Single crystalline 3C-SiC epitaxial layers are grown on φ 50mm Si wafers by a new resistively heated CVD/LPCVD system,using SiH_4,C_2H_4 and H_2 as gas precursors.X-ray diffraction and Raman scattering measurements a...Single crystalline 3C-SiC epitaxial layers are grown on φ 50mm Si wafers by a new resistively heated CVD/LPCVD system,using SiH_4,C_2H_4 and H_2 as gas precursors.X-ray diffraction and Raman scattering measurements are used to investigate the crystallinity of the grown films.Electrical properties of the epitaxial 3C-SiC layers with thickness of 1～3μm are measured by Van der Pauw method.The improved Hall mobility reaches the highest value of 470cm 2/(V·s) at the carrier concentration of 7.7×10 17 cm -3 .展开更多
High quality GaN is grown on GaN substrate with stripe pattern by metalorganic chemical vapor deposition by means of epitaxial lateral overgrowth. AFM,wet chemical etching, and TEM experiments show that with a two-ste...High quality GaN is grown on GaN substrate with stripe pattern by metalorganic chemical vapor deposition by means of epitaxial lateral overgrowth. AFM,wet chemical etching, and TEM experiments show that with a two-step ELOG procedure, the propagation of defects under the mask is blocked, and the coherently grown GaN above the window also experiences a drastic reduction in defect density. In addition, a grain boundary is formed at the coalescence boundary of neighboring growth fronts. The extremely low density of threading dislocations within wing regions makes ELOG GaN a potential template for the fabrication of nitride-based lasers with improved performance.展开更多
To reveal the possible mechanism of silica deposition in higher plants, lignin was isolated from rice straw following a modified method to conduct a simulation experiment in vitro. UV and infrared absorption spectra s...To reveal the possible mechanism of silica deposition in higher plants, lignin was isolated from rice straw following a modified method to conduct a simulation experiment in vitro. UV and infrared absorption spectra showed that the substance had the unique characteristics of pure lignin. The presence of silicon in the precipitation was revealed by TEM (transmission electron microscopy) with EDXA (energy dispersive X-ray analysis) device. It was found that in the borax solution where lignin precipi-tation occurred silica-lignin co-precipitation was produced but not in the DMSO solution where lignin was broken into its com-position compounds and did not precipitate. This means that it is macromolecular lignin itself but not its compounds that could induce silica deposition in higher plants.展开更多
A strain HB-03 to produce alkaline extracellular lipase was isolated from oil-rich soil samples and identified as Aspergillus awamori. The growth conditions and nutritional factors for lipase production by strain HB-0...A strain HB-03 to produce alkaline extracellular lipase was isolated from oil-rich soil samples and identified as Aspergillus awamori. The growth conditions and nutritional factors for lipase production by strain HB-03 were optimized, and the maximum lipase production of （45.9±2.3） U/mL was obtained at 30 ℃ and pH 7.0 after 36 h using olive oil （1%） and sucrose （0.5%） as carbon sources and combination of peptone （2%）, yeast extract （0.5%） and ammonium sulfate （0.1%） as nitrogen sources. The lipase was purified to homogeneity with 10.6-fold, 18.84% yield and a specific activity of 1 862.2 U/mg using ammonium sulfate precipitation followed by SephadexG-75 gel filtration chromatography. The purified lipase with molecular mass of 68 ku was estimated by SDS-PAGE. The optimum pH and temperature for the purified lipase were found to be 8.5 and 40 ℃, respectively. The lipase kept more than 80% of activity in pH 7.0-10.0 and temperatures up to 45 ℃. The metal ions of Mn2＋, Ba2＋ significantly enhanced the lipase activity, whereas Cu2＋, Fe3＋ and Mg2＋ strongly reduced the lipase activity. The Km and Vmax values of the purified enzyme for p-nitrophenyl palmitate were 0.13 mrnol/L and 60.6 mmol/（L.min）, respectively. The results show that this novel lipase has potential industrial applications.展开更多
A cyanophage strain and its host Synechococcus were isolated from the East China Sea. The host Synechococcus sp. S J01 was characterized by its 16S rRNA, ITS, andpsbA gene sequences as well as by its morphological app...A cyanophage strain and its host Synechococcus were isolated from the East China Sea. The host Synechococcus sp. S J01 was characterized by its 16S rRNA, ITS, andpsbA gene sequences as well as by its morphological appearance and pigmentation. The cyanophage, strain S-SJ2, was able to cause a lytic infection of the coastal Synechococcus. TEM of negative-stained specimens showed that the phage isolate has an isometric head with a diameter of 68 nm and a long tail with a length of 280 nm. The cyanophage-Synechococcus system from the East China Sea shares many properties with other marine cyanophage-Synechocoecus systems worldwide.展开更多
