Field synergy analysis of different flow patterns in falling-film dehumidification system with horizontal pipes

Effects of the flow pattern of intertubular liquid film on mass and heat transfer synergies in a falling-film dehumidification system with horizontal pipes are studied.A flow model of the dehumidifying solution between horizontal pipes is established using Fluent software,the rule of transitions of the flow pattern between pipes is studied,critical Reynolds numbers of flow pattern transitions are obtained,and the accuracy of the model is verified by experiments.The mass transfer synergy angle and heat transfer synergy angle are respectively used as evaluation criteria for the mass transfer synergy and heat transfer synergy,and distribution laws of the synergy angles for droplet,droplet columnar and curtain flow patterns are obtained.Simulation results show that the mass transfer synergy angles corresponding to droplet,droplet columnar and curtain flow patterns all rise to a plateau with time.The mean mass-transfer synergy angle is 98°for the droplet flow pattern,higher than 96.5°for the droplet columnar flow pattern and 95°for the curtain flow pattern.The results show that the mass transfer synergy of the droplet flow pattern is better than that of the droplet columnar flow pattern and that of the curtain flow pattern.

The study of the shape anisotropy in patterned permalloy films

In this paper a systematic ferromagnetic resonance study shows that an in-plane magnetic anisotropy in the patterned micron octagon permalloy （Ni80Fe20） elements is mainly determined by the element geometry. The easy-axis is along the edge of the elements, and the hard-axis is along the diagonal. The shape anisotropy of the octagon elements is determined by square and equilateral octagon, and the theoretical calculation was studied on the shape anisotropy. The shape anisotropy of rectangular was calculated by using the same theory.

Demagnetizing factors in patterned CoNiFe films with rectangular elements

CoNiFe patterned films with rectangular elements, all 600-nm wide but of different lengths, were fabricated and inves- tigated by ferromagnetic resonance experiment and micromagnetic simulation. An in-plane magnetic uniaxial anisotropy was exhibited, and its value increases with the increase of the aspect ratio of the elements, which was fitted by the model, including a quasi-ellipsoid demagnetizing field and a non-uniform demagnetizing field. The relative importance of the non- uniform demagnetizing field decreased from 0.26 to 0.16 with the increase of the length-width aspect ratio of the patterned element from 1.5 to 10. The demagnetizing factors in the three principal axes were determined from the experimental data of ferromagnetic resonance, which agreed reasonably well with the values calculated by micromagnetic simulation. The calculation also indicated that the interaction between elements could be neglected when the edge-to-edge spacing between neighboring elements was larger than 3 μm in our patterned films.

Formation mechanism of ordered stress-relief patterns in a free sustained Cu film system

A nearly free sustained copper （Cu） film system has been successfully fabricated by thermal evaporation deposition of Cu atoms on silicone oil surfaces, and a characteristic ordered pattern has been systematically studied. The ordered pattern, namely, band, is composed of a large number of parallel key-formed domains with different width w but nearly uniform length L; its characteristic values of w and L are very susceptible to the growth period, deposition rate and nominal film thickness. The formation mechanism of the ordered patterns is well explained in terms of the relaxation of the internal stress in the films, which is related to the nearly zero adhesion of the solid-liquid interface. By using a two-time deposition method, it is confirmed that the ordered patterns really form in the vacuum chamber.

DEFORMATION MEASUREMENT OF CON-DUCTING POLYTHIOPHENE THIN FILMS BY AN ELECTRONIC SPECKLE PATTERN INTERFEROMETRIC METHOD

The deformation measurement of electrosynthesized polythiophene(Pth) thin films is difficult because of the small thickness and highflexibility of the specimen. An electronic speckle patterninterferom- etry (ESPI) method is used to measure the deformation ofPth films of thicknesses in the range of 4-65 μm . Theirstress-strain curves are obtained. It is found that the mechanicalproperties of Pth films are sensitive to the specimen thickness. Thetensile strength increases with decreasing thickness of thin filmfrom 10 μm. The influence of the electrochemical synthesisconditions on the mechanical properties of Pth films is also dis-Cussed.

