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1,131 results on '"Li Xiuping"'

236. An X-Band Multifrequency Difference Frequency-Shift Keying CMOS Radar for Range Tracking and AI-Based Human Gesture Recognition

Author

Li, Yubing, Wu, Qichao, Tian, Ziye, Wang, Jianpeng, Liu, Chujun, Qi, Rui, Li, Shoulin, and Li, Xiuping

Abstract

This article presents an ${X}$ -band single-chip fully integrated multifrequency difference frequency-shift keying (FSK) in-phase and quadrature (I/Q) direct-conversion radar transceiver implemented in a 130-nm CMOS process. Combined with the artificial intelligence (AI)-based algorithm, accurate gesture recognition is realized. The phase-locked loop (PLL)-based dual-frequency difference FSK waveform and ranging algorithm are proposed to solve the tradeoff between the maximum unambiguous range and the ranging accuracy. The loop bandwidth optimized integer- ${N}$ PLL is integrated to generate standard-compliant FSK signals with predictable frequency differences. The relationship between instantaneous ranging bias and PLL loop parameters is analyzed in detail. The proposed bias noise filter fully suppresses the flicker noise and improves the receiver noise figure (NF). The quadrature signal generator (QSG) adopts a fully differential amplifier buffered resistance compensation quadrature all-pass filter (QAF) to improve the I/Q balance and insertion loss. The chip consumes a current of 56 mA and provides a conversion gain (CG) of 22–102 dB. The single-ended transmit power is 1.5 dBm. To the best of our knowledge, the implemented transceiver is the first recorded ${X}$ -band FSK radar transceiver and provides a low-cost solution for indoor human detection.

Published
2023
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250. The Size-dependent Cytotoxicity of Amorphous Silica Nanoparticles: A Systematic Review of in vitro Studies

Author

Dong,Xuemeng, Wu,Zehao, Li,Xiuping, Xiao,Liyan, Yang,Man, Li,Yang, Duan,Junchao, and Sun,Zhiwei

Subjects
International Journal of Nanomedicine
Abstract

Xuemeng Dong,1 Zehao Wu,1 Xiuping Li,1 Liyan Xiao,1 Man Yang,1,2 Yang Li,1,2 Junchao Duan,1,2 Zhiwei Sun1,2 1School of Public Health, Capital Medical University, Beijing 100069, People’s Republic of China; 2Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, People’s Republic of ChinaCorrespondence: Zhiwei Sun; Yang LiBeijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing 100069, People’s Republic of ChinaTel/Fax +86 010 83911507; +86 010 83911868Email zwsun@ccmu.edu.cn; li_yang@ccmu.edu.cnAbstract: With the increasing production and application of engineered amorphous silica nanoparticles (aSiNPs), people have more opportunities to be exposed to aSiNPs. However, the knowledge of its adverse health effects and related mechanisms is still limited, compared with the well-studied crystalline micron-sized silica. Since small differences in the physical–chemical properties of nanoparticles could cause significant differences in the toxic effect, it is important to distinguish how these variations influence the outcoming toxicity. Notably, particle size, as one of the essential characterizations of aSiNPs, is relevant to its biological activities. Thus, the aim of this systematic review was to summarize the relationship between the particle size of aSiNPs and its adverse biological effects. In order to avoid the influence of complicated in vivo experimental conditions on the toxic outcome, only in vitro toxicity studies which reported on the cytotoxic effect of different sizes aSiNPs were included. After the systematic literature retrieval, selection, and quality assessment process, 76 eligible scientific papers were finally included in this review. There were 76% of the studies that concluded a size-dependent cytotoxicity of aSiNPs, in which smaller-sized aSiNPs possessed greater toxicity. However, this trend could be modified by certain influence factors, such as the synthetic method of aSiNPs, particle aggregation state in cell culture medium, toxicity endpoint detection method, and some other experimental conditions. The effects of these influence factors on the size-dependent cytotoxicity of aSiNPs were also discussed in detail in the present review.Keywords: silica nanoparticles, particle size, cytotoxicity, cell death, nanotoxicology, influence factors

Published
2020

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