The strict positive realness of a class of multilinearly parametrized interval systems is discussed, and a strong Kharitonov-like theorem is established. This result is applied to the absolute stability study of a cla...The strict positive realness of a class of multilinearly parametrized interval systems is discussed, and a strong Kharitonov-like theorem is established. This result is applied to the absolute stability study of a class of nonlinear feedback systems with both parameter uncertainty and unstructured uncertainty, and an extreme point criterion for robust absolute stability is obtained. The robust strict positive realness of the shifted interval plant-controller family is discussed, and some previous results in literature are improved.展开更多
Hydrogen energy development is transitioning from vision and plan-ning to widespread application.To date,more than 60 countries and regions have announced hydrogen energy development strategies focused on accelerating...Hydrogen energy development is transitioning from vision and plan-ning to widespread application.To date,more than 60 countries and regions have announced hydrogen energy development strategies focused on accelerating demonstration projects and real-world deployment.展开更多
The website of the Ministry of Ecology and Environment features a section on the national automatic monitoring system for surface water quality Every four hours,it releases real-time data on the water quality at the n...The website of the Ministry of Ecology and Environment features a section on the national automatic monitoring system for surface water quality Every four hours,it releases real-time data on the water quality at the nearly 10,000 moni-toring points across the country.At 2 p.m.on January 12,for instance,the system showed the proportion of monitoring points registering Grade Ⅲ quality or above surpassed 85 percent.展开更多
聚焦小学英语“教学评一体化”的教学理念,针对当前课堂评价存在的“独揽式”评价、“延迟式”反馈、“单维式”聚焦、“虚化式”情境等问题,以外研社《英语》四年级下册Unit 5 School Events中第三课时“Field trip”为例,创新性地提...聚焦小学英语“教学评一体化”的教学理念,针对当前课堂评价存在的“独揽式”评价、“延迟式”反馈、“单维式”聚焦、“虚化式”情境等问题,以外研社《英语》四年级下册Unit 5 School Events中第三课时“Field trip”为例,创新性地提出并构建基于REAL模式的“问题链驱动型”表现性评价体系。展开更多
Actuator faults can be critical in turbofan engines as they can lead to stall,surge,loss of thrust and failure of speed control.Thus,fault diagnosis of gas turbine actuators has attracted considerable attention,from b...Actuator faults can be critical in turbofan engines as they can lead to stall,surge,loss of thrust and failure of speed control.Thus,fault diagnosis of gas turbine actuators has attracted considerable attention,from both academia and industry.However,the extensive literature that exists on this topic does not address identifying the severity of actuator faults and focuses mainly on actuator fault detection and isolation.In addition,previous studies of actuator fault identification have not dealt with multiple concurrent faults in real time,especially when these are accompanied by sudden failures under dynamic conditions.This study develops component-level models for fault identification in four typical actuators used in high-bypass ratio turbofan engines under both dynamic and steady-state conditions and these are then integrated with the engine performance model developed by the authors.The research results reported here present a novel method of quantifying actuator faults using dynamic effect compensation.The maximum error for each actuator is less than0.06%and 0.07%,with average computational time of less than 0.0058 s and 0.0086 s for steady-state and transient cases,respectively.These results confirm that the proposed method can accurately and efficiently identify concurrent actuator fault for an engine operating under either transient or steady-state conditions,even in the case of a sudden malfunction.The research results emonstrate the potential benefit to emergency response capabilities by introducing this method of monitoring the health of aero engines.展开更多
In this paper,we introduce the real pairwise completely positive(RPCP)matrices with one of them is necessarily positive semidefinite while the other one is necessarily entrywise nonnegative,which has a real pairwise c...In this paper,we introduce the real pairwise completely positive(RPCP)matrices with one of them is necessarily positive semidefinite while the other one is necessarily entrywise nonnegative,which has a real pairwise completely positive(RPCP)decomposition.We study the properties of RPCP matrices and give some necessary and sufficient conditions for a matrix pair to be RPCP.First,we give an equivalent decomposition for the RPCP matrices,which is different from the RPCP-decomposition and show that the matrix pair(X,X)is RPCP if and only if X is completely positive.Besides,we also prove that the RPCP matrices checking problem is equivalent to the separable completion problem.A semidefinite algorithm is also proposed for detecting whether or not a matrix pair is RPCP.The asymptotic and finite convergence of the algorithm are also discussed.If it is RPCP,we can further give a RPCP-decomposition for it;if it is not,we can obtain a certificate for this.展开更多
