检索结果-南通市图书馆

Large-area straight,regular periodic surface structures produced on fused silica by the interference of two femtosecond laser beams through cylindrical lens

在线全文

学校读者我要写书评

暂无评论

Opto-Electronic Advances 2021年第12期4卷 34-42页

作者： Long Chen Kaiqiang Cao Yanli Li Jukun Liu Shian Zhang donghai Feng Zhenrong sun Tianqing Jia State Key Laboratory of Precision Spectroscopy School of Physics and Electronic ScienceEast China Normal UniversityShanghai 200062China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China.

Inhomogeneity and low efficiency are two important factors that limit the application of laser-induced periodic surface structures(LIPSSs),especially on glass *** this study,two-beam interference(TBI)of femtosecond lasers was used to produce large-area straight LIPSSs on fused silica using cylindrical *** with those produced us-ing a single circular or cylindrical lens,the LIPSSs produced by TBI are much straighter and more *** on the laser fluence and scanning velocity,LIPSSs with grating-like or spaced LIPSSs are produced on the fused silica *** structural colors are blue,green,and red,and only green and red,***-like LIPSS patterns oriented in different directions are obtained and exhibit bright and vivid colors,indicating potential applications in surface coloring and anti-counterfeiting logos.

关键词： laser-induced periodic surface structures two-beam interference structural coloring fused silica cylindrical lens

在线全文

学校读者我要写书评

暂无评论

提高纤维素酶水解效率和降低水解成本

化学进展 2007年第7期19卷 1147-1152页

作者：苏东海孙君社北京电子科技职业学院北京100029 中国农业大学食品科学与营养工程学院北京100083

在我国可大量转化乙醇的是纤维质材料。纤维质材料转化乙醇的关键问题是纤维质转化为糖的过程,提高纤维素酶转化效率的方法有:(1)对纤维质材料进行预处理;(2)研究纤维素酶的最适作用条件;(3)纤维素酶的重复利用;(4)合理的发酵工艺等。... 详细信息

在我国可大量转化乙醇的是纤维质材料。纤维质材料转化乙醇的关键问题是纤维质转化为糖的过程,提高纤维素酶转化效率的方法有:(1)对纤维质材料进行预处理;(2)研究纤维素酶的最适作用条件;(3)纤维素酶的重复利用;(4)合理的发酵工艺等。本文分析了纤维素的结构以及纤维素酶的作用方式,总结了目前研究较多的几种纤维质材料预处理方法,及其对纤维素酶水解率的影响,并对研究纤维素酶的最适作用条件、纤维素酶的重复利用以及合理的发酵工艺进行了综述和分析。

关键词：纤维素酶木质纤维素水解效率乙醇

2D-to-3D buckling transformability enabled reconfigurable metamaterials for tunable chirality and focusing effect

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2023年第10期11卷 1770-1780页

作者： donghai HAN WENKANG LI TAO sun MIN LIU XIAOMING CHEN HONGYU SHI ZHENGJIE FAN FANQI MENG LIUYANG ZHANG XUEFENG CHEN State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710049China School of Information and Communications Engineering Xi’an Jiaotong UniversityXi’an 710049China Physikalisches Institut Goethe-Universität60438 Frankfurt am MainGermany

Recently,multifarious deformation approaches in nature have promoted dynamic manipulation for electromagnetic(EM)waves in metamaterials,and those representative strategies are mainly focused on the modulation of spectral *** works have also achieved tunable phase-gradient ***,to broaden the modulation freedom of mechanical deformation,we initially propose two reconfigurable metamaterials consisting of mirrored S-shaped meta-atoms selectively bonded on biaxially pre-stretched *** meta-atoms with spin-insensitive transmittance are buckled into 3D morphologies to break residual symmetries by releasing the stress and to facilitate spin-dependent transmittance under circularly polarized *** to the geometric anisotropy of S-shaped meta-atoms along the x and y axes,3D chiral meta-atoms exhibit discriminate circularly cross-polarized transmittance under opposite *** underlying physical mechanism reveals that EM resonance originates from the excitation of electric dipoles and magnetic dipoles,and their cross coupling finally triggers the chiral effects of 3D *** introducing the gradient-phase design that keeps unchanged under various strains,two types of meta-atoms with specified orientations are interleaved to design a double-foci metalens,and its 2D-to-3D morphology transformation shortens the focusing length and facilitates the intensity change of two *** approach in designing reconfigurable EM metamaterials with 2D-to-3D buckling transformability can be further extended toward terahertz even optical wavebands,and it may assist with deriving more applicable multi-functionalities in the aspects of imaging,sensing,and holograms.