From a production viewpoint , the optical thin films used to transparent substrates such as window glass for automobiles and the coating treatment process are reviewed. The state of the ar t of the technologies, and t...From a production viewpoint , the optical thin films used to transparent substrates such as window glass for automobiles and the coating treatment process are reviewed. The state of the ar t of the technologies, and the problems to be solved and possible solutions ar e discussed. Market trends are forecasted.展开更多
AIM:To report a patient with C282Y homozygocity,depleted body iron and intestinal atrophy caused by celiac disease (CD) who experienced resolution of the enteropathy with subsequent normalization of iron metabolism up...AIM:To report a patient with C282Y homozygocity,depleted body iron and intestinal atrophy caused by celiac disease (CD) who experienced resolution of the enteropathy with subsequent normalization of iron metabolism upon gluten free diet. METHODS:To obtain information on the tissue distribution and quantitative expression of proteins involved in duodenal iron trafficking,we determined the expression of divalent-metal transporter 1 (DMT1),ferroportin 1 (FP1) and transferrin receptor (TfR1) by means of immunohist-ochemistry and real-time PCR in duodenal biopsies of this patient. RESULTS:Whereas in hereditary hemochromatosis patients without CD, DMT1 expression was up-regulated leading to excessive uptake of iron, we identified a significant reduction in protein ana mRNA expression of DMT1 as a compensatory mechanism in this patient with HH and CD. CONCLUSION:Occult CD may compensate for increased DMT1 expression in a specific subset of individuals with homozygous C282Y mutations in the hemochromatosis (HFE) gene,thus contributing to the low penetrance of HH.展开更多
Submicro α-Fe2O3 coatings were formed using electrophoretic deposition(EPD) technique in aqueous media. The zeta potentials of different α-Fe2O3 suspensions with different additives were measured as a function of p ...Submicro α-Fe2O3 coatings were formed using electrophoretic deposition(EPD) technique in aqueous media. The zeta potentials of different α-Fe2O3 suspensions with different additives were measured as a function of p H to identify the optimum suspension condition for deposition. Electrophoretic depositions of α-Fe2O3 coatings under different applied electric fields and deposition time were studied and the effects of applied voltages and deposition time on deposition rates and thicknesses were investigated. The particle packing densities of the deposits at various applied voltages and deposition time were also analyzed by a scanning electron microscope(SEM). The results show that crack-free α-Fe2O3 coatings with uniform microstructure and good adherence to the nickel substrates are successfully obtained. Electrophoretic deposited α-Fe2O3 coating from aqueous suspension is a feasible, low-cost and environmental friendly method.展开更多
The potential protective effect of marine green algae （Codium iyengerii） was examined in UV-C treated seedlings of Vigna radiata. The study comprises of three treatments of UV-C radiation （100-290 nm） dose for one...The potential protective effect of marine green algae （Codium iyengerii） was examined in UV-C treated seedlings of Vigna radiata. The study comprises of three treatments of UV-C radiation （100-290 nm） dose for one min in alternative days. This results in deformed morphological parameters, including： decrease in plant height, fresh mass of leaves, shoots and roots, as well as leaf areas, which may be attributed with decreased in the relative growth rate, carbohydrate, amino acids, and protein contents of plant. A drastic effect of UV-C radiation was found on the photosynthetic apparatus where increase in red pigmentations on the leaves surface indicates the presence of UV-C absorbing pigments instead of chloroplast pigments. Visible spectrum of leaves chlorophyll showed reduced concentration of visible absorbing pigments which showed the deleterious effect of these radiations on physiological processes of seedlings. These negative effects of UV-C radiation on plant growth were found to be decreased by the application of green seaweed （Codium iyengerii）, and absorption spectrums of chloroplast contents showed that UV-C radiation inducing damages were appropriately managed by enhanced concentration of seaweeds which significantly increased morphological and physiological parameters like leaf, stem, root biomass, and plant height under UV-C radiation were observed.展开更多
