检索结果-南通市图书馆

Effect of operational and geometric parameters on the hydrodynamics of a Wurster coater:A cFD-DEM study

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第2期85卷 62-76页

作者： Yinqiang Song Tuo Zhou Ruiqi Bai man Zhang Hairui Yang Department of Energy and Power Engineering Tsinghua UniversityBeijing100084China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Tsinghua UniversityBeijing100084China State Key Laboratory of Power System and Generation Equipment Tsinghua UniversityBeijing100084China

A coupled cFD-DEM method was used to study the hydrodynamics of a Wurster ***,the cFD part of the model was validated by the accurate prediction of the pressure drops over a pseudo-2D fluidized bed under various gas *** effect of gas velocity,gap height,tube length and batch volume of the particles on the cycle time and the residence time of the particles was thoroughly *** central jet gas velocity ui was found to speed up the particle cycle but undermine the coating *** gas velocity at the horizontal transport zone u2 was able to promote the horizontal transport of the particles but should not be too high,otherwise,it would obstruct the normal falling back of the particles in the downward *** gap heights would decrease the coating efficiency but tube length had little impact on *** increment of batch volume would commonly abase the cycle time and the working efficiency under a given *** de-fluidization problem arose when the batch volume increased to 550 ***,this problem could be swept out by the optimization of u1 and *** a mixture of different sizes,the coarse particles enjoyed higher coating efficiency and could travel closer to the *** may shield the fine particles from getting enough coating liquids,and thus coarse particles and fine particles were not recommended to get coated in the same batch.

关键词： Numerical simulation cFD-DEM Wurster coater Hydrodynamics cycle time Residence time

A phylogenetic approach identifies patterns of beta diversity and floristic subregions of the Qinghai-Tibet Plateau

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

Plant Diversity 2024年第1期46卷 59-69页

作者： Haibin Yu man Yang Zixin Lu Weitao Wang Fangyuan Yu Yonghua Zhang Xue Yin Hongjun Yu Junjie Hu David c.Deane Key Laboratory of conservation and Application in Biodiversity of South china School of Life SciencesGuangzhou UniversityGuangzhou 510006China School of Ecology Sun Yat-Sen UniversityShenzhen 510275China School of Geography and Remote Sensing Guangzhou UniversityGuangzhou 510006China college of Life and Environmental Science Wenzhou UniversityWenzhou 325035China centre for Future Landscapes and Department of Environment and Genetics La Trobe UniversityBundooraVIC 3083Australia

Patterns of taxonomic and phylogenetic beta diversity and their relationships with environmental correlates can help reveal the origin and evolutionary history of regional *** Qinghai-Tibet Plateau(QTP)harbors an exceptionally diverse flora,however,a phylogenetic perspective has rarely been used to investigate its beta diversity and floristic *** this study,we used a phylogenetic approach to identify patterns of beta diversity and quantitatively delimit floristic regions on the Qinghai-Tibet *** also examined the relationships between multifaceted beta diversity,geographical distance,and climatic difference,and evaluated the relative importance of various factors(i.e.,climate,topography and history)in shaping patterns of beta diversity.Sørensen dissimilarity indices indicated that patterns of species turnover among sites dominated the *** also found that patterns of both taxonomic and phylogenetic beta diversity were significantly related to geographical distance and climatic *** environmental factors that contributed most to these patterns of beta diversity include annual precipitation,mean annual temperature,climatic gradients and climatic *** dendrograms of dissimilarity and non-metric multidimensional scaling ordination based on phylogenetic beta diversity data identified ten floristic subregions in the *** results suggest that the contemporary environment and historical climate changes have filtered species composition among sites and eventually determined beta diversity patterns of plants in the QTP.

