动力学控制合成原子精确的银纳米团簇及催化还原4-硝基苯酚

Synthesizing atomically precise Ag nanoclusters (NCs), which is essential for the general development of NCs, is quite challenging. In this study, we report the synthesis of high-purity atomically precise Ag NCs via a kinetically controlled strategy. The Ag NCs were prepared using a mild reducing agent via a one-pot method. The as-prepared Ag NCs were confirmed to be Ag₄₉(D-pen)₂₄ (D-pen: D-penicillamine) on the basis of their matrix-assisted laser desorption ionization time-of-flight mass spectrometric and thermogravimetric characteristics. The interfacial structures of the Ag NCs were illustrated by proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy. The Ag NCs were supported on activated carbon (AC) to form Ag NCs/AC, which displayed excellent activity for the catalytic reduction of 4-nitrophenol with a kinetic reaction rate constant k of 0.21 min?1. Such a high k value indicates that the composite could outperform several previously reported catalysts. Moreover, the catalytic activity of Ag NCs/AC remained nearly constant after six times of recycle, which suggests its excellent stability.     

中关村引领我国战略性新兴产业发展的战略思考

立足中关村国家自主创新示范区创新与产业优势,从中关村抢占战略性新兴产业制高点的战略价值出发,探讨了中关村引领我国战略性新兴产业发展的战略着力点。     

带有非线性测量方程的跟踪系统的仿真研究

探讨了具有非线性测量方程的跟踪系统的计算机仿真方法。给出了一类常见的跟踪系统的数学模型和仿真模型。并以一个实例说明了该仿真方法的可行性。     

神经网络PID控制

以工业ＰＩＤ控制中控制器参数调整困难为背景，在分析神经网络特性的基础上，提出神经网络控制方法，设计了具有自适应性的神经网络ＰＩＤ控制器，在描述了神经网络的学习机理的基础上，给出了控制器控制算法。通过２个实例验证了神经网络在线控制的可行性。     

Low-frequency damping behavior of closed-cell Mg alloy foams reinforced with SiC particles

The damping properties of an Mg alloy foam and its composite foams were investigated using a dynamic mechanical thermal analyzer. The results show that the loss factors of both the Mg alloy and its composite foams are insensitive to temperature and loading frequency when the temperature is less than a critical temperature T_crit. However, it increases when the temperature exceeds the T_crit values, which are 200 and 250℃ for the Mg alloy foam and the Mg alloy/SiC_p composite foams, respectively. The Mg alloy/SiC_p composite foams exhibit a higher damping capacity than the Mg alloy foam when the temperature is below 200℃. By contrast, the Mg alloy foam exhibits a better damping capacity when the temperature exceeds 250℃. The variation in the damping capacity is attributed to differences in the internal friction sources, such as the characteristics of the matrix material, abundant interfaces, and interfacial slipping caused by SiC particles, as well as to macrodefects in the Mg alloy and its composite foams.     

浅析室内装饰设计的创新思考

在室内装饰设计中,创新设计一直是设计师不遗余力追求的目标.创新设计是设计师的立足之本与核心竞争力,也是室内装饰企业和行业实现可持续发展的必经之路.本文阐述了室内装饰设计与设计创新概念、分析必要性以及如何进行室内设计创新.     

剡江流域地下水与地表水联合调度模型

以宁波剡江流域为例，建立了地下水与地表水联合调度模型，给出了联合调度的优化方案，并与其单独开发进行了对比，结果表明，联合调度是提高主流域水资源利用率的有效途径。     

软件开发过程的开发图描述

提出一种开发图工具用来将程序开发过程形式化，描述开发中涉及的各种与不同方式相关的单元集，从而解决对开发过程的分析个性和管理问题。并用ＵＭＩＸ下的ＬＥＸ作为例子说明了这种工具的使用。     

简化Ostrovsky方程的周期尖波解

用微分方程动力系统理论研究了简化Ostrovsky方程的周期尖波解.在一些参数条件下画出了该方程平面系统的相图,根据相图找到了周期尖波的存在条件,求出了周期尖波的解.在特定的参数条件下用数学软件Maple得到了周期尖波的平面模拟图.