谈辐射板在煤矿生产系统建筑采暖中的应用

本文根据煤矿生产系统建筑的特点，阐述了应用辐射板采暖的优越性及节能意义，并提出了改进旧式钢制辐射板的意见。

生物样品中硒的形态分析方法研究进展

对近年来关于生物样品中微量元素硒的形态分析方法的研究成果进行了综述,总结了高硒生物样品(>10 mg Se/kg)和低硒生物样品(<1 mg Se/kg)的硒形态组分提取方法,以及利用液相色谱-原子荧光光谱(LC-AFS)、高效液相色谱与电感耦合等离子质谱(HPLC-ICP-MS)等仪器联用的方法分离、检测硒的形态组分。此外,对利用同步辐射X射线微区分析方法(STXM)原位微区分析微生物样品的硒形态及其分布进行了综述与展望。

3-Dimensional Irradiance Imaging with a Single Camera System

The focusing tomography is presented to reconstruct 3 dimensional irradiance distribution. A 3 dimensional luminous body could be considered as the combination of many 2 dimensional parallel luminous sections. Focus on these discrete sections respectively by a single camera, a group of images would be captured to form governing equations of irradiance. After inversion procedure, the irradiance distribution of different sections could be decoded. In this experimentation two lightbulbs are used to simulate two luminous sections. Reasonable results demonstrate that this technique could be a useful method in irradiance reconstruction after further development.

A Preliminary Global Analysis of Remotely Sensed Radiation Characteristics of Ground Features:Ⅱ. Result Discussion

Based on the L,B and V statistics of the 106 ground feature groups or the 769 ground feature class units in the world presented in the part I of the paper,the distribution of the world ground features on the axes of L,B and V,in the planes of L-B,L-V and B-V and in the space of L-B-V was discussed.And the typical numerical characteristics of the various ground features were also summarized.

In situ analysis of multi-twin morphology and growth using synchrotron polychromatic X-ray microdiffraction

Synchrotron polychromatic X-ray microdiffraction（micro-XRD） was applied to study in situ deformation twinning of commercially AZ31（Mg-3Al-1Zn） strip subjected to uniaxial tension.The morphology and growth of twins were analyzed in situ under the load level from 64 to 73 MPa.The X-ray microdiffraction data,collected on beamline 12.3.2 at the Advanced Light Source,were then used to map an area of 396μm x 200μm within the region of interest.The experimental set-up and X-ray diffraction microscopy with a depth resolution allow the position and orientation of each illuminated grain to be determined at the submicron size.A list of parent grains sorted by crystallographic orientation were selected to examine their twinning behavior.The results depict twin variant selection,local misorientation fluctuation and mosaic spread for multi-twins within the same parent grain.As load increases,the amplitude of misorientation fluctuation along twin trace keeps increasing.This is attributable to the accumulation of geometrically necessary dislocations.

IMPACTS OF ATOVS DATA ASSIMILATION ON PREDICTION OF A RAINSTORM OVER SOUTHEAST CHINA

Using the Advanced Research WRF (ARW WRF) model and the Gridpoint Statistical Interpolation (GSI) three-dimensional variational analysis (3DVAR) system,the impact of assimilating ATOVS (Advanced TIROS Operational Vertical Sounder) radiance through the prototype Community Radiative Transfer Model (pCRTM) is evaluated on the forecasting of a heavy rainstorm occurring over the central Guangdong province in the southeast of China on 20-21 June 2005. A pair of comparison experiments (NODA and DA) for this case is conducted with multiple configurations,including nesting domains with 4-km and 12-km grid distances. The results showed that by changing the initial condition through data assimilation,a modified divergence and moisture field with the structure of dipoles has been added to the axis of the rainband with a southwest-northeast orientation. When more moisture carried by a southwesterly low level jet (LLJ) was converged into the northeast portion of the rainband around the observatory station of Longmen,the amplitude of moisture static energy (MSE) increased substantially at low levels much more than at middle levels,resulting in the enlarging of differences in MSE between 500 hPa and 850 hPa; the atmosphere became more unstable. Consequently,the convective rainfall increased in the northeast part of the province around the Longmen station,which was consistent with the observed distribution of rainfall.

