检索结果-南通市图书馆

Experimental Study on Measurement and Calculation of Heat Flux in Supersonic Combustor of Scramjet

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 Thermal Science 2015年第3期24卷 254-259页

作者： ZHANG Cong YAO Zhanli QIN jiang bao Wen Harbin Institute of Technology

An experimental measurement and calculation method which consist of thermal response model, convergence criteria and control algorithms, is proposed in this paper for the determination of heat flux in a scramjet combus- tot. Numerical simulations are done to evaluate the effectiveness of the proposed method, and experiments are made in the direct-connect hydrocarbon fueled scramjet combustor of Mach-6 flight for different equivalence ra- tios. The distribution of heat flux along the axial and circumferential directions can be obtained using the pro- posed method. The distribution of heat flux is uneven which is caused by the aerodynamic heating, combustion heat release and changes of section area, and the peak heat flux can be more than 2MW/m^2 during the experi- ments. Heat flux increases with the increase in equivalence ratio for the same Mach number. And axial distribu- tion of heat flux is uniform for different equivalence ratios. In addition, the combustion heat release area of the combustion chamber can therefore be concluded which is useful for guiding the structural design of the thermal protection system.

关键词： Scramjet Heat flux Thermal response model Thermal protection

A Study on the Physical Properties of Banana Straw Based on the Discrete Element Method

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2023年第5期19卷 1159-1172页

作者： sen Zhang Jie jiang Yuedong Wang School of Mechanical and Electrical Engineering Kunming University of Science and TechnologyKunming650500China Engineering School of Honghe University Mengzi661199China Yunnan University Research Center of Mechatronics Technology and Applied Engineering of Plateau Agricultural Machinery Mengzi661199China Honghe Agricultural Machinery Research Institute Mengzi661199China

To improve the application of discrete element models(DEM)to the design of agricultural crushers,in this study a new highly accurate model is *** model takes into account the fiber structure,porous nature of the material and the leaf sheath coating *** experimental tests are conducted to determine the required“intrinsic”and basic contact parameters of the considered banana straw materials.A large number of bonding parameters are examined in relation to the particle aggregation model in order to characterize different actual banana *** the particle surface energy contact model,the viscosity characteristics of the crushed material are determined together with the related stacking angle(considered as the main response factor).Through single factor experiment analysis,it is found that when the surface energy is 0.9 J·m-2,the relative error between simulations and physical experiments is 5.288%.

关键词： Banana straw discrete element model contact model surface energy DEM

Three-dimensional forest foodscape in large herbivores’habitat based on UAV with LiDAR detection

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2024年第2期19卷 343-346页

作者： Heng bao Guangshun jiang College of Wildlife and Protected Area Northeast Forestry UniversityHarbinChina Feline Research Center of National Forestry and Grassland Administration HarbinChina Research Center for Northeast Asia Biodiversity Conservation HarbinChina

Traditionally,wildlife habitat research mainly extracts two-dimensional habitat ***,they live in three-dimensional space,and the three-dimensional structure of the forest ecosystem is an important factor affecting the composition of the mammal community(Fig.1a,b),and the three-dimensional structure of the forest also determines the behavior pattern of wildlife multidimensional habitat selection or use(Flaspohler et al.2010;Palminteri et al.2012;Müller et al.2014).For instance,forest structure determines the vertical distribution of annual edible shoots,fruits,or seed nuts resources in space,providing additional ecological niches for frugivores,rodents,and other species,and then leading to niche differentiation of wild animals in vertical space utilization,thus increasing species coexistence(*** et al.2023).

关键词： habitat forest dimensional

Variation in egg and clutch size of the Black Redstart(Phoenicurus ochruros) at the northeastern edge of the Qinghai-Tibetan Plateau

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 Birds 2016年第4期7卷 218-223页

作者： sen Song Jiani Chen Bo jiang Naifa Liu School of Life Sciences Lanzhou University

Background: In birds, the trade-off between the quality and number of nestlings is one of the most important theories of the evolution of life history of birds, which is closely related with climate. We investigated variation in egg and clutch size of the Black Redstart(Phoenicurus ochruros) on the northeastern edge of the Qinghai-Tibetan Plateau in order to explore and test the relation between egg size and clutch size and the rules governing the variation in these two components with climate ***: We monitored each located nest daily to determine the exact laying order of the eggs and measured their sizes. The variations in egg volume and clutch size between 2008 and 2009 were studied by independent sample t tests. The difference in egg volume in the sequence of the laying order was tested by Kendall's W test and we employed Pearson correlations to investigate the relation between egg size and laying order. All statistical analyses were performed with IBM SPSS Statistics, version 19.0Results: In 2008, the mean egg volume of the Black Redstart was 2.40 and clutch size wer± 0.20 cm^3(n e 2.26 = 50), and the mean clutch size 4.90 ± 0.57(n = 11). In 2009, the mean egg volumeation between eg± 0.18 cm^3(n g size and layin= 74) and 5.20 g order(r ± 0.26(n = 15) respectively. We found a significantly positive correl, while egg size was strongly and negatively correlated with clutch size(r = 0.397, p = 0.030) smaller eggs but a larger clutch in a brood in a resource-rich year, w= h-0.274, p ereas large= 0.002). Black Redstarts tend to layr eggs but smaller clutches are produced in a harsh ***: The Black Redstart adopted a "brood survival strategy" to ensure that more offspring could survive. The Black Redstart' trade-off in egg volume and clutch size would guarantee that it will gain maximum benefit in any case.

