一种微型空调器的优化设计

介绍了一种微型空调器的研制背景及设计方案 ,采用仿真优化的设计手段对空调器的制冷、制热系统进行了优化设计 ,实践证明其设计是成功的。同时说明了该型空调器所具有的特点及应用场合     

Upward and downward heat and mass transfer with miniature periodically operating loop thermosyphons

Upward and downward two-phase heat and mass transfer has been considered in the present paper. The heat and mass transfer with the condenser located below the evaporator has been obtained by inserting an accumulator tank in the liquid line of a loop thermosyphon and enforcing a pressure pulsation. In previous papers these heat transfer devices have been called pulsated two phase thermosyphons (PTPT). A mini PTPT has been experimentally investigated. It has shown a stable periodic heat transfer regime weakly influenced by the position of the condenser with respect to the evaporator. In contrast a classical loop mini thermosyphon (diameter of connecting pipes 4 mm) did not achieve a stable functioning for the investigated level differences between evaporator and condenser lower than 0.37 m. The present study shows that the functioning of a PTPT device does not directly depend on the level difference or the presence of noncondensable gas. In order to obtain a natural circulation in mini or micro loops, a periodically operating heat transfer regime should therefore be considered.     

基于Fabry-Perot腔阵列的集成化微型光谱仪方案及模拟

提出了一种微型光谱仪,该微型光谱仪基于法布里-珀罗腔滤波性的阵列式微型光谱仪。其基本结构是在硅基底上实现多个不同腔长的阵列,从而实现对多个波长的监测。探测单元即为一个法布里-珀罗腔,由硅基底-金属薄膜-二氧化硅层-金属薄膜构成。进行了相应的模拟计算,结果表明在基本结构为铝膜(14 nm)-SiO₂-银膜(39 nm)的情况下,通带半宽度可达到15 nm,单个探测单元面积仅为0.14 mm×0.14 mm即可达到微型光栅式光谱仪(最小体积在cm量级)的光通量,整个光谱探测部分体积仅在mm量级。该微型光谱仪设计尺寸在几个mm的量级、无活动部件,可以同时对多个波长进行检测,并可望利用现有IC加工手段实现光谱仪传感器化。     

电喷雾/光电离双源型小型离子阱质谱仪的研制

构建了一套电喷雾/紫外灯双电离源离子阱质谱仪系统,用于气体和液体样品的快速检测.仪器采用非连续大气压进样技术,通过夹管阀装置来同时完成电喷雾离子和中性气态样品的采集和传输.所配备的两种电离源适合不同的分析对象,在应用上具有一定的互补性,其中电喷雾源用于溶液中极性化合物的电离,而紫外电离源主要用于分析气态有机物.本研究选择了苯甲醚、甲苯、2,4-二甲基苯胺、精氨酸、利血平和阿斯巴甜等不同类型的样品,测试了仪器在使用不同电离模式下的工作性能.结果表明,电喷雾源和紫外光电离源可用于不同类型样品的电离,在分析2,4-二甲基苯胺时还能分别生成不同类型的分子离子.两种电离源在工作时互不干扰,既能单独使用,也能同时开启,可根据检测需求随意切换工作模式,获得更全面的样品成分信息.双离子源设计是扩展小型质谱仪应用范围的一种有效途径,这种方案不会明显增加仪器的体积,却能提供更多样化的分析功能,满足对不同类型样品的检测需求.     

Biochip fluorescence detection system with spatial and spectral separation

A novel optical arrangement for fluorescence detection that employs spatial separation as well as spectral filter to increase the signal to noise ratio is proposed. Using a prism and two mirrors, the elliptical laser beam of a laser diode, as an excitation light, is homogenized and the transmitted excitation light is separated from the fluorescence not to reach the collecting optics. Uncooled CCD can capture the fluorescence image of up to 40 fluorescently-labeled protein patterns without scanning or mechanical translation. This paper presents the simulation, construction and measurement results of the developed optical system. The measurements show that the combination of prism and mirrors converts the excitation light from the laser diode to uniform illumination on the specimen, and provides the separation between excitation and fluorescence light to give high signal to noise ratio. It is also possible to assay various protein concentrations ranging from 1000 to 10 ng/ml reliably. We believe that the proposed fluorescence detection system can be used to build a commercially valuable, low cost, hand-held or miniature fast detection device for point-of-care applications.     

