综合集成研讨厅的几个示例

顺应于国际系统反思的浪潮,以钱学森为首的我国系统科学家于1990年正式提出了从定性到定量综合集成方法论用以处理以往还原论所无法解决的开放复杂巨系统问题.1992年钱学森又继而提出了综合集成研讨厅的概念(简称为HWMSE)作为该方法论的实践平台,其中特别强调利用信息技术的优势.此后,不断有HWMSE的研制来体现综合集成方法论的功力,同样也引来质疑.通过3个未自称为HWMSE的示例,包括国外实验室反恐系统、笔者提出的“在线会场”及众所周知的搜索引擎,对每一个示例阐明了其中含有的构成研讨厅的专家体系、机器体系与知识体系的内容及在该研讨厅中正在进行的综合集成复杂问题求解的活动.期望以此扩展对HWMSE功能的理解,促进HWMSE的推广和综合集成方法论的实践.     

The molecular composition of non-modified and acac-modified propoxide and butoxide precursors of zirconium and hafnium dioxides

Long-term storage at 0 °C of a paraffin-sealed flask with commercial 70 wt% solution of zirconium n-propoxide in n-propanol resulted in crystallization of an individual oxoalkoxide complex Zr₄O(OⁿPr)₁₄(ⁿPrOH)₂ in over 20% yield. The structure of this molecule can be described as a triangular Zr₃(μ₃-O)(OR)₁₀(ROH) core of 3 edge-sharing octahedrons with an additional Zr(OR)₄(ROH) unit attached through a pair of (μ-OR) bridges. Mass spectrometric and ¹H NMR investigation of the commercial samples of the most broadly applied zirconium and hafnium n-propoxides and n-butoxides indicate the presence of analogous species in the commercial alkoxide precursors. The content of oxo-alkoxide species in the commercial precursors has been estimated to be ~20% for n-propoxide and ~35% for zirconium n-butoxide. A new route has been presented for synthesis of the individual crystalline mixed ligand precursor [Zr(OⁿPr)(OⁱPr)₃(ⁱPrOH)]₂, from zirconium n-propoxide. A high yield has been observed (~90%), indicative of an almost complete precursor transformation. Mass spectrometry has shown that the synthesized mixed ligand precursor is dimeric, which makes it an attractive alternative to zirconium n-propoxide. Addition of 1 eq of Acetylacetone to zirconium or hafnium alkoxide precursors results in formation of dimeric [M(OR)₃(acac)]₂ in high yields. These species have limited stability (much higher for Hf than for Zr) and transform in solution into hydrolysis-insensitive M(acac)₄ through very unstable M(acac)₃(OR) intermediates containing 7-coordinated metal centers. This transformation can be followed kinetically in hydrocarbon solvents by ¹H NMR and is noticeably accelerated by addition of parent alcohols. The obtained results clearly reveal limited applicability of EXAFS and XANES techniques for the study of such systems, especially in the context of structure prediction. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

离子反应中几个问题的质疑

对离子反应的概念、离子反应的实质、离子方程式表示的意义及离子方程式的书写步骤产生质疑,指出这些问题并纠正。     

基于元素观的专题式复习教学法在高职有机化学教学中的应用

采用专题式复习教学法对高职有机化学进行教学。教学过程设计主要分为专题问题、专题导读、专题讨论、专题总结、专题升华等5个步骤。结果显示效果良好,并能使学生建立化学观念,有效提高学生的化学素养。     

概念转变理论的发展及面临的挑战

经过30年的发展,经典概念转变理论的内涵已发生了变化。通过对概念转变理论发展历程的分析,总结了概念转变研究的视角、研究的共识和研究的争议,指出当前概念转变研究面临3方面的挑战:寻找概念转变有效证据的研究方法;如何将成功的概念转变策略引入课堂教学实践;要进一步明确"概念转变"的含义。     

发展高中生有机物化学性质核心概念理解的研究——“卤代烃”教学案例

在"卤代烃"的教学中,基于探查学生的迷思概念,采用在教师引导下进行实验探究的策略,发展高中生有机物化学性质核心概念的理解能力。主要介绍教学内容分析、核心概念分析、学生情况分析、教学目标、教学过程和教学效果评价等。     

试论化学核心素养的结构

化学核心素养包含了“化学”的素养、“核心”的素养、“人”的素养三重意蕴。基于对化学核心素养的概念分析和层次分析,提出其四维度结构模型。在4个维度中,“化学基本观念”是基础维度,“化学过程”和“化学在生活中的应用”是2个活化维度,“对化学的态度”是动力维度。化学核心素养为学术性化学素养和生活性化学素养的发展同时奠定了基础。把握3种化学素养在结构和具体维度上的差异有助于理解化学核心素养的内涵,也有助于把握中学化学课程中不同模块的教学定位。     

施工扰动状态下软土力学指标的确定

基于扰动状态概念理论, 提出了统一扰动函数, 并结合宁波轨道交通1号线和2号线的十字板剪切试验资料, 预测了扰动状态下的软土工程指标(如地基承载力、压缩模量等), 研究结果可为宁波软土工程勘察设计中受扰动的软土物理力学参数的取值提供指导.     

Lanthanoid Antimonides Ln2Sb5 (Ln = Sm,Gd, Tb,Dy) and Rationalization of Chemical Bonding within the Antimony Polyanion by Combining the Zintl‐Klemm Concept with Bond‐Length Bond‐Strength Relationships

The title compounds are formed by peritectic reactions. Single crystals could be isolated from samples with high antimony content. Their structure was determined for Dy₂Sb₅ from four‐circle X‐ray diffractometer data: P2₁/m, a = 1306.6(1) pm, b = 416.27(4) pm, c = 1458.4(1) pm, β = 102.213(8)°, Z = 4, R = 0.061 for 2980 structure factors and 86 variable parameters. All dysprosium atoms have nine antimony neighbors forming tricapped trigonal prisms with Dy–Sb distances varying between 308 and 338 pm. The antimony atoms occupy ten different sites with greatly varying coordination. One extreme case is an antimony atom surrounded only by dysprosium atoms in trigonal prismatic arrangement, the other one is an antimony atom in distorted octahedral antimony coordination. The various antimony‐antimony interactions (with Sb–Sb distances varying between 284 and 338 pm) are rationalized by combining the Zintl‐Klemm concept with bond‐length bond‐strength considerations.     

概念格的规则约简与属性特征

在研究了概念格形成的偏序结构的基础上，引进了由两个形式背景形成的决策形式背景，讨论了外延集类上等价关系和交一致关系，给出了决策形式背景下规则提取与属性约简方法．同时对于在规则约简中起不同作用的属性，区分了核心（存在于任何约简中）、相对必要属性（存在于某些约简中）和不必要属性（不存在于任何约简中），给出了各类属性的特征和判别方法．这些方法为概念格规则提取的启发式算法打下了基础．