在通常的模具生产车间,模具电极只能依靠人来监控和管理,导致工作量大且效率低.为了解决这一问题,研究了无线射频识别技术在模具电极管理中的应用.利用微软Visual Studio 2008作为开发工具,采用B/S(浏览器/服务器)的系统架构,开发了一...在通常的模具生产车间,模具电极只能依靠人来监控和管理,导致工作量大且效率低.为了解决这一问题,研究了无线射频识别技术在模具电极管理中的应用.利用微软Visual Studio 2008作为开发工具,采用B/S(浏览器/服务器)的系统架构,开发了一套基于无线射频识别技术的模具电极管理系统.首先,对系统总体结构进行设计,包括主要硬件的选型及参数的设置;接着,对系统业务流程进行了规范,再根据业务流程进行了功能需求分析;然后,对系统各功能模块进行了划分,对数据库结构进行了设计;最后,运用NET技术开发了系统各界面及功能.实践证明该系统对电极的管理方便有效,提高了模具电极管理的智能化水平.展开更多
A power management unit （PMU） chip supplying dual panel supply voltage, which has a low electro-magnetic interference （EMI） characteristic and is favorable for miniaturization, is designed. A two-phase charge pump...A power management unit （PMU） chip supplying dual panel supply voltage, which has a low electro-magnetic interference （EMI） characteristic and is favorable for miniaturization, is designed. A two-phase charge pump circuit using external pumping capacitor increases its pumping current and works out the charge-loss problem by using bulk-potential biasing circuit. A low-power start-up circuit is also proposed to reduce the power consumption of the band-gap reference voltage generator. And the ring oscillator used in the ELVSS power circuit is designed with logic devices by supplying the logic power supply to reduce the layout area. The PMU chip is designed with MagnaChip＇s 0.25 μ high-voltage process. The driving currents of ELVDD and ELVSS are more than 50 mA when a SPICE simulation is done.展开更多
The white organic light emitting device (OLED) with single-structure using a polymer blend as the light emitting layer is fabricated.Heat treatment is used to control the ratio between the intensities of main electrol...The white organic light emitting device (OLED) with single-structure using a polymer blend as the light emitting layer is fabricated.Heat treatment is used to control the ratio between the intensities of main electroluminescent spectral peaks.The electroluminescent spectrum of our device is quite similar to that of white inorganic LED produced by Nichia Corporation after being annealed,and its turn-on voltage can be decreased by 1 V.展开更多
Realizing low contact resistance between graphene and metal electrodes remains a well-known challenge for building high-performance graphene devices. In this work, we attempt to reduce the contact resistance in graphe...Realizing low contact resistance between graphene and metal electrodes remains a well-known challenge for building high-performance graphene devices. In this work, we attempt to reduce the contact resistance in graphene transistors and further explore the resistance limit between graphene and metal contacts. The Pd/graphene contact resistance at room temperature is reduced below the 100 Ω·μm level both on mechanically exfoliated and chemical-vapor-deposition graphene by adopting high-purity palladium and high-quality graphene and controlling the fabrication process to not contaminate the interface. After excluding the parasitic series resistances from the measurement system and electrodes, the retrieved contact resistance is shown to be systematically and statistically less than 100 Ω·μm, with a minimum value of 69 Ω·μm, which is very close to the theoretical limit. Furthermore, the contact resistance shows no clear dependence on temperature in the range of 77-300 K; this is attributed to the saturation of carrier injection efficiency between graphene and Pd owing to the high quality of the graphene samples used, which have a sufficiently long carrier mean-free-path.展开更多
An interferometer based optical sensor for displacement measurement is reported. This method requires quite simple signal processing as well as least electronic components. Referring to this technique, two photodiodes...An interferometer based optical sensor for displacement measurement is reported. This method requires quite simple signal processing as well as least electronic components. Referring to this technique, two photodiodes spatially shifted by 90 degrees were used. The output of photodiodes was converted into rectangular signals which were extracted in LabVIEW using the data acquisition card without using an analog to digital converters （ADC）. We have also processed the signals in C＋＋ after acquiring via parallel port. A Michelson interferometer configuration was used to produce linear fringes for the detection of displacements. The displacement less than 100nm could be measured using this technique.展开更多
文摘在通常的模具生产车间,模具电极只能依靠人来监控和管理,导致工作量大且效率低.为了解决这一问题,研究了无线射频识别技术在模具电极管理中的应用.利用微软Visual Studio 2008作为开发工具,采用B/S(浏览器/服务器)的系统架构,开发了一套基于无线射频识别技术的模具电极管理系统.首先,对系统总体结构进行设计,包括主要硬件的选型及参数的设置;接着,对系统业务流程进行了规范,再根据业务流程进行了功能需求分析;然后,对系统各功能模块进行了划分,对数据库结构进行了设计;最后,运用NET技术开发了系统各界面及功能.实践证明该系统对电极的管理方便有效,提高了模具电极管理的智能化水平.
