摘要：This paper is concerned with the problems of robust admissibility and static output feedback( SOF)stabilization for a class of discrete-time switched singular systems with norm-bounded parametric *** objective is to design a suitable robust SOF controller guaranteeing the regularity,causality and asymptotic stability of the resulting closed-loop system under arbitrary switching laws. Based on the basic matrix inequality sufficient condition for checking the admissibility of switched singular systems,together with some matrix inequality convexifying techniques,the SOF controller synthesis is developed for the underlying systems. It is shown that the controller gains can be obtained by solving a set of strict linear matrix inequalities( LMIs). A simulation example is given to show the effectiveness of the proposed method.

摘要：沙漠公路从建设期到运营期一直受到风沙威胁,沙漠公路合理选线能有效从源头上减少风沙灾害。为研究尉犁至且末沙漠公路不同形态流动沙丘区减灾选线,对尉犁至且末沙漠公路沿线8种流动沙丘地貌进行了遥感影像判译,并按照形态-成因法将尉犁至且末沙漠公路沿线8种地貌流动沙丘划分成了横向沙丘、纵向沙丘、多方向风作用沙丘3大形态;从研究3大形态流动沙丘区地形地貌、沙丘运动规律、沙丘表面特征与尉犁至且末沙漠公路路线减灾走向关系,提出了具有普适性的3大形态流动沙丘环境中沙漠公路减灾选线要点。研究成果可为今后流动沙丘区沙漠公路减灾选线提供一定指导和参考。

摘要：城镇化背景下,人口的规模外流重塑了中国农村家庭类型,耕地利用方式相应呈多元化特征。区别于既往强调家庭特征的独立指标,本文提供了一种兼顾家庭离村情况、留村人口代际组合的农村家庭类型划分范式,并构建了农户耕地利用决策假说。基于全国抽样的万份农户问卷数据,采用多项Logit模型分析了农村家庭类型分化对耕地利用方式的影响。研究发现:(1)全家在村家庭比率呈“东—中—西”递减态势,城乡两栖家庭比率呈“东—中—西”递增态势。留村人口中,中坚型农户集中于东部,完整型、老幼型农户集中于中、西部。(2)全家在村家庭倾向于种植经济作物;城乡两栖家庭倾向于土地转出及种植粮食。(3)全家在村的中坚型、完整型农户分别倾向于种植粮食、经济作物;城乡两栖的中坚型、完整型农户倾向于种植粮食作物,老幼型农户倾向于转出、撂荒耕地或种植林木。(4)农村家庭的本地非农就业、地块数量、家庭资产、农业补贴等因素也对耕地利用方式产生显著影响。研究结论可为耕地用途管制政策的顶层设计提供农村家庭耕地决策行为的底层逻辑,为因户、因类施策依据提供现实参考。

摘要：Wearable bioelectronic devices have the capacity for real-time human health monitoring,the provision of tailored services,and natural interaction with smart ***,these wearable bioelectronic devices rely on conventional rigid batteries that are frequently charged or replaced and are incompatible with the skin,leading to a discontinuity in complex therapeutic tasks related to human health monitoring and human-machine *** triboelectric nanogenerator(TENG)is a high-efficiency energy harvesting technology that converts mechanical into electrical energy,effectively powering wearable bioelectronic *** study comprehensively overviews recent advances in stretchable TENG for use in wearable bioelectronic *** working mechanism of stretchable TENG is initially explained.A comprehensive discussion presents the approaches for fabricating stretchable TENG,including the design of stretchable structures and the selection of stretchable ***,applications of wearable bioelectronic devices based on stretchable TENG in human health monitoring(body movements,pulse,and respiration)and human-machine interaction(touch panels,machine control,and virtual reality)are ***,the challenges and developmental trends regarding wearable bioelectronic devices based on stretchable TENG are elaborated.

摘要：在拉曼光谱测试中某些物质存在荧光发射背景,由于荧光强度一般比拉曼散射强度高几个数量级,在荧光干扰时几乎无法获得有效的拉曼光谱信号。为抑制荧光背景,可选用近红外波段激光作为激发光源,而硅基探测器在1 000 nm以上波段时光量子效率严重下降,导致近红外拉曼光谱仪器难以探测3 000 cm^(-1)以上的波段,存在荧光抑制效果与检测范围无法兼顾的问题。由于高波数的拉曼特征峰是识别材料种类和解析材料结构的重要依据,如氨基的N—H伸缩振动峰在3 300 cm^(-1)附近、 OH-伸缩振动峰在3 650 cm^(-1),这些基团是分析材料腐蚀产物、水合物、有机物等的重要依据。因此,迫切需要开发一种解决拉曼光谱仪器无法兼顾荧光抑制效果和检测光谱范围问题的方法。该工作提出一种采用光谱仪固定检测波段、 730和830 nm双波长激光“接力”激发的方案(即830 nm激发低波数拉曼、 730 nm激发高波数拉曼)。通过双激光波长“接力”激发、固定检测波段的新设计,可有效拓宽检测范围至200~3 700 cm^(-1),并且不会降低光谱分辨率(达到6 cm^(-1)),与此同时整机光路无机械可动部件,可靠性高便于实现便携式设计。通过样机进行测试,证明该技术方案具备高灵敏度、较好荧光抑制效果、宽检测范围和较高光谱分辨率等优势。通过研制的双波长近红外拉曼光谱仪获得了铀腐蚀产物、有机涂层下的LiH潮解产物的清晰拉曼信号,解决了特种材料无损检测的技术难题。该技术也适用于其他研究及检测领域,特别是拉曼散射截面小、荧光背景高的物质检测。由于双波长近红外拉曼光谱仪可覆盖200~3 700 cm^(-1)检测范围,为多数水合物、含羟基及氨基官能团物质的拉曼检测提供了一种可行的技术途径。

