TA2/TA15 graded structural material（GSM） was fabricated by the laser additive manufacturing（LAM） process. The chemical composition, microstructure and micro-hardness of the as-deposited GSM were investigated. The ...TA2/TA15 graded structural material（GSM） was fabricated by the laser additive manufacturing（LAM） process. The chemical composition, microstructure and micro-hardness of the as-deposited GSM were investigated. The results show that the TA2 part of exhibiting near-equiaxed grains was Widmanst？tten α-laths microstructure. The TA15 part containing large columnar grains was fine basket-weave microstructure. The graded zone was divided into four deposited layers with 3000 μm in thickness. As the distance from the TA2 part increases, the alloy element contents and the β phase volume fraction increase, the α phase volume fraction decreases and the microstructure shows the evolution from Widmanst？tten α-laths to basket-weave α-laths gradually. The micro-hardness increases from the TA2 part to the TA15 part due to the solid solution strengthening and grain boundary strengthening.展开更多
Calcium modified lead titanate nanocrystal material Pb0.85Ca0.15TiO3 was synthesized by means of a solgel method.The changes of crystal structure and grainsize of the samples were investigated under different conditio...Calcium modified lead titanate nanocrystal material Pb0.85Ca0.15TiO3 was synthesized by means of a solgel method.The changes of crystal structure and grainsize of the samples were investigated under different conditions of heat treatment.the results show that the tetragonal symmetry is reduced and the ferroelectricparaelectric phase transformation temperature is decreased with the reduce of the grainsize of the sample.the critical grainsize for the ferroelectricparaelectric phase transformation at room temperature was calculated.The change regularities of the lattice constant and tetragonality with the grainsize are discussed.展开更多
The Patagonian Shelf is a very productive region with dif ferent ecosystem structures. A long history of fishing in the Southwestern Atlantic Ocean combined with a complex hydrographic structure, with a permanent fron...The Patagonian Shelf is a very productive region with dif ferent ecosystem structures. A long history of fishing in the Southwestern Atlantic Ocean combined with a complex hydrographic structure, with a permanent front over the shelf-break and dif ferent coastal frontal regions, and a wide non-frontal area in between have made the food web in this area more complex and have resulted in changes to the spatialtemporal scale. Stable isotopes of carbon and nitrogen were used to determine the trophic structure of the Patagonian shelf break which was previously poorly understood. The results indicated that the average δ^(15)N value of pelagic guild(I llex argentinus) was remarkable lower than those of the other guilds. The δ^(13)C values of almost all species ranged from-17‰ to-18‰, but S tromateus brasiliensis had a significant lower δ^(13)C value. Compared with the southern Patagonian shelf, short food chain length also occurred. The impact of complex oceanographic structures has resulted in food web structure change to the temporal-spatial scale on the Patagonian shelf. The Patagonian shelf break can be considered as a separated ecosystem structure with lower δ^(15)N values.展开更多
The compound 15α-hydroxyl-oleanolic acid was biotransformed from oleanolic acid with Colletotrichum lini AS3.4486,and its structure was characterized by 1H NMR,13C NMR,HR-ESI-MS and single-crystal X-ray diffraction.T...The compound 15α-hydroxyl-oleanolic acid was biotransformed from oleanolic acid with Colletotrichum lini AS3.4486,and its structure was characterized by 1H NMR,13C NMR,HR-ESI-MS and single-crystal X-ray diffraction.The crystal of the title compound belongs to monoclinic,space group R3 with a=34.255（5）,b=34.255（5）,c=6.8671（14）,β=90°,Z=9,V=6978（2）3,Mr=490.70,Dc=1.051 mg/m3,μ=0.069 mm-1,F（000）=2430,R=0.0375 and wR=0.0808.The title compound is stacked into a three-dimensional network through hydrogen bonds.展开更多
