35 research outputs found
A Measurement of Psi(2S) Resonance Parameters
Cross sections for e+e- to hadons, pi+pi- J/Psi, and mu+mu- have been
measured in the vicinity of the Psi(2S) resonance using the BESII detector
operated at the BEPC. The Psi(2S) total width; partial widths to hadrons,
pi+pi- J/Psi, muons; and corresponding branching fractions have been determined
to be Gamma(total)= (264+-27) keV; Gamma(hadron)= (258+-26) keV, Gamma(mu)=
(2.44+-0.21) keV, and Gamma(pi+pi- J/Psi)= (85+-8.7) keV; and Br(hadron)=
(97.79+-0.15)%, Br(pi+pi- J/Psi)= (32+-1.4)%, Br(mu)= (0.93+-0.08)%,
respectively.Comment: 8 pages, 6 figure
Measurements of the Mass and Full-Width of the Meson
In a sample of 58 million events collected with the BES II detector,
the process J/ is observed in five different decay
channels: , , (with ), (with
) and . From a combined fit of all five
channels, we determine the mass and full-width of to be
MeV/ and
MeV/.Comment: 9 pages, 2 figures and 4 table. Submitted to Phys. Lett.
Evaluating the hedging error in price processes with jumps present
In this draft, we consider a hedging strategy concerning only the continuous parts of two asset price processes which have jumps. Two consistent estimators of the hedging strategy, ρ̂ and ρ̃, are presented in terms of realized bipower variation and threshold quadratic variation, respectively. Based on ρ̂, estimators for operational risk, market risk (risk due to jumps) and total risk are investigated. It turns out that the variance of ρ̂ enters into the bias of the operational risk estimator, whereas the variance is mainly due to jump influenced bipower estimation error. The convergence rate of the operational risk estimator (properly centralized) is OP ((δt)̄1/2. The convergence rate of the market risk is however OP ((δt)̄1/2. Based on ρ̃, the total risk is also studied, and it has the same convergence rate as that based on ρ̂. Besides the interest in financial econometrics, it is also of significance in a statistical sense when we are interested in estimating the quadratic variation of the corresponding unhedgeable residual process
Identification of Components of the Female Sex Pheromone of the Simao pine caterpillar moth, Dendrolimus kikuchii Matsumura
The pine caterpillar moth, Dendrolimus kikuchii Matsumura (Lepidoptera: Lasiocampidae), is a pest of economic importance on pine in southwest China. Three active compounds were detected during analyses of solvent extracts and effluvia sampled by solid phase microextraction (SPME) from virgin female D. kikuchii using gas chromatography (GC) coupled with electroantennographic (EAG) recording with antennae from a male moth. The compounds were identified as (5Z,7E)-5,7-dodecadien-1-yl acetate (Z5,E7-12:OAc), (5Z,7E)-5,7-dodecadien-1-ol (Z5,E7-12:OH), and (5Z)-5-dodecenyl acetate (Z5-12:OAc) by comparison of their GC retention indices, mass spectra, and EAG activities with those of synthetic standards. Microchemical reactions of gland extracts provided further information confirming the identifications of the three components. Solvent extractions and SPME samples of pheromone effluvia from virgin calling females provided 100:18:0.6 and 100:7:1 ratios of Z5,E7-12:OAc:Z5,E7-12:OH:Z5-12:OAc, respectively. Field behavioral assays showed that Z5,E7-12:OAc and Z5,E7-12:OH were essential for attraction of male D. kikuchii moths. However, the most attractive blend contained these three components in a 100:20:25 ratio in a gray rubber septa. Our results demonstrated that the blend of Z5,E7-12:OAc, Z5,E7-12:OH, and Z5-12:OAc comprise the sex pheromone of D. kikuchii. The optimized three-component lure blend is recommended for monitoring D. kikuchii infestation
ELECTRICAL PROPERTIES AND PHOTOLUMINESCENCE OF AMORPHOUS SILICON
The temperature dependence of conductivity, photoluminescence and ion-implantation doping effect of glow discharge (GD) and low pressure CVD a-Si films have been investigated. Post-hydrogenation significantly reduces the gap state density of LPCVD a-Si. Phosphorus and boron ion-implantation show that LPCVD a-Si has a higher doping efficiency than GD samples, reaching a maximum R.T. conductivity of 0.3 Ω-1 cm-1. Two peaks were observed in the luminescence spectrum of GD a-Si films and the origin of the peaks is discussed