Heating by electricity rather than coal is considered one effective way to reduce environmental problems. Thus, the electric heating load is growing rapidly, which may cause undesired problems in distribution grids be...Heating by electricity rather than coal is considered one effective way to reduce environmental problems. Thus, the electric heating load is growing rapidly, which may cause undesired problems in distribution grids because of the randomness and dispersed integration of the load. However, the electric heating load may also function as an energy storage system with optimal operational control. Therefore, the optimal modeling of electric heating load characteristics, considering its randomness, is important for grid planning and construction. In this study, the heating loads of distributed residential users in a certain area are modeled based on the Fanger thermal comfort equation and the predicted mean vote thermal comfort index calculation method. Different temperatures are considered while modeling the users' heating loads. The heat load demand curve is estimated according to the time-varying equation of interior temperature. A multi-objective optimization model for the electric heating load with heat energy storage is then studied considering the demand response(DR), which optimizes economy and the comfort index. A fuzzy decision method is proposed, considering the factors influencing DR behavior. Finally, the validity of the proposed model is verified by simulations. The results show that the proposed model performs better than the traditional method.展开更多
Photovoltaics,energy storage,direct current and flexibility(PEDF)are important pillars of achievement on the path to manufacturing nearly zero energy buildings(NZEBs).HVAC systems,which are an important part of public...Photovoltaics,energy storage,direct current and flexibility(PEDF)are important pillars of achievement on the path to manufacturing nearly zero energy buildings(NZEBs).HVAC systems,which are an important part of public buildings,play a key role in adapting to PDEF systems.This research studied the basic principles and operational control strategies of a DC inverter heat pump using a DC distribution network with the aim of contributing to the development and application of small DC distribution systems.Along with the characteristics of a DC distribution network and different operating conditions,a DC inverter heat pump has the ability to adapt to changes in the DC bus voltage and adds flexibility to the system.Theoretical models of the DC inverter heat pump integrated with an ice storage unit were developed.The control strategies of the DC inverter heat pump system considered the influence of both room temperature and varied bus voltage.A simulation study was conducted using MATLAB&Simulink software with simulation results validated by experimental data.The results showed that:(1)The bus fluctuation under the rated working voltage had little effect on the operation of the unit;(2)When the bus voltage was fluctuating from 80%-90%or 105%-107%,the heat pump could still operate normally by reducing the frequency;(3)When the bus voltage was less than 80%or more than 107%,the unit needed to be shut down for the sake of equipment safety,so that the energy storage device could adjust to the sharp decrease or rise of voltage.展开更多
Size effects and compositions constitute new properties for inorganic particles in different application fields.The physical method has recently attracted more attention in the preparation of inorganic materials.Herei...Size effects and compositions constitute new properties for inorganic particles in different application fields.The physical method has recently attracted more attention in the preparation of inorganic materials.Herein,a low-cost,eco-friendly,simple-operating,and time-saving technique,named electrical discharge,is reviewed in relation to developments from the nature of this technique in different dielectric media to the practical experience in controlling the main processing parameters,apparatuses,types of discharge,from the various structures and components to the wide applications.The development of the electrical discharge technique will play an important role in improving the technology to prepare superfine inorganic particles with high purity.Meanwhile,electrical discharge contributes to easily mixing solid materials from the atomic scale to several micrometers with different structures.Moreover,metal oxides or doping materials are accessible as the dielectric medium is changed.Considering some excellent advantages,new inorganic particles exploited through the electrical discharge method will promise to be the most rewarding in some potential applications.展开更多
Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous priority pollutants that cause great damage to the natural environment and health.Average genome size in a community is critical for shedding light on microbiome...Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous priority pollutants that cause great damage to the natural environment and health.Average genome size in a community is critical for shedding light on microbiome's functional response to pollution stress within an environment.Here,microcosms under different concentrations were performed to evaluate the selection of PAHs stress on the average genome size in a community.We found the distinct communities of significantly larger genome size with the increase of PAHs concentration gradients in soils,and consistent trends were discovered in soils at different latitudes.The abundance of Proteobacteria and Deinococcus-Thermus with relatively larger genomes increased along with PAHs stress and well adapted to polluted environments.In contrast,the abundance of Patescibacteria with a highly streamlined and smaller genome decreased,implying complex interactions between environmental selection and functional fitness resulted in bacteria with larger genomes becoming more abundant.Moreover,we confirmed the increased capacity for horizontal transfer of degrading genes between communities by showing an increased connection number per node positively related to the nid A gene along the concentration gradients in the co-occurrence network.Our findings suggest PAHs tend to select bacterial taxa with larger genome sizes,with significant consequences for community stability and potential biodegradation strategies.展开更多
Ultrasound-aided electric discharge machining(EDM) is an emerging technology for producing hollow nickel microspheres.This technology combines traditional EDM with the cavitation and vibration effects of ultrasound ...Ultrasound-aided electric discharge machining(EDM) is an emerging technology for producing hollow nickel microspheres.This technology combines traditional EDM with the cavitation and vibration effects of ultrasound to produce hollow microspheres.In this paper,ultrasound-aided EDM was carried out in a kerosene medium(the working solution).The effects of various parameters on the sizes of microspheres were investigated using scanning electronic microscopy(SEM).Smileview software was used to measure the sizes of the microspheres.Originpro software was used for statistical analysis to determine the size distributions of the microspheres.To study the effects of the system parameters on the sizes of the microspheres,we first investigated the necessity of using an ultrasonic wave with EDM.After comparing the experimental results with and without the ultrasonic field,we found that ultrasound-induced cavitation and vibration effects reduced the diameters of the microspheres.We then studied the effects of several electrical parameters,including the arc current,pulse width,and gap voltage,on the sizes of the microspheres at an ultrasound frequency of 40 kHz.Smaller microspheres could be obtained by lowering the arc current,pulse width,and gap voltage.展开更多
Osteogenesis,osteoclastogenesis,and angiogenesis play crucial roles in bone regeneration.Parathyroid hormone(PTH),an FDA-approved drug with pro-osteogenic,pro-osteoclastogenic and proangiogenic capabilities,has been e...Osteogenesis,osteoclastogenesis,and angiogenesis play crucial roles in bone regeneration.Parathyroid hormone(PTH),an FDA-approved drug with pro-osteogenic,pro-osteoclastogenic and proangiogenic capabilities,has been employed for clinical osteoporosis treatment through systemic intermittent administration.However,the successful application of PTH for local bone defect repair generally requires the incorporation and delivery by appropriate carriers.Though several scaffolds have been developed to deliver PTH,they suffer from the weaknesses such as uncontrollable PTH release,insufficient porous structure and low mechanical strength.Herein,a novel kind of NIR-activable scaffold(CBP/MBGS/PTHrP-2)with dual-mode PTHrP-2(a PTH derivative)release capability is developed to synergistically promote osteogenesis and angiogenesis for high-efficacy bone regeneration,which is fabricated by integrating the PTHrP-2-loaded hierarchically mesoporous bioactive glass(MBG)into the N-hydroxymethylacrylamide-modified,photothermal agent-doped,poly(N-isopropylacrylamide)-based thermosensitive hydrogels through assembly process.Upon on/off NIR irradiation,the thermoresponsive hydrogel gating undergoes a reversible phase transition to allow the precise control of on-demand pulsatile and long-term slow release of PTHrP-2 from MBG mesopores.Such NIR-activated dual-mode delivery of PTHrP-2 by this scaffold enables a well-maintained PTHrP-2 concentration at the bone defect sites to continually stimulate vascularization and promote osteoblasts to facilitate and accelerate bone remodeling.In vivo experiments confirm the significant improvement of bone reparative effect on critical-size femoral defects of rats.This work paves an avenue for the development of novel dual-mode delivery systems for effective bone regeneration.展开更多
