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Rare Metals 2024年第9期43卷 4387-4400页

作者： Ao Xia Jia-Guang zheng Qing-Bo Zhang yu-Gang Shu Cheng-Guo Yan Liu-Ting Zhang Zhan-Liang Tao Li-xin Chen School of Energy and Power Jiangsu University of Science and Technology Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai University State Key Laboratory of Silicon and Advanced Semiconductor Materials School of Materials Science and EngineeringZhejiang University

The facile construction of nanoscale NbHxsupported by Ti3C2（NbHx@Ti3C2） was achieved using facile ball milling strategy to improve the hydrogen desorption kinetics and reversibility of magnesium borohydride (Mg（BH4）2).The doping of 30 wt%NbHx@Ti3C2catalyst reduced the onset dehydrogenation temperature of Mg（BH4）2to 71.2℃.Additionally,the Mg（BH4）2+30NbHx@Ti3C2composite achieved remarkable hydrogen release of over 9.2 wt% at a temperature as low as 230℃,indicating unexpected dehydrogenation ***,the reversibility of NbHx@Ti3C2doped Mg（BH4）2was retained to more than 4.2 wt%after four cycles,which was increased by 68% compared to that of undoped Mg（BH4）*** strong catalysis of NbHx@Ti3C2catalyst could be attributed to the synergistic effect of NbHxand Ti3C2in hydrogen spillover and *** as a??hydrogen pump??for effective hydrogen spillover,while Ti3C2created numerous diffusion channels for hydrogen dissolution and provided the active catalytic site to facilitate the re/dehydrogenation of Mg（BH4）2.

关键词： Catalysts Hydrogen storage Magnesium borohydride Mxene

Optimization of Gas Production from Hydrate-Bearing Sediments with Fluctuation Characteristics

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Journal of Ocean University of China 2024年第3期23卷 618-632页

作者： LI Yaobin XU Tianfu xin xin yu Han yuAN Yilong ZHU Huixing Key Laboratory of Groundwater Resources and Environment Ministry of EducationJilin UniversityChangchun 130021China Jilin Provincial Key Laboratory of Water Resources and Environment Jilin UniversityChangchun 130021China

As an important source of low-carbon,clean fossil energy,natural gas hydrate plays an important role in improving the global energy consumption *** the hydrate industry in the South China Sea is important to achieving‘carbon peak and carbon neutrality’goals as soon as ***-water areas subjected to the action of long-term stress and tectonic movement have developed complex and volatile terrains,and as such,the morphologies of hydrate-bearing sediments(HBSs)fluctuate *** key to numerically simulating HBS morphologies is the establishment of the conceptual model,which represents the objective and real description of the actual geological ***,current numerical simulation models have characterized HBSs into horizontal strata without considering the fluctuation *** representing the HBS as a horizontal element reduces simulation ***,the commonly used horizontal HBS model and a model considering the HBS’s fluctuation characteristics with the data of the SH2 site in the Shenhu Sea area were first constructed in this ***,their production behaviors were compared,and the huge impact of the fluctuation characteristics on HBS production was *** this basis,the key parameters affecting the depressurization production of the fluctuating HBSs were studied and *** research results show that the fluctuation characteristics have an obvious influence on the hydrate production of HBSs by affecting their temperatures and pressure distributions,as well as the transmission of the pressure drop and methane gas ***,the results show that the gas productivity of fluctuating HBSs was about 5%less than that of horizontal *** optimizing the depressurization amplitude,well length,and layout location of vertical wells,the productivity of fluctuating HBSs increased by about 56.6%.

关键词： natural gas hydrate numerical simulation fluctuation characteristics depressurization production production well optimization

Investigation on the vortical structures by the Liutex method in turbulent channels at Re_(τ)=180 with scalloped and triangular riblet control

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Journal of Hydrodynamics 2024年第1期36卷 35-52页

作者： Zhang-dan yu Shang Jiang Hai-dong yu Bi-yu Pang xin Dong Yi-qian Wang School of Mathematical Sciences Soochow UniversitySuzhou215006China Beijing Institute of Astronautical System Engineering Beijing100076China

