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Secure Path Cycle Selection Method Using Fuzzy Logic System for Improving Energy Efficiency in Statistical En-Route Filtering Based WSNs
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作者 Su Man Nam Chung Il Sun Tae Ho Cho 《Wireless Sensor Network》 2011年第11期357-361,共5页
Sensor nodes are easily compromised to malicious attackers due to an open environment. A false injected attack which takes place on application layer is elected by the compromised node. If the false report arrives in ... Sensor nodes are easily compromised to malicious attackers due to an open environment. A false injected attack which takes place on application layer is elected by the compromised node. If the false report arrives in a base station, a false alarm is occurred, and the energy of the nodes is consumed. To detect the false report, statistical en-route filtering method is proposed. In this paper, we proposed the secure path cycle selection method using fuzzy rule-based system to consume effective energy. The method makes balanced energy consumption of each node. Moreover, the lifetime of the whole network will be increased. The base station determines the path cycle using the fuzzy rule-based system. The performance of the proposed method is demonstrated using simulation studies with the three methods. 展开更多
关键词 Wireless Sensor Network securE PATH CYCLE SELECTION STATISTICAL en-route FILTERING PATH SELECTION Method Fuzzy System
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Progress and prospects of innovative coal-fired power plants within the energy internet 被引量:7
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作者 Yongping Yang Chengzhou Li +1 位作者 Ningling Wang Zhiping Yang 《Global Energy Interconnection》 2019年第2期160-179,共20页
The development of electrical engineering and electronic, communications, smart power grid, and ultra-high voltage transmission technologies have driven the energy system revolution to the next generation: the energy ... The development of electrical engineering and electronic, communications, smart power grid, and ultra-high voltage transmission technologies have driven the energy system revolution to the next generation: the energy internet. Progressive penetration of intermittent renewable energy sources into the energy system has led to unprecedented challenges to the currently wide use of coal-fired power generation technologies. Here, the applications and prospects of advanced coal-fired power generation technologies are analyzed. These technologies can be summarized into three categories:(1) large-scale and higher parameters coal-fired power generation technologies, including 620/650/700 oC ultra-supercritical thermal power and double reheat ultra-supercritical coal-fired power generation technologies;(2) system innovation and specific, highefficiency thermal cycles, which consist of renewable energy-aided coal-fired power generation technologies, a supercritical CO_2 Brayton cycle for coal-fired power plants, large-scale air-cooling coal-fired power plant technologies, and innovative layouts for waste heat utilization and enhanced energy cascade utilization;(3) coal-fired power generation combined with poly-generation technologies, which are represented by integrated gasification combined cycle(IGCC) and integrated gasification fuel cell(IGFC) technologies. Concerning the existing coal-fired power units, which are responsible for peak shaving, possible strategies for enhancing flexibility and operational stability are discussed. Furthermore, future trends for coal-fired power plants coupled with cyber-physical system(CPS) technologies are introduced. The development of advanced, coal-fired power generation technologies demonstrates the progress of science and is suitable for the sustainable development of human society. 展开更多
关键词 en ergy In ternet Coal-fired POWER Gen eration FLEXIBILITY Cyber-physical system Smart POWER plant
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PREPARING NANO-CRYSTALLINE La DOPED WC/Co POWDER BY HIGH ENERGY BALL MILLING 被引量:5