Cooperative planning is one of the critical problems in the field of multi-agent system gaming.This work focuses on cooperative planning when each agent has only a local observation range and local communication.We pr...Cooperative planning is one of the critical problems in the field of multi-agent system gaming.This work focuses on cooperative planning when each agent has only a local observation range and local communication.We propose a novel cooperative planning architecture that combines a graph neural network with a task-oriented knowledge fusion sampling method.Two main contributions of this paper are based on the comparisons with previous work:(1)we realize feasible and dynamic adjacent information fusion using GraphSAGE(i.e.,Graph SAmple and aggreGatE),which is the first time this method has been used to deal with the cooperative planning problem,and(2)a task-oriented sampling method is proposed to aggregate the available knowledge from a particular orientation,to obtain an effective and stable training process in our model.Experimental results demonstrate the good performance of our proposed method.展开更多
A parameter estimation method,called PMCMC in this paper,is proposed to estimate a continuous-time model of the term structure of interests under Markov regime switching and jumps.There is a closed form solution to te...A parameter estimation method,called PMCMC in this paper,is proposed to estimate a continuous-time model of the term structure of interests under Markov regime switching and jumps.There is a closed form solution to term structure of interest rates under Markov regime.However,the model is extended to be a CKLS model with non-closed form solutions which is a typical nonlinear and non-Gaussian state-space model(SSM)in the case of adding jumps.Although the difficulty of parameter estimation greatly prevents from researching models,we prove that the nonlinear and non-Gaussian state-space model has better performances in studying volatility.The method proposed in this paper will be implemented in simulation and empirical study for SHIBOR.Empirical results illustrate that the PMCMC algorithm has powerful advantages in tackling the models.展开更多
基金supported by the State Grid Science and Technology Project(No.52020118000M)
文摘Heating by electricity rather than coal is considered one effective way to reduce environmental problems. Thus, the electric heating load is growing rapidly, which may cause undesired problems in distribution grids because of the randomness and dispersed integration of the load. However, the electric heating load may also function as an energy storage system with optimal operational control. Therefore, the optimal modeling of electric heating load characteristics, considering its randomness, is important for grid planning and construction. In this study, the heating loads of distributed residential users in a certain area are modeled based on the Fanger thermal comfort equation and the predicted mean vote thermal comfort index calculation method. Different temperatures are considered while modeling the users' heating loads. The heat load demand curve is estimated according to the time-varying equation of interior temperature. A multi-objective optimization model for the electric heating load with heat energy storage is then studied considering the demand response(DR), which optimizes economy and the comfort index. A fuzzy decision method is proposed, considering the factors influencing DR behavior. Finally, the validity of the proposed model is verified by simulations. The results show that the proposed model performs better than the traditional method.
基金funded by State Grid Science&Technology Project“Research and Demonstration of Key Technologies on Electric-Heating Collaboration Cross-Network Mutual Supply for Typical Regional Clean Energy”,Grant Number 5400-202111575A-0-5-SF.
文摘Photovoltaics,energy storage,direct current and flexibility(PEDF)are important pillars of achievement on the path to manufacturing nearly zero energy buildings(NZEBs).HVAC systems,which are an important part of public buildings,play a key role in adapting to PDEF systems.This research studied the basic principles and operational control strategies of a DC inverter heat pump using a DC distribution network with the aim of contributing to the development and application of small DC distribution systems.Along with the characteristics of a DC distribution network and different operating conditions,a DC inverter heat pump has the ability to adapt to changes in the DC bus voltage and adds flexibility to the system.Theoretical models of the DC inverter heat pump integrated with an ice storage unit were developed.The control strategies of the DC inverter heat pump system considered the influence of both room temperature and varied bus voltage.A simulation study was conducted using MATLAB&Simulink software with simulation results validated by experimental data.The results showed that:(1)The bus fluctuation under the rated working voltage had little effect on the operation of the unit;(2)When the bus voltage was fluctuating from 80%-90%or 105%-107%,the heat pump could still operate normally by reducing the frequency;(3)When the bus voltage was less than 80%or more than 107%,the unit needed to be shut down for the sake of equipment safety,so that the energy storage device could adjust to the sharp decrease or rise of voltage.
