GaAs单片集成激光器驱动电路在片测量

用多触头微波探针 ,对 Ga As单片集成激光器驱动电路芯片进行了在片测试和筛选 ,测得芯片频率响应带宽为 3.8GHz.使用高速增益开关半导体激光器作为采样光脉冲源 ,采用了背面直接采样方式建立了电光采样测试仪 .检测了 Ga As单片集成激光器驱动电路芯片内部点的高速电信号波形 .     

一静一动双基地SAR改进非线性CS算法

本文基于双基地一站固定（接收机固定）的特殊模式,首先建立了在该模式下双基地SAR的几何构型和信号模型;然后根据该模式的几何特点,分析了斜视情况下高次相位和调频率空变性对距离向聚焦的影响,考虑到利用驻定相位原理将信号从二维频域转换到距离多普勒域时二次模型的失效,引入了三次模型实现了距离向三次相位的补偿,其后通过距离多普勒域二次和三次扰动函数的相乘,并将距离向调频率在参考点进行展开,实现了距离向的聚焦和距离徙动的校正改进,并给出了距离向校正函数的解析表达式;最后,通过仿真和实测数据的处理验证了校正函数的正确性。      

Understanding Boosted Selective CO2-to-CO Photoreduction with Pure Water Vapor over Hierarchical Biomass-Derived Carbon Matrix

Solar-driven CO₂ reduction reaction (CO₂RR) with water into carbon-neutral fuels is of great significance but remains challenging due to thermodynamic stability and kinetic inertness of CO₂. Biomass-derived nitrogen-doped carbon (N-C_b) have been considered as promising earth-abundant photocatalysts for CO₂RR, although their activities are not ideal and the reaction mechanism is still unclear. Herein, an efficient catalyst is developed for CO₂-to-CO conversion realized on diverse N-C_b materials with hierarchical pore structures. It is demonstrated that the CO₂-to-CO conversion preferentially takes place on positively charged carbon atoms next to pyridinic-N using two representatives treated pollens with the largest difference in pyridinic-N density and N content as model photocatalysts. Systematic experimental results indicate that surface local electric field originating from charge separation can be boosted by hierarchical pore structures, doped N, as well as pyridinic-N. Mechanistic studies reveal that positively charged carbon atoms next to pyridinic-N serve as active sites for CO₂RR, reduce the energy barrier on the formation of CO*, and facilitate the CO₂RR performance. All these benefits cooperatively contribute to treated chrysanthemum pollen catalyst exhibiting excellent CO formation rate of 203.2 µmol h⁻¹ g⁻¹ with 97.2% selectivity in pure water vapor. These results provide a new perspective into CO₂RR on N-C_b, which shall guide the design of nature-based photocatalysts for high-performance solar-fuel generation.     

Miniaturized Dual-Mode Ring Bandpass Filters With Patterned Ground Plane

Miniaturized dual-mode ring bandpass filters with a patterned ground plane are proposed. By loading the resonator periodically with the butterfly radial slot cells on the ground plane, the size of a ring filter is reduced along with an extended upper stopband. Based on the equivalent circuits, the mode-splitting characteristics and impact of the patterned ground plane on the electrical performances of the filter are investigated. A slotline ring filter with a patterned ground plane is also proposed. The miniaturization is achieved by loading the periphery of the slotline ring with the butterfly radial stubs at the backside. The filter has a higher first spurious response and deeper stopband rejection than a conventional microstrip ring filter. Measured results validate the analysis and theoretical prediction with good agreement.     

Analysis of the time response of multiconductor transmission lineswith frequency-dependent losses by the method ofconvolution-characteristics

A new method for analysis of the time response of multiconductor transmission lines with frequency-dependent losses is presented. This method can solve the time response of various kinds of transmission lines with arbitrary terminal networks. Particularly, it can analyze nonuniform lines with frequency-dependent losses, for which no effective method for analyzing their time response exists. This method starts from the frequency-domain telegrapher's equations. After decoupling and inversely Fourier transforming, then a set of decoupled time-domain equations including convolutions are given. These equations can be solved with the characteristic method. The results obtained with this method are stable and accurate. Two examples are given to illustrate the application of this method to various multiconductor transmission lines     