From an era when even basic necessities like matches and soap had to be imported,China has transformed into the world's largest manufacturing powerhouse with the most comprehensive range of industrial sectors.&quo...From an era when even basic necessities like matches and soap had to be imported,China has transformed into the world's largest manufacturing powerhouse with the most comprehensive range of industrial sectors."China has always adhered to the path of developing the real economy…which has proven to be the right path".展开更多
This paper systematically examines the impact of environmental,social,and governance(ESG)factors on the financial performance and long-term value of real estate investment trusts(REITs).Adopting comparative analysis a...This paper systematically examines the impact of environmental,social,and governance(ESG)factors on the financial performance and long-term value of real estate investment trusts(REITs).Adopting comparative analysis as the quantitative research method,the paper selects representative cases of ESG-integrated REITs and traditional REITs at home and abroad,constructs a regression model,and compares projects from multiple key value dimensions,including yield,risk-adjusted returns,asset appreciation potential,financing costs,and market liquidity.The study finds that ESG-integrated REITs demonstrate significant advantages in long-term financial performance,risk resilience,and market valuation.Based on these findings,the paper proposes a series of policy recommendations,including improving ESG information disclosure standards,optimizing tax incentive mechanisms,and constructing an ESG evaluation system,to promote the high-quality and sustainable development of China’s REIT market.The paper consists of five parts:introduction of the research problem,theoretical framework,research methods(data sources and model construction),quantitative comparative analysis between ESG-integrated REITs and traditional REITs,and conclusion with recommendations.展开更多
The information exchange among satellites is crucial for the implementation of cluster satellite cooperative missions.However,achieving fast perception,rapid networking,and highprecision time synchronization among nod...The information exchange among satellites is crucial for the implementation of cluster satellite cooperative missions.However,achieving fast perception,rapid networking,and highprecision time synchronization among nodes without the support of the Global Navigation Satellite System(GNSS)and other prior information remains a formidable challenge to real-time wireless networks design.Therefore,a self-organizing network methodology based on multi-agent negotiation is proposed,which autonomously determines the master node through collaborative negotiation and competitive elections.On this basis,a real-time network protocol design is carried out and a high-precision time synchronization method with motion compensation is proposed.Simulation results demonstrate that the proposed method enables rapid networking with the capability of selfdiscovery,self-organization,and self-healing.For a cluster of 8 satellites,the networking time and the reorganization time are less than 4 s.The time synchronization accuracy exceeds 10-10s with motion compensation,demonstrating excellent real-time performance and stability.The research presented in this paper provides a valuable reference for the design and application of spacebased self-organizing networks for satellite cluster.展开更多
Boron-doped diamond(BDD)is a well-known anode material with a high pollutant degradation ability for electrochemical oxidation wastewater treatment.Nevertheless,the cost of production and mechanical strength of BDD me...Boron-doped diamond(BDD)is a well-known anode material with a high pollutant degradation ability for electrochemical oxidation wastewater treatment.Nevertheless,the cost of production and mechanical strength of BDD membranes remain unsatisfactory.Magnetic BDD particles derived from industrial waste may represent a promising alternative to BDD membranes,although the challenge remains in assembling these particles into a usable electrode.In this study,magnetic BDD particles were attracted to a Ti/RuO_(2)-IrO_(2)electrode using a magnet,thus constituting a novel 2.5-dimensional(2.5D)electrode.To ascertain the structure-activity relationship of the novel electrode,essential characterizations,multi-physics simulations,pollutant degradation and electrosynthesis experiments were conducted.The results indicate that an appropriate quantity of BDD particles(0.1 g/cm^(2))can enhance the number of active sites by approximately 20%.A strong synergistic effect was observed between the Ti/Ti/RuO_(2)-IrO_(2)and BDD particles in the degradation of various pollutants,including azo dye,p-benzoquinone,succinic acid and four kinds of real wastewaters,as well as glycerol conversion.The joint active sites on the interface between Ti/RuO_(2)-IrO_(2)and BDD particles,as well as the inner active sites on BDD particles,have been identified as crucial in the mineralization of pollutants and the generation of value-added products.The optimal amount of BDD particles(0.1 g/cm^(2))is sufficient to preserve the joint active sites and to maintain an adequate polarization on the BDD particles.Nevertheless,the hybrid feature of the 2.5D electrode is diminished when a greater quantity of BDD particles(0.3 g/cm^(2))is loaded.展开更多
