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水利水电施工 2024年第2期 96-99页

作者：杨印友刘腾飞施强强中国电建集团港航建设有限公司

连拱隧道具有布线方便、线形流畅、洞外占地面积少等特点,常应用于地形限制或布线困难的山区短隧道。通常连拱隧道在中导洞开挖完成后设置双洞共用中隔墙,对靠近山体外侧的小偏压左洞先行开挖,再进行靠近山体内侧的大偏压右洞开挖。依... 详细信息

连拱隧道具有布线方便、线形流畅、洞外占地面积少等特点,常应用于地形限制或布线困难的山区短隧道。通常连拱隧道在中导洞开挖完成后设置双洞共用中隔墙,对靠近山体外侧的小偏压左洞先行开挖,再进行靠近山体内侧的大偏压右洞开挖。依托工程左洞二衬在右洞施工过程中出现部分地段纵向开裂,针对该隧道实际情况,分析现有地质和施工条件下该隧道二衬开裂的主要原因,提出了可靠的处置方案,保证质量安全。

关键词：径背隧道连拱隧道裂缝处置

How variable progenitor clones construct a largely invariant neocortex

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National Science Review 2024年第1期11卷 129-144页

作者： Zhongfu Shen Jiajun Yang qiangqiang Zhang Kuiyu Wang Xiaohui Lv Xiaolin Hu Jian Ma Song-Hai shi New Cornerstone Science Laboratory IDG/McG overn Institute for Brain Research Tsinghua-Peking Center for Life Sciences Beijing Frontier Research Center for Biological Structure School of Life Sciences Tsinghua University Department of Computer Sciences Tsinghua University College of Life Sciences Nankai University Chinese Institute for Brain Research

The neocortex contains a vast collection of diverse neurons organized into distinct layers. While nearly all neocortical neurons are generated by radial glial progenitors(RGPs), it remains largely unclear how a complex yet organized neocortex is constructed reliably and robustly. Here, we show that the division behavior and neuronal output of RGPs are highly constrained with patterned variabilities to support the reliable and robust construction of the mouse neocortex. The neurogenic process of RGPs can be well-approximated by a consistent Poisson-like process unfolding over time, producing deep to superficial layer neurons progressively. The exact neuronal outputs regarding layer occupation are variable; yet, this variability is constrained systematically to support all layer formation, largely reflecting the variable intermediate progenitor generation and RGP neurogenic entry and exit timing differences. Together, these results define the fundamental features of neocortical neurogenesis with a balanced reliability and variability for the construction of the complex neocortex.

关键词： neocortex radial glial progenitor intermediate progenitor neurogenesis clonal variability layer formation

Ultra-fast charge-discharge and high-energy storage performance realized in K_(0.5)Na_(0.5)NbO_(3)-Bi(Mn_(0.5)Ni_(0.5))O_(3) ceramics

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Journal of Advanced Dielectrics 2023年第1期13卷 46-56页

作者： Xinru Nie Yan He qiangqiang shi Yuqian Liang Lingling Wei Pengfei Liang Xiaolian Chao Guoxin Hu Zupei Yang Key Laboratory for Macromolecular Science of Shaanxi Province Shaanxi Key Laboratory for Advanced Energy DevicesShaanxi Engineering Laboratory for Advanced Energy Technology School of Materials Science and Engineering Shaanxi Normal UniversityXi’an710062ShaanxiP.R.China School of Chemistry and Chemical Engineering Shaanxi Normal University Xi’an710062ShaanxiP.R.China School of Physics and Information Technology Shaanxi Normal UniversityXi’an 710062ShaanxiP.R.China

Lead-free relaxor ceramics(1−x)K_(0.5)Na_(0.5)NbO_(3)−xBi(Mn_(0.5)Ni_(0.5))O_(3)((1−x)KNN-xBMN)with considerable charge-discharge characteristics and energy storage properties were prepared by a solid state ***,a BMN doping level of 0.04,0.96KNN-0.04BMN ceramic obtained good energy storage performance with acceptable energy storage density Wrec of 1.826 J/cm^(3) and energy storage efficiencyηof 77.4%,as well as good frequency stability(1-500 Hz)and fatigue resistance(1-5000 cycles).Meanwhile,a satisfactory charge-discharge performance with power density PD~98.90 MW/cm^(3),discharge time t0.9<70 ns and temperature stability(30-180°C)was obtained in 0.96KNN-0.04BMN *** small grain size(~150 nm)and the high polarizability of Bi3+are directly related to its good energy storage *** work proposes a feasible approach for lead-free KNN-based ceramics to achieve high-energy storage and ultra-fast charge-discharge performance as well as candidate materials for the application of advanced high-temperature pulse capacitors.

