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Exploring the mechanical behavior and microstructure of compacted loess subjected to dry-wet cycles and chemical contamination

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3673-3695页

作者： Yongpeng nie Wankui ni Xiangfei lü Wenxin Tuo College of Geological Engineering and Geomatics Chang'an UniversityXi'an710054China Department of Civil Engineering Nagoya Institute of TechnologyNagoya466-8555Japan School of Water and Environment Chang'an UniversityXi'an710054China

Due to climatic factors and rapid urbanization,the soil in the loess Plateau,China,experiences the coupled effects of dry-wet cycles and chemical *** the mechanical behavior and corresponding microstructural evolution of contaminated loess subjected to dry-wet cycles is essential to elucidate the soil degradation ***,direct shear and consolidation tests were performed to investigate the variations in mechanical properties of compacted loess contaminated with acetic acid,sodium hydroxide,and sodium sulfate during dry-wet *** mechanical response mechanisms were investigated using zeta potential,mineral chemical composition,and scanning electron microscopy(SEM)*** results indicate that the mechanical deterioration of sodium hydroxidecontaminated loess during dry-wet cycles decreases with increasing contaminant concentration,which is mainly attributed to the thickening of the electrical double layer(EDl)by Nat and the precipitation of calcite,as well as the formation of colloidal flocs induced by OH,thus inhibiting the development of large pores during the dry-wet *** contrast,the attenuation of mechanical properties of both acetic acid-and sodium sulfate-contaminated loess becomes more severe with increasing contaminant concentration,with the latter being more particularly *** is primarily due to the reduction of the EDl thickness and the erosion of cement in the acidic environment,which facilitates the connectivity of pores during dry-wet ***,the salt expansion generated by the drying process of saline loess further intensifies the structural ***,the mechanical performance of compacted loess is sensitive to both pollutant type and concentration,exhibiting different response patterns in the dry-wet cycling condition.

关键词： Contaminated loess Dry-wet cycles Compressibility Shear strength Microstructural evolution

Effects of Rattling Behavior of K and Cd Atoms along Different Directions in Anisotropic KCdAs on lattice Thermal Transport and Thermoelectric Properties

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ENERGY & ENVIRONMENTAl MATERIAlS 2024年第6期7卷 388-398页

作者： Wang, Yue Zhao, Yinchang ni, Jun Dai, Zhenhong Yantai Univ Dept Phys Yantai 264005 Peoples R China Tsinghua Univ Dept Phys State Key Lab Low Dimens Quantum Phys Beijing 100084 Peoples R China Frontier Sci Ctr Quantum Informat Beijing 100084 Peoples R China

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 KCdAs. Notably, 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 lifetimes. Through various methodologies, including examining atomic vibrational modes and analyzing 3ph and 4ph scattering processes, the article unveils microphysical mechanisms contributing to the low kappa(l) within KCdAs. Key features include significant anisotropy in Cd atoms, pronounced anharmonicity in K atoms, and relative vibrations in non-equivalent As atomic layers. Cd atoms, situated between As layers, exhibit rattling modes and strong lattice anharmonicity, contributing to the observed low kappa(l). Remarkably flat bands near the valence band maximum translate into high PF, aligning with ultralow kappa(l) for exceptional thermoelectric performance. Under optimal temperature and carrier concentration doping, outstanding ZT values are achieved: 4.25 (a(b)-axis, p-type, 3 x 10(19) cm(-3), 500 K), 0.90 (c-axis, p-type, 5 x 10(20) cm(-3), 700 K), 1.61 (a(b)-axis, n-type, 2 x 10(18) cm(-3), 700 K), and 3.06 (c-axis, n-type, 9 x 10(17) cm(-3), 700 K).

关键词： anharmonic lattice dynamics electron transport characteristics first principles calculation lattice thermal transport octahedron thermoelectric properties TOTAl-ENERGY CAlCUlATIONS FIGURE CONDUCTIVITY MERIT CRYSTAlS lIMIT HEAT PBSE PBTE

Forgeron des futurs Un salon de l'emploi connecte les entreprises chinoises en Afrique du Sud avec les chercheurs d'emiploi locaux

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中国与非洲（法文版） 2024年第5期16卷 40-41页

作者： ni YANSHUO 不详

The importance of post-COVID condition phenotypes characterization to decipher the mechanisms underlying this post-viral syndrome

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World Journal of Pediatrics 2024年第6期20卷 633-634页

作者： Jon Izquierdo-Pujol Sara moron-lopez IrsiCaixa and Institute for Health Science Research Germans Trias i Pujol(IGTP) Can Ruti CampusBadalonaSpain Biomedicine doctoral programme Faculty of BiologyUniversity of BarcelonaBarcelonaSpain CIBERINFEC MadridSpain

The coronavirus disease-19(COVID-19)outbreak,caused by the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),was declared a global pandemic in March *** has affected over 700 million people worldwide and resulted in almost 7 million deaths,equating to a 1%mortality *** present,the majority of COVID-19 cases are either asymptomatic or mild,typically resolving within two ***,between 1%and 10%of COVID-19 survivors do not fully recover and experience a post-viral syndrome referred to as"long COVID","post-acute COVID-19 syndrome"(PASC),or"post-COVID condition"(PCC).This post-viral syndrome affects both adult and pediatric ***,most of the studies published to date evaluate the adult population,leaving a gap in our understanding of its impact on children and adolescents.