Many experiments have supported the contact models,such as the GW and MB models,but the majority of previous validations have been performed under light loads,resulting in a linear relationship between normal force an...Many experiments have supported the contact models,such as the GW and MB models,but the majority of previous validations have been performed under light loads,resulting in a linear relationship between normal force and contact area.However,the real contact area fraction should never equal one;there must be a limit smaller than the apparent area,implying that the real contact area cannot increase linearly indefinitely.In this paper,the real contact area between two polymethylmethacrylate(PMMA)blocks under heavy load is measured using the total reflection method,and the contact area is analyzed using the image processing method.The results show that the real contact area increases with normal load linearly in light loads but non-linearly in heavy loads;the number of contact spots increases with load linearly in light loads but also non-linearly in heavy loads,synchronous with the change in the real contact area.The GW,MB,and Zhao,Maietta,and Chang(ZMC)models were used to predict the experiment results,but none of them predicted the non-linear stage.A revised GW model based on the bulk deformation hypothesis performs better in predicting the non-linear stage.The study’s findings can be applied to PMMA or other similar materials,and they can serve as a useful reference for future research on the contact mechanisms of other materials.展开更多
The regulation of catalytic pyrolysis products of coal tar(CT)is a great challenge due to its complex chemical composition and inter-component interactions.Herein,Fe-Ca/H-Si catalysts were prepared and used for cataly...The regulation of catalytic pyrolysis products of coal tar(CT)is a great challenge due to its complex chemical composition and inter-component interactions.Herein,Fe-Ca/H-Si catalysts were prepared and used for catalytic pyrolysis of CT for upgrading quality by acid treatment and impregnation methods,and the effect of carrier crystallinity on the distribution of CT pyrolysis products was investigated.The results showed that acid treatment disrupted the ordered crystals of silica(H-Si),creating more E’-centres defects as crystallinity decreased,and generating more sites for phenol removal reactions.The phenolic conversion of CT over H-Si increased by 12.42%at 700℃ during pyrolysis compared to SiO2.Meanwhile,the lower crystallinity of H-Si produced a larger free volume,providing sites for the anchoring of Fe and Ca.Fe facilitated the cleavage of C-C bonds and promoted the conversion of naphthalenes to aliphatic hydrocarbons.Additionally,CaO altered the electron distribution of compounds such as 2-ethyl-phenol and promoted their deoxygenation.Model compound experiments showed that the Fe-Ca/H-Si catalyst achieved 79.82% phenol conversion at 700℃,and also promoted the one-step deep reduction of naphthalene to 1-decene.These findings indicate that the Fe-Ca/H-Si catalyst offers a promising strategy for utilization of real CT.展开更多
Demand Side Management(DSM)is a vital issue in smart grids,given the time-varying user demand for electricity and power generation cost over a day.On the other hand,wireless communications with ubiquitous connectivity...Demand Side Management(DSM)is a vital issue in smart grids,given the time-varying user demand for electricity and power generation cost over a day.On the other hand,wireless communications with ubiquitous connectivity and low latency have emerged as a suitable option for smart grid.The design of any DSM system using a wireless network must consider the wireless link impairments,which is missing in existing literature.In this paper,we propose a DSM system using a Real-Time Pricing(RTP)mechanism and a wireless Neighborhood Area Network(NAN)with data transfer uncertainty.A Zigbee-based Internet of Things(IoT)model is considered for the communication infrastructure of the NAN.A sample NAN employing XBee and Raspberry Pi modules is also implemented in real-world settings to evaluate its reliability in transferring smart grid data over a wireless link.The proposed DSM system determines the optimal price corresponding to the optimum system welfare based on the two-way wireless communications among users,decision-makers,and energy providers.A novel cost function is adopted to reduce the impact of changes in user numbers on electricity prices.Simulation results indicate that the proposed system benefits users and energy providers.Furthermore,experimental results demonstrate that the success rate of data transfer significantly varies over the implemented wireless NAN,which can substantially impact the performance of the proposed DSM system.Further simulations are then carried out to quantify and analyze the impact of wireless communications on the electricity price,user welfare,and provider welfare.展开更多
