Fine debismuthizing with calcium,magnesium and antimony

In order to achieve fine debismuthizing of lead bullion,the effects of temperature,adding amount of calcium and magnesium and antimony on the bismuth removal from lead bullion were investigated.The mechanism of debismuthizing was also discussed.The results show that when adding amounts of calcium and magnesium reach 0.112% and 0.395%,respectively,bismuth level of 0.001%（mass fraction） in the final lead is achieved at 330 ℃,without the need for antimony addition.Maintaining addition amount of magnesium at 0.155%,when calcium addition amount is less than 0.09%,the concentration of peritectic reaction point,the bismuth concentration can be easily decreased to 0.001% by the following antimony treatment.But the effect of antimony treatment on debismuthizing gets bad if the calcium addition exceeds 0.09%.

Oilfield produced water treatment in internal-loop airlift reactor using electrocoagulation/flotation technique

Oilfield produced water is large quantities of salty water trapped in underground formations and subsisted under high temperatures and pressures that are brought to the surface along with oil during production. Produced water(PW) contains a lot of pollutants such as hydrocarbons and metals, this water must be treated before disposal. Therefore, different techniques are being used to treat produced water. Electrocoagulation is an efficient treatment technique involving the dissolution of anodes and formation of electro-coagulants, while the simultaneous generation of H_2 bubbles at the cathode leads to the pollutant removal by flotation. Electrocoagulation(EC)method is one of the most promising and widely used processes to treat oilfield produced water. In the present work, a conventional internal-loop(draught tube) airlift reactor was utilized as electrocoagulation/flotation cell for PW treatment by inserting two aluminum electrodes in the riser section of the airlift reactor. The EC airlift reactor was operated in a batch mode for the liquid phase. Different experimental parameters were studied on the oil and turbidity removal efficiencies such as current density, initial pH, electrocoagulation time, and air injection.The experimental results showed that mixing of the oil droplets in the PW was accomplished using only the liquid recirculation resulted by H_2 microbubbles generated by EC process which enhanced the oil removal. The experimental results further showed that the EC time required achieving ≥ 90% oil removal efficiency decreases from 46 to 15 min when operating current density increases from 6.8 to 45.5 mA·cm^(-2). This reactor type was found to be highly efficient and less energy consuming compared to conventional existing electrochemical cells which used mechanical agitation.

High-temperature thermal stability of C/C−ZrC−SiC composites via region labeling method

To investigate the thermal stability of ceramic-matrix composites,three kinds of C/C−ZrC−SiC composites with different Zr/Si molar ratios were synthesized by reactive melt infiltration.Employing region labeling method,the high-temperature thermal stability of the composites was systematically studied by changing the temperature and holding time of thermal treatment.Results show that the mass loss rate of low Si composites has a growth trend with increasing temperature,and a crystal transformation from β-SiC toα-SiC occurs in the composites.In the calibrated area,SiC phase experiences Ostwald ripening and volume change with location migration,while ZrC phase experiences a re-sintering process with diffusion.Moreover,it is found that increasing temperature has a more obvious effect on the thermal stability than extending holding time,which is mainly attributed to the faster diffusion rate of atoms.

Exploring the Wenchuan earthquake fault through the accurate location of WFSD-4#Well using seismic reflection

Deep drilling data on seismogenic faults that are obtained directly can help in understanding earthquake mechanisms and the resulting changes in deep structure and material composition.However,geophysical data are necessary to ensure that the planned borehole accurately drills through the target faults.In this study,the deep crustal structure of the Longmenshan fault is explored to obtain seismogenic fault characteristics of the Wenchuan earthquake.A scientific drilling project,Wenchuan Earthquake Fault Scientific Drilling No.4 Borehole(WFSD-4)is proposed with a borehole designed to drill through the north section of the fault zone while penetrating as many geological bodies and target layers related to seismogenic fault slip as possible.High-precision seismic exploration is then carried out to study the deep structure of the fault zone and achieve the scientific objective of the borehole.Two high-precision deep seismic reflection lines were arranged perpendicularly to the fault zone,and data were obtained through special acquisition schemes and processing methods.Finally,the surface position and drilling depth route of WFSD-4 are determined based on the interpretation results of seismic profiles.The seismic reflection method for site selection of the Wenchuan earthquake fault scientific drilling is proven feasible by comparing the interpretation with the actual drilling results,laying the foundation for further study on the deep structures of fault zones.

Seismic Data Processing and Interpretation on the Loess Plateau, Part 2: Seismic Data Interpretation

The loess plateau covering the North Shaanxi slope and Tianhuan depression consists of a regional monocline, high in the east and low in the west, with dips of less than 1^0, Structural movement in this region was weak so that faults and local structures were not well developed. As a result, numerous wide and gentle noses and small traps with magnitudes less than 50 m were developed on the large westward-dipping monocline. Reservoirs, including Mesozoic oil reservoirs and Paleozoic gas reservoirs in the Ordos Basin, are dominantly lithologic with a small number of structural reservoirs. Single reservoirs are characterized as thin with large lateral variations, strong anisotropy, low porosity, low permeability, and low richness. A series of approaches for predicting reservoir thickness, physical properties, and hydrocarbon potential of subtle lithologic reservoirs was established based on the interpretation of erosion surfaces.

