Beryllium Extraction and Utilisation— Prospects and Constraints

Beryllium and beryllium compounds find wide variety of applications in diverse industries. Low density, high strength, and attractive nuclear properties like low neutron absorption cross section and high scattering cross section have created great interest in the metal for space, aeronautical, and nuclear applications. The extraction technology of beryllium is now fairly well established and significant progress has also been made in the powder metallurgy fabrication of the metal. Conventional fabrication methods like rolling, wire drawing, extrusion etc. have not been found quite suitable for beryllium because of its low ductility.

This paper presents an overview of the extraction processes and the fabrication methods presently employed for beryllium metal and alloys. The various applications are described and the prospects and constraints in the large scale utilization of beryllium in industry are analysed.     

Homogenization and RecrystaHization of AI-6Mg Alloys with and without Sc and Zr

Plates of A1-6Mg alloys with and without scandium were prepared by semi-continuous cast, homogenization,hot-rolled, cold-rolled and annealing. Based on studying of effects of temperature and time on hardness and conductivity during homogenization, it was found that homogenization of ingot with Sc and Zr can result in dispersion strengthening.Recrystallization temperature of alloys was studied by hardness method and optical metallographic method. Staring recrystallization temperature of A1-6Mg alloys with Sc and Zr is 375℃, increasing by 150℃ than AI-6Mg alloys without Sc and Zr. Mechanical properties (δb,δ0.2,δ) of hot-rolled alloy with Sc and Zr are 400 MPa, 280 MPa and 18% ; cold-rolled and anneal alloy with Sc and Zr are 420 MPa, 310 MPa and 12% respectively.     

Homogenization and Recrystallization of Al-6Mg Alloys with and without Sc and Zr

ДрицМ .Е .[1,2 ] reportedthatscandium ,com paringwiththeotherrareelements ,isthemosteffec tiveadditiontopromotethestrengthofaluminumal loys .Thestrengthofas extrusionAl 6 5Mgalloyrodcontaining 0 .2 %Screaches 4 0 0MPa (σb)and 2 5 0MPa (σ0 .2 ) ,higherthanAl 6 5Mgalloywithoutscandiumonetime .Willey[3] fromAluminumCompa nyofAmericapatentedthefirstaluminumscandiumalloyin 1971.Since 70′soflastcentury ,theformerSovietUnionengagedcompletelyresearchonthepro ductionandapplicationofalum…     

Parental depression and interparental conflict: Children and adolescents’ self-blame and coping responses.

The present study examined the role of children and adolescents’ perceptions of self-blame specific to interparental conflict and children and adolescents’ coping behaviors in the context of parental depression as predictors of internalizing and externalizing symptoms in a sample of 108 youth (age 9–15 years old) of parents with a history of depression. Higher levels of current depressive symptoms in parents were associated with higher levels of interparental conflict and higher levels of internalizing symptoms in children and adolescents, and interparental conflict was positively associated with both internalizing and externalizing symptoms in children/adolescents. Consistent across a series of multiple regression models, children and adolescents’ perceptions of self-blame and use of secondary control coping (acceptance, distraction, cognitive restructuring, positive thinking) were significant, independent predictors of both internalizing and externalizing symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis and forecast of the supply and demand of electric power and its operation situation

Earlier May, China Electricity Council made forecast to the nationwide power supply and demand for the 2nd quarter of 2007 .     

Aluminium and cerium co-doped ZnO nanoparticles:Facile and inexpensive synthesis and visible light photocatalytic performances

Facile combustion route synthesized Al and Ce co-doped ZnO nanoparticles photocatalysts were characterized using XRD,SEM,BET,EDS,UV-visible DRS,PL,photocurrent and EIS techniques.XRD and SEM analyses identify that crystallite and particle size is reduced from 13.26 to 11.88 nm with introduction of Al and Ce into ZnO which assists inhibiting the recombination of photo generated charge carriers.UVvisible DRS spectra indicate that optical assimilation of ZnO is significantly increased to visible region(-406 nm)and band gap reduces from 3.18 to 3.06 eV with introduction of Al and Ce co-dopants.Electrochemical impedance spectroscopy analysis under visible light illumination confirms the enhancement in visible light activity of Al and Ce co-doped ZnO nanoparticles as photocatalysts.The enhanced activity of Al and Ce co-doped ZnO photocatalyst can be ascribed to enhanced light assimilation,high surface area and efficient charge transfer process.Our results reveal that by incorporating precise amount of Al(~2%)and Ce(~2%)into ZnO,a highly efficient catalyst can be synthesized that have degraded almost 95%methyl orange(MO)dye in just 45 min.Further,the influence of various operational parameters such as solution pH,catalyst dose,dye concentration,airflow rate and light intensity on photodecomposition of MO was evaluated.Furthe rmore,a possible mechanism for Al and Ce modified ZnO was proposed and designed photocatalysts demonstrates good stability in aqueous medium.     

