State of research： characteristics, function, and dating of Roman brass tokens Tokens （tesserae） formed part of everyday material culture of both Greeks and Romans.1 Made of wood, bone, clay, or metal, they facilit...State of research： characteristics, function, and dating of Roman brass tokens Tokens （tesserae） formed part of everyday material culture of both Greeks and Romans.1 Made of wood, bone, clay, or metal, they facilitated, for example, entry into the theatre, identification of soldiers, participation in political meetings, or the receipt of a special amount of grain.2展开更多
This article presents the results of a series of ethnographic observations at the Berlin fire brigade control and dispatch center during routine and severe weather situations.The weather-related challenges of a fire b...This article presents the results of a series of ethnographic observations at the Berlin fire brigade control and dispatch center during routine and severe weather situations.The weather-related challenges of a fire brigade lie between the anticipation of events and their potential consequences,and the ad hoc reactions to actual impacts of weather.The results show that decisions and actions related to high impact weather are not necessarily motivated by weather warnings alone.Instead,they are reactions to the experience of impacts,for example,an increased number of missions or emergency calls.Impacts are the main trigger for the decision making.Weather is one additional external factor that influences the operational capability of a fire brigade.While commanding officers in a fire brigade control and dispatch center experience weather primarily through technical equipment,verified by ground truth,observations showed that direct personal contact with the regional weather service and colleagues on the ground takes on a greater role in actual severe weather situations.The observations point to the need for increased interagency communication between the emergency services,the weather service,and other organizations to integrate weather information,impacts,and non-weather-related tasks into coherent weather-related decision making.展开更多
Lysophosphatidic acid(LPA)is a pleiotropic lipid agonist essential for functions of the central nervous system(CNS).It is abundant in the developing and adult brain while its concentration in biological fluids,includi...Lysophosphatidic acid(LPA)is a pleiotropic lipid agonist essential for functions of the central nervous system(CNS).It is abundant in the developing and adult brain while its concentration in biological fluids,including cerebrospinal fluid,varies significantly(Figure 1Α;Yung et al.,2014).LPA actually corresponds to a variety of lipid species that include different stereoisomers with either saturated or unsaturated fatty acids bearing likely differentiated biological activities(Figure 1Α;Yung et al.,2014;Hernández-Araiza et al.,2018).展开更多
开展生态脆弱区农户环境经济代谢研究对于乡村精准治理和区域可持续发展具有重要意义。作为我国典型生态脆弱区和北方重要生态安全屏障的辽西北地区,其生态环境质量改善与农牧民生计提升对东北地区乡村振兴至关重要。本文以辽西北地区...开展生态脆弱区农户环境经济代谢研究对于乡村精准治理和区域可持续发展具有重要意义。作为我国典型生态脆弱区和北方重要生态安全屏障的辽西北地区,其生态环境质量改善与农牧民生计提升对东北地区乡村振兴至关重要。本文以辽西北地区风沙危害最严重的彰武县北部7个乡镇为研究区,采用问卷调研与半结构式访谈等方法,基于家庭尺度环境经济代谢框架,对该地区以碳排放和水资源消耗为核心表征的典型农户家庭环境经济代谢活动进行研究。结果表明:辽西北北部地区乡村户均水资源消耗量和用水强度分别为14105 m^(3)和0.14 m^(3)·元^(-1),户均碳排放量和碳强度分别为36.72 t CO_(2)·a^(-1)和0.31 kg CO_(2)·元^(-1),人均碳排放量达9.90 t CO_(2)·a^(-1);以种植、养殖和种养结合为主的家庭水资源消耗量、碳排放量及其强度均存在较大差异,其中,种植主导型家庭水资源消耗量和用水强度均最高,养殖主导型家庭碳排放量最高,而种养结合型碳排放强度最大,但三种类型家庭环境经济代谢特征均表现为“高耗水高碳排”;家庭生计模式不同是造成环境经济代谢水平存在差异的主要原因,其中,养殖主导型家庭单位收入环境经济代谢效率相对较佳。未来应采取更加切实可行的策略加快引导辽西北地区乡村向低碳、绿色、循环的可持续发展模式进行转型,以实现乡村振兴。展开更多
The growing need for sustainable energy solutions,driven by rising energy shortages,environmental concerns,and the depletion of conventional energy sources,has led to a significant focus on renewable energy.Solar ener...The growing need for sustainable energy solutions,driven by rising energy shortages,environmental concerns,and the depletion of conventional energy sources,has led to a significant focus on renewable energy.Solar energy,among the various renewable sources,is particularly appealing due to its abundant availability.However,the efficiency of commercial solar photovoltaic(PV)modules is hindered by several factors,notably their conversion efficiency,which averages around 19%.This efficiency can further decline to 10%–16%due to temperature increases during peak sunlight hours.This study investigates the cooling of PV modules by applying water to their front surface through Computational fluid dynamics(CFD).The study aimed to determine the optimal conditions for cooling the PV module by analyzing the interplay between water film thickness,Reynolds number,and their effects on temperature reduction and heat transfer.The CFD analysis revealed that the most effective cooling condition occurred with a 5 mm thick water film and a Reynolds number of 10.These specific parameters were found to maximize the heat transfer and temperature reduction efficiency.This finding is crucial for the development of practical and efficient cooling systems for PV modules,potentially leading to improved performance and longevity of solar panels.Alternative cooling fluids or advanced cooling techniques that might offer even better efficiency or practical benefits.展开更多
