Search

A 600 MW coal-fired power plant was taken as the object. How to optimize the operations conditions to keep good economics was investigated. The results show that the turbine heat rate of this unit after class I, II correction and aging correction was lower than the designed value. The unit was operated under good conditions. Throttling can decrease the performance ability of the steam in the turbine. Decreasing the throttling loss is beneficial to enhance the economics of the coal-fired power plant in practice.

In the concrete salt-soaking durability test, the dynamic elastic modulus of concrete is more sensitive to the concrete damage than the mass, and can reflect the concrete durability better. In this paper,the relative dynamic elastic modulus of concrete is used as the evaluation index of concrete durability. Its attenuation law is made the multiple linear regression by using MATLAB software. The evaluation model and its applicable conditions of the relative dynamic elastic modulus of air-entraining concrete under the action of the long-term salt immersion are obtained, which can be used to evaluate and precast the durable degree of air-entraining concrete in the salt environment.

In this paper, under the environment of saline soil in the western region of Jilin Province, a series tests research on the durability of concrete has been made. The test results show that: there are a lot of factors that influence the durability of concrete, including the concrete itself internal factors and the external environmental factors. The correlation degrees between these influence factors and the durability of concrete are uncertain. In this paper, a grey correlation degree method has been used to analyze the correlation degrees between these influence factors and the dynamic elastic modulus loss rates of concrete, in order to determine the influence degree of each factor on the durability of concrete.

Under the saline soil environment in the western area of Jilin Province, the concrete durability is affected by a lot of factors, which include wet-dry cycles, freeze-thaw cycles, wet-dry and freeze-thaw cycles, salt soaking time, salts concentration, fly-ash content, air content. These factors impact on the durability of concrete is uncertain, and there may be a problem of duplicate action, with some roughness characteristics. In this article, the rough set theory is used to analyze the degree that these seven factors affect the concrete durability, and to calculate weights. In this article, the loss rate of dynamic elasticity modulus is looked as the evaluation index of concrete durability. The results show that: the importance degrees of 7 factors influencing the loss rate of concrete dynamic elasticity modulus in order are: wet-dry and freeze-thaw cycles > wet-dry cycle > freeze-thaw cycles > multiple salts concentration > air content > long-term soak > fly-ash content.

This article take LuoCheng MuLao Nationality Autonomous County in Guangxi province as a sample, decomposing the new construction land quota in this county based on AHP in determining the quota decomposition weights. In addition, this paper selected rural fixed assets investment, urban population, the total construction land during planning and implementation period, gross domestic product, four factors as the significant influencing ones. And standardized treatment of these factors to the indicators’ vector set.

Collection efficiency is a key indicator for the design and evaluation of municipal solid waste (MSW) landfill gas (LFG) collection and utilization system. Although most Chinese sanitary landfills have been equipped with LFG collection systems, there are no accurate data on collection efficiencies, lack of which always result in huge loss of LFG or investment. The fates of methane generated in a landfill include collection through LFG pipes, fugitive emission from the surface, and oxidation by methanotrophs. Field campaigns for measuring methane emission and oxidation were conducted at one landfill located in Beijing. Methane samples were collected by means of static flux chambers. The measurements were carried out at soil covered road and operating and slope surfaces. Two methods, i.e. landGEM model based and field measurement based estimation were used for calculating the collection efficiency in this research. The methane emission amount were 262.1 and 53222.4 m3 in July 2013 for the working and slope surfaces, respectively. The collection efficiency was 94.3% according to field measurement. Calculated with the LandGEM model, the collection efficiencies for 2011 and 2012 were 48.5 and 47.7% (k=0.09 yr-1) and 20.9 and 22.2% (k=0.3 yr-1), respectively. The estimation based on field measurement was more credible than the other, although the lateral migration and the storage insitu were naglected. The model method did not perform well probably due to the inapplicability of the landGEM model on this landfill, where the MSW was packed into small-subcells, and inaccurate parameter, k.

