检索结果-南通市图书馆

Completeness of Induced Cotorsion Pairs in Representation Categories of Rooted Quivers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第10期40卷 2436-2452页

作者： Zhen Xing DI li ping li li liANG Fei XU School of Mathematical Sciences Huaqiao University LCSM (Ministry of Education) School of Mathematics and Statistics Hunan Normal University Department of Mathematics Lanzhou Jiaotong University Gansu Provincial Research Center for Basic Disciplines of Mathematics and Statistics Department of Mathematics Shantou University

This paper focuses on a question raised by Holm and J?rgensen, who asked if the induced cotorsion pairs(Φ（X）, Φ（X）⊥) and(⊥Ψ（Y）, Ψ（Y）) in Rep（Q, A）—the category of all A-valued representations of a quiver Q—are complete whenever（X, Y） is a complete cotorsion pair in an abelian category A satisfying some mild conditions. We give an affirmative answer if the quiver Q is rooted. As an application, we show under certain mild conditions that if a subcategory L, which is not necessarily closed under direct summands, of A is special precovering（resp., preenveloping）, then Φ（L）(resp.,Ψ（L）) is special precovering（resp., preenveloping） in Rep（Q, A）.

关键词： 16G20 18G25 complete cotorsion pair Rooted quiver special precovering (preenveloping) subcategory

Bioinspired Additive Manufacturing of Hierarchical Materials: From Biostructures to functions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research 2024年第1期2023卷 533-559页

作者： Jingjiang Wei Fei Pan Hang ping Kun Yang Yanqing Wang Qingyuan Wang Zhengyi fu Institute for Advanced Materials Deformation and Damage from Multi-Scale Institute for Advanced StudyChengdu UniversityChengdu 610106P.R.China Department of Chemistry University of BaselBasel 4058Switzerland State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070P.R.China College of Polymer Science and Engineering Sichuan UniversityChengdu 610065P.R.China

Throughout billions of years,biological systems have evolved sophisticated,multiscale hierarchical structures to adapt to changing *** are synthesized under mild conditions through a bottom-up self-assembly process,utilizing substances from the surrounding environment,and meanwhile are regulated by genes and *** manufacturing,which mimics this natural process,provides a promising approach to developing new materials with advantageous properties similar to natural biological *** review presents an overview of natural biomaterials,emphasizing their chemical and structural compositions at various scales,from the nanoscale to the macroscale,and the key mechanisms underlying their ***,this review describes the designs,preparations,and applications of bioinspired multifunctional materials produced through additive manufacturing at different scales,including nano,micro,micro-macro,and macro levels.

关键词： materials structures utilizing

Fabrication and properties of lightweight zirconia with fine closed porosity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第6期31卷 1449-1458页

作者： Yi-bo Zhang Hua-zhi Gu Lv-ping fu Ao Huang Mei-je Zhang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

lightweight refractory materials with thermal insulation properties and erosion resistance are advantageous for hightemperature *** zirconia refractories were prepared using starch as a pore-forming agent,basic magnesium carbonate as a stabilizer,and nano-zirconia as an *** effects of the nano-zirconia content on the pore and thermal insulation properties of the lightweight zirconia refractories were investigated based on the porosity,phase composition,microstructure,and thermal ***-zirconia was shown to have a high surface energy,and its addition effectively increased the driving force for sintering,reduced the sintering temperature,and promoted the sintering reaction,thereby reducing the apparent porosity and improving the density of the prepared *** to the superplasticity of nano-zirconia,the surface stress caused plastic deformation between particles,which increased the migration rate of grain boundaries and trapped more gas inside the material before it diffused to the surface,thereby enhancing the closed porosity of the *** presence of closed pores could extend the thermal conduction path,decrease the conduction rate,and hinder the conduction effect to effectively reduce the thermal conductivity of the *** a nano-zirconia content of 0.75 wt.%,the prepared lightweight zirconia had the highest closed porosity and the lowest thermal *** apparent porosity,closed porosity,and total porosity of the material were 2.8%,7.0%,and 9.8%,respectively,and the thermal conductivity at 800℃was 1.37 W m^(-1)k^(-1).

