基于数字微镜器件的数字线扫描荧光显微成像技术

在激光扫描共聚焦显微镜的基础上,线扫描荧光显微术利用线扫描代替点扫描,提升图像获取速度,具有系统结构简单、成像速度快、光毒性弱、更适合于活体厚样品的高分辨快速成像,对于生命科学和生物医学等领域的研究具有重要的意义.然而,目前的线扫描显微技术在系统灵活性、成像速度、分辨率和光学层析能力等方面仍面临着许多亟需解决的问题.因此,本文提出一种基于数字微镜器件(digital micromirror device,DMD)的数字线扫描荧光显微(digital line-scanning fluorescence microscopy, DLSFM)成像方法和系统,在照明光路中引入高速空间光调制器DMD实现多线并行扫描激发,简化光学系统,提升系统灵活性和扫描速度;提出基于荧光信号标准差的DLSFM图像重构算法,结合三维Landweber解卷积算法实现了三维高分辨光切片图像重构.在此基础上,利用搭建DLSFM开展了荧光珠和老鼠肾切片标准样品的成像实验,实验结果表明, DLSFM具有快速三维高分辨层析成像能力.

Properties and mechanism of red mud in preparation of ultra-lightweight sludge-red mud ceramics

New ultra-lightweight sludge-red mud ceramics(ULS-RMC) were prepared by red mud(RM),clay and dried sewage sludge(DSS).The properties and mechanism of RM in the preparation of ULS-RMC were discussed.The chemical components,thermal properties and mineral phases of RM were determined by energy dispersive X-ray(EDX),differential scanning calorimetry/thermal gravimetric analysis(DSC/TGA) and X-ray diffraction(XRD),respectively.Constant dosage of DSS to clay and different amounts of RM were utilized in the preparation of ULS-RMC.Physical properties test(bulk density,grain density,water absorption and expansion ratio),XRD and scanning electron microscopy(SEM) were employed to characterize the ULS-RMC.The results show that RM exhibits high hydroscopic property and good water-retention property,and bloating property and fluxing property of RM are caused by abound of gaseous components and flux,respectively.The two chemical properties are utilized to discuss the mineral phases and microstructures differences between ULSC and ULS-RMC.

Sedimentary characteristics and depositional model of a Paleocene-Eocene salt lake in the Jiangling Depression,China

We studied the sedimentary characteristics of a Paleocene-Eocene salt lake in the Jiangling Depression through field core observation,thin section identification,scanning electron microscopy,and X-ray diffraction analysis.On the basis of sedimentary characteristics we have summarized the petrological and mineralogical characteristics of the salt lake and proposed 9 types of grade IV salt rhythms.The deposition shows a desalting to salting order of halite-argillaceous-mudstone-mud dolostonemud anhydrock-glauberite-halite.The relationship among grade IV rhythms,water salinity and climate fluctuations was analyzed.Based on the analysis of the relationship between boron content and mudstone color and by combining the mineralogy and sedimentary environment characteristics,we propose that the early and late Paleocene Shashi Formation in the Jiangling Depression was a paleolacustrine depositional environment with a high salt content,which is a representation of the shallow water salt lake depositional model.The middle Paleocene Shashi Formation and the early Eocene Xingouzui Formation were salt and brackish sedimentary environments with low salt content in a deep paleolake,which represents a deep salt lake depositional model.

Experimental research on electromagnetic continuous casting high-speed steel composite roll

A high speed steel composite roll billet was fabricated, which is regular in shape, smooth in surface, slight in trace, compact in internal structure, free of slag inclusion, shrinkage cavity, cracks and other flaws, and good in macro quality of junction surface using a vertical continuous casting machine. The interface zone microstructure of bimetallic in billet of high speed steel composite roll was analyzed by metallurgical microscope(OM), X-ray diffractmeter(XRD), scanning electron microscopy(SEM) and energy-dispersive X-ray analysis(EDS). The results indicate that the microstructure of roll billet is composed of chilled solidified layer, dendrite zone, interfacial zone of bimetal and core material zone. The microstructure of outer shell material is composed of martensite + bainite + residual austenite + some small labyrinth-shape, small-short lath-shape, or dollop-shape eutectic carbides. The microstructure of core material is slice-shape pearlite and a little ferrite along boundary of cells. The interface region microstructure of bimetallic composite roll consists of diffusion region, chilled solidified layer and columnar grain region.

