A357-SiCp/A357 layered composites were prepared using a semi-solid vacuum stirring suction casting method.The microstructures,mechanical properties,and thermal conductivities of the composites fabricated under differe...A357-SiCp/A357 layered composites were prepared using a semi-solid vacuum stirring suction casting method.The microstructures,mechanical properties,and thermal conductivities of the composites fabricated under different suction casting processes were compared.Additionally,the microstructural evolution characteristics and performance enhancement mechanism of the A357-SiCp/A357 layered composites were discussed.The results demonstrate that suction casting at 610°C with a low solid phase ratio can significantly enhance the material density and reduce the agglomeration of SiCp.The A357-SiC_(p)/A357 interface is clear and straight with good bonding.With an increase in the suction casting temperature,the bending resistance and thermal conductivity of the A357-SiC_(p)/A357 layered composites exhibit a trend of significantly increase at first and then slowly decrease owing to casting defects,interface bonding,and SiCp distribution.Compared with SiCp/A357 composites,the bending strength,deflection,and thermal conductivity of the A357-SiCp/A357 layered composites increase from 257 MPa,1.07 mm,and 155.72 W·(m·K)^(-1) to 298 MPa,2.1 mm,and 169.86 W·(m·K)^(-1),respectively.This study provides a reference for improving the rheological casting of aluminum matrix layered composites.展开更多
To the Editor:Osteoporosis is becoming a common,serious,and costly health problem,which causes over nine million fractures annually worldwide.[1] Currently,osteoporotic fractures are a considerable burden to public he...To the Editor:Osteoporosis is becoming a common,serious,and costly health problem,which causes over nine million fractures annually worldwide.[1] Currently,osteoporotic fractures are a considerable burden to public health services and have fairly high morbidity and mortality.[2] Vertebral fractures are the most common osteoporotic fracture and may lead to a high risk of further fracture and could be prevalent in both females and males.[3] Ling et al[4] and Ms.OS studies[5] evaluated the prevalence of vertebral fractures in Beijing and Hong Kong,respectively.However,our knowledge of the descriptive epidemiology and risk factors for vertebral fracture in China still remains poor.展开更多
Tumor-induced osteomalacia(TIO)is a rare paraneoplastic syndrome caused by excessive fibroblast growth factor 23(FGF23)production by a tumor,which often arises from a mesenchymal origin.[1-3]Most clinical symptoms of ...Tumor-induced osteomalacia(TIO)is a rare paraneoplastic syndrome caused by excessive fibroblast growth factor 23(FGF23)production by a tumor,which often arises from a mesenchymal origin.[1-3]Most clinical symptoms of TIO are the consequences of prolonged FGF23-mediated hypophosphatemia as muscle weakness,bone pain,impaired mobility,and fractures.[4]Clinical diagnosis and management of TIO are challenging because knowledge about this condition is still restricted to a few specialized centers,leading to delay in diagnosis and appropriate treatment.The scope of the present consensus is to provide up-to-date guidance on the assessment and treatment of TIO.展开更多
Based on an analysis of the 1H NMR,FT-IR,UV-vis spectra,a chiral trimeric phenylene vinylene derivative（ChTPV） synthesized by a Wittig reaction was determined to have a trans-cis configuration, and it could be isome...Based on an analysis of the 1H NMR,FT-IR,UV-vis spectra,a chiral trimeric phenylene vinylene derivative（ChTPV） synthesized by a Wittig reaction was determined to have a trans-cis configuration, and it could be isomerized to the trans-trans isomer when treated with iodine.The melting point of ChTPV with a trans-trans configuration increased by 162.1℃compared to the trans-cis isomer,and the ChTPV with trans-trans configuration exhibited the typical liquid-crystalline texture of the smectic A in the heating process.The results indicated that the molecular configuration can influence the formation of the liquid crystalline phase of ChTPV.展开更多
