Danh Gia Hieu Qua Mot So Mo Hinh Nong Lam Ngu Ket Hop Tai Xa Dao Hon Tre, Kien Giang.

Abstract

Among the islands belonging to Kien Giang province, Hon Tre has geographical comparative advantages for ecological - economic models. This paper will focuse on studying and evaluating the pros and cons of natural and social economic conditions of the island that may afftect the ecological - economic models available in the Hon Tre island, Since then, characteristics of each ecological - economic models will be analysed. Finally, effective evaluation of these models based on economic, social and eviromwntal issues will be given.

Spin Transport in Magnetically Ordered Systems: Ferromagnets, Antiferromagnets and Frustrated Systems

“…More details can be found in Refs. [26,27]. We found that the resistivity ρ in the frustrated regime can go downward or upward at the transition temperature depending on D 1 [27], unlike in non-frustrated ferromagnets and antiferromagnnets shown earlier.…”

“…The system is very unstable due to its large degeneracy. In the case of the Ising spin on the SC lattice treated here, we found that the first-order character of the phase transition is even stronger [27].…”

“…In antiferromagnets, one observes only a broad maximum [29]. In addition to ferromagnets and antiferromagnets, we have investigated the spin resistivity in the following two frustrated systems: the face-centered cubic (FCC) lattice with Ising spins [26] and the J 1 − J 2 simple cubic (SC) lattice [27]. We found that that the first-order phase transition in these frustrated systems causes a discontinuity of the spin resistivity at T C .…”

“…The spin resistivity at temperatures below T N oscillates with varying D 1 . By analyzing the ratio of the number of up spins to the number of down spins in the sphere of radius D 1 , we found that it oscillates with varying D 1 : the maxima (minima) of ρ correspond to the case of largest (smallest) numbers of parallel (antiparallel) spins in the sphere [26,27]. At very high temperatures where the lattice spins are disordered, the numbers of up spins and down spins in the sphere of radius D 1 should be equal.…”

“…The behavior of ρ as a function of T has been shown to be in general agreement with experiments and theories mentioned above. In addition to ferromagnets and antiferromagnets, we have also studied the spin resistivity in frustrated spin systems [26,27]. These systems discovered in the early 80's have been intensively studied.…”