Based on theoretical analysis and computer-aided simulation, optimized design principles for Si/SiGe PMOSFET are given in this paper, which include choice of gate materials,determination of germanium percentage and pr...Based on theoretical analysis and computer-aided simulation, optimized design principles for Si/SiGe PMOSFET are given in this paper, which include choice of gate materials,determination of germanium percentage and profile in SiGe channel, optimization of thickness of dioxide and silicon cap layer, and adjustment of threshold voltage. In the light of these principles,a SiGe PMOSFET is designed and fabricated successfully. Measurement indicates that the SiGe PMOSFET's (L=2μm) transconductance is 45 mS/mm (300K) and 92mS/mm (77K), while that is 33 mS/mm (300K) and 39mS/mm (77K) in Si PMOSFET with the same structure.展开更多
A facile and user friendly technique to immobilize the late-transition metal complexes on spherical MgCl2/SiO2/THF support has been developed. The spherical MgCl2/SiO2/THF-supported late-transition metal catalysts 2,6...A facile and user friendly technique to immobilize the late-transition metal complexes on spherical MgCl2/SiO2/THF support has been developed. The spherical MgCl2/SiO2/THF-supported late-transition metal catalysts 2,6-bis-[1-(2,6-dimethylphenylimino)ethyl]pyridine iron(II) dichloride(SC-A) and 1,4-bis(2,6-dimethylphenyl)- acenaphthene diimine nickel(II) dibromide(SC-B) for ethylene polymerization has been prepared by spray-drying technique using tetrahydrofuran suspension containing MgCl2, SiO2 and late-transition metal complexes. The catalysts were characterized by BET, XRD, SEM and the polymers were analyzed using GPC, DSC and 13C-NMR. The test results show that spray-drying is a very effective method for immobilizing late-transition metal catalysts for ethylene polymerization. Among six kinds of cocatalysts for olefin polymerization, TMA and TEA were confirmed to be more effective than other compounds for the ethylene polymerization system using the catalyst SC-A. For the case of the catalyst SC-B, DEAC showed the best performance as cocatalysts in ethylene polymerization. The replication of the catalyst morphology was found in the resultant polyethylene.展开更多
A new MeTAMP （thiazolylazo dye ligand 2-[2-（5-methyl thiazolyl）azo]-4-methoxy phenol） was prepared by coupling reaction between 5-methyl thiazolylazonium chloride with 4-methoxy phenol in alkaline alcoholic soluti...A new MeTAMP （thiazolylazo dye ligand 2-[2-（5-methyl thiazolyl）azo]-4-methoxy phenol） was prepared by coupling reaction between 5-methyl thiazolylazonium chloride with 4-methoxy phenol in alkaline alcoholic solution. The structure of azo dye ligand has been characterized by available technique such as 1H-NMR, mass spectrum, FT-IR, UV-vis and elemental analysis. Eight new chelate complexes of Cr（III）, Mn（II）, Fe（II）, Fe（III）, Co（III）, Ni（II）, Cu（II） and Zn（II） ions were prepared and identified by elemental analysis, atomic absorption, magnetic susceptibility, molar conductance measurements, FT-IR and electronic spectra. The spectral and analytical data show that the ligand a tridentate and coordinating with metal ions through the phenolate O, azo N atom which is the farthest of thiazole molecule and with thiazole N atom. The molar ratio （M：L） was also studied which was found 1：1 for Zn（II） and 1：2 for the rest metal ions. Conductivity measurements for prepared complexes showed 1：1 electrolyte for Cr（III）, Fe（IlI）, and Co（llI） complexes and non-electrolyte for rest complexes. Stability constants of complexes were calculated by spectrophotometry. Octahedral configuration suggested for Cr（III）, Mn（II）, Fe（II）, Fe（III）, Co（III）, Ni（II） and Cu（II） but tetrahedral for Zn（IlI） complex. The solid complexes are found to have the general formula IML2]Cl H2O where M = Cr（III）, Fe（III） and Co（IIl） and [ML2] H2O where M = Mn（II）, Fe（II）, Ni（II） and Cu（II） while [MLCI].H20 for Zn（II）-complex. The biological activity of ligand and its complexes against five types of bacteria, Strepto coccus and Staphylococcus aureus as example of gram positive, Pseudomonas, Proteus and Esherichia coli as example of gram negative bacteria by agar plate different technique was studied. The activity was also assayed on molecular level by using PCR in an attempt to monitor DNA banding pattern.展开更多
A discrete centrosymmetric （H2O）20（CH3OH）4 binary cluster was confined in the cavity of a metaMigand hybrid [Ag4（bpda）2（bpp）4＂ 14H2O.2CH3OH], （1） （where bpp = 1,3-bis（4-pyridyl）propane and H2bpda = 2,2＇...A discrete centrosymmetric （H2O）20（CH3OH）4 binary cluster was confined in the cavity of a metaMigand hybrid [Ag4（bpda）2（bpp）4＂ 14H2O.2CH3OH], （1） （where bpp = 1,3-bis（4-pyridyl）propane and H2bpda = 2,2＇-biphenyldicarboxylic acid） The novel mixed water-methanol cluster consists of one grail-shaped hexadecameric cluster, four dangling water and four hanging methanol molecules. The （H2O）16 cluster is composed of two pairs of edge-sharing （H2O）5 rings attached to one （H2O）4 core with twenty hydrogen bonds. Alternatively, the （H2O）16 cluster is structurally similar to a complicated hydrocarbon generated by undergoing [2＋2] cycloaddition of 1,2,3,4,5,6-hexahydropentalene, which reveals the resemblance between water clusters and organic compounds.展开更多
基金Supported by National Key Laboratory Fund (99Js09 5.1)
文摘Based on theoretical analysis and computer-aided simulation, optimized design principles for Si/SiGe PMOSFET are given in this paper, which include choice of gate materials,determination of germanium percentage and profile in SiGe channel, optimization of thickness of dioxide and silicon cap layer, and adjustment of threshold voltage. In the light of these principles,a SiGe PMOSFET is designed and fabricated successfully. Measurement indicates that the SiGe PMOSFET's (L=2μm) transconductance is 45 mS/mm (300K) and 92mS/mm (77K), while that is 33 mS/mm (300K) and 39mS/mm (77K) in Si PMOSFET with the same structure.
