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961.
Two dynamic grey models DGM (1, 1) for the verification cycle and the lifecycle of measuring instrument based on time sequence and frequency sequence were set up, according to the statistical feature of examination data and weighting method. By a specific case, i. e. vernier caliper, it is proved that the fit precision and forecast precision of the models are much higher, the cycles are obviously different under different working conditions, and the forecast result of the frequency sequence model is better than that of the time sequence model. Combining dynamic grey model and auto-manufacturing case the controlling and information subsystems of verification cycle and the lifecycle based on information integration, multi-sensor controlling and management controlling were given. The models can be used in production process to help enterprise reduce error, cost and flaw. Foundation item: Project (70272032) supported by the National Natural Science Foundation of China  相似文献   
962.
The solution chemical and optical characteristics of formation of amine-terminated polyamidoamine dendrimer G2.0(NH2-PAMAM G2.0)-Au nanocomposites in the aqueous solution of NH2-PAMAM G2.0 at various mole ratios of Au(III) to NH2-PAMAM G2.0 were studied by both UV-visible spectrometry and fluorospectrometry. The NH2-PAMAM G2.0-Au nanocomposites, with a type of structure in which one Au nanoparticle is surrounded by several NH2-PAMAM G2.0 dendrimers, emit strong bluish violet fluorescence, and are uniform, water soluble and biocompatible as well as very stable in frozen conditions. The size of gold nanoparticles in the nanocomposites is about 2.5 nm and decreases with the increase of NH2-PAMAM G2.0 concentration. The NH2-PAMAM G2. 0 plays an important role in acting as host or micro-reactor for Au(III) before Au(III) reduction and acting as dispersant and stabilizer for gold nanoparticles after Au(III) reduction. Preliminary experiments of cells staining to human embryonic lung fibroblast cell lines show that the NH2-PAMAM G2.0-Au nanocomposites can be used as optical imaging markers for bioanalyses and medical diagnoses.  相似文献   
963.
The p-type (Bi0.15Sb0.85)2Te3 and PbTe are typical thermoelectric materials used for low and middle temperature range and functional graded materials (FGM) is an inevitable way to widen the working temperature range. Here two segments graded thermoelectric materials (GTM) consisting of (Bi0.15Sb0.85)2Te3, PbTe and different barriers were fabricated by the common hot pressure method. Metals Fe, Mg and Ni were used as barriers between the two segments. The diffusion of different barriers between the barriers and bases were analyzed by electron microprobe analysis (EMA). The phase and crystal structures were determined by X-ray diffraction analysis (XRD). The thermoelectric properties were measured at 303 K along the direction parallel to the pressing direction. The results show that the compositional diffusion occurs when there is no barrier at the interface of the two segments, and the diffusion of Pb is most obvious; as the barrier material, the diffusion of metals Fe, Mg and Ni between different bases is not very obvious, and the thermoelectric properties of GTM is much better than that of the original segment.  相似文献   
964.
合成了N-双取代亚甲基磷酸壳聚糖,并且对其进行了表征。通过戊二醛交联的方法将N- 双取代亚甲基磷酸壳聚糖固定在壳聚糖薄膜表面。对接枝前后膜表面的结构性能和血液相容性进行表征,结果显示N -双取代亚甲基磷酸壳聚糖被有效地固定在壳聚糖膜表面,并且能够有效地抑制血小板在壳聚糖膜表面的粘附。  相似文献   
965.
云南省拥有丰富的褐煤资源,用作燃料使用会造成很大浪费,并严重污染环境。阐述了以褐煤资源为原料制备铁合金用褐煤成型半焦的工艺,研究了粘结剂腐植酸钠的制备方法及半焦成型工艺,得出当腐植酸钠配入质量分数为8%~10%时,褐煤型焦具有理想的性质,可满足铁合金厂的使用要求。  相似文献   
966.
超临界流体具有粘度低,密度大,较好的流动、传质、传热和溶解性等特性。超临界流体对状态参数的改变十分敏感,温度和压力较小的变化就会使流体的性质发生较大的改变。超临界流体可作为热敏性物质分离纯化方法及产品分析和测定手段,本文主要介绍超临界流体在纳米材料制备中的应用。  相似文献   
967.
CeO2-ZrO2mixed oxides have a number of i mpor-tant catalytic applications[1].They are extensively em-ployed in current automotive three-way catalysts(TWCs)as the oxygen storage promoters,i.e.materi-als that regulate the oxygen partial pressure throughtheC…  相似文献   
968.
分析了国内外热轧板带的板形检测技术及几种板形检测方法的发展应用状况,并就热轧板带产 品的发展及要求展望了未来板形检测的发展方向。  相似文献   
969.
Risk Concession Model for Build/Operate/Transfer Contract Projects   总被引:1,自引:0,他引:1  
This paper extends the build–operate–transfer (BOT) concession model (BOTCcM) to establishing a risk concession model for BOT contract projects. The decision for a concession period is one of the most important decisions in determining a BOT contract. BOTCcM presents an alternative method to assist in determining a concession period that can protect the basic interests of both the investor and the government concerned. However, there is a major limitation in using the model, namely it gives no consideration to the impacts of risks on the estimation of various economic variables in the model. This study considers the risk impacts to the BOTCcM model and presents an additional risk concession model. This model provides an approach for formulating a concession period to consider the impacts of risks and, at the same time, protect the basic interests of both the investor and the government concerned. A hypothetical case is used to show the procedures of formulating the risk concession period through the assistance of the Monte Carlo simulation method.  相似文献   
970.
Project delays due to late availabilities of resource and information (RI) prerequisites are one of the major threats to construction management. It is desirable to avoid such delays through better means of constraint management. With most contemporary planning methodologies and tools, it is generally difficult to represent many hidden flow constraints in a construction work plan. However, evaluating the impact of flow constraints is crucial in determining their criticalities, based on which the flow constraints may be prioritized and consequently resolved to minimize project delays. Due to the fact that limited resources are often shared among various trades, it may not be practical to resolve all the constraints simultaneously so that a tradeoff is inevitable, which suggests that management should focus on the most important ones termed as key constraints (i.e., those directly contributing to project delays). This paper presents a methodology that augments the traditional critical path method with RI availability constraints to analyze the causes of delays and locate the key constraints binding on project completion without ambiguity based on the principles of the theory of constraints. The methodology of key constraint analysis has been implemented with the integrated production scheduler, a constraint-based scheduling tool which facilitates the modeling, analysis, and management of constraints at the production planning level. An illustrative example is depicted to demonstrate how the proposed methodology works.  相似文献   
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