RESEARCH OF VOXELIZATION PROCESS IN SWEPT-VOLUME TECHNIQUE

Now the image display techniques have made great progress. The planar display and a fully new true 3-D volumetric display technique are rapidly researched and come into the application. A method based on the voxel makes the observer able to get a true 3-D effect freely without any additional facilities. This paper introduces the basic form of the swept-volume display technique and discusses its voxelization process. By the translational motion prototype, this paper emphasizes how to get the voxel mapping matrix. The translated image data are the data of the beam source deflections. Finally the voxel ordering and the optimizing are also discussed.

Taper barrel rheomoulding process for semi-solid slurry preparation and microstructure evolution of A356 aluminum alloy

The self-developed taper barrel rheomoulding (TBR) machine for light alloy semi-solid slurry preparation was introduced.The semi-solid slurry was obtained from the intense shearing turbulence of the alloy melt in the cause of solidification, which was further caused by the relative rotation of the internal and external taper barrel whose surface contained wale and groove.The heat transmission model of TBR process, the flow rules and the shearing model of the alloy melt were deduced.Taking A365 as experimental material, the microstructure evolution rules under different slurry preparation processes were analyzed.The results show that decreasing the pouring temperature of A365 alloy melt properly or increasing the shearing rate helps to obtain ideal semi-solid microstructure with the primary particle size of about 70 μm and the shape factor of above 0.8.

Formation and evolution of Emeishan basalt saprolite in vadose zones of Touzhai landslide source rockmass

In order to explain the formation process of slope hazards, and to identify the key factors leading to instability of a slope, Emeishan basalt saprolite in vadose zones of the Touzhai landslide in Zhaotong, Yunnan, was studied. The formation and evolution of Emeishan basalt saprolite was examined using, amongst other techniques, field investigations,thin section analysis, scanning electron microscopy(SEM) observations, chemical analysis, physical and water-physical property tests of rock masses. Field observations revealed that the majority of the weathered rock blocks were presented as a concentric layer structure in which an internal corestone was enveloped with several layers of external saprolized crust. Chemical and mineralogical analysis identified that iron was the most sensitive element and that the weathering progress usually started with the oxidation of Fe2+ to Fe3+ in rock blocks. Alkaline elements such as Si, Ca, Mg, Na and K were also dissolved and Fe and Al were concentrated in saprolized crusts. Results indicated that loss on ignition(LOI) also increased significantly. SEM results showed that the weathering intensity of thebasalt blocks decreased gradually from the outside to the inside, and the mineral morphology significantly differed on both sides of the weathering front. The saprolized crusts presented cellular microstructure features due to the generation of micropore and clay minerals. Thin section analysis showed that plagioclase was relatively more stable than pyroxene and chlorite during weathering. With a centripetal propagation of the weathering front, saprolized crusts became thicker and corestones became smaller; fresh Emeishan basalt blocks gradually turned into saprolized blocks. Due to the loose structure and low strength of saprolite, the quality of the Emeishan basalt mass significantly deteriorated, this being a potentially important factor which caused the Touzhai landslide to occur.

Study of Biofilm Formed by Lactic Acid Bacteria on the Surface of Mild Steel

Biocorrosion processes at metal surfaces are associated with microorganisms, or the products of their metabolic activities including enzymes, exopolymers, organic and inorganic acids, as well as volatile compounds such as ammonia or hydrogen sulfde. It was proved that strain Lactobacillus delbrueckii B5 constituted biofilms in the presence of different amounts of carbohydrates （5% sucrose and a mixture of 5% lactose, 5% fructose and 5% maltose）. The obtained information was used in a study treating the anticorrosive properties of microbial biofilms synthesized by the latter strain. The study of the corrosive stability of steel samples was conducted on the gravimetrique method. The rate of corrosion, calculated. The structure of layer over steel plates was analyzed by the degree of protection, and coefficient of protection has been Scanning Electron Microscopy （SEM） JSM 5510.