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作者 S. Liu, D.Q. Yi, Y.X. Li and D.ZouSchool of Materials Science & Engineering, Central South University, Changsha 410083, ChinaHunan Yin Zhou Nonferrous Metals Hi.-Tech. Limited Company, Changsha 410083, China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2002年第5期448-452,共5页
The La doped WC/Co powder was prepared by high energy ball milling. The changes of crystal structure, micrograph and defect of the powder were investigated by means of XRD (X-ray diffraction), SEM (scanning electron m... The La doped WC/Co powder was prepared by high energy ball milling. The changes of crystal structure, micrograph and defect of the powder were investigated by means of XRD (X-ray diffraction), SEM (scanning electron microscope) and DTA (differential thermal analysis). The results show that adding trace La element into carbides is effective to minish the grain size of WC/Co powder. The La doped carbides powder with grain size of 30nm can be obtained after 10h ball milling. The XRD peak of Co phase disappeared after 20h ball milling, which indicated solid solution (or secondary solid solution) of Co phase in WC phase. The La doped powder with grain size of 10nm is obtained after 30h ball milling. A peak of heat release at the temperature of 470℃ was emerged in DTA curve within the range of heating temperature, which showed that the crystal structure relaxation of the powder appeared in the process of high energy ball milling. After consolidated the La doped WC/Co alloy by high energy ball milling exhibits ultra-fine grain sizes and better mechanical properties. 展开更多
关键词 cemented carbide nano-crystalline powder rare earth high en-ergy ball milling
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Integration and development of energy and information network in the Pan-Arctic region 被引量:2
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作者 Xiaoxia Wei Jinyu Xiao +2 位作者 Zhe Wang Zhichun Wang Yun Tian 《Global Energy Interconnection》 2019年第6期505-513,共9页
The Global Energy Interconnection is an important strategic approach used to achieve efficient worldwide energy allocation.The idea of developing integrated power,information,and transportation networks provides incre... The Global Energy Interconnection is an important strategic approach used to achieve efficient worldwide energy allocation.The idea of developing integrated power,information,and transportation networks provides increased power interconnection functionality and meaning,helps condense forces,and accelerates the integration of global infrastructure.Correspondingly,it is envisaged that it will become the trend of industrial technological development in the future.In consideration of the current trend of integrated development,this study evaluates a possible plan of coordinated development of fiber-optic and power networks in the Pan-Arctic region.Firstly,the backbone network architecture of Global Energy Interconnection is introduced and the importance of the Arctic energy backbone network is confirmed.The energy consumption and developmental trend of global data centers are then analyzed.Subsequently,the global network traffic is predicted and analyzed by means of a polynomial regression model.Finally,in combination with the current construction of fiber-optic networks in the Pan-Arctic region,the advantages of the integration of the fiber-optic and power networks in this region are clarified in justification of the decision for the development of a Global Energy Interconnection scheme. 展开更多
关键词 energy Interconnection Data center Network traffic Integrated development of energy and information networks Global en ergy In terconnection
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Research on key technologies of deduction of multinational power trading in the context of Global Energy Interconnection 被引量:1
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作者 Jijie Huang Changnian Lin +2 位作者 Haiming Zhou Zhengqing Xu Chunzhe Lin 《Global Energy Interconnection》 2019年第6期561-567,共7页