水平管降膜换热器性能规律研究进展

水平管降膜换热器具有热质传递效率高、阻力小、结构简单等优点,被广泛应用于化工等传统领域及能源利用的节能减排领域。降膜换热器内部发生复杂的流动及传热传质相互耦合过程。介绍了实验及模拟研究手段的进展,综述了不同操作参数(气体温度、流向及流量,溶液流量、温度及浓度,内部媒介流量及温度等)与结构参数(管径、管间距等)对水平管降膜管间流型、液膜厚度与润湿性等流动特性的影响规律,以及对蒸发传热特性、吸收传热传质特性等换热器性能的影响规律,包括整体性能和局部微细特征,为水平管降膜换热器的性能优化提供理论支撑。指出在不同气流特征以及多因素相互作用下多维度的局部流动与传热传质性能的耦合影响规律以及强化换热手段会是水平管降膜换热器未来研究的重点方向。

Preparation and Optical Patterning of Organic-Inorganic Hybrid Color-Filter Films Using Latent Pigments by Utilizing Photo-Acid-Generator and Microwave Irradiation

Preparation and photo-patterning characteristics of organic-inorganic hybrid thin film containing latent pigment by using photo-acid-generator (PAG) and microwave irradiation have been investigated. The acrylic thin film modified with methoxysilane containing PAG was formed on a glass substrate and irradiated with ultraviolet rays to promote sol-gel reaction by catalytic action of acid which was generated from PAG. And then the film was hardened with microwave irradiation, yielding organic-inorganic hybrid polymer film having hardness, highly transparency and strong adhesion with a glass substrate. Since this reaction only occurred in the optically (UV) irradiated regions, by exploiting the difference between the adhesivenesses of these regions photo-irradiated through photomask with a glass substrate, it was possible to form a patterned film with pitch of 100 to 50 μm by a simple lift-off method. A pigment-containing film using latent pigments (with subtractive three primary colors of coloring materials) and a patterned film were prepared, and it was possible to make these films multi-colored by varying the mixing ratio of the pigments. This multi-colored film-preparation method is effective for simply and efficiently forming a color-filter film by applying optical and microwave irradiation.

卫星展开机构用热刀切割器大气失效机理分析

目的分析图案化电阻Pt薄膜在大气环境下使用寿命下降的原因。方法基于此,选取现有型号热刀切割器图案化电阻薄膜,制备不同厚度Pt/Ti膜,重点考察大气环境下薄膜表界面形貌、成分、晶体结构随温度的变化规律及其对电阻率特性以及力学性能影响。结果大气高温下,Ti过渡层从底层扩散至表面与Pt形成合金,部分Ti扩散至表面被氧化,合金化与氧化导致薄膜电阻率先升高后降低。同时,充当Pt薄膜与基底之间“黏合剂”的Ti过渡层扩散耗尽,导致Pt薄膜与氮化硅基底结合力降低。结论以上因素最终导致了图案化薄膜热刀大气高温环境下切割寿命下降。

特发性脊柱侧弯患者步行生物力学特征:三维运动捕捉的横断面分析

背景:脊柱侧弯的生物力学分析病例数量有限,仅限于对脊柱或下肢独立进行生物力学分析,缺乏对人体多维度整体的评估,难以反映躯干与下肢在日常活动中的运动关系,不利于综合指导临床治疗。目的:通过测量脊柱侧弯患者在步行活动中的脊柱运动学,研究脊柱不同节段及下肢运动学/动力学在步态活动中的关系,以全方位多层次评估脊柱侧弯患者与正常人群在生物力学的差异,为临床防治脊柱侧弯提供循证依据。方法:此研究为一项横断面研究,于2020年7月至2021年6月,在福州大学城、福建中医药大学附属康复医院纳入脊柱侧弯患者28例及同年龄段正常人28例。采用三维运动捕捉系统以100 Hz的采样频率捕捉步态的运动学数据,2块测力台(AMTI 400600,采样频率1500 Hz)嵌于长10 m(数据采集有效长度为4 m),宽2.4 m平地走道采集动力学数据。比较两组受试者执行平地步行时步态时空参数,运动学及动力学参数的差异。所有受试者在纳入后立即接受全脊柱X射线片测量比较两组差异。结果与结论:(1)脊柱侧弯患者肩胛带-躯干相对旋转活动度、胸廓-骨盆相对旋转活动度较正常组小(P<0.05),骨盆旋转活动度相较正常组大(P<0.05)。(2)脊柱侧弯患者髋、膝关节屈伸活动度,髋关节凹凸侧屈伸峰力矩、地反力凸侧内外向峰值较正常组小(P<0.05)。(3)脊柱侧弯患者的膝关节屈伸活动度非对称性指数、肩胛带-躯干相对旋转活动度非对称性指数、胸廓-骨盆相对旋转活动度非对称性指数较正常组大(P<0.05)。(4)上述结果证实,脊柱侧弯患者在平地行走时肩胛带-胸廓-骨盆之间僵硬的运动模式,髋膝关节屈伸活动度减少,髋关节双侧屈伸力矩峰值及地反力凸侧内外向峰值降低。这些特征可以作为康复评估及治疗方案制定的依据。

