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人口学视野下APC方法的困境及解决策略——以中国老年人口健康研究为例
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作者 秋丽雅 李建新 《人口与经济》 北大核心 2026年第1期91-105,共15页
老年健康研究与年龄、时期、队列等时间因素息息相关,这三个时间因素共同构成了社会科学研究的基本理论模型。人口学的列克西斯图为实现该理论模型提供了基本解析思路,而后来发展出来的APC三维分析模型实现了该理论模型的统计方法尝试,... 老年健康研究与年龄、时期、队列等时间因素息息相关,这三个时间因素共同构成了社会科学研究的基本理论模型。人口学的列克西斯图为实现该理论模型提供了基本解析思路,而后来发展出来的APC三维分析模型实现了该理论模型的统计方法尝试,虽然具体模型存在“天然缺陷”,但其试图从统计技术和概念上解决“识别问题”。以HAPC模型为例,提出合理应用APC三维分析模型应该重视队列分组依据,以理论驱动分组,明确结论适用范围。遵循上述步骤,分析中国老年人口健康的社会分化与演变,通过HAPC模型描绘不同出生队列的真实年龄效应。研究发现:教育和经济带来的中国老年人健康的社会分化稳健且持久,贯穿了不同年龄和出生队列;中国老年人健康的社会分层演变存在年龄效应和出生队列效应,累计优势/劣势理论、死亡选择性和病态状态扩展假设都无法单独解释老年人健康社会分化的演变。未来APC三维分析模型研究可能在范式转变、队列内轨迹细化、数据使用等方面获得突破。 展开更多
关键词 apc模型 出生队列分组 老年健康 生长曲线模型 列克西斯图
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Low-Density Pulsed Current Induced Refinement of Secondary α Phase for Strengthening Ti-6Al-4V-0.5Mo-0.5Zr Alloy Without Sacrificing Ductility
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作者 Tu Yanni Luo Wei +2 位作者 Liu Huiqun Feng Weizhong Zhang Pinghui 《稀有金属材料与工程》 北大核心 2026年第1期78-91,共14页
Low-density short-duration pulsed current-assisted aging treatment was applied to the Ti-6Al-4V-0.5Mo-0.5Zr alloy subjected to different solution treatments.The results show that numerous α_(p) phases redissolve into... Low-density short-duration pulsed current-assisted aging treatment was applied to the Ti-6Al-4V-0.5Mo-0.5Zr alloy subjected to different solution treatments.The results show that numerous α_(p) phases redissolve into the new β phase during the pulsed current-assisted aging process,and then the newly formed β phase is mainly transformed into the β_(t) phase,with occasional transition to new α_(p) phase,leading to a remarkable grain refinement,especially for the lamellarαs phases.In comparison to conventional aging treatment,the pulsed current-assisted aging approach achieves a significant enhancement in strength without degrading ductility,yielding an excellent mechanical property combination:a yield strength of 932 MPa,a tensile strength of 1042 MPa,and an elongation of 12.2%.It is primarily ascribed to the increased fraction of β_(t) phases,the obvious grain refinement effect,and the slip block effect induced by the multiple-variantαs colonies distributed within β_(t) phases. 展开更多
关键词 titanium alloy pulsed current microstructure refinement strength DUCTILITY
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Robust current tracking control for three-phase grid-connected inverters with LCL filter
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作者 LIU Wei WU Ben +2 位作者 SUN Wei-jie XUE Ying CAI Feng-huang 《控制理论与应用》 北大核心 2026年第1期41-51,共11页
This article investigates the robust current tracking control problem of three-phase grid-connected inverters with LCL filter under external disturbance by a dynamic state feedback control method.First,this paper cons... This article investigates the robust current tracking control problem of three-phase grid-connected inverters with LCL filter under external disturbance by a dynamic state feedback control method.First,this paper constructs an internal model to learn the information of the states and input of the grid-connected inverter under steady state.Second,by utilizing the internal model principle,the paper turns the tracking control problem into the robust stabilization control problem based on some appropriate coordinate transformations.Then,The paper designs a dynamics state feedback control law to deal with this robust stabilization problem,and thus the solution of the robust current tracking control problem of three-phase grid-connected inverters can be obtained.This control method can ensure the asymptotic stability of the closedloop system.Finally,the paper illustrates the effectiveness of the proposed control approach through several groups of simulations,and compares it with the feedforward control method to verify the robustness of the proposed control method to uncertain parameters. 展开更多
关键词 grid-connected inverter internal model principle current tracking disturbance suppression robust control
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Does transcranial direct current stimulation enhance the hypoalgesic effect of exercise?
