并联谐振变换器式电容器充电电源

针对采用串联谐振变换器电容器充电电源的不足,通过分析、改进并联谐振变换器拓扑,研制了基于并联谐振全桥变换器研制的10 kJ/s,100 kV电容器充电电源,变换器开关采用脉冲宽度调制技术,开关频率达40 kHz,电源的反馈控制电路基于数字信号处理全数字控制器。并给出了充电电源及主要部件高频高压变压器的设计注意事项、经验及实验结果。     

Positive Solution of Elliptic Systems Involving Critical Growth

In this paper, we consider the asymptotic behaviour of the positive solution of elliptic systems with critical growth and obtain the growth rate.     

A General Preparation of Solid Solution-Oxide Heterojunction Photocatalysts through Metal–Organic Framework Transformation Induced Pre-nucleation

Solid solution-oxide heterostructures combine the advantages of solid solution and heterojunction materials to improve electronic structure and optical properties by metal doping, and enhance charge separation and transfer in semiconductor photocatalysts by creating a built-in electric field. Nevertheless, the effective design and synthesis of these materials remains a significant challenge. Here, we develop a generally applicable strategy that leverages the transformable properties of metal–organic frameworks (MOFs) to prepare solid solution-oxide heterojunctions with controllable structural and chemical compositions. The process consists of three main steps. First, MOFs with different topological structures and metal centers are transformed, accompanied by pre-nucleation of a metal oxide. Second, solid solution is prepared through calcination of the transformed MOFs. Finally, a heterojunction is formed by combining solid solution with another metal oxide group through endogenous overflow. DFT calculations and study on carrier dynamics show that the structure of the material effectively prevents electrons from returning to the bulk phase, exhibiting superior photocatalytic reduction performance of CO₂. This study is expected to promote the controllable synthesis and research of MOF-derived heterojunctions.     

Plasmon-Induced Charge Transfer-Enhanced Raman Scattering on a Semiconductor: Toward Amplification-Free Quantification of SARS-CoV-2

Semiconductors demonstrate great potentials as chemical mechanism-based surface-enhanced Raman scattering (SERS) substrates in determination of biological species in complex living systems with high selectivity. However, low sensitivity is the bottleneck for their practical applications, compared with that of noble metal-based Raman enhancement ascribed to electromagnetic mechanism. Herein, a novel Cu₂O nanoarray with free carrier density of 1.78×10²¹ cm⁻³ comparable to that of noble metals was self-assembled, creating a record in enhancement factor (EF) of 3.19×10¹⁰ among semiconductor substrates. The significant EF was mainly attributed to plasmon-induced hot electron transfer (PIHET) in semiconductor which was never reported before. This Cu₂O nanoarray was subsequently developed as a highly sensitive and selective SERS chip for non-enzyme and amplification-free SARS-CoV-2 RNA quantification with a detection limit down to 60 copies/mL within 5 min. This unique Cu₂O nanoarray demonstrated the significant Raman enhancement through PIHET process, enabling rapid and sensitive point-of-care testing of emerging virus variants.     

Wet-laiding hybrid PVA fibers into high electrolyte-uptake zinc-air battery separators: an efficient and cost-saving approach

Journal of Solid State Electrochemistry - Zinc-air battery receives continuous attention as an environment-friendly energy storage device, whose potential commercialization is calling for...