Objective Rheumatoid arthritis(RA)is a systemic autoimmune disease that affects the small joints of the whole body and degrades the patients’quality of life.Zhengqing Fengtongning(ZF)is a traditional Chinese medicine...Objective Rheumatoid arthritis(RA)is a systemic autoimmune disease that affects the small joints of the whole body and degrades the patients’quality of life.Zhengqing Fengtongning(ZF)is a traditional Chinese medicine preparation used to treat RA.ZF may cause liver injury.In this study,we aimed to develop a prediction model for abnormal liver function caused by ZF.Methods This retrospective study collected data from multiple centers from January 2018 to April 2023.Abnormal liver function was set as the target variable according to the alanine transaminase(ALT)level.Features were screened through univariate analysis and sequential forward selection for modeling.Ten machine learning and deep learning models were compared to find the model that most effectively predicted liver function from the available data.Results This study included 1,913 eligible patients.The LightGBM model exhibited the best performance(accuracy=0.96)out of the 10 learning models.The predictive metrics of the LightGBM model were as follows:precision=0.99,recall rate=0.97,F1_score=0.98,area under the curve(AUC)=0.98,sensitivity=0.97 and specificity=0.85 for predicting ALT<40 U/L;precision=0.60,recall rate=0.83,F1_score=0.70,AUC=0.98,sensitivity=0.83 and specificity=0.97 for predicting 40≤ALT<80 U/L;and precision=0.83,recall rate=0.63,F1_score=0.71,AUC=0.97,sensitivity=0.63 and specificity=1.00 for predicting ALT≥80 U/L.ZF-induced abnormal liver function was found to be associated with high total cholesterol and triglyceride levels,the combination of TNF-αinhibitors,JAK inhibitors,methotrexate+nonsteroidal anti-inflammatory drugs,leflunomide,smoking,older age,and females in middle-age(45-65 years old).Conclusion This study developed a model for predicting ZF-induced abnormal liver function,which may help improve the safety of integrated administration of ZF and Western medicine.展开更多
Pre-sale and second-hand housing transaction modes dominate China’s real estate market. However, many existing studies tend to treat the housing market as a homogeneous entity, overlooking the heterogeneity in core i...Pre-sale and second-hand housing transaction modes dominate China’s real estate market. However, many existing studies tend to treat the housing market as a homogeneous entity, overlooking the heterogeneity in core influencing factors across different transaction types. Thoroughly understanding the factors affecting various housing types can assist policymakers in formulating differentiated regulatory decisions through environmental intervention. Therefore, this study utilized multi-source big data and compared the performance of multiple machine learning models to evaluate the relative importance and nonlinear effects of buildinglevel, neighborhood-level, and street-level built environment factors on pre-sale and secondhand housing prices. The empirical study of Chengdu, China revealed that distance to city center was the most significant explanatory factor influencing pre-sale and second-hand housing prices among all factors. Significant differences existed between neighborhood-level and street-level built environment factors’ nonlinear and threshold effects on pre-sale and second-hand housing prices. Notably, subway accessibility showed a U-shaped impact on pre-sale housing prices. To the best of our knowledge, our study is one of the early studies systematically investigating the influencing differences between pre-sale housing prices and second-hand housing prices, providing robust evidence for regulating housing prices through environmental interventions and offering critical references for policymakers and market participants.展开更多
文摘The strict positive realness of a class of multilinearly parametrized interval systems is discussed, and a strong Kharitonov-like theorem is established. This result is applied to the absolute stability study of a class of nonlinear feedback systems with both parameter uncertainty and unstructured uncertainty, and an extreme point criterion for robust absolute stability is obtained. The robust strict positive realness of the shifted interval plant-controller family is discussed, and some previous results in literature are improved.
