基于原子任务构建职业教育“微”教学资源

在我国数字化教学资源建设领域,建设微型教学资源受到了广泛的关注。建设职业教育微型教学资源时,因工作过程知识类别多、情境多样、注重实践等特点,使资源建设存在一定的难度。分析工作任务的关联逻辑,借助工作流技术对工作流程建模,划分最小粒度的原子任务,并通过分析原子任务工作过程知识的要素组织逻辑,设计资源的框架结构,为职业教育＂微＂资源建设提供了更具操作性的方法。     

Initial Deposition of Colloidal Particles on a Rough Nanofiltration Membrane

The initial rate of colloid deposition onto semi‐permeable membranes is largely controlled by the coupled influence of permeation drag and particle‐membrane colloidal interactions. Recent studies show that the particle‐membrane interactions are subject to immense local variations due to the inherent morphological heterogeneity (roughness) of reverse osmosis (RO) and nanofiltration (NF) membranes. This experimental investigation reports the effect of membrane roughness on the initial deposition of polystyrene latex particles on a rough NF membrane during cross flow membrane filtration under different operating pressures and solution chemistries. Atomic force microscopy was used to characterize the roughness of the membrane and observe the structure of particle deposits. At the initial stages of fouling, the AFM images show that more particles preferentially accumulate near the “peaks” than in the “valleys” of the rough NF membrane surface.     

悬浮液进样-火焰原子吸收光谱法测定茶叶中的微量铬

将茶叶悬浮于琼脂胶体中制成悬浮液 ,直接喷入空气 -乙炔火焰 ,用火焰原子吸收光谱法测定茶叶中的微量铬 ,方法简便、快速、灵敏度和精密度高、测定结果与用灰化法处理样品一致 ,检验表明 ,两种样品前处理方法之间无显著性差异。相对标准偏差为 3.4 %～ 6 .1% ,加标回收率为 95 .7%～ 10 3.8 %。     

Films formed from polystyrene latex/clay composites: A fluorescence study

This study reports a steady-state fluorescence (SSF) technique for studying film formation from surfactant-free polystyrene (PS) latex and Na-montmorillonite (SNaM) composites. The composite films were prepared from pyrene (P)-labeled PS particles and SNaM clay at room temperature and annealed at elevated temperatures in 10-min intervals above glass transition temperature (t₃) of polystyrene. During the annealing processes, the transparency of the film improved considerably. Scattered light (I_s) and fluorescence intensity (I_p) from P were measured after each annealing step to monitor the stages of film formation. Evolution of transparency of composite films was monitored by using photon transmission intensity, I_tr. Scanning electron microscopy (SEM) was used to detect the variation in physical structure of annealed composite films. Minimum film formation temperature, T_q, and healing temperatures, T_h, were determined. Void closure and interdiffusion stages were modeled and related activation energies were determined. It was observed that both activation energies increased as the percent of SNaM was increased in composite films.     

地球物理资料非线性反演方法讲座（十一）模拟原子跃迁反演法

模拟原子跃迁反演法源于原子物理学,它模拟了物理学中原子从激发态向基态跃迁的物理过程。模拟原子跃迁反演算法的基本思想是：将地球物理反演理论中的反演目标函数生成目标能级函数,然后通过能级跃迁过程使模拟的系统最终达到系统能级最小值的过程。模拟原子跃迁反演法是利用了地球物理反演问题求解过程与原子中能级跃迁过程的相似性建立的一种新的地球物理反演方法。本讲座概要地介绍了模拟原子跃迁法的基本原理、目标能级化过程、能级跃迁、模型搜索及解的接受准则及模拟原子跃迁法的实现过程,并给出了模拟原子跃迁法对典型测试函数和大地电磁资料反演,最后总结和归纳了模拟原子跃迁法的特点。     

填充玻璃纤维滤膜基钛酸锶钡的手控注射式富集器对水中锌的富集性能

以多孔玻璃纤维滤膜基钛酸锶钡（BBST）为吸附材料,制备了手控注射式富集器;考察了该富集器对水中Zn2＋的吸附富集性能.结果表明：当介质的pH值为3-7时,多孔玻璃纤维滤膜基钛酸锶钡对水中的Zn2＋具有很强吸附能力,其静态吸附容量为24.30 mg/g;制备的富集器可实现对Zn2＋的动态吸附,被吸附的Zn2＋可用2.0%的EDTA溶液动态洗脱回收,其浓集因子可达500.提出了手控注射式钛酸锶钡富集器富集,火焰原子吸收光谱法测定水中痕量Zn2＋的新方法.方法检出限为0.09μg/L.应用于一次蒸馏水和纯净水中痕量Zn2＋的富集,用火焰原子吸收法测定,回收率为93.0%-102.0%.     

非奇异H矩阵的一个判定条件及一类实矩阵逆的无穷范数估计

通过理论证明,给出了判断一个矩阵为H矩阵的实用充分条件及一类实矩阵逆的无穷范数估计公式,并给出数值例子进行了说明.此结果对于判定系统的稳定性、特征值分布、线性方程组迭代解及矩阵范数估计等都具有重要的理论和实际意义.     

生态伦理规范的社会化路径探析

文章探讨生态伦理规范的社会化路径,消除生态危机,再现"天人合一"的伦理境界.     

科技论文的写作规范及顺利发表

为帮助年轻的科研、教学人员提高论文写作水平,以有关国家标准、行业标准为依据,介绍了供期刊发表的科技论文的组成部分,比较详细地阐明了论文各部分的写作要求和写作中应注意的一些问题,并指出怎样才能使论文顺利发表。     

流动注射在线预富集测定环境样品中痕量铅

流动注射在线无过滤沉淀-溶解系统被应用于火焰原子吸收测定环境水样中痕量铅。通过样品溶液和氨溶液的混合已经可以达到痕量铅的在线析出。结果沉淀物无需过滤就被收集在编结反应器的内壁上。引入1mol/L的HNO3溶液来溶解沉淀物并将分析物输送至火焰原子吸收光谱仪(FAAS)进行在线分析。样品载入流速为3.5mol?L-1/m in,富集时间40 s,增强因子37,检测频率60/h。检测限(3σ)为7.5μg/L。50μg/L水平时,精密度(RSD,n=11)为2.9%。采用该方法测定用简单水溶液标准校准后的国家标准材料(GBW 08607,河道水),所得铅浓度0.96±0.04g/g。结果与标准值(1.00±0.02g/g)非常接近。该方法也可以成功应用于多种水样中痕量铅的测定。