摘要：New energy sources such as solar energy and hydrogen energy have been applied to the Unmanned Aerial Vehicle(UAV), which could be formed as the hybrid power sources due to the requirement of miniaturization, lightweight, and environmental protection issue for UAV. Hybrid electrical propulsion technology has been used in UAV and it further enforces this trend for the evolution to the Hybrid-Powered System(HPS). In order to realize long endurance flight mission and improve the energy efficiency of UAV, many researching works are focused on the Energy Management Strategy(EMS) of the HPS with digital simulation, ground demonstration platforms and a few flight tests for the UAV in recent years. energy management strategy, in which off-line or on-line control algorithms acted as the core part, could optimize dynamic electrical power distribution further and directly affect the efficiency and fuel economy of hybrid-powered system *** order to give the guideline for this emerging technology for UAV, this paper presents a review of the topic highlighting energy optimal management strategies of UAV. The characteristics of typical new energy sources applied in UAV are summarized firstly, and then the classification and analysis of the architecture for hybrid power systems in UAV are presented. In the context of new energy sources and configuration of energy system, a comprehensive comparison and analysis for the state of art of EMS are presented, and the various levels of complexity and accuracy of EMS are considered in terms of real time, computational burden and optimization performance based on the optimal control and operational modes of UAV. Finally, the tendency and challenges of energy management strategy applied to the UAV have been forecasted.

摘要：Short-range ordering(SRO)is one of the most important structural features of high entropy alloys(HEAs).However,the chemical and structural analyses of SROs are very difficult due to their small size,complexed compositions,and varied *** electron microscopy(TEM)as well as its aberration correction techniques are powerful for characterizing SROs in these compositionally complex *** this short communication,we summarized recent progresses regarding characterization of SROs using TEM in the field of *** using advanced TEM techniques,not only the existence of SROs was confirmed,but also the effect of SROs on the deformation mechanism was ***,the perspective related to application of TEM techniques in HEAs are also discussed.

摘要：我国现有近视患者多达5亿,具有"早发高发、程度重、并发症多"的鲜明特点,社会经济负担沉重,防治形势严峻。近视及其并发症防治的重要前提是阐明其发病机制,目前相关研究主要有遗传、环境调控、视网膜多巴胺-脉络膜血流-巩膜缺氧和炎症四类学说,但都不能很好地解释近视及其并发症的共性机制,最根本的科学问题尚无理想答案。根据2014—2023年近视领域国家自然科学基金项目申请和资助情况,近视领域基础研究相对滞后,顶层设计尚有欠缺,科学问题凝练不足,缺乏有组织的研究,研究方向相对独立且分散,缺乏深度交叉融合,未形成突破性、引领性的成果,研究水平尚需进一步提高。未来国家自然科学基金将进一步加强近视领域基础研究的顶层设计,优化资助布局,加大资助强度,引导高水平临床学者和基础研究人员,着力提高近视及其并发症防治的基础研究水平,真正实现全生命周期的近视防治。

摘要：为了探究潜液式液氢泵电机发热引起的气泡对泵吸入口流动的影响,建立了液氢低温潜液泵泵池内流固耦合两相流CFD数值模型,分析了不同泵装置气蚀余量(NPSHa)下泵池内三维流场、温度场及相位分布的瞬态特性,特别关注蒸发产生的气泡在泵池内的动态分布。研究结果表明,在不同NPSHa下,泵池内由于电机发热,周围局部液氢会气化产生两相流,泵池内温度分布与两相分布保持稳定;部分未经泵池出口排出的气相会聚集在泵池上方,形成稳定的分界层,且不会对流到泵诱导轮吸入口,即漏热及电机发热等产生的两相流不会对液氢潜液泵的稳定运行产生影响,验证了液氢泵与泵池设计方案的合理性和可靠性;但当NPSHa低于0.9 m时,泵池中过多的气相会导致泵转动部件与电机散热及润滑恶化,可能会导致潜液泵运行失稳与损坏。

