检索结果-南通市图书馆

Unveiling the Re,Cr,and I diffusion in saturated compacted bentonite using machine-learning methods

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第6期35卷 65-77页

作者： Zheng-Ye Feng Jun-Lei Tian Tao Wu Guo-Jun Wei Zhi-Long Li Xiao-Qiong Shi Yong-Jia Wang Qing-Feng Li department of engineering Huzhou UniversityHuzhou 313000China Institute of Theoretical physics Shanxi UniversityTaiyuan 030006China college of physics Science and Technology Shenyang Normal UniversityShenyang 110034China

The safety assessment of high-level radioactive waste repositories requires a high predictive accuracy for radionuclide diffusion and a comprehensive understanding of the diffusion *** this study,a through-diffusion method and six machine-learning methods were employed to investigate the diffusion of ReO_(4)^(−),HCrO_(4)^(−),and I−in saturated compacted bentonite under different salinities and compacted dry *** machine-learning models were trained using two *** dataset contained six input features and 293 instances obtained from the diffusion database system of the Japan Atomic Energy Agency(JAEA-DDB)and 15 *** other dataset,comprising 15,000 pseudo-instances,was produced using a multi-porosity model and contained eight input *** results indicate that the former dataset yielded a higher predictive accuracy than the *** gradient-boosting exhibited a higher prediction accuracy(R2=0.92)and lower error(MSE=0.01)than the other machine-learning *** addition,Shapley Additive Explanations,Feature Importance,and Partial Dependence Plot analysis results indicate that the rock capacity factor and compacted dry density had the two most significant effects on predicting the effective diffusion coefficient,thereby offering valuable insights.

关键词： Machine learning Effective diffusion coefficient Through-diffusion experiment Multi-porosity model Global analysis

Doping engineering of iron oxide nanoparticles towards high performance and biocompatible T_(1)-weighted MRI contrast agents

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第1期43卷 298-308页

作者： Xue Xu Ping-Li Dong Yu-Yun Chai Run Yang Zhen-Hui Ma Chi-Chong Lu department of Chemistry College of Chemistry and Materials EngineeringBeijing Technology and Business UniversityBeijing 100048China department of physics Beijing Technology and Business UniversityBeijing 100048China

Extremely small-sized iron oxide nanoparticles(IONPs) are of great interest in magnetic resonance imaging(MRI) due to their biosafety as an alternative to clinical gadolinium(Ⅲ) complexes-based contrast *** when the particle size is less than 10 nm,it has strong diffusion ability and deep penetration distance in tumor *** doping can significantly enhance the T_(1)contrast effect of nanoparticles by regulating the surface exposed ***,the nucleation and growth processes of multi-component synthesis systems are complex and difficult to be accurately controlled,leading to great challenges in the synthesis of ultra-small-sized nanoparticles with different components and ***,extremely smallsized superparamagnetic gadolinium-doped iron oxide nanoparticles(GdIONPs,Gd_(x)Fe_(3-x)O_(4) NPs) with adjustable doping amount and controllable size in the range of 3.5-7.5 nm were synthesized by thermal ***,as-synthesized GdIONPs were surface modified with a highly water-soluble and biocompatible carboxyl-polyethylene glycol-phosphoric acid ligand with high binding ***_(0.65)Fe_(2.35)O_(4) NPs exhibited very high r_(1) relaxivity of 10.6 mmol^(-1)·L·s^(-1) in terms of all metal concentrations and 49.0 mmol^(-1)·L·s^(-1) in terms of gadolinium alone,respectively,3 and 14 times higher than clinical T_(1) contrast agents(Gd-DTPA).GdIONPs can continuously obtain high resolution images of blood vessels,and can be used as an efficient and multifunctional contrast agent for MR T_(1)*** stable and efficient doping strategy provides an easy and effective method to individually optimize the magnetic properties of complex oxides and their relaxation effects for a variety of biomedical applications.

