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The electrical design of a membrane antenna for a lunar-based low-frequency radio telescope

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Astronomical Techniques and Instruments 2024年第4期1卷 227-238页

作者： Suonanben Fengquan Wu Kai He Shijie Sun Wei Zhou Minquan Zhou Cong Zhang jiaqin xu Qisen Yan Shenzhe xu Jiacong Zhu Zhao Wang Ke Zhang Haitao Miao Jixia Li Yougang Wang Tianlu Chen xuelei Chen Key Laboratory of Cosmic Rays(Tibet University) Ministry of EducationLhasa 850000China Department of Physics College of ScienceTibet UniversityLhasa 850000China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Key Laboratory of Radio Astronomy and Technology Chinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Shanxi University Taiyuan 030000China School of Mechanical Engineering Hangzhou Dianzi UniversityHangzhou 310018China Center for Astronomy and Space Sciences China Three Gorges UniversityYichang 443002China Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Center of High Energy Physics Peking UniversityBeijing 100871China

Detecting primordial fluctuations from the cosmic dark ages requires extremely large low-frequency radio telescope arrays deployed on the far side of the *** antenna of such an array must be lightweight,easily storable and transportable,deployable on a large scale,durable,and capable of good electrical performance.A membrane antenna is an excellent candidate to meet these *** study the design of a low-frequency membrane antenna for a lunar-based low-frequency(<30 MHz)radio telescope constructed from polyimide film widely used in aerospace applications,owing to its excellent dielectric properties and high stability as a substrate *** first design and optimize an antenna in free space through dipole deformation and coupling principles,then simulate an antenna on the lunar surface with a simple lunar soil model,yielding an efficiency greater than 90%in the range of 12-19 MHz and greater than 10%in the range of 5-35 *** antenna inherits the omni-directional radiation pattern of a simple dipole antenna in the 5-30 MHz frequency band,giving a large field of view and allowing detection of the 21 cm global signal when used alone.A demonstration prototype is constructed,and its measured electrical property is found to be consistent with simulated results using|S11|*** membrane antenna can potentially fulfill the requirements of a lunar low-frequency array,establishing a solid technical foundation for future large-scale arrays for exploring the cosmic dark ages.

关键词： Membrane antenna Lunar-based radio array Cosmic dark ages

Clinical practice of rapid antigen tests for SARS-CoV-2 Omicron variant:A single-center study in China

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Virologica Sinica 2022年第6期37卷 842-849页

作者： Mengyuan Chen jiaqin xu Lingjun Ying Miaoguo Cai Tao-Hsin Tung Kai Zhou Yufen Zheng Xiaojie Bi Jing Wang Xi Tu Bo Shen Dongqing Lv Department of Laboratory Medicine Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical UniversityTaizhou317000China Hepatology and Infectious Diseases Center Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical UniversityTaizhou317000China Department of Radiation Oncology Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical UniversityTaizhou317000China Evidence-based Medicine Center Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical UniversityTaizhou317000China Department of Respiratory and Critical Diseases Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical UniversityTaizhou317000China

Responding to the fast-spreading SARS-CoV-2 Omicron variant, to improve screening efficiency, rapid antigen tests(RATs) were first added as a supplementary detection method in China in mid-March, 2022. What and how big a role RATs should play need to be supported by clinical data. Here, RAT performance and relevant factors in comparison with nucleic acid amplification tests(NAATs) were assessed in Omicron-infected inpatients. From the NAAT results, nasopharyngeal swabs(NPs) performed better than oropharyngeal swabs(OPs). RATs tested on NAAT positive NPs performed better than those with OP-positive samples. The RAT positivity rate was strongly associated with high levels of N and OFR1ab genes, especially in NPs where patients also had significantly longer hospital stays and shorter days from symptom onset to RAT testing. Self-performed RATs had a detection accuracy that was comparable to professionally performed RATs when the subjects were well guided. The antigen negative rate of the studied patients was 100% at discharge. These findings suggest that, in addition to a supplementary detection role, RATs can be an important strategy for evaluating the disease progression of Omicron-infected inpatients. This study provides important clinical data to support better rules regarding RATs under China’s COVID-19 prevention and control policy.

关键词： SARS-CoV-2 Omicron variant Rapid antigen tests(RATs) Dynamic zero-COVID policy COVID-19 progression evaluation

Retention Mechanism of Phenolic Compounds in Subcritical Water Chromatography

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Chemical Research in Chinese Universities 2015年第1期31卷 103-106页

作者： WUYichao DENG Xiuqing MAO Yinchun ZHANG Yan LIU jiaqin RONG Li xu Zhihong School of Physics and Chemistry Xihua University Chengdu 610039 P. R. China

The transfer enthalpies and entropies of hydroxyl and nitryl in different mobile phase systems were compared by van＇t Hoff curve. Results suggest that the presence of acetonitrile and methanol in the mobile phase may decrease the interaction of solute and stationary phase with respect to subcritical water, thereby reducing the contribution of enthalpy to the retention. Retention mechanisms of phenolic compound appear to be more similar in subcritical water and water/methanol systems on the PRP-1 column. Hydrogen bond in subcritical water system plays a very important role in the retention of the phenols.

