Steroids from the Fungus Pleurotus ostreatus

Twelve steroids, including eight ergostane-type sterols and four mono-glucosides of ergostane-type sterols, were isolated from the ethyl acetate soluble fraction of the fungus Pleurotus ostreatus ( Jacq. : Fr.) Kummer. A new compound 3-O-beta-D-glucopyranosyl-22E, 24R-ergosta-7, 22-diene-5alpha, 6beta, 9alpha-triol, was structurally elucidated by spectroscopic and chemical methods. The eleven known compounds were 22E, 24R-ergosta-7, 22-diene-3beta, 5alpha, 6beta, 9alpha-tetraol; 3-O-beta-D-glucopyranosyl-22E, 24R-ergosta-7, 22-diene-5alpha, 6beta-diol; 22E, 24R-ergosta-7, 22-diene-3beta, 5alpha, 6beta-triol; 22E, 24R-ergosta-5, 7, 22-trien-3beta-ol 3-O-beta-D-glucopyranoside; ergosterol; 22E, 24R-ergosta-7, 22-dien-3beta-ol 3-O-beta-D-glucopyranoside; 22E, 24R-ergosta-7, 22-diene-3beta-ol; 22E, 24R-ergosta-4, 6, 8, 22-tetraen-3-one; 22E, 24R-ergosta-7, 22-diene-3beta, 5alpha, 6alpha-triol; ergosterol peroxide; 22E, 24R-ergosta-7, 22-diene-3beta, 5alpha-diol-6-one.

浅谈3D电视技术流程

本文浅析了3D电视的发展划分与我国3D电视制、播、传的总体流程。

Self-organized Criticality Model for Ocean Internal Waves

In this paper, we present a simple spring-block model for ocean internal waves based on the self-organized criticality （SOC）. The oscillations of the water blocks in the model display power-law behavior with an exponent of -2 in the frequency domain, which is similar to the current and sea water temperature spectra in the actual ocean and the universal Garrett and Munk deep ocean internal wave model [Geophysical Fluid Dynamics 2 （1972） 225; J. Geophys. Res. 80 （1975） 291]. The influence of the ratio of the driving force to the spring coefficient to SOC behaviors in the model is also discussed.

IMAGE RECONSTRUCTION AND OBJECT CLASSIFICATION IN CT IMAGING SYSTEM

By obtaining a feasible filter function,reconstructed images can be got with linear interpolation and liftered backprojection techniques.Considering the gray and spstial correlation neighbour informations of each pixel,a new supervised classification method is put forward for the reconstructed images,and an experiment with noise image is done,the result shows that the method is feasible and accurate compared with ideal phantoms.

Quasiparticle Spectrum of Quantum Degenerate Fermi Gas in the Presence of Self—Consistent Magnetization Field

In this paper, we develop a systematic and simple method to derive quasiparticle spectrum of the quantum degenerate Fermi gases within the framework of Hartree–Fock–Bogoliubov theory which turns a general nonlinear two-body interaction Hamiltonian into a bilinear Hamiltonian by introducing certain self-consistent mean fields. Applying the approach, we obtain the quasi-particle spectrum of the model describing the superfluid phase transition that arises when a Feshbach resonance pairing occurs in a dilute Fermi gas in the presence of the magnetization fields and . When the gap parameter Δ is smaller than one or both of the magnetization fields, the spectrum manifests roton-type structure dramatically different from the spectrum in the absence of the magnetization fields.

Blind Source Separation based on Time-Frequency Morphological Characteristics for Rigid Acoustic Scattering by Underwater Objects

Separation of the components of rigid acoustic scattering by underwater objects is essential in obtaining the structural characteristics of such objects. To overcome the problem of rigid structures appearing to have the same spectral structure in the time domain, time-frequency Blind Source Separation （BSS） can be used in combination with image morphology to separate the rigid scattering components of different objects. Based on a highlight model, the separation of the rigid scattering structure of objects with time-frequency distribution is deduced. Using a morphological filter, different characteristics in a Wigner-Ville Distribution （WVD） observed for single auto term and cross terms can be simplified to remove any cross-term interference. By selecting time and frequency points of the auto terms signal, the accuracy of BSS can be improved. A simulation experimental has been used to analyze the feasibility of the new method, with changing the pulse width of the transmitted signal, the relative amplitude and the time delay parameter. And simulation results show that the new method can not only separate rigid scattering components, but can also separate the components when elastic scattering and rigid scattering exist at the same time. Experimental results confirm that the new method can be used in separating the rigid scattering structure of underwater objects.