关键词： acute mortality respiratory

High-throughput and simultaneous inertial separation of tumor cells and clusters from malignant effusions using spiral-contraction-expansion channels

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Microsystems & Nanoengineering 2024年第2期10卷 91-99页

作者： Zhixian Zhu Hui Ren Dan Wu Zhonghua ni Nan Xiang School of Mechanical Engineering and Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical InstrumentsSoutheast University211189NanjingChina School of Mechanical Technology Wuxi Institute of TechnologyNo.1600 Gaolang West Road214129WuxiChina Department of Oncology Jiangyin People’s Hospital214400JiangyinChina

Tumor cell clusters are regarded as critical factors in cancer pathophysiology,and increasing evidence of their higher treatment resistance and metastasis compared to single tumor cells has been ***,existing cell separation methods that are designed for single tumor cells cannot be used to simultaneously purify tumor cell *** address this problem,we demonstrated a microfluidic approach for the high-throughput,continuous-flow ternary separation of single tumor cells,tumor cell clusters,and WBCs from clinical pleural or abdominal effusions by coupling slanted spiral channels and periodic contraction-expansion *** first systematically explored the influence of particle size and flow rate on particle *** separation performance indicated that 94.0%of WBCs were removed and more than 97%of MDA-MB-231 tumor cells were recovered at a high flow rate of 3500µl/***,more than 90%of tumor cell clusters were effectively preserved after ***,we successfully applied our device for the ternary separation of single tumor cells,tumor cell clusters,and WBCs from different malignant effusions collected from patients with metastatic ***,our spiral-contraction-expansion device has potential as a sample pretreatment tool for the cytological diagnosis of malignant effusions.

关键词： separation contraction removed

Utilization of recycled solid waste as ecological reclamation materials based on plant growth experiments and soil quality analysis

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Journal of Mountain Science 2024年第3期21卷 820-834页

作者： QIN Xiaochun ni Anchen YANG Dongxiao XING Wenhu lIU Shiliang College of Civil Engineering Beijing Jiaotong UniversityBeijing 100044China Shanxi Road&Bridge Construction Group Co. LtdShanxi 030006China School of Environment Beijing Normal UniversityBeijing 111875China

During the highway construction,a large number of spoil areas will be generated while a large amount of waste slag and soil could not be rationally ***,the vegetation recovery is slow in the spoil areas due to the soil *** at recycling the solid waste,the sieved engineering waste slag with local red clay and corn straw biochar was supplied to solve the problem of insufficient nutrients in engineering waste slag and *** addition,planting experiments of alfalfa(Medicago sativa l.)and Amorpha fruticosa *** with physical and chemical experiments were carried out to prove the feasibility of the novel improved substrate for the reclamation of spoil *** results show that the substrate's improvement effect is mainly affected by the soil to slag ratio and the biochar *** improvement effect of soil matrix in highway spoil area decreases with the increase of the waste slag content,especially when the soil-slag ratio is less than 3,and the promotion of plants is *** the contrary,the improvement effect is proportional to the biochar content(3%-8%).But it is noted that the Cu and Pb in the soil will exceed the clean limit corresponding to the Nemero soil pollution index level when the biochar content is 8%.Therefore,it is recommended that the soil-slag ratio should be≥3,and the biochar content should reach 3%-5%.This research provides experimental basis and technical support for utilizing solid waste resources in the reclamation of highway spoil areas.

关键词： Highway Spoil area Waste slag Modified soil Ecological reclamation

Reconstruct recent multi-population migration history by using identical-by-descent sharing

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Journal of Genetics and Genomics 2024年第6期51卷 642-651页

作者： Wenxiao Zhang Kai Yuan Ru Wen Haifang li Xumin ni School of Mathematics and Statistics Beijing Jiaotong UniversityBeijing 100044China The Stanley Center for Psychiatric Research Broad Institute of MIT and HarvardCambridgeMA 02142USA Baidu Incorporated Beijing 100085China

Identical-by-descent(IBD)is a fundamental genomic characteristic in population genetics and has been widely used for population history ***,limited by the nature of IBD,which could only capture the relationship between two individuals/haplotypes,existing IBD-based history inference is constrained to two *** this study,we propose a framework by leveraging IBD sharing in multipopulation and develop a method,MatrixiBD,to reconstruct recent multi-population migration ***,we employ the structured coalescent theory to precisely model the genealogical process and then estimate the IBD sharing across multiple *** our model,we establish a theoretical connection between migration history and IBD *** method is rigorously evaluated through simulations,revealing its remarkable accuracy and ***,we apply MatrixiBD to Central and South Asia in the Human Genome Diversity Project and successfully reconstruct the recent migration history of three closely related populations in South *** taking into account the IBD sharing across multiple populations simultaneously,MatrixlBD enables us to attain clearer and more comprehensive insights into the history of regions characterized by complex migration dynamics,providing a holistic perspective on intricate patterns embedded within the recent population migration history.

