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铀对α-Al_(2)O_(3)中氢与本征点缺陷相互作用的影响
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作者 杨飞龙 向鑫 +2 位作者 胡立 张桂凯 陈长安 《原子与分子物理学报》 CAS 北大核心 2025年第5期123-129,共7页
在长期高温服役过程中,铀床的氚渗透泄露问题是聚变堆涉氚系统中需要关注的焦点之一,而一种行之有效的解决思路是在内壁制备阻氚涂层.然而,服役过程中通过热扩散渗入涂层内部的铀可能在阻氚涂层氢行为中起作用,进而影响其服役可靠性.基... 在长期高温服役过程中,铀床的氚渗透泄露问题是聚变堆涉氚系统中需要关注的焦点之一,而一种行之有效的解决思路是在内壁制备阻氚涂层.然而,服役过程中通过热扩散渗入涂层内部的铀可能在阻氚涂层氢行为中起作用,进而影响其服役可靠性.基于此,采用第一性原理计算方法,研究了铀对α-Al_(2)O_(3)中氢与本征点缺陷相互作用的影响.结果发现,铀对α-Al_(2)O_(3)中空位型本征点缺陷及氢相关缺陷的存在形式、电荷态及相对稳定性有重要影响.从形成能观点来看,铀对α-Al_(2)O_(3)中空位型本征点缺陷及氢相关缺陷的形成有利,且α-Al_(2)O_(3)中空位型点缺陷对氢的捕陷能力因铀的引入显著增加.研究结果对α-Al_(2)O_(3)基内壁阻氚涂层在氚工艺系统铀床中应用的可靠性评估具有重要的指导意义. 展开更多
关键词 本征点缺陷 氢相关缺陷 相互作用 α-Al_(2)O_(3)
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基于Point Transformer v2的点云枝叶分离方法研究
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作者 马津 陈一平 +3 位作者 韩汀 王朝磊 张小海 张吴明 《航天返回与遥感》 CSCD 北大核心 2024年第3期62-72,共11页
准确高效的点云枝叶分离对精确计算森林树木的垂直参数至关重要。然而,当前的研究方法计算成本高,且依赖先验知识导致泛化能力不足。针对以上问题,文章提出利用基于点特征的Transformer网络进行自动化的森林场景三维点云的枝叶分离研究... 准确高效的点云枝叶分离对精确计算森林树木的垂直参数至关重要。然而,当前的研究方法计算成本高,且依赖先验知识导致泛化能力不足。针对以上问题,文章提出利用基于点特征的Transformer网络进行自动化的森林场景三维点云的枝叶分离研究。该方法使用Point Transformer v2网络,首先利用网格编码模块提取可学习的局部结构关系,保留点云的几何拓扑结构;其次使用分组注意力实现多通道联合学习,降低特征的冗余度,提高计算的效率;最后构建了基于点的Transformer网络实现高精度森林树木三维点云语义分割,降低了对于先验知识的需求。使用地基激光扫描仪获取的加拿大和芬兰7个不同树种样地的三维点云数据,进行枝叶分离实验和精度评价。实验结果表明,网络整体精度(OA)为94.42%,mIoU为78.89%,能够适应不同树种、不同点云密度的森林场景的枝叶分离。 展开更多
关键词 三维点云 深度学习 枝叶分离 point TRANSFORMER V2
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单层Cs_(2)PbI_(2)Cl_(2)中点缺陷的形成与稳定性
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作者 何诗颖 赵宇清 +3 位作者 邹代峰 许英 廖雨洁 禹卓良 《原子与分子物理学报》 CAS 北大核心 2025年第5期130-136,共7页
Cs_(2)PbI_(2)Cl_(2)是卤化铅钙钛矿材料的新成员,由于其高的光吸收系数和长的载流子迁移距离等优异的光电物理性能,在太阳能电池、光电探测器、场效应晶体管以及发光二极管等领域受到广泛的关注.其中光电材料及器件的优良特性由电子结... Cs_(2)PbI_(2)Cl_(2)是卤化铅钙钛矿材料的新成员,由于其高的光吸收系数和长的载流子迁移距离等优异的光电物理性能,在太阳能电池、光电探测器、场效应晶体管以及发光二极管等领域受到广泛的关注.其中光电材料及器件的优良特性由电子结构决定,而钙钛矿的点缺陷对电子结构具有重要的调控,且单层Cs_(2)PbI_(2)Cl_(2)中点缺陷的研究尚且缺乏.本文基于密度泛函理论的第一性原理计算,对单层Cs_(2)PbI_(2)Cl_(2)的铯空位、碘空位、氯空位、铯替代铅、碘替代铯、碘替代铅、碘替代氯、氯替代铯、氯替代铅和氯替代碘的缺陷形成能和稳定性进行了研究.结果表明:在富铅和缺铅条件下,碘替代氯和氯替代碘的缺陷形成能偏低,且氯替代碘能有效降低体系总能,提高体系稳定性.在缺铅条件下铯空位缺陷形成能低于富铅条件,在缺铅条件下更易形成铯空位;富铅和缺铅条件下对碘替代氯和氯替代碘的缺陷形成能基本无影响.上述研究结果有助于理解点缺陷对钙钛矿材料稳定性的影响,同时也为未来实验上设计基于Cs_(2)PbI_(2)Cl_(2)的高效的光电子器件提供理论依据. 展开更多
关键词 单层Cs_(2)PbI_(2)Cl_(2) 形成能 点缺陷 稳定性
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Drosophila models used to simulate human ATP1A1 gene mutations that cause Charcot-Marie-Tooth type 2 disease and refractory seizures
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作者 Yao Yuan Lingqi Yu +8 位作者 Xudong Zhuang Dongjing Wen Jin He Jingmei Hong Jiayu Xie Shengan Ling Xiaoyue Du Wenfeng Chen Xinrui Wang 《Neural Regeneration Research》 SCIE CAS 2025年第1期265-276,共12页
