The restoration mechanisms for static recrystallization of work-hardened austenite were investigated by using double-pass compression tests performed on medium-carbon steel containing chromium and molybdenum. The soft...The restoration mechanisms for static recrystallization of work-hardened austenite were investigated by using double-pass compression tests performed on medium-carbon steel containing chromium and molybdenum. The softening fraction was defined by 2% offset method. The results show that Avrami exponent of about 0.21 is insensitive to deformation temperature, indicating that the action of steel grade should be considered. The time of 50% recrystallization (t0.5) decreases noteworthily with the increase of deformation temperature. Apparent activation energy for static recrystallization of 195 kJ/mol, which is close to that of vanadium microalloyed steel, is obtained by calculating. The increasing trend of the driving force for recrystallization is opposite to that of the deformation temperature, which is attributed to the number of operative slip system increasing as temperature increasing.展开更多
Group signature schemes are fundamental cryptographic tools. A group signature scheme allows members of a group to anonymously sign misuse, the anonymity messages. To counter can be revoked by the group manager. The g...Group signature schemes are fundamental cryptographic tools. A group signature scheme allows members of a group to anonymously sign misuse, the anonymity messages. To counter can be revoked by the group manager. The group joining operation is a critical component of group signature scheme, the framing attack can be prevented by group joining processes. This paper presents an efficient group signature scheme with a simple joining protocol that is based on a ＂single message and signature response＂ interaction between the prospective user and the group manager. The security of our group signature is based on the Discrete Logarithm assumption and Decisional Linear Diffie- Hellman assumption. The formal security proof of our scheme is given in the random oracle model. Our scheme is also a very efficient short group signature scheme with efficient concurrent join.展开更多
文摘The restoration mechanisms for static recrystallization of work-hardened austenite were investigated by using double-pass compression tests performed on medium-carbon steel containing chromium and molybdenum. The softening fraction was defined by 2% offset method. The results show that Avrami exponent of about 0.21 is insensitive to deformation temperature, indicating that the action of steel grade should be considered. The time of 50% recrystallization (t0.5) decreases noteworthily with the increase of deformation temperature. Apparent activation energy for static recrystallization of 195 kJ/mol, which is close to that of vanadium microalloyed steel, is obtained by calculating. The increasing trend of the driving force for recrystallization is opposite to that of the deformation temperature, which is attributed to the number of operative slip system increasing as temperature increasing.
基金This paper is supported by the National Natural Science Foundation of China under Grant No. 61072140, 61373171 the Program of Introducing Talents of Discipline to Universities NO. B08038 the Specialized Research Fund for the Doctoral Program of Higher Education No. 20100203110003.
文摘Group signature schemes are fundamental cryptographic tools. A group signature scheme allows members of a group to anonymously sign misuse, the anonymity messages. To counter can be revoked by the group manager. The group joining operation is a critical component of group signature scheme, the framing attack can be prevented by group joining processes. This paper presents an efficient group signature scheme with a simple joining protocol that is based on a ＂single message and signature response＂ interaction between the prospective user and the group manager. The security of our group signature is based on the Discrete Logarithm assumption and Decisional Linear Diffie- Hellman assumption. The formal security proof of our scheme is given in the random oracle model. Our scheme is also a very efficient short group signature scheme with efficient concurrent join.