In order to synthesize ZnO nanoparticles economically, industrial-grade zinc sulfate and urea were utilized to synthesize ZnO precursors in a stirred-tank reactor or a Teflon-lined autoclave at 100-180 ℃ under comple...In order to synthesize ZnO nanoparticles economically, industrial-grade zinc sulfate and urea were utilized to synthesize ZnO precursors in a stirred-tank reactor or a Teflon-lined autoclave at 100-180 ℃ under complete sealing condition. The ZnO precursors were calcined at 450 ℃ for 3 h to, synthesize ZnO nanoparticles. The composition of the precursors and the formation mechanism of ZnO were studied by thermogravimetric analysis and Fourier transform infrared spectroscopy. The results of X-ray diffraction, transmission electron microscopy and scanning electron microscopy of the ZnO powders demonstrate that high-purity zincite ZnO nanoparticles are synthesized. Orthogonal experiments were performed to find out the optimal conditions for the maximum yield and the minimum size. The ettect of temperature on the size ofZnO nanoparticles was investigated. The results show that a higher temperature is propitious to obtain smaller nanoparticles.展开更多
Reducing the module prices by increasing the efficiency of solar cells is one of the major challenges in today＇s photovoltaic research. The emitter formation by epitaxial growth offers a cost-efficient and faster alt...Reducing the module prices by increasing the efficiency of solar cells is one of the major challenges in today＇s photovoltaic research. The emitter formation by epitaxial growth offers a cost-efficient and faster alternative to the standard furnace diffusion process. The efficiency potential of epitaxial emitters 〉 22% has already been proven using a single wafer, low pressure, chemical vapour deposition tool. The purpose of this work is to show the potential of epitaxially grown emitters by APCVD （atmospheric pressure chemical vapour deposition） compared to diffused emitters. The APCVD formation of epitaxial emitters at 1,050 ~C can be realised as high throughput inline process and only takes 1-2 min, whereas the diffusion process using POCI3 takes up to 60 min. Simulations show an increase in voltage of AVoc = ＋10 mV and a reduction in saturation current ,1o of 30% for the epitaxial emitter. The lifetime experiments of solar cells with epitaxial emitter exhibit a diffusion length Leff〉 750μm and an emitter saturation current of Joe 〈 50 fA/cm2 on a planar 10 Ω2cm p-type FZ wafer. Another important aim of this work is to evaluate the limitations of epitaxial emitters due to high thermal budget, interface recombination and the change of reflective properties on textured wafers due to the deposition process. Solar cell efficiencies up to 18.4% on p-type and 20.0% on n-type wafers presented in this paper underline that the emitter epitaxy by APCVD is a competitive process for the emitter formation.展开更多
HOW TO ORDER SALES PUBLICATIONSIAEA publications may be purchased from the following sources,or through major local booksellers.Paymentmay be made in local currency or with UNESCO coupons.AUSTRALIAHunter Publications5...HOW TO ORDER SALES PUBLICATIONSIAEA publications may be purchased from the following sources,or through major local booksellers.Paymentmay be made in local currency or with UNESCO coupons.AUSTRALIAHunter Publications58A Gipps Street,Collingwood,Victoria 3066Telephone:+61 3 9417 5361·Fax:+61 3 9419 7154E-mail:jpdavies@ozemail.com.auBELGIUMJean de Lannoyavenue du Roi 202,B-1060 BrusselsTelephone:+32 2 538 43 08·Fax:+32 2 538 08 41E-mail:jean.de.lannoy@infoboard.beWeb site:http://www.jean-de-lannoy.be4087528·Fax:+60 3 407 9180E-mail:haja@pop 3.jaring.my·Web site:http://www.mol.net.my/～parrybook/parrys.htmNETHERLANDSMartinus Nijhoff InternationalRO.Box 269,NL-2501 AX The HagueTelephone:+31 793 684 400·Fax:+31 793 615 698E-mail:info@nijhoff..nlWeb site:http://www.nijhoff.nlSwets and Zeitlinger b.v.,P.O.Box 830,NL-2160 SZ展开更多
文摘Single crystalline 3C-SiC epitaxial layers are grown on φ 50mm Si wafers by a new resistively heated CVD/LPCVD system,using SiH_4,C_2H_4 and H_2 as gas precursors.X-ray diffraction and Raman scattering measurements are used to investigate the crystallinity of the grown films.Electrical properties of the epitaxial 3C-SiC layers with thickness of 1～3μm are measured by Van der Pauw method.The improved Hall mobility reaches the highest value of 470cm 2/(V·s) at the carrier concentration of 7.7×10 17 cm -3 .