Existing Regions of Either Rarefactive or Compressive Solitary Waves for Particular Dusty Plasma

By deriving a Korteweg-de Vries （KdV） equation for particular dusty plasma, we find the existing regions of solitary waves. The regions of both rarefactive and compressive solitary waves have also been given in this paper for a two-temperature ions and a hot adiabatic dusty fluid, where the dust charges can vary.

Multiple Soliton-Like Solutions and Similarity Reductions of a Spherical Kadomtsev-Petviashvili Equation from Plasma Physics

A spherical Kadomtsev-Petviashvili （SKP） equation for dust acoustic or ion-acoustic waves is studied. Similarity reductions of the SKP equation are obtained with the one-parameter （ε） Lie group of infinitesimal transformations and Clarkson-Kruskal direct method, The SKP equation is also solved with a generalized tanh function method.

An All-Solid-State Tunable Dual-Wavelength Ti：Sapphire Laser with Quasi-Continuous-Wave Outputs

A high power dual-wavelength Ti：sapphire laser system with wide turning range and high efficiency is described, which consists of two prism-dispersed resonators pumped by an a11-solid-state frequency-doubled Nd：YAG laser. Tunable dual-wavelength outputs, with one wavelength range from 750nm to 795nm and the other from 80Ohm to 850nm, have been demonstrated. With a pump power of 23 W at 532nm, a repetition rate of 6.5kHz and a pulse width of 67.6ns, the maximum dual-wavelength output power of 5.6 W at 785.3nm and 812.1 run, with a pulse width of 17.2ns and a line width of 2nm, has been achieved, leading to an optical-to-optical conversion efficiency of 24.4%.

Viscoelastic Analysis of a Surface Acoustic Wave Gas Sensor Coated by a New Deposition Technique

An analysis of the response of surface acoustic wave sensors coated with polymer film based on new coating deposition （self-assemble and molecularly imprinted technology） is described and the response formulas are hence deduced. Using the real part of shear modulus, the polymer can be classified into three types： glassy film, glassy-rubbery film and rubbery film, Experimental results show that the attenuation response is in better consistence with the simulation than in Martin＇s theory, but the velocity response does not accord with the calculation exactly. Maybe it is influenced by the experimental methods and environment. In addition, simulations of gas sorption for polymer films are performed. As for glassy film, the SAW sensor response increases with increasing fihn thickness, and the relationship between the sensor response and the concentration of gas is pretty linear, while as for glassy-rubbery flint and rubbery film, the relationship between the sensor sensitivity anti concentration of gas is very complicated. The ultimately calculated results indicate that the relationship between the sensor response and frequency is not always linear due to the viscoelastic prooerties of the polymer.

TRACKING DEFORMABLE AND OCCLUDED OBJECTS USING PARTICLE FILTERING AND GVF-SNAKE

An adaptive object tracking algorithm based on particle filtering and a modified Gradient Vector Flow (GVF) Snake is proposed for tracking moving and deforming objects. The original contours of objects are obtained by using the background differencing method,and the true contours of objects can be converged by means of the powerful searching ability of a modified GVF-Snake. Finally,an Energetic Particle Filtering (EPF) algorithm is obtained by combining particle filtering and a modified GVF-Snake,and by using K-means and the EPF algorithm,multiple objects can be tracked. The proposed tracking tactic for partially occluded objects can effectively improve its anti-occlusion ability. Experiments show that this algorithm can obtain better tracking effect even though the tracked object is occluded.

