In order to save space for storing precision equipments,lower the center of mass of Lander and reduce lunar rover's dimension constraint limited by mechanism of Lander,the locking-releasing mechanism of side-loade...In order to save space for storing precision equipments,lower the center of mass of Lander and reduce lunar rover's dimension constraint limited by mechanism of Lander,the locking-releasing mechanism of side-loaded lunar rover loaded outside Lander is presented,which is a kind of metamorphic mechanism.To ensure the working of this mechanism as the metamorphic process designed,configuration analysis of the locking-releasing mechanism is carried out,and topological structures are described by Huston lower numbered arrays.A kinematic mathematical model of the mechanism is established through homogeneous transformation matrix.The kinematic simulation validates the feasibility of the locking-releasing mechanism when the configurations are shifted from one to the other.展开更多
Green transformation is an unavoidable choice for resource-based cities(RBCs)that face resource depletion and environmental pollution.Existing research has focused primarily on specific RBCs,making it challenging to a...Green transformation is an unavoidable choice for resource-based cities(RBCs)that face resource depletion and environmental pollution.Existing research has focused primarily on specific RBCs,making it challenging to apply green transformation strategies universally across cities.The fuzzy set qualitative comparative analysis(fsQCA)is a combination of qualitative and quantitative analyses that can handle multiple concurrent causality problems and determine how different conditions combine into configurations and generate an outcome.Thus,to address this gap,in this study,we established a research framework for green transformation and utilized the fsQCA to examine the configurations of 113 RBCs in China.By incorporating the element of time,this study explored the dynamic evolution of solutions in 2013,2016,and 2019.The main findings indicate that individual elements do not constitute the necessary conditions for improving the green transformation efficiency(GTE),and the systematic combination of multiple conditions is an effective path for realizing the improvement of the GTE in RBCs.Green transformation paths of RBCs exhibit the same destination through different paths.Additionally,the combination of system environment elements and system structure elements is both complementary and alternative.Differences in RBCs have led to various factor combinations and development paths,but there are some similarities in the key elements of the factor combinations at different stages.Economic environment,government support,and technological innovation are key factors that universally enhance the GTE in RBCs.These insights can assist city managers in formulating policies to drive green transformation and contribute to a better theoretical understanding of green transformation paths in RBCs.展开更多
The rapid growth of the education industry and private education groups has brought the high-quality development of listed private education companies into focus for both the educational sector and the capital market....The rapid growth of the education industry and private education groups has brought the high-quality development of listed private education companies into focus for both the educational sector and the capital market.This study employs the fuzzy-set qualitative comparative analysis(fsQCA)method to explore pathways to high-quality development for these companies.Necessity analysis confirms that no single factor guarantees a company’s success,highlighting the importance of multi-factor interactions.Three main paths to high-quality development are identified:human resource optimization,precise market positioning,and comprehensive advantage.Conversely,four development paths for non-high-level companies are identified:dual insufficiency in resources and market,high turnover and over-investment,scale expansion with resource mismatch,and inadequate human resource development.The findings indicate that optimal allocation of educational resources,precise market positioning,rational resource allocation,and staff training are crucial for achieving high-quality development.Robustness tests,which raise the consistency threshold,verify the reliability and stability of the results.These findings provide a reference for policymakers,investors,and managers in the education industry.展开更多