基金supported by the National Natural Science Foundation of China(Grant No.51972045)the Fundamental Research Funds for the Chinese Central Universities,China(Grant No.ZYGX2019J025)the Sichuan Science and Technology Program(Grant Nos.2020JDRC0015 and 2020JDRC0045).
文摘Size effects and compositions constitute new properties for inorganic particles in different application fields.The physical method has recently attracted more attention in the preparation of inorganic materials.Herein,a low-cost,eco-friendly,simple-operating,and time-saving technique,named electrical discharge,is reviewed in relation to developments from the nature of this technique in different dielectric media to the practical experience in controlling the main processing parameters,apparatuses,types of discharge,from the various structures and components to the wide applications.The development of the electrical discharge technique will play an important role in improving the technology to prepare superfine inorganic particles with high purity.Meanwhile,electrical discharge contributes to easily mixing solid materials from the atomic scale to several micrometers with different structures.Moreover,metal oxides or doping materials are accessible as the dielectric medium is changed.Considering some excellent advantages,new inorganic particles exploited through the electrical discharge method will promise to be the most rewarding in some potential applications.
基金supported by the National Natural Science Foundation of China(No.31670507)National Key R&D Program of China(No.2019YFC1805803)+1 种基金the National Natural Science Foundation of China(Nos.41907273 and 91951108)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA23010400)。
文摘Polycyclic aromatic hydrocarbons(PAHs)are ubiquitous priority pollutants that cause great damage to the natural environment and health.Average genome size in a community is critical for shedding light on microbiome's functional response to pollution stress within an environment.Here,microcosms under different concentrations were performed to evaluate the selection of PAHs stress on the average genome size in a community.We found the distinct communities of significantly larger genome size with the increase of PAHs concentration gradients in soils,and consistent trends were discovered in soils at different latitudes.The abundance of Proteobacteria and Deinococcus-Thermus with relatively larger genomes increased along with PAHs stress and well adapted to polluted environments.In contrast,the abundance of Patescibacteria with a highly streamlined and smaller genome decreased,implying complex interactions between environmental selection and functional fitness resulted in bacteria with larger genomes becoming more abundant.Moreover,we confirmed the increased capacity for horizontal transfer of degrading genes between communities by showing an increased connection number per node positively related to the nid A gene along the concentration gradients in the co-occurrence network.Our findings suggest PAHs tend to select bacterial taxa with larger genome sizes,with significant consequences for community stability and potential biodegradation strategies.
基金financially supported by the Natural Science Foundation of China(NSFC)under Grants 51275324 and 51175355supported by the Program for New Century Excellent Talents(NCET)of the Ministry of Education of China(Grant No.12-0385)
文摘Ultrasound-aided electric discharge machining(EDM) is an emerging technology for producing hollow nickel microspheres.This technology combines traditional EDM with the cavitation and vibration effects of ultrasound to produce hollow microspheres.In this paper,ultrasound-aided EDM was carried out in a kerosene medium(the working solution).The effects of various parameters on the sizes of microspheres were investigated using scanning electronic microscopy(SEM).Smileview software was used to measure the sizes of the microspheres.Originpro software was used for statistical analysis to determine the size distributions of the microspheres.To study the effects of the system parameters on the sizes of the microspheres,we first investigated the necessity of using an ultrasonic wave with EDM.After comparing the experimental results with and without the ultrasonic field,we found that ultrasound-induced cavitation and vibration effects reduced the diameters of the microspheres.We then studied the effects of several electrical parameters,including the arc current,pulse width,and gap voltage,on the sizes of the microspheres at an ultrasound frequency of 40 kHz.Smaller microspheres could be obtained by lowering the arc current,pulse width,and gap voltage.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC2403203)the National Natural Science Foundation of China(Nos.51972112,82202695,and 52172279)+3 种基金Basic Research Program of Shanghai(21JC1406003 and 19JC1411700)Leading Talents in Shanghai in 2018,Shanghai Rising Star Program(21QA1402200)the Natural Science Foundation of Shanghai(21ZR1416600)the 111 project(B14018).
