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1.
为缓解我国水、能源和粮食资源紧张问题,促进资源可持续利用,构建水-能源-粮食系统,利用耦合协调度模型对我国的30个省(自治区、直辖市)进行测算,并利用空间杜宾模型分析主要影响因素。结果表明:2003—2017年,我国能源、粮食评价[JP]指数高于水资源评价指数,系统综合评价指数逐年递增;大部分省份耦合协调度处于初级协调水平且呈现逐年上升的态势,个别省份耦合协调度濒临失调;耦合协调度空间自相关性较强,虽有明显波动,但是呈现逐年加强的态势;影响耦合协调度的主要因素有从业人口数、固定资产投资额、人均生产总值、人口总数、[JP]文盲人口占比、工业污染排放、城镇化。 相似文献
2.
目的 旅游服务设计发展态势良好,从旅游服务设计的角度进行文献可视化分析,可从中获得当前领域的知识结构、研究热点和发展态势,为未来提供旅游服务设计研究和旅游产业的服务设计参考。方法 从CNKI和Web of Science数据库收集1990—2020年国内外的相关数据,运用CiteSpace对旅游服务设计的文献发表时间、高度被引用的文献、研究热点和研究前沿进行可视化分析,比较国内外研究差异。结论 在1990—2020年国内外旅游服务设计研究皆呈上升趋势。国外的研究热度、被引频次高于国内,以跨学科领域研究尤为突出,研究重点在建筑环境和交通相关策略;而国内研究以产品服务系统为主,偏向于技术的实现方式。综观研究现状和趋势,本文从智慧科技旅游、可持续发展和全域旅游进行深入探讨,提出旅游服务设计新发展趋势。 相似文献
3.
Jiachen Wang Jian Li Rui Wang Fei-Yue Xu Xin-An Zeng 《International Journal of Food Science & Technology》2022,57(2):791-800
Frozen poultry meat is the most widely consumed animal-based food. However, water loss often leads to quality loss of poultry meat. Therefore, the present study sought to investigate the combined effect of calcium chloride (CaCl2) and pulsed electric fields (PEF) treatment on chicken breast meats and the mechanisms underlying protein degradation. The results showed that the synergistic effect was superior to the single treatment. Compared with the untreated group, the combination of CaCl2 and PEF increased water holding capacity of chicken breast meats by 16.61% and decreased cooking loss by 28.93%. Low-field nuclear magnetic resonance (LF-NMR) results indicated that the synergistic treatment promoted water molecules' binding capacity in myofibrils of poultry meat, which exhibited higher immobilised water. Additionally, the combination of CaCl2 and PEF led to increased degradation of proteins of high-molecular weight and surface hydrophobicity of myofibrillar protein. Furthermore, the extension of the protein molecule and microenvironmental changes promoted interaction between protein and water. In conclusion, the synergistic treatment of CaCl2 and PEF enhanced water retention and improved physicochemical properties of the myofibrillar protein in chicken breast meats. 相似文献
4.
目的 将数字化服务融入老年患者就诊流程,建立适老化就诊等待服务系统,在APP开发设计研究中实现软件流程优化。方法 依据ERG理论对老年患者在就诊等待过程中的需求点进行分类整理和层次划分。调研目标用户将分析结果融入服务设计理论,为指导软件开发所涉及的医院就诊流程、用户需求痛点,提出系统性的解决策略。基于交互设计原则展开APP界面设计。结论 构建了以老年患者为中心的就诊等待服务系统,帮助提升其等待过程中的自我效能。完善了基于产品使用方式层级的适老化就诊等待服务APP设计策略,为适老化、数字化产品研发提供了新思路;最终产出APP设计实例,提高了老年群体社会参与度,鼓励老年患者自主就诊,帮助其更加轻松地享受信息化时代带来的红利。 相似文献
5.
《International Journal of Hydrogen Energy》2022,47(92):39239-39254
The energy management and trajectory tracking control are crucial to realize long-endurance autonomous flight for hybrid electric UAVs. This study aims to comprehensively consider energy management and trajectory tracking for hybrid electric fixed wing UAVs with photovoltaic panel/fuel cell/battery. A double-layer fuzzy adaptive nonlinear model predictive control method (DFNMPC) is proposed. Separated by the surplus demand power, energy management and trajectory tracking problem are decoupled into the high-layer fuzzy adaptive nonlinear model predictive controll problem (H-FNMPC) and low-layer fuzzy adaptive nonlinear model predictive controll problem (L-FNMPC). H-FNMPC solves the trajectory tracking and navigation control probelm for the greatest benefit of solar energy. L-FNMPC solves the power allocation problem of hybrid energy system for minimum equivalent hydrogen consumption. A fuzzy adaptive prediction horizon adjustment method based on UAV maneuvering degree is proposed to effectively improve proposed method adaptability to different mission profiles. Analogously, a fuzzy adaptive equivalent hydrogen consumption factor adjustment method in L-FNMPC is proposed to ensure the flexible utilization of battery. In addition, an equivalent hydrogen flow rate calculation method based on the real-time current ratio is proposed for PV/FC/Battery hybrid energy system. Numerical simulation results including a spiral trajectory tracking and a quadrilateral trajectory tracking, demonstrate that DFNMPC can simultaneously handle energy management and trajectory tracking problem for hybrid electric UAVs. Compared to hierarchical fuzzy state machine strategy, DFNMPC can save 13.3% hydrogen for the spiral trajectory tracking, and 56.9% for the quadrilateral trajectory tracking. It indicates that the energy efficiency can be improved from both levels of energy management and flight motion. The proposed method prospected for exploring high-energy-efficiency autonomous flight of hybrid electric UAVs in the future. 相似文献
6.