Certain amino acids changes in the human Na^(+)/K^(+)-ATPase pump,ATPase Na^(+)/K^(+)transporting subunit alpha 1(ATP1A1),cause Charcot-Marie-Tooth disease type 2(CMT2)disease and refractory seizures.To develop in viv... Certain amino acids changes in the human Na^(+)/K^(+)-ATPase pump,ATPase Na^(+)/K^(+)transporting subunit alpha 1(ATP1A1),cause Charcot-Marie-Tooth disease type 2(CMT2)disease and refractory seizures.To develop in vivo models to study the role of Na^(+)/K^(+)-ATPase in these diseases,we modified the Drosophila gene homolog,Atpα,to mimic the human ATP1A1 gene mutations that cause CMT2.Mutations located within the helical linker region of human ATP1A1(I592T,A597T,P600T,and D601F)were simultaneously introduced into endogenous Drosophila Atpαby CRISPR/Cas9-mediated genome editing,generating the Atpα^(TTTF)model.In addition,the same strategy was used to generate the corresponding single point mutations in flies(Atpα^(I571T),Atpα^(A576T),Atpα^(P579T),and Atpα^(D580F)).Moreover,a deletion mutation(Atpα^(mut))that causes premature termination of translation was generated as a positive control.Of these alleles,we found two that could be maintained as homozygotes(Atpα^(I571T)and Atpα^(P579T)).Three alleles(Atpα^(A576T),Atpα^(P579)and Atpα^(D580F))can form heterozygotes with the Atpαmut allele.We found that the Atpαallele carrying these CMT2-associated mutations showed differential phenotypes in Drosophila.Flies heterozygous for Atpα^(TTTF)mutations have motor performance defects,a reduced lifespan,seizures,and an abnormal neuronal morphology.These Drosophila models will provide a new platform for studying the function and regulation of the sodium-potassium pump. 展开更多
关键词 ATP1A1 Atpα bang-sensitive paralysis Charcot-Marie-Tooth disease type 2 CRISPR/Cas9 homology-directed repair Na^(+)/K^(+)-ATPase point mutation seizures sodium pump
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基于三维点云计算的CO_(2)-水-岩反应程度量化表征方法 被引量:1
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作者 蒋长宝 程岳 +5 位作者 李春梅 侯典东 杨毅毫 焦冰洋 赵冬 邓博知 《实验技术与管理》 CAS 北大核心 2024年第6期9-19,共11页
CO_(2)地质封存是减少大气中CO_(2)排放,降低温室效应的重要途径,CO_(2)注入含水地层中时,CO_(2)-水-岩反应可能引起岩石矿物的侵蚀,对CO_(2)地质封存安全性产生显著影响。在室内实验中,通过表征岩石表面的形貌特征可以有效地评估CO_(2)... CO_(2)地质封存是减少大气中CO_(2)排放,降低温室效应的重要途径,CO_(2)注入含水地层中时,CO_(2)-水-岩反应可能引起岩石矿物的侵蚀,对CO_(2)地质封存安全性产生显著影响。在室内实验中,通过表征岩石表面的形貌特征可以有效地评估CO_(2)-水-岩反应程度,为CO_(2)地质封存的安全性评估提供科学依据。通过三维点云计算可以精确量化地表征CO_(2)-水-岩反应程度,这种方法首先运用三维激光扫描技术,构建岩石表面的三维模型,确定CO_(2)-水处理前岩石表面三维模型的基准面,并基于处理前的均方根粗糙度确定处理后岩石表面三维模型的基准面。基于三维模型点云信息,提出了两种不同的体积计算新方法,并通过对规则模型体积的计算比较了两种计算方法的准确性与适用性,可根据实际情况选择两种计算方法量化表征CO_(2)-水处理前后岩石表面的侵蚀体积。最后,以陕西省咸阳市某煤矿煤样为例,开展了CO_(2)-水-岩反应模拟试验,验证了计算的可行性。试验结果表明:该文提出的侵蚀体积计算方法可有效地量化表征CO_(2)-水-岩反应程度,CO_(2)-水处理后岩石表面不同区域的侵蚀差异性明显,岩石表面的侵蚀体积与均方根粗糙度之间存在显著的正比关系,随着均方根粗糙度的增大,侵蚀体积也相应上升。 展开更多
关键词 三维点云 CO_(2)-水-岩 基准面 均方根粗糙度 反应程度
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49-2游泳池式轻水反应堆池底点缺陷超声测量技术研究
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作者 杨笑 张宇 +2 位作者 王硕 吴东栋 丁松 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第8期1616-1620,共5页
为掌握49-2游泳池式轻水反应堆(简称49-2堆)堆水池铝质池底点缺陷的现状,以进一步为堆水池的服役性能评估提供数据支撑,确保反应堆的安全稳定运行,根据池底结构、池内介质、池壁材料等信息,研发了水浸超声测量系统,对池底点缺陷的分布... 为掌握49-2游泳池式轻水反应堆(简称49-2堆)堆水池铝质池底点缺陷的现状,以进一步为堆水池的服役性能评估提供数据支撑,确保反应堆的安全稳定运行,根据池底结构、池内介质、池壁材料等信息,研发了水浸超声测量系统,对池底点缺陷的分布情况进行了全面检查,实现了点缺陷深度的精确测量。该研究实现了首次对49-2堆池底点缺陷实际状态的远程水下无损检测,检测结论显示:与历史数据相比,池底点缺陷的分布和点坑深度测量数据基本一致,最大点坑深度为1.495 mm。研究结论为49-2堆池底材料的时限老化分析提供了重要数据支撑,研发的水下超声测量技术也可应用于同类型池式堆堆容器及乏燃料贮存池的老化管理工作以及服役寿命分析论证工作中。 展开更多