When transnationalized electricity trade is conducted in the context of Global Energy Interconnection(GEI),the transaction settlement usually has a long cycle and high cost and is influenced by the volatility of the e... When transnationalized electricity trade is conducted in the context of Global Energy Interconnection(GEI),the transaction settlement usually has a long cycle and high cost and is influenced by the volatility of the exchange rate.It is thus necessary to overcome the problems associated with the transaction settlement,change in the trading model data,and trading strategy in the transnational transaction deduction.To overcome the problem of trade settlement,this paper proposes the use of a digital currency(energy currency)for the cross-border electricity trading settlement based on the special drawing rights of the International Monetary Fund,which is controlled by the Global Energy Interconnection Development and Cooperation Organization(GEIDCO),to enable the proposed currency to become a stable digital currency.The traders can use the energy coins as a unit of currency for quotes,combined with the data pertaining to the changes in the energy information obtained from the GEI framework and data regarding the optimally extrapolated reference trading indicators.To realize the implementation of the multi-trader concurrent transaction deduction using a microservice architecture,this paper proposes a method of computing the microservice and synchronous interaction among the traders,based on the database table data,because the large amount of computation is required to be accomplished asynchronously with a single process.The key technology behind these cross-national electricity trading simulations can not only enable the GEI transnational traders to performed daily real-time trading,but it also demonstrates the advantages of the rapid settlement of the energy currency and the realization of a stable payment in the global energy interconnection cross-border electricity trading. 展开更多
关键词 Global en ergy Interconn ection Multinational power trading deducti on Micro-service Digital curre ncy
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Weather index insurance for wind energy 被引量:1
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作者 Xiao Han Guoxing Zhang +5 位作者 Yixiang Xie Jiaxuan Yin Haiming Zhou Yunxi Yang Junhui Li Wenlei Bai 《Global Energy Interconnection》 2019年第6期542-549,共8页
As China vigorously promotes the development of new energy,photovoltaic power curtailment and wind power curtailment have been effectively resolved.At the same time,the yield from new energy power generation is becomi... As China vigorously promotes the development of new energy,photovoltaic power curtailment and wind power curtailment have been effectively resolved.At the same time,the yield from new energy power generation is becoming an important factor that affects the scale of investment in new energy.This paper focuses on the weather risks faced by wind power producers.By studying current research on weather index insurance in China and abroad,the functions and design methods for weather index insurance have been clarified.In addition,the feasibility of wind-power generation index insurance is discussed.The calculation methods for wind power generation index and the weather index insurance pricing methods for wind power enterprises are proposed.A weather index insurance model for wind power generation was established.The rationality and feasibility of the weather index insurance model proposed in this paper were verified using data from an existing power plant.The simulation results show that wind power enterprises can effectively avoid economic losses caused by weather risks through weather index insurance. 展开更多
关键词 New en ergy sources Wind power Weather risk Wind-power gen eration index insurance
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A Secure Routing Method for Detecting False Reports and Wormhole Attacks in Wireless Sensor Networks 被引量:1
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作者 Hyeon Myeong Choi Su Man Nam Tae Ho Cho 《Wireless Sensor Network》 2013年第3期33-40,共8页
