Datong coal was extracted with CS2, n-hexane, benzene, methanol, acetone, tetrahydro-furan(THF) and THF/methanol(1:3,v/v) mixed solvent sequentially. The extracts were analyzed with GC/MS. It is presented that gr...Datong coal was extracted with CS2, n-hexane, benzene, methanol, acetone, tetrahydro-furan(THF) and THF/methanol(1:3,v/v) mixed solvent sequentially. The extracts were analyzed with GC/MS. It is presented that group seperation of soluble organic compounds in the coal can be achieved by fractionated extraction using different solvents. The results show that CS2 was effective for extracting arenes from the coal sample, n-Hexane extractable fraction from Datong coal mainly consists of n-alkanes. A great variety of oxygen-containing compounds are dominant in the components of methanol-soluble fraction. Acyclic isoprenoids, pentecyclic triterpanes and a series of cyclohexanes with long-chain alkyl-substitutes are detected in acetone-soluble fraction. Dicyclic aramatic hydrocarbons are identified in benzene-soluble fraction and 4-6 cyclic condensed aramatic hydrocarbons are identified in THF-soluble fraction. The molecular structures detection of 1,2-dichlorobenzene, 2,4-dibromophnol, 2,4,6-tribromophenol and 4-chlorobenzophenone firstly provide information for existence form of bromine and chlorine in coal.展开更多
Aim To study the effect of complexation with hydroxylpropyl-β-cyclodextrin(HP-β-CD) on the solubility, dissolution rate and chemical stability of prostaglandin E_1 (PGE_1) ,thereby providing a basis for preparing a ...Aim To study the effect of complexation with hydroxylpropyl-β-cyclodextrin(HP-β-CD) on the solubility, dissolution rate and chemical stability of prostaglandin E_1 (PGE_1) ,thereby providing a basis for preparing a stable solid or aqueous preparation of PGE_1 formulatedwith HP-β-CD. Methods The effect of HP-β-CD on the solubility of PGE_1 was studied by phasesolubility method. The formation of inclusion complexes of PGE_1 with HP-β-CD in the aqueoussolution was confirmed by UV spectra, circular dichroism spectroscopy, and that in the solid stateby IR spectra and X-ray diffractome-try. An solid inclusion complex of PGE_1 with HP-β-CD wasprepared by lyophilization. The dissolution rate and stability of the inclusion complex weredetermined and compared with those of PGE_1 alone. Meanwhile, the stability of PGE_1 aqueoussolutions in the presence of HP-β-CD was studied under different pH conditions. Results Thesolubility of PGE_1 increased linearly with increasing HP-β-CD concentration in various pH bufferedsolutions, showing typical A_L-type phase solubility diagrams. The stability and dissolution rateof the solid inclusion complex of PGE_1 were significantly increased, compared with those of purePGE_1 . The stability of PGE_1 in HP-β-CD solutions was also obviously improved under acidic andbasic conditions, but the stabilizing effect was absent under neutral conditions. Conclusions Thesolubility,dissolution rate and chemical stability of PGE_1 are markedly improved by complexationwith HP-β-CD: It is quite possible to prepare a stable PGE_1 inclusion complex-containing soliddosage forms, but almost impossible to obtain a stable aqueous preparation of PGE_1 formulated withHP-β-CD.展开更多
In this paper, the symmetry method has been carried over to the generalized variable coefficients Zakharov- Kuznetsov equation. The infinitesimal symmetries and the optimal system are deduced and from this optimal sys...In this paper, the symmetry method has been carried over to the generalized variable coefficients Zakharov- Kuznetsov equation. The infinitesimal symmetries and the optimal system are deduced and from this optimal system seven basic fields are determined, and for every vector field in the optimal system the admissible forms of the coefficients are found and this also leads us to transform the given equation into partial differential equations in two variables. After using some referenced transformations the mentioned partial differential equations eventually reduce to ordinary differential equations. The search for solutions to those equations has yielded many exact solutions in most cases.展开更多
For a maximal subgroup M of a group G, a g-completion for M is a subgroup C such that C is not contained in M while MG, the core of M in G, is contained in C and C/MG has no proper normal subgroup of G/MG. This concep...For a maximal subgroup M of a group G, a g-completion for M is a subgroup C such that C is not contained in M while MG, the core of M in G, is contained in C and C/MG has no proper normal subgroup of G/MG. This concept was introduced by ZHAO Yao-qing in 1998. In this paper we characterize the solvability of finite groups by means of g-completions and obtain some new results.展开更多
