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Unconventional photon blockade in the two-photon Jaynes–Cummings model with two-frequency cavity drivings and atom driving
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作者 刘欣 田梦雨 +1 位作者 崔晓宁 张馨鹤 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期164-168,共5页
In a two-frequency cavity driving and atom driving atom-cavity system,we find the photon blockade effect.In a truncated eigenstates space,we calculate the zero-delay second-order correlation function of the cavity mod... In a two-frequency cavity driving and atom driving atom-cavity system,we find the photon blockade effect.In a truncated eigenstates space,we calculate the zero-delay second-order correlation function of the cavity mode analytically and obtain an optimal condition for the photon blockade.By including three transition pathways,we find that higher excitations of the cavity mode can be further suppressed and the zero-delay second-order correlation function can be reduced additionally.Based on the master equation,we simulate the system evolution and find that the analytical solutions match well with the numerical results.Our scheme is robust with small fluctuations of parameters and may be used as a new type of single photon source. 展开更多
关键词 photon blockade single photon source quantum interference
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QoS Routing Optimization Based on Deep Reinforcement Learning in SDN
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作者 Yu Song Xusheng Qian +2 位作者 Nan Zhang Wei Wang Ao Xiong 《Computers, Materials & Continua》 SCIE EI 2024年第5期3007-3021,共15页
To enhance the efficiency and expediency of issuing e-licenses within the power sector, we must confront thechallenge of managing the surging demand for data traffic. Within this realm, the network imposes stringentQu... To enhance the efficiency and expediency of issuing e-licenses within the power sector, we must confront thechallenge of managing the surging demand for data traffic. Within this realm, the network imposes stringentQuality of Service (QoS) requirements, revealing the inadequacies of traditional routing allocation mechanismsin accommodating such extensive data flows. In response to the imperative of handling a substantial influx of datarequests promptly and alleviating the constraints of existing technologies and network congestion, we present anarchitecture forQoS routing optimizationwith in SoftwareDefinedNetwork (SDN), leveraging deep reinforcementlearning. This innovative approach entails the separation of SDN control and transmission functionalities, centralizingcontrol over data forwardingwhile integrating deep reinforcement learning for informed routing decisions. Byfactoring in considerations such as delay, bandwidth, jitter rate, and packet loss rate, we design a reward function toguide theDeepDeterministic PolicyGradient (DDPG) algorithmin learning the optimal routing strategy to furnishsuperior QoS provision. In our empirical investigations, we juxtapose the performance of Deep ReinforcementLearning (DRL) against that of Shortest Path (SP) algorithms in terms of data packet transmission delay. Theexperimental simulation results show that our proposed algorithm has significant efficacy in reducing networkdelay and improving the overall transmission efficiency, which is superior to the traditional methods. 展开更多
关键词 Deep reinforcement learning SDN route optimization QOS
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Polar codes based OFDM-PLC systems in the presence of impulsive noise
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作者 周玉 LI Yue +4 位作者 ZHAO Shuangshuang GAO Fan ZHOU Chao MU Zhuowen CHEN Rui 《High Technology Letters》 EI CAS 2024年第2期188-198,共11页
Power line communication(PLC)has the potential to become the preferred technique for providing broadband communication to homes and offices with advantage of eliminating the need for new wiring infrastructure and redu... Power line communication(PLC)has the potential to become the preferred technique for providing broadband communication to homes and offices with advantage of eliminating the need for new wiring infrastructure and reducing the cost.But it suffers from the impulsive noise because it introduces significant time variance into the power line channel.In this paper,a polar codes based orthogonal frequency division multiplexing(OFDM)PLC system is proposed to deal with the impulsive noise and thereby improve the transmission performance.Firstly,the impulsive noise is modelled with a multi-damped sine function by analyzing the time behavior of impulse events.Then the polar codes are used to combat the impulsive noise of PLC channel,and a low complexity bit-flipping decoding method based on CRC-aided successive cancellation list(CA-SCL)decoding algorithm is proposed.Simulations evaluate the proposed decoding algorithm and the results validate the suggested polar codes based OFDM-PLC scheme which can improve the BER performance of PLC with impulsive interference. 展开更多
关键词 orthogonal frequency division multiplexing(OFDM) polar code impulsivenoise power line communication(PLC) bit-flipping
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The influences of canopy temperature measuring on the derived crop water stress index
