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Scenario-based analysis and probability assessment of sub-synchronous oscillation caused by wind farms with direct-driven wind generators

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Journal of Modern Power Systems and Clean Energy 2019年第2期7卷 243-253页

作者： Zhi AN Chen SHEN Zetian ZHENG Feng LIU xiaoqing chang Wei WEI Department of Electrical Engineering Tsinghua UniversityBeijingChina China State Key Laboratory of Power System and Generation Equipment BeijingChina Electric Power Research Institute of Sichuan Electric Power Company ChengduChina

Recently, explanations of the sub-synchronous oscillation(SSO) caused by wind farms based on directdriven wind generators(DDWGs) have been published in the literatures, in which the controller parameters of DDWGs and the system equivalent parameters play an important role. However, more than one set of parameters can cause weakly damped sub-synchronous modes. The most vulnerable and highly possible scenario is still unknown. To find scenarios that have potential oscillation risks, this paper proposes a small disturbance model of wind farms with DDWGs connected to the grid using a state-space modeling technique. Taguchi’s orthogonal array testing is introduced to generate different *** scenarios with different parameter settings that may lead to SSOs are found. A probabilistic analysis method based on the Gaussian mixture model is employed to evaluate the consistency of these scenarios with the actual accidents. Electromagnetic transient simulations are performed to verify the findings.

关键词： Direct-driven wind generator Subsynchronous oscillation Probabilistic assessment Randomness

Preparation of monodisperse, superparamagnetic, luminescent, and multifunctional PGMA microspheres with amino-groups

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Chinese Science Bulletin 2008年第8期53卷 1165-1170页

作者： WANG WeiCai ZHANG Qi ZHANG BingBo LI DeNa DONG xiaoqing ZHANG Lei chang Jin Institute of Nanobiotechnology School of Materials Science & Engineering Tianjin University Tianjin 300072 China

Micron-sized, monodisperse, superparamagnetic, luminescent composite poly(glycidyl methacrylate) (PGMA) microspheres with functional amino-groups were successfully synthesized in this study. The process of preparation was as follows: preparation of monodisperse poly(glycidyl methacrylate) mi- crospheres by dispersion polymerization method; modification of poly(glycidyl methacrylate) micro- spheres with ethylene diamine to form amino-groups; impregnation of iron ions (Fe2+ and Fe3+) inside the microspheres and subsequently precipitating them with ammonium hydroxide to form magnetite (Fe3O4) nanoparticles within the polymer microspheres; infusion of CdSe/CdS core-shell quantum dots (QDs) into magnetic polymer microspheres. Scanning electron microscopy (SEM) was used to char- acterize surface morphology and size distribution of composite microspheres. The average size of mi- crospheres was 1.42 μm with a size variation of 3.8%. The composite microspheres were bright enough and easily observed using a conventional fluorescence microscope. The composite microspheres were easily separated from solution by magnetic decantation using a permanent magnet. The new multi- functional composite microspheres are promising to be used in a variety of bioanalytical assays in- volving luminescence detection and magnetic separation.

关键词：发光性磁性缩水甘油基异丁烯酸盐量子点

Synthesis and structure of a novel polyoxovanadium borate decorated by Cd-ligand unit

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Synthesis and structure of a novel polyoxovanadium borate de...

Synthesis and structure of a novel polyoxovanadium borate decorated by Cd-ligand unit

中国化学会第五届全国多酸化学学术研讨会

作者： xiaoqing chang Zhangang Han College of Chemistry＆Material Science Hebei Normal University

＜正＞Polyoxometalates （POMs） with structural versatility and potential applications in diverse fields including catalysis, medicine, and materials science, have attracted more attentions. The polyoxovanadium borate...

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Synthesis and structure of a novel polyoxovanadium borate de...