The perylene diimide derivatives（s-THBPDI and d-THBPDI） bearing oxygen bridged twisty heptatomic biphenyl in the bay positions of the perylene core through acetylene bond were designed and synthesized.The photophysi...The perylene diimide derivatives（s-THBPDI and d-THBPDI） bearing oxygen bridged twisty heptatomic biphenyl in the bay positions of the perylene core through acetylene bond were designed and synthesized.The photophysical properties of the functionalized dyes were investigated in solution and solid state by UV-vis and photoluminescence（PL） spectra.Their UV-vis and PL spectrum both exhibited the different concentration-dependent behaviors due to the difference of chemical structure.Moreover,cyclic voltammetry results indicated that the introduction of oxygen bridged twisted heptatomic biphenyl could decrease the LUMO energy level of the perylene diimide effectively and made it promising material in photoelectric devices.展开更多
Cholesteryl trimeric phenylene vinylene （ChoI-TPV） has been synthesized and characterized. The self- assembly behaviors of ChoI-TPV in THF/H20 system at different water content （water content： 40% and 80%） and di...Cholesteryl trimeric phenylene vinylene （ChoI-TPV） has been synthesized and characterized. The self- assembly behaviors of ChoI-TPV in THF/H20 system at different water content （water content： 40% and 80%） and different solute concentration （solute concentration： 1.0 ×10^-5 mol/L and saturated concentration） were studied using UV-vis spectrophotometry, photoluminescence spectrophotometry, and circular dichroism spectroscopy. Based on an analysis of the UV-vis and photoluminescence spectra, Chol-TPV shows the typical H-type aggregation at saturated concentration in 80% aqueous THF. However, ChoI-TPV shows the non-typical H-type aggregation under other conditions. The circular dichroism signal suggests that the Chol-TPV exists in the right handed helical architectures with high water content at a concentration of 1.0 × 10^-5 mol/L, and a helix inversion was found at saturated concentration.展开更多
基金the financial support from the National Science and Technology Major Project of China (No. J2019-VI-0004-0117)National Natural Science Foundation of China (No. 51905301)。
文摘A357-SiCp/A357 layered composites were prepared using a semi-solid vacuum stirring suction casting method.The microstructures,mechanical properties,and thermal conductivities of the composites fabricated under different suction casting processes were compared.Additionally,the microstructural evolution characteristics and performance enhancement mechanism of the A357-SiCp/A357 layered composites were discussed.The results demonstrate that suction casting at 610°C with a low solid phase ratio can significantly enhance the material density and reduce the agglomeration of SiCp.The A357-SiC_(p)/A357 interface is clear and straight with good bonding.With an increase in the suction casting temperature,the bending resistance and thermal conductivity of the A357-SiC_(p)/A357 layered composites exhibit a trend of significantly increase at first and then slowly decrease owing to casting defects,interface bonding,and SiCp distribution.Compared with SiCp/A357 composites,the bending strength,deflection,and thermal conductivity of the A357-SiCp/A357 layered composites increase from 257 MPa,1.07 mm,and 155.72 W·(m·K)^(-1) to 298 MPa,2.1 mm,and 169.86 W·(m·K)^(-1),respectively.This study provides a reference for improving the rheological casting of aluminum matrix layered composites.
基金supported by the National Natural Science Foundation of China (No.21688102,No.21803066,and No.22003061)the Chinese Academy of Sciences Pioneer Hundred Talents Program (KJ2340000031,KJ2340007002)+7 种基金the National Key Research and Development Program of China(2016YFA0200604)the Anhui Initiative in Quantum Information Technologies (AHY090400)the Strategic Priority Research of Chinese Academy of Sciences(XDC01040100)CAS Project for Young Scientists in Basic Research (YSBR-005)the Fundamental Research Funds for the Central Universities (WK2340000091,WK2060000018)the Hefei National Laboratory for Physical Sciences at the Microscale (SK2340002001)the Research Start-Up Grants (KY2340000094)the Academic Leading Talents Training Program(KY2340000103) from University of Science and Technology of China
文摘To the Editor:Osteoporosis is becoming a common,serious,and costly health problem,which causes over nine million fractures annually worldwide.[1] Currently,osteoporotic fractures are a considerable burden to public health services and have fairly high morbidity and mortality.[2] Vertebral fractures are the most common osteoporotic fracture and may lead to a high risk of further fracture and could be prevalent in both females and males.[3] Ling et al[4] and Ms.OS studies[5] evaluated the prevalence of vertebral fractures in Beijing and Hong Kong,respectively.However,our knowledge of the descriptive epidemiology and risk factors for vertebral fracture in China still remains poor.