关键词： Egg size Clutch size Laying order Trade-off Black Redstart Phoenicurus ochruros

Influence of cooling rate on magneto-structural transition and magnetocaloric effect of Ni_(30)Cu)8Co_(12)Mn_(37)Ga_(13) alloy

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2017年第7期24卷 711-717页

作者： Zhu-jun jiang Yu-ye Wu Jing-min Wang Cheng-bao jiang School of Materials Science and Engineering Beihang University School of Physics and Nuclear Energy Engineering Beihang University

The influence of heat treatment with different cooling rates on phase transition behaviors and magnetocaloric effect is systematically *** in atomic order is induced by changing cooling rates,where ordered phase is obtained in the furnace cooled（FC）sample while disordered phase is reserved in the water quenched（WQ）*** coupled magneto-structural transition is detected in both samples but the characteristic temperature significantly shifts to lower temperatures with increasing atomic *** magnetic entropy change（ΔS_（mag））derived from magnetic field induced martensitic transformation is confirmed for both samples,and can be remarkably enhanced by the atomic *** largestΔS_（mag） of 20.9J/（kg·K）is obtained at 307.5Kunder 5Tin the FC sample.

关键词： Ferromagnetic shape memory alloy Heat treatment Martensitic transformation Magnetocaloric effect Cooling rate Magneto-structural transition

Edge Effects on Growth of Ordered Stress Relief Patterns in Free Sustained Aluminum Films

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2010年第6期27卷 156-159页

作者： YU sen-jiang ZHANG Yong-Ju CHEN Miao-Gen Department of Physics China Jiliang University Hangzhou 310018 Department of Physics Taizhou University Linhai 317000 Department of Physics Zhejiang University Hangzhou 310027

An unusual form of ordered stress relief patterns is observed in a nearly free sustained aluminum film system deposited on liquid substrates by the therm^l evaporation method. The edge effects on the growth of the ordered patterns are systematically studied. It is found that the patterns initiate from the film edges, preexisting ordered patterns, or other imperfections of the film. When the patterns extend in the film regions, they decay gradually and finally disappear. If they develop along the boundaries, however, the sizes are almost unchanged over several millimeters. The stress relief patterns look like rectangular waves in appearance, which are proven to evolve from sinusoidal to triangular waves gradually. The morphological evolution can be well explained by the general theory of buckling of plates.

关键词： Packaging materials Films Stress

Spinless Excitons Implicit in SO(5) Theory

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2001年第11期36卷 623-624页

作者： jiang Yong-Jin TAO Rui-bao Surface Physics Laboratory Fudan UniversityShanghai 200433China Surface Physics LaboratoryFudan UniversityShanghai 200433China CCAST (World Laboratory) P.O.Box 8730Beijing 100080China

A pair of up-down operators are constructed explicitly for ***'s SO(5) theory of high Tc *** them two good quantum numbers are *** up-down operators are related to the spin-independent excitons which are not considere... 详细信息

关键词： high Tc superconductivity,SO(5) theory,Lie algebra,spinless exciton

Assembly of peptide nanostructures with controllable sizes

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1期17卷 151-161页

作者： Dan Cheng Fan Jia Yun-bao jiang Vincent P.Conticello Tao jiang The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China Department of Chemistry Emory UniversityAtlanta 30033USA

Controlled peptide assembly offers significant promise to develop synthetic supramolecular nanostructures to display material and biological properties that mimic protein assemblies in *** the progress in forming peptide nanostructures of various morphology,there exists a distinct gap between natural and synthetic assembly systems in terms of size *** nanostructures with a narrow size distribution that can be tuned over a wide range of length-scales is essential for applications that require precise spacing between *** approach provides the opportunity to correlate materials and biological properties of interest with assembly *** this review,we discuss representative endeavors over the past two decades for design of size-controllable peptide nanostructures using tunable building *** mechanisms for size control,e.g.,molecular frustration,template-directed peptide assembly,and multi-component peptide co-assembly,will also be *** also demonstrate the applicable scopes of these strategies and suggest potential future avenues for scientific advances in this field.

关键词： peptide assembly controllable size template multi-component

One-Dimensional Scanning of Electronic Wavefunction in Carbon Nanotubes by Molecular Encapsulation

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 Journal of Chemical Physics 2015年第6期28卷 -页

作者： Gui Ye Jun Li Ming-sen Deng Jun jiang Hefei National Laboratory for Physical Sciences at the Microscale Collaborative Innovation Center of Chemistry for Energy Materials School of Chemistry and Materials Science University of Science and Technology of China Hefei 230026 China Guizhou Provincial Key Laboratory of Computational Nano-Material Science Guizhou Normal College Guiyang 550018 China

On the basis of first-principles calculations, we have designed a novel type of molecular systems in which a single-walled carbon nanotube (SWNT) is encapsulated by acyclic CB[n]-type molecular container. The electronic structures and coherent electron transportation properties of the molecules were simulated at the density functional theory level. Due to the weak interactions between the inner SWNT and outer molecular container, the acyclic part can slide along the nanotube direction, which in turn effectively changes the electron tunneling ability through the SWNT. The dependences of tunneling conductance on the position of the acyclic container attached to the SWNT were examined, which reflect clearly a Bloch form distribution of molecular wavefunction along the nanotube direction. We thus proposes a convenient way to scan the one-dimensional electron wavefunction in carbon nanotubes.

关键词： Single-walled carbon nanotube Molecular container One-dimensional electron wavefunction distribution Density functional theory