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Case study of flood risk and vulnerability in the city of Atlanta-A social,economic,technical,and institutional perspective
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作者 Prerna Singh Adjo Amekudzi-Kennedy +5 位作者 Baabak Ashuri Ty Parrillo Derek Rizzi Russell Clark Brian Woodall Heejun Chang 《Resilient Cities and Structures》 2025年第2期1-13,共13页
The negative impacts of natural hazards on communities at all scales have been increasing.Floods comprise one such natural hazard that has emerged as one of the most destructive in the US and worldwide.While a lot of ... The negative impacts of natural hazards on communities at all scales have been increasing.Floods comprise one such natural hazard that has emerged as one of the most destructive in the US and worldwide.While a lot of damage is estimated in terms of the cost of rebuilding infrastructure and direct loss of economy,the negative impacts of such disruptions go beyond the physical infrastructure.The impact on(and of)the social and institutional framework is rarely examined in conjunction with the physical and technical aspects.This paper examines flood vulnerability and risk of a community at an intersection of social,ecological,technical,and intuitional perspectives,and presents a framework for a holistic flood vulnerability and risk assessment that has a strong foundation in all four aspects of a resilient community.The study builds on the existing risk,vulnerability,and hazard assessment approaches,and refines them with a holistic perspective.The study uses a mixed method approach with qualitative and quantitative methodologies to assess flood occurrence probabilities,vulnerability,and risk from the social,ecological,technical,and institutional perspectives.A case study of the City of Atlanta is conducted using the framework to assess the overall vulnerability and risk of the city.The results of this analysis show that the regions that have the highest probability of flood hazard occurrence also appear to have the highest social,ecological,and technical vulnerabilities in the Atlanta area.While the results are intuitive,the applications support a focus on holistic resilience building across these four criteria.This study is potentially useful to practitioners,researchers,government agencies,and community organizations working to mitigate flood risk particularly as this risk continues to evolve with the changing climate. 展开更多
关键词 RESILIENCE Infrastructure VULNERABILITY Inland flooding
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Impact of Low-Impact Development Technologies from an Ecological Perspective in Different Residential Zones of the City of Atlanta, Georgia 被引量:2
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作者 Zackery B. Morris Stephen M. Malone +2 位作者 Abigail R. Cohen Marc J. Weissburg Bert Bras 《Engineering》 2018年第2期30-35,共6页
Low-impact development (LID) technologies have a great potential to reduce water usage and stormwa- ter runoff and are therefore seen as sustainable improvements that can be made to traditional water infrastructure,... Low-impact development (LID) technologies have a great potential to reduce water usage and stormwa- ter runoff and are therefore seen as sustainable improvements that can be made to traditional water infrastructure, These technologies include bioretention areas, rainwater capturing, and xeriscaping, all of which can be used in residential zones, Within the City of Atlanta, residential water usage accounts for 53% of the total water consumption; therefore, residential zones offer significant impact potential for the implementation of LID, This study analyzes the use of LID strategies within the different residen- tial zones of the City of Atlanta from an ecological perspective by drawing analogies to natural ecosys- tems, The analysis shows that these technologies, especially with the addition of a graywater system, work to improve the conventional residential water network based upon these ecological metrics, The higher metric values suggest greater parity with healthy, natural ecosystems. 展开更多
