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A sound velocity method for determining isobaric specific heat capacity

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InfoMat 2022年第12期4卷 103-111页

作者： Jun Pei Hezhang Li hua-lu zhuang Jinfeng Dong Bowen Cai Haihua Hu Jing-Wei Li Yilin Jiang Bin Su Li-Dong Zhao Jing-Feng Li State Key Laboratory of New Ceramics and Fine Processing School of M aterials Science and EngineeringTsinghua UniversityBeijngPeople's Republic of China National Institute for Materials Science(NIMS) TsukubaJapan Schoo of Materials Science and Engineering Beihang UniversityBejingPeople's Republic of China

Isobaric specific heat capacity(Cp)is an important parameter not only in physics but also for most materials.Its accurate measurement is particularly critical for performance evaluation of thermoelectric materials,but the experiments by differential scanning calorimetry(DSC)often lead to large uncertainties in the measurements,especially at elevated temperatures.In this study,we propose a simple method to determine Cp by measuring the sound velocity(υ)based on lattice vibration and expansion theory.The relative standard error of theυis smaller than 1%,showing good accuracy and repeatability.The calculated Cp at elevated temperature(>300 K)increases slightly with increasing temperature due to the lattice expansion,which is more reasonable than the Dulong–Petit value.

关键词： heat capacity sound velocity thermoelectric

Advances in the treatment of IgA nephropathy with biological agents

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Chronic Diseases and Translational Medicine 2024年第1期10卷 1-11页

作者： Yongze zhuang Hailing lu Junxia Li Department of Nephrology 900 Hospital of the Joint Logistics TeamPLAFuzhou General Clinical Medical CollegeFujian Medical UniversityFuzhouFujianChina

Immunoglobulin A nephropathy(IgAN)is the most common primary glomerular disease,and the“four-hit”theory represents its currently accepted pathogenic mechanism.Mucosal immunity triggered by infections in the respiratory tract,intestines,or other areas leads to antigen presentation,T cell stimulation,B cell maturation,and the production of IgA-producing plasma cells.The proteins B-lymphocyte stimulator(BLyS)and a proliferation-inducing ligand(APRIL)are involved in this process,and alternative complement and lectin pathway activation are also part of the pathogenic mechanism.Kidney Disease Improving Global Outcomes guidelines indicate that a specific effective treatment for IgAN is lacking,with renin-angiotensin-aldosterone system inhibitors being the primary therapy.Recent research shows that biological agents can significantly reduce proteinuria,stabilize the estimated glomerular filtration rate,and reverse some pathological changes,such as endocapillary proliferation and crescent formation.There are four main categories of biological agents used to treat IgA nephropathy,specifically anti-CD20 monoclonal antibodies,anti-BLyS or APRIL monoclonal antibodies,monoclonal antibodies targeting both BLyS and APRIL(telitacicept and atacicept),and monoclonal antibodies inhibiting complement system activation(narsoplimab and eculizumab).However,further research on the dosages,treatment duration,long-term efficacy,and safety of these biological agents is required.

关键词： anti-CD20 monoclonal antibodies APRIL biological agents BLyS complement IgAnephropathy

A novel high-Cr CoNi-based superalloy with superior high-temperature microstructural stability, oxidation resistance and mechanical properties

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1373-1381页

作者： Xiaorui Zhang Min Zou Song lu Longfei Li Xiaoli zhuang Qiang Feng Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced MetalsUniversity of Science and Technology BeijingBeijing 100083China