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作者 WANG Hongxi LI Fei +4 位作者 SHEN Hongtao LI Mengyu YIN Gongchao FANG Qin SHAO Liwei 《中国生态农业学报(中英文)》 CAS CSCD 北大核心 2024年第9期1503-1519,共17页
Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the... Crop water stress index(CWSI)is widely used for efficient irrigation management.Precise canopy temperature(T_(c))measurement is necessary to derive a reliable CWSI.The objective of this research was to investigate the influences of atmospheric conditions,settled height,view angle of infrared thermography,and investigating time of temperature measuring on the performance of the CWSI.Three irrigation treatments were used to create different soil water conditions during the 2020-2021 and 2021-2022 winter wheat-growing seasons.The CWSI was calculated using the CWSI-E(an empirical approach)and CWSI-T(a theoretical approach)based on the T_(c).Weather conditions were recorded continuously throughout the experimental period.The results showed that atmospheric conditions influenced the estimation of the CWSI;when the vapor pressure deficit(VPD)was>2000 Pa,the estimated CWSI was related to soil water conditions.The height of the installed infrared thermograph influenced the T_(c)values,and the differences among the T_(c)values measured at height of 3,5,and 10 m was smaller in the afternoon than in the morning.However,the lens of the thermometer facing south recorded a higher T_(c)than those facing east or north,especially at a low height,indicating that the direction of the thermometer had a significant influence on T_(c).There was a large variation in CWSI derived at different times of the day,and the midday measurements(12:00-15:00)were the most reliable for estimating CWSI.Negative linear relationships were found between the transpiration rate and CWSI-E(R^(2)of 0.3646-0.5725)and CWSI-T(R^(2)of 0.5407-0.7213).The relations between fraction of available soil water(FASW)with CWSI-T was higher than that with CWSI-E,indicating CWSI-T was more accurate for predicting crop water status.In addition,The R^(2)between CWSI-T and FASW at 14:00 was higher than that at other times,indicating that 14:00 was the optimal time for using the CWSI for crop water status monitoring.Relative higher yield of winter wheat was obtained with average seasonal values of CWSI-E and CWSI-T around 0.23 and 0.25-0.26,respectively.The CWSI-E values were more easily influenced by meteorological factors and the timing of the measurements,and using the theoretical approach to derive the CWSI was recommended for precise irrigation water management. 展开更多
关键词 Canopy temperature Measuring time Measuring height and direction Crop water stress index
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Research on Total Electric Field Prediction Method of Ultra-High Voltage Direct Current Transmission Line Based on Stacking Algorithm
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作者 Yinkong Wei Mucong Wu +3 位作者 Wei Wei Paulo R.F.Rocha Ziyi Cheng Weifang Yao 《Computer Systems Science & Engineering》 2024年第3期723-738,共16页
Ultra-high voltage(UHV)transmission lines are an important part of China’s power grid and are often surrounded by a complex electromagnetic environment.The ground total electric field is considered a main electromagn... Ultra-high voltage(UHV)transmission lines are an important part of China’s power grid and are often surrounded by a complex electromagnetic environment.The ground total electric field is considered a main electromagnetic environment indicator of UHV transmission lines and is currently employed for reliable long-term operation of the power grid.Yet,the accurate prediction of the ground total electric field remains a technical challenge.In this work,we collected the total electric field data from the Ningdong-Zhejiang±800 kV UHVDC transmission project,as of the Ling Shao line,and perform an outlier analysis of the total electric field data.We show that the Local Outlier Factor(LOF)elimination algorithm has a small average difference and overcomes the performance of Density-Based Spatial Clustering of Applications with Noise(DBSCAN)and Isolated Forest elimination algorithms.Moreover,the Stacking algorithm has been found to have superior prediction accuracy than a variety of similar prediction algorithms,including the traditional finite element.The low prediction error of the Stacking algorithm highlights the superior ability to accurately forecast the ground total electric field of UHVDC transmission lines. 展开更多
关键词 DC transmission line total electric field effective data multivariable outliers LOF algorithm Stacking algorithm
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Simplified Technique for Predicting Offshore Pipeline Expansion 被引量:1
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作者 J.H.Seo D.K.Kim +2 位作者 H.S.Choi S.Y.Yu K.S.Park 《Journal of Marine Science and Application》 CSCD 2018年第1期68-78,共11页
