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Unlocking the Potential of Poly(butylene succinate)through Incorporation of Vitrimeric Network Based on Dynamic Imine Bonds

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Chinese Journal of Polymer Science 2024年第10期42卷 1414-1424,I0006页

作者： Shan-Song Wu Hui-Juan Lu yi-dong Li Shui-dong Zhang Jian-Bing Zeng Chongqing Key Laboratory of Soft-Matter Material Manufacturing School of Chemistry and Chemical EngineeringSouthwest UniversityChongqing400715China School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou510640China

Poly(butylene succinate)(PBS)exhibits many advantages,such as renewability,biodegradability,and impressive thermal and mechanical properties,but is limited by the low melt viscosity and strength resulted from the linear *** address this,vitrimeric network was introduced to synthesize PBS vitrimers(PBSVs)based on dynamic imine bonds through melt polymerization of hydroxyl-terminated PBS with vanillin derived imine containing compound and hexamethylene diisocyanate using trimethylolpropane as a crosslinking *** with different crosslinking degrees were synthesized through changing the content of the crosslinking *** effect of crosslinking degree on the thermal,theological,mechanical properties,and stress relaxation behavior of the PBSVs was studied in *** results demonstrated that the melt viscosity,melt strength,and heat resistance were enhanced substantially without obvious depression in crystallizability,thermal stability,and mechanical properties through increasing crosslinking *** addition,the PBSVs exhibit thermal reprocessability with mechanical properties recovered by more than 90%even after processing for three ***,PBSV with improved melt properties shows significantly improved foamability compared to commercial *** research contributes to the advancement of polymer technology by successfully developing PBS vitrimers with improved properties,showcasing their potential applications in sustainable and biodegradable materials.

关键词： Poly(butylene succinate) Vitrimer Imine bonds Foamability

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

Effect of lens surgery on health-related quality of life in preschool children with congenital ectopia lentis

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International Journal of Ophthalmology(English edition) 2024年第1期17卷 66-72页

作者： Yan-qiao Huang Qian-Zhong Cao yi-Yao Wang yi-Jing Zhou Dan-ying Zheng State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangdong Provincial Clinical Research Center for Ocular DiseasesGuangzhou 510060Guangdong ProvinceChina

AIM:To evaluate the effect of lens surgery on health-related quality of life(HRQoL)of preschool children with congenital ectopia lentis(CEL).METHODS:A prospective self-controlled study was conducted in Zhongshan Ophthalmic *** aged from 5 to 7y whom were diagnosed with CEL and underwent phacoemulsification with scleral-fixated posterior chamber intraocular lens implantation and their parents were enrolled in this *** of them completed the child and proxy(parental)PedsQL™4.0 before and after the *** preoperative scores were compared to their postoperative *** analyses were performed based on gender and preoperative bilateral presenting visual acuity of the ***:Thirty-two children with CEL successfully underwent surgery without any complications,among whom 8 had monocular surgery and 24 had binocular *** and postoperative questionnaires were completed by 32 child-parent *** intervention could significantly improve the vision of affected children(P<0.001).The medians of physical,psychosocial and total health scores self-reported by the children were 68.75(62.50,81.25),65.00(60.00,80.00)and 67.39(60.87,78.26)preoperatively and were 93.75(87.50,100.00),90.00(83.33,96.67)and 89.13(85.32,95.65)*** preoperative scores of the affected children were significantly lower in all scales than age-matched healthy children(P<0.001).All the postoperative scores were significantly higher than the preoperative scores in affected children and their parents(P<0.001).In the physical functioning evaluation,the preoperative score reported by parents of girls was higher than parents of boys(P=0.041),and the postoperative score of girls was higher than that of boys(P=0.036).CONCLUSION:CEL is associated with significantly worse quality of life in preschool *** intervention can significantly improve the HRQoL in affected children from both personal and family perspective.