CT引导下经皮肺穿刺组织和支气管肺泡灌洗液宏基因组二代测序在肺部感染病原学诊断中的价值

中国化学会2013年中西部地区无机化学化工学术研讨会

作者： xiaoqing chang Zhangang Han Xueliang Zhai College of Chemistry & Material Science Hebei Normal University

Polyoxometalates(POMs) with structural versatility and potential applications in diverse fields including catalysis,medicine,and materials science,have attracted more *** polyoxovanadium borate remain largely unexplor...

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中华实用诊断与治疗杂志 2024年第3期38卷 280-284页

作者：李丹丹胡莎莎常晓青安云霞张茜茜任红岩汪铮况红艳张晓菊河南省人民医院郑州大学人民医院呼吸与危重症医学科河南郑州450003 河南大学人民医院河南省人民医院呼吸与危重症医学科河南郑州450003

目的分析拟诊肺部感染患者CT引导下经皮肺穿刺活检组织宏基因组二代测序(mNGS)和支气管肺泡灌洗液(BALF)mNGS结果,探讨二者在肺部感染病原学诊断中的价值。方法 2020年6月—2021年5月河南省人民医院拟诊为肺部感染、传统病原学检测(CMT... 详细信息

目的分析拟诊肺部感染患者CT引导下经皮肺穿刺活检组织宏基因组二代测序(mNGS)和支气管肺泡灌洗液(BALF)mNGS结果,探讨二者在肺部感染病原学诊断中的价值。方法 2020年6月—2021年5月河南省人民医院拟诊为肺部感染、传统病原学检测(CMT)未明确诊断的患者8例,均行CT引导下经皮肺穿刺活检组织mNGS,肺组织mNGS未明确诊断者行BALF mNGS。记录患者病史、胸部CT检查等临床资料,CMT、mNGS诊断结果及病原体检出率,治疗及预后情况。结果 8例患者中2例有类风湿关节炎病史,1例有肺结核病史,1例有慢性支气管炎病史,余4例既往体健。6例胸部CT主要表现为多发结节或团块影,伴或不伴空洞;2例表现为大片状高密度影。3例患者行肺组织mNGS,其中1例肺组织mNGS检出结核分枝杆菌复合群,CMT阴性,诊断为肺结核;1例肺组织mNGS阴性,CMT检出肺隐球菌,诊断为肺隐球菌病;1例肺组织mNGS、CMT均阴性,组织病理检查诊断为抗中性粒细胞胞浆抗体(ANCA)相关性血管炎。5例患者行肺组织mNGS和BALF mNGS,其中3例BALF mNGS分别检出耶氏肺孢子菌、黑曲霉+百岁兰曲霉、肺炎链球菌,肺组织mNGS、CMT均阴性,分别诊断为耶氏肺孢子菌肺炎、肺曲霉菌病、肺炎链球菌肺炎,其中1例2次BALF mNGS均检出黑曲霉;1例肺组织及BALF mNGS均阴性,CMT检出结核分枝杆菌,诊断为肺结核;1例肺组织mNGS检出胶红酵母,BALF mNGS、CMT均阴性,诊断为肺部真菌感染;5例BALF mNGS病原体检出率为66.7%,肺组织mNGS病原体检出率为20.0%。7例肺部感染患者(肺结核2例,肺部真菌感染4例,肺炎链球菌肺炎1例)肺组织mNGS病原体检出率为28.6%,BALF mNGS病原体检出率为66.7%,CMT病原体检出率为28.6%。除1例肺结核患者失访,1例ANCA相关性血管炎患者未规律用药导致病情加重外,余患者根据病原学结果给予抗感染治疗后病情好转。结论对CMT诊断不明的肺部感染,CT引导下经皮肺穿刺组织mNGS、BALF mNGS可作为补充诊断方法,尤其在少见肺部真菌感染诊断中有一定价值;BALF mNGS较肺组织mNGS病原体检出率高,BALF可作为mNGS的优选标本。

关键词：肺部感染病原学宏基因组二代测序 CT引导下经皮肺穿刺支气管肺泡灌洗液

Effects of traditional Chinese medicine on treatment outcomes in severe COVID-19 patients:a single-centre study

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Chinese Journal of Natural Medicines 2024年第1期22卷 89-96页