In this study,we propose a method for estimating the amount of expansion that occurs in subsea pipelines,which could be applied in the design of robust structures that transport oil and gas from offshore wells.We begi... In this study,we propose a method for estimating the amount of expansion that occurs in subsea pipelines,which could be applied in the design of robust structures that transport oil and gas from offshore wells.We begin with a literature review and general discussion of existing estimation methods and terminologies with respect to subsea pipelines.Due to the effects of high pressure and high temperature,the production of fluid from offshore wells is typically caused by physical deformation of subsea structures,e.g.,expansion and contraction during the transportation process.In severe cases,vertical and lateral buckling occurs,which causes a significant negative impact on structural safety,and which is related to on-bottom stability,free-span,structural collapse,and many other factors.In addition,these factors may affect the production rate with respect to flow assurance,wax,and hydration,to name a few.In this study,we developed a simple and efficient method for generating a reliable pipe expansion design in the early stage,which can lead to savings in both cost and computation time.As such,in this paper,we propose an applicable diagram,which we call the standard dimensionless ratio(SDR)versus virtual anchor length(LA)diagram,that utilizes an efficient procedure for estimating subsea pipeline expansion based on applied reliable scenarios.With this user guideline,offshore pipeline structural designers can reliably determine the amount of subsea pipeline expansion and the obtained results will also be useful for the installation,design,and maintenance of the subsea pipeline. 展开更多
关键词 PIPE EXPANSION HP/HT THERMAL EXPANSION Subsea PIPELINE
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Change of Mineral Elements and Amino Acids in <i>Malus hupehensis var. pingyiensis</i>Leaves under Cd Treatment 被引量:3
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作者 Li Wang Weiguo Fan +5 位作者 Kaixuan Ma Jin Liu Shu Chen Mingyun Du Wei Qiang Hongqiang Yang 《Agricultural Sciences》 2018年第2期221-227,共7页
The objective of this paper is to research the effects of CdCl2 treatment on mineral elements and amino acids in leaves of Malus hupehensis var. pingyiensis. The seedlings of Malus hupehensis var. pingyiensis with 6 l... The objective of this paper is to research the effects of CdCl2 treatment on mineral elements and amino acids in leaves of Malus hupehensis var. pingyiensis. The seedlings of Malus hupehensis var. pingyiensis with 6 leaf were cultured in 1/2 Hoagland nutrient solutions of different CdCl2 treatments (0, 0.5, 5 and 10 mg·L-1), respectively. The mineral elements and amino acids of the leaves in Malus hupehensis var. pingyiensis were measured in the day 30. Compared with the control (0 mg·L-1 CdCl2), the treatments significantly decreased the contents of Mg, Fe and Zn in the tested leaves and obviously increased the contents of Cd in the experimental leaves. As to Ca and Mn, low concentration Cd treatment (0.5 mg·L-1 CdCl2) promoted their absorption, however, high concentration Cd treatments (5 and 10 mg·L-1 CdCl2) inhibited their absorption. The metabolism pathway and content of amino acids in the Malus hupehensis var. pingyiensis leaves under Cd treatment were modified, the content of amino acids in the glycolate pathway became larger than that in control, the content of amino acids in the pyruvic acid synthesis pathway and tyrosine and phenylalanine became smaller than that in control, the content of other amino acids also had made a certain degree change. The results provided the important basis for safety production and quality evaluation of leaves in Malus hupehensis var. pingyiensis. 展开更多
关键词 MALUS hupehensis VAR. pingyiensis CDCL2 TREATMENT Mineral Elements Amino Acids
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Optimum active and inert ratios for different metamorphic grade coals
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作者 LI Deping WEI Zheng TANG Qin 《Baosteel Technical Research》 CAS 2017年第3期12-17,共6页
In order to quantitatively describe the difference of optimum active and inert ratio of various metamorphic grade coking coals, the rule of coke micro-strength index (MSI), determinated by adding different proportio... In order to quantitatively describe the difference of optimum active and inert ratio of various metamorphic grade coking coals, the rule of coke micro-strength index (MSI), determinated by adding different proportions of inert content to ten kinds of single coal, changing with active and inert ratio has been investigated. Three kinds of change rule of the MSI of ten kinds of single coal changing with active and inert ratio have been obtained in the research. It has been demonstrated that Gauss curve model is the optimal model to describe the optimum active and inert ratio of different metamorphic grade coals. On this basis, the optimum active and inert ratio of different metamorphic grade coals can be given. 展开更多
关键词 metamorphic grade coking coal active and inert ratio Gauss curve
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PoQ-Consensus Based Private Electricity Consumption Forecasting via Federated Learning
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作者 Yiqun Zhu Shuxian Sun +3 位作者 Chunyu Liu Xinyi Tian Jingyi He Shuai Xiao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第9期3285-3297,共13页
