Traditional requirements method has some problems when it is used for large distributed systems. Multiple viewpoints oriented requirements method (MVORM) is a new method for resolving these problems. This paper develo...Traditional requirements method has some problems when it is used for large distributed systems. Multiple viewpoints oriented requirements method (MVORM) is a new method for resolving these problems. This paper develops two generic formal frameworks of MVORM, framework based on refinement relation (FBRR) and framework based on implementation relation (FBIR). They are generic, because no assumptions are made about the development process or the formal description languages to be used. Three kinds of specification relations and three kinds of specification transformations are discussed over FBIR and FBRR. This paper also compares the equivalence between FBIR and FBRR. We point out that an equivalent FBIR can be found for any FBRR, but reverse transformation is not always possible. We think FBIR is better than FBRR on most cases.展开更多
A simple and fast route for the synthesis of metal-organic framework（MOF） particles was presented.Cu 3（BTC） 2（HKUST-1,BTC=1,3,5-benzenetricarboxylate）,one of the most well-known MOFs,was synthesized at room temp...A simple and fast route for the synthesis of metal-organic framework（MOF） particles was presented.Cu 3（BTC） 2（HKUST-1,BTC=1,3,5-benzenetricarboxylate）,one of the most well-known MOFs,was synthesized at room temperature via coordination modulation method.By adding different modulators（monocarboxylic acids） into the reaction system,the morphologies of HKUST-1 crystals were tuned from nano spheres to micro octahedrons at room temperature without any complex equipment.X-Ray diffractions and gas sorption measurements revealed highly crystalline particles with large Brunauer-Emmett-Teller（BET） surface areas（1116―1273 m^ 2 /g） and total pore volumes（0.62―0.73 cm^ 3 /g）.The significantly small particle sizes and high capacity of gas sorption are considered advantageous for envisaged application in practical industrial process.展开更多
Community resilience is becoming a growing concern for authorities and decision makers.This paper introduces two indicator-based methods to evaluate the resilience of communities based on the PEOPLES framework.PEOPLES...Community resilience is becoming a growing concern for authorities and decision makers.This paper introduces two indicator-based methods to evaluate the resilience of communities based on the PEOPLES framework.PEOPLES is a multi-layered framework that defines community resilience using seven dimensions.Each of the dimensions is described through a set of resilience indicators collected from literature and they are linked to a measure allowing the analytical computation of the indicator’s performance.The first method proposed in this paper requires data on previous disasters as an input and returns as output a performance function for each indicator and a performance function for the whole community.The second method exploits a knowledge-based fuzzy modeling for its implementation.This method allows a quantitative evaluation of the PEOPLES indicators using descriptive knowledge rather than deterministic data including the uncertainty involved in the analysis.The output of the fuzzy-based method is a resilience index for each indicator as well as a resilience index for the community.The paper also introduces an open source online tool in which the first method is implemented.A case study illustrating the application of the first method and the usage of the tool is also provided in the paper.展开更多
A new lanthanide formate oxalate framework [Eu（C2O4）（HCOO）]n （1） has been synthesized via hydrothermal method and characterized by single-crystal X-ray diffraction （SC-XRD）. The framework crystallizes in the o...A new lanthanide formate oxalate framework [Eu（C2O4）（HCOO）]n （1） has been synthesized via hydrothermal method and characterized by single-crystal X-ray diffraction （SC-XRD）. The framework crystallizes in the orthorhombic Pnma space group, with a = 7.0984（4）, b = 6.6442（3）, c = 10.6793（6） ？, V = 503.68（4） ？3, Z = 3, C3HO6Eu, Mr = 285.00 g/mol, Dc = 3.7581 g/cm3, F（000） = 520.3796, μ = 12.413 mm-1, the final R = 0.0264 and wR = 0.0628 for 797 observed reflections with I 〉 2σ（I）. The photoluminescence （PL） measurements reveal the significant red emission of the framework is dominated by the （5D0 → 7F2） electronic transition at 614 nm. Further variable-temperature powder X-ray diffraction （VT-PXRD） indicates that framework 1 shows slight negative thermal expansion （NTE） along the a-axis, and positive thermal expansion （PTE） along the b and c axes.展开更多
In this study, the efects of various methods of washing and drying of MOF-5 nanocrystals on structure formation were investigated. Eight samples of MOF-5 were synthesized under diferent conditions. TGA, XRD and PSD an...In this study, the efects of various methods of washing and drying of MOF-5 nanocrystals on structure formation were investigated. Eight samples of MOF-5 were synthesized under diferent conditions. TGA, XRD and PSD analysis were applied to characterize of the samples. The methods of washing and drying were found to be important in determining the final structure of MOF-5s. MOF-5 with high BET surface area can be obtained by choosing a suitable method of washing and drying. According to the results obtained in this work, it was found that vacuum drying at 425℃ is sufcient to dissolve the MOF-5-DMF. Similar results were obtained by washing method（withCH2Cl2 andCHCl3）, when compared with vacuum drying at 425℃ according to XRD test. The pore size distribution of samples 1-5 and 8 were calculated by SHN1 method and results showed that the samples in which solvent vacuum was DMF, have lower pore volume, uniform pore size distribution and the pore size are smaller than samples 3, 4 and 8. It was also found that activated MOF-5 can be converted to its deactivated form prior to drying of the samples.展开更多
The desire to increase spatial and temporal resolution in modeling groundwater system has led to the requirement for intensive computational ability and large memory space. In the course of satisfying such requirement...The desire to increase spatial and temporal resolution in modeling groundwater system has led to the requirement for intensive computational ability and large memory space. In the course of satisfying such requirement, parallel computing has played a core role over the past several decades. This paper reviews the parallel algebraic linear solution methods and the parallel implementation technologies for groundwater simulation. This work is carried out to provide guidance to enable modelers of groundwater systems to make sensible choices when developing solution methods based upon the current state of knowledge in parallel computing.展开更多
基金Supported by Natural Science Foundation of Hubei Province (98J0 75 ) Ziqiang Technical Innovation Foundation ofWuhan Universi
文摘Traditional requirements method has some problems when it is used for large distributed systems. Multiple viewpoints oriented requirements method (MVORM) is a new method for resolving these problems. This paper develops two generic formal frameworks of MVORM, framework based on refinement relation (FBRR) and framework based on implementation relation (FBIR). They are generic, because no assumptions are made about the development process or the formal description languages to be used. Three kinds of specification relations and three kinds of specification transformations are discussed over FBIR and FBRR. This paper also compares the equivalence between FBIR and FBRR. We point out that an equivalent FBIR can be found for any FBRR, but reverse transformation is not always possible. We think FBIR is better than FBRR on most cases.