Wireless sensor networks (WSNs) consist of a large number of sensor nodes that monitor the environment and a few base stations that collect the sensor readings. Individual sensor nodes are subject to compromised secur... Wireless sensor networks (WSNs) consist of a large number of sensor nodes that monitor the environment and a few base stations that collect the sensor readings. Individual sensor nodes are subject to compromised security because they may be deployed in hostile environments and each sensor node communicates wirelessly. An adversary can inject false reports into the networks via compromised nodes. Furthermore, an adversary can create a wormhole by directly linking two compromised nodes or using out-of-band channels. If these two kinds of attacks occur simultaneously in a network, existing methods cannot defend against them adequately. We thus propose a secure routing method for detecting false report injections and wormhole attacks in wireless sensor networks. The proposed method uses ACK messages for detecting wormholes and is based on a statistical en-route filtering (SEF) scheme for detecting false reports. Simulation results show that the proposed method reduces energy consumption by up to 20% and provide greater network security. 展开更多
关键词 WIRELESS Sensor Network security STATISTICAL en-Route WORMHOLE securE ROUTING
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Ion irradiation-induced structure damage to botanic samples using the ion transmission energy spectrum
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作者 WANGSi-xue WANGYu-Gang 《Nuclear Science and Techniques》 SCIE CAS CSCD 2002年第1期31-36,共6页
In order to study the mechanism of irradiation-induced damage ofbotanic samples caused by low energy heavy ions, transmission energy spectrum mea-surement was performed. Kidney bean slice samples 100μm in thickness w... In order to study the mechanism of irradiation-induced damage ofbotanic samples caused by low energy heavy ions, transmission energy spectrum mea-surement was performed. Kidney bean slice samples 100μm in thickness were irradi-ated by 50 kev N+ ions. The irradiation beam current density was about 30μA/cm2,and the irradiation ion doses were 1×1015, 1×1016, 3×1016 and 1×1017 ions@cm-2,respectively. A target set up that could greatly reduce the incident ion current densitywas designed to achieve the damage-free measurement. The 3.2 MeV H+ transmittedion energy spectrum measurement was carried out before and after the irradiation.From the transmission ion energy spectrum, it was found that the kidney bean sliceitself was structurally inhomogeneous compared with the PET films (C10HsO4). Ourresults indicated that the average mass thickness changed little when the N+ iondose was below 3×1016 ions.cm-2, but changed obviously whcn ion dose was beyond3×1016 ions.cm-2. 展开更多
关键词 重离子 辐照损失 离子传输能谱
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Energy Integration in South America Region and the Energy Sustainability of the Nations
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作者 Miguel Edgar Morales Udaeta Antonio Gomes dos Reis +1 位作者 José Aquiles Baesso Grimoni Antonio Celso de Abreu Junior 《Energy and Power Engineering》 2015年第5期161-173,共13页
The objective of this manuscript is to analyze relation involving the energy sector and socioeco-nomic growth and, then, contextualize the process of energy integration within the development policies in South America... The objective of this manuscript is to analyze relation involving the energy sector and socioeco-nomic growth and, then, contextualize the process of energy integration within the development policies in South America. The methodology considers data related to the world’s economy and energy consumption and energy integration policy in countries and regions;and, South America’s energy potential and the energy integration process. Results show that despite the political and institutional difficulties involving the process, energy integration can bring a lot of benefits for countries