Liquid-phase preparation and electrochemical property of LiFePO_4/C nanowires

Olivine LiFePO4/C nanowires have been successfully synthesized by a simple and eco-friendly solution preparation.The phase,structure,morphology and composition of the as-prepared products were characterized by powder X-ray diffraction(XRD),scanning electron microscopy(SEM),thermogravimetric and differential-thermogravimetric analysis(TG-DTA) and energy dispersive X-ray spectrometry(EDS) techniques,showing uniform nanowire shape of LiFePO4/C with a diameter of 80-150 nm and a length of several microns.The heat-treated LiFePO4/C nanowires show excellent electrochemical properties of specific discharge capacity,rate capacity and cycling stability.In particular,the LiFePO4/C nanowires heat-treated at 400 °C show preferable first discharge specific capacity of 161 mA·h/g at 0.1C rate,while the voltage platform is 3.4 V and the first discharge specific capacity is 93 mA·h/g at 20C rate.The specific capacity retention is 98% after 50 cycles at 5C rate.

Characterization and recycling of nickel- and chromium-contained pickling sludge generated in production of stainless steel

Pickling sludge generated during the neutralization of pickling wastewater with calcium hydroxide in stainless steel pickling process was characterized using X-ray fluorescence spectrometry, X-ray diffractometry, scanning electron microscopy, thermogravimetry and differential scanning calorimetry, etc. The major compositions of pickling sludge are CaF2, CaSO4, Me（OH）, （M： Fe, Cr, Ni）, and the content of CaF2 is high in the sludge. The melting point of pickling sludge is about 1350℃ and the viscosity is about 0.14 Pa.s at 1450 ℃, which are comparatively lower than those of normal refining slag. After heat treatment, the contents of sulfur and fluorine in the pickling sludge were reduced, confirming the thermal decomposition of sulfate in the sludge. Fluorine in the sludge is reduced by the gaseous SiF4 and A1F3 generated through the reactions of CaF2 with SiO2 and Al2O3. The preliminary results from the reduction test indicate that the sulfur content in the steel is not affected by the presence of sulfur in the sludge. The recovery of nickel is about 40%, and the chromium content changes marginally due to the protective atmosphere under the reduction condition of chromic oxide. The pickling sludge is a potential auxiliary material for the production of stainless steel.

Understanding the Function of Rays and Wood Density on Transverse Fracture Behaviour of Green Wood in Three Species

In recent years, there has been an increasing interest in wood properties, because wood is a commonly used and advanced building material. In this paper, the effect of anatomical characters on the transverse fracture properties of green wood was investigated. The specific fracture energy （Gf J/m2） of ash （Fraxinus excelsior）, cherry （Prunus avium） and birch （Betula pendula） was evaluated using double edge notched tensile tests. The tests were performed on both earlywood （EW） and latewood （LW） zones in both the radial-tangential （RT） and the tangential-radial （TR） crack propagation systems. Wood anatomy and the failure patterns of each species were also investigated using environmental scanning electron microscopy （ESEM） and light microscopy （LMC）. The results showed that the Gfof RT fracture systems was around 1.5 times greater than in the TR one, whereas there were no significant differences between EW and LW zones. ESEM micrographs showed that the RT fracture system had a rougher fracture surface, while the TR had a nearly smooth and fiat fracture surface. In particular, the wood ofF. excelsior was the toughest, because of its greater percentage of rays and homogenous distribution of ray cells, while P. avium and B. pendula showed a lower Gf due to their smaller percentage of rays with a distinctive arrangement of ray cells.

Nanocrystalline Mg and Mg alloy powders by hydriding-dehydriding processing

The process of mechanically assisted hydriding and subsequent thermal dehydriding was proposed to produce nanocrystalline Mg and Mg alloy powders using pure Mg and Mg-5.5%Zn-0.6%Zr(mass fraction)(ZK60 Mg) alloy as the starting materal.The hydriding was achieved by room-temperature reaction milling in hydrogen.The dehydriding was carried out by vacuum annealing of the as-milled powders.The microstructure and morphology of both the as-milled and subsequently dehydrided powders were characterized by X-ray diffraction analysis(XRD) ,transmission electron microscopy(TEM) ,and scanning electron microscopy(SEM) ,respectively.The results show that,by reaction milling in hydrogen,both Mg and ZK60 Mg alloy can be fully hydrided to form nanocrystalline MgH2 with an average grain size of 10 nm.After subsequent thermal dehydriding at 300℃,the MgH2 can be turned into Mg again,and the newly formed Mg grains are nanocrystallines,with an average grain size of 25 nm.