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作者 Aidan Lewis Ben Rattray +1 位作者 Constantino Toufexis Andrew Flood 《Sports Medicine and Health Science》 2026年第1期102-109,共8页
Exercise produces a decrease in pain sensitivity via an effect called exercise-induced hypoalgesia(EIH).Transcranial direct current stimulation(tDCS),acting on similar analgesic mechanisms as EIH,represents a potentia... Exercise produces a decrease in pain sensitivity via an effect called exercise-induced hypoalgesia(EIH).Transcranial direct current stimulation(tDCS),acting on similar analgesic mechanisms as EIH,represents a potential complementary intervention that may amplify the effects of exercise on pain.This study aimed to explore if anodal tDCS could enhance the effect of exercise on pain compared to exercise alone.A total of 35 healthy participants aged 19–37 years completed a familiarisation session followed by two separate sessions where active and sham tDCS was applied in a randomised cross-over design.The familiarisation session involved familiarisation to the pain assessment and exercise tasks,while the subsequent tDCS sessions involved pain sensitivity assessment,exercise and either anodal tDCS or sham tDCS.tDCS doses were applied at 2 mA over the primary motor cortex for 10 min,with the reference electrode placed over the contralateral supraorbital area.The exercise task involved a sustained isometric grip strength contraction at 35%of maximal voluntary contraction(MVC)until volitional exhaustion.Pain sensitivity was evaluated as pressure pain threshold before tDCS,after tDCS,and after exercise.Across both tDCS conditions,pain threshold was higher after exercise when compared to pre-and post-tDCS measurement.This increase in pain threshold did not differ between active and sham tDCS conditions.Our findings suggest that the hypoalgesic effects of active anodal tDCS over the motor cortex prior to exercise are no greater than the effects of sham tDCS prior to exercise. 展开更多
关键词 Transcranial direct current stimulation Grip strength Pain sensitivity Time to exhaustion Pain pressure threshold TDCS
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工业锅炉的基础控制优化及APC控制器应用 被引量:1
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作者 吴科学 吴赟盟 《工业锅炉》 2025年第4期50-53,58,共5页
采用先进过程控制(APC)实施控制性能优化,进而提高锅炉的自控率和控制精度,确保运行稳定性并降低能耗,经过对控制系统基础控制回路PID参数自适应优化,提升工业锅炉自动化水平,并对锅炉进行系统性控制性能优化,提升关键过程参数的控制品... 采用先进过程控制(APC)实施控制性能优化,进而提高锅炉的自控率和控制精度,确保运行稳定性并降低能耗,经过对控制系统基础控制回路PID参数自适应优化,提升工业锅炉自动化水平,并对锅炉进行系统性控制性能优化,提升关键过程参数的控制品质,提升燃煤效率并降低操作人员的劳动强度,从而提高锅炉装置的运行平稳性,节约生产运行成本。 展开更多
关键词 先进过程控制(apc) 锅炉控制性能优化 PID控制回路
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搭接长度等对Ⅱ型APC接头拉伸性能的影响
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作者 余琼 敖晟瑞 +4 位作者 唐子鸣 郭霖 谢青海 张志 陈振海 《哈尔滨工业大学学报》 EI CAS 北大核心 2025年第1期128-139,共12页
为研究搭接长度和钢筋直径对Ⅱ型APC接头力学性能的影响,对63个该接头进行单向拉伸试验,分析了接头破坏模式、极限承载力、延性和黏结应力等。结果表明:钢筋直径相同时,随搭接长度增加,平均黏结应力降低,试件强度、延性、最大力总伸长... 为研究搭接长度和钢筋直径对Ⅱ型APC接头力学性能的影响,对63个该接头进行单向拉伸试验,分析了接头破坏模式、极限承载力、延性和黏结应力等。结果表明:钢筋直径相同时,随搭接长度增加,平均黏结应力降低,试件强度、延性、最大力总伸长率明显提高,残余变形整体呈下降趋势;钢筋拉断破坏试件强度、延性、最大力总伸长率和残余变形满足规范要求;加载过程中,套筒中部截面短边纵向和长边环向始终受拉;极限荷载下,随搭接长度增加,套筒中部截面短边侧环向压应变先转变为拉应变再向压应变发展,长边侧纵向压应变转变为拉应变;相对搭接长度相同时,极限承载力随钢筋直径增加而提高;提出的极限黏结强度及临界搭接长度计算公式与试验值吻合较好,可为实际工程应用提供参考。单拉工况下,钢筋直径不大于18 mm时,建议接头搭接长度大于12 d。 展开更多
关键词 Ⅱ型apc接头 拉伸性能 搭接长度 黏结强度
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APC接头连接的T型全预制剪力墙抗震试验
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作者 余琼 袁越 +3 位作者 程浩 唐子鸣 郭霖 谢青海 《哈尔滨工业大学学报》 北大核心 2025年第5期100-113,共14页