关键词 Low-impact development Ecological network analysis Residential water consumption
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Water, Air Emissions, and Cost Impacts of Air-Cooled Microturbines for Combined Cooling, Heating, and Power Systems: A Case Study in the Atlanta Region
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作者 Jean-Ann James Valerie M. Thomas +2 位作者 Arka Pandit Duo Li John C. Crittenden 《Engineering》 SCIE EI 2016年第4期470-480,共11页
The increasing pace of urbanization means that cities and global organizations are looking for ways to increase energy efficiency and reduce emissions. Combined cooling, heating, and power (CCHP) systems have the po... The increasing pace of urbanization means that cities and global organizations are looking for ways to increase energy efficiency and reduce emissions. Combined cooling, heating, and power (CCHP) systems have the potential to improve the energy generation efficiency of a city or urban region by providing energy for heating, cooling, and electricity simultaneously. The purpose of this study is to estimate the water consumption for energy generation use, carbon dioxide (CO2) and NOx emissions, and economic impact of implementing CCHP systems for five generic building types within the Atlanta metropolitan region, under various operational scenarios following the building thermal (heating and cooling) demands. Operating the CCHP system to follow the hourly thermal demand reduces CO2 emissions for most building types both with and without net metering. The system can be economically beneficial for all building types depending on the price of natural gas, the implementation of net metering, and the cost structure assumed for the CCHP system. The greatest reduction in water consumption for energy production and NOx emissions occurs when there is net metering and when the system is operated to meet the maximum yearly thermal demand, although this scenario also results in an increase in greenhouse gas emissions and, in some cases, cost. CCHP systems are more economical for medium office, large office, and multifamilv residential buildings. 展开更多
关键词 Combined cooling heating and power (CCHP) Air-cooled microturbines Distributed energy generation Water for energy production Net metering
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通过Metropolitan Atlanta评估的1979—1998年唐氏综合征患儿的存活情况
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作者 Rasmussen S.A Wong L.-Y. +1 位作者 Correa A. 贺莉 《世界核心医学期刊文摘(儿科学分册)》 2006年第11期27-27,共1页
Objective: Factors influencing survival among persons with Down syndrome (DS) are not well understood. We sought to evaluate survival of infants with DS and potential prognostic factors. Study design: Infants with DS ... Objective: Factors influencing survival among persons with Down syndrome (DS) are not well understood. We sought to evaluate survival of infants with DS and potential prognostic factors. Study design: Infants with DS who were born alive during 1979 to 1998 were identified using the Metropolitan Atlanta Congenital Defects Program (MACDP), a population based surveillance system. To document vital status, we used data from hospital records, the National Death Index (NDI), and Georgia vital records. We estimated survival probability