With the rapid development of artificial intelligence and computer technology,grid corporations have also begun to move towards comprehensive intelligence and informatization.However,data-based informatization can bri... With the rapid development of artificial intelligence and computer technology,grid corporations have also begun to move towards comprehensive intelligence and informatization.However,data-based informatization can bring about the risk of privacy exposure of fine-grained information such as electricity consumption data.The modeling of electricity consumption data can help grid corporations to have a more thorough understanding of users’needs and their habits,providing better services for users.Nevertheless,users’electricity consumption data is sensitive and private.In order to achieve highly efficient analysis of massive private electricity consumption data without direct access,a blockchain-based federated learning method is proposed for users’electricity consumption forecasting in this paper.Specifically,a blockchain systemis established based on a proof of quality(PoQ)consensus mechanism,and a multilayer hybrid directional long short-term memory(MHD-LSTM)network model is trained for users’electricity consumption forecasting via the federal learning method.In this way,the model of the MHD-LSTM network is able to avoid suffering from severe security problems and can only share the network parameters without exchanging raw electricity consumption data,which is decentralized,secure and reliable.The experimental result shows that the proposed method has both effectiveness and high-accuracy under the premise of electricity consumption data’s privacy preservation,and can achieve better performance when compared to traditional long short-term memory(LSTM)and bidirectional LSTM(BLSTM). 展开更多
关键词 Blockchain consensus mechanism federated learning electricity consumption forecasting privacy preservation
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Kalman-Filtering-Based Frequency Control Strategy Considering Electrolytic Aluminum Load
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作者 Yuqin Chen Shihai Yang +1 位作者 Yueping Kong Mingming Chen 《Energy Engineering》 EI 2022年第4期1517-1529,共13页
Traditional thermal power units are continuously replaced by renewable energies,of which fluctuations and intermittence impose pressure on the frequency stability of the power system.Electrolytic aluminum load(EAL)acc... Traditional thermal power units are continuously replaced by renewable energies,of which fluctuations and intermittence impose pressure on the frequency stability of the power system.Electrolytic aluminum load(EAL)accounts for large amount of the local electric loads in some areas.The participation of EAL in local frequency control has huge application prospects.However,the controller design of EAL is difficult due to the measurement noise of the system frequency and the nonlinear dynamics of the EAL’s electric power consumption.Focusing on this problem,this paper proposes a control strategy for EAL to participate in the frequency control.For the controller design of the EAL system,the system frequency response model is established and the EAL transfer function model is developed based on the equivalent circuit of EAL.For the problem of load-side frequency measurement error,the frequency estimation method based on Kalman-filtering is designed.To improve the performance of EAL in the frequency control,a fuzzy EAL controller is designed.The testing examples show that the designed Kalman-filter has good performance in de-noising the measured frequency,and the designed fuzzy controller has better performance in stabilizing system frequency than traditional methods. 展开更多
关键词 Electrolytic aluminum load kalman-filtering frequency control
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Analysis of Price and Industry Dynamics of Sustainable and Specialty Coffee in Costa Rica
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作者 Bemard Kilian Lloyd Rivera 《Journal of Agricultural Science and Technology(B)》 2014年第5期375-385,共11页
Volatility of commodity prices has affected dramatically the coffee industry in recent years, particularly small holder farmers. Differentiation of coffee through certification, such as sustainahility and quality attr... Volatility of commodity prices has affected dramatically the coffee industry in recent years, particularly small holder farmers. Differentiation of coffee through certification, such as sustainahility and quality attributes, has been proposed as a strategy for protection of the farmers against volatility in the international prices. This research paper evaluated three different models to explore the effectiveness of the differentiation strategies in protecting the farmer against price volatility in recent years, focusing on the case of Costa Rica. Evidence showed important differences in the price dynamics over time when comparing three groups of coffee. 展开更多
关键词 Commodity prices price volatility sustainable development coffee prices.
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Focus on the Chicken Manure Power Generation in China: How to Promote the Biomass Waste Industry?
