In the year 2002, Lin detected a nontrivial family in the stable homotopy groups of spheres ;π-6S which is represented by hngoγ^-3 ∈ Ext^6tA（Zp, Zp） in the Adams spectral sequence, where t = 2p^n（p- 1）＋ 6（p^2...In the year 2002, Lin detected a nontrivial family in the stable homotopy groups of spheres ;π-6S which is represented by hngoγ^-3 ∈ Ext^6tA（Zp, Zp） in the Adams spectral sequence, where t = 2p^n（p- 1）＋ 6（p^2 ＋p ＋ 1）（p- 1） and p ≥ 7 is a prime number. This article generalizes the result and proves the existence of a new nontrivial family of filtration s ＋ 6 in the stable homotopy groups of spheres πt1-8-6S which is represented by bygoγ^s＋3 ∈ Ext^s＋6＋t1Atl （Zp, Zp） in the Adams spectral sequence, where n≥ 4, 0 ≤ s 〈 p - 4, t1 = 2p^n（p- 1） ＋ 2（p- 1）（（s ＋ 3）p^2 ＋ （s ＋ 3）p ＋ （s ＋ 3）） ＋ s.展开更多
We investigated the magnetocaloric effect in commercial Er_(2)O_(3) powders which presents almost no hysteresis losses at low temperature.At a magnetic field change of 5 T,it displays large magnetic entropy change(-Δ...We investigated the magnetocaloric effect in commercial Er_(2)O_(3) powders which presents almost no hysteresis losses at low temperature.At a magnetic field change of 5 T,it displays large magnetic entropy change(-ΔSM)max of 15.02 J/(kg·K)and a refrigerant capacity(RC)of 311 J/K at Neel temperature TN=3.32 K.The magnetic transition was found to be of a second-order.The maximum values of adiabatic temperature change(ΔTad)max reach 0.70 K for a magnetic field change of 1 T.The large value,of(-ASM)max as well as no hysteresis loss,makes Er_(2)O_(3) a promising material as a magnetic refrigerant at low temperature.展开更多
In this paper, through an information-theoretic approach, we construct estimations and confidence intervals of Z-functionals involving finite population and with the presence of auxiliary information. In particular, w...In this paper, through an information-theoretic approach, we construct estimations and confidence intervals of Z-functionals involving finite population and with the presence of auxiliary information. In particular, we give a method of estimating the variance of finite population with known mean. The modified estimates and confidence intervals for Z-functionals can adequately use the auxiliary information, at least not worse than what the standard ones do. A simulation study is presented to assess the performance of the modified estimates for the finite sample case.展开更多
基金Supported by the National Natural Science Foundation of China (1051045)the Youth Project of Tianyuan Foundation of China (10426028)the China Postdoctoral,Science Foundation and Fund of the Personnel Division of Nankai University
文摘In the year 2002, Lin detected a nontrivial family in the stable homotopy groups of spheres ;π-6S which is represented by hngoγ^-3 ∈ Ext^6tA（Zp, Zp） in the Adams spectral sequence, where t = 2p^n（p- 1）＋ 6（p^2 ＋p ＋ 1）（p- 1） and p ≥ 7 is a prime number. This article generalizes the result and proves the existence of a new nontrivial family of filtration s ＋ 6 in the stable homotopy groups of spheres πt1-8-6S which is represented by bygoγ^s＋3 ∈ Ext^s＋6＋t1Atl （Zp, Zp） in the Adams spectral sequence, where n≥ 4, 0 ≤ s 〈 p - 4, t1 = 2p^n（p- 1） ＋ 2（p- 1）（（s ＋ 3）p^2 ＋ （s ＋ 3）p ＋ （s ＋ 3）） ＋ s.
文摘We investigated the magnetocaloric effect in commercial Er_(2)O_(3) powders which presents almost no hysteresis losses at low temperature.At a magnetic field change of 5 T,it displays large magnetic entropy change(-ΔSM)max of 15.02 J/(kg·K)and a refrigerant capacity(RC)of 311 J/K at Neel temperature TN=3.32 K.The magnetic transition was found to be of a second-order.The maximum values of adiabatic temperature change(ΔTad)max reach 0.70 K for a magnetic field change of 1 T.The large value,of(-ASM)max as well as no hysteresis loss,makes Er_(2)O_(3) a promising material as a magnetic refrigerant at low temperature.
基金Supported by National Natural Science Foundation of China (Grant Nos.10571093 and 10871104)SRFDP of China (Grant No.20050055038)
文摘In this paper, through an information-theoretic approach, we construct estimations and confidence intervals of Z-functionals involving finite population and with the presence of auxiliary information. In particular, we give a method of estimating the variance of finite population with known mean. The modified estimates and confidence intervals for Z-functionals can adequately use the auxiliary information, at least not worse than what the standard ones do. A simulation study is presented to assess the performance of the modified estimates for the finite sample case.