为研究套筒灌浆搭接接头(简称APC接头)连接的T型全预制剪力墙的抗震性能,在Ⅰ、Ⅱ型APC接头的基础上,对1片现浇墙和2片预制墙进行拟静力试验。结果表明:现浇墙初始水平裂缝出现在基础顶面,由于套筒对混凝土的约束,预制墙的初始水平裂缝... 为研究套筒灌浆搭接接头(简称APC接头)连接的T型全预制剪力墙的抗震性能,在Ⅰ、Ⅱ型APC接头的基础上,对1片现浇墙和2片预制墙进行拟静力试验。结果表明:现浇墙初始水平裂缝出现在基础顶面,由于套筒对混凝土的约束,预制墙的初始水平裂缝出现在套筒上方;极限状态下,试件均为弯剪破坏,现浇墙墙脚边缘混凝土压碎、钢筋压屈,预制墙为套筒上方钢筋压屈、混凝土压碎、套筒外混凝土剥落;在开裂、屈服、峰值荷载,刚度、延性和耗能能力方面,采用Ⅰ型套筒的预制墙与现浇墙相当,而采用Ⅱ型套筒的预制墙大于现浇墙;两种套筒在预制剪力墙的受力过程中保持弹性状态,均能有效传递钢筋应力;预制试件平面外位移在加载过程中出现负向累积,但相同加载级时预制墙与现浇墙平面外位移绝对值相当。 展开更多
关键词 T型全预制剪力墙 套筒灌浆搭接接头 搭接连接 拟静力试验 抗震性能
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基于APCS-MLR受体模型的江西省宜丰县土壤重金属来源解析及生态风险评价 被引量:3
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作者 唐志敏 周墨 +6 位作者 张明 张晓东 田福金 刘冰权 周强强 文帮勇 姜宏裕 《环境科学》 北大核心 2025年第7期4674-4683,共10页
土壤中重金属的富集是自然过程和人为活动共同作用的结果,开展土壤重金属来源解析及生态风险评价是服务土壤重金属污染防治的必要手段.为查明江西省宜丰县土壤中重金属来源及其生态风险特征,采集分析了宜丰县表层土壤中重金属含量以及p... 土壤中重金属的富集是自然过程和人为活动共同作用的结果,开展土壤重金属来源解析及生态风险评价是服务土壤重金属污染防治的必要手段.为查明江西省宜丰县土壤中重金属来源及其生态风险特征,采集分析了宜丰县表层土壤中重金属含量以及pH值等指标,采用绝对主成分得分-多元线性回归(APCS-MLR)受体模型解析了土壤中重金属来源并定量计算了各来源贡献率,基于地累积指数法和潜在生态风险指数法对土壤重金属生态风险进行了评价,同时采用GIS技术对土壤重金属的空间分布规律进行了探讨.结果显示,宜丰县土壤中ω(As)、ω(Cd)、ω(Cr)、ω(Cu)、ω(Hg)、ω(Ni)、ω(Pb)和ω(Zn)的平均值分别为9.7、0.211、68、25、0.113、24、37和87 mg·kg^(−1),均高于江西省土壤背景值.受地质背景控制,土壤As、Cr、Cu和Ni的高含量区与区内青白口系变质岩建造的分布相吻合,受人为活动干扰,Cd、Hg、Pb和Zn的空间分布与岩石建造类型分布呈现显著差异.生态风险评价发现宜丰县土壤重金属污染风险总体较低,但局部存在以As、Cd和Hg为主的轻微污染和中等风险.APCS-MLR受体模型解析出了3个重金属来源:As、Cr、Cu和Ni主要为自然来源,贡献率分别为80.06%、69.92%、80.49%和94.27%,Pb和Zn主要为交通来源,贡献率分别为74.73%和66.99%,Cd和Hg主要受工农业来源的控制,贡献率分别为43.62%和58.09%.研究结果可为宜丰县土壤污染防治提供数据理论支撑. 展开更多
关键词 土壤 重金属 来源 apcS-MLR受体模型 生态风险
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APCS-MLR结合PMF模型解析大气PM_(2.5)中重金属元素来源及健康风险 被引量:3
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作者 彭家美 于瑞莲 +2 位作者 胡恭任 陈衍婷 吴雅清 《环境科学》 北大核心 2025年第11期7371-7384,共14页
为探究江西省南康市大气PM_(2.5)中重金属的污染特征、来源及健康风险,对该地区4个季节的大气PM_(2.5)进行采样,用ICP-MS分析测定11种重金属元素(Cu、Fe、Zn、Mn、Cd、Co、As、Ba、Pb、Cr和Ti)的含量,分析了Cu、Fe、Zn、Mn、Cd、Co、As... 为探究江西省南康市大气PM_(2.5)中重金属的污染特征、来源及健康风险,对该地区4个季节的大气PM_(2.5)进行采样,用ICP-MS分析测定11种重金属元素(Cu、Fe、Zn、Mn、Cd、Co、As、Ba、Pb、Cr和Ti)的含量,分析了Cu、Fe、Zn、Mn、Cd、Co、As、Ba和Pb的污染特征.结合富集因子分析、多变量分析方法(最大方差旋转因子分析)、APCS-MLR(绝对主成分线性回归)和PMF(正定矩阵因子分解)模型定量解析大气PM_(2.5)中重金属来源,并对重金属元素的人体健康风险进行评价.结果表明,采样期间研究区ρ(PM_(2.5))平均值为46.98μg·m^(-3),超过国家环境空气质量二级标准,且PM_(2.5)质量浓度在冬季最高.PM_(2.5)中9种重金属浓度年平均值高低依次为:Fe>Zn>Pb>As>Mn>Cu>Ba>Cd>Co.富集因子分析结果显示,研究区大气PM_(2.5)中大部分金属元素含量超过了江西省A层土壤环境背景值,除Fe和Ba外,其余重金属在环境中均相对富集,且受人类活动影响较大.因子分析表明,研究区大气PM_(2.5)的重金属污染源主要有4类:机动车源、工业源、燃煤源和自然源,Mn、Cu和Zn主要来源为机动车排放源,Co主要来源于以家具厂为代表的工业源,As、Cd和Pb主要来源于燃煤,Fe和Ba以自然源为主.APCS-MLR和PMF模型分析结果表明,由人类活动所引起的污染来源(机动车源、工业源和燃煤源)具有更高的贡献率,其中的燃煤源,在两个模型中的贡献率为20%~40%.健康风险分析结果显示,9种重金属均不存在非致癌风险,As和Mn对3类人群均存在潜在致癌风险,且对成年男性的致癌风险最大. 展开更多
关键词 PM_(2.5) 重金属 富集因子 绝对主成分线性回归(apcS-MLR) 正定矩阵因子分解(PMF) 健康风险
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基于PMF和APCS-MLR模型的会仙湿地沉积物重金属源解析及污染风险评价 被引量:2
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作者 刘涛 沈利娜 +1 位作者 于奭 秦金福 《环境科学》 北大核心 2025年第9期6024-6036,共13页
基于会仙湿地14个点位沉积物样品测试分析结果,探讨(Cu、Pb、Cd、Cr、Zn、Ni、Hg和As)8种重金属的含量特征,并运用地累积指数法和潜在生态风险指数对重金属进行风险评估,结合相关性分析、聚类分析、绝对主成分-多元线性回归(APCS-MLR)... 基于会仙湿地14个点位沉积物样品测试分析结果,探讨(Cu、Pb、Cd、Cr、Zn、Ni、Hg和As)8种重金属的含量特征,并运用地累积指数法和潜在生态风险指数对重金属进行风险评估,结合相关性分析、聚类分析、绝对主成分-多元线性回归(APCS-MLR)和正定矩阵因子分解(PMF)等多种方法,识别和定量解析污染源及贡献.结果表明:①8种重金属的平均含量均高于背景值,其中Cd超过《土壤环境质量-农用地土壤污染风险管控标准》(GB 15618-2018)筛选值.②地累积指数评价结果表明,Cd属于中度污染,Zn属于偏中度污染,Hg、Ni、Cr和Pb属于轻度污染,As和Cu属于无污染.③潜在风险指数评价结果表明,Cd(245.91)属于很强生态风险,Hg(134.59)属于强生态风险,其它元素均属于轻微生态风险;研究区综合生态风险指数均值为433.33,整体呈现出强的潜在生态风险.④APCS-MLR识别出4个污染源,分别为农业源、自然与农业源、大气沉降与生活源和未识别源(交通与农业源),贡献率分别为33.16%、15.75%、9.50%和41.59%;PMF识别出3个污染源,分别为大气沉降与生活源、自然与农业源和交通与农业源,贡献率分别为21.92%、35.24%和42.84%. 展开更多