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作者 Han Li Pinjie Xie +1 位作者 Chao Wang Zhuowen Mu 《Energy and Power Engineering》 2021年第4期127-145,共19页
With the vigorous growth of animal husbandry, animal feces in the agriculture sector gradually deteriorate the environment. The chicken manure power generation is becoming viable and useful for energy conversion to co... With the vigorous growth of animal husbandry, animal feces in the agriculture sector gradually deteriorate the environment. The chicken manure power generation is becoming viable and useful for energy conversion to comply with the context of environmental protection in China. Based on resource endowments and technical conditions, this paper studies the current situation of chicken manure power generation in China. Combined with the policy environment, the research conducts a PEST-SWOT matrix analysis to thoroughly look into the strengths and weaknesses, the opportunities and challenges. Then, the paper analyzes the distribution of chicken manure and gives some solutions from respects of government regulatory behavior, industrial-organizational behavior and corporation strategic behavior. Finally, it is concluded that: 1) the government should strengthen policy support by actively improving the subsidy mechanism and lowering the threshold of financing and credit;2) enterprises should focus on improving power generation technology and boiler treatment technology. 展开更多
关键词 BIOMASS Chicken Manure Power Generation PEST-SWOT SOLUTIONS
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Carbon Footprint across the Coffee Supply Chain: The Case of Costa Rican Coffee
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作者 Bernard Killian Lloyd Rivera +1 位作者 Melissa Soto David Navichoc 《Journal of Agricultural Science and Technology(B)》 2013年第3期151-170,共20页
The issue of carbon emissions has been on the corporate sustainability agenda for some years. For those working in agricultural supply chains, the challenges remain significant, given the diverse direct and indirect e... The issue of carbon emissions has been on the corporate sustainability agenda for some years. For those working in agricultural supply chains, the challenges remain significant, given the diverse direct and indirect emissions occurring throughout the value chain. This study determines the carbon footprint of the supply chain of Costa Rican coffee exported to Europe, using best practice methodology to calculate greenhouse gas emissions. Overall, it was found that the total carbon footprint across the entire supply chain is 4.82 kg CO2e kgx green coffee. The carbon footprint of the processes in Costa Rica to produce l km of green coffee is 1.77 kg CO2e. The processes within Europe generate 3.05 kg CO2e kg-1 green coffee. This carbon footprint is considered as "very high intensity". This paper also identifies the sources of the most intense emission and discusses mitigation possibilities on which efforts must be focused. 展开更多
关键词 Climate change carbon footprint coffee supply chain Costa Rica.
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Assessment of Electricity Productivity in China:Regional Differences and Convergence
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作者 Pinjie Xie Ying Zhai +2 位作者 Fan Yang Zhuowen Mu Chao Wang 《Energy Engineering》 EI 2021年第5期1353-1374,共22页
Electricity productivity is regarded as a major assessment indicator in the design of energy saving policies,given that China has entered a“New Normal”of economic development.In fact,enhancing electricity productivi... Electricity productivity is regarded as a major assessment indicator in the design of energy saving policies,given that China has entered a“New Normal”of economic development.In fact,enhancing electricity productivity in an all-round way,as is one of the binding indicators for energy and environmental issues,means that non-growth target of total electric energy consumption in the economic development is feasible.The Gini coefficient,Theil index,and Mean log deviation are utilized to measure regional differences in China’s electricity productivity from 1997 to 2016 in five regions,and conditionalβconvergence is empirically analyzed with the spatial Durbin model.The results show that:(1)China’s electricity productivity is improving,while the overall feature is that the eastern area has a higher efficiency than the western area.(2)The difference in electricity productivity is the smallest in the northeast and the largest in the northwest.Interregional difference plays an important role and is the main cause for the differences.(3)The electricity productivity in China exhibitsβconvergence,except for the northwest.The positive driving factor is urbanization level(0.0485%),and the negative driving factor is FDI(–0.0104%).Moreover,the urbanization rate(0.0669%),foreign direct investment(0.0960%),and the industrial structure(–0.0769%)have a spatial spillover effect on improving regional electricity productivity.Based on this conclusion,the study provides some recommendations for saving energy policy design in China’s power industry. 展开更多
关键词 Electricity productivity regional differences CONVERGENCE spatial Durbin model
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The operation of the Norwegian NOX Fund and its inspiration
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作者 Weng Yubo 《中国船检》 2018年第12期114-115,共2页
Norway has a well-established legal system and advanced environmental science and technology in environmental protection.In 2007,the country introduced a tax on the emissions of NOx(nitrogen oxide)in order to control ... Norway has a well-established legal system and advanced environmental science and technology in environmental protection.In 2007,the country introduced a tax on the emissions of NOx(nitrogen oxide)in order to control the emission,and it has achieved remarkable result in reducing NOx emission afterwards with the support of NOx Fund and realized the emission reduction target for 2020 under Gothenburg Protocol in 2016 in advance.The NOx Fund has achieved a balance between emission reduction and the development of new technology,which is worth learning from. 展开更多
关键词 NORWEGIAN NOX FUND LEGAL SYSTEM
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Will Daily Chemical and Washing Industry Embrace Reform in the Wake of COVID-19?