关键词： congenital ectopia lentis surgical intervention health-related quality of life preschool children

Biomimetic MXene membranes with negatively thermo-responsive switchable 2D nanochannels for graded molecular sieving

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Green Energy & Environment 2024年第6期9卷 1058-1067页

作者： yi Wang Yangyang Wang Chang Liu dongjian Shi Weifu dong Baoliang Peng Liangliang dong Mingqing Chen The Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxiJiangsu214122China International Research Center for Photo-responsive Molecules and Materials Jiangnan UniversityWuxiJiangsu214122China Research Institute of Petroleum Exploration&Development(RIPED) PetroChina/Key Laboratory of Oilfield ChemistryCNPCBeijing100083China

Negatively thermo-responsive 2D membranes,which mimic the stomatal opening/closing of plants,have drawn substantial interest for tunable molecular separation ***,these membranes are still restricted significantly on account of low water permeability and poor dynamic tunability of 2D nanochannels under temperature ***,we present a biomimetic negatively thermo-responsive MXene membrane by covalently grafting poly(N-isopropylacrylamide)(PNIPAm)onto MXene *** uniformly grafted PNIPAm polymer chains can enlarge the interlayer spacings for increasing water permeability while also allowing more tunability of 2D nanochannels for enhancing the capability of gradually separating multiple molecules of different *** expected,the constructed membrane exhibits ultrahigh water permeance of 95.6 L m^(-2) h^(-1) bar^(-1) at 25℃,which is eight-fold higher than the state-of-the-art negatively thermoresponsive 2D ***,the highly temperature-tunable 2D nanochannels enable the constructed membrane to perform excellent graded molecular sieving for dye-and antibiotic-based ternary *** strategy provides new perspectives in engineering smart 2D membrane and expands the scope of temperature-responsive membranes,showing promising applications in micro/nanofluidics and molecular separation.

关键词： Thermo-responsive 2D membrane MXene nanosheets PNIPAm Temperature-tunable 2D nanochannels Graded molecular sieving

Temporally consistent video colorization with deep feature propagation and self-regularization learning

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Computational Visual Media 2024年第2期10卷 375-395页

作者： yihao Liu Hengyuan Zhao Kelvin CKChan Xintao Wang Chen Change Loy Yu qiao Chao dong Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China Department of Electrical&Computer Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798 Applied Research Center Tencent PCGShenzhenChina

Video colorization is a challenging and highly ill-posed *** recent years have witnessed remarkable progress in single image colorization,there is relatively less research effort on video colorization,and existing methods always suffer from severe flickering artifacts(temporal inconsistency)or unsatisfactory *** address this problem from a new perspective,by jointly considering colorization and temporal consistency in a unified ***,we propose a novel temporally consistent video colorization(TCVC)*** effectively propagates frame-level deep features in a bidirectional way to enhance the temporal consistency of ***,TCVC introduces a self-regularization learning(SRL)scheme to minimize the differences in predictions obtained using different time *** does not require any ground-truth color videos for training and can further improve temporal *** demonstrate that our method can not only provide visually pleasing colorized video,but also with clearly better temporal consistency than state-of-the-art methods.A video demo is provided at https://***/watch?v=c7dczMs-olE,while code is available at https://***/lyh-18/TCVC-Tem porally-Consistent-Video-Colorization.

关键词： video colorization temporal consistency feature propagation self-regularization

Preparation and characterization of high-reactivity explosive-based nano-boron microspheres

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Particuology 2024年第10期93卷 125-136页

作者： Chen dong yi Wang Kanghui Jia Dan Song Xiaolan Song Chongwei An School of Materials Science and Engineering North University of ChinaTaiyuan030051China Jinxi Group Shanxi Jiangyang Chemical Co. Ltd.Taiyuan030051China China Ordnance Institute of Science and Technology Beijing100089China School of Environment and Safety Engineering North University of ChinaTaiyuan030051China

Boron nanoparticles,with their remarkably high gravimetric and volumetric calorific values,emerge as the most promising fuel in energetic ***,challenges such as susceptibility to oxidation,high ignition temperature,and low combustion efficiency have constrained their further *** this study,we fabricated high explosives based nano-boron microspheres with uniform size using the electrostatic spray method,in which the boron nanoparticles and high explosives(CL-20 or PETN)are closely bonded together by fluorinated polymer(F2602)and evenly *** results indicated that the microspheres exhibited high sphericity and showed an enhanced antioxidant *** addition of high-energy explosives not only reduced the thermal oxidation temperature of nano-boron powder within the microspheres but also significantly enhanced the pressurization ***,the microspheres with added high-energy explosives released more energy during the combustion *** to physically mixed samples,electrostatically sprayed microspheres with a uniform microstructure still exhibited higher ***,the design and synthesis of microspheres with controllable structures using the electrostatic spray method show promising application prospects.