This paper applies the exp-function method, which was originally proposed to find new exact travelling wave solutions of nonlinear evolution equations, to the Riccati equation, and some exact solutions of this equatio...This paper applies the exp-function method, which was originally proposed to find new exact travelling wave solutions of nonlinear evolution equations, to the Riccati equation, and some exact solutions of this equation are obtained. Based on the Riccati equation and its exact solutions, we find new and more general variable separation solutions with two arbitrary functions of (1+1)-dimensional coupled integrable dispersionless system. As some special examples, some new solutions can degenerate into variable separation solutions reported in open literatures. By choosing suitably two independent variables p(x) and q(t) in our solutions, the annihilation phenomena of the fiat-basin soliton, arch-basin soliton, and fiat-top soliton are discussed.展开更多
It is known that the building sector consumes about 40% of earth's resources in their process of commissioning, erection and subsequent operation. As a consequence there is significant amount of CO2 emission to the a...It is known that the building sector consumes about 40% of earth's resources in their process of commissioning, erection and subsequent operation. As a consequence there is significant amount of CO2 emission to the atmosphere. Assessment of environmental performances of buildings has assumed immense significance in such backdrop and calls for assessing the "Carbon Footprint" of building systems for estimating their environmental compatibility. The present paper discusses a case specific environmental evaluation exercise by estimating the Carbon Footprint of a conventionally constructed tourist accommodation by tracking its resource consumption pattern during both the execution and operational phases in the hot and humid climatic zone of Indian sea-side. The result of the analysis is compared against the average carrying capacity of Earth to develop a method of measuring and quantifying the building's environmental performance with respect to Earth's reported threshold of tolerance and check the extent of failure or success, as the case may be. This process also leads to a tool named 'Sustainability Quotient'. The method of quantification is simple and can be adopted for environmental assessment of both new and old buildings.展开更多
The author studies the global convergence of a solution of p-Ginzburg-Landau equations when the parameter tends to zero. The convergence is in C^α sense, which is derived by establishing a uniform gradient estimate f...The author studies the global convergence of a solution of p-Ginzburg-Landau equations when the parameter tends to zero. The convergence is in C^α sense, which is derived by establishing a uniform gradient estimate for some solution of a regularized p-Ginzburg-Landau equations.展开更多
This article reviews climate change within the Sendai Framework for Disaster Risk Reduction 2015–2030(SFDRR), analyzing how climate change is mentioned in the framework’s text and the potential implications for deal...This article reviews climate change within the Sendai Framework for Disaster Risk Reduction 2015–2030(SFDRR), analyzing how climate change is mentioned in the framework’s text and the potential implications for dealing with climate change within the context of disaster risk reduction. Three main categories are examined. First,climate change affecting disaster risk and disasters,demonstrating too much emphasis on the single hazard driver and diminisher of climate change. Second, crosssectoral approaches, for which the SFDRR treads carefully,thereby unfortunately entrenching artificial differences and divisions, although appropriately offering plenty of support to other sectors from disaster risk reduction. Third,implementation, for which climate change plays a suitable role without being overbearing, but for which other hazard influencers should have been treated similarly. Overall, the mentions of climate change within the SFDRR put too much emphasis on the hazard part of disaster risk. Instead,within the context of the three global sustainable development processes that seek agreements in 2015, climate change could have been used to further support an allvulnerabilities and all-resiliences approach. That could be achieved by placing climate change adaptation as one subset within disaster risk reduction and climate change mitigation as one subset within sustainable development.展开更多
For Lie triple systems in the characteristic zero setting, we obtain by means of the Killing forms two criterions for semisimplicity and for solvability respectively, and then investigate the relationship among the Ki...For Lie triple systems in the characteristic zero setting, we obtain by means of the Killing forms two criterions for semisimplicity and for solvability respectively, and then investigate the relationship among the Killing forms of a real Lie triple system To, the complexification T of To, and the realification of T.展开更多
