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Multi-physics multi-scale simulation of unique equiaxed-to-columnar-to-equiaxed transition during the whole solidification process of Al-li alloy laser welding

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Journal of Materials Science & Technology 2024年第4期171卷 235-251页

作者： Chu Han ping Jiang Shaoning Geng liangyuan Ren School of Mechanical Science and Engineering Huazhong University of Science&Technology(HUST)Wuhan430074China

In this study,a novel multi-physics multi-scale model with the dilute multicomponent phase-field method in three-dimensional(3D)space was developed to investigate the complex microstructure evolu-tion in the molten pool during laser welding of Al-li *** accurately compute mass data within both two and three-dimensional computational domains,three efficient computing methods,including central processing unit parallel computing,adaptive mesh refinement,and moving-frame algorithm,were *** was placed on the distinctive equiaxed-to-columnar-to-equiaxed transition phenomenon that occurs during the entire solidification process of Al-li alloy laser *** results indi-cated that the growth distance of columnar grains that epitaxially grew from the base metal(BM)de-creased as the nucleation rate *** the nucleation rate increased,the morphology of the newly formed grains near the fusion boundary(FB)changed from columnar to equiaxed,and newly formed equiaxed grains changed from having high-order dendrites to no obvious dendrite *** the nucleation rate was sufficiently high,non-dendritic equiaxed grains could directly form near the FB,and there was nearly no epitaxial growth from the ***,simulation results illustrated the com-petition among multiple grains with varying orientations that grow in 3D space near the ***,how equiaxed grain bands develop was *** equiaxed band not only hindered the growth of early columnar grains but also some of its grains could grow epitaxially to form new columnar *** predicted results were in good agreement with experimental measurements and observations.

关键词： Laser welding Al-li alloy Equiaxed-to-columnar-to-equiaxed transition Multi-physics multi-scale model Multicomponent alloys 3D phase-field model

Effect and mechanism of reductive polyaniline on the stability of nitrocellulose

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Defence Technology（防务技术） 2024年第8期38卷 217-225页

作者： Wenjiang li Binbin Wang Huimin Chen Aoao Lu Chenguang li Qiang li Fengqiang Nan ping Du School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China Key Laboratory of Special Energy Materials Ministry of EducationNanjing 210094China

The search for new green and efficient stabilizers is of great importance for the stabilization of nitrocellulose(NC). This is due to the shortcomings of traditional stabilizers, such as high toxicity. In this study, reduced polyaniline(r-PANI), which has a similar functional structure to diphenylamine(DPA) but is non-toxic, was prepared from PANI based on the action with N_(2)H_(4) and NH_(3)-H_(2)O, and used for the first time as a potential stabilizer for NC. XPS, FTIR, Raman, and SEM were used to characterize the reduced chemical structure and surface morphology of r-PANI. In addition, the effect of r-PANI on the stabilization of NC was characterized using DSC, VST, isothermal TG, and MMC. Thermal weight loss was reduced by 83% and 68% and gas pressure release by 75% and 49% compared to pure NC and NC&3%DPA, *** and XPS were used to characterize the structural changes of r-PANI before and after reaction with NO_(2). The 1535 cm^(-1) and 1341 cm^(-1) of the FTIR and the 404.98 eV and 406.05 eV of the XPS showed that the -NO_(2) was generated by the absorption of NO_(2). Furthermore, the quantum chemical calculation showed that NO_(2) was directly immobilized on r-PANI by forming -NO_(2) in the neighboring position of the benzene ring.

