1,833 research outputs found
Technology Review System of Water-Temperature Prediction for Reservoir Construction Project
AbstractIt is the important technical support for technology appraisal to establish technology review system of water-temperature prediction for reservoir construction project. In this study, the technical route, implementation method and process, the required basic data, and key issues were proposed for the water-temperature technology review. The realization of water-temperature technology review can provide technical guarantee for regulating the technical requirements on water temperature prediction in environment impact assessment (EIA) report. Technology review can also prevent arbitrariness in some EIA reports. Moreover technology review could resolve some experts doubts on the prediction result during the process of technology appraisal
Diaquabis{2-hydroxy-5-[(pyridin-2-yl)methylideneamino]benzoato-κ2 N,N′}zinc(II) dihydrate
The complex molecule of the title compound, [Zn(C13H9N2O3)2(H2O)2]·2H2O, has 2 symmetry with the ZnII cation located on a twofold rotation axis. The Zn cation is N,N′-chelated by two 5-[(pyridin-2-yl)methylideneamino]-2-hydroxybenzoate anions and coordinated by two water molecules in a distorted octahedral geometry. Within the anionic ligand, the pyridine ring is oriented at a dihedral angle of 49.54 (10)° with respect to the benzene ring. The carboxylate group of the anionic ligand is not involved in coordination but is O—H⋯O hydrogen bonded to the coordinated and uncoordinated water molecules. Weak intermolecular C—H⋯O hydrogen bonding is also present in the crystal structure
The top quark rare decays with flavor violation
In the present study, we investigate the decays of the top quark
, , and . They are extremely rare processes in the Standard Model (SM). As the
extension of the minimal supersymmetric standard model, the
SSM features new superfields such as the right-handed neutrinos and
three Higgs singlet states. We analyze the effects of different sensitivity
parameters on the results and make reasonable theorecial predictions useful for
future experimental developments. Considering the constraint of the updated
experimental data, the numerical results show that the branching ratios of all
four processes can reach the same order of
magnitude as their experimental upper limits. Among them, has the
most obvious effect on each process and is the main parameter. , ,
, , , and are important parameters
for the processes, and have effects on the numerical results.Comment: pages 22, figures 1
Variational-based data assimilation to simulate sediment concentration in the Lower Yellow River, China
The heavy sediment load of the Yellow River makes it difficult to simulate sediment concentration using classic numerical models. In this paper, on the basis of the classic one-dimensional numerical model of open channel flow, a variational-based data assimilation method is introduced to improve the simulation accuracy of sediment concentration and to estimate parameters in sediment carrying capacity. In this method, a cost function is introduced first to determine the difference between the sediment concentration distributions and available field observations. A one-dimensional suspended sediment transport equation, assumed as a constraint, is integrated into the cost function. An adjoint equation of the data assimilation system is used to solve the minimum problem of the cost function. Field data observed from the Yellow River in 2013 are used to test the proposed method. When running the numerical model with the data assimilation method, errors between the calculations and the observations are analyzed. Results show that (1) the data assimilation system can improve the prediction accuracy of suspended sediment concentration; (2) the variational inverse data assimilation is an effective way to estimate the model parameters, which are poorly known in previous research; and (3) although the available observations are limited to two cross sections located in the central portion of the study reach, the variational-based data assimilation system has a positive effect on the simulated results in the portion of the model domain in which no observations are available
Node-line Dirac semimetal manipulated by Kondo mechanism in nonsymmorphic CePtSi
Dirac node lines (DNLs) are characterized by Dirac-type linear crossings
between valence and conduction bands along one-dimensional node lines in the
Brillouin zone (BZ). Spin-orbit coupling (SOC) usually shifts the degeneracy at
the crossings thus destroys DNLs, and so far the reported DNLs in a few
materials are non-interacting type, making the search for robust interacting
DNLs in real materials appealing. Here, via first-principle calculations, we
reveal that Kondo interaction together with nonsymmorphic lattice symmetries
can drive a robust interacting DNLs in a Kondo semimetal CePt_2Si_2, and the
feature of DNLs can be significantly manipulated by Kondo behavior in different
temperature regions. Based on the density function theory combining dynamical
mean-field theory (DFT+DMFT), we predict a transition to Kondo-coherent state
at coherent temperature T_coh= 80 K upon cooling, verified by temperature
dependence of Ce-4f self-energy, Kondo resonance peak, magnetic susceptibility
and momentum-resolved spectral. Below T_coh, well-resolved narrow heavy-fermion
bands emerge near the Fermi level, constructing clearly visualized interacting
DNLs locating at the BZ boundary, in which the Dirac fermions have strongly
enhanced effective mass and reduced velocity. In contrast, above a crossover
temperature T_KS =600 K, the destruction of local Kondo screening drives
non-interacting DNLs which are comprised by light conduction electrons at the
same location. These DNLs are protected by lattice nonsymmorphic symmetries
thus robust under intrinsic strong SOC. Our proposal of DNLs which can be
significantly manipulated according to Kondo behavior provides an unique
realization of interacting Dirac semimetals in real strongly correlated
materials, and serves as a convenient platform to investigate the effect of
electronic correlations on topological materials.Comment: 9 pages, 9 figure
Effects of silica–gentamicin nanohybrids on osteogenic differentiation of human osteoblast-like SaOS-2 cells
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