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Investigation on the particle loss and applicability of aviation nvPM measurement methodology for wide particle size ranges

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Particuology 2024年第12期95卷 154-165页

作者： Minghua Wang liuyong chang Xuehuan Hu Meiyin Zhu Bin Zhang Guangze Li Zheng Xu Hangzhou International Innovation Institute Beihang UniversityHangzhou311115China School of Energy and Power Engineering Beihang UniversityBeijing100083China

The precise measurement of non-volatile Particulate Matter(nvPM)is outlined in aviation engine emissions regulations by the International Civil Aviation Organization(ICAO).However,assessing particle losses in the sampling and transfer unit presents challenges,raising concerns about the system's ***,nvPM emissions from small and medium aircraft engines,with thrust not exceeding 26.7 kN,vary widely in size,adding complexity to the measurement *** provide a comprehensive analysis of particle losses in the sampling and transfer subsystems,this study established a test bench equipped with a nanoparticle *** generator simulates nvPM emissions from medium and small aircraft engines and can consistently produce nvPMs with a wide range of concentrations(103–107/cm^(3))and size distributions(20–160 nm).Thermophoretic loss verification experiments were conducted within the sampling pipeline under significant temperature differences,investigating the effects of particle size,temperature gradient,and airflow rate on thermophoretic particle *** experimental results demonstrated good agreement with the predictions of the model proposed by United Technologies Research Centre(UTRC).After correcting for temperature,the experimental data showed a maximum disparity of 2%under typical engine exhaust conditions,validating the predictability of the thermophoretic loss model for various engine ***,verification experiments for particle diffusion and bending losses were *** analysis with the UTRC model revealed nvPM inertial deposition under laminar flow conditions with low Reynolds numbers(Re).As the Re increased,the measured data more closely aligned with the *** losses due to secondary flow patterns ranged from 1%to 10%,depending on particle size and flow *** finding supports the applicability of aviation nvPM measurement methods across a wide particle size *** research provides theoretic

关键词： Non-volatile particulate matter Thermophoretic loss Transfer loss Particle number concentration Particle size distribution

Abnormal Austenite-Ferrite Transformation Behaviors of Fe-ISi: Dilatometric Measurements

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材料热处理学报 2004年第5期25卷 49-52页

作者： liuyong-chang ZHANGZhe-ping ZHAOKai LIBao-yin CollegeofMaterialsScience＆Engineering TianjinUniversityTianjin300072China

The isochronal y—m transformation of Fe-ISi alloy was measured by high-resolution dilatometry. According to the variation of the ferrite formation rate, an abnormal y—>a phase transformation was recognized, while normal reaction, i.e. one peak continuous reaction, was also detected. The occurrence the one or the other type of y—?a transformation strongly depends on the grain size: the transformation type changes from abnormal to normal with decreasing grain size. In the abnormal transformation process the first stage of the transformation corresponds to the first peaks in the transformation rate, which are not thermally activated.

关键词：固态相位变换铁合金显微结构膨胀测定法

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在用车排放颗粒测量仪器标定及实验研究

中国计量大学学报 2024年第3期35卷 390-398页

作者：李袁昊常刘勇李光泽周泉陈龙飞中国计量大学机电工程学院浙江杭州310018 杭州市北京航空航天大学中法航空研究院浙江杭州310005 中国计量大学光学与电子科技学院浙江杭州310018 北京航空航天大学能源与动力工程学院北京100191

目的:在用车尾气排放颗粒物数目含量检测技术和设备国产化。方法:基于凝结核增长计数原理,采用自稀释结构,并调整温度设置,研发了纳米级细颗粒物计数仪器,并在洁净间进行了标定实验,同时,基于标定完成的自研CPC仪器对在用车排放尾气颗... 详细信息

