Recent studies have shown that many challenges encountered in conventional single crystal growth methods, including high production costs, can be overcome by using the solid-state single-crystal growth(SSCG) approach,...Recent studies have shown that many challenges encountered in conventional single crystal growth methods, including high production costs, can be overcome by using the solid-state single-crystal growth(SSCG) approach, which has been recognized as a simple and cost-effective alternative for obtaining single crystals. In this work, YAlO(YAG) and Nd-doped YAG(Nd:YAG) single crystals were grown via the SSCG method using spark plasma sintering(SPS). The growth of single crystals was initiated at the surface of(110) YAG single-crystal seeds embedded inside YAG and Nd:YAG powder beds, and this growth continued as the surrounding polycrystalline matrix was converted into a single crystal. The application of external pressure during the SPS process has been found beneficial for reducing the porosity of the grown single crystals. Moreover, high Nddoping levels had a positive effect on the conversion kinetics,with a growth rate of almost 50 μm/h, which increased the driving force for single-crystal growth through the solute drag effect. EDS elemental mapping and line scans confirmed the compositional uniformity of the grown single crystals, while EBSD images verified their crystallization in the(110) direction. The obtained results confirm the strong potential of the SSCG technique coupled with SPS for the growth of undoped and highly doped YAG single crystals with excellent quality.展开更多
With sustainable development of biotechnology,increasing attention has been placed on utilization of solid-state fermented feed(SFF).Solid-state fermented feed has been a candidate strategy to alleviate the contradict...With sustainable development of biotechnology,increasing attention has been placed on utilization of solid-state fermented feed(SFF).Solid-state fermented feed has been a candidate strategy to alleviate the contradiction between supply and demand of feed resources,ensure food hygiene safety,promoting energy conservation,and emission reduction.In production of SFF,a variety of organic acids,enzymes,vitamins,peptides,and other unknown growth factors are produced,which could affect performance of animals.Solid-state fermented feed produced by different fermentation techniques has great instability on different physiological stages of different animals,which hinders the application and standardized production of SFF.Herein,we summarize the current advances in the role of the characteristics of SFF prepared by different manufacturing technique and its research progress in animal experiments on growth performance,gastrointestinal ecology,and immune system,so as to provide references for further acquiring a relatively perfect set of SFF production and evaluation systems.展开更多
To prepare the porous NC-based(nitrocellulose-based) gun propellants,the batch foaming process of using supercritical CO_2 as the physical blowing agent is used.The solubilities of CO_2 in the single-base propellants ...To prepare the porous NC-based(nitrocellulose-based) gun propellants,the batch foaming process of using supercritical CO_2 as the physical blowing agent is used.The solubilities of CO_2 in the single-base propellants and TEGDN(trimethyleneglycol dinitrate) propellants are measured by the gravimetric method,and SEM(scanning electron microscope) is used to observe the morphology of foamed propellants.The result shows that a large amount of CO_2 could be dissolved in NC-based propellants.The experimental results also reveal that the energetic plasticizer TEGDN exerts an important influence on the pore structure.The triaxial tensile failure mechanism for solid-state nucleation is used to explain the nucleation of NC-based propellants in the sol id state.Since some specific foaming behaviors of NC-based propellants can not be explained by the failure mechanism,a solid-state nucleation mechanism which revises the triaxial tensile failure mechanism is proposed and discussed.展开更多
During investigating what causes the low yield of the polymerization product of 1,4-bis(quinolyl)-1,3-butadiyne(DQ), we found that the DQ crystals formed on the surface of PDQ cauld be polymerized to give blue cryst...During investigating what causes the low yield of the polymerization product of 1,4-bis(quinolyl)-1,3-butadiyne(DQ), we found that the DQ crystals formed on the surface of PDQ cauld be polymerized to give blue crystals, in which DQ could be sublimated and crystallized on the surface of PDQ film. According to the experimental results, the reason why the DQ crystals can be polymerized is that the sublimation of DQ changes the molecular orientation of DQ in the crystal. The crystals formed in epitaxial growth on the surface of DQ or PDQ during sublimation of DQ are suitable for 1,4-addition polymerization.展开更多
