The rotating disk electrode technique is commonly used for screening and characterizing the performance of electrocatalysts for the oxygen reduction reaction(ORR).However,a reliable performance comparison of different...The rotating disk electrode technique is commonly used for screening and characterizing the performance of electrocatalysts for the oxygen reduction reaction(ORR).However,a reliable performance comparison of different electrocatalysts from different labs remains a challenge because of the inconsistency in the measurement of commercial Pt/C.Commercial Pt/C has been adopted extensively as a reference for evaluating the ORR performance of a new electrocatalyst.However,the reported ORR performances of commercial Pt/C from different labs could be significantly different because of multiple factors.Herein,we conducted a meta‐analysis of the ORR performance of commercial Pt/C via data mining of the literature.This revealed the optimal testing conditions for the most repeatable ORR performance,with commercial Pt/C in both acid and alkaline electrolytes;the optimal Pt loading was 20μg/cm^(2) on a 4 mm glassy carbon working electrode.The value of 0.84±0.03 V was suggested as the“Golden reference”of the commercial Pt/C(with Pt 20 wt%)ORR half‐wave potential for the performance evaluation of other ORR catalysts in both acid and alkaline electrolytes.The conclusion obtained through the meta‐analysis was confirmed by experiments.This study provides general guidance for a reliable measurement of the ORR performance of commercial Pt/C as a reference.展开更多
In the development and operation of real estate, real estate development enterprises as the principal subject would often establish contractual relationships with subjects of diverse interests including removed househ...In the development and operation of real estate, real estate development enterprises as the principal subject would often establish contractual relationships with subjects of diverse interests including removed households, banks, construction project contractors, and buyers. At times, conflicts of interests might occur among these contractual subjects requesting civil and commercial claims of the same subject matter based on agreements or legal rights. As for the causes of these conflicts and their solutions, a majority of existing researches still stay at the superficial causes from the perspective of civil and commercial law, and the solution of determining the order of priority of compensation of related rights. Due to the lack of research into deep-seated reasons and solutions from the perspective of economic law, the current legislative and judicial approaches to this kind of problems tend to give more protection to the rights of one subject while lack sufficient attention to other subjects. This paper attempts to carry out analyses and research on the causes and solutions to this kind of conflicts from the perspective of economic law, to achieve integrated protection of diverse interests in real estate development and operation so as to better safeguard the order in real estate development and operation and facilitate the healthy and ordered development of the real estate industry.展开更多
Let R be a commutative ring with identity, Nn(R) the matrix algebra consisting of all n × n strictly upper triangular matrices over R with the usual product operation. An R-linear map φ : Nn(R) → Nn(R) is said ...Let R be a commutative ring with identity, Nn(R) the matrix algebra consisting of all n × n strictly upper triangular matrices over R with the usual product operation. An R-linear map φ : Nn(R) → Nn(R) is said to be an SZ-derivation of Nn(R) if x2 = 0 implies that φ(x)x+xφ(x) = 0. It is said to be an S-derivation of Nn(R) if φ(x2) = φ(x)x+xφ(x) for any x ∈ Nn(R). It is said to be a PZ-derivation of Nn(R) if xy = 0 implies that φ(x)y+xφ(y) = 0. In this paper, by constructing several types of standard SZ-derivations of Nn(R), we first characterize all SZ-derivations of Nn(R). Then, as its application, we determine all S-derivations and PZ- derivations of Nn(R), respectively.展开更多
文摘The rotating disk electrode technique is commonly used for screening and characterizing the performance of electrocatalysts for the oxygen reduction reaction(ORR).However,a reliable performance comparison of different electrocatalysts from different labs remains a challenge because of the inconsistency in the measurement of commercial Pt/C.Commercial Pt/C has been adopted extensively as a reference for evaluating the ORR performance of a new electrocatalyst.However,the reported ORR performances of commercial Pt/C from different labs could be significantly different because of multiple factors.Herein,we conducted a meta‐analysis of the ORR performance of commercial Pt/C via data mining of the literature.This revealed the optimal testing conditions for the most repeatable ORR performance,with commercial Pt/C in both acid and alkaline electrolytes;the optimal Pt loading was 20μg/cm^(2) on a 4 mm glassy carbon working electrode.The value of 0.84±0.03 V was suggested as the“Golden reference”of the commercial Pt/C(with Pt 20 wt%)ORR half‐wave potential for the performance evaluation of other ORR catalysts in both acid and alkaline electrolytes.The conclusion obtained through the meta‐analysis was confirmed by experiments.This study provides general guidance for a reliable measurement of the ORR performance of commercial Pt/C as a reference.
文摘In the development and operation of real estate, real estate development enterprises as the principal subject would often establish contractual relationships with subjects of diverse interests including removed households, banks, construction project contractors, and buyers. At times, conflicts of interests might occur among these contractual subjects requesting civil and commercial claims of the same subject matter based on agreements or legal rights. As for the causes of these conflicts and their solutions, a majority of existing researches still stay at the superficial causes from the perspective of civil and commercial law, and the solution of determining the order of priority of compensation of related rights. Due to the lack of research into deep-seated reasons and solutions from the perspective of economic law, the current legislative and judicial approaches to this kind of problems tend to give more protection to the rights of one subject while lack sufficient attention to other subjects. This paper attempts to carry out analyses and research on the causes and solutions to this kind of conflicts from the perspective of economic law, to achieve integrated protection of diverse interests in real estate development and operation so as to better safeguard the order in real estate development and operation and facilitate the healthy and ordered development of the real estate industry.
基金Fond of China University of Mining and Technology
文摘Let R be a commutative ring with identity, Nn(R) the matrix algebra consisting of all n × n strictly upper triangular matrices over R with the usual product operation. An R-linear map φ : Nn(R) → Nn(R) is said to be an SZ-derivation of Nn(R) if x2 = 0 implies that φ(x)x+xφ(x) = 0. It is said to be an S-derivation of Nn(R) if φ(x2) = φ(x)x+xφ(x) for any x ∈ Nn(R). It is said to be a PZ-derivation of Nn(R) if xy = 0 implies that φ(x)y+xφ(y) = 0. In this paper, by constructing several types of standard SZ-derivations of Nn(R), we first characterize all SZ-derivations of Nn(R). Then, as its application, we determine all S-derivations and PZ- derivations of Nn(R), respectively.
