Electrospinning-hot pressing technique for the fabrication of thermal and electrical storage membranes and its applications

The combination of electrospinning and hot pressing,namely the electrospinning-hot pressing technique(EHPT),is an efficient and convenient method for preparing nanofibrous composite materials with good energy storage performance.The emerging composite membrane prepared by EHPT,which exhibits the advantages of large surface area,controllable morphology,and compact structure,has attracted immense attention.In this paper,the conduction mechanism of composite membranes in thermal and electrical energy storage and the performance enhancement method based on the fabrication process of EHPT are systematically discussed.Moreover,the state-of-the-art applications of composite membranes in these two fields are introduced.In particular,in the field of thermal energy storage,EHPT-prepared membranes have longitudinal and transverse nanofibers,which generate unique thermal conductivity pathways;also,these nanofibers offer enough space for the filling of functional materials.Moreover,EHPT-prepared membranes are beneficial in thermal management systems,building energy conservation,and electrical energy storage,e.g.,improving the electrochemical properties of the separators as well as their mechanical and thermal stability.The application of electrospinning-hot pressing membranes on capacitors,lithium-ion batteries(LIBs),fuel cells,sodium-ion batteries(SIBs),and hydrogen bromine flow batteries(HBFBs)still requires examination.In the future,EHPT is expected to make the field more exciting through its own technological breakthroughs or be combined with other technologies to produce intelligent materials.

Integrated Techniques of Underground CO_2 Storage and Flooding Put into Commercial Application in the Jilin Oilfield, China

Global warming touches everybody＇s nerve, and direct reason for sharp increasing of CO2 in the atmosphere results mainly from the use of fossil fuel in power generation and other industries. How can humans return this ＂devil＂ to underground, and keep a peaceful environment for human？ Scientists from all over the world have been exploring them.

Research on the New Mobile Development Paradigm based on HTML5 and Database Storage Optimization Techniques

In this paper, we conduct research on the new mobile development paradigm based on the HTML5 and core database storage optimization techniques. With the development of mobile Internet technology and the popularity of smart mobile devices, mobile Internet is becoming more and more obvious in the importance of life, mobile application development is also becoming more and more important. The current mainstream development include the mode of traditional native application development, Web application development based on it, and based on the mixed mode of third-party framework development. The practice of software engineering, points out that productivity of the software breakthrough is the introduction of basic software reuse. Object-oriented framework is an important research content in modern software engineering. Under this basis, we propose the related optimization countermeasures for systematic modifi cation that is meaningful.

Research progress on construction and energy storage performance of MXene heterostructures

MXenes are a family of two-dimensional (2D) transition metal carbides, carbonitrides/nitrides with superior physical and chemical properties, which have attracted extensive attention since the discovery in 2011. The impressive electrochemical activity of MXene makes it one of the most potential electrode materials in rechargeable batteries and supercapacitors. However, single-component MXene electrodes are difficult to achieve high specific capacity, efficient ion/electron transport, and high stability compatibility in an electrochemical environment. Studies have shown that it is an effective method to introduce nanomaterials between MXene layers to construct heterostructures and to improve the electrochemical performance through the synergistic effect among the components in the heterostructures. The introduction of nanomaterials can effectively suppress the restacking of MXene nanosheets, shorten the diffusion path of ions and promote the electrolyte transport, which is beneficial to enhance the rate performance of MXene;moreover, the excellent mechanical flexibility of MXene can reduce the volume expansion of nanomaterials during charge/discharge, thereby effectively protecting the integrity of the electrode structure and improving the cycling stability. Therefore, in this review, combined with theoretical calculations, we summarize the recent advances of MXene heterostructures in terms of synthesis strategies and energy storage applications, including supercapacitors, metal-ions batteries (Li, Na, K, Mg, Zn, Al) and metal anode protection. Furthermore, potential challenges and application perspectives for MXene heterostructures are also outlined.

Development of Strip Casting Technology in Rare Earth Permanent Magnet Alloys and Hydrogen Storage Alloys in China

The SC technique is now being applied widely in material preparation, especially in rare earth functional materials in virtue of its advanced process and high performance product. The applications of SC technique in rare earth permanent magnet alloys and hydrogen storage alloys were analyzed integrative, on the basis of summary of SC technique development in this paper. The paper mainly includes development history of SC technology, effect of SC technology on alloy microstructure, application of SC technology in RE storage hydrogen alloy and sintered Nd-Fe-B alloy, development of SC equipment and SC product industry. At the same time, the paper points out the existing problem of SC products.