Numerical simulation of standing waves for ultrasonic purification of magnesium alloy melt

It was attempted to enhance and accelerate the separation of oxidation inclusions from magnesium alloy melt by virtue of ultrasonic agglomeration technology.In order to investigate the feasibility and effectiveness of standing waves for ultrasonic purification of magnesium alloy melt,numerical simulation and relevant experiment were carried out.The numerical simulation was broken into two main aspects.On one hand,the ultrasonic field propagations within the cells with various shapes were characterized by numerical solutions of the wave equation and with a careful choice of geometry a nearly idealized standing wave field was finally obtained.On the other hand,within such a standing wave field the agglomeration behavior of oxidation inclusions in magnesium alloy melt was analyzed and discussed.The agglomeration time and agglomeration position of oxidation inclusions were predicted with numerical simulation method.The results show that the oxidation inclusions whose apparent densities are close to the density of the melt can agglomerate at wave nodes in a short time which to a great extent enhances and accelerates the separation of oxidation inclusions from magnesium alloy melt.

Extracorporeal shock wave lithotripsy for pancreatic and large common bile duct stones

Extraction of large pancreatic and common bile duct(CBD)calculi has always challenged the therapeutic endoscopist.Extracorporeal shockwave lithotripsy(ESWL)is an excellent tool for patients with large pancreatic and CBD calculi that are not amenable to routine endotherapy.Pancreatic calculi in the head and body are targeted by ESWL,with an aim to fragment them to<3 mm diameter so that they can be extracted by subsequent endoscopic retrograde cholangio-pancreatography(ERCP).In our experience,complete clearance of the pancreatic duct was achieved in 76% and partial clearance in 17%of 1006 patients.Short-term pain relief with reduction in the number of analgesics ingested was seen in 84%of these patients.For large CBD calculi,a nasobiliary tube is placed to help target the calculi,as well as bathe the calculi in salinea simple maneuver which helps to facilitate fragmenta-tion.The aim is to fragment calculi to<5 mm size and clear the same during ERCP.Complete clearance of the CBD was achieved in 84.4%of and partial clearance in 12.3%of 283 patients.More than 90%of the patients with pancreatic and biliary calculi needed three or fewer sessions of ESWL with 5000 shocks being de-livered at each session.The use of epidural anesthesia helped in reducing patient movement.This,together with the better focus achieved with newer third-gen-eration lithotripters,prevents collateral tissue damage and minimizes the complications.Complications in our experience with nearly 1300 patients were minimal,and no extension of hospital stay was required.Similar rates of clearance of pancreatic and biliary calculi with minimal adverse effects have been reported from the centers where ESWL is performed regularly.In view of its high efficiency,non-invasive nature and low complication rates,ESWL can be offered as the first-line therapy for selected patients with large pancreatic and CBD calculi.

Identification of Cholera Source in Mariupol City

The cases of cholera in Mariupol and adjacent areas which were observed within the period of May-August, 2011 are investigated. Thirty-two diseased and 22 vibriocarriers were found on the territory of the city in the course of epidemic. The potential sources of infection are specified. The ways to avoid similar situations in the future are suggested. The analysis of the locations of the cholera contamination sources results in the obvious conclusion that most of them are connected with the place where the river Kalmius meets the Azov Sea. Waste flow from the residential solid waste landfill brings a considerable harm to the river Kalmius and the Azov Sea.

Power Generation from Municipal Solid Waste Plastics

Generation of electrical energy from imported fossil fuels is subject to the price fluctuations of the global marketplace and, thus, constitutes a major expense in its distribution to the end users. Even with the current low prices of fuel, residents and businesses in the United States pay a significant price for their utilities, if not higher than most other countries in the world. Emissions from the evaporation and combustion of these traditional fossil fuels contribute to a range of environmental and health problems, causing poor air quality, and emitting greenhouse gases that contribute to global warming. Alternative fuel created from domestic sources has been proposed as a solution to these problems and much alternative energy are being developed based on solar, wind, biomass, hydropower, fuel cell, geothermal, etc. A new alternative hydrocarbon fuel which is produced from waste plastics can be used with compatble power plants and generators appliances to produce electricity that can be supplied into homes, businesses, power grids and other sectors.

Electrostatic Waves in Weakly Magnetized Quantum Plasmas

By using the quantum magnetohydrodynamic model, the electrostatic waves in weakly magnetized quantum plasmas are investigated. The electrons are treated as a quantum and magnetized species, while the ions are classical unmagnetized ones. The general dispersion relations are derived. It is shown that, both the high frequency electron waves （Langmuire wave and upper-hybrid wave） and the low frequency ion acoustic wave can propagate when the plasmas are cold.

