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虞爱华任安徽省委副书记刘国宾任安徽省委常委 001

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虞爱华任安徽省委副书记刘国宾任安徽省委常委

The effective hydrodynamic radius in the Stokes-Einstein relation is not a constant

安徽日报

作者：任淦

本报讯（通讯员任淦）日前，中央批准：虞爱华同志任安徽省委副书记;刘国宾同志任安徽省委委员、常委。

关键词：安徽刘国书记

来源： cnki报纸评论

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Communications in Theoretical Physics 2022年第9期74卷 177-182页

作者：任淦 School of Science Civil Aviation Flight University of ChinaGuanghan 618307China

Variants based on the assumption of effective hydrodynamic radius being a constant are usually adopted to test the Stokes-Einstein(SE)relation.The rationality of the assumption is examined by performing molecular dynamics simulations with the truncated Lennard-Jones-like(TLJ)model,Kob-Andersen model and ortho-terphenyl(OTP)model.The results indicate the assumption is generally not established except for special case.The effective hydrodynamic radius is observed to increase with decreasing temperature for TLJ model but is decreased for Kob-Andersen and OTP model;and which is almost a constant for TLJ particle with enough rigidity.The variant of SE relation D~Th is invalid for the three models except for the TLJ particle with enough rigidity.We propose similar inconsistency may be also existed in other liquids and the assumption should be critically evaluated when adopted to test the SE relation.

关键词： Stokes-Einstein relation effective hydrodynamic radius Stokes’formula

Dynamic crossover in [VIO^(2+)][Tf_(2)N-]_(2) ionic liquid

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Chinese Physics B 2021年第1期30卷 374-379页

作者：任淦 Departments of Physics&Key Laboratory of Photonic and Optical Detection in Civil Aviation Civil Aviation Flight University of ChinaGuanghan 618307China

Ionic liquids usually behave as fragile liquids,and the temperature dependence of their dynamic properties obeys supper-Arrhenius law.In this work,a dynamic crossover is observed in([VIO^(2+)][Tf_(2)N-]_(2)) ionic liquid at the temperature of 240-800 K.The diffusion coefficient does not obey a single Arrhenius law or a Vogel-Fulcher-Tammann(VFT) relation,but can be well fitted by three Arrhenius laws or a combination of a VFT relation and an Arrhenius law.The origin of the dynamic crossover is analyzed from correlation,structure,and thermodynamics.Ion gets a stronger backward correlation at a lower temperature,as shown by the fractal dimension of the random walk.The temperature dependence function of fractal dimension,heterogeneity order parameter,and thermodynamic data can be separated into three regions similar to that observed in the diffusion coefficient.The two crossover temperatures observed in the three types of data are almost the same as that in diffusion coefficient fitted by three Arrhenius laws.The results indicate that the dynamic crossover of[VIO2+][Tf2 N-]2 is attributed to the heterogeneous structure when it undergoes cooling.

关键词： ionic liquids dynamic crossover heterogeneity order parameter fractal dimension fragile

Saturated sodium chloride solution under an external static electric field: A molecular dynamics study

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Chinese Physics B 2015年第12期24卷 79-86页

作者：任淦王延颋 State Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

The behavior of saturated aqueous Na Cl solutions under a constant external electric field（E） was studied by molecular dynamics（MD） simulation. Our dynamic MD simulations indicated that the irreversible nucleation process towards crystallization is accelerated by a moderate E but retarded or even prohibited under a stronger E, which can be understood by the competition between self-diffusion and drift motion. The former increases with E, thereby accelerating the nucleation process, whereas the latter pulls oppositely charged ions apart under a stronger E, thereby decelerating nucleation.Additionally, our steady-state MD simulations indicated that a first-order phase transition occurs in saturated solutions at a certain threshold Ec. The magnitude of Ec increases with concentration because larger clusters form more easily when the solution is more concentrated and require a stronger E to dissociate.

关键词： NaCl solution,nucleation,static external electric field,molecular dynamics simulation

Fractional variant of Stokes–Einstein relation in aqueous ionic solutions under external static electric fields

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Chinese Physics B 2020年第3期29卷 323-329页

作者：任淦田时开 Departments of Physics&Key Laboratory of Photonic and Optical Detection in Civil Aviation Civil Aviation Flight University of ChinaGuanghan 618307China

Both ionic solutions under an external applied static electric field E and glassy-forming liquids under undercooled state are in non-equilibrium state.In this work,molecular dynamics(MD)simulations with three aqueous alkali ion chloride(NaCl,KCl,and RbCl)ionic solutions are performed to exploit whether the glass-forming liquid analogous fractional variant of the Stokes–Einstein relation also exists in ionic solutions under E.Our results indicate that the diffusion constant decouples from the structural relaxation time under E,and a fractional variant of the Stokes–Einstein relation is observed as well as a crossover analogous to the glass-forming liquids under cooling.The fractional variant of the Stokes–Einstein relation is attributed to the E introduced deviations from Gaussian and the nonlinear effect.