Salicylaldehyde-2-(4-isobutylphenyl)-propionyl hydrazone Schiff base(H2L) has been synthesized and characterized by elemental analysis,IR,1H-NMR spectrum and single-crystal X-ray diffraction.Single-crystal X-ray d...Salicylaldehyde-2-(4-isobutylphenyl)-propionyl hydrazone Schiff base(H2L) has been synthesized and characterized by elemental analysis,IR,1H-NMR spectrum and single-crystal X-ray diffraction.Single-crystal X-ray diffraction analysis showed that H2L is of monoclinic system,space group P21/c with a = 5.6844(5),b = 33.568(3),c = 9.6959(9) ,β = 91.758(2)°,V = 1849.2(3) 3,Mr = 324.41,F(000) = 696,Z = 4,Dc = 1.165 g/cm3,μ = 0.076 mm-1,R = 0.0448 and wR = 0.1221.In the solid form,the strong intramolecular hydrogen bonds make H2L fully extended into an E isomer about the N=N bond,and each molecule interacts with two neighbors to form 1D hydrogen-bonded chains.The Schiff base presents two different sets of signals in the 1H-NMR and 13C-NMR spectra in either chloroform or dimethylsulfoxide solution,showing the presence of both E and Z isomers.展开更多
Today's manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for com...Today's manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for companies to achieve their objectives. Efforts to mass customisation should be made on two aspects: (1) To modularize products and make them as less differences as possible; (2) To design manufacturing resources and make them provide as many processes variations as possible. This paper reports our recent work on aspect (2), i.e. how to design a reconfignrable manufacturing system (RMS) so that it can be competent to accomplish various processes optimally; Reconfignrable robot system (RRS) is taken as an example. RMS design involves architecture design and configuration design, and configuration design is further divided in design analysis and design synthesis. Axiomatic design theory (ADT) is applied to architecture design, the features and issues of RRS configuration design are discussed, automatic modelling method is developed for design analysis, and concurrent design methodology is presented for design synthesis.展开更多
The crystal structure of the title compound cis 2 (P, P Diethoxy)phosphono( m nitro)benzyloxy 4 Phenyl 5,5 Dimethyl 1,3,2 Dioxaphosphorinane 2 Sulfide, C 22 H 29 NO 8P 2S, was determin...The crystal structure of the title compound cis 2 (P, P Diethoxy)phosphono( m nitro)benzyloxy 4 Phenyl 5,5 Dimethyl 1,3,2 Dioxaphosphorinane 2 Sulfide, C 22 H 29 NO 8P 2S, was determined by single crystal X ray diffraction. It crystallizes in the monoclinic system, space group P2 1/c, with M r=529.49, a=9.888(2), b=20.831(4), c=12.797(3) , β=94.42(3)°, V=2628(1) 3, Z=4, D x =1.338 g/cm 3 , λ=0.71073 , μ =0.2796 mm 1 and F(000) =556. The structure was solved by direct methods. The final R factor is 0.052 and R w is 0.057 for 1793 unique observed reflections I≥3σ(I) . A cis configuration and a preferred chair conformation for the molecule have been established by X ray diffraction analysis. The results presented also give a good explanation to the correlation between the configurational assignments and the regularity in the chemical shifts of C 4-H and 31 P NMR.展开更多
This paper concerns the theme of the universal accessibility to urban spaces, proposing the contribution of configurational approach to their inclusive design. Born in the first Nineties on the roots of the efforts an...This paper concerns the theme of the universal accessibility to urban spaces, proposing the contribution of configurational approach to their inclusive design. Born in the first Nineties on the roots of the efforts and the studies for reducing material and architectural barriers for disabled people, such discipline extends its sphere and purposes so as to mitigate the effects of spatial exclusion of a wider and wider variety of human categories, up to virtually include any potential urban user. Several questions persuade that a merely functional approach, essentially based on the position of the located activities, cannot be said satisfying: only a configurational approach can account for the effects of the grid configuration on the actual accessibility of its spaces. Our research focuses on Italian urban settlements, which appear as ideal case studies, due to the typical consistency of their urban spaces, which, especially in the inner historical cores, are densely build, geometrically irregular and hence generally far from actually providing a universal material accessibility. Here the impedance of space is much more than a theoretical hypothesis and concrete interventions are generally requested to eliminate or reduce its barriers and to make space actually and safely usable. Rather than at indicating the technical solution of single urban problems, which of course are strongly different each other, the research aims at defining a method suitable for any local context. Such method, integrating into a reliable tool the configurational vision with the functional and interactional approach, will provide a hierarchy of urban spaces with reference to the necessity of their universal accessibility.展开更多