目的:在用车尾气排放颗粒物数目含量检测技术和设备国产化。方法:基于凝结核增长计数原理,采用自稀释结构,并调整温度设置,研发了纳米级细颗粒物计数仪器,并在洁净间进行了标定实验,同时,基于标定完成的自研CPC仪器对在用车排放尾气颗粒物数目含量进行了实地测量。结果:在使用自稀释结构,采样温度为6~50℃下,自研仪器的D50达到了9.2 nm,满足机动车D50为23±1 nm的检测要求,仪器瞬态响应误差为9.53%,检测范围在0~5×10^(4)个/mL,满足仪器误差指标。此外,针对在用车排放尾气的实地测量结果表明,自研CPC具有较好的辨识能力,可以准确地捕捉到不同量级的颗粒物数目含量变化趋势,且自研CPC与TSI CPC的峰值相对误差变化均低于10%。结论:研制的仪器达到机动车尾气检测标准,且仪器检测范围内一致性较高。

关键词：颗粒物数目含量发动机排放仪器标定在用车检测细颗粒物

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Microscopic sdgIBM-2 description of low-lying excitation spectra of ^(48,52,56)Cr

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Nuclear Science and Techniques 1999年第4期10卷 235-239页

作者： SHIZhuyi liuyong 等 DepartmentofPhysics GuizhouInstituteforNationalitiesGuiyang550025 InstituteofParticlePhysics Huazhon

Starting from the shell model configurations,valence nucleon effctive interactions and fermion E2 transition operator,a microscopic approach of sdgIBM-2 is used to calculate the energy spectra,E2 transitions,and bindi... 详细信息

关键词：核壳层模型 Cr同位素低能激谱

Discussion on data-security of space-earth integrated network and analysis ofspace communications protocol standards

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Journal of Systems Engineering and Electronics 2005年第2期16卷 290-294页

作者： LiZehui liuyong SunJin DepartmentofArmamentEngineering NavalAeronauticalEngineeringAcademyYantai264001P.R.China ShandongInstituteofAerospaceElectronicTechnology Yantai264000P.R.China

The architecture and protocols of Internet can't work well in space environments. To form a reliable and safe space network, characteristics of space communication network one discusse, brief synthesis is performed for consultative committee for space data system (CCSDS) space communications protocol standards (SCPS), and a model accounting for data security problem of space-earth integrated network is provided.

关键词： space network protocol security.

Kinetics and Mechanism of Dechlorination of o-Chlorophenol by Nanoscale Pd/Fe

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Chemical Research in Chinese Universities 2004年第1期20卷 73-76页

作者： WEIJian-jun XUXin-hua liuyong DepartmentofEnvironmentalEngineering ZhejiangUniversityHangzhou310027P.R.China

Nanoscale Pd/Fe bimetallic particles were synthesized with an efficient method to dechlorinate o-chlorophenol. The nanoscale Pd/Fe particles were determined by transmission electron microscopy and BET specific surface area analysis. Most of the particles are in the size range of 20—100 nm. The BET specific surface area of synthesized nanoscale Pd/Fe particles is 12.4 m 2/g. In contrast, a commercially available fine iron powder(<100 mesh) has a specific surface area of 0.49 m 2/g. Batch studies demonstrated that the nanoscale particles can effectively dechlorinate o-chlorophenol. The dechlorination reaction takes place on the surface of synthesized nanoscale Pd/Fe bimetallic particles in a pseudo-first order reaction. The surface-area-normalized rate coefficients(k_ SA) are comparable to those reported in the literature for chlorinated ethenes. The observed reaction rate constants(k_ obs) are dominated by the mass fraction of Pd and the mass concentration of the nanoscale Pd/Fe particles.