关键词： Biogeographical regionalization Phylogenetic beta diversity Seed plants Sørensen dissimilarity Qinghai-Tibet Plateau

V0405 Dra:A New Deep and Low Mass Ratio contact Binary with Extremely Fast Decrease in the Orbital Period

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第6期24卷 287-293页

作者： chao-Yue Li Lin-Qiao Jiang Jie Zheng Yi-man Liu Xiao-Yu Long Min Sun Han-Lu Zhang Xiao-man Tian School of Science Leshan Normal UniversityLeshan 614000China center for Applied Optics Research Leshan Normal UniversityLeshan 614000China Key Laboratory of Detection and Application of Space Effect in Southwest Sichuan Leshan 614000China cAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Aeronautics Shandong Jiaotong UniversityJinan 250000China

V0405 Dra is a W UMa-type binary *** on the TESS data,we have conducted an orbital period study and performed a light curve analysis for the *** orbital period study reveals that the O-c curve for V0405 Dra exhibits secular decrease at an extremely high rate of d P/dt=-2.71×10^(-6)day year^(-1),along with periodic variations characterized by an amplitude of A_(3)=0.0032 day and a period of P_(3)=1.413 *** orbital periodic change is possibly due to the light-travel time effect resulting from an additional third body in the system,for which we estimate a minimum mass of M_(3)=0.77M_(⊙).By employing the 2013 version of the Wilson-Devinney(W-D)method to synthesize a light curve,we derived photometric solutions indicating that V0405 Dra is a new deep(f=68.7%)and low-mass ratio(q=0.175)contact *** fast decrease in its orbital period is likely caused by mass transfer from the more massive primary star to the less massive secondary star,or due to angular momentum *** further mass transfer and loss of angular momentum,the binary will gradually evolve into a tighter contact configuration,eventually leading to a merger into a single star,following the evolutionary paths suggested for such deep and low mass ratio contact binaries.

关键词： (stars:)binaries(including multiple):close (stars:)binaries:eclipsing stars:individual(V0405 Dra)

Robust reinforcement learning with UUB guarantee for safe motion control of autonomous robots

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2024年第1期67卷 172-182页

作者： ZHANG RuiXian HAN YiNing SU man LIN ZeFeng LI HaoWei ZHANG LiXian School of Astronautics Harbin Institute of TechnologyHarbin 150001China School of management Harbin Institute of TechnologyHarbin 150001China Beijing Institute of Tracking and Telecommunication Technology Beijing 100094China

This paper addresses the issue of safety in reinforcement learning(RL)with disturbances and its application in the safety-constrained motion control of autonomous *** tackle this problem,a robust Lyapunov value function(rLVF)is *** rLVF is obtained by introducing a data-based LVF under the worst-case disturbance of the observed *** the rLVF,a uniformly ultimate boundedness criterion is *** criterion is desired to ensure that the cost function,which serves as a safety criterion,ultimately converges to a range via the policy to be ***,to mitigate the drastic variation of the rLVF caused by differences in states,a smoothing regularization of the rLVF is *** train policies with safety guarantees under the worst disturbances of the observed states,an off-policy robust RL algorithm is *** proposed algorithm is applied to motion control tasks of an autonomous vehicle and a cartpole,which involve external disturbances and variations of the model parameters,*** experimental results demonstrate the effectiveness of the theoretical findings and the advantages of the proposed algorithm in terms of robustness and safety.

关键词： motion control reinforcement learning robustness stability

A universal cooperative assembly-oriented strategy for VS_(4) nanorod decoration on carbon nanostructures with enhanced magnesium storage properties

在线全文

学校读者我要写书评

暂无评论

Science china chemistry 2024年第9期67卷 3153-3161页

作者： Yuehua man An Li Haowei Tang Jianlu Sun Yating Fei Yichen Du Xiaosi Zhou School of chemistry and Materials Science Nanjing Normal UniversityNanjing 210023China

