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Angle-sensitive and fast photovoltage of silver nanocluster embeded ZnO thin films induced by 1.064-μm pulsed laser 被引量:1
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作者 赵嵩卿 杨立敏 +3 位作者 刘闻炜 赵昆 周岳亮 周庆莉 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第8期559-562,共4页
Silver nanocluster embedded ZnO composite thin film was observed to have an angle-sensitive and fast photovoltaic effect in the angle range from -90° to 90° , its peak value and the polarity varied regularly... Silver nanocluster embedded ZnO composite thin film was observed to have an angle-sensitive and fast photovoltaic effect in the angle range from -90° to 90° , its peak value and the polarity varied regularly with the angle of incidence of the 1.064-μm pulsed Nd:YAG laser radiation onto the ZnO surface. Meanwhile, for each photovoltaic signal, its rising time reached -2 ns with an open-circuit photovoltage of -2 ns full width at half-maximum. This angle-sensitive fast photovoltaic effect is expected to put this composite film a candidate for angle-sensitive and fast photodetector. 展开更多
关键词 angle-sensitive detector ZnO thin film silver nanocluster fast photovoltage
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Investigation on interface of NiFeCr/NiFe/Ta films with high magnetic field sensitivity 被引量:6
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作者 Sheng, Shu Li, Wei +1 位作者 Li, Minghua Yu, Guanghua 《Rare Metals》 SCIE EI CAS CSCD 2012年第1期22-26,共5页
NiFeCr/NiFe/Ta films with excellent performance were prepared by magnetron sputtering system.The anisotropic magetoresistance (AMR) value (ΔR/R) and magnetic filed sensitivity (Sv,Sv=[d(ΔR/R)/dH]max.) for the 12 nm ... NiFeCr/NiFe/Ta films with excellent performance were prepared by magnetron sputtering system.The anisotropic magetoresistance (AMR) value (ΔR/R) and magnetic filed sensitivity (Sv,Sv=[d(ΔR/R)/dH]max.) for the 12 nm NiFe film deposited on NiFeCr buffer layer were 3.66% and 1.42×10-4%·T-1,respectively.The higher Sv of the film is close to that of a spin valve (SV).The microstructure analysis shows that the NiFeCr buffer layer has adopted the same structure with the same interplanar distance as the NiFe layer,inducing a strong NiFe (111) texture,and that the NiFeCr/NiFe interface is quite smooth,leading to a high degree of specular reflection of conduction electrons.Both increase the ΔR and reduce the R in the film,which lead to the high ΔR/R.Clean substrate surfaces are critical for preparation of high performance NiFeCr/NiFe/Ta films,and sputter cleaning or pre-deposition of 5 nm amorphous Al2O3 layer in the deposition chamber can provide the re-quired clean substrate surfaces for the growth of the buffer layer. 展开更多
关键词 ultrathin NiFe films magnetic field sensitivity lattice matching
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Characterization of Passive Films Formed on As-received and Sensitized AISI 304 Stainless Steel 被引量:3
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作者 Yubo Zhang Hongyun Luo +2 位作者 Qunpeng Zhong Honghui Yu Jinlong Lv 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第2期61-72,共12页