Optimization of High-Gravity Chelated Iron Process for Removing H_2S Based on Response Surface Methodology

By using a mixture of N2 and H2S as the simulated APG(associated petroleum gas), the desulfurization experiment was performed in a cross-flow rotating packed bed(RPB) based on the chelated iron oxidation-reduction method. In order to determine the operating conditions of the system, the effects of the concentration of Fe3+ ions(ranging from 0.1 to 0.2 mol/L), the liquid-gas volume ratio(ranging from 15 to 25 L/m3) and the high gravity factor(ranging from 36 to 126) on the removal of H2 S were studied by means of the Box-Behnken design(BBD) under response surface methodology(RSM). The overall results have demonstrated that the BBD with an experimental design can be used effectively in the optimization of the desulfurization process. The optimal conditions based on both individualized and combined responses(at a Fe3+ ion concentration of 0.16 mol/L, a liquid-gas volume ratio of 20.67 L/m3 and a high gravity factor of 87) were found. Under this optimum condition, the desulfurization efficiency could reach 98.81% when the H2 S concentration was 7 g/m3 in APG. In this work, the sulfur product was analyzed by X-ray diffraction(XRD), scanning electron microscopy(SEM) and the energy dispersive X-ray spectrometer(EDX). The results of analysis show that the sulfur is made of the high-purity orthorhombic crystals, which are advantageous to environmental conservation.

Carbonaceous Adsorbents Prepared from Sewage Sludge and Its Application for Hg^0 Adsorption in Simulated Flue Gas

The carbonaceous adsorbent was prepared from mixtures of dewatered sludge and sawdust with enhanced ZnCl2 chemical activation.Characteristics of the adsorbent were studied using scanning electron microscope(SEM) ,Fourier transform infrared spectroscopy(FT-IR) ,and adsorption of nitrogen.The surface analysis showed that the carbonaceous adsorbent had good specific surface and porosity(394 m 2 ·g-1of BET surface,0.12 and 0.10 ml·g-1of microporous and mesoporous volume,respectively) .The oxygen functional groups such as OH,C O and C O were found on the surface by FTIR and XPS(X-ray photoelectron spectroscopy) .The adsorption of elemental mercury(Hg0) on the carbonaceous adsorbent was studied in a fixed bed reactor.The dynamic adsorption capacity of carbonaceous adsorbent increased with influent mercury concentration,from 23.6μg·g-1at 12.58μg·m-3to 87.9μg·g-1at 72.50μg·m-3,and decreased as the adsorption temperature increased,from 246 μg·g-1 at 25°C to 61.3μg·g-1 at 140°C,when dry nitrogen was used as the carrier gas.The carbonaceous adsorbent presented higher dynamic adsorption capacity than activated carbon,which was 81.2μg·g-1and 53.8μg·g-1respectively.The adsorption data were fitted to the Langmuir adsorption model.The physical and chemical adsorption were identified on the adsorbent.

Wear mechanism for spray deposited Al-Si/SiC_p composites under dry sliding condition

Al-Si/15%SiCp(volume fraction) composites with different silicon contents were fabricated by spray deposition technique, and typical microstructures of these composites were studied by optical microscopy(OM). Dry sliding wear tests were carried out using a block-on-ring wear machine to investigate the effect of applied load range of 10-220 N on the wear and friction behavior of these composites sliding against SAE 52100 grade bearing steel. Scanning electron microscopy(SEM) and energy-dispersive X-ray microanalysis(EDAX) were utilized to examine the morphologies of the worn surfaces in order to observe the wear characteristics and investigate the wear mechanism. The results show that the wear behavior of these composites is dependent on the silicon content in the matrix alloy and the applied load. Al-Si/15%SiCp composites with higher silicon content exhibit better wear resistance in the applied load range. Under lower loads, the major wear mechanisms are oxidation wear and abrasive wear for all tested composites. Under higher loads, severe adhesive wear becomes the main wear mechanisms for Al-7Si/15%SiCp and Al-13Si/15%SiCp composites, while Al-20Si/15%SiCp presents a compound wear mechanism, consisting of oxidation, abrasive wear and adhesion wear.