Riblets are a series of small protrusions formed along the flow direction,which have been extensively studied as a passive turbulent drag reduction *** and numerical simulations have shown that well-designed riblets can significantly reduce drag in turbulent flows,making them highly promising and valuable for various *** this study,we focus on a scalloped riblet,which is designed by smoothly connecting two third-order polynomials,and thus the sharpness of the tip and the curvature of the valley can be well *** conduct direct numerical simulations of turbulent channel with smooth plate,scalloped riblet-mounted and triangular riblet-mounted *** in wall units of W^(+)=20 and height-width ratio ofγ=0.5 are selected for both riblet *** with the smooth plate case,the scalloped riblet case achieves an 8.68%drag reduction,while the triangular riblet case achieves a 4.79%drag *** obtained drag reduction rate of the triangular riblet is consistent with previous experiments and simulations,and the results indicate that the scalloped riblet is more effective in reducing drag and deserves further *** compare turbulent statistics of the scalloped riblet case with those of the triangular riblet *** mean velocity profiles of riblets are similar,but both the Reynolds shear stress and second-order statistics of velocity fluctuations and Liutex are significantly reduced in the scalloped riblets controlled turbulent channel,indicating that the scalloped riblet can more effectively suppress the spanwise and wall-normal turbulent intensity near the *** also compare the pre-multiplied spectra of streamwise velocity and streamwise Liutex component for the three cases to investigate the energy distribution and characteristics of Liutex *** Liutex vortex identification method is also utilized to analyze the instantaneous flow field,which provides insights into the flow field and could be bene

关键词： Liutex vector riblet drag reduction tip sharpness turbulent channel scalloped

Upgraded durian genome reveals the role of chromosome reshuffling during ancestral karyotype evolution,lignin biosynthesis regulation,and stress tolerance

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Science China(Life Sciences) 2024年第6期67卷 1266-1279页

作者： Wanwan Li xin Chen Jianing yu yuxian Zhu College of Life Sciences Shaanxi Normal UniversityXi’an 710119China The State Key Laboratory of Protein and Gene Research College of Life SciencesPeking UniversityBeijing 100871China The Institute for Advanced Studies Wuhan UniversityWuhan 430072China

Durian(Durio zibethinus)is a tropical fruit that has a unique flavor and *** occupies a significant phylogenetic position within the Malvaceae *** core-eudicot plants are reported to share seven ancestral karyotypes that have undergone reshuffling,resulting in an abundant genomic ***,the ancestral karyotypes of the Malvaceae family,as well as the evolution trajectory leading to the28 chromosomes in durian,remain poorly ***,we report the high-quality assembly of the durian genome with comprehensive comparative genomic *** analyzing the collinear blocks between cacao and durian,we inferred 11 Malvaceae ancestral *** blocks were present in a single-copy form in cacao and mainly in triplicates in durian,possibly resulting from a recent whole genome triplication(WGT)event that led to hexaploidization of the durian genome around 20(17–24)million years ago.A large proportion of the duplicated genes in durian,such as those involved in the lignin biosynthesis module for phenylpropane biosynthesis,are derived directly from whole genome duplication,which makes it an important force in reshaping its genomic *** studies have revealed that genes involved in feruloyl-Co A formations were highly preferentially expressed in fruit peels,indicating that the thorns produced on durian fruit may comprise guaiacyl and syringyl *** all the analyzed transcription factors(TFs),members of the heat shock factor family(HSF)were the most significantly upregulated under heat *** subfamilies of genes encoding heat shock proteins(HSPs)in the durian genome appear to have undergone *** potential interactions between HSF Dzi05.397 and HSPs were examined and experimentally *** study provides a high-quality durian genome and reveals the reshuffling mechanism of ancestral Malvaceae chromosomes to produce the durian *** also provide insights into the mechanism underlying lignin bi

关键词： Durio zibethinus whole genome duplication whole genome triplication Malvaceae ancestral karyotypes chromosome reshuffling lignin biosynthesis heat stress

MSADCN:Multi-Scale Attentional Densely Connected Network for Automated Bone Age Assessment

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Computers, Materials & Continua 2024年第2期78卷 2225-2243页

作者： Yanjun yu Lei yu Huiqi Wang Haodong zheng Yi Deng College of Computer and Information Science Chongqing Normal UniversityChongqing401331China College of Mathematics and Statistics Chongqing UniversityChongqing401331China

Bone age assessment(BAA)helps doctors determine how a child’s bones grow and develop in clinical *** BAA methods rely on clinician expertise,leading to time-consuming predictions and inaccurate *** deep learning-based BAA methods feed the extracted critical points of images into the network by providing additional *** operation is costly and *** address these problems,we propose a multi-scale attentional densely connected network(MSADCN)in this *** constructs a multi-scale dense connectivity mechanism,which can avoid overfitting,obtain the local features effectively and prevent gradient vanishing even in limited training ***,MSADCN designs multi-scale structures in the densely connected network to extract fine-grained features at different ***,coordinate attention is embedded to focus on critical features and automatically locate the regions of interest(ROI)without additional *** addition,to improve the model’s generalization,transfer learning is applied to train the proposed MSADCN on the public dataset IMDB-WIKI,and the obtained pre-trained weights are loaded onto the Radiological Society of North America(RSNA)***,label distribution learning(LDL)and expectation regression techniques are introduced into our model to exploit the correlation between hand bone images of different ages,which can obtain stable age *** experiments confirm that our model can converge more efficiently and obtain a mean absolute error(MAE)of 4.64 months,outperforming some state-of-the-art BAA methods.