关键词： K_(0.5)Na_(0.5)NbO_(3)ceramics microstructure ultra-fast charge-discharge energy storage.

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一种直升机旋翼应变参数采集设计

国外电子测量技术 2021年第4期40卷 93-98页

作者：张亚维史强强西安航空职业技术学院西安710089 西安远方航空技术发展有限公司西安710089

针对直升机旋翼应变应力参数试飞测试数据获取,设计了一种能够实时采集直升机旋翼应变参数设备,为解决旋翼应变参数无线传输的高精度实时采集提供方案。打破国外产品垄断,提高设备的维修性、降低成本、缩短开发周期,要求设备满足高速旋... 详细信息

针对直升机旋翼应变应力参数试飞测试数据获取,设计了一种能够实时采集直升机旋翼应变参数设备,为解决旋翼应变参数无线传输的高精度实时采集提供方案。打破国外产品垄断,提高设备的维修性、降低成本、缩短开发周期,要求设备满足高速旋转产生的离心加速度及恶劣的安装环境,要求牢固可靠、测量精确且体积小型化。动部件采用数据采集与无线射频发射、静部件采用无线接收与数据转换架构,实现旋翼应变数据多通道同步采集,输出形式为以太网及RS422总线,上位机软件实现程序加载与数据实时检查。结果表明,该设备信号采集精度可达0.5%以内,数据延迟为2.5 ms级且稳定可靠,无线数据丢包率小于10^(-6)。目前用于某型机旋翼试飞中,对于动部件测量有一定借鉴意义。

关键词：应变采集旋翼测试无线传输动部件测试

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旋转件的松耦合无线感应供电应用研究

国外电子测量技术 2021年第7期40卷 105-109页

作者：张亚维史强强西安航空职业技术学院西安710089 西安远方航空技术发展有限公司西安710089

针对机载旋转部件测试中稳定的电源传输方式,设计了一种适用于各种高速转动场合下的松耦合方式近距式感应供电传输方式,为特殊旋转环境下的测量设备供电难题提供思路。基于松耦合方式的分离式变压器原理,巧妙采取了U型铁芯与铺设导磁体... 详细信息

针对机载旋转部件测试中稳定的电源传输方式,设计了一种适用于各种高速转动场合下的松耦合方式近距式感应供电传输方式,为特殊旋转环境下的测量设备供电难题提供思路。基于松耦合方式的分离式变压器原理,巧妙采取了U型铁芯与铺设导磁体减小电磁信号损耗,提高极低电磁耦合环境条件下电源传输功率的需求。经过理论分析与试验测试,对发射调制频率和初次级线圈匝比进行试验,结果为传输功率达到不小于2 W,传输效率不小于10%。通过装机测试,结果表明,该方法的可行性与有效性对于各类旋转部件供电设计具有一定的参考意义。

关键词：感应供电松耦合旋转件供电系统

Adaptive Space Expansion for Fast Motion Planning

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IEEE/CAA Journal of Automatica Sinica 2024年第6期11卷 1499-1514页

作者： Shenglei shi Jiankui Chen State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The sampling process is very inefficient for sam-pling-based motion planning algorithms that excess random sam-ples are generated in the planning *** this paper,we pro-pose an adaptive space expansion(ASE)approach which belongs to the informed sampling category to improve the sampling effi-ciency for quickly finding a feasible *** ASE method enlarges the search space gradually and restrains the sampling process in a sequence of small hyper-ellipsoid ring subsets to avoid exploring the unnecessary ***,for a con-structed small hyper-ellipsoid ring subset,if the algorithm cannot find a feasible path in it,then the subset is ***,the ASE method successively does space exploring and space expan-sion until the final path has been ***,we present a particular construction method of the hyper-ellipsoid ring that uniform random samples can be directly generated in *** last,we present a feasible motion planner BiASE and an asymptoti-cally optimal motion planner BiASE*using the bidirectional exploring method and the ASE *** demon-strate that the computation speed is much faster than that of the state-of-the-art *** source codes are available at https://***/shshlei/ompl.