关键词： Population genetics IBD sharing Migration history Structured coalescent theory Gene flow

Effects of different concentrations of nicotinamide on hematopoietic stem cells cultured in vitro

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World Journal of Stem Cells 2024年第2期16卷 163-175页

作者： Yan Ren Yan-ni Cui Hong-Wei Wang The Second Clinical Medical College Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Hematology The Second Hospital of Shanxi Medical UniversityTaiyuan 030001Shanxi ProvinceChina Department of Hematology Key Laboratory of Molecular Diagnosis and Treatment of Blood Diseases in Shanxi ProvinceTaiyuan 030001Shanxi ProvinceChina

BACKGROUND In vitro expansion to increase numbers of hematopoietic stem cells(HSCs)in cord blood could improve clinical efficacy of this vital ***(NAM)can promote HSC expansion ex vivo,but its effect on hematopoietic stem and progenitor cells(HSPCs,CD34^(+)CD38)and functional subtypes of HSCs-shortterm repopulating HSCs(ST-HSCs,CD34^(+)CD38CD45RACD49f^(+))and long-term repopulating HSCs(lT-HSCs,CD34^(+)CD38CD45RACD49f^(+)CD90^(+))is not yet *** a sirtuin 1(SIRT1)inhibitor,NAM participates in regulating cell adhesion,polarity,migration,proliferation,and ***,SIRT1 exhibits dual effects by promoting or inhibiting differentiation in different tissues or *** propose that the concentration of NAM may influence proliferation,differentiation,and SIRT1 signaling of *** To evaluate the effects and underlying mechanisms of action of different concentrations of NAM on HSC proliferation and *** CD34^(+)cells were purified from umbilical cord blood using MacsCD34 beads,and cultured for 10-12 d in a serum-free medium supplemented with cytokines,with different concentrations of NAM added according to experimental *** cytometry was used to detect phenotype,cell cycle distribution,and apoptosis of the cultured ***-time polymerase chain reaction was used to detect the transcription levels of target genes encoding stemness-related factors,che mokines,components of hypoxia pathways,and antioxidant ***-dihydro-fluorescein diacetate probes were used to evaluate intracellular production of reactive oxygen species(ROS).Determination of the effect of different culture conditions on the balance of cytokine by cytometric bead *** Compared with the control group,the proportion and expansion folds of HSPCs(CD34^(+)CD38)incubated with 5 mmol/l or 10 mmol/l NAM were significantly increased(all Pld expansion of the 5 mmol/l NAM group were significantly

关键词： Hematopoietic stem cells nicotinamide Concentration Proliferation Differentiation Sirtuin 1

A statistical analysis of the Kappa-type energy spectrum distribution of radiation belt electrons observed by Van Allen Probes

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Earth and Planetary Physics 2024年第2期8卷 368-374页

作者： luHuai Jiao Xin Ma YuanNong Zhang TaiFeng Jin Song Fu BinBin ni Department of Space Physics School of Electronic InformationWuhan UniversityWuhan 430072China

The energy spectrum of energetic electrons is a key factor representing the dynamic variations of Earth’s Van Allen radiation *** measurements have indicated that the commonly used Maxwellian and Kappa distributions are inadequate for capturing the realistic spectral distributions of radiation belt *** we adopt the Kappa-type(KT)distribution as the fitting function and perform a statistical analysis to investigate the radiation belt electron flux spectra observed by the Van Allen *** calculating the optimal values of the key KT distribution parameters(i.e.,κandθ2)from the observed spectral shapes,we fit the radiation belt electron fluxes at different l-shells under different geomagnetic *** this manner,we obtain typical values of the KT distribution parameters,which are statistically feasible for modeling the radiation belt electron flux profiles during either geomagnetically quiet or active periods.A comparison of the KT distribution model results with those using the Maxwellian or Kappa distribution reveals the advantage of the KT distribution for studying the overall properties of the radiation belt electron spectral distribution,which has important implications for deepening the current understanding of the radiation belt electron dynamics under evolving geomagnetic conditions.

关键词： radiation belt electron Kappa-type distribution fitting geomagnetic storm