318 research outputs found
Automatic Generation of Basis Component Path Coverage for Software Architecture Testing
Architecture-centric development is one of the most promising methods for improving software quality, reducing software cost and raising software productivity. Software architecture research not only focuses on the design phase, but also covers every phase of software life cycle. Software architecture has characteristics different from traditional software, conventional testing methods do not apply directly to software architecture. Basis path testing is a very simple and efficient white-box testing method. Traditional methods generate basis path according to the control flow graph, they are not suitable for generating component path when we detect more software architecture errors. This paper presents a new concept - Basis Component Path (BCP) for C2-style architecture, and proposes a method to generate the BCPs. C2-style architecture is represented by components, connectors, and interfaces, and uses an architecture component interaction graph (CIG) to describe interface connection relationship. We also provide an algorithm to generate BCP set. Experiments apply the proposed method in a typical C2-style architecture and the result shows that the proposed method can generate BCP set which contains as many BCPs as possible efficiently, and it meets the requirements of the basis component path testing
Existence and stability of multiple solutions to the gap equation
We argue by way of examples that, as a nonlinear integral equation, the gap
equation can and does possess many physically distinct solutions for the
dressed-quark propagator. The examples are drawn from a class that is
successful in describing a broad range of hadron physics observables. We apply
the homotopy continuation method to each of our four exemplars and thereby find
all solutions that exist within the interesting domains of light current-quark
masses and interaction strengths; and simultaneously provide an explanation of
the nature and number of the solutions, many of which may be associated with
dynamical chiral symmetry breaking. Introducing a stability criterion based on
the scalar and pseudoscalar susceptibilities we demonstrate, however, that for
any nonzero current-quark mass only the regular Nambu solution of the gap
equation is stable against perturbations. This guarantees that the existence of
multiple solutions to the gap equation cannot complicate the description of
phenomena in hadron physics.Comment: 14 pages, 15 figure
Direct fiber vector eigenmode multiplexing transmission seeded by integrated optical vortex emitters
Spatial modes have received substantial attention over the last decades and are used in optical communication applications. In fiber-optic communications, the employed linearly polarized modes and phase vortex modes carrying orbital angular momentum can be synthesized by fiber vector eigenmodes. To improve the transmission capacity and miniaturize the communication system, straightforward fiber vector eigenmode multiplexing and generation of fiber-eigenmode-like polarization vortices (vector vortex modes) using photonic integrated devices are of substantial interest. Here, we propose and demonstrate direct fiber vector eigenmode multiplexing transmission seeded by integrated optical vortex emitters. By exploiting vector vortex modes (radially and azimuthally polarized beams) generated from silicon microring resonators etched with angular gratings, we report data-carrying fiber vector eigenmode multiplexing transmission through a 2-km large-core fiber, showing low-level mode crosstalk and favorable link performance. These demonstrations may open up added capacity scaling opportunities by directly accessing multiple vector eigenmodes in the fiber and provide compact solutions to replace bulky diffractive optical elements for generating various optical vector beams
SDSS J013127.34032100.1: A newly discovered radio-loud quasar at with extremely high luminosity
Only very few z>5 quasars discovered to date are radio-loud, with a
radio-to-optical flux ratio (radio-loudness parameter) higher than 10. Here we
report the discovery of an optically luminous radio-loud quasar, SDSS
J013127.34-032100.1 (J0131-0321 in short), at z=5.18+-0.01 using the Lijiang
2.4m and Magellan telescopes. J0131-0321 has a spectral energy distribution
consistent with that of radio-loud quasars. With an i-band magnitude of 18.47
and radio flux density of 33 mJy, its radio-loudness parameter is ~100. The
optical and near-infrared spectra taken by Magellan enable us to estimate its
bolometric luminosity to be L_bol ~ 1.1E48 erg/s, approximately 4.5 times