基金Supported by the National Natural Science Foundation of China(Nos.21173034,20907006)
文摘A simple and fast route for the synthesis of metal-organic framework（MOF） particles was presented.Cu 3（BTC） 2（HKUST-1,BTC=1,3,5-benzenetricarboxylate）,one of the most well-known MOFs,was synthesized at room temperature via coordination modulation method.By adding different modulators（monocarboxylic acids） into the reaction system,the morphologies of HKUST-1 crystals were tuned from nano spheres to micro octahedrons at room temperature without any complex equipment.X-Ray diffractions and gas sorption measurements revealed highly crystalline particles with large Brunauer-Emmett-Teller（BET） surface areas（1116―1273 m^ 2 /g） and total pore volumes（0.62―0.73 cm^ 3 /g）.The significantly small particle sizes and high capacity of gas sorption are considered advantageous for envisaged application in practical industrial process.
基金European Research Council under Grant Agreement No.ERC_IDEAL RESCUE_637842 of the project IDEAL RESCUE-Integrated Design and Control of Sustainable Communities during Emergencies
文摘Community resilience is becoming a growing concern for authorities and decision makers.This paper introduces two indicator-based methods to evaluate the resilience of communities based on the PEOPLES framework.PEOPLES is a multi-layered framework that defines community resilience using seven dimensions.Each of the dimensions is described through a set of resilience indicators collected from literature and they are linked to a measure allowing the analytical computation of the indicator’s performance.The first method proposed in this paper requires data on previous disasters as an input and returns as output a performance function for each indicator and a performance function for the whole community.The second method exploits a knowledge-based fuzzy modeling for its implementation.This method allows a quantitative evaluation of the PEOPLES indicators using descriptive knowledge rather than deterministic data including the uncertainty involved in the analysis.The output of the fuzzy-based method is a resilience index for each indicator as well as a resilience index for the community.The paper also introduces an open source online tool in which the first method is implemented.A case study illustrating the application of the first method and the usage of the tool is also provided in the paper.
基金supported by the National Natural Science Foundation of China(21571072)
文摘A new lanthanide formate oxalate framework [Eu（C2O4）（HCOO）]n （1） has been synthesized via hydrothermal method and characterized by single-crystal X-ray diffraction （SC-XRD）. The framework crystallizes in the orthorhombic Pnma space group, with a = 7.0984（4）, b = 6.6442（3）, c = 10.6793（6） ？, V = 503.68（4） ？3, Z = 3, C3HO6Eu, Mr = 285.00 g/mol, Dc = 3.7581 g/cm3, F（000） = 520.3796, μ = 12.413 mm-1, the final R = 0.0264 and wR = 0.0628 for 797 observed reflections with I 〉 2σ（I）. The photoluminescence （PL） measurements reveal the significant red emission of the framework is dominated by the （5D0 → 7F2） electronic transition at 614 nm. Further variable-temperature powder X-ray diffraction （VT-PXRD） indicates that framework 1 shows slight negative thermal expansion （NTE） along the a-axis, and positive thermal expansion （PTE） along the b and c axes.
文摘In this study, the efects of various methods of washing and drying of MOF-5 nanocrystals on structure formation were investigated. Eight samples of MOF-5 were synthesized under diferent conditions. TGA, XRD and PSD analysis were applied to characterize of the samples. The methods of washing and drying were found to be important in determining the final structure of MOF-5s. MOF-5 with high BET surface area can be obtained by choosing a suitable method of washing and drying. According to the results obtained in this work, it was found that vacuum drying at 425℃ is sufcient to dissolve the MOF-5-DMF. Similar results were obtained by washing method（withCH2Cl2 andCHCl3）, when compared with vacuum drying at 425℃ according to XRD test. The pore size distribution of samples 1-5 and 8 were calculated by SHN1 method and results showed that the samples in which solvent vacuum was DMF, have lower pore volume, uniform pore size distribution and the pore size are smaller than samples 3, 4 and 8. It was also found that activated MOF-5 can be converted to its deactivated form prior to drying of the samples.
基金supported by the National Basic Research Program (973 Program) of China under Grant No.2010CB428804 and 2011CB 309702
文摘The desire to increase spatial and temporal resolution in modeling groundwater system has led to the requirement for intensive computational ability and large memory space. In the course of satisfying such requirement, parallel computing has played a core role over the past several decades. This paper reviews the parallel algebraic linear solution methods and the parallel implementation technologies for groundwater simulation. This work is carried out to provide guidance to enable modelers of groundwater systems to make sensible choices when developing solution methods based upon the current state of knowledge in parallel computing.