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作者 Gu Jun 《China Detergent & Cosmetics》 2020年第1期25-27,共3页
The outbreak of COVID-19 during the Spring Festival in 2020 caught the whole China and its people off guard.Stay-at-home,quarantine and examination,people’s lives were changing unprecedentedly.Disinfectant water,sani... The outbreak of COVID-19 during the Spring Festival in 2020 caught the whole China and its people off guard.Stay-at-home,quarantine and examination,people’s lives were changing unprecedentedly.Disinfectant water,sanitizer,antibacterial soap,has become the first choice for people to face the virus.The memory of SARS was triggered.History about SARS On March 12th,2003,the WHO sounded the global alarm on SARS.It was a war without gun shots.Someone passed away while others survived.However,the deepest impression was the image when people were“fighting against SARS with concerted efforts”.According to experts,we needed to pay attention to health by washing our hands frequently and conducting regular disinfection.At that time,liquid soap and sterilized water were out of stock.The discussion on the bad habits of hygiene turned into a hot topic. 展开更多
关键词 FIGHTING CONDUCTING GUARD
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Petrogenesis and Tectonic Implications of the Paleoproterozoic A-Type Granites in the Xiong’ershan Area along the Southern Margin of the North China Craton
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作者 Jinhong Xu Yuping Jiang +7 位作者 Shuli Hu Zhengwei Zhang Chengquan Wu Chaofei Zheng Xiyao Li Ziru Jin Sensen Zhang Yatao Zhou 《Journal of Earth Science》 SCIE CAS CSCD 2024年第2期416-429,共14页
Paleoproterozoic A-type granites are widely distributed in the southern margin of the North China Craton(SNCC),providing important information for understanding the Paleoproterozoic tectonic regimes in this area.This ... Paleoproterozoic A-type granites are widely distributed in the southern margin of the North China Craton(SNCC),providing important information for understanding the Paleoproterozoic tectonic regimes in this area.This paper reports newly obtained whole-rock compositions and zircon U-Pb ages for the Tieluping syenogranite porphyry(TLP)and Huoshenmiao alkali granite porphyry(HSM)in the SNCC.Zircons from the TLP and HSM have U-Pb ages of 1805±12 and 1792±14 Ma,respectively.These ages are taken to date the emplacement of these intrusions.They had high total alkali contents(K_(2)O+Na_(2)O>7.13 wt.%),with high 10000×Ga/Al ratios(3.06–3.41)and Zr+Y+Nb+Ce values(709 ppm–910 ppm)as well as high zircon saturation temperatures(864–970℃),indicative of A-type granite affinities.High Y/Nb(1.75–3.32),Ce/Nb(7.72–9.72),and Yb/Ta(2.89–5.60)ratios suggested that TLP and HSM belonged to the A2-type granite.The negative whole rockε_(Nd)(t)values(−8.4 to−6.6)and negative zirconε_(Hf)(t)values(−15.9 to−6.3)confirmed that TLP and HSM were likely generated by the partial melting of an ancient continental crust.TheεHf(t)(−7.4 to+4.0)values of inherited zircons in the TLP suggested that they were derived from the partial melting of Archean basement rocks.Considering the geochemical similarity of the 1.80 Ga A-type granitoids in the SNCC,we propose that the TLP and HSM were formed in a post-collisional regime that was likely associated with the break-off of the Paleoproterozoic subducted slab.Upwelling of the asthenosphere provided huge heat to generate the regional 1.80 Ga A-type granite in the SNCC. 展开更多
关键词 PALEOPROTEROZOIC A-type granite POST-COLLISIONAL North China Craton TECTONIC GEOCHEMISTRY
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An internal power angle control strategy for high-speed sensorless brushless DC motors 被引量:1
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作者 Bo TAN Xingyuan GUO +2 位作者 Jun ZHAO Xiaofeng DING Wei FANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2022年第11期309-321,共13页
High-speed Brushless DC Motors(BLDCMs)usually adopt a sensorless control strategy and operate in three-phase six-state drive mode.However,the sampling errors of the rotor position and the driving method increase the I... High-speed Brushless DC Motors(BLDCMs)usually adopt a sensorless control strategy and operate in three-phase six-state drive mode.However,the sampling errors of the rotor position and the driving method increase the Internal Power Angle(IPA),resulting in a decrease in the efficiency of the system.Conventional IPA reduction strategies are either sensitive to motor parameters,or ignore diode freewheeling during the commutation process,or require additional current sensors.In this paper,a new