, a variable substitution method is introduced. The frequency domain solutions of the decoupled equations are obtained by using Fourier transforms as well as Laplace transforms successively. The time domain solution in the generalized integral form are then obtained by employing the corresponding inverse transforms, i.e. Fourier transform and inverse Laplace transform. The solution is verified by numerical examples, and the effects of parameters on the response are also investigated.

关键词： infinite two double beam transforms

Steganalysis of Low Embedding Rates LSB Speech Based on Histogram Moments in Frequency Domain

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Chinese Journal of Electronics 2017年第6期26卷 1254-1260页

作者： YANG Wanxia TANG Shanyu LI Miaoqi cheng yongfeng ZHOU Zhili School of Computer Science China University of Geosciences College of Technology Gansu Agricultural University School of Computer and Software Nanjing University of Information Science and Technology

As wavelet packet transform is able to focus on minute change of signals, this study proposes an analytic approach of low embedding steganograpy based on high order Histogram moments in frequency domain(HMFD), which provides a key solution to the feature selection and extraction of HMFD. The detection results are tested with the LSB matching steganograpy of different embedding rates in speech signals, respectively, it is proved that the detection performance with HMFD applied is greater than that of histogram statistical moments.HMFD by Wavelet packet decomposition(WPD) can effectively detect low embedding rates Least significant bit(LSB) speech steganography, its accuracy can be 60.8%while the embedding rate is only 3%.

关键词： Steganalysis Statistical moments of his togram Wavelet packet decomposition(WPD) Voice over IP(VoIP) Speech steganography

A two degree of freedom stable quasi-zero stiffness prototype and its applications in aseismic engineering

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Science China(Technological Sciences) 2020年第3期63卷 496-505页

作者： ZHU GuangNan LIU JiYe CAO QingJie cheng yongfeng LU Zhicheng ZHU ZhuBing School of Astronautics Harbin Institute of TechnologyHarbin 150001China China Electric Power Research Institute Beijing 100055China

In this paper, an archetypal aseismic system is proposed with 2-degree of freedom based on a smooth and discontinuous(SD)oscillator to avoid the failure of electric power system under the complex excitation of seismic waves. This model comprises two vibration isolation units for the orthogonal horizontal directions, and each of them admits the stable quasi-zero stiffness(SQZS)with a pair of inclined linear elastic springs. The equation of motion is formulated by using Lagrange equation, and the SQZS condition is obtained by optimizing the parameters of the system. The analysis shows that the system behaves a remarkable vibration isolation performance with low resonant frequency and a large stroke of SQZS interval. The experimental investigations are carried out to show a high sonsistency with the theoretical results, which demonstrates the improvement of aseismic behavior of the proposed model under the seismic wave.

关键词： SD oscillator two-DOF vibration isolation stable quasi-zero stiffness low-frequency vibration isolation aseismic experiment

BDS-3/Galileo四频精密单点定位模型及性能分析

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中国惯性技术学报 2024年第5期32卷 484-491页

作者：王尚祺刘岭郑勇峰程正逢张健杨长江中国能源建设集团浙江省电力设计院有限公司杭州310000 中国电力工程顾问集团中南电力设计院有限公司武汉430071

北斗三号系统(BDS-3)与欧盟伽利略系统(Galileo)都能提供四频及以上的卫星信号。为充分利用多频信号数据,提高定位精度和可靠性,建立了BDS-3/Galileo四频精密单点定位模型并进行了性能分析。首先在传统双频模型基础上推导了两个四频无... 详细信息

北斗三号系统(BDS-3)与欧盟伽利略系统(Galileo)都能提供四频及以上的卫星信号。为充分利用多频信号数据,提高定位精度和可靠性,建立了BDS-3/Galileo四频精密单点定位模型并进行了性能分析。首先在传统双频模型基础上推导了两个四频无电离层组合模型(QF1和QF2)和一个四频非差非组合模型(QF3),并给出了各模型组合系数、电离层和噪声放大系数等参数。其次分析了各模型参数对定位性能的影响。最后通过静态和仿动态PPP实验评估了各模型的定位性能,实验结果表明:提出的四频模型QF1、QF2、QF3静态PPP收敛时间相较于双频模型IF12缩短了约50%、57%、25%,收敛后定位精度分别提升约44%、44%、41%;动态PPP实验中,QF1、QF2、QF3模型所用收敛时间较IF12模型分别缩短约26%、26%、3%,收敛后定位精度分别提升约23%、22%、13%。QF1和QF2模型性能相当,优于QF3模型。

