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Understanding unusually high levels of peroxyacetyl nitrate(PAN) in winter in Urban Jinan,China

Journal of Environmental Sciences 2018年第9期30卷 249-260页

作者： lu Liu Xinfeng Wang Jianmin Chen Likun Xue Wenxing Wang Liang Wen Dandan Li tianshu Chen Environment Research Institute School of Environmental Science and EngineeringShandong University Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention Department of Environmental Science and EngineeringInstitute of Atmospheric SciencesFudan University Institute for Climate and Global Change Research School of Atmospheric SciencesNanjing University

Peroxyacetyl nitrate （PAN）, as a major secondary pollutant, has gained increasing worldwide attentions, but relevant studies in China are still quite limited. During winter of 2015 to summer of 2016, the ambient levels of PAN were measured continuously by an automatic gas chromatograph equipped with an electron capture detector （GC-ECD） analyzer at an urban site in Jinan （China）, with related parameters including concentrations of 03, NO, NO2, PM2.5, HONO, the photolysis rate constant of NO2 and meteorological factors observed concurrently. The mean and maximum values of PAN concentration were （1.89 ± 1.42） and 9.61 ppbv respectively in winter, and （2.54 ± 1.44） and 13.47 ppbv respectively in summer. Unusually high levels of PAN were observed during severe haze episodes in winter, and the formation mechanisms of them were emphatically discussed, Study showed that high levels of PAN in winter were mainly caused by local accumulation and strong photochemical reactions during haze episodes, while mass transport played only a minor role. Accelerated photochemical reactions （compared to winter days without haze） during haze episodes were deduced by the higher concentrations but shorter lifetimes of pAN, which was further supported by the sufficient solar radiation in the photolysis band along with the high concentrations of precursors （NO2, VOCs） and HONO during haze episodes. In addition, significant PAN accumulation during calm weather of haze episodes was verified by meteorological data.

关键词： Peroxyacetyl nitrate Winter Haze episodes North China Plain

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Impacts of subsynchronous and supersynchronous frequency components on synchrophasor measurements

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Journal of Modern Power Systems and Clean Energy 2016年第3期4卷 362-369页

作者： Hao LIU tianshu BI Xiqiang CHANG Xiaolong GUO lu WANG Chuang CAO Qing YAN Jinsong LI State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China State Grid Xinjiang Electric Power Company Xinjiang 830063China Power Automation Department China Electric Power Research InstituteBeijing 100192China

Phasor measurement units(PMU) are playing an increasingly important role in power system dynamic security monitoring and control. However, the wide-area deployments of the renewable energy sources and the high voltage direct current(HVDC) transmission bring a large number of inter-harmonics to the power grid, which may result in further power system security problems. The impacts of inter-harmonics on synchrophasor measurements are revealed. This paper derives the phasor expressions of the signal, which contains the fundamental component and the inter-harmonics. It is found that the inter-harmonics will lead to the subsynchronous oscillation of the phasor measurements. The frequency transmutation principle between the harmonic and the phasor oscillation is revealed. Then, the field PMU data recorded during a subsynchronous oscillation, which occurred in an area of China with a high concentration of wind farms and HVDC transmission lines, are studied. A geographical wiring diagram with the subsynchronous oscillation distribution depicts the severe consequences of the inter-harmonics. In addition, the correctness of the theoretical derivation and the possibility of the inter-harmonics monitoring are verified.

关键词： Inter-harmonics Frequency Subsynchronous oscillations Phasor measurement units(PMU) Renewable energy source

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Ferroelectric,magnetic,and optical properties of Aurivillius compound Bi_(5)FeTi_(2.5)Co_(0.5)O_(15)

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Journal of Materiomics 2018年第4期4卷 353-359页

作者： Hui Sun Yuying Wu Xi Xie Yuxi lu tianshu Yao Jiansheng Zhong Xiaobing Chen College of Physics Science and Technology Yangzhou UniversityYangzhou225002China Guangling College of Yangzhou University Yangzhou225002China

Bi_(5)FeTi_(2.5)Co_(0.5)O_(15)(BFTC)ceramics was successfully synthesized using the sol-gel *** exhibits simultaneously visible-light response,ferroelectric and weak ferromagnetic orders at room *** narrow band gap of 2.06 eV was determined via the UVevis diffuse absorption *** x-ray photoelectron spectroscopy results show that the Fe ions in the samples is 3 t and 2 t valence states while the doped Co ions is 2 t valence *** BFTC sample undergoes a ferromagnetic-like transition at~552 *** ferromagnetism is mainly due to spin-canting of Fe-based and Co-based sublattices via Dzyaloshinskii-Moriya(DM)*** loss and dielectric modulus exhibit the characteristics of dielectric relaxation,which can be ascribed to oxygen/vacancy *** results reveal many potentially useful physical phenomena and open a new avenue to design of novel solar-energy conversion devices and multiferroic applications.

