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冷锋推进中的大气波导变化及其对AIS传播影响研究

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现代雷达 2024年第4期46卷 76-81页

作者：王望荣察豪田斌李靖郝赫海军工程大学湖北武汉430033 解放军92677部队山东青岛266500 解放军92261部队海南海口570100

冷锋推进中会使得海域内的气温、相对湿度、风速等气象要素分布发生显著改变,导致与气象要素紧密关联的大气波导出现的类型及分布范围随之改变。文中利用大气再分析数据分析了2018年3月中旬某次冷锋过境中不同阶段大气波导的变化过程,... 详细信息

冷锋推进中会使得海域内的气温、相对湿度、风速等气象要素分布发生显著改变,导致与气象要素紧密关联的大气波导出现的类型及分布范围随之改变。文中利用大气再分析数据分析了2018年3月中旬某次冷锋过境中不同阶段大气波导的变化过程,并利用电磁波传播模型研究了冷锋推进过程中大气波导对船舶自动识别系统(AIS)传播的影响,结果表明:冷锋开始和发展阶段,出现的蒸发波导对AIS传播影响较弱;冷锋延伸和结束阶段,出现的多类型大气波导对AIS传播影响较强。因此,为有效监控海域内的船舶状态,应增加对冷锋开始和发展阶段的补充监控措施。

关键词：冷锋大气波导再分析数据通信传播船舶自动识别系统

血清lncRNA CCDC18-AS1、miR-501在HPV感染宫颈癌中的表达及其与预后的关系

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国际检验医学杂志 2024年第2期45卷 155-159页

作者：查平邓梦海南省妇女儿童医学中心妇产科海南海口570206 海南省妇女儿童医学中心妇保科海南海口570206

目的探究血清长链非编码RNA(lncRNA)CCDC18-AS1、微小RNA-501(miR-501)在人乳头瘤病毒(HPV)感染宫颈癌中的表达及其与预后的关系。方法选取2019年5月至2020年5月该院诊治的78例HPV感染宫颈癌患者作为研究组,同期80例单纯的HPV感染患者... 详细信息

目的探究血清长链非编码RNA(lncRNA)CCDC18-AS1、微小RNA-501(miR-501)在人乳头瘤病毒(HPV)感染宫颈癌中的表达及其与预后的关系。方法选取2019年5月至2020年5月该院诊治的78例HPV感染宫颈癌患者作为研究组,同期80例单纯的HPV感染患者及81例单纯非HPV感染的宫颈癌患者作为对照1、2组,采用实时荧光定量PCR检测血清lncRNA CCDC18-AS1、miR-501相对表达量,分析研究组临床特征、术后总生存期及无进展生存期。结果研究组血清lncRNA CCDC18-AS1、miR-501相对表达量均高于对照1、2组(P<0.05),对照2组血清lncRNA CCDC18-AS1、miR-501相对表达量均高于对照1组(P<0.05)。经Pearson相关性分析显示,研究组血清lncRNA CCDC18-AS1和miR-501呈正相关(r=0.421,P<0.001)。研究组血清lncRNA CCDC18-AS1、miR-501与年龄无关,但与临床分期、分化程度、淋巴结转移情况、鳞状上皮细胞抗原有关(P<0.05)。Kaplan Meier生存曲线法分析结果显示,lncRNA CCDC18-AS1与miR-501高表达组术后总生存期及无进展生存期均短于低表达组(P<0.05)。结论lncRNA CCDC18-AS1、miR-501相对表达量在HPV感染宫颈癌患者血清中明显升高,这一变化与患者临床特征及术后生存期具有关联性,可作为病情及其预后评估的辅助指标。

关键词：长链非编码RNA CCDC18-AS1 微小RNA-501 人乳头瘤病毒宫颈癌总生存期无进展生存期

论博士研究生教育中导师组机制与导师转换制的实施

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高教学刊 2024年第17期10卷 14-17页

作者：茶丽娟张秋林茶丽华昆明理工大学环境科学与工程学院昆明650500 大理大学马克思主义学院云南大理671000 中央财经大学法学院北京100081

近年来,随着博士研究生规模的不断扩大,博士研究生培养质量遇到挑战,一些问题便突显出来,如博士生延期毕业率逐年攀升。在博士研究生培养过程中,学校、学院与导师形成培养共同体,其中导师应是博士研究生培养的第一责任人与具体培养政策... 详细信息

近年来,随着博士研究生规模的不断扩大,博士研究生培养质量遇到挑战,一些问题便突显出来,如博士生延期毕业率逐年攀升。在博士研究生培养过程中,学校、学院与导师形成培养共同体,其中导师应是博士研究生培养的第一责任人与具体培养政策执行人。基于博士研究生培养的现状,目前很多实施单一导师制,形成导师与研究生之间的导学共同体,该文通过研究发现师生初始互选的信息错位从而引起导师与学生产生矛盾。为解决这一问题,该文提出以两位及以上导师组成导师组,有利于更加科学地培养具有复合特性的博士生人才,也有利于将导师对博士生第一责任进行分置,减轻导师责任;最后但同样重要的是,实施导师转换制用以解决导师组也无法克服的导学矛盾,以避免引发学校、学院、导师与学生之间产生更严重的矛盾,避免可控的导学问题演化为不可控的恶性纠纷,给学校乃至社会造成恶劣影响。