Evaluation of On-Line MPPT Algorithms for PV-Based Battery Storage Systems

This paper presents a novel Simulink models with an evaluation study of more widely used On-Line Maximum Power Point tracking(MPPT)techniques for Photo-Voltaic based Battery Storage Systems(PV-BSS).To have a full comparative study in terms of the dynamic response,battery state of charge(SOC),and oscillations around the Maximum Power Point(MPP)of the PV-BSS to variations in climate conditions,these techniques are simulated in Matlab/Simulink.The introduced methodologies are classified into two types;the first type is conventional hill-climbing techniques which are based on instantaneous PV data measurements such as Perturb&Observe and Incremental Conductance techniques.The second type is a novel proposed methodology is based on using solar irradiance and cell temperature measurements with pre-build Adaptive Neuro-Fuzzy Inference System(ANFIS)model to predict DC–DC converter optimum duty cycle to track MPP.Then evaluation study is introduced for conventional and proposed On-Line MPPT techniques.This comparative study can be useful in specifying the appropriateness of the MPPT techniques for PV-BSS.Also the introduced model can be used as a valued reference model for future research related to Soft Computing(SC)MPPT techniques.A significant improvement of SOC is achieved by the proposed model and methodology with high accuracy and lower oscillations.

Improved Cloud Storage Encryption Using Block Cipher-Based DNA Anti-Codify Model

When it comes to data storage,cloud computing and cloud storage providers play a critical role.The cloud data can be accessed from any location with an internet connection.Additionally,the risk of losing privacy when data is stored in a cloud environment is also increased.A variety of security techniques are employed in the cloud to enhance security.In this paper,we aim at maintaining the privacy of stored data in cloud environment by implementing block-based modelling to boost the privacy level with Anti-Codify Technique(ACoT)and block cipher-based algorithms.Initially,the cipher text is generated using Deoxyribo Nucleic Acid(DNA)model.Block-cipher-based encryption is used by ACoT,but the original encrypted file and its extension are broken up into separate blocks.When the original file is broken up into two separate blocks,it raises the security level and makes it more difficult for outsiders to cloud data access.ACoT improves the security and privacy of cloud storage data.Finally,the fuzzy-based classification is used that stores various access types in servers.The simulation results shows that the ACoT-DNA method achieves higher entropy against various block size with reduced computational cost than existing methods.

Novel Data Placement Algorithm for Distributed Storage System Based on Fault-Tolerant Domain

The 3-replica redundancy strategy is widely used to solve the problem of data reliability in large-scale distributed storage systems. However, its storage capacity utilization is only 33%. In this paper, a data placement algorithm based on fault-tolerant domain (FTD) is proposed. Owing to the fine-grained design of the FTD, the data reliability of systems using two replicas is comparable to that of current mainstream systems using three replicas, and the capacity utilization is increased to 50%. Moreover, the proposed FTD provides a new concept for the design of distributed storage systems. Distributed storage systems can take FTDs as the units for data placement, data migration, data repair and so on. In addition, fault detection can be performed independently and concurrently within the FTDs.

压缩空气储能系统地下人工硐室技术及其评价技术研究

压缩空气储能是大规模长时间的新型物理储能形式。储气库是压缩空气储能系统中至关重要的组成部分。对常用储气装置特点进行分析与总结,针对地下人工硐室进行比较详细的讨论;对压缩空气储能系统地下人工硐室相对于其他类型储气库的优势进行了归纳;对地下人工硐室承载结构、密封系统、传热管理系统等自身设计因素进行了分析;分析讨论了影响地下人工硐室运行过程中的选址、埋深以及压力设计准则等关键技术;对影响人工硐室稳定运行的相关因素提出了评价方法以及评价指标。在此基础上,对压缩空气储能地下人工硐室未来发展方向进行了展望,为地下人工硐室的结构合理性设计与稳定性运行提供参考。