Influence of synthesis parameters on the properties of LiFePO4/C cathode material

The influence of sintering temperature, carbon content and dispersive agent in bail-milling was investigated on the properties of LiFePO4/C prepared using Fe2O3, NH4H2PO4, Li2CO3 and glucose via solid state reaction. X-ray powder diffraction, scanning electron microscopy and charge-discharge test were applied to the characterization of the LiFePO4/C samples synthesized under different conditions. Sintering temperature affects the crystallite/ particle size and degree ofcrystallinity of LiFePO4, formation of Fe2P and maintenance of carbon in LiFePO4/C. Car- bon maintenance is favored by low sintering temperature, and 700 ℃ is optimum for synthesis of LiFePO4/C with superior electrochemical performance. A higher carbon content in the range of 4.48%-11.03% results in a better rate capability for LiFePO4/C. The dispersive agent used in ball-milling impacts the existent state of carbon in the final product which subsequently determines its charge-discharge behavior. The sample prepared at 700 ℃ by using acetone as the dispersive agent in ball-milling exhibits an excellent rate capability and capacity retention without any fade at 0.1 C, 1C and 2C, with corresponding average discharge capacities of 153.8, 128.3 and 121.0 mA·h·g-1. rest2ectivelv, in the first 50 cvcles.

Synthesis of Li_2Fe_(0.9)Mn_(0.1)SiO_4/C composites using glucose as carbon source

Li2Fe0.9Mn0.1SiO4/C composites were synthesized by using X-ray diffractometry （XRD）, scanning electron microscopy （SEM） glucose as carbon source. The samples were characterized by and electrochemical measurements. All Li2Fe0.9Mn0.1SiO4/C composites are of the similar crystal structure. With increasing the carbon content in the range of 5%-20% （mass fraction）, the diffraction peaks in XRD patterns broaden and the particle sizes and the tap density of samples decrease. The Li2Fe0.9Mn0.1SiO4/C composites with carbon content of 14.12% show excellent electrochemical performances with an initial discharge capacity of 154.7 mA.h/g at C/16 rate, and the capacity retention remains 92.2% after 30 cycles.

Recovery of high specific area silica and sodium fluoride from sodium hexafluorosilicate

Sodium fluoride and high specific area silica were synthesized by using sodium hexafluorosilicate(Na2Si F6) and sodium carbonate decahydrate(Na2CO3·10H2O). The influencing factors of react temperature, contact time, sodium dodecyl sulfate(SDS) and molar ratio of Na2 Si F6 to Na2CO3·10H2O were investigated. The optimum process involves the reaction of 0.075 mol Na2 Si F6 and 150 m L, 0.225 mol Na2CO3·10H2O(molar ratio of 1:3) at 85 °C for 90 min, and 2.0×10-3 mol sodium dodecyl sulfate(SDS) as additive. The results show that the purities of Si O2 and Na F at extraction yields of 96.5% and 98.0% are 91.0% and 98.6%, respectively. The obtained Si O2 were characterized by X-ray diffraction(XRD), scanning electron microscope(SEM), Fourier transform infrared ray(FTIR), differential scanning calorimetry and thermogravimetric analysis(DSC-TGA), N2 absorption/desorption(BET) and laser particle size analyzer. The result demonstrates that Si O2 particles have a high BET surface area of 103 m2/g, and a mean grain size of 985 nm.

Liquidus and phase equilibria in CaO-SiO2-5%MgO-20%Al2O3-TiO2 system

The single hot thermocouple technique （SHTT） and high temperature equilibrium technique were combined to investigate the phase diagram of the CaO-SiO2-5%MgO-20%AlzO3-TiO2 system. The 1300 ℃ to 1500 ℃ liquidus lines are calculated according to the thermodynamic equations based on the pseudo-melting temperatures measured by the single hot thermocouple technique. The phase equilibria relationships are experimentally determined at 1400 ℃ using the high temperature equilibria technique followed by X-ray fluorescence （XRF）, X-ray diffraction（XRD）, scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDX） analysis. The liquid phase（L）, melilite solid solution phase （（C2MSz,C2AS）ss）, diopside phase（CMS2） and perovskite phase （CaO·TiO2） are found. Coupled with the liquidus lines and equilibria results, the phase diagram is constructed for the specified region of the CaO-SiO2-5%MgO-20%Al2O3-TiO2 system.

