The Dependent Patient: Diagnosis, Assessment, and Treatment.

Although dependent psychotherapy patients are compliant and eager to please, they also use more psychological and medical resources than nondependent patients, have more pseudoemergencies, and have difficulty terminating treatment. This article reviews research on diagnosis, assessment, and treatment of dependent patients and offers recommendations for implementing effective diagnostic, assessment, and treatment strategies in inpatient and outpatient settings. Integration is key: Clinicians must combine different types of data (e.g., diagnostic, assessment) and blend different therapeutic modalities (e.g., cognitive, psychodynamic) to work effectively with dependent patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Monte-Carlo simulation of the Cahn-Hillard model of spinodal decomposition

A lattice version of the nonlinear Cahn-Hilliard equation describing spinodal decomposition of binary alloys is studied via Monte-Carlo simulation, considering a two-dimensional system at critical concentration. The linearization approximation is found to be rather inaccurate even if the final temperature of the quench is very low and thermal fluctuations are unimportant. The structure function is found to exhibit anisotropy consistent with the chosen square lattice geometry. The relation of this study to Ising model simulations and experimental work is briefly discussed.     

Dependent Effect Sizes in Meta-Analysis: Incorporating the Degree of Interdependence.

In the present article, a commonly used meta-analytic procedure for handling dependent effect sizes from a single sample was examined, and 2 revised procedures that estimate and incorporate the degree of interdependence were proposed. The authors' simulation results reveal that the commonly used procedure that averages the effect sizes from a single sample (denoted as the samplewise procedure) underestimates the degree of heterogeneity. The proposed variations are less biased than the samplewise procedure in estimating the degree of heterogeneity in most of the situations that we examined. Future directions to further improve the procedures for handling dependent effect sizes from a single sample are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

铜在含碘酸钾的CeO2浆料中CMP的抛光速率及影响因素的研究

研究了氧化剂碘酸钾及抛光粒子CeO2的浓度、抛光转速和抛光压力对铜的化学机械抛光速率的影响,并初步解释了影响因素的机理。实验表明在一定范围内材料的去除速率与抛光压力、抛光转速的关系可以用Preston方程的一般式R=KPαVβ来表示,并据此可得到α,β和K的值;而氧化剂和抛光粉浓度对抛光速率的影响无明确的规律。在0.2 mol/L KIO3+5%CeO2、压力11.703 kPa、转速25 r/min的条件下,铜去除速率为43.9 nm/min,抛光效果Ra=10.9 nm,Rmax=112 nm。     

Nucleation and growth processes with concentration fluctuations

The time evolution of the volume fraction of stable ordered domains is studied in nucleation and growth processes with concentration fluctuations. Simulating a model equation in three dimensions, we find that such fluctuations result in the crossover for the time dependent behavior of the volume fraction.     

Physico-Chemical Factors Affecting the Separation of Cassiterite and Fluorite by Froth Flotation

Abstract

Cassiterite flotation is achieved industrially with some anionic collectors. However, the presence of fluorite in primary tin ores usually poses a problem in relation to the selectivity between the two minerals. In this work, a comparative study was undertaken involving adsorption, electrophoretic mobility and suspension stability measurements of both cassiterite and fluorite as a function of oleic acid concentration. These properties are discussed with reference to the calculated free energy of adsorption equation pending of oleic acid on the two minerals. Hallimond tube flotation tests conducted with the two minerals showed a distinctly higher floatability of fluorite at low oleic acid concentration. Micro-flotation studies using Procol CA-540. a sulphosuccinamate collector, presented similar results, indicating that fluorite can be floated selectively from cassiterite at low collector concentration and neutral pH.     

K+] dependence of open-channel conductance in cloned inward rectifier potassium channels (IRK1, Kir2.1)

Potassium conduction through unblocked inwardly rectifying (IRK1, Kir2.1) potassium channels was measured in inside-out-patches from Xenopus oocytes, after removal of polyamine-induced strong inward rectification. Unblocked IRK1 channel current-voltage (I-V) relations show very mild inward rectification in symmetrical solutions, are linearized in nonsymmetrical solutions that bring the K+ reversal potential to extreme negative values, and follow Goldman-Hodgkin-Katz constant field equation at extreme positive E alpha. When intracellular K+ concentration (KIN) was varied, at constant extracellular K+ concentration (KOUT) the conductance at the reversal potential (GREV) followed closely the predictions of the Goldman-Hodgkin-Katz constant field equation at low concentrations and saturated sharply at concentrations of > 150 mM. Similarly, when KOUT was varied, at constant KIN, GREV saturated at concentrations of > 150 mM. A square-root dependence of conductance on KOUT is a well-known property of inward rectifier potassium channels and is a property of the open channel. A nonsymmetrical two-site three-barrier model can qualitatively explain both the I-V relations and the [K+] dependence of conductance of open IRK1 (Kir2.1) channels.     