基金by grants from the CAMS Innovation Fund for Medical Science(No.2016-I2M-3-003)the National Natural Science Foundation of China(No.81970757 and No.81670714).
文摘Tumor-induced osteomalacia(TIO)is a rare paraneoplastic syndrome caused by excessive fibroblast growth factor 23(FGF23)production by a tumor,which often arises from a mesenchymal origin.[1-3]Most clinical symptoms of TIO are the consequences of prolonged FGF23-mediated hypophosphatemia as muscle weakness,bone pain,impaired mobility,and fractures.[4]Clinical diagnosis and management of TIO are challenging because knowledge about this condition is still restricted to a few specialized centers,leading to delay in diagnosis and appropriate treatment.The scope of the present consensus is to provide up-to-date guidance on the assessment and treatment of TIO.
基金supported by the National Natural Science Foundation of China(No.51173155)the Hebei Province Science Foundation of China(No.E2010001182)
文摘Based on an analysis of the 1H NMR,FT-IR,UV-vis spectra,a chiral trimeric phenylene vinylene derivative（ChTPV） synthesized by a Wittig reaction was determined to have a trans-cis configuration, and it could be isomerized to the trans-trans isomer when treated with iodine.The melting point of ChTPV with a trans-trans configuration increased by 162.1℃compared to the trans-cis isomer,and the ChTPV with trans-trans configuration exhibited the typical liquid-crystalline texture of the smectic A in the heating process.The results indicated that the molecular configuration can influence the formation of the liquid crystalline phase of ChTPV.
基金supported by the National Natural Science Foundation of China (Nos: 51173155,51472214)the Colleges and Universities Science and Technology Research Project of Hebei Province (No.QN20131070)
文摘The perylene diimide derivatives（s-THBPDI and d-THBPDI） bearing oxygen bridged twisty heptatomic biphenyl in the bay positions of the perylene core through acetylene bond were designed and synthesized.The photophysical properties of the functionalized dyes were investigated in solution and solid state by UV-vis and photoluminescence（PL） spectra.Their UV-vis and PL spectrum both exhibited the different concentration-dependent behaviors due to the difference of chemical structure.Moreover,cyclic voltammetry results indicated that the introduction of oxygen bridged twisted heptatomic biphenyl could decrease the LUMO energy level of the perylene diimide effectively and made it promising material in photoelectric devices.
基金supported by the National Science Foundation of China(No.51173155)the Hebei Province Science Foundation of China(No.F2011203160)
文摘Cholesteryl trimeric phenylene vinylene （ChoI-TPV） has been synthesized and characterized. The self- assembly behaviors of ChoI-TPV in THF/H20 system at different water content （water content： 40% and 80%） and different solute concentration （solute concentration： 1.0 ×10^-5 mol/L and saturated concentration） were studied using UV-vis spectrophotometry, photoluminescence spectrophotometry, and circular dichroism spectroscopy. Based on an analysis of the UV-vis and photoluminescence spectra, Chol-TPV shows the typical H-type aggregation at saturated concentration in 80% aqueous THF. However, ChoI-TPV shows the non-typical H-type aggregation under other conditions. The circular dichroism signal suggests that the Chol-TPV exists in the right handed helical architectures with high water content at a concentration of 1.0 × 10^-5 mol/L, and a helix inversion was found at saturated concentration.