河北省露地菜田固碳增活对策及解决方案

河北省是蔬菜生产大省,但露地蔬菜生产中养分管理较为粗放,长期存在有机物料施用种类单一、偏施化学氮肥、肥料养分配比失衡等问题,导致土壤有机质水平低、有效养分供应能力弱、连作障碍频发。针对露地蔬菜生产中存在的施肥问题,建立了固碳增效与沃土增活综合施肥技术,制定了全程施肥解决方案。有助于改善与提升菜田土壤质量,促进蔬菜稳产增产和菜农增收,具有广阔的应用前景。

原料肉冻藏品质劣变机制及其改善策略

原料肉在冷冻、冻藏和解冻过程中会发生一系列物理化学变化,其品质特性不可避免地遭到破坏,主要表现为持水能力下降、色泽和质构劣变,采用新型冷冻及其辅助技术能够有效地降低由此造成的品质劣变。本文概述了原料肉在冷冻、冻藏过程中品质劣变机制,综述了新型冷冻技术、抗冻保护剂、新型包装技术以及新型解冻技术等提升原料肉品质的方法,以期为原料肉冻藏品质的改善提供理论依据和技术指导。

海参贮藏过程中品质变化、影响因素和调控技术研究进展

海参高蛋白、低脂肪,具有极高的营养价值,其独特的自溶特性导致捕捞后必须马上进行加工处理。海参贮藏过程中通常会发生一系列复杂的生化变化,从而导致其营养损失、品质下降,严重影响其商业价值。本文在概述海参贮藏过程中品质变化的基础上,对其内源性蛋白酶、微生物、非酶凝胶劣化、贮藏条件和预处理方式等主要影响因素以及低温、超高压、天然生物保鲜剂、蛋白酶抑制剂和生物交联等主要调控技术进行了系统地归纳和总结,并对未来品质劣化机制揭示、贮藏技术体系构建等研究重点方向和发展趋势进行了展望,以期能为海参精深加工产业的高质量发展提供一定的理论参考与借鉴。

电池储能系统状态估计综述

为了提高多场景应用的技术经济性,本文对电池储能系统状态估计进行了综述。首先,分析了电池性能衰减的机理,介绍了目前常用的物理建模和数据建模方法,进而对荷电状态(state of charge,SOC)和健康状态(state of health,SOH)进行了定义与关联性分析,并对电池及其系统的状态估计方法进行了汇总;其次,为了获取更多精确的电池运行数据,重点介绍了能够刻画电池内部演化机理的原位/非原位表征技术,进而分析了嵌入式电池管理系统(battery management system,BMS)实际应用的主流开发路线;第三,提出了基于联邦学习的电池储能系统状态估计方法,基于轻量化模型在本地进行电池储能系统SOC的估计以保证控制实时性,基于大数据驱动策略在云中心进行其SOH估计以保证容量可信度,由此实现云边的交互与协同;最后,对电池储能系统未来可能的发展方向和研究重点进行了预测。研究结果表明:活性锂损失是锂离子电池容量衰退的主要原因,高温、低温、过充放等滥用也会加速电池性能衰减;数据驱动在电池系统级建模与状态评估方面具有较大优势;利用原位/非原位表征技术可以获取更多的电池内部状态数据,基于FPGA的BMS轻量化建模更易实现,基于联邦学习的状态评估方法能够提高电池储能系统的智慧化运维水平。

基于AHP和TOPSIS-模糊综合评价的多场景储能选型方法

目前储能技术路线多样,不同类型的储能各具应用前景,但储能选型需要综合考虑经济性、安全性等因素,是一个复杂的多目标决策问题,因此储能选型是工程应用中的关键问题之一。提出一种将层次分析法(analytic hierarchy process,AHP)和优劣解距离法(technique for order preference by similarity to ideal solution,TOPSIS)-模糊综合分析法相结合的储能选型评价体系。首先,通过建立评价体系的判断矩阵,利用AHP获取指标权重;其次,将判断矩阵里量纲不同的指标类型用TOPSIS做规范化处理,以此获得更客观的权重向量,改善AHP法的主观性;而后,将指标权重对角化处理并与标准化后的矩阵相乘获得加权判断矩阵,并求取贴近度向量。最后,加权判断矩阵与模糊综合分析法关系矩阵相乘获取储能类型的隶属度评价结果,并以隶属度最大值所在的等级为最终评价,处于等级Ⅰ中最佳,等级Ⅱ次之并以此类推;由此通过TOPSIS获得更客观的权重向量,改善AHP法的主观性,得到的权重向量也更客观。最后以锂离子电池、钠硫电池和铅酸电池等七种储能类型在应用于削峰填谷、电网保供电和改善电压质量场景为例,并与现有的储能选型方法进行比较,体现该评价体系的创新,检验所提评价体系和选型方法的有效性。