The current research of corrosion resistance of stainless steels mainly focuses on characterization of the passive films by point defect mode and mixed-conduction model. The corrosion resistance of the passive films f... The current research of corrosion resistance of stainless steels mainly focuses on characterization of the passive films by point defect mode and mixed-conduction model. The corrosion resistance of the passive films formed on asreceived and sensitized AISI304 stainless steel in borate bu er solution were evaluated in this paper. The degree of sensitization and corrosion resistance of AISI304 stainless steels was evaluated by double loop electrochemical potentiodynamic reactivation and electrochemical impedance spectroscopy. The passive films formed on the stainless steels were studied by XPS technique. It was found that as-received specimen had higher pitting corrosion potential and corrosion resistance than sensitized one. The Mott-Schottky results showed that sensitized stainless steel had more defects in the passive film than as-received one. The compositions of the passive films were mainly Cr and Fe oxides according to XPS results. 展开更多
关键词 304 STAINLESS steel sensitIZATION Passive films XPS Impedance
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Study on Property of Desensitized Explosive Film
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作者 李国新 王晓丽 +1 位作者 焦清介 刘淑珍 《Journal of Beijing Institute of Technology》 EI CAS 2004年第3期336-340,共5页
The mechanical sensitivity, the critical thickness of detonation wave propagation and detonation velocity of desensitized PETN film were studied by experiments. The relationship between the mass of desensitizer paraff... The mechanical sensitivity, the critical thickness of detonation wave propagation and detonation velocity of desensitized PETN film were studied by experiments. The relationship between the mass of desensitizer paraffin wax and the friction sensitivity of desensitized PETN film was tested. According to the microstructure of film, the function of desensitizer was explained. It was proved that the explosive film could make explosive element micromation and kept its inherence properties by the result of testing the propagating critical dimension of the desensitized PETN film detonation wave. The explosive velocity of confined desensitized PETN film was tested by the multiplex optical fibre.. 展开更多
关键词 desensitized PETN film MICROSTRUCTURE friction sensitivity detonation velocity
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Fabrication and Fluorescence Study of Sensitizing Dye/TiO_2 Films
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作者 Hai Ning CUl Li Ying WANG +2 位作者 Dong Met WANG Gut Fen SUN Shi Quan XI(National Analytical Research Center of Electrochemistry and Spectroscopy, Changchun Instituteof Applied Chemistry, Chinese Academy of Sciences, Chang Chun 130022) 《Chinese Chemical Letters》 SCIE CAS CSCD 1998年第3期311-314,共4页
Fluorescence spectra of the sensitizing dye/ TiO2 bilayer films were studied. Charge-transfer complexes were formed in the above bilayer.
关键词 TiO_2 film sensitizing dye fluorescence spectra CHARGE-TRANSFER
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Gas Sensitivity of Poly (3, 4-ethylene dioxythiophene) Prepared by a Modified LB Film Method
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作者 郑华靖 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第1期70-74,共5页