加热器ITO膜层图案刻蚀对改变热量分布的研究

为了控制加热器的加热均匀性,改变加热器表面的热量分布,提出一种基于ITO膜层图案刻蚀的加热器设计与加工方法。首先结合理论计算设计初步图案,用图案刻蚀的方法加工样品进行测试,找到ITO膜层图案刻蚀与热量分布的规律;然后结合具体项目设计一种可以满足产品要求的ITO膜层图案,制作加热器样品并测试热量分布;最后将相关数据进行整理与总结,为ITO膜层图案设计及加热器制作提供一种可行性方案。

条带宽度对NiFe薄膜磁性能的影响

采用电子束蒸发法和光刻技术在5×5 mm^(2)的Si衬底上制备了长度为5 mm、条带间距固定为30μm、条带宽度为20~140μm的Ni_(80)Fe_(20)软磁薄膜,分析了条带宽度对薄膜静态及动态磁性能的影响。结果表明,薄膜的面内矫顽力和各向异性场随着条带宽度的增大而减小,各向异性场从235 Oe减小到131 Oe。薄膜的共振频率f_(r)从连续薄膜的0.75 GHz增高到条带宽度为20μm时的2.81 GHz,起始磁导率大于350,制备了兼具较高磁导率和高共振频率的NiFe薄膜。

干膜显影悬浮液产生原因分析

显影是印制电路板(PCB)线路图形制作的重要工序,显影液中滞留的干膜悬浮物极易造成产品线路短路缺陷并报废,造成生产成本上升。通过设计对比实验,对干膜显影悬浮液产生的原因进行了分析和探讨,有效降低短路不良率,以期为同行解决类似问题提供一定参考。

基于卫星遥感的卫片执法防灾减灾信息系统

近年来,卫片执法复核补报、信访维稳等重点工作对顺利开展卫片执法工作具有十分重要的推动作用。目前下发的卫片并未对疑似违法图斑进行详细描述,对图斑的人工排查也需要耗费大量时间,无法实现快速及时的发现并处理问题,亟需采用信息化手段破解执法难题。基于此研究利用卫星遥感、测绘、地理信息、云平台、大数据、互联网等技术建设卫片执法防灾减灾信息系统,达到天上看、网上查、地上管、远程指挥的管理体系,将极大促进自然资源节约集约利用和有效保护。

光交联聚乙烯醇/银纳米线复合透明导电薄膜的稳定性研究

通过简单的溶液工艺将水溶性光交联聚乙烯醇-苯乙烯基吡啶盐(SbQ-PVA)溶液涂敷至银纳米线(AgNWs)薄膜上形成SbQ-PVA/AgNWs复合薄膜,分析了不同面密度的AgNWs薄膜在涂敷SbQ-PVA前后的光电性能和形貌,对比了AgNWs裸膜和SbQ-PVA/AgNWs复合薄膜的机械和环境稳定性。结果表明,SbQ-PVA涂层不影响银纳米线网络的导电性,还能起到减小光散射和减反增透的作用,复合薄膜方阻低至约20Ω/sq时,也具有约90%的高透过率。同时,相比于AgNWs薄膜,SbQ-PVA/AgNWs复合薄膜具有更优异的稳定性,其对外部刺激(5000次弯曲、3B铅笔刮擦、空气老化、酸碱盐溶液腐蚀)的抵抗力显著提升。此外,SbQ-PVA/AgNWs复合薄膜能够在去离子水超声处理中保持稳定,利用此特点配合光掩模进一步实现了银纳米线薄膜的图案化。

Measuring and modeling two-dimensional irrigation infiltration under film-mulched furrows

Furrow irrigation with film-mulched agricultural beds is being promoted in the arid region of northwest China because it improves water utilization. Two-dimensional infiltration patterns under film-mulched furrows can provide guidelines and criteria for irrigation design and operation. Our objective was to investigate soil water dynamics during ponding irrigation infiltration of mulched furrows in a cross-sectional ridge-furrow configuration, using laboratory experiments and mathematical simulations. Six experimental treatments, with two soil types （silt loam and sandy loam）, were investigated to monitor the wetting patterns and soil water distribution in a cuboid soil chamber. Irrigation of mulched furrows clearly increased water lateral infiltration on ridge shoulders and ridges, due to enhancement of capillary driving force. Increases to both initial soil water content （SWC） and irrigation water level resulted in increased wetted soil volume. Empirical regression equations accurately estimated the wetted lateral distance （Rl） and downward distance （Rd） with elapsed time in a variably wetted soil medium. Optimization of model parameters followed by the Inverse approach resulted in satisfactory agreement between observed and predicted cumulative infiltration and SWC. On the basis of model calibration, HYDRUS-2D model can accurately simulate two-dimensional soil water dynamics under irrigation of mulched furrows. There were significant differences in wetting patterns between unmulched and mulched furrow irrigation using HYDRUS-2D simulation. The Rd under the mulched furrows was 32.14% less than the unmulched furrows. Therefore, film-mulched furrows are recommended in a furrow irrigation system.