关键词： Bone age assessment deep learning attentional densely connected network muti-scale

High-Performanceα-Diimine Nickel Complexes for Facile Access of PE Elastomers with Exceptional Material Properties

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Chinese Journal of Polymer Science 2024年第5期42卷 620-635,I0008页

作者： Li-Dong Qin xin-yu Wang Qaiser Mahmood Zhi-xin yu Yi-Zhou Wang Song Zou Tong-Ling Liang Wen-Hua Sun School of Pharmaceutical Sciences Changchun University of Chinese MedicineChangchun130117China Chemistry and Chemical Engineering Guangdong Laboratory Shantou515031China Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science Institute of ChemistryChinese Academy of SciencesBeijing100190China

For practicable elastomeric polyethylene,achieving high catalyst thermal stability and activity,along with precise control of polymer properties such as branching density,molecular weights,and distribution,is crucial but *** this study,two sets of symmetricalα-diimine nickel complexes,each comprising four nickel bromide or chloride complexes,were synthesized and investigated their performance for ethylene polymerization under various reaction *** activation with either Et2AlCl or MMAO cocatalysts,these complexes displayed not only high activity but also generated high molecular weight polyethylenes with controlled polydispersity and a substantial number of *** catalyst with the least steric hindrance displayed the remarkable high activity(up to 1.2×10^(7) g·mol^(-1)·h^(-1)).Notably,nickel bromides demonstrated higher activity compared to their chloride *** investigation into the effect of reaction temperature on catalytic performance revealed that NiBrMe-MMAO system displayed high thermal stability(activity up to 2.51×10^(6) g·mol^(-1)·h^(-1) at 100℃)and consistently yielded high polymer molecular weights with narrow polydispersity over a broad temperature range of 30-100℃.Of significant note,mechanical analysis of the resulting polyethylene demonstrated excellent ultimate tensile strength and high strain at ***,the polyethylene sample prepared at 100℃exhibited ultimate tensile strength up to 10 MPa with 1863%maximum strain at break and a strain recovery of up to 54.9%after ten cycles at a fixed strain of 300%,indicating excellent material properties of prepared thermoplastic polyethylene elastomers(TPE).

关键词： Thermoplastic polyethylene elastomers α-Diimine nickel pre-catalysts Ethylene polymerization Mechanical properties Highly branched polyethylene

Facile synthesis of high-brightness green-emitting carbon dots with narrow bandwidth towards backlight display

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Chinese Chemical Letters 2024年第5期35卷 277-282页

作者： Rui Cheng Tingting Zhang xin Huang Jian yu State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 210009China

High-performance carbon dots(CDs)allowing the application in high-end display devices are highly desirable and usually limited by the absence of simple and easy synthesis *** this work,we exploited an easy-to-implement strategy for the one-step synthesis of green-emitting CDs(G-CDs)with superb optical *** G-CDs were synthesized using m-phenylenediamine(m-PD)as a single precursor,and the reaction reacted at 180℃for 12 h The resultant G-CDs exhibit high-purity and excitationindependent green fluorescence with the photoluminescence(PL)peak located at 516 nm,full width at half maximum(FWHM)of 46 nm,and PL quantum yield(QY)of∼80%under the 470nm excitation *** G-CDs and corresponding composite film prepared with polyvinyl butyral(G-CDs@PVB)exhibit good PL stability after undergoing long-time storage for one year and 360 h exposure under 460nm blue *** G-CDs@PVB film was used as color-conversion materials in green-emitting light-emitting diode(LED)application,exhibiting a Commission internationale de l’Eclairage(CIE)chromaticity coordinate of(0.21,0.44).The film was also used in CD-based liquid crystal display(CD-LCD)application,achieving a color gamut value of 85%.This work will offer a working basis for the synthesis of high-performance CDs as well as their application in displays.

关键词： Carbon dots One-step synthesis Narrow bandwidth High quantum yield Display

Dissolution kinetics and reaction mechanism of Al_(2)O_(3) in molten CaF_(2)-CaO-Al_(2)O_(3) slag

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Journal of Iron and Steel Research International 2024年第4期31卷 861-869页

作者： Yao-xin Du Yan-wu Dong Zhou-hua Jiang Ganna Stovpchenko yu-shuo Li Jun Huang xin-wei Wang yu-xiao Liu School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina Key Laboratory of Ecological Metallurgy of Multimetallic Mineral Northeastern UniversityShenyang 110819LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina E.O.Paton Electric Welding Institute of the National Academy of Science of Ukraine Kiev 03115Ukraine

