摘要：针对传统的水下机器人运动效率低、水下作业时产生的噪声污染会影响鱼群生活环境、隐蔽性差容易被雷达探测识别,而大多数仿生鱼尾部摆动模式不够灵活、环境适应性差的问题,提出了一种基于多自由度鱼尾的仿生机器鱼的结构方案。该鱼尾能够产生横向和纵向两个方向的运动矢量,尾部能够进行更加灵活的摆动。对机器鱼尾部结构进行了实验,实验结果表明:在横向上驱动线变化量为50 mm时达到最大摆角116°,纵向上驱动线变化量在46 mm时达到纵向最大摆角61°。

摘要：以一种大功率机车用氢燃料电池热管理系统为基础,通过对氢燃料电池热管理系统的总体结构特点、技术参数、技术设计进行计算分析,并根据整车联调试验验证不同运行工况下的控制策略,达到热的集成化、模块化设计,满足大功率机车用氢燃料电池冷却需求,使燃料电池系统保持在最佳工作温度下工作。

摘要：针对电机驱动中SiC MOSFET模块发热及其在自身器件内热量传导问题,分析功耗来源和计算方法,计算功率器件工作时的功耗,建立功率器件热模型,结合模块属性和参数,列出传热方程并确定边界条件,最终得出一种基于分离变量法快速计算功率器件内某点热量的方法。将数值计算结果分别与Icepak中得到的仿真结果和实际工程测量结果对比,验证此计算方法的准确性,为设计阶段功率器件的选型和热量计算提供有效参考和借鉴。

摘要：目的了解上海和陕西中职生的性与生殖健康知识、性教育状况及相关因素,为中职校开展性教育提供科学依据。方法2021年4—6月,采用方便与整群抽样相结合的方法在上海市和陕西省3座城市(商洛、安康和宝鸡)共选取6所中职学校一至三年级3180名中职生进行调查。采用自行设计的调查问卷进行线上调查,调查内容包括个人特征、家庭背景、家庭及学校性教育现况、青少年的性与生殖健康(SRH)知识及来源。采用t检验和χ^(2)检验进行组间比较,对SRH知识总分按四分位数进行分组拟合多分类有序Logistic回归模型分析。结果中职生性与生殖健康知识总均分为(51.36±21.61),在不同维度的知识得分中,以性骚扰/性侵害知识得分(66.45±42.27)较高,生殖生理(47.67±31.94)和避孕知识得分(43.85±26.81)较低。两地中职生最主要的知识来源是学校/老师、网络、同学或朋友。学校性教育主题以青春期发育与保健为主(占比超过80%),与父母讨论SRH最多的话题是人际关系(占比超过55%),且两地中职生的报告率差异均有统计学意义(χ^(2)值分别为28.56,32.02,P值均<0.05)。多因素Logistic回归分析结果显示,居住地区、性别、年级、户籍、与父母讨论的SRH话题数量、接受学校SRH教育主题数量、从同学/朋友交流过SRH信息、从书籍/杂志/报纸获取过SRH信息、从网络和社区获取过SRH信息与中职生性知识水平均有关(OR值分别为1.62,0.72,1.20,1.58,2.09,1.17,1.18,1.66,1.62,1.69,1.22,P值均<0.05)。结论上海和陕西中职生的性与生殖健康知识水平普遍偏低。应加强学校老师和家长的培训,提高其性教育意识和性教育能力,推动中职生性教育的开展。

摘要：During advanced water detection using the transient electromagnetic method, the exploration effect for water-rich area is often poor due to the interference of bolts that are distributed in different positions in working face. Thus, the study on the interference characteristics of bolts in different states has important directive significance for improving the acquisition quality and data processing method in water detection. Based on the analysis of the distribution laws of magnetic field excited by small multi-turn coincident loop in full space of homogeneity, the test on the interference of bolts has been designed in the mine. Through drilling 18 holes around the overlapping coil in the working face, mass data are collected in order with the posi- tion change and the exposed bolt length. The results of comprehensive data analysis show that the transient electromagnetic field is strongly interfered as the distance between the bolt and the center of the coil is less than 3 m, and the interference varies greatly as the distance varies. On the other hand, the field induced by the bolts can be ignored as the distance exceeds 3 m. The findings can help to improve data acquisition and correction during advanced water detection when using the transient electromagnetic method.