Solid-state reaction of praseodymium （III） oxide,K2CO3 and MoO3 at high temperature leads to a potassium lanthanide double molybdate,namely,KPr（MoO4）2. The structural and optical properties of the title compound h...Solid-state reaction of praseodymium （III） oxide,K2CO3 and MoO3 at high temperature leads to a potassium lanthanide double molybdate,namely,KPr（MoO4）2. The structural and optical properties of the title compound have been investigated by means of single-crystal X-ray diffraction and spectroscopic measurements at room temperature. KPr（MoO4）2 crystallizes in tetragonal,space group I41/a with a = 5.401（3）,c = 12.044（10）,Z = 2 and R （I 〉 2σ（I）） = 0.0416. It features the famous scheelite-type structure （CaWO4）,which can be thought as the substitution of two Ca^2＋ ions in CaWO4 by a couple of K^＋ and Pr^3＋ ions in a statistical manner,and W^6＋ by Mo^6＋ cations.展开更多
A new nonlinear optical crystal of sodium terbium borate （Na2.67Tb2.11B3O9, Mr = 573.14） was synthesized by solid reaction method. The colorless transparent single crystals were grown from the high temperature solut...A new nonlinear optical crystal of sodium terbium borate （Na2.67Tb2.11B3O9, Mr = 573.14） was synthesized by solid reaction method. The colorless transparent single crystals were grown from the high temperature solution by employing NaBO2 as flux. The structure was deter- mined by single-crystal X-ray diffraction method. The compound crystallizes in the orthorhombic system, space group Amm2 with a = 5.0744（10）, b = 10.990（2）, c = 6.9078（14） A, V = 385.24（13） A3, Dc = 4.941 g/cm3, F（000） = 250, Z = 2, μ= 9.205 mm-1, the final R = 0.0253 and wR = 0.0610. Its three-dimensional network structure is constructed from isolated BO33-, Na（1）O8, Na（2）O6, Na（3）O6 and Tb（1）O9 polyhedra. Variable-temperature magnetic susceptibility measurements show the compound is paramagnetic （μj = 7.04 μb）. The intensity of the second harmonic generation of Na2.67Tb2.11B3O9 is 2.5 times that of KDP.展开更多
采用无籽固相晶体生长技术制备99.7(99.6K_(0.5)Na_(0.5)NbO_3-0.4LiBiO_3)-0.3CaZrO_3无铅压电单晶,研究了预合成温度对合成粉末的特性以及后续生长的单晶生长特性、微结构、压电和介电性能的影响。结果表明:随着预合成温度的升高,合...采用无籽固相晶体生长技术制备99.7(99.6K_(0.5)Na_(0.5)NbO_3-0.4LiBiO_3)-0.3CaZrO_3无铅压电单晶,研究了预合成温度对合成粉末的特性以及后续生长的单晶生长特性、微结构、压电和介电性能的影响。结果表明:随着预合成温度的升高,合成粉末趋于形成更稳定的正交相结构,但粉末粒度和形貌没有明显变化。采用不同预合成温度合成的粉末均能制备出厘米级的单晶,晶体呈淡黄色半透明状。在研究范围内,预合成温度的变化对晶体的生长特性和晶体结构没有明显影响。但随着预合成温度的升高,晶体压电常数d33先增加后减小,当预合成温度为850℃时,达到最大值d33=284 p C/N。展开更多
基金the NSF grant (No.1554094) for supporting the research。
文摘Recent studies have shown that many challenges encountered in conventional single crystal growth methods, including high production costs, can be overcome by using the solid-state single-crystal growth(SSCG) approach, which has been recognized as a simple and cost-effective alternative for obtaining single crystals. In this work, YAlO(YAG) and Nd-doped YAG(Nd:YAG) single crystals were grown via the SSCG method using spark plasma sintering(SPS). The growth of single crystals was initiated at the surface of(110) YAG single-crystal seeds embedded inside YAG and Nd:YAG powder beds, and this growth continued as the surrounding polycrystalline matrix was converted into a single crystal. The application of external pressure during the SPS process has been found beneficial for reducing the porosity of the grown single crystals. Moreover, high Nddoping levels had a positive effect on the conversion kinetics,with a growth rate of almost 50 μm/h, which increased the driving force for single-crystal growth through the solute drag effect. EDS elemental mapping and line scans confirmed the compositional uniformity of the grown single crystals, while EBSD images verified their crystallization in the(110) direction. The obtained results confirm the strong potential of the SSCG technique coupled with SPS for the growth of undoped and highly doped YAG single crystals with excellent quality.
基金supported by the National Natural Science Foundation of China(U180220167)the Beijing Swine Innovation Team of Modern Agriculture Industry Technological System。
文摘With sustainable development of biotechnology,increasing attention has been placed on utilization of solid-state fermented feed(SFF).Solid-state fermented feed has been a candidate strategy to alleviate the contradiction between supply and demand of feed resources,ensure food hygiene safety,promoting energy conservation,and emission reduction.In production of SFF,a variety of organic acids,enzymes,vitamins,peptides,and other unknown growth factors are produced,which could affect performance of animals.Solid-state fermented feed produced by different fermentation techniques has great instability on different physiological stages of different animals,which hinders the application and standardized production of SFF.Herein,we summarize the current advances in the role of the characteristics of SFF prepared by different manufacturing technique and its research progress in animal experiments on growth performance,gastrointestinal ecology,and immune system,so as to provide references for further acquiring a relatively perfect set of SFF production and evaluation systems.