development. The process of energy integration in South America is divided in three moments, but in both periods the transnational energy projects were restricted, mostly, by a bi-lateral plan and the creation of physical links in a region. In the 21th century’s context, it should be noted Brazil’s participation which has been consolidated as a lead country in this process, and, also the IIRSA (Initiative for the Integration of Regional Infrastructure in South America, nowadays renamed as COSIPLAN) like the main initiative in energy integration in the continent, in a context where the projects are no longer limited to traditional economic blocs. Finally, we note a lack of consensus in defining a comprehensive model of integration and solving asymmetries both within countries and between them. 展开更多
关键词 energy Integration energy Planning energy RESOURCES REGIONAL Geo-energy SOUTH AMERICA en-ergy POLICY Development
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Energy Optimisation in Wireless Sensor Network
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作者 Guy Landry Diety Kouadio Eugène Ali +2 位作者 Olivier Asseu Bolou Bi Zehero Soumaya Hamouda 《Engineering(科研)》 2017年第10期880-889,共10页
The solution we propose optimizes the energy inside the wireless sensor network (WSN) with higher performance. The WSN is composed of many sensors nodes which collect the information, treat that information then send ... The solution we propose optimizes the energy inside the wireless sensor network (WSN) with higher performance. The WSN is composed of many sensors nodes which collect the information, treat that information then send it to the base station. The information is received by the base station (BS) then data?are?sent to the users by that BS. The most important element in sensor node is energy, as the lifetime of wireless sensor network depends on the sensor node energy. So many researches had been made in order to improve this energy basing routing protocols. As a result, we are able to propose a solution that optimizes this energy. In this paper, we are presenting a new approach of selecting node sensor base on routing protocol and process to send data to the base station. This ameliorates wireless sensor network lifetime and increases?the transmission sensor node to base station. 展开更多
关键词 Wireless SenSOR Network (WSN) Base STATION (BS) SenSOR NODE (SN) en-ergy ROUTING Protocol Transmission Optimisation
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Photon Can Be Described as the Normalized Mutual Energy Flow
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作者 Shuang-Ren Zhao 《Journal of Modern Physics》 2020年第5期668-682,共15页
Einstein guessed that the macroscopic electromagnetic wave is built by thousands of photons, however, no one has offered a theory about how the macroscopic electromagnetic wave is built from photons. A concrete theory... Einstein guessed that the macroscopic electromagnetic wave is built by thousands of photons, however, no one has offered a theory about how the macroscopic electromagnetic wave is built from photons. A concrete theory about photons is needed to answer this question. Current theory for photons is Maxwell’s equation which has the solution of waves, but it is difficult to describe the photon as a particle. There is the paradox problem of wave-particle duality. This article offers one solution to solve this problem by introducing the normalized mutual energy flow. The interaction of the retarded wave and advanced wave produce the mutual energy flow. The mutual energy flow satisfies the mutual energy flow theorem. The mutual energy flow theorem tells us that the energy that goes through each surface between the emitter and the absorber is all same. That means the mutual energy flow is different in comparison to the waves. The wave, for example, the retarded wave, its amplitude is decreased with the distance from the source to the point of the field. The mutual energy flow does not decrease. The author noticed this and claimed that the photon is the mutual energy flow. In this