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Energy & Environmental Materials 2024年第6期7卷 388-398页

作者： Yue Wang Yinchang Zhao Jun ni Zhenhong Dai Department of Physics Yantai UniversityYantai 264005China State Key Laboratory of Low-Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China

We employ advanced first principles methodology,merging self-consistent phonon theory and the Boltzmann transport equation,to comprehensively explore the thermal transport and thermoelectric properties of ***,the study accounts for the impact of quartic anharmonicity on phonon group velocities in the pursuit of lattice thermal conductivity and investigates 3ph and 4ph scattering processes on phonon *** various methodologies,including examining atomic vibrational modes and analyzing 3ph and 4ph scattering processes,the article unveils microphysical mechanisms contributing to the lowκL within *** features include significant anisotropy in cd atoms,pronounced anharmonicity in K atoms,and relative vibrations in non-equivalent As atomic *** atoms,situated between As layers,exhibit rattling modes and strong lattice anharmonicity,contributing to the observed lowκ*** flat bands near the valence band maximum translate into high PF,aligning with ultralowκL for exceptional thermoelectric *** optimal temperature and carrier concentration doping,outstanding ZT values are achieved:4.25(a(b)-axis,p-type,3×10^(19)cm^(−3),500 K),0.90(c-axis,p-type,5×10^(20)cm^(−3),700 K),1.61(a(b)-axis,n-type,2×10^(18)cm^(−3),700 K),and 3.06(c-axis,n-type,9×10^(17)cm^(−3),700 K).

关键词： anharmonic lattice dynamics electron transport characteristics first principles calculation lattice thermal transport octahedron thermoelectric properties

nicoZn/c@melamine sponge-derived carbon composites with highperformance electromagnetic wave absorption

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2274-2286页

作者： Xiubo Xie heshan Wang hideo Kimura cui ni Wei Du Guanglei Wu School of Environmental and Material Engineering Yantai UniversityYantai 264005China Shandong Key Laboratory of Eco-Environmental Science for the Yellow River Delta Shandong University of AeronauticsBinzhou 256603China Institute of Materials for Energy and Environment State Key Laboratory of Bio-fibers and Eco-textilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China

niMZn/c@melamine sponge-derived carbon(MSDc)composites(M=co,Fe,and Mn)were prepared by a vacuum pump-ing solution method followed by carbonization.A large number of carbon nanotubes(cNTs)homogeneously attached to the surfaces of the three-dimensional cross-linked of the sponge-derived carbon in the nicoZn/c@MSDc composite,and cNTs were detected in the niFeZn/c@MSDc and niMnZn/c@MSDc ***_(3)Znc_(0.7),ni_(3)Fe,and MnO in-situ formed in the niFeZn/c@MSDc and niMnZn/c@MSDc *** cNTs in the nicoZn/c@MSDc composite efficiently modulated its complex ***,the composite exhibited the best performance among the composites,with the minimum reflection loss(RL_(min))of-33.1 dB at 18 Ghz and thickness of 1.4 *** bandwidth for RL of≤-10 dB was up to 5.04 Ghz at the thickness of 1.7 mm and loading of 25wt%.The op-timized impedance matching,enhanced interfacial and dipole polarization,remarkable conduction loss,and multiple reflections and scat-tering of the incident microwaves improved the microwave absorption *** effects of co,ni,and Fe on the phase and mor-phology provided an alternative way for developing highly efficient and broadband microwave absorbers.

关键词： microwave absorption carbon nanotube element substitution melamine sponge-derived carbon

Effects of weaning on intestinal longitudinal muscle-myenteric plexus function in piglets

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Science china(Life Sciences) 2024年第2期67卷 379-390页

作者： Jing Li Fenfen Liu Kaibin Mo hengjia ni Yulong Yin Key Laboratory of Agro-Ecological Processes in Subtropical Region Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic ProcessHunan Research Center of Livestock and Poultry SciencesSouth Central Experimental Station of Animal Nutrition and Feed Science in the Ministry of AgricultureInstitute of Subtropical AgricultureChinese Academy of SciencesChangsha 410125China University of chinese Academy of Sciences Beijing 100008China Guangdong Key Laboratory for Veterinary Drug Development and Safety Evaluation College of Veterinary MedicineSouth China Agricultural UniversityGuangzhou 510642China

