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Thermal effects on wear behavior of additively manufactured NiTi shape memory alloys

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Chinese journal of Aeronautics 2025年第1期38卷 147-164页

作者： Xianghui HUANG nan KANG Pei WANG Mohamed EL MANSORI Arts et Metiers Institute of Technology MSMPHESAM UniversitéChâlons-en-Champagne 51006France Henan Key Laboratory of High-Performance Carbon Fiber Reinforced Composites Institute of Carbon Matrix CompositesHenan Academy of SciencesZhengzhou 450046China Texas A&M Engineering Experiment Station Institute for Manufacturing SystemsCollege StationTX 77843USA

NiTi alloys fabricated by laser powder bed fusion(LPBF)additive manufacturing technology not only address the compositional instability resulting from complex processes but also solve the challenges of difficult machining of intricate aerospace ***,there are very few reports on the wear behavior of LPBF-NiTi *** the present work,the effects of microstructure and thermal treatment,including heat treatment and frictional heat,on the wear behavior of LPBF-NiTi alloy and 100Cr6 ball were analyzed through a series of tribological experiments with different sliding *** the average sliding speed increases(0.079–0.216 m/s),the wear rate of the as-built and heat-treated samples tends to decrease in the range of 2.69×10^(-3)–0.97×10^(-3)mm^(3)/*** the heat-treated LPBF-NiTi alloy is 46%harder than the as-built alloy is,the latter has a higher toughness(505 MJ/m^(3))and greater transformation strain of SIM(0.097).This leads to a coupling effect of heat treatment and sliding speed on the wear *** addition,the wear track morphologies under different sliding speeds are asymmetric due to the 24% greater acceleration at the far end from the motor and the 2.15 mm deviation between the maximum speed position and the geometric center of the *** wear modes of the as-built and heat-treated samples included adhesive,abrasive and delamination ***,the wear morphologies and dominant wear modes change with the frictionally caused heat release induced by the sliding speed.

关键词： Additive manufacturing Laser powder bed fusion NiTi alloys Wear resistance Sliding speed

Melting Evaluation of Phase Change Materials Impregnated into Cascaded Metal Foams with Regionalized Enhancement

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journal of Thermal Science 2025年第1期34卷 223-241页

作者： WEI Xinyi ZHANG nan ZHANG Zhaoli CAO Xiaoling YUAN Yanping School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China

Metal foam promotes the heat transfer of phase change materials(PCMs)in the penalty of reducing the energy storage density of the composite *** this work,the effects of constant porosity(0.96,0.94,0.92,or 0.90)and pore density(PPI)of metal foam on heat transfer of composite PCMs are *** rate could be enhanced by employing with low porosity copper ***,aiming to the right bottom phase changing"dead region",a regionalized enhancement strategy of cascaded metal foams is *** dynamic melting performances of all the composite PCMs are comprehensively *** results reveal that the cascaded configuration is beneficial for *** show that the horizontal strategy enhances melting performance:a maximum of 17.98% reduction in total melting time could be reached when the rear part porosity is 90%.The energy storage density rate could be raised by 5.48%.Besides,the vertical strategy performs with a better average temperature uniformity of 0.441 and brings a lower temperature in the heated *** sum up,the regionalized enhancement of copper foam provides better performance in the phase change *** shows significant potential for solar heat storage and thermal protection.

关键词： phase change materials copper metal foam heat transfer enhancement regionalized enhancement

Doubly-Fed Pumped Storage Units Participation in Frequency Regulation Control Strategy for New Energy Power Systems Based on Model Predictive Control

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Energy Engineering 2025年第2期122卷 765-783页

作者： Yuanxiang Luo Linshu Cai nan Zhang School of Electrical Engineering Northeast Electric Power UniversityJilin132012China

Large-scale new energy grid connection leads to the weakening of the system frequency regulation capability,and the system frequency stability is facing unprecedented *** order to solve rapid frequency fluctuation caused by new energy units,this paper proposes a new energy power system frequency regulation strategy with multiple units including the doubly-fed pumped storage unit(DFPSU).Firstly,based on the model predictive control(MPC)theory,the state space equations are established by considering the operating characteristics of the units and the dynamic behavior of the system;secondly,the proportional-differential control link is introduced to minimize the frequency deviation to further optimize the frequency modulation(FM)output of the DFPSU and inhibit the rapid fluctuation of the frequency;lastly,it is verified on theMatlab/Simulink simulation platform,and the results show that the model predictive control with proportional-differential control link can further release the FM potential of the DFPSU,increase the depth of its FM,effectively reduce the frequency deviation of the system and its rate of change,realize the optimization of the active output of the DFPSU and that of other units,and improve the frequency response capability of the system.