作者： XIAO Yongjiu LI Binbin LIU chang HUANG Xiuyu MA Ling QIAN Zhirong ZHANG Xiaopeng ZHANG Qian LI Dunqing CAI xiaoqing YAN Xiangyong LUO Shuping XIANG Dawei XIAO Kun Emergency Department the 940th Hospital of Jiont Logistics Support Force of Chinese People’s Liberation ArmyLanzhou 730050China Scientific Research Center the Seventh Affiliated HospitalSun Yat-sen UniversityShenzhen 518000China School of Medicine Nankai universityTianjin 300000China Department of Cardiology the 940th Hospital of Joint Logistics Support Force of Chinese People’s Liberation ArmyLanzhou 730050China Department of Radiation Oncology Fujian Medical University Union HospitalFuzhou 350000China Department of Traditional Chinese Medicine the 940th Hospital of Joint Logistics Support Force of Chinese People’s Liberation ArmyLanzhou 730050China Department of Geriatric Diseases the Seventh Medical Center of Chinese PLA General HospitalBeijing 100700China Health and Sport Administration Muskingum UniversityOhioanUSA Laboratory of Vaccine and Antibody Engineering Beijing Institute of BiotechnologyBeijing 100071China Department of Pulmonary and Critical Care Medicine the 940th Hospital of Joint Logistics Support Force of Chinese People’s Liberation ArmyLanzhou 730050China Center of Pulmonary&Critical Care Medicine Chinese People’s Liberation Army(PLA)General HospitalBeijing 100853China

As the search for effective treatments for COVID-19 continues,the high mortality rate among critically ill patients in Intensive Care Units(ICU)presents a profound *** study explores the potential benefits of traditional Chinese medicine(TCM)as a supplementary treatment for severe COVID-19.A total of 110 critically ill COVID-19 patients at the Intensive Care Unit(ICU)of Vulcan Hill Hospital between Feb.,2020,and April,2020(Wuhan,China)participated in this observational *** patients received standard supportive care protocols,with a subset of 81 also receiving TCM as an adjunct *** characteristics during the treatment period and the clinical outcome of each patient were closely monitored and *** findings indicated that the TCM group exhibited a significantly lower mortality rate compared with the non-TCM group(16 of 81 vs 24 of 29;0.3 vs 2.3 person/month).In the adjusted Cox proportional hazards models,TCM treatment was associated with improved survival odds(P<0.001).Furthermore,the analysis also revealed that TCM treatment could partially mitigate inflammatory responses,as evidenced by the reduced levels of proinflammatory cytokines,and contribute to the recovery of multiple organic functions,thereby potentially increasing the survival rate of critically ill COVID-19 patients.

关键词： COVID-19 Pneumonia Novel coronavirus Critically ill Traditional Chinese medicine Clinical outcome

Analysis on Sub-Synchronous Oscillation Associated with Wind Farms Based on Direct-Driven Wind Generators

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Analysis on Sub-Synchronous Oscillation Associated with Wind...

应用虚拟样机技术进行岸边集装箱起重机结构强度破坏原因分析

第37届中国控制会议

作者： Zhi An Chen Shen Zetian Zheng Feng Liu Xuemin Zhang xiaoqing chang Wei Wei Department of Electrical Engineering Tsinghua University Electric Power Research Institute of Sichuan Electric Power Company

Recently,several literatures reported that sub-synchronous oscillation（SSO） events occurred in wind farms based on direct-driven wind generators（DDWGs）.This paper focuses on whether a wind farm consists of only DDWGs would bring an ***,a small-signal model of the DDWG-based wind farm is ***-analysis indicates that there are natural modes with sub-synchronous frequency;however,their damping ratios are significantly large under specific control ***,the relationships between the sub-synchronous modes and the number of grid-connected DDWGs,the connecting reactance and the circuit topologies of the wind farm are ***’s orthogonal array testing is also introduced to analyze the impact of the wind farm’s stochastic operating conditions on the *** show that if the DDWGs are well-tuned,the dynamics of the wind farm are similar to one DDWG,and the sub-synchronous modes have little correlation with those factors,thus SSO can hardly arise when the model of wind farm only includes *** transient simulations are also carried out to prove the accuracy and efficiency of the results.

