Fractal surface for calibration of an optical profiler

The surface profiler has become a basic metrology tool for the characterization of high-quality optical surfaces. The unknown effective resolution of the surface profiler is problematic in using the instrument, as it distorts the measured surface profile. In this paper, we suggest and describe the use of a fractal surface as a standard test surface with which to calibrate the effective resolution of a surface profiler. Fractal surfaces have the characteristics of irregularity, self-similarity and low correlation, with the correlation length being approximately equal to the length of the profile; therefore, a log-log plot of the power spectral density curve is a straight line. The power spectral density curves of fractal surfaces, which can be acquired through surface characterization techniques such as atomic force microscopy, are fitted to a straight line to act as a standard with which to calibrate an optical profiler in different ranges. Through calibration, we can obtain the effective resolution of the optical profiler, and the surface profiler is found to have good transmission capacity within the effective spatial frequency range.     

Omega- and Omega+ production in central Pb + Pb collisions at 40 and 158A GeV

Results are presented on Omega production in central Pb+Pb collisions at 40 and 158A GeV beam energy. For the first time in heavy ion reactions, rapidity distributions and total yields were measured for the sum Omega(-) + Omega(+) at 40A GeV and for Omega(-) and Omega(+) separately at 158A GeV. The yields are strongly underpredicted by the string-hadronic UrQMD model but agree better with predictions from hadron gas models.     

Large coercivity and unconventional exchange coupling in manganese-oxide-coated manganese gallium nanoparticles

The microstructures and magnetic properties of nanoparticles, each composed of an antiferromagnetic （AFM） manganese-oxide shell and a ferromagnetic-like core of manganese-gallium （MnGa） compounds, are studied. The coreshell structure is confirmed by transmission electron microscope （TEM）. The ferromagnetic-like core contains three kinds of MnGa binary compounds, i.e., ferrimagnetic （FI） DO22-type MnaGa, ferromagnetic （FM） Mn8Gas, and AFM DO19-type Mn3Ga, of which the first two correspond respectively to a hard magnetic phase and to a soft one. Decoupling effect between these two phases is found at low temperature, which weakens gradually with increasing temperature and disappears above 200 K. The exchange bias （EB） effect is observed simultaneously, which is caused by the exchange coupling between the AFM shell and FM-like core. A large coercivity of 6.96 kOe （1Oe = 79.5775 A·m^-1） and a maximum EB value of 0.45 kOe are achieved at 300 K and 200 K respectively.     

潜空战术导弹纵向特性分析及控制系统设计

对潜空战术导弹的水下和空中运动分别建立了纵向质心运动方程,分析了出水前后的弹体纵向特性并完成了经典方法的控制系统设计,最后分别给出了Simulink质心弹道和六自由度弹道对比仿真验证;结果表明,潜空导弹质心运动方程可简捷有效地设计期望弹道和分析弹体特性,据此设计出的控制系统可以顺利实现对潜空导弹的全程控制,提供了一套完整的潜空战术导弹纵向特性分析方法和控制系统设计方法。     

Dual-Color Quantum Dot–Encoded Nanoprobe for DNA Assays and Cell Imaging

In this article, a novel dual-color quantum dot–encoded fluorescent nanoprobe was prepared by the reverse microemulsion method and layer-by-layer assembly method. First, red fluorescence–emitting CdTe quantum dots were encapsulated in silica nanoparticles by the reverse microemulsion method. Yellow fluorescence–emitting quantum dots were deposited on the surface of silica nanoparticles to form a dual-color quantum dot@silica beads/quantum dot nanoprobe. Then capture DNA was linked to a QSQ nanoprobe via covalent bonding. We utilized the quantum dot@silica beads/quantum dot nanoprobe to capture and detect the mutant BRAF DNA sequence through the competitive immunoassay method. The resulting quantum dot@silica beads/quantum dot nanoprobe-capture DNA conjugates showed sequence-specific hybridization with target DNA. Furthermore, a multispectral imaging system was utilized to distinguish the quantum dot optical code in the quantum dot@silica beads/quantum dot nanoprobe. The quantum dot@silica beads/quantum dot nanoprobe was used in human osteoblast-like HepG2 cell imaging. The proposed quantum dot@silica beads/quantum dot nanoprobe and decoding analysis method could be used for targeting imaging, biological assays, and early detection of cancer.     

The solution of the characteristic equation of circular-rectangular groove guide

Circular-rectangular groove guide is a new type of structure we have presented for coupling between circular groove guide and rectangular groove guide. In this paper, as the continuity of our previous work, the characteristic equation of circular-rectangular groove guide has been solved and the numerical results have been given and discussed.The Project Supported by National Natural Science Foundation of P. R. China