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EXPERIMENTAL INVESTIGATION OF CHARACTERISTIC FREQUENCY IN UNSTEADY HYDRAULIC BEHAVIOUR OF A LARGE HYDRAULIC TURBINE

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Journal of Hydrodynamics 2009年第1期21卷 12-19页

作者： WANG Fu-jun LI Xiao-qin ma jia-mei YANG Min ZHU Yu-liang College of Water Conservancy and Civil Engineering China Agricultural University Beijing 100083 China Beijing Huake Tongan Monitoring Technology Co. Ltd. Beijing 100037 China

The features of unsteady flow such as pressure variation and fluctuation in a large hydraulic turbine usually lead to the instability of operation. This article reports the recent in site investigation concerning the characteristic frequencies in pressure fluctuation, shaft torsional oscillation and structural vibration of a prototype 700 MW Francis turbine unit. The investigation was carried out for a wide load range of 200 MW-700 MW in the condition of water head 57 m-90 m. An extensive analysis of both time-history and frequency data of these unsteady hydraulic behaviours was conducted. It was observed that the pressure fluctuation in a draft tube is stronger than that in upstream flow passage. The low frequency with about one third of rotation frequency is dominative for the pressure fluctuation in part load range. Also the unsteady features of vibration of head cover and torsional oscillation of shaft exhibited the similar features. Numerical analysis showed that the vibration and oscillation are caused by vortex rope in the draft tube. In addition, a strong vibration with special characteristic frequency was observed for the head cover in middle load range. The pressure fluctuation in the draft tube with the same frequency was also recorded. Because this special vibration has appeared in the designed normal running condition, it should be avoided by carefully allocating power load in the future operation.

关键词： hydraulic turbine part load swirling flow unsteady behaviour characteristic frequency power load allocation

西双版纳地区流苏石斛遗传多样性的ISSR分析

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云南植物研究 2009年第1期31卷 35-41页

作者：马佳梅殷寿华中国科学院西双版纳热带植物园云南勐腊666303 中国科学院研究生院北京100049

采用ISSR分子标记技术,对西双版纳分布的兰科濒危植物流苏石斛(Dendrobium fimbriatum)5个居群共114个个体的遗传多样性进行了研究。从100条引物中筛选出了12条用于扩增,共检测到117个位点,其中105个为多态位点。分析结果表明,流苏石斛... 详细信息

采用ISSR分子标记技术,对西双版纳分布的兰科濒危植物流苏石斛(Dendrobium fimbriatum)5个居群共114个个体的遗传多样性进行了研究。从100条引物中筛选出了12条用于扩增,共检测到117个位点,其中105个为多态位点。分析结果表明,流苏石斛居群水平遗传多样性较低。在物种水平上,流苏石斛多态位点百分率PPB为89.74%,Nei′s基因多样性指数H为0.3227,Shannon′s多样性信息指数Hsp为0.4779;在居群水平上,各个居群的多态位点百分率PPB差异较大(6.84%～39.32%),平均值为23.93%,Nei′s基因多样性指数H为0.0871,各个居群的Shannon′s多样性信息指数Ho平均为0.1290。AMOVA分析的结果显示,流苏石斛的遗传变异大多数存在于居群间,占总遗传变异的74.79%。基于Nei′s遗传多样性分析得出的居群间遗传分化系数Gst=0.7443。各居群间的Nei′s遗传一致度(I)范围为0.5882～0.8331。mantel检测发现,居群间的遗传距离和地理距离之间无显著的正相关关系(r=0.2419,P=0.2416)。鉴于流苏石斛的遗传多样性现状和居群遗传结构,我们建议对流苏石斛居群所有个体实施及时的就地保护,同时建立迁地保护居群,促进基因交流。

关键词：流苏石斛 ISSR 遗传多样性遗传结构

Integration of Electrical Properties and Polarization Loss Modulation on Atomic Fe–N‑RGO for Boosting Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第2期17卷 517-532页

作者： Kaili Zhang Yuefeng Yan Zhen Wang Guansheng ma Dechang jia Xiaoxiao Huang Yu Zhou State Key Laboratory of Precision Welding&Joining of materials and Structures Harbin Institute of TechnologyHarbin 150001People’s Republic of China School of materials Science and Engineering Harbin Institute of TechnologyHarbin 150001People’s Republic of China MIIT Key Laboratory of Advanced Structural‑Functional Integration materials&Green manufacturing Technology Harbin Institute of TechnologyHarbin 150001People’s Republic of China