关键词 沉积物 重金属 源解析 正定矩阵因子分解(PMF) 绝对主成分-多元线性回归(apcS-MLR)
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茶树APC/C基因家族全基因组鉴定及表达模式分析
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作者 李红建 王青 +7 位作者 方开星 倪尔冬 姜晓辉 秦丹丹 王秋霜 潘晨东 李波 吴华玲 《江苏农业科学》 北大核心 2025年第19期52-61,共10页
APC/C是一类多亚基E3泛素连接酶,在植物生长发育和逆境反应中起着重要作用。为研究茶树APC/C基因家族的特征,探讨其功能和在逆境适应中的潜在作用,利用生物信息学方法从茶树基因组中鉴定到15个APC/C基因,分析其染色体定位、基因结构、... APC/C是一类多亚基E3泛素连接酶,在植物生长发育和逆境反应中起着重要作用。为研究茶树APC/C基因家族的特征,探讨其功能和在逆境适应中的潜在作用,利用生物信息学方法从茶树基因组中鉴定到15个APC/C基因,分析其染色体定位、基因结构、保守结构域及进化关系;基于转录组数据分析各成员组织表达特异性及在非生物胁迫、激素处理下的响应模式。结果表明,15个APC/C基因家族成员不均匀地分布在6条染色体上;其蛋白长度为65~1 786 aa,分子量介于7.34~197.42 ku之间,等电点介于3.73~9.49之间。共线性分析结果显示,茶树APC/C基因家族成员与玫瑰同源基因亲缘关系较近,有7对基因存在共线性关系。启动子分析发现,茶树APC/C基因启动子中含有光响应元件最多。miRNA靶向预测显示,8个APC/C基因受16个miRNA靶向调控。表达模式分析结果显示,多数APC/C基因在茎和叶中表达量较高,且随着叶片成熟度增加表达量逐渐降低;APC/C基因在非生物胁迫和激素处理下呈现不同的响应模式。 展开更多
关键词 茶树 apc/C基因家族 非生物胁迫 激素响应 表达模式
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Integrated Equipment with Functions of Current Flow Control and Fault Isolation for Multiterminal DC Grids 被引量:1
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作者 Shuo Zhang Guibin Zou 《Energy Engineering》 EI 2025年第1期85-99,共15页
The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow ... The multi-terminal direct current(DC)grid has extinctive superiorities over the traditional alternating current system in integrating large-scale renewable energy.Both the DC circuit breaker(DCCB)and the current flow controller(CFC)are demanded to ensure the multiterminal DC grid to operates reliably and flexibly.However,since the CFC and the DCCB are all based on fully controlled semiconductor switches(e.g.,insulated gate bipolar transistor,integrated gate commutated thyristor,etc.),their separation configuration in the multiterminal DC grid will lead to unaffordable implementation costs and conduction power losses.To solve these problems,integrated equipment with both current flow control and fault isolation abilities is proposed,which shares the expensive and duplicated components of CFCs and DCCBs among adjacent lines.In addition,the complicated coordination control of CFCs and DCCBs can be avoided by adopting the integrated equipment in themultiterminal DC grid.In order to examine the current flow control and fault isolation abilities of the integrated equipment,the simulation model of a specific meshed four-terminal DC grid is constructed in the PSCAD/EMTDC software.Finally,the comparison between the integrated equipment and the separate solution is presented a specific result or conclusion needs to be added to the abstract. 展开更多
关键词 Integrated equipment multiterminal direct current grid current flow control fault isolation
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基于APCS-MLR模型的农用地土壤重金属污染溯源研究进展 被引量:1
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作者 于澍 李剑炜 +3 位作者 吕星浩 万大娟 袁腾跃 吴珏 《绿色科技》 2025年第8期139-145,共7页
我国农用地土壤重金属污染形势严峻,对生态环境和粮食安全构成重大威胁,准确解析污染来源是防控污染的关键前提。系统综述了APCS-MLR模型的农用地土壤重金属污染溯源应用及其进展。该模型在农用地土壤重金属溯源研究中,能有效识别主要... 我国农用地土壤重金属污染形势严峻,对生态环境和粮食安全构成重大威胁,准确解析污染来源是防控污染的关键前提。系统综述了APCS-MLR模型的农用地土壤重金属污染溯源应用及其进展。该模型在农用地土壤重金属溯源研究中,能有效识别主要污染源,并定量评估其对重金属元素的贡献。此外,APCS-MLR模型与PMF模型、地理信息系统及机器学习等技术的联合应用,进一步提升了重金属污染溯源的精度与空间可视化能力。尽管该模型在动态污染过程及小尺度解析中存在局限,但通过算法优化和多技术融合,其在农用地污染分区管控、生态修复评估及政策制定中具有广阔前景。未来需结合同位素示踪、高分辨率遥感等技术,推动APCS-MLR模型在精准农业环境管理中的应用,为保障土壤健康与粮食安全提供科学支撑。 展开更多
