This paper presents some important properties emanating from the pair of conjugate trees. The properties are obtained by resorting to the fundamental loops and cutsets in the circuit topology. The existence of such a ...This paper presents some important properties emanating from the pair of conjugate trees. The properties are obtained by resorting to the fundamental loops and cutsets in the circuit topology. The existence of such a pair is one of the conditions for a nonlinear resistive circuit to have one and only one DC solution.展开更多
In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selec...In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selectively modified the doping site structure,ultimately constructing a B,N co-doped frustrated Lewis acid-base pair catalyst.This catalyst exhibited remarkable catalytic activity,selectivity,and stability in the dehydrochlorination reaction of 1,1,2-trichloroethane(TCE).Detailed characterization and theoretical calculations revealed that the primary active center of this catalyst was the BN_(3)configuration.Compared to conventional graphitic N structures,the BN_(3)structure had a higher p-band center,ensuring superior adsorption and activation capabilities for TCE during the reaction.Within the BN_(3)site,three negatively charged nitrogen atoms acted as Lewis bases,while positively charged boron atoms acted as Lewis acids.This synergistic interaction facilitated the specific dissociation of chlorine and hydrogen atoms from TCE,significantly enhancing the 1,1-dichloroethene selectivity.Through this research,we not only explored the active site structure and catalytic mechanism of B,N co-doped catalysts in depth but also provided an efficient,selective,and stable catalyst for the dehydrochlorination of TCE,contributing significantly to the development of non-metallic catalysts.展开更多
Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herei...Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.展开更多
Let∇be a linear connection on a 2n-dimensional almost anti-Hermitian manifold M equipped with an almost complex structure J,a pseudo-Riemannian metric g and the twin metric G=g◦J.In this paper,we first introduce three...Let∇be a linear connection on a 2n-dimensional almost anti-Hermitian manifold M equipped with an almost complex structure J,a pseudo-Riemannian metric g and the twin metric G=g◦J.In this paper,we first introduce three types of conjugate connections of linear connections relative to g,G and J.We obtain a simple relation among curvature tensors of these conjugate connections.To clarify the relations of these conjugate connections,we prove a result stating that conjugations along with an identity operation together act as a Klein group,which is analogue to the known result for the Hermitian case in[2].Secondly,we give some results exhibiting occurrences of Codazzi pairs which generalize parallelism relative to∇.Under the assumption that(∇,J)being a Codazzi pair,we derive a necessary and sufficient condition the almost anti-Hermitian manifold(M,J,g,G)is an anti-K¨ahler relative to a torsion-free linear connection∇.Finally,we investigate statistical structures on M under∇(∇is a J−parallel torsion-free connection).展开更多
The construction of heterogeneous frustrated Lewis pairs(FLPs)catalysts is crucial for realizing highly efficient and recyclable pyridines catalytic hydrogenation.In this work,we prepared a recyclable heterogenous FLP...The construction of heterogeneous frustrated Lewis pairs(FLPs)catalysts is crucial for realizing highly efficient and recyclable pyridines catalytic hydrogenation.In this work,we prepared a recyclable heterogenous FLPs catalyst CMP-BF with conjugated microporous polymer CMP-ethynyl as the support via self-catalyzed 1,1-carboboration reaction with commercial Lewis acid B(C_(6)F_(5))_(3).The as-synthesized CMP-BF demonstrates superior heterogenous catalytic hydrogenation performance(conversion>99%),and considerable stability(84%conversion after three cycles)in recyclable hydrogenation of 2,6-phenylpyridine.This work provides insights into the fabrication and catalytic application of recyclable heterogenous FLP catalysts.展开更多
Let K be a right-continuous and nondecreasing function. A function f analytic in the unit disk D belongs to the space OK if ∫D｜f＇（z）｜2K（1 - ｜z｜2）dA（z） 〈 ∞. Decomposition theorems for OK spaces are establ...Let K be a right-continuous and nondecreasing function. A function f analytic in the unit disk D belongs to the space OK if ∫D｜f＇（z）｜2K（1 - ｜z｜2）dA（z） 〈 ∞. Decomposition theorems for OK spaces are established in this paper. As an application, we obtain a characterization of interpolation by functions in DK spaces. Furthermore, we characterize functions in DK spaces by conjugate pairs.展开更多
文摘This paper presents some important properties emanating from the pair of conjugate trees. The properties are obtained by resorting to the fundamental loops and cutsets in the circuit topology. The existence of such a pair is one of the conditions for a nonlinear resistive circuit to have one and only one DC solution.