Municipal solid waste (MSW) landfills are one of main sources of anthropogenic methane emissions in China, and methane has been predicted to be the most significant greenhouse gas after 2030. In landfills, oxidation can take place naturally with methane migrating through the landfill cover. The value of fraction of methane oxidation recommended by the US EPA is 10%, which, however, is being challenged with more and more field measurement data from the Europe and the US. The characteristic of MSW in China is extremely different from that in the US, probably resulting in distinct differences in both methane generation and oxidation. The objective of this study was to determine the fraction of methane oxidized at MSW landfills in China and its spatial and temporal variations. Stable isotope technique was applied to determine the fraction of methane oxidized. The results showed that the fraction of methane oxidized where MSW was covered by soil ranged from 6.3% to 100% in Northeast China and 31% to 100% in North China. Methane oxidation could hardly occur in the operating surface. Besides, soil cover always had a high methane oxidation efficiency in summer. The fractional oxidation of methane in summer was more than 2 times than that in winter. All over the year, with the sampling depth decreasing, the fraction of methane oxidation of soil cover increased.

Supercritical CO2extraction ofPlumula nelumbinisoil rich in γ-sitosterol was investigated with a 42full factorial design and response surface analysis. At optimal conditions (P=35 MPa,T=55 C,dp=0.22 mm,Q=2.0 L/min), the yield of the extracted oil was up to 12.2%, in which the concentration of γ-sitosterol was 7.38%, indicating that the γ-sitosterol contents inPlumula nelumbinisand its oil were much higher than that in other vegetables.

We have designed lateral contact thin film silicon-based solar cells with and without one-dimensional photonic crystals as back surface field layer. The photonic crystal comprises a distributed Bragg reflector (DBR) for trapping the light. Simulations demonstrate that energy conversion efficiency and short circuit current ISCfor c-Si solar cells with the photonic crystal structure are increased to 21.11% and 27.0 mA, respectively, from 18.33% and 22.8mA of the one without photonic crystal. In addition, the effects of DBRs consisting of different materials are investigated in our simulations. When the refractive index difference between sub-layers of the DBR is larger, the forbidden band width is broader, the reflectance of the DBR is higher, and more photons are reflected and trapped into the active region, then the absorption efficiency and the energy conversion efficiency of the solar cell are both increased. The bigger the refractive index difference of the DBRs sub-layers is, the broader the forbidden band width is. In addition, a-Si solar cells with and without DBR are also discussed.

The performance of doubly fed induction generator (DFIG) based wind turbines supplying local isolated load is manly up to the stator-voltage control strategy. Compared with conventional steady mathematic model based one, a dynamic mathematic model based stator-voltage decoupling control strategy was proposed in the paper, by which the accuracy of stator voltage was improved greatly. In this paper, the dynamic mathematic model of stator voltage and then the proposed stator-voltage decoupling control were deduced, based on which the corresponding decoupling control strategy was designed and analyzed. At last, the stator-voltage decoupling control strategy for DFIG based wind turbine supplying local isolated load was achieved. To validate the design and analysis, the simulation model was built in the Matlab/Simulink environment, and some important results were reported in the paper.

The distribution characteristics of six typical antibiotics in the aquatic environment (wastewater treatment plant effluent, Shiao-ching River, Yellow River, Yellow river Reservoir, drinking water treatment plant effluent) of a city in china were analyzed by using high performance liquid chromatography-tandem mass spectrometry. The results show that except for erythromycin, other five antibiotics include sulfamethoxazole, sulfamethazine, amoxicillin, tetracycline and oxytetracycline were detected in the aquatic environment, the concentrations of tetracycline and oxytetracycline were relatively higher, the tetracycline and oxytetracycline concentrations of wastewater treatment plant effluent were 32.39 ng/L and 59.36 ng/L respectively. The wasterwater treatment plant process can not completely remove the antibiotic,and the five antibiotics concentrations in the wastewater treatment plant effluent were higher than their concentrations in the other water bodies. A certain content antibiotics was discharged into the receiving water and wastewater treatment plant drainage is the main way of antibiotics to release into the water environment. Traces of antibiotics were detected in the water samples which were taken from the Yellow River and the Shiao-ching River in the city, but they were less polluted by antibiotics levels. The antibiotics removal effect of conventional drinking water treatment process is not obvious.

A series of single-phase Sr5(PO4)3F: Eu2+, Tb3+, Na+ phosphors have been synthesized by high temperature solid-state reaction. The photoluminescence excitation and emission spectra, concentration effect and energy transfer from Eu2+ to Tb3+ are investigated in detail. The work shows that there is an effective energy transfer from Eu2+ to Tb3+, where Eu2+ reveals an intense excitation band from 280 nm to 400 nm, matching well with the emission of n-UV chips, and Tb3+ emits an intense green emitting light.

