Manipulation of Helicity-Dependent Photocurrent and Stokes Parameter Detection in Topological Insulator Bi2Te3 Nanowires.

Helicity-dependent photocurrent (HDPC) and its modulation in topological insulator Bi2Te3 nanowires have been investigated. It is revealed that when the incident plane of a laser is perpendicular to the nanowire, the HDPC is an odd function of the incident angle, which is mainly contributed by the circular photogalvanic effect originating from the surface states of Bi2Te3 nanowire. When the incident plane of a laser is parallel to the nanowire, the HDPC is approximately an even function of the incident angle, which is due to the circular photon drag effect coming from the surface states. It is found that the HDPC can be effectively tuned by the back gate and the ionic liquid top gate. By analyzing the substrate dependence of the HDPC, we find that the HDPC of the Bi2Te3 nanowire on the Si substrate is an order of magnitude larger than that on SiO2, which may be due to the spin injection from the Si substrate to the Bi2Te3 nanowire. In addition, by applying different biases, the Stokes parameters of a polarized light can be extracted by arithmetic operation of the photocurrents measured in the Bi2Te3 nanowire. This work suggests that topological insulator Bi2Te3 nanowires may provide a good platform for opto-spintronic devices, especially in chirality and polarimtry detection.

Vibration Detection and Degraded Image Restoration of Space Camera Based on Correlation Imaging of Rolling-Shutter CMOS.

To mitigate the influence of satellite platform vibrations on space camera imaging quality, a novel approach is proposed to detect vibration parameters based on correlation imaging of rolling-shutter CMOS. In the meantime, a restoration method to address the image degradation of rolling-shutter CMOS caused by such vibrations is proposed. The vibration parameter detection method utilizes the time-sharing and row-by-row imaging principle of rolling-shutter CMOS to obtain relative offset by comparing two frames of correlation images from continuous imaging. Then, the space camera's vibration parameters are derived from the fitting curve parameters of the relative offset. According to the detected vibration parameters, the discrete point spread function is obtained, and the rolling-shutter CMOS image degradation caused by vibration is restored row by row. The verification experiments demonstrate that the proposed detection method for two-dimensional vibration achieves a relative accuracy of less than 1% in period detection and less than 2% in amplitude detection. Additionally, the proposed restoration method can enhance the MTF index by over 20%. The experimental results demonstrate that the detection method is capable of detecting high-frequency vibrations through low-frame-frequency image sequences, and it exhibits excellent applicability in both push-scan cameras and staring cameras. The restoration method effectively enhances the evaluation parameters of image quality and yields a remarkable restorative effect on degraded images.

In-situ detection scheme for EGFR gene with temperature and pH compensation using a triple-channel optical fiber biosensor.

An advanced multi-parameter optical fiber sensing technology for EGFR gene detection based on DNA hybridization technology is demonstrated in this paper. For traditional DNA hybridization detection methods, temperature and pH compensation can not be realized or need multiple sensor probes. However, the multi-parameter detection technology we proposed can simultaneously detect complementary DNA, temperature and pH based on a single optical fiber probe. In this scheme, three optical signals including dual surface plasmon resonance signal (SPR) and Mach-Zehnder interference signal (MZI) are excited by binding the probe DNA sequence and pH-sensitive material with the optical fiber sensor. The paper proposes the first research to achieve simultaneous excitation of dual SPR signal and Mach-Zehnder interference signal in a single fiber and used for three-parameter detection. Three optical signals have different sensitivities to the three variables. From a mathematical point of view, the unique solutions of exon-20 concentration, temperature and pH can be obtained by analyzing the three optical signals. The experimental results show that the exon-20 sensitivity of the sensor can reach 0.07 nm nM-1, and the limit of detection is 3.27 nM. The designed sensor gives a fast response, high sensitivity, and low detection limit, which is important for the field of DNA hybridization research and for solving the problems of biosensor susceptibility to temperature and pH.

Dye-Encapsulated Metal-Organic Frameworks for the Multi-Parameter Detection of Temperature.

Temperature is an important physical parameter and plays a significant role in scientific research, the detection of which cannot be too crucial to study. In order to reduce the interference of the external environment on the detection of temperature and improve the accuracy of the detection results, a multi-parameter detection method using several optical signals was proposed. Here, a novel porous metal-organic framework (MOF), Zn-CYMPN, was synthesized and structurally characterized. Then, fluorescent organic dyes, either DPEE or DPEM, were encapsulated into the pores of Zn-CYMPN independently. The successful synthesis of the composites Zn-CYMPN⊃DPEE or Zn-CYMPN⊃DPEM could easily introduce other fluorescent centers into the original material and made it more convenient to realize multi-parameter temperature detection. More specifically, when the temperature changed, the maximum fluorescent emission wavelength (W) and the maximum optical intensity (I) of the Zn-CYMPN⊃DPEE/DPEM both showed good linear responses with temperature over a wide range, indicating that the composites were highly sensitive thermometers with multi-parameter temperature readouts. In addition, the quantum efficiency and thermal stability of the organic dyes, which bother every researcher, were improved as well.

Monitoring and Control of Medical Air Disinfection Parameters of Nosocomial Infection System Based on Internet of Things.

To include the two key parameters of circulating air volume and instantaneous ultraviolet illuminance, as well as the minor influencing factors such as temperature, humidity, comings and goings of personnel and other parameters into the scope of conventional monitoring, and monitor and alarm each parameter, the key problem is to design the data transmission of sensors of existing products and debug the network management system, and solve every problem in the research process through the cycle of experiment-trial-experiment. The specific functions of a single instrument and system software can be achieved by solving the key links such as type selection of various sensors, circuit interface, guarantee measures for measurement accuracy of various parameters, research and development of networked air disinfection management system software, design of WiFi interface, cost control of single machine and system and so on. And ultraviolet luminance sensors can be used to monitor the ultraviolet intensity in the machine in real time, and monitor 7 parameters, including circulating air volume, ozone concentration, comings and goings of personnel, temperature, humidity and leaked ultraviolet intensity.

Study on quality control before application and after maintenance of the infantincubator / 中国医学装备

Objective:To implement quality control in whole life cycle for infant incubator, and ensure it working in safe and efficient situation.Methods:The parameter detection cases of infant incubator was analyzed and researched according to relative standards and requirements of technique for medical equipment.Results:The detection data and frequent failures of clinical cases revealed that there were parameter deviation existing in infant incubators. These deviations should be adjusted in time according to relative standards and requirements of technique for medical equipment.Conclusion:The quality control of whole life cycle for infant incubator is the necessary condition for ensuring medical quality and safety of patients. To pay attention to the quality control before and after application and after maintenance of the infant medical incubator, in order to ensure the medical equipment can achieve to meet the performance requirement of treatment and provide safe and efficient quality service for patients.