基金funded by the priority academic program development of Jiangsu Higher Education Institutions
文摘To prepare the porous NC-based(nitrocellulose-based) gun propellants,the batch foaming process of using supercritical CO_2 as the physical blowing agent is used.The solubilities of CO_2 in the single-base propellants and TEGDN(trimethyleneglycol dinitrate) propellants are measured by the gravimetric method,and SEM(scanning electron microscope) is used to observe the morphology of foamed propellants.The result shows that a large amount of CO_2 could be dissolved in NC-based propellants.The experimental results also reveal that the energetic plasticizer TEGDN exerts an important influence on the pore structure.The triaxial tensile failure mechanism for solid-state nucleation is used to explain the nucleation of NC-based propellants in the sol id state.Since some specific foaming behaviors of NC-based propellants can not be explained by the failure mechanism,a solid-state nucleation mechanism which revises the triaxial tensile failure mechanism is proposed and discussed.
基金Supported by Core Research for Evolutional Science and Technology(CREST),Japan Science and Technology Corpo-ration(JST)
文摘During investigating what causes the low yield of the polymerization product of 1,4-bis(quinolyl)-1,3-butadiyne(DQ), we found that the DQ crystals formed on the surface of PDQ cauld be polymerized to give blue crystals, in which DQ could be sublimated and crystallized on the surface of PDQ film. According to the experimental results, the reason why the DQ crystals can be polymerized is that the sublimation of DQ changes the molecular orientation of DQ in the crystal. The crystals formed in epitaxial growth on the surface of DQ or PDQ during sublimation of DQ are suitable for 1,4-addition polymerization.
基金Supported by the NNSFC (20373073)the National Basic Research Program of China (No. 2007CB815307)+2 种基金the Funds of CAS (KJCX2-YW-H01)Fujian Key Laboratory of Nanomaterials (No. 2006L2005)the Knowledge Innovation Program of CAS
文摘Solid-state reaction of praseodymium （III） oxide,K2CO3 and MoO3 at high temperature leads to a potassium lanthanide double molybdate,namely,KPr（MoO4）2. The structural and optical properties of the title compound have been investigated by means of single-crystal X-ray diffraction and spectroscopic measurements at room temperature. KPr（MoO4）2 crystallizes in tetragonal,space group I41/a with a = 5.401（3）,c = 12.044（10）,Z = 2 and R （I 〉 2σ（I）） = 0.0416. It features the famous scheelite-type structure （CaWO4）,which can be thought as the substitution of two Ca^2＋ ions in CaWO4 by a couple of K^＋ and Pr^3＋ ions in a statistical manner,and W^6＋ by Mo^6＋ cations.
基金supported by the National Natural Science Foundation of China (91022025, 51072036)the Natural Science Foundation of Fujian Province (2010J01284)
文摘A new nonlinear optical crystal of sodium terbium borate （Na2.67Tb2.11B3O9, Mr = 573.14） was synthesized by solid reaction method. The colorless transparent single crystals were grown from the high temperature solution by employing NaBO2 as flux. The structure was deter- mined by single-crystal X-ray diffraction method. The compound crystallizes in the orthorhombic system, space group Amm2 with a = 5.0744（10）, b = 10.990（2）, c = 6.9078（14） A, V = 385.24（13） A3, Dc = 4.941 g/cm3, F（000） = 250, Z = 2, μ= 9.205 mm-1, the final R = 0.0253 and wR = 0.0610. Its three-dimensional network structure is constructed from isolated BO33-, Na（1）O8, Na（2）O6, Na（3）O6 and Tb（1）O9 polyhedra. Variable-temperature magnetic susceptibility measurements show the compound is paramagnetic （μj = 7.04 μb）. The intensity of the second harmonic generation of Na2.67Tb2.11B3O9 is 2.5 times that of KDP.
文摘采用无籽固相晶体生长技术制备99.7(99.6K_(0.5)Na_(0.5)NbO_3-0.4LiBiO_3)-0.3CaZrO_3无铅压电单晶,研究了预合成温度对合成粉末的特性以及后续生长的单晶生长特性、微结构、压电和介电性能的影响。结果表明:随着预合成温度的升高,合成粉末趋于形成更稳定的正交相结构,但粉末粒度和形貌没有明显变化。采用不同预合成温度合成的粉末均能制备出厘米级的单晶,晶体呈淡黄色半透明状。在研究范围内,预合成温度的变化对晶体的生长特性和晶体结构没有明显影响。但随着预合成温度的升高,晶体压电常数d33先增加后减小,当预合成温度为850℃时,达到最大值d33=284 p C/N。