A near Infrared (NIR) quantum cutting (QC) Sr3AlO4F:Tb3+,Yb3+phosphor was synthesized by the conventional high temperature solid-state reaction. The luminescence spectra both in visible (VIS) and NIR regions and decay lifetime curves of Tb3+have been measured to prove energy transfer (ET) from Tb3+to Yb3+. Quantum efficiency (QE) related to Yb3+concentration was calculated and the highest QE was found to be 135% hen Yb3+doped concentration at 20%. The present Tb3+and Yb3+co-doped Sr3AlO4F phosphor may be a promising candidate to modify the spectral of the solar light.

The upconversion (UC) luminescence properties of phosphor Tm3+/Yb3+co-doped Gd2Mo3O9were investigated in detail. Tm3+/Yb3+co-doped Gd2Mo3O9was prepared by solid-state reaction method using Na2CO3as flux and characterized by powder X-ray diffractometry. Under 980nm excitation, Tm3+/Yb3+co-doped Gd2Mo3O9has exhibited a weak red emission near 651nm and strong blue emission at 476nm. Tm3+/Yb3+co-doped Gd2Mo3O9phosphor has been considered as a better candidate in solid-state lighting applications.

The SrSO4 spherical aggregates with hierarchical architecture was fabricated by using Sr(NO3)2 react with Na2SO4 aqueous solution under ambient conditions at room temperature. The SrSO4 spherical aggregates have a uniform diameter of about 10μm, which are composed of numerous well-aligned single tablet-like SrSO4 crystalline oriented radially to their centre. The phase structure, microstructure and luminescence properties were characterized by XRD, SEM, PL and DRS, respectively.

Earthquake or rainfall can arouse landslide, which will cause debris flow. Free surface water waves generated by plunging of debris flow cause devastating damage on human life. In this study, a numerical scheme for debris flow and free surface water wave was developed based on shallow water approximation, in which the interaction between these two flows was included newly. Generation of waves by plunging of debris flow is highly non-linear phenomena. Original CIP method and first order up-wind scheme mixed with second order central derivative scheme were adopted to simulate collision of two initially separated fluids (debris flow and still water). Six cases have been adopted to simulate the generation, propagation and run-up of water waves generated by debris flow. The time series of these two flows for these six calculating cases show the interaction of these two flows. Numerical results for interaction of debris flow and generated water wave are quite satisfactory and reasonable.

The purpose of this paper is to build a three-dimensional groundwater flow model of the affected zone along the Yellow River, and to conduct equilibrium analysis and resource evaluation to the groundwater of the research area according to the simulation results. In the beginning, the groundwater flow numerical simulation model (1999.1-2009.12) is established and verified through the GMS software on the basis of the establishment of hydrogeological conceptual and mathematical models. Results of the simulation model show that the perennial average of the resources of shallow groundwater recharge is 29.32×108m3/a, the average recharge modulus is 22.35×104m3/km2•a and the safe yield of groundwater resource is 27.04×108m3/a.

Limestone is modified with acetic acid solution as a CO2sorbent in order to solve the problem that the carbonation conversion of limestone decays sharply with the number of cycles. The results show that the carbonation conversion of modified limestone is much higher than original one, and it still achieves as high as 0.5 after 20 cycles. The mechanism of the carbonation conversion improvement for modified limestone was investigated by means of XRD, SEM and nitrogen adsorption instrument. It indicates that the grain size of CaO from modified limestone is smaller than original one. The acetification restrains the increase of grain size for CaO as the number of cycles increase. Sequentially, the extent of sintering for modified limestone is reduced. The fractal dimension of calcined modified limestone is higher than calcined original one. The inner surface of calcined modified limestone is much rougher and more complicated. The acetification makes limestone produce abundant pores. The surface area and pore volume of calcined modified limestone are far greater than those of calcined original one after the same cycles.