[Na (N- (p-chlorophenyl ) aza-15--crown--5 ) (Et2O )]2 (Na2W0.5 Mo7.5 O26), Mr= 2119. 4, monoclinic, space group P21/c, a= 17. 803(4), b= 13. 674 (3), c= 14. 610(3), β= 112. 33(3)°, V=3290(1) A3, Z= 2, Dc= 2. 13...[Na (N- (p-chlorophenyl ) aza-15--crown--5 ) (Et2O )]2 (Na2W0.5 Mo7.5 O26), Mr= 2119. 4, monoclinic, space group P21/c, a= 17. 803(4), b= 13. 674 (3), c= 14. 610(3), β= 112. 33(3)°, V=3290(1) A3, Z= 2, Dc= 2. 139 g/cm3, μ= 1.704 mm-1, F (000) = 2079, R = 0. 026, Rw= 0. 030. The supermolecular complexconsists of one [Na2W0.5Mo7.5O28)2- anion in which only two Mo atoms are replaced byW in 25% (M= l/4W+3/4Mo) and the two Na+ are linked symmetrically to neighbouring [W0.5Mo7.5O26]4- units on the right and the left respectively and two complexcanons in which each Na+ deviates from the plane of the four ether oxygens and is coordinated to every hetero--atom in the crownether ring, and is also coordinated to the Oatom of Et2O.展开更多
Progesterone（1） was biotransformed into the title compound 12β,15α-dihydroxy-progesterone（2） with Colletotrichum lini AS3.4486.The biotransformation process was monitored with HPLC.The structure of 2 was determi...Progesterone（1） was biotransformed into the title compound 12β,15α-dihydroxy-progesterone（2） with Colletotrichum lini AS3.4486.The biotransformation process was monitored with HPLC.The structure of 2 was determined by 1H NMR,13C NMR,ESI-MS and single-crystal X-ray diffraction.The crystal of the compound belongs to orthorhombic,space group P212121 with a = 8.0671（9）,b = 12.3970（15）,c = 18.532（3） ,Z = 4,V = 1853.3（4）3,Dc = 1.242 mg/m3,μ = 0.084 mm-1,F（000） = 752,R = 0.0373 and wR = 0.0850.Single-crystal X-ray diffraction analysis reveals that a 1D supramolecular structure of 2 has been constructed by multiply intermolecular O（2）-H（2）…O（4） and O（3）-H（3）…O（2） H-bonding interactions.展开更多
Nb3Sn and other A15 members have been widely applied in nuclear power, nuclear magnetic resonance, and high-energy particle accelerators for their high critical current density （Jc） and upper critical field （Bc2）....Nb3Sn and other A15 members have been widely applied in nuclear power, nuclear magnetic resonance, and high-energy particle accelerators for their high critical current density （Jc） and upper critical field （Bc2）. There have been comprehensive and intensive studies on the applications, the fundamental lattice dynamic and electronic properties, etc., of A15 superconductors. Various reviews on the preparations, structures, and properties have already been written in the last few years. Nevertheless, on account of the large amount of existing facts and views, a coherent view on the relations between the structures and properties has not appeared to unify the facts. This article sketches a multi-scale point of view on the relations between the multi- scale structures and the corresponding properties.展开更多
The compound phenol,2-[4（S）-4,5-dihydro-4-phenyl-2-ozazolinyl（1,C15H13NO2） was synthesized with a simple,one step method free of water and air.It was obtained in a moderate yield from the reaction of 2-hydroxybenz...The compound phenol,2-[4（S）-4,5-dihydro-4-phenyl-2-ozazolinyl（1,C15H13NO2） was synthesized with a simple,one step method free of water and air.It was obtained in a moderate yield from the reaction of 2-hydroxybenzonitrile with optically active amino alcohol in chloroben-zene under dry,anaerobic conditions.It belongs to the orthorhombic system,space group P212121 with a = 5.786（5）,b = 10.730（5）,c = 19.722（5）,C15H13NO2,Mr = 239.26,V = 1224.4（12）3,Z = 4 and Dc = 1.298 mg/m3.The final R = 0.0324 for 1627 observed reflections with Ⅰ 〉 2σ（Ⅰ） and Rw = 0.0826 for all data.The structure of compound 1 was determined by X-ray diffraction,NMR and HRMS.展开更多
采用固相反应法制备了Ca_(0.94)Ce_(0.06)Bi_(4)Ti_(4-x)Nb_(x)O_(15)(CCBTN)铋层状高温压电陶瓷,研究了B位Nb掺杂对陶瓷晶体结构、微观形貌、介电、压电性能的影响规律。结果表明:制备的CCBTN陶瓷均具有单一的铋层状结构相,少量Nb掺杂...采用固相反应法制备了Ca_(0.94)Ce_(0.06)Bi_(4)Ti_(4-x)Nb_(x)O_(15)(CCBTN)铋层状高温压电陶瓷,研究了B位Nb掺杂对陶瓷晶体结构、微观形貌、介电、压电性能的影响规律。结果表明:制备的CCBTN陶瓷均具有单一的铋层状结构相,少量Nb掺杂有利于陶瓷压电常数及热稳定性能的提升。当Nb掺杂量x=0.06时,陶瓷具有最高的压电常数(d33=19.2pC·N^(-1)),是纯CBT陶瓷压电常数(d33=8 p C·N^(-1))的2.4倍,且退火至500℃时其压电常数仍保持室温值的90%以上,表现出较优异的热稳定性。同时,该陶瓷具有高的居里温度(Tc=769℃)、低的介电损耗(tanδ=0.65%)及高的电阻率(ρdc=2.0×10^(7)Ω·cm@500℃),是高温压电传感器制作的优异候选材料。展开更多
4′-acetylbenzo-15-crown-5thiosemicarbazone was synthesized with high yield (94%)via the reaction of 4′-acetylbenzo-15-crown-5 and thiosemicarbazide under the microwave irradiation and hydrochloric acid as the cataly...4′-acetylbenzo-15-crown-5thiosemicarbazone was synthesized with high yield (94%)via the reaction of 4′-acetylbenzo-15-crown-5 and thiosemicarbazide under the microwave irradiation and hydrochloric acid as the catalyst.Its structure was determined by single-crystal X-ray diffraction.The crystal belongs to triclinic crystal system,P-1 space group,a=9.5470(19)?,b=13.637(3)?,c=16.029(3)?,α=75.33(3)°,β=83.62(3)°,γ=70.99(3)°,V=1097.8(7)s assembled into supramolecule structure by intermolecular hydrogen bonds.展开更多
