Sociogenèse et psychobiologie: Les sources de la continuité et de la discontinuité du développement.

The aim of this article is to reflect conceptually upon the various stakes in development from both psychobiological and sociogenetical perspectives, two prominent contemporary theories of social sciences. Where does developmental continuity belong?...Does it belong within the individual or within his or her environment? Despite explicitly recognizing the influence of social experience in human development, the traditionally old nature-nurture debate remains at the center of theoretical analyses and leads to a futile integration of the two positions. The authors propose a theoretical model, which suggests not to integrate these two antagonistic positions but rather to recognize and utilize their interdependency as a means of viewing continuity and discontinuity as complementary facets of development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

全站仪矿山自动测绘集成技术原理及应用

集测角、测距和数据处理一体化的电子全站仪已在矿山测量中日益普及，本文提出一种能自动读数、自动记录、自动预处理、自动建立数据文件、自动与微机交换数据、自动绘图并建立数据库的矿山自动测绘系统。该系统由全站仪、Ｅ５００袖珍计算机、ＣＥ－１２６热敏打印机、微机、绘图仪等硬件组成，实践证明，该系统是先进、实用的系统。     

多尺度岩体结构面抗剪强度直剪试验一体机的分级和验证

岩体结构面抗剪强度尺寸效应变化规律的研究需要在专门的多尺度岩体结构面抗剪强度直剪试验机上进行,以获得稳定的抗剪强度力学参数。为保证测试数据的可靠性,在满足测试载荷范围为2～1000 kN时要求恒定荷载示值精度为1％。由于现有测试系统的技术限制,无法实现在同一台设备上进行全部荷载的试验。为此,首先在提出一种设备荷载分级方法的基础上开发了一种多尺度岩体结构面抗剪强度直剪试验一体机,在满足测试精度的要求下分3级尺度直剪仪进行直剪测试,每一级尺度直剪仪设置了荷载重叠区以保证测试数据的等效性。最后对该直剪试验一体机的精度和载荷范围进行了测试,通过了多尺度试样的测试要求。目前该多尺度岩体结构面抗剪直剪试验一体机为多尺度试样的测试研究提供了平台。     

Strength modelling of geomaterials with random systems of structural joints

Strong-geomaterial samples-such as monolithic rock, concrete, and firm clay-are often weakened by random discontinuities called weak joints (fissures, cracks). The paper focuses on a theoretical strength evaluation of such samples using standard methods of series reliability systems; it is assumed that the shearing failure modes generated by structural joints are independent elements of the system. Special attention is paid to the number k of elements in the system which is randomized by making use of the Poisson probability distribution. Closed-form solutions for the random strength of samples, i.e. distribution functions, are derived for randomly equivalent continua, both anisotropic and isotropic. In particular, such solutions can yield the average strength of the structured sample (the homogenized or the effective one) and its higher-order moments, etc. The examples reveal a strong reduction of the strength if weak joints concentrate around some critical angles, but primarily if the number of discontinuities increases.     

Discrete fracture in high performance fibre reinforced concrete materials

In this paper a simple, but effective methodology to simulate opening mode fracture in high performance fibre reinforced concrete is presented. The main contribution of the paper is a technique to extrapolate the load displacement curves of three point bending experiments on fibre reinforced concrete. The extrapolation allows the full work of fracture to be determined, from which the fracture energy may be obtained. The fracture energy is used in the definition of a cohesive softening function with crack tip singularity. The softening relation is implemented in an embedded discontinuity method, which is employed for the numerical simulation of three point bending experiments. The experimental work includes a size effect study on three point bending specimens. The numerical simulation provides a satisfactory prediction of the flexural behaviour and the size effect observed in the experiments.     

农村公路桥梁损伤状况调查研究

通过湖北黄石地区农村公路桥梁的实地调查,采用权重综合评定法,对农村公路桥梁按损伤程度进行了分类研究,结果表明中等损伤的三类桥居多,损伤基本集中在7个部位,病害类型以混凝土裂缝、混凝土腐蚀、钢筋锈蚀、桥面铺装损伤为主。为后期桥梁加固提供了调查依据。     

大孤山铁矿边坡岩体结构数字识别及力学参数研究

针对目前岩体结构面信息获取主要以人工现场接触测量为主,劳动强度大、效率低下的现状,借助于先进的ShapeMetrix 3D三维数字摄影测量系统,对大孤山铁矿边坡岩体结构面进行摄影测量,对获取到的结构面进行分组、分析,得到结构面各种几何信息的详细数据,并对其进行数理统计计算、分析,拟合出结构面各种几何信息的概率分布模型。采用蒙特卡洛方法编制的程序和根据数字摄影测量系统得到的统计数据,模拟岩体内部结构面三维分布情况。在此基础之上,采用修正广义Hoek-Brown准则,估计节理化岩体强度,得到岩体强度指标。根据已获得的结构面三维分布情况和岩体强度指标综合评价了大孤山铁矿边坡岩体稳定性。     

An extended displacement discontinuity method for analysis of stress wave propagation in viscoelastic rock mass

An extended displacement discontinuity method (EDDM) is proposed to analyze the stress wave propagation in jointed viscoelastic rock mass (VRM).The discontinuities in a rock mass are divided into two groups.The primary group with an average geometrical size larger than or in the same order of magnitude of wavelength of a concerned stress wave is defined as "macro-joints",while the secondary group with a high density and relatively small geometrical size compared to the wavelength is known as "micro-defects"...     

Beyond the group mind: A quantitative review of the interindividual-intergroup discontinuity effect.

This quantitative review of 130 comparisons of interindividual and intergroup interactions in the context of mixed-motive situations reveals that intergroup interactions are generally more competitive than interindividual interactions. The authors identify 4 moderators of this interindividual-intergroup discontinuity effect, each based on the theoretical perspective that the discontinuity effect flows from greater fear and greed in intergroup relative to interindividual interactions. Results reveal that each moderator shares a unique association with the magnitude of the discontinuity effect. The discontinuity effect is larger when (a) participants interact with an opponent whose behavior is unconstrained by the experimenter or constrained by the experimenter to be cooperative rather than constrained by the experimenter to be reciprocal, (b) group members make a group decision rather than individual decisions, (c) unconstrained communication between participants is present rather than absent, and (d) conflict of interest is severe rather than mild. (PsycINFO Database Record (c) 2010 APA, all rights reserved)