渐近拟非扩张型映象的Ishikawa迭代序列的强收敛性

通过引入一新型条件,研究了渐近拟非扩张型映象不动点的具误差的修正的Ish ikaw a迭代序列的迭代逼近问题,得到新的结果.     

非包覆型油井水泥自修复剂的制备与评价

采用反向悬浮聚合法,丙烯酸(AA)和丙烯酰胺(AM)为单体,过硫酸钾（KBS）作引发剂,N,N-亚甲基双丙烯酰胺(MBA)作交联剂,制备了一种非包覆遇水膨胀型自修复剂LF-1,其结构经SEM和IR表征。结果表明,LF-1分散均匀,表观形态呈多孔、粗糙褶皱状。将2%LF-1加入水泥浆中,水泥浆流动度为20.1 cm,失水52 mL,稠化时间217 min;用5000 mg/L的盐水养护造缝水泥石,12 h内即无渗透性;水泥石24 h抗压强度为16.1 MPa,抗折强度为4.92 MPa。      

Blind convolutive separation method for speech signals via joint block diagonalization

A blind speech source separation method for the overdetermined convolutive mixture model in time-domain is proposed via joint block-diagonalization based on the mutual- independence and short-time stationarity properties of the speech signals. Taking the sum of the F-norms of all off-diagonal sub-matrices as a criterion, a novel joint block-diagonalization method is proposed to estimate the whole mixture matrix through minimizing a sequence of quadratic sub-functions corresponding to mixture sub-matrices. Both theoretical analysis and simulations show that the proposed method has much lower complexity and faster convergence speed than the classical Jacobi-like method with no performance loss. In addition, there are almost no obvious impacts of the channel order and initialization values on the convergence speed.     

Study of the circumstance influence on the elemental distribution in ancient animal bone using μ-XRF

Elemental analysis of archaeological bone plays an important role in the study of the dietary habits of ancient animals. The elemental characteristic of diagenetic skeletons depends on the surrounding circumstance. The study of environmental influence on the elemental concentration of ancient bone is significant. In this paper, the diagenetic influence on archaeological skeletons is analyzed by microbeam X-ray fluorescence （p.-XRF）. The results show that the enamel is an excellent barrier to the diagenesis and the element Sr in bone isn＇t susceptible to contamination from the buried environment.     

ARGO-YBJ detector simulation using GEANT4

‘G4argo＇, a GEANT4-based simulation package for the ARGO-YBJ detector, is described in this paper. C4argo incorporates in the simulation the true RPC time resolution and another 0.5 ns time uncertainty which is introduced from the offline calibration of TDC. In addition, the correct RPC geometry and the true materials for the ARGO-YBJ experimental hall are implemented. As a result, G4argo simulation shows a very good agreement with real data.     

Rapidity distributions of net protons from AGS to LHC energy regions

Taking the conservation of baryon number into account in a non-uniform flow model, the rapidity distribution of the net protons at the LHC is predicted. The energy dependence of the rapidity distribution, baryon stopping and collective flow from BNL/AGS to CERN/LHC are systematically investigated.     

Radiative leptonic decay Bc^-→τ^vτ^-γ in the standard model and the two-Higgs-doublet model

We analyze the radiative leptonic Bc decay Bc^-→τ^vτ^-γ in the Standard Model and the two- Higgs-doublet model using the non-relativistic constituent quark model. The results confirm that this channel is experimentally promising in view of the large number of Bc mesons which are expected to be produced at future hadron facilities. We also find that this decay is sensitive to the parameters of the two-Higgs-doublet model, and it can be tested in future experiments.     

Correlated Photon Pair Generation in Silicon Wire Waveguides at 1.5 μm

Correlated photon pairs at 1.5 μm are generated in a silicon wire waveguide （SWW） with a length of only 1.6 mm. Experimental results show that the single-side count rates on both sides increase quadratically with pump light, indicating that photons are generated from the spontaneous four-wave mixing （SFWM） processes. The quantum correlation property of the generated photons is demonstrated by the ratio between coincident and accidental coincident count rates. The highest ratio measured at room temperature is to be about 19, showing that generated photon pairs have strong quantum correlation property and low noise. What is more, the wavelength correlation property of the coincident count is also measured to demonstrate the correlated photon pair generation. The experimental results demonstrate that SWWs have great potential in on-chip integrated low-noise correlated photon pair sources at 1.5 μm.     

Effects of Rapid Thermal Processing on Microstructure and Optical Properties of As-Deposited Ag2O Films by Direct-Current Reactive Magnetron Sputtering

（111） preferentially oriented Ag2O film deposited by direct current reactive magnetron sputtering is annealed by rapid thermal processing at different annealing temperatures for 5 min. The film microstructure and optical properties are then characterized by x-ray diffractometry, scanning electron microscopy, and spectrophotometry, respectively. The results indicate that no clear Ag diffraction peak is discernable in the Ag2O film annealed below 200°C. In comparison, the Ag2O film annealed at 200°C begins to exhibit characteristic Ag diffraction peaks, and in particular the Ag2O film annealed at 250°C can demonstrate enhanced Ag diffraction peaks. This implies that the threshold of the thermal decomposition reaction to produce Ag particles is approximately 200°C for the Ag2O film. In addition, an evolution of the film surface morphology from compact and pyramid-like to a rough and porous structure clearly occurred with increasing annealing temperature. The porous structure might be attributable to the escape of the oxygen produced during annealing, while the rough surface might originate from the reconstruction of the surface. The dispersion of interference peak intensity in the reflectance and transmission spectra could be attributed to the Ag particles produced. The lowered crystallinity and Ag particles produced induce a lattice defect, which results in an enhanced transmissivity in the violet region and a weakened transmissivity in the infrared region.     

方波激发下Er~(3+)上转换红光激发机理的研究

用方波电源驱动808 nm激光二极管(LD)激发Er3+掺杂的亚碲酸盐氟氧化物玻璃,测量4F9/2能级上转换发光的上升和衰减,根据上升的时间常数确定中间能级的寿命,从而确定4F9/2能级粒子数积累的过程。通过建立速率方程模型分析4F9/2能级的上升和衰减特性与中间能级的关系,确定808 nm LD激发下上转换红光的激发机理,同时提供了一种通过上转换发光,用光电倍增管测量红外能级寿命的方法。