Electron Beam Application for Regeneration of Catalysts Used in Refinery Cracking Units

A catalyst is a substance that alters the rate of a reaction. The process of catalysis is essential to the modem day manufacturing industry, mainly in FCC （Fluid Catalytic Cracking） process units. However, long-term exploitation of oil and gas processing catalysts leads to formation of carbon- and sulfur-containing structures of coke and dense products on the catalyst surface. They block reactive catalyst sites and reduce the catalytic activity. The main advantage of radiation processing by EB （electron beam） and gamma rays is chain cracking reaction in crude oil. Otherwise, under exposure to ionize radiation, considerable structure modification of equilibrium silica-alumina catalyst from FCC process may occur, in addition to the removal of impurities. The conditions applied in the irradiation range （20-150 kGy） of gamma rays and EB were not sufficient to alter the structure of the catalyst, whether for removal of the contaminant nickel, a major contaminant of the FCC catalyst, either to rupture of the crystalline structure either for the future reutilization of chemical elements. ATR-FTIR （Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy and EDXRFS （Energy Dispersive X-Ray Fluorescence Spectrometry） analysis were used to characterize and evaluate effects of radiation processing on equilibrium catalysts purification. To evaluate and comprehend the reactive catalyst sites, SEM （Scanning Electron Microscopy） and particle size distribution analyses were carried out.

Electrocatalytic behaviour of Ni and NiCu alloy modified glassy carbon electrode in electro-oxidation of contraflam

The electrocatalytic oxidation of contraflam was investigated in alkaline solution on nickel and nickel–copper alloy modified glassy carbon electrodes(GC/Ni and GC/NiCu). We prepared these electrodes by galvanostatic deposition and the surface morphologies and compositions of electrodes were determined by energy-dispersive X-ray(EDX) and scanning electron microscopy(SEM). Cyclic voltammetry and chronoamperometric methods were employed to characterize the oxidation process and its kinetics. Voltammetric studies exhibit one pair of well-defined redox peaks, which is ascribed to the redox process of the nickel and followed by the greatly enhanced current response of the anodic peak in the presence of contraflam and a decrease in the corresponding cathodic current peak. This indicates that the immobilized redox mediator on the electrode surface was oxidized contraflam via an electrocatalytic mechanism. The catalytic currents increased linearly with the concentration of contraflam in the range of 0.25– 1.5 mmol/L. The anodic peak currents were linearly proportional to the square root of scan rate. This behaviour is the characteristic of a diffusion-controlled process. The determination of contraflam in capsules is applied satisfactorily by modified electrode.

借力图象思维 提升核心素养

借力图象思维,能很好地表达规律、理解规律、拓展规律,能清晰地呈现过程、简化过程、显化过程,从而提升解决问题的能力。

论物理教学中科学思维核心素养的落实途径

模型建构、科学推理、科学论证、质疑创新是物理学科核心素养中科学思维这一素养的四个主要方面。但目前教学中还存在诸如机械记忆模型、忽视推理过程、对科学论证教学缺乏清晰的理论认知、教学问题难以触发学生的质疑等问题。要把科学思维这一核心素养在教学中落到实处,必须要重视以下相应四个方面的教学:以实际问题进行模型建构;不可缺失的科学推理的过程教学;注重显化科学论证的要素和过程;重视质疑教学,发展学生思维的批判性与独创性。

