The preparation procedure of DD5 single crystal castings was optimized. The microstructure characteristics of DD5 single crystal superalloy were investigated by microstructure observation and segregation behavior exam...The preparation procedure of DD5 single crystal castings was optimized. The microstructure characteristics of DD5 single crystal superalloy were investigated by microstructure observation and segregation behavior examination. The results show that the grain orientation is optimized by constraining the spiral crystallizer in [001] orientation and spatial scale. Also, the γ＇ phase of inter-dendrites is larger and more irregular than that in dendrite arms. High temperature tensile tests of DD5 single crystal castings exhibit that the peak stress increases with increasing temperature, while the area reduction shows an opposite trend, when the temperature is below 800℃; meanwhile, when the temperature is between 800℃ and 1000℃, the fracture stress of the alloy is the same as the peak stress. The fracture mode changes from shear to ductile with increasing temperature from 600℃ and 1000℃.展开更多
(CH_3)_4C_2(C_5H_4)_2Sm(C_5H_5)OC_4H_, Mr=499.4, orthorhombic, Cc2a, a=11.696(6), b=12.539(5), c=29.432(15), V=4316(4)~, Z=8, Dc=1.54g. cm^(-3), μ (MoKα)=27.8cm^(-1), F(000)=2024, R=0.077 for 1833 observed reflectio...(CH_3)_4C_2(C_5H_4)_2Sm(C_5H_5)OC_4H_, Mr=499.4, orthorhombic, Cc2a, a=11.696(6), b=12.539(5), c=29.432(15), V=4316(4)~, Z=8, Dc=1.54g. cm^(-3), μ (MoKα)=27.8cm^(-1), F(000)=2024, R=0.077 for 1833 observed reflections. In the molecule the samarium atom is bonded to three cyclopentadienyl rings and an oxygen of tetrahydrofuran(THF). The three centroids of the cyclopentadienyl rings and the oxygen form a tetrahedral configuration around the Sm(Ⅲ) atom, The average Sm-C(η~) bond distances for the three cyclopentadienyl groups are 2.72(3), 2.76(3), 2.78(8) respectively, and Sm-0 bond is 2.53(1).展开更多
In this paper, we report the growth of single crystals of Co_x Zn_(1-x)S and Co_x Zn_(1-x)Se (0<x<0.3) by the method of chemical transport, using iodine as a transport agent. The light green color of single crys...In this paper, we report the growth of single crystals of Co_x Zn_(1-x)S and Co_x Zn_(1-x)Se (0<x<0.3) by the method of chemical transport, using iodine as a transport agent. The light green color of single crystal Co_xZn_(1-x)S as well as the light brown color of Co_xZn_(1-x)Se become deep with an increase in x. The compositions of the single crystals were nearly stoichiometric. The transfer rate decreases with an increase of the x value. The growth rate was related to the temperature difference. The large temperature difference speed up the growth rate, but the size of crystal obtained was small. In general, the optimal temperature difference was 15℃. From X-ray diffraction measurements, the structures of crystals Co_xZn_(1-x)S and Co_xZn_(1-x)Se (0<x<0.1) were identified to be zinc blende structure similar to that of ZnS and ZnSe.展开更多
A solid phase crystallizing method has been developed to grow a Si crystal at tem-peratures as low as 550 ℃. Using this method, a high-quality thin-film polycrystalline silicon (Poly-Si) was obtained. The largest gra...A solid phase crystallizing method has been developed to grow a Si crystal at tem-peratures as low as 550 ℃. Using this method, a high-quality thin-film polycrystalline silicon (Poly-Si) was obtained. The largest grain size, examined with X-ray diffraction spectroscopy and scanning electron microscopy images of recrystallized samples, is approximately 1 /μm for substrate temperature at 300 ℃ and annealed at 550℃ for 3 hours.展开更多
