排序方式: 共有24条查询结果,搜索用时 15 毫秒
11.
就扩大居民消费对GDP的影响机理进行了分析,并从扩大居民外生消费和居民内生消费两个方面测算了扩大居民消费对中国GDP的影响.推导出了部分消费内生化的投入产出局部闭模型下的GDP乘数,并对其进行了分解分析,找出了影响GDP乘数的关键因素.测算结果显示:扩大农林牧渔、教育、住宿和餐饮业等部门的外生消费能够对GDP起到相对较大的拉动作用.但从长远看,应建立起扩大居民消费的长效机制.需采取措施改善当前的收入分配格局,完善社会保障体系以扩大居民的内生消费. 相似文献
12.
13.
By using the coupled duster method and the numerical density matrix renormalization group method, we investigate the properties of the quantum plateau state in an alternating Heisenberg spin chain. In the absence of a magnetic field, the results obtained from the coupled cluster method and density matrix renormalization group method both show that the ground state of the aiternating chain is a gapped dimerized state when the parameter a exceeds a critical point ac. The value of the critical points can be determined precisely by a detailed investigation of the behavior of the spin gap. The system therefore possesses an m = 0 plateau state in the presence of a magnetic field When a 〉 ac. In addition to the m = 0 plateau state, the results of density matrix renormaiization group indicate that there is an m = 1/4 plateau state that occurs between two critical fields in the alternating chain if a 〉 1. The mechanism for the m = 1/4 plateau state and the critical behavior of the magnetization as one approaches this plateau state are also discussed. 相似文献
14.
在外加垂直磁场的石墨烯系统中,基于格林函数方法以自能的形式理论研究了电荷杂质散射和光学声子散射中心对朗道能谱的影响,采用久保(Kubo)公式研究了单层石墨烯的磁光电导谱以及跃迁选择定则。具体计算中电子-杂质库仑相互作用考虑了介电环境的屏蔽效应,对由散射引起的自能以及单粒子格林函数做自洽计算,另外在强磁场下单杂质散射是一个很好的近似模型。理论计算结果表明电荷杂质散射引起朗道能级对称展宽;同时考虑电荷杂质和光学声子两类散射后态密度表现为非对称的展宽。研究结果表明磁光电导谱的峰值和强度强烈依赖于填充因子和态密度。 相似文献
15.
The methods of multiple scales and approximate potential are used to study pendulums with linear damping and variable length. According to the order of the coefficient of friction compared with that of the slowly varying parameter of length, three different cases are discussed in details. Asymptotic analytical expressions of amplitude, frequency and solution are obtained. The method of approximate potential makes the results effective for large oscillations. A modified multiple scales method is used to get more accurate leading order approximations when the coefficient friction is not small. Comparisons are also made with numerical results to show the efficiency of the present method. 相似文献
16.
IIntroductlonConsider the n-spedes biological systemlit\1.=IJ!厂.+》*i,工上D、忍=上,’··。n.ti)Ifffi=1,it is S S-SpSCllS LOthaka-VoltOOYY SystSS.Iftti=2,It Is S S-sPeCieSKolmongorov system.As to the n-spedes Gause-Lotb-Volterra system矿ti 乙工.=T;Ii、y Qiil.I。Ti 7 U,on M U,t6)174 AnnofDiff Eqs.VO18M叫 and Leonard[1],Ho凡aner and Sigmund问 have studied this system forthe case n二 3 respectlvelyand noted that thereprobably exists aheterocllnlccyclefor… 相似文献
17.
具有HOLLINGⅢ型功能性反应的两种群捕食—被捕食系统的极限环和中心的存在性 总被引:2,自引:0,他引:2
本文通过对研究具有HOLLINGⅢ型功能性反应的两种群捕食-被捕食系统,得到其极限环和中心存在性的充分条件,并得到中心的个数以及相应的条件。 相似文献
18.
19.
以新疆为研究区域,计算14个地州的变异系数和泰尔指数,利用ESDA方法对82个县市单元进行空间自相关分析,分析1995-2017年新疆区域经济发展时间和空间总体差异水平变化,并识别经济发展空间格局中的热点区域,探讨新疆区域经济差异,最后从区域机制、产业转移、重点领域、开放战略等方面提出策略建议. 相似文献
20.