检索结果-南通市图书馆

Phase structures of neutral dense quark matter and applicationto strange stars

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2022年第1期46卷 180-187页

作者： shu-sheng Xu School of Science Nanjing University of Posts and TelecommunicationsNanjing 210023China

In the contact interaction model,the quark propagator has only one solution,namely,the chiral symmetry breaking solution,at vanishing temperature and density in the case of physical quark *** generalize the condensate feedback onto the coupling strength from the 2 flavor case to the 2+1 flavor case,and find the Wigner solution appears in some regions,which enables us to tackle chiral phase transition as two-phase *** finite chemical potential,we analyze the chiral phase transition in the conditions of electric charge neutrality andβ*** four chemical potentials,μ_(u),μ_(d),μ_(s) and He,are constrained by three conditions,so that one inde-pendent variable remains:we choose the average quark chemical potential as the free *** quark masses and number densities suffer discontinuities at the phase transition *** strange quarks appear after the phase trans-ition since the system needg more energy to produce a d.-quark than an *** the EOS as an input,the TOV equations are solved numerically,and we show that the mass--radius relation is sensitive to the *** max-imum mass of strange quark stars is not susceptible to the parameter Aq we introduced.

关键词： chiral phase transition dense quark matter quark stars

An Online Fault Detection Model and Strategies Based on SVM-Grid in Clouds

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2018年第2期5卷 445-456页

作者： PeiYun Zhang sheng shu MengChu Zhou the School of Mathematics and Computer Science Anhui Normal UniversityWuhu 241003China Department of Electrical and Computer Engineering New Jersey Institute of TechnologyNewarkNJ 07102USA Renewable Energy Research Group King Abdulaziz UniversityJeddah21589Saudi Arabia IEEE

Online fault detection is one of the key technologies to improve the performance of cloud systems. The current data of cloud systems is to be monitored, collected and used to reflect their state. Its use can potentially help cloud managers take some timely measures before fault occurrence in clouds. Because of the complex structure and dynamic change characteristics of the clouds, existing fault detection methods suffer from the problems of low efficiency and low accuracy. In order to solve them, this work proposes an online detection model based on asystematic parameter-search method called SVM-Grid, whose construction is based on a support vector machine(SVM). SVM-Grid is used to optimize parameters in SVM. Proper attributes of a cloud system's running data are selected by using Pearson correlation and principal component analysis for the model. Strategies of predicting cloud faults and updating fault sample databases are proposed to optimize the model and improve its *** comparison with some representative existing methods, the proposed model can achieve more efficient and accurate fault detection for cloud systems.

关键词： Index Terms-Cloud computing fault detection support vectormachine (SVM) grid.

Influence of Combination of Casimir Force and Residual Stress on the Behaviour of Micro-and Nano-Electromechanical Systems

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2002年第6期19卷 832-834页

作者： Zheng Mao-sheng, Zhou Gen-shu State Key Laboratory for Mechanical Behavior of Materials Xi"an Jiaotong University

Casimir force and residual stresses actually appear in over-layers or films simultaneously. The study of the behaviour of micro- and nano-electromechanical systems in the presence of Casimir force and residual stress is of significance to the design of the relevant devices. We derive analytical expressions of the deflection of a bridge-shaped device under the mutual actions of Casimir force and residual stress in films. It is shown that the tensile residual stress enhances wavy behaviour of the deflection, while the compressive residual stress increases the deflection value and reduces the wavy behaviour.

关键词： tensile residual stress Residual stress compressive residual stress Nanoelectromechanical Systems Deflection micro Casimir effect Electromechanical systems

Θ-type Calderón-Zygmund Operators with Non-doubling Measures

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

Acta Mathematicae Applicatae Sinica 2013年第2期29卷 263-280页

作者： Ru-long XIE Li-sheng shu School of Mathematical Sciences University of Science and Technology of China Department of Mathematics Chaohu University Department of Mathematics Anhui Normal University

Let μ be a Radon measure on Rd which may be non-doubling. The only condition that μ must satisfy is μ（B（x,r）） ≤ Urn for all x∈Rd, r 〉 0 and for some fixed 0 〈 n 〈 d. In this paper, under this assumption, we prove that 0-type Calder6n-Zygmund operator which is bounded on L2 （μ） is also bounded from L^∞（μ） into RBMO （μ） and from Hb （μ） into L1（μ）. According to the interpolation theorem introduced by Tolsa, the LP（μ）-boundedness （1 〈 p 〈 ∞） is established for θ-type Calder6n-Zygmund operators. Via a sharp maximal operator, it is shown that commutators and multilinear commutators of θ-type CMderθn-Zygmundoperator with RBMO （μ） function are bounded on LP（μ）（1 〈 p 〈 ∞）.

关键词： non-doubling measure θ-type Calderón-Zygmund operator, commutators multilinear commuta-tors RBMO ( μ ) space H1,∞atb ( μ ) space

Density enhancement mechanism of upwind schemes for low Mach number flows

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2018年第3期34卷 431-445页

作者： Bo-Xi Lin Chao Yan shu-sheng Chen School of Aeronautic Science and Engineering Beihang University

Many all-speed Roe schemes have been proposed to improve performance in terms of low speeds. Among them, the F-Roe and T-D-Roe schemes have been found to get incorrect density fluctuation in low Mach flows, which is expected to be with the square of Mach number. Asymptotic analysis presents the mechanism of how the density fluctuation problem relates to the incorrect order of terms in the energy equation paU△U. It is known that changing the upwind scheme coefficients of the pressure-difference dissipation term DP and the velocity-difference dissipation term in the momentum equation DPU to the order of O （c- 1） and O（c0） can improve the level of pressure and velocity accuracy at low speeds. This paper shows that corresponding changes in energy equation can also improve the density accuracy in low speeds. We apply this modification to a recently proposed scheme, TV-MAS, to get a new scheme, TV-MAS2. Unsteady Gresho vortex flow, double shear-layer flow, low Mach number flows over the inviscid cylinder, and NACA0012 airfoil show that energy equation modification in these schemes can obtain the expected square Ma scaling of density fluctuations, which is in good agreement with corresponding asymptotic analysis. Therefore, this density correction is expected to be widely implemented into allspeed compressible flow solvers.