Synthesis of Macro-Mesostructured γ-Al_2O_3 with Large Pore Volume and High Surface Area by a Facile Secondary Reforming Method

Through improving the aging process during synthesis of the support, γ-Al2O3 with large pore volume and high surface area was synthesized by a facile secondary reforming method. The synthesis parameters, such as the reaction temperature, the first aging temperature and the second aging temperature, were investigated. The textural properties of γ-Al2O3 were characterized by means of N2 adsorption-desorption isotherms, X-ray powder diffractometry （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared （FTIR） spectroscopy and thermogravimetry （TG）. The experimental results indicated that AACH and amorphous A1OOH were the precursors of alumina, which were formed via precipitation from solutions after reaction of aluminum sulphate with ammonium hydrogen carbonate. The precursor nanocrystallites grew and re-assembled during the secondary reforming process, which resulted in an increased pore size and pore volume and a decreased bulk density. The as-synthesized γ-Al2O3 materials featured meso/macroporosity, large pore volume （2.175 cm^3/g）, high surface area （237.8 m^2/g）, and low bulk density （0.284 g/mL）.

Improvement of Magnetic Field on Tribological Properties of Lubricating Oils with Zinc Butyloctyldithiophosphate

Tribological properties of 150 SN mineral oil and the oils doped with different contents of zinc butyloctyldithiophosphate(T202) under magnetic field or non-magnetic field were evaluated on a four-ball tribotester by applying an external magnetic field around the friction region. Moreover, the morphology and the tribochemical characteristics of worn surfaces were examined by a scanning electron microscope(SEM) and an X-ray photoelectron spectrometer(XPS). Then the lubrication mechanisms were discussed. The tribological test results indicated that the wear scar diameters(WSDs) of steel balls lubricated by the T202-containing lubricating oils and the friction coefficients of the corresponding oil under magnetic field were smaller than those without magnetic affection. The worn surface lubricated with the T202-formulated oils in a magnetic field was smoother than that obtained under the normal condition. Furthermore, the results of XPS analysis indicated that tribochemical films on the surfaces lubricated with T202-doped oils were mainly composed of compounds such as FeSO_4, FeS and ZnS. The atomic concentrations of oxygen, sulfur, iron, zinc and phosphorus species identified in T202 under magnetic field were higher than those without magnetic impact. It can be inferred that the improved anti-wear and friction-reducing ability of T202-doped oils was attributed to the promoted tribochemical reactions and the modification of the worn surfaces induced by magnetic field.

Effects of ultrasonic dispersion on structure of electrodeposited Ni coating on AZ91D magnesium alloy

To obtain the refined electrodeposited nickel layer on AZ91D magnesium alloy,ultrasonic technology was applied in the processes of pre-treatment and electrodeposition.The phases of pre-treatment layer and the nickel coating were analyzed by X-ray diffractometry(XRD)and X-ray photoelectron spectroscopy(XPS),and the microstructure was observed by scanning electron microscopy(SEM).Then,the effects of ultrasonic dispersion on the microstructure of pre-treatment layer and the grain refinement of electrodeposited nickel layer were discussed.The results showed that the pre-treatment electrodeposited Cu-Sn layer with compact microstructure could be synthesized in alkaline copper-tin liquid with ultrasonic agitation,as a result,smooth and refined nickel coating formed on AZ91D magnesium alloy.On the other hand,preferred orientation in the coating decreased because of the refined grains.

Tribological Performances of Fatty Acyl Amino Acids Used as Green Additives in Lubricating Oil

The friction and wear characteristics of lauroyl glutamine, lauroyl glycine and lauroyl alanine, used as green additives in HVI 350 mineral lubricating oil, were evaluated on a four-ball tribotester. The morphologies and chemical species of the worn surfaces were analyzed by scanning electron microscope （SEM） and X-ray photoelectron spectroscope （XPS）, respectively. The test results indicated that the three fatty acyl amino acids could effectively improve the anti-wear and friction-reducing abilities of the HVI 350 mineral oil. The improvement in anti-wear and friction-reducing abilities of the mineral oil by the related amino acids was mainly ascribed to the formation of a composite boundary lubrication film due to the adsorption of amino acids on the friction surfaces.

Process mineralogy of copper-nickel sulphide flotation by a cyclonic-static micro-bubble flotation column

In our study we investigated a refractory copper-nickel sulfide ore separation by using a cyclonic-static micro-bubble flotation column (FCSMC). The process mineralogy of the main products was studied. Using a scanning electron microscope-energy dispersive system (SEM-EDS) and an X-ray spectrometer the mineral category and content of samples were analyzed. By using a mineral liberation analyzer (MLA) the mineral liberation characteristics were revealed. It is shown that in roughing feed the monomers liberation degree of nickel pyrite and chalcopyrite take up 84.11% and 88.82%, respectively. In tailings, the lost nickel pyrite and chalcopyrite are mainly monomers. Therefore, strengthening the micro-fine particle recovery capacity is the key to increase recovery.