Developing effective strategies to regulate graphene’s conduction loss and polarization has become a key to expanding its application in the electromagnetic wave absorption(EMWA)*** on the unique energy band structure of graphene,regulating its bandgap and electrical properties by introducing heteroatoms is considered a feasible ***,metal-nitrogen doping reduced graphene oxide(M–N-RGO)was prepared by embedding a series of single metal atoms M–N_(4) sites(M=Mn,Fe,Co,Ni,Cu,Zn,Nb,Cd,and Sn)in RGO using an N-coordination atom-assisted *** composites had adjustable conductivity and polarization to optimize dielectric loss and impedance matching for efficient EMWA *** results showed that the minimum reflection loss(RL_(min))of Fe–N-RGO reaches−74.05 dB(2.0 mm)and the maximum effective absorption bandwidth(EAB_(max))is 7.05 GHz(1.89 mm)even with a low filler loading of only 1 wt%.Combined with X-ray absorption spectra(XAFS),atomic force microscopy,and density functional theory calculation analysis,the Fe–N_(4) can be used as the polarization center to increase dipole polarization,interface polarization and defect-induced polarization due to d-p orbital hybridization and structural ***,electron migration within the Fe further leads to conduction loss,thereby synergistically promoting energy *** study demonstrates the effectiveness of metal-nitrogen doping in regulating the graphene′s dielectric properties,which provides an important basis for further investigation of the loss mechanism.

关键词： Electromagnetic wave absorption Fe-N-RGO Dipole polarization Conduction loss Impedance matching

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泡沫铜无溶剂催化氧化苄醇的应用研究

化学研究与应用 2021年第1期33卷 129-136页

作者：马佳美张淑华钟伟沈忠权桂林理工大学化学与生物工程学院广西桂林541000 嘉兴学院生物与化学工程学院浙江嘉兴341001

本文报道了在模拟的鼓泡床反应器中,以1-甲基咪唑(NMI)和2,2,6,6-四甲基-1-哌啶基氧基(TEMPO)作为助催化剂,空气泵鼓入空气作为氧源,泡沫铜作为催化剂,室温、无溶剂条件下催化氧化苄醇的应用研究。具体优化条件为:以50 mmol苯甲醇为反... 详细信息

本文报道了在模拟的鼓泡床反应器中,以1-甲基咪唑(NMI)和2,2,6,6-四甲基-1-哌啶基氧基(TEMPO)作为助催化剂,空气泵鼓入空气作为氧源,泡沫铜作为催化剂,室温、无溶剂条件下催化氧化苄醇的应用研究。具体优化条件为:以50 mmol苯甲醇为反应底物,2.5 mmol泡沫铜,0.625 mmol NMI,2.5 mmol TEMPO,空气流速300mL·min-1,室温无溶剂条件下反应6小时,苯甲醛产率达99%以上,并且催化剂在经过6次循环使用后产率仍然达82%。

关键词：醇氧化无溶剂泡沫铜鼓泡床反应器

Decreased levels of phosphorylated synuclein in plasma are correlated with poststroke cognitive impairment

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Neural Regeneration Research 2025年第9期20卷 2598-2610页

作者： Yi Wang Yuning Li Yakun Gu Wei ma Yuying Guan Mengyuan Guo Qianqian Shao Xunming Ji jia Liu Department of Clinical Laboratory Beijing Bo’ai HospitalChina Rehabilitation Research CenterCapital Medical UniversityBeijingChina Beijing Institute of Brain Disorders Laboratory of Brain DisordersMinistry of Science and TechnologyCollaborative Innovation Center for Brain DisordersBeijing Advanced Innovation Center for Big Data-based Precision MedicineCapital Medical UniversityBeijingChina Department of Neurosurgery Xuanwu HospitalCapital Medical UniversityBeijingChina

Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this *** aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive *** found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic *** addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic *** phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic ***,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein *** ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein *** together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.