文摘High quality GaN is grown on GaN substrate with stripe pattern by metalorganic chemical vapor deposition by means of epitaxial lateral overgrowth. AFM,wet chemical etching, and TEM experiments show that with a two-step ELOG procedure, the propagation of defects under the mask is blocked, and the coherently grown GaN above the window also experiences a drastic reduction in defect density. In addition, a grain boundary is formed at the coalescence boundary of neighboring growth fronts. The extremely low density of threading dislocations within wing regions makes ELOG GaN a potential template for the fabrication of nitride-based lasers with improved performance.
基金Projects supported by the National Natural Science Foundation of China (No. 30170550), the Natural Science Foundation of Anhui Provincial Education Department (No. 2005kj398zc) and the Culture Project for "the Tenth Five-year" Learning Leaders of Higher School of Anhui Province, China
文摘To reveal the possible mechanism of silica deposition in higher plants, lignin was isolated from rice straw following a modified method to conduct a simulation experiment in vitro. UV and infrared absorption spectra showed that the substance had the unique characteristics of pure lignin. The presence of silicon in the precipitation was revealed by TEM (transmission electron microscopy) with EDXA (energy dispersive X-ray analysis) device. It was found that in the borax solution where lignin precipi-tation occurred silica-lignin co-precipitation was produced but not in the DMSO solution where lignin was broken into its com-position compounds and did not precipitate. This means that it is macromolecular lignin itself but not its compounds that could induce silica deposition in higher plants.
文摘A strain HB-03 to produce alkaline extracellular lipase was isolated from oil-rich soil samples and identified as Aspergillus awamori. The growth conditions and nutritional factors for lipase production by strain HB-03 were optimized, and the maximum lipase production of （45.9±2.3） U/mL was obtained at 30 ℃ and pH 7.0 after 36 h using olive oil （1%） and sucrose （0.5%） as carbon sources and combination of peptone （2%）, yeast extract （0.5%） and ammonium sulfate （0.1%） as nitrogen sources. The lipase was purified to homogeneity with 10.6-fold, 18.84% yield and a specific activity of 1 862.2 U/mg using ammonium sulfate precipitation followed by SephadexG-75 gel filtration chromatography. The purified lipase with molecular mass of 68 ku was estimated by SDS-PAGE. The optimum pH and temperature for the purified lipase were found to be 8.5 and 40 ℃, respectively. The lipase kept more than 80% of activity in pH 7.0-10.0 and temperatures up to 45 ℃. The metal ions of Mn2＋, Ba2＋ significantly enhanced the lipase activity, whereas Cu2＋, Fe3＋ and Mg2＋ strongly reduced the lipase activity. The Km and Vmax values of the purified enzyme for p-nitrophenyl palmitate were 0.13 mrnol/L and 60.6 mmol/（L.min）, respectively. The results show that this novel lipase has potential industrial applications.