A novel multicomponent high-Cr CoNi-based superalloy with superior comprehensive performance was prepared,and the evaluation of its high-temperature microstructural stability,oxidation resistance,and mechanical properties was conducted mainly using its cast polycrystalline alloy.The results disclosed that the morphology of theγ′phase remained stable,and the coarsening rate was slow during the long-term aging at 900–1000℃.The activation energy forγ′precipitate coarsening of alloy 9CoNi-Cr was(402±51)kJ/mol,which is higher compared with those of CMSX-4 and some other Ni-based and Co-based superalloys.Importantly,there was no indica-tion of the formation of topologically close-packed phases during this process.All these factors demonstrated the superior microstructural stability of the alloy.The mass gain of alloy 9CoNi-Cr was 0.6 mg/cm^(2) after oxidation at 1000℃ for 100 h,and the oxidation resistance was comparable to advanced Ni-based superalloys CMSX-4,which can be attributed to the formation of a continuous Al_(2)O_(3) protective layer.Moreover,the compressive yield strength of this cast polycrystalline alloy at high temperatures is clearly higher than that of the conventional Ni-based cast superalloy and the compressive minimum creep rate at 950℃ is comparable to that of the conventional Ni-based cast superalloy,demonstrating the alloy’s good mechanical properties at high temperature.This is partially because high Cr is bene-ficial in improving theγandγ′phase strengths of alloy 9CoNi-Cr.

关键词： CoNi-based superalloys microstructure coarsening oxidation mechanical properties

Flow Boiling Heat Transfer Characteristics and Delayed Dry-Out Ability of Non-Azeotropic Mixtures R245fa/R134a in Microchannels

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Journal of Thermal Science 2024年第3期33卷 1174-1188页

作者： lu Yongjie LING Yongjun zhuang Yuan LI Chenyang OUYANG Hongsheng HAN Xiaohong Key Laboratory of Refrigeration and Cryogenic Technology of Zhejiang Province Institute of Refrigeration and CryogenicsZhejiang UniversityHangzhou310007China Zhejiang Zhongguang Electrical Co. Ltd.Lishui323000China State Key Lab for Fluorine Greenhouse Gases Replacement and Control Treatment Zhejiang Research Institute of Chemical IndustryHangzhou310014China

Microchannel flow boiling heat transfer has the advantages of strong heat dissipation capacity,good temperature uniformity,and compact structure.It is an excellent way to thermally manage electronic devices,but when the heat flux exceeds CHF(Critical Heat Flux),the heat transfer performance deteriorates as the working fluid dries out.Non-azeotropic mixtures have the potential to effectively delay or avoid dry-out during the boiling process due to their temperature slide characteristics which causes the mass transfer resistance.To understand the influence of non-azeotropic mixtures on microchannel flow boiling,using the phase-change microchannel heat sink as the research object,the experiments on the flow boiling heat transfer performance of R245fa/R134a mixtures under different working conditions were carried out,and the characteristics of flow boiling heat transfer were obtained under the different working conditions,and comparison was developed with those of pure substance R245fa.The results demonstrated that a small amount of low-boiling-point components in the high-boiling-point working fluid inhibited boiling heat transfer to some extent,and lowered the average heat transfer coefficient under the non-dryout condition slightly lower than that of the pure substance;however,it also effectively delayed the onset of local dry-out and prevented significant deterioration in thermal transfer performance under the lower mass flow rate and higher heat flux,which could enhance the heat sink's stability.

关键词： microchannel flow boiling non-azeotropic mixture heat transfer characteristics dry-out

Greenhouse gas emissions from Daihai Lake,China:Should eutrophication and salinity promote carbon emission dynamics?

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Journal of Environmental Sciences 2024年第1期135卷 407-423页

作者： Xiangwei Li Ruihong Yu Jun Wang Heyang Sun Xinyu Liu Xiaohui Ren Shuai zhuang Zhiwei Guo Xixi lu Inner Mongolia Key Laboratory of River and Lake Ecology School of Ecology and EnvironmentInner Mongolia UniversityHohhot 010070China Key Laboratory of Mongolian Plateau Ecology and Resource Utilization Ministry of EducationHohhot 010070China Autonomous Region Collaborative Innovation Center for Integrated Management of Water Resources and Water Environment in the Inner Mongolia Reaches of the Yellow River Hohhot 010018China Department of Geography National University of Singapore117570Singapore