关键词： ionic solutions Stokes–Einstein relation non-equilibrium steady state molecular dynamics simulation

Fractional Stokes–Einstein relation in TIP5P water at high temperatures

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Chinese Physics B 2018年第6期27卷 307-314页

作者：任淦桑革 Science and Technology on Surface Physics and Chemistry Laboratory Jiangyou 621908China

Fractional Stokes–Einstein relation described by D ～（τ/T）~ξ is observed in supercooled water, where D is the diffusion constant, τ the structural relaxation time, T the temperature, and the exponent ξ =τ^（-1）. In this work, the Stokes–Einstein relation in TIP5 P water is examined at high temperatures within 400 K–800 K. Our results indicate that the fractional Stokes–Einstein relation is explicitly existent in TIP5P water at high temperatures, demonstrated by the two usually adopted variants of the Stokes–Einstein relation, D ～τ^（-1）τand D ～ T/τ, as well as by D ～ T/η, where η is the shear viscosity. Both D ～τ^（-1）τand D ～ T/τ are crossed at temperature Tx= 510 K. The D ～τ^（-1）τis in a fractional form as D ～ τ ξwith ξ =-2.09 for T ≤ Txand otherwise ξ =τ^（-1）.25. The D ～ T/τ is valid with ξ =τ^（-1）.01 for T ≤ Txbut in a fractional form for T Tx. The Stokes–Einstein relation D ～ T/η is satisfied below Tx = 620 K but in a fractional form above Tx. We propose that the breakdown of D ～ T/η may result from the system entering into the super critical region, the fractional forms of D ～τ^（-1）τand D ～ T/τ are due to the disruption of the hydration shell and the local tetrahedral structure as well as the increase of the shear viscosity.

关键词： Stokes-Einstein relation TIP5P water molecular dynamics hydration shells

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水稻种子衰老相关基因定位

作物学报 2005年第2期31卷 183-187页

作者：任淦彭敏唐为江徐才国邢永忠华中农业大学生命科学技术学院华中农业大学作物遗传改良国家重点实验室湖北武汉430070

利用ZS97×MH6 3组合衍生的 16 0份重组自交系进行种子衰老遗传分析。每份自交系 3批种子 ,即在武汉室温条件下存放 3年的自然衰老种子 ,收获 3个月后的种子 ,收获 3个月后再经过高温、高湿加快衰老处理的种子 ,供 2 5℃条件下考查发芽... 详细信息

利用ZS97×MH6 3组合衍生的 16 0份重组自交系进行种子衰老遗传分析。每份自交系 3批种子 ,即在武汉室温条件下存放 3年的自然衰老种子 ,收获 3个月后的种子 ,收获 3个月后再经过高温、高湿加快衰老处理的种子 ,供 2 5℃条件下考查发芽率和发芽势来衡量种子衰老状况。复合区间作图方法进行了 2批衰老种子的发芽势与发芽率QTL定位。自然衰老的那批种子在第 3染色体定位 2个影响发芽率QTL ,加性效应作用方向相反 ,第 1染色体上定位 1个发芽势QTL ;加速衰老的那批种子 ,在第 9染色体上定位了 2个发芽率QTL ,加性效应作用方向相反 ,第 1和 8染色体上分别定位了 1个发芽势QTL。这些发芽率和发芽势QTL不存在紧密连锁和一因多效关系 ,表明水稻种子自然衰老和加速衰老的机制可能由不同的遗传因子控制。

关键词：自然老化加速老化发芽率发芽势

基于混合液晶分子动力学模拟比较液晶分子旋转黏度大小

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物理学报 2015年第12期64卷 57-64页

作者：王启东彭增辉刘永刚姚丽双任淦宣丽中国科学院长春光学精密机械与物理研究所应用光学国家重点实验室长春130022 中国科学院大学北京100039 中国科学院理论物理研究所理论物理国家重点实验室北京100190

提高液晶波前校正器的响应速度是增加液晶自适应光学系统校正带宽的关键,而研究设计低旋转黏度的液晶分子是提高液晶波前校正器响应速度的根本方法.利用原子水平上的分子动力学方法获得了目标分子的液相、向列相以及近晶相,给出了理论... 详细信息

提高液晶波前校正器的响应速度是增加液晶自适应光学系统校正带宽的关键,而研究设计低旋转黏度的液晶分子是提高液晶波前校正器响应速度的根本方法.利用原子水平上的分子动力学方法获得了目标分子的液相、向列相以及近晶相,给出了理论计算液晶分子序参数以及旋转黏度的方法.与此同时,结合实验方法,提出利用混合液晶分子动力学模拟来比较液晶分子旋转黏度的大小,通过多次模拟、多起始点数据处理最大限度消除了因边界尺寸效应带来的数据波动,最后给出了两种高性能液晶分子的具体比较结果.这种分子动力学模拟方法能够探查分子结构细微差别对液晶相态以及旋转黏度的影响,为设计低旋转黏度的液晶分子提供了理论支持,必将为快速响应液晶材料的设计提供帮助.

关键词：液晶响应速度分子动力学模拟旋转黏度

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我国对外直接投资的逆向技术溢出效应分析

中国商贸 2015年第5期 116-118页

作者：任淦西南财经大学国际商学院

索洛经济增长模型显示,技术进步是一国经济持续增长的原动力。传统观点认为,本国R&D投入和外国直接投资是一国技术进步的主要动力。但从历史数据和国际贸易实务中我们往往发现,以R&D的投入孕育新的技术是一个周期长而且投入成本高昂的选... 详细信息

索洛经济增长模型显示,技术进步是一国经济持续增长的原动力。传统观点认为,本国R&D投入和外国直接投资是一国技术进步的主要动力。但从历史数据和国际贸易实务中我们往往发现,以R&D的投入孕育新的技术是一个周期长而且投入成本高昂的选择;同时,国外直接投资带来技术往往在国外早已形成产业链,边际收益低甚至濒临淘汰。在此情况下,对外直接投资的逆向技术外溢进入了我们的视野。无论技术获取型对外直接投资还是市场导向型对外直接投资都对我国有着逆向技术溢出效应,对促进我国技术进步有着重要的影响。

关键词：逆向技术溢出技术获取型对外直接投资市场导向型对外直接投资