文摘Hydrogen energy development is transitioning from vision and plan-ning to widespread application.To date,more than 60 countries and regions have announced hydrogen energy development strategies focused on accelerating demonstration projects and real-world deployment.
文摘The website of the Ministry of Ecology and Environment features a section on the national automatic monitoring system for surface water quality Every four hours,it releases real-time data on the water quality at the nearly 10,000 moni-toring points across the country.At 2 p.m.on January 12,for instance,the system showed the proportion of monitoring points registering Grade Ⅲ quality or above surpassed 85 percent.
文摘聚焦小学英语“教学评一体化”的教学理念,针对当前课堂评价存在的“独揽式”评价、“延迟式”反馈、“单维式”聚焦、“虚化式”情境等问题,以外研社《英语》四年级下册Unit 5 School Events中第三课时“Field trip”为例,创新性地提出并构建基于REAL模式的“问题链驱动型”表现性评价体系。
基金support by the National Natural Science Foundation of China(Grant No.52402520)。
文摘Actuator faults can be critical in turbofan engines as they can lead to stall,surge,loss of thrust and failure of speed control.Thus,fault diagnosis of gas turbine actuators has attracted considerable attention,from both academia and industry.However,the extensive literature that exists on this topic does not address identifying the severity of actuator faults and focuses mainly on actuator fault detection and isolation.In addition,previous studies of actuator fault identification have not dealt with multiple concurrent faults in real time,especially when these are accompanied by sudden failures under dynamic conditions.This study develops component-level models for fault identification in four typical actuators used in high-bypass ratio turbofan engines under both dynamic and steady-state conditions and these are then integrated with the engine performance model developed by the authors.The research results reported here present a novel method of quantifying actuator faults using dynamic effect compensation.The maximum error for each actuator is less than0.06%and 0.07%,with average computational time of less than 0.0058 s and 0.0086 s for steady-state and transient cases,respectively.These results confirm that the proposed method can accurately and efficiently identify concurrent actuator fault for an engine operating under either transient or steady-state conditions,even in the case of a sudden malfunction.The research results emonstrate the potential benefit to emergency response capabilities by introducing this method of monitoring the health of aero engines.
文摘In this paper,we introduce the real pairwise completely positive(RPCP)matrices with one of them is necessarily positive semidefinite while the other one is necessarily entrywise nonnegative,which has a real pairwise completely positive(RPCP)decomposition.We study the properties of RPCP matrices and give some necessary and sufficient conditions for a matrix pair to be RPCP.First,we give an equivalent decomposition for the RPCP matrices,which is different from the RPCP-decomposition and show that the matrix pair(X,X)is RPCP if and only if X is completely positive.Besides,we also prove that the RPCP matrices checking problem is equivalent to the separable completion problem.A semidefinite algorithm is also proposed for detecting whether or not a matrix pair is RPCP.The asymptotic and finite convergence of the algorithm are also discussed.If it is RPCP,we can further give a RPCP-decomposition for it;if it is not,we can obtain a certificate for this.
