In the long-term production and life practice, Hakka ethnic group has created its own unique culture, and the sports culture is an important part of Hakka culture. Hakka sports culture has attained constant developmen...In the long-term production and life practice, Hakka ethnic group has created its own unique culture, and the sports culture is an important part of Hakka culture. Hakka sports culture has attained constant development and integration along with the migration of the Hakka ethnic group. In the meantime, it has been fully inherited promoted.展开更多
Value generation is defined as meeting client requirements while minimizing waste. Researchers concur on the issues related to sequential design in handling client requirements, and suggest the use of an integrated de...Value generation is defined as meeting client requirements while minimizing waste. Researchers concur on the issues related to sequential design in handling client requirements, and suggest the use of an integrated design approach as an alternative. Little has been said, however, about the impact of adopting integrated design＇s work organization to traditional design practice, processes and tools, nor about the importance of breaking down socio-cognitive barriers related to mental model fragmentation between design professionals, clients and users. This may result in cognitive inertia, a major source of waste. The objective of this research is to develop and test the introduction of boundary objects, such as new technologies, to the context of integrated teams and organizations to break the cognitive inertia that hinders value generation. The research is conclusive about the effectiveness of using boundary objects to transform practices in construction. This research also contributes to a better understanding of the new purposes of construction projects by framing its context and process dimensions within a theoretical framework, as well as to the evolution of practices in construction - and of practices that could be applicable to other fields.展开更多
The high-temperature(HT) and low-temperature(LT) hydrothermal stabilities of molecular-sieve-based catalysts are important for the selective catalytic reduction of NOx with ammonia(NH3-SCR). In this paper, we report a...The high-temperature(HT) and low-temperature(LT) hydrothermal stabilities of molecular-sieve-based catalysts are important for the selective catalytic reduction of NOx with ammonia(NH3-SCR). In this paper, we report a catalyst, Cu2+ loading SAPO-17, synthesized using cyclohexylamine(CHA), which is commercially available and inexpensive and is utilized in NH3-SCR reduction for the first time. After systematic investigations on the optimization of Si and Cu2+ contents, it was concluded that Cu-SAPO-17-8.0%-0.22 displays favorable catalytic performance, even after being heated at 353 K for 24 h and at 973 K for 16 h. Moreover, the locations of CHAs, host–guest interaction and the Bronsted acid sites were explored by Rietveld refinement against powder X-ray diffraction data of as-made SAPO-17-8.0%. The refinement results showed that two CHAs exist within one eri cage and that the protonated CHA forms a hydrogen bond with O4, which indicates that the proton bonding with O4 will form the Bronsted acid site after the calcination.展开更多
Through the mechanochemical method,sulfamic acid(SA)is successfully introduced into UiO-66-NH_(2)to form SA@UiO-66-NH_(2).In SA@UiO-66-NH_(2),the acidic cationic sulfiliminium(—S=NH_(2)^(+))moiety formed by the bridg...Through the mechanochemical method,sulfamic acid(SA)is successfully introduced into UiO-66-NH_(2)to form SA@UiO-66-NH_(2).In SA@UiO-66-NH_(2),the acidic cationic sulfiliminium(—S=NH_(2)^(+))moiety formed by the bridging bidentate binding mode between SA and the zirconium metal center can release protons,and SA actively participates in the construction of hydrogen-bonded network,thereby accelerating the proton conduction.At 95%RH(relative humidity)and 358 K,the proton conductivity of SA@UiO-66-NH_(2)can reach 1.42×10^(-2)S·cm^(-1),which is four orders of magnitude higher than that of the parent framework UiO-66-NH_(2).Meanwhile,this high proton conductivity can be maintained for at least 90 h.展开更多
Benzotriazole,N,N'-dimethylpiperazine and N-methylpiperazine were applied to crystallize with 5-sulfosalicylic acid(5-H2SSA),affording three new binary molecular cocrystals [(C6H6N3+).(C7H5O6S-)].H2O(1),[(C6H16N22...Benzotriazole,N,N'-dimethylpiperazine and N-methylpiperazine were applied to crystallize with 5-sulfosalicylic acid(5-H2SSA),affording three new binary molecular cocrystals [(C6H6N3+).(C7H5O6S-)].H2O(1),[(C6H16N22+)1/2.(C7H5O6S-)].H2O(2) and [(C5H14N22+).(C7H5O6S-)2].3H2O(3) under general conditions.Proton-transferring occurs from acid to nitrogen of N-donor compounds in all compounds 1,2 and 3.Analysis of the hydrogen-bonding synthons and their effects on crystal packing were also presented in the context of crystal engineering and host-guest chemistry.In compound 1,1-D infinite chains are extended to a 2-D layered architecture via strong O-H...O hydrogen bonds and then to a 3-D network by N-H...O interactions.Compound 2 and 3 both have the 1-D chain which is formed by O-H...O bonds and weak C-H...O hydrogen bonds.A common intramolecular S(6) [synthon I] ring is formed by the hydroxyl with the carboxyl group in all three compounds.展开更多