关键词： Sintering Nano-zirconia Closed pore:Thermal conductivity Refractory material

Ultrahigh thermoelectric properties of p‐type Bi_(x)Sb_(2−x)Te_(3)thin films with exceptional flexibility for wearable energy harvesting

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carbon Energy 2024年第8期6卷 273-284页

作者： Zhuang‐Hao Zheng Yi‐Ming Zhong Yi‐liu li Mohammad Nisar Adil Mansoor fu li Shuo Chen Guang‐Xing liang ping Fan Dongyan Xu Meng Wei Yue‐Xing Chen Shenzhen Key Laboratory of Advanced Thin Films and Applications Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhenChina Department of Mechanical and Automation Engineering The Chinese University of Hong KongSha TinChina

Use of a flexible thermoelectric source is a feasible approach to realizing selfpowered wearable electronics and the Internet of *** thin films are promising candidates for fabricating flexible power supply,but obtaining highthermoelectric‐performance thin films remains a big *** the present work,a p‐type Bi_(x)Sb_(2−x)Te_(3)thin film is designed with a high figure of merit of 1.11 at 393 K and exceptional flexibility(less than 5%increase in resistance after 1000 cycles of bending at a radius of∼5 mm).The favorable comprehensive performance of the Bi_(x)Sb_(2−x)Te_(3)flexible thin film is due to its excellent crystallinity,optimized carrier concentration,and low elastic modulus,which have been verified by experiments and theoretical ***,a flexible device is fabricated using the prepared p‐type Bi_(x)Sb_(2−x)Te_(3)and n‐type Ag_(2)Se thin ***,an outstanding power density of∼1028μWcm^(−2)is achieved at a temperature difference of 25 *** work extends a novel concept to the fabrication of highperformance flexible thin films and devices for wearable energy harvesting.

关键词： Bi_(x)Sb_(2−x)Te_(3) electrical transport properties flexibility thermoelectric

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2383-2392页

作者： li-Ming Zhao Cai-ping Lu Yang liu Chao-Chao li School of Mines China University of Mining and Technology Henan Institute of Geophysical Space Information

The similarities and differences in inherent mechanism and characteristic frequency between the onedimensional(1D) poroelastic model and the layered White model were investigated. This investigation was conducted under the assumption that the rock was homogenous and isotropic at the mesoscopic scale. For the inherent mechanism, both models resulted from quasi-static flow in a slow P-wave diffusion mode, and the differences between them originated from saturated fluids and boundary conditions. On the other hand, for the characteristic frequencies of the models, the characteristic frequency of the 1D poroelastic model was first modified because the elastic constant and formula for calculating it were misused and then compared to that of the layered White model. Both of them moved towards higher frequencies with increasing permeability and decreasing viscosity and diffusion length. The differences between them were due to the diffusion length. The diffusion length for the 1D poroelastic model was determined by the sample length, whereas that for the layered White model was determined by the length of the representative elementary volume(REV). Subsequently, a numerical example was presented to demonstrate the similarities and differences between the models. Finally, published experimental data were interpreted using the 1D poroelastic model combined with the Cole-Cole *** prediction of the combined model was in good agreement with the experimental data, thereby validating the effectiveness of the 1D poroelastic model. furthermore, the modified characteristic frequency in our study was much closer to the experimental data than the previous prediction, validating the effectiveness of our modification of the characteristic frequency of the 1D poroelastic model. The investigation provided insight into the internal relationship between wave-induced fluid flow(WIFF)models at macroscopic and mesoscopic scales and can aid in a better understanding of the elastic modulus d

关键词： 1D poroelastic model Layered White model Quasi-static flow Slow P-wave diffusion Characteristic frequency Diffusion length

Microdeletion on Xq27.1 in a Chinese VACTERL-like Family with Kidney and Anal Anomalies

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2024年第5期37卷 503-510页

作者： li Min ZHANG Yu Lan ZHANG Kai li li ping ping LYU Yu Han liANG Ya Xin YU Yue Department of Gynecology and Obstetrics Beijing HospitalNational Center of GerontologyInstitute of Geriatric MedicineChinese Academy of Medical SciencesBeijing 100730China Chinese Academy of Medical Sciences and Peking Union Medical College Beijing HospitalBeijing 100730China The Key Laboratory of Geriatrics Beijing Institute of GeriatricsBeijing HospitalNational Center of GerontologyInstitute of Geriatric MedicineChinese Academy of Medical SciencesBeijing 100730China

Objective VATER/VACTERL-like association is associated with adverse pregnancy *** evidence of this disorder is *** this study,we aimed to provide genetic insights to improve the diagnosis of *** We have described a Chinese family in which four members were affected by renal defects or agenesis,anal atresia,and anovaginal fistula,which is consistent with the diagnosis of a VACTERL-like *** and genetic analyses were conducted using genome and exome *** Segregation analysis revealed the presence of a recessive X-linked microdeletion in two living affected individuals,harboring a 196–380 kb microdeletion on Xq27.1,which was identified by familial exome *** sequencing was performed on the affected male,confirming a-196 kb microdeletion in Xq27.1,which included a 28%loss of the CDR-1 *** family members were included in the co-segregation analysis,and only VACTERL-like cases with microdeletions were reported in *** These results suggest that the 196–380 kb microdeletion in Xq27.1 could be a possible cause of the VATER/VACTERL-like ***,further genetic and functional analyses are required to confirm or rule out genetic background as the definitive cause of the VACTERL association.