关键词： Iron oxide nanoparticles Small size Magnetic resonance imaging Substitutional doping Gd dopant

A novel diurnal and seasonal variation analysis of BTEX in Bengaluru urban area

在线全文

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2024年第1期16卷 14-19页

作者： H.N.Sowmya M.Dinamani G.P.Shivashankara H.K.Ramaraju B.S.Surendra Vijaya V.Shanbhag R.Prajwal department of Civil engineering Dayananda Sagar College of EngineeringBangalore 560078India department of Chemistry Dayananda Sagar College of EngineeringBangalore 560078India department of physics GFGCVijayanagarBengaluru 560040India

In the urban atmosphere of Bengaluru, various volatile organic compounds(VOCs), particularly Benzene,Toluene, Ethylbenzene, and Xylene(BTEX), have shown an increasing trend in concentration. The present research was conducted during summer and monsoon seasons, focusing on Kadubeesanahalli, a high-traffic area within the Bengaluru Metropolitan City. Hourly sample data was collected using a BTEX analyzer(Model GC955-600) and subsequently transformed into daily, monthly, and seasonal values. The study revealed distinct patterns in benzene concentrations. Benzene levels were lowest during the early morning hours, specifically from 1:00 *** 7:00 a.m.. Concentrations then increased from 7:00 a.m. to 9:00 a.m. and again from 4:00 p.m. to 11:00 p.m.,corresponding to the morning and evening peak traffic hours. However, between 10:00 a.m. and 4:00 p.m., the concentration decreased due to reduced traffic levels. These diurnal variations in benzene concentration are influenced by meteorological parameters. Comparing the two seasons, higher concentrations of Benzene, EthylBenzene, and MP-xylene were observed during the summer season. This increase is attributed to the elevated temperatures during summer, which promote the vaporization of BTEX compounds. Conversely, lower BTEX concentrations were recorded during the monsoon season due to the wet deposition process. The observed positive correlation(r > 0.5) among BTEX parameters strongly suggests a common source, most likely originating from vehicular emissions.

关键词： BTEX Summer variation Meteorological parameters Correlation

Automatic detection and assessment of crack development in ultra-high performance concrete in the spatial and Fourier domains

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil engineering 2024年第3期18卷 350-364页

作者： Jixing CAO Yao ZHANG Haijie HE Weibing PENG Weigang ZHAO Zhiguo YAN Hehua ZHU School of Safety engineering and Emergency management Shijiazhuang Tiedao UniversityShijiazhuang 050043China college of Civil engineering and Architecture Zhejiang UniversityHangzhou 310058China college of Civil and Architectural engineering Taizhou UniversityTaizhou 318000China college of Civil engineering and Architecture Zhejiang University of TechnologyHangzhou 310014China department of Geotechnical engineering Tongji UniversityShanghai 200092China

Automatic detection and assessment of surface cracks are beneficial for understanding the mechanical performance of ultra-high performance concrete(UHPC).This study detects crack evolution using a novel dynamic mode decomposition(DMD)*** this method,the sparse matrix‘determined’from images is used to reconstruct the foreground that contains cracks,and the global threshold method is adopted to extract the crack *** application of the DMD method to the three-point bending test demonstrates the efficiency in inspecting cracks with high ***,the geometric features,including the area and its projection in two major directions,are evaluated over *** relationship between the geometric properties of cracks and load-displacement curves of UHPC is *** to the irregular shape of cracks in the spatial domain,the cracks are then transformed into the Fourier domain to assess their *** indicate that crack patterns in the Fourier domain exhibit a distinct concentration around a central ***,the power spectral density of cracks exhibits an increasing trend over *** investigation into crack evolution in both the spatial and Fourier domains contributes significantly to elucidating the mechanical behavior of UHPC.

关键词： dynamic mode decomposition ultra-high performance concrete crack detection geometric features Fourier domain

Negative enthalpy alloys and local chemical ordering:a concept and route leading to synergy of strength and ductility

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第4期11卷 172-184页

作者： Zibing An Tao Yang Caijuan Shi Shengcheng Mao Lihua Wang Ang Li Wei Li Xianmeng Xue Ming Sun Yifan Bai Yapeng He Fuzeng Ren Zhouguang Lu Ming Yan Yang Ren Chain-Tsuan Liu Ze Zhang Xiaodong Han Beijing Key Lab of Microstructure and Property of Advanced Materials College of Materials Science &Engineering Beijing University of Technology department of Materials Science and engineering City University of Hong Kong Key Laboratory of Partial Acceleration physics& Technology Institute of High Energy PhysicsChinese Academy of Sciences department of Materials Science &engineering Southern University of Science and Technology department of physics City University of Hong Kong State Key Laboratory of Silicon Materials Department of Materials Science and Engineering Zhejiang University