It was ascertained that when a RE element was added in bath,the sample was improved on the anti-corrosion power of the coating because of the increasing of covering rate of formless crystal Zn2Fe(PO4) 2·4H2O(mark...It was ascertained that when a RE element was added in bath,the sample was improved on the anti-corrosion power of the coating because of the increasing of covering rate of formless crystal Zn2Fe(PO4) 2·4H2O(marked P) crystals and the ratio of P/(P+H) (H was the mark of Zn3(PO4) 2 crystal) in the coating,combination of which with components parsing by EDS indicated that the sequence of contribution elements P and Zn to erosion resistance of coatings was P】Zn. And the correlative mechanism was discussed,which made it clear that owing to the particularity of the outer-shell electron structure and larger ionic radius,RE was so easy to be polarized and metamorphosed itself that it adsorbed lightly on the basic body to pose gels. They efficiently reduced the activation energy which was required for formation of a new solid phase of phosphates and made it also possible to engender effectively active nucleation regions of cathode and anode under low temperature phosphating condition,which was propitious to formation,densification and uniformization of the phosphate crystal nucleus and growth of the crystallite and coating buildup. Thus it could be seen that REN played the role of surface regulator and accelerant,which speeded up the phosphating,as well as bids amount of porosity of the coating fall to improve the corrosion resistance of the coating.展开更多
Molecular Recognition of α,α,α,β-ZnT(o-BocThr)APP (1) toward a series of imidazole derivatives and amino acid esters was investigated. Association constants were determined in chloroform by means of UV-Vis tit...Molecular Recognition of α,α,α,β-ZnT(o-BocThr)APP (1) toward a series of imidazole derivatives and amino acid esters was investigated. Association constants were determined in chloroform by means of UV-Vis titration method. The association constants of 1 with imidazole derivatives are larger than those of 1 with amino acid esters. 1H NMR spectra were investigated to describe the binding mode of the recognition system, showing that all the protons of the guests were shifted to upfield. The circular dichroism spectra of 1-L-/D-ValOMe showed a split cotton effect in Soret region, while those of 1-L-/D-PheOMe showed no split cotton effect. Molecular modeling was performed to understand chiral recognition on a molecular level. Quantum chemical calculation was carried out based on the stable conformations of these recognition systems, which gave a reasonable explanation for the behavior of molecular recognition. The results indicated that the conformation of 1-D-ValOMe was more stable than that of 1-L-ValOMe.展开更多
基金Sponsored by the National High Technology Research and Development Program of China(Grant No.2006AA04Z231)Natural Science Foundation of Heilongjiang Province of China(Grant No.ZJG0709)Development Program of the Excellent Youth Scholars of Harbin Institute of Technology(Grant No.CACZ98504837)
文摘In order to save space for storing precision equipments,lower the center of mass of Lander and reduce lunar rover's dimension constraint limited by mechanism of Lander,the locking-releasing mechanism of side-loaded lunar rover loaded outside Lander is presented,which is a kind of metamorphic mechanism.To ensure the working of this mechanism as the metamorphic process designed,configuration analysis of the locking-releasing mechanism is carried out,and topological structures are described by Huston lower numbered arrays.A kinematic mathematical model of the mechanism is established through homogeneous transformation matrix.The kinematic simulation validates the feasibility of the locking-releasing mechanism when the configurations are shifted from one to the other.
基金supported by the Chongqing Social Science Planning Fund,China(2023BS034)the Science and Technology Project of Chongqing Jiaotong University,China(F1230069).
