The polymorphism characteristics of p-tert-octyl phenol was studied.It was found that after thermal treatment of differential scanning calorimetry(DSC), the melting point of p-tert-octyl phenol sample was about 75.0℃...The polymorphism characteristics of p-tert-octyl phenol was studied.It was found that after thermal treatment of differential scanning calorimetry(DSC), the melting point of p-tert-octyl phenol sample was about 75.0℃,lower than that of the untreated original sample which was 85.4℃.The fusion enthalpy of p-tert-octyl phenol decreased with increasing cooling rate of the thermal treatment.The samples before and after the thermal treatment of DSC were analyzed with DSC, FTIR spectroscopy,and powder X-ray diffraction.The results showed that through the thermal treatment, p-tert-octyl phenol generated a new crystalline form with a lower melting point and lower fusion enthalpy.The solid stability of the polymorphs was further studied.It was found that the two polymorphs belonged to monotropy.The α form with a higher melting point was stable at temperatures below its melting point.The β form with a lower melting point was metastable, which could convert into the α form at a low temperature.展开更多
研究了单月桂酸甘油酯(glycerol monolaurate,GML)添加量对大豆分离蛋白(soy protein isolate,SPI)复合膜成膜特性的影响,并运用傅里叶变换红外光谱、X射线衍射、差示扫描量热和扫描电子显微镜技术初步探讨了两者的成膜机制。结果表明:...研究了单月桂酸甘油酯(glycerol monolaurate,GML)添加量对大豆分离蛋白(soy protein isolate,SPI)复合膜成膜特性的影响,并运用傅里叶变换红外光谱、X射线衍射、差示扫描量热和扫描电子显微镜技术初步探讨了两者的成膜机制。结果表明:随着GML添加量的增加,GML-SPI复合膜的抗拉强度和断裂延伸率呈先上升后下降趋势,该复合膜的水蒸气透过率、透光率、水溶性逐渐下降,而亮度和白度有所增加。傅里叶变换红外光谱证实,复合膜中GML和SPI两种组分主要通过氢键、疏水作用力等次级键相互结合;X射线衍射和差示扫描量热结果显示,与空白对照组相比,GML-SPI复合膜的结晶度和熔融温度均有所提高;扫描电子显微镜结果表明,添加GML有利于减少复合膜内部空隙,但GML添加量超过0.8%时,复合膜中GML和SPI两类组分会出现两相分离现象。本研究成果可为以SPI复合膜为代表的新型可食性包装材料的研发与应用提供理论依据。展开更多
Calcium carbonate （CaCO3） crystals in their preferred orientation were obtained in BG11 culture media inoculated with Synechocystis sp. PCC6803 （inoculated BG11）. In this study, the features of calcium carbonate d...Calcium carbonate （CaCO3） crystals in their preferred orientation were obtained in BG11 culture media inoculated with Synechocystis sp. PCC6803 （inoculated BG11）. In this study, the features of calcium carbonate deposition were investigated. Inoculated BGll in different calcium ion concentrations was used for the experimental group, while the BGll culture medium was used for the control group. The surface morphologies of the calcium carbonate deposits in the experimental and control groups were determined by scanning and transmission electron microscopy. The deposits were analyzed by electronic probe micro-analysis, Fourier transform infrared spectrum, X-ray diffraction, thermal gravimetric analysis and differential scanning calorimetry. The results show that the surfaces of the crystals in the experimental group were hexahedral in a scaly pattern. The particle sizes were micrometer-sized and larger than those in the control group. The deposits of the control group contained calcium （Ca）, carbon （C）, oxygen （O）, phosphorus （P）, iron （Fe）, copper （Cu）, zinc （Zn）, and other elements. The deposits in the experimental group contained Ca, C, and O only. The deposits of both groups contained calcite. The thermal decomposition temperature of the deposits in the control group was lower than those in the experimental group. It showed that the CaCO3 deposits of the experimental group had higher thermal stability than those of the control group. This may be due to the secondary metabolites produced by the algae cells, which affect the carbonate crystal structure and result in a close-packed structure. The algae cells that remained after thermal weight loss were heavier in higher calcium concentrations in BGll culture media. There may be more calcium- containing crystals inside and outside of these cells. These results shall be beneficial for understanding the formation mechanism of carbonate minerals.展开更多
The effects of alkali oxides （Na2O and K2O addition on both the sintering behavior and dielectric properties of Ca-AI-B-Si-O glass/Al2O3 composites were investigated by Fourier transform infrared spectroscopy （FTIR...The effects of alkali oxides （Na2O and K2O addition on both the sintering behavior and dielectric properties of Ca-AI-B-Si-O glass/Al2O3 composites were investigated by Fourier transform infrared spectroscopy （FTIR）, differential scanning calorimeter （DSC）, X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. The results show that the increasing amount of alkali oxides in the glass causes the decrease of [SiO4], which results in the decrease of the continuity of glass network, and leads to the decrease of the softening temperature Tf of the samples and the increasing trend of crystallization. And that deduces corresponding rise of densification, dielectric constant, dielectric loss of the low temperature co-fired ceramic （LTCC） materials and the decrease of its thermal conductivity. By contrast, the borosilicate glass/A1203 composites with 1.5% （mass fraction） alkali oxides sintered at 875 ℃ for 30 rain exhibit better properties of a bulk density of 2.79 g/cm3, a porosity of 0.48%, a 2 value of 2.28 W/（m.K）, a er value of 7.82 and a tand value of 9.1 × 10-4 （measured at 10 MHz）.展开更多
文摘The polymorphism characteristics of p-tert-octyl phenol was studied.It was found that after thermal treatment of differential scanning calorimetry(DSC), the melting point of p-tert-octyl phenol sample was about 75.0℃,lower than that of the untreated original sample which was 85.4℃.The fusion enthalpy of p-tert-octyl phenol decreased with increasing cooling rate of the thermal treatment.The samples before and after the thermal treatment of DSC were analyzed with DSC, FTIR spectroscopy,and powder X-ray diffraction.The results showed that through the thermal treatment, p-tert-octyl phenol generated a new crystalline form with a lower melting point and lower fusion enthalpy.The solid stability of the polymorphs was further studied.It was found that the two polymorphs belonged to monotropy.The α form with a higher melting point was stable at temperatures below its melting point.The β form with a lower melting point was metastable, which could convert into the α form at a low temperature.
