健那绿作光谱探针共振瑞利散射法测定藻酸钠

本文提出了共振瑞利散射法测定藻酸钠的新方法。研究发现在pH=4.0的Britton-Robinson缓冲溶液中,藻酸钠或健那绿单独存在时共振瑞利散射(RRS)强度非常弱,当两者反应形成复合物时,RRS大大增强并产生新的RRS光谱,其最大RRS峰位于560nm,另在328nm和397nm处产生两个强度较低的散射峰。在560nm处,藻酸钠的浓度在0.015～1.0μg/mL范围内与RRS强度有良好的线性关系,检出限(3σ/k)为5ng/mL。方法灵敏度高,选择性好,可用于面条和海带提取液中的藻酸钠测定。     

Hardware for multi-superconducting qubit control and readout

We have developed an electronic hardware system for the control and readout of multi-superconducting qubit devices. The hardware system is based on the design ideas of good scalability, high synchronization and low latency. The system, housed inside a VPX-6U chassis, includes multiple arbitrary-waveform generator (AWG) channels, analog-digital-converter (ADC) channels as well as direct current source channels. The system can be used for the control and readout of up to twelve superconducting transmon qubits in one chassis, and control and readout of more and more qubit can be carried out by interconnecting the chassis. By using field programmable gate array (FPGA) processors, the system incorporates three features that are specifically useful for superconducting qubit research. Firstly, qubit signals can be processed using the on-board FPGA after being acquired by ADCs, significantly reducing data processing time and data amount for storage and transmission. Secondly, different output modes, such as direct output and sequential output modes, of AWG can be implemented with pre-encoded FPGA. Thirdly, with data acquisition ADCs and control AWGs jointly controlled by the same FPGA, the feedback latency can be reduced, and in our test a 178.4 ns latency time is realized. This is very useful for future quantum feedback experiments. Finally, we demonstrate the functionality of the system by applying the system to the control and readout of a 10 qubit superconducting quantum processor.     

溶剂热制备氧化锌纳米线

ZnO nanowires were synthesized mildly through an absolute alcohol solvothermal process at 120 ℃ for 12 h using ZnAc₂·2H₂O and NaOH as raw materials and PEG400 as a soft template. The cyrstal structure and morphology of the nanowires were characterized by XRD, SEM, TEM and HRTEM. The results indicate that the diameter of ZnO nanowires is 40 nm, the length can reach 2 μm and the nanowires are of high purity, homogeneity and well crystallinty. The influence of the various factors on the formation of ZnO nanowires and formation mechanism were also discussed.