Relationship between cation–π and anion–π interactions: individual binding energies in the π–Mz+–π–X−–π system

The mutual influence of cation–π and anion–π interactions in the π–M^z+–π–X^?–π system (M^z+ = Li⁺, Na⁺, K⁺, Be²⁺, Mg²⁺, Ca²⁺ and X^? = F^?, Cl^?) has been studied by quantum mechanical calculations. Both geometric parameters and energy data reveal that cation–π and anion–π interactions enhance each other in the π–M^z+–π–X^?–π system. Individual binding energies (E_ion···π) have been estimated in the quintuplet system using a simple new method from electron charge densities calculated at the bond critical points (BCPs) of the ion···π interaction by the atoms in molecules (AIM) method at the M062X/6-31+G(d) level of theory. With respect to the obtained individual binding energies, the strength of an ion···π interaction depends on the cooperative effects of other components.     

Surface‐enhanced Raman spectra of individual multiwalled carbon nanotubes with small innermost diameters

The Raman spectra of individual multiwalled carbon nanotubes (MWCNTs) with the innermost diameters of 0.6–0.9 nm are studied by surface‐enhanced Raman scattering. The influences of small innermost diameters to Raman features are investigated. A clear and relatively sharp Raman peak appears at 1510 cm⁻¹ when the innermost diameter is close to 0.6 nm. Lorentzian fits of G band indicate that its splitting is affected by the small innermost diameter of MWCNT. Moreover, the splitting of 2iTO mode is also observed at 2800–3000 cm⁻¹. Copyright © 2012 John Wiley & Sons, Ltd.     

Epidemic spreading in scale-free networks including the effect of individual vigilance

In this paper, we study the epidemic spreading in scale-free networks and propose a new susceptible-infected- recovered (SIR) model that includes the effect of individual vigilance. In our model, the effective spreading rate is dynamically adjusted with the time evolution at the vigilance period. Using the mean-field theory, an analytical result is derived. It shows that individual vigilance has no effect on the epidemic threshold. The numerical simulations agree well with the analytical result. Furthermore, we investigate the effect of individual vigilance on the epidemic spreading speed. It is shown that individual vigilance can slow the epidemic spreading speed effectively and delay the arrival of peak epidemic infection.     

Ruin problems with stochastic premium stochastic return on investments

In this paper, ruin problems in the risk model with stochastic premium incomes and stochastic return on investments are studied. The logarithm of the asset price process is assumed to be a Lévy process. An exact expression for expected discounted penalty function is established. Lower bounds and two kinds of upper bounds for expected discounted penalty function are obtained by inductive method and martingale approach. Integro-differential equations for the expected discounted penalty function are obtained when the Lévy process is a Brownian motion with positive drift and a compound Poisson process, respectively. Some analytical examples and numerical examples are given to illustrate the upper bounds and the applications of the integro-differential equations in this paper.      

Revenue recycling of a CO2 tax: Results from a general equilibrium model for Switzerland

This paper combines a recent proposal by the Swiss government for a CO₂ tax with a policy that uses the tax revenues to lower the pre-existing marginal labor income tax rates, and examines the efficiency and distribution effects of such a revenue recycling policy. The investigation, based on a large-scale general equilibrium model, contrary to other studies, indicates that an environmental tax reform involves negative gross cost, that is, increases welfare even when environmental benefits are not accounted for. The simulation results further show that the adverse distributional effects of a pure CO₂ tax are neutralized or even reversed when tax revenues finance cuts of existing taxes.We thank Tom Rutherford, Reto Schleiniger and two anonymous referees for helpful comments on an earlier draft of this paper. Financial support by the Federal Agency for Energy under the SOEFF program is gratefully acknowledged. The views expressed here are those of the authors and do not represent the opinions of the granting agency.     

生产税对居民初次分配总收入影响研究

基于国民经济核算的一般原理及核算账户之间的平衡关系,构建生产税影响居民初次分配总收入的路径图,并运用比例分析法和投入产出法对资金流量表及投入产出表进行建模,从生产税的角度研究居民初次分配总收入占比下降的原因。结果表明,2000年以来企业部门缴纳的生产税占比的上升挤占企业部门支付的劳动者报酬份额,是导致居民部门初次分配总收入占比下降的重要原因。     

我国乡镇邮政网点成本收入分析——来自4省(市)的61处乡镇邮政网点的调查

乡镇邮政网点的可持续运营是邮政服务三农、服务农村经济发展的重要保障.结合邮政网络运行特点,运用成本核算方法——作业成本法,建立乡镇邮政网点运营成本模型,并明确了间接成本的分摊依据和方法.实证分析了乡镇邮政网点的成本和收入情况,实证发现,我国乡镇邮政网点业务结构单一,普遍服务业务亏损严重,运营较为困难.最后为促进乡镇邮政网点可持续运营提供一些参考建议.     

异差性税率、Learning-by-doing和随机经济增长

讨论Learning-by-doing随机经济增长模型,利用随机最优化方法,确定了均衡状态下的消费—财富比、期望经济增长率.讨论了差异性税率、随机扰动和技术积累参数对上述诸要素的影响.     

商业银行个人信用风险评价的投影寻踪建模及其实证研究

根据已有的商业银行个人信用风险评价指标体系和数据,应用投影寻踪分类（PPC）技术进行建模,通过改变指标归一化方式前后权重是否互为相反数等性质,以确保PPC建模时求得真正的全局最优解．实证研究表明：对于商业银行个人信用分类问题,PPC模型的识别正确率高于判别分析模型;在评价指标的四个方面中,借贷人与本行关系最重要,其次是其基本情况,而偿债能力和稳定性的影响很小;而且,删除偿债能力和稳定性两个均值差异不存在显著性的指标后建立的PPC模型,不仅不会降低识别正确率,还有利于银行降低采集数据的成本和节约时间,简化流程,对提高PPC模型的实用性等具有重要理论意义和实践价值．     

社会保障税的经济归宿分析

社会保障税的税负应由雇主与雇员共同分担,采用数理方法可以理论上推理出:在其他条件不变的情况下,雇主与雇员所分担的社会保障税税负比例为劳动供给弹性与未征税时劳动需求弹性.在政府设计社会保障税制度时,要减少征税成本与税负转嫁成本,以减少社会保障税对经济效率所产生的扭曲及其他负面影响;要结合现时劳动供求状况制定雇主与雇员的法定分担比例;社会保障税税率在短期内应是相对稳定的,但在长期内应是动态变化的.