An arachidic acid/poly (3, 4-ethylene dioxythiophene) (AA/PEDOT) multilayer Langmuir-Blodgett (LB) film was prepared by a modified LB film method. The theories were utilized to explain the effects between HCl mo... An arachidic acid/poly (3, 4-ethylene dioxythiophene) (AA/PEDOT) multilayer Langmuir-Blodgett (LB) film was prepared by a modified LB film method. The theories were utilized to explain the effects between HCl molecule and LB film. The gas sensitivity mechanism of poly (3, 4-ethylene dioxythiophene) (PEDOT) multilayer film can be explained by the charge transfer between p system of PEDOT and oxidization HCl system. The gas sensitivity of PEDOT LB film deposited interdigital electrode to HCl was tested. The results showed that film thickness, treating temperature, deposition speed had different influence on film gas sensitivity. The AA/PEDOT film deposited device exhibited nonlinear behavior to HCl gas at lower concentration (20-60 ppm) and linear response behavior at higher gas concentration was observed. The time of the compound LB film of the AA/PEDOT responding to the 30 ppm HCl gas is about 20 seconds, which is far quicker than the time of the film to the PEDOTPRESS film(about 80 seconds). It is not higher film press to better film. When the film press attains 45 mNs/m, the sensitivity of the AA/PEDOT film on the contrary descends. 展开更多
关键词 poly (3 4-ethylene dioxythiophene) (PEDOT) Langmuir-Blodgett (LB) film method gas sensitivity measurement
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CHT/CFD Analysis of Thermal Sensitivity of a Transonic Film-Cooled Guide Vane
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作者 Prasert Prapamonthon Soemsak Yooyen Suwin Sleesongsom 《Computer Modeling in Engineering & Sciences》 SCIE EI 2019年第6期593-615,共23页
Thermal parameters are important variables that have great influence on life time of turbine vanes.Therefore,accurate prediction of the thermal parameters is essential.In this study,a numerical approach for conjugate ... Thermal parameters are important variables that have great influence on life time of turbine vanes.Therefore,accurate prediction of the thermal parameters is essential.In this study,a numerical approach for conjugate heat transfer(CHT)and computational fluid dynamics(CFD)is used to investigate thermal sensitivity of a transonic guide vane which is fully film-cooled by 199 film holes.Thermal barrier coating(TBC),i.e.,the typical TBC and a new one as the candidate TBC,and turbulence intensity(Tu),i.e.,Tu=3.3%,10%and 20%,are two variables used for the present study.At first the external surface temperatures of the vane material are compared.Next,the TBC surface temperatures are considered.Results show the major role of the lower thermal conductivity of TBC which results in the lower and more uniform temperature on the external surface of the vane substrate.Finally,the thermal sensitivity is presented in terms of the percentage reduction of the external surface temperatures of the vane material and the structural temperatures of the vane material at midspan,including the variations of average and maximum vane temperatures.Results show that TBC and Tu have significant effects on the external surface and structural temperatures of the vane substrate.The lower thermal conductivity of TBC leads to the higher difference between the thermal conductivity of the vane substrate and TBC,the reduction of heat transfer and the more uniform temperature within the vane structure.The results also show more effective protection for the average vane temperature from the two TBCs at higher Tus.However,Tu does not significantly affect the reduction of the maximum vane temperature even though the new TBC,which has the very low thermal conductivity,is used. 展开更多