Foundation failure mode of high filling culverts involves calculation theory and method of subgrade bearing capacity, and it has great theoretical and practical values. After model of the culvert has been established, finite difference method will be used to do the numerical simulation in FLAC3D. Reaserch suggests that traditional Terzaghi/Meyerhof failure mode are not suitable for relatively deep buried subgrade of high filling culvert. Foundation failure of high filling culvert is caused by difference in stiffness and earth press, which result in settlement difference, and then forms subsidiary shear stress on the sliding surface. When stress value reaches shear strength of the foundation soil, shear failure occured.

An elasto-plastic total stress finite-element computational model is established in two dimensional space to study pile response due to excavation-induced soil movement on the basis of the general-purpose finite element software ABAQUS. And the soil is assumed to be a uniform normally consolidated clay layer. Influences of various parameters including undrained shear strength of soil, excavation depth, strut stiffness and distance from excavation on pile response are investigated. The results indicate that the excavation-induced soil movement is critical for adjacent piles and increasing the undrained shear strength of soil and distance from excavation face would be helpful to control passive pile responses.

Use FLAC 3D finite difference software for numerical simulation and static calculation of the different models. Study the deformation and forces condition of different model during the process of excavation. The results show that setting invert of highway tunnel in Ⅳ1-grade rock section can improve the stress state of the supporting structure and reduce the surrounding rock deformation effectively. At the same time, the flat bottom tunnel applying C25 concrete and grouting bolts could improve the integrity of surrounding rock below the tunnel sidewall. It is can be considered to cancel the setting of invert to achieve the purpose of simplifying the construction and design.

A new manufacturing method of spiral hot bending process for the end sheet of tubular pile was introduced in this paper. A three-dimensional (3-D) thermal-mechanical coupled elastic-plasticity finite element model was setup to simulate the hot bending process, and then, the section deformation mechanism from hot bar by rolling to the end sheet has been investigated from the simulation results. The industry manufacture conditions show that the efficiency and quality has been highly improved by the spiral hot bending process. The thickness variety along the radial direction of the workpiece has also been analyzed, the moment and force during the hot bending was also presented in this paper. These conclusions obtained can guide for the forming technology making for both the end sheet of tubular pile and other ring parts.

The influence of the strain rate on the plastic deformation of the metals was significant during the high strain rate of loading. However, it was very difficult to obtain high strain rate data (≥ 104 s-1) by experimental techniques. Therefore, the finite element method and iterative method were employed in this study. Numerical simulation was used to characterise the deformation behavior of Hadfield steel during explosion treatment. Base on experimental data, a modified Johnson-Cook equation for Hadfield steel under various strain rate was fitted. The development of two field variables was quantified during explosion hardening: equivalent stress and strain rates.

The experiment choose optimum technological parameter of wood residues railway sleeper composite to manufacture test pieces, select UV accelerated aging test method, use static bending strength (MOR), modulus of elasticity (MOE) , dry internal bond strength (D-IB) , wet internal bond strength (W-IB) and 24h absorbent thickness swelling (TS) and other performance index as reference standard, utilize DPS data analysis software to process variance analysis and regression analysis on the obtained data , analysis the UV accelerated aging effects on wood residues railway sleeper composite physical and mechanical properties

In this study, a mental matrix composite (MMC) made of Mg-3Zn-0.8Zr alloy as a matrix and β-TCP particles as reinforcements were prepared for investigating the effect of β-TCP spherical particles sized in 100 nm on the microstructure of that alloy. The grains of as-cast or as-extruded Mg alloys systematically decreased from about 80 μm to about 30 μm with the choice of β-TCP contents. X-ray diffraction (XRD) analysis and optical microscopy (OM) observations show that the Mg-3Zn-0.8Zr-β-TCP (1.0 or 1.5, in wt %) composites were composed of various phases in addition to Mg and MgZn2 comparied with Mg-Zn-Zr alloy. New diffraction peaks appearing in the MMC, which suggests that a potential interaction occurred between β-TCP and the matrix. Transmission electron microscopy (TEM) images reveal that secondary phases, which wraps upon the surface of β-TCP, are uniformly distributed in the grains of Mg-Zn-Zr alloy. Energy spectrum analysis shows that the component of dark-colored parts is equivalent to β-TCP, but the component of light-colored parts is Mg-Zn-Ca, which demonstrates that there is a real interaction occurred between the matrix and β-TCP.