摘要：直流变电站失压补偿方法直接对蓄电池容量配置模型进行构建，未对直流变电站失压机理表征信息进行抽取，导致方法失压、补偿效果差。为此，提出考虑蓄电池容量配置的直流变电站失压补偿方法，抽取直流变电站失压机理表征信息，为模型构建提供基础。考虑蓄电池容量配置构建蓄电池容量配置模型，设计了直流变电站失压补偿流程实现失压补偿。实验结果表明，该方法中蓄电池的利用效率更高，直流变电站失压补偿效果更好，值得推广。

摘要：问题导向是规划设计方案编制中常用的方法,但须层层发掘、主动设问,从找寻解决问题的对策中获得设计思路。三门现代农业园区核心区规划设计方案采取问题导向,探寻场地的制约条件和区域角色,明确功能定位和主题理念,塑造适宜的空间氛围与景观格局,营造出具有地域特色的空间形态。

摘要：有源调谐型混合滤波器（active tuned hybrid power filter,ATHPF）是一种新型的混合电力滤波器,其直流侧电压值的大小与波动将直接影响ATHPF补偿性能。该文讨论了ATHPF的工作原理和功率交换过程,从理论层面分析直流侧电压波动的原因和特性,并提出能够大幅降低直流侧电压值的选取方法。结果发现由于ATHPF中无源滤波器对基波呈现高阻抗,所以很难采用自励方式对直流侧电压进行稳定控制,因此采用他励式ATHPF结构,应用比例谐振控制对电压波动进行抑制,搭建他励式ATHPF仿真模型与实验系统。仿真和实验结果说明,直流侧电压值在大幅降低后仍保证了ATHPF补偿性能,验证了理论分析和电压选取方法的正确性及控制策略的有效性,为ATHPF的工程应用提供设计参考依据。

摘要：针对微网柔性并网系统中储能装置接口电路运行效率低、动态性能差的问题,提出一种基于PI或PID与最优轨迹混合控制的L-LLC谐振双向全桥变换器(L-LLC resonant bidirectional DC-DC converter,L-LLC BDC),实现了输入侧开关管的零电压开通和输出侧整流管的零电流关断,显著提高了变换器的动态性能,相对于最优轨迹控制,大量减小了运算的复杂度,提高了开关管的开关频率。采用状态平面法从理论层面对L-LLC-BDC的运行状态及特性进行了详细描述,在此基础上设计了储能装置接口电路控制系统。仿真结果表明,基于PI或PID与最优轨迹混合控制的L-LLC-BDC储能装置接口电路理论分析的正确性和动态性能的优越性,保证了微网柔性并网系统的运行性能。

摘要：为研究叶轮式通风器分离特性并建立满足工程设计要求的分离效率计算方法,在对油滴进行了受力分析后,推导了油滴运动轨迹模型,结合油滴捕获条件,给出了不同工况条件下油滴的最小分离直径,进而实现了叶轮式通风器分离效率的理论计算。研究表明:在不同转速、通风量和通风器入口温度时,分离效率和最小分离直径计算值与实验值趋势一致;分离效率最大误差分别为0.95%、1.01%和1.01%;最小分离直径最大误差分别为1.33%、2.29%和6.20%。计算结果与实验结果吻合较好,该方法可为叶轮式通风器设计及分离性能优化提供参考。

摘要：方形断面的细长结构广泛的应用在工程领域,其在特定风向角和特定的风速范围下会发生具有较大危害性的驰振,目前斜置或者斜风向作用下的细长方柱驰振不稳定性的规律尚不清楚。采用刚性模型测压风洞试验,通过对斜置方柱气动力的分析,讨论了风偏角对方柱气动力的影响,基于准定常假设,分析了考虑风偏角的方柱驰振不稳定性。结果表明:方形断面是典型的驰振不稳定断面形状;随着来流与柱体轴向夹角的变小,方形断面的驰振不稳定区域增大,斜风向下的方柱更容易发生驰振,需要在类似结构抗风设计中引起重视。