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靛蓝与异构体靛玉红的量子化学研究 被引量:15
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作者 王艳 刘玉明 +1 位作者 杨明 梁晓琴 《四川大学学报(自然科学版)》 CAS CSCD 北大核心 2004年第1期143-147,共5页
靛蓝与靛玉红是青黛的主要成分,也是同分异构体,但是它们的理化性质和生物活性却显示出明显的差异.作者选用B3LYP的方法,基组为6 31G ,优化了这两种同分异构体的几何构型,得到了两者之间的异构化能.进行了集居数分析、自然键轨道(NBO)... 靛蓝与靛玉红是青黛的主要成分,也是同分异构体,但是它们的理化性质和生物活性却显示出明显的差异.作者选用B3LYP的方法,基组为6 31G ,优化了这两种同分异构体的几何构型,得到了两者之间的异构化能.进行了集居数分析、自然键轨道(NBO)分析、成键轨道分析及振动光谱分析.通过计算得知,靛蓝分子与靛玉红分子的所有原子均处于同一平面,两个分子都是由碳骨架及环上的氮原子参与的大的π共轭体系构成,环上存在很强的离域.分子内存在较强的氢键,氢键与环上的碳碳键形成六元或七元环,使分子的各原子保持与吲哚环在同一平面并使分子的稳定性增加. 展开更多
关键词 靛蓝 靛玉红 B3LYP 共轭体系 氢键
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我国70年高考改革的回顾与反思 被引量:10
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作者 项贤明 《高等教育研究》 CSSCI 北大核心 2019年第2期18-26,共9页
中华人民共和国成立之初,在中央政府威望高涨和计划经济体制取得成功的大背景下,我国高考制度与政治经济的发展之间建立了牢固的共轭关系。这种共轭关系奠定了我国高考改革70年历史的基本格局。改革开放以来,经济作为共轭关系中的重要... 中华人民共和国成立之初,在中央政府威望高涨和计划经济体制取得成功的大背景下,我国高考制度与政治经济的发展之间建立了牢固的共轭关系。这种共轭关系奠定了我国高考改革70年历史的基本格局。改革开放以来,经济作为共轭关系中的重要变量对高考改革的影响日益突出。科举文化的消极影响、计划经济的思维惯性、局限于具体考试技术的狭隘思路,是导致当前我国高考改革陷入困境的三大症结。面对新时代、新形势和新任务,我们应当尽快将高考改革的工作重点从考试改革转向高校录取制度改革,努力革除高考自身的科举文化特质,为选拔和培养各行各业创新型人才打开新局面。 展开更多
关键词 高考改革 共轭关系 考试制度 录取制度 科举文化
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烃类燃烧热的简易推算 被引量:8
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作者 彭津 《消防科学与技术》 CAS 1999年第4期9-11,共3页
本文介绍了利用物质结构和化学键理论对烃类标准燃烧热的简易推算方法,计算的准确性和文献值较接近,可做半定量估算。
关键词 燃烧热 化学键
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Extended Jury criterion 被引量:4
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作者 ZHENG BaoDong 1,LIANG LiJie 1 & ZHANG ChunRui 2 1 Department of mathematics,Harbin Institute of Technology,Harbin 150001,China 2 Department of mathematics,Northeast Forestry University,Harbin 150040,China 《Science China Mathematics》 SCIE 2010年第4期1133-1150,共18页
In this paper,algebraic criteria are established to determine whether or not a real coefficient polynomial has one or two pairs of conjugate complex roots whose moduli are equal to 1 and the other roots have moduli le... In this paper,algebraic criteria are established to determine whether or not a real coefficient polynomial has one or two pairs of conjugate complex roots whose moduli are equal to 1 and the other roots have moduli less than 1 directly from its coefficients.The form and the function of the criteria are similar to those of the Jury criterion which can be used to determine whether or not all the moduli of the roots of a real coefficient polynomial are less than 1. 展开更多
关键词 dynamic system JURY CRITERION conjugate COMPLEX ROOTS
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RNA-based nanomedicines and their clinical applications
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作者 Lin-Jia Su Zi-Han Ji +5 位作者 Mo-Xi Xu Jia-Qing Zhu Yi-Hai Chen Jun-Fei Qiao Yi Wang Yao-Xin Lin 《Nano Research》 SCIE EI CSCD 2023年第12期13182-13204,共23页
RNA-based nanomedicines encompass a range of therapeutic approaches that utilize RNA molecules or molecules that target RNAs for the treatment or prevention of diseases.These include antisense oligonucleotides(ASOs),s... RNA-based nanomedicines encompass a range of therapeutic approaches that utilize RNA molecules or molecules that target RNAs for the treatment or prevention of diseases.These include antisense oligonucleotides(ASOs),small interfering RNAs(siRNAs),endogenous microRNAs(miRNAs),messenger RNAs(mRNAs),clustered regularly interspersed short palindromic repeats-associated protein 9(CRISPR/Cas9),single guide RNAs(sgRNAs),as well as RNA aptamers.These therapeutic agents exert their effects through various mechanisms such as gene inhibition,addition,replacement,and editing.The advancement of RNA biology and the field of RNA