article the author updated this claim that the photon is the normalized mutual energy flow. Here the normalization of mutual energy flow will normalize the mutual energy flow to the energy of a photon, which is E = hf. E is the energy of the photon;h is Planck constant;f is the frequency of the light. This normalization is similar to the normalization in quantum mechanics. After this normalization the relation between an electromagnetic wave and photon as a particle becomes clear. This article will prove that the macroscopic wave of an electromagnetic field can be built by thousands of normalized mutual energy flows, which describes the photons. The mutual energy flow is an interaction of the retarded wave and the advanced wave. The retarded wave and the advanced wave satisfy the Maxwell equations. There are two additional waves which are the time-reversal waves which satisfy time-reversal Maxwell equations. The advanced wave and the two time-reversal waves are all real and physical electromagnetic fields. The time-reversal waves cancel all self-energy flows of the retarded wave and advanced wave. Hence, the waves do not carry any energy, the energy is only transferred by the normalized mutual energy flows which are the photons. Hence, all energy is transferred by the photon instead of waves. This offers a solution to paradox of the duality of wave-particle. 展开更多
关键词 Advanced WAVE Retarded WAVE TIME-REVERSAL WAVE PHOTON Mutual en-ergy energy Flow Electromagnetic FIELDS NORMALIZATION Wave-Particle DUALITY Electron Quantum
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CLASSICAL SOLUTIONS OF GENERAL GINZBURG-LANDAU EQUATIONS
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作者 陈淑红 郭柏灵 《Acta Mathematica Scientia》 SCIE CSCD 2016年第3期717-732,共16页
In this paper, we prove the existence of global classical solutions to time-dependent Ginzburg-Landau(TDGL) equations. By the properties of Besov and Sobolev spaces, together with the energy method, we establish the... In this paper, we prove the existence of global classical solutions to time-dependent Ginzburg-Landau(TDGL) equations. By the properties of Besov and Sobolev spaces, together with the energy method, we establish the global existence and uniqueness of classical solutions to the initial boundary value problem for time-dependent Ginzburg-Landau equations. 展开更多
关键词 classical solution time-dependent Ginzburg-Landau theory Besov space en ergy method
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RAW MEALS CONTAINING TRACE RE OXIDES TO IMPROVE QUALITY OF CEMENT CLINKER
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作者 苏达根 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2000年第1期18-22,共5页
Clay or industrial wastes containing trace rare earth (RE) oxides as one of the components are used to burn cement clinker. When the total amount of RE oxides reaches 0. 2×10-4 - 2. 0×10-4 (wt), it has posit... Clay or industrial wastes containing trace rare earth (RE) oxides as one of the components are used to burn cement clinker. When the total amount of RE oxides reaches 0. 2×10-4 - 2. 0×10-4 (wt), it has positive effect on the burnability of raw meals? and the Alite content in clinker increases. However, with the addition of lan-thanide, the formation process of clinker and the distribu-tion of lanthanide in clinker are different from those of yt-trium. If the burning temperature is 1 450 C , yttrium shiws negative effect on the formation of clinker. There-fore, to improve the quality of cement clinkern, the raw meals in which yttrium content is lower and lanthanide con-tent is higher is preferable; to reduce the consumption of coal, the raw meals that yttrium content is higher is suit-able. Using raw meals containing trace RE oxides can re-duce the cost of fluorite and protect environment. 展开更多
关键词 rare earth cement quality save en-ergy protection of environment
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The spin-one Duffin Kemmer Petiau equation in the presence of pseudo-harmonic oscillatory ring-shaped potential