关键词： Adaptive space expansion(ASE) hyper-ellipsoid ring informed sampling motion planning.

No Reference Image Sharpness Assessment Based on Global Color Difference Variation

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Chinese Journal of Electronics 2024年第1期33卷 293-302页

作者： Chenyang shi Yandan LIN School of Artificial Intelligence Anhui Polytechnic University School of Mechanical Engineering Anhui Polytechnic University Department of Light Sources and Illuminating Engineering Fudan University Academy for Engineering & Technology Fudan University

Image quality assessment(IQA) model is designed to measure the image quality in consistent with subjective ratings by computational models. In this research, a valid no reference IQA(NR-IQA) model for color image sharpness assessment is proposed based on local color difference map in a color space. In the proposed model, the absolute color difference variation and relative color difference variation are combined to evaluate sharpness in YIQ color space(a color coordinate system for the development of the United States color television system). The difference between sharpest and blurriest spot of an image is represented by the absolute color difference variation, and relative color difference variation expresses the variation in the image content. Extensive experiments are performed on five publicly available benchmark synthetic blur databases and two real blur databases, and the results prove that the proposed model work better than the other state-of-the-art and latest NR-IQA models for the prediction accuracy on blurry images. Besides, the model maintains the lowest computational complexity.

关键词： Image quality TV Image color analysis Databases Computational modeling Color Predictive models

An uncertainty investigation for liner impedance eduction methods

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Chinese Journal of Aeronautics 2024年第3期37卷 49-59页

作者： Weihao shi Xiaodong JING School of Energy and Power Engineering Beihang UniversityBeijing 100191China

Impedance eduction methods have been developed for decades to meet the increasing need for high-quality impedance data in the design and optimization of acoustic *** this end,it is important to fully investigate the uncertainty problem,to which only limited attention has been devoted so *** paper considers the possibility of acoustically-induced structural vibration as a nonnegligible uncertainty or error source in impedance eduction *** the frequency moves away from the resonant frequency,with the increase in the value of cavity reactance,the acoustic particle velocity inside liner orifices possibly decreases to the extent comparable to the vibration velocity of liner facing ***,the acoustically-induced vibration,although generally being weak except at the inherent structural frequencies,may considerably affect the impedance eduction results near the anti-resonant frequency where the liner has poor *** demonstrate the effect of structural vibration,the vibration velocity of liner facing sheet is estimated from the experimentally educed admittance of the liner samples whose orifices are sealed with ***,a three-dimensional numerical model is set up,in which normal particle velocity is introduced over the solid portion of liner facing sheet to imitate structural vibration,rather than directly solving the acoustic-structural coupling *** shown by the results,the vibration of liner facing sheet,whose velocity is as small as estimated by the experiment,can result in anomalous deviation of the educed impedance from the impedance model near the anti-resonant *** trend that the anomalous deviation varies with frequency is numerically captured.

关键词： Impedance eduction Uncertainty analysis Acoustically-induced structural vibration Anti-resonant frequency Perforated liner

Quantization and Event-Triggered Policy Design for Encrypted Networked Control

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 946-955页

作者： Yongxia shi Ehsan Nekouei the Department of Electrical Engineering City University of Hong KongHong KongChina

This paper proposes a novel event-driven encrypted control framework for linear networked control systems(NCSs),which relies on two modified uniform quantization policies,the Paillier cryptosystem,and an event-triggered *** to the fact that only integers can work in the Pailler cryptosystem,both the real-valued control gain and system state need to be first quantized before *** is dramatically different from the existing quantized control methods,where only the quantization of a single value,e.g.,the control input or the system state,is *** handle this issue,static and dynamic quantization policies are presented,which achieve the desired integer conversions and guarantee asymptotic convergence of the quantized system state to the ***,the quantized system state is encrypted and sent to the controller when the triggering condition,specified by a state-based event-triggered strategy,is *** doing so,not only the security and confidentiality of data transmitted over the communication network are protected,but also the ciphertext expansion phenomenon can be ***,by tactfully designing the quantization sensitivities and triggering error,the proposed event-driven encrypted control framework ensures the asymptotic stability of the overall closedloop ***,a simulation example of the secure motion control for an inverted pendulum cart system is presented to evaluate the effectiveness of the theoretical results.

关键词： Cyber-security encrypted control event-triggered control(ETC) networked control systems(NCSs) semi-homomorphic encryption