19,032 research outputs found
Dietary Vitamin B6 Requirement of Juvenile Grass Carp (Ctenopharyngodon idella)
We evaluated the effects of dietary vitamin B6 levels on growth, survival, and serum biochemical parameters in juvenile grass carp (Ctenopharyngodon idella). Fish were fed one of seven purified diets containing 0.12 (control), 1.16, 2.37, 4.82, 9.20, 17.51, or 36.52 mg/kg B6. We observed abnormal swimming behavior in some fish fed the control diet after 17 days. The survival rate (24.44±1.92%) was low in the control group. Supplementation with vitamin B6 resulted in significantly higher (P<0.05) weight gain, specific growth rate, final weight, and weight gain rate. Feed efficiency was significantly lower in the fish fed the control diet than the remaining groups (P<0.05). Dietary vitamin B6 levels had no significant effect on fish body composition or serum albumin and total protein content. Dietary vitamin B6 supplementation caused a decrease in serum triacylglycerol content and an increase in total cholesterol content, high density lipoprotein cholesterol content, and α-amylase activity levels (P<0.05). Broken-line regression analysis of SGR, HDL-C content, and α-AMY activity, showed that the optimum dietary vitamin B6 requirement for juvenile grass carp was 1.13, 3.73, 1.57 mg B6/kg, respectively
Real Scalar Field Scattering with Polynomial Approximation around Schwarzschild-de Sitter Black-hole
As one of the fitting methods, the polynomial approximation is effective to
process sophisticated problem. In this paper, we employ this approach to handle
the scattering of scalar field around the Schwarzschild-de Sitter black-hole.
The complex relationship between tortoise coordinate and radial coordinate is
replaced by the approximate polynomial. The Schrdinger-like equation,
the real boundary conditions and the polynomial approximation construct a full
Sturm-Liouville type problem. Then this boundary value problem can be solved
numerically according to two limiting cases: the first one is the Nariai
black-hole whose horizons are close to each other, the second one is when the
horizons are widely separated. Compared with previous results (Brevik and
Tian), the field near the event horizon and cosmological horizon can have a
better description.Comment: revtex4 source file, 11 pages, 8 figure
Fermions tunnelling from the charged dilatonic black holes
Kerner and Mann's recent work shows that, for an uncharged and non-rotating
black hole, its Hawking temperature can be exactly derived by fermions
tunnelling from its horizons. In this paper, our main work is to improve the
analysis to deal with charged fermion tunnelling from the general dilatonic
black holes, specifically including the charged, spherically symmetric
dilatonic black hole, the rotating Einstein-Maxwell-Dilaton-Axion (EMDA) black
hole and the rotating Kaluza-Klein (KK) black hole. As a result, the correct
Hawking temperatures are well recovered by charged fermions tunnelling from
these black holes.Comment: 16 pages, revised version to appear in Class. Quant. Gra
The First Release of the CSTAR Point Source Catalog from Dome A, Antarctica
In 2008 January the 24th Chinese expedition team successfully deployed the
Chinese Small Telescope ARray (CSTAR) to DomeA, the highest point on the
Antarctic plateau. CSTAR consists of four 14.5cm optical telescopes, each with
a different filter (g, r, i and open) and has a 4.5degree x 4.5degree field of
view (FOV). It operates robotically as part of the Plateau Observatory, PLATO,
with each telescope taking an image every 30 seconds throughout the year
whenever it is dark. During 2008, CSTAR #1 performed almost flawlessly,
acquiring more than 0.3 million i-band images for a total integration time of
1728 hours during 158 days of observations. For each image taken under good sky
conditions, more than 10,000 sources down to 16 mag could be detected. We
performed aperture photometry on all the sources in the field to create the
catalog described herein. Since CSTAR has a fixed pointing centered on the
South Celestial Pole (Dec =-90 degree), all the sources within the FOV of CSTAR
were monitored continuously for several months. The photometric catalog can be
used for studying any variability in these sources, and for the discovery of
transient sources such as supernovae, gamma-ray bursts and minor planets.Comment: 1 latex file and 9 figures The paper is accepted by PAS
Metamagnetic transition in EuFeAs single crystals
We report the measurements of anisotropic magnetization and magnetoresistance
on single crystals of EuFeAs, a parent compound of ferro-arsenide
high-temperature superconductor. Apart from the antiferromagnetic (AFM)
spin-density-wave transition at 186 K associated with Fe moments, the compound
undergoes another magnetic phase transition at 19 K due to AFM ordering of
Eu spins (). The latter AFM state exhibits metamagnetic
transition under magnetic fields. Upon applying magnetic field with at 2 K, the magnetization increases linearly to 7.0 /f.u. at
=1.7 T, then keeps at this value of saturated Eu moments under
higher fields. In the case of , the magnetization increases
step-like to 6.6 /f.u. with small magnetic hysteresis. A metamagnetic
phase was identified with the saturated moments of 4.4 /f.u. The
metamagnetic transition accompanies with negative in-plane magnetoresistance,
reflecting the influence of Eu moments ordering on the electrical
conduction of FeAs layers. The results were explained in terms of
spin-reorientation and spin-reversal based on an -type AFM structure for
Eu spins. The magnetic phase diagram has been established.Comment: 10 pages, 8 figures. accepted for publication in New Journal of
Physics as a special issue articl
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