关键词 农用地 土壤重金属 溯源研究 apcS-MLR模型 研究进展
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基于APCS-MLR和PMF模型的石煤矿区及周边区域农田土壤重金属污染来源解析 被引量:5
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作者 董天浩 潘淑芳 +4 位作者 张仁杰 姜立恒 郭焱 纪雄辉 谢运河 《环境科学》 北大核心 2025年第5期3209-3219,共11页
为了探究石煤开采带来的农田土壤重金属污染风险,对某石煤矿区及周边区域农田土壤进行了采样分析及污染源解析.结果表明:①该石煤矿区及周边农田土壤重金属污染风险很高.按内梅罗综合污染指数确定的轻污染风险以上的采样点占比为61.6%,... 为了探究石煤开采带来的农田土壤重金属污染风险,对某石煤矿区及周边区域农田土壤进行了采样分析及污染源解析.结果表明:①该石煤矿区及周边农田土壤重金属污染风险很高.按内梅罗综合污染指数确定的轻污染风险以上的采样点占比为61.6%,其中重污染风险采样点占比达21.9%.研究区土壤Cd污染很严重,超出风险筛选值和风险管制值的采样点占比分别为71.5%和18.5%.②土壤Cd、Zn、Ni、Cu和As之间,As、Hg和Pb之间,Cr与As和Ni,Hg与Zn、Ni和Cu,均存在极显著正相关关系.Cd与Cr和Pb的相关性均不显著,其余重金属元素组合均存在显著正相关关系.③基于不同受体模型对研究区进行土壤重金属污染来源解析,识别出3个污染来源,即石煤开采源,大气沉降源和自然源.APCS-MLR模型判定土壤Cd、As、Cu、Zn和Ni主要受石煤开采源影响,Pb和Hg主要受大气沉降源影响,Cr主要受自然源影响;3个污染源的贡献率依次为43.2%、31.5%和25.3%.PMF模型的源解析结果与之总体上相同,但判定土壤Cd和Hg均受石煤开采-大气沉降混合源影响;3个污染源的贡献率依次为45.0%、34.5%和20.5%.研究表明,石煤矿区及周边区域农田土壤有较大的重金属污染风险,联合使用两种受体模型能够更合理地判别各土壤重金属主要的污染来源. 展开更多
关键词 土壤重金属 石煤 源解析 apcS-MLR模型 PMF模型
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中国劳动者失业风险感知变迁——基于APC模型的动态分析
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作者 吕风光 张顺 《人口与经济》 北大核心 2025年第6期44-58,共15页
劳动者的失业风险感知是客观就业处境的主观映射及预测指标。结合多重变迁趋势理论构建动态分析框架,基于2013—2021年中国社会状况综合调查(CSS)数据,使用“年龄-时期-世代”(APC)模型分解劳动者失业风险感知的年龄、时期和世代效应,... 劳动者的失业风险感知是客观就业处境的主观映射及预测指标。结合多重变迁趋势理论构建动态分析框架,基于2013—2021年中国社会状况综合调查(CSS)数据,使用“年龄-时期-世代”(APC)模型分解劳动者失业风险感知的年龄、时期和世代效应,得到以下核心结论:第一,在年龄效应上,失业风险感知随着年龄增长而下降,且下降趋势集中于劳动者就业初期;进一步分析发现,专用性人力资本和社会资本累积是失业风险感知在就业初期大幅下降的重要因素。第二,在时期效应上,2013—2021年失业风险感知逐年上升,这一趋势主要由数字经济推动就业形态快速变化所致,而劳动力成本上升和国际贸易形势的相对贡献较小。第三,在世代效应上,1960年左右世代群体的失业风险感知较低,而1975—1985年世代群体相对偏高;原因在于,1960年左右世代在就业初期失业率低,同辈竞争压力低,且劳动力素质与产业结构相匹配,因而具有较低的失业风险感知,而1975—1985年世代群体在就业初期失业率偏高,劳动力素质与产业结构出现分离,造成结构性失业与较高的失业风险感知。以上发现为治理失业风险提供了实证依据,对实现新时代高质量充分就业具有重要政策意义。 展开更多
关键词 失业风险感知 高质量充分就业 apc模型 劳动力
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Ru/NiMnB spherical cluster pillar for highly proficient green hydrogen electrocatalyst at high current density 被引量:1
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作者 Md Ahasan Habib Shusen Lin +4 位作者 Mehedi Hasan Joni Sumiya Akter Dristy Rutuja Mandavkar Jae-Hun Jeong Jihoon Lee 《Journal of Energy Chemistry》 2025年第1期397-408,共12页
Advanced OER/HER electrocatalytic alternatives are crucial for the wide adaptation of green hydrogen energy.Herein,Ru/NiMnB spherical cluster pillar(SCP),denoted as Ru/NiMnB,is synthesized using a combination of elect... Advanced OER/HER electrocatalytic alternatives are crucial for the wide adaptation of green hydrogen energy.Herein,Ru/NiMnB spherical cluster pillar(SCP),denoted as Ru/NiMnB,is synthesized using a combination of electro-deposition and hydrothermal reaction.Systematic investigation of Ru doping in the NiMnB matrix revealed significant improvements in electrocatalytic performance.The Ru/NiMnB SCPs demonstrate superior OER/HER activity with low overpotentials of 150 and 103 mV at 50mA/cm^(2)in 1 M KOH,making them highly competitive with state-of-the-art electrocatalysts.Remarkably,the Ru/NiMnB SCPs exhibit a low 2-E cell voltage of 2.80 V at ultra-high current density of 2,000 m A/cm^(2)in 1 M KOH,outperforming the standard benchmark electrodes of RuO_(2)||Pt/C,thereby positioning Ru/NiMnB as one of the best bifunctional electrocatalysts.These SCPs exhibit exceptional high-current characteristics,stability and corrosion resistance,as evidenced by continuous operation at 1,000 mA/cm^(2)high-current density for over 150 h in 6 M KOH at elevated temperatures under harsh industrial conditions.Only a small amount of Ru incorporation significantly enhances the electrocatalytic performances of NiMnB,attributed to increased active sites and improved intrinsic properties such as conductivity,adsorption/desorption capability and reaction rates.Consequently,Ru/NiMnB SCPs present a promising bi-functional electrode concept for efficient green H_(2)production. 展开更多