关键词：博士研究生培养导学共同体单一导师制导师组制度导师转换制

基于色谱-质谱联用技术检测尿液中类固醇激素及代谢物的研究进展

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环境科学研究 2024年第6期37卷 1363-1377页

作者：马晓查玉娥刘娟任惠敏赵力常红唐宋山东大学公共卫生学院山东济南250061 中国疾病预防控制中心环境与人群健康重点实验室中国疾病预防控制中心环境与健康相关产品安全所北京100021 北京林业大学环境科学与工程学院北京100083 南京医科大学公共卫生学院全球健康中心江苏南京211166

类固醇激素在人体新陈代谢、免疫调节、生长发育、维持生命功能等方面具有重要作用,但其同时又作为一类新型有机污染物,干扰人体正常的内分泌机能从而对人体产生危害,因此类固醇激素的研究已逐渐成为国际上环境和健康领域的研究热点。... 详细信息

类固醇激素在人体新陈代谢、免疫调节、生长发育、维持生命功能等方面具有重要作用,但其同时又作为一类新型有机污染物,干扰人体正常的内分泌机能从而对人体产生危害,因此类固醇激素的研究已逐渐成为国际上环境和健康领域的研究热点。尿液具有无创收集、前处理简单、能敏感地反映生理变化等优势,更适用于定期、重复监测。色谱-质谱联用技术灵敏度高、选择性好、通量高,在尿液类固醇激素检测中得到了广泛应用。本文基于色谱-质谱联用技术综述了检测类固醇激素的尿样的采集和储存条件、前处理技术、色谱-质谱分析方法、分析软件和数据库,以及部分类固醇激素在我国不同健康人群尿液中的检出情况等研究进展,指出尿液中类固醇激素及其代谢物的检测基质复杂、种类繁多以及含量较低,仍需进行广泛而深入的研究,实现对多种类固醇激素及其代谢物的精确定量仍面临挑战。未来研究需建立标准化采集和储存方法,开发更高效和环境友好型的前处理技术以及高灵敏度、高可靠性和高通量的色谱-质谱仪器,合成更多类固醇激素及代谢物标准品和同位素,同时不断完善数据库信息以满足精确定量的需求,为尿液中类固醇激素检测及人群健康风险评估等研究提供参考。

关键词：尿液类固醇激素代谢物前处理技术色谱-质谱分析

数智时代地方文献专题建设优化路径探讨——以南京图书馆“水韵江苏”专题建设为例

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新世纪图书馆 2024年第7期 59-63,91页

作者：董倩雯查璐南京图书馆江苏南京210018

在大数据驱动、智能化应用逐渐成为技术核心的时代,江苏作为全国唯一同时拥有大江、大河、大湖和大海的省份,孕育出独具禀赋的水韵文化,在地方文献专题建设方面具有得天独厚的优势。论文以南京图书馆“水韵江苏”地方文献专题建设为例,... 详细信息

在大数据驱动、智能化应用逐渐成为技术核心的时代,江苏作为全国唯一同时拥有大江、大河、大湖和大海的省份,孕育出独具禀赋的水韵文化,在地方文献专题建设方面具有得天独厚的优势。论文以南京图书馆“水韵江苏”地方文献专题建设为例,从制度建设、人才保障、共建共享、阅读推广等角度探讨数智时代背景下地方文献专题建设的意义和优化路径,以期地方文献专题建设的内容价值能培育文旅融合新动能,辐射社会经济文化新发展。

关键词：数智时代地方文献专题建设专题数据库文旅融合

A theoretical and 1-D numerical investigation on a valve/valveless air-breathing pulse detonation engine

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Chinese Journal of Aeronautics 2021年第1期34卷 68-78页

作者： Hua QIU cha XIONG Jianling LI School of Power and Energy Northwestern Polytechnical UniversityXi'an 710072China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

The important operating characteristics of pulsed Pressure Gain Combustion(PGC)propulsion are the pressure gain of the combustor component and the propulsive performance gain of the engine.A ramjet-type valve/valveless air-breathing pulsed detonation engine with a supersonic internal compression inlet is *** on an ideal thermal cycle,the ideal equivalent pressure ratios(pcb)of the Pulsed Detonation Combustor(PDC)are obtained theoretically which are directly related with the propulsive performance of the *** introducing an orifice loss model into the cycles,the critical pressure drop ratios through the orifice for the PDC achieving pressure gain and the engine achieving thrust gain are *** influencing factors are investigated by the use of a one-dimensional(1-D)numerical simulation *** operating characteristics of the pulse detonation engine are investigated with changes of the valve type,the inlet/outlet area ratio of the PDC,the nozzle area ratio,and flight *** these factors can affect pcbof the PDC,and pcbcan be optimized by changing the geometry of the *** most important influence parameter is the valve *** using an orifice-type aerodynamic valve,simulation results show that the PDC cannot achieve the pressure gain *** a supersonic internal compression inlet is introduced to the engine,whether the Pulse Detonation Engine(PDE)can achieve thrust gain comparable with that of an ideal Brayton cycle engine not only is related to the pressure gain of the combustor,but also needs to optimize the engine structure to reduce the total pressure loss.