关键词： Energy equation Density fluctuation Roe TV-MAS Low speeds All speeds Computational fluid dynamics

Tomato yellow leaf curl virus infection of tomato does not affect the performance of the Q and ZHJ2 biotypes of the viral vector Bemisia tabaci

在线全文

学校读者我要写书评

暂无评论

Insect Science 2011年第1期18卷 40-49页

作者： Meng Li Jian Liu shu-sheng Liu Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects Institute of Insect Sciences Zhejiang UniversityHangzhou China

To better understand the etiology of begomovirus epidemics in regions under invasion we need to know how indigenous and invasive whitefly vectors respond to virus infection. We investigated both direct and indirect effects of infection with Tomato yellow leaf curl virus （TYLCV） on the performance of the invasive Q biotype and the indigenous Asian ZHJ2 biotype of whitefly Bemisia tabaci. The Q biotype performed better than the ZHJ2 biotype on either uninfected or virus-infected tomato plants. However, virus-infection of host plants did not, or only marginally affected, the performance of either biotype of whiteflies in terms of fecundity, longevity, survival, development and population increase. Likewise, association of the vectors with TYLCV did not affect fecundity and longevity of the Q or ZHJ2 biotypes on cotton, a non-host of TYLCV. These results indicate that the alien Q biotype whitefly, but not the indigenous ZHJ2 biotype, is likely to become the major vector of TYLCV in the field and facilitate virus epidemics.

关键词： Bemisia tabaci performance tomato Tomato yellow leaf curl virus virusinfection

Investigation on interface of NiFeCr/NiFe/Ta films with high magnetic field sensitivity

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

Rare Metals 2012年第1期31卷 22-26页

作者： sheng, shu Li, Wei Li, Minghua Yu, Guanghua Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China

NiFeCr/NiFe/Ta films with excellent performance were prepared by magnetron sputtering *** anisotropic magetoresistance (AMR) value (ΔR/R) and magnetic filed sensitivity (Sv,Sv=[d(ΔR/R)/dH]max.) for the 12 nm NiFe film deposited on NiFeCr buffer layer were 3.66% and 1.42×10-4%·T-1,*** higher Sv of the film is close to that of a spin valve (SV).The microstructure analysis shows that the NiFeCr buffer layer has adopted the same structure with the same interplanar distance as the NiFe layer,inducing a strong NiFe (111) texture,and that the NiFeCr/NiFe interface is quite smooth,leading to a high degree of specular reflection of conduction *** increase the ΔR and reduce the R in the film,which lead to the high ΔR/*** substrate surfaces are critical for preparation of high performance NiFeCr/NiFe/Ta films,and sputter cleaning or pre-deposition of 5 nm amorphous Al2O3 layer in the deposition chamber can provide the re-quired clean substrate surfaces for the growth of the buffer layer.

关键词： ultrathin NiFe films magnetic field sensitivity lattice matching

Synthesis and Characterization of Novel Thiosemicarbazones Bearing Sugar Moieties

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2006年第6期22卷 738-741页

作者： YANG Bo ZHANG shu-sheng LI Hui-xiang College of Chemistry and Molecular Engineering Qingdao University of Science and Technology Qingdao 266042 P. R. China

Six novel thiosemicarbazones containing sugar and thiosemicarbazide moieties were synthesized by a five-step procedure using D-galactose and D-xylose as the starting materials and the corresponding glycosyl isothiocyanates as the intermediates. The target compounds were characterized by IR, ^1H NMR, and elemental analysis. The coupliug constants between H1 and H2 in the sugar rings, all fail within the range of J = 9. 2-10.0 Hz, confirming the β-configuration of the compounds.

关键词： Thiosemicarbazone Sugar Synthesis Characterization

Different headspace profiles in wild crucifer species in response to Plutella xylostella herbivory and exogenous jasmonic acid application

在线全文

学校读者我要写书评

暂无评论

Insect Science 2010年第1期17卷 29-37页

作者： Peng-Jun Zhang Jin-Ping shu Marcel Dicke shu-sheng Liu Institute of Insect Sciences Zhejiang University Hangzhou China Laboratory of Entomology Wageningen University Wageningen The Netherlands

Although exogenous treatment of plants withjasmonic acid （JA） may result in induced responses similar to plant defences induced by herbivory, few studies have compared the details of insect herbivory and JA-mimicked responses. We compared volatiles of two crucifer species, Cardamine impatiens and Lepidium virginicum, in response to Plutella xylostella larval feeding and exogenous application of JA, over the entire period of time when induced changes were detectable. Significant differences in the composition and timing of volatiles occurred between herbivory and JA treatments in both plants. The quantity ofnitrile and isothiocyanate released in response to herbivory was significantly larger than that upon JA treatment. In each of the two plant species, most volatile components were emitted immediately upon larval feeding and their quantity dropped rapidly once feeding ceased. In contrast, the emission of volatiles in response to JA treatment lasted for a longer period of time, and the maximum emission rate was recorded 2 and 3 days after JA treatment in L. virginicum and C. impatiens respectively. These findings are discussed in the context of signal-transduction pathways and mechanisms involved in induced emissions of plant volatiles, as well as induced defences mediated by plant volatiles.

关键词： Brassicaceae herbivory induced response jasmonic acid Plutella xylostella volatile emission