therapy has paved the way for the development and utilization of RNA-based nanomedicine in human healthcare.One remarkable example of RNA-based nanomedicine is the mRNA-based vaccines including mRNA-1273(Moderna)and BNT162b2(Pfizer/BioNTech)that have been successfully employed in response to the coronavirus disease 2019(COVID-19)pandemic.This review aims to highlight the advantages of RNA-based nanomedicines,provides an overview of significant developments in delivery systems,elucidates the molecular mechanisms of action underlying RNA-based nanomedicines,and discusses their clinical applications.Additionally,the review will address the existing challenges and innovations in delivery platforms while exploring the future possibilities for these promising RNA-based nanomedicines. 展开更多
关键词 RNA-based nanomedicine conjugate-based delivery system nanoparticle-based delivery system clinical trial
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Design and performance testing of a novel building integrated photovoltaic thermal roofing panel
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作者 Mehdi Zadshir Chunlin Wu +1 位作者 Xiaokong Yu Huiming Yin 《Building Simulation》 SCIE EI CSCD 2023年第10期1863-1879,共17页
A novel building integrated photovoltaic thermal(BIPVT)roofing panel has been designed considering both solar energy harvesting efficiency and thermal performance.The thermal system reduces the operating temperature o... A novel building integrated photovoltaic thermal(BIPVT)roofing panel has been designed considering both solar energy harvesting efficiency and thermal performance.The thermal system reduces the operating temperature of the cells by means of a hydronic loop integrated into the backside of the panel,thus resulting in maintaining the efficiency of the solar panels at their feasible peak while also harvesting the generated heat for use in the building.The performance of the proposed system has been evaluated using physical experiments by conducting case studies to investigate the energy harvesting efficiency,thermal performance of the panel,and temperature differences of inlet/outlet working liquid with various liquid flow rates.The physical experiments have been simulated by coupling the finite element method(FEM)and finite volume method(FVM)for heat and mass transfer in the operation.Results show that the thermal system successfully reduced the surface temperature of the solar module from 88℃to as low as 55℃.Accordingly,the output power that has been decreased from 14.89 W to 10.69 W can be restored by 30.2%to achieve 13.92 W.On the other hand,the outlet water from this hydronic system reaches 45.4℃which can be used to partially heat domestic water use.Overall,this system provides a versatile framework for the design and optimization of the BIPVT systems. 展开更多
关键词 building integrated photovoltaic thermal panels conjugate heat transfer energy harvesting efficiency solar panels hydronic system
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在常规故障条件下具有易损坏储备部件可修复系统的稳定性分析 被引量:2
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作者 李新阳 张丽娜 王辉 《数学的实践与认识》 CSCD 北大核心 2008年第24期165-172,共8页
讨论了在常规故障条件下具有易损坏储备部件可修复系统的渐进稳定性;证明了系统非负稳定解恰是系统算子0本征值对应的本征向量;系统算子的谱点均位于复平面的左半平面,且在虚轴上除0外无谱点;此外,证明了0的代数重数为1和求解了系统算... 讨论了在常规故障条件下具有易损坏储备部件可修复系统的渐进稳定性;证明了系统非负稳定解恰是系统算子0本征值对应的本征向量;系统算子的谱点均位于复平面的左半平面,且在虚轴上除0外无谱点;此外,证明了0的代数重数为1和求解了系统算子的共轭算子. 展开更多
关键词 渐进稳定性 共轭算子 C0-半群 可修复系统
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Cenozoic tectonic evolution of regional fault systems in the SE Tibetan Plateau 被引量:3
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作者 Yang WANG Yuejun WANG +7 位作者 Peizhen ZHANG Jinjiang ZHANG Bo ZHANG Jing LIU-ZENG Renjie ZHOU Weitao WANG Huiping ZHANG Zhangjun LI 《Science China Earth Sciences》 SCIE EI CSCD 2022年第4期601-623,共23页
