基于对象-关系的超媒体数据模型

为了有效地实现多媒体地理信息系统 ( multimediageographic information system,MGIS)数据的存储和管理 ,必须设计有效的数据模型。但现有的几种多媒体数据模型( NF2模型、面向对象模型和超媒体模型等 )尚不能满足MGIS数据管理的要求。为此 ,深入分析了现有几种多媒体数据模型的优缺点及其相互关系 ,提出了一种新的、集现有几种多媒体数据模型优点于一体的多媒体数据组织和管理模型 ,即基于对象关系的超媒体数据模型 ( hyper-mediadata model based on object-relation,O-RHDM) ,论述了 O-RHDM的原理和方法 ,并给出了该模型的规范化描述和操作运算的数学定义。该模型已在海南省多媒体旅游信息系统中得到了初步应用     

Synthesis,one‐ and two‐photon properties of poly[9,10‐bis(3,4‐bis(2‐ethylhexyl‐oxy)phenyl)‐2,6‐anthracenevinylene‐alt‐N‐octyl‐3,6‐/2,7‐carbazolevinylene]

The synthesis, one‐ and two‐photon absorption (TPA) and emission properties of two novel 2,6‐anthracenevinylene‐based copolymers, poly[9,10‐bis(3,4‐bis(2‐ethylhexyloxy)phenyl)‐2,6‐anthracenevinylene‐alt‐N‐octyl‐3,6‐carbazolevinyl‐ene] ( P1 ) and poly[9,10‐bis(3,4‐bis(2‐ethylhexyloxy)phenyl)‐2,6‐anthracenevinyl‐ene‐alt‐N‐octyl‐2,7‐carbazolevinylene] ( P2 ) were reported. The as‐synthesized polymers have the number‐average molecular weights of 1.56 × 10⁴ for P1 and 1.85 × 10⁴ g mol^?1 for P2 and are readily soluble in common organic solvents. They emit strong bluish‐green one‐ and two‐photon excitation fluorescence in dilute toluene solution (? _P1 = 0.85, ? _P2 = 0.78, λ_em( P1 ) = 491 nm, λ_em( P2 ) = 483 nm). The maximal TPA cross‐sections of P1 and P2 measured by the two‐photon‐induced fluorescence method using femtosecond laser pulses in toluene are 840 and 490 GM per repeating unit, respectively, which are obviously larger than that (210 GM) of poly[9,10‐bis‐(3,4‐bis(2‐ethylhexyloxy) phenyl)‐2,6‐anthracenevinylene], indicating that the poly(2,6‐anthracenevinylene) derivatives with large TPA cross‐sections can be obtained by inserting electron‐donating moieties into the polymer backbone. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 463–470, 2010     

现代教育理念下计算机创新实践平台的构建

以布鲁纳的知识结构组织理论和发现学习理论、罗杰斯的非指导学习理论、约翰逊的合作学习模式等现代教育理念为依据,结合大学生的认知特点,构建了以提高学生的元认知能力为特色的计算机创新实验平台,通过调查表明该创新实验平台不但有利于学生提高理论和实践水平,而且学生的元认知能力也有了较大的提高.     

一种基于“流”的复合系统协调管理模型

对可用于复合系统协调管理建模的方法作了分析，并以区域经济，资源，环境协调发展问题为背景，探讨了一种基于“流”的复合系统协调管理模型的建模及协调控制方法，并就一简单的经济－资源－环境复合系统，建立了基于“流”的协调管理模型。     

软件组合复用方式的思辩

提出了组合复用方式的两种实方法：即配即用方式和基于用户图形界面的组装台式，并探讨了组装方式的优点和局限性。     

柴黄颗粒的红外指纹图谱研究

分别采用相似度、聚类分析法和基于主成分分析的投影判别法对柴黄颗粒红外图谱的一致性进行了考察,结果显示30个柴黄颗粒样本的红外图谱一致性良好,采用平均值法建立了柴黄颗粒的红外指纹图谱。     

Combined use of cyclofructans and an amino acid ester‐based ionic liquid for the enantioseparation of huperzine A and coumarin derivatives in CE