文摘Osteogenesis,osteoclastogenesis,and angiogenesis play crucial roles in bone regeneration.Parathyroid hormone(PTH),an FDA-approved drug with pro-osteogenic,pro-osteoclastogenic and proangiogenic capabilities,has been employed for clinical osteoporosis treatment through systemic intermittent administration.However,the successful application of PTH for local bone defect repair generally requires the incorporation and delivery by appropriate carriers.Though several scaffolds have been developed to deliver PTH,they suffer from the weaknesses such as uncontrollable PTH release,insufficient porous structure and low mechanical strength.Herein,a novel kind of NIR-activable scaffold(CBP/MBGS/PTHrP-2)with dual-mode PTHrP-2(a PTH derivative)release capability is developed to synergistically promote osteogenesis and angiogenesis for high-efficacy bone regeneration,which is fabricated by integrating the PTHrP-2-loaded hierarchically mesoporous bioactive glass(MBG)into the N-hydroxymethylacrylamide-modified,photothermal agent-doped,poly(N-isopropylacrylamide)-based thermosensitive hydrogels through assembly process.Upon on/off NIR irradiation,the thermoresponsive hydrogel gating undergoes a reversible phase transition to allow the precise control of on-demand pulsatile and long-term slow release of PTHrP-2 from MBG mesopores.Such NIR-activated dual-mode delivery of PTHrP-2 by this scaffold enables a well-maintained PTHrP-2 concentration at the bone defect sites to continually stimulate vascularization and promote osteoblasts to facilitate and accelerate bone remodeling.In vivo experiments confirm the significant improvement of bone reparative effect on critical-size femoral defects of rats.This work paves an avenue for the development of novel dual-mode delivery systems for effective bone regeneration.
基金Project supported by the National Natural Science Foundation。
文摘Cooperative planning is one of the critical problems in the field of multi-agent system gaming.This work focuses on cooperative planning when each agent has only a local observation range and local communication.We propose a novel cooperative planning architecture that combines a graph neural network with a task-oriented knowledge fusion sampling method.Two main contributions of this paper are based on the comparisons with previous work:(1)we realize feasible and dynamic adjacent information fusion using GraphSAGE(i.e.,Graph SAmple and aggreGatE),which is the first time this method has been used to deal with the cooperative planning problem,and(2)a task-oriented sampling method is proposed to aggregate the available knowledge from a particular orientation,to obtain an effective and stable training process in our model.Experimental results demonstrate the good performance of our proposed method.
基金Supported by National Natural Science Foundation of China(71471075)Fundamental Research Funds for the Central University(19JNLH09)Humanities and Social Sciences Foundation of Ministry of Education,China(14YJAZH052).
文摘A parameter estimation method,called PMCMC in this paper,is proposed to estimate a continuous-time model of the term structure of interests under Markov regime switching and jumps.There is a closed form solution to term structure of interest rates under Markov regime.However,the model is extended to be a CKLS model with non-closed form solutions which is a typical nonlinear and non-Gaussian state-space model(SSM)in the case of adding jumps.Although the difficulty of parameter estimation greatly prevents from researching models,we prove that the nonlinear and non-Gaussian state-space model has better performances in studying volatility.The method proposed in this paper will be implemented in simulation and empirical study for SHIBOR.Empirical results illustrate that the PMCMC algorithm has powerful advantages in tackling the models.