Greenhouse gases(GHGs)emitted or absorbed by lakes are an important component of the global carbon cycle.However,few studies have focused on the GHG dynamics of eutrophic saline lakes,thus preventing a comprehensive understanding of the carbon cycle.Here,we conducted four sampling analyses using a floating chamber in Daihai Lake,a eutrophication saline lake in Inner Mongolia Autonomous Region,China,to explore its carbon dioxide(CO_(2))and methane(CH_(4))emissions.The mean CO_(2)emission flux(FCO_(2))and CH_(4)emission flux(FCH_(4))were 17.54±14.54 mmol/m^(2)/day and 0.50±0.50 mmol/m^(2)/day,respectively.The results indicated that Daihai Lake was a source of CO_(2)and CH_(4),and GHG emissions exhibited temporal variability.The mean CO_(2)partial pressure(p CO_(2))and CH_(4)partial pressure(p CH_(4))were 561.35±109.59μatm and 17.02±13.45μatm,which were supersaturated relative to the atmosphere.The regression and correlation analysis showed that the main influencing factors of p CO_(2)were wind speed,dissolved oxygen(DO),total nitrogen(TN)and Chlorophyll a(Chl.a),whereas the main influencing factors of p CH_(4)were water temperature(WT),Chl.a,nitrate nitrogen(NO_(3)^(-)-N),TN,dissolved organic carbon(DOC)and water depth.Salinity regulated carbon mineralization and organic matter decomposition,and it was an important influencing factor of p CO_(2)and p CH_(4).Additionally,the trophic level index(TLI)significantly increased p CH_(4).Our study elucidated that salinity and eutrophication play an important role in the dynamic changes of GHG emissions.However,research on eutrophic saline lakes needs to be strengthened.

关键词： Eutrophication Salinity Greenhouse gas emissions Inland lake Inner Mongolia Autonomous Region

On-Chip Sub-Picometer Continuous Wavelength Fiber-Bragg-Grating Interrogator

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Photonic Sensors 2024年第1期14卷 73-84页

作者： Yuan zhuang Jun ZOU Jiqiang ZHANG lu ZHANG Jiahe ZHANG Leixin MENG Qing YANG Research Center for Humanoid Sensing Zhejiang LabHangzhou 311121China ZJU-Hangzhou Global Scientific and Technological Innovation Center Hangzhou 310014China State Key Laboratory of Modern Optical Instrumentation College of Optical Science and EngineeringInternational Research Center for Advanced PhotonicsZhejiang UniversityHangzhou 310058China

Miniaturized fiber-Bragg-grating(FBG)interrogators are of interest for applications in the areas where weight and size controlling is important,e.g.,airplanes and aerospace or in-situ monitoring.An ultra-compact high-precision on-chip interrogator is proposed based on a tailored arrayed waveguide grating(AWG)on a silicon-on-insulator(SOI)platform.The on-chip interrogator enables continuous wavelength interrogation from 1544 nm to 1568 nm with the wavelength accuracy of less than 1 pm[the root-mean-square error(RMSE)is 0.73 pm]over the whole wavelength range.The chip loss is less than 5 dB.The 1×16 AWG is optimized to achieve a large bandwidth and a low noise level at each channel,and the FBG reflection peaks can be detected by multiple output channels of the AWG.The fabricated AWG is utilized to interrogate FBG sensors through the center of gravity(CoG)algorithm.The validation of an on-chip FBG interrogator that works with sub-picometer wavelength accuracy in a broad wavelength range shows large potential for applications in miniaturized fiber optic sensing systems.

