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Design and fabrication of a sub-millimeter multi-beam folded waveguide structure

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Optoelectronics Letters 2017年第1期13卷 33-37页

作者： yan Sheng-mei SU Wei ZHANG Guo-liang Institute of Electronic Engineering China Academy of Engineering Physics Mianyang 621900 China

A novel multi-beam folded waveguide(MBFW) circuit,which can enhance the output power and interaction efficiency of sub-terahertz(THz) traveling wave tube(TWT),is presented in the paper. Operating with fundamental mode and multiple electron beams means that a larger beam current can be used for a higher output power. The characteristics of the MBFW structure are analyzed and optimized. Compared with the single-beam folded waveguide(SBFW) TWT,the output power of the MBFW TWT increases from 3.64 W to 25.45 W at 140 GHz and its electronic efficiency increases from 1.06% to 7.4% under the conditions of an input peak power of 10 m W,a beam voltage of 9.55 k V and a current of 12 m A. The optimized MBFW structure can be successfully fabricated by micro milling,with dimension errors below expectation,and the measured transmission characteristics are in good agreement with the design.

关键词： waveguide folded fabrication millimeter terahertz milling match expectation dimensions traveling

上海市0~6岁儿童血砷水平与体格生长的关系

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中国儿童保健杂志 2024年第9期32卷 969-973页

作者：林崟刘军霞张林颜崇淮上海交通大学医学院附属新华医院教育部和上海市环境与儿童健康重点实验室上海200092 兰州大学公共卫生学院劳动卫生与环境卫生学系

目的研究上海市儿童血砷水平、影响因素以及与体格生长的关联,为预防和干预由砷暴露引起的健康问题提供参考。方法选取2013—2015年招募的具有血液样本、体格生长指标和人口基线数据的2263名上海市0~6岁儿童作为研究对象,使用电感耦合... 详细信息

目的研究上海市儿童血砷水平、影响因素以及与体格生长的关联,为预防和干预由砷暴露引起的健康问题提供参考。方法选取2013—2015年招募的具有血液样本、体格生长指标和人口基线数据的2263名上海市0~6岁儿童作为研究对象,使用电感耦合等离子体质串联谱仪(ICP-MS/MS)测定全血总砷水平,采用单因素线性回归和多重线性回归分析砷暴露与儿童体格生长的关联。结果上海市儿童血砷的中位数水平为1.57μg/L。女童血砷水平高于男童(1.67μg/L vs.1.47μg/L,Z=510794.50,P<0.05);主要照看人吸烟的儿童血砷水平高于未吸烟的儿童(1.83μg/L vs.1.52μg/L,Z=275783.00,P<0.05),经常摄入海水鱼和淡水鱼的儿童血砷水平高于偶尔摄入海水鱼者(1.69μg/L vs.1.34μg/L,Z=417778.00,P<0.05)和淡水鱼者(1.69μg/L vs.1.37μg/L,Z=443342.00,P<0.05)。调整父母身高、体重、家庭经济状况后,砷暴露水平与儿童年龄别身高Z评分(β=-0.08,95%CI:-0.12~-0.03,P<0.01)、年龄别体重Z评分(β=-0.07,95%CI:-0.11~-0.03,P<0.01)及年龄别BMI-Z评分(β=-0.05,95%CI:-0.10~0.00,P=0.03)均呈显著负相关。结论上海市0~6岁儿童的血砷水平存在性别差异,与膳食等因素有关,并与儿童体格生长存在负向关联。

关键词：血砷电感耦合等离子体质串联谱仪体格生长儿童

DPA-Zn（Ⅱ） based BINOL fluorescent probe for detection of phosphate anions

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DPA-Zn（Ⅱ） based BINOL fluorescent probe for detection of ...

The Structure of a Typical mei-Yu Front Identified by the Equivalent Temperature

第八届全国化学生物学学术会议

作者： Shu-yan jiao Kun Li Xiao-qi Yu Key Laboratory of Green Chemistry and Technology（Ministry of Education） College of ChemistrySichuan University

＜正＞Among various anions,phosphate derivatives,which include nucleoside pyrophosphates such as adenosine triphosphate（ATP）,inorganic pyrophosphate and phosphoproteins are significant sensing targets because of their pivotal roles in biological ***,multiple Zn（II）-DPA ligands are involved in binding a single anionic ***（II）-DPA receptors show high selectivity for phosphate

关键词： Phosphate derivatives Biological systems DPA-Zn ligands

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Atmospheric and Oceanic Science Letters 2011年第2期4卷 109-113页

作者： FU jiao-Lan QIAN Wei-Hong National Meteorological Center of Chinese MeteorologicalAdministration Beijing 100081 China Department of Atmospheric and Oceanic Sciences Peking University Beijing 100871 China

In China's Mainland, the summer monsoon rainy band is referred to as the mei-yu precipitation front, which extends northward from South China to the yangtze River, Huaihe River, and Yellow River, depending on the season. This paper describes the structure of the mei-yu front associated with a persistent heavy rainfall event that occurred in the summer of 2007. The mei-yu front occurs when the subtropical oceanic warm, moist air mass and the extra tropical continental dry, cold air mass converge on the lee side of the Tibetan Plateau. The authors defined the equivalent temperature using two terms of dry-air temperature and the specific humidity and calculated its horizontal gradient to indicate the mei-yu front. The vertical structure of the mei-yu front and the moist thermal winds surrounding it were examined based on the equivalent temperature.