关键词： Subcritical water chromatography Phenols Retention mechanism Hydrogen bond

基于CRM-TE模型的抗肿瘤药物最适剂量估计方法

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中国卫生统计 2023年第2期40卷 195-198页

作者：周克强李爽徐佳钦李康哈尔滨医科大学卫生统计学教研室 150081

目的研究一种新的抗肿瘤药物剂量探索模型(continual reassessment method based on toxicity and efficacy,CRM-TE),这种模型可以在I期临床试验中同时考虑毒性和疗效的药物作用,给II期临床试验推荐最适剂量(recommend the optimal dose... 详细信息

目的研究一种新的抗肿瘤药物剂量探索模型(continual reassessment method based on toxicity and efficacy,CRM-TE),这种模型可以在I期临床试验中同时考虑毒性和疗效的药物作用,给II期临床试验推荐最适剂量(recommend the optimal dose,RP2D)。方法基于连续重评估模型(continual reassessment model,CRM)对药物的剂量-毒性和剂量-疗效曲线分别进行估计,并根据给出的权衡函数选择最适剂量。结果本文提出最适剂量估计方法与目前现有的同类型方法相比,能够在保证安全性的前提下,同时综合考虑不同剂量下的疗效,使选择的RP2D更为合理。结论本文为药物临床试验最适推荐剂量提供了一种新的方法,对于抗肿瘤等药物剂量探索具有一定的实用价值。

关键词：临床试验最适剂量权衡函数

Riverine sulfate sources and behaviors in arid environment,Northwest China:Constraints from sulfur and oxygen isotopes

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Journal of Environmental Sciences 2024年第3期137卷 716-731页

作者： Yifu xu Wenjing Liu Bing xu Zhifang xu Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The fate of riverine sulfate ion (SO_(4)^(2-)) and its environmental effects in arid environment are difficult to evaluate due to its complicated sources and strongly coupled behaviors with water cycle which is significantly modified by *** understand the sulfur cycle in aquatic systems in arid environment,the chemical and sulfur and oxygen isotopic compositions (δ^(34)S_(SO4)and δ^(18)O_(SO4)) of major rivers around the Badain Jaran Desert,northwestern China,were *** rivers had averaged SO_(4)^(2-)content at 1336μmol/L,over 10times higher than the global *** δ^(34)S_(SO4)and δ^(18)O_(SO4)values ranged from-5.3‰to+11.8‰and+1.6‰to+12.8‰,*** end-member analysis and the inverse model showed that riverine sulfate was mainly derived from evaporites dissolution (0-87%),sulfide oxidation (13%-100%) and precipitation (0-33%),indicating heterogeneity in sulfur sources and behaviors along the river drainage with the lithology variations and climate *** isotopic tools combining with hydro-chemistry compositions could be applied to reveal sulfur cycle in arid *** on the calculation,sulfide oxidation plays the primary role in the headwater and upstream in the Qilian-Mountains area,where sulfide is widely *** the proportion of evaporites dissolution contributing to riverine sulfate is much higher in downstream in a drier ***,less precipitation and higher temperature can lead to more intensive evaporation,affecting the process of sulfide oxidation and enhancing the rates of evaporites dissolution and sulfate precipitation in the basin.

关键词： Sulfur and oxygen isotopes Source apportionment Inverse model Arid environment Inland rivers Northwestern China

Laboratory evaluation of high-friction thin overlays for pavement preservation

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Frontiers of Structural and Civil Engineering 2024年第6期18卷 936-948页

作者： Ouming xu Rentao xu Lintong JIN School of Highway Chang’an UniversityXi’an 710064China School of Materials Science and Engineering Chang’an UniversityXi’an 710061China

Traditional asphalt concrete(AC)and stone matrix asphalt(SMA),which are used as thin asphalt overlays,are common maintenance strategies to enhancing ride quality,skid resistance,and ***,several studies have used a novel asphalt mixture known as a high-friction thin overlay(HFTO)to improve surface ***,it remains uncertain whether the laboratory properties of HFTO differ significantly from those of conventional *** study aims to evaluate the laboratory properties of HFTO mixtures and compare them with those of AC and *** mixtures with nominal maximum size of 9.5 mm were produced in the laboratory,and performance tests were conducted,including wheel tracking test,low temperature flexural creep test,moisture susceptibility test,Cantabro Abrasion Test,Marshall Test,sand patch test,British pendulum test,and indoor tire-rollingdown *** results showed that the HFTO exhibited a lower tire/pavement noise than the AC and ***,HFTO had superior high-temperature stability,larger macro texture,and higher skid resistance in comparison to those of AC,but lower than those of ***,HFTO mixtures may be considered a suitable replacement for traditional AC mixtures in regions where skid resistance and noise reduction are concerns.