基金supported by the National Natural Science Foundation of China (Grant No.U1162114)the Science Foundation of Tianjin University of Science & Technology (20090420)
文摘A facile and user friendly technique to immobilize the late-transition metal complexes on spherical MgCl2/SiO2/THF support has been developed. The spherical MgCl2/SiO2/THF-supported late-transition metal catalysts 2,6-bis-[1-(2,6-dimethylphenylimino)ethyl]pyridine iron(II) dichloride(SC-A) and 1,4-bis(2,6-dimethylphenyl)- acenaphthene diimine nickel(II) dibromide(SC-B) for ethylene polymerization has been prepared by spray-drying technique using tetrahydrofuran suspension containing MgCl2, SiO2 and late-transition metal complexes. The catalysts were characterized by BET, XRD, SEM and the polymers were analyzed using GPC, DSC and 13C-NMR. The test results show that spray-drying is a very effective method for immobilizing late-transition metal catalysts for ethylene polymerization. Among six kinds of cocatalysts for olefin polymerization, TMA and TEA were confirmed to be more effective than other compounds for the ethylene polymerization system using the catalyst SC-A. For the case of the catalyst SC-B, DEAC showed the best performance as cocatalysts in ethylene polymerization. The replication of the catalyst morphology was found in the resultant polyethylene.
文摘A new MeTAMP （thiazolylazo dye ligand 2-[2-（5-methyl thiazolyl）azo]-4-methoxy phenol） was prepared by coupling reaction between 5-methyl thiazolylazonium chloride with 4-methoxy phenol in alkaline alcoholic solution. The structure of azo dye ligand has been characterized by available technique such as 1H-NMR, mass spectrum, FT-IR, UV-vis and elemental analysis. Eight new chelate complexes of Cr（III）, Mn（II）, Fe（II）, Fe（III）, Co（III）, Ni（II）, Cu（II） and Zn（II） ions were prepared and identified by elemental analysis, atomic absorption, magnetic susceptibility, molar conductance measurements, FT-IR and electronic spectra. The spectral and analytical data show that the ligand a tridentate and coordinating with metal ions through the phenolate O, azo N atom which is the farthest of thiazole molecule and with thiazole N atom. The molar ratio （M：L） was also studied which was found 1：1 for Zn（II） and 1：2 for the rest metal ions. Conductivity measurements for prepared complexes showed 1：1 electrolyte for Cr（III）, Fe（IlI）, and Co（llI） complexes and non-electrolyte for rest complexes. Stability constants of complexes were calculated by spectrophotometry. Octahedral configuration suggested for Cr（III）, Mn（II）, Fe（II）, Fe（III）, Co（III）, Ni（II） and Cu（II） but tetrahedral for Zn（IlI） complex. The solid complexes are found to have the general formula IML2]Cl H2O where M = Cr（III）, Fe（III） and Co（IIl） and [ML2] H2O where M = Mn（II）, Fe（II）, Ni（II） and Cu（II） while [MLCI].H20 for Zn（II）-complex. The biological activity of ligand and its complexes against five types of bacteria, Strepto coccus and Staphylococcus aureus as example of gram positive, Pseudomonas, Proteus and Esherichia coli as example of gram negative bacteria by agar plate different technique was studied. The activity was also assayed on molecular level by using PCR in an attempt to monitor DNA banding pattern.
基金supported by the National Natural Science Foundation of China(50971063,21053001)the Natural Science Foundation of Fujian Province(2011J01047,2010J01042)+1 种基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Education of Ministrythe Startup Package Funding of Huaqiao University (10BS210)
文摘A discrete centrosymmetric （H2O）20（CH3OH）4 binary cluster was confined in the cavity of a metaMigand hybrid [Ag4（bpda）2（bpp）4＂ 14H2O.2CH3OH], （1） （where bpp = 1,3-bis（4-pyridyl）propane and H2bpda = 2,2＇-biphenyldicarboxylic acid） The novel mixed water-methanol cluster consists of one grail-shaped hexadecameric cluster, four dangling water and four hanging methanol molecules. The （H2O）16 cluster is composed of two pairs of edge-sharing （H2O）5 rings attached to one （H2O）4 core with twenty hydrogen bonds. Alternatively, the （H2O）16 cluster is structurally similar to a complicated hydrocarbon generated by undergoing [2＋2] cycloaddition of 1,2,3,4,5,6-hexahydropentalene, which reveals the resemblance between water clusters and organic compounds.