基金the funding support from the National Natural Science Foundation of China(Nos.22202036 and 22302001)the Jilin Province Scientific,the Technological Planning Project of China(No.20230101292JC).
文摘In this study,a novel non-metallic carbon-based catalyst co-doped with boron and nitrogen(B,N)was successfully synthesized.By precisely controlling the carbonization temperature of a binary mixed ionic liquid,we selectively modified the doping site structure,ultimately constructing a B,N co-doped frustrated Lewis acid-base pair catalyst.This catalyst exhibited remarkable catalytic activity,selectivity,and stability in the dehydrochlorination reaction of 1,1,2-trichloroethane(TCE).Detailed characterization and theoretical calculations revealed that the primary active center of this catalyst was the BN_(3)configuration.Compared to conventional graphitic N structures,the BN_(3)structure had a higher p-band center,ensuring superior adsorption and activation capabilities for TCE during the reaction.Within the BN_(3)site,three negatively charged nitrogen atoms acted as Lewis bases,while positively charged boron atoms acted as Lewis acids.This synergistic interaction facilitated the specific dissociation of chlorine and hydrogen atoms from TCE,significantly enhancing the 1,1-dichloroethene selectivity.Through this research,we not only explored the active site structure and catalytic mechanism of B,N co-doped catalysts in depth but also provided an efficient,selective,and stable catalyst for the dehydrochlorination of TCE,contributing significantly to the development of non-metallic catalysts.
基金supported by the National Natural Science Foundation of China (52161025)the Natural Science Foundation of Gansu Province (20JR10RA241)。
文摘Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.
文摘Let∇be a linear connection on a 2n-dimensional almost anti-Hermitian manifold M equipped with an almost complex structure J,a pseudo-Riemannian metric g and the twin metric G=g◦J.In this paper,we first introduce three types of conjugate connections of linear connections relative to g,G and J.We obtain a simple relation among curvature tensors of these conjugate connections.To clarify the relations of these conjugate connections,we prove a result stating that conjugations along with an identity operation together act as a Klein group,which is analogue to the known result for the Hermitian case in[2].Secondly,we give some results exhibiting occurrences of Codazzi pairs which generalize parallelism relative to∇.Under the assumption that(∇,J)being a Codazzi pair,we derive a necessary and sufficient condition the almost anti-Hermitian manifold(M,J,g,G)is an anti-K¨ahler relative to a torsion-free linear connection∇.Finally,we investigate statistical structures on M under∇(∇is a J−parallel torsion-free connection).
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000,Z.Y.T.)the National Key R&D Program of China(Nos.2021YFA1200302,2022YFA1205400)the National Natural Science Foundation of China(Nos.92356304,92056204).
文摘The construction of heterogeneous frustrated Lewis pairs(FLPs)catalysts is crucial for realizing highly efficient and recyclable pyridines catalytic hydrogenation.In this work,we prepared a recyclable heterogenous FLPs catalyst CMP-BF with conjugated microporous polymer CMP-ethynyl as the support via self-catalyzed 1,1-carboboration reaction with commercial Lewis acid B(C_(6)F_(5))_(3).The as-synthesized CMP-BF demonstrates superior heterogenous catalytic hydrogenation performance(conversion>99%),and considerable stability(84%conversion after three cycles)in recyclable hydrogenation of 2,6-phenylpyridine.This work provides insights into the fabrication and catalytic application of recyclable heterogenous FLP catalysts.
基金Supported by National Natural Science Foundation of China(Grant No.11071153)the first author is supportby Department of Education of Anhui Province(Grant No.KJ2013A101)+1 种基金the second author is supported by National Natural Science Foundation of China(Tianyuan fund for Mathematics,Grant No.11226182)the Scientific Research Fund of Zhaoqing University(201209)
文摘Let K be a right-continuous and nondecreasing function. A function f analytic in the unit disk D belongs to the space OK if ∫D｜f＇（z）｜2K（1 - ｜z｜2）dA（z） 〈 ∞. Decomposition theorems for OK spaces are established in this paper. As an application, we obtain a characterization of interpolation by functions in DK spaces. Furthermore, we characterize functions in DK spaces by conjugate pairs.