Na2ZnSn_2S6:A mixed-metal thiostannate with large second-harmonic generation response activated by penta-tetrahedral [ZnSn4S(14)]^(10-) clusters

A sodium zinc thiostannate Na2ZnSn2S6 is reported with its interesting structural features and property characteristics. It crystallizes in the polar space group Fdd2 （No. 43） with the unit cell parameters ofa=12.945（3） A, b=23.556（5） A, c=7.2774（15）/k and Z=8. In its structure, Zn-centered penta-tetrahedra [ZnSn4S15]Z2- clusters arrange regularly along the diagonals of ab and ac planes to form a 3D tunnel structure with charge-balanced Na＋ cations located inside the tunnels. Note that SnS4 tetrahedra connect with each other by sharing comers to form infinite ∞[SnS3]n chains that are rarely found in known alkali-thiostannates. Remarkably, NazZnSnzS6 exhibits the good NLO performances, such as large SHG response （4 times that of AgGaS2 at 55-88 μm under the 2.09 μm radiation）, wide infrared （IR） transmission region （0.35-25 μm） and relatively high laser damage threshold （77.5 MW/cm2, -2 times that of AgGaS2）. Theoretical calculations have also been performed to investigate the structure-property relationship and the results indicate that the origin of NLO effect can be attributed to the penta-tetrahedra [ZnSn4S15]12- clusters.

Four-Channel Label-Free Photonic Crystal Biosensor Using Nanocavity Resonators

In this paper, we design and characterize a novel small size four-channel biosensor based on the two-dimensional photonic crystal with introducing waveguides and nano-cavities in the hexagonal lattice of air pores in the silicon slab. By removing a group of air pores, waveguides are achieved, and nano-cavities are shaped by modifying the radius of air pores. Highly parallel operation of this biosensor due to the special architecture is the capability of the designed structure. The biomaterials which are suspended in a liquid medium inside nano-cavities cause effective refractive index changes which lead to the resonant wavelength shift in the output terminal. According to results, with increasing the refractive index of nano-cavities, resonant wavelengths shifts to longer values. For biochemical sensing like DNA molecule and protein and for the refractive index detection, this novel designed biosensor can be utilized.

In situ carrier tuning in high temperature superconductor Bi2Sr2CaCu2O(8+δ)by potassium deposition

We report a successful tuning of the hole doping level over a wide range in high temperature superconductor Bi2Sr2CaCu2O8＋δ （Bi2212） through successive in situ potassium （K） deposition. By taking high resolution angleresolved photoemission measurements on the Fermi surface and band structure of an overdoped Bi2212 （To = 76 K） at different stages of K deposition, we found that the area of the hole-like Fermi surface around the Brillouin zone corner （n,n） shrinks with increasing K deposition. This indicates a continuous hole concentration change from initial - 0.26 to eventual 0.09 after extensive K deposition, a net doping level change of 0.17 that makes it possible to bring Bi2212 from being originally overdoped, to optimally-doped, and even- tually becoming heavily underdoped. The electronic behaviors with K deposition are consistent with those of Bi2212 samples with different hole doping levels. These results demonstrate that K deposition is an effective way of in situ controlling the hole concentration in Bi2212. This work opens a good way of studying the doping evolution of electronic structure and establishing the electronic phase diagram in Bi2212 that can be extended to other cuprate superconductors.

Self-Similar Solution of Spherical Shock Wave Propagation in a Mixture of a Gas and Small Solid Particles with Increasing Energy under the Influence of Gravitational Field and Monochromatic Radiation

Similarity solution for a spherical shock wave with or without gravitational field in a dusty gas is studied under the action of monochromatic radiation. It is supposed that dusty gas be a mixture of perfect gas and micro solid particles. Equilibrium flow condition is supposed to be maintained and energy is varying which is continuously supplied by inner expanding surface. It is found that similarity solution exists under the constant initial density. The comparison between the solutions obtained in gravitating and non-gravitating medium is done. It is found that the shock strength increases with an increase in gravitational parameter or ratio of the density of solid particles to the initial density of the gas, whereas an increase in the radiation parameter has decaying effect on the shock waves.