The SE Tibetan Plateau,tectonically situated in the eastern India-Eurasia oblique convergence zone,has experienced multiple stages of deformation since the Cenozoic.Three major tectonic boundaries—the Ailaoshan-Red R... The SE Tibetan Plateau,tectonically situated in the eastern India-Eurasia oblique convergence zone,has experienced multiple stages of deformation since the Cenozoic.Three major tectonic boundaries—the Ailaoshan-Red River,ChongshanLincang-Inthanon,and Gaoligong-Mogok shear zones—delineate the first-order tectonic framework in this region.The most striking structural features in the block interiors are a series of NW-and NE-trending fault systems,such as the Dayingjiang,Longlin-Ruili,Nantinghe,Red River,Weixi-Qiaohou,and Lancang-Genma faults,which have conjugate geometric relationships.In this study,we review these structures’geometric and kinematic characteristics and deformation histories.A synthesis of existing geological observations,geomorphological analyses,and chronological data reveals three major Cenozoic tectonothermal events,including crustal shortening,strike-slip shearing,and kinematic reversal.The boundary structures controlled the tectonic extrusion of plateau material during the early Oligocene-early Miocene.In the mid-late Miocene,NW-and NE-trending fault systems mostly experienced diachronous slip-sense inversions.The onset and spatial trend of regional kinematic reversal are constrained by existing chronologic data.Together with geophysical and geodetic observations,the activity and geodynamic drivers of the major fault systems and regional deformation styles are explored,revealing that the SE Tibetan Plateau underwent a transition from discrete(lateral block extrusion)to diffuse deformation in the mid-late Miocene.The intracontinental crustal deformation and its coupling with dynamic processes at depth during the plateau growth are discussed in the context of the IndiaEurasia convergence. 展开更多
关键词 CENOZOIC SE Tibetan Plateau tectonic boundary conjugate fault system tectonic evolution
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DYNAMICAL ANALYSIS OF A 3-D CHAOTIC SYSTEM WITH ONLY TWO QUADRATIC NONLINEARITIES 被引量:3
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作者 Zeraoulia ELHADJ 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2008年第1期67-75,共9页
The paper reports the dynamical study of a three-dimensional quadratic autonomous chaotic system with only two quadratic nonlinearities, which is a special case of the so-called conjugate Lue system. Basic properties ... The paper reports the dynamical study of a three-dimensional quadratic autonomous chaotic system with only two quadratic nonlinearities, which is a special case of the so-called conjugate Lue system. Basic properties of this system are analyzed by means of Lyapunov exponent spectrum and bifurcation diagram. The analysis shows that the system has complex dynamics with some interesting characteristics in which there are several periodic regions, but each of them has quite different periodic orbits. 展开更多
关键词 Bifurcation conjugate attractors DEGENERATION Lyapunov exponent quadratic chaotic system.
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物质显色的一般规律 被引量:2
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作者 车全义 《宝鸡文理学院学报(自然科学版)》 CAS 1994年第1期68-72,62,共6页
本文通过对离子的电子层结构、离子的极化作用和有机物分子中共轭体系等情况的分析,总结了物质显色的一般规律。
关键词 显色 颜色 极化 变性
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分子结构与偶氮化合物吸收光谱的关系
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作者 杨晰 傅正生 陈洁 《甘肃农业大学学报》 CAS CSCD 2007年第5期143-146,共4页
设计合成了12种含偶氮苯光学活性侧基的乙烯基单体,利用分光光度计测定测定了它们在乙醇溶液中的吸收峰的变化.结果表明,偶氮乙烯基单体的吸收波长受结构因素的影响很大,共轭体系与吸电子基的存在均会导致其波长向长波长方向移动.