文摘From an era when even basic necessities like matches and soap had to be imported,China has transformed into the world's largest manufacturing powerhouse with the most comprehensive range of industrial sectors."China has always adhered to the path of developing the real economy…which has proven to be the right path".
文摘This paper systematically examines the impact of environmental,social,and governance(ESG)factors on the financial performance and long-term value of real estate investment trusts(REITs).Adopting comparative analysis as the quantitative research method,the paper selects representative cases of ESG-integrated REITs and traditional REITs at home and abroad,constructs a regression model,and compares projects from multiple key value dimensions,including yield,risk-adjusted returns,asset appreciation potential,financing costs,and market liquidity.The study finds that ESG-integrated REITs demonstrate significant advantages in long-term financial performance,risk resilience,and market valuation.Based on these findings,the paper proposes a series of policy recommendations,including improving ESG information disclosure standards,optimizing tax incentive mechanisms,and constructing an ESG evaluation system,to promote the high-quality and sustainable development of China’s REIT market.The paper consists of five parts:introduction of the research problem,theoretical framework,research methods(data sources and model construction),quantitative comparative analysis between ESG-integrated REITs and traditional REITs,and conclusion with recommendations.
基金supported by the National Natural Science Foundation of China(No.62401597)the Natural Science Foundation of Hunan Province,China(No.2024JJ6469)the Scientific Research Project of National University of Defense Technology,China(No.ZK22-02)。
文摘The information exchange among satellites is crucial for the implementation of cluster satellite cooperative missions.However,achieving fast perception,rapid networking,and highprecision time synchronization among nodes without the support of the Global Navigation Satellite System(GNSS)and other prior information remains a formidable challenge to real-time wireless networks design.Therefore,a self-organizing network methodology based on multi-agent negotiation is proposed,which autonomously determines the master node through collaborative negotiation and competitive elections.On this basis,a real-time network protocol design is carried out and a high-precision time synchronization method with motion compensation is proposed.Simulation results demonstrate that the proposed method enables rapid networking with the capability of selfdiscovery,self-organization,and self-healing.For a cluster of 8 satellites,the networking time and the reorganization time are less than 4 s.The time synchronization accuracy exceeds 10-10s with motion compensation,demonstrating excellent real-time performance and stability.The research presented in this paper provides a valuable reference for the design and application of spacebased self-organizing networks for satellite cluster.
基金the National Natural Science Foundation of China(Nos.21706153,52270078)Natural Science Basic Research Program of Shaanxi Province(Nos.2018JQ2066,2022JM065)。
文摘Boron-doped diamond(BDD)is a well-known anode material with a high pollutant degradation ability for electrochemical oxidation wastewater treatment.Nevertheless,the cost of production and mechanical strength of BDD membranes remain unsatisfactory.Magnetic BDD particles derived from industrial waste may represent a promising alternative to BDD membranes,although the challenge remains in assembling these particles into a usable electrode.In this study,magnetic BDD particles were attracted to a Ti/RuO_(2)-IrO_(2)electrode using a magnet,thus constituting a novel 2.5-dimensional(2.5D)electrode.To ascertain the structure-activity relationship of the novel electrode,essential characterizations,multi-physics simulations,pollutant degradation and electrosynthesis experiments were conducted.The results indicate that an appropriate quantity of BDD particles(0.1 g/cm^(2))can enhance the number of active sites by approximately 20%.A strong synergistic effect was observed between the Ti/Ti/RuO_(2)-IrO_(2)and BDD particles in the degradation of various pollutants,including azo dye,p-benzoquinone,succinic acid and four kinds of real wastewaters,as well as glycerol conversion.The joint active sites on the interface between Ti/RuO_(2)-IrO_(2)and BDD particles,as well as the inner active sites on BDD particles,have been identified as crucial in the mineralization of pollutants and the generation of value-added products.The optimal amount of BDD particles(0.1 g/cm^(2))is sufficient to preserve the joint active sites and to maintain an adequate polarization on the BDD particles.Nevertheless,the hybrid feature of the 2.5D electrode is diminished when a greater quantity of BDD particles(0.3 g/cm^(2))is loaded.