The thermal conductivity of methane hydrate is an important physical parameter affecting the processes of methane hydrate exploration,mining,gas hydrate storage and transportation as well as other applications.Equilib...The thermal conductivity of methane hydrate is an important physical parameter affecting the processes of methane hydrate exploration,mining,gas hydrate storage and transportation as well as other applications.Equilibrium molecular dynamics simulations and the Green-Kubo method have been employed for systems from fully occupied to vacant occupied sI methane hydrate in order to estimate their thermal conductivity.The estimations were carried out at temperatures from 203.15 to 263.15 K and at pressures from 3 to 100 MPa.Potential models selected for water were TIP4P,TIP4P-Ew,TIP4P/2005,TIP4P-FQ and TIP4P/Ice.The effects of varying the ratio of the host and guest molecules and the external thermobaric conditions on the thermal conductivity of methane hydrate were studied.The results indicated that the thermal conductivity of methane hydrate is essentially determined by the cage framework which constitutes the hydrate lattice and the cage framework has only slightly higher thermal conductivity in the presence of the guest molecules.Inclusion of more guest molecules in the cage improves the thermal conductivity of methane hydrate.It is also revealed that the thermal conductivity of the sI hydrate shows a similar variation with temperature.Pressure also has an effect on the thermal conductivity,particularly at higher pressures.As the pressure increases,slightly higher thermal conductivities result.Changes in density have little impact on the thermal conductivity of methane hydrate.展开更多
文摘In the long-term production and life practice, Hakka ethnic group has created its own unique culture, and the sports culture is an important part of Hakka culture. Hakka sports culture has attained constant development and integration along with the migration of the Hakka ethnic group. In the meantime, it has been fully inherited promoted.
文摘Value generation is defined as meeting client requirements while minimizing waste. Researchers concur on the issues related to sequential design in handling client requirements, and suggest the use of an integrated design approach as an alternative. Little has been said, however, about the impact of adopting integrated design＇s work organization to traditional design practice, processes and tools, nor about the importance of breaking down socio-cognitive barriers related to mental model fragmentation between design professionals, clients and users. This may result in cognitive inertia, a major source of waste. The objective of this research is to develop and test the introduction of boundary objects, such as new technologies, to the context of integrated teams and organizations to break the cognitive inertia that hinders value generation. The research is conclusive about the effectiveness of using boundary objects to transform practices in construction. This research also contributes to a better understanding of the new purposes of construction projects by framing its context and process dimensions within a theoretical framework, as well as to the evolution of practices in construction - and of practices that could be applicable to other fields.
文摘The high-temperature(HT) and low-temperature(LT) hydrothermal stabilities of molecular-sieve-based catalysts are important for the selective catalytic reduction of NOx with ammonia(NH3-SCR). In this paper, we report a catalyst, Cu2+ loading SAPO-17, synthesized using cyclohexylamine(CHA), which is commercially available and inexpensive and is utilized in NH3-SCR reduction for the first time. After systematic investigations on the optimization of Si and Cu2+ contents, it was concluded that Cu-SAPO-17-8.0%-0.22 displays favorable catalytic performance, even after being heated at 353 K for 24 h and at 973 K for 16 h. Moreover, the locations of CHAs, host–guest interaction and the Bronsted acid sites were explored by Rietveld refinement against powder X-ray diffraction data of as-made SAPO-17-8.0%. The refinement results showed that two CHAs exist within one eri cage and that the protonated CHA forms a hydrogen bond with O4, which indicates that the proton bonding with O4 will form the Bronsted acid site after the calcination.