关键词 偶氮乙烯基单体 吸收波长 共轭体系 吸电子基
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Feigenbaum吸引子的动力性质 被引量:2
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作者 汪威 朱晓刚 +2 位作者 李俊杰 李健 廖梦兰 《东北师大学报(自然科学版)》 CAS CSCD 北大核心 2014年第4期48-51,共4页
阐述了一类非单谷的Feigenbaum映射的一些主要性质,通过与进位系统建立拓扑共轭关系,证明了该映射限制在其吸引子上具有简单的动力性质,即极小的、唯一遍历的、拓扑熵为零.
关键词 FEIGENBAUM映射 拓扑共轭 进位系统
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具size结构单种群系统的最优化控制问题 被引量:1
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作者 巴争刚 尹雪文 《洛阳理工学院学报(自然科学版)》 2013年第2期77-80,92,共5页
考虑了一类具size结构种群系统的最优控制问题,利用特征线法给出了系统的形式解,并证明了系统解的存在唯一性,然后根据法锥和其共扼系统技巧推导出了最优性条件,从而推广了一些文献工作。
关键词 size结构的生物种群系统 特征方程 共轭系统 最优性条件
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Inverse estimation for unknown fouling geometry on inner wall of forced-convection pipe
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作者 陳文立 楊俞青 +1 位作者 李浩榕 J.L.SALAZAR 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2011年第1期55-68,共14页
A conjugate gradient method (CGM) based on the inverse algorithm is used to estimate the unknown fouling-layer profile on the inner wall of a pipe system using simulated temperature measurements taken within the pip... A conjugate gradient method (CGM) based on the inverse algorithm is used to estimate the unknown fouling-layer profile on the inner wall of a pipe system using simulated temperature measurements taken within the pipe wall. It is assumed that no prior information is available about the functional form of the unknown profile. Therefore, the procedure is classified as the function estimation in inverse calculation. The temperature data obtained from the direct problem are used to simulate the temperature measurements. The accuracy of the inverse analysis is examined using the simulated exact and inexact temperature measurements. The results show that the excellent estimation of the fouling-layer profile can be obtained for the test case considered in this study. The technique presented in this study can be used in a warning system to call for pipe maintenance when the thickness of fouling exceeds a predefined criterion. 展开更多
关键词 inverse problem fouling layer pipe system conjugate gradient method
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纺织品潜在酚黄变测试机制分析
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作者 梁春冉 曹政 +1 位作者 陆林光 申屠鲜艳 《毛纺科技》 CAS 北大核心 2022年第9期24-28,共5页
为了分析纺织品酚黄变现象及相关测试标准机制,考察影响潜在酚黄变显色的因素,通过分析纺织品潜在酚黄变测试标准中用到的2,6-二叔丁基-4-硝基苯酚(DTNP)性能,结合共轭显色相关理论,探讨了潜在酚黄变测试和实际酚黄变现象之间的关系,DTN... 为了分析纺织品酚黄变现象及相关测试标准机制,考察影响潜在酚黄变显色的因素,通过分析纺织品潜在酚黄变测试标准中用到的2,6-二叔丁基-4-硝基苯酚(DTNP)性能,结合共轭显色相关理论,探讨了潜在酚黄变测试和实际酚黄变现象之间的关系,DTNP显色机制以及多种化学物质对DTNP显色的影响。结果表明:实际酚黄变现象是2,6-二叔丁基-4-甲基苯酚(BHT)同氮氧化物(NO_(X))发生反应,反应产物在一定条件下显色造成黄变;潜在酚黄变测试标准则直接将DTNP同纺织品进行接触,考察纺织品对DTNP的电离显色能力;DTNP的显色机制是酚羟基电离造成共轭体系改变,B带吸收峰从320 nm红移至451 nm,DTNP颜色由浅黄绿色变为黄色;强碱、胺类化合物可以不同程度地诱导DTNP电离显色,沸点较高的有机酸可以有效抑制DTNP在锦纶布面的电离显色。 展开更多
关键词 纺织品 补色 酚黄变 共轭体系 诱导电离
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一种武器系统制导精度仿真方法研究 被引量:1
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作者 张国林 《计算机仿真》 CSCD 北大核心 2014年第12期98-101,245,共5页
