Can a functionalized phosphine ligand promote room temperature luminescence of the [Ru(bpy)(tpy)]2+ core?

Unexpected room temperature luminescence is observed and rationalized by highly challenging excited state calculations for a functionalized phosphine ligand coordinated on the [Ru(bpy)(tpy)](2+) core.     

Calculation of the dynamic response of a viscoelastic railway structure based on a quasi-stationary approach

A semi-analytical method has been developed for computing the dynamic response of railways composed of viscoelastic layers under moving loads. One of the aims of this new approach is to be able to simulate railways incorporating asphalt materials. These materials are increasingly used or highly considered for construction projects. We have modeled the mechanical behavior of bituminous mixes with the Huet–Sayegh thermo-sensitive viscoelastic law that is specifically intended for such materials. This method, implemented in a numerical program, is based on a quasi-stationary approach, so that time is not a specific factor in the solution. The required calculation time is therefore small, for the convenience of parametric studies. The capability of this method is proved with a numerical example that provides several validation points and illustrates at the same time the temperature effect on the response of a railway including an asphalt layer.     

Mechanism‐Dependent Modulation of Ultrafast Interfacial Water Dynamics in Intrinsically Disordered Protein Complexes

The recognition of intrinsically disordered proteins (IDPs) is highly dependent on dynamics owing to the lack of structure. Here we studied the interplay between dynamics and molecular recognition in IDPs with a combination of time‐resolving tools on timescales ranging from femtoseconds to nanoseconds. We interrogated conformational dynamics and surface water dynamics and its attenuation upon partner binding using two IDPs, IBB and Nup153FG, both of central relevance to the nucleocytoplasmic transport machinery. These proteins bind the same nuclear transport receptor (Importinβ) with drastically different binding mechanisms, coupled folding–binding and fuzzy complex formation, respectively. Solvent fluctuations in the dynamic interface of the Nup153FG‐Importinβ fuzzy complex were largely unperturbed and slightly accelerated relative to the unbound state. In the IBB‐Importinβ complex, on the other hand, substantial relative slowdown of water dynamics was seen in a more rigid interface. These results show a correlation between interfacial water dynamics and the plasticity of IDP complexes, implicating functional relevance for such differential modulation in cellular processes, including nuclear transport.     

MULTIDIMENSIONAL UPWIND RESIDUAL DISTRIBUTION SCHEMES FOR THE CONVECTION–DIFFUSION EQUATION

Multidimensional residual distribution schemes for the convection–diffusion equation are described. Compact upwind cell vertex schemes are used for the discretization of the convective term. For the diffusive term, two approaches are compared: the classical finite element Galerkin formulation, which preserves the compactness of the stencil used for the convective part, and various residual-based approaches in which the diffusive term, evaluated after a reconstruction step, is upwinded along with the convective term.     

电感耦合等离子体原子发射光谱(ICP-AES)法测定铅锭中11种杂质元素

研究了用酸分解试样后不需分离基体直接用电感耦合等离子体原子发射光谱(ICP-AES)法测定铅锭中银、铜、铋、砷、锑、锡、锌、铁、镉、镍、铊11种杂质元素的方法。优化了样品前处理条件及仪器检测条件。方法的检出限为0.0012～0.0168μg/mL,回收率为89%～110%,RSD为2.3%～5.0%。方法简便快速,检出限低,精密度和准确度能满足铅锭中杂质元素的检测要求,具有较强的实用性和可操作性,可用于铅锭中杂质元素的测定。     

Peeling of polydimethylsiloxane adhesives at low velocities: Cohesive failure

This work presents results obtained in 90‐degree peeling tests at low velocities in the case of Newtonian adhesives, when failure is cohesive. Peeling experiments are described and consider the influence of the thickness, viscosity, and surface tension of the adhesive, as well as the backing rigidity. A simple model, based on lubrication effects in thin films, is considered and compared with the measurements, when peeling is a two‐dimensional phenomenon. Furthermore, a criterion for predicting the transition between the two‐dimensional regime and the three‐dimensional regime at higher velocities is proposed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 145–157, 2005     

共振辐射的理论研究——Holstein方程的解

解决介质中共振辐射的关键问题是求解Holstein方程。本文直接利用算符运算将方程积分,给出了激发态粒子集居数的含无限项的级数表达式。基于对这个级数高阶系数的极限行为的研究,成功地克服了无穷项求和的困难,整理出一个在任意给定精度下都只含有限项的解式,由它可以计算出任何时刻的结果。 关键词：     

Rotational and hyperfine constants of CD3I

The rotational spectra of CD₃I (v = 0; v₃ = 1; v₆ = 1) and of ¹³CD₃I in its ground state were observed between 8 and 320 GHz. For the ground state of CD₃I, pure quadrupole resonances were also measured by laser-radiofrequency double resonance. These data have been used to determine with high accuracy the rotational, centrifugal distortion, and hyperfine constants.     

Shear rheometry of polydimethylsiloxanes. Master curves and testing of Gleissle and Yamamoto relations

This study concerns the shear rheometry of a series of nine silicone fluids, all linear or branched polydimethylsiloxanes (PDMS), with varying mass distributions.The use of a rotative rheometer enabled characterization of these products in a dynamic regime for about five decades of pulsation . In addition, because of the use of rotative rheometers together with a capillary rheometer with controlled piston speed, the behavior of these products could be determined for about six orders of magnitude of shear rate , notably for the permanent regime viscosity coefficient .On the other hand, to obtain the variations of the first normal stress difference coefficient ₁, over a significant range of shear rate , it was necessary to complete the experimental measurements by using empirical relations. Particularly, after having defined the application conditions, the Gleissle and Yamamoto relations were tested for these products.Finally, all the results obtained in dynamic and in transitory regimes by using the rheometers and empirical relations mentioned above were combined in dimensionless form. Indeed, the existence of master curves for the linear and branched PDMS was demonstrated. Our study therefore enables the validity of the master curve method, initially established for a series of linear monodisperse polystyrenes, to be extended to the case of a family of linear or branched PDMS of wide mass distribution.