VS_(4) has a unique layered atomic chain structure and has the potential to become a high-performance cathode material of magnesium-ion batteries with a high capacity and long cycle ***,low conductivity and sluggish Mg^(2+)diffusivity during cycling limit its practical application in large-scale energy ***,a cooperative assembly-directed strategy is adopted to synthesize VS_(4) nanorods grown in situ on carbon nanotubes(cNTs/VS_(4)).VS_(4) nanorods are tightly anchored to cNTs through V-O-c interface covalent bonds,and cNTs can enhance the electronic conductivity of the *** addition,the ion insertion reaction using Mg^(2+)and Mg cl^(+)as carriers reduces the polar barrier for divalent Mg^(2+)ion *** rationally designed architecture promotes ion diffusion and electron transfer,thus facilitating reaction *** cooperative assembly-oriented strategy can endow cNTs/VS_(4) with excellent magnesium storage properties,including a high reversible capacity of 223.2 m Ah g^(-1)at a current density of 50 m A g^(-1),a remarkable discharge capacity of 91.8 m Ah g^(-1)even at 2,000 m A g^(-1),and an impressive capacity retention of 85.2% after 1,000 cycles at 500 m A g^(-1).Moreover,this strategy can serve as a general synthetic method for the complexation of VS_(4) with other carbon nanostructures.

关键词： transition metal sulfides carbon nanostructure interfacial covalent bond magnesium-ion batteries cathode

The medium-temperature dependence of jet transport coefficient in high-energy nucleus-nucleus collisions

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第7期35卷 173-191页

作者： man Xie Qing-Fei Han En-Ke Wang Ben-Wei Zhang Han-Zhong Zhang Key Laboratory of Atomic and Subatomic Structure and Quantum control(MOE) Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of MatterInstitute of Quantum Matter South China Normal UniversityGuangzhou510006China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Guangdong Provincial Key Laboratory of Nuclear ScienceSouthern Nuclear Science Computing CenterSouth China Normal UniversityGuangzhou 510006China Key Laboratory of Quark and Lepton Physics(MOE)and Institute of Particle Physics Central China Normal UniversityWuhan430079China

The medium-temperature T dependence of the jet transport coefficient̂q was studied via the nuclear modification factor RAA(p_(T))and elliptical flow parameter v_(2)(p_(T))for large transverse momentum p_(T) hadrons in high-energy nucleus-nucleus *** a next-to-leading-order perturbative QcD parton model for hard scatterings with modified fragmentation functions due to jet quenching controlled by q,we check the suppression and azimuthal anisotropy for large p_(T) hadrons,and extract q by global fits to RAA(pT)and v_(2)(pT)data in A+A collisions at RHIc and LHc,*** numerical results from the best fits show that q∕T^(3) goes down with local medium-temperature T in the parton jet *** with the case of a constant q∕T^(3),the going-down T dependence of q∕T^(3) makes a hard parton jet to lose more energy near T_(c) and therefore strengthens the azimuthal anisotropy for large pT *** a result,v_(2)(p_(T))for large pT hadrons was enhanced by approximately 10%to better fit the data at RHIc/*** the first-order phase transition from QGP to the hadron phase and the additional energy loss in the hadron phase,v_(2)(p_(T))is again enhanced by 5-10%at RHIc/LHc.

关键词： Jet quenching Jet transport parameter Hadron suppression Elliptic flow coefficient Energy loss asymmetry

Synergistic Ru/RuO_(2) heterojunctions stabilized by carbon coating as efficient and stable bifunctional electrocatalysts for acidic overall water splitting

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第8期17卷 6931-6939页

作者： man Wu Yuying Fan Yang Huang Dongxu Wang Ying Xie Aiping Wu chungui Tian Key Laboratory of Functional Inorganic Material chemistry Ministry of Education of the People’s Republic of ChinaHeilongjiang UniversityHarbin 150080China

The development of highly active and stable acidic water oxidation electrocatalysts is of great significant for promoting the industrial application of proton exchange membrane ***-based catalysts have broad application prospects in acidic water oxidation,but their limitations in stability and activity hinder their further ***,a nitrogen-doped carbon(Nc)coated porous Ru/RuO_(2) heterojunctional hollow sphere(Ru/RuO_(2)/Nc)is designed as high-active and stable bifunctional electrocatalyst for acidic oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).In synthesis,the key is to use mesoporous polydopamine spheres as a template for forming hollow spheres,a source of Nc coating and a reducing agent for forming Ru/RuO_(2) *** Ru/RuO_(2) heterojunction adjusts the electronic structure of Ru active sites,optimizing the adsorption of intermediate ***,the Nc coating and the interaction between Nc and Ru/RuO_(2) effectively prevent Ru from over-oxidation and *** porous hollow structure provides more exposed active sites and promotes mass ***,Ru/RuO_(2)/Nc exhibits outstanding OER and HER performance with low overpotentials of 211 and 32 mV at 10 mA·cm^(−2),respectively,and shows excellent *** acid water splitting electrolyzer,based on the bifunctional Ru/RuO_(2)/Nc,requires low cell voltages of 1.46 and 1.76 V at 10 and 100 mA·cm^(−2),respectively,with good stability for over 100 h operation,surpassing Pt/c||RuO_(2) and most of the reported catalysts.