关键词 CONJUGATE HEAT TRANSFER film COOLING thermal sensitivity
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Improved carrier transport in Mn:ZnSe quantum dots sensitized La-doped nano-TiO2 thin film
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作者 Shao Li Gang Li +1 位作者 Li-Shuang Yang Kui-Ying Li 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第4期351-359,共9页
Mn:ZnSe/ZnS/L-Cys core-shell quantum dots(QDs)sensitized La-doped nano-TiO2 thin film(QDSTF)was prepared.X-ray photoelectron spectroscopy(XPS),nanosecond transient photovoltaic(TPV),and steady state surface photovolta... Mn:ZnSe/ZnS/L-Cys core-shell quantum dots(QDs)sensitized La-doped nano-TiO2 thin film(QDSTF)was prepared.X-ray photoelectron spectroscopy(XPS),nanosecond transient photovoltaic(TPV),and steady state surface photovoltaic(SPV)technologies were used for probing the photoelectron behaviors in the Mn-doped QDSTF.The results revealed that the Mn-doped QDSTF had a p-type TPV characteristic.The bottom of the conduction band of the QDs as a sensitizer was just 0.86 eV above that of the La-doped nano-TiO2 thin film,while the acceptor level of the doped Mn2+ions was located at about 0.39 eV below and near the bottom of the conduction band of the QDs.The intensity of the SPV response of the Mn-doped QDSTF at a specific wavelength was ~2.1 times higher than that of the undoped QDSTF.The region of the SPV response of the Mn-doped QDSTF was extended by 191 nm to almost the whole visible region as compared with the undoped QDSTF one.And the region of the TPV response of the Mn-doped QDSTF was also obviously wider than that of the undoped QDSTF.These PV characteristics of the Mn-doped QDSTF may be due to the prolonged lifetime and extended diffusion length of photogenerated free charge carriers injected into the sensitized La-doped nano-TiO2 thin film. 展开更多
关键词 doping effects ZNSE quantum DOTS sensitIZATION NANO-TIO2 thin film PHOTOELECTRON spectroscopy
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High Sensitivity of Porous Cu-Doped SnO2 Thin Films to Methanol
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作者 Sara Benzitouni Mourad Zaabat +6 位作者 Aicha Khial Djamil Rechem Ahlem Benaboud Dhikra Bouras Abdelhakim Mahdjoub Mahdia Toubane Raphael Coste 《Advances in Nanoparticles》 2016年第2期140-148,共9页
Porous Cu-doped SnO<sub>2</sub> thin films were synthesized by the sol-gel dip-coating method for enhancing methanol sensing performance. The effect of Cu doping concentration on the SnO<sub>2</su... Porous Cu-doped SnO<sub>2</sub> thin films were synthesized by the sol-gel dip-coating method for enhancing methanol sensing performance. The effect of Cu doping concentration on the SnO<sub>2</sub> sensibility was investigated. XRD data confirm that the fabricated SnO<sub>2</sub> films are polycrystalline with tetragonal rutile crystal structure. AFM and SEM micrographs confirmed the roughness and the porosity of SnO<sub>2</sub> surface, respectively. UV-Vis spectrum shows that SnO<sub>2</sub> thin films exhibit high transmittance in the visible region &#126;95%. The band gap (3.80 - 3.92 eV) and the optical thickness (893 - 131 nm) of prepared films were calculated from transmittance data. The sensing results demonstrate that SnO<sub>2</sub> films have a high sensitivity and a fast response to methanol. In particular, 3% Cu-SnO<sub>2</sub> films have a higher sensitivity (98%), faster response (10-<sup>2</sup> s) and shorter recovery time (18 s) than other films. 展开更多