using the Kaplan-Meier product limit method and hazard ratios using a Cox proportional hazards model. Results: Survival probability to 1 year was 92.9%(95%CI: 90.9-94.9) and to 10 years was 88.6%(95%CI: 85.0-92.2). Univariate analysis demonstrated that black maternal race, low birth weight, preterm birth, lower paternal education, presence of heart defects, and presence of other major congenital anomalies were important prognostic factors. After multivariate analysis, maternal race, presence of heart defects, low birth weight, and an interaction between maternal race and presence of heart defects were significantly associated with mortality risk. Conclusions: A racial disparity is apparent in survival for children with Down syndrome. Further study is needed to elucidate possible reasons for the racial disparity. 展开更多
关键词 唐氏综合征 存活情况 比例危险率模型 先天性缺陷 黑色人种 活产 监视系统 范围法 先天异常 乔治亚
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Assessing the impact of bicycle infrastructure on safety and operations using microsimulation and surrogate safety measures:A case study in Downtown Atlanta
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作者 Katherine Lee Amirarsalan Mehrara Molan +4 位作者 Anurag Pande Uijeong Hwang Subhrajit Guhathakurta Mirabel Nkanor Benedetta Sergio 《International Journal of Transportation Science and Technology》 2025年第2期148-159,共12页
This research assessed the impact of efficiently expanding the biking network in Atlanta,Georgia,using dedicated lanes for bicycles.A total of three different conditions,i.e.,exist-ing,proposed(by the authors),and alt... This research assessed the impact of efficiently expanding the biking network in Atlanta,Georgia,using dedicated lanes for bicycles.A total of three different conditions,i.e.,exist-ing,proposed(by the authors),and alternative(suggested by the City of Atlanta)condi-tions,were modeled to see the effectiveness of bike infrastructure design improvement and expansion.Trajectory data collected from the VISSIM simulation model were used in the Federal Highway Administration(FHWA)’s surrogate safety assessment model(SSAM)to analyze the safety effect on the bike infrastructure improvement and expansion.Based on the results,both the proposed and alternative conditions resulted in safer travel through the network during the peak hour period without any apparent deterioration in delays.For instance,compared to the existing condition,the average stop delays decreased from 190 s to 164 s for the proposed and the alternative conditions.These findings showed that the introduction of bicycle lanes and narrower lanes for automobiles may not adversely affect the peak hour congestion.Also,fewer conflicts were observed in the sim-ulated network of proposed and alternative conditions compared to existing conditions.Conflicts involving bicyclists were also reduced since the bicyclists can use their own lanes and do not have to interact with automobile traffic in the sharrows. 展开更多
关键词 Complete street MICROSIMULATION Street transformation Bike network Surrogate safety assessment model(SSAM)
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川滇地区人工智能地震预测模型应用
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作者 孟令媛 胡峰 +7 位作者 臧阳 司旭 闫伟 田雷 赵小艳 张致伟 韩颜颜 王月 《地震研究》 北大核心 2026年第1期43-50,共8页
针对中国地震科学实验场的科学目标和主要科学问题,基于川滇地区地震目录和地球物理观测数据,在对川滇地区进行区域划分并建立图神经网络的基础上,构建了川滇地区地震预测模型。该模型综合考虑约3万条地震目录数据、基于地震目录的3种... 针对中国地震科学实验场的科学目标和主要科学问题,基于川滇地区地震目录和地球物理观测数据,在对川滇地区进行区域划分并建立图神经网络的基础上,构建了川滇地区地震预测模型。该模型综合考虑约3万条地震目录数据、基于地震目录的3种地震活动性参数,以及116台项地球物理观测数据,通过将传统经验预测指标方法与人工智能技术结合,给出了适用于川滇地区的多源异构数据图神经网络地震预测模型,实现了川滇地区不同数据源下短期与中期地震预测功能。模型应用结果显示,在CD2、CD8和CD10区域月尺度预测效果较好,年尺度无震预测有一定对应效果。 展开更多
关键词 中国地震科学实验场 多源异构数据 图神经网络 地震预测模型 川滇地区
