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81.
研究了锡青铜(QSn4-3)与A3铜复合板热轧复合的工艺,确定了其最佳工艺参数.QSn4-3的原始厚度为4mm,A3钢厚度为6mm时,QSn4-3与A3钢热轧复合较适宜的温度为800~850℃;复合所需的最小变形率为60%。  相似文献   
82.
气流式加速度传感器的敏感机理   总被引:2,自引:0,他引:2  
介绍了在研制气流式加速度传感器过程中,为对气流式加速度传感器进行建模,作者对气流式加速度传感器的工作机理进行了理论性探讨。在分析过程中以流体力学、传热学和惯性理论为基础并结合实验结果,建立了适合于气流式加速度传感器的气体运动方程和能量方程。同时还讨论了热线测量加速度的方法及根据实验分析了输入加速度对腔体内温度及传感器输出电压的影响,从而为进一步研究一系列气流式传感器的工作机理提供了方法。  相似文献   
83.
概述了美国几种较成熟的热煤气脱硫吸附剂的配方、制备技术及吸附剂在若干试验条件下强度、活性、寿命等宏观特性的测试结果。  相似文献   
84.
介绍了一种结构更加简单的热壁外延装置,以及用该装置在GaAs(100)面上生长ZnSe单晶外延层的工艺。扫描电镜和X射线衍射分析表明用该装置生长的ZnSe单晶外延层是比较理想的。  相似文献   
85.
采用超微Al2O3粉和热压烧结工艺制备出两种Al2O3基陶瓷(Al2O3-MgO-TiC、Al2O3-MgO-TiC-Y-PSZ)。研究了这两种材料烧结体的密度、显微组织和力学性能。并将烧成陶瓷加工成切削刀片,对35CrMnSiA超高强度调质钢进行切削试验,所得结果与其它几种陶瓷刀具的切削性能进行了比较。  相似文献   
86.
The physical, dielectric, and optical properties of hot isostatically pressed lead magnesium niobate polycrystalline ceramics modified with 1/2 mol% La2O3, Pb1–3/2 x La x x /2-(Mg1/3Nb2/3)O3, have been investigated. Methods used to characterize the ceramics included determination of the dielectric permittivity, optical transmittance, and refractive index dispersion. The materials exhibited relaxor ferroelectric type behavior with a peak dielectric constant K > 14000 and average T c ∼−35°C. Various sintering, hot isostatic pressing, and annealing conditions were examined to produce highly dense and optically transparent materials. Through the use of hot isostatic pressing, densities more than 99.5% theoretical and transmittance greater than 50% at 633-nm wavelength were obtained. Hot isostatic pressing technique appears to be a good alternative to hot uniaxial pressing without the associated problem of PbO volatility, reactivity with the pressure vessel, and geometrical constraints.  相似文献   
87.
The pursuit for efficient deep blue material is an ever-increasing issue in organic optoelectronics field. It is a long-standing challenge to achieve high external quantum efficiency (EQE) exceed 10% at brightness of 1000 cd m−2 with a Commission International de L'Eclairage (CIEy) <0.08 in non-doped organic light-emitting diodes (OLEDs). Herein, this study reports a deep blue luminogen, PPITPh, by bonding phenanthro[9,10-d]imidazole moiety with m-terphenyl group via benzene bridge. The non-doped OLED based on PPITPh exhibits an exceptionally high EQE of 11.83% with a CIE coordinate of (0.15, 0.07). The EQE still maintains 10.17% at the brightness of 1000 cd m−2, and even at a brightness as high as 10000 cd m−2, an EQE of 7.5% is still remained, representing the record-high result among non-doped deep-blue OLEDs at 1000 cd m−2. The unprecedented device performance is attributed to the reversed intersystem crossing process through hot exciton mechanism. Besides, the maximum EQE of orange phosphorescent OLED with PPITPh as host is 32.02%, and remains 31.17% at the brightness of 1000 cd m−2. Such minimal efficiency roll-off demonstrates that PPITPh is also an excellent phosphorescent host material. The result offers a new design strategy for the enrichment of high-efficiency deep blue luminogen.  相似文献   
88.
对铸态AZ91D合金进行400~460℃不同温度下的正挤压,制备出直径为3~4 mm的线材。利用光学显微镜分析线材的组织,测试其拉伸力学性能和热膨胀系数。结果表明,在不同挤压温度下均可制备出AZ91D镁合金线材,挤压温度越低,线材晶粒越细小。线材具有优异的力学性能,经400℃热挤压成形的线材抗拉强度和伸长率高达285.6 MPa和5.3%,明显高于同牌号铸态合金的性能。线材的平均线膨胀系数为(21.3~27.4)×10-6K-1。较低挤压温度下制备的线材具有较高的力学性能与较小的线膨胀系数。  相似文献   
89.
InAs/AlAsxSb1 − x quantum wells are investigated for their potential as hot carrier solar cells. Continuous wave power and temperature‐dependent photoluminescence indicate a transition in the dominant hot carrier relaxation process from conventional phonon‐mediated carrier relaxation below 90 K to a regime where inhibited radiative recombination dominates the hot carrier relaxation at elevated temperatures. At temperatures below 90 K, photoluminescence measurements are consistent with type‐I quantum wells that exhibit hole localization associated with alloy/interface fluctuations. At elevated temperatures, hole delocalization reveals the true type‐II band alignment, where it is observed that inhibited radiative recombination due to the spatial separation of the charge carriers dominates hot carrier relaxation. This decoupling of phonon‐mediated relaxation results in robust hot carriers at higher temperatures, even at lower excitation powers. These results indicate type‐II quantum wells offer potential as practical hot carrier systems. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
90.
An investigation into the relative merits of three standard laboratory procedures for lipid determination in fish meal is described. It was found that the amount of lipid extracted by these methods from both stabilised and non-stabilised anchovy meals decreased on storage of the meals. The decrease in lipid yield as a function of the storage time may be approximated by straight lines, which reveal clear distinctions between the three methods as well as the two types of meal. The cold Bligh and Dyer method gave consistently higher lipid yields than either the hot hexane or a modified EEC method, and the decrease in the Bligh and Dyer lipid content with storage was less than that found in the hot hexane or the EEC lipid content. This difference was more pronounced in the non-stabilised than in the stabilised meals. No fundamental difference between the hot hexane and the modified EEC lipid extraction method could be established since the hydrolysis step in the EEC procedure does not de polymerise the lipid portion which is unextractable by hot hexane. The effectiveness of the antioxidant ethoxyquin in protecting polyunsaturated fatty acids in anchovy meal from oxidation is demonstrated.  相似文献   
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