关键词： road engineering pavement maintenance high friction thin overlay performance skid resistance tire/pavement noise

Aldehyde oxidase mediated enantioselective metabolic health risk of dinotefuran

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Science China Chemistry 2024年第6期67卷 2079-2091页

作者： Liwei xu Xinxin xu Hua Kuang Chuanlai xu Xiaoling Wu State Key Laboratory of Food Science and Resources Jiangnan UniversityWuxi214122China International Joint Research Laboratory for Biointerface and Biodetection and School of Food Science and Technology Jiangnan UniversityWuxi214122China Collaborative Innovation center of Food Safety and Quality Control in Jiangsu Province Jiangnan UniversityWuxi214122China

Chiral pollutants often pose significant differential environmental health *** this study,the biotransformation of chiral dinotefuran(DIN)and its enantioselective metabolic toxicity mechanisms have been systemically ***,reversedphase chromatography-high resolution mass spectrometry was developed to quantify the content of DIN R/S chiral enantiomer with pg level sensitivity,revealing a lower elimination rate constant(K_(e))of S-DIN(0.730 h^(-1))than R-DIN(0.746 h^(-1)).Secondly,the interaction mechanism between DIN metabolism and important endogenous bioactive molecules,such as aldehyde oxidase(AOX)and neurotransmitters,was *** DIN nitro-group was converted into a guanidine group by the reducing site of nearby flavin adenine dinucleotide(FAD)in AOX with the preferred higher affinity of ***,the endogenous tryptophan(Trp)aldehyde metabolic intermediate,5-hydroxyindoleacetaldehyde(5-HIAL),provides a persistent electron donor for DIN reduction via the oxidation-catalyzed site in AOX,resulting in remarkable up-regulation of monoamine neurotransmitters such as serotonin and ***,the higher level of neurotransmitters further mediated dysregulation of oxylipin homeostasis via the serotonergic pathway,where S-DIN exhibited more pronounced liver lipid damage and environmental health risk with the accumulated lipid biomarkers,oxidized triglyceride(OxTG)and oxidized sphingomyelin(OxSM).This study elucidates the AOX-mediated enantioselectivity metabolic pathway of DIN,providing a new analytical method for chiral pollutants and paves the way for their health risk assessments.

关键词： neonicotinoid dinotefuran enantiomer aldehyde oxidase metabolomics health risk

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地方高师院校体育学院羽毛球专选课教学探究

当代体育科技 2023年第9期13卷 45-48页

作者：张基徐佳琴菲律宾卡威迪国立大学菲律宾卡威迪99900 江西省石城中学江西赣州341000

羽毛球运动发展的炽热化使得羽毛球运动在地方高师院校一片火热,也使得在地方高师院校体育学院中选择将羽毛球作为专业选修课的学生越来越多。面对地方高师院校羽毛球发展如此良好的势头,地方高师院校体育学院羽毛球专选课教学却存在许... 详细信息

羽毛球运动发展的炽热化使得羽毛球运动在地方高师院校一片火热,也使得在地方高师院校体育学院中选择将羽毛球作为专业选修课的学生越来越多。面对地方高师院校羽毛球发展如此良好的势头,地方高师院校体育学院羽毛球专选课教学却存在许多问题。为了对地方高师院校体育学院羽毛球专选课教学现状进行分析,该文主要采用文献资料法和逻辑分析法,通过查阅大量的文献资料,主要从地方高师院校体育学院羽毛球专选课现存教学问题、地方高师院校体育学院羽毛球专选课教学特点分析、羽毛球教学内容分析、羽毛球教学方法分析以及地方高师院校体育学院羽毛球专选课教学改革的对策这5个方面,来对地方高师院校体育学院羽毛球专选课教学情况进行全面了解和分析,希望能够为地方高师院校体育学院羽毛球专选课教学提供一些参考。

关键词：地方院校羽毛球专选课教学

敏捷梯训练对8~10岁儿童羽毛球步伐训练的影响探析

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当代体育科技 2023年第13期13卷 73-77页

作者：张基徐佳琴菲律宾卡威迪国立大学卡威迪99900 江西省石城中学江西赣州341000

该文将32名金华市浦江县篮羽体育8~10岁羽毛球学员分成水平均等的实验组和对照组,每组男生和女生各8名,进行为期24周的实验,实验组在常规步伐训练的基础上加入敏捷梯训练,对照组则只采用常规羽毛球步伐训练。经过24周的实验后发现,在常... 详细信息

该文将32名金华市浦江县篮羽体育8~10岁羽毛球学员分成水平均等的实验组和对照组,每组男生和女生各8名,进行为期24周的实验,实验组在常规步伐训练的基础上加入敏捷梯训练,对照组则只采用常规羽毛球步伐训练。经过24周的实验后发现,在常规羽毛球步伐训练的基础上,加入敏捷梯训练和只采用常规羽毛球步伐训练都能有效提升8~10岁儿童羽毛球步伐移动速度。但相较于只采用常规羽毛球步伐训练,在常规羽毛球步伐训练的基础上加入敏捷梯训练,对8~10岁儿童羽毛球步伐移动速度的提升幅度更大。表明敏捷梯训练对8~10岁儿童羽毛球步伐训练有积极影响。

关键词：敏捷梯训练 8~10岁儿童羽毛球步伐训练