pH-Potentiometric Study on Rare Earths and Calcium Binary and Ternary Complexes with DL-Malic Acid and L-Hydroxyproline

ｐＨＰｏｔｅｎｔｉｏｍｅｔｒｉｃＳｔｕｄｙｏｎＲａｒｅＥａｒｔｈｓａｎｄＣａｌｃｉｕｍＢｉｎａｒｙａｎｄＴｅｒｎａｒｙＣｏｍｐｌｅｘｅｓｗｉｔｈＤＬＭａｌｉｃＡｃｉｄａｎｄＬＨｙｄｒｏｘｙｐｒｏｌｉｎｅＷａｎｇＲｕｉｙａｏ（王瑞瑶），ＧａｏＦ...     

China''''s imports and exports of nickel and cobalt by category

~~China's imports and exports of nickel and cobalt by category~~     

The artificial heart and neuromonitoring? Technical and clinical aspects

There is a steady progress in the development of artificial heart and circulatory assist devices. There is also no doubt that further advances in energy systems, materials, and electronics will provide for smaller and more reliable electrically driven blood pumps, but the present engineering design appears to be adequate to provide devices satisfactory for initial clinical use. Due to problems in the availability of suitable donor hearts, the concept of replacing the natural heart with an artificial heart as a "bridge to transplantation" has gained attention in recent years. The present paper shows technical and clinical aspects of multivariable electrophysiologic neuromonitoring in a patient with an artificial heart assist device in the intensive care unit. The data (EEG, 40 Hz brain oscillations, brainstem auditory- and somatosensory evoked potentials) are discussed with respect to the influence of the artificial heart on their quality and reliability. Reasons for artifacts and problems of interpretation are shown.     

Internal Friction and Profile of Property and Structure of PD3 and PD3RE Rail Steels

~~Internal Friction and Profile of Property and Structure of PD_3 and PD_3RE Rail Steels     

Viscosity and Viscosity Estimate Model of Fluoride-free and Titanium-Bearing Mold Fluxes

The relationship between the binary basicity (CaO/SiO2),TiO2,Na2O,Li2O,MgO,MnO,B2O3 and viscosity for fluoride-free and titanium-bearing mold fluxes were systematically researched. The rotating cylinder method was employed in the experiment to measure the viscosity of the slag. The results indicate that Li2O, B2O3 and Na2O play major roles in decreasing viscosity, especially Li2O, which is the most effective flux, while MgO and MnO exert little influence on viscosity. Meanwhile, it can be concluded that with increasing TiO2 content, the viscosity of fluoride-free and titanium-bearing mold fluxes increases at first but then falls when the amount of TiO2 is greater than 6.0%. Based on large amounts of experimental statistics of the viscosity of fluoride-free and titanium-bearing mold fluxes, an available model in literature for predicting the mold-slag viscosity was modified. This modified model can be used to predict the viscosity of fluoride-free and titanium-bearing mold fluxes. In fact, the predicted values approximate the observed values with a ±10.6% average deviation. Compared with the classical models,the average deviation is higher and it was found that the modified model can be used to estimate the viscosity of fluoride-free and titanium-bearing mold fluxes.     

Preparation and Luminescent Properties of BAM Blue Phosphor forPDP and CCFL

The Bax-0.05MgAl10O16 x :Eu0.05^2 (0.88≤ x≤ 1.02) phosphors with different Ba^2 content and the Ba0.85MgAl10O16.94:Eu0.05^2 phosphors with different fluxes (BaF2, MgF2, AlF3, BaCl2, MgCl2, AlCl3, H3BO3)were prepared by high temperature solid-state reaction method and their luminescence characteristics were studied under 254 nm excitation and vacuum ultraviolet (VUV) excitation. With the increase of the Ba^2 content, there is an increase in the emission intensity, and when x = 0.94, it reaches a maximum. Then, as the Ba^2 content increases, the emission intensity slowly falls. The fluorides have better flux-effects than chlorides and H3BO3. The possible mechanism in the process of particle growth was discussed when fluorides were used as fluxes. The effect of the activator concentration on this system was also investigated. The quenching concentration is 0.13 mol in per mole host.     

