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The Effect of Reflector with Sound-Absorbing Material on Supersonic Jet Noise

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Journal of Thermal Science 2005年第1期14卷 22-27页

作者： Y.-h.KWEON M.TSUChIDA Y.MIYAZATO T.AOKI h.-D.KIM T.SETOgUChI Department of Energy and Environmental Engineering Kyushu University Kasuga 816-8580Japan School of Mechanical Engineering Andong National University Andong 760-749Korea Department of Mechanical Engineering Saga University Saga 840-8502Japan

This paper describes an experimental work to investigate the effect of a reflector on supersonic jet noise radiated from a convergent-divergent nozzle with a design Mach number *** the present study,a metal reflector and reflectors made of three different sound-absorbing materials(grass wool and polyurethane foam)were employed,and the reflector size was *** measurement is carried out to obtain the acoustic characteristics such as frequency,amplitude of screech tone and overall sound pressure level(OASPL).A high-quality schlieren optical system is used to visualize the detailed structure of supersonic *** results obtained show that the acoustic characteristics of supersonic jet noise are strongly dependent upon the jet pressure ratio and the reflector *** is also found that the reflector with sound-absorbing material reduces the screech tone amplitude by about 5-13dB and the overall sound pressure levels by about 2-5dB,compared with those of the metal reflector.

关键词： supersonic jet supersonic jet noise screech tone OASPL reflector sound-absorbing material.

Convection–Diffusion Model for the Prediction of Anthropogenically-Initiated Wildfire Ignition

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International Journal of Disaster Risk Science 2014年第4期5卷 274-295页

作者： Ravi Sadasivuni Shanti Bhushan William h.Cooke Department of geosciences Mississippi State UniversityStarkvilleMS 39759USA Center for Advance Vehicular Systems Mississippi State UniversityStarkvilleMS 39759USA

A spatial interaction model to predict anthropogenically-initiated accidental and incendiary wildfire ignition probability is developed using fluid flow analogies for human movement patterns. Urban areas with large populations are identified as the sites of global influencing factors, and are modeled as the gravity term. The transportation corridors are identified as local influencing factors, and are modeled using fluid flow analogy as diffusion and convection terms. The model is implemented in ArcgIS, and applied for the prediction of wildfire hazard distribution in southeastern Mississippi. The model shows87 % correlation with historic data in the winter season,whereas the previously developed gravity model shows only 75 % correlation. The normalized error for convection–diffusion model predictions is about 5 % in the winter season, whereas the gravity model shows an error of 7 %.The proposed model is robust as it couples a multi-criteria behavioral pattern within a single dynamic equation to enhance predictive capability. At the same time, the proposed model is more costly than the gravity model as it requires evaluation of distance from intermodal transportation corridors, transportation corridor density, and traffic volume maps. Nonetheless, the model is developed in a modular fashion, such that either global or local terms can be neglected if required.

关键词： Anthropogenic-fire Convection–diffusion model Fire ignition potential Mississippi Wildfire hazard

Monotonicity and Best Approximation in Banach Lattices

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Acta Mathematica Sinica,English Series 2009年第5期25卷 785-794页

作者： Shu Tao ChEN Xin hE h. hUDZIK Department of Mathematics Harbin Normal University Harbin 150080 P. R. China Faculty of Mathematics and Computer Science Adam Mickiewicz University Umultowska 87 61-614 Poznan Poland

hudzik and Kurc discussed some best approximation problems in Banach lattices by means of monotonicities. This paper deals with more general best approximation problems in Banach lattices. Existence, uniqueness, stabi... 详细信息

关键词： Banach lattice uniform monotonicity strict monotonicity upper (lower) locally uniform monotonicity best approximation

Detailed Description of Mixed Symmetry States in ^94Mo Using Interacting Boson Model

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Communications in Theoretical Physics 2002年第6期37卷 699-705页

作者： F.h.Al－Khudair LONggui－Lu DepartmentofPhysics TsinghuaUniversityBeijing100084China

We have investigated the low-lying collective states and electromagnetic transitions in 94Mo within the framework of the interacting boson model. The influence of model parameters on the energy levels and electromagnetic properties has been investigated. The analysis of the obtained results and the parameter values predict that the 23+state is the lowest mixed symmetry state with pure F = Fmax - 1 in this nucleus. The calculated results predicate that the 25+ (two-Q-phonon) mixed symmetry state is closed to the J = 2+ at 2.870 MeV in the experimental data, and the 2.965 MeV state is the lowest mixed symmetry with J = 3+.

关键词：核物理 ^94Mo混合对称态相互作用玻色子模型

The Presence and Localization of Thioredoxins in Diatoms, Unicellular Algae of Secondary Endosymbiotic Origin

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Molecular Plant 2009年第3期2卷 468-477页

作者： Till Weber Ansgar gruber Peter g. Kroth Fachbereich Biologie Universitat Konstanz 78457 Konstanz Germany

Diatoms are unicellular algae of great ecological importance. So far, very little is known about the regulation of carbon fixation in these algae; however, there are strong indications that in diatom plastids, the ferredoxin/thioredoxin system might play a minor role in redox regulation of the photosynthetic reactions compared to land plants. Until now, it is unknown whether there are fewer or other target enzymes of thioredoxins in diatoms. Only a single potential target enzyme for thioredoxin, the plastidic fructose-l,6-bisphosphatase, has yet been identified. Nevertheless, during the annotation of the genome of the diatom Phaeodactylum tricornutum, we identified several genes encoding different thioredoxins. Utilizing in vivo expression of gFP：presequence fusion proteins in P. tricornutum, we were able to show that these thioredoxins are targeted either into plastids, mitochondria, or remain in the cytosol. Surprisingly, two of the three usually cytosolic thioredoxin h proteins are apparently plastid associated and, together with a thioredoxin reductase, putatively located in the periplastidic compartment. This is one of the few indications for so far unknown enzymatic reactions in the space between the two pairs of diatom plastid envelope membranes.