关键词： Aurivillius phase Weak ferromagnetism Optical properties Co-doping

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OPD-Scan Ⅲ型屈光分析仪在评估SBL-3型多焦点人工晶状体中的应用

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中华眼科医学杂志（电子版） 2019年第3期9卷 153-159页

作者：刘一昀孙彤高玉菲马思翼秦思源唐楚皓鲁恬舒齐虹北京大学第三医院 100191 北京大学第三医院眼科眼部神经损伤的重建保护与康复北京市重点实验室100191

目的利用OPD-ScanⅢ型屈光分析仪评估SBL-3型多焦点人工晶状体的轴位和居中性。方法回顾性研究。收集2017年6月至2018年7月在北京大学第三医院眼科行超声乳化白内障吸除联合SBL-3型多焦点人工晶状体植入术的33例(66只眼)患者。分别由两... 详细信息

目的利用OPD-ScanⅢ型屈光分析仪评估SBL-3型多焦点人工晶状体的轴位和居中性。方法回顾性研究。收集2017年6月至2018年7月在北京大学第三医院眼科行超声乳化白内障吸除联合SBL-3型多焦点人工晶状体植入术的33例(66只眼)患者。分别由两名经验丰富的研究人员利用OPD-ScanⅢ型的屈光分析仪检查术后3个月术眼的屈光分布和日-夜瞳孔分析情况,来评估术眼视近区、视远区分布的SBL-3居中性。再利用组内相关系数(ICC)和Bland-Altman法评估该方法的可靠性和一致性。以日-夜瞳孔分析图像中术眼人工晶状体中心与相对于视轴的距离和夹角来代表SBL-3型多焦点人工晶状体的居中性。以屈光分布图中术眼晶状体视近区及视远区间的过渡区对应角度来代表SBL-3型多焦点人工晶状体的轴位。结果本研究发现不同研究人员测量的轴位间无统计学意义(Z=-0.994,P>0.05),(ICC=0.950,P0.05),(ICC=0.913,P0.05),(ICC=0.607,P<0.05)。95%LoA分别为0.17 mm、 348.2°。结论利用OPD-ScanⅢ型屈光分析仪评估SBL-3型多焦点人工晶状体的轴位及居中性,不同研究人员间表现出有良好的可靠性及一致性,但SBL-3居中性的角度评估可靠性较差。

关键词：白内障多焦点人工晶状体区域折射居中性轴位

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Non-smooth dynamic modeling and simulation of an unmannedbicycle on a curved pavement

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Applied Mathematics and Mechanics(English Edition) 2022年第1期43卷 93-112页

作者： Kaiming ZHANG Xudong ZHENG Zhang CHEN Bin LIANG tianshu WANG Qi WANG School of Aeronautic Science and Engineering Beihang UniversityBeijing100083China Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhenGuangdong Province518055China Department of Automation Tsinghua UniversityBeijing100084China School of Aerospace Engineering Tsinghua UniversityBeijing100084China

The non-smooth dynamic model of an unmanned bicycle is established to study the contact-separate and stick-slip non-smooth phenomena between wheels and the *** to the Carvallo-Whipple configuration,the unmanned bicycle is reduced to four rigid bodies,namely,rear wheel,rear frame,front fork,and front wheel,which are connected by perfect revolute *** interaction between each wheel and the ground is simplified as the normal contact force and the friction force at the contact point,and these forces are described by the Hunt-Crossley contact force model and the lu Gre friction force model,*** to the characteristics of flat and curved pavements,calculation methods for contact forces and their generalized forces are *** dynamics of the system is modeled by the Lagrange equations of the first kind,a numerical solution algorithm of the dynamic equations is presented,and the Baumgarte stabilization method is used to restrict the drift of the *** correctness of the dynamic model and the numerical algorithm is verified in comparison with the previous *** feasibility of the proposed model is demonstrated by simulations under different motion states.

