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981.
根据一套10kw级微型分布式冷热电联产系统(采用燃气内燃机发电,地板辐射采暖,吸附制冷机提供空调制冷)在冬夏两季实验研究获得的数据,从热力学第一及第二定律角度,进行热力学分析,与传统的冷、热、电分产系统进行比较,并对不同评价标准得出的结果展开了进一步的探讨。分析揭示了冷热电联产系统高效节能的原因,得出的相关结论为实验系统的改进以及未来实际应用系统的设计,提供了理论依据. 相似文献
982.
微惯性仪表技术的研究与发展 总被引:6,自引:0,他引:6
论述了当前国内外微惯性仪表设计和制造技术的研究与发展,强调了对相关基础理论研究的重要性,提出了计算机集成微制造单元的概念。 相似文献
983.
基于光压原理的微堆积制造技术 总被引:2,自引:0,他引:2
使用光力和光压来引导微粒进行输运并在确定空间位置进行排列和堆积,可以构造二维或者三维的微结构,成为一种新的制造技术,其中也包括了激光引导直写技术。这是将直写技术和快速原型制造技术相结合而取得的最新进展.文章介绍了利用光压来引导材料进行微制造的基本原理和研究进展,阐述了其中的关键技术和应用前景。 相似文献
984.
Elahe Kazemi Ali Mohammad Haji Shabani Shayessteh Dadfarnia Amir Abbasi Mohammad Reza Rashidian Vaziri Abbas Behjat 《Analytica chimica acta》2016
This study aims at developing a novel, sensitive, fast, simple and convenient method for separation and preconcentration of trace amounts of fluoxetine before its spectrophotometric determination. The method is based on combination of magnetic mixed hemimicelles solid phase extraction and dispersive micro solid phase extraction using 1-hexadecyl-3-methylimidazolium bromide coated magnetic graphene as a sorbent. The magnetic graphene was synthesized by a simple coprecipitation method and characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The retained analyte was eluted using a 100 μL mixture of methanol/acetic acid (9:1) and converted into fluoxetine-β-cyclodextrin inclusion complex. The analyte was then quantified by fiber optic linear array spectrophotometry as well as mode-mismatched thermal lens spectroscopy (TLS). The factors affecting the separation, preconcentration and determination of fluoxetine were investigated and optimized. With a 50 mL sample and under optimized conditions using the spectrophotometry technique, the method exhibited a linear dynamic range of 0.4–60.0 μg L−1, a detection limit of 0.21 μg L−1, an enrichment factor of 167, and a relative standard deviation of 2.1% and 3.8% (n = 6) at 60 μg L−1 level of fluoxetine for intra- and inter-day analyses, respectively. However, with thermal lens spectrometry and a sample volume of 10 mL, the method exhibited a linear dynamic range of 0.05–300 μg L−1, a detection limit of 0.016 μg L−1 and a relative standard deviation of 3.8% and 5.6% (n = 6) at 60 μg L−1 level of fluoxetine for intra- and inter-day analyses, respectively. The method was successfully applied to determine fluoxetine in pharmaceutical formulation, human urine and environmental water samples. 相似文献
985.
Our Expedition in Linear Neutral Platinum‐Acetylide Complexes: The Preparation of Micro/nanostructure Materials,Complicated Topologies,and Dye‐Sensitized Solar Cells 下载免费PDF全文
During the past few decades, the construction of various kinds of platinum‐acetylide complexes has attracted considerable attention, because of their wide applications in photovoltaic cells, non‐linear optics, and bio‐imaging materials. Among these platinum‐acetylide complexes, the linear neutral platinum‐acetylide complexes, due to their attractive properties, such as well‐defined linear geometry, synthetic accessibility, and intriguing photoproperties, have emerged as a rising star in this field. In this personal account, we will discuss how we entered the field of linear neutral platinum‐acetylide chemistry and what we found in this field. The preparation of various types of linear neutral platinum‐acetylide complexes and their applications in the areas of micro/nanostructure materials, complicated topologies, and dye‐sensitized solar cells will be summarized in this account. 相似文献
986.