Mass transfer,detection and repair technologies in micro-LED displays

Micro-light emitting diode(micro-LED)is an emerging display technology with excellent performance of high contrast,low power consumption,long lifetime,and fast response time compared with the current display(e.g.,liquid crystal and organic LED(OLED)).With technological advantages,micro-LED holds promise to be widely applied in augmented reality(AR),flexible screens,etc.and is thus regarded as the next generation of display technology.In the process flow of micro-LED,the step known as mass transfer that requires transferring millions of micro-LEDs from a growth substrate to a display plane,is one of the key challenges limiting the commercialization of micro-LED from laboratory.Worldwide academic and industrial efforts have been devoted to developing mass transfer strategies with purposes of improving yield and reducing cost.Herein we review three main categories of mass transfer technologies for micro-LED display(pick-and-place,fluid self-assembly and laser-enabled advanced placement)and the coupled detection and repair technologies after transfer.Discussions and comparisons have been provided about the underlying general principle,history,and representative parties,advantages,and disadvantages(yield/efficiency/cost)of these technologies.We further envision the application prospect of these transfer technologies and the promise of the future display of micro-LED.

Pathways related to PMA-differentiated THP1 human monocytic leukemia cells revealed by RNA-Seq

Previous analyses have reported that the human monocytic cell line THP1 can be differentiated into cells with macrophage-like characteristics by phorbol 12-myristate 13-acetate(PMA). However, little is known about the mechanism responsible for regulating this differentiation process. Here, we performed high-throughput RNA-Seq analysis to investigate the genes differently expressed in THP1 cells treated with and without PMA and examined those that may be responsible for the PMA-induced differentiation of monocytes into macrophages. We found 3,000 genes to be differentially expressed after PMA treatment. Gene ontology analysis revealed that genes related to cellular processes and regulation of biological processes were significantly enriched. KEGG analysis also demonstrated that the differentially expressed genes(DEGs) were significantly enriched in the PI3K/AKT signaling pathway and phagosome pathway. Importantly, we reveal an important role of the PI3K/AKT pathway in PMA-induced THP1 cell differentiation. The identified DEGs and pathways may facilitate further study of the detailed molecular mechanisms of THP1 differentiation. Thus, our results provide numerous potential therapeutic targets for modulation of the differentiation of this disease.

Electrooxidation of ethylene glycol using gold nanoparticles electrodeposited on pencil graphite in alkaline medium

The electrooxidation of ethylene glycol(EG) on the surface of gold nanoparticles(AuNPs) in alkaline medium was investigated.AuNPs were electrodeposited on pencil graphite(PG) by fast scan cyclic voltammetry.Different sizes of AuNPs deposited on the surface of PG(AuNPs/PG) were used for the electrooxidation process.AuNPs were electrodeposited on PG at various deposition times in the same potential range but with different scan rates and scan cycles.Scanning electron microscopy(SEM),transmission electron microscopy(TEM) and X-ray diffraction(XRD) were used to visualize and characterize the prepared AuNPs/PG electrodes.Cyclic voltammograms were also used to investigate the electrooxidation of EG.The effects of EG and supporting electrolyte concentrations,scan rate,particle size of AuNPs and final potential limit on the electrooxidation process have been investigated.Further studies showed that the electrooxidation of EG is affected by temperature of the medium.The prepared AuNPs showed stability after long-term use.

Robust reduction of graphene fluoride using an electrostatically biased scanning probe

We report a novel and easily accessible method to chemically reduce graphene fluoride （GF） sheets with nanoscopic precision using high electrostatic fields generated between an atomic force microscope （AFM） tip and the GF substrate. Reduction of fluorine by the electric field produces graphene nanoribbons （GNR） with a width of 105-1,800 nm with sheet resistivity drastically decreased from 〉1 TΩ.sq.^-1 （GF） down to 46 kΩ.sq.^-1 （GNR）. Fluorine reduction also changes the topography, friction, and work function of the GF. Kelvin probe force microscopy measurements indicate that the work function of GF is 180-280 meV greater than that of graphene. The reduction process was optimized by varying the AFM probe velocity between 1.2 μm.s^-1 and 12 μm.s^-1 and the bias voltage applied to the sample between -8 and -12 V. The electrostatic field required to remove fluorine from carbon is -1.6 V.nm-1. Reduction of the fluorine may be due to the softening of the C-F bond in this intense field or to the accumulation and hydrolysis of adventitious water into a meniscus.