14,606 research outputs found
Some Results for a Finite Family of Uniformly -Lipschitzian Mappings in Banach Spaces
The purpose of this paper is to prove a strong convergence theorem for a finite family of uniformly L-Lipschitzian mappings in Banach spaces. The results presented in the paper not only correct some mistakes appeared in the paper by Ofoedu (2006) but also improve and extend some recent results by Chang (2001), Cho et al. (2005), Ofoedu (2006), Schu (1991), and Zeng (2003, 2005)
Conditioning of BPM pickup signals for operations of the Duke storage ring with a wide range of single-bunch current
The Duke storage ring is a dedicated driver for the storage ring based
oscillator free-electron lasers (FELs), and the High Intensity Gamma-ray Source
(HIGS). It is operated with a beam current ranging from about 1 mA to 100 mA
per bunch for various operations and accelerator physics studies. High
performance operations of the FEL and gamma-ray source require a stable
electron beam orbit, which has been realized by the global orbit feedback
system. As a critical part of the orbit feedback system, the electron beam
position monitors (BPMs) are required to be able to precisely measure the
electron beam orbit in a wide range of the single-bunch current. However, the
high peak voltage of the BPM pickups associated with high single-bunch current
degrades the performance of the BPM electronics, and can potentially damage the
BPM electronics. A signal conditioning method using low pass filters is
developed to reduce the peak voltage to protect the BPM electronics, and to
make the BPMs capable of working with a wide range of single-bunch current.
Simulations and electron beam based tests are performed. The results show that
the Duke storage ring BPM system is capable of providing precise orbit
measurements to ensure highly stable FEL and HIGS operations
Multiple Unpinned Dirac Points in Group-Va Single-layers with Phosphorene Structure
Emergent Dirac fermion states underlie many intriguing properties of
graphene, and the search for them constitute one strong motivation to explore
two-dimensional (2D) allotropes of other elements. Phosphorene, the ultrathin
layers of black phosphorous, has been a subject of intense investigations
recently, and it was found that other group-Va elements could also form 2D
layers with similar puckered lattice structure. Here, by a close examination of
their electronic band structure evolution, we discover two types of Dirac
fermion states emerging in the low-energy spectrum. One pair of (type-I) Dirac
points is sitting on high-symmetry lines, while two pairs of (type-II) Dirac
points are located at generic -points, with different anisotropic
dispersions determined by the reduced symmetries at their locations. Such
fully-unpinned (type-II) 2D Dirac points are discovered for the first time. In
the absence of spin-orbit coupling, we find that each Dirac node is protected
by the sublattice symmetry from gap opening, which is in turn ensured by any
one of three point group symmetries. The spin-orbit coupling generally gaps the
Dirac nodes, and for the type-I case, this drives the system into a quantum
spin Hall insulator phase. We suggest possible ways to realize the unpinned
Dirac points in strained phosphorene.Comment: 30 pages, 6 figure
Strong convergence theorems for nonlinear operator equations with total quasi-ϕ-asymptotically nonexpansive mappings and applications
Autoimmune pancreatitis associated with a pancreatic pseudocyst treated by distal pancreatectomy with splenectomy: case report
Autoimmune pancreatitis is a unique type of chronic pancreatitis, which is rarely associated with pseudocyst. A 48-year-old lady was admitted to our department with a rapidly growing cystic mass in the pancreatic tail with an elevated concentration of serum carbohydrate antigen 19-9 (CA19-9). She had a history of autoimmune pancreatitis and received steroid treatment. Imaging studies demonstrated a cystic mass in the pancreatic tail. The mass kept growing despite restoration of steroid treatment. Eventually, the patient underwent distal pancreatectomy with splenectomy. Histopathological examination revealed the existence of pseudocyst, significant lymphocytic infiltration, and fibrotic change in the pancreatic tail
Intraclass reliability for assessing how well Taiwan constrained hospital-provided medical services using statistical process control chart techniques
BACKGROUND: Few studies discuss the indicators used to assess the effect on cost containment in healthcare across hospitals in a single-payer national healthcare system with constrained medical resources. We present the intraclass correlation coefficient (ICC) to assess how well Taiwan constrained hospital-provided medical services in such a system. METHODS: A custom Excel-VBA routine to record the distances of standard deviations (SDs) from the central line (the mean over the previous 12 months) of a control chart was used to construct and scale annual medical expenditures sequentially from 2000 to 2009 for 421 hospitals in Taiwan to generate the ICC. The ICC was then used to evaluate Taiwan’s year-based convergent power to remain unchanged in hospital-provided constrained medical services. A bubble chart of SDs for a specific month was generated to present the effects of using control charts in a national healthcare system. RESULTS: ICCs were generated for Taiwan’s year-based convergent power to constrain its medical services from 2000 to 2009. All hospital groups showed a gradually well-controlled supply of services that decreased from 0.772 to 0.415. The bubble chart identified outlier hospitals that required investigation of possible excessive reimbursements in a specific time period. CONCLUSION: We recommend using the ICC to annually assess a nation’s year-based convergent power to constrain medical services across hospitals. Using sequential control charts to regularly monitor hospital reimbursements is required to achieve financial control in a single-payer nationwide healthcare system
New Vacuum Solar Telescope and Observations with High Resolution
The New Vacuum Solar Telescope (NVST) is a 1 meter vacuum solar telescope
that aims to observe the fine structures on the Sun. The main tasks of NVST are
high resolution imaging and spectral observations, including the measurements
of solar magnetic field. NVST is the primary ground-based facility of Chinese
solar community in this solar cycle. It is located by the Fuxian Lake of
southwest China, where the seeing is good enough to perform high resolution
observations. In this paper, we first introduce the general conditions of
Fuxian Solar Observatory and the primary science cases of NVST. Then, the basic
structures of this telescope and instruments are described in detail. Finally,
some typical high resolution data of solar photosphere and chromosphere are
also shown.Comment: 16 pages, 14 figures, accepted by RAA (Research in Astronomy and
Astrophysics
Electronic and magnetic properties of multishell Co nanowires coated with Cu
The structural, electronic, and magnetic properties of ultrathin Cu-coated Co
nanowires have been studied by using empirical genetic algorithm simulations
and a tight-binding model Hamiltonian in the unrestricted Hartree-Hock
approximation. For some specific stoichiometric compositions, Cu atoms occupy
the surface, while Co atoms prefer to stay in the interior, forming the perfect
coated multishell structures. The outer Cu layers lead to substantial
variations of the magnetic moment of interior Co atoms, depending on the
structure and thickness of Cu layers. In particular, single Co atom row in the
center of nanowire is found to be nonmagnetic when coated with two Cu layers.
All the other Co nanowires in the coated Cu shell are still magnetic but the
magnetic moments are reduced as compared with Co nanowires without Cu coating.
The interaction between Cu and Co atoms induces nonzero magnetic moment for Cu
atoms.Comment: 7 pages, 2 fugure
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