关键词 SnO2 Cu-Doped sensitivity Porosity Response Time Band Gap Thin films
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Light scattering of nanocrystalline TiO_2 film used in dye-sensitized solar cells
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作者 熊必涛 周保学 +4 位作者 白晶 郑青 刘艳彪 蔡伟民 蔡俊 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第10期3713-3719,共7页
This paper studies the light scattering and adsorption of nanocrystalline TiO2 porous films used in dye-sensitized solar cells composed of anatase and/or rutile particles by using an optical four-flux radiative transf... This paper studies the light scattering and adsorption of nanocrystalline TiO2 porous films used in dye-sensitized solar cells composed of anatase and/or rutile particles by using an optical four-flux radiative transfer model. These light properties are difficult to measure directly on the functioning solar cells and they can not be calculated easily from the first-principle computational or quantitative theoretical evaluations. These simulation results indicate that the light scattering of 1 25 nm TiO2 particles is negligible, but it is effective in the range of 80 and 180 nm. A suitable mixture of small particles (10 nm radius), which are resulted in a large effective surface, and of larger particles (150 nm radius), which are effective light scatterers, have the potential to enhance solar absorption significantly. The futile crystals have a larger refractive index and thus the light harvest of the mixtures of such larger rutile and relatively small anatase particles is improved in comparison with that of pure anatase films. The light absorption of the 10μm double-layered films is also examined. A maximal light absorption of double-layered film is gotten when the thickness of the first layer of 10 urn-sized anatase particles is comparable to that of the second larger rutile layer. 展开更多
关键词 light scattering modelling filmS dye-sensitized solar cells
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Dye-sensitized solid-state solar cells fabricated by screen-printed TiO_2 thin film with addition of polystyrene balls
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作者 Jing Han Jin Mao Chen +3 位作者 Xiao Wen Zhou Yuan Lin Jing Bo Zhang Jian Guang Jia 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第8期1004-1007,共4页
The screen-printed nanoporous TiO2 thin film was employed to fabricate dye-sensitized solid-state solar cells using CuI as hole-transport materials. The solar cell based on nanoporous TiO2 thin film with large pores f... The screen-printed nanoporous TiO2 thin film was employed to fabricate dye-sensitized solid-state solar cells using CuI as hole-transport materials. The solar cell based on nanoporous TiO2 thin film with large pores formed by the addition of polystyrene balls with diameter of 200 nm to the TiO2 paste exhibits photovoltaic performance enhancement, which is attributed to the good contact of CuI with surface of dye-sensitized thin film due to easy penetration of CuI in the film with large pores. 展开更多
关键词 Dye-sensitized solar ceils Screen-printed TiO2 film Cuprous iodide Polystyrene balls
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Enhanced transient photovoltaic characteristics of core–shell ZnSe/ZnS/L-Cys quantum-dot-sensitized TiO_2 thin-film
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作者 Kui-Ying Li Lun Ren Tong-De Shen 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第6期415-423,共9页