关键词： Detonation Pressure gain characteristics Propulsive performance Supersonic internal compression inlet Valve/valveless Thermal cycle

What determines irrigation efficiency when farmers face extreme weather events? A field survey of the major wheat producing regions in China

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Journal of Integrative Agriculture 2018年第8期17卷 1888-1899页

作者： SONG Chun-xiao les Oxley MA Heng-yun College of Economics and Management Henan Agricultural University Department of Economics and Finance University of Waikato

Water availability is a major constraint on grain production in China, therefore, improving irrigation efficiency is particularly important when agriculture faces extreme weather events. This paper first calculates irrigation efficiency with a translog stochastic frontier production function and then investigates what happens when extreme weather events occur via a Tobit model. The estimated results reveal several important features of irrigation practices: i) irrigation efficiency is lower when extreme weather events occur; ii) large variations in irrigation efficiency occur across irrigation facilities; iii) the farm plots exhibit an extreme distribution across efficiency levels; and iv) water-saving techniques, technology adoption, and the maintenance of farmers’ economic resilience are major determinants of irrigation efficiency. Based on these results we propose the following recommendations: i) farmers should balance crop yield and water use; undertake relevant training programs and adopt water-saving techniques; ii) local governments and researchers should help farmers to find the optimal level of irrigation water use based on their own circumstances and provide better water-saving techniques and training programs rather than simply encouraging farmers to invest in irrigation facilities in the most extreme weather years; and iii) the income level of farm households should be increased so as to improve their resilience to natural disasters.

关键词： irrigation efficiency determinants irrigation facilities water-saving techniques extreme weather events

Effects of excluding bottom-disturbing mobile fishing gear on abundance and biomass of groundfishes in the Stellwagen Bank National Marine Sanctuary,USA

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Current Zoology 2010年第1期56卷 134-143页

作者： Briana K.BROWN Elizabeth SOULE les KAUFMAN Biology Department Boston University

The Stellwagen Bank National Marine Sanctuary （southern Gulf of Maine, northwest Atlantic） is partially overlapped by the Western Gulf of Maine Closure Area （WGMCA）. This is a region in which mobile, bottom-disturbing fishing gear has been banned by the New England Fishery Management Council to facilitate the rebuilding of depleted gronndfish populations. We assessed the effects and effectiveness of the WGMCA on groundfish assemblages using habitat-stratified （gravel, sand, mixed benthic habitats） sampling by means of a commercial trawler, inside and outside of the WGMCA. Sampling occurred over three mouth-long sampling periods in 2004-2005, two during the spring seasons and one during the fall season. A total of 18 species were analyzed for protection effects. After controlling for substratum, location and sampling season, eight groundfish species exhibited higher mean proportional abundance inside than outside the WGMCA while two were proportionally more abundant on average outside of the closure. Four species had higher mean proportional biomasses on average inside the closure and three outside. We conclude that the WGMCA may be achieving its goal of rebuilding abundance and biomass for some commercially targeted groundfishes but not all. This study, six to seven years post-closure establishment, reveals fine-scale spatial and taxonomic complexity which will require a very different monitoring protocol than the one currently in place if adaptive management is to be successful in the region [Current Zoology 56 （1）： 134-143, 2010].

关键词： Effects of fishing Groundfish Gulf of Maine Stellwagen Bank National Marine Sanctuary Trawl closure

Updates on esophageal and gastric cancers

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World Journal of Gastroenterology 2006年第20期12卷 3237-3242页

作者： Amy Gallo cha.les cha Resident Department of Surgery Yale University School of Medicine333 Cedar St.FMB 121New HavenCT 06520United States Department of Surgery Yale University of School of Medicine 333 Cedar St.FMB 121New HavenCT 06520United States

Esophageal and gastric cancers are both common and deadly. Patients present most often after disease progression and survival is therefore poor. Due to demographic variability and recent changes in disease incidence, much emphasis has been placed on studying risk factors for both esophageal and gastric cancers. However, with increasing understanding of these diseases, low survival rates persist and continued intensive studies are necessary to optimize treatment plans. This review article discusses updates in the evolving epidemiology, clinical presentation, risk factors, and diagnostic and treatment modalities of esophageal and gastric cancers.

关键词： Gastric cancer Esophageal cancer Surgery Treatment