关键词 49-2 超声检测 点缺陷
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New Unique Common Fixed Point Results for Four Mappings with Ф-Contractive Type in 2-Metric Spaces 被引量:14
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作者 Yongjie Piao Yuanfeng Jin 《Applied Mathematics》 2012年第7期734-737,共4页
In this paper, some new unique common fixed points for four mappings satisfying Ф-contractive conditions on non-complete 2-metric spaces are obtained, in which the mappings do not satisfy continuity and commutation. ... In this paper, some new unique common fixed points for four mappings satisfying Ф-contractive conditions on non-complete 2-metric spaces are obtained, in which the mappings do not satisfy continuity and commutation. The main results generalize and improve many well-known and corresponding conclusions in the literatures. 展开更多
关键词 2-Metric Space Class Ф CAUCHY Sequence COINCIDENCE point UNIQUE Common Fixed point
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UNIQUE COMMON FIXED POINT OF A FAMILY OF SELF-MAPS WITH SAME TYPE CONTRACTIVE CONDITION IN 2-METRIC SPACE 被引量:15
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作者 Yongjie Piao 《Analysis in Theory and Applications》 2008年第4期316-320,共5页
In this paper, we prove that a family of self-maps {Ti,j}i,j∈N in 2-metric space has a unique common fixed point if (i) {Ti,j}i,j∈N satisfies the same type contractive condition for each j ∈ N; (ii) Tm,μ .Tn,v... In this paper, we prove that a family of self-maps {Ti,j}i,j∈N in 2-metric space has a unique common fixed point if (i) {Ti,j}i,j∈N satisfies the same type contractive condition for each j ∈ N; (ii) Tm,μ .Tn,v = Tn,v.Tm.μ for all m,n,μ,v ∈ N with μ≠v. Our main result generalizes and improves many known unique common fixed point theorems in 2-metric spaces. 展开更多
关键词 2-metric space contractive condition Cauchy sequence common fixed point
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ON A FIXED POINT THEOREM IN 2-BANACH SPACES AND SOME OF ITS APPLICATIONS 被引量:5
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作者 Janusz BRZDEK Krzysztof CIEPLINSKI 《Acta Mathematica Scientia》 SCIE CSCD 2018年第2期377-390,共14页
The aim of this article is to prove a fixed point theorem in 2-Banach spaces and show its applications to the Ulam stability of functional equations. The obtained stability re- sults concern both some single variable ... The aim of this article is to prove a fixed point theorem in 2-Banach spaces and show its applications to the Ulam stability of functional equations. The obtained stability re- sults concern both some single variable equations and the most important functional equation in several variables, namely, the Cauchy equation. Moreover, a few corollaries corresponding to some known hyperstability outcomes are presented. 展开更多