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人口老龄化对地方财政风险的影响:自缚还是破茧?
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作者 刘建民 凌惠馨 刘嘉意 《财经理论与实践》 北大核心 2025年第5期80-87,共8页
基于中国2012—2023年31个省份的面板数据,实证检验人口老龄化对地方财政风险的非线性影响。研究表明:人口老龄化与地方财政风险具有稳定的U形关系,在产业结构不够高级、中度关注数字经济以及中西部地区更为显著;人口老龄化通过区域创... 基于中国2012—2023年31个省份的面板数据,实证检验人口老龄化对地方财政风险的非线性影响。研究表明:人口老龄化与地方财政风险具有稳定的U形关系,在产业结构不够高级、中度关注数字经济以及中西部地区更为显著;人口老龄化通过区域创业活动、创新能力以及经济效能显著影响地方财政风险;有效劳动供给、老龄消费需求对U形关系具有负向调节作用。为此,应分级监测人口老龄化,因地制宜应对冲击;合理利用创业创新机制,促进经济提质增效;弹性供给释放经验红利,拉动内需缓释财政风险。 展开更多
关键词 人口老龄化 地方财政风险 非线性关系 调节效应
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Inflammasome links traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease 被引量:4
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作者 Gabriela Seplovich Yazan Bouchi +8 位作者 Juan Pablo de Rivero Vaccari Jennifer C.Munoz Pareja Andrew Reisner Laura Blackwell Yehia Mechref Kevin K.Wang J.Adrian Tyndall Binu Tharakan Firas Kobeissy 《Neural Regeneration Research》 SCIE CAS 2025年第6期1644-1664,共21页
Traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease are three distinct neurological disorders that share common pathophysiological mechanisms involving neuroinflammation. One sequela ... Traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease are three distinct neurological disorders that share common pathophysiological mechanisms involving neuroinflammation. One sequela of neuroinflammation includes the pathologic hyperphosphorylation of tau protein, an endogenous microtubule-associated protein that protects the integrity of neuronal cytoskeletons. Tau hyperphosphorylation results in protein misfolding and subsequent accumulation of tau tangles forming neurotoxic aggregates. These misfolded proteins are characteristic of traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease and can lead to downstream neuroinflammatory processes, including assembly and activation of the inflammasome complex. Inflammasomes refer to a family of multimeric protein units that, upon activation, release a cascade of signaling molecules resulting in caspase-induced cell death and inflammation mediated by the release of interleukin-1β cytokine. One specific inflammasome, the NOD-like receptor protein 3, has been proposed to be a key regulator of tau phosphorylation where it has been shown that prolonged NOD-like receptor protein 3 activation acts as a causal factor in pathological tau accumulation and spreading. This review begins by describing the epidemiology and pathophysiology of traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease. Next, we highlight neuroinflammation as an overriding theme and discuss the role of the NOD-like receptor protein 3 inflammasome in the formation of tau deposits and how such tauopathic entities spread throughout the brain. We then propose a novel framework linking traumatic brain injury, chronic traumatic encephalopathy, and Alzheimer's disease as inflammasomedependent pathologies that exist along a temporal continuum. Finally, we discuss potential therapeutic targets that may intercept this pathway and ultimately minimize long-term neurological decline. 展开更多
关键词 Alzheimer's disease caspase-1 chronic traumatic encephalopathy INFLAMMASOMES neurodegeneration NEUROINFLAMMATION NLRP1 NLRP3 PYROPTOSIS TAUOPATHY traumatic brain injury
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基于分布感知优化的高鲁棒推荐方法
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作者 檀彦超 周子皓 +4 位作者 马国芳 王石平 黄维 阳及 李天瑞 《计算机科学与探索》 北大核心 2025年第10期2667-2682,共16页