Photoanodic properties greatly determine the overall performance of quantum-dot-sensitized solar cells(QDSCs). In the present report, the microdynamic behaviors of carriers in the nanocomposite thin-film, a Zn Se QD... Photoanodic properties greatly determine the overall performance of quantum-dot-sensitized solar cells(QDSCs). In the present report, the microdynamic behaviors of carriers in the nanocomposite thin-film, a Zn Se QD-sensitized mesoporous La-doped nano-TiO2 thin-film, as a potential candidate for photoanode, are probed via nanosecond transient photovoltaic(TPV) spectroscopy. The results confirm that the L-Cys ligand has a dual function serving as a stabilizer and molecular linker. Large quantities of interface states are located at the energy level with a photoelectric threshold of1.58 eV and a quantum well(QW) depth of 0.67 eV. This QW depth is approximately 0.14 eV deeper than the depth of QW buried in the Zn Se QDs, and a deeper QW results in a higher quantum confinement energy. A strong quantum confinement effect of the interface state may be responsible for the excellent TPV characteristics of the photoanode. For example, the peak intensity of the TPV response of the QD-sensitized thin-film lasts a long time, from 9.40 × 10^(-7) s to 2.96 × 10^(-4) s,and the end time of the PTV response of the QD-sensitized thin-film is extended by approximately an order of magnitude compared with those of the TiO2 substrate and the QDs. The TPV characteristics of the QD-sensitized thin-film change from p-type to n-type for the QDs before and after sensitizing. These properties strongly depend on the extended diffusion length of the photogenerated carries and the reduced recombination rate of photogenerated electron-hole pairs, resulting in prolonged carrier lifetime and an increased level of electron injection into the TiO2 thin-film substrate. 展开更多
关键词 sensitIZATION core-shell ZnSe quantum dots mesoporous Ti02 thin-film time-resolution photo- voltage
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花青素-壳聚糖基新鲜度指示膜的研究进展
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作者 王凯 付红军 彭湘莲 《食品与发酵工业》 CAS CSCD 北大核心 2024年第4期365-371,共7页
消费者食品安全意识的提高为包装技术带来了新机遇,基于天然色素和生物聚合物的智能包装作为食品包装的最新技术被引入。这类包装可以将食品的状态在包装膜上显示出来,依据膜的颜色变化实时评估食品的新鲜度。近年来,花青素作为指示剂... 消费者食品安全意识的提高为包装技术带来了新机遇,基于天然色素和生物聚合物的智能包装作为食品包装的最新技术被引入。这类包装可以将食品的状态在包装膜上显示出来,依据膜的颜色变化实时评估食品的新鲜度。近年来,花青素作为指示剂被广泛应用于智能包装膜,其中以壳聚糖为基质的指示膜用于食品的新鲜度监测较多。该文阐述了新鲜度指示膜的组成及监测原理,重点介绍了花青素-壳聚糖基指示膜的物理特性和功能特性及其在食品新鲜度监测中的研究进展,并指出新鲜度指示膜在应用过程中存在的问题,为进一步开发实用且准确的新鲜度指示膜提供一些思路。 展开更多
关键词 花青素 壳聚糖 新鲜度指示膜 稳定性 灵敏性
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压电检测陀螺薄膜材料分析及仿真研究
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作者 张一飞 陈光伟 赵前程 《传感器与微系统》 CSCD 北大核心 2024年第6期11-14,共4页
理论分析了影响压电微机电系统(MEMS)陀螺检测电压输出幅值的因素,结合MEMS领域常用的氮化铝(AlN)、氧化锌(ZnO)和锆钛酸铅(PZT)这3种压电薄膜材料,设计了一种微梁构型的检测陀螺。利用有限元软件COMSOL进行了陀螺的模态、功能的仿真分... 理论分析了影响压电微机电系统(MEMS)陀螺检测电压输出幅值的因素,结合MEMS领域常用的氮化铝(AlN)、氧化锌(ZnO)和锆钛酸铅(PZT)这3种压电薄膜材料,设计了一种微梁构型的检测陀螺。利用有限元软件COMSOL进行了陀螺的模态、功能的仿真分析。仿真结果显示:使用AlN柔度系数的陀螺结构驱动与检测模态固有频率频差为22 Hz;陀螺结构可以敏感z轴角速度输入;ZnO、AlN和PZT陀螺电压灵敏度分别为2.23,2.16,0.79μV/((°)·s^(-1)),AlN和ZnO的电压灵敏度大于PZT,且AlN的工艺性好于ZnO;因此,AlN在3种压电材料中最适合用于压电检测MEMS陀螺。 展开更多
关键词 压电陀螺 薄膜材料 COMSOL仿真 电压灵敏度
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光纤氢气传感器氢敏钯(Pd)薄膜材料的制备
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作者 杨孟宇 江新峰 +4 位作者 葛琪 李宝峰 黄浩然 郑高凯 李金希 《电工材料》 CAS 2024年第4期25-28,共4页