基金Supported by National Natural Science Foundation of China(Grant No.11872033)Beijing Municipal Natural Science Foundation(Grant No.3172017)。
文摘Many experiments have supported the contact models,such as the GW and MB models,but the majority of previous validations have been performed under light loads,resulting in a linear relationship between normal force and contact area.However,the real contact area fraction should never equal one;there must be a limit smaller than the apparent area,implying that the real contact area cannot increase linearly indefinitely.In this paper,the real contact area between two polymethylmethacrylate(PMMA)blocks under heavy load is measured using the total reflection method,and the contact area is analyzed using the image processing method.The results show that the real contact area increases with normal load linearly in light loads but non-linearly in heavy loads;the number of contact spots increases with load linearly in light loads but also non-linearly in heavy loads,synchronous with the change in the real contact area.The GW,MB,and Zhao,Maietta,and Chang(ZMC)models were used to predict the experiment results,but none of them predicted the non-linear stage.A revised GW model based on the bulk deformation hypothesis performs better in predicting the non-linear stage.The study’s findings can be applied to PMMA or other similar materials,and they can serve as a useful reference for future research on the contact mechanisms of other materials.
基金the Reserve Program for Young and Middle-aged Academic and Technical Leaders in Yunnan Province(202205AC160031)the Yunnan Fundamental Research Projects(202301BF070001-010,202501AS070077)+1 种基金the National College Student Innovation and Entrepreneurship Project(202310673093)the Yunnan University Students Innovation and Entrepreneurship Project(S202310673170).
文摘The regulation of catalytic pyrolysis products of coal tar(CT)is a great challenge due to its complex chemical composition and inter-component interactions.Herein,Fe-Ca/H-Si catalysts were prepared and used for catalytic pyrolysis of CT for upgrading quality by acid treatment and impregnation methods,and the effect of carrier crystallinity on the distribution of CT pyrolysis products was investigated.The results showed that acid treatment disrupted the ordered crystals of silica(H-Si),creating more E’-centres defects as crystallinity decreased,and generating more sites for phenol removal reactions.The phenolic conversion of CT over H-Si increased by 12.42%at 700℃ during pyrolysis compared to SiO2.Meanwhile,the lower crystallinity of H-Si produced a larger free volume,providing sites for the anchoring of Fe and Ca.Fe facilitated the cleavage of C-C bonds and promoted the conversion of naphthalenes to aliphatic hydrocarbons.Additionally,CaO altered the electron distribution of compounds such as 2-ethyl-phenol and promoted their deoxygenation.Model compound experiments showed that the Fe-Ca/H-Si catalyst achieved 79.82% phenol conversion at 700℃,and also promoted the one-step deep reduction of naphthalene to 1-decene.These findings indicate that the Fe-Ca/H-Si catalyst offers a promising strategy for utilization of real CT.
文摘Demand Side Management(DSM)is a vital issue in smart grids,given the time-varying user demand for electricity and power generation cost over a day.On the other hand,wireless communications with ubiquitous connectivity and low latency have emerged as a suitable option for smart grid.The design of any DSM system using a wireless network must consider the wireless link impairments,which is missing in existing literature.In this paper,we propose a DSM system using a Real-Time Pricing(RTP)mechanism and a wireless Neighborhood Area Network(NAN)with data transfer uncertainty.A Zigbee-based Internet of Things(IoT)model is considered for the communication infrastructure of the NAN.A sample NAN employing XBee and Raspberry Pi modules is also implemented in real-world settings to evaluate its reliability in transferring smart grid data over a wireless link.The proposed DSM system determines the optimal price corresponding to the optimum system welfare based on the two-way wireless communications among users,decision-makers,and energy providers.A novel cost function is adopted to reduce the impact of changes in user numbers on electricity prices.Simulation results indicate that the proposed system benefits users and energy providers.Furthermore,experimental results demonstrate that the success rate of data transfer significantly varies over the implemented wireless NAN,which can substantially impact the performance of the proposed DSM system.Further simulations are then carried out to quantify and analyze the impact of wireless communications on the electricity price,user welfare,and provider welfare.
