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介绍了微生物的特点和化学组成,同时介绍了废水的来源、特征,废水处理方法以及在废水处理中的微生物特征和净化废水的作用机理。随着微生物学的发展、微生物应用技术的进步,微生物在废水处理中起着日益重要的作用。 相似文献
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As the front-end preamplifiers in optical receivers, transimpedance amplifiers (TIAs) are commonly required to have a high gain and low input noise to amplify the weak and susceptible input signal. At the same time, the TIAs should possess a wide dynamic range (DR) to prevent the circuit from becoming saturated by high input currents. Based on the above, this paper presents a CMOS transimpedance amplifier with high gain and a wide DR for 2.5 Gbit/s communications. The TIA proposed consists of a three-stage cascade pull push inverter, an automatic gain control circuit, and a shunt transistor controlled by the resistive divider. The inductive-series peaking technique is used to further extend the bandwidth. The TIA proposed displays a maximum transimpedance gain of 88.3 dBΩ with the -3 dB bandwidth of 1.8 GHz, exhibits an input current dynamic range from 100 nA to 10 mA. The output voltage noise is less than 48.23 nV/√Hz within the -3 dB bandwidth. The circuit is fabricated using an SMIC 0.18 μm 1P6M RFCMOS process and dissipates a dc power of 9.4 mW with 1.8 V supply voltage. 相似文献
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依据国家标准GBT 14849.4-2014,采用电感耦合等离子体光谱法,对工业硅(质量分数99%以上)中铁元素含量进行测量不确定度分析.从标准溶液、标液配制、人员操作、标准曲线拟合、样品处理、仪器设备、试验环境等多个方面进行不确定度评估。结果显示铁质量分数在0.60%时,该方法合成不确定度为0.015%,扩展不确定度为0.030%(k=2)。同时根据不确定度引入分量占比评估发现,对不确定度引入最大因素为:人员操作(重复性)、标准曲线拟合和标准溶液。试剂称量及体积影响较小。 相似文献
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