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377 results on '"Liu, Wencong"'

1. Metal Mesh-Based Infrared Transparent Electromagnetic Shielding Windows with Balanced Shielding Properties over a Wide Frequency Range

Author

Liang, Yuanlong, Wen, Kui, Wu, Zhaofeng, Pan, Jisheng, Liu, Wencong, Yao, Lixiang, Liu, Peiguo, and Huang, Xianjun

Subjects
Physics - Optics, Physics - Applied Physics
Abstract

With the increasing complexity of the electromagnetic environment, electromagnetic interference has already been an important problem for optoelectronic systems to be reckoned with. The metal mesh film is a kind of widely used electromagnetic shielding material with both visible and infrared transparency. However, the shielding performance of previously reported mesh materials is frequency dependent. Here, we report an infrared-transparent electromagnetic shielding windows based on metal mesh with irregular patterns. The mesh coatings are prepared on sapphire substrate using ultraviolet photolithography technology, and provide efficient electromagnetic shielding effectiveness of more than 20 dB in the wide frequency range of 1.7~18 GHz while maintaining high infrared optical transparency. In addition, there is no distinct variation in shielding effectiveness between low and high frequency range, exhibiting a balanced shielding characteristic throughout a broad frequency band. This work could be significant in protecting infrared optoelectronic devices from electromagnetic interference., Comment: 17 pages, 5 figures

Published
2022

2. Shorted Micro-Waveguide Array for High Optical Transparency and Superior Electromagnetic Shielding in Ultra-Wideband Frequency Spectrum

Author

Liang, Yuanlong, Huang, Xianjun, Pan, Jisheng, Liu, Wencong, Wen, Kui, Zhai, Duocai, Shang, Peng, and Liu, Peiguo

Subjects
Physics - Optics, Condensed Matter - Materials Science, Physics - Applied Physics
Abstract

While functional materials with both light transmitting and electromagnetic shielding are highly desirable, only very few of them meet the stringent electromagnetic interference (EMI) shielding criteria for optoelectronic systems. Here, a design strategy of shorted micro-waveguides (SMWs) array to decouple the light transmission and EMI shielding is proposed and experimentally demonstrated. The array of SMWs, consisting of cut-off metallic micro-waveguides and shorting indium tin oxide (ITO) continuous conductive film, exhibits high optical transmittance of 90.4% and superior EMI shielding effectiveness of 62.2 dB on average over ultra-wide frequency spectrum (0.2-1.3 GHz & 1.7-18 GHz). Compared to previously reported works, an improvement of 19 dB in average shielding effectiveness has been achieved under the same level of light transmission, and the shielding frequency spectrum has been significantly expanded. The working principle has been explained in depth and factors influencing the performance have been investigated for design optimization.

Published
2022

3. On the generalized exponential sums and their fourth power mean

Author

Liu Wencong and Ning Shushu

Subjects
two-term exponential sums, gauss sums, fourth power mean, analytic method, calculating formula, 11l03, 11l05, Mathematics, QA1-939
Abstract

The main purpose of this article is to study the calculating problem of the fourth power mean of the two-term exponential sums and provide an accurate calculating formula for utilizing analytical methods and character sums’ properties. In the meantime, a result of the fourth power mean of Gauss sums is improved.

Published
2024
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40. Application of Surface Coil for Nuclear Magnetic Resonance Studies of Semi-conducting Thin Films

Author

Liu, Wencong, Lu, Lu, and Mitrović, V. F.

Subjects
Physics - Instrumentation and Detectors, Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science, Condensed Matter - Superconductivity
Abstract

We conduct a comprehensive set of tests of performance of surface coils used for nuclear magnetic resonance (NMR) study of quasi 2-dimensional samples. We report ${^{115} \rm{In}}$ and ${^{31} \rm{P}}$ NMR measurements on InP, semi-conducting thin substrate samples. Surface coils of both zig-zag meander-line and concentric spiral geometries were used. We compare reception sensitivity and signal-to-noise ratio (SNR) of NMR signal obtained by using surface-type coils to that obtained by standard solenoid-type coils. As expected, we find that surface-type coils provide better sensitivity for NMR study of thin films samples. Moreover, we compare the reception sensitivity of different types of the surface coils. We identify the optimal geometry of the surface coils for a given application and/or direction of the applied magnetic field., Comment: 7 pages, 9 figures

Published
2017
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41. Exposure to mixtures of PM2.5 components and term premature rupture of membranes: a case-crossover study in Shijiazhuang, China.