Weaning piglets usually suffer from severe diarrhea(commonly known as postweaning diarrhea,PWD)along with intestinal motility *** peristalsis is mainly regulated by the longitudinal muscle-myenteric plexus(LM-MP).To understand the relationship between intestinal LM-MP function and the development of PWD,we compared the intestinal electrical activity,and the transcriptional profile of the LM-MP between 21-day-old piglets(just weaned,n=7)and 24-day-old piglets(suffered the most severe weaning stress,n=7).The results showed that 24-day-old piglets exhibited different degrees of diarrhea.A significant increase in the slow-wave frequency in the ileum and colon was observed in 24-day-old piglets,while c-kit expression in the intestinal LM-MPs was significantly decreased,indicating that PWD caused by elevated slow-wave frequency may be associated with loss of *** real-time quantitative PcR(RT-q PcR)and enzyme-linked immunosorbent assay(ELISA)showed that intestinal LM-MPs in 24-day-old piglets may undergo inflammation and oxidative *** increases in 8-hydroxy-2′-deoxyguanosine and decreases in thioredoxin suggest that weaning may lead to DNA damage in the LM-MP of 24-day-old *** addition,activating transcription factor 3 was significantly upregulated,indicating nerve damage in the LM-MP of 24-day-old *** transcriptomic results showed that most of the differentially expressed genes in the ileal LM-MP after weaning were downregulated and closely related to the cell cycle *** RT-q PcR analysis showed that the relative expression of p21 was upregulated,while the expression of cyclin A2,cyclin B1,and proliferating cell nuclear antigen was downregulated in the ileal and colonic LM-MP of 24-day-old piglets,suggesting that weaning may inhibit cell proliferation and cause G1/S cell cycle arrest in ileal and colonic *** conclusion,weaning may lead to cell cycle arrest by causing DNA damage in the LM-MP,impairing i

关键词： weaning piglets diarrhea longitudinal muscle-myenteric plexus

Decline in tree-ring growth of Picea mongolica and its intra-annual eco-physiological responses to drought and cO_(2) enrichment in semi-arid china

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Journal of Forestry Research 2024年第4期35卷 89-101页

作者： Xiaomin Zeng Ping ni Xiaohong Liu Wenzhi Wang Yao Li Wenchao Wang School of Geography and Tourism Shaanxi Normal UniversityXi’an 710119People’s Republic of China The Key Laboratory of Mountain Environment Evolution and Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu 610041People’s Republic of China cAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016People’s Republic of China University of chinese Academy of Sciences Beijing 100049People’s Republic of China

Episodes of drought-induced decline in tree growth and mortality are becoming more frequent as a result of climate warming and enhanced water stress in semi-arid ***,the ecophysiological mechanisms under-lying the impact of drought on tree growth remains *** this study,earlywood and latewood tree-ring growth,δ^(13)c,andδ^(18)O chronologies of Picea mongolica from 1900 to 2013 were developed to clarify the intra-and inter-annual tree-ring growth responses to increasingly fre-quent *** results indicate that annual basal area increment residuals(BAI_(res)),which removed tree age and size effects,have significantly decreased since ***-ever,the decreasing trend of earlywood BAI_(res) was higher than that of *** response analysis suggests that the dominant parameters for earlywood and latewood proxies(BAI_(res),δ^(13)c andδ^(18)O)were drought-related climate variables(Palmer drought severity index,temperature,rela-tive humidity,and vapor pressure deficit).The most signifi-cant period of earlywood and latewood proxies’responses to climate variables were focused on June-July and July-August,***_(res),andδ^(13)c were significantly affected by temperature and moisture conditions,whereasδ^(18)O was slightly *** stomatal conduct-ance due to drought outweighed the influence of increasing cO_(2) on intrinsic water use efficiency(iWUE),and ultimately led to a decline in BAI_(res).compared to latewood,the faster decreasing BAI_(res) and smaller increasing iWUE of early-wood suggested trees were more vulnerable to water stress in the early growing *** study provides insights into the inter-and intra-annual mechanisms of tree-ring growth in semi-arid regions under rising cO_(2) and climate change.