A variety of new N-(5-(benzofuranol-7-oxymethyl)-1,3,4-thiadiazol-2-yl)amide compounds(8a-i)were synthesized through four steps from benzofuranol as raw materials.The crystal structure of compound 8a(C17H21N3O3S,Mr=34...A variety of new N-(5-(benzofuranol-7-oxymethyl)-1,3,4-thiadiazol-2-yl)amide compounds(8a-i)were synthesized through four steps from benzofuranol as raw materials.The crystal structure of compound 8a(C17H21N3O3S,Mr=347.43)was measured by X-ray diffraction,which was classified as monoclinic system,Z=4,V=1742.72(8)Å3,Dc=1.324 Mg/m3,F(000)=736,S=1.03,μ=0.21 mm-1,space group P21 with a=9.9177(3),b=8.9519(2),c=19.8679(5)Å,the final R=0.035 and wR=0.105 for 3873 observed reflections(I>2σ(I)).The X-ray structure presented N(3)-H(3)···N(2)and C(6)-H(6)···O(3)intermolecular hydrogen bonds,which acted as an important role in stabilizing the crystal structure.Additionally,preliminary biological assay on compound 8a showed good fungicidal activity in vivo,with the inhibition of 75%against Pseudoperonospora cu-bensis at 200 mg/L.展开更多
A nickel(Ⅱ) complex containing both dithiolato and phosphine ligands, Ni_2(PPh_3)_2(edt)_2 (edt = SCH_2CH_2S^(2-)), has been prepared and characterized by X-ray diffration. The complex crystallizes in the triclinic s...A nickel(Ⅱ) complex containing both dithiolato and phosphine ligands, Ni_2(PPh_3)_2(edt)_2 (edt = SCH_2CH_2S^(2-)), has been prepared and characterized by X-ray diffration. The complex crystallizes in the triclinic system, space group P-1, with a = 10.693(3), b = 17.457 (6), c = 10.606 (3)A, α= 102.84(2), β = 96.49 (2), γ = 82.56(3)°; V = 1906.8 A^3; D_c = 1.439g.cm^(-3) for Z=2; the final con- ventional R was 0.052 based on 3338 observed reflections. Nickel atoms are linked by two sulfur atoms from two edt ligands with the Ni--Ni distance of 2.893 A, and each Ni atom is coordinated by one phosphorus atom and three sulfur atoms with a square-planar geometry, where the average: length of Ni--S bond is 2.180 A and Ni--P bond 2.188 A. The UV-Vis and ~1H NMR spectra have also been recorded.展开更多
Single-crystalline silicon materials with large dimensions have been widely used as assemblies in plasma silicon etching machines.However,information about large-diameter low-cost preparation technology has not been s...Single-crystalline silicon materials with large dimensions have been widely used as assemblies in plasma silicon etching machines.However,information about large-diameter low-cost preparation technology has not been sufficiently reported.In this paper,it was focused on the preparation of 400-mm silicon（100） crystal lightly doped with boron from 28-in.hot zones.Resistivity uniformity and oxygen concentration of the silicon crystal were investigated by direct-current（DC） four-point probes method and Fourier transform infrared spectroscopy（FTIR）,respectively.The global heat transfer,melt flow and oxygen distribution were calculated by finite element method（FEM）.The results show that 28-in.hot zones can replace conventional 32 in.ones to grow 400-mm-diameter silicon single crystals.The change in crucible diameter can save energy,reduce cost and improve efficiency.The trend of oxygen distribution obtained in calculations is in good agreement with experimental values.The present model can well predict the 400-mm-diameter silicon crystal growth and is essential for the optimization of furnace design and process condition.展开更多