Here, PbCrO4 nanorods, a commonly used and low-cost yellow pigment, was synthesized via a simple pre-cipitation reaction and can serve as a highly efficient oxygen production and photodegradation photocatalyst. The ob...Here, PbCrO4 nanorods, a commonly used and low-cost yellow pigment, was synthesized via a simple pre-cipitation reaction and can serve as a highly efficient oxygen production and photodegradation photocatalyst. The obtained PbCrO4 nanorods exhibit excellent stability and pho-tocatalytic performance for O2 evolution from water. The production rate is approximately 314.0μmol h^-1 g^-1 under visible light, and the quantum efficiency is approximately 2.16% at 420±10 nm and 0.05% at 600±10 nm. In addition, the PhCrO4 shows good degradation performance for methylene blue, methyl blue, methyl orange and phenol under visible-light irradiation. These results indicate that it is potential to fabricate an effective, robust PbCrO4 photocatalyst by trans-forming heavy-metal pollutants Pb(II) and Cr(VI) into a highly efficient O2 evolution and photodegradation material. This strategy which uses pollutant to produce clean energy and degrade contaminants is completely green and environmentally benign, and thus could be a promising way for practical environmental applications. Keywords: 02 evolution, pollutant, PbCrO4 nanorods, visible-light-active, photocatalyst展开更多
基金Projects 20076051, G1999022101, and 98029016 supported by National Natural Science Foundation of China, the Special Found for Major State BasicResearch Project, and Research Found for the Doctoral Program of Higher Education
文摘Datong coal was extracted with CS2, n-hexane, benzene, methanol, acetone, tetrahydro-furan(THF) and THF/methanol(1:3,v/v) mixed solvent sequentially. The extracts were analyzed with GC/MS. It is presented that group seperation of soluble organic compounds in the coal can be achieved by fractionated extraction using different solvents. The results show that CS2 was effective for extracting arenes from the coal sample, n-Hexane extractable fraction from Datong coal mainly consists of n-alkanes. A great variety of oxygen-containing compounds are dominant in the components of methanol-soluble fraction. Acyclic isoprenoids, pentecyclic triterpanes and a series of cyclohexanes with long-chain alkyl-substitutes are detected in acetone-soluble fraction. Dicyclic aramatic hydrocarbons are identified in benzene-soluble fraction and 4-6 cyclic condensed aramatic hydrocarbons are identified in THF-soluble fraction. The molecular structures detection of 1,2-dichlorobenzene, 2,4-dibromophnol, 2,4,6-tribromophenol and 4-chlorobenzophenone firstly provide information for existence form of bromine and chlorine in coal.
文摘Aim To study the effect of complexation with hydroxylpropyl-β-cyclodextrin(HP-β-CD) on the solubility, dissolution rate and chemical stability of prostaglandin E_1 (PGE_1) ,thereby providing a basis for preparing a stable solid or aqueous preparation of PGE_1 formulatedwith HP-β-CD. Methods The effect of HP-β-CD on the solubility of PGE_1 was studied by phasesolubility method. The formation of inclusion complexes of PGE_1 with HP-β-CD in the aqueoussolution was confirmed by UV spectra, circular dichroism spectroscopy, and that in the solid stateby IR spectra and X-ray diffractome-try. An solid inclusion complex of PGE_1 with HP-β-CD wasprepared by lyophilization. The dissolution rate and stability of the inclusion complex weredetermined and compared with those of PGE_1 alone. Meanwhile, the stability of PGE_1 aqueoussolutions in the presence of HP-β-CD was studied under different pH conditions. Results Thesolubility of PGE_1 increased linearly with increasing HP-β-CD concentration in various pH bufferedsolutions, showing typical A_L-type phase solubility diagrams. The stability and dissolution rateof the solid inclusion complex of PGE_1 were significantly increased, compared with those of purePGE_1 . The stability of PGE_1 in HP-β-CD solutions was also obviously improved under acidic andbasic conditions, but the stabilizing effect was absent under neutral conditions. Conclusions Thesolubility,dissolution rate and chemical stability of PGE_1 are markedly improved by complexationwith HP-β-CD: It is quite possible to prepare a stable PGE_1 inclusion complex-containing soliddosage forms, but almost impossible to obtain a stable aqueous preparation of PGE_1 formulated withHP-β-CD.
文摘In this paper, the symmetry method has been carried over to the generalized variable coefficients Zakharov- Kuznetsov equation. The infinitesimal symmetries and the optimal system are deduced and from this optimal system seven basic fields are determined, and for every vector field in the optimal system the admissible forms of the coefficients are found and this also leads us to transform the given equation into partial differential equations in two variables. After using some referenced transformations the mentioned partial differential equations eventually reduce to ordinary differential equations. The search for solutions to those equations has yielded many exact solutions in most cases.
文摘For a maximal subgroup M of a group G, a g-completion for M is a subgroup C such that C is not contained in M while MG, the core of M in G, is contained in C and C/MG has no proper normal subgroup of G/MG. This concept was introduced by ZHAO Yao-qing in 1998. In this paper we characterize the solvability of finite groups by means of g-completions and obtain some new results.
