New Supernova Candidates from SDSS-DR7 of Spectral Survey

The letter presents 25 discovered supernova candidates from SDSS-DR7 with our dedicated method, called Sample Decrease, and 10 of them were confirmed by other research groups, and listed in this letter. Another 15 are first discovered including 14 type Ia and one type II based on Supernova Identification (SNID) analysis. The results proved that our method is reliable, and the description of the method and some detailed spectra analysis procedures were also presented in this letter.Comment: 6 pages, 3 figure

Sensitive frequency-dependence of the carrier-envelope phase effect on bound-bound transition: an interference perspective

We investigate numerically with Hylleraas coordinates the frequency dependence of the carrier-envelope phase (CEP) effect on bound-bound transitions of helium induced by an ultrashort laser pulse of few cycles. We find that the CEP effect is very sensitive to the carrier frequency of the laser pulse, occurring regularly even at far-off resonance frequencies. By analyzing a two-level model, we find that the CEP effect can be attributed to the quantum interference between neighboring multi-photon transition pathways, which is made possible by the broadened spectrum of the ultrashort laser pulse. A general picture is developed along this line to understand the sensitivity of the CEP effect to laser's carrier frequency. Multi-level influence on the CEP effect is also discussed

Sinkage, trim, drag of a common freely floating monohull ship

A practical method — well suited for early ship design and hull form optimization — for estimating the sinkage, the trim and the drag of a freely-floating common monohull ship at moderate Froude numbers F ≤ 0.45 is considered. The sinkage and the trim are realistically estimated via two alternative simple methods: an experimental approach based on an analysis of experimental measurements (involving no flow computations), and a numerical approach based on a practical linear potential-flow theory (the Neumann-Michell theory) that only requires simple flow computations for the hull surface ΣH of the ship at rest. The drag is also estimated in a simple way, based on the classical Froude decomposition into viscous and wave components: well-known semi empirical expressions for the friction drag, the viscous drag and the drag due to hull roughness are used, and the wave drag is evaluated via the Neumann-Michell theory. The drag is more sensitive to the hull position than the sinkage and the trim. Accordingly, it must be computed for a ‘dynamic’ ship hull surface ΣH that accounts for sinkage and trim effects, although the hull surface ΣH does not need to be very precise. In fact, the total drag computed for the hull surface ΣH chosen as the hull surface ΣH predicted by the numerical approach, or as st 1 the hull surface ΣH predicted by the even simpler experimental approach, are nearly identical. Moreover, the drag of the hull surface ΣH and the (nearly identical) drag of the hull surface ΣH 1 a are significantly higher, and also in much better agreement with experimental measurements, than the drag of the hull surface Σ

A global approximation to the green function for diffraction-radiation of regular water waves in deep water

The Green function of the theory of diffraction radiation of time-harmonic (regular) waves by an offshore structure, or a ship at low speed, in deep water is considered. The Green function G and its gradient ∇G are expressed in the usual manner as the sum of three com- ponents that correspond to the fundamental free-space singularity, a non-oscillatory local flow, and waves. Simple approximations that only involve elementary continuous functions (algebraic, exponential, logarithmic) of real arguments are given for the local flow components in G and G. These approximations are global approximations valid within the entire flow region, rather regions as can be found in the literature

2-{(1R,2R)-2-[Bis(4-methyl­benz­yl)amino]­cyclo­hex­yl}isoindoline-1,3-dione

In the title mol­ecule, C30H32N2O2, the two tolyl rings form dihedral angles of 65.8 (1) and 6.6 (1)° with the isoindole-1,3-dione mean plane. The cyclo­hexane ring adopts a chair conformation