随着个性化推荐系统在各类平台上的广泛应用,如何精确理解并建模复杂的用户行为和海量物品信息成为关键挑战。传统推荐系统经常忽视由好奇心或误操作产生的困难样本,这些未经处理的困难样本如果处理不当,则可能会导致模型偏差和性能降... 随着个性化推荐系统在各类平台上的广泛应用,如何精确理解并建模复杂的用户行为和海量物品信息成为关键挑战。传统推荐系统经常忽视由好奇心或误操作产生的困难样本,这些未经处理的困难样本如果处理不当,则可能会导致模型偏差和性能降低。此外,传统推荐系统往往仅考虑单一用户-物品交互,未能从分布的角度捕捉高阶关联。针对上述问题,提出了一种基于分布感知优化的高鲁棒推荐方法(DORRec),旨在无监督条件下匹配全局用户分布与物品分布,同时甄别困难样本并建模分布匹配,以实现高鲁棒性推荐。在基于分布的困难样本识别模块,通过利用放宽Sinkhorn距离下的正则化约束,计算复杂的用户-物品间匹配分数的闭式解,从而找到每个用户的困难样本;在基于自适应阈值的高鲁棒推荐模块,提出了一种个性化阈值机制,通过自适应调整交互权重以强化困难样本的训练,满足高鲁棒推荐需求。在四个公共数据集上的实验验证了该方法的有效性,显示出DORRec在准确性和鲁棒性上的提升,通过与多个最先进推荐算法和高鲁棒组件在多个评价指标上进行比较分析,验证了DORRec在推荐性能上的显著优越性。 展开更多
关键词 推荐系统 困难样本 分布感知 鲁棒推荐 最优传输
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Industrial solid wastes to environmental protection materials for removal of gaseous pollutants:A review 被引量:2
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作者 Jiacheng Bao Xin Sun +5 位作者 Ping Ning Kai Li Jie Yang Fei Wang Lei Shi Maohong Fan 《Green Energy & Environment》 SCIE EI CAS 2025年第1期34-83,共50页
The application of industrial solid wastes as environmentally functional materials for air pollutants control has gained much attention in recent years due to its potential to reduce air pollution in a cost-effective ... The application of industrial solid wastes as environmentally functional materials for air pollutants control has gained much attention in recent years due to its potential to reduce air pollution in a cost-effective manner.In this review,we investigate the development of industrialwaste-based functional materials for various gas pollutant removal and consider the relevant reaction mechanism according to different types of industrial solid waste.We see a recent effort towards achieving high-performance environmental functional materials via chemical or physical modification,in which the active components,pore size,and phase structure can be altered.The review will discuss the potential of using industrial solid wastes,these modified materials,or synthesized materials from raw waste precursors for the removal of air pollutants,including SO_(2),NO_(x),Hg^(0),H_(2)S,VOCs,and CO_(2).The challenges still need to be addressed to realize this potential and the prospects for future research fully.The suggestions for future directions include determining the optimal composition of these materials,calculating the real reaction rate and turnover frequency,developing effective treatment methods,and establishing chemical component databases of raw industrial solid waste for catalysts/adsorbent preparation. 展开更多
关键词 Industrial solid waste Reaction mechanism Modification method Air pollutants
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孔边裂纹缺陷的Lamb波S0模态增量散射
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作者 周书辰 陈鑫 +3 位作者 刘宏业 张旭 孙茂循 田振华 《声学学报》 北大核心 2025年第6期1524-1536,共13页
针对航空铝合金结构中孔边裂纹的结构健康监测问题,考虑紧固孔初始结构特征对Lamb波主动监测基线信号的影响,开展孔边裂纹缺陷的Lamb波S0模态离面位移增量散射研究。首先,从各向同性板的基本控制方程出发,通过将位移场用勒让德正交多项... 针对航空铝合金结构中孔边裂纹的结构健康监测问题,考虑紧固孔初始结构特征对Lamb波主动监测基线信号的影响,开展孔边裂纹缺陷的Lamb波S0模态离面位移增量散射研究。首先,从各向同性板的基本控制方程出发,通过将位移场用勒让德正交多项式展开,并将物性参数表示为空间位置函数,推导了各向同性弹性板中Lamb波模态耦合的特征方程,系统揭示了Lamb波S0模态与A0模态离面-面内位移的耦合机理。然后,构建超声Lamb波与孔-槽缺陷相互作用的线性三维有限元模型,发展结合频散损耗与几何传播损耗的联合补偿算法,并基于基线相减法提出周向增量散射系数计算方法。最后,搭建扫描激光测振实验系统,对不同激励频率和入射角度下的S0模态远场散射离面位移进行高精度表征。仿真与实验结果一致表明:孔边裂纹对S0模态的增量散射分布幅值和指向性具有显著影响,特别是在Lamb波沿平行于裂纹方向传播时更为敏感。此外,研究还揭示了孔边裂纹缺陷的Lamb波反向散射机制。 展开更多
关键词 LAMB波 激光测振仪 增量散射 裂纹
原文传递
Acute and chronic excitotoxicity in ischemic stroke and late-onset Alzheimer's disease
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作者 Shan Ping Yu Emily Choi +1 位作者 Michael QJiang Ling Wei 《Neural Regeneration Research》 SCIE CAS 2025年第7期1981-1988,共8页
