关于职业院校默会知识若干问题的探讨

对默会知识的占有和传播程度,是职业院校能否具有比较优势的关键。默会知识具有特定的内涵与特点。职业院校默会知识主要表现为三种形式:基于个体技能表现的默会知识;基于组织惯例的默会知识;基于学校文化的默会知识。要促进职业院校默会知识的传播,必须建立有利于默会知识传播的组织结构,形成组织中各个相关成员之间交流默会知识的机制;重新审视学徒制的地位和作用,提倡和重视学徒制,同时引导个体反复自主训练;致力于营造一种有利于默会知识传播并体现企业文化精神的学校文化。     

中国粮食生产主体功能区的核心设计——构筑国家生存安全保障线

设立国家粮食生产主体功能区是我国应对国际粮食问题,实现国内粮食安全的战略选择。本文在分析我国粮食供需形势和耕地资源面临压力的基础上,从国家粮食安全战略角度提出在东北平原等粮食生产基地设立8亿亩的国家粮食生产主体功能区,以提供80%的粮食需求和防范特大自然灾害。在现有商品粮生产基地的基础上,对粮食主体功能区进行了空间布局,以便为国家的生存安全提供基础保障。     

项目型组织成员知识转移动机实证研究—与组织情境的跨层次作用

知识是项目型组织(project-based organizations,PBOs)持续发展的关键资源,其有效地转移和共享不但有助于项目的成功,更有利于PBOs的长远发展。本研究运用多层线性模型,通过采集和分析来自中国建筑第*工程局有限公司的480个项目型组织样本问卷数据,探讨组织情景对项目型组织成员知识转移动机和知识转移效果的跨层次影响。结果表明:知识转移动机是决定知识转移行为的关键所在;组织情境差异化影响成员的知识转移动机和知识转移效果。这一发现揭示了组织情景影响成员知识动机和知识转移效果的内在机理,拓展了主流文献的相关研究,并为项目型组织知识管理实践提供借鉴。     

Construction and operation of a microrobot based on magnetotactic bacteria in a microfluidic chip

Magnetotactic bacteria (MTB) are capable of swimming along magnetic field lines. This unique feature renders them suitable in the development of magnetic-guided, auto-propelled microrobots to serve in target molecule separation and detection, drug delivery, or target cell screening in a microfluidic chip. The biotechnology to couple these bacteria with functional loads to form microrobots is the critical point in its application. Although an immunoreaction approach to attach functional loads to intact MTB was suggested, details on its realization were hardly mentioned. In the current paper, MTB-microrobots were constructed by attaching 2 μm diameter microbeads to marine magnetotactic ovoid MO-1 cells through immunoreactions. These microrobots were controlled using a special control and tracking system. Experimental results prove that the attachment efficiency can be improved to ∼30% via an immunoreaction. The motility of the bacteria attached with different number of loads was also assessed. The results show that MTB can transport one load at a velocity of ∼21 μm/s and still move and survive for over 30 min. The control and tracking system is fully capable of directing and monitoring the movement of the MTB-microrobots. The rotating magnetic fields can stop the microrobots by trapping them as they swim within a circular field with a controllable size. The system has potential use in chemical analyses and medical diagnoses using biochips as well as in nano/microscale transport.     

基于GOCI影像的杭州PM2.5遥感建模及时空变异分析

地球静止卫星上的GOCI(geostationary ocean color imager)传感器具有较高的时间分辨率,在研究短时间尺度内大气PM2.5浓度时空变化方面具有一定的应用潜力.本文根据GOCI影像的波段特征,利用2011-2013年实测PM2.5浓度、大气气溶胶光学厚度(aerosol optical depth,AOD)与气象因子数据,分别进行了GOCI PM2.5浓度单变量和多变量反演建模研究,并结合2013年12月6日的GOCI AOD数据,实现了单日杭州市PM25浓度遥感反演与时空变异分析.结果表明:在单变量模型中,分季节模型的平均相对误差最高值28.11％比年度模型的平均相对误差34.04％低,分季节模型精度优于年度模型;单变量模型的平均相对误差34.04％比多变量模型的平均相对误差48.96％低,单变量模型精度优于多变量模型;把单变量冬季模型应用于杭州GOCI AOD数据,得出逐时大气PM2.5的空间分布,并计算了PM2.5浓度的变异系数,发现杭州各区县变异系数大都在0.5以下,东部和北部的数值较高,中西部地区的值较低.     

浅谈青少年运动员的长跑训练策略

随着广大人民群众对于长跑的理解更加深入,人们对于长跑这项运动就越来越重视.伴随着时代的进一步发展,长跑这一体育运动的项目竞争越来越激烈.传统的训练方式已经无法满足当今青少年长跑训练的要求.所以就需要在实践的过程当中,在思想和技术指导以及合理的安排运动员每天的运动量等方面进行一定程度上的革新.本文旨在结合笔者多年的运动员指导经验,简要地阐述如何进行长跑运动的训练,以便于更好地促进运动员整体水平的提升.     

Stabilization of a class of nonlinear parametrized systems by a flexible switching adaptive backstepping

In this paper, we consider global adaptive feedback control of nonlinear systems with unknown parameters entering nonlinearly. Such unknown parameters are also not required to lie in a known compact set. Unlike previous results, our proposed adaptive controller is a new double dynamical switching-type controller in which the controller parameter is tuned in a flexible switching manner via a monotonically decreasing switching logic and the controller combines the traditional adaptive theorem with the switching scheme perfectly. Global stability results of the closed-loop system have been proved.     

GIS技术体系及其在矿产资源评价中的应用

本章论述了GIS的技术体系与发展趋势,包括目前主流的GIS研究方向.针对GIS在矿产资源评价中的应用,介绍了国内外应用现状、应用步骤,并对其应用前景和趋势加以评述.     

漂浮基空间机器人的基于模糊神经网络的自适应补偿控制

针对自由漂浮状态的空间机器人模型不确定性及其动力传动机构的摩擦死区非线性,将一种自适应模糊小脑模型关联控制( FCMAC)补偿策略用于轨迹跟踪及补偿问题.利用模糊神经网络并引入GL矩阵及其乘法算子“.”分别对执行机构中的摩擦死区及系统模型不确定部分进行自适应补偿,其补偿误差及外界扰动通过滑模控制器来消除.基于Lyapunov理论证明了闭环系统跟踪误差的有界性.仿真表明控制器可以达到较高精度,且能满足实时性要求.     

Security control for two-time-scale cyber physical systems with multiple transmission channels under DoS attacks: The input-to-state stability

This paper investigates the security control problem for a class of two-time-scale cyber-physical systems (TTSCPSs) with multiple transmission channels under the denial-of-service (DoS) attacks. A linear TTSCPSs model is first proposed with slow and fast transmission channels, which correspond to slow and fast physical components in terms of their communicating capacities and sampling rates. The measurement data-packets are transmitted via slow and fast transmission channels which are compromised by asynchronous DoS attacks. A novel composite controller depending on the singular perturbation parameter (SPP) is formulated and corresponding switching laws are designed to achieve certain resilience against DoS attacks. Then, by establishing a SPP-dependent Lyapunov function, sufficient conditions are obtained on the duration and frequency of the DoS attacks, such that, for any SPP less than or equal to a predefined upper bound, the input-to-state stability can be guaranteed for the closed-loop TTSCPSs. Finally, a networked DC motor control system is employed to demonstrate the effectiveness of the proposed security control algorithm.