关键词： Nitrocellulose Green stabilizer Polyaniline Mechanism of stability

Constructing long-cycling crystalline C_(3)N_(4)-based carbonaceous anodes for sodium-ion battery via N configuration control

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Carbon Energy 2024年第1期6卷 159-171页

作者： Ying Wang Hongguan li Shuanlong Di Boyin Zhai ping Niu Antonios Kelarakis Shulan Wang li li School of Metallurgy Northeastern UniversityShenyangLiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyangLiaoningChina Department of Chemistry College of ScienceNortheastern UniversityShenyangLiaoningChina School of Natural Sciences UCLan Research Centre for Smart MaterialsUniversity of Central LancashirePrestonUK Foshan Graduate School of Innovation Northeastern UniversityFoshanGuangdongChina

Carbon nitrides with two-dimensional layered structures and high theoretical capacities are attractive as anode materials for sodium-ion batteries while their low crystallinity and insufficient structural stability strongly restrict their practical *** carbon nitrides with conductive carbon may relieve these ***,little is known about the influence of nitrogen(N)configurations on the interactions between carbon and C_(3)N_(4),which is fundamentally critical for guiding the precise design of advanced C_(3)N_(4)-related ***,highly crystalline C_(3)N_(4)(poly(triazine imide),PTI)based all-carbon composites were developed by molten salt *** importantly,the vital role of pyrrolic-N for enhancing charge transfer and boosting Na+storage of C_(3)N_(4)-based composites,which was confirmed by both theoretical and experimental evidence,was spot-highlighted for the first *** elaborately controlling the salt composition,the composite with high pyrrolic-N and minimized graphitic-N content was *** from the formation of highly crystalline PTI and electrochemically favorable pyrrolic-N configurations,the composite delivered an unusual reverse growth and record-level cycling stability even after 5000 cycles along with high reversible capacity and outstanding full-cell capacity *** work broadens the energy storage applications of C_(3)N_(4) and provides new prospects for the design of advanced all-carbon electrodes.

关键词： anode highly crystalline C_(3)N_(4) N configuration sodium-ion batteries ultra-long cyclic stability

Optimal production strategy for auto manufacturers with government subsidies in competitive environments

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Frontiers of Engineering Management 2024年第2期11卷 345-355页

作者： Jingjing xue Bin ZHENG Sijie li School of Economics and Management Nanjing Tech UniversityNanjing 211816China School of Economics and Management Southeast UniversityNanjing 211189China

Using the Hotelling model and evolutionary game theory,this paper studies the optimal production strategy of duopoly auto manufacturers and explores the impacts of two government policies(manufacturer and consumer subsidies)on strategies related to the production of electric vehicles(EVs)or fuel vehicles(FVs).The study finds that consumers’environmental preferences have direct effects on manufacturers’market shares and profits,which in turn,affect the manufacturers’production strategy ***,when consumer environmental preference is sufficiently high,both auto manufacturers will eventually choose to produce EVs;when it is moderate,only one with a cost advantage will choose to produce ***,when it is low,neither auto manufacturer will produce *** findings further reveal that the more significant the difference in EV production costs is,the more inclined auto manufacturers are to choose a different final stable *** of whether the government subsidizes manufacturers or consumers,the policy only works if subsidies reach a certain *** study also identifies the conditions under which government subsidies are considered more cost-effective.

关键词： supply chain management low-carbon emission electric vehicle subsidy evolutionary game theory

Investigation of HNO_3 Chemincally Oxidized Porous Silicon

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Chinese Chemical Letters 1996年第11期7卷 1037-1038页

作者： Feng YIN xue ping li Zhen Zong ZHANG Tie Feng CHEN Xu Rui XIAO(Instiute of photographic Chemistry,Academia Sinica, Beijing 100101)

The stability of the photoluminescence (PS) has evidently improvedby HNO3 chemical oxidation The PL intensity and peak wavelength of PS were changed with theHNO3 of HNO3 concentration and oxidation time. Being different from other oxidation time. Being different from other oxidized ways, the PSoxidized by HNO3 remains remains sensitive to adsorbates. FTTR spectroscopic data suggest that these phenomena are attributed to the presence of HSi(SiaO30a)(a≤3)layer on PS surface.