Stroke and Alzheimer's disease are common neurological disorders and often occur in the same individuals.The comorbidity of the two neurological disorders represents a grave health threat to older populations.This... Stroke and Alzheimer's disease are common neurological disorders and often occur in the same individuals.The comorbidity of the two neurological disorders represents a grave health threat to older populations.This review presents a brief background of the development of novel concepts and their clinical potentials.The activity of glutamatergic N-methyl-D-aspartate receptors and N-methyl-D-aspartate receptor-mediated Ca^(2+)influx is critical for neuronal function.An ischemic insult induces prompt and excessive glutamate release and drastic increases of intracellular Ca^(2+)mainly via N-methyl-D-aspartate receptors,particularly of those at the extrasynaptic site.This Ca^(2+)-evoked neuronal cell death in the ischemic core is dominated by necrosis within a few hours and days known as acute excitotoxicity.Furthermore,mild but sustained Ca^(2+)increases under neurodegenerative conditions such as in the distant penumbra of the ischemic brain and early stages of Alzheimer's disease are not immediately toxic,but gradually set off deteriorating Ca^(2+)-dependent signals and neuronal cell loss mostly because of activation of programmed cell death pathways.Based on the Ca^(2+)hypothesis of Alzheimer's disease and recent advances,this Ca^(2+)-activated“silent”degenerative excitotoxicity evolves from years to decades and is recognized as a unique slow and chronic neuropathogenesis.The N-methyl-D-aspartate receptor subunit GluN3A,primarily at the extrasynaptic site,serves as a gatekeeper for the N-methyl-D-aspartate receptor activity and is neuroprotective against both acute and chronic excitotoxicity.Ischemic stroke and Alzheimer's disease,therefore,share an N-methyl-D-aspartate receptor-and Ca^(2+)-mediated mechanism,although with much different time courses.It is thus proposed that early interventions to control Ca^(2+)homeostasis at the preclinical stage are pivotal for individuals who are susceptible to sporadic late-onset Alzheimer's disease and Alzheimer's disease-related dementia.This early treatment simultaneously serves as a preconditioning therapy against ischemic stroke that often attacks the same individuals during abnormal aging. 展开更多
关键词 Ca^(2+)hypothesis cognitive deficits HYPERACTIVITY late-onset Alzheimer's disease NEURODEGENERATION N-methyl-D-aspartate receptors N-methyl-D-aspartate receptor subunits pathogenesis preventive treatment
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非等温条件下截渗工程对海底地下水排泄的影响研究
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作者 郑天元 辛晓 +5 位作者 王和 高绍博 刘乐成 张博 郑西来 罗剑 《水文地质工程地质》 北大核心 2025年第1期1-11,共11页
温度变化会影响海岸带地下水运移特征,但之前关于截渗工程条件下地下水排泄过程的研究仅限于等温条件,没有考虑非等温过程的影响。文章构建了场地尺度的二维地下水-盐-热耦合数值模型,探究非等温条件下截渗墙对地下水排泄过程的影响,重... 温度变化会影响海岸带地下水运移特征,但之前关于截渗工程条件下地下水排泄过程的研究仅限于等温条件,没有考虑非等温过程的影响。文章构建了场地尺度的二维地下水-盐-热耦合数值模型,探究非等温条件下截渗墙对地下水排泄过程的影响,重点关注地下水排泄动态变化特征与温度的关系,采用地下水排海通量(Q)与相对排泄量(Q')定量评价海水温度对地下水排海通量的影响。研究结果表明:(1)在高温海水条件下,Q'达到平衡的时间显著缩短;(2)海水温度变化会改变截渗墙与咸水楔对地下水渗流的影响程度;(3)低温海水情况下咸水楔对地下水渗流的阻碍作用大于墙体本身,而高温海水条件下截渗墙的阻碍效果更为显著;(4)海水温度高于地下水15°C时,咸水区内更易产生并维持反向环流,导致咸水区地下水循环加速,进而增加地下水排海总量。研究成果可为截渗工程结构优化和滨海地下水资源可持续利用提供重要技术支撑。 展开更多
关键词 海水入侵 热效应 滨海含水层 数值模拟
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Complement-dependent neuroinflammation in spinal cord injury:from pathology to therapeutic implications
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作者 Hassan Saad Bachar El Baba +10 位作者 Ali Tfaily Firas Kobeissy Juanmarco Gutierrez Gonzalez Daniel Refai Gerald R.Rodts Christian Mustroph David Gimbel Jonathan Grossberg Daniel L.Barrow Matthew F.Gary Ali M.Alawieh 《Neural Regeneration Research》 SCIE CAS 2025年第5期1324-1335,共12页