关键词： unmanned bicycle non-smooth dynamics lu Gre model contact-impact stick-slip

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Migration and accumulation mechanisms and main controlling factors of tight oil enrichment in a continental lake basin

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Petroleum Exploration and Development 2023年第3期50卷 547-557页

作者： HU Suyun TAO Shizhen WANG Min PANG Zhenglian BAI Bin CHEN Yanyan lu Shuangfang CHEN Yue YANG Yiqing JIN Xu JIA Jinhua WANG Jian ZHANG tianshu LIN Senhu WU Yinye Research Institute of Petroleum Exploration&Development PetroChinaBeijing 100083China China University of Petrolum(East China) Qingdao 266580China

Based on the typical dissection of various onshore tight oil fields in China,the tight oil migration and accumulation mechanism and enrichment-controlling factors in continental lake basins are analyzed through nuclear magnetic resonance(NMR)displacement physical simulation and Lattice Boltzmann numerical simulation by using the samples of source rock,reservoir rock and crude *** continental lake basins,the dynamic forces driving hydrocarbon generation and expulsion of high-quality source rocks are the foundational power that determines the charging efficiency and accumulation effect of tight oil,the oil migration resistance is a key element that influences the charging efficiency and accumulation effect of tight oil,and the coupling of charging force with pore-throat resistance in tight reservoir controls the tight oil accumulation and sweet spot *** degree of tight oil enrichment in continental lake basins is controlled by four factors:source rock,reservoir pore-throat size,anisotropy of reservoir structure,and *** high-quality source rocks control the near-source distribution of tight oil,reservoir physical properties and pore-throat size are positively correlated with the degree of tight oil enrichment,the anisotropy of reservoir structure reveals that the parallel migration rate is the highest,and intralayer fractures can improve the migration and accumulation efficiency and the oil saturation.

关键词： tight oil NMR displacement physical simulation Lattice Boltzmann numerical simulation migration and accumulation mechanism enrichment-controlling factor continental lake basin tight reservoir

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Sensor Fault Diagnosis of Control System Based on CMKPCA and BP Neural Network

Sensor Fault Diagnosis of Control System Based on CMKPCA and...

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第37届中国控制会议

作者： Yinsong Wang tianshu Sun Bo Cai lu lu Xiongjie Jiang Xiang Hu North China Electric Power University Zhejiang Energy Technology Research Institute Co. Ltd Zhejiang Energy Jiahua Power Generation Co. Ltd

Higher levels of automation and intelligence put higher demands on fault diagnosis. BP neural network has great advantages in fault identification and classification, but its efficiency and accuracy are restricted in practical application. In this paper, Class Mean Kernel Principal Component Analysis（CMKPCA） is applied to the optimization of BP neural network. By extracting the characteristic information of the fault samples, this method highlights the main components that cause faults and at the same time achieves lossless dimensionality reduction. The processed data will reduce the complexity of the neural network and further optimize the network parameters. The training result will be compared with that only using BP neural network. Simulation shows that this method can improve the recognition rate of fault diagnosis.

关键词： CMKPCA BP neural network fault diagnosis

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长江口鳗苗定置网多样性调查

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环境监控与预警 2024年第5期16卷 94-102页

作者：陈昱颖王晓东施金金赵度宾陆天宇刘企昂钟俊生汤建华熊天舒上海海洋大学海洋动物系统分类与进化上海高校重点实验室上海201306 江苏省海洋水产研究所江苏南通226000 南京外国语学校江苏南京210018

为探明长江十年禁渔工作实施后长江口鳗苗定置网兼捕鱼类种类组成,于2023年2—4月在长江口禁捕区北界外海域(31°42′—31°43′N,122°10′—122°16′E),收集鳗苗定置网内渔获物118网次。共采集到兼捕鱼类5482尾,隶属25科47属64种。其... 详细信息

为探明长江十年禁渔工作实施后长江口鳗苗定置网兼捕鱼类种类组成,于2023年2—4月在长江口禁捕区北界外海域(31°42′—31°43′N,122°10′—122°16′E),收集鳗苗定置网内渔获物118网次。共采集到兼捕鱼类5482尾,隶属25科47属64种。其中,海洋性鱼类26种,河口性鱼类31种,洄游性鱼类5种,淡水性鱼类2种。发育阶段包括从后弯曲期到成鱼期,其中幼鱼最多,占总兼捕鱼类尾数的52.39%,其次是稚鱼,占23.61%。相对重要性指数(IRI)分析结果表明,优势种为矛尾虾虎鱼(Chaeturichthys stigmatias)和拉氏狼牙虾虎鱼(Odontamblyopus lacepedii);重要种为刀鲚(Coilia nasus)、大银鱼(Protosalanx hyalocranius)、安氏新银鱼(Neosalanx anderssoni)、莱氏舌鳎(Cynoglossus lighti)、鲻(Mugil cephalus)、赤鼻棱鳀(Thryssa kammalensis)、陈氏新银鱼(Neosalanx tangkahkeii)、凤鲚(Coilia mystus)、棘头梅童鱼(Collichthys lucidus);以上11种鱼类占总兼捕鱼类尾数的84.77%,占总兼捕鱼类重量的87.51%。兼捕鱼类数量2月最高,4月最低,渔获物重量也呈相同趋势。渔获物中兼捕经济鱼类共47种,平均每网44.13尾。采集鳗苗1363尾,平均每采集1尾鳗苗,兼捕经济鱼类3.82尾。结果表明,鳗苗定置网对非目标兼捕鱼类以及一些经济性鱼类的早期资源存在严重损害。