Solid solutions are ubiquitous in metals and alloys. Local chemical ordering(LCO) is a fundamental sub-nano/nanoscale process that occurs in many solid solutions and can be used as a microstructure to optimize strength and ductility. However, the formation of LCO has not been fully elucidated, let alone how to provide efficient routes for designing LCO to achieve synergistic effects on both superb strength and ductility. Herein, we propose the formation and control of LCO in negative enthalpy alloys. With engineering negative enthalpy in solid solutions, genetic LCO components are formed in negative enthalpy refractory high-entropy alloys(RHEAs). In contrast to conventional ‘trial-and-error' approaches, the control of LCO by using engineering negative enthalpy in RHEAs is instructive and results in superior strength(1160 MPa) and uniform ductility(24.5%) under tension at ambient temperature, which are among the best reported so far. LCO can promote dislocation cross-slip, enhancing the interaction between dislocations and their accumulation at large tensile strains; sustainable strain hardening can thereby be attained to ensure high ductility of the alloy. This work paves the way for new research fields on negative enthalpy solid solutions and alloys for the synergy of strength and ductility as well as new functions.

关键词： negative enthalpy alloys local chemical ordering strength ductility dislocation

Rational molecular engineering towards efficient heterojunction solar cells based on organic molecular acceptors

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese physics B 2024年第6期33卷 575-587页

作者：张凯彦宋朋马凤才李源作 college of Materials Science and engineering Northeast Forestry UniversityHarbin 150040China college of Science Northeast Forestry UniversityHarbin 150040China department of physics Liaoning UniversityShenyang 110036China

The selection of photoactive layer materials for organic solar cells(OSCs) is essential for the photoelectric conversion *** is well known that chlorophyll is an abundant pigment in nature and is extremely valuable for ***,there is little research on how to improve the efficiency of chlorophyll-based OSCs by matching chlorophyll derivatives with excellent non-fullerene acceptors to form *** in this study we utilize a chlorophyll derivative,Ce_(6)Me_(3),as a donor material and investigate the performance of its heterojunction with acceptor *** density functional theory,the photoelectric performances of acceptors,i ncluding the fullerene derivative PC_(71)BM and the terminal halogenated non-fullerene DTBCIC series,are compared in *** is found that DTBCIC-C1 has better planarity,light absorption,electron affinity,charge reorganization energy and charge mobility than ***_(6)Me_(3) has good energy level matching and absorption spectral complementarity with the investigated acceptor molecules and also shows good electron donor ***,the designed Ce_(6)Me_(3)/DTBCIC interfaces have improved charge separation and reorganization rates(K_(CS)/K_(CR)) compared with the Ce_(6)Me_(3)/PC_(71)BM *** research provides a theoretical basis for the design of photoactive layer materials for chlorophyll-based OSCs.

关键词： organic solar cells density functional theory chlorophyll derivative non-fullerene acceptors

Multiplicity dependence of the freezeout parameters in high energy hadron-hadron collisions

在线全文

学校读者我要写书评

暂无评论

Chinese physics C 2024年第5期48卷 124-133页

作者： Muhammad Ajaz Majid Shehzad Muhammad Waqas Haifa I.Alrebdi Mohammad Ayaz Ahmad Antalov Jagnandan Shawn Jagnandan Murad Badshah Jalal Hasan Baker Abdul Mosawir Quraishi department of physics Abdul Wali Khan University MardanMardan 23200Pakistan School of Mathematics Physics and Optoelectronic EngineeringHubei University of Automotive TechnologyShiyan 442002China department of physics College of SciencePrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh 11671Saudi Arabia department of Mathematics Physics and StatisticsFaculty of Natural SciencesUniversity of Guyana101110 GeorgetownGuyananSouth America department of physics Faculty of ScienceUniversity of TabukTabukKingdom of Saudi Arabia department of Electrical engineering College of EngineeringQassim UniversityUnaizahSaudi Arabia