文摘A power management unit （PMU） chip supplying dual panel supply voltage, which has a low electro-magnetic interference （EMI） characteristic and is favorable for miniaturization, is designed. A two-phase charge pump circuit using external pumping capacitor increases its pumping current and works out the charge-loss problem by using bulk-potential biasing circuit. A low-power start-up circuit is also proposed to reduce the power consumption of the band-gap reference voltage generator. And the ring oscillator used in the ELVSS power circuit is designed with logic devices by supplying the logic power supply to reduce the layout area. The PMU chip is designed with MagnaChip＇s 0.25 μ high-voltage process. The driving currents of ELVDD and ELVSS are more than 50 mA when a SPICE simulation is done.
文摘The white organic light emitting device (OLED) with single-structure using a polymer blend as the light emitting layer is fabricated.Heat treatment is used to control the ratio between the intensities of main electroluminescent spectral peaks.The electroluminescent spectrum of our device is quite similar to that of white inorganic LED produced by Nichia Corporation after being annealed,and its turn-on voltage can be decreased by 1 V.
基金This work was supported by the Ministry of Sdence and Technology of China （Grant Nos. 2011CB933001 and 2011CB933002）, National Natural Science Foundation of China （Grant Nos. 61322105, 61271051, 61321001, and 61390504）, and Beijing Municipal Science and Technology Commission （Grant Nos. Z131100003213021 and D141100000614001）.
文摘Realizing low contact resistance between graphene and metal electrodes remains a well-known challenge for building high-performance graphene devices. In this work, we attempt to reduce the contact resistance in graphene transistors and further explore the resistance limit between graphene and metal contacts. The Pd/graphene contact resistance at room temperature is reduced below the 100 Ω·μm level both on mechanically exfoliated and chemical-vapor-deposition graphene by adopting high-purity palladium and high-quality graphene and controlling the fabrication process to not contaminate the interface. After excluding the parasitic series resistances from the measurement system and electrodes, the retrieved contact resistance is shown to be systematically and statistically less than 100 Ω·μm, with a minimum value of 69 Ω·μm, which is very close to the theoretical limit. Furthermore, the contact resistance shows no clear dependence on temperature in the range of 77-300 K; this is attributed to the saturation of carrier injection efficiency between graphene and Pd owing to the high quality of the graphene samples used, which have a sufficiently long carrier mean-free-path.
文摘An interferometer based optical sensor for displacement measurement is reported. This method requires quite simple signal processing as well as least electronic components. Referring to this technique, two photodiodes spatially shifted by 90 degrees were used. The output of photodiodes was converted into rectangular signals which were extracted in LabVIEW using the data acquisition card without using an analog to digital converters （ADC）. We have also processed the signals in C＋＋ after acquiring via parallel port. A Michelson interferometer configuration was used to produce linear fringes for the detection of displacements. The displacement less than 100nm could be measured using this technique.