Characteristics impedance is a very important physics parameter for many applications in rock fragmenting and percussive drilling. When the shape of the elastic bar is very complicate, it is difficult to calculate the characteristics impedance of the elastic bar with its definition. A method which uses the incident wave and reflected wave to calculate the characteristics impedance of elastic rods is presented. Firstly, the relationship of the incident wave, reflected wave and the characteristics impedance of elastic rods is studied on the basis of the reflection and transmission laws of elastic waves and, the resolution model is established; Then impact experiments were carried out in which a drilling bit with step cross-section was designed. The signal processing of eliminating polynomial trend item and discrete wavelet de-noising were done to stress signals before calculation to decrease the error. It is proved that the method is adequately accurate from the testing results.

Calcium looping technology is an attractive method for CO2 capture in dual fluidized bed combustion (FBC) reactors. The major limit for this technology is that the capture capacity of CaO-based sorbents sharply decreases with increasing cycle numbers. Attrition and consequent elutriation of CaO-based sorbents from FBC reactors also limit its application. In order to overcome these shortcomings, doping with framework materials is shown as a promising potential solution. Therefore, this work looks at a review of the CO2 capture capacities of CaO-based sorbents doped with different framework materials, such as aluminate cements, kaolin, aluminum oxides, magnesium oxide, titanium dioxide, and lanthanum salt. The synthetic sorbents have a better performance in CO2 capture capacities than the original sorbents in long term carbonation/calcination cycles.

In this paper, the energy balance of black liquor gasification (BLG) and coal-water slurry (CWS) gasification was analyzed. The results showed that the conversion efficiency of BLG (43.71%) process was slightly lower than that of CWS gasification (44.71%). Meanwhile, the material cost of BLG to synthesis gas was 0.36 Yuan/ m3 while CWS gasification was 0.69 Yuan/ m3. On account of above analysis, BLG was expected to have similar industrial applied prospect like CWS gasification

An efficient near-infrared (NIR) quantum cutting (QC) Tb3+ and Yb3+ co-doped phosphor Sr3Gd(PO4)3 has been synthesized by conventional high temperature solid technique. Upon excitation of Tb3+ with a visible photon at 485 nm, two NIR photons could be emitted by Yb3+ through cooperative energy transfer (CTE) from Tb3+ to two Yb3+ ions. Excitation and emission spectra as well as fluorescence decay measurements have been carried out to examine the occurrence of cooperative energy transfer (CET ) from Tb3+ to Yb3+ ions. The result indicates Tb3+ and Yb3+ co-doped Sr3Gd(PO4)3 is potentially used as down-converter layer in silicon-based solar cell.

Ce3+ and Tb3+ co-doped Strontium Pyroborate phosphors were synthesized by the solid-state method. The luminescent properties of phosphors were investigated by using the photoluminescence emission and excitation spectra. Under the excitation of near ultraviolet (n-UV) light, Ce3+ and Tb3+ co-doped Strontium Pyroborate phosphors exhibited blue emission corresponding to the f-d transition of Ce3+ ions and green emission bands corresponding to the f-f transition of Tb3+ ions, respectively. In the Ce3+ and Tb3+ co-activated samples the Ce3+ ions strongly sensitize the luminescence of the Tb ions. The Ce3+ and Tb3+ co-doped Strontium Pyroborate phosphor could be considered as one of double emission phosphor for n-UV excited white light emitting diodes.

A new red-emitting Rare-earth silicon carbonitrides phosphor, Y2Si4N6C, was prepared by a carbothermal reduction and nitridation method. X-ray powder diffraction (XRD), the photoluminescence excitation and emission spectra, temperature dependent was measured. The emission spectrum obtained by excitation into 410 nm contains exclusively the characteristic emission of Sm3+ at 568, 607 and 654 nm which correspond to the transitions from4G5/2to6H5/2,6H7/2, and6H9/2of Sm3+, respectively. The strongest one is located at 606 nm due to4G5/2to6H7/2transition of Sm3+.