文摘研究了单月桂酸甘油酯(glycerol monolaurate,GML)添加量对大豆分离蛋白(soy protein isolate,SPI)复合膜成膜特性的影响,并运用傅里叶变换红外光谱、X射线衍射、差示扫描量热和扫描电子显微镜技术初步探讨了两者的成膜机制。结果表明:随着GML添加量的增加,GML-SPI复合膜的抗拉强度和断裂延伸率呈先上升后下降趋势,该复合膜的水蒸气透过率、透光率、水溶性逐渐下降,而亮度和白度有所增加。傅里叶变换红外光谱证实,复合膜中GML和SPI两种组分主要通过氢键、疏水作用力等次级键相互结合;X射线衍射和差示扫描量热结果显示,与空白对照组相比,GML-SPI复合膜的结晶度和熔融温度均有所提高;扫描电子显微镜结果表明,添加GML有利于减少复合膜内部空隙,但GML添加量超过0.8%时,复合膜中GML和SPI两类组分会出现两相分离现象。本研究成果可为以SPI复合膜为代表的新型可食性包装材料的研发与应用提供理论依据。
基金Supported by the National Natural Science Foundation of China(Nos.40972043,41040018,41210104058,21176145,41372108,41302079)the Higher Educational Science and Technology Program of Shandong Province(No.J10LC15)+4 种基金the China Postdoctoral Science Foundation(No.2013M540560)the Program for Scientific Research Innovation Team in Colleges and Universities of Shandong Province,and SDUST Research Fund(No.2010KYTD103)the Open Project of Key Lab of Marine Bioactive Substance and Modern Analytical Technique,State Oceanic Administration,China(No.MBSMAT-2012-03)the Scientific and Technological Program of Qingdao(No.13-1-4-232-jch)the Domestic Visiting Scholar Program for Young Core Teachers in Shandong Universities,Shandong Province,China
文摘Calcium carbonate （CaCO3） crystals in their preferred orientation were obtained in BG11 culture media inoculated with Synechocystis sp. PCC6803 （inoculated BG11）. In this study, the features of calcium carbonate deposition were investigated. Inoculated BGll in different calcium ion concentrations was used for the experimental group, while the BGll culture medium was used for the control group. The surface morphologies of the calcium carbonate deposits in the experimental and control groups were determined by scanning and transmission electron microscopy. The deposits were analyzed by electronic probe micro-analysis, Fourier transform infrared spectrum, X-ray diffraction, thermal gravimetric analysis and differential scanning calorimetry. The results show that the surfaces of the crystals in the experimental group were hexahedral in a scaly pattern. The particle sizes were micrometer-sized and larger than those in the control group. The deposits of the control group contained calcium （Ca）, carbon （C）, oxygen （O）, phosphorus （P）, iron （Fe）, copper （Cu）, zinc （Zn）, and other elements. The deposits in the experimental group contained Ca, C, and O only. The deposits of both groups contained calcite. The thermal decomposition temperature of the deposits in the control group was lower than those in the experimental group. It showed that the CaCO3 deposits of the experimental group had higher thermal stability than those of the control group. This may be due to the secondary metabolites produced by the algae cells, which affect the carbonate crystal structure and result in a close-packed structure. The algae cells that remained after thermal weight loss were heavier in higher calcium concentrations in BGll culture media. There may be more calcium- containing crystals inside and outside of these cells. These results shall be beneficial for understanding the formation mechanism of carbonate minerals.
基金Project(2007AA03Z0455) supported by the National High Technology Research and Development Program ("863" Program) of ChinaProject(BE2010194) supported by Science & Technology Pillar Program of Jiangsu in China+3 种基金Project(BE2009168) supported by Science & Technology Pillar Program of Jiangsu in ChinaProject supported by the Priority Academic Program Development (PAPD) of Jiangsu Higher Education InstitutionsProject(KF201103) supported by State Key Laboratory of New Ceramic and Fine Processing Tsinghua UniversityProject(CXZZ12_0415) supported by Innovation Foundation for Graduate Students of Jiangsu Province,China
文摘The effects of alkali oxides （Na2O and K2O addition on both the sintering behavior and dielectric properties of Ca-AI-B-Si-O glass/Al2O3 composites were investigated by Fourier transform infrared spectroscopy （FTIR）, differential scanning calorimeter （DSC）, X-ray diffractometry （XRD） and scanning electron microscopy （SEM）. The results show that the increasing amount of alkali oxides in the glass causes the decrease of [SiO4], which results in the decrease of the continuity of glass network, and leads to the decrease of the softening temperature Tf of the samples and the increasing trend of crystallization. And that deduces corresponding rise of densification, dielectric constant, dielectric loss of the low temperature co-fired ceramic （LTCC） materials and the decrease of its thermal conductivity. By contrast, the borosilicate glass/A1203 composites with 1.5% （mass fraction） alkali oxides sintered at 875 ℃ for 30 rain exhibit better properties of a bulk density of 2.79 g/cm3, a porosity of 0.48%, a 2 value of 2.28 W/（m.K）, a er value of 7.82 and a tand value of 9.1 × 10-4 （measured at 10 MHz）.