关键词 fixed point theorem 2-normed space Ulam stability HYPERSTABILITY
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Uniqueness of Common Fixed Points for a Family of Mappings with <i>Φ</i>-Contractive Condition in 2-Metric Spaces 被引量:9
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作者 Yong-Jie Piao 《Applied Mathematics》 2012年第1期73-77,共5页
In this paper, we will introduce a class of 5-dimensional functions Φ and prove that a family of self-mappings {Ti,j} iεN in 2-metric space have an unique common fixed point if 1) {Ti,j} iεN satisfies Φj-contracti... In this paper, we will introduce a class of 5-dimensional functions Φ and prove that a family of self-mappings {Ti,j} iεN in 2-metric space have an unique common fixed point if 1) {Ti,j} iεN satisfies Φj-contractive condition, where ΦjεΦ, for each jεN;2) Tm,μ n,v for all m,n,μ,vεN with μ ≠ v . Our main result generalizes and unifies many known unique common fixed point theorems in 2-metric spaces. 展开更多
关键词 2-Metric Space 5-Dimensional Functions Φ Φ-Contractive CONDITION CAUCHY Sequence Common Fixed point
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基于夹点的带喷射器CO_(2)热泵系统性能分析
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作者 杨俊兰 张鑫 +2 位作者 王林秀 韩一飞 杜雨帆 《暖通空调》 2024年第3期92-97,171,共7页
为了研究带喷射器的跨临界CO_(2)内部过冷热泵系统(TCISE),基于夹点建立了TCISE的热力学模型,分析了冷却水进出水温度及流量对系统性能的影响。研究表明:冷却水进水温度从25℃降低到15℃时,最优高压压力从9.3 MPa降至8.8 MPa,降低了5.4%... 为了研究带喷射器的跨临界CO_(2)内部过冷热泵系统(TCISE),基于夹点建立了TCISE的热力学模型,分析了冷却水进出水温度及流量对系统性能的影响。研究表明:冷却水进水温度从25℃降低到15℃时,最优高压压力从9.3 MPa降至8.8 MPa,降低了5.4%,最大COP从3.83提升至4.27,提高了11.49%;TCISE存在临界冷却水出水温度和临界冷却水质量流量,当冷却水进水温度一定时,在出水温度低于临界出水温度或质量流量高于临界质量流量时,系统COP保持不变。 展开更多
关键词 CO_(2)热泵 喷射器 夹点 内部过冷 冷却水 进水温度 出水温度 流量
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基于MS(2)-AR-TVTP模型的I_(BD)波动周期非对称性和持续性分析
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作者 陈丽芬 谢新连 林嘉俊 《中国航海》 CSCD 北大核心 2024年第2期65-71,共7页
国际干散货运输市场源于国际贸易的衍生需求,受世界经济的影响,是一个典型的周期性市场。选取1999年11月~2021年12月的波罗的海干散货运价指数(I_(BD))月度数据,在检验序列平稳性的基础上,确定最优滞后长度,构建两区制的时变转换概率马... 国际干散货运输市场源于国际贸易的衍生需求,受世界经济的影响,是一个典型的周期性市场。选取1999年11月~2021年12月的波罗的海干散货运价指数(I_(BD))月度数据,在检验序列平稳性的基础上,确定最优滞后长度,构建两区制的时变转换概率马尔科夫转换自回归模型,分析I_(BD)波动周期的持续时间、转换拐点和非对称性等主要特征。研究结果表明:模型能有效拟合I_(BD)波动周期的主要特征,周期平均持续时间为33.7个月,自2008年9月之后呈缩短态势,上升期和下降期交互更频繁;I_(BD)波动周期具有非对称性,周期内上升期持续时间比下降期长,I_(BD)维持上升期更具有稳定性。周期性特征结果可为干散货航运业造船投资和市场经营提供决策依据。 展开更多
关键词 MS(2)-AR-TVTP模型 I_(BD)波动周期 转换拐点 持续时间
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Four Mappings Satisfying Ψ-Contractive Type Condition and Having Unique Common Fixed Point on 2-Metric Spaces 被引量:2
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作者 Hailan Jin Yongjie Piao 《Advances in Pure Mathematics》 2013年第2期277-281,共5页
In this paper, we introduce a class Ψ of real functions defined on the set of non-negative real numbers, and obtain a new unique common fixed point theorem for four mappings satisfying Ψ-contractive condition on a n... In this paper, we introduce a class Ψ of real functions defined on the set of non-negative real numbers, and obtain a new unique common fixed point theorem for four mappings satisfying Ψ-contractive condition on a non-complete 2-metric space and give the versions of the corresponding result for two and three mappings. 展开更多