数字全息是用数字的方式记录和处理全息图像,避免了传统全息照相的化学处理,既简化了处理过程,更便于用数字图像处理的方式来改进图像质量和提取信息。数字全息干涉计量技术是一种全场、非接触的光学测量方法,该方法测量精度高,光路简单,对防振要求低,实验条件容易满足,特别适合微小物体的微小位移或变形的精确测量。本文运用数字全息干涉计量法测定了两端固支梁的微小离面位移;经实验验证数字全息计量术能精确测量物体0.01微米量级位移或变形;而且该方法可靠性好、成本低;是非接触的无损测量。数字全息计量技术的这些特点使得该技术在小物体的微小变形测量上具有特别的优越性,因而在MEMS结构及MEMS材料参数(如弹性模量、泊松比、热变形系数等)的测定中有广阔的应用前景。 相似文献
987.
0Introduction Hingesareafundamentalelementforbuildingmechanicaldevices,appearingwheneverarotation aroundapointisneeded.Differentkindsofhingescanworkwellformillionsofcyclesinthemacro world.Howeverinthemicro world,smallsizedrealhingesorbearingsdonotlastlong… 相似文献
988.
Multi-scale dual-phase cyclic plasticity with quantitative transitions and size effects of layered structures 总被引:1,自引:0,他引:1
A method is developed for cyclic elastoplastic analysis across micro/meso/macro scales which is effective for the quantitative
transition of physical variables and for evaluating the size effects of microstructures. By using the improved self-consistent
scheme proposed by Fan[1] and carrying out a delicate mesoscopic analysis based on a shear-lag model, the size effects including the thickness of hard
and soft layers relative to the inclusion dimension are obtained on the overall elastoplastic responses of materials up to
50 cycles. The dominant characteristics of the analysis are that the characteristic dimensions of a microstructure such as
the thickness of the layers and the inclusion dimension can be explicitly incorporated into the formulation. Results of numerical
analysis using only 4 plastic constants show that the thicker the layer relative to the inclusion size, the softer the material
in producing more plastic strain values for a given applied stress amplitude. This is in agreement with the well-known experimental
rule that the yield strength of layered structures is inversely proportional to the square root of the spacing between layers.
It is found that ratcheting depends very much on the size of the layered-structure and that the thinner the relative thickness
of the layer the less the ratcheting displacement. This finding may be used to explain why phenomenological models on ratcheting
are not quite successful so far, indicating the significance of across scale analysis in understanding issues which have existed
for a long time. 相似文献
989.
A simple micro‐extraction plate assay for automated LC‐MS/MS analysis of human serum 25‐hydroxyvitamin D levels 下载免费PDF全文
Timon Geib Florian Meier Pascal Schorr Frank Lammert Caroline S. Stokes Dietrich A. Volmer 《Journal of mass spectrometry : JMS》2015,50(1):275-279
This short application note describes a simple and automated assay for determination of 25‐hydroxyvitamin D (25(OH)D) levels in very small volumes of human serum. It utilizes commercial 96‐well micro‐extraction plates with commercial 25(OH)D isotope calibration and quality control kits. Separation was achieved using a pentafluorophenyl liquid chromatography column followed by multiple reaction monitoring‐based quantification on an electrospray triple quadrupole mass spectrometer. Emphasis was placed on providing a simple assay that can be rapidly established in non‐specialized laboratories within days, without the need for laborious and time consuming sample preparation steps, advanced calibration or data acquisition routines. The analytical figures of merit obtained from this assay compared well to established assays. To demonstrate the applicability, the assay was applied to analysis of serum samples from patients with chronic liver diseases and compared to results from a routine clinical immunoassay. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
990.
Combined atom‐transfer radical polymerization and ring‐opening polymerization to design polymer–polypeptide copolymer conjugates toward self‐aggregated hybrid micro/nanospheres for dye encapsulation 下载免费PDF全文