大气压非平衡等离子体注入烟气脱硝研究

为改进羟基自由基烟气脱硝效率,采用强电离电场放电方法制取高浓度羟基自由基,并直接注入烟气中氧化NOx生成硝酸,整个过程无催化剂、吸收剂.研究了·OH注入量和气体温度的变化对脱硝率的影响.结果表明,NO及NOx的脱除率随·OH注入量的增大明显上升,烟气温度为70℃,流量1.2 m3/h,NO被完全脱除,NOx脱除率可达92%以上.温度是影响脱硝率的主要因素之一,温度每升高10℃,NOx脱除率降低约13.3%.在一定范围内,NOx初始浓度对于脱硝率影响甚微.     

阳极流场结构对直接甲醇燃料电池性能影响研究

直接甲醇燃料电池(DMFC)以其能量密度高、环境友好、结构简单和储存携带方便等优点在便携式产品领域得到广泛关注。流场结构设计是否合理是影响燃料电池输出性能的关键因素之一。本文采用非均衡流场的设计思路,对比了非均衡蛇形流场和均衡蛇形流场的DMFC输出性能。实验结果表明,非均衡蛇形流场结构能够提高DMFC的输出性能,当DMFC水平放置时,非均衡蛇形流场的DMFC峰值功率比均衡蛇形流场的DMFC提高33%左右;均衡蛇形流场的DMFC竖直方式放置时,其输出性能比水平放置时有明显提高,而非均衡蛇形流场的DMFC竖直方式放置时,其输出性能与水平放置时相差不多。     

微针刺入皮肤过程数值模拟

微针作为一种全新的经皮给药技术,由于无痛性、微创,引起越来越多的关注.研究微针刺入皮肤的力学机理不仅有助于设计最优的微针材料和形貌,也有利于更好发挥微针在药物输送中的作用.利用数值模拟方法,基于大型通用有限元软件Abaqus,考虑不同皮肤层的力学性能及材料的失效和破坏,对微针刺入皮肤过程进行数值仿真,形象地揭示了微针刺入皮肤过程中微针与皮肤的相互作用机理.讨论了刺入过程中皮肤的变形和破坏及微针受力随刺入位移的变化关系,得到了微针刺破皮肤时的刺入力大小,并详细分析了微针形状参数(尖端端面面积、针壁角、壁厚等)对刺入力的影响.通过分析发现微针尖端端面面积以及微针壁角是微针刺入多层结构皮肤的主要控制参数,而微针壁厚对刺入力的影响较小.另外,对比实验结果发现数值模拟结果同实验观察基本吻合.研究结果可能为微针给药系统及微针的优化设计提供了一定的帮助.     

Large-Eddy Simulations of turbulent flows with lattice Boltzmann dynamics and dynamical system sub-grid models

In this paper,two sub-grid scale (SGS) models are introduced into the Lattice Boltzmann Method (LBM),i.e.,the dynamics SGS model and the dynamical system SGS model,and applied to numerically solving three-dimensional high Re turbulent cavity flows.Results are compared with those obtained from the Smagorinsky model and direct numerical simulation for the same cases.It is shown that the method with LBM dynamics SGS model has advantages of fast computation speed,suitable to simulate high Re turbulent flows.In ...     

Matrix-bound phosphine in Ny-Alesund Area of Arctic

Phosphine,a ubiquitous trace gas in the atmosphere,acts as a carrier of gasous phosphorus in the biogeochemical cycle.The research of phosphine will show new light on the mechanisms of how the phos- phorus supplement influence the biogeochemical cycle and global warming.In this paper,we detect the phosphine in Arctic Pole area for the first time.The result shows that matrix-bound phosphine(MBP)ex- ists in all the samplings.Phosphine distributions varied with different environmental origins.Average phosphine...     

Fabrication and its characteristics of low-temperature polycrystalline silicon thin films

In order to reduce the cost of solar cells or flat-panel display,it is very important to synthesis polycrystalline silicon films on low cost substrate such as glass at low temperature.In this work,electron cyclotron resonance(ECR)plasma enhanced chemical vapor deposition(PECVD)system was successfully applied to synthesize poly-Si thin-film on common glass substrate using H2 as the plasma source and SiH4(Ar:SiH4=19:1)as the precursor gas at low temperature.Since the multicusp cavity-coupling ECR plasma sourc...     

Crystal structure and photoelectricity property of Fe(Ⅱ/Ⅲ) coordination supermolecules

Three new mixed-ligand Fe(Ⅱ/Ⅲ) complexes [Fe2(μ2–btec)( μ2–H2btec)(phen)2(H2O)2]n (1), [Fe2(btec) (phen)2(H2O)4] (2), and {[Fe(o-pha)(phen)(H2O)]·H2O}n (3) (phen=1,10-phenanthroline, o-H2pha=o-phthalic acid, H4btec=1,2,4,5-benzenetetracarboxylic acid) have been hydrothermally synthesized and detected by single crystal X-ray diffraction, showing that complexes (1) and (2) are both bridged by the betc4? ligands to form 1D chain and dinuclear structure and complex (3) is bridged by the o-pha groups to form 1D ...     

轴承钢中TiN夹杂物析出的控制

通过对轴承钢中TiN夹杂析出的理论分析,得到不同凝固率下TiN夹杂析出溶解度饱和线,据此提出防止TiN夹杂析出的[Ti]、[N]控制范围,同时提出了生产过程中[Ti]、[N]的控制措施.     

星形细胞瘤CT脑水肿与微结构改变的相互关系

一般认为CT瘤周低密度区是脑水肿。为阐明CT瘤周低密度区的本质,本文分析了2例星形细胞瘤CT瘤周低密度区和瘤中央区标本的微结构变化。发现CT瘤周低密度区标本内有间变的星形细胞,间质疏松。故作者认为CT瘤周低密度区是肿瘤的实际范围,伴有水肿变化。此外,本文对CT瘤周低密度区的成因和脑水肿的发病机制进行了探讨。