Single-phaseα-CaSO4·0.5H2O whiskers were directly synthesized from waste Ca(NO3)2 solution using a hydrothermal method,and HNO3 was synchronously regenerated.The effects of reaction temperature and Ca^2+concentr...Single-phaseα-CaSO4·0.5H2O whiskers were directly synthesized from waste Ca(NO3)2 solution using a hydrothermal method,and HNO3 was synchronously regenerated.The effects of reaction temperature and Ca^2+concentration on the phase composition and morphology of products were determined by X-ray diffraction and optical microscopy.On the basis of the experimental results,the formation diagram ofα-CaSO4·0.5H2O was plotted within the range of 5–35 g·L^-1 Ca^2+and 115°C–150°C.In addition,the conditions of the direct synthesis ofα-CaSO4·0.5H2O were determined.Well-crystallized,single-phaseα-CaSO4·0.5H2O whiskers with high aspect ratios(length,1785μm;diameter,10.63μm;aspect ratio,168)and HNO3(70.25 g·L^-1)were obtained at the optimal conditions of 25 g·L^-1 Ca^2+and 125°C.展开更多
An innovative technology,nitric acid pressure leaching of limonitic laterite ores,was proposed by our research team.The HNO3 regeneration is considerable significance for the improvement of the proposed technology and...An innovative technology,nitric acid pressure leaching of limonitic laterite ores,was proposed by our research team.The HNO3 regeneration is considerable significance for the improvement of the proposed technology and its commercial application,but it has not been systematically investigated.Herein,regenerating HNO3 from Ca(NO3)2 solution with low-cost H2SO4,and simultaneous synthesis of fibrous CaSO4·2H2O by-products were studied.As a theoretical basis,the solubility of CaSO4·2H2O in HNO3 medium is studied.It is concluded that the solubility of CaSO4·2H2O increases with increasing temperature or increasing HNO3 concentration,which has considerable guiding significance for the subsequent experimental research and analysis.Then,the effects of various factors on the residual Ca^2+ concentration of filtrate,the regenerated HNO3 concentration and the morphology of synthesized products are investigated using ICP-AES and SEM.And the effect mechanism is also analyzed.The results indicate the regenerated HNO3 concentration reaches 116 g/L with the residual Ca^2+ concentration being 9.7 g/L at the optimum conditions.Moreover,fibrous CaSO4·2H2O by-products with high aspect ratios(length,406.32μm;diameter,14.71μm;aspect ratio,27.62)can be simultaneously synthesized.展开更多
Synthesis of oxynitride solid solutions CaAl4-xSixO7-xNx:Eu2+ (x = 0 - 4) was attempted by the solid state reaction (SSR) methods using Si3N4 and AlN as nitrogen sources. The Ca3Al8Si4O17N4 (x = 4/3) sample with the h...Synthesis of oxynitride solid solutions CaAl4-xSixO7-xNx:Eu2+ (x = 0 - 4) was attempted by the solid state reaction (SSR) methods using Si3N4 and AlN as nitrogen sources. The Ca3Al8Si4O17N4 (x = 4/3) sample with the high phase purity was obtained when AlN was used as a nitrogen source whereas the sample synthesized using Si3N4 as another nitrogen source contained a Ca2Al2SiO7 impurity. Thus, it was revealed that AlN was a preferable nitrogen source for the synthesis of Ca3Al8Si4O17N4 by the SSR method. The solid solutions around x = 4/3 activated with Eu2+ exhibited bluish-green luminescence with emission maxima at 480 nm by the excitation at 250 - 450 nm. Thus, the CaAl4-xSixO7-xNx: Eu2+ solid solutions especially for Ca3Al8Si4O17N4:Eu2+ (x = 4/3) were developed as novel展开更多
哺乳动物精子获能是精卵成功结合的前提。精子获能时,胞内环磷酸腺苷(cAMP)、环磷酸尿苷(cGMP)浓度显著升高,调节精子活力及顶体反应。精子中cAMP作用于cAMP依赖性蛋白激酶(cAMP dependent protein kinase,PKA),通过蛋白质磷酸化作用传...哺乳动物精子获能是精卵成功结合的前提。精子获能时,胞内环磷酸腺苷(cAMP)、环磷酸尿苷(cGMP)浓度显著升高,调节精子活力及顶体反应。精子中cAMP作用于cAMP依赖性蛋白激酶(cAMP dependent protein kinase,PKA),通过蛋白质磷酸化作用传递信息;cGMP与cGMP依赖性蛋白激酶(cGMP dependent protein kinase,PKG)、环核苷酸门控离子通道(cyclicnucleotide gated ion channel,CNG)、磷酸二酯酶(phosphodiesteras,PDEs)等蛋白结合,调控信号通路;Ca2+、HCO3-等离子通道同样与精子获能关系密切。展开更多