基金supported by the National Natural Science Foundation of China(22071019 and 21872021)the Basic Scientific Research Project of Liaoning Provincial Department of Education(LJKMZ20220968)
文摘Through the mechanochemical method,sulfamic acid(SA)is successfully introduced into UiO-66-NH_(2)to form SA@UiO-66-NH_(2).In SA@UiO-66-NH_(2),the acidic cationic sulfiliminium(—S=NH_(2)^(+))moiety formed by the bridging bidentate binding mode between SA and the zirconium metal center can release protons,and SA actively participates in the construction of hydrogen-bonded network,thereby accelerating the proton conduction.At 95%RH(relative humidity)and 358 K,the proton conductivity of SA@UiO-66-NH_(2)can reach 1.42×10^(-2)S·cm^(-1),which is four orders of magnitude higher than that of the parent framework UiO-66-NH_(2).Meanwhile,this high proton conductivity can be maintained for at least 90 h.
基金supported by the National Natural Science Foundation of China(20701023 & 20971076)the Natural Science Foundation of Shandong Province,China(BS2010NJ004 & 2009ZRB019KH)
文摘Benzotriazole,N,N'-dimethylpiperazine and N-methylpiperazine were applied to crystallize with 5-sulfosalicylic acid(5-H2SSA),affording three new binary molecular cocrystals [(C6H6N3+).(C7H5O6S-)].H2O(1),[(C6H16N22+)1/2.(C7H5O6S-)].H2O(2) and [(C5H14N22+).(C7H5O6S-)2].3H2O(3) under general conditions.Proton-transferring occurs from acid to nitrogen of N-donor compounds in all compounds 1,2 and 3.Analysis of the hydrogen-bonding synthons and their effects on crystal packing were also presented in the context of crystal engineering and host-guest chemistry.In compound 1,1-D infinite chains are extended to a 2-D layered architecture via strong O-H...O hydrogen bonds and then to a 3-D network by N-H...O interactions.Compound 2 and 3 both have the 1-D chain which is formed by O-H...O bonds and weak C-H...O hydrogen bonds.A common intramolecular S(6) [synthon I] ring is formed by the hydroxyl with the carboxyl group in all three compounds.
基金supported by the National Natural Science Foundation of China(51106163)the National Basic Research Program of China (2009CB219504)the Joint Funds of NSFC with the Government of Guangdong Province(U0933004)
文摘The thermal conductivity of methane hydrate is an important physical parameter affecting the processes of methane hydrate exploration,mining,gas hydrate storage and transportation as well as other applications.Equilibrium molecular dynamics simulations and the Green-Kubo method have been employed for systems from fully occupied to vacant occupied sI methane hydrate in order to estimate their thermal conductivity.The estimations were carried out at temperatures from 203.15 to 263.15 K and at pressures from 3 to 100 MPa.Potential models selected for water were TIP4P,TIP4P-Ew,TIP4P/2005,TIP4P-FQ and TIP4P/Ice.The effects of varying the ratio of the host and guest molecules and the external thermobaric conditions on the thermal conductivity of methane hydrate were studied.The results indicated that the thermal conductivity of methane hydrate is essentially determined by the cage framework which constitutes the hydrate lattice and the cage framework has only slightly higher thermal conductivity in the presence of the guest molecules.Inclusion of more guest molecules in the cage improves the thermal conductivity of methane hydrate.It is also revealed that the thermal conductivity of the sI hydrate shows a similar variation with temperature.Pressure also has an effect on the thermal conductivity,particularly at higher pressures.As the pressure increases,slightly higher thermal conductivities result.Changes in density have little impact on the thermal conductivity of methane hydrate.