Northward expansion of the western Pacific Warm Pool in late 1990s and early 2000s

Based on 48-year (1958-2006) ocean reanalysis data of Simple Ocean Data Assimilation and 23-year (1984-2006) global ocean-surface heat flux products developed by the Objectively Analyzed Air-Sea Heat Flux Project, meridional variation of the western Pacific Warm Pool (WPWP) is addressed. The results show that there is a significant expansion of the northern edge of the WPWP in the late 1990s and early 2000s. This variation is mainly within 120°E-160°E by 8°N-20°N, we define this region (120°E-160°E by 8°N-20°N) as the core region. Furthermore, analyses on upper ocean heat budget show that the short wave radiation plays a key role in the northward expansion of the northern edge of the WPWP in the core region. It is proved that the northward expansion may be caused by the change of the mixed layer which became shallower in 1994-2006 compared with 1984-1993 in the study region. The short wave radiation flux distribution within the shallower mixed layer leads to a positive anomaly in seawater temperature, promoting the northward expansion of the WPWP.

COMPARISON OF CHARACTERISTICS BETWEEN THE SOUTH CHINA SEA SUMMER MONSOON OUTBREAKS IN 2004 AND 2008

The South China Sea summer monsoon is an important system affecting the weather and climate in China;its outbreak and evolution vary from year to year.Using the reanalysis data from the U.S.National Centers for Environmental Prediction (NCEP) and outgoing longwave radiation (OLR) data from the National Oceanic and Atmospheric Administration (NOAA),USA,we analyze the circulation pattern,precipitation distribution,convection,temperature,and humidity around the monsoon outbreaks in 2004 and 2008.Results show that the monsoon had a late onset in 2004 (May 19) but an early outbreak in 2008 (May 4).Prior to the monsoon outbreak in 2008,cross-equatorial flows in Somalia were weaker than in 2004,subtropical precipitation did not arrive in southern China as it did in 2004,and the strongest convection was located more southward than in 2004.The results also indicate that accumulated rainfall in the Indochina Peninsula was about 61% of that in 2004 during a period of 25 days leading up to the monsoon outbreak,causing differences in land surface processes and then different activity levels for the summer monsoon.Post-onset warm and humid conditions in 2008 (2004) maintained through the end of October (mid-September),while the summer monsoon lasted longer in 2008 than in 2004.

Optical Properties of Nd^3＋ in Nd（DBM）3Phen-doped Poly（methyl methacrylate）

Nd（DBM）3Phen-doped （DBM is dibenzoylmethane and Phen is phenanthroline） polymethyl methacrylate （PMMA） is prepared. Optical absorption, excitation and emission spectra were analyzed for Nd^3＋ in Nd（DBM）3Phen-doped PMMA. Using the Judd-Ofelt theory, the absorption spectrum was analyzed. The Judd-Ofelt（J-O） intensity parameters of Nd（DBM）3Phen-doped polymethyl methacrylate were calculated to be Ω2 = 20.97 × 10^-20 cm^2, Ω4= 3.42 × 10^-20 cm^2, Ω6 = 2.90 × 10^-20 cm^2. The radiative lifetime （631 μs） of the excited 4F3/2 level is given. The stimulated emission cross-sections and the fluorescence branch ratios for the ^4F3/2 →^4Ij′ transitions are also evaluated. Analysis reveals that Nd（DBM）3Phen-doped PMMA is promising for application in polymer optical fibers and planar waveguides.

A Preliminary Global Analysis of Remotely Sensed Radiation Characteristics of Ground Features: Ⅰ. Methodology and Results

A Landsat data transformation method which was proposed by the author was applied to extract useful information from data of 769 ground feature classification units of worldwide scope.Three most important characteristic values--the general radiance level L,the visible-infrared radiation balance B and the band radiance variation vector (direction and speed) V were calculated.Then the 769 class units were sorted into 106 groups based on their natural characteristics.The means and standard deviations of L,B and V values for all the groups were calculated.The distributions of the 106 groups or the 769 units on the number axes of L,B and V,in the planes of L-B,L-V and B-V,and in the space of L-B-V were investigated.Finally,the typical numerical characteristics of the various ground features are discussed in consideration of their worldwide variations in the present paper.