We examined the transverse momentum(pT)spectra of various identified particles,encompassing both light-flavored and strange hadrons(π++π−,K++K−,p+p¯,ϕ,K0s,Λ+Λ¯,Ξ−+Ξ¯+,andΩ−+Ω¯+),across different multiplicity classes in proton-proton collisions(p-p)at a center-of-mass energy of s√=7 *** the Tsallis and Hagedorn models,parameters relevant to the bulk properties of nuclear matter were *** models exhibit good agreement with experimental *** our analyses,we observed a consistent decrease in the effective temperature(T)for the Tsallis model and the kinetic or thermal freeze-out temperature(T0)for the Hagedorn model,as we transitioned from higher multiplicity(class-I)to lower multiplicity(class-X).This trend is attributed to the diminished energy transfer in higher multiplicity ***,we observed that the transverse flow velocity(βT)experiences a decline from class-I to *** normalization constant,which represents the multiplicity of produced particles,was observed to decrease as we moved toward higher multiplicity *** the effective and kinetic freeze-out temperatures,as well as the transverse flow velocity,show a mild dependency on multiplicity for lighter particles,this dependency becomes more pronounced for heavier *** multiplicity parameter for heavier particles was observed to be smaller than that of lighter particles,indicating a greater abundance of lighter hadrons compared to heavier *** particle species were observed to undergo decoupling from the fireball at distinct temperatures:lighter particles exhibit lower temperatures,while heavier ones show higher temperatures,thereby supporting the concept of multiple freeze-out ***,we identified a positive correlation between the kinetic freeze-out temperature and transverse flow velocity,a scenario where particles experience stronger collective motion at a higher freeze-out *** reason for this positive correlation is th

关键词： multiplicity dependence collective properties thermal energy

Parametric investigation on the novel and cost-effective nano fly ash impregnated geopolymer system for sustainable construction

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil engineering 2024年第2期18卷 170-183页

作者： R.MOHANA S.M.Leela BHARATHI department of Civil engineering Mepco Schlenk Engineering CollegeSivakasi 626123India

The hazardous environmental effects of greenhouse gas emissions and climate change demand alternative sources for cementitious materials in the construction *** development of geopolymer structures provides a way of producing 100%cement-free *** this research work,a novel and simple way of deriving nano particles from waste fly ash particles is *** effect of adding the synthesized nano fly ash particles as a filler medium in geopolymer mortars was investigated by considering strength and durability *** optimization was done by using regression analysis on the geopolymer mortar and the impact of adding nano fly ash particles was studied by varying different percentages of addition ranging from 0 to 7.5%by weight of binder *** the results,it was observed that 1%nano fly ash acted not only as a filler but also as nano-sized precursors of the polymerization process,resulting in denser geopolymer *** can explain the extraordinary gain in strength of 72.11 MPa as well as the denser core with negligible level of chloride ion penetration,making the material suitable for the development of structures susceptible to marine environment.

关键词： geopolymer nano fly ash chloride ion penetration durability polymerization fillers

GaInX_3(X=S,Se,Te):Ultra-low thermal conductivity and excellent thermoelectric performance

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese physics B 2024年第8期33卷 460-465页

作者：段志福丁长浩丁中科肖威华谢芳罗南南曾犟唐黎明陈克求 department of physics School of Physics and ElectronicsHunan UniversityChangsha 410082China college of Physical Science and engineering Technology Yichun UniversityYichun 336000China

Seeking intrinsically low thermal conductivity materials is a viable strategy in the pursuit of high-performance thermoelectric ***,by using first-principles calculations and semiclassical Boltzmann transport theory,we systemically investigate the carrier transport and thermoelectric properties of monolayer Janus GaInX_(3)(X=S,Se,Te).It is found that the lattice thermal conductivities can reach values as low as 3.07 W·m^(-1)·K^(-1),1.16 W·m^(-1)·K^(-1)and 0.57 W·m^(-1)·K^(-1)for GaInS_(3),GaInSe_(3),and GaInTe_(3),respectively,at room *** notably low thermal conductivity is attributed to strong acoustic-optical phonon coupling caused by the presence of low-frequency optical phonons in GaInX_(3) ***,by integrating the charac teristics of electronic and thermal transport,the dimensionless figure of merit ZT can reach maximum values of 0.95,2.37,and 3.00 for GaInS_(3),GaInSe_(3),and GaInTe_(3),*** results suggest that monolayer Janus GaInX_(3)(X=S,Se,Te)is a promising candidate for thermoelectric and heat management applications.

关键词： thermoelectric performance thermal conductivity Boltzmann transport two-dimensional materials