Cyclofructans (CFs) and their derivatives have recently been proven to be efficient chiral selectors (CSs) for the enantioseparation of several analytes in CE, HPLC, and GC. In this study, the chiral separation ability of a number of native and derivatized CFs was examined in CE. Particularly, six different CFs, with different derivatization groups and cavity sizes [native CF‐6 and CF‐7, isopropyl cyclofructan‐6 (IPCF‐6), IPCF‐7, sulfated cyclofructan‐6 (SCF‐6), and SCF‐7] were used as CSs for the enantioseparation of huperzine A, warfarin, and coumachlor. Almost all of the examined CFs, except from SCF‐6 & ‐7, demonstrated relatively low and sometimes no chiral separation ability for huperzine A. In an effort to improve both resolution and efficiency, the chiral ionic liquid D‐Alanine tert butyl ester lactate (D‐AlaC₄Lac) was added into the BGE. In most of the cases, the combination of CF with D‐AlaC₄Lac resulted in an improvement in peak efficiency and/or resolution. When CF‐6 was utilized with D‐AlaC₄Lac, a resolution of 1.4 was obtained, while the use of IPCF‐6/D‐AlaC₄Lac provided a baseline enantioseparation. Although the combination of SCF‐7 and 40 mM D‐AlaC₄Lac did not affect resolution, it dramatically increased peak efficiency from 24 000 to 117 000. In the case of warfarin and coumachlor, IPCF‐6 and IPCF‐7 proved to be the most effective CSs. It is, therefore, concluded that the size of the cavity and the CF derivatization are the key parameters for the chiral separation capability. It is also clear from this study that D‐AlaC₄Lac is necessary for improved peak efficiencies and resolutions.     

Study of Electrochemical Non-enzyme Glucose Sensor Based on Cu(Ⅱ)Co(Ⅱ) Bimetallic Carbon Nanosheets北大核心CSCD

CuCo-MOF nanofibers are synthesized by one-step solvent blending process at room temperature. Then CuCo-MOF nanofibers are used as the precursors,carbon nanosheets（Cu（Ⅱ）Co（Ⅱ）@C）uniformly loaded with nano-sized copper oxide and cobalt oxide are obtained by calcination at high temperature in air. Cu（Ⅱ）Co（Ⅱ）@C is modified on the glassy carbon electrode to directly catalyze glucose in alkaline solution. Because CuO and CoO are uniformly and firmly embedded on the carbon nanosheets,the agglomeration of catalyst is prevented,which greatly improves the specific surface area,and increases the catalytic active site. Meanwhile,due to the synergistic effect of copper and cobalt bimetals in the carbon nanosheet material,the enzyme free glucose sensor has excellent electrical conductivity and excellent catalytic performance. The detection range of the non-enzymatic electrochemical glucose sensors for glucose is 0. 03 µμmol/L~13. 6 mmol/L, the detection limit is 0. 01 µμmol/L（S/N=3）,and the sensitivity is 10. 56 mA·L/（cm2·mmol）. In addition, the non-enzyme sensor also has good anti-interference and high stability. © 2022, Science Press (China). All rights reserved.     

基于案例分析的建筑垃圾资源化处理研究

建筑垃圾资源化处理是建筑垃圾减量化的重要途径,我国建筑垃圾资源化利用项目在建设和运营过程中逐渐暴露出许多的问题及风险。为解决这些问题,本文以案例分析的方式,利用系统动力学方法,对2个建筑垃圾资源化利用失败项目进行研究,从管理和政府政策的角度对项目利益相关者及宏观层面的深层次原因进行了分析。发现我国建筑垃圾资源化处理主要面临的四大问题,即建筑垃圾资源化立法少、处理标准低、政策的强制性弱和销售渠道窄等。对应这四大问题,提出具体的建议措施,指出在总体经济增长和技术进步的同时,政府政策对行业发展发挥着重要的作用,以期为更多的建筑垃圾资源化项目提供借鉴和参考。     

基于DMFC的上肢外骨骼人—机协调控制系统

上肢外骨骼人—机协调控制系统中的一个关键问题是直角坐标系中的力信号转换成联合坐标系中力矩,该过程中奇点几乎一直存在。为了解决这个问题,提出了一种基于动态模型力控制器(dynamic model of force control, DMFC)的控制系统。利用阻尼最小二乘法处理负载,转矩补偿负载质量,避免了奇异性。在外骨骼的末端执行器处安装力传感器用于测量外骨骼和负载之间的力,通过相互作用力自动反映使用者的运动意图。实验结果表明,提出的控制系统具有非常好的稳定性和可负载性,当施加负载补偿时,不附加任何物体与附加5公斤对象的外骨骼末端执行器位置之间的稳态误差可减小至0.01 以下,完全满足起吊重物的上肢外骨骼需求。