摘要：传统的大地电磁二维反演方法较为成熟,但仍存在反演结果依赖初始模型和正则化参数选取、容易陷入局部极小值等问题。监督下降法是一种学习平均下降方向来预测数据残差的机器学习算法。本文尝试采用监督下降法解决传统的大地电磁二维反演存在的问题,基于监督下降法理论开发了大地电磁二维反演算法,设计理论模型合成算例验证了算法的正确性,并对西藏高原实测数据进行反演,检验了监督下降法的实用性。理论模型合成数据和实测数据反演结果表明,相较于传统的非线性共轭梯度反演,基于监督下降法的反演具有收敛速度快、反演效果好、抗噪能力强等特点。

摘要：旨在探索中医古籍知识库在临床辅助决策系统中的应用与建设。中医古籍包含了丰富的临床经验和中医理论知识,然而由于古籍数量庞大且馆藏分散,保存状态参差不齐,使得医生在临床实践难以充分运用。因此,将中医古籍知识库与临床辅助决策系统相结合,逐渐成为提升中医临床诊疗水平的重要趋势之一。本研究收集岭南中医古籍共计278本,涵盖488种疾病,1198种证候,3907种症状,系统对中医古籍进行整理和分类,构建出一个结构化和标准化的中医古籍库,同时关联引入现代临床医学相关知识,形成了综合性的中医临床知识库。本文设计了一套基于规则的推理引擎和机器学习算法,根据患者的症状、体质等信息,从中医古籍知识库中检索出相应的诊断和治疗建议。通过实际应用和测试,验证了基于中医古籍知识库的临床辅助决策系统可提高中医诊疗的有效性,系统的建设不仅有助于传承和发扬中医古籍知识,也为现代中医临床实践提供了有力的支持。

摘要：Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor ***,the lack of tumor models able to precisely emulate natural brain tumor tissue has impeded the study of the effects of hypoxia on the progression and growth of tumor *** study reports a three-dimensional(3D)brain tumor model obtained by encapsulating U87MG(U87)cells in a hydrogel containing type I *** also documents the effect of various oxygen concentrations(1%,7%,and 21%)in the culture environment on U87 cell morphology,proliferation,viability,cell cycle,apoptosis rate,and ***,it compares two-dimensional(2D)and 3D *** comparison purposes,cells cultured in flat culture dishes were used as the control(2D model).Cells cultured in the 3D model proliferated more slowly but had a higher apoptosis rate and proportion of cells in the resting phase(G0 phase)/gap I phase(G1 phase)than those cultured in the 2D ***,the two models yielded significantly different cell ***,hypoxia(e.g.,1%O2)affected cell morphology,slowed cell growth,reduced cell viability,and increased the apoptosis rate in the 3D *** results indicate that the constructed 3D model is effective for investigating the effects of biological and chemical factors on cell morphology and function,and can be more representative of the tumor microenvironment than 2D culture *** developed 3D glioblastoma tumor model is equally applicable to other studies in pharmacology and pathology.

摘要：[目的]为了解决城市轨道交通供电系统存在的再生能量利用和网压波动大的问题,提出一种基于双向变流供电技术的牵引系统供电方案。[方法]介绍了双向变流器的主电路拓扑及其运行逻辑;提出了独立供电和混合供电两种模式下的双向变流器控制特性,并设计了恒压和下垂相结合的外特性曲线;以徐州地铁2号线为例,进行了车辆段试车线单列车AW0(空载)牵引及制动工况下的独立供电和混合供电试验,以及正线12列车正常运行工况下的独立供电和混合供电试验,测试了列车运行性能指标和双向变流器性能指标。[结果及结论]双向变流器可根据线路上的列车运行工况,自动、平滑地切换整流及逆变运行模式,与列车的牵引及制动工况自动适应。采用双向变流供电能够显著改善列车网压的波动,避免网压低于1500 V的工况,改善了列车的牵引运行特性。

摘要：针对卫星姿态控制系统(ACSs)在复杂工况下的执行器、传感器并发故障估计问题,设计了一种基于优化超基函数神经网络的自适应有限时间故障估计观测器。首先,视执行器和传感器故障为系统的附加状态变量,建立时滞广义系统。其次,利用Levy飞行分布改进矮猫鼬优化算法,优化了超基函数神经网络。设计了自适应有限时间观测器,并分析了误差动态和残差对运行噪声的有限时间有界性和鲁棒性,将观测器设计问题转化为线性矩阵不等式问题。最后,进行了仿真验证分析,仿真结果表明:相较于基于传统矮猫鼬优化-超基函数神经网络的自适应有限时间观测器,所提方法对于不确定性和外部扰动的联合估计误差降低了13.0%,状态估计误差平均降低了11.3%,并发故障估计误差平均降低了3.2%,验证了所提方法的有效性。