关键词 Advanced electrocatalyst High current Corrosion resistance Industrial requirement
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Currents from relativistic laser-plasma interaction as a novel metrology for the system stability of high-repetition-rate laser secondary sources 被引量:1
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作者 Michael Ehret Iuliana-Mariana Vladisavlevici +16 位作者 Philip Wykeham Bradford Jakub Cikhardt Evgeny Filippov Jose Luis Henares Rubén Hernández Martín Diego de Luis JoséAntonio Pérez-Hernández Pablo Vicente Tomas Burian Enrique García-García Juan Hernández Cruz Mendez Marta Olivar Ruíz Óscar Varela Maria Dolores Rodríguez Frías João Jorge Santos Giancarlo Gatti 《Matter and Radiation at Extremes》 2025年第2期24-34,共11页
This work demonstrates experimentally the close relation between return currents from relativistic laser-driven target polarization and the quality of the relativistic laser–plasma interaction for laser-driven second... This work demonstrates experimentally the close relation between return currents from relativistic laser-driven target polarization and the quality of the relativistic laser–plasma interaction for laser-driven secondary sources,taking as an example ion acceleration by target normal sheath acceleration.The Pearson linear correlation of maximum return current amplitude and proton spectrum cutoff energy is found to be in the range from~0.70 to 0.94.kA-scale return currents rise in all interaction schemes where targets of any kind are charged by escaping laser-accelerated relativistic electrons.Their precise measurement is demonstrated using an inductive scheme that allows operation at high repetition rates.Thus,return currents can be used as a metrological online tool for the optimization of many laser-driven secondary sources and for diagnosing their stability.In particular,in two parametric studies of laser-driven ion acceleration,we carry out a noninvasive online measurement of return currents in a tape target system irradiated by the 1 PW VEGA-3 laser at Centro de Láseres Pulsados:first the size of the irradiated area is varied at best compression of the laser pulse;second,the pulse duration is varied by means of induced group delay dispersion at best focus.This work paves the way to the development of feedback systems that operate at the high repetition rates of PW-class lasers. 展开更多
关键词 relativistic laser plasma interaction pearson linear correlation proton spectrum cutoff energy interaction schemes ion acceleration target normal sheath accelerationthe return current return currents
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Electroacupuncture with different current intensities can improve gastrointestinal motility in diabetic gastroparesis via vagal and sympathetic pathways 被引量:1
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作者 Yi-Wen Tang You Zhang +4 位作者 Jin Zhou Yu-Ting Peng Yan Zi Yan-Rong Wei Zeng-Hui Yue 《World Journal of Diabetes》 2025年第8期249-262,共14页
