用试片法测量管道的极化电位

本文通过分析管道极化电位的测量原理，论述了用试片法进行管道断电点位的测量方法，详细介绍了如何确定自然电位以及测量中需要注意的问题。     

Structural fluctuations in ensembles of nanoparticles

Caused by the interaction between the particles, structural fluctuations influence thermodynamics and order of transformation of an ensemble of nanoparticles. A stringed thermodynamic analysis revealed that, in fluctuating ensembles, the ratio of particle numbers in the equilibrium over the one in the non-equilibrium phase is independent of any metastable in between. Structural transformations in such ensembles, connected to latent heat, are of infinite order. These findings are summarized in a set of theorems ruling structural fluctuations. Finally, the consequences of fluctuations are demonstrated by an example.     

Semiconductor Research Needs in the Nanoscale Physical Sciences: A Semiconductor Research Corporation Working Paper

The purpose of this paper is to identify areas in the basic physical sciences where additional research is needed to sustain the extraordinary progress in electronics that has now extended for several decades. Also, it is argued that basic research will provide the foundation for the discovery of new generations of nanoelectronic devices that will continue the experimental rate of reduction in cost per function. Some of the fundamental areas requiring further research are the chemistry and physics of material interfaces, conductivity at small dimensions, deterministic doping effects, and nanomagnetics. Discovery research also is needed in the functional synergy of nanoelectronic materials and non-traditional fabrication methods.     

Simultaneous determination of nitroaromatic compounds in water using capillary electrophoresis with amperometric detection on an electrode modified with a mesoporous nano‐structured carbon material

In this article, a carbon disk electrode modified with mesoporous carbon material (CMK‐3) was used in CE with amperometric detection system for the simultaneous determination of four types of important nitroaromatic compounds, including 2,4,6‐trinitrotoluene (TNT), 1,3,5‐trinitrobenzene (TNB), 2,4‐dinitrotoluene (DNT) and 1,3‐dinitrobenzene (DNB). Compared with the bare carbon electrode, the CMK‐3 modified electrode greatly improved the sensitivity at a relatively positive detection potential due to its excellent electrocatalytic activities, high conductivity and large effective surface area. The four analytes could be well separated and detected within 480 s. A good linear response was obtained for TNB, DNB, TNT and DNT from 8.4 to 5.0×10³ μg/L, with correlation coefficients higher than 0.9992. And the detection limits were established between 3.0 and 4.7 μg/L for the four investigated nitroaromatic compounds (S/N=3). The CMK‐3‐modified electrode was successfully employed to analyze coking wastewater, tap water and river samples with recoveries in the range of 94.8–109.0%, and RSDs less than 5.0%. The presented results demonstrated that the CMK‐3‐modified carbon electrode used in CE with amperometric detection was of convenient preparation, high sensitivity and good repeatability, which could be employed in the rapid determination of practical samples.     

MULTI-SCALE NUMERICAL MODEL FOR SIMULATING CONCRETE MATERIAL BASED ON FRACTAL THEORY

A new multi-scale numerical model is presented using the fractal theory and adopting FEM to simulate the failure of concrete.The relation between the fractal box dimension in large scale and the damage to concrete in small scale is deduced.And the evolutionary process of elastic modulus and strength in small scale is given.Consequently,the multi-scale numerical model is proposed to describe the constitutive relation of concrete between small scale and large scale.A two-dimensional static analysis of a concrete block is performed by using this model and the calculation result is discussed.The propagation of cracks of the concrete block is also studied.     

Infinitely Many Contact Process Transitions on a Tree

We continue our study of the ergodic behavior of the contact process on infinite connected graphs of bounded degree. Examples are provided of trees on which, as the infection parameter increases, complete convergence alternates between holding and failing infinitely many times.     

Existence results for dynamic adhesive contact of a rod

The existence and uniqueness of the weak solution to the model for the dynamics of a viscoelastic rod which is in adhesive contact with an obstacle is established. The model consists of a hyperbolic equation for the vibrations of the rod coupled with a nonlinear ordinary differential equation (ODE) for the evolution of the bonding function. The model allows for failure, i.e., complete debonding, in finite time. The existence of the weak solution is established by using an existence result for ODEs and the Schauder fixed-point theorem. The limit of an elastic rod when the viscosity vanishes is studied, too.     

Entropy criterion of random states for granular material in a mixing process

Mathematical assessment of homogenisation progress of the granular material mixing process is presented. The mixing process was realised using a vessel in the form of two partly penetrating horizontal cylinders equipped with two multi-ribbon agitators. The experimental system consisted of three sets of particles of different colour. Random states of the mixed granular material were characterised by the sampling procedure at different moments of the mixing process. Informational entropy as well as the flow of quantum of information were applied to describe the progress of the homogenisation process. Analysis of this process was based on experimental investigations in the form of informational entropy patterns and described by means of the average informational entropy or the quantum of information. Presented at the 34th International Conference of the Slovak Society of Chemical Engineering, Tatranské Matliare, 21–25 May 2007.     

Effect of tin concentration on the electrical properties of ceramic membranes used as separators in electrochemical reactors

This paper deals with the study of different microporous ceramic membranes used as separators in electrochemical reactors to treat the activating solutions coming from the electroless plating of polymers. The main component of these solutions is Sn(IV) in HCl as diluting agent, then, the effect of the complex species formed between Sn⁴⁺ and Cl⁻ ions on the electrical properties of the membranes has been studied.