关键词： Carbohydrate metabolism enzymology genomics diatoms and phytoplankton

Predicting Soil Moisture Characteristic Curves from Continuous Particle-Size Distribution Data

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Pedosphere 2013年第1期23卷 70-80页

作者： M.h.MOhAMMADI F.MESKINI-VIShKAEE Department of Soil Science Faculty of Agriculture University of Zanjan

Soil moisture characteristic curve （SMC） is a fundamental soil property and its direct measurement is tedious and time consuming. Therefore, various indirect methods have been developed to predict SMC from particle-size distribution （PSD）. however, the majority of these methods often yield intermittent SMC data because they involve estimating individual SMC points. The objectives of this study were 1） to develop a procedure to predict continuous SMC from a limited number of experimental PSD data points and 2） to evaluate model predictions through comparisons with measured values. In this study, an approach that allowed predicting SMC from the knowledge of PSD, parameterized by means of the closed-form van genuchten model （Vg）, was used. Through using Mohammadi and Vanclooster （MV） model, the parameters obtained from fitting of Vg to PSD data were applied to predict SMC curves. Since the residual water content （Or） could not be obtained through fitting of Vg-MV integrated model to PSD data, we also examined and compared four different methods estimating 0r. Results showed that the proposed equation （MV-Vg integrated model） provided an excellent fit to all the PSD data and the model could adequately predict SMC as measured in forty-two soils sampled from different regions of Iran. For all soils, the method in which Or Was obtained through parameter optimization procedure provided the best overall predictions of SMC. The two methods estimating Or with Campbell and Shiozawa （CS） model resulted in less accuracy than the optimization procedure. Furthermore, the proposed model underestimated the moisture content in the dry range of SMC when the value of 0r was assumed to equal zero. 0r could be attributed to the incomplete desorption of water coated on soil particles and the accurate estimation of 0r was critical in prediction of SMC, especially for fine-textured soils at high suction heads. It could be concluded that the advantages of our approach were the continuity, rob

关键词： fine-textured soils modeling residual water content soil hydraulic properties van genuchten model

Teleportation with Multiple Accelerated Partners

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Communications in Theoretical Physics 2015年第9期64卷 287-294页

作者： A.Sagheer h.hamdoun N.Metwally Department of Computer Science Faculty of Computer Science and Information Technology King Faisal University Center for Artificial Intelligence and RObotics (CAIRO) Faculty of Science Aswan University Department of Mathematics College of Science University of Bahrain

As the current revolution in communication is underway, quantum teleportation can increase the level of security in quantum communication applications. In this paper, we present a quantum teleportation procedure that capable to teleport either accelerated or non-accelerated information through different quantum channels. These quantum channels are based on accelerated multi-qubit states, where each qubit of each of these channels represents a ***, these states are the W state, greenberger–horne–Zeilinger(ghZ) state, and the ghZ-like state. here, we show that the fidelity of teleporting accelerated information is higher than the fidelity of teleporting non-accelerated information, both through a quantum channel that is based on accelerated state. Also, the comparison among the performance of these three channels shows that the degree of fidelity depends on type of the used channel, type of the measurement, and value of the acceleration. The result of comparison concludes that teleporting information through channel that is based on the ghZ state is more robust than teleporting information through channels that are based on the other two states. For future work, the proposed procedure can be generalized later to achieve communication through a wider quantum network.

关键词： non-inertial frames entanglement acceleration

Analytic Results in the Position-Dependent Mass Schrdinger Problem

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Communications in Theoretical Physics 2013年第12期60卷 642-650页

作者： M.S.Cunha h.R.Christiansen grupo de Física Teórica State University of Cear(UECE) State University Vale do Acaraú

We investigate the Schr6dinger equation for a particle with a nonuniform solitonic mass density. First, we discuss in extent the （nontrivial） position-dependent mass V（x） = 0 case whose solutions are hypergeometric functions in tanh2 x. Then, we consider an external hyperbolic-tangent potential. We show that the effective quantum mechanical problem is given by a heun class equation and find analytically an eigenbasis for the space of solutions. We also compute the eigenstat, es for a potential of the form V （x） = Vo sinh2 z.

关键词： Schr6dinger equation position-dependent mass heun equation

Study of depth-dependent tetragonal distortion of quaternary AlIngaN epilayer by Rutherford backscattering/channeling

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Chinese Physics B 2010年第8期19卷 563-566页

作者： g.husnain 陈田祥法涛姚淑德 State Key Laboratory of Nuclear Physics and Technology Peking University

A 240-nm thick Al0.4In0.02ga0.58N layer is grown by metal organic chemical vapour deposition, with an over 1-μm thick gaN layer used as a buffer layer on a substrate of sapphire （0001）. Rutherford backscattering and channeling are used to characterize the microstructure of AlIngaN. The results show a good crystalline quality of AIIngaN （χmin = 1.5%） with gaN buffer layer. The channeling angular scan around an off-normal {1213} axis in the {1010} plane of the AlIngaN layer is used to determine tetragonal distortion eT, which is caused by the elastic strain in the AIIngaN. The resulting AlIngaN is subjected to an elastic strain at interracial layer, and the strain decreases gradually towards the near-surface layer. It is expected that an epitaxial AlIngaN thin film with a thickness of 850 nm will be fully relaxed （^eT = 0）.

关键词： Ⅲ-Ⅴ semiconductors Rutherford backscattering and channeling tetragonal distortion