A unified prediction solution for vibro-acoustic analysis of composite laminated elliptical shells immersed in air

A semi-analytical method to conduct vibro-acoustic analysis of a composite laminated elliptical shell immersed in air is proposed.A variational method and multi-segment technique are used to formulate the dynamic model.The sound radiation of the exterior fluid field is calculated by a spectral Kirchhoff–Helmholtz integral formulation.The variables containing displacements and sound pressure are expanded by the combination of Fourier series and Chebyshev orthogonal polynomials.The collocation points are introduced to construct an algebraic system of acoustic integral equations,where these points are distributed on the roots of Chebyshev polynomials,and the non-uniqueness solution of system is eliminated by a combined Helmholtz integral.Numerical examples for sound radiation problems of composite laminated elliptical shells are presented and individual contributions of the circumferential modes to the acoustical results of composite laminated elliptical shells are also given.The effects of geometric and material parameters on sound radiation of composite laminated elliptical shells are also investigated.

Analytical investigation of temperature of a single micron sized iron particle during combustion

The present study deals with analytical investigation of temperature of a single burning iron particle.Three mathematical methods including AGM(Akbari-Ganji’s method),CM(Collocation method)and GM(Galerkin Method)are applied to solving non-linear differential governing equation and effectiveness of these methods is examined as well.For further investigation,forth order Runge-Kutta approach,a numerical method,is used to validate the obtained analytical results.In the present study,the developed mathematical model takes into account the effects of thermal radiation,convective heat transfer and particle density variations during combustion process.Due to particles’small size and high thermal conductivity,the system is assumed to be lumped in which the particle temperature does not change within the body and all of its regions are at the same temperature.The temperature distributions obtained by analytical methods have satisfactory agreement with numerical outputs.Finally,the results indicate that AGM is a more appropriate method than GM and CM due to its lower mean relative error and less run time.

Entropy analysis of SWCNT & MWCNT flow induced by collecting beating of cilia with porous medium

In this article, we considers the thermodynamics analysis of creeping viscous nanofluid flow in a horizontal ciliated tube under the effects of a uniform magnetic field and porous medium. Moreover, energy analysis is performed in the presence of an internal heat source and thermal radiation phenomena. The thermal conductivity of base fluid water is strengthened by considering the carbon nanotubes (CNTs). Mathematical formulation operated, results in a set of non-linear coupled partial differential equations. The governed differential system is transformed into an ordinary differential system by considering suitable similarity variables. Exact solutions in the closed form are computed for the temperature, momentum and pressure gradient profiles. In this study, special attention is devoted to the electrical conductivity of the CNTs. Streamlines patterns are also discussed to witness the flow lines for different parameters. Thermodynamics analysis shows that entropy of the current flow system is an increasing function of Brinkmann number, magnetic parameter, nanoparticle concentration parameter and Darcy number.

Structural evolution of chars from biomass components pyrolysis in a xenon lamp radiation reactor

The structural evolution of the chars from pyrolysis of biomass components （cellulose, hemicellulose and lignin） in a xenon lamp radiation reactor was investigated. The elemental composition analysis showed that the C content increased at the expense of H and O contents during the chars formation. The values of AH/C/ZSO/c for the formation of cellulose and hemicellulose chars were close to 2, indicating that dehydration was the dominant reaction. Meanwhile, the value was more than 3 for lignin char formation, suggesting that the occurrence of demethoxylation was prevalent. FTIR and XRD analyses further disclosed that the cellulose pyrolysis needed to break down the stable crystal structure prior to the severe depolymerization. As for hemicellulose and lignin pyrolysis, the weak branches and linkages decomposed firstly, followed by the major decomposition. After the devolatilization at the main pyrolysis stage, the three components encountered a slow carbonization process to form condensed aromatic chars. The SEM results showed that the three components underwent different devolatilization behaviors, which induced various surface mornhologies of the chars.

Study on Atomic Fluorescence Spectrometry Excited by Synchrotron Radiation

A novel analysis approach using atomic fluorescence excited by synchrotron radiation is presented. A system for synchrotron radiation-atomic fluorescence spectrometry is developed, and experimental conditions such as flow rate, analyte acidity, concentration of pre-reducing and hydrogenation system are optimized. The proposed method is successfully applied to get an excitation spectrum of arsenic. Seven of ten primary spectral lines, four of which have never been reported by means of atomic fluorescence spectrometry, agree well with the existing reports. The other three are proposed for the first time. Excitation potentials and possible transitions are investigated. Especially for the prominent line at 234.99 nm, the mechanism of generation is discussed and a model of energy transition processes is proposed.