关键词： Prenatal diagnosis VACTERL whole-genome sequencing whole-exome sequencing X-linked

维普期刊数据库

Reaction pathways and selectivity in the chemo-catalytic conversion of cellulose and its derivatives to ethylene glycol:A review

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第2期66卷 310-331页

作者： Yao li Yuchun Zhang Zhiyu li Huiyan Zhang Peng fu College of Agricultural Engineering and Food Science Shandong University of TechnologyZibo 255000China Key Laboratory of Energy Thermal Conversion and Control Ministry of EducationSchool of Energy and EnvironmentSoutheast UniversityNanjing 210096China

Biomass-to-ethylene glycol is an effective means to achieve high-value utilisation of cellulose but is hindered by low conversion efficiency and poor catalyst activity and *** and cellobiose are derivatives of cellulose conversion to ethylene glycol,and it is found that studying the reaction process of both can help to understand the reaction mechanism of *** is desirable to develop a reusable,highly active catalyst to convert cellulose into ethylene *** ideal catalyst might have one or more active sites described the conversion steps ***,we discuss the catalyst development of celluloseto-ethylene glycol,including tungsten,tin,lanthanide,and other transition metal catalysts,and special attention is given to the reaction mechanism and kinetics for preparing ethylene glycol from cellulose,and the economic advantages of biomass-to-ethylene glycol are briefly *** insights given in this review will facilitate further development of efficient catalysts,for addressing the global energy crisis and climate change related to the use of fossil fuels.

关键词： Ethylene glycol Cellulose Catalyst Retro-aldol condensation Hydrolysis Kinetics

维普期刊数据库

Rapid prediction of damaged ship roll motion responses in beam waves based on stacking algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第2期36卷 394-405页

作者： Xin-ran liu Ting-qiu li Zi-ping Wang School of Naval Architecture Ocean and Energy Power EngineeringWuhan University of TechnologyWuhan430063China

Accurate modeling for highly non-linear coupling of a damaged ship with liquid sloshing in waves is still of considerable interest within the computational fluid dynamics(CFD)and AI *** paper describes a data-driven Stacking algorithm for fast prediction of roll motion response amplitudes in beam waves by constructing a hydrodynamics model of a damaged ship based on the dynamic overlapping grid CFD *** general idea is to optimize various parameters varying with four types of classical base models like multi-layer perception,support vector regression,random forest,and hist gradient boosting *** offers several attractive properties in terms of accuracy and efficiency by choosing the standard DTMB 5415 model with double damaged compartments for *** is clearly demonstrated that the predicted response amplitude operator(RAO)in the regular beam waves agrees well with the experimental data available,which verifies the accuracy of the established damaged ship hydrodynamics *** high-quality CFD samples,therefore,implementation of the designed Stacking algorithm with its optimal combination can predict the damaged ship roll motion amplitudes effectively and accurately(e.g.,the coefficient of determination 0.9926,the average absolute error 0.0955 and CPU 3s),by comparison of four types of typical base models and their various ***,the established Stacking algorithm provides one potential that can break through problems involving the time-consuming and low efficiency for large-scale lengthy CFD simulations.

关键词： Ship motion damaged ship computational fluid dynamics(CFD) machine learning stacking algorithm

Precise immobilization of metal single atoms into a porphyrinic metal-organic framework for an efficient alkene hydrosilylation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2024年第7期17卷 5914-5921页

作者： Chun-Ying Chen Qi-Jie Mo fu-Zhen li Hai-li Song li Zhang MOE Laboratory of Bioinorganic and Synthetic Chemistry Lehn Institute of Functional MaterialsSchool of ChemistrySun Yat-Sen UniversityGuangzhou 510006China

Alkene hydrosilylation is one of the most concise and atom-economical methods to synthesize organosilicon ***,we reported the precise immobilization of metal single atoms(M-SAs;M=Ru,Rh,Ir,Pd,Pt,and Au)into a porphyrinic metalorganic framework(MOF)of PCN-222(PCN=porous coordination network),and then applied the resultant MOF composites of M-SAs@PCN-222 to alkene *** solvent-free conditions,Pt-SAs@PCN-222 displayed an especially high catalytic efficiency with the turnover frequency up to 119 s−1 and the maximum turnover number of 906,250 at room *** and theoretical studies revealed that there existed strong interactions between Pt-SAs@PCN-222 and the substrates,which helped to condense the substrates in the cavities of the porous *** density functional theory calculations and molecular dynamics simulations disclosed that PCN-222 could transfer electrons to Pt-SAs to enhance the silane oxidative addition and drive the reaction to proceed smoothly via Chalk–Harrod pathway.

关键词： alkene hydrosilylation single atom catalysts metal-organic frameworks precision chemistry synergistic catalysis