关键词： Tree growth Drought Water-use efficiency Seasonal differences Stable isotopes

Growth kinetics of titanium carbide coating by molten salt synthesis process on graphite sheet surface

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International Journal of Minerals,Metallurgy and Materials 2024年第8期31卷 1858-1864页

作者： Xiaoyu Shi chongxiao Guo Jiamiao ni Songsong Yao Liqiang Wang Yue Liu Tongxiang Fan State Key Lab of Metal Matrix composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The synthesis of carbide coatings on graphite substrates using molten salt synthesis(MSS),has garnered significant interest due to its cost-effective *** study investigates the reaction process and growth kinetics involved in MSS,shedding light on key aspects of the *** involvement of Ti powder through liquid-phase mass transfer is revealed,where the diffusion distance and quantity of Ti powder play a crucial role in determining the reaction rate by influencing the c content gradient on both sides of the ***,the growth kinetics of the carbide coating are predominantly governed by the diffusion behavior of c within the carbide layer,rather than the chemical reaction *** analyze the kinetics,the thickness of the carbide layer is measured with respect to heat treatment time and temperature,unveiling a parabolic relationship within the temperature range of 700-1300℃.The estimated activation energy for the reaction is determined to be 179283 J·mol^(-1).These findings offer valuable insights into the synthesis of carbide coatings via MSS,facilitating their optimization and enhancing our understanding of their growth mechanisms and properties for various applications.

关键词： titanium carbide graphite molten salt kinetic analysis

Numerical modeling and experimental investigation of a two-phase sink vortex and its fluid-solid vibration characteristics

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第1期25卷 47-62页

作者： Zichao YIN Yesha ni Lin LI Tong WANG Jiafeng WU Zhe LI Dapeng TAN college of Mechanical Engineering Zhejiang University of TechnologyHangzhou310014China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou310058China

A sink vortex is a common physical phenomenon in continuous casting,chemical extraction,water conservancy,and other industrial processes,and often causes damage and loss in ***,the real-time monitoring of the sink vortex state is important for improving industrial production ***,its suction-extraction phenomenon and shock vibration characteristics in the course of its formation are complex mechanical dynamic factors for flow field state *** address this issue,we set up a multi-physics model using the level set method(LSM)for a free sink vortex to study the two-phase interaction ***,a fluid–solid coupling dynamic model was deduced to investigate the shock vibration characteristics and reveal the transition mechanism of the critical flow *** numerical results show that the coupling energy shock induces a pressure oscillation phenomenon,which appears to be a transient enhancement of vibration at the vortex penetration *** central part of the transient enhancement signal is a high-frequency *** on the dynamic coupling model,an experimental observation platform was established to verify the accuracy of the numerical *** water-model experiment results were accordant with the numerical *** above results provide a reference for fluid state recognition and active vortex control for industrial monitoring systems,such as those in aerospace pipe transport,hydropower generation,and microfluidic devices.

关键词： Free sink vortex Fluid-solid coupling Level set method(LSM) Multi-physics model Vibration characteristics

Efficient guiding and focusing of intense laser pulse using periodic thin slits

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Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu T.W.huang K.Jiang c.N.Wu h.Peng P.c.hen R.Li h.B.Zhuo c.T.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

An improved pulse coupled neural networks model for semantic IoT

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Digital communications and Networks 2024年第3期10卷 557-567页

作者： Rong Ma Zhen Zhang Yide Ma Xiping hu Edith c.h.Ngai Victor c.M.Leung School of Information Science and Engineering Lanzhou UniversityLanzhou 730000China School of Medical Technology Beijing Institute of TechnologyBeijing100081China Department of Electrical and Electronic Engineer The University of Hong KongHong Kong 999077China college of computer Science and Software Engineering Shenzhen UniversityShenzhen 518060China Department of Electrical and computer Engineering the University of British ColumbiaVancouverBC V6T 1Z4Canada

In recent years,the Internet of Things(IoT)has gradually developed applications such as collecting sensory data and building intelligent services,which has led to an explosion in mobile data ***,with the rapid development of artificial intelligence,semantic communication has attracted great attention as a new communication ***,for IoT devices,however,processing image information efficiently in real time is an essential task for the rapid transmission of semantic *** the increase of model parameters in deep learning methods,the model inference time in sensor devices continues to *** contrast,the Pulse coupled Neural Network(PcNN)has fewer parameters,making it more suitable for processing real-time scene tasks such as image segmentation,which lays the foundation for real-time,effective,and accurate image ***,the parameters of PcNN are determined by trial and error,which limits its *** overcome this limitation,an Improved Pulse coupled Neural Networks(IPcNN)model is proposed in this *** IPcNN constructs the connection between the static properties of the input image and the dynamic properties of the neurons,and all its parameters are set adaptively,which avoids the inconvenience of manual setting in traditional methods and improves the adaptability of parameters to different types of *** segmentation results demonstrate the validity and efficiency of the proposed self-adaptive parameter setting method of IPcNN on the gray images and natural images from the Matlab and Berkeley Segmentation *** IPcNN method achieves a better segmentation result without training,providing a new solution for the real-time transmission of image semantic information.

