Haliotis discus hannai Ino （abalone shell） and Hemifusus tuba conch shell have been studied for the purpose to comparatively investigate the mechanisms by which nature designs composites. It is shown that both shell...Haliotis discus hannai Ino （abalone shell） and Hemifusus tuba conch shell have been studied for the purpose to comparatively investigate the mechanisms by which nature designs composites. It is shown that both shells are composed of aragonite and a small amount of proteins while the conch shell shows finer microstructure but lower strength than aba- lone shell. It is also shown that the fresh shells exhibits better property than those after heat-treatments. It is therefore sup- posed that the size of inorganic substance is not a dominant factor to improve strength, while both proteins in shells and the microstructure of inorganic matter also play important roles.展开更多
The mollusk shell mobilizes calcium from environment for skeletal mineralization.This occurs through synthesizing solidsin solution in the presence of organic molecules of specific interior regions of the conch shell....The mollusk shell mobilizes calcium from environment for skeletal mineralization.This occurs through synthesizing solidsin solution in the presence of organic molecules of specific interior regions of the conch shell.The ultrastructure and microhardnessof the Hemifusus tuba conch shell living in the Huang/Bo sea area are investigated in the paper.It is shown that thecomposition and microstructure of the mollusk shell vary in different positions.The prodissoconch shell consists only of aragonitewith the crossed-lamellar microstructure.While the spiral shell and the body shell of the Hemifusus tuba conch shell arecomposed of one calcite layer and several aragonite layers.The calcite layer consists of cylindrical grains,but the aragonitelayers are crossed-lamellar ultrastructure at three size scales.The minimum structure size(the third-order lamella)is at about20 nm-80 nm.The margin of shell aperture is only composed of calcite with cylindrical grains.This natural optimization of theshell microstructure is intimately due to the growth of the Organic matrix.At different positions the microhardness of molluscshell is different due to different crystal structures and crystal arrangements.The growth process of shells allows a constantrenewal of the material,thus enabling their functional adaptation to external environments.展开更多
The microstructures of conch shell were observed with scanning electronic microscope （SEM）, and a kind of inclined-cross microstructure of aragonite sheets was found. The maximal pull-out force of the inclined-cros...The microstructures of conch shell were observed with scanning electronic microscope （SEM）, and a kind of inclined-cross microstructure of aragonite sheets was found. The maximal pull-out force of the inclined-cross microstructure was analyzed based on its representative model and compared with that of a conventional 0 °- structure. The experimental result indicates that the maximal pull-out force of the inclined-cross microstructure is markedly larger than that of the 0°- structure.展开更多
应用傅里叶变换红外(FTIR)漫反射光谱首次获得海螺珠及大凤螺壳的原生表面与相应断面的光谱差异性特征,并结合扫描电子显微镜(scanning electron microscopy,SEM)、X射线衍射(X-ray diffraction,XRD)就上述差异性形成机制予以探究。结...应用傅里叶变换红外(FTIR)漫反射光谱首次获得海螺珠及大凤螺壳的原生表面与相应断面的光谱差异性特征,并结合扫描电子显微镜(scanning electron microscopy,SEM)、X射线衍射(X-ray diffraction,XRD)就上述差异性形成机制予以探究。结果表明:海螺珠及大凤螺壳珍珠层的原生表面与其对应的断面红外漫反射光谱存在显著的差异性,体现在:①两者原生表面生物文石的ν_(3)谱带强度与ν_(2)谱带的强度比值大于相应断面上文石对应峰位的强度比值;②两者珍珠层原生表面生物文石的ν_(2)谱带较断面上文石ν_(2)谱带峰位出现明显频移,同时原生表面上的ν_(2)谱带的半高宽小于断面上文石ν_(2)谱带的半高宽;③海螺珠与大凤螺壳珍珠层断面上的文石存在842 nm处的特征峰,但该特征峰并未见于海螺珠与大凤螺壳珍珠层的原生表面。SEM及XRD测试发现,原生表面与断面方向上文石晶体的结晶学各向异性是造成上述红外谱图及XRD衍射谱峰出现特异性的直接原因。研究工作对于认知生物矿化、海螺珠与基于大凤螺壳磨制的圆珠的检测鉴别具有较重要的指导意义。展开更多
目的建立柱前衍生高效液相色谱法(HPLC)测定紫贝齿饮片中11种氨基酸的方法,并比较不同基原的差异。方法以异硫氰酸苯酯为柱前衍生化试剂,采用C18色谱柱,流动相A为乙腈,流动相B为0.1 mol/L醋酸钠溶液(p H 6.5),梯度洗脱,检测波长254 nm,...目的建立柱前衍生高效液相色谱法(HPLC)测定紫贝齿饮片中11种氨基酸的方法,并比较不同基原的差异。方法以异硫氰酸苯酯为柱前衍生化试剂,采用C18色谱柱,流动相A为乙腈,流动相B为0.1 mol/L醋酸钠溶液(p H 6.5),梯度洗脱,检测波长254 nm,色谱柱温度40℃。运用主成分分析(PCA)、偏最小二乘法判别分析(PLS-DA)和方差分析研究了紫贝齿中4种基原的氨基酸成分的差异。结果11种氨基酸呈良好的线性关系(R>0.999);精密度、稳定性、重复性试验相对标准偏差(RSD)值分别小于1.77%、2.54%、1.98%;平均回收率为90.7%~108.9%(RSD为0.67%~1.58%,n=6)。紫贝齿4种基原之间氨基酸成分存在差异,并发现3种氨基酸差异性成分。结论建立的氨基酸测定方法稳定可靠,可用于紫贝齿饮片的质量评价。展开更多
文摘Haliotis discus hannai Ino （abalone shell） and Hemifusus tuba conch shell have been studied for the purpose to comparatively investigate the mechanisms by which nature designs composites. It is shown that both shells are composed of aragonite and a small amount of proteins while the conch shell shows finer microstructure but lower strength than aba- lone shell. It is also shown that the fresh shells exhibits better property than those after heat-treatments. It is therefore sup- posed that the size of inorganic substance is not a dominant factor to improve strength, while both proteins in shells and the microstructure of inorganic matter also play important roles.