Solution and Thermodynamic Studies on Binary and Ternary Complexes of Lanthanides

The interactions of La(Ⅲ), Pr(Ⅲ), Nd(Ⅲ), Sm(Ⅲ), Eu(Ⅲ), Gd(Ⅲ), Dy(Ⅲ), and Yb(Ⅲ) with cytosine, 5-bromocytosine, 5-azacytosine and 5-flurocytosine as primary ligands (L) and guanine (A) as secondary ligand for both binary (1:1) as well as ternary (1:1:1) systems were investigated by potentiometric equilibrium measurements at 25, 35 and 45 ℃ in aqueous solution (ionic strength, μ=0.1 mol·dm-3 NaNO3). The stability constants of the binary (1:1) and ternary (1:1:1) metal-ligand complexes follow the following order La＜Pr＜Nd＜Sm＜Eu＞Gd＜Dy＞Yb. Results also indicate that the ternary lanthanide complexes of La(Ⅲ), Pr(Ⅲ), Nd(Ⅲ), Sm(Ⅲ), Eu(Ⅲ), Gd(Ⅲ), Dy(Ⅲ), and Yb(Ⅲ) are more stable than corresponding binary lanthanide complexes. The enthalpy (Δhof) and entropy (Δsof) changes for the formation of binary and ternary complexes were calculated from temperature coefficient data. The ΔΔSof values are positive for all the metal ligand systems. The negative ΔΔHof values indicate the extra stability of the ternary complexes by the exothermic enthalpy changes (ΔΔSof=ΔTSof-ΔBSof and ΔΔHof=ΔTHof-ΔBHof where ΔTSof, ΔTHof and ΔBSof, ΔBHof are the entropy and enthalpy values associated with the ternary and binary complexes, respectively). It was also proposed that the guanine is bonded to metal ions through N1/C6=O and N7 whereas cytosine and its derivatives are bonded through N3 atoms in ternary complexes.     

Interaction between Eu-phenylalanine and DNA Using Cyclic Voltammetry and UV Spectroscopy

ＩｎｔｅｒａｃｔｉｏｎｂｅｔｗｅｎＥｕｐｈｅｎｙｌａｌａｎｉｎｅａｎｄＤＮＡＵｓｉｎｇＣｙｃｌｉｃＶｏｌｔａｍｍｅｔｒｙａｎｄＵＶＳｐｅｃｔｒｏｓｃｏｐｙＳｈｅｎＨｅｂａｉ（沈鹤柏），ＫｕａｉＬｉｈｅｎｇ（蒯丽衡），ＮｉＬｉｈｕａ（倪丽华），...     

Flutter and Buffeting Analysis.?I: Finite-Element and RPE Solution

A finite-element formulation is developed for analyzing flutter instability and buffeting response of long-span bridges and their interaction. The flutter derivatives, instead of the indicial functions used by previous researchers, are applied in the random parametric excitation (RPE) analysis. This application makes finite-element formulation possible and results in much less computational effort in RPE analysis than those of previous analyses. With the finite-element program developed in the present study, as many modes as desired can be easily included in the flutter and buffeting analyses. Users have the choice of RPE or eigenvalue method for flutter analysis and RPE or spectral method for buffeting analysis.     

Preparation of cerium and yttrium doped ZnO nanoparticles and tracking their structural,optical,and photocatalytic performances

Yttrium(Y) and cerium(Ce) co-doped ZnO nanoparticles(NPs) were synthesized via the simple sol-gel auto-combustion route.The effect of Ce and Y doping on the structure,morphology,optical,Zeta potential,and photocatalytic activities of ZnO NPs was examined by Fourier transform infrared(FTIR)spectrometer,X-ray diffraction(XRD),transmission electron microscope(TEM),UV-vis spectrophotometer,and Zetasizer instrument.XRD data show that the fabricated samples crystallize into a hexagonal wurtzite struct...     

Preparation and Luminescent Characteristics of LaPO4：Eu Nanoparticles and Nanowires

Nanoparticles and nanowires of LAPO4: Eu phosphors were synthesized by hydrothermal method. Their luminescent properties including electronic transition, surface effect, and temperature-dependent luminescent characteristics were systemically studied and compared to the bulk powders. It can be concluded that in comparison with the bulk powders, the fluorescence intensity decreases in nanoparticles and nanowires, while the lifetime increases, indicating that the radiative transition rate decreases. The nonradiative transition rate in nanowires decreases than that in nanoparticles due to its decreased surface to volume ratio. The temperature-dependent experiments indicate that the thermal quenching in nanopowders becomes weaker than that in the bulk powders.     

Effect of Boron and Cerium on Microstructures and Properties of Cu-Fe-P Alloy

The effects of B and Ce on the removal of inclusions, microstructures, and properties of Cu-Fe-P alloys were studied. Certain impurity elements and the microstructures, mechanical properties, and conductivity of four experimental alloys, Cu-0.22Fe-0.06P, Cu-0.22Fe-0.06P-0.05Ce, Cu-0.22Fe-0.06P-0.02B, and Cu-0.22Fe-0.06P-0.05Ce-0. 02B （ %, mass fraction）, were tested and analyzed. Results show that on one hand, B and Ce have a remarkable function of removing S, Pb, and Bi from copper alloys ; on the other hand, the recrystallization temperature of the Cu-Fe-P alloy is considerably increased by adding trace B and Ce, resulting in the combined strengthening effect of precipitation hardening and cold work hardening after cold working and aging, while the negative effect of B and Ce on conductivity is slight. Therefore, a good combination of high strength and conductivity is achieved.