Autonomous microfluidic system for phosphate detection

Miniaturization of analytical devices through the advent of microfluidics and micro total analysis systems is an important step forward for applications such as medical diagnostics and environmental monitoring. The development of field-deployable instruments requires that the entire system, including all necessary peripheral components, be miniaturized and packaged in a portable device. A sensor for long-term monitoring of phosphate levels has been developed that incorporates sampling, reagent and waste storage, detection, and wireless communication into a complete, miniaturized system. The device employs a low-power detection and communication system, so the entire instrument can operate autonomously for 7 days on a single rechargeable, 12 V battery. In addition, integration of a wireless communication device allows the instrument to be controlled and results to be downloaded remotely. This autonomous system has a limit of detection of 0.3 mg/L and a linear dynamic range between 0 and 20 mg/L.     

溶胀性能自动检测仪的研制

应用应力传感及计算机技术，研制了网状高分子溶胀性能自动检测仪。该仪灵敏度和精度高，准确性好，可用于研究高分子综合溶胀行为，测定平衡压缩模量，溶胀动力学过程，松弛动力学过程等。     

Comparison of two-typed (3-mercaptopropyl)trimethoxysilane-based networks on Au substrates

Two-typed (3-mercaptopropyl)trimethoxysilane-based networks which had been used to fabricate biosensors were prepared on Au substrates by two methods: layer-by-layer assembly, and the combination of sol-gel and self-assembly process. The formation mechanism and their surface properties, as well as stabilities were examined by cyclic voltammetry, electrochemical impedance spectroscopy, and X-ray photoelectron spectroscopy. It was found that the precursors formed bilayers with the thickness of ca. 1.8 nm on Au by layer-by-layer assembly only with SH on the uppermost surface. The sol-gel and self-assembly processed multilayers with the thickness of ca. 6.8 nm and abundant SH all over the network provided a rigid and stable network. Therefore, the coupling of sol-gel and self-assembly process provided a faster, simpler and more effective method to fabricate more rigid and stable networks; in this case, the local aqueous microenvironment as in biological media could preserve the native stabilities and reactivities of biological macromolecules better, which was expected to guarantee the high biological activity and stability of biosensors.     

引入模拟辅助样本提高BP网络的泛化能力

以2－吲哚醇在20种不同参数固定液上的保留值、19种不同物质在同一固定液上的保留值以及脂肪胺的电谱保留值分别作为网络的训练样本和检验样本，建立了多元线性回归（LR）模型和BP网络模型，并基于LR模型运用随机搜索最优化方法，产生模拟辅助样本并将其引入BP网络训练样本集。预测结果表明，该方法的使用提高了BP网络的泛化能力，对于残缺样本问题的预测研究，提供了一种有效的方法，与线性回归模型及原BP网络模型相比，预测精度有了明显的改善。     

IONIC CONDUCTIVITY IN CROSSLINKED POLY (METHYLSILOXANE-g-ETHYLENE OXIDE) NETWORK FILMS CONTAINING LITHIUM PERCHLORATE

Polymer electrolytes based on poly (methylsiloxane-g-ethylene oxide) and LiClO_4 have been prepared. The network films crosslinked by a crosslinking agent are found to exhibit a considerably high ionic conductivity of about 10~(-4) Scm~(-1) at room temperature and have good flexibility.     

Oxidation of methanol at the network film of polyoxometallate-linked ruthenium-stabilized platinum nanoparticles

We explore here the ability of ruthenium hydroxo species to undergo spontaneous deposition on Pt nanoparticles and to form colloidal solutions of oxoruthenium-protected (-stabilized) nanoparticles of Pt. These particles can be spontaneously attracted to carbon substrates, and they form ultrathin self-assembled films. Fabrication of the multilayer network films on electrodes has been achieved by linking the positively charged oxoruthenium-covered Pt clusters with heteropolyanions of tungsten. By repeated alternate treatments in a solution of phosphododecatungstate (PW₁₂O₄₀^3–) and in a colloidal suspension of oxoruthenium-protected (-stabilized) Pt nanoparticles, the film thickness can be increased systematically (layer by layer) to form stable three-dimensional assemblies on carbon electrodes. It is apparent from cyclic voltammetric and chronoamperometric measurements (that were performed at 20 and 60 °C) that the resulting hybrid films show attractive properties towards the oxidation of methanol at fairly low potentials (0.25–0.4 V versus the saturated calomel electrode). With approximately the same loading of oxoruthenium-covered Pt nanoparticles and under analogous conditions, linking or derivatizing the nanoparticles with phosphotungstate leads to the systems higher electrocatalytic activity. It is possible that, in addition to ruthenium hydroxo species, PW₁₂O₄₀^3– exhibits an activating effect on dispersed Pt particles. An alternative explanation may involve the possibility of different morphologies of the catalytic films in the presence and absence of phosphotungstate anions.Dedicated to Zbigniew Galus on the occation of his 70th birthday     

"高分子化学"网络课件的研制

本课件应用Photoshop8.0处理图片、制作按钮;用Front page2003编辑为静态网页;用Dream weaver MX2004建立链接所需的空白网页。教案采用Power point,其中化学反应方程式采用Chemical word,聚合反应机理采用3DWAX制成三维动画。在界面的设计方面,考虑到了整体布局和用户操作上的方便;在网页中图片使用、颜色搭配得当,版面设计合理,实现了形式与内容的统一。“高分子化学”课程具有化学反应方程式多且冗长、聚合反应机理抽象难以理解等特点。将该课程制成网络课件,以便提高教学质量,达到更好的教学效果。     

A network penalty method

We consider the minimum cost network flow problem and describe how the non-linear penalty function methods of Conn and Bartels can be specialized to a combinatorial algorithm for this problem. We report on preliminary computational results which show that this method can require fewer pivots than the simplex method while the amount of work required for each pivot is comparable. The algorithm can be proven finite using a modification of Cunningham's strongly feasible basis pivoting rule.Supported by the Natural Sciences and Engineering Research Council of Canada, and the joint research project Combinatorial Optimization of the Natural Sciences and Engineering Research Council, Canada and the German Research Association (Deutsche Forschungsgemeinschaft, SFB 303).     

Modelling the effects of interconnection between electricity markets subject to uncertainty

Interconnecting distinct electricity markets by adding a new transmission line affects the outcomes in these markets in a complicated way when there is uncertainty in demand or participant behaviour. We use market distribution functions to examine the effects of interconnection using a single transmission line under the assumption that this line has a differentiable loss function and agents in each of the interconnected markets do not change their behaviour in response to the interconnection. We also show how the case with capacity constraints on flows can be represented with appropriately formulated loss functions. We give analytical formulae for computing market outcomes when the uncertain events in the markets being connected are statistically independent, and show by example how to compute these outcomes when these events are correlated.     

有向网络中具有一个枢纽点的最小支撑树的计算方法

对有向网络中具有一个枢纽点的支撑树的问题和性质进行了研究,给出了在有向网络图中寻找以某一定点为枢纽点的最小支撑树的计算方法,并对算法的复杂性进行了讨论,最后将该算法应用于实际算例的计算．