FEATURE PRESERVING IMAGE INTERPOLATION BY ADAPTIVE BIDIRECTIONAL FLOW

Most image interpolation algorithms currently used suffer visually to some extent the effects of blurred edges and jagged artifacts in the image. This letter presents an adaptive feature preserving bidirectional flow process, where an inverse diffusion is performed to enhance edges along the normal directions to the iso-phote lines (edges), while a normal diffusion is done to remove artifacts ('jaggies') along the tangent directions. In order to preserve image features such as edges, angles and textures, the nonlinear diffusion coefficients are locally adjusted according to the first order and the second order directional derivatives of the image. Experimental results on the Lena image demonstrate that our interpolation algorithm substantially improves the subjective quality of the interpolated images over conventional interpolations.

AN ANALYSIS ON THE ACCIDENT OF PNEUMOTHORAX INDUCED BY INCORRECT ACUPUNCTURE TREATMENT

Acupuncture induced pneumothorax is a rarely seen clinical accident. In the present paper, the authors analyze its causes of onset, clinical manifestations and measures for prevention and management.

A Decentralized Parallel One-Pass Fixed-Interval Deconvolution Algorithm for Multisensor Systems with Multiplicative Noises

A decentralized parallel one-pass deconvolution algorithm for multisensor systems with multiplicative noises is proposed. Comparing with the conventional deconvolution algorithm, it avoids the computational overload and the high storage requirement. The algorithm is optimal in the sense of linear minimum-variance. The simulation results illustrate the validity of the proposed algorithm.

Carbon spheres prepared via solvent-thermal reaction method and their microstructures after high temperature treatment

Carbon spheres with size of 50-300 nm were synthesized via a solvent-thermal reaction with calcium carbide and chloroform as reactants in a sealed autoclave.The morphologies and microstructures of carbon spheres before and after high temperature treatment(HTT) were characterized by X-ray diffractometry(XRD) ,scanning electronic microscopy(SEM) ,energy diffraction spectroscopy(EDS) ,and transmission electron microscopy(TEM) .The formation mechanism of carbon spheres was discussed.The results indicate that the carbon spheres convert to hollow polyhedron through HTT.Carbon spheres are composed of entangled and curve graphitic layers with short range order similar to cotton structure,and carbon polyhedron with dimension of 50-250 nm and shell thickness of 15-30 nm.The change of solid spheres to hollow polyhedron with branches gives a new evidence for formation mechanism of hollow carbon spheres.

Neural network identification for underwater vehicle motion control system based on hybrid learning algorithm

Based on the structure of Elman and Jordan neural networks, a new dynamic neural network is constructed. The network can remember the past state of the hidden layer and adjust the effect of the past signal to the current value in real-time. And in order to enhance the signal processing capabilities, the feedback of output layer nodes is increased. A hybrid learning algorithm based on genetic algorithm （GA） and error back propagation algorithm （BP） is used to adjust the weight values of the network, which can accelerate the rate of convergence and avoid getting into local optimum. Finally, the improved neural network is utilized to identify underwater vehicle （UV） ＇ s hydrodynamic model, and the simulation results show that the neural network based on hybrid learning algorithm can improve the learning rate of convergence and identification nrecision.

Aniline destruction by supercritical water oxidation and its reaction kinetics

Supercritical water oxidation （SCWO） is an effective method for wastewater treatment. In this study, a lot of experiments are carried out to study the influence of various factors on the aniline destruction rate in the SCWO process with a novel experiment setup. The experimental results show that the aniline destruction rate rises with the increase of the residence time, the reaction temperature and the reaction pressure. A dynamics analysis of the aniline SCWO reaction is conducted and the dynamic equation is obtained.

The Status of the Isotope Separation by PSP

Experiments, prqiects and patents, concerning practical usage of a separation method, based on ICR （ion cyclotron resonance） in plasma, carried out in the 2000s in USA, EU and in Russia, are discussed in this article. It was planned to use ICR method for production of isotopically enriched burnable poisons for nuclear reactor fuel, and also to use this method for extraction of neutron-excess isotopes for the purpose of observation of neutrinoless double beta decay （ββ0v）. One more application of this method can be a nuclear waste treatment technology. Current situation with realization of these plans is considered.

Jacobian matrix for the inversion of P-and S-wave velocities and its accurate computation method

The optimization inversion method based on derivatives is an important inversion technique in seismic data processing,where the key problem is how to compute the Jacobian matrix.The computation precision of the Jacobian matrix directly influences the success of the optimization inversion method.Currently,all AVO(Amplitude Versus Offset) inversion techniques are based on approximate expressions of Zoeppritz equations to obtain derivatives.As a result,the computation precision and application range of these AVO inversions are restricted undesirably.In order to improve the computation precision and to extend the application range of AVO inversions,the partial derivative equation(Jacobian matrix equation(JME) for the P-and S-wave velocities inversion) is established with Zoeppritz equations,and the derivatives of each matrix entry with respect to Pand S-wave velocities are derived.By solving the JME,we obtain the partial derivatives of the seismic wave reflection coefficients(RCs) with respect to P-and S-wave velocities,respectively,which are then used to invert for P-and S-wave velocities.To better understand the behavior of the new method,we plot partial derivatives of the seismic wave reflection coefficients,analyze the characteristics of these curves,and present new understandings for the derivatives acquired from in-depth analysis.Because only a linear system of equations is solved in our method,the computation of Jacobian matrix is not only of high precision but also is fast and efficient.Finally,the theoretical foundation is established so that we can further study inversion problems involving layered structures(including those with large incident angle) and can further improve computational speed and precision.