基金supported by the Budgeted Fund of Shanghai University of Traditional Chinese Medicine(Natural Science)(No.2021LK037)the Open Project of Qinghai Province Key Laboratory of Tibetan Medicine Pharmacology and Safety Evaluation(No.2021-ZY-03).
文摘Objective Rheumatoid arthritis(RA)is a systemic autoimmune disease that affects the small joints of the whole body and degrades the patients’quality of life.Zhengqing Fengtongning(ZF)is a traditional Chinese medicine preparation used to treat RA.ZF may cause liver injury.In this study,we aimed to develop a prediction model for abnormal liver function caused by ZF.Methods This retrospective study collected data from multiple centers from January 2018 to April 2023.Abnormal liver function was set as the target variable according to the alanine transaminase(ALT)level.Features were screened through univariate analysis and sequential forward selection for modeling.Ten machine learning and deep learning models were compared to find the model that most effectively predicted liver function from the available data.Results This study included 1,913 eligible patients.The LightGBM model exhibited the best performance(accuracy=0.96)out of the 10 learning models.The predictive metrics of the LightGBM model were as follows:precision=0.99,recall rate=0.97,F1_score=0.98,area under the curve(AUC)=0.98,sensitivity=0.97 and specificity=0.85 for predicting ALT<40 U/L;precision=0.60,recall rate=0.83,F1_score=0.70,AUC=0.98,sensitivity=0.83 and specificity=0.97 for predicting 40≤ALT<80 U/L;and precision=0.83,recall rate=0.63,F1_score=0.71,AUC=0.97,sensitivity=0.63 and specificity=1.00 for predicting ALT≥80 U/L.ZF-induced abnormal liver function was found to be associated with high total cholesterol and triglyceride levels,the combination of TNF-αinhibitors,JAK inhibitors,methotrexate+nonsteroidal anti-inflammatory drugs,leflunomide,smoking,older age,and females in middle-age(45-65 years old).Conclusion This study developed a model for predicting ZF-induced abnormal liver function,which may help improve the safety of integrated administration of ZF and Western medicine.
基金supported by the 2024 Zhejiang Provincial Philosophy and Social Sciences Planning“Provincial and municipal cooperation”Project(No.24SSHZ140YB).-。
文摘Pre-sale and second-hand housing transaction modes dominate China’s real estate market. However, many existing studies tend to treat the housing market as a homogeneous entity, overlooking the heterogeneity in core influencing factors across different transaction types. Thoroughly understanding the factors affecting various housing types can assist policymakers in formulating differentiated regulatory decisions through environmental intervention. Therefore, this study utilized multi-source big data and compared the performance of multiple machine learning models to evaluate the relative importance and nonlinear effects of buildinglevel, neighborhood-level, and street-level built environment factors on pre-sale and secondhand housing prices. The empirical study of Chengdu, China revealed that distance to city center was the most significant explanatory factor influencing pre-sale and second-hand housing prices among all factors. Significant differences existed between neighborhood-level and street-level built environment factors’ nonlinear and threshold effects on pre-sale and second-hand housing prices. Notably, subway accessibility showed a U-shaped impact on pre-sale housing prices. To the best of our knowledge, our study is one of the early studies systematically investigating the influencing differences between pre-sale housing prices and second-hand housing prices, providing robust evidence for regulating housing prices through environmental interventions and offering critical references for policymakers and market participants.