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作者 H.Hassanabadi M.Kamali Physics 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第10期107-111,共5页
The Duffin-Kemmer-Petiau equation (DKP) is studied in the presence of a pseudo-harmonic oscillatory ring-shaped potential in (1 + 3)-dimensional space-time for spin-one particles. The exact energy eigenvalues and... The Duffin-Kemmer-Petiau equation (DKP) is studied in the presence of a pseudo-harmonic oscillatory ring-shaped potential in (1 + 3)-dimensional space-time for spin-one particles. The exact energy eigenvalues and the eigenfunctions are obtained using the Nikiforov-Uvarov method. 展开更多
关键词 DKP equation pseudo-harmonic oscillatory ring-shaped potential Nikiforov-Uvarov method en-ergy eigenvalues eigenfunctions
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Proteome Changes in Maize Embryo(Zea mays L)Induced by Ion Beam Implantation Treatment
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作者 李永亮 汤继华 +2 位作者 秦广雍 霍裕平 田双起 《Plasma Science and Technology》 SCIE EI CAS CSCD 2009年第4期510-514,共5页
Low energy ion beam implantation was applied to the maize (Zea mays L) embryo proteome using two-dimensional gel electrophoresis. Protein profile analysis detected more than Ii00 protein spots, 72 of which were dete... Low energy ion beam implantation was applied to the maize (Zea mays L) embryo proteome using two-dimensional gel electrophoresis. Protein profile analysis detected more than Ii00 protein spots, 72 of which were determined to be expressed differently in the treated and control (not exposed to ion beam implantation) embryos. Of the 72 protein spots, 53 were up- regulated in the control and 19 were more abundantly expressed in the ion beam-treated embryos. The spots of up- or down-regulated proteins were identified by matrix assisted laser desorption /ionization-time of flight mass spectrometry (MALDI-TOF-MS). Among the identified proteins, ii were up-regulated in the treated embryos. Four of these up-regulated proteins were antioxidant molecules, three were related to stress response, two to sugar metabolism and two were associated with heat shock response. Of the five proteins up-regulated in the control embryos, three were functionally related to carbohydrate metabolism; the functions of the remaining two proteins were unknown. The data collected during this study indicate that treatment of maize embryos with low energy ion beam implantation induces changes in stress tolerance enzymes/proteins, possibly as a result of alterations in metabolism. 展开更多
关键词 maize (Zea mays L) two-dimensional gel electrophoresis PROTEOME low en- ergy ion beam
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Recent Development and Application of Geothermal Heat Pump Systems in Cold-Climate Regions of the US: A Further Investigation
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作者 Yao Yu Rui Miao +2 位作者 Louis Miller Huojun Yang Gaylord Olson 《Engineering(科研)》 2017年第7期625-648,共24页
A Geothermal Heat Pump (GHP) system is known to have enormous potential for building energy savings and the reduction of associated greenhouse gas emissions, due to its high Coefficient Of Performance (COP). The use o... A Geothermal Heat Pump (GHP) system is known to have enormous potential for building energy savings and the reduction of associated greenhouse gas emissions, due to its high Coefficient Of Performance (COP). The use of a GHP system in cold-climate regions is more attractive owing to its higher COP for heating compared to conventional heating devices, such as furnaces or boilers. Many factors, however, determine the operational performance of an existing GHP system, such as control strategy, part/full-load efficiency, the age of the system, defective parts, and whether or not regular maintenance services are provided. The omitting of any of these factors in design and operation stages could have significant impacts on the normal operation of GHP systems. Therefore, the objectives of this paper are to further investigate and study the existing GHP systems currently used in buildings located in cold-climate regions of the