关键词： biomarker high-density lipoprotein ischemic stroke phosphorylatedα-synuclein poststroke cognitive impairment

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天津部分儿童脂代谢相关指标分析

中国儿童保健杂志 2007年第3期15卷 260-262页

作者：叶涛王华吕莉马佳梅天津市妇女儿童保健中心天津300074

【目的】了解天津市3～7岁儿童血糖、血脂、尿酸的水平及分布特点，为及早防治心血管疾病提供参考依据。【方法】按不同性别、年龄和体型分组，检测3～7岁儿童手指末梢血的血糖、总胆固醇、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白... 详细信息

【目的】了解天津市3～7岁儿童血糖、血脂、尿酸的水平及分布特点，为及早防治心血管疾病提供参考依据。【方法】按不同性别、年龄和体型分组，检测3～7岁儿童手指末梢血的血糖、总胆固醇、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇和尿酸浓度。【结果】男童血糖水平高于女童，超重男童的高密度脂蛋白胆固醇高于女童，体型匀称组中男童血尿酸水平高于女童。超重者明显伴有总胆固醇、尿酸升高和高密度脂蛋白胆固醇下降。不同体型的儿童血脂异常率差异无显著性。在体型匀称儿童中，高密度脂蛋白胆固醇水平与年龄呈正相关，血糖水平只在女童中显示了与年龄的正相关关系，而其它指标与幼儿年龄没有明显关系。【结论】在幼儿期，无论是否肥胖，均存在血脂代谢异常的可能，应注意监测儿童血脂水平，尽早发现血脂异常，防范心血管疾病。

关键词：血糖血脂尿酸儿童

Visualization of the protective role of estrogen against female liver fibrosis via an ER viscosity NIR fluorescent probe

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Science China Chemistry 2025年第1期 360-368页

作者： Zheng Liu Changyu Zhang Zipeng Li Wanying ma jia Liu Xiang Xia Ning Xu Wen Sun jianjun Du jiangli Fan Xiaojun Peng State Key Laboratory of Fine Chemicals Dalian University of Technology Ningbo Institute of Dalian University of Technology

Endoplasmic reticulum(ER) viscosity has emerged as a new potential biomarker for hepatic fibrosis(HF). Herein, we report the first ER-targeting viscosity-responsive near-infrared(NIR) fluorescent probe HBT-PP for investigations of HF *** twisted intramolecular charge transfer(TICT) and the excited state intramolecular proton transfer(ESIPT) are combined to endow HBT-PP with the selective response towards viscosity(～62-fold) and a super large stokes shift(～320 nm). HBT-PP mainly targets organelle ER and is able to image the drug-or alcohol-induced viscosity elevation in living cells. Significantly,HBT-PP was successfully applied to visualize the gender difference in HF and the protective role of estrogen in restraining HF progression. Of note, after 10 min of stain with HBT-PP, HF lesions showed a stage-based response, indicating the potential of this probe in fast and early diagnosis of HF. These results clearly demonstrated the promising application of HBT-PP as a new tool for exploring ER viscosity-involved physiological and pathological processes.

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高水碘地区甲状腺抗体阴性妊娠期妇女甲状腺功能分析

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中国地方病学杂志 2010年第1期29卷 86-89页

作者：张翠萍董玲叶涛李义民李宝娟温静马佳梅王临虹中国疾病预防控制中心妇幼保健中心北京100001

目的探讨高水碘地区甲状腺抗体阴性妇女妊娠各期甲状腺功能的变化特征。方法在高水碘地区选天津市静海县妇幼保健院（饮水水碘〉200μg／L）和在适碘地区选天津市和平区妇幼保健院（饮水水碘〈10μg／L，碘盐普及率〉90％，居民尿碘中... 详细信息