A novel red-emitting NaSrPO4:Eu3+ phosphor was prepared by a conventional solid-state reaction. The luminescence properties and temperature dependence of 4:Eu3+ were investigated. The phosphor exhibited red luminescence under the near-UV excitation of 395 nm, corresponding to the 5F0→7L6 transition of Eu3+ ions, which matched well with the excitation wavelength of near-UV LED chips. The electronic transition due to 5D0→7F2 transition of Eu3+ ions is stronger than the magnetic dipole transition due to 5D0→7F1 of Eu3+ ions. Furthermore, Eu3+-doped NaSrPO4 phosphor shows higher thermally stable luminescence comparable tocommercially available Y3Al5O12:Ce3+ phosphor. All the investigated suggested that this newly developed phosphor could find applications in white light devise utilizing InGaN-based excitation in the near-UV chips.

YVO4 co-doped with Tm3+/Ho3+/Yb3+ were synthesized by the high temperature solid state method and the optical properties of phosphors were characterized. Intense visible emissions centered at around 475, 541 and 649 nm, originated from the transitions of Tm3+:1G4→3H6, Ho3:5S2/>:5F4 →5I8, Tm3+:5G4→3F4 and Ho3+:5F5→5I8, respectively, have been observed in samples upon excitation with a 980 nm laser diode, and the involved mechanisms have been explained.

In order to improve the free surface machining accuracy and processing efficiency, this paper proposes a processing parameters such as free surface method, through to the free surface parts for the parameters such as the curvature analysis, and then get free surface modeling geometry characteristic change rule, choose reasonable parameters optimization cutting knife, a path, the improvement of the machining accuracy and processing efficiency. We introduce the conception of curvature to analyze the curvature and optimize the cutting parameter and cutting tool parameter to avoid interference phenomena happening and improve the processing efficiency and precision. Take the ball end cutter for example to process simulation, it shows that through the analysis of the free surface curvature method to avoid the intervention process is feasible, and has been verified by the experiment.

Large-size Ni-based alloy sheet was prepared by electron beam physical vapor deposition (EB-PVD). Thickness uniformity of large-size sheet for application is important. Based on the Knudsen’s cosine law and the character of the evaporation during EB-PVD, thickness distribution model of condensate on rotary substrate by EB-PVD was established. The thickness model is not consistent with the traditional cosine law, but cosnθ relationship, n=5.3 in this paper. The predicted data of thickness model agrees well with the measured data. The thickness distribution model is not limited to specific vapor source material, therefore, it provides significant insight on the thickness distribution profile for film, coating and sheet deposited on the rotary substrate by EB-PVD.

Taking moving trestle of machine tool as example,the modal analysis and harmonic response analysis were done by means of finite element method. Find out its characteristics of vibration modal. The analysis is conducive to the design of the moving trestle of machine tool. It makes a base for optimized design and remanufacturing.

Taking machine tool bed as example,the modal analysis and harmonic response analysis were done by means of finite element method. Find out its characteristics of vibration modal. The analysis is conducive to the design of the machine tool bed. It makes a base for optimized design and remanufacturing.

This paper analyzes the influence of processing surface curvature of the free surface to the cutting width to improve the cutting width of free surface. The results show that this analysis is feasible to improve the process if the machining accuracy allows. It shows that the curvature of the machined surface and the curvature of the cutting tools have a great impact on the cutting width if they are matched reasonable. Therefore, analyzing the curvature of the surface of the surface of free-form surface machining can improve the cutting width effectively.

A three-dimensional model of a machine tool frame was established. The modal analysis and harmonic response analysis were done by means of finite element method. Its characteristics of vibration modal were obtained.Then we select one point in the largest deformation area and make the harmonic response analysis. The analysis is conducive to the design of the machine tool frame and it is of great significance for improving the quality of design of machine tools.

This paper proposes the Gaussian Curvature by analyzing the free surface of the blade surface curvature, which is based on the Gaussian Curvature parameter mapping method to study the Gaussian curvature of free surface NC machining process interference. We introduce the conception of curvature to analyze the curvature and optimize the cutting parameter and cutting tool parameter to avoid interference phenomena happening and improve the processing efficiency and precision. Take the ball end cutter for example to process simulation, it shows that through the analysis of the free surface curvature method to avoid the intervention process is feasible, and has been verified by the experiment.

