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121.
双层滑片回转运动机构的力学特性 总被引:1,自引:0,他引:1
建立双层滑片运动机构的力学模型,并全面分析其力学特性,通过分析发现,与机械摩擦损失相比,双层滑片之间相对运动产生的粘性磨擦损失很小,可以忽略不计,采用双层滑片能够明显改善滑片端部的密封效果,减轻滑片的磨擦磨损,但滑片应力有所增加,强度有所降低,厚度比对双层滑片的受力及摩擦磨损影响很小,只对强度产生较大影响,从增加强度和便于加工的角度考虑,优化出双层滑片机构厚度的比的适宜值。 相似文献
122.
R. Eric Berson Rajesh K. Dasari Thomas R. Hanley 《Applied biochemistry and biotechnology》2006,130(1-3):621-630
Computational fluid dynamic simulations are employed to predict flow characteristics in a continuous auger driven reactor
designed for the dilure acid pretreatment of biomass. Slurry containing a high concentration of biomass solids exhibits a
high viscosity, which poses unique mixing issues within the reactor. The viscosity increases significantly with a small increase
in solids concentration and also varies with temperature. A well-mixed slurry is desirable to evenly distribute acid on biomass,
prevent buildup on the walls of the reactor, and provides an uniform final product. Simulations provide flow patterns obtained
over a wide range of viscosities and pressure distributions, which may affect reaction rates. Results provide a tool for analyzing
sources of inconsistencies in product quality and insight into future design and operating parameters. 相似文献
123.
ZHENG Jian-long 《应用数学和力学(英文版)》2005,26(8):1047-1055
IntroductionPiezoelectric materials have potentials for use in many modern devices and compositestructures. The presence of various defects, such as inclusions, holes, dislocations andcracks, can greatly influence their characteristics and coupled behavio… 相似文献
124.
The main purpose of this paper is to study the deformed Riemannian extension▽g +VG··in the cotangent bundle, where G is a twin Norden metric on the base manifold. 相似文献
125.
Li2ZnSnS4 is a new diamond-like semiconductor, which is of interest as a host structure for the creation of potentially interesting electronic, magnetic and photovoltaic materials. The compound was synthesized via traditional high-temperature solid-state methods and was predicted to adopt a wurtz-stannite structure with all atoms possessing tetrahedral environments. Initial analysis of single-crystal X-ray diffraction data indicated crystallographic disorder that upon closer examination violated basic chemical principles. The structure was subsequently re-evaluated and the apparent “disorder” problem was found to be the result of pseudo-merohedral twinning. The crystal structure was finally solved in the monoclinic space group Pn, which resulted in a chemically reasonable model. The refinement converged with R1=1.68% (for all data). Additional characterization of the sample, including diffuse reflectance, thermal analysis and second harmonic generation measurements, was also performed. 相似文献
126.
HUANG XuDong CHEN HaiXin SHI Ke & FU Song School of Aerospace Tsinghua University Beijing China 《中国科学:物理学 力学 天文学(英文版)》2010,(2)
The stall mechanism of the NASA Rotor 37 is investigated through the analysis of the critical flow structures near the stall under the transonic condition. The performance of the rotor with Circumferential Grooves Casing Treatment (CGCT) is also studied based on the Reynolds-Averaging Navier-Stokes approach. The study finds that stall margin improvement can be achieved without significant penalty on the efficiency for the two CGCT configurations applied. The effects of circumferential grooves on the critica... 相似文献
127.
128.
采用现场多步FTIR光谱技术结合CO吸附分子探针方法,研究了Rh电极表面分子过程,在电化学处理后的光滑Rh电极表面上首次检测到两种CO孪生吸附态及其随电位变化过程,使用电位循环扫描方法改变Rh电极表面状态,在0.05mol/L,H2SO4酸性溶液中,取取-0.275至2.4V电位区间和1.5V/s扫描速率对Rh电极进行循环扫描处理2min处理后的Rh电极表面积累一层氧化物,CO以孪生态吸附于表面R 相似文献
129.
Srgio Azevedo 《International journal of quantum chemistry》2002,90(6):1596-1599
We consider a bounded quantum mechanical particle with spin ?1/2 and a gyromagnetic ratio g, which is placed in a uniform magnetic field, in a space with a linear topological defect. We obtain the exact expressions for eigenfunctions and eigenvalues, using the approach of the continuum theory of defects, and show the dependence on the topological parameters and potential harmonic. Besides, we study the limits case and obtained the results described in the literature. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002 相似文献
130.