With the widespread adoption of electric vehicles and energy storage systems,predicting the remaining useful life(RUL)of lithium-ion batteries(LIBs)is critical for enhancing system reliability and enabling predictive ...With the widespread adoption of electric vehicles and energy storage systems,predicting the remaining useful life(RUL)of lithium-ion batteries(LIBs)is critical for enhancing system reliability and enabling predictive maintenance.Traditional RUL prediction methods often exhibit reduced accuracy during the nonlinear aging stages of batteries and struggle to accommodate complex degradation processes.This paper introduces a novel adaptive long short-term memory(LSTM)approach that dynamically adjusts observation and prediction horizons to optimize predictive performance across various aging stages.The proposed method employs principal component analysis(PCA)for dimensionality reduction on publicly available NASA and Mendeley battery datasets to extract health indicators(HIs)and applies K-means clustering to segment the battery lifecycle into three aging stages(run-in,linear aging,and nonlinear aging),providing aging-stage-based input features for the model.Experimental results show that,in the NASA dataset,the adaptive LSTM reduces the MAE and RMSE by 0.042 and 0.043,respectively,compared to the CNN,demonstrating its effectiveness in mitigating error accumulation during the nonlinear aging stage.However,in the Mendeley dataset,the average prediction accuracy of the adaptive LSTM is slightly lower than that of the CNN and Transformer.These findings indicate that defining aging-stage-based adaptive observation and prediction horizons for LSTM can effectively enhance its performance in predicting battery RUL across the entire lifecycle.展开更多
A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This pape...A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This paper investigates the thermal processing capability of lunar regolith without the addition of binders,with a focus on large-scale applications for the construction of lunar habitats and infrastructure.The study used a simulant of lunar regolith found on the Schr?dinger Basin in the South Pole region.This regolith simulant consists of20 wt%basalt and 80 wt%anorthosite.Experiments were conducted using a high power CO_(2)laser to sinter and melt the regolith in a 80 mm diameter laser spot to evaluate the effectiveness of direct large area thermal processing.Results indicated that sintering begins at approximately 1180℃and reaches full melt at temperatures above 1360℃.Sintering experiments with this material revealed the formation of dense samples up to 11 mm thick,while melting experiments successfully produced larger samples by overlapping molten layers and additive manufacturing up to 50 mm thick.The energy efficiency of the sintering and melting processes was compared.The melting process was about 10 times more energy efficient than sintering in terms of material consolidation,demonstrating the promising potential of laser melting technologies of anorthosite-rich regolith for the production of structural elements.展开更多
Endoscopic retrograde cholangiopancreatography is considered the gold standard for treating benign and malignant biliary obstructions.However,its use in complex biliary obstructions is limited.Over the past decades,th...Endoscopic retrograde cholangiopancreatography is considered the gold standard for treating benign and malignant biliary obstructions.However,its use in complex biliary obstructions is limited.Over the past decades,therapeutic endosonography(EUS)and emerging technologies such as lumen-apposing metal stents have enabled endoscopic treatment of conditions previously requiring nonendoscopic or surgical approaches.Studies show that EUS-guided choledochoduodenostomy is a reliable alternative to endoscopic retrograde cholangiopancreatography in the treatment of distal malignant biliary obstructions and can be considered a primary drainage modality in centers with adequate expertise.For malignant hilar biliary obstructions,draining at least 50%of viable liver tissue often requires combining different modalities.The treatment strategy in these patients should be individualized,depending on the Bismuth classification,patient physical status,and intended systemic therapy.Due to the lack of evidence,general recommendations cannot be made for EUS-guided hepaticoduodenostomy or combined procedures with transhepatic bridging stents.These novel techniques should be limited to selected palliative cases where conventional methods have failed and conducted within clinical trials to generate evidence before broader application.展开更多
文摘State of research： characteristics, function, and dating of Roman brass tokens Tokens （tesserae） formed part of everyday material culture of both Greeks and Romans.1 Made of wood, bone, clay, or metal, they facilitated, for example, entry into the theatre, identification of soldiers, participation in political meetings, or the receipt of a special amount of grain.2
基金This research network of universities,research institutes,and the Deutscher Wetterdienst is funded by the BMVI(Federal Ministry of Transport and Digital Infrastructure).