《International Journal of Hydrogen Energy》2022,47(85):36216-36231
The fuel cell/battery durability and hybrid system stability are major considerations for the power management of fuel cell hybrid electric bus (FCHEB) operating on complicated driving conditions. In this paper, a real time nonlinear adaptive control (NAC) with stability analyze is formulated for power management of FCHEB. Firstly, the mathematical model of hybrid power system is analyzed, which is established for control-oriented design. Furthermore, the NAC-based strategy with quadratic Lyapunov function is set up to guarantee the stability of closed-loop power system, and the power split between fuel cell and battery is controlled with the durability consideration. Finally, two real-time power management strategies, state machine control (SMC) and fuzzy logic control (FLC), are implemented to evaluate the performance of NAC-based strategy, and the simulation results suggest that the guaranteed stability of NAC-based strategy can efficiently prolong fuel cell/battery lifespan and provide better fuel consumption economy for FCHEB. 相似文献
7.
One of the most challenging issues in radio received signal strength (RSS)-based localization systems is the generation and distribution of a radio map with a coordinate system linked with spatial information in a large indoor space. This study proposes a novel spatial-tagged radio-mapping system (SRS) that effectively combines the heterogeneous properties of LiDAR and mobile phones to simultaneously perform both spatial and radio mappings. The SRS consists of synchronization, localization, and map building processes, and enables real-time spatial and radio mapping. In the synchronization process, the distance range, motion data, and radio signals obtained through the LiDAR and mobile phone are collected in nodal units according to the sensing time. In the localization process, a feature variance filter is used to control the number of features generated from LiDAR and estimate the positions at which the nodes are generated in real time according to the motion data and radio signals. In map building, the estimated positions of the nodes are used to extract spatial and radio maps by using a unified location coordinate system. To ensure mobility, the SRS is manufactured in the form of a backpack supporting LiDAR and a mobile phone; the usefulness of the system is experimentally verified. The experiments are performed in a large indoor shopping mall with a complex structure. The experimental results demonstrated that a common coordinate system could be used to build spatial and radio maps with high accuracy and efficiency in real time. In addition, the field applicability of the SRS to location-based services is experimentally verified by applying the constructed radio map to well-known fingerprinting algorithms using the heterogeneous mobile phones. 相似文献
8.
摘 要:核心网业务模型的建立是5G网络容量规划和网络建设的基础,通过现有方法得到的理论业务模型是静态不可变的且与实际网络存在偏离。为了克服现有5G核心网业务模型与现网模型适配性较差以及规划设备无法满足用户实际业务需求的问题,提出了一种长短期记忆(long short-term memory,LSTM)网络与卷积LSTM (convolution LSTM,ConvLSTM)网络双通道融合的 5G 核心网业务模型预测方法。该方法基于人工智能(artificial intelligence,AI)技术以实现高质量的核心网业务模型的智能预测,形成数据反馈闭环,实现网络自优化调整,助力网络智能化建设。 相似文献
9.
《International Journal of Hydrogen Energy》2022,47(79):33571-33596
This article provides a critical assessment of H2 from the standpoint of more widespread use as a sustainable fuel for Indian mobility applications in the global context. The potential techno-economic advantages of utilizing H2 for automobiles rather than battery electric vehicles or conventional internal combustion engine vehicles are emphasized. The present assessment demonstrates that H2 production, storage, and distribution costs are the primary challenges, and a significant improvement is still necessary for H2 to compete either against the internal combustion engine vehicle or the battery electric vehicle to win the race, arguably. The secondary challenges have also been demonstrated, which include the cost of the fuel cell stack and the modifications associated with internal combustion engine vehicles, as well as regulatory and safety concerns, which impede the widespread usage of H2. It is critical that policy-making for sustainable mobility in India is possible with the aid of a National H2 Energy Road-Map. This in turn can achieve a cost target of $0.5/kg for H2. 相似文献
10.
在广电总局和省局指示精神的指导下,江苏有线三网融合枢纽中心建成了省中心集中汇聚,分中心独立管控的三级安播监管体系。本文从建设目标,网络结构,系统组成等方面介绍了江苏有线安播监管系统,提出了“播监控三维一体”,“省市县三位一体”的省级全覆盖式安播监管体系解决方案。 相似文献