关键词： Fiber optic sensing on-chip interrogator arrayed waveguide grating center of gravity

Research on the longitudinal protection of a through-type cophase traction direct power supply system based on the empirical wavelet transform

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Global Energy Interconnection 2024年第2期7卷 206-216页

作者： lu Li Zeduan Zhang Wang Cai Qikang zhuang Guihong Bi Jian Deng Shilong Chen Xiaorui Kan Faculty of Electric Power Engineering Kunming University of Science and TechnologyKunming 650500P.R.China Brunel University London London UB83PHUnited Kingdom Yunnan Power Grid Co. Ltd.Kunming 650041P.R.China

This paper proposes a longitudinal protection scheme utilizing empirical wavelet transform(EWT)for a through-type cophase traction direct power supply system,where both sides of a traction network line exhibit a distinctive boundary structure.This approach capitalizes on the boundary’s capacity to attenuate the high-frequency component of fault signals,resulting in a variation in the high-frequency transient energy ratio when faults occur inside or outside the line.During internal line faults,the high-frequency transient energy at the checkpoints located at both ends surpasses that of its neighboring lines.Conversely,for faults external to the line,the energy is lower compared to adjacent lines.EWT is employed to decompose the collected fault current signals,allowing access to the high-frequency transient energy.The longitudinal protection for the traction network line is established based on disparities between both ends of the traction network line and the high-frequency transient energy on either side of the boundary.Moreover,simulation verification through experimental results demonstrates the effectiveness of the proposed protection scheme across various initial fault angles,distances to faults,and fault transition resistances.

关键词： Through-type Cophase traction direct power supply system Traction network Empirical wavelet transform(EWT) Longitudinal protection

Equivariant Tautological Integrals on Flag Varieties

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Chinese Annals of Mathematics,Series B 2024年第3期45卷 463-486页

作者： Xiaobo zhuang Department of Mathematical Sciences Zhejiang Sci-Tech UniversityHangzhou 310018China

The author apples the Atiyah-Bott-Berline-Vergne formula to the equivariant tautological integrals over flag varieties of types A,B,C,D,and recovers the formulas expressing the integrals as iterated residues at infini... 详细信息

关键词： Localization Flag variety Residue

Improvement of titanium alloy TA19 fatigue life by submerged abrasive waterjet peening:Correlation of its process parameters with surface integrity and fatigue performance

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Chinese Journal of Aeronautics 2024年第1期37卷 377-390页

作者： Gongyu WANG Shulei YAO Yuxin CHI Chengcheng ZHANG Ning WANG Yalong CHEN Rongsheng lu zhuang LI Xiancheng ZHANG Key Laboratory of Pressure Systems and Safety Ministry of EducationSchool of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai 200237China AECC Commercial Aircraft Engine Co.LTD Shanghai Engineering Research Center for Commercial Aircraft EngineShanghai 201108China

Submerged abrasive waterjet peening(SAWJP)is an effective anti-fatigue manufacturing technology that is widely used to strengthen aeroengine components.This study investigated the correlation of SAWJP process parameters on surface integrity and fatigue life of titanium alloy TA19.SAWJP with different water pressures and standoff distances(SoDs)was conducted on the TA19 specimens.The surface integrity of the specimens before and after SAWJP with different process parameters was experimentally studied,including microstructure,surface roughness,microhardness,and compressive residual stress(CRS).Finally,fatigue tests of the specimens before and after SAWJP treatment with different process parameters were carried out at room temperature.The results highlighted that the fatigue life of the TA19 specimen can be increased by 5.46,5.98,and 6.28 times under relatively optimal process parameters,which is mainly due to the improved surface integrity of the specimen after SAWJP treatment.However,the fatigue life of specimens treated with improper process parameters is decreased by 0.55 to 0.69 times owing to the terrible surface roughness caused by the material erosion.This work verifies that SAWJP can effectively improve the surface integrity and fatigue life of workpieces,and reveals the relationship between process parameters,surface integrity,and fatigue life,which provides support for the promotion of SAWJP in the manufacturing fields.

关键词： Fatigue testing Process parameters Submerged abrasive waterjet peening Surface integrity Surface treatment Titanium alloy TA19