Theoretical analysis of radiation-balanced double clad fiber laser

In this letter,a theoretical model of radiation-balanced double clad fiber laser is presented.The characteristic of the laser with Yb doped double clad fiber is analyzed numerically.It is concluded that high output laser power can be obtained by selecting output coupling mirror with lower reflectivity,improving Yb doped concentration and choosing fiber length. This result can help us to design radiation balanced fiber laser.

Temperature gradients in concrete box girder bridge under effect of cold wave

The temperature distributions of a prestressed concrete box girder bridge under the effect of cold wave processes were analyzed. The distributions were found different from those under the effect of solar radiation or nighttime radiation cooling and should not be simplified as one dimensional. A temperature predicting model that can accurately predict temperatures over the cross section of the concrete box girder was developed. On the basis of the analytical model, a two-dimensional temperature gradient model was proposed and a parametric study that considered meteorological factors was performed. The results of sensitivity analysis show that the cold wave with shorter duration and more severe temperature drop may cause more unfavorable influences on the concrete box girder bridge. Finally, the unrestrained linear curvatures, self-equilibrating stresses and bending stresses when considering the frame action of the cross section, were derived from the proposed temperature gradient model and current code provisions, respectively. Then, a comparison was made between the value calculated against proposed model and several current specifications. The results show that the cold wave may cause more unfavorable effect on the concrete box girder bridge, especially on the large concrete box girder bridge. Therefore, it is necessary to consider the thermal effect caused by cold wave during the design stage.

Radicalizing Arab University Students： A Global Emerging Threat

The purpose of the study was to explore the factors mediating college students＇ radicalization. A sample of 1,116 students was drawn from four different Jordanian universities. The construct validity of the scale was estimated by calculating the correlation between the radicalization items and the negative emotion items. A positive significant relationship was found （0.12, a = 0.000）, a sign of validity of the scale. The scale reliability was also strong and was estimated at 0.90 using Cronbach Alpha. Factor analysis produced five factors explaining 45% of the total variance of radicalization. The first factor labeled ＂political radicalization＂ explained 18.5% of the variance, the second factor ＂religious radicalization＂ explained 12.7%, the third factor ＂violent radicalization＂ explained 6.4% of the variance, the fourth ＂group radicalization＂ accounted for 4%, and the fifth factor ＂social radicalization＂ only accounted for 3% of the total variance. Significant differences in student radicalization were found according to the geographical region of the university （North, Center and South）, F = 14, a = 0.000. However, no significant differences were found in radicalization as it relates to gender, and type of college （i.e., Humanities vs. Pure Sciences）.

Effect of aging treatment on irradiation-induced segregation of high Mn-Cr steel

To investigate the effect of aging treatment on irradiation-induced segregation of high Mn-Cr steel, specimens for electron-beam irradiation were prepared from the high Mn-Cr austenitic steel which was solution treated at 1 373 K for 1 h and aging treated at 573 K for 1 000 h, respectively. The electron-beam irradiation was performed at 573 K up to doses of 5.4 dpa in a 1 250 kV HVEM and irradiation-induced segregation analyses were carried out by an EDX in a 200 kV FE-TEM. The results show that void formation is not observed in both solution treated and aging treated ones. The amount of Cr segregation at the grain boundary decreases in the aged one; however, that of Mn is not changed in solution treated one.

STUDY ON A NOVEL ELLIPSOIDAL HELICAL ANTENNA

A novel ellipsoidal helical antenna is proposed and studied in this letter. As a special in-stance,the hemispherical helical antennas are analyzed firstly,which indicates that the characteristics of a two-arm unit are better than that of a single-arm unit. Based on this,the ellipsoidal helical antenna,formed by changing the axial direction’s dimension of the two-arm hemispherical helical antenna,is analyzed by the moment method with curved basic and testing function. The effects to VSWR (Voltage Standing Wave Ratio),gain,polarization and patterns by the axial direction’s dimensions are inves-tigated. The study results provide dependable gist to the choice of antenna format according to the practical requirements.