BACKGROUND Diabetic gastroparesis(DGP)disrupts gastric motility.Electroacupuncture(EA)at Zusanli(ST36)may alleviate DGP symptoms via neural pathways.AIM To investigate how EA current intensities at ST36 regulate neura... BACKGROUND Diabetic gastroparesis(DGP)disrupts gastric motility.Electroacupuncture(EA)at Zusanli(ST36)may alleviate DGP symptoms via neural pathways.AIM To investigate how EA current intensities at ST36 regulate neural pathways and improve gastric motility in DGP models.METHODS A DGP model was established using intraperitoneal injection of streptozotocin.Gastrointestinal motility was measured in rats after 2 weeks of continuous EA at ST36.Current intensity was selected as 0.5 mA,1 mA,and 3 mA.Gastric electrodynamics were detected by recording and analyzing the number of gastric discharges.The gastric emptying rate and propulsion rate of the small intestine were measured to assess dynamic gastrointestinal function.Hematoxylin-eosin staining was conducted to measure histopathological changes in the gastric sinus.Reverse transcription-polymerase chain reaction was conducted to determine mRNA levels of Rho guanine nucleotide-binding protein A and Rho-associated coiled-coil forming protein kinase.Western blotting was conducted to determine the expression levels of choline acetyltransferase,tyrosine hydroxylase,Rho guanine nucleotide-binding protein A,and Rho-associated coiled-coil forming protein kinase.Immunofluorescence staining in the stomach was conducted to detect the distribution of C-kit,an interstitial cell of Cajal marker.An enzymelinked immunosorbent assay was conducted to detect serum levels of acetylcholine and norepinephrine.RESULTS Treatment with EA improved gastric emptying and gastric smooth muscle disorders in rats with DGP,mitigated pathological damage,and restored the function of interstitial cells of Cajal.In addition,different current intensities of EA affected gastrointestinal function of rats with DGP.The 0.5 mA,1 mA,and 3 mA EA groups all improved gastrointestinal function.0.5 mA EA increased acetylcholine levels by increasing protein expression of choline acetyltransferase(P<0.05),thereby upregulating vagus nerve activity and enhancing parasympathetic nerve regulation.3 mA EA increased norepinephrine levels(P<0.05)by increasing protein expression of tyrosine hydroxylase,thereby activating the sympathetic nervous pathway.1 mA coordinated the function of the vagus and sympathetic nerves to improve gastrointestinal motility.CONCLUSION EA with ST36 improved gastric motility in rats with DGP.0.5 mA EA activated the vagus nerve,while 3 mA EA regulated gastrointestinal motility by activating the sympathetic nerves. 展开更多
关键词 Diabetic gastroparesis ELECTROACUPUNCTURE current intensity Vagus nerve Sympathetic nerve
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Ionospheric F-region currents estimated from Macao Science Satellite-1 and Swarm satellite magnetic data 被引量:1
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作者 JuYuan Xu HongBo Yao Keke Zhang 《Earth and Planetary Physics》 2025年第3期731-739,共9页
