Experimental Study on the Microscale Weissenberg Effect for Pumping Appliations

基于电液耦合原理的静电纺丝直写可按需喷印多种材料，实现高精度图案化沉积，被认为是一种极具潜力的微纳增材制造技术。现有的静电纺丝供液存在时滞长、压阻幅度大等问题，无法满足电纺直写的连续、稳定、响应快速的液体输运需求，制约了其在微纳制造领域的应用与发展。因此，本文以电纺直写供液为目标，展开了对微尺度包轴效应、微纳流体包轴输运以及强电场作用下的包轴效应的研究，探索了基于液体包轴输运的电纺直写技术在微纳制造、柔性电子领域中的应用。为此，围绕这几个关键问题开展了如下研究工作： 搭建包轴效应供液装置，实现了针芯高精度对中装配，获取针芯振幅小于10μm稳定旋转运动，达到直写的供液要求。从实验和理论研究宏—...Electrohydrodynamic direct writing can be used for high precision patterned deposition of a variety of materials, therefore it is considered as a technology with great potential for micro/nano additive manufacturing. As is well-known, there are some problems in solution supplying of concentional electrospinning technology, such as the big time lag and great fluid flow resistance. So it can’t be re...学位：工学博士院系专业：航空航天学院_精密仪器及机械学号：1992012015388

滴灌与沟灌马铃薯覆膜效应研究

田间对照试验研究薄膜覆盖对滴灌土壤水分分布与消散过程及滴灌和沟灌马铃薯生长的影响结果表明 ,马铃薯生长前期覆膜能明显减少表层土壤蒸发 ,并使表层土壤维持较高的含水量。马铃薯生长中后期蒸腾作用占主导地位 ,覆膜对减少表层土壤蒸发作用较小。气温较高时覆膜对马铃薯生长产生明显抑制作

滴灌调控土壤水分对马铃薯生长的影响

研究了滴灌灌溉频率和土壤水势对马铃薯生长和水分利用效率的影响。研究结果表明,滴灌灌溉频率和土壤水势对土壤水分的分布有很大影响,灌水频率越低,灌水前的表层土壤干燥的范围越大,灌水后的土壤湿润范围越大;控制滴头下面20cm处土壤水势明显影响到50cm深度以上的土壤水势,20cm深度处土壤水势越高,50cm深度范围内的平均土壤水势越高;土壤表面土壤水势越低,以滴头为中心形成的干燥范围越大。当土壤基质势低于-45kPa时,马铃薯的块茎膨大率会迅速下降,总产量、商品薯产量和水分利用效率高低顺序为:-25kPa>-3国家杰出青年科学(40125002);国家自然科学(40071020

Rotatory Multiple Needles Electrospinning Based on Weissenberg Effect

文中研究了用静电纺丝法批量制备纳米纤维的方法。基于韦森堡效应的原理,圆盘的旋转使溶液沿转轴爬升,从而为静电纺丝连续供液,由此设计了一种装置。纺丝头是由固定在圆盘上的针尖阵列组成的。圆盘的旋转使针尖蘸取爬升的溶液,在针尖和收集板间高电压的作用下制备出直径较小（200~800 nm）、比较均一的整齐的纤维。随着针数量和圆盘转速的增加,纤维的产率呈增加的趋势,产率可达3.3 g/h。纤维直径随着溶液浓度的增加而增加,但会随着圆盘转速以及电极至收集板之间的距离的增加而减小。A new technique to generate nanofibers in batches using electrospinning is studied in this paper. The rotation of the rod enables the solution to climb to realize the continuous supply of the solution. A device for eleetrospinning is designed based on the Weissenberg effect. The electrospinning head is composed of the circular needle arrays attached to the disc. The needles dip the polymer solution supplied by reciprocating ro- tation of the disc. Thin and uniform nanofibers and ordered fibers with small diameters （200 - 800 nm） can be obtained under high voltage between needles and the collecting board. The production rate of nanofibers in- creases gradually with the increase of the number of needles and the rotation speed of the disc. The productivi- ty can be as high as 3.3 g/h. The fiber diameter increases with the increase of solution concentration, but de- creases with the decrease of the rotation speed of the disc and the distance between the electrode and the col- lecting board.国家自然科学基金资助项目（51475398,U1505243

Direct mass measurements of neutron-rich ~(86)Kr projectile fragments and the persistence of neutron magic number N=32 in Sc isotopes

<span style="color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; font-size: 13px; line-height: 22px; background-color: rgb(248, 248, 248);">In this paper, we present direct mass measurements of neutron-rich Kr-86 projectile fragments conducted at the HIRFL-CSR facility in Lanzhou by employing the Isochronous Mass Spectrometry (IMS) method. The new mass excesses of 52-54SC nuclides are determined to be -40492(82), -38928(114), -34654(540) keV, which show a significant increase of binding energy compared to the reported ones in the Atomic Mass Evaluation 2012 (AME12). In particular, Sc-53 and Sc-64 are more bound by 0.8 MeV and 1.0 MeV, respectively. The behavior of the two neutron separation energy with neutron numbers indicates a strong sub-shell closure at neutron number N=32 in Sc isotopes.</span