greater than that of the most distant quasar known to date. The black hole mass
of J0131-0321 is estimated to be 2.7E9 solar masses, with an uncertainty up to
0.4 dex. Detailed physical properties of this high-redshift, radio-loud,
potentially super-Eddington quasar can be probed in the future with more
dedicated and intensive follow-up observations using multi-wavelength
facilities.Comment: 5 pages, 3 figures, accepted to ApJ
Effect of Contact Time and Gas Component on Interfacial Tension of CO 2 /Crude Oil System by Pendant Drop Method
Pendant drop method has been used to measure the equilibrium interfacial tension and dynamic interfacial tension of CO 2 /crude oil system under the simulated-formation condition, in which the temperature is 355.65 K and pressure ranges from 0 MPa to 30 MPa. The test results indicated that the equilibrium interfacial tension of CO 2 /crude oil systems decreased with the increase of the systematic pressure. The dynamic interfacial tension of CO 2 /original oil, CO 2 /remaining oil, and CO 2 /produced oil systems is large at the initial contact and decreases gradually after that, and then finally it reaches dynamic balance. In addition, the higher the pressure is, the larger the magnitude of changing of CO 2 /crude oil interfacial tension with time will reduce. Moreover, by PVT phase experiment, gas-oil ratio, gas composition, and well fluid composition have been got, and different contents of light components in three oil samples under reservoir conditions have also been calculated. The relationship between equilibrium interfacial tensions and pressures of three different components of crude oil and CO 2 system was studied, and the higher C 1 is, the lower C 2 -C 10 will be, and the equilibrium interfacial tension will get higher. Therefore, the effect of light weight fractions on interfacial tension under formation conditions was studied
The physical constraints on a new LoBAL QSO at z=4.82
Very few low-ionization broad absorption line (LoBAL) QSOs have been found at
high redshifts to date. One high-redshift LoBAL QSO, J0122+1216, was recently
discovered at the Lijiang 2.4-m Telescope with an initial redshift
determination of 4.76. Aiming to investigate its physical properties, we
carried out follow-up observations in the optical and near-IR spectroscopy.
Near-IR spectra from UKIRT and P200 confirms that it is a LoBAL, with a new
redshift determination of based on the \mgii~ emission-line. The
new \mgii~ redshift determination reveals strong blueshifts and asymmetry of
the high-ionization emission lines. We estimated a black hole mass of and Eddington ratio of according to the
empirical \mgii-based single-epoch relation and bolometric correction factor.
It is possible that strong outflows are the result of an extreme quasar
environment driven by the high Eddington ratio. A lower limit on the outflowing
kinetic power () was derived from both emission and absorption
lines, indicating these outflows play a significant role in the feedback
process to regulate the growth of its black hole as well as host galaxy
evolution.Comment: 12 pages, 10 figures. Accepted for publication in The Astrophysical
Journa
Tanshinone IIA Inhibits Growth of Keratinocytes through Cell Cycle Arrest and Apoptosis: Underlying Treatment Mechanism of Psoriasis
The aim of the present investigation was to elucidate the cellular mechanisms whereby Tanshinone IIA (Tan IIA) leads to cell cycle arrest and apoptosis in vitro in keratinocytes, the target cells in psoriasis. Tan IIA inhibited proliferation of mouse keratinocytes in a dose- and time-dependent manner and induced apoptosis, resulting in S phase arrest accompanied by down-regulation of pCdk2 and cyclin A protein expression. Furthermore, Tan IIA-induced apoptosis and mitochondrial membrane potential changes were also further demonstrated by DNA fragmentation, single-cell gel electrophoresis assay (SCGE), and flow cytometry methods. Apoptosis was partially blocked by the caspase-3 inhibitor Ac-DEVD-CHO. Mitochondrial regulation of apoptosis further downstream was investigated, showing changes in the mitochondrial membrane potential, cytochrome c release into the cytoplasm, and enhanced activation of cleaved caspase-3 and Poly ADP-ribose polymerase (PARP). There was also no translocation of apoptosis-inducing factor (AIF) from mitochondria to the nucleus in apoptotic keratinocytes, indicating Tan IIA-induced apoptosis occurs mainly through the caspase pathway. Our findings provide the molecular mechanisms by which Tan IIA can be used to treat psoriasis and support the traditional use of Salvia miltiorrhiza Bungee (Labiatae) for psoriasis and related skin diseases
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