The dissolution behavior of Al_(2)O_(3) in molten CaF_(2)-CaO-Al_(2)O_(3) slag,a basic slag system of electroslag remelting process,was investigated by rotating cylinder method using corundum rods to simulate Al_(2)O_(3) inclusions in *** experimental results show that the dissolution rate of Al_(2)O_(3);rods in CaF_(2)-CaO-Al_(2)O_(3) slag increases with the increase in rotating speed and temperature,and the rate-controlling step is the mass transfer in the *** dissolution rate of Al_(2)O,in CaF_(2)-CaO-Al_(2)O_(3) slag increases with the increase in the ratio of CaO to Al_(2)O_(3),which is due to the increase in dissolution driving force and the decrease in slag *** apparent activation energy of the mass transfer of AlOs in slag C is calculated to be 222.86 kJ mol^(-1).During the dissolution of Al_(2)0,inclusions in the slag,it reacts with F in liquid slag at first,then reacts with CaO to form the intermediate compounds of xCaO-yAl_(2)O_(3) system,and finally dissolves in molten *** dissolution rate of Al_(2)O_(3) inclusions in CaF_(2)-CaO-Al_(2)O_(3) slag for electroslag remelting is positively correlated with the ratio of the dissolution driving force and slag viscosity,and the correlation coeficient is 2.487×10^(-11).

关键词： Inclusion Electroslag remelting Mass transfer:Dissolution rate-Dissolution driving force

Research on the mechanism of the two-dimensional ultrasonic surface burnishing process to enhance the wear resistance for aluminum alloy

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Friction 2024年第3期12卷 490-509页

作者： Zhen-yu ZHOU Qiu-Yang zheng yu LI Cong DING Guang-Jian PENG Zhong-yu PIAO College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310014China

The gradient nanostructure is machined on the aluminum(Al)alloy by the two-dimensional ultrasonic surface burnishing process(2D-USBP).The mechanism of why the gradient nanostructure enhances wear resistance is *** mechanical properties and microstructure characterization for the gradient nanostructure are performed by operating a nanoindenter,transmission electron microscopy(TEM),and electron backscattered diffraction(EBSD).Dry wear tests are performed on the samples before and after machining to evaluate the wear resistance and *** effect of the gradient nanostructure on the wear resistance is explored by developing the crystal plasticity(CP)finite element and molecular dynamics(MD)*** characterization results show that the 2D-USBP sample prepared a gradient structure of~600μm thick on the aluminum surface,increasing the surface hardness from 1.13 to 1.71 GPa and reducing the elastic modulus from 78.84 to 70.14 *** optimization of the surface microstructure and the increase of the mechanical properties effectively enhance the wear resistance of the sample,with 41.20%,39.07%,and 54.58% of the wear scar areas for the 2D-USBP treated samples to the original samples under 5,10,and 15 N loads,*** gradient nanostructure hinders the slip of dislocations inside the sample during the wear process and reduces the size and scope of plastic deformation;meanwhile,the resistance to deformation,adhesion,and crack initiation and propagation of the sample surface is improved,resulting in enhanced wear resistance.

关键词： structural superlubricity lattice registry elastic deformation strained solitons crystal plasticity molecular dynamics simulations

Controlling reversible complexation-mediated polymerization(RCMP)via deep eutectic solvents:fast kinetics,narrow molecular weight distribution and mechanistic insights

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Science China Chemistry 2024年第8期67卷 2728-2736页

作者： xin Fu Zhen Lu Shen Li zheng-Hong Luo Lin-Xi Hou Department of Materials-Oriented Chemical Engineering College of Chemical EngineeringFuzhou UniversityFuzhou 350116China Department of Chemical Engineering School of Chemistry and Chemical EngineeringState Key Laboratory of Metal Matrix CompositesShanghai Jiao Tong UniversityShanghai 200030China Chemical Engineering Zhicheng College of Fuzhou UniversityFuzhou 350116China Qingyuan Innovation Laboratory Quanzhou 362801China

The exploitation of new green polymerization avenues for the effective synthesis of polymers by reversible-deactivation radical polymerization plays a critical role in pursuing the development of polymeric *** this work,serials of deep eutectic solvents(DES)with intermolecular-hydrogen-bonding interaction were constructed as catalysts and medium for actuating reversible complexation-mediated polymerization(RCMP)for the first time,yielding methacrylate polymers with high monomer conversion and narrow dispersion molecular weight in both water and oil *** mechanism and elementary reaction of RCMP were explored deeply,revealing that the complexation of initiator with DES to generate radicals was a ratecontrolling step and intermolecular-hydrogen-bond was primary factor to influence polymerization ***,the insights of density functional theory calculations revealed that negative electrostatic potential ensured nucleophilic *** investigation demonstrated the considerable potential of DES for RCMP,which is anticipated for other polymerization applications as a novel medium mode.

关键词： deep eutectic solvent reversible complexation-mediated polymerization intermolecular hydrogen bonding density functional theory elementary reaction steps