Study of ionic currents across a model membrane channel using Brownian dynamics

Brownian dynamics simulations have been carried out to study ionic currents flowing across a model membrane channel under various conditions. The model channel we use has a cylindrical transmembrane segment that is joined to a catenary vestibule at each side. Two cylindrical reservoirs connected to the channel contain a fixed number of sodium and chloride ions. Under a driving force of 100 mV, the channel is virtually impermeable to sodium ions, owing to the repulsive dielectric force presented to ions by the vestibular wall. When two rings of dipoles, with their negative poles facing the pore lumen, are placed just above and below the constricted channel segment, sodium ions cross the channel. The conductance increases with increasing dipole strength and reaches its maximum rapidly; a further increase in dipole strength does not increase the channel conductance further. When only those ions that acquire a kinetic energy large enough to surmount a barrier are allowed to enter the narrow transmembrane segment, the channel conductance decreases monotonically with the barrier height. This barrier represents those interactions between an ion, water molecules, and the protein wall in the transmembrane segment that are not treated explicitly in the simulation. The conductance obtained from simulations closely matches that obtained from ACh channels when a step potential barrier of 2-3 kTr is placed at the channel neck. The current-voltage relationship obtained with symmetrical solutions is ohmic in the absence of a barrier. The current-voltage curve becomes nonlinear when the 3 kTr barrier is in place. With asymmetrical solutions, the relationship approximates the Goldman equation, with the reversal potential close to that predicted by the Nernst equation. The conductance first increases linearly with concentration and then begins to rise at a slower rate with higher ionic concentration. We discuss the implications of these findings for the transport of ions across the membrane and the structure of ion channels.     

在光纤传输过程中的广义RKL方程新的孤波解

广义的RKL方程能够较好表述光子在光纤传输过程中一般特征,作者利用辅助方程法并借助计算机辅助程序构建更多的RKL方程一般精确解,结果发现这个方程的一些新孤波解.另外此方法也可用来研究其他非线性发展方程并获取新的孤波解.     

Classification of concentration profiles in quaternary diffusion couples

Concentration profiles that can occur in quaternary diffusion couples have been classified into five types according to the number of extrema, the initial concentration differences, and the concentration gradient at the initial interface. The various profiles that are possible have zero, two or four extrema and are illustrated in this work by plotting appropriate error function solutions to the diffusion equation. The conditions under which the different types occur and the transitions between types, are given as well for quaternary systems. The only assumptions made are that the diffusivity is constant in the reaction zone and that the system is single phase.     

Interaction of nonionic polymers at a clay interface

The structure and dynamics at the interface of swelling clays (smectites) are crucial to such diverse applications as drilling for oil, cosmetics, paints, water treatment, or chemical reactions. From our previous NMR studies on clay suspensions, we have shown how the orientation of interfacial molecules is affected by the clay structure1, by the nature of counterions 2, or by the composition of the liquid phase3. These results have been mainly obtained from the analysis of residual quadrupolar splittings of nuclei from interfacial species. In this work, we report our studies on a clay montmorillonite suspended in aqueous solutions of non ionic polymers. The polymer perturbs the structure within the interfacial region as deduced from the variations of the splittings of water quadrupolar nuclei and of sodium-23 relaxation parameters in terms of the polymer concentration. Proton self-diffusion coefficients and carbon-13 relaxation times are measured to describe the influence of the clay on the polymer mobility. The dependence of the polymer nature on these parameters is also investigated.     

Direct molecular level measurements of the electrostatic properties of a protein surface

In this work, we used direct measurements with the surface force apparatus to determine the pH-dependent electrostatic charge density of a single binding face of streptavidin. Mean field calculations have been used with considerable success to model electrostatic potential fields near protein surfaces, but these models and their inherent assumptions have not been tested directly at the molecular level. Using the force apparatus and immobilized, oriented monolayers of streptavidin, we measured a pI of 5-5.5 for the biotin-binding face of the protein. This differs from the pI of 6.3 for the soluble protein and confirms that we probed the local electrostatic features of the macromolecule. With finite difference solutions of the linearized Poisson-Boltzmann equation, we then calculated the pH-dependent charge densities adjacent to the same face of the protein. These calculated values agreed quantitatively with those obtained by direct force measurements. Although our study focuses on the pH-dependence of surface electrostatics, this direct approach to probing the electrostatic features of proteins is applicable to investigations of any perturbations that alter the charge distribution of the surfaces of immobilized molecules.     