文摘This article presents the results of a series of ethnographic observations at the Berlin fire brigade control and dispatch center during routine and severe weather situations.The weather-related challenges of a fire brigade lie between the anticipation of events and their potential consequences,and the ad hoc reactions to actual impacts of weather.The results show that decisions and actions related to high impact weather are not necessarily motivated by weather warnings alone.Instead,they are reactions to the experience of impacts,for example,an increased number of missions or emergency calls.Impacts are the main trigger for the decision making.Weather is one additional external factor that influences the operational capability of a fire brigade.While commanding officers in a fire brigade control and dispatch center experience weather primarily through technical equipment,verified by ground truth,observations showed that direct personal contact with the regional weather service and colleagues on the ground takes on a greater role in actual severe weather situations.The observations point to the need for increased interagency communication between the emergency services,the weather service,and other organizations to integrate weather information,impacts,and non-weather-related tasks into coherent weather-related decision making.
基金supported by the Hellenic Foundation for Research and Innovation,HFRI,“2nd Call for HFRI Research Projects to support Faculty Members&Researchers”Project 02667 to GL.
文摘Lysophosphatidic acid(LPA)is a pleiotropic lipid agonist essential for functions of the central nervous system(CNS).It is abundant in the developing and adult brain while its concentration in biological fluids,including cerebrospinal fluid,varies significantly(Figure 1Α;Yung et al.,2014).LPA actually corresponds to a variety of lipid species that include different stereoisomers with either saturated or unsaturated fatty acids bearing likely differentiated biological activities(Figure 1Α;Yung et al.,2014;Hernández-Araiza et al.,2018).
文摘开展生态脆弱区农户环境经济代谢研究对于乡村精准治理和区域可持续发展具有重要意义。作为我国典型生态脆弱区和北方重要生态安全屏障的辽西北地区,其生态环境质量改善与农牧民生计提升对东北地区乡村振兴至关重要。本文以辽西北地区风沙危害最严重的彰武县北部7个乡镇为研究区,采用问卷调研与半结构式访谈等方法,基于家庭尺度环境经济代谢框架,对该地区以碳排放和水资源消耗为核心表征的典型农户家庭环境经济代谢活动进行研究。结果表明:辽西北北部地区乡村户均水资源消耗量和用水强度分别为14105 m^(3)和0.14 m^(3)·元^(-1),户均碳排放量和碳强度分别为36.72 t CO_(2)·a^(-1)和0.31 kg CO_(2)·元^(-1),人均碳排放量达9.90 t CO_(2)·a^(-1);以种植、养殖和种养结合为主的家庭水资源消耗量、碳排放量及其强度均存在较大差异,其中,种植主导型家庭水资源消耗量和用水强度均最高,养殖主导型家庭碳排放量最高,而种养结合型碳排放强度最大,但三种类型家庭环境经济代谢特征均表现为“高耗水高碳排”;家庭生计模式不同是造成环境经济代谢水平存在差异的主要原因,其中,养殖主导型家庭单位收入环境经济代谢效率相对较佳。未来应采取更加切实可行的策略加快引导辽西北地区乡村向低碳、绿色、循环的可持续发展模式进行转型,以实现乡村振兴。
文摘The growing need for sustainable energy solutions,driven by rising energy shortages,environmental concerns,and the depletion of conventional energy sources,has led to a significant focus on renewable energy.Solar energy,among the various renewable sources,is particularly appealing due to its abundant availability.However,the efficiency of commercial solar photovoltaic(PV)modules is hindered by several factors,notably their conversion efficiency,which averages around 19%.This efficiency can further decline to 10%–16%due to temperature increases during peak sunlight hours.This study investigates the cooling of PV modules by applying water to their front surface through Computational fluid dynamics(CFD).The study aimed to determine the optimal conditions for cooling the PV module by analyzing the interplay between water film thickness,Reynolds number,and their effects on temperature reduction and heat transfer.The CFD analysis revealed that the most effective cooling condition occurred with a 5 mm thick water film and a Reynolds number of 10.These specific parameters were found to maximize the heat transfer and temperature reduction efficiency.This finding is crucial for the development of practical and efficient cooling systems for PV modules,potentially leading to improved performance and longevity of solar panels.Alternative cooling fluids or advanced cooling techniques that might offer even better efficiency or practical benefits.
