基于ATmega128的精密空调控制系统设计

为了能够准确监测和控制机房的温湿度,以保证通信机房内计算机的高效运行。系统采用ATmega128单片机为控制中心,由STH11温湿度传感器、RS485通信接口及12864字符型液晶模块构成的精密空调控制系统,实现对机房的温湿度精确测量与控制。该系统电路简单、工作稳定、集成度高,调试方便,测试精度高,具有一定的实用价值。     

Bias-Free Solar Water Splitting by Tetragonal Zircon BiVO4 Nanocrystal Photocathode and Monoclinic Scheelite BiVO4 Nanoporous Photoanode

p-type tetragonal zircon BiVO₄ nanocrystal photocathodes (P-BVO) and n-type monoclinic scheelite BiVO₄ nanoporous photoanodes (N-BVO) are prepared by a hydrothermal method and an electrochemical synthesis method, respectively. Pt nanoparticles and cobalt-phosphate (Co-Pi) as co-catalysts are loaded by an electrodeposition way to improve the photoelectrochemical (PEC) performance of BiVO₄ (BVO) electrodes. After modification, a monochromatic incident photon-to-current conversion efficiency (IPCE) of P-BVO/Pt at 360 nm is improved by 2.2 times, and the highest IPCE of N-BVO/Co-Pi at 440 nm is increased by 1.7 times. The calculated electron-hole separation yield and the charge carrier injection yield of N-BVO/Co-Pi at 1.23 V_RHE are further improved to 80% and 86%, respectively. The surface modification also results in the latest ≈0.2% half-cell solar-to-hydrogen energy conversion efficiency (HC-STH) for a P-BVO/Pt photocathode and a higher ≈1.16% half-cell applied bias photon-to-current conversion efficiency (ABPE) for an N-BVO/Co-Pi photoanode. Furthermore, the prepared photoelectrodes are proved to have excellent stability for water splitting. Above all, a tandem-type PEC cell containing the newly developed P-BVO/Pt photocathode and an N-BVO/Co-Pi photoanode is built for the first time, which evolves H₂ and O₂ at a stoichiometric ratio of 2:1 with a bias-free STH of 0.14%.     

Direct solar water splitting cell using water, WO3, Pt, and polymer electrolyte membrane

A solar water splitting cell composed of WO₃, Polymer Electrolyte Membrane (PEM) and Pt was constructed for producing hydrogen from deionized water in sunlight. Spectral responsivity measurements under various temperatures and bias voltages were conducted for the cell using the Incident Photon to Current Efficiency (IPCE) method. For comparison, a known WO₃ Photo Electro Chemical (PEC) cell containing H₃PO₄ electrolyte, WO₃/H₃PO₄/Pt, was tested using the same test method. The WO₃/PEM–H₂O/Pt cell showed better Quantum Efficiency (QE) performance compared to that obtained from the cell with the chemical electrolyte. For the first time, spectral responsivity of photo water splitting process without bias power was unveiled in the new WO₃ cell, demonstrating the self-sustained photo electrolysis capability. Bias voltage effect on Solar to Hydrogen (STH) conversion efficiency was dramatic in the range from 0.2 V to 1.2 V and suppressions of STH were observed when high bias voltages were applied. In addition, a strong temperature effect on the energy conversion efficiency at high bias voltage was observed in the cell containing PEM–H₂O, revealing that the STH at 54 °C is nearly five times that at 14 °C.     

仓库温湿度监测与nRF905无线传输系统的设计

基于MSP430的仓库温湿度监测系统采用了先进的数字式温湿度一体化SHT芯片,通过nRF905无线方式传输数据,大大简化了硬件成本.SHT传感芯片接口简单,内部集成了包括补偿电路在内的各种元器件,具有较高的测量精度.nRF905是一种集收发于一体的单片无线收发器,能够自动产生前导码和CRC,误码率低.给出了比较详细的框...