Current Reversal Due to Coupling Between Asymmetrical Driving Force and Ratchet Potential

Transport of a Brownian particle moving in a periodic potential is investigated in the presence of an asymmetric unbiased external force. The asymmetry of the external force and the asymmetry of the potentlal are the two ways of inducing a net current. It is found that the competition of the spatial asymmetry of potential with the temporal asymmetry of the external force leads to the phenomena like current reversal The competition between the two opposite driving factors is a necessary but not a sufficient condition for current reversals.

Logistics Cost Control Research based on Hengtong Transportation Company

Facing the rapid development of economy and the increasingly fierce market competition, the role of logistics control is becoming far more important. Choosing the best way to play the role of logistics, improving overall efficiency of the enterprise, reducing logistics cost and coping well with market competition, these things have great important practical significances. This article take hengtong transportation company as research object, giving the present situation of logistics cost and analyzing the causes of logistics cost increased year by year. At last, putting forward the concrete measures to realize better logistic control.

我国高速公路市场现状及投资前景展望

过去三十多年,我国高速公路网建设取得了辉煌的成就,为国民经济发展和社会稳定做出了重要贡献。展望未来,高速公路项目在稳固经济大盘、促进产业链供应链稳定等方面仍将发挥关键作用,但这也离不开该领域社会投资人的广泛参与。然而,当前已运营的高速公路项目普遍面临一定的收支缺口,投资效益不佳,导致相关企业资金压力巨大,影响其参与后续项目投资的积极性。从未来来看,高速公路项目仍面临收入下滑、投资高企以及其他运输方式竞争及地区内既有高速项目分流等一系列不利因素,而且收支缺口有进一步扩大的趋势。本文对我国高速公路市场的现状及未来投资前景进行了深入分析,旨在揭示当前面临的挑战,探索可行的解决方案,并为企业和相关部门提供策略建议,以促进高速公路行业可持续发展。