摘要：万寿菊是重要的药食同源中药材,需求广泛,年种植量巨大。然而,由于收获要求高、花朵垂直分布范围大,其采摘目前依然只能手工完成,劳动强度大、效费比低,已严重制约了其产业的发展。为此,设计了一种全新的万寿菊采摘机,其主要由高通过性机架、电动驱动轮、智能升降采摘系统、激光雷达、储花袋和控制系统组成,锂电池组为全机提供动力。其一,该机梳齿式采摘台根据万寿菊生理参数和结构特点设计,以拔摘式方式摘除,其特点是进花率高、且对未达采摘要求的花苞误摘率低。其二,控制系统可据激光雷达数据求得万寿菊平均高度,并据此自主决定摘台位置,从而提高花朵采摘率,降低劳动强度,达到应收尽收。田间试验表明:该采摘机运行流畅,万寿菊平均高度的测量误差在1 cm之内。当梳齿间距为12 mm、梳齿长度为250 mm、前进速度为0.3 m/s时,采摘效果最佳,采摘率不低于91.55%,误摘率不超过8.82%。该成果是智能检测及控制系统在中药材收获领域的一次有益尝试,为精准农业理念更深入的推广应用提供了新借鉴。

摘要：针对继电保护小室内的二次电缆线束因设计排布及装配不合理导致线束故障频发的问题,提出了一种新的基于IPS的继电保护小室二次电缆柔性线束运动仿真分析及优化设计方法。该方法以继电保护小室柜内的多组二次电缆柔性线束为研究对象,首先通过获取线束的材料参数及空间结构,基于IPS软件建立继电保护小室与二次电缆线束的力学约束和运动模型;然后对柔性长线束进行动态仿真分析,通过提取线束运动过程的几何变形、间隙、应力应变、弯曲扭曲等变量,准确定位线束故障发生的位置和时刻并进行定量分析,基于IPS实现优化设计,实现了线束虚拟装配、风险动态分析及评估、线束疲劳分析及寿命预测等;最后通过现场实物验证对仿真结果进行了验证。验证结果表明,通过仿真分析能有效地定位故障位置,仿真分析结果与实物测量结果一致,满足对标要求,该方法能够有效发现和消除线束的故障隐患,提高线束设计和安装的可靠性。

摘要：构建了一种全新的专业设计型实验体系:双阳离子液体的制备及萃取分离甲苯-正庚烷共沸体系。合成并表征新型“绿色溶剂”双阳离子液体;以双阳离子液体作为萃取剂,测定其对甲苯-正庚烷共沸体系的分离能力并进行相图绘制。通过该综合实验教学,既促进学生对多学科基础知识的掌握,又能激发学生科研探索兴趣,培养其绿色化学意识与理念。

摘要：Coupled with anionic and cationic redox chemistry,li-rich/excess cathode materials are prospective high-energy-density candidates for the next-generation li-ion ***,irreversible lattice oxygen loss would exacerbate irreversible transition metal migration,resulting in a drastic voltage decay and capacity ***,a metastable layered li-excess cathode material,T2-type li_(0.72)[li_(0.12)Ni_(0.36)Mn_(0.52)]O_(2),was developed,in which both oxygen stacking arrangement and li coordination environment fundamentally differ from that in conventional O3-type layered *** means of the reversible li migration processes and structural evolutions,not only can voltage decay be effectively restrained,but also excellent capacity retention can be achieved upon long-term ***,irreversible/reversible anionic/cationic redox activities have been well assigned and quantified by various in/ex-situ spectroscopic techniques,further clarifying the charge compensation mechanism associated with(de)*** findings of the novel T2 structure with the enhanced anionic redox stability will provide a new scope for the development of high-energy-density li-rich cathode materials.

摘要：To design heap biooxidation process,it is necessary to understand its internal *** heap biooxidation of gold ore from Anhui province was researched in this *** results showed that the main microorganisms in the heap were ***,*** and *** their combined action,gold leaching extent rose from 35.62%to 78.08%in 80 *** model matches the actual oxidation effect better and the model equations were *** model predicted that the oxidation extents of arsenic and sulfur are 58.577%and 42.122%after one year,and the gold leaching extent was 80.40%.The arsenic and sulfur oxidation extents,and gold leaching extent were all linearly *** is more reliable to predict gold leaching extent by sulfur oxidation *** results provided good guidance for practical application in the actual production.