Spinal cord injury remains a major cause of disability in young adults,and beyond acute decompression and rehabilitation,there are no pharmacological treatments to limit the progression of injury and optimize recovery... Spinal cord injury remains a major cause of disability in young adults,and beyond acute decompression and rehabilitation,there are no pharmacological treatments to limit the progression of injury and optimize recovery in this population.Following the thorough investigation of the complement system in triggering and propagating cerebral neuroinflammation,a similar role for complement in spinal neuroinflammation is a focus of ongoing research.In this work,we survey the current literature investigating the role of complement in spinal cord injury including the sources of complement proteins,triggers of complement activation,and role of effector functions in the pathology.We study relevant data demonstrating the different triggers of complement activation after spinal cord injury including direct binding to cellular debris,and or activation via antibody binding to damage-associated molecular patterns.Several effector functions of complement have been implicated in spinal cord injury,and we critically evaluate recent studies on the dual role of complement anaphylatoxins in spinal cord injury while emphasizing the lack of pathophysiological understanding of the role of opsonins in spinal cord injury.Following this pathophysiological review,we systematically review the different translational approaches used in preclinical models of spinal cord injury and discuss the challenges for future translation into human subjects.This review emphasizes the need for future studies to dissect the roles of different complement pathways in the pathology of spinal cord injury,to evaluate the phases of involvement of opsonins and anaphylatoxins,and to study the role of complement in white matter degeneration and regeneration using translational strategies to supplement genetic models. 展开更多
关键词 COMPLEMENT NEUROINFLAMMATION NEUROPLASTICITY regeneration spinal cord injury targeted therapy
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走出西方中心主义:科技史研究的空间与历时转向
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作者 邢麟舟 肖中显 《自然辩证法研究》 北大核心 2025年第8期99-106,共8页
20世纪末以降,西方学界的科技史学者开始反思早前研究中的西方中心主义倾向,发展出以复数性、混生性、多向性为取向的空间意识和以历时性为取向的时间意识,力图改变非西方国家(如中国)在全球科技现代性中的边缘地位。“中国中心观”等... 20世纪末以降,西方学界的科技史学者开始反思早前研究中的西方中心主义倾向,发展出以复数性、混生性、多向性为取向的空间意识和以历时性为取向的时间意识,力图改变非西方国家(如中国)在全球科技现代性中的边缘地位。“中国中心观”等历时性取向为突破空间转向的局限性提供了可能。科技史研究特别是中国科技史研究进一步走出西方中心主义的方向是:对称地兼顾研究问题中的每个相关区域,避免空间转向下分析大区域范畴时造成对特定范畴的本质化,适当处理西方科学革命、启蒙运动、工业革命、殖民和全球化在科技史中的位置。 展开更多
关键词 全球科技史 空间转向 历时转向 中国中心观 西方中心主义
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扫描参数对激光粉末床熔融Ti-6Al-4V表面粗糙度的影响
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作者 王孟达 丁佳明 +1 位作者 季霞 Steven Y.Liang 《表面技术》 北大核心 2025年第19期143-152,197,共11页
目的研究不同扫描参数对激光粉末床熔融(Laser powder bed fusion,LPBF)加工Ti-6Al-4V合金表面粗糙度的影响,为优化LPBF工艺提供理论依据。方法采用条纹和棋盘2种扫描路径,并设置0.11、0.14 mm等2种扫描间距制备试样,结合电子背散射衍射... 目的研究不同扫描参数对激光粉末床熔融(Laser powder bed fusion,LPBF)加工Ti-6Al-4V合金表面粗糙度的影响,为优化LPBF工艺提供理论依据。方法采用条纹和棋盘2种扫描路径,并设置0.11、0.14 mm等2种扫描间距制备试样,结合电子背散射衍射(EBSD)和三维轮廓仪对试样的微观组织及表面粗糙度进行定量分析。结果相较于条纹路径,采用棋盘路径能够优化热输入分布,显著促进晶粒细化和取向随机化,其平均晶粒尺寸降低了10.78%,晶粒长宽比下降了7.29%,晶粒取向散度(Grain orientation spread,GOS)提升了3.03%,表明柱状晶生长受到有效抑制,晶粒趋于等轴化。当棋盘单元由3 mm缩小至1 mm时,晶粒取向进一步趋于均匀,GOS值从0.68°提升至0.8°,提升幅度为17.65%,但平均晶粒尺寸回升18.15%,晶粒长宽比回升1.98%,表明晶粒细化效果趋于稳定。在表面质量方面,条纹路径因往复扫描造成热积累,导致表面粗糙度较高,Sa为(71.978±3.02)μm;棋盘路径显著改善了熔池流动均匀性,使Sa降至(46.325±2.85)μm,改善幅度达到35.65%。在棋盘单元从3 mm减至1 mm后,表面粗糙度进一步降至(45.131±2.10)μm,改善幅度为2.58%。此外,虽然缩小扫描间距在一定程度上促进了晶粒细化,但热积累增强,导致晶粒择优生长加剧,表面粗糙度改善效果不明显。结论通过优化扫描策略,可有效调控熔池稳定性和晶粒组织演化,进而降低成形件的表面粗糙度。 展开更多
关键词 激光粉末床熔融 扫描参数 TI-6AL-4V 表面粗糙度 晶粒取向 晶粒尺寸
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Optimizing care for gastric cancer with overt bleeding:Is systemic therapy a valid option?