关键词： Sub-synchronous oscillation Wind farm Direct-driven wind generator

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机械强度 2009年第1期31卷 73-77页

作者：卢耀祖常晓清喻艳张氢同济大学机械工程学院上海200092 上海市特种设备监督检验技术研究院上海200062

运用虚拟样机技术,建立岸边集装箱起重机(简称"岸桥")的虚拟样机。通过对岸桥前大梁仰起40°时整机运行的起制动工况进行仿真计算,并将其应力与实际测试应力值相比较,两者基本吻合;同时得到引起拉耳疲劳破坏的原因是拉杆摆动所产生的转... 详细信息

运用虚拟样机技术,建立岸边集装箱起重机(简称"岸桥")的虚拟样机。通过对岸桥前大梁仰起40°时整机运行的起制动工况进行仿真计算,并将其应力与实际测试应力值相比较,两者基本吻合;同时得到引起拉耳疲劳破坏的原因是拉杆摆动所产生的转矩和弯矩在拉耳根部形成较大的交替变化的应力。文中也证实应用虚拟样机技术在港口机械动力学分析中是可行的,而且是行之有效的。

关键词：虚拟样机技术多体动力学岸边集装箱起重机瞬态分析

亚热带常绿针叶林光能利用率模型优化与总初级生产力估算

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森林工程 2021年第5期37卷 28-36页

作者：徐珂邢艳秋常晓晴东北林业大学森林作业与环境研究中心哈尔滨150040

为使光能利用率模型在亚热带常绿针叶林区得到更好的应用,以江西省太和县千烟洲为例,利用2003—2005年卫星遥感数据(GLASS LAI叶面积指数产品数据集、MODIS地表反射率产品数据集(MOD09A1)和MODIS GPP产品(MOD17A2))及中国陆地生态系统... 详细信息

为使光能利用率模型在亚热带常绿针叶林区得到更好的应用,以江西省太和县千烟洲为例,利用2003—2005年卫星遥感数据(GLASS LAI叶面积指数产品数据集、MODIS地表反射率产品数据集(MOD09A1)和MODIS GPP产品(MOD17A2))及中国陆地生态系统通量研究网络(ChinaFLUX)千烟洲常绿针叶林的通量观测数据,对13种不同光能利用率模型中的光合有效辐射吸收比率(Fraction of absorbed photosynthetically active radiation,FPAR)、7种水分限制因子(f_(θ))和3种温度限制因子(f_(t))进行模型重组,通过对比通量站观测值与273种模型组合的估算值的决定系数及均方根误差(RMSE)得到更优的模型组合。同时使用该优化模型进行总初级生产力(Gross Primary Productivity,GPP)估算,并进行敏感性分析。结果表明,优化所得到的优选模型组合:用EVI表示的光合有效辐射吸收比率FPAR_(EVI)、3PG模型中的水分影响因子f_(θ-3PG)、TEM模型中的温度影响因子f_(t-TEM)(R^(2)=0.86,RMSE=0.47μmol/(m^(2)·s))的模拟效果最好。优化模型的GPP模拟值均优于MODIS陆地四级标准数据产品(MOD17A2)。敏感性分析结果表明,最大光量子效率α_(max)、增强型植被指数(Enhanced vegetation index,EVI)和光合有效辐射(Photosynthetically active radiation,PAR)为模型的直接线性变量,对模型输出结果影响最大,其他参数敏感性由大到小排序依次为:光合最低温度T_(min)、光合最适温度T_(opt)、月均温度T、光合最高温度T_(max)。因此,本文的优化模型具有较强的实用意义,对进一步提高GPP估算精度具有重要意义。

关键词：光能利用率模型千烟洲通量观测站亚热带常绿针叶林模型优化敏感性分析