关键词： mei-yu equivalent temperature front structure moist thermal wind

Expression of Transcription Factor FOXO3a is Decreased in Patients with Ulcerative Colitis

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Chinese Medical Journal 2015年第20期128卷 2759-2763页

作者： Min Min Jing yang Yun-Sheng yang yan Liu Li-mei Liu yang Xu Department of Gastroenterology and Hepatology Affiliated Hospital of Academy of Military Medical Sciences Beijing 100071 China Department of Gastroenterology and Hepatology Institute of Digestive Diseases Chinese People's Liberation Army General Hospital Beijing 100853 China Department of Gastroenterology and Hepatology Tonghua Hospital Tonghua Jilin 134001 China

Background： Ulcerative colitis （UC） is associated with differential expression of genes involved in inflammation and tissue remodeling, including FOXO3a, which encodes a transcription factor known to promote inflammation in several, tissues. However, FOXO3a expression in tissues affected by UC has not been examined. This study investigated the effects of FOXO3a on UC pathogenesis. Methods： FOXO3a expression, in 23 patients with UC and in HT29 cells treated with tumor necrosis factor-α （TNF-α） for various durations, was detected by quantitative real-time polymerase chain reaction and Western blotting analysis. Enzyme-linked immunosorbent assay was used to quantity interleukin （IL）-8 expression in FOXO3a-silenced HT29 cells treated with TNF-α for various durations. Results： The messenger RNA and protein expression of FOXO3a were significantly lower in UC tissues than those in normal subjects （P 〈 0.01 ）. TNF-α treatment for 0, 0.5, 1, 6, and 24 h induced FOXO3 degradation in HT29 ceils. FOXO3a silencing increased IL-8 levels in HT29 cells treated with TNF-α for 6 h （P 〈 0.05）. Conclusion： FOXO3a may play an important role in the intestinal inflammation of patients with UC.

关键词： FOXO3a, lnterleukin-8 Ulcerative Colitis

AI for Science:智能化科学设施变革基础研究

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中国科学院院刊 2024年第1期39卷 59-69页

作者：杨小康许岩岩陈露王韫博高岳田济东俞凯金耀辉梅宏上海交通大学人工智能研究院上海200240 上海交通大学计算机科学与工程系上海200240 北京大学信息科学技术学院北京100871

近年来,人工智能(AI)在前沿科技领域取得了诸如AlphaFold2、核聚变智能控制、新冠药物设计等诸多令人瞩目成果,表明AI for Science正在成为一种新的研究范式。实现智能时代的基础科学源头创新及其下游重大技术创新,需破解2个方面的核心... 详细信息

近年来,人工智能(AI)在前沿科技领域取得了诸如AlphaFold2、核聚变智能控制、新冠药物设计等诸多令人瞩目成果,表明AI for Science正在成为一种新的研究范式。实现智能时代的基础科学源头创新及其下游重大技术创新,需破解2个方面的核心问题:(1)如何利用新一代AI(特别是生成式AI及大模型)的通用性和创造性推动新范式的形成;(2)如何利用AI实现对传统科学设施的赋能与改造。文章提出一种智能化科学设施的建设构想,兼顾“高度智能化的科学新设施”和“AI赋能已有科学大设施”2个层面的需求,构筑AI for Science的科学设施体系,形成科学领域大模型、生成式模拟与反演、自主智能无人实验及大规模可信科研协作等创新功能,加速重大科学发现、变革性物质合成,以及重大工程技术应用。

关键词：人工智能驱动科学研究生成式人工智能语言大模型科学设施

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宇宙黎明全天频谱实验研究进展

电波科学学报 2024年第4期39卷 589-594页

作者：吴锋泉许嘉钦朱嘉聪张聪何凯孙士杰周嘉周民权徐沈哲周巍张皓然严琦森严瑞斌李吉夏邓辅仁陆宇杰索南本张骄张巨勇陈学雷中国科学院国家天文台北京100101 山西大学太原237016 杭州电子科技大学杭州310018

探索宇宙黑暗时代、黎明时代和再电离时代对于理解宇宙的演化具有重要意义,一直是天文学研究的一个重要方向。从2000年前后开始,人们尝试利用200 MHz以下的红移中性氢21 cm辐射对宇宙早期的演化进行探测,主要是两条路径,一种是利用大规... 详细信息

探索宇宙黑暗时代、黎明时代和再电离时代对于理解宇宙的演化具有重要意义,一直是天文学研究的一个重要方向。从2000年前后开始,人们尝试利用200 MHz以下的红移中性氢21 cm辐射对宇宙早期的演化进行探测,主要是两条路径,一种是利用大规模阵列对中性氢辐射进行三维成像或空间功率谱测量,另一种是通过单天线对21 cm中性氢全天平均频谱进行测量。后一种测量设备规模小,只需要单天线,但要求接收机具有高精度的校准能力。本文主要介绍近年来我们在国家天文台红柳峡观测站开展的全天频谱探测实验的进展情况,包括多种非频变天线设计、创新性的多通道交叉验证接收系统设计思想,以及初步的实验进展等,实验结果显示利用天线模拟器得到系统校准精度残差小于0.025 K,达到了自校准精度的国际水平。这些设备的研制和实验的开展将有力地推动我国未来的月球轨道或月基全天频谱探测项目。