文摘A cyanophage strain and its host Synechococcus were isolated from the East China Sea. The host Synechococcus sp. S J01 was characterized by its 16S rRNA, ITS, andpsbA gene sequences as well as by its morphological appearance and pigmentation. The cyanophage, strain S-SJ2, was able to cause a lytic infection of the coastal Synechococcus. TEM of negative-stained specimens showed that the phage isolate has an isometric head with a diameter of 68 nm and a long tail with a length of 280 nm. The cyanophage-Synechococcus system from the East China Sea shares many properties with other marine cyanophage-Synechocoecus systems worldwide.
基金Natural Science Foundation of Henan Province(20011400019)
文摘From a production viewpoint , the optical thin films used to transparent substrates such as window glass for automobiles and the coating treatment process are reviewed. The state of the ar t of the technologies, and the problems to be solved and possible solutions ar e discussed. Market trends are forecasted.
文摘AIM:To report a patient with C282Y homozygocity,depleted body iron and intestinal atrophy caused by celiac disease (CD) who experienced resolution of the enteropathy with subsequent normalization of iron metabolism upon gluten free diet. METHODS:To obtain information on the tissue distribution and quantitative expression of proteins involved in duodenal iron trafficking,we determined the expression of divalent-metal transporter 1 (DMT1),ferroportin 1 (FP1) and transferrin receptor (TfR1) by means of immunohist-ochemistry and real-time PCR in duodenal biopsies of this patient. RESULTS:Whereas in hereditary hemochromatosis patients without CD, DMT1 expression was up-regulated leading to excessive uptake of iron, we identified a significant reduction in protein ana mRNA expression of DMT1 as a compensatory mechanism in this patient with HH and CD. CONCLUSION:Occult CD may compensate for increased DMT1 expression in a specific subset of individuals with homozygous C282Y mutations in the hemochromatosis (HFE) gene,thus contributing to the low penetrance of HH.
基金Project(51021063)supported by the National Natural Science Foundation for Innovation Group of ChinaProject(2012M521540)supported by China Postdoctoral Science Foundation+1 种基金Project(2013RS4027)supported by the Post Doctoral Scientific Foundation of Hunan Province,ChinaProject(CSUZC2013023)supported by the Precious Apparatus Open Share Foundation of Central South University,China
文摘Submicro α-Fe2O3 coatings were formed using electrophoretic deposition(EPD) technique in aqueous media. The zeta potentials of different α-Fe2O3 suspensions with different additives were measured as a function of p H to identify the optimum suspension condition for deposition. Electrophoretic depositions of α-Fe2O3 coatings under different applied electric fields and deposition time were studied and the effects of applied voltages and deposition time on deposition rates and thicknesses were investigated. The particle packing densities of the deposits at various applied voltages and deposition time were also analyzed by a scanning electron microscope(SEM). The results show that crack-free α-Fe2O3 coatings with uniform microstructure and good adherence to the nickel substrates are successfully obtained. Electrophoretic deposited α-Fe2O3 coating from aqueous suspension is a feasible, low-cost and environmental friendly method.
文摘The potential protective effect of marine green algae （Codium iyengerii） was examined in UV-C treated seedlings of Vigna radiata. The study comprises of three treatments of UV-C radiation （100-290 nm） dose for one min in alternative days. This results in deformed morphological parameters, including： decrease in plant height, fresh mass of leaves, shoots and roots, as well as leaf areas, which may be attributed with decreased in the relative growth rate, carbohydrate, amino acids, and protein contents of plant. A drastic effect of UV-C radiation was found on the photosynthetic apparatus where increase in red pigmentations on the leaves surface indicates the presence of UV-C absorbing pigments instead of chloroplast pigments. Visible spectrum of leaves chlorophyll showed reduced concentration of visible absorbing pigments which showed the deleterious effect of these radiations on physiological processes of seedlings. These negative effects of UV-C radiation on plant growth were found to be decreased by the application of green seaweed （Codium iyengerii）, and absorption spectrums of chloroplast contents showed that UV-C radiation inducing damages were appropriately managed by enhanced concentration of seaweeds which significantly increased morphological and physiological parameters like leaf, stem, root biomass, and plant height under UV-C radiation were observed.