目的探讨高水碘地区甲状腺抗体阴性妇女妊娠各期甲状腺功能的变化特征。方法在高水碘地区选天津市静海县妇幼保健院（饮水水碘〉200μg／L）和在适碘地区选天津市和平区妇幼保健院（饮水水碘〈10μg／L，碘盐普及率〉90％，居民尿碘中位数〉100μg／L）作为调查地点。在妇幼保健院门诊，选取妊娠资料完整的妊娠早、中、晚期孕妇各50名，采集血样，用化学发光法检测甲状腺功能。同时收集日间随意一次尿样、家中饮用水样和食用盐样，尿碘测定采用砷铈催化分光光度法，水碘测定采用快速定量检测试剂盒，盐碘测定采用硫代硫酸钠滴定法。结果①甲状腺抗体阴性孕妇中，高水碘地区孕早期妇女血清TT4、TT3、FT4明显低于适碘地区（111．97nmol／Lvs140．46nmol／L，Z=3．56，P〈0．01；1．86nmol／Lvs52．26nmol／L，Z=2．35，P〈0．65；14．13pmol／Lvs16．32pmol／L，Z=5．14，P〈0．01）；孕中期妇女血清FT4、FT3明显低于适碘地区（11．98pmol／Lvs14．30pmol／L，Z=5．75，P〈0．01；4．04pmol／Lvs54．32pmol／L，Z=2．76，P〈0．01）；孕晚期妇女血清，TT3、TSH明显高于适碘地区（2188nmol／Lvs2．70nmol／L，Z=-2．27，P〈0．05；2．37mU／Lvs1．75mU／L。Z=-2．70，P〈0．01）。②高水碘地区孕妇家中饮水碘和孕妇尿碘明显高于适碘地区（205．57μg／Lvs8．22μg／L，Z=-14．71，P〈0．01；305．91μg／Lvs191．86μg／L，Z=-4．01，P〈0．01），家中盐碘明显低于适碘地区（26．5mg／kgvs31．7mg／kg，Z=5．68，P〈0．01）。③健康且没有甲状腺病史的被调查孕妇中，妊娠各期甲状腺抗体阳性率在高水碘和适碘地区之间比较差异无统计学意义（孕早期：10．20％vs10，64％；孕中期：14．00％vs9．52％：孕晚期：4．00％vs57．69％，P均〉0．05）。结论高水碘地区甲状腺抗体阴性孕妇妊娠各期甲状腺功能不同于适碘地区，对高水碘地区孕妇应加强孕期（特别是孕早、中期）甲状腺功能监测。

关键词：饮水碘孕妇甲状腺功能

基于猪繁殖与呼吸综合征病毒ORF2a基因的RT-RAA-LF检测方法的建立

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中国兽医科学 2023年第10期53卷 1249-1253页

作者：陈素贞马佳镁黄春媛范悦轩郑佳馨刘光亮曹宗喜新疆农业大学动物医学学院新疆乌鲁木齐830000 海南省农业科学院畜牧兽医研究所海南省热带繁育与疫病研究重点实验室海南海口571100

本研究针对猪繁殖与呼吸综合征病毒ORF2a基因序列,设计特异性RAA引物和标记探针,通过反转录酶与重组酶扩增结合,旨在建立一种高效检测PRRSV的基于侧流层析试纸条的可视化RT-RAA方法。结果,建立的RT-RAA-LF方法的最佳反应条件是39℃恒温... 详细信息

本研究针对猪繁殖与呼吸综合征病毒ORF2a基因序列,设计特异性RAA引物和标记探针,通过反转录酶与重组酶扩增结合,旨在建立一种高效检测PRRSV的基于侧流层析试纸条的可视化RT-RAA方法。结果,建立的RT-RAA-LF方法的最佳反应条件是39℃恒温扩增10 min,可在2 min内实现对检测结果的可视化判定;该方法特异性强,仅对PRRSV出现阳性扩增,对本研究中其他病原均无交叉反应;以含PRRSV ORF2a基因全段序列的重组质粒作为模板,RT-RAA-LF的检出限为160 copies/μL。应用建立的RT-RAA-LF方法对临床采集的160份样本进行检测,与PCR方法进行比较,两种方法的符合率为96.8%(65/68),一致性检验为χ2<3.84,在95%的置信区间内没有显著性差异,当中3份临床样品在PCR检测中为阴性。综上,基于PRRSV ORF2a建立的RT-RAA-LF方法操作简单,对仪器设备要求不高,能够高效且直观的实现临床检测,满足现场检测的要求,对猪养殖场快速诊断和防控PRRSV具有重要意义。

关键词：猪繁殖与呼吸综合征病毒 ORF2a 侧流层析试纸条重组酶介导扩增法(RAA) 临床检测