文摘Green transformation is an unavoidable choice for resource-based cities(RBCs)that face resource depletion and environmental pollution.Existing research has focused primarily on specific RBCs,making it challenging to apply green transformation strategies universally across cities.The fuzzy set qualitative comparative analysis(fsQCA)is a combination of qualitative and quantitative analyses that can handle multiple concurrent causality problems and determine how different conditions combine into configurations and generate an outcome.Thus,to address this gap,in this study,we established a research framework for green transformation and utilized the fsQCA to examine the configurations of 113 RBCs in China.By incorporating the element of time,this study explored the dynamic evolution of solutions in 2013,2016,and 2019.The main findings indicate that individual elements do not constitute the necessary conditions for improving the green transformation efficiency(GTE),and the systematic combination of multiple conditions is an effective path for realizing the improvement of the GTE in RBCs.Green transformation paths of RBCs exhibit the same destination through different paths.Additionally,the combination of system environment elements and system structure elements is both complementary and alternative.Differences in RBCs have led to various factor combinations and development paths,but there are some similarities in the key elements of the factor combinations at different stages.Economic environment,government support,and technological innovation are key factors that universally enhance the GTE in RBCs.These insights can assist city managers in formulating policies to drive green transformation and contribute to a better theoretical understanding of green transformation paths in RBCs.
基金2024 Guangdong Provincial Private Colleges and Universities Research Project“Research on the Path of High-Quality Development of Listed Companies in Private Education Groups:An Analysis of Complex Factor Groups”(GMG2024023)。
文摘The rapid growth of the education industry and private education groups has brought the high-quality development of listed private education companies into focus for both the educational sector and the capital market.This study employs the fuzzy-set qualitative comparative analysis(fsQCA)method to explore pathways to high-quality development for these companies.Necessity analysis confirms that no single factor guarantees a company’s success,highlighting the importance of multi-factor interactions.Three main paths to high-quality development are identified:human resource optimization,precise market positioning,and comprehensive advantage.Conversely,four development paths for non-high-level companies are identified:dual insufficiency in resources and market,high turnover and over-investment,scale expansion with resource mismatch,and inadequate human resource development.The findings indicate that optimal allocation of educational resources,precise market positioning,rational resource allocation,and staff training are crucial for achieving high-quality development.Robustness tests,which raise the consistency threshold,verify the reliability and stability of the results.These findings provide a reference for policymakers,investors,and managers in the education industry.
基金supported by the Natural Science Foundation of Hubei Province (No.2008CDA067)South-central University for Nationalities Foundation (No.YZZ08014)
文摘Salicylaldehyde-2-(4-isobutylphenyl)-propionyl hydrazone Schiff base(H2L) has been synthesized and characterized by elemental analysis,IR,1H-NMR spectrum and single-crystal X-ray diffraction.Single-crystal X-ray diffraction analysis showed that H2L is of monoclinic system,space group P21/c with a = 5.6844(5),b = 33.568(3),c = 9.6959(9) ,β = 91.758(2)°,V = 1849.2(3) 3,Mr = 324.41,F(000) = 696,Z = 4,Dc = 1.165 g/cm3,μ = 0.076 mm-1,R = 0.0448 and wR = 0.1221.In the solid form,the strong intramolecular hydrogen bonds make H2L fully extended into an E isomer about the N=N bond,and each molecule interacts with two neighbors to form 1D hydrogen-bonded chains.The Schiff base presents two different sets of signals in the 1H-NMR and 13C-NMR spectra in either chloroform or dimethylsulfoxide solution,showing the presence of both E and Z isomers.
文摘Today's manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for companies to achieve their objectives. Efforts to mass customisation should be made on two aspects: (1) To modularize products and make them as less differences as possible; (2) To design manufacturing resources and make them provide as many processes variations as possible. This paper reports our recent work on aspect (2), i.e. how to design a reconfignrable manufacturing system (RMS) so that it can be competent to accomplish various processes optimally; Reconfignrable robot system (RRS) is taken as an example. RMS design involves architecture design and configuration design, and configuration design is further divided in design analysis and design synthesis. Axiomatic design theory (ADT) is applied to architecture design, the features and issues of RRS configuration design are discussed, automatic modelling method is developed for design analysis, and concurrent design methodology is presented for design synthesis.
