Numerical study on the influence mechanism of inlet distortion on the stall margin in a transonic axial rotor

A numerical study is conducted to investigate the influence of inlet flow condition on tip leakage flow (TLF) and stall margin in a transonic axial rotor.A commercial software package FLUENT,is used in the simulation.The rotor investigated in this paper is ND_TAC rotor,which is the rotor of one-stage transonic compressor in the University of Notre Dame.Three varied inlet flow conditions are simulated.The inlet boundary condition with hub distortion provides higher axial velocity for the incoming flow near tip region than that for the clean inflow,while the incoming main flow possesses lower axial velocity near the tip region at tip distortion inlet boundary condition.Among the total pressure ratio curves for the three inlet flow conditions,it is found that the hub dis-torted inlet boundary condition improves the stall margin,while the tip distorted inlet boundary condition dete-riorates compressor stability.The axial location of interface between tip leakage flow (TLF) and incoming main flow (MF) in the tip gap and the axial momentum ratio of TLF to MF are further examined.It is demonstrated that the axial momentum balance is the mechanism for interface movement.The hub distorted inflow could de-crease the axial momentum ratio,suppress the movement of the interface between TLF and MF towards blade leading edge plane and thus enhance compressor stability.     

光热对薄膜CdS／Cu2S太阳电池物理参数的影响

研究了光、热和湿气对ＣｄＳ／Ｃｕ２Ｓ电池效率及电池成结、结电容、二极管特性和光谱响应特性的影响。结果表明，对未成结电池光加速成结作用，对成结电池光引起电池性能下降，这种衰降是不可逆过程。     

玻璃行业窑炉余热利用与烟气环保治理一体化的研究与应用

随着国家"十二五"对节能减排的深入推进,玻璃作为高耗能、高污染的行业被国家纳入控制范围中,受玻璃生产特点和烟气特点的制约,一直以来,如何将窑炉的节能与减排有效地结合起来,是一项有利于国家、有利于社会,也有利于企业健康发展的重要课题。本文重点结合玻璃生产实际案例进行分析,提出有效的解决办法。结果表明,将窑炉的余热利用发电、窑炉烟气的脱除NO、脱除SO、除尘一体化的方案是未来玻璃行业的必然选择。X2     

镁合金AZ61碱性阳极氧化工艺研究

文章用正交试验对镁合金AZ61的碱性阳极氧化工艺进行了优化研究,对优化条件下得到的氧化膜进行了耐蚀性能和物相分析。封孔氧化膜的主要成分是Mg（OH）2、MgSiO3、Mg0.36Al2.44O4,能够在镁合金表面形成致密膜,膜厚可达30μm,且实行封孔阻塞了腐蚀介质到达基体的通路,从而能保证氧化膜具有较强的防腐蚀性。     

Polymer Electrolytes Based on Polymeric Ionic Liquid Poly(methyl 2-(3-vinylimidazolidin-1-yl)acetate bis(trifluoromethane sulfonyl)imide)

A new kind of ionic liquid monomer methyl 2-(3-vinylimidazolidin-1-yl)acetate bromide (MVIm-Br) and polymeric ionic liquid (PIL), poly(methyl 2-(3-vinylimidazolidin-1-yl)acetate bis(trifluoromethanesulfonyl)imide) (PMVIm-TFSI), were synthesized and characterized. Different compositions of polymer electrolytes were prepared by blending PMVIm-TFSI and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) with poly(methylmethacrylate-co-vinyl acetate) (P(MMA-VAc)). The thermal stability and ionic conductivity improved significantly when PMVIm-TFSI was added into P(MMA-VAc)/LiTFSI polymer. For the polymer electrolytes obtained, the highest ionic conductivity at 30 °C is 4.71 × 10⁻⁴ S cm⁻¹ and the corresponding decomposition temperature is ca. 308 °C. Moreover, P(MMA-VAc)/PMVIm-TFSI/LiTFSI electrolyte membrane (transmittance ≥90%) can be used as the ion-conductive layer material for electrochromic devices, which reveal excellent electrochromic performance.     

巯基改性毛发状聚苯乙烯微球的制备

通过顺序添加单体到表面负载可逆加成断裂链转移(RAFT)试剂的亚微米级单分散聚苯乙烯微球胶乳中,采用紫外光引发制备了聚N-异丙基丙烯酰胺-b-聚甲基丙烯酸缩水甘油酯(PNIPA-b-PGMA)两嵌段毛发状聚苯乙烯微球.反应过程中,单体的转化率以及微球的粒径随反应时间基本呈线性增长,具有活性自由基聚合的特征.然后分别在酸...     

Synthesis, Crystal Structures and Fluorescence Properties of Two One-Dimensional Cadmium(II) Coordination Polymers Containing Flexible Bis(benzimidazole) Ligands

Two one-dimensional Cd(II) coordination polymers constructed by ribbon-like molecules, {[Cd(L₁)₂(NO₃)]·NO₃} _n (1) (L₁ = 1,3-bis(5,6-dimethylbenzimidazol-1-yl)benzene) and [Cd(L₂)₂(NO₃)₂] _n (2) (L₂ = 1,3-bis(benzimidazol-1-yl)benzene) have been obtained through assembly of the two structurally similar flexible bis(benzimidazole)-based ligands and cadmium nitrate tetrahydrate. The cadmium(II) centers display different coordination environments with trigonal-bipyramidal geometry in 1, and a octahedral geometry in 2. Weak C–H···O interactions in 1 result in a two-dimensional supramolecular layer; two π–π interactions are present in 2 forming a three-dimensional supramolecular network structure. The solid state fluorescence properties of 1 and 2 were investigated.     

海藻纤维应用研究进展

海藻酸是一种从褐藻提取的天然线性多糖,文章简单介绍了海藻纤维的特殊结构及其制备方法,并且重点描述了海藻纤维在重金属离子和染料吸附材料、阻燃材料、医用材料、电磁屏蔽材料领域的最新研究进展。     

化工原理课程设计教学内容和模式探索与实践

本文针对化工原理课程设计存在的题目单一、物系和案例库不完善、考核方式过于简单、工程能力和创新能力训练不理想、抄袭严重等问题,对课程设计的教学内容、教学模式和考核方式等方面提出了改进措施。我校的实践表明,这些改进措施有效地提高了课程设计教学质量。     

Corrosion Inhibition Mechanism of Imidazoline-Based Dissymmetric Bis-Quaternary Ammonium Salts with Different Hydrophobic Chain Length on Q235 Steel in 1 M HCl Solution

The surface properties of a series of imidazoline‐based dissymmetric bis‐quaternary ammonium (DBA) salts with different hydrophobic chain lengths DBA‐12, DBA‐14 and DBA‐16 were determined. The adsorption behaviors of these compounds in 1 M HCl solution and their inhibitive effect on Q235 steel (U12350) were investigated using the weight‐loss method, polarization, and electrochemical impedance spectroscopy. Results indicate that the three inhibitors all showed good inhibition performance for Q235 Steel in 1 M HCl solution and were found to be mixed‐type inhibitors. The adsorption behavior of the three inhibitors can fit the Langmuir isotherm equation and the values of are around or lower than 40 kJ mol^?1, indicating that there is a stronger chemical adsorption.