strategy to reduce the IPA is proposed.Firstly,a Zero-Crossing Point(ZCP)detection method for the back-EMF without filter is proposed to reduce the sampling errors of the rotor position.Secondly,the relationship between the non-energized terminal voltage and the ZCP of the corresponding back-EMF is analyzed.The non-energized terminal voltage that has completed the diode freewheeling is divided into two triangles by half of the bus voltage.When the IPA is suppressed,the areas of the two triangles are equal.Thirdly,an advanced angle for reducing the IPA is obtained through a PI regulator which can eliminate the deviation between the two areas.Finally,both a simulation model and an experimental circuit are built to verify the proposed control strategy. 展开更多
关键词 Back-EMF detection Brushless DC motors Commutation control Electric drive Internal power angle
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Multivariate Two-stage Adaptive-stacking Prediction of Regional Integrated Energy System 被引量:1
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作者 Leijiao Ge Yuanliang Li +3 位作者 Jan Yan Yuanliang Li Jiaan Zhang Xiaohui Li 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2023年第5期1462-1479,共18页
To reduce environmental pollution and improve the efficiency of cascaded energy utilization, regional integrated energy system(RIES) has received extensive attention. An accurate multi-energy load prediction is signif... To reduce environmental pollution and improve the efficiency of cascaded energy utilization, regional integrated energy system(RIES) has received extensive attention. An accurate multi-energy load prediction is significant for RIES as it enables stakeholders to make effective decisions for carbon peaking and carbon neutrality goals. To this end, this paper proposes a multivariate two-stage adaptive-stacking prediction(M2ASP) framework. First, a preprocessing module based on ensemble learning is proposed. The input data are preprocessed to provide a reliable database for M2ASP, and highly correlated input variables of multi-energy load prediction are determined. Then, the load prediction results of four predictors are adaptively combined in the first stage of M2ASP to enhance generalization ability. Predictor hyper-parameters and intermediate data sets of M2ASP are trained with a metaheuristic method named collaborative atomic chaotic search(CACS) to achieve the adaptive staking of M2ASP. Finally, a prediction correction of the peak load consumption period is conducted in the second stage of M2ASP. The case studies indicate that the proposed framework has higher prediction accuracy, generalization ability, and stability than other benchmark prediction models. 展开更多
关键词 Collaborative atomic chaotic search(CACS) multivariate two-stage adaptive-stacking prediction(M2ASP)framework prediction error correction regional integrated energy system(RIES)
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Leveraging Continuous Prompt for Few-Shot Named Entity Recognition in Electric Power Domain with Meta-Learning
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作者 Yang Yu Wei He +1 位作者 Yu-meng Kang You-lang Ji 《Data Intelligence》 EI 2023年第2期494-509,共16页
Conventional named entity recognition methods usually assume that the model can be trained with sufficient annotated data to obtain good recognition results.However,in Chinese named entity recognition in the electric ... Conventional named entity recognition methods usually assume that the model can be trained with sufficient annotated data to obtain good recognition results.However,in Chinese named entity recognition in the electric power domain,existing methods still face the challenges of lack of annotated data and new entities of unseen types.To address these challenges,this paper proposes a meta-learning-based continuous cue adjustment method.A generative pre-trained language model is used so that it does not change its own model structure when dealing with new entity types.To guide the pre-trained model to make full use of its own latent knowledge,a vector of learnable parameters is set as a cue to compensate for the lack of training data.In order to further improve the model's few-shot learning capability,a meta-learning strategy is used to train the model.Experimental results show that the proposed approach achieves the best results in a few-shot electric Chinese power named entity recognition dataset compared to several traditional named entity approaches. 展开更多
关键词 Named Entity Recognition Pre-trained model Prompt-Tuning META-LEARNING Few-Shot
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