压气机叶顶间隙流动与控制研究进展

压缩空气储能被视为最具发展潜力的物理储能技术,作为其核心部件,压气机的性能表现在较大程度上决定着储能系统的经济性和效率。叶顶间隙流动因其复杂的三维流动特性,对压气机内部流场结构变化存在重要作用,是影响整机性能的关键因素。文章依照叶顶结构特点分类总结了带冠、无冠轴流压气机和开式/半开式、闭式离心压气机叶顶间隙流动产生的机理,根据压气机流动特性,进一步综述国内外压气机叶顶间隙流动的研究进展,形成以下结论:对于无冠轴流压气机,非定常叶顶间隙流动与失速、叶片噪声及振动问题密切相关,需扩充研究成果以优化叶顶设计;带冠轴流压气机缺乏实验和数据支撑,流动控制手段单一,可尝试跨领域应用控制技术;离心压气机叶顶间隙流动研究仍需探索变间隙特性和周向不均匀性对流动结构的影响,并提升应对流场变化的能力。未来研究可着重于高精度数值模拟方法的应用推广、跨领域控制技术的尝试和复合结构的探索。

基于回声感知技术的介质温度监测

声学温度感知技术具有测温范围广、精度高、速度快等特点,在空冷系统和仓储室测温领域应用前景广阔。针对空冷系统和仓储室现有测温技术的问题,该文研究了回声法测温的可行性及稳定性,利用改进后的互相关法测得时延估计,进一步计算得到介质温度。分别用扫频脉冲信号和高斯脉冲信号作为激励声源信号进行仿真,得到高斯脉冲信号测温效果更好。在常温下进行大空间回声测温实验,并在管道内进行不同温度下的回声测温实验。结果表明,上述工况均能得到准确稳定的待测温度,最大绝对误差为±0.85◦C,有望应用在空冷系统测温和粮温测量中。

国外固体火箭发动机药柱结构完整性评估技术发展及启示

药柱结构完整性评估对于固体火箭发动机的设计和使用维护至关重要。文章第一部分以二十年为一个阶段,回顾了美国从20世纪50年代到本世纪初药柱结构完整性评技术的发展历史。每个阶段按发展重点,从黏弹性理论分析、强度失效、试验测试方法、药柱状态监测及老化性能研究等角度进行了概述,分析了技术演变过程和相互关系。第二部分,分析了美国药柱结构完整性评估技术发展历程对固体推进剂性能试验技术、固体推进剂数值方法、失效评估及寿命预估四个关键问题研究带来的启示,讨论了固体推进剂及粘接界面性能表征方法、多尺度本构与仿真技术、高精度失效评估与寿命预测、药柱结构验证性试验技术以及跨学科方法的发展趋势。

分子模拟技术在食品领域中的应用研究进展

从食品领域的上游实验室研发到下游工厂生产过程中,有许多问题无法用传统试验方法从宏观上得到解决。分子模拟技术不仅简洁高效、成本低廉,还可以通过对分子行为的分析快速预测或解释试验结果,是连接微观与宏观的重要工具。文章阐述了食品领域分子模拟技术的基本原理,梳理了食品领域分子模拟技术常用的数据库和软件及其特点,综述了近几年分子模拟技术在食品安全、食品加工和贮藏、食品功能因子筛选及其机制研究领域中的应用研究进展。

影响油茶籽油品质的因素分析

油茶籽油属于高品质的烹饪食用油,还是一种新型的天然植物油。其营养价值丰富,且有益于人体健康,在世界范围内受到了广泛的研究与关注。然而,油茶籽油的品质受其品种特性、栽培方式、土壤性质、管理措施、加工工艺、海拔高度等诸多因素的影响,使油茶籽油的理化指标和成分含量等发生变化,因此有必要研究影响其品质的因素。本文对影响油茶籽油品质的因素,如产地、预处理方式、加工工艺、贮藏方式等进行了综合评述。