关键词： hollow heterojunction bifunctional electrocatalysts oxygen evolution hydrogen evolution acidic water splitting

Higher-dimensional chen-Lee-Liu equation and asymmetric peakon soliton

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4期33卷 224-229页

作者：韩巧红贾曼 School of Physical Science and Technology Ningbo UniversityNingbo 315211China

Integrable systems play a crucial role in physics and *** particular,the traditional(1+1)-dimensional and(2+1)-dimensional integrable systems have received significant attention due to the rarity of integrable systems in higher *** studies have shown that abundant higher-dimensional integrable systems can be constructed from(1+1)-dimensional integrable systems by using a deformation *** we establish a new(2+1)-dimensional chen-Lee-Liu(c-L-L)equation using the deformation algorithm from the(1+1)-dimensional c-L-L *** new system is integrable with its Lax pair obtained by applying the deformation algorithm to that of the(1+1)-*** is challenging to obtain the exact solutions for the new integrable system because the new system combines both the original c-L-L equation and its reciprocal *** traveling wave solutions are derived in implicit function expression,and some asymmetry peakon solutions are found.

关键词： higher dimensional chen-Lee-Liu equation Lax integrable system deformation algorithm implicit traveling wave solutions

Flame-retardant ammonium polyphosphate/MXene decorated carbon foam materials as polysulfide traps for fire-safe and stable lithium-sulfur batteries

在线全文

学校读者我要写书评

暂无评论

Journal of Energy chemistry 2024年第2期89卷 313-323,I0008页

作者： Yang Li Yong-cheng Zhu Sowjanya Vallem man Li Seunghyun Song Tao chen Long-cheng Tang Joonho Bae Department of Physics Gachon UniversitySeongnam-siGyeonggi-do 13120South Korea Key Laboratory of Organosilicon chemistry and Material Technology of Ministry of Education College of MaterialChemistry and Chemical EngineeringHangzhou Normal UniversityHangzhou 311121ZhejiangChina Key laboratory of Advanced Energy Materials chemistry(Ministry of Education) College of ChemistryNankai UniversityTianjin 300071China School of Materials Engineering Changzhou Vocational Institute of Industry TechnologyChangzhou 213164JiangsuChina

Lithium-sulfur(Li-S)batteries are one of the most promising modern-day energy supply systems because of their high theoretical energy density and low ***,the development of high-energy density Li-S batteries with high loading of flammable sulfur faces the challenges of electrochemical performance degradation owing to the shuttle effect and safety issues related to fire or explosion *** this work,we report a three-dimensional(3D)conductive nitrogen-doped carbon foam supported electrostatic self-assembled MXene-ammonium polyphosphate(NcF-MXene-APP)layer as a heat-resistant,thermally-insulated,flame-retardant,and freestanding host for Li-S batteries with a facile and costeffective synthesis ***,through the use of NcF-MXene-APP hosts that strongly anchor polysulfides,the Li-S batteries demonstrate outstanding electrochemical properties,including a high initial discharge capacity of 1191.6 mA h g^(-1),excellent rate capacity of 755.0 mA h g^(-1)at 1 c,and long-term cycling stability with an extremely low-capacity decay rate of 0.12%per cycle at 2 *** importantly,these batteries can continue to operate reliably under high temperature or flame attack ***,this study provides valuable insights into the design of safe high-performance Li-S batteries.

关键词： Flame-retardant MXene Ammonium polyphosphate Safety Lithium-sulfur battery