US, in terms of system operational performance, potential energy and energy cost savings, system cost information, the reasons for installing geothermal systems, current operating difficulties, and owner satisfaction to date. After the comprehensive investigation and in-depth analysis of 24 buildings, the results indicate that for these buildings, about 75% of the building owners are very satisfied with their GHP systems in terms of noise, cost, and indoor comfort. About 71% of the investigated GHP systems have not had serious operating difficulties, and about 85% of the respondents (building owners) would suggest this type of system to other people. Compared to the national median of energy use and energy cost of typical buildings of the same type nationwide, the overall performance of the actual GHP systems used in the cold-climate regions is slightly better, i.e. about 7.2% energy savings and 6.1% energy cost savings on average. 展开更多
关键词 Existing GEOTHERMAL Heat Pump Heating COP ONSITE Survey energy and en-ergy Cost SAVINGS COLD Climate
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分布式数据库隐私数据细粒度安全访问控制研究 被引量:5
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作者 杨洋 《淮北师范大学学报(自然科学版)》 CAS 2024年第1期71-76,共6页
为控制隐私数据的细粒度安全访问行为,提出分布式数据库隐私数据细粒度安全访问控制。通过分布式数据库空间划分,过滤隐私数据,利用分区方程,分解数据库空间内隐私数据,将隐私数据反应函数的构建过程定义为对分布式数据库中隐私数据挖... 为控制隐私数据的细粒度安全访问行为,提出分布式数据库隐私数据细粒度安全访问控制。通过分布式数据库空间划分,过滤隐私数据,利用分区方程,分解数据库空间内隐私数据,将隐私数据反应函数的构建过程定义为对分布式数据库中隐私数据挖掘的博弈过程,获取博弈因子,将细粒度划分问题转化为隐私数据在最小二乘准则下的规划问题,划分隐私数据的细粒度。利用加密算法,对隐私数据加密,依据密钥分发算法为用户分发密钥,通过密钥转换,将加密后的隐私数据上传到分布式数据库,利用数据库验证用户的令牌是否包含隐私数据的信息,建立令牌请求机制,实现隐私数据的细粒度安全访问控制。实验结果表明,经过文中方法控制后,分布式数据库的响应性能有所提高,在保证正确性的同时,还可以提高对恶意访问行为的控制能力,具有较高的实际应用价值。 展开更多
关键词 隐私数据 博弈因子 安全访问控制 细粒度 分布式数据库 数据加密
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Na-Mn共掺对磷酸铁锂正极材料结构与性能的影响
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作者 刘庆生 符亲武 喻修远 《稀有金属与硬质合金》 CAS CSCD 北大核心 2024年第1期90-98,共9页
利用碳热还原法成功制备了Li_(0.97)Na_(0.03)Fe_(7/8)Mn_(1/8)PO_(4)正极材料,运用XRD、SEM、EDS和电化学测试等手段对其晶体结构、形貌、元素分布和电化学性能进行研究,并结合第一性原理计算分析材料性能提升的机理。结果表明,Na-Mn... 利用碳热还原法成功制备了Li_(0.97)Na_(0.03)Fe_(7/8)Mn_(1/8)PO_(4)正极材料,运用XRD、SEM、EDS和电化学测试等手段对其晶体结构、形貌、元素分布和电化学性能进行研究,并结合第一性原理计算分析材料性能提升的机理。结果表明,Na-Mn掺杂一方面导致LiFePO_(4)晶格畸变,晶格体积增大,扩大了锂离子迁移通道,为锂离子嵌入/脱出提供更大的空间;另一方面使材料在电化学性能上表现出优异的高倍率性能和循环稳定性。Na-Mn掺杂有利于提高材料的锂离子扩散系数和电导率,从而提高其电化学性能。基于第一性原理计算结果表明,Na-Mn共掺杂使LiFePO_(4)晶格膨胀,晶格体积增大,并促使带隙宽度减小,增强了费米能级附近的电子态密度,提高了材料的电子电导率和锂离子迁移率。 展开更多
关键词 Na-Mn共掺 LiFePO_(4) 正极材料 晶体结构 电化学性能 能带 第一性原理计算
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气凝胶灭火剂抑制锂离子储能电池热失控特性研究 被引量:2
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作者 刘通 唐国才 +1 位作者 王亮 朱国庆 《消防科学与技术》 CAS 北大核心 2024年第1期107-112,共6页
通过对比试验探究了气凝胶灭火剂对锂离子储能电池热失控的抑制效果。研究满荷电状态下的100 Ah磷酸铁锂储能电池热失控演变过程特征参数,识别出3个灾害演变特征拐点作为灭火剂施加的指导节点。在相同节点分别施加灭火参数一致的气凝胶... 通过对比试验探究了气凝胶灭火剂对锂离子储能电池热失控的抑制效果。研究满荷电状态下的100 Ah磷酸铁锂储能电池热失控演变过程特征参数,识别出3个灾害演变特征拐点作为灭火剂施加的指导节点。在相同节点分别施加灭火参数一致的气凝胶灭火剂与细水雾开展灭火对比测试。结果表明:触发明火前施加灭火剂均可有效阻断电池内部放热副反应,两者表现出相似的冷却效能;电池起火后,气凝胶灭火剂展现出更为出色的明火抑制效果,其接触电池表面形成的致密泡沫可有效阻隔氧气,实现快速灭火;对于已经触发热失控的情形,气凝胶灭火剂凭借预热覆盖效果,显著缩短电池射流火持续时间,可大幅降低电池火灾危害。 展开更多
关键词 磷酸铁锂电池 热失控特征 气凝胶灭火剂 细水雾 储能电池 射流火
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循环载荷作用下煤岩复合结构宏-细观破坏特征及能量-损伤本构模型 被引量:2
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作者 王凯 左晓欢 +3 位作者 杜锋 孙加智 鞠杨 丰程涛 《煤炭学报》 EI CAS CSCD 北大核心 2024年第2期767-784,共18页
煤炭深部开采过程中,周期性开采扰动行为会使邻近煤层的煤岩复合结构承受循环载荷的作用,因此,研究不同循环载荷作用下煤岩复合试样的力学响应行为及宏-细观失效特征具有重要工程意义。选取3种不同的加(卸)载速率,开展了2种循环加卸载... 煤炭深部开采过程中,周期性开采扰动行为会使邻近煤层的煤岩复合结构承受循环载荷的作用,因此,研究不同循环载荷作用下煤岩复合试样的力学响应行为及宏-细观失效特征具有重要工程意义。选取3种不同的加(卸)载速率,开展了2种循环加卸载路径下的单轴循环压缩试验(同步测定声发射信号),分析了煤岩复合试样的损伤失效特征;基于能量耗散原理,构建了煤岩复合试样在循环载荷作用下的能量-损伤本构模型,最后结合试验实测数据进行验证。结果表明:加(卸)载速率与复合试样的峰值强度呈正相关,当加(卸)载速率从0.05 mm/min增大到0.15 mm/min时,恒定下限逐步循环加卸载路径(路径I)、变上下限等幅循环加卸载路径(路径II)下,试样的峰值应力分别增加了22.44%和28.89%;高加(卸)载速率下,试样的内部裂纹扩展越快,煤岩复合试样中煤组分的破碎程度加剧,分形维数随之增大,试样的内部裂纹扩展越快;随着加(卸)载速率的增大,煤组分中沿基质破坏增多。循环分级跨度大的路径(路径I)有助于试样内部的应力传递,为试样内部裂纹的发育提供了有利条件,导致对应试样的破坏程度更高。试验曲线和能量-损伤本构理论曲线具有较强的一致性,表明所建的能量-损伤本构模型能够很好地描述煤岩复合试样在循环加卸载过程中的变形行为。 展开更多
关键词 煤岩复合结构 循环载荷作用 加(卸)载速率 宏-细观特征 能量-损伤本构模型
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