Author

Ren, Weiyan, Yang, Huangmin, Liu, Wencong, Zhang, Shaochong, Yang, Yanjing, Yang, Lei, Liu, Wenxuan, Zhang, Haijuan, He, Ke, Li, Xia, and Ge, Jun

Subjects
SULFATES analysis, NITRATE analysis, ORGANIC compound analysis, CARBON analysis, AIR pollution, RISK assessment, POISSON distribution, MATERNAL exposure, RESEARCH funding, LOGISTIC regression analysis, PREGNANT women, DESCRIPTIVE statistics, CROSSOVER trials, HUMIDITY, RESEARCH, QUATERNARY ammonium compounds, PREGNANCY complications, PARTICULATE matter, TEMPERATURE, DISEASE risk factors
Abstract

This study aims to explore the acute effects of short-term exposure to PM2.5 components and their mixture on PROM. Counts of hospital admissions due to PROM were collected at the Fourth Hospital of Shijiazhuang. The associations between the PROM and PM2.5 components was examined using a time-stratified case-crossover approach. The overall effects of components on TPROM were examined using the BKMR. During the study period 30,709 cases of PROMwere identified. The relative risks and the 95% CI of TPROM were 1.013 (1.002, 1.028) and 1.015 (1.003, 1.028) associated with per interquartile range increase in nitrate and ammonium ion on the current day and they were 1.007 (1.001, 1.013) and 1.003 (1.000, 1.005) on the previous day. The results from the BKMR models showed a higher risk of TPROM was associated with exposure to mixtures, in which, nitrate and organic matter were the main contributors to the overall effect. [ABSTRACT FROM AUTHOR]

Published
2024
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42. Mechanism of Action of Dihydroquercetin in the Prevention and Therapy of Experimental Liver Injury.

Author

Wei, Hewei, Zhao, Ting, Liu, Xinglong, Ding, Qiteng, Yang, Junran, Bi, Xiaoyu, Cheng, Zhiqiang, Ding, Chuanbo, and Liu, Wencong

Subjects
ALCOHOLIC liver diseases, BIOAVAILABILITY, FATTY liver, TREATMENT effectiveness, LIVER injuries, LIVER cells
Abstract

Liver disease is a global health problem that affects the well-being of tens of thousands of people. Dihydroquercetin (DHQ) is a flavonoid compound derived from various plants. Furthermore, DHQ has shown excellent activity in the prevention and treatment of liver injury, such as the inhibition of hepatocellular carcinoma cell proliferation after administration, the normalization of oxidative indices (like SOD, GSH) in this tissue, and the down-regulation of pro-inflammatory molecules (such as IL-6 and TNF-α). DHQ also exerts its therapeutic effects by affecting molecular pathways such as NF-κB and Nrf2. This paper discusses the latest research progress of DHQ in the treatment of various liver diseases (including viral liver injury, drug liver injury, alcoholic liver injury, non-alcoholic liver injury, fatty liver injury, and immune liver injury). It explores how to optimize the application of DHQ to improve its effectiveness in treating liver diseases, which is valuable for preparing potential therapeutic drugs for human liver diseases in conjunction with DHQ. [ABSTRACT FROM AUTHOR]

Published
2024
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49. Preparation and evaluation of Gastrodia elata polysaccharide loaded electrospinning nanofiber facial mask.

Author

Wang, Yao, Wang, Ning, Liu, Wencong, Cheng, Zhiqiang, Li, Wei, Zhao, Yan, and Zhu, Hongyan

Abstract

Facial masks available in the market are primarily made of non‐woven fabric. To extend their shelf life, preservatives, and essences are added to their ingredients. However, this practice has a significant impact on the environment and human health. As a result, consumers nowadays prefer to choose "Clean Beauty" products for their skincare routines. Herein, electrospinning technology was used to prepare a novel Janus nanofiber membrane comprising Polylactic acid/Polyvinylpyrrolidone (PLA/PVP) and Chitosan/Gelatin (CS/GEL), loaded with Gastrodia elata polysaccharide (GEP) and melatonin (MT). The Janus nanofiber facial mask is a solid mask that provides excellent moisturizing, antioxidant, and biocompatibility benefits. It can dissolve quickly and be absorbed by the skin, while the hydrophobic fiber helps slow down the rapid evaporation of water in the mask. This, combined with the Janus structure, helps delay the loss of water and allows for quick penetration, resulting in a long‐lasting moisturizing effect. Therefore, the Janus nanofiber facial mask is an ideal choice for solid facial masks and provides technical support for its application in this field. [ABSTRACT FROM AUTHOR]

Published
2024
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