Silica-based yb3＋-doped glass is prepared by non-chemical vapor deposition. The drawn photonic crystal fiber （PCF） has a strong absorption at 976 nm and emission wavelength of approximately 1 037 nm. The intensity ...Silica-based yb3＋-doped glass is prepared by non-chemical vapor deposition. The drawn photonic crystal fiber （PCF） has a strong absorption at 976 nm and emission wavelength of approximately 1 037 nm. The intensity and spectral lineshape of the near infrared （NIR） luminescence of the Yb3＋-doped PCF are recorded and discussed in terms of excitation power, excitation wavelength, fiber length, and Yba＋ ion concentration. The emission intensifies as the excitation power and Yb3＋ ion concentration increase. The intensity of the shorter wavelength side of the luminescence spectrum decreases as the length of the PCF increases.展开更多
基金financially supported by Jiangsu Industrial Support Project (Nos. BE2014007-2, BE2014007-3, and BE2014007-4)the financial support from Jiangsu Development and Reform Commission (No. [2013]2027)Jiangsu Postgraduates Innovating Scientific Research Project (No. KYLX15-1061)
文摘The preparation procedure of DD5 single crystal castings was optimized. The microstructure characteristics of DD5 single crystal superalloy were investigated by microstructure observation and segregation behavior examination. The results show that the grain orientation is optimized by constraining the spiral crystallizer in [001] orientation and spatial scale. Also, the γ＇ phase of inter-dendrites is larger and more irregular than that in dendrite arms. High temperature tensile tests of DD5 single crystal castings exhibit that the peak stress increases with increasing temperature, while the area reduction shows an opposite trend, when the temperature is below 800℃; meanwhile, when the temperature is between 800℃ and 1000℃, the fracture stress of the alloy is the same as the peak stress. The fracture mode changes from shear to ductile with increasing temperature from 600℃ and 1000℃.
文摘(CH_3)_4C_2(C_5H_4)_2Sm(C_5H_5)OC_4H_, Mr=499.4, orthorhombic, Cc2a, a=11.696(6), b=12.539(5), c=29.432(15), V=4316(4)~, Z=8, Dc=1.54g. cm^(-3), μ (MoKα)=27.8cm^(-1), F(000)=2024, R=0.077 for 1833 observed reflections. In the molecule the samarium atom is bonded to three cyclopentadienyl rings and an oxygen of tetrahydrofuran(THF). The three centroids of the cyclopentadienyl rings and the oxygen form a tetrahedral configuration around the Sm(Ⅲ) atom, The average Sm-C(η~) bond distances for the three cyclopentadienyl groups are 2.72(3), 2.76(3), 2.78(8) respectively, and Sm-0 bond is 2.53(1).
文摘In this paper, we report the growth of single crystals of Co_x Zn_(1-x)S and Co_x Zn_(1-x)Se (0<x<0.3) by the method of chemical transport, using iodine as a transport agent. The light green color of single crystal Co_xZn_(1-x)S as well as the light brown color of Co_xZn_(1-x)Se become deep with an increase in x. The compositions of the single crystals were nearly stoichiometric. The transfer rate decreases with an increase of the x value. The growth rate was related to the temperature difference. The large temperature difference speed up the growth rate, but the size of crystal obtained was small. In general, the optimal temperature difference was 15℃. From X-ray diffraction measurements, the structures of crystals Co_xZn_(1-x)S and Co_xZn_(1-x)Se (0<x<0.1) were identified to be zinc blende structure similar to that of ZnS and ZnSe.
基金This work was supported by the Guangdong Provincial Natural Science Foundation of China No.990781.
文摘A solid phase crystallizing method has been developed to grow a Si crystal at tem-peratures as low as 550 ℃. Using this method, a high-quality thin-film polycrystalline silicon (Poly-Si) was obtained. The largest grain size, examined with X-ray diffraction spectroscopy and scanning electron microscopy images of recrystallized samples, is approximately 1 /μm for substrate temperature at 300 ℃ and annealed at 550℃ for 3 hours.
