Implications of globalization for co 2 emissions from transport

Transport accounts for about 25% of global CO 2 emissions. Transport activities are on the rise in the coming decades. Would associated CO 2 emissions move upwards as well, and at what rate? The present paper explores the future of these CO 2 emissions, starting from four scenarios for global transport. Considering fuel consumption, energy efficiencies in transport, occupancy rates of transport means, size of cars on the market, and possible environmental policies we find CO 2 emissions are persistently increasing, especially in the less wealthy areas of the world. In Europe, policies that attempt to control mobility and also limit CO 2 emissions may succeed in reducing emissions growth by about 30%. Efforts to increase energy efficiency of transport, in particular road transport, would contribute most to such reduction.     

Determination of anthropogenic CO2 in the North Atlantic Ocean using water mass ages and CO2 equilibrium chemistry

A new method to calculate the anthropogenic CO₂ (ΔDIC_ant) within the water column of the North Atlantic Ocean is presented. The method exploits the equilibrium chemistry of the carbonate system with reference to temperature, salinity and the partial pressure of atmospheric CO₂ (pCO_2,atm). ΔDIC_ant is calculated with reference to the ventilation ages of water masses derived from tracer data and to the time history of pCO_2,atm. The method is applied to data recorded during the WOCE program on the WHP A1/E transect in the North Atlantic Ocean, where we characterise six key water masses by their relationships of dissolved inorganic carbon (DIC) and apparent oxygen utilisation (AOU). The error in determining ΔDIC_ant is reduced significantly by minimising the number of values referred to, especially by avoiding any use of remineralisation ratios of particulate organic matter. The distribution of ΔDIC_ant shows highest values of up to 45 μmol kg⁻¹ in the surface waters falling to 28–33 μmol kg⁻¹ in the Irminger Sea west of the Mid-Atlantic Ridge. The eastern basin is imprinted by older water masses revealing decreasing values down to 10 μmol kg⁻¹ ΔDIC_ant in the Antarctic Bottom Water. These findings indicate the penetration of the whole water column of the North Atlantic Ocean by anthropogenic CO₂.     

TP2紫铜管弯制开裂原因分析

TP2紫铜管在进行弯制时开裂,为找到原因,用退火试验模拟生产中的退火工艺。试验数据表明,铜管经多道次拉拔产生加工硬化,其外表面金相组织和内部金相组织不均匀,导致在进行弯制时铜管产生开裂。通过对比试验,找到铜管弯制的最佳退火温度区间为550～580℃,为铜管弯制退火工艺提供指导。     

基于Java体系的网络办公系统

介绍J2EE和Struts以及MVC设计模式,并根据铁路的网络覆盖面广的特点,论述了采用J2EE和Struts框架,运用MVC的设计思想构建基于网络的办公系统,将数据和文件集中存放,统一管理,并通过授权限制,使信息既方便共享又安全保密,从而提高办公效率.     

新型船用2D气动数字阀动态特性仿真分析

利用伺服螺旋机构设计的二级气动数字伺服阀(简称“2D气动数字阀”),简化了传统二级气动伺服阀的结构,但性能却有较大提高[1]。由于该阀是一种闭环机构的结构设计,所以要同时提高它的稳定性、快速性和精度等性能指标是不可能的,改变阀机构的模型结构参数和工作参数对上述性能指标的影响也是非线性、非单调的。因此,为了提高2D气动数字阀的综合性能,必须对其特性作进一步的分析和研究。针对2D气动数字阀左侧端盖是否设置阻尼腔、阻尼腔结构参数变化及阀体结构参数变化对该阀动态特性产生的影响进行仿真分析。     

长江中游新洲—九江河段河床演变分析及整治方案研究

根据新洲-九江河段近几十年来原型观测资料,深入分析了顺直分汉形过渡河段的演变特点及碍航特性,提出了“固滩守槽,稳定主流”的治理原则,在此基础上提出治理方案,并结合平面二维水沙数学模型,对治理方案效果进行了计算。结果表明：河段采取以守护为主、调整为辅,利用整治建筑物稳定并适当抬高已有滩体,归顺过渡浅区枯期水流的治理思路是正确的,工程方案实施后可以较好地解决本河段的碍航问题。     

河口垂向二维悬沙输移数学模型

针对窄深的潮汐河口建立了沿宽度方向积分平均的垂向二维悬沙输移数学模型,潮流场的模拟采用三维MOHID模型,悬沙对流扩散方程采用Galerkin有限元法进行求解。利用该模型模拟了长江口北槽段潮流输沙过程,计算结果与实测资料较好吻合,表明了该模型能够模拟窄深的潮汐型河口地区悬沙输移过程。     

基于J2EE平台的CRM系统的实现

客户关系管理(CRM)系统近几年得到普遍关注,通过对J2EE体系结构的分析,本文介绍了基于J2EE平台的CRM系统的实现,重点对客户信息管理模块的实现进行了详细的叙述。     

基于J2EE三层体系结构的网上商城的设计与实现

采用J2EE Web Services技术,通过对一个网上商城的分析,建模,编程,模拟实现了各种电子商务功能,对中小型用户,性能十分优越;对一些大型网站,采用合理的数据库,也能充分实现移植。     

河道二维数值模拟糙率横向分布研究

糙率是河道对水流阻力大小的描述。文中系统地总结了推求糙率的各种常用方法,分析了糙率沿河道横断面分布的非统一性。采用横断面各个垂线能坡相同的假定原理,利用谢才—曼宁公式,推导出了断面糙率再分配函数。通过点绘多条河流不同河型的不同断面形态的实测水文资料,建立了可应用于平面二维水流数值模拟中阻力沿河宽分布的经验公式,将得到的断面糙率再分配函数应用到对应的河段的平面二维流场数值计算中,计算结果与实测结果吻合良好,解决了计算流速与天然实测流速断面分布不一致的问题,提高了水流二维数值模拟的精度。