基金Project(2010CB731705)supported by the National Basic Research Program of China
文摘TA2/TA15 graded structural material（GSM） was fabricated by the laser additive manufacturing（LAM） process. The chemical composition, microstructure and micro-hardness of the as-deposited GSM were investigated. The results show that the TA2 part of exhibiting near-equiaxed grains was Widmanst？tten α-laths microstructure. The TA15 part containing large columnar grains was fine basket-weave microstructure. The graded zone was divided into four deposited layers with 3000 μm in thickness. As the distance from the TA2 part increases, the alloy element contents and the β phase volume fraction increase, the α phase volume fraction decreases and the microstructure shows the evolution from Widmanst？tten α-laths to basket-weave α-laths gradually. The micro-hardness increases from the TA2 part to the TA15 part due to the solid solution strengthening and grain boundary strengthening.
文摘Calcium modified lead titanate nanocrystal material Pb0.85Ca0.15TiO3 was synthesized by means of a solgel method.The changes of crystal structure and grainsize of the samples were investigated under different conditions of heat treatment.the results show that the tetragonal symmetry is reduced and the ferroelectricparaelectric phase transformation temperature is decreased with the reduce of the grainsize of the sample.the critical grainsize for the ferroelectricparaelectric phase transformation at room temperature was calculated.The change regularities of the lattice constant and tetragonality with the grainsize are discussed.
基金Supported by the National Key Technology R&D Program of China(No.2013BAD13B03)the National Natural Science Foundation of China(No.41776185)the Special Fund for Agro-Scientifi c Research in the Public Interest of China(No.201203018)
文摘The Patagonian Shelf is a very productive region with dif ferent ecosystem structures. A long history of fishing in the Southwestern Atlantic Ocean combined with a complex hydrographic structure, with a permanent front over the shelf-break and dif ferent coastal frontal regions, and a wide non-frontal area in between have made the food web in this area more complex and have resulted in changes to the spatialtemporal scale. Stable isotopes of carbon and nitrogen were used to determine the trophic structure of the Patagonian shelf break which was previously poorly understood. The results indicated that the average δ^(15)N value of pelagic guild(I llex argentinus) was remarkable lower than those of the other guilds. The δ^(13)C values of almost all species ranged from-17‰ to-18‰, but S tromateus brasiliensis had a significant lower δ^(13)C value. Compared with the southern Patagonian shelf, short food chain length also occurred. The impact of complex oceanographic structures has resulted in food web structure change to the temporal-spatial scale on the Patagonian shelf. The Patagonian shelf break can be considered as a separated ecosystem structure with lower δ^(15)N values.
基金supported by the starting Foundation of Tianjin University of Science and Technology (No. 20070449)the Natural Science Foundation of Tianjin (Nos. 08JCZDJC15200 and 08JCZDJC15300)
文摘The compound 15α-hydroxyl-oleanolic acid was biotransformed from oleanolic acid with Colletotrichum lini AS3.4486,and its structure was characterized by 1H NMR,13C NMR,HR-ESI-MS and single-crystal X-ray diffraction.The crystal of the title compound belongs to monoclinic,space group R3 with a=34.255（5）,b=34.255（5）,c=6.8671（14）,β=90°,Z=9,V=6978（2）3,Mr=490.70,Dc=1.051 mg/m3,μ=0.069 mm-1,F（000）=2430,R=0.0375 and wR=0.0808.The title compound is stacked into a three-dimensional network through hydrogen bonds.
文摘[Na (N- (p-chlorophenyl ) aza-15--crown--5 ) (Et2O )]2 (Na2W0.5 Mo7.5 O26), Mr= 2119. 4, monoclinic, space group P21/c, a= 17. 803(4), b= 13. 674 (3), c= 14. 610(3), β= 112. 33(3)°, V=3290(1) A3, Z= 2, Dc= 2. 139 g/cm3, μ= 1.704 mm-1, F (000) = 2079, R = 0. 026, Rw= 0. 030. The supermolecular complexconsists of one [Na2W0.5Mo7.5O28)2- anion in which only two Mo atoms are replaced byW in 25% (M= l/4W+3/4Mo) and the two Na+ are linked symmetrically to neighbouring [W0.5Mo7.5O26]4- units on the right and the left respectively and two complexcanons in which each Na+ deviates from the plane of the four ether oxygens and is coordinated to every hetero--atom in the crownether ring, and is also coordinated to the Oatom of Et2O.
