We analytically investigate the dynamics of quantum Fisher information of two qubits in independent environments for both uncorrelated and entangled input states.Especially,we observe that,in the non-Markovian regime ...We analytically investigate the dynamics of quantum Fisher information of two qubits in independent environments for both uncorrelated and entangled input states.Especially,we observe that,in the non-Markovian regime and resonant case,quantum Fisher information of uncorrelated input state vanishes only at discrete time point whereas that of entangled input state can disappear during finite time interval.It shows that quantum Fisher information,which determines the parameter estimation precision,is strongly affected by the environment memory effects,and the advantage of entanglement-enhance metrology no longer exists even for a very short time.We also note that quantum Fisher information for two kinds of input states can be preserved under appropriate qubit-reservoir detuning.展开更多
In order to have an overview of implementation of the subsidy policy for purchase of plant protection machinery in Fujian Province, based on the questionnaire data on Fujian Province, we use Logit model to conduct emp...In order to have an overview of implementation of the subsidy policy for purchase of plant protection machinery in Fujian Province, based on the questionnaire data on Fujian Province, we use Logit model to conduct empirical analysis of factors influencing farmers' willingness to participate in the subsidy policy for purchase of plant protection machinery. Research results show that there are 69.4% of farmers willing to participate in the subsidy policy for purchase of plant protection machinery; farmers' growing area has a significant impact on the willingness to participate in the subsidy policy for purchase of plant protection machinery, and there is negative correlation; educational level, experience in planting, family farming pure income all have a significant positive impact on the willingness to participate in the subsidy policy.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.11275064,11075050the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20124306110003+1 种基金the Scientific Research Foundation of the Education Department of Hunan Province under Grant No.13C039the Construct Program of the National Key Discipline
文摘We analytically investigate the dynamics of quantum Fisher information of two qubits in independent environments for both uncorrelated and entangled input states.Especially,we observe that,in the non-Markovian regime and resonant case,quantum Fisher information of uncorrelated input state vanishes only at discrete time point whereas that of entangled input state can disappear during finite time interval.It shows that quantum Fisher information,which determines the parameter estimation precision,is strongly affected by the environment memory effects,and the advantage of entanglement-enhance metrology no longer exists even for a very short time.We also note that quantum Fisher information for two kinds of input states can be preserved under appropriate qubit-reservoir detuning.
基金Supported by Key Project of Fujian Provincial Department of Education(JA11131S)
文摘In order to have an overview of implementation of the subsidy policy for purchase of plant protection machinery in Fujian Province, based on the questionnaire data on Fujian Province, we use Logit model to conduct empirical analysis of factors influencing farmers' willingness to participate in the subsidy policy for purchase of plant protection machinery. Research results show that there are 69.4% of farmers willing to participate in the subsidy policy for purchase of plant protection machinery; farmers' growing area has a significant impact on the willingness to participate in the subsidy policy for purchase of plant protection machinery, and there is negative correlation; educational level, experience in planting, family farming pure income all have a significant positive impact on the willingness to participate in the subsidy policy.