关键词 2-Metric Space Class Ψ CAUCHY Sequence COINCIDENCE point Common Fixed point
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Electroacupuncture at He-Mu points reduces P2X_4 receptor expression in visceral hypersensitivity 被引量:10
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作者 Xinxin Guo Jifei Chen +7 位作者 Yuan Lu Luyi Wu Zhijun Weng Ling Yang Yuhu Xin Xianming Lin Yi Liang Jianqiao Fang 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第22期2069-2077,共9页
Electroacupuncture at Shangjuxu (ST37) and Tianshu (ST25) was reported to improve visceral hypersensitivity in rats, Colorectal distension was utilized to generate a rat model of chronic visceral hypersensitivity ... Electroacupuncture at Shangjuxu (ST37) and Tianshu (ST25) was reported to improve visceral hypersensitivity in rats, Colorectal distension was utilized to generate a rat model of chronic visceral hypersensitivity in irritable bowel syndrome, Results showed that abdominal withdrawal reflex scores noticeably increased after model establishment. Simultaneously, P2X4 receptor immunore- activity significantly increased in the colon and spinal cord. Electroacupuncture and pinaverium bromide therapy both markedly decreased abdominal withdrawal reflex scores in rats with visceral hypersensitivity, and significantly decreased P2X4 receptor immunoreactivity in the colon and spinal cord. These data suggest that electroacupuncture treatment can improve visceral hypersensitivity in rats with irritable bowel syndrome by diminishing P2X4 receptor immunoreactivity in the colon and spinal cord, 展开更多
关键词 neural regeneration traditional Chineseture irritable bowel syndrome visceralported paper neuroregenerationmedicine combination of He-Mu points electroacupunc-hypersensitivity P2X4 receptor acupuncture grants-sup-
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ICESat-2水深提取方法及其反演应用 被引量:2
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作者 胡琪鑫 程亮 +2 位作者 楚森森 程俭 徐亚 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2024年第3期997-1012,共16页
相比于传统水深测量方法,结合主动激光卫星ICESat-2数据与被动光学遥感影像的主被动融合水深反演方法具有低成本、覆盖面积广、不受地域限制、无需地面实测数据等优点.研究选取澳大利亚大堡礁中部的John Brewer Reef和南部的Fitzroy Ree... 相比于传统水深测量方法,结合主动激光卫星ICESat-2数据与被动光学遥感影像的主被动融合水深反演方法具有低成本、覆盖面积广、不受地域限制、无需地面实测数据等优点.研究选取澳大利亚大堡礁中部的John Brewer Reef和南部的Fitzroy Reef为实验区,开展主被动融合水深反演实验.针对ICESat-2光子点群信噪比低、光子点水深信息提取和改正难的问题,本文提出基于光子点群高斯分布特征的海面光子点群提取方法和基于深度自适应DBSCAN的海底光子点群提取方法,并顾及海面倾斜引起的入射角偏移,改进了Parrish水体折射改正几何模型.实验表明,基于光子点群高斯分布特征的海面光子点群提取方法和基于深度自适应DBSCAN的海底光子点群提取方法可以高效准确地提取出有效的海面、海底光子点群;经过地球物理改正和基于改进模型的水体折射改正后,水深变浅,且改正项与改正前水深呈线性关系,线性系数约为-0.2550.实验将提取并改正后的ICESat-2光子点水深与经大气校正、耀斑校正、空间域滤波等预处理后的Sentinel-2影像进行空间匹配构建水深反演样本集,并利用单波段模型(SB)、比值模型(BR)、Lyzenga多项式模型(LP)、二次多项式模型(QP)、三次多项式模型(CP)、支持向量回归模型(SVR)、多层感知器模型(MLP)、随机森林回归模型(RF)等水深反演模型对实验区全域水深进行反演.通过对比分析多种水深反演模型在不同地理区域和ICESat-2水深样本分布条件下的表现,研究为不同场景下的主被动融合水深反演策略提供了一定的科学依据. 展开更多