Thin liquid film morphology driven by electro-static field

The development of stationary patterns on a thin polymer surface subject to an electric field is studied by means of the hexagonal-planform weakly nonlinear stability analysis and numerical simulations. The time evolution of the interface between the air and the polymer film on the unbounded spatial domain is described by a thin film equation, incorporating the electric driving force and the surface diffusion.The nonlinear interfacial growth includes the amplitude equations and superposition of one-dimensional structures at regular orientations. The pattern selection is driven by the subcritical instability mechanism in which the relative thickness of the polymer film plays a critical role.

Nonlinear analysis of photo-induced wrinkling of glassy twist nematic films on compliant substrates

A kinetics approach is developed for the geometrically nonlinear analysis of photo-induced wrinkling of glassy twist nematic films on soft elastic substrates.In this way,the problem is reduced to finding the steady state of an overdamped evolution system according to a kinetic law,rather than directly solving the coupled nonlinear equations.This enables one to account for the complicated director distribution and obtain the precise wrinkling morphology of the film.Though the approach proposed here is for a twist nematic film,it can be extended to study glassy nematic films with other director distributions.

Preparation and Properties of Copper Fine Wire on Polyimide Film in Air by Laser Irradiation and Mixed-Copper-Complex Solution Containing Glyoxylic Acid Copper Complex and Methylamine Copper Complex

Formation of copper wiring on a polyimide film by laser irradiation to a stable copper-complex film consisting of glyoxylic acid copper complex and methylamine copper complex in air has been investigated. A stable metallic copper on the polyimide film was precipitated even in air. Since this copper was generated only in the laser-irradiated parts, direct patterning of copper wiring was possible. It was also found that copper was precipitated by electroless copper plating on the laser-deposited copper wiring and it was possible to thicken the copper wiring by this precipitation. The resistivity of the copper wiring was almost the same as that of the bulk of metallic copper. The developed method—combining laser irradiation to a copper-complex-coated film and electroless copper plating—enables the high-speed deposition of fine copper wiring on a polyimide film in air by a printing process, indicating an inexpensive and useful process for fabricating copper wiring without high vacuum facility and heat-treatment under inert gas.

Machining characteristics of complex prism pattern on electroplated roll by copper

The BLU (back light unit) is the core component of the LCD for notebook, mobile-phone, navigation, as well as large sized TV, PID (public information display), etc. In order to enhance optical efficiency of LCD, optical films with the uniform prism patterns have been used for BLU by stacking two films up orthogonally. In this case, light interference-phenomenon occurred such as Morie, wet-out, u-turning, etc. It caused several problems such as low brightness, spots and stripes in LCD. Recently, the high-luminance micro complex prism patterns are actively studied to avoid the light interference-phenomenon and enhance the optical efficiency. In this study, the roll master to manufacture complex micro prism pattern film was machined by using the high precision lathe. The machined patterns on the roll master were 50, 45, 40, 35, 30, 25, 20, 15, 10 and 5 μm in the pitch with 25.0, 22.5, 20.0, 17.5, 15.0, 12.5, 10.0, 7.5, 5.0 and 2.5 μm in the peak height, respectively. The roll was 2 000 mm in length and 320 mm in diameter. The electroplated roll by copper and the natural single crystal diamond tool was used for machining the patterns. The cutting force was measured and analyzed for each cutting condition by using the dynamometer. The chips and the surfaces after being machined were analyzed by SEM and microscope.

Patterning Technology of Ferrite and Insulating Material in a Single Layer of the Multilayer Ceramic Device

Patterning technology of ferrite and insulating material in multilayer ceramic devices is proposed. In the conventional technology, the different ceramic materials such as the ferrite and the insulating material have been prepared in the form of the each different green sheet, and then they have been stacked each other. Otherwise the different material has filled cavities that were formed by a mechanical punching in advanced. In our proposing technology, arbitrary patterning of the different ceramic material inside the same green sheet is possible. In this process, the arbitrary shape of the through pattern is formed in the green sheet of the base material by making use of photo resist films as sacrifice patterns, and then the base material is masked by the patterned photo resist film. After filling the slurry of the different material into the through pattern of the base material passing the resist mask, the pattern of the different ceramic material in the green sheet is achieved. In the present paper, the ferrite magnetic material and the alumina-glass composite material are used. The patterned structure inside the green sheet is obtained. The slurry preparation, the thickness of the mask resist film, and the obtained structure of the green sheet are discussed.