关键词： Internet of things(IoT) Semantic information Real-time application Improved pulse coupled neural network Image segmentation

Uncovering the hierarchical clusters in the heat-affected zone of an electron beam weldedα/βtitanium alloy joint

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Journal of Materials Science & Technology 2024年第7期174卷 120-132页

作者： c.Xu X.h.Shao h.J.Yang M.Lv h.Q.Liu X.L.Ma Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Suzhou laboratory Suzhou 215028China Department of Mechanical Engineering Kyushu UniversityFukuoka 819-0395Japan Bay Area center for Electron Microscopy Songshan Lake Materials LaboratoryDongguan 523808China

Using high-resolution transmission Kikuchi diffraction(TKD)and transmission electron microscopy(TEM),we examined the hierarchical clusters that form in situ in the heat-affected zone(hAZ),which are com-monly referred to as“ghost”structures,of bimodal titanium alloy Ti-5Al-2Sn-2Zr-4Mo-4cr(wt%,Tc17).The ghost structures are enriched with Al elements but poor in Mo and cr compared to the surroundingβ*** results show that the ghost structure in middle-hAZ mainly consists ofα_(L)laths with a high-angle grain boundary,which exhibits the classic Burgers orientation relationship(BOR)with the host matrix,while it encircles theα_(P)grains in *** the ghost structure is evidenced to form via in-complete martensitic *** results further confirm that the ghost structure is composed ofαL and tinyβ_(L)laths with BOR,with the former being enriched with Al and poor with cr and Mo,while the latter is the ***,twoα_(L)variant clusters with a check-mark morphology are fre-quently observed viewed along[0001]_(αL)//[110]_(βL)directions,which are dominated by the crystallographic and geometrical relationships betweenαandβ*** on the microstructural characterization,it is hypothesized that the ghost structure is transformed from the initialα_(P)phase,due to the coupling ef-fect of high thermal stress(which induces the formation of a large number of dislocations)and element diffusion caused by sudden temperature increase and plunge cooling in the hAZ during the welding pro-cess.

关键词： Tc17 titanium alloy Electron beam welding(EBW) The ghost structure Transmission Kikuchi diffraction(TKD) Transmission electron microscopy(TEM)

Random Terpolymer of carbon Dioxide,Butadiene and Epoxides:Synthesis,Functionalization and Degradability

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chinese Journal of chemistry 2024年第14期42卷 1630-1636页

作者： Zi Wang Wuyi Zheng Sicong Yue Kaihao chen Jun Ling Xufeng ni MOE Key Laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhouZhejiang310058 China Westlake Electronics Group co. Ltd.HangzhouZhejiang310012 China

The utilization of carbon dioxide(cO_(2))as a c1 feedstock is consistently attractive,especially in the preparation of sustainable polymeric *** this contribution,a terpolymer of cO_(2),1,3-butadiene(BD)and epoxide is synthesized by scandium triflate catalyzed cationic ring-opening copolymerization ofα-ethylidene-δ-vinyl-δ-valerolactone(EVL),an intermediate derived from cO_(2)and BD,with *** obtained terpolymer with a cO_(2)content of 22 mol%has a number-average molecular weight(M_(n))up to 7.8 kg/mol and a dispersity(Đ)of *** reactivity ratios of EVL and cyclohexene oxide(chO)are determined as 0.01 and 1.07,respectively,suggesting random characteristic of the *** preserved c=c double bonds from BD allow for the further modification of the terpolymer by photoinitiated *** yielded networks are fluorescent and *** method offers enhanced versatility to the synthesis and additional functionalization of cO_(2)-based polymers.

关键词： Ring-opening polymerization copolymerization carbon dioxide Butadiene Scandium triflate Fluorescence