关键词：北斗三号系统伽利略系统四频精密单点定位定位性能

新型电力系统下的天然气市场与电力市场协调机制探讨

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南方电网技术 2024年第2期18卷 57-66页

作者：杨韵江昕玥段秦尉涂炼程永峰杨莉广东电网有限责任公司电力调度控制中心广州510220 浙江大学电气工程学院杭州310027

随着新型电力系统的发展,燃气机组比重增加,协调电力系统和天然气系统对于可持续的能源供应和能源转型的成功非常关键。首先综述了天然气市场与电力市场信息交互环境下的协调机制设计和市场主体多时间尺度交易决策等方面的工作,并从市... 详细信息

随着新型电力系统的发展,燃气机组比重增加,协调电力系统和天然气系统对于可持续的能源供应和能源转型的成功非常关键。首先综述了天然气市场与电力市场信息交互环境下的协调机制设计和市场主体多时间尺度交易决策等方面的工作,并从市场交易模式、运营机构组织方式等方面对国外成熟天然气市场与电力市场协调机制实践进行了介绍。然后,从国外电价异常事件出发分析了极端天气下天然气供应短缺导致的市场风险和应对经验,并总结了国内天然气市场和电力市场在发展过程中市场协调机制方面的关键问题。最后,从完善气-电价格传导机制和补偿机制、加强天然气市场多元化竞争格局、提升气-电系统间的信息交互和应急管理能力等方面提出适应国内实际情况的市场协调机制建议。

关键词：电力市场天然气市场协调机制燃气发电风险联动

CLE14 functions as a "brake signal" to suppress age-dependent and stress-induced leaf senescence by promoting JUB1-mediated ROS scavenging in Arabidopsis

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Molecular Plant 2022年第1期15卷 179-188页

作者： Zenglin Zhang cheng Liu Kui Li Xiaoxu Li Mengmeng Xu yongfeng Guo Tobacco Research Institute Chinese Academy of Agricultural SciencesQingdaoShandong 266101China

Leaf senescence is an important developmental process in the plant life cycle and has a significant impact on agriculture.When facing harsh environmental conditions,monocarpic plants often initiate early leaf senes-cence as an adaptive mechanism to ensure a complete life cycle.Upon initiation,the senescence process is fine-tuned through the coordination of both positive and negative regulators.Here,we report that the small secreted peptide CLAVATA3/ESR-RELATED 14(CLE14)functions in the suppression of leaf senescence by regulating ROS homeostasis in Arabidopsis.Expression of the CLE14-encoding gene in leaves was signifi-cantly induced by age,high salinity,abscisic acid(ABA),salicylic acid,and jasmonic acid.CLE14 knockout plants displayed accelerated progression of both natural and salinity-induced leaf senescence,whereas increased CLE14 expression or treatments with synthetic CLE14 peptides delayed senescence.CLE14 pep-tide treatments also delayed ABA-induced senescence in detached leaves.Further analysis showed that over-expression of CLE14 led to reduced.ROS levels in leaves,where higher expression of ROS scavenging genes was detected.Moreover,CLE14 signaling resulted in transcriptional activation of JUB1,a NAC family tran-scription factor previously identified as a negative regulator of senescence.Notably,the delay of leaf senes-cence,reduction in H202 level,and activation of ROS scavenging genes by CLE14 peptides were dependent on JUB1.Collectively,these results suggest that the small peptide CLE14 serves as a novel"brake signal"to regulate age-dependent and stress-induced leaf senescence through JUB1-mediated ROS scavenging.

