蒙特卡洛法在单缝衍射光强分析中的应用

介绍了基础物理教学中引入蒙特卡洛方法的一个实例,将蒙特卡洛方法应用在夫琅和费单缝衍射光强分布特点的分析讨论中,得到光强次极大的位置.和现有文献中普遍采用的图解法相比,蒙特卡洛法求解超越方程的方法所得结果的精度更高.     

相干态光场与运动二能级原子系统光场压缩效应

采用求解Schrodinger方程和数值计算方法.研究了相干态光场与运动二能级原子相互作用过程中的光场压缩效应.结果表明:通过适当选择系统参数,可使光场产生完全压缩效应;随系统参数的变化,光场呈现完全压缩、不完全压缩和不压缩周期性变化.     

大数据时代的数字资源融合研究

"大数据"时代,数据即资源、数据即财富、数据即资产已成为共识。数据开放、信息公开已成大趋势,将分散分布、零碎存在的数字资源融合成完整的"大数据",从中提取有价值的信息,转化为有用的知识和规则,并加以利用,对于组织的生存与发展至关重要,对于提升组织的核心能力和竞争优势至关重要,成为关注的焦点。论文界定了数字资源融合的内涵和特点,回顾了大数据和数字资源融合研究的现有研究成果,分析了数字资源融合的主要内容,构建了数字资源融合的框架模型,并指出数字资源融合存在的问题及发展趋势。     

苏锡常地区全民健身运动发展水平的研究初探

运用逻辑推理、层次分析等方法,构建了全民健身运动发展评价指标体系,采用线性加权法合成系统的全民健身发展水平指数,对苏锡常地区全民健身运动发展水平进行了研究初探,以期为该地区政府及相关体育部门顺利地实施《全民健身计划(2011～2015年)》提供参考.     

Interplay between motility and cell-substratum adhesion in amoeboid cells

The effective migration of amoeboid cells requires a fine regulation of cell-substratum adhesion. These entwined processes have been shown to be regulated by a host of biophysical and biochemical cues. Here, we reveal the pivotal role played by calcium-based mechanosensation in the active regulation of adhesion resulting in a high migratory adaptability. Using mechanotactically driven Dictyostelium discoideum amoebae, we uncover the existence of optimal mechanosensitive conditions—corresponding to specific levels of extracellular calcium—for persistent directional migration over physicochemically different substrates. When these optimal mechanosensitive conditions are met, noticeable enhancement in cell migration directionality and speed is achieved, yet with significant differences among the different substrates. In the same narrow range of calcium concentrations that yields optimal cellular mechanosensory activity, we uncovered an absolute minimum in cell-substratum adhesion activity, for all considered substrates, with differences in adhesion strength among them amplified. The blocking of the mechanosensitive ion channels with gadolinium—i.e., the inhibition of the primary mechanosensory apparatus—hampers the active reduction in substrate adhesion, thereby leading to the same undifferentiated and drastically reduced directed migratory response. The adaptive behavioral responses of Dictyostelium cells sensitive to substrates with varying physicochemical properties suggest the possibility of novel surface analyses based on the mechanobiological ability of mechanosensitive and guidable cells to probe substrates at the nanometer-to-micrometer level.     

中国高等教育经费来源的变化趋势

近十年来,我国高教经费收入总量呈不断上涨趋势,但生均教育经费支出增长缓慢,经费成本分担尚未形成合理的机制。此外,科研经费不足、生均学杂费偏高等问题比较突出。为此,政府不仅要加大科研经费向高校倾斜的力度,进一步减少经费对学杂费收入来源的依赖性,而且更要通过加强民办投资、社会捐赠、校办产业和社会服务等途径来促进高教经费投入的优化。     

Fibroblast proliferation alters cardiac excitation conduction and contraction: a computational study

In this study, the effects of cardiac fibroblast proliferation on cardiac electric excitation conduction and mechanical contraction were investigated using a proposed integrated myocardial-fibroblastic electromechanical model. At the cellular level, models of the human ventricular myocyte and fibroblast were modified to incorporate a model of cardiac mechanical contraction and cooperativity mechanisms. Cellular electromechanical coupling was realized with a calcium buffer. At the tissue level, electrical excitation conduction was coupled to an elastic mechanics model in which the finite difference method (FDM) was used to solve electrical excitation equations, and the finite element method (FEM) was used to solve mechanics equations. The electromechanical properties of the proposed integrated model were investigated in one or two dimensions under normal and ischemic pathological conditions. Fibroblast proliferation slowed wave propagation, induced a conduction block, decreased strains in the fibroblast proliferous tissue, and increased dispersions in depolarization, repolarization, and action potential duration (APD). It also distorted the wave-front, leading to the initiation and maintenance of re-entry, and resulted in a sustained contraction in the proliferous areas. This study demonstrated the important role that fibroblast proliferation plays in modulating cardiac electromechanical behaviour and which should be considered in planning future heart-modeling studies.     

促进大学教师的“卓越教学”:从行为主义走向反思性认可

把大学教学当作法律事务、经济事务或教育事务,其内在机制可视为"刺激—反应"或"控制者—受控者"的行为主义模式。本文以北京大学教师教学发展现状调查为依据,将大学教学置入伦理事务的范畴,经由教师对教学进行"反思性审查"分化出来3种状态——反思性认可、反思性缺失和反思性排斥,结合行为主义动机模式的外部刺激的强弱程度,区分出大学教师6种不同的教学投入状态。大学如果认识到追求认知理性的教师同时也是学者,他们追求伦理维度的反思性认可形成独特的反思性权威并在相互尊重的原则下组成学术共同体,那么大学教学经由教师的反思性审查,可以使其在整体功能上呈现出最卓越的特征。     

用“若飞精神”塑造大学生的灵魂

“一切要为人民打算”是王若飞为人民利益而献身的伟大精神.高校思想政治教育要用“一切要为人民打算”的“若飞精神”塑造大学生科学的世界观、人生观、价值观.引导大学生热爱祖国,回报祖国,回报社会,回报人民,实现中华民族伟大复兴.     

中小企业数字化转型如何提升创新效率？基于经验取样法的调查

在数字技术与实体经济深度融合的背景下,为揭示中小企业数字化转型对创新效率的影响后果、作用机制与作用边界,从组织和个体多层面出发并引入员工忘却学习,对我国261家传统行业中小企业展开连续5个月的经验取样调查,利用DEAP 2.1、SPSS 19.0等统计软件进行实证分析.结果 发现:中小企业数字化转型能够显著强化组织韧性并进一步提升创新效率;同时,员工的忘却学习可以有效推动这一效果的显著提升.故而,建议相关中小企业在数字化转型过程中突破传统管理思维,关注"技术"与"人"之间的平衡,改善组织创新氛围,强化数字化教育培训,使员工从抵制数字化到主动学习数字化技术,以激发企业创新内生动力,并不断挖掘市场潜力,科学数字创新,进而实现企业创立初衰.