素描的审视——对绘画基础教学的再认识

本文从"素描"一词的东西方观念解读,以素描是一切造型艺术的基础理论为出发点,深入强化基础绘画教学的重要性。在构造上把握物体内在本质的变化规律,注重素描训练中的形体塑造和结构分析,通过比例、解剖、透视等基本法则构成画面,更为重要的是提高学生运用理性的头脑和感性的动力,培养学生对自然物象的认识能力、观察能力、塑造能力及思维创造能力。     

钻孔灌注桩加圆环形内支撑支护结构在厦门某基坑工程中的应用

本文介绍了钻孔灌注桩加圆环形内支撑支护结构在厦门某基坑工程中的应用，并对这种支护型式的设计计算方法进行了探索，以利同行借签。     

Contact Interface Model for Shallow Foundations Subjected to Combined Cyclic Loading

It has been recognized that the ductility demands on a superstructure might be reduced by allowing rocking behavior and mobilization of the ultimate capacity of shallow foundations during seismic loading. However, the absence of practical reliable foundation modeling techniques to accurately design foundations with the desired capacity and energy dissipation characteristics and concerns about permanent deformations have hindered the use of nonlinear soil–foundation–structure interaction as a designed mechanism for improving performance of structural systems. This paper presents a new “contact interface model” that has been developed to provide nonlinear relations between cyclic loads and displacements of the footing–soil system during combined cyclic loading (vertical, shear, and moment). The rigid footing and the soil beneath the footing in the zone of influence, considered as a macroelement, are modeled by keeping track of the geometry of the soil surface beneath the footing, along with the kinematics of the footing–soil system, interaction diagrams in vertical, shear, and moment space, and the introduction of a parameter, critical contact area ratio (A/Ac); the ratio of footing area (A) to the footing contact area required to support vertical and shear loads (Ac). Several contact interface model simulations were carried out and the model simulations are compared with centrifuge model test results. Using only six user-defined model input parameters, the contact interface model is capable of capturing the essential features (load capacities, stiffness degradation, energy dissipation, and deformations) of shallow foundations subjected to combined cyclic loading.     

Axial Compression of Footings in Cohesionless Soils. II: Bearing Capacity

An extensive database of full-scale field load tests was used to examine the bearing capacity for footings in cohesionless soils. Each load test curve was evaluated consistently to determine the interpreted failure load (i.e., bearing capacity) using the L1-L2 method. This test value then was compared with the theoretical bearing capacity, computed primarily using the basic Vesi? model. The comparisons show that, for footing widths B>1?m, the field results agree very well with the Vesi? predictions. However, for B<1?m, the results indicated a relationship between B and the predicted-to-measured bearing capacity ratio. Accordingly, a simple modification was made to the bearing capacity equation, and the resulting predictions are very good.     

Fertigation in Furrows and Level Furrow Systems. II: Field Experiments, Model Calibration, and Practical Applications

Furrow fertigation can be an interesting practice when compared to traditional overland fertilizer application. In the first paper of this series, a model for furrow fertigation was presented. The simulation model combined overland water flow (Saint-Venant equations), solute transport (advection-dispersion), and infiltration. Particular attention was paid to the treatment of junctions present in level furrow systems. In this paper, the proposed model is validated using five furrow fertigation evaluations differing in irrigation discharge, fertilizer application timing, and furrow geometry. Model parameters for infiltration and roughness were estimated using error minimization techniques. The error norm was based on observed and simulated values of advance time, flow depth, and fertilizer concentration. Model parameters could be adequately predicted from just one discharge experiment, although the use of more experiments resulted in decreased error. The validated model was applied to the simulation of a level furrow system from the literature. The model adequately reproduced irrigation advance and flow depth. Fertigation events differing in application timing were simulated to identify conditions leading to adequate fertilizer uniformity.     

Gold Medal Award for Life Achievement in the Application of Psychology: Walter C. Borman.

The American Psychological Foundation (APF) Gold Medal Awards recognize distinguished and enduring records of accomplishment in four areas of psychology: the application of psychology, the practice of psychology, psychology in the public interest, and the science of psychology. The 2011 recipient of the Gold Medal Award for Life Achievement in the Application of Psychology is Walter C. Borman. Dorothy W. Cantor, president of the APF, will present the APF Gold Medal Awards at the 119th Annual Convention of the American Psychological Association on August 5, 2011, at 4:00 p.m. Members of the 2011 APF Board of Trustees are Dorothy W. Cantor, president; William Howell, vice president/secretary; Gerald Koocher, treasurer; Elisabeth R. Straus, executive vice president/executive director; Norman Anderson; David H. Barlow, Camilla Benbow; Sharon Stephens Brehm; Charles L. Brewer; Connie Chan; Anthony Jackson; Ronald F. Levant; Sandra Shullman; Archie L. Turner; and Kurt Geisinger, APA Board of Directors liaison. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Mass Transport in Shallow Turbulent Wake Flow by Planar Concentration Analysis Technique

A planar concentration analysis (PCA) system is used for observing the transport and mixing of a tracer mass in a shallow turbulent free-surface wake flow of a large cylindrical obstacle. The nonintrusive, fieldwise PCA measuring technique is applied to evaluate depth-averaged mass concentrations by making use of light attenuation due to absorption and scattering processes related to a dissolved tracer mass. The scalar fields are decomposed into a low-frequency quasiperiodic part, the coherent flow, and a randomly fluctuating part. From accompanying near-surface velocity measurements, large-scale coherent structures are identified and related to the coherent mass fields. This allows one to assess the role of the large-scale vortices for advection and diffusion in shallow wake flows. The time–mean wake flow displays a self-similar spanwise distribution both for mass and velocity. The longitudinal development of shallow wakes initially shows the growth of unbounded wakes; in the wake far field an attenuated behavior applies.     

Thermal analysis in coated cutting tools

This work studies the heat influence in cutting tools considering the variation of the coating thickness and the heat flux. K10 and diamond tools substrate with TiN and Al₂O₃ coatings were used. The numerical methodology utilizes the ANSYS^® CFX software. Boundary conditions and constant thermo physical properties of the solids involved in the numerical analysis are known. To validate the proposed methodology an experiment is used. The TiN and Al₂O₃ coatings did not show satisfying results during a continuous cutting process. It showed a slight reduction in the heat flux for the 10 (µm) TiN and Al₂O₃ coatings.