关键词： CLE14 peptide signal leaf senescence salt stress ABA ROS JUB1

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情景教学法在药理课程教学中的应用研究

创新创业理论研究与实践 2024年第7期7卷 160-162页

作者：程玥翟梦婷许哲昊程永凤安徽医科大学临床医学院安徽合肥230012

在创新人才培养模式下,高等教育的教学重点在于培养学生的专业素养,提升学生的科学思维能力,并通过理论联系实际进一步培养学生科研创新能力。情景教学法强调以学生为主体,将学生从传统教学的倾听式学习转化为主动的思考式学习。该文主... 详细信息

在创新人才培养模式下,高等教育的教学重点在于培养学生的专业素养,提升学生的科学思维能力,并通过理论联系实际进一步培养学生科研创新能力。情景教学法强调以学生为主体,将学生从传统教学的倾听式学习转化为主动的思考式学习。该文主要介绍了情景教学法在药理课程教学中的具体应用,并探讨其在医药学专业课教学中的应用前景与挑战。

关键词：情景教学法药理学医药学教育实践教学教学研究教学方法

Sandwich教学法在本科护理药理学教学中应用的研究

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创新创业理论研究与实践 2024年第7期7卷 130-132页

作者：翟梦婷程玥许哲昊程永凤安徽医科大学临床医学院安徽合肥230012

目的探究Sandwich教学法在本科护理专业药理学教学中的应用效果。方法选取安徽医科大学2021级护理专业学生,随机分为对照组与试验组。对照组接受传统教学法,试验组接受Sandwich教学法,比较两种教学法对两组护生教学后理论知识和实验技... 详细信息

目的探究Sandwich教学法在本科护理专业药理学教学中的应用效果。方法选取安徽医科大学2021级护理专业学生,随机分为对照组与试验组。对照组接受传统教学法,试验组接受Sandwich教学法,比较两种教学法对两组护生教学后理论知识和实验技能考核结果、评判性思维能力的影响。结果与对照组相比,试验组学生理论和实验成绩均提高(P<0.05),试验组学生评判性思维能力得分差值在5个维度上均提高(P<0.05)。结论Sandwich教学法有助于本科护生对理论知识和实验技能的掌握,提高评判性思维能力和学习效率。

关键词： Sandwich教学法药理学护理评判性思维能力教学质量成绩

杨氏牵引旋后法手法复位小夹板外固定治疗Galeazzi骨折

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中医正骨 2024年第5期36卷 72-75,80页

作者：李巍曹谦成勇峰张琼湘潭市中医医院湖南湘潭411100

目的:观察杨氏牵引旋后法手法复位小夹板外固定治疗Galeazzi骨折的临床疗效和安全性。方法:2017年1月至2022年12月,门诊治疗Galeazzi骨折患者68例。男35例,女33例;左侧23例,右侧45例;年龄5~75岁,中位数35岁;新鲜骨折52例,陈旧性骨折16... 详细信息

目的:观察杨氏牵引旋后法手法复位小夹板外固定治疗Galeazzi骨折的临床疗效和安全性。方法:2017年1月至2022年12月,门诊治疗Galeazzi骨折患者68例。男35例,女33例;左侧23例,右侧45例;年龄5~75岁,中位数35岁;新鲜骨折52例,陈旧性骨折16例。采用杨氏牵引旋后法通过牵引和前臂旋后手法复位下尺桡关节脱位和桡骨骨折,复位后用小夹板外固定。记录骨折愈合时间,观察并发症发生情况。分别于治疗前、复位固定后7 d及末次随访时,采用疼痛视觉模拟量表(visual analogue scale,VAS)评分评价患肢疼痛情况;于末次随访时,采用Anderson成人前臂骨折治疗效果评价分级标准评价前臂功能,采用Cooney腕关节评分评价腕关节功能。结果:68例患者均顺利完成治疗;均获随访,随访时间3~12个月,中位数7个月;骨折均愈合,愈合时间8~12周,中位数9周。患肢疼痛VAS评分,治疗前(7.8±1.2)分,复位固定后7 d(3.5±1.3)分,末次随访时(1.3±0.4)分。末次随访时,前臂旋前80.3°±4.5°、旋后83.5°±5.3°;前臂功能Anderson评级,优56例、良11例、可1例;Cooney腕关节评分(93.6±3.4)分,优59例、良9例。并发皮肤压疮2例,经对症治疗后皮肤愈合;均未出现缺血性肌挛缩等并发症。结论:杨氏牵引旋后法手法复位小夹板外固定治疗Galeazzi骨折,可有效缓解患肢疼痛,有利于骨折愈合和前臂及腕关节功能的恢复,且并发症少。

关键词：桡骨骨折关节脱位正骨手法小夹板固定术