关键词： buckling polarized circular

In-chamber thermocatalytic tar cracking and syngas reforming using char-supported NiO catalyst in an updraft biomass gasifier

在线全文

学校读者我要写书评

暂无评论

International Journal of Agricultural and Biological Engineering 2014年第6期7卷 91-97页

作者： Arthur M.James R Wenqiao Yuan Michael D.Boyette donghai Wang Ajay Kumar Department of Biological and Agricultural Engineering North Carolina State UniversityRaleighNC 27695-7625USA Department of Biological and Agricultural Engineering Kansas State UniversityManhattanKS 66506-2906USA Department of Biosystems and Agricultural Engineering Oklahoma State UniversityStillwaterOK74078-6016USA

The objective of this study was to evaluate the performance of an in-chamber tar cracking and syngas reforming *** unit was composed of a two-stage tubular reactor placed within the combustion zone of an updraft biomass *** generated in the exothermic combustion reactions of biomass gasification drove tar cracking and syngas reforming in the tubes,eliminating the need of external *** performance of the unit was evaluated using char-supported NiO catalysts and was found to be very effective in tar removal and syngas composition enhancement.A tar removal rate of 95% was achieved at 0.3 s residence time and 10%nickel *** condition also gave syngas high-heating value increment of 36%(to 7.3 MJ/m^(3)).The effect of gas residence time and Ni loading on tar removal and syngas composition of the unit was also *** residence of 0.2-0.3 s and Ni loading of 5%-10% were found appropriate to produce clean syngas with tar content appropriate for industrial applications(<0.6 g/m^(3))in an updraft biomass gasifier without external heating.

关键词： biomass gasification tar cracking syngas reforming nickel catalyst char catalyst

Extremely regular periodic surface structures in a large area efficiently induced on silicon by temporally shaped femtosecond laser

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2021年第5期9卷 839-847页

作者： YUCHAN ZHANG QILIN JIANG KAIQIANG CAO TIANQI CHEN KE CHENG SHIAN ZHANG donghai FENG TIANQING JIA ZHENRONG sun JIANRONG QIU State Key Laboratory of Precision Spectroscopy School of Physics and Materials ScienceEast China Normal UniversityShanghai 200062China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China State Key Laboratory of Optical Instrumentation Zhejiang UniversityHangzhou 310027China

Femtosecond laser-induced periodic surface structures(LIPSS) have several applications in surface structuring and functionalization. Three major challenges exist in the fabrication of regular and uniform LIPSS: enhancing the periodic energy deposition, reducing the residual heat, and avoiding the deposited debris. Herein, we fabricate an extremely regular low-spatial-frequency LIPSS(LSFL) on a silicon surface by a temporally shaped femtosecond laser. Based on a 4 f configuration zero-dispersion pulse shaping system, a Fourier transform limit(FTL) pulse is shaped into a pulse train with varying intervals in the range of 0.25–16.2 ps using periodic π-phase step modulation. Under the irradiation of the shaped pulse with an interval of 16.2 ps, extremely regular LSFLs are efficiently fabricated on silicon. The scan velocity for fabricating regular LSFL is 2.3 times faster, while the LSFL depth is 2 times deeper, and the diffraction efficiency is 3 times higher than those of LSFL using the FTL *** formation mechanisms of regular LSFL have been studied experimentally and theoretically. The results show that the temporally shaped pulse enhances the excitation of surface plasmon polaritons and the periodic energy deposition while reducing the residual thermal effects and avoiding the deposition of the ejected debris, eventually resulting in regular and deeper LSFL on the silicon surface.

关键词： laser shaped periodic

在线全文

学校读者我要写书评

暂无评论

叶片前缘偏转对H型垂直轴水轮机性能的影响

太阳能学报 2022年第9期43卷 391-401页

作者：周东海孙晓晶上海理工大学能源与动力工程学院上海200093

为提高传统直叶片升力型(H型)垂直轴水轮机的获能效率,提出一种带前缘可偏转叶片的新型垂直轴水轮机,利用计算流体力学(CFD)方法,结合重叠网格和动网格技术对这种新型垂直轴水轮机叶轮的水动力性能进行系统的数值模拟计算,分析不同叶尖... 详细信息

为提高传统直叶片升力型(H型)垂直轴水轮机的获能效率,提出一种带前缘可偏转叶片的新型垂直轴水轮机,利用计算流体力学(CFD)方法,结合重叠网格和动网格技术对这种新型垂直轴水轮机叶轮的水动力性能进行系统的数值模拟计算,分析不同叶尖速比下带前缘偏转叶片的垂直轴水轮机绕流流场,从而探究前缘偏转角度和偏转长度对这种水轮机动力性能和获能效率的影响规律。结果表明,根据叶片旋转到不同位置时实施前缘偏转可改变来流攻角从而减缓或抑制叶片吸力面的流动分离,有效改善其动态失速特性,进而使H型垂直轴水轮机的水动力性能和获能效率得到明显提升。研究发现,低叶尖速比下这种改善效果最为显著,可拓宽H型垂直轴水轮机高效运行的工作范围。

关键词：水电计算流体力学能量转换效率前缘偏转垂直轴水轮机

在线全文

学校读者我要写书评

暂无评论

基于果蝇算法的过热汽温自抗扰优化控制

清华大学学报（自然科学版） 2014年第10期54卷 1288-1292页

作者：孙立董君伊李东海清华大学热能工程系电力系统及发电设备控制和仿真国家重点实验室北京100084

锅炉过热汽温的动态特性会随运行工况发生较大变化,传统的控制方法难以达到理想的控制性能。该文基于线性自抗扰控制器设计串级优化控制方案,根据现有的比例-积分-微分(PID)控制器参数计算自抗扰控制器参数初值,进而基于改进的优化指标... 详细信息