文摘The crystal structure of the title compound cis 2 (P, P Diethoxy)phosphono( m nitro)benzyloxy 4 Phenyl 5,5 Dimethyl 1,3,2 Dioxaphosphorinane 2 Sulfide, C 22 H 29 NO 8P 2S, was determined by single crystal X ray diffraction. It crystallizes in the monoclinic system, space group P2 1/c, with M r=529.49, a=9.888(2), b=20.831(4), c=12.797(3) , β=94.42(3)°, V=2628(1) 3, Z=4, D x =1.338 g/cm 3 , λ=0.71073 , μ =0.2796 mm 1 and F(000) =556. The structure was solved by direct methods. The final R factor is 0.052 and R w is 0.057 for 1793 unique observed reflections I≥3σ(I) . A cis configuration and a preferred chair conformation for the molecule have been established by X ray diffraction analysis. The results presented also give a good explanation to the correlation between the configurational assignments and the regularity in the chemical shifts of C 4-H and 31 P NMR.
文摘This paper concerns the theme of the universal accessibility to urban spaces, proposing the contribution of configurational approach to their inclusive design. Born in the first Nineties on the roots of the efforts and the studies for reducing material and architectural barriers for disabled people, such discipline extends its sphere and purposes so as to mitigate the effects of spatial exclusion of a wider and wider variety of human categories, up to virtually include any potential urban user. Several questions persuade that a merely functional approach, essentially based on the position of the located activities, cannot be said satisfying: only a configurational approach can account for the effects of the grid configuration on the actual accessibility of its spaces. Our research focuses on Italian urban settlements, which appear as ideal case studies, due to the typical consistency of their urban spaces, which, especially in the inner historical cores, are densely build, geometrically irregular and hence generally far from actually providing a universal material accessibility. Here the impedance of space is much more than a theoretical hypothesis and concrete interventions are generally requested to eliminate or reduce its barriers and to make space actually and safely usable. Rather than at indicating the technical solution of single urban problems, which of course are strongly different each other, the research aims at defining a method suitable for any local context. Such method, integrating into a reliable tool the configurational vision with the functional and interactional approach, will provide a hierarchy of urban spaces with reference to the necessity of their universal accessibility.
文摘It was ascertained that when a RE element was added in bath,the sample was improved on the anti-corrosion power of the coating because of the increasing of covering rate of formless crystal Zn2Fe(PO4) 2·4H2O(marked P) crystals and the ratio of P/(P+H) (H was the mark of Zn3(PO4) 2 crystal) in the coating,combination of which with components parsing by EDS indicated that the sequence of contribution elements P and Zn to erosion resistance of coatings was P】Zn. And the correlative mechanism was discussed,which made it clear that owing to the particularity of the outer-shell electron structure and larger ionic radius,RE was so easy to be polarized and metamorphosed itself that it adsorbed lightly on the basic body to pose gels. They efficiently reduced the activation energy which was required for formation of a new solid phase of phosphates and made it also possible to engender effectively active nucleation regions of cathode and anode under low temperature phosphating condition,which was propitious to formation,densification and uniformization of the phosphate crystal nucleus and growth of the crystallite and coating buildup. Thus it could be seen that REN played the role of surface regulator and accelerant,which speeded up the phosphating,as well as bids amount of porosity of the coating fall to improve the corrosion resistance of the coating.
基金Project supported by the National Natural Science Foundation of China (Nos. 20271030 and 20303009) and the Tianjin Natural Science Foundation (No. 023604011).
文摘Molecular Recognition of α,α,α,β-ZnT(o-BocThr)APP (1) toward a series of imidazole derivatives and amino acid esters was investigated. Association constants were determined in chloroform by means of UV-Vis titration method. The association constants of 1 with imidazole derivatives are larger than those of 1 with amino acid esters. 1H NMR spectra were investigated to describe the binding mode of the recognition system, showing that all the protons of the guests were shifted to upfield. The circular dichroism spectra of 1-L-/D-ValOMe showed a split cotton effect in Soret region, while those of 1-L-/D-PheOMe showed no split cotton effect. Molecular modeling was performed to understand chiral recognition on a molecular level. Quantum chemical calculation was carried out based on the stable conformations of these recognition systems, which gave a reasonable explanation for the behavior of molecular recognition. The results indicated that the conformation of 1-D-ValOMe was more stable than that of 1-L-ValOMe.