在武器系统制导精度优化控制的研究中,由于导弹的陀螺运动造成脱靶量增加。为解决上述问题,提出一种定量计算由螺旋运动引起的脱靶量的计算方法。首先根据螺旋运动对导弹飞行速度的影响机理,分析了螺旋运动对导弹质心运动的影响规律。... 在武器系统制导精度优化控制的研究中,由于导弹的陀螺运动造成脱靶量增加。为解决上述问题,提出一种定量计算由螺旋运动引起的脱靶量的计算方法。首先根据螺旋运动对导弹飞行速度的影响机理,分析了螺旋运动对导弹质心运动的影响规律。然后考虑到制导过程中的多目标约束要求,采用共轭系统分析法推导了无量纲化的脱靶量显性表达式。最后建立了螺旋运动速度控制的导弹制导模型,在不同动力学模型和导引模型条件下分析了导弹的制导精度,进一步发现了导致武器系统制导精度大幅降低的主要因素。仿真结果表明,采用该脱靶量计算方法得到的仿真结果具有较好的可行性和正确性,为优化导弹螺旋运动速度控制和提高制导精度,提供了理论基础。 展开更多
关键词 螺旋运动 速度控制 脱靶量 共轭系统
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显色理论与染料的颜色综述 被引量:1
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作者 周志 《南昌高专学报》 1996年第1期10-14,共5页
有机染料的颜色非常丰富。本文通过实例,从物质结构的内在因素——电子跃迁的诸种形式进行综合分析,揭示有机染料的生色原理。
关键词 显色理论 染料颜色 电子跃迁 生色原理 共轭体系 分子离子化
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Minor Self-conjugate and Skewpositive Semidefinite Solutions to a System of Matrix Equations over Skew Fields
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作者 姜学波 《Chinese Quarterly Journal of Mathematics》 CSCD 2001年第2期86-90,共5页
Minor self conjugate (msc) and skewpositive semidefinite (ssd) solutions to the system of matrix equations over skew fields [A mn X nn =A mn ,B sn X nn =O sn ] are considered. Necessary and su... Minor self conjugate (msc) and skewpositive semidefinite (ssd) solutions to the system of matrix equations over skew fields [A mn X nn =A mn ,B sn X nn =O sn ] are considered. Necessary and sufficient conditions for the existence of and the expressions for the msc solutions and the ssd solutions are obtained for the system. 展开更多
关键词 minor self conjugate matrix skewpositive semidefinite matrix system of matrix equations skew field the real quatrnion field
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4-双(1-苯基-3-甲基-4-吡唑啉-5-酮)甲烷的晶体结构
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作者 王瑾玲 杨云 +1 位作者 李爱秀 缪方明 《化学研究与应用》 CAS CSCD 北大核心 2003年第2期237-240,共4页
The crystal structure and molecular structures of the title compound were determined using Xray analysis.The crystal belongs to monoclinic system with the space group P21/c,C21H20N4O2,with Mr=358... The crystal structure and molecular structures of the title compound were determined using Xray analysis.The crystal belongs to monoclinic system with the space group P21/c,C21H20N4O2,with Mr=35839,a=12845(3),b=19334(4),c=073112(5)nm,β=9443(3)°,V=18103(4)nm3,Z=4,DC=132Mg·m-3,μ=0088mm-1,and F(000)=752.The final discrepancy factor R1=01508,and S=0942.The result showed that the dihedral angles between the two pyrazolinone rings and phenyl rings were 1267 and 798°,which indicated that these two planes roughly coplanar to each other forming a big conjugate system. 展开更多
关键词 4-双(1-苯基-3-甲基-4-吡唑啉-5-酮)甲烷 晶体结构 共轭体系 单晶X-射线衍射
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具有两对共轭复不变直线和一条实不变直线的三次系统(Ⅲ)
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作者 陈国维 《福州大学学报(自然科学版)》 CAS CSCD 1997年第1期7-12,共6页
研究三次系统具有一条实不变直线和两对共轭复不变直线时的极限环问题,得出在m=δ,l=1,2α+δβ=0时系统最多有一个极限环,并给出确有一个极限环的条件.还证明当m≠δ,l≠1,a03=0,a30=b202α+mβ=... 研究三次系统具有一条实不变直线和两对共轭复不变直线时的极限环问题,得出在m=δ,l=1,2α+δβ=0时系统最多有一个极限环,并给出确有一个极限环的条件.还证明当m≠δ,l≠1,a03=0,a30=b202α+mβ=0时系统没有极限环.对a01=0时也证明系统没有极限环.综合以前的工作〔1。 展开更多
关键词 三次系统 复不变直线 极限环 实不变直线
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