Radial source velocity estimation based on cross-spectrum equalization accumulation compensation in shallow water.

In the former work, the histogram was effectively used to improve the interference immunity of target velocity estimation based on the cross-spectrum. This paper proposes a new method to eliminate the bias introduced by the histogram and to further improve interference immunity. The equalization window is designed to preserve the cross-spectrum peaks while suppressing the interference peaks. All frequency points are compensated and accumulated to improve the interference immunity. Finally, the simulation and sea trial data verify the effectiveness of the proposed method in this paper.

[Simultaneous Determination of Three Kinds of Effective Constituents in Cannabis Plants by Reversed-phase HPLC].

OBJECTIVES: To establish a high performance liquid chromatographic （HPLC） method for simultaneous determination of three effective constituents, including tetrahydrocannabinol （THC）, cannabidiol （CBD） and cannabinol （CBN） in Cannabis plants. METHODS: A C18 column was used in this study, and acetonitrile-phosphate buffer （0.015 mol/L KH2PO4） was used as mobile phase at a flow rate of 1.0 mL/min. At a detection wavelength of 220 mm, UV absorption spectra were collected at the wavelength range of 190-400 nm, and the spectra and retention time were counted as qualitative evidence. RESULTS: THC, CBD and CBN could be well separated by this method. Three components had good linear relationship in the range of 0.4-40 µg/mL （R²≥0.999 3）. The recoveries were over 87%. The limits of detection were 1.8 ng, 2.0 ng and 1.3 ng, respectively. The relative standard deviation （RSD） were less than 5% for both inter-day and intra-day precisions. CONCLUSIONS: Reversed-phase HPLC method is simple, rapid and accurate, and it is suitable for the qualitative and quantitative detection of THC, CBD and CBN in Cannabis plants.

Structure and growth of quasi-one-dimensional YSi2 nanophases on Si(100).

Quasi-one-dimensional YSi(2) nanostructures are formed via self-assembly on the Si(100) surface. These epitaxial nanowires are metastable and their formation strongly depends on the growth parameters. Here, we explore the various stages of yttrium silicide formation over a range of metal coverages and growth temperatures, and establish a rudimentary phase diagram for these novel and often coexisting nanophases. We identify, in addition to previously identified stoichiometric wires, several new nanowire systems. These nanowires exhibit a variety of surface reconstructions, which sometimes coexist on a single wire. From a comparison of scanning tunneling microscopy images, tunneling spectra, and first-principles density functional theory calculations, we determine that these surface reconstructions arise from local orderings of yttrium vacancies. Nanowires often agglomerate into nanowire bundles, the thinnest of which are formed from single wire pairs. The calculations show that such bundles are energetically favored compared to well-separated single wires. Thicker bundles are formed at slightly higher temperature. They extend over several microns, forming a robust network of conducting wires that could possibly be employed in nanodevice applications.

Structure of YSi(2) nanowires from scanning tunneling spectroscopy and first principles.

Exceptionally long and uniform YSi(2) nanowires are formed via self-assembly on Si(001). The in-plane width of the thinnest wires is known to be quantized in odd multiples of the silicon lattice constant. Here, we identify a class of nanowires that violates the "odd multiple" rule. The structure of the thinnest wire in this category is determined by comparing scanning tunneling spectroscopy measurements with the calculated surface density of states of candidate models by means of the Pendry R-factor analysis. The relative stability of the odd and even wire systems is analyzed via first-principles calculations.

Percutaneous superfine-needle aspiration biopsy of intrathoracic lesions guided by simulator.

The result of percutaneous superfine-needle aspiration biopsy in 100 patients with intrathoracic lesions guided by simulator is reported. The success rate of aspiration biopsy was 94%, and no major complication was observed. The method of localization by simulator had advantages such as accuracy in localization, no limitation of mass size and site, and a high rate of puncture success. Cell smears obtained by superfine needle were similar to those obtained by fine- or large-bore needles, but fewer complications were encountered. This is a useful technique that can provide early cytological diagnosis, especially for the peripheral type of pulmonary mass.