基金Supported by the National Natural Science Foundation of China under Grant No.11005092the Program for Innovative Research Team of Young Teachers under Grant No.2009RC01Scientific Research,and Developed Fund under Grant No.2009FK42 of Zhejiang A&F University
文摘This paper applies the exp-function method, which was originally proposed to find new exact travelling wave solutions of nonlinear evolution equations, to the Riccati equation, and some exact solutions of this equation are obtained. Based on the Riccati equation and its exact solutions, we find new and more general variable separation solutions with two arbitrary functions of (1+1)-dimensional coupled integrable dispersionless system. As some special examples, some new solutions can degenerate into variable separation solutions reported in open literatures. By choosing suitably two independent variables p(x) and q(t) in our solutions, the annihilation phenomena of the fiat-basin soliton, arch-basin soliton, and fiat-top soliton are discussed.
文摘It is known that the building sector consumes about 40% of earth's resources in their process of commissioning, erection and subsequent operation. As a consequence there is significant amount of CO2 emission to the atmosphere. Assessment of environmental performances of buildings has assumed immense significance in such backdrop and calls for assessing the "Carbon Footprint" of building systems for estimating their environmental compatibility. The present paper discusses a case specific environmental evaluation exercise by estimating the Carbon Footprint of a conventionally constructed tourist accommodation by tracking its resource consumption pattern during both the execution and operational phases in the hot and humid climatic zone of Indian sea-side. The result of the analysis is compared against the average carrying capacity of Earth to develop a method of measuring and quantifying the building's environmental performance with respect to Earth's reported threshold of tolerance and check the extent of failure or success, as the case may be. This process also leads to a tool named 'Sustainability Quotient'. The method of quantification is simple and can be adopted for environmental assessment of both new and old buildings.
基金NNSF of China (19271086)Tianyuan Fund of Mathematics (A0324628) (China)
文摘The author studies the global convergence of a solution of p-Ginzburg-Landau equations when the parameter tends to zero. The convergence is in C^α sense, which is derived by establishing a uniform gradient estimate for some solution of a regularized p-Ginzburg-Landau equations.
文摘This article reviews climate change within the Sendai Framework for Disaster Risk Reduction 2015–2030(SFDRR), analyzing how climate change is mentioned in the framework’s text and the potential implications for dealing with climate change within the context of disaster risk reduction. Three main categories are examined. First,climate change affecting disaster risk and disasters,demonstrating too much emphasis on the single hazard driver and diminisher of climate change. Second, crosssectoral approaches, for which the SFDRR treads carefully,thereby unfortunately entrenching artificial differences and divisions, although appropriately offering plenty of support to other sectors from disaster risk reduction. Third,implementation, for which climate change plays a suitable role without being overbearing, but for which other hazard influencers should have been treated similarly. Overall, the mentions of climate change within the SFDRR put too much emphasis on the hazard part of disaster risk. Instead,within the context of the three global sustainable development processes that seek agreements in 2015, climate change could have been used to further support an allvulnerabilities and all-resiliences approach. That could be achieved by placing climate change adaptation as one subset within disaster risk reduction and climate change mitigation as one subset within sustainable development.
基金the Natural Science Foundation of Hebei Province (Nos.A200500008A2007000138)
文摘For Lie triple systems in the characteristic zero setting, we obtain by means of the Killing forms two criterions for semisimplicity and for solvability respectively, and then investigate the relationship among the Killing forms of a real Lie triple system To, the complexification T of To, and the realification of T.
基金jointly supported by the National Natural Science Foundation of China(21401190)the Science and Technology Project of Research Foundation of China Postdoctoral Science(2017M612710 and 2016M592519)+2 种基金Shenzhen Peacock Plan(827-000059,827-000113 and KQTD2016053112042971)the Science and Technology Planning Project of Guangdong Province(2016B050501005)the Educational Commission of Guangdong Province(2016KCXTD006 and 2016KSTCX126)
文摘Here, PbCrO4 nanorods, a commonly used and low-cost yellow pigment, was synthesized via a simple pre-cipitation reaction and can serve as a highly efficient oxygen production and photodegradation photocatalyst. The obtained PbCrO4 nanorods exhibit excellent stability and pho-tocatalytic performance for O2 evolution from water. The production rate is approximately 314.0μmol h^-1 g^-1 under visible light, and the quantum efficiency is approximately 2.16% at 420±10 nm and 0.05% at 600±10 nm. In addition, the PhCrO4 shows good degradation performance for methylene blue, methyl blue, methyl orange and phenol under visible-light irradiation. These results indicate that it is potential to fabricate an effective, robust PbCrO4 photocatalyst by trans-forming heavy-metal pollutants Pb(II) and Cr(VI) into a highly efficient O2 evolution and photodegradation material. This strategy which uses pollutant to produce clean energy and degrade contaminants is completely green and environmentally benign, and thus could be a promising way for practical environmental applications. Keywords: 02 evolution, pollutant, PbCrO4 nanorods, visible-light-active, photocatalyst