关键词： Investigation of HNO3 Chemincally Oxidized Porous Silicon

Effects of inorganic nutrients and environmental factors on the removal of n-propylbenzene and isopropylbenzene in seawater by cryptophytes Rhinomonas reticulata S6A

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Journal of Oceanology and limnology 2024年第4期42卷 1200-1215页

作者： Jiali CUI Shuhao DU Yumei li Haiping li ping ZHANG Fanping MENG Key Laboratory of Marine Environment and Ecology Ministry of EducationOcean University of ChinaQingdao 266100China College of Environmental Science and Engineering Ocean University of ChinaQingdao 266100China

To effectively remove n-propylbenzene(n-PBZ)and isopropylbenzene(i-PBZ)leaked into seawater using Rhinomonas reticulata S6A(a newly isolated marine microalga),the effects of three inorganic nutrients and four environmental factors on their degradation were determined after 7 d of *** show that NaNO_(3) at 300 mg/L caused a higher removal efficiency of both n-PBZ and i-PBZ(44.79%and 39.26%),while for NaH_(2) PO_(4)·H_(2) O,greater removal rates of two PBZs(47.30%and 42.23%)were achieved at 30 and 20 mg/L,***_(3) supplementation(500-750 mg/L)resulted in a large reduction(43.67%-45.04%)in i-PBZ *** change in seawater pH(from 6 to 9)did not affect the elimination of n-PBZ and *** most suitable salinity and temperature were 30 and 25-30℃,respectively,leading to the PBZs removal of~40%.light intensity exhibited significant influence on elimination of PBZs,and the maximum removal efficiencies of 56.07%(n-PBZ)and 55.00%(i-PBZ)were recorded under 200 and 600μmol/(m^(2)·s),*** addition,the microalga could still remove PBZs when it failed to grow well due to darkness,strong light,low temperature,or low salinity,which might mean that good growth of alga is not always a necessary condition for PBZs ***,attention should be paid to the suitability of nutrient levels and environmental conditions(excluding pH)in seawater when using microalgae for bioremediating PBZs-contaminated seawater.

关键词： propylbenzene(PBZ) Rhinomonas reticulata seawater inorganic nutrient environmental factor

Long Non-coding RNA PCED1B Antisense RNA 1 Promotes Cell Proliferation and Invasion in Hepatocellular Carcinoma by Regulating the MicroRNA-34a/CD44 Axis

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Current Medical Science 2024年第3期44卷 503-511页

作者： Jian-gang BI Qi li Yu-sheng GUO li-ping liU Shi-yun BAO ping XU Department of Hepatobiliary and Pancreatic Surgery Shenzhen People's HospitalThe Second Clinical Medical CollegeJinan UniversityThe First Affiliated HospitalSouthern University of Science and TechnologyShenzhen 518020China Department of Endocrinology Shenzhen People's HospitalThe Second Clinical Medical CollegeJinan UniversityThe First Affiliated HospitalSouthern University of Science and TechnologyShenzhen 518020China

Objective This study aimed to examine the role of long non-coding RNA PCED1B antisense RNA 1(PCED1B-AS1)in the development of hepatocellular carcinoma(HCC).Methods A total of 62 pairs of HCC tissues and adjacent non-tumor tissues were obtained from 62 HCC *** interactions of PCED1B-AS1 and microRNA-34a(miR-34a)were detected by dual luciferase activity assay and RNA pull-down *** RNA expression levels of PCED1B-AS1,miR-34a and CD44 were detected by RT-qPCR,and the protein expression level of CD44 was determined by Western *** cell proliferation was detected by cell proliferation assay,and the cell invasion and migration by transwell invasion *** HCC tumor growth after PCED1B-AS1 was downregulated was determined by in vivo animal *** PCED1B-AS1 was highly expressed in HCC tissues,which was associated with poor survival of HCC ***,PCED1B-AS1 interacted with miR-34a in HCC cells,but they did not regulate the expression of each ***,PCED1B-AS1 increased the expression level of CD44,which was targeted by *** cell proliferation and invasion assay revealed that miR-34a inhibited the proliferation and invasion of HCC in vitro,while CD44 exhibited the opposite ***,PCED1B-AS1 suppressed the role of ***,the knockdown of PCED1B-AS1 repressed the HCC tumor growth in nude mice in *** PCED1B-AS1 may play an oncogenic role by regulating the miR-34a/CD44 axis in HCC.