新颖角振动微硅陀螺的设计

在分析原有双框架式角振动微硅陀螺的基础上,提出了一种新颖的微硅陀螺,给出了工作原理、运动方程及设计尺寸,并分析了新颖陀螺提高灵敏度的途径。     

集成电路工艺模拟软件SSUPREM4的校验

本文对知名的集成电路工艺模拟软件ＳＳＵＰＲＥＭ４进行了较仔细的校验,用ＳＳＵＰＲＥＭ４模拟了氧化、扩散工艺,并同实验值进行了比较,模拟值和实验值的偏差在１０％以内,与集成电路器件模拟软件Ｓ－ＰＩＳＣＥＳ联用校验了ＳＳＵＰＲＥＭ４的工序模拟结果,校验结果有较大参考价值。     

TiO2/MXene-Assisted LDI-MS for Urine Metabolic Profiling in Urinary Disease

Cancer remains an intractable medical problem. Rapid diagnosis and identification of cancer are critical to differentiate it from nonmalignant diseases. High-throughput biofluid metabolic analysis has potential for cancer diagnosis. Nevertheless, the present metabolite analysis method does not meet the demand for high-throughput screening of diseases. Herein, a high-throughput, cost-effective, and noninvasive urine metabolic profiling method based on TiO₂/MXene-assisted laser desorption/ionization mass spectrometry (LDI-MS) is presented for the efficient screening of bladder cancer (BC) and nonmalignant urinary disease. Combined with machine learning, TiO₂/MXene-assisted LDI-MS enables high diagnostic accuracy (96.8%) for the classification of patient groups (including 47 BC and 46 ureteral calculus (UC) patients) from healthy controls (113 cases). In addition, BC patients can also be identified from noncancerous UC individuals with an accuracy of 88.3% in the independent test cohort. Furthermore, metabolite variations between BC and UC individuals are investigated based on relative quantification, and related pathways are also discussed. These results suggest that this method, based on urine metabolic patterns, provides a potential tool for rapidly distinguishing urinary diseases and it may pave the way for precision medicine.     

Modulation of Electron Structure and Dehydrogenation Kinetics of Nickel Phosphide for Hydrazine-Assisted Self-Powered Hydrogen Production in Seawater

The electrocatalytic production of hydrogen from seawater provides a low-cost way to realize energy conversion, but is restricted by high potential for seawater electrolysis and the chlorine oxidation reaction (ClOR) at the anode. Here, the self-growth of Mo-doped Ni₂P nanosheet arrays with rich P vacancies on molybdenum-nickel foam (MNF) (Mo-Ni₂P_v@MNF) is reported as bifunctional catalyst for Cl-free hydrogen production by coupling hydrogen evolution reaction (HER) with hydrazine oxidation reaction (HzOR) in seawater. Impressively, the Mo-Ni₂P_v@MNF electrode as bifunctional catalyst has an excellent activity for overall hydrazine splitting (OHzS) with an ultralow voltage of only 571 mV at 1000 mA cm⁻² and can maintain stability for an ultra-long time of 1000 h at 100 mA cm⁻². Moreover, integration of OHzS into self-assembled hydrazine fuel cells (DHzFC) or solar cells can enable the self-powered H₂ production. The industrial hydrazine sewage as feed for the above eletrolysis system can be degraded to ≈5 ppb rapidly. Density functional thoery calculations demonstrate that the electronic structure modulation induced by P vacancies and Mo doping can not only achieve thermoneutral ΔG_H* for hydrogen evolution reaction but also enhance dehydrogenation kinetics from *N₂H₄ to *NHNH₂ for HzOR, achieving enhanced dehydrogenation kinetics.     

Quantum size impacts on the threshold voltage in nanocrystalline silicon thin film transistors

Based on the analysis of Poisson equation, an analytical threshold voltage model including quantum size effect of nc-TFTs (nanocrystalline silicon thin film transistor) has been proposed in this paper. The results demonstrate that the proposed simplified expression of threshold voltage agree perfectly with numerical calculation. The threshold voltage in nc-TFTs strongly depends on the size of silicon grain when the size of silicon grain is less than 20 nm. Such a strong dependent relation results from the large changes in the bandgap and dielectric constant due to quantum size effects when the size of silicon grain is in the regime of nano-scale. The theoretical investigation also demonstrates that the grain boundary trap density compared to the active dopant density gives a main contribution to the threshold voltage. This implies that the grain size must be larger than 30 nm in order to avoid threshold voltage variation from different technological processes.