Immobilization of trypsin on miniature incandescent bulbs for infrared-assisted proteolysis

A novel efficient proteolysis approach was developed based on trypsin-immobilized miniature incandescent bulbs and infrared (IR) radiation. Trypsin was covalently immobilized in the chitosan coating on the outer surface of miniature incandescent bulbs with the aid of glutaraldehyde. When an illuminated enzyme-immobilized bulb was immersed in protein solution, the emitted IR radiation could trigger and accelerate heterogeneous protein digestion. The feasibility and performance of the novel proteolysis approach were demonstrated by the digestion of hemoglobin (HEM), cytochrome c (Cyt-c), lysozyme (LYS), and ovalbumin (OVA) and the digestion time was significantly reduced to 5 min. The obtained digests were identified by MALDI-TOF-MS with the sequence coverages of 91%, 77%, 80%, and 52% for HEM, Cyt-c, LYS, and OVA (200 ng μL⁻¹ each), respectively. The suitability of the prepared bulb bioreactors to complex proteins was demonstrated by digesting human serum.     

A miniature and field-applicable multipumping flow analyzer for ammonium monitoring in seawater with fluorescence detection

In this article, a simple, economic, and miniature flow analyzer for ammonium in seawater based on the solenoid micropumps is presented. A single reagent of sodium tetraborate, ortho-phthaldialdehyde (OPA), and sodium sulfite was used and optimized applying the modified SIMPLEX method. A special-made detection cell for fluorescence detection of the reaction product isoindol-1-sulfonat was made and combined with a commercial photomultiplier tube, a long-pass optical filter, and an UV-LED as excitation light source. A LOD down to 13 nmol/L was achieved. The fabrication and application of a miniature reaction coil heating device for reaction rate enhancement is further described. The system featured an injection frequency of 32 h⁻¹ at average standard deviation of 3%.     

Direct identification of prohibited substances in cosmetics and foodstuffs using ambient ionization on a miniature mass spectrometry system

Significantly simplified work flows were developed for rapid analysis of various types of cosmetic and foodstuff samples by employing a miniature mass spectrometry system and ambient ionization methods. A desktop Mini 12 ion trap mass spectrometer was coupled with paper spray ionization, extraction spray ionization and slug-flow microextraction for direct analysis of Sudan Reds, parabens, antibiotics, steroids, bisphenol and plasticizer from raw samples with complex matrices. Limits of detection as low as 5 μg/kg were obtained for target analytes. On-line derivatization was also implemented for analysis of steroid in cosmetics. The developed methods provide potential analytical possibility for outside-the-lab screening of cosmetics and foodstuff products for the presence of illegal substances.     

基于平板波导的小型红外光栅光谱仪光学设计

为实现红外光谱仪器的小型化,通过分析现有小型光谱仪,提出了一种基于平板波导的小型红外光栅光谱仪的设计方法。平板波导光谱仪的小型化原理与一般的微小型光谱仪不同。在平板波导光谱仪中,光束被限制在一层薄薄的平板波导介质中传播,看起来像是整个光学系统被压扁了。在垂直于平板波导的方向上光学元件的尺寸可以做到很小,从而显著减小光学系统的尺寸。该系统的设计可分为Czerny-Turner结构设计、波导结构设计。先根据像差理论设计Czerny-Turner结构,目标是保证光谱分辨率及校正像差;然后根据几何光学理论设计波导结构,包括平板波导和两个柱面透镜,目标是压缩光束并校正像散;最后将它们输入Zemax软件中进行综合优化,以获得最优的光学系统。据此方法设计了一个平板波导红外光栅光谱仪,工作波段为8~12 μm,数值孔径为0.22,采用线阵探测器。通过Zemax软件对结果进行分析和评价,表明仪器光学系统的尺寸为130 mm×125 mm×20 mm,工作波段内光谱分辨率达到80 nm,满足设计指标要求。证明了该优化设计方法是可行的,所得系统尺寸小、性能高。