关键词： Nanoscale Pd/Fe Dechlorination o-Chlorophenol Kinetics Mechanism

Efficient and simple synthesis of B_(2)O_(3)-Al_(2)O_(3)nanocomposites assisted by deep eutectic solvent for production of 5-hydroxymethylfurfural from glucose

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Nano Research 2025年第1期18卷 236-248页

作者： Yuchen Wang Kai Rong Shanlei chang Youxing Fang Shaojun Dong State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China College of Chemistry Jilin UniversityChangchun 130012China

The catalytic conversion of glucose to high valueadded platform chemical 5-hydroxymethylfurfural(HMF)is a promising biorefinery process,and alumina-boria catalysts are considered to be green and mild solid acid catalysts for this catalytic ***,compared to the common synthesis methods with complicated steps,we reported a simple and efficient strategy to prepare B_(2)O_(3)-Al_(2)O_(3)nanocomposites by calcining cost-effective glucose-urea deep eutectic solvent(DES)solution containing the *** prepared B_(2)O_(3)-Al_(2)O_(3)nanocomposites exhibited an open three-dimensional skeleton and two-dimensional porous lamellar substructure,endowing them with a high specific surface area(228.27 m2/g).The introduction of boron changed the ratios of different aluminum species(AlⅣ,AlⅤ,and AlⅥ)and borate species(BO3 and BO4),thus further affecting the acidity and the types of acid sites of the *** prepared B_(2)O_(3)-Al_(2)O_(3)bifunctional acid catalysts possessing abundant Lewis acid sites and adjustable Brønsted acid sites showed complete glucose conversion and 55.38%of HMF yield under the optimum *** study proposed a concise method to synthesize alumina-boria solid acid catalysts assisted by glucose-urea *** hope to extend the application and prospect of this efficient and simple synthesis strategy.

关键词： 5-hydroxymethylfurfural(HMF) deep eutectic solvent glucose alumina-boria acid catalyst

Interconnections between diabetic corneal neuropathy and diabetic retinopathy:diagnostic and therapeutic implications

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Neural Regeneration Research 2025年第8期20卷 2169-2180页

作者： Mingyi Yu Faith Teo En Ning chang Liu Yu-Chi Liu Tissue Engineering and Stem Cell Group Singapore Eye Research InstituteSingapore Yong Loo Lin School of Medicine National University of SingaporeSingapore Department of Cornea and External Eye Disease Singapore National Eye CenterSingapore Ophthalmology and Visual Sciences Academic Clinical Program Duke-NUS Medical SchoolSingapore

Diabetic corneal neuropathy and diabetic retinopathy are ocular complications occurring in the context of diabetes *** corneal neuropathy refers to the progressive damage of corneal *** retinopathy has traditionally been considered as damage to the retinal ***,growing evidence suggests that diabetic retinopathy is a complex neurovascular disorder resulting from dysfunction of the neurovascular unit,which includes both the retinal vascular structures and neural *** retinopathy is one of the leading causes of blindness and is frequently screened for as part of diabetic ocular ***,diabetic corneal neuropathy is commonly overlooked and underdiagnosed,leading to severe ocular surface *** studies have found that these two conditions tend to occur together,and they share similarities in their pathogenesis pathways,being triggered by a status of chronic *** review aims to discuss the interconnection between diabetic corneal neuropathy and diabetic retinopathy,whether diabetic corneal neuropathy precedes diabetic retinopathy,as well as the relation between the stage of diabetic retinopathy and the severity of corneal *** also endeavor to explore the relevance of a corneal screening in diabetic eyes and the possibility of using corneal nerve measurements to monitor the progression of diabetic retinopathy.

关键词： cornea corneal nerves diabetes diabetic corneal neuropathy diabetic retinopathy retina

A New Low-Impedance High Power Microwave Source

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Chinese Physics Letters 2004年第6期21卷 1111-1113页

作者： HEJun-Tao ZHONGHui-Huang liuyong-Gui CollegeofScience NationalUniversityofDefenseTechnologyChangsha410073

We propose a new low-impedance high power microwave source based on the axial transit time effect, i.e.a low-impedance axial transit-time oscillator. The analysis and simulation are carried out to investigate the characteristics of this new configuration. In the numerical simulation, the microwave output peak power of 6GW is obtained with an electron beam in the electron energy 580keV and in the beam current 20kA. The diode impedance is 29Ω. The power of the input electron beam is 11.6GW. The beam-to-microwave power conversion efficiency is 51.7%. The frequency is 3.9GHz by numerical simulation.

关键词： Electron beams