A series of new Na3CaB5O10:Eu3+ phosphor was synthesized by a solid-state reaction method, and its luminescent properties were investigated. The phase formation of phosphors was confirmed by X-ray powder diffraction (XRD). The excitation spectra exhibited that the phosphors could be effectively excited by near ultraviolet (392 nm) and blue (464 nm) light, which perfectly match the emission wavelength of near-UV light-emitting diodes (LEDs). The emission spectra showed that two characteristic red emission lines peaking at 592 and 613 nm can be obtained upon 394 and 463 excitation with the chromaticity coordinates of (0.6347, 0.3649), which are due to 5D0- 7F1 and 5D0-7F2transitions of Eu3+ ions. The effect of Eu3+ concentration on the emission spectrum of Na3CaB5O10:Eu3+ phosphor was studied. The results showed that the emission intensity increased with increasing Eu3+ concentration, and then decreased because of concentration quenching. The obtained results indicated that this phosphor could be a promising candidate for near-UV white LEDs.

A blue-emitting phosphor, NaBaPO4:Eu2+, was prepared by solution combustion synthesis method, and its luminescence properties were investigated in detail. It was found that NaBaPO4:Eu2+could be efficiently excited by the UV-visible light of 230-420 nm and exhibited bright blue emission, which matched well with the emission wavelength of near-UV LED chips. NaBaPO4:Eu2+showed high thermally stable luminescence compared to commercial phosphor YAG:Ce3+. With the increase of the temperature, the normalized emission intensity of NaBa0.98PO4:0.02Eu2+decreased to 92.3% of the initial value at 423 K, and the emission band exhibited a little blue-shift.

Electron trapping materials SrS:Eu2+,Sm3+ were prepared by hydrothermal method at 200 °C for 5 h. The phase structure, microstructure and optical properties were characterized by XRD, SEM, EDAX, PL, PSL, and TL, respectively. The sample was stimulated by a 980 nm infrared laser after exposing to the sun light, It can be seen that the PSL emission spectra was a band spectrum with one peak at 605 nm, and this emission was ascribed to characteristic 5d → 4f transition of Eu2+, and the photo stimulated luminescence phenomenon was observed.

Erbium and ytterbium co-doped sodium yttrium fluoride (NaYF4:Er3+,Yb3+) was synthesized by combusting in home microwave oven directly. The structure and morphology of the sample was characterized by the X-ray diffraction (XRD) and scanning electron microscopy (SEM), and its upconversion luminescence properties were investigated in detail. Under 980nm semiconductor laser excitation, the color of upconversion luminescence of NaYF4:Er3+,Yb3+ was green and red, and its upconversion spectrum exhibited distinct emission peaks at 522, 543 and 652 nm, the emission appears yellow-orange to the naked eye. The law of luminescence intensity versus pump power proved that the intense green emission at 522 and 543 nm were from Er3+(2H11/2→4I15/2and4S3/2→4I15/2), and the weaker red emission at 652 nm was from Er3+(4F9/2→4I15/2), which belong to the two photon process.

The ultraviolet (UV) fluorescent anti-counterfeiting offset printing ink, which can emit visible light (400-800 nm) under the excitation of ultraviolet light (200-400 nm), has been extensively adopted in the modern printing technology. In this paper, we used the red-emitting phosphor BaCaBO3F: Eu3+, Li+ as the fluorescent pigment for printing ink and investigated the influence on additive amount of the luminescence properties of fluorescent ink in order to determine a more ideal ratio of fluorescent ink .Besides, the shear viscosity, thixotropy, visco-elasticity and the temperature dependence of viscosity according to the rheology theory and rheological technique were also studied, and finally the valuable parameters and patterns were successfully obtained.

Four kinds of structure schemes were designed based on studying the properties, structure design principles and processing technique requirements of railway sleeper composites. The method of material performance increasing with cost level was applied in the layer jacketed type, which could ensure the performance of railway sleeper materials, as well as reduce the cost with highest possibility.

The anti-aging property of wood residues composite is an important indicator for measuring the service performance of products. And the aging problems of these composite materials have attracted more and more attention from people. So we had a research on such problems. By means of experiments, this paper analyzed the reasons for the aging of wood residues composite. Through contrast experimental methods, we analyzed the way to accelerate the aging of them. At last, we adopted the 6-cycle accelerated aging method of ASTM D1037and the aging instrument detecting method according to their characteristics and available experimental conditions. Based on actual conditions, we analyzed the aging factors of wood residues composite such as temperature, humidity, specimen size ,surface decoration and so on.