关键词： Nano-boron CL-20 PETN Electrospraying Ignition and combustion

The size effect and analogous boundary states in a circular non-Hermitian chain

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Communications in Theoretical Physics 2024年第2期76卷 157-165页

作者： Xin-Yu Ma yi-Han Guan qiao-Nan Li Ai-Lei He Lu Qi School of Physical Science and Technology Yangzhou UniversityYangzhou 225002China

We investigate the size effect and boundary states based on a circular non-Hermitian chain under the nonreciprocal intra-cell coupling and inter-cell coupling *** find that the circular non-Hermitian chain exhibits an even–odd effect on the unit cell corresponding to a large chain,which is different from the open non-Hermitian chain only exhibiting the same effect for a small ***,we find that the originally localized bulk states become totally extended via designing the boundary coupling strength *** extended bulk states reveal the fact of the disappearance of the non-Hermitian skin *** particular,we show that the circular non-Hermitian chain also possesses the analogous edge states under some parameter regimes,which is pretty counterintuitive since the circular chain usually cannot define a *** investigations supply the different non-Hermitian phenomena in a circular non-Hermitian chain.

关键词： boundary states non-Hermitian chain topological state

Numerical study of submerged bending vegetation under unidirectional flow

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Water Science and Engineering 2024年第1期17卷 92-100页

作者： Pei-pei Zhang yi-qing Gong Ken Vui Chua Jie Dai Jing-qiao Mao College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China Institute of Water Science and Technology Hohai UniversityNanjing 210098China School of Engineering Cardiff UniversityCardiff CF243AAUK

Submerged vegetation commonly grows and plays a vital role in aquatic ecosystems,but it is also regarded as a barrier to the passing *** simulations of flow through and over submerged vegetation were carried out to investigate the effect of vegetation density on flow *** simulations were computationally set up to replicate flume experiments,in which vegetation was mimicked with flexible plastic *** fluid-structure interaction between flow and flexible vegetation was solved by coupling the two modules of the COMSOL *** cases with different vegetation densities were simulated,and the results were successfully validated against the experimental *** contours of the simulated time-averaged streamwise velocity and Reynolds stress were extracted to highlight the differences in mean and turbulent flow *** turbulence intensity was found to be more sensitive to vegetation density than the time-averaged *** developing length increased with the spacing between *** snapshots of the bending vegetation under instantaneous velocity and vorticity revealed that flexible vegetation responded to the effects of eddies in the shear layer by swaying *** first two rows of vegetation suffered stronger approaching flow and were prone to more streamlined *** addition,the origin of tip vortices was investigated via the distribution of *** results reveal the variation of flow properties with bending submerged vegetation and provide useful reference for optimizationofrestorationprojects.

关键词： Computational fluid dynamics Fluid-structure interaction Turbulence Flexible and submerged vegetation

Theoretical analysis and engineering application of controllable shock wave technology for enhancing coalbed methane in soft and low‑permeability coal seams

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International Journal of Coal Science & Technology 2024年第2期11卷 123-142页

作者： Guodong qiao Zegong Liu Yongmin Zhang Changping yi Kui Gao Shigui Fu Youzhi Zhao School of Safety Science and Engineering Anhui University of Science and TechnologyHuainan 232001AnhuiChina Institute of Energy Hefei Comprehensive National Science CenterHefei 230031AnhuiChina School of Electrical Engineering Xi’an Jiaotong UniversityXi’an 710049ShanxiChina Division of Mining and Geotechnical Engineering LuleåUniversity of TechnologyLuleåSweden

Coalbed methane(CBM)is a significant factor in triggering coal and gas outburst disaster,while also serving as a clean *** the increasing depth of mining operations,coal seams that exhibit high levels of gas content and low permeability have become increasingly *** controllable shockwave(CSW)technology has proven effective in enhancing CBM in laboratory settings,there is a lack of reports on its field applications in soft and low-permeability coal *** study establishes the governing equations for stress waves induced by *** numerical inversion was employed to analyse the dynamic response of the coal seam during CSW ***,quantitative calculations were performed for the crushed zone,fracture zone,and effective CSW influence range,which guided the selection of field test *** results of the field test unveiled a substantial improvement in the gas permeability coefficient,the average rate of pure methane flowrate,and the mean gas flowrate within a 10 m radius of the antireflection *** enhancements were notable,showing increases of 3 times,13.72 times,and 11.48 times,***,the field test performed on the CSW antireflection gas extraction hole cluster demonstrated a noticeable improvement in CBM *** antireflection,the maximum peak gas concentration and maximum peak pure methane flow reached 71.2%and 2.59 m^(3)/min,*** findings will offer valuable guidance for the application of CSW antireflection technology in soft and low-permeability coal seams.

关键词： CSW antireflection in coal seams CBM extraction enhancement Soft and low-permeability coal seams Field test