关键词 ICESat-2 Sentinel-2 光子点群提取 折射校正 水深反演
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An Improvement of a Known Unique Common Fixed Point Result for Four Mappings on 2-Metric Spaces 被引量:1
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作者 Ailian Jin Yongjie Piao 《Applied Mathematics》 2013年第11期1-5,共5页
In this paper, we introduce a new class Γ, which is weak than a known class Ψ, of real continuous functions defined on [0, +∞), and use another method to prove the known unique common fixed point theorem for four m... In this paper, we introduce a new class Γ, which is weak than a known class Ψ, of real continuous functions defined on [0, +∞), and use another method to prove the known unique common fixed point theorem for four mappings with γ-contractive condition instead of Ψ-contractive condition on 2-metric spaces. 展开更多
关键词 2-Metric Space CLASS Γ CLASS ψ Common Fixed point
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Unique Common Fixed Points for Two Weakly C~*-contractive Mappings on Partially Ordered 2-metric Spaces 被引量:1
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作者 Piao Yong-jie 《Communications in Mathematical Research》 CSCD 2018年第1期77-88,共12页
In this paper, we give existence theorems of common fixed points for two mappings with a weakly C*-contractive condition on partially ordered 2-metric spaces and give a sufficient condition under which there exists a ... In this paper, we give existence theorems of common fixed points for two mappings with a weakly C*-contractive condition on partially ordered 2-metric spaces and give a sufficient condition under which there exists a unique common fixed point. 展开更多
关键词 2-metric space weak C*-contraction common fixed point
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First-Principle Calculations of Hardness and Melting Point of Mo_2C 被引量:1
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作者 X.R. Wang M.F. Yan H.T. Chen 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2009年第3期419-422,共4页
This paper has constructed two kinds of atomic and electronic models for hexagonal β-Mo2C and orthorhombic α-Mo2C. The optimized lattice parameters, elastic constant matrixes and overlap population for Mo2C crystal ... This paper has constructed two kinds of atomic and electronic models for hexagonal β-Mo2C and orthorhombic α-Mo2C. The optimized lattice parameters, elastic constant matrixes and overlap population for Mo2C crystal cells have been obtained to realize the characterization of the hardness and melting point of the two structures by the first-principles plane wave pseudo potential method based on the density functional theory. The results reveal that the calculated lattice parameters of the Mo2C crystal cells agree with the experimental and other calculated data. The calculated melting point/hardness are 2715 K/11.38 GPa for β-Mo2C and 2699 K/10.57-12.67 GPa for α-Mo2C, respectively. The calculated results from the density of states (DOS) demonstrate that the hybridization effect between Mo-3d and C-2p states in α-Mo2C crystal cell is much stronger than that in β-Mo2C one. 展开更多