关键词： Doubly-fed pumped storage unit model predictive control proportional-differential control link frequency regulation

Phenanthrene perturbs hematopoietic development and causes hematopoietic defects in zebrafish

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journal of Environmental Sciences 2025年第5期151卷 573-581页

作者： Lingyu Ren Yue Wang Ying Ren Guangke Li nan Sang College of Environment and Resource Research Center of Environment and HealthShanxi UniversityTaiyuan 030006China

Phenanthrene(Phe)is one of the common polycyclic aromatic hydrocarbons in the environment,and recent studies show that it can cause cardiac developmental toxicity and ***,it is still unknown whether it can affect the hematopoietic development in aquatic *** address this question,zebrafish(Danio rerio)were chronically exposed to Phe at different *** found that Phe caused structural damage to the renal tubules in the kidney,induced malformed erythrocytes in peripheral blood,and decreased the proportion of myeloid cells in adult zebrafish,suggesting possible negative impacts that Phe posed to hematopoietic ***,using in situ hybridization technology,we found that Phe decreased the expression of primitive hematopoietic marker genes,specifically gata1 and pu.1,accompanied by an obstruction of primitive erythrocyte ***,Phe impaired definitive hematopoiesis,increased aberrations of the transient hematopoietic site(PBI),and reduced the generation of hematopoietic stem cells,ultimately influencing the number of erythrocytes and myeloid *** findings suggested that Phe could induce hematopoietic toxicity in zebrafish embryos and pose unknown ecological risks.

关键词： Phenanthrene Zebrafish Hematopoietic development Hematopoietic defect

Characterization of size-resolved aerosol hygroscopicity and liquid water content in nanjing of the Yangtze River Delta

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journal of Environmental Sciences 2025年第5期151卷 26-41页

作者： Youling Jiang Yan Ma Jun Zheng nan Ye Cheng Yuan School of Environmental Science and Engineering Nanjing University of Information Science and TechnologyNanjing 210044China Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing University of Information Science&TechnologyNanjing 210044China School of Emergency Management Nanjing University of Information Science&TechnologyNanjing 210044China

Aerosol hygroscopicity and liquid water content(ALWC)have important influences on the environmental and climate effect of *** this study,we measured the hygroscopic growth factors(GF)of particles with dry diameters of 40,80,150,and 200 nm during the wintertime in *** the GF-derived hygroscopicity parameter(κ_(gf))and ALWC increased with particle size,but displayed differing diurnal variations,withκ_(gf)peaking around the midday,while ALWC peaking in the early ***,ammonium and oxygenated organic aerosols(OOA)were found as the chemical components mostly strongly correlated with ALWC.A closure study suggests that during midday photo-oxidation and nighttime high ALWC periods,theκof organic aerosols(κ_(org))was underestimated when using previous ***,we re-constructed parameterizations forκ_(org)and the oxidation level of organics for these periods,which indicates a higher hygroscopicity of photochemically formed OOA than the aqueous OOA,yet both being much higher than the generally assumed OOA ***,in a typical high ALWC episode,concurrently increased ALWC,nitrate,OOA as well as aerosol surface area and mass concentrations were observed under elevated ambient *** strongly indicates a coupled effect that the hygroscopic secondary aerosols,in particular nitratewith strong hygroscopicity,led to large increase in ALWC,which in turn synergistically boosted nitrate and OOA formation by heterogeneous/aqueous *** interaction may represent an important mechanism contributing to enhanced formation of secondary aerosols and rapid growth of fine particulate matter under relatively high RH conditions.

关键词： Aerosol hygroscopicity Aerosol liquid water content Photo-oxidation Aqueous/heterogeneous reactions

Effects of different water levels on phytoplankton in the Harbin section of the Songhua River

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journal of Oceanology and Limnology 2025年第1期43卷 134-146页

作者： Yi’nan SUN Jingshen LI Yawen FAN Xinxin LU College of Life Science and Technology Harbin Normal UniversityHarbin 150025China Key Laboratory of Aquatic Organisms Harbin Normal UniversityHarbin 150025China

The functional diversity index of a phytoplankton body has gradually become a new mean of measuring and *** explore the response of phytoplankton taxonomy and the functional diversity index to interannual environmental changes,a survey on the structure of the phytoplankton community and water physicochemical characteristics of the water was carried out at 28 sampling points in the Harbin section of the Songhua River for three consecutive years in every May from 2021 to *** taxonomy diversity index and the functional diversity index were ***,The relationship between the structure of the characteristics of the community and environmental factors was explored;secondly,we reveal the responses of taxonomic and functional diversity indices to different habitats between years;finally,we explore the main environmental factors that control the taxonomic and functional diversity indices of *** show that,initially,environmental factors in water changes caused by different water levels between years affected the composition of phytoplankton ***,by comparing the taxonomic diversity index and the functional diversity index on a time scale,we found that the taxonomic diversity index was more responsive to environmental ***,the main environmental factors on the phytoplankton taxonomic diversity index were dissolved oxygen,Taxonomic diversity index,and specific conductivity,and the main environmental factors that affected the functional diversity index were dissolved oxygen,turbidity,and water *** study reveals the important role of the taxonomic diversity index in river water quality evaluation,obtained new information on the relative precision of the taxonomic diversity index and the functional diversity index in the evaluation of ecological health of the water,and provided a reliable tool for monitoring river water quality based on aquatic organisms.