关键词： long non-coding RNA PCED1B antisense RNA 1(PCED1B-AS1) hepatocellular carcinoma microRNA-34a(miR-34a) CD44 proliferation invasion

Pushing the frontiers: Chip-based detection based on micro-and nano-structures

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Chinese Chemical Letters 2024年第4期35卷 86-98页

作者： Meihui liu Xinyuan Zhou Xiao li Zhenjie xue Tie Wang Tianjin Key Laboratory of life and Health Detection Life and Health Intelligent Research InstituteTianjin University of TechnologyTianjin 300384China

Changes in trace substances in human metabolites, which are related to disease processes and health status, can serve as chemical markers for disease diagnosis and symptom monitoring. Real-time online detection is an inevitable trend for the future of health monitoring, and the construction of chips for detection faces major challenges. The response of sensors often fails to meet the requirements for chipbased detection of trace substances due to the low efficiency of interfacial heterogeneous reactions, necessitating a rational design approach for micro-and nano-structures to improve sensor performance with respect to sensitivity and detection limits. This review focuses on the influence of micro-and nanostructures that used in chip on sensing. Firstly, this review categorizes sensors into chemiresistors, electrochemical sensors, fluorescence sensors, and surface enhanced Raman scattering(SERS) sensors based on their sensing principle, which have significant applications in disease diagnosis. Subsequently, commencing from the application requirements in the field of sensing, this review focuses on the different structures of nanoparticle(NP) assemblies, including wire, layered, core-shell, hollow, concave and deformable structures. These structures change in the size, shape, and morphology of conventional structures to achieve characteristics such as ordered alignment, high specific surface area, space limitation,vertical diffusion, and swaying behavior with fluid, thereby addressing issues such as poor signal transmission efficiency, inadequate adsorption and capture capacity, and slow mass transfer speed during sensing. Finally, the design direction of micro-and nano-structures, and possible obstacles and solutions to promote chip-based detection have been discussed. It is hope that this article will inspire the exploration of interface micro-and nano-structures modulated sensing methods.

关键词： Chip-based detection Micro-and nano-structures Real-time online detection Sensing Health monitoring

Synthesis of crystalline g-C_(3)N_(4) with rock/molten salts for efficient photocatalysis and piezocatalysis

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Green Energy & Environment 2024年第5期9卷 890-898页

作者： Tingting Xu Jung Hur ping Niu Shulan Wang Sangwook Lee Sang-Eun Chun li li Department of Chemistry College of ScienceNortheastern UniversityShenyang110819China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819China School of Metallurgy Northeastern UniversityShenyang110819China School of Materials Science and Engineering Kyungpook National UniversityDaegu41566Republic of Korea School of Industrial Technology Advances Kyungpook National UniversityDaegu41566Republic of Korea

Graphitic carbon nitride(g-C_(3)N_(4))is emerging as a promising visible-light photocatalyst while the low crystallinity with sluggish charge separation/migration dynamics signiﬁcantly restricts its practical ***,synthesizing highly crystalline g-C_(3)N_(4) with sufﬁcient surface activities still remains ***,different from using alkali molten salts which is commonly reported,we propose an approach for synthesis of highly crystalline g-C_(3)N_(4) with FeCl3/KCl rock/molten mixed *** rock salt can serve as the structure-directing template while molten salt provides the required liquid medium for ***,the synthesized photocatalyst showed further enhanced crystallinity and improved surface area along with high p/p*excitation compared with crystalline C_(3)N_(4) prepared from conventional molten-salt *** catalytically advantageous features lead to its superior photocatalytic and piezocatalytic activities with a high reactivity for overall water splitting that is not commonly reported for C_(3)N_(4).This work provides an effective strategy for structural optimization of organic semiconductor based materials and may inspire new ideas for the design of advanced photocatalysts.

关键词： High crystallinity Carbon nitride Photocatalysis Piezocatalysis Overall water splitting