基金supported by the Natural Science Foundation of Tianjin (Nos. 08JCZDJC15200 and 11JGYBJC14300)the Program for New Century Excellent Talents in University (No. NCET-08-0911)
文摘Progesterone（1） was biotransformed into the title compound 12β,15α-dihydroxy-progesterone（2） with Colletotrichum lini AS3.4486.The biotransformation process was monitored with HPLC.The structure of 2 was determined by 1H NMR,13C NMR,ESI-MS and single-crystal X-ray diffraction.The crystal of the compound belongs to orthorhombic,space group P212121 with a = 8.0671（9）,b = 12.3970（15）,c = 18.532（3） ,Z = 4,V = 1853.3（4）3,Dc = 1.242 mg/m3,μ = 0.084 mm-1,F（000） = 752,R = 0.0373 and wR = 0.0850.Single-crystal X-ray diffraction analysis reveals that a 1D supramolecular structure of 2 has been constructed by multiply intermolecular O（2）-H（2）…O（4） and O（3）-H（3）…O（2） H-bonding interactions.
基金financially supported by the Science Foundation for International Cooperation of Sichuan Province (2014HH0016)the Fundamental Research Funds for the Central Universities (SWJTU2014: A0920502051113-10000)National Magnetic Confinement Fusion Science Program (2011GB112001)
文摘Nb3Sn and other A15 members have been widely applied in nuclear power, nuclear magnetic resonance, and high-energy particle accelerators for their high critical current density （Jc） and upper critical field （Bc2）. There have been comprehensive and intensive studies on the applications, the fundamental lattice dynamic and electronic properties, etc., of A15 superconductors. Various reviews on the preparations, structures, and properties have already been written in the last few years. Nevertheless, on account of the large amount of existing facts and views, a coherent view on the relations between the structures and properties has not appeared to unify the facts. This article sketches a multi-scale point of view on the relations between the multi- scale structures and the corresponding properties.
文摘The compound phenol,2-[4（S）-4,5-dihydro-4-phenyl-2-ozazolinyl（1,C15H13NO2） was synthesized with a simple,one step method free of water and air.It was obtained in a moderate yield from the reaction of 2-hydroxybenzonitrile with optically active amino alcohol in chloroben-zene under dry,anaerobic conditions.It belongs to the orthorhombic system,space group P212121 with a = 5.786（5）,b = 10.730（5）,c = 19.722（5）,C15H13NO2,Mr = 239.26,V = 1224.4（12）3,Z = 4 and Dc = 1.298 mg/m3.The final R = 0.0324 for 1627 observed reflections with Ⅰ 〉 2σ（Ⅰ） and Rw = 0.0826 for all data.The structure of compound 1 was determined by X-ray diffraction,NMR and HRMS.
文摘采用固相反应法制备了Ca_(0.94)Ce_(0.06)Bi_(4)Ti_(4-x)Nb_(x)O_(15)(CCBTN)铋层状高温压电陶瓷,研究了B位Nb掺杂对陶瓷晶体结构、微观形貌、介电、压电性能的影响规律。结果表明:制备的CCBTN陶瓷均具有单一的铋层状结构相,少量Nb掺杂有利于陶瓷压电常数及热稳定性能的提升。当Nb掺杂量x=0.06时,陶瓷具有最高的压电常数(d33=19.2pC·N^(-1)),是纯CBT陶瓷压电常数(d33=8 p C·N^(-1))的2.4倍,且退火至500℃时其压电常数仍保持室温值的90%以上,表现出较优异的热稳定性。同时,该陶瓷具有高的居里温度(Tc=769℃)、低的介电损耗(tanδ=0.65%)及高的电阻率(ρdc=2.0×10^(7)Ω·cm@500℃),是高温压电传感器制作的优异候选材料。
文摘4′-acetylbenzo-15-crown-5thiosemicarbazone was synthesized with high yield (94%)via the reaction of 4′-acetylbenzo-15-crown-5 and thiosemicarbazide under the microwave irradiation and hydrochloric acid as the catalyst.Its structure was determined by single-crystal X-ray diffraction.The crystal belongs to triclinic crystal system,P-1 space group,a=9.5470(19)?,b=13.637(3)?,c=16.029(3)?,α=75.33(3)°,β=83.62(3)°,γ=70.99(3)°,V=1097.8(7)s assembled into supramolecule structure by intermolecular hydrogen bonds.