基金supported by the Scientific Research Foundation of Hebei Educational Committee (No. QN2019058)Natural Science Foundation of Hebei Province of China (No. H2021201059)
文摘A variety of new N-(5-(benzofuranol-7-oxymethyl)-1,3,4-thiadiazol-2-yl)amide compounds(8a-i)were synthesized through four steps from benzofuranol as raw materials.The crystal structure of compound 8a(C17H21N3O3S,Mr=347.43)was measured by X-ray diffraction,which was classified as monoclinic system,Z=4,V=1742.72(8)Å3,Dc=1.324 Mg/m3,F(000)=736,S=1.03,μ=0.21 mm-1,space group P21 with a=9.9177(3),b=8.9519(2),c=19.8679(5)Å,the final R=0.035 and wR=0.105 for 3873 observed reflections(I>2σ(I)).The X-ray structure presented N(3)-H(3)···N(2)and C(6)-H(6)···O(3)intermolecular hydrogen bonds,which acted as an important role in stabilizing the crystal structure.Additionally,preliminary biological assay on compound 8a showed good fungicidal activity in vivo,with the inhibition of 75%against Pseudoperonospora cu-bensis at 200 mg/L.
基金Project supported partly by the National Naural Science Foundation of China the Provincial Science Fund of Fujian.
文摘A nickel(Ⅱ) complex containing both dithiolato and phosphine ligands, Ni_2(PPh_3)_2(edt)_2 (edt = SCH_2CH_2S^(2-)), has been prepared and characterized by X-ray diffration. The complex crystallizes in the triclinic system, space group P-1, with a = 10.693(3), b = 17.457 (6), c = 10.606 (3)A, α= 102.84(2), β = 96.49 (2), γ = 82.56(3)°; V = 1906.8 A^3; D_c = 1.439g.cm^(-3) for Z=2; the final con- ventional R was 0.052 based on 3338 observed reflections. Nickel atoms are linked by two sulfur atoms from two edt ligands with the Ni--Ni distance of 2.893 A, and each Ni atom is coordinated by one phosphorus atom and three sulfur atoms with a square-planar geometry, where the average: length of Ni--S bond is 2.180 A and Ni--P bond 2.188 A. The UV-Vis and ~1H NMR spectra have also been recorded.
基金financially supported by the Major National Science and Technology Projects(No.2008ZX02401)
文摘Single-crystalline silicon materials with large dimensions have been widely used as assemblies in plasma silicon etching machines.However,information about large-diameter low-cost preparation technology has not been sufficiently reported.In this paper,it was focused on the preparation of 400-mm silicon（100） crystal lightly doped with boron from 28-in.hot zones.Resistivity uniformity and oxygen concentration of the silicon crystal were investigated by direct-current（DC） four-point probes method and Fourier transform infrared spectroscopy（FTIR）,respectively.The global heat transfer,melt flow and oxygen distribution were calculated by finite element method（FEM）.The results show that 28-in.hot zones can replace conventional 32 in.ones to grow 400-mm-diameter silicon single crystals.The change in crucible diameter can save energy,reduce cost and improve efficiency.The trend of oxygen distribution obtained in calculations is in good agreement with experimental values.The present model can well predict the 400-mm-diameter silicon crystal growth and is essential for the optimization of furnace design and process condition.
基金supported by the State Key Development Program for Basic Research of China (No.2010CB327604)the State Key Program of National Science of China (No. 60637010)+3 种基金the National Natural Science Foundation of China (No. 61205084)the Natural Science Foundation of Hebei Province (No.F2012203122)the College Science Research Program of Hebei Province (No. Z2010336)the Jiangsu Meteorological Observation and Information Processing Key Laboratory Open Subject (No. KDXS1107)
文摘Silica-based yb3＋-doped glass is prepared by non-chemical vapor deposition. The drawn photonic crystal fiber （PCF） has a strong absorption at 976 nm and emission wavelength of approximately 1 037 nm. The intensity and spectral lineshape of the near infrared （NIR） luminescence of the Yb3＋-doped PCF are recorded and discussed in terms of excitation power, excitation wavelength, fiber length, and Yba＋ ion concentration. The emission intensifies as the excitation power and Yb3＋ ion concentration increase. The intensity of the shorter wavelength side of the luminescence spectrum decreases as the length of the PCF increases.