文摘The mollusk shell mobilizes calcium from environment for skeletal mineralization.This occurs through synthesizing solidsin solution in the presence of organic molecules of specific interior regions of the conch shell.The ultrastructure and microhardnessof the Hemifusus tuba conch shell living in the Huang/Bo sea area are investigated in the paper.It is shown that thecomposition and microstructure of the mollusk shell vary in different positions.The prodissoconch shell consists only of aragonitewith the crossed-lamellar microstructure.While the spiral shell and the body shell of the Hemifusus tuba conch shell arecomposed of one calcite layer and several aragonite layers.The calcite layer consists of cylindrical grains,but the aragonitelayers are crossed-lamellar ultrastructure at three size scales.The minimum structure size(the third-order lamella)is at about20 nm-80 nm.The margin of shell aperture is only composed of calcite with cylindrical grains.This natural optimization of theshell microstructure is intimately due to the growth of the Organic matrix.At different positions the microhardness of molluscshell is different due to different crystal structures and crystal arrangements.The growth process of shells allows a constantrenewal of the material,thus enabling their functional adaptation to external environments.
文摘The microstructures of conch shell were observed with scanning electronic microscope （SEM）, and a kind of inclined-cross microstructure of aragonite sheets was found. The maximal pull-out force of the inclined-cross microstructure was analyzed based on its representative model and compared with that of a conventional 0 °- structure. The experimental result indicates that the maximal pull-out force of the inclined-cross microstructure is markedly larger than that of the 0°- structure.
文摘应用傅里叶变换红外(FTIR)漫反射光谱首次获得海螺珠及大凤螺壳的原生表面与相应断面的光谱差异性特征,并结合扫描电子显微镜(scanning electron microscopy,SEM)、X射线衍射(X-ray diffraction,XRD)就上述差异性形成机制予以探究。结果表明:海螺珠及大凤螺壳珍珠层的原生表面与其对应的断面红外漫反射光谱存在显著的差异性,体现在:①两者原生表面生物文石的ν_(3)谱带强度与ν_(2)谱带的强度比值大于相应断面上文石对应峰位的强度比值;②两者珍珠层原生表面生物文石的ν_(2)谱带较断面上文石ν_(2)谱带峰位出现明显频移,同时原生表面上的ν_(2)谱带的半高宽小于断面上文石ν_(2)谱带的半高宽;③海螺珠与大凤螺壳珍珠层断面上的文石存在842 nm处的特征峰,但该特征峰并未见于海螺珠与大凤螺壳珍珠层的原生表面。SEM及XRD测试发现,原生表面与断面方向上文石晶体的结晶学各向异性是造成上述红外谱图及XRD衍射谱峰出现特异性的直接原因。研究工作对于认知生物矿化、海螺珠与基于大凤螺壳磨制的圆珠的检测鉴别具有较重要的指导意义。
文摘目的建立柱前衍生高效液相色谱法(HPLC)测定紫贝齿饮片中11种氨基酸的方法,并比较不同基原的差异。方法以异硫氰酸苯酯为柱前衍生化试剂,采用C18色谱柱,流动相A为乙腈,流动相B为0.1 mol/L醋酸钠溶液(p H 6.5),梯度洗脱,检测波长254 nm,色谱柱温度40℃。运用主成分分析(PCA)、偏最小二乘法判别分析(PLS-DA)和方差分析研究了紫贝齿中4种基原的氨基酸成分的差异。结果11种氨基酸呈良好的线性关系(R>0.999);精密度、稳定性、重复性试验相对标准偏差(RSD)值分别小于1.77%、2.54%、1.98%;平均回收率为90.7%~108.9%(RSD为0.67%~1.58%,n=6)。紫贝齿4种基原之间氨基酸成分存在差异,并发现3种氨基酸差异性成分。结论建立的氨基酸测定方法稳定可靠,可用于紫贝齿饮片的质量评价。