基金supported by the Beijing Natural Science Foundation of China(2182040)the National Natural Science Foundation of China(51674026,U1802253)+1 种基金the Fundamental Research Funds for the Central Universities(FRF-TT-19-001)the China Scholarship Council(201906465004)。
文摘Single-phaseα-CaSO4·0.5H2O whiskers were directly synthesized from waste Ca(NO3)2 solution using a hydrothermal method,and HNO3 was synchronously regenerated.The effects of reaction temperature and Ca^2+concentration on the phase composition and morphology of products were determined by X-ray diffraction and optical microscopy.On the basis of the experimental results,the formation diagram ofα-CaSO4·0.5H2O was plotted within the range of 5–35 g·L^-1 Ca^2+and 115°C–150°C.In addition,the conditions of the direct synthesis ofα-CaSO4·0.5H2O were determined.Well-crystallized,single-phaseα-CaSO4·0.5H2O whiskers with high aspect ratios(length,1785μm;diameter,10.63μm;aspect ratio,168)and HNO3(70.25 g·L^-1)were obtained at the optimal conditions of 25 g·L^-1 Ca^2+and 125°C.
基金Project(2182040)supported by the Beijing Natural Science Foundation,ChinaProjects(51674026,51974025,U1802253)supported by the National Natural Science Foundation of ChinaProject(FRF-TT-19-001)supported by the Fundamental Research Funds for the Central Universities,China。
文摘An innovative technology,nitric acid pressure leaching of limonitic laterite ores,was proposed by our research team.The HNO3 regeneration is considerable significance for the improvement of the proposed technology and its commercial application,but it has not been systematically investigated.Herein,regenerating HNO3 from Ca(NO3)2 solution with low-cost H2SO4,and simultaneous synthesis of fibrous CaSO4·2H2O by-products were studied.As a theoretical basis,the solubility of CaSO4·2H2O in HNO3 medium is studied.It is concluded that the solubility of CaSO4·2H2O increases with increasing temperature or increasing HNO3 concentration,which has considerable guiding significance for the subsequent experimental research and analysis.Then,the effects of various factors on the residual Ca^2+ concentration of filtrate,the regenerated HNO3 concentration and the morphology of synthesized products are investigated using ICP-AES and SEM.And the effect mechanism is also analyzed.The results indicate the regenerated HNO3 concentration reaches 116 g/L with the residual Ca^2+ concentration being 9.7 g/L at the optimum conditions.Moreover,fibrous CaSO4·2H2O by-products with high aspect ratios(length,406.32μm;diameter,14.71μm;aspect ratio,27.62)can be simultaneously synthesized.
文摘Synthesis of oxynitride solid solutions CaAl4-xSixO7-xNx:Eu2+ (x = 0 - 4) was attempted by the solid state reaction (SSR) methods using Si3N4 and AlN as nitrogen sources. The Ca3Al8Si4O17N4 (x = 4/3) sample with the high phase purity was obtained when AlN was used as a nitrogen source whereas the sample synthesized using Si3N4 as another nitrogen source contained a Ca2Al2SiO7 impurity. Thus, it was revealed that AlN was a preferable nitrogen source for the synthesis of Ca3Al8Si4O17N4 by the SSR method. The solid solutions around x = 4/3 activated with Eu2+ exhibited bluish-green luminescence with emission maxima at 480 nm by the excitation at 250 - 450 nm. Thus, the CaAl4-xSixO7-xNx: Eu2+ solid solutions especially for Ca3Al8Si4O17N4:Eu2+ (x = 4/3) were developed as novel
文摘哺乳动物精子获能是精卵成功结合的前提。精子获能时,胞内环磷酸腺苷(cAMP)、环磷酸尿苷(cGMP)浓度显著升高,调节精子活力及顶体反应。精子中cAMP作用于cAMP依赖性蛋白激酶(cAMP dependent protein kinase,PKA),通过蛋白质磷酸化作用传递信息;cGMP与cGMP依赖性蛋白激酶(cGMP dependent protein kinase,PKG)、环核苷酸门控离子通道(cyclicnucleotide gated ion channel,CNG)、磷酸二酯酶(phosphodiesteras,PDEs)等蛋白结合,调控信号通路;Ca2+、HCO3-等离子通道同样与精子获能关系密切。