基金Project(20876100) supported by the National Natural Science Foundation of ChinaProject(20090451176) supported by the China Post-doctoral Science Foundation+3 种基金Project(2009CB219904) supported by the National Basic Research Program of ChinaProjects(YJS0917,SG0978) supported by the Commission of Science and Technology of Suzhou MunicipalityProject(11C26223204581) supported by the Ministry of Science and TechnologyProject(BK2011328) supported by the Natural Science Foundation of Jiangsu Province,China
文摘In order to synthesize ZnO nanoparticles economically, industrial-grade zinc sulfate and urea were utilized to synthesize ZnO precursors in a stirred-tank reactor or a Teflon-lined autoclave at 100-180 ℃ under complete sealing condition. The ZnO precursors were calcined at 450 ℃ for 3 h to, synthesize ZnO nanoparticles. The composition of the precursors and the formation mechanism of ZnO were studied by thermogravimetric analysis and Fourier transform infrared spectroscopy. The results of X-ray diffraction, transmission electron microscopy and scanning electron microscopy of the ZnO powders demonstrate that high-purity zincite ZnO nanoparticles are synthesized. Orthogonal experiments were performed to find out the optimal conditions for the maximum yield and the minimum size. The ettect of temperature on the size ofZnO nanoparticles was investigated. The results show that a higher temperature is propitious to obtain smaller nanoparticles.
文摘Reducing the module prices by increasing the efficiency of solar cells is one of the major challenges in today＇s photovoltaic research. The emitter formation by epitaxial growth offers a cost-efficient and faster alternative to the standard furnace diffusion process. The efficiency potential of epitaxial emitters 〉 22% has already been proven using a single wafer, low pressure, chemical vapour deposition tool. The purpose of this work is to show the potential of epitaxially grown emitters by APCVD （atmospheric pressure chemical vapour deposition） compared to diffused emitters. The APCVD formation of epitaxial emitters at 1,050 ~C can be realised as high throughput inline process and only takes 1-2 min, whereas the diffusion process using POCI3 takes up to 60 min. Simulations show an increase in voltage of AVoc = ＋10 mV and a reduction in saturation current ,1o of 30% for the epitaxial emitter. The lifetime experiments of solar cells with epitaxial emitter exhibit a diffusion length Leff〉 750μm and an emitter saturation current of Joe 〈 50 fA/cm2 on a planar 10 Ω2cm p-type FZ wafer. Another important aim of this work is to evaluate the limitations of epitaxial emitters due to high thermal budget, interface recombination and the change of reflective properties on textured wafers due to the deposition process. Solar cell efficiencies up to 18.4% on p-type and 20.0% on n-type wafers presented in this paper underline that the emitter epitaxy by APCVD is a competitive process for the emitter formation.
文摘HOW TO ORDER SALES PUBLICATIONSIAEA publications may be purchased from the following sources,or through major local booksellers.Paymentmay be made in local currency or with UNESCO coupons.AUSTRALIAHunter Publications58A Gipps Street,Collingwood,Victoria 3066Telephone:+61 3 9417 5361·Fax:+61 3 9419 7154E-mail:jpdavies@ozemail.com.auBELGIUMJean de Lannoyavenue du Roi 202,B-1060 BrusselsTelephone:+32 2 538 43 08·Fax:+32 2 538 08 41E-mail:jean.de.lannoy@infoboard.beWeb site:http://www.jean-de-lannoy.be4087528·Fax:+60 3 407 9180E-mail:haja@pop 3.jaring.my·Web site:http://www.mol.net.my/～parrybook/parrys.htmNETHERLANDSMartinus Nijhoff InternationalRO.Box 269,NL-2501 AX The HagueTelephone:+31 793 684 400·Fax:+31 793 615 698E-mail:info@nijhoff..nlWeb site:http://www.nijhoff.nlSwets and Zeitlinger b.v.,P.O.Box 830,NL-2160 SZ