关键词： Songhua River Basin phytoplankton functional diversity biodiversity index watershed ecology

On-chip light control of semiconductor optoelectronic devices using integrated metasurfaces

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Opto-Electronic Advances 2025年第1期8卷 5-30页

作者： Cheng-Long Zheng Pei-nan Ni Yi-Yang Xie Patrice Genevet Henan Key Laboratory of Diamond Optoelectronic Materials and Devices Key Laboratory of Materials PhysicsMinistry of EducationSchool of PhysicsZhengzhou UniversityZhengzhou 450052China Key Laboratory of Optoelectronics Technology Beijing University of TechnologyMinistry of EducationBeijing 100124China Colorado School of Mines 1523 Illinois St.GoldenCO 80401USA

Semiconductor optoelectronics devices,capable of converting electrical power into light or conversely light into electrical power in a compact and highly efficient manner represent one of the most advanced technologies ever developed,which has profoundly reshaped the modern life with a wide range of *** recent decades,semiconductor technology has rapidly evolved from first-generation narrow bandgap materials(Si,Ge)to the latest fourth-generation ultra-wide bandgap semiconductor(GaO,diamond,AlN)with enhanced performance to meet growing ***,merging semiconductor devices with other techniques,such as computer assisted design,state-of-the-art micro/nano fabrications,novel epitaxial growth,have significantly accelerated the development of semiconductor optoelectronics *** them,integrating metasurfaces with semiconductor optoelectronic devices have opened new frontiers for on-chip control of their electromagnetic response,providing access to previously inaccessible degrees of *** review the recent advances in on-chip control of a variety of semiconductor optoelectronic devices using integrated metasurfaces,including semiconductor lasers,semiconductor light emitting devices,semiconductor photodetectors,and low dimensional *** integration of metasurfaces with semiconductors offers wafer-level ultracompact solutions for manipulating the functionalities of semiconductor devices,while also providing a practical platform for implementing cuttingedge metasurface technology in real-world applications.

关键词： optoelectronics nanophotonics metasurfaces semiconductor

Heavy metal stress strengthens the stability and complexity of microbial molecular ecological networks in Sanyang wetland sediments

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journal of Oceanology and Limnology 2025年第1期43卷 103-118页

作者： Shengwei WU Huixi ZOU nan LI Xiufeng YAN Wen LIU College of Life and Environmental Science Wenzhou UniversityWenzhou 325035China Institute for Eco-environmental Research of Sanyang Wetland Wenzhou UniversityWenzhou 325035China Key Laboratory of Soil Contamination Bioremediation of Zhejiang Province School of Environmental&Resource SciencesZhejiang Agriculture and Forestry UniversityHangzhou 311300China

Pollution from heavy metals(HMs)(Cd,As,Cr,and Ni,etc.)has become a serious environmental issue in urban wetland ecosystems with more and more *** studies conducted in agricultural soils,rivers,and lakes demonstrated that microbial communities exhibit a response to HM ***,little is known about the response of microbial communities to HM pollution in urban wetland *** examined how heavy metals affect the stability of the microbial networks in the sediments of Sanyang wetland,Wenzhou,*** environmental parameters,including HMs,TC(total carbon),TN(total nitrogen),TP(total phosphorus),S,and pH,varied profoundly between moderately and heavily polluted areas in shaping microbial ***,the microbial community composition in moderately polluted sites correlated significantly(P<0.05)with Ni,Cu,Cd and TP,whereas in heavily polluted sites,they correlated significantly with Cd,TN,TP,and *** show that the heavily polluted sites demonstrated more intricate and more stable microbial networks than those of the moderately polluted *** heavily polluted sites exhibited higher values for various network parameters including total nodes,total links,average degree,average clustering coefficient,connectance,relative modularity,robustness,and ***,the structural equation modeling analysis demonstrated a positive correlation between the stability of microbial networks and Cd,TN,TP,and S in heavily polluted ***,in moderately polluted sites,the correlation was positively linked to Cd,Ni,and sediment *** implies that Cd could potentially play a crucial role in affecting the stability of microbial *** study shall enhance our comprehension of microbial co-occurrence patterns in urban wetland ecosystems and offer insights into the ways in which microbial communities respond to environmental factors in varying levels of HM pollution.

关键词： heavy metal(HM) urban wetland microbial networks network stability

Association between echocardiography utilization and prognosis in patients with cardiac arrest

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World journal of Emergency Medicine 2025年第1期16卷 63-66页

作者： nan Zhang Qingting Lin Huadong Zhu Emergency Department State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College HospitalChinese Academy of Medical Science and Peking Union Medical CollegeBeijing 100730China Department of Radiology the Second Affi liated Hospital of Zhejiang University School of MedicineHangzhou 310009China

Despite efforts to develop treatment technology for cardiac arrest (CA),CA incidence and mortality rates are still high.^([1,2])A recent study of CA patients in emergency departments revealed that the incidence of CA is increasing annually,and the in-hospital survival rate of CA patients is only approximately 28.7%.^([3])Echocardiography has been widely used as an important monitoring tool in critical care and helps to identify the cause of shock,monitor hemodynamics,and guide fluid therapy utilization.^([4])One study reported that approximately one-third of patients underwent formal echocardiography during hospitalization in the intensive care unit (ICU).

关键词： patients echocardiography cardiac