Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity,making them suitable for high-performance applicatio...Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity,making them suitable for high-performance applications.N-doping has been widely investigated because of its similar atom radius to carbon,high electronegativity as well as many different configurations.We summarize the preparation methods and properties of N-doped carbon materials,and discuss their possible use in sodium ion storage.The relationships between N content/configuration and crystallinity,electronic conductivity,wettability,chemical reactivity as well as sodium ion storage performance are discussed.展开更多
The thermal phonon transport is a key matter for heat managing in materials science which is crucial for device miniaturization and power density increase. Herein, we report the synthesis, structure and characterizati...The thermal phonon transport is a key matter for heat managing in materials science which is crucial for device miniaturization and power density increase. Herein, we report the synthesis, structure and characterization of a new compound, Cs2Ge3Ga6Se14, with a unique anisotropic structure simultaneously containing Ge^3+ and Ge^2+ that adopt(Ge1)2^3+ Se6 dimer or(Ge2)^2+Se6 octahedron, respectively. The thermal conductivity was measured to be 0.57–0.48 W m^-1 K^-1 from 323 to 773 K, the lowest value among all the known Ge-containing compounds, approaching its glass limit according to the Cahill’s formulation. More importantly, we discover for the first time that the vibration uncoupling of Ge with different valence states hinders the effective thermal energy transport between the(Ge1)2^3+ Se6 dimer and(Ge2)^2+Se6 octahedron, and consequently lowers the thermal conductivity. In addition, we propose a structure factor f = sin(180) ×d/l(i =A, B)iGe Qi, with which a structure map of the Cs2 Ge3 M6 Q14 family is given.展开更多
We propose a self-adaptive process （SAP） that maintains the software architecture quality using the MAPE-K standard model. The proposed process can be plugged into various software development processes and service-...We propose a self-adaptive process （SAP） that maintains the software architecture quality using the MAPE-K standard model. The proposed process can be plugged into various software development processes and service-oriented meth- odologies due to its explicitly defined inputs and outputs. To this aim, the proposed SAP is integrated with the service-oriented modeling and application （SOMA） methodology in a two-layered structure to create a novel methodology, named self-adaptive service-oriented architecture methodology （SASOAM）, which provides a semi-automatic self-aware method by the composition of architectural tactics. Moreover, the maintenance activity of SOMA is improved using architectural and adaptive patterns, which results in controlling the software architecture quality. The improvement in the maintainability of SOMA is demonstrated by an analytic hierarchy process （AHP） based evaluation method. Furthermore, the proposed method is applied to a case study to represent the feasibility and practicality of SASOAM.展开更多
In the deep Earth, hydrogen mainly occurs as structural hydroxyl and molecular water in minerals and melts, constituting mobile and immobile aqueous components. Hydrous minerals contain hydrogen which occupies a speci...In the deep Earth, hydrogen mainly occurs as structural hydroxyl and molecular water in minerals and melts, constituting mobile and immobile aqueous components. Hydrous minerals contain hydrogen which occupies a specific structural position and constitutes an indispensable component of chemical formulae. On the other hand, nominally anhydrous minerals do not contain hydrogen in their chemical formulae, but can host trace amounts of water in structural position and lattice defect. The molecular water may occur in the lattice defect as fluid/melt inclusions in minerals. Even though the water content of nominally anhydrous minerals is very limited generally in the order of ppm(parts per million), they may play a significant role in influencing the physicochemical properties of mineral and rock systems. With the continuous improvement of modern instrumentations, the analytical methodology exhibits trends for higher spatial resolution, lower detection limit and integral multiple methods on the water amount and its isotopic ratio. Among these methods, Fourier transform infrared spectrometry remains the most widely used, while secondary ion mass spectrometry, continuous flow mass spectrometry, elastic recoil detection analysis and Raman spectrometry are promising. This paper provides a brief review on the methodological progress and their applications to the analysis of structural water in nominally anhydrous minerals.展开更多
文摘Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity,making them suitable for high-performance applications.N-doping has been widely investigated because of its similar atom radius to carbon,high electronegativity as well as many different configurations.We summarize the preparation methods and properties of N-doped carbon materials,and discuss their possible use in sodium ion storage.The relationships between N content/configuration and crystallinity,electronic conductivity,wettability,chemical reactivity as well as sodium ion storage performance are discussed.
基金supported by the National Natural Science Foundation of China (21975032 and 21571020)the National Key Research and Development Program of China (2018YFA0702100)
文摘The thermal phonon transport is a key matter for heat managing in materials science which is crucial for device miniaturization and power density increase. Herein, we report the synthesis, structure and characterization of a new compound, Cs2Ge3Ga6Se14, with a unique anisotropic structure simultaneously containing Ge^3+ and Ge^2+ that adopt(Ge1)2^3+ Se6 dimer or(Ge2)^2+Se6 octahedron, respectively. The thermal conductivity was measured to be 0.57–0.48 W m^-1 K^-1 from 323 to 773 K, the lowest value among all the known Ge-containing compounds, approaching its glass limit according to the Cahill’s formulation. More importantly, we discover for the first time that the vibration uncoupling of Ge with different valence states hinders the effective thermal energy transport between the(Ge1)2^3+ Se6 dimer and(Ge2)^2+Se6 octahedron, and consequently lowers the thermal conductivity. In addition, we propose a structure factor f = sin(180) ×d/l(i =A, B)iGe Qi, with which a structure map of the Cs2 Ge3 M6 Q14 family is given.
文摘We propose a self-adaptive process （SAP） that maintains the software architecture quality using the MAPE-K standard model. The proposed process can be plugged into various software development processes and service-oriented meth- odologies due to its explicitly defined inputs and outputs. To this aim, the proposed SAP is integrated with the service-oriented modeling and application （SOMA） methodology in a two-layered structure to create a novel methodology, named self-adaptive service-oriented architecture methodology （SASOAM）, which provides a semi-automatic self-aware method by the composition of architectural tactics. Moreover, the maintenance activity of SOMA is improved using architectural and adaptive patterns, which results in controlling the software architecture quality. The improvement in the maintainability of SOMA is demonstrated by an analytic hierarchy process （AHP） based evaluation method. Furthermore, the proposed method is applied to a case study to represent the feasibility and practicality of SASOAM.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41373010 & 41590624)
文摘In the deep Earth, hydrogen mainly occurs as structural hydroxyl and molecular water in minerals and melts, constituting mobile and immobile aqueous components. Hydrous minerals contain hydrogen which occupies a specific structural position and constitutes an indispensable component of chemical formulae. On the other hand, nominally anhydrous minerals do not contain hydrogen in their chemical formulae, but can host trace amounts of water in structural position and lattice defect. The molecular water may occur in the lattice defect as fluid/melt inclusions in minerals. Even though the water content of nominally anhydrous minerals is very limited generally in the order of ppm(parts per million), they may play a significant role in influencing the physicochemical properties of mineral and rock systems. With the continuous improvement of modern instrumentations, the analytical methodology exhibits trends for higher spatial resolution, lower detection limit and integral multiple methods on the water amount and its isotopic ratio. Among these methods, Fourier transform infrared spectrometry remains the most widely used, while secondary ion mass spectrometry, continuous flow mass spectrometry, elastic recoil detection analysis and Raman spectrometry are promising. This paper provides a brief review on the methodological progress and their applications to the analysis of structural water in nominally anhydrous minerals.