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作者 Emad Qayed 《World Journal of Clinical Oncology》 2025年第1期1-4,共4页
Gastric cancer(GC)and gastroesophageal junction cancer(GEJC)represent a significant burden globally,with complications such as overt bleeding(OB)further exacerbating patient outcomes.A recent study by Yao et al evalua... Gastric cancer(GC)and gastroesophageal junction cancer(GEJC)represent a significant burden globally,with complications such as overt bleeding(OB)further exacerbating patient outcomes.A recent study by Yao et al evaluated the effectiveness and safety of systematic treatment in GC/GEJC patients presenting with OB.Using propensity score matching,the study balanced the comparison groups to investigate overall survival and treatment-related adverse events.The study's findings emphasize that systematic therapy can be safe and effective and contribute to the ongoing debate about the management of advanced GC/GEJC with OB,highlighting the complexities of treatment decisions in these high-risk patients. 展开更多
关键词 Gastric cancer Overt bleeding Systemic therapy Endoscopic therapy HEMOSTASIS
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Advances in Graphene‑Based Electrode for Triboelectric Nanogenerator
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作者 Bin Xie Yuanhui Guo +7 位作者 Yun Chen Hao Zhang Jiawei Xiao Maoxiang Hou Huilong Liu Li Ma Xin Chen Chingping Wong 《Nano-Micro Letters》 SCIE EI CAS 2025年第1期378-403,共26页
With the continuous development of wearable electronics,wireless sensor networks and other micro-electronic devices,there is an increasingly urgent need for miniature,flexible and efficient nanopower generation techno... With the continuous development of wearable electronics,wireless sensor networks and other micro-electronic devices,there is an increasingly urgent need for miniature,flexible and efficient nanopower generation technology.Triboelectric nanogenerator(TENG)technology can convert small mechanical energy into electricity,which is expected to address this problem.As the core component of TENG,the choice of electrode materials significantly affects its performance.Traditional metal electrode materials often suffer from problems such as durability,which limits the further application of TENG.Graphene,as a novel electrode material,shows excellent prospects for application in TENG owing to its unique structure and excellent electrical properties.This review systematically summarizes the recent research progress and application prospects of TENGs based on graphene electrodes.Various precision processing methods of graphene electrodes are introduced,and the applications of graphene electrode-based TENGs in various scenarios as well as the enhancement of graphene electrodes for TENG performance are discussed.In addition,the future development of graphene electrode-based TENGs is also prospectively discussed,aiming to promote the continuous advancement of graphene electrode-based TENGs. 展开更多
关键词 Triboelectric nanogenerator Precision processing Graphene electrode Self-powered sensor
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Robust Detection and Analysis of Smart Contract Vulnerabilities with Large Language Model Agents
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作者 Nishank P. Kuppa Vijay K. Madisetti 《Journal of Information Security》 2025年第1期197-226,共30页
Smart contracts on the Ethereum blockchain continue to revolutionize decentralized applications (dApps) by allowing for self-executing agreements. However, bad actors have continuously found ways to exploit smart cont... Smart contracts on the Ethereum blockchain continue to revolutionize decentralized applications (dApps) by allowing for self-executing agreements. However, bad actors have continuously found ways to exploit smart contracts for personal financial gain, which undermines the integrity of the Ethereum blockchain. This paper proposes a computer program called SADA (Static and Dynamic Analyzer), a novel approach to smart contract vulnerability detection using multiple Large Language Model (LLM) agents to analyze and flag suspicious Solidity code for Ethereum smart contracts. SADA not only improves upon existing vulnerability detection methods but also paves the way for more secure smart contract development practices in the rapidly evolving blockchain ecosystem. 展开更多
关键词 Blockchain Ethereum Smart Contracts Security Decentralized Applications WEB3 Cryptocurrency Large Language Models
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Information Security, Ethics, and Integrity in LLM Agent Interaction
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作者 Ying-Jung Chen Vijay K. Madisetti 《Journal of Information Security》 2025年第1期184-196,共13页
This study addresses security and ethical challenges in LLM-based Multi-Agent Systems, as exemplified in a blockchain fraud detection case study. Leveraging blockchain’s secure architecture, the framework involves sp... This study addresses security and ethical challenges in LLM-based Multi-Agent Systems, as exemplified in a blockchain fraud detection case study. Leveraging blockchain’s secure architecture, the framework involves specialized LLM Agents—ContractMining, Investigative, Ethics, and PerformanceMonitor, coordinated by a ManagerAgent. Baseline LLM models achieved 30% accuracy with a threshold method and 94% accuracy with a random-forest method. The Claude 3.5-powered LLM system reached an accuracy of 92%. Ethical evaluations revealed biases, highlighting the need for fairness-focused refinements. Our approach aims to develop trustworthy and reliable networks of agents capable of functioning even in adversarial environments. To our knowledge, no existing systems employ ethical LLM agents specifically designed to detect fraud, making this a novel contribution. Future work will focus on refining ethical frameworks, scaling the system, and benchmarking it against traditional methods to establish a robust, adaptable, and ethically grounded solution for blockchain fraud detection. 展开更多
关键词 Multi LLM Agents Systems Blockchain Cooperative Interactions Fraud Detection Ethics and Safety
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