关键词：宇宙黎明宇宙黑暗时代全天频谱实验精密频谱校准中性氢21 cm辐射

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Structure modification,antialgal,antiplasmodial,and toxic evaluations of a series of new marine-derived 14-membered resorcylic acid lactone derivatives

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Marine Life Science & Technology 2022年第1期4卷 88-97页

作者： Wei-Feng Xu Na-Na Wu yan-Wei Wu Yue-Xuan Qi mei-yan Wei Laura M.Pineda Michelle G.Ng Carmenza Spadafora Ji-Yong Zheng Ling Lu Chang-Yun Wang Yu-Cheng Gu Chang-Lun Shao Key Laboratory of Marine Drugs the Ministry of Education of ChinaSchool of Medicine and PharmacyOcean University of ChinaQingdao266003China Laboratory for Marine Drugs and Bioproducts Qingdao National Laboratory for Marine Science and TechnologyQingdao266237China State Key Laboratory for Marine Corrosion and Protection Luoyang Ship Material Research Institute(LSMRI)Qingdao266237China Center of Cellular and Molecular Biology of Diseases Instituto de Investigaciones Científcas y Servicios de Alta TecnologíaCity of KnowledgeClaytonApartado0816-02852Panama Syngenta Jealott’s Hill International Research Centre BracknellBerkshireRG426EYUK

Marine natural products play critical roles in the chemical defense of many marine organisms and are essential,reputable sources of successful drug ***-seven 14-membered resorcylic acid lactone derivatives 3–27 and 30–71 of the natural product zeaenol(1)isolated from the marine-derived fungus Cochliobolus lunatus were semisynthesized by chlorination,acylation,esterification,and acetalization in one to three *** structures of these new derivatives were established by HRESIMS and NMR *** the compounds(1–71)were evaluated for their antialgal and antiplasmodial *** them,14 compounds displayed antifouling activities against adhesion of the fouling *** particular,9 and 34 exhibited strong and selective inhibitory effects against the diatoms Navicula laevissima and Navicula exigua(EC50=6.67 and 8.55μmol/L),respectively,which were similar in efficacy to those of the positive control SeaNine 211(EC50=2.90 and 9.74μmol/L).More importantly,38,39,and 69–71 showed potent antiplasmodial activities against Plasmodium falciparum with IC50 values ranging from 3.54 to 9.72μmol/*** interestingly,the five antiplasmodial derivatives displayed non-toxicity in the cytotoxicity assays and the zebrafish embryos model,thus,representing potential promising antiplasmodial drug *** preliminary structure–activity relationships indicated that biphenyl substituent at C-2,acetonide at positions C-5′and C-6′,and tri-or tetra-substituted of acyl groups increased the antiplasmodial ***,combining evaluation of chemical ecology with pharmacological models will be implemented as a systematic strategy,not only for environmentally friendly antifoulants but also for structurally novel drugs.

关键词： Marine natural product 14-Membered resorcylic acid lactone Zeaenol Semisynthesis Antialgal activity Antiplasmodial activity

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鄱阳湖区土地利用景观格局特征研究

农业工程学报 2007年第4期23卷 79-83页

作者：陈文波郑蕉鄢帮有江西农业大学国土资源与环境学院江西农业大学计算机与信息工程学院南昌330045 江西省山江湖开发治理委员会办公室南昌330046

在RS与G IS技术的支持下,该文对鄱阳湖区1990-2002年间的土地利用景观变化进行了分析。研究结果表明,1990-2002年鄱阳湖区面积变化的趋势是耕地减少、林地增加、草地减少、水体增加、居民点与工矿用地大幅度增加,未利用地维持不变。利... 详细信息

在RS与G IS技术的支持下,该文对鄱阳湖区1990-2002年间的土地利用景观变化进行了分析。研究结果表明,1990-2002年鄱阳湖区面积变化的趋势是耕地减少、林地增加、草地减少、水体增加、居民点与工矿用地大幅度增加,未利用地维持不变。利用二级土地利用景观类型,对景观变化的原因进行了分析。利用多样性指数、优势度、分维数、破碎度等景观指数对鄱阳湖区土地利用景观格局特征的研究表明,1990-2002年鄱阳湖区土地利用景观格局总体变化趋势是多样性增加、优势度减少、分数维减少、破碎度增加。最后,该文利用典型相关分析法对鄱阳湖区景观格局变化的社会经济驱动力进行了定量分析,认为导致景观分维数、景观破碎度变化的主要驱动力是人口与国内生产总值,导致景观多样性和优势度变化的主要驱动力是境内公路里程与农村居民年均纯收入。

关键词：鄱阳湖区土地利用景观格局驱动力