Affecting the salience of the social responsibility norm: effects of past help on the response to dependency relationships.

A series of experiments by the authors assumes that many people in our society are motivated to aid others who are dependent upon them because such help is prescribed by a "social responsibility norm." The present study also assumes that prior help can increase the salience of this norm. In a 2 X 2 X 2 factorial design using 80 Ss (college women), ? of the Ss were individually helped by a peer (E's confederate) on a preliminary task, while the others were not aided. After this, the Ss worked on another task under the supposed supervision of yet another peer, with ? of the Ss being told the supervisor was highly dependent upon their work and the others told she was less dependent upon them. The 1st peer would supposedly learn of their work in ? of the cases but not in the other ?. The previously helped Ss tended to exert the greatest effort in behalf of their dependent peer. A self-report scale assessing social responsibility tendencies was significantly correlated with the effort measure in the Prior Help-High Dependency condition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling diffusion through nonuniform concentrations of traps

Cases in which traps are nonuniformly distributed in a solid can be treated by using a modification of the Caskey-Pillinger finite difference method of obtaining solutions to the McNabb-Foster diffusion and trapping equations. The special case of low mobility impurity atom traps that have been previously diffused into one surface of a flat membrane was studied by math modeling with regard to the effect of the traps on the time dependent permeation of faster diffusing atoms. Results obtained for uniformly distributed traps are compared with those expected for nouniformly distributed traps.     

The role of diffusion in determining the controlling creep mechanisms in Al-Zn solid-solutions: Part II

The theoretically appropriate diffusion coefficients for creep in binary solid solutions are verified in Part I. Furthermore it is observed that the observed composition dependence of the steady-state creep rate for Al-Zn alloys may be described by these diffusion coefficients. Part II further examines the creep behavior of the Al-Zn system. Stress exponent and activation energy measurements indicate that a transition from climb-controlled to glide-controlled creep occurs as the Zn concentration increases. It is found that the observed creep behavior can be explained by a combination of climb and glide controlled creep processes. Glide creep is dependent on the chemical diffusivity which approaches zero at the miscibility gap composition and temperature. This causes a minimum in the creep rate at the miscibility gap composition. By using a sequential summation of a semiempirical climb equation and the Cottrell-Jaswon glide equation, the absolute magnitude of the observed creep rate can be rationalized for all compositions. The observed behavior of the stress exponent and activation energy is also predicted. Formerly Graduate Research Assistant     

Application of the quasi-random lattice model to rare-earth halide solutions for the computation of their osmotic and mean activity coefficients

This work dealt with the computation of the mean activity coefficients of rare-earth halide aqueous solutions at 25℃, by means of the Quasi Random Lattice（QRL） model. The osmotic coefficients were then calculated consistently, through the integration of the Gibbs-Duhem equation. Using of QRL was mainly motivated by its dependence on one parameter, given in the form of an electrolyte-dependent concentration, which was also the highest concentration at which the model could be applied. For all the electrolyte solutions here considered, this parameter was experimentally known and ranged from 1.5 to 2.2 mol/kg, at 25 ℃.Accordingly, rare- earth halide concentrations from strong dilution up to 2 mol/kg about could be considered without need for best-fit treatment in order to compute their osmotic and mean activity coefficients. The experimental knowledge about the parameter was an advantageous feature of QRL compared to existing literature models. Following a trend already observed with low charge electrolytes,a satisfactory agreement was obtained with the experimental values for all the investigated rare-earth chlorides and bromides. For the sake of compactness, in this work the considered rare-earth halides were all belonging to the P63/m space group in their crystalline（anhydrous） form.     

Performance Dependent Failure Criterion for Normal- and High-Strength Concretes

A new approach to describe the maximum strength criterion of concretes with different strength capacities is formulated. The proposed failure criterion incorporates the so-called “performance parameter” (βP) that controls the dependence of the maximum strength on the concrete quality. To assure the feasibility of the solution procedure for any possible set of known data, different methods are proposed to determine βP according to the available material data. The performance dependent strength criterion presented in this work is expressed in terms of the Haigh Westergaard stress coordinates and as a function of four material parameters that fully define the compressive and tensile meridians of the failure criterion. The variation of the shear strength between these two meridians follows an earlier elliptic interpolation. The proposal includes approximating functions that define the dependence of the above mentioned four material parameters on the two fundamental mechanical properties of concrete: the uniaxial compressive strength fc′ and the performance parameter βP. The capability of the proposed criterion to predict peak stresses of both normal- and high-strength concretes is verified with experimental data available in the literature corresponding to uniaxial, biaxial, and triaxial compression tests.