关键词：长江口鳗苗网兼捕鱼类鳗苗种类组成

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新型半解耦式除湿热泵系统的降温除湿性能

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化工学报 2018年第A02期69卷 55-60页

作者：陆繁莉葛天舒代彦军王如竹上海交通大学制冷与低温工程研究所上海200240

提出一种新型半解耦式除湿热泵系统,并对该系统在夏季工况下的降温除湿性能进行了测试。结果表明,该系统可实现对空气温湿度的高效处理:送风温湿度分别为18.36℃、11.67 g/kg,送风温度波动范围仅为1℃,系统COP高达4.71。此外,还对不同... 详细信息

提出一种新型半解耦式除湿热泵系统,并对该系统在夏季工况下的降温除湿性能进行了测试。结果表明,该系统可实现对空气温湿度的高效处理:送风温湿度分别为18.36℃、11.67 g/kg,送风温度波动范围仅为1℃,系统COP高达4.71。此外,还对不同新风温湿度下的系统性能进行了实验研究。

关键词：吸附剂除湿换热器蒸汽压缩式系统热泵半解耦

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电针早期干预对肌萎缩侧索硬化症小鼠大脑皮层TDP-43及HMGB1/RhoA信号通路的影响

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中国康复医学杂志 2024年第3期39卷 312-319页

作者：卢苑蓉刘隽阳郭婕李华王渊赵颖倩李杰王强陕西中医药大学第二临床医学院陕西省咸阳市712046 陕西中医药大学针灸推拿学院陕西省针药结合重点实验室

目的:观察电针早期干预对肌萎缩侧索硬化症(amyotrophic lateral sclerosis,ALS)小鼠大脑皮层TARDNA结合蛋白43(TARDNA binding protein,TDP-43)及HMGB1/RhoA信号通路表达的影响,探究电针早期干预改善ALS小鼠运动功能的潜在机制。方法:... 详细信息

目的:观察电针早期干预对肌萎缩侧索硬化症(amyotrophic lateral sclerosis,ALS)小鼠大脑皮层TARDNA结合蛋白43(TARDNA binding protein,TDP-43)及HMGB1/RhoA信号通路表达的影响,探究电针早期干预改善ALS小鼠运动功能的潜在机制。方法:符合SOD1G93A基因表型小鼠按随机数字表法分为模型组(SOD1G93A)、针刺干预组(electroacupuncture,EA)、利鲁唑组(Riluzole),同窝SOD1G93A阴性小鼠为空白对照组(control),每组15只。电针组针刺干预百会穴、双侧天柱穴、双侧天枢穴,5次/7d,7d为一个疗程,共治疗4个疗程。利鲁唑组予利鲁唑30mg/(kg·d)灌胃治疗,1次/d,5次/周,持续2周。采用后肢功能神经学评分和转棒疲劳实验评估各组小鼠运动功能,免疫荧光法观察大脑皮层TDP-43阳性细胞率;Western Blot法检测大脑皮质离子钙结合接头分子1(Iba-1)、HMGB1、RhoA蛋白相对表达量;Elisa法检测血清TNF-α及MCP-1的含量;透射电镜观察大脑皮层神经元形态变化。结果:与对照组比较,模型组转棒潜伏期时间减少和神经学评分增高(P<0.01),血清MCP-1、TNF-α含量和大脑皮层Iba-1、HMGB1、RhoA蛋白表达以及TDP-43阳性细胞率均升高(P<0.01)。与模型组比较,电针组和利鲁唑组转棒潜伏期时间增加和神经学评分降低(P<0.01,P<0.05),血清MCP-1、TNF-α含量和大脑皮质Iba-1、HMGB1、RhoA蛋白表达以及TDP-43阳性细胞率均降低(P<0.01,P<0.05)。电镜结果显示,对照组小鼠皮层神经元细胞结构正常,模型组小鼠神经细胞有明显病理变化,电针组和利鲁唑组神经细胞损伤减轻,结构较完整,可见部分正常细胞器。结论:电针干预可改善ALS模型小鼠的运动功能,其机制可能与抑制HMGB1/RhoA信号通路进而减轻小胶质细胞诱导的神经炎症有关,并推测其对于减少ALS病理底物TDP-43的沉积具有正相关作用。

关键词：肌萎缩侧索硬化症电针神经炎症单核细胞趋化蛋白-1 Ras同源基因家族成员A TARDNA结合蛋白-43

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