基金supported by National Natural Science Foundation of China(Grant No.62403475).
文摘With the widespread adoption of electric vehicles and energy storage systems,predicting the remaining useful life(RUL)of lithium-ion batteries(LIBs)is critical for enhancing system reliability and enabling predictive maintenance.Traditional RUL prediction methods often exhibit reduced accuracy during the nonlinear aging stages of batteries and struggle to accommodate complex degradation processes.This paper introduces a novel adaptive long short-term memory(LSTM)approach that dynamically adjusts observation and prediction horizons to optimize predictive performance across various aging stages.The proposed method employs principal component analysis(PCA)for dimensionality reduction on publicly available NASA and Mendeley battery datasets to extract health indicators(HIs)and applies K-means clustering to segment the battery lifecycle into three aging stages(run-in,linear aging,and nonlinear aging),providing aging-stage-based input features for the model.Experimental results show that,in the NASA dataset,the adaptive LSTM reduces the MAE and RMSE by 0.042 and 0.043,respectively,compared to the CNN,demonstrating its effectiveness in mitigating error accumulation during the nonlinear aging stage.However,in the Mendeley dataset,the average prediction accuracy of the adaptive LSTM is slightly lower than that of the CNN and Transformer.These findings indicate that defining aging-stage-based adaptive observation and prediction horizons for LSTM can effectively enhance its performance in predicting battery RUL across the entire lifecycle.
文摘A key component of future lunar missions is the concept of in-situ resource utilization(ISRU),which involves the use of local resources to support human missions and reduce dependence on Earth-based supplies.This paper investigates the thermal processing capability of lunar regolith without the addition of binders,with a focus on large-scale applications for the construction of lunar habitats and infrastructure.The study used a simulant of lunar regolith found on the Schr?dinger Basin in the South Pole region.This regolith simulant consists of20 wt%basalt and 80 wt%anorthosite.Experiments were conducted using a high power CO_(2)laser to sinter and melt the regolith in a 80 mm diameter laser spot to evaluate the effectiveness of direct large area thermal processing.Results indicated that sintering begins at approximately 1180℃and reaches full melt at temperatures above 1360℃.Sintering experiments with this material revealed the formation of dense samples up to 11 mm thick,while melting experiments successfully produced larger samples by overlapping molten layers and additive manufacturing up to 50 mm thick.The energy efficiency of the sintering and melting processes was compared.The melting process was about 10 times more energy efficient than sintering in terms of material consolidation,demonstrating the promising potential of laser melting technologies of anorthosite-rich regolith for the production of structural elements.
文摘Endoscopic retrograde cholangiopancreatography is considered the gold standard for treating benign and malignant biliary obstructions.However,its use in complex biliary obstructions is limited.Over the past decades,therapeutic endosonography(EUS)and emerging technologies such as lumen-apposing metal stents have enabled endoscopic treatment of conditions previously requiring nonendoscopic or surgical approaches.Studies show that EUS-guided choledochoduodenostomy is a reliable alternative to endoscopic retrograde cholangiopancreatography in the treatment of distal malignant biliary obstructions and can be considered a primary drainage modality in centers with adequate expertise.For malignant hilar biliary obstructions,draining at least 50%of viable liver tissue often requires combining different modalities.The treatment strategy in these patients should be individualized,depending on the Bismuth classification,patient physical status,and intended systemic therapy.Due to the lack of evidence,general recommendations cannot be made for EUS-guided hepaticoduodenostomy or combined procedures with transhepatic bridging stents.These novel techniques should be limited to selected palliative cases where conventional methods have failed and conducted within clinical trials to generate evidence before broader application.