关键词 FIRST-PRINCIPLE Mo2C HARDNESS Melting point Density of states
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Is the present cut-point to define type 2 diabetes appropriate in Latin-Americans? 被引量:1
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作者 Patricio López-Jaramillo Carlos Velandia-Carrillo +1 位作者 Diego Gómez-Arbeláez Martin Aldana-Campos 《World Journal of Diabetes》 SCIE CAS 2014年第6期747-755,共9页
The diagnosis of diabetes mellitus type 2(DM2) is based either on increased plasma glucose or Glycated hemoglobin levels. Since these measures are the only means for diagnosis of DM2, they must be well adapted to each... The diagnosis of diabetes mellitus type 2(DM2) is based either on increased plasma glucose or Glycated hemoglobin levels. Since these measures are the only means for diagnosis of DM2, they must be well adapted to each population according to their metabolic characteristics, given that these may vary in each population. The World Health Organization(WHO) determined the cut-points of plasma glucose levels for the diagnosis of DM2 by associating hyperglycemia with the risk of a specific microvascular complication-retinopathy. Cardiovascular diseases are however the principal causes of mortality in patients with DM2 and we reported that in the Colombo-Ecuadorian population impaired fasting glucose and impaired glucose tolerance are both riskmarkers for myocardial infarction. We propose that the current cut-points accepted by the WHO need to be revaluated in populations such as Latin America and that there should be lower cut points for glycaemia in this population, to reduce the prevalence of cardiovascular complications associated with DM2. 展开更多
关键词 Type 2 diabetes Cut-off points Cardiovascular diseases Plasma glucose Coronary disease
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Common Fixed Points for Two Mappings with Implicit-linear Contractions on Partially Ordered 2-metric Spaces
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作者 PIAO YONG-JIE 《Communications in Mathematical Research》 CSCD 2019年第3期225-234,共10页
In this paper, we introduce a new class U of 3-dimensional real functions, use U and a 2-dimensional real function ? to construct a new implicit-linear contractive condition and obtain some existence theorems of commo... In this paper, we introduce a new class U of 3-dimensional real functions, use U and a 2-dimensional real function ? to construct a new implicit-linear contractive condition and obtain some existence theorems of common fixed points for two mappings on partially ordered 2-metric spaces and give a sufficient condition under which there exists a unique common fixed point. The obtained results goodly generalize and improve the corresponding conclusions in references. 展开更多
关键词 2-metric space class U of functions implicit-linear CONTRACTION common fixed point
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