Accurate modeling of Earth's ionospheric F-region currents is essential for refining geomagnetic field models and understanding magnetosphere-ionosphere coupling.In this study,we develop averaged models to charact... Accurate modeling of Earth's ionospheric F-region currents is essential for refining geomagnetic field models and understanding magnetosphere-ionosphere coupling.In this study,we develop averaged models to characterize F-region currents using magnetic data from the MSS-1(Macao Science Satellite-1) and Swarm satellite missions.Our approach employs a toroidal field representation,utilizing spherical harmonics to capture spatial variations and Fourier series to represent temporal dynamics.Two models,Model-A and Model-B,derived from distinct datasets,are constructed to represent current patterns at altitudes of 450 km and 512 km,respectively.Our models successfully capture the primary spatial structures and seasonal variations of polar field-aligned currents.Additionally,they accurately reproduce the localized inter-hemispheric field-aligned currents observed in mid and low latitudes during solstices,particularly between 14:00 and 16:00 magnetic local times.These findings enhance our understanding of ionospheric F-region currents and contribute to more precise geomagnetic field modeling. 展开更多
关键词 Macao Science Satellite-1 SWARM field-aligned currents GEOMAGNETISM ionosphere
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Pulsed electric current treatment: from regulating non-metallic inclusions to inhibiting submerged entry nozzle clogging 被引量:1
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作者 Wen-wen Yu Jin-gang Qi Heng Cui 《Journal of Iron and Steel Research International》 2025年第4期833-848,共16页
Non-metallic inclusions in steel are a significant challenge,affecting material properties and leading to issues such as stress concentration,cracking,and accelerated corrosion.Current methods for removing inclusions,... Non-metallic inclusions in steel are a significant challenge,affecting material properties and leading to issues such as stress concentration,cracking,and accelerated corrosion.Current methods for removing inclusions,including bubble,electromagnetic stirring,filtration separation,fluid flow,and sedimentation,often struggle with the removal of fine inclusions.Apart from these known methods,pulsed electric current(PEC),as an emerging technology,has demonstrated immense potential and environmental advantages.PEC offers adjustable current parameters and simple equipment,making it an attractive alternative to traditional methods.Its green energy-saving features and excellent results in regulating inclusion morphology and migration,as well as inhibiting submerged entry nozzle(SEN)clogging,make it a promising technology.In comparison to continuous current technology,PEC has shown significant advantages in regulating inclusions,not only improving purification efficiency but also demonstrating outstanding performance in flow stability and energy consumption.The ability of PEC to efficiently reduce inclusion numbers enhances the purity and quality of molten steel,improving its mechanical properties.Currently,the theoretical basis for controlling the movement of inclusions by current is mainly composed of three major theories:the double electric layer theory,electromagnetic force reverse separation theory,and electric free energy drive theory.These theories together form an important framework for researchers to understand and optimize the behavior of impurity movement controlled by electric current.Looking ahead,PEC is expected to pave the way for new solutions in directional regulation of inclusion migration,efficient inclusion removal,SEN clogging prevention,and the purification of molten steel. 展开更多
关键词 Pulsed electric current Non-metallic inclusion REGULATION Submerged entry nozzle CLOGGING
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