提出了化学镀法制备以光纤包层为基底的钯薄膜材料。经过反复多次试验,优化了化学镀钯的试验方案,在镀膜前对光纤包层进行清洗,预先进行敏化活化(S&A)能够增强非金属基底材料与钯薄膜的附着力,增强机械强度。采用光学显微镜(OM)、... 提出了化学镀法制备以光纤包层为基底的钯薄膜材料。经过反复多次试验,优化了化学镀钯的试验方案,在镀膜前对光纤包层进行清洗,预先进行敏化活化(S&A)能够增强非金属基底材料与钯薄膜的附着力,增强机械强度。采用光学显微镜(OM)、扫描电镜(SEM)和能谱仪(EDS)对薄膜的物相结构、表面形貌、元素组成与含量进行了详细的表征和分析,结果显示:薄膜表面呈花菜状,增大了薄膜的表面积,加快了吸收氢气的速率;EDS分析所镀钯薄膜钯元素含量约76%~99%,镀膜效果较好。 展开更多
关键词 氢敏材料 钯(Pd)薄膜 制备工艺 性能
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InSb-In共晶体磁阻薄膜的制备及特性分析
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作者 李锋 《黑龙江科学》 2024年第12期90-93,共4页
利用纯度为99.99%的铟和锑单质为原料,采用真空蒸发法,制备了InSb-In共晶体磁阻薄膜,对薄膜进行热处理。通过实验对锑化铟薄膜的物相构成、表面形貌进行分析,探讨成膜条件、退火条件等因素对薄膜结构及性能的影响。结果表明,InSb薄膜是I... 利用纯度为99.99%的铟和锑单质为原料,采用真空蒸发法,制备了InSb-In共晶体磁阻薄膜,对薄膜进行热处理。通过实验对锑化铟薄膜的物相构成、表面形貌进行分析,探讨成膜条件、退火条件等因素对薄膜结构及性能的影响。结果表明,InSb薄膜是InSb和In的共晶体。 展开更多
关键词 INSB薄膜 真空蒸发 热处理 灵敏度
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基于聚酰亚胺的柔性湿度传感器制备及研究
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作者 张海力 谢光忠 +1 位作者 刘太君 代静 《仪表技术与传感器》 CSCD 北大核心 2024年第4期11-18,47,共9页
文中以聚酰胺酸(PAA)为前驱体,通过热处理工艺可得聚酰亚胺(PI)薄膜,添加氧化石墨烯(GO)合成PI/GO复合薄膜及后续电极制备得到基于聚酰亚胺的平行板电容式柔性湿度传感器。在此基础上深入研究了叉指电极式和平行板式构型、PAA旋涂转速、... 文中以聚酰胺酸(PAA)为前驱体,通过热处理工艺可得聚酰亚胺(PI)薄膜,添加氧化石墨烯(GO)合成PI/GO复合薄膜及后续电极制备得到基于聚酰亚胺的平行板电容式柔性湿度传感器。在此基础上深入研究了叉指电极式和平行板式构型、PAA旋涂转速、PAA酰亚胺化温度、GO喷涂量对湿度传感器性能的影响,最终得到的湿度传感器具有良好重复性、快速的响应恢复时间,最大湿滞仅为3.8%RH,且具有优异的柔性性能,在可穿戴柔性电子器件领域具有广泛的应用前景。 展开更多
关键词 柔性 湿度传感器 聚酰亚胺(PI) 氧化石墨烯(GO) PI/GO复合薄膜 平行板电容结构 湿敏特性
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凹坑对并排气膜孔冷却性能的影响研究
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作者 赵胜岩 贺业光 +1 位作者 冯国淼 李润东 《推进技术》 EI CAS CSCD 北大核心 2024年第9期147-156,共10页
为提高燃气轮机热端部件的冷却性能,探索了一种并排气膜孔和波浪形凹坑的组合冷却结构,添加椭圆形凹坑考虑凹坑形状变化的影响。利用压力敏感漆(PSP)技术实验测量了组合结构的冷却性能,结合数值模拟分析了流场结构。在吹风比0.5~2.0内,... 为提高燃气轮机热端部件的冷却性能,探索了一种并排气膜孔和波浪形凹坑的组合冷却结构,添加椭圆形凹坑考虑凹坑形状变化的影响。利用压力敏感漆(PSP)技术实验测量了组合结构的冷却性能,结合数值模拟分析了流场结构。在吹风比0.5~2.0内,PSP实验结果显示,并排气膜孔结构产生的气膜冷却效果优于单圆孔结构,布置波浪形凹坑可以显著改善气膜孔下游的流场结构。经过计算,在吹风比为1.0时,波浪形并排凹坑孔对比单圆孔面平均冷却效率提高147.8%,对比椭圆形并排凹坑孔提高46.7%。在四个吹风比下,波浪形并排凹坑孔产生了最佳的气膜冷却效果。 展开更多
关键词 涡轮叶片 气膜冷却 压力敏感漆 冷却效率 凹坑型气膜孔
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相位敏感飞秒和频光谱技术及在高分子表界面表征的应用
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作者 王子云 李柏霖 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2024年第4期111-118,共8页
高分子材料表面是表界面科学的一个重要研究领域。然而,从分子水平上对高分子薄膜表面进行原位无损精准探测仍具有挑战性。文中自主研发了表界面敏感的共线相位敏感飞秒和频光谱,其具有分子绝对取向结构的分辨能力、高的相位稳定性和信... 高分子材料表面是表界面科学的一个重要研究领域。然而,从分子水平上对高分子薄膜表面进行原位无损精准探测仍具有挑战性。文中自主研发了表界面敏感的共线相位敏感飞秒和频光谱,其具有分子绝对取向结构的分辨能力、高的相位稳定性和信噪比以及弱表面信号的探测能力。本系统采用35fs的宽频红外激光,一次数据采集具有较宽的光谱测试范围。将此系统应用到聚甲基丙烯酸甲酯(PMMA)、聚苯乙烯(PS)和聚己二酰己二胺(尼龙6/6)高分子薄膜表面的精准结构(绝对取向结构)的探测。结果表明,PMMA的酯甲基、PS的侧基苯环以及尼龙6/6的N—H基团在表面上有序取向且朝向空气一侧,其他基团在表面上相对无序取向或者倾向于平躺于表面上。文中开发了相位敏感飞秒和频光谱,并将其应用到了高分子薄膜表面领域,对高分子薄膜表面精准结构的认识以及表面性能的优化具有十分重要的意义。 展开更多
关键词 相位敏感和频光谱 高分子薄膜 表界面
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考虑精铸变形的涡轮叶片气膜冷却效率灵敏度计算方法研究
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作者 尤鑫添 董一巍 +3 位作者 刘松 吴超林 郭文 龚雨晗 《机械科学与技术》 CSCD 北大核心 2024年第7期1151-1157,共7页
精铸加工使得涡轮叶片几何结构与设计之间产生随机性偏差,这一偏差对叶片气膜冷却效率造成不确定性影响。涡轮叶片外形偏差的不确定性是几何层面的小扰动问题。本文通过精铸模拟建立了涡轮叶片精铸变形模型。基于PIV与数值模拟建立了适... 精铸加工使得涡轮叶片几何结构与设计之间产生随机性偏差,这一偏差对叶片气膜冷却效率造成不确定性影响。涡轮叶片外形偏差的不确定性是几何层面的小扰动问题。本文通过精铸模拟建立了涡轮叶片精铸变形模型。基于PIV与数值模拟建立了适用于流热耦合计算的Realizable k-epsilon湍流模型,建立了考虑叶片变形的气膜冷却效率灵敏度计算方法,计算了涡轮叶片的气膜冷却效率随吹风比变化的灵敏度。结果表明:涡轮叶片精铸产生的变形越大,对原有气膜冷却效率的损失越大。叶片整体平均形变0.25 mm使得整体气膜冷却效率损失约5%,局部形变如叶尖叶片后缘处的0.70 mm可使叶尖平均气膜冷却效率损失约8%。由灵敏度分析确定的精铸后气膜冷却效率相对误差较明显,达到了1.62%。 展开更多
关键词 涡轮叶片 精铸变形 CFD仿真 气膜冷却效率 灵敏度
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