锅炉过热汽温的动态特性会随运行工况发生较大变化,传统的控制方法难以达到理想的控制性能。该文基于线性自抗扰控制器设计串级优化控制方案,根据现有的比例-积分-微分(PID)控制器参数计算自抗扰控制器参数初值,进而基于改进的优化指标,采用果蝇算法优化出一组适用于不同工况的固定控制器参数。仿真结果表明:该方案能够很好地平衡快速性与稳定性的矛盾,且具有更好的性能鲁棒性。

关键词：过热汽温自抗扰控制果蝇优化鲁棒性

用于吸附养殖尾水中Cu^(2+)的温度敏感型淀粉基水凝胶制备及性能分析

在线全文

学校读者我要写书评

暂无评论

大连海洋大学学报 2024年第3期39卷 462-469页

作者：姜硕孙萌孙惠张丽萍何天晓李姝诺李苗刘鹰田野大连海洋大学海洋科技与环境学院辽宁大连116023 设施渔业教育部重点实验室(大连海洋大学) 辽宁大连116023 大连工业大学生物工程学院辽宁大连116034 浙江大学生物系统工程与食品科学学院浙江杭州310058 杭州萧山东海养殖有限责任公司浙江杭州311500

为了快速移除水产养殖尾水中的铜离子(Cu^(2+)),合成了一种新型温度敏感多糖基水凝胶,以具有结构和性能优势的2-羟基-3-异丙氧基丙基淀粉醚(HIPS)和羧甲基淀粉钠(CMS)为原料,以乙二醇二缩水甘油醚(EDGE)和CaCl 2为交联剂,通过形成共价... 详细信息

为了快速移除水产养殖尾水中的铜离子(Cu^(2+)),合成了一种新型温度敏感多糖基水凝胶,以具有结构和性能优势的2-羟基-3-异丙氧基丙基淀粉醚(HIPS)和羧甲基淀粉钠(CMS)为原料,以乙二醇二缩水甘油醚(EDGE)和CaCl 2为交联剂,通过形成共价键和离子键的混合交联方式制备具有温度敏感性能的HIPS/CMS复合凝胶,利用傅里叶转换红外光谱(FT-IR)、扫描电镜(SEM)对复合凝胶的结构和内部形貌进行表征,研究复合凝胶的温度敏感性能,并探究了复合凝胶对水产养殖尾水中Cu^(2+)的吸附效果。结果表明:HIPS/CMS复合凝胶具有优异的温度敏感性能,当温度高于其体积相转变温度(VPTT,34.1℃)时,复合凝胶体积明显收缩,溶胀率从62.1倍下降至33.6倍;HIPS/CMS复合凝胶对水产养殖尾水中Cu^(2+)具有良好的吸附性能,最大吸附量可达25.2 mg/g;复合凝胶对Cu^(2+)吸附过程符合Langmuir吸附模型,属于单分子层化学吸附;利用该复合凝胶的温度敏感性能,可实现HIPS/CMS复合凝胶的回收再利用,并且经5次吸附-解吸循环后吸附量仍可达15.1 mg/g。研究表明,本研究制备的HIPS/CMS复合凝胶对养殖尾水中的Cu^(2+)的去除效果较好且绿色环保,可以重复使用。

关键词：水产养殖尾水 Cu^(2+)吸附水凝胶温度敏感淀粉衍生物

前列腺增生术后尿失禁患者盆底肌康复训练方案的构建

在线全文

学校读者我要写书评

暂无评论

医药高职教育与现代护理 2024年第4期7卷 306-311页

作者：孙瑜陈香东海县人民医院泌尿外科江苏连云港222322

目的探讨前列腺增生患者前列腺电切除术后盆底肌康复训练方案的构建。方法通过文献检索、定性访谈和专家组会议讨论,初步构建前列腺增生术后患者盆底肌康复训练方案。采用德尔菲法进行两轮专家函询,根据专家意见和建议对方案进行修改。... 详细信息

目的探讨前列腺增生患者前列腺电切除术后盆底肌康复训练方案的构建。方法通过文献检索、定性访谈和专家组会议讨论,初步构建前列腺增生术后患者盆底肌康复训练方案。采用德尔菲法进行两轮专家函询,根据专家意见和建议对方案进行修改。结果最终构建的前列腺增生术后患者盆底肌康复训练方案包括3个一级指标(康复训练评估、康复训练时间及内容、康复训练形式),12个二级指标,以及53个三级指标。结论构建的前列腺增生术后患者盆底肌康复训练方案科学、安全、可行,可为前列腺增生术后患者盆底肌康复训练临床护理实践提供指导。

关键词：前列腺增生盆底肌康复前列腺电切术德尔菲法护理