基于MSC的变矩器膨胀变形分析

为了准确快速地预测钣金型液力变矩器在工作负载下壳体的膨胀变形、提高液力变矩器性能、减少由于整体轴向刚体位移导致与周围零件的干涉,借助三坐标测量仪及UG软件平台建立并简化了变矩器内流道模型和变矩器壳体模型;利用仿真软件Gambit,Fluent对内流道模型进行分析,得出了壳体所受油压面力和轴向力;最后,借助软件MSC.Patran和MSC.Nastran对液力变矩器壳体的膨胀变形进行模拟仿真预测,并通过试验对仿真的结果进行验证.试验结果表明:试验与仿真分析的结果基本吻合;液力变矩器的轴向位移与油压大小呈线性关系;最大应力出现在壳体循环圆曲率发生突变最大的部分;最大应变出现在泵轮出口面和涡轮进口面所对应的壳体上.     

Maritime interests in the EU policy-making: Structures,practices, and governability of collective action

Throughout Europe, a number of maritime interests have re-targeted their lobbying structures and strategies aiming to influence the development of the maritime related European Union (EU) policies. The paper examines these maritime interests’ mobilisation in the making of the Common EU Maritime Transport Policy (CMTP). First, it provides a review of the role of these interest groups and the implications of the observed collective interests’ representation. Then, with the contribution a data-set of replies to a questionnaire distributed to all the interest groups that are involved in EU maritime affairs, the paper analyses the variety of interest groups representing the maritime sector in EU affairs. The focus is on the structures (i.e. membership numbers and types, location, internal structures, budget) and the lobbying practices of the 37 identified EU level maritime related organisations. The paper also presents an evaluation of the most positive and most negative parameters of the ‘EU environment’ and the ‘economic environment’ that assist, or undermine, the governability cohesiveness of this collective action. This study provides information on whether and under what conditions maritime interests are able to form comprehensive EU-level organisations capable of representing their members and their interests in the EU policy making process     

Surface CO2 measurements in the English Channel and Southern Bight of North Sea using voluntary observing ships

Ships of opportunity have been used to investigate ocean–atmosphere CO₂ fluxes in the English Channel and Southern Bight of the North Sea. Continuous underway measurements of the fugacity of seawater carbon dioxide (fCO₂^sw), chlorophyll, temperature and salinity have been performed along 26 transects during the spring and autumn periods. The spatial fCO₂^sw distribution along the Channel and Southern Bight is modulated by the photosynthetic activity, temperature changes and water mixing between inputs from the North Atlantic Ocean and riverine discharges. The seasonal variability of fCO₂^sw is assessed and discussed in terms of the biology and temperature effects, these having similar impacts. The variation of fCO₂^sw shows similar interannual patterns, with lower values in spring. The annual average of air–sea CO₂ fluxes places the English Channel as neutral area of CO₂ uptake. The spring and autumn data allow differentiating between distal and proximal continental areas. The Southern Bight shows a tendency towards net CO₂ uptake on the distal continental shelf, whereas the Scheldt and Thames Plumes show a CO₂ source behaviour on the proximal continental shelves.     

地铁隧道偏移分析

结合上海轨道交通九号线二期工程商城路站一世纪大道站区间下行线盾构偏移计算问题，提出解决曲线地段地铁隧道偏移的计算方法。通过分析推导出解决问题的方程。对由于圆曲线偏移而引起的缓和曲线调整，可用“圆心不变”作为控制条件寻求合适的缓和曲线进行解决，为类似工程问题提供一种有效的解决途径。     

An approach to estimating the hull girder response of a ship due to springing

This article describes an estimation method for the hull girder response of a ship due to springing. The linear and nonlinear springing effects on the hull girder are evaluated. Previous studies on the springing response focused mainly on the symmetric response, or vertical response. In this article, however, the springing analysis is extended to asymmetric responses, or horizontal and torsional responses. The Timoshenko beam model was used to calculate the hull girder response and the quadratic strip method was employed to calculate hydrodynamic forces and moments on the hull. To remove irregular frequencies, a rigid lid was adopted on the hull free surface level and hydrodynamic coefficients were interpolated for asymptotic values. Applications to two ships for the symmetric and asymmetric responses were carried out and the effect of springing responses is also discussed.     

机车车辆产品零件检测方案的优化

通过比较、选择、统计分析、验证等方法，对铁路机车车辆产品零配件的检测方法进行优化，建立了一套具有一致测量策略、高效可靠、减少人工干扰的测量程序。     

荷麻溪特大桥T构0号块施工方案的确定和实施

针对荷麻溪大桥的具体情况,就T构0#块的施工如何选择支架,如何保证混凝土的实体和外观质量及安全作了阐述。确保了0#块内实外美,无安全质量事故,节约了工期,控制了施工成本,取得了较好的经济效益和良好的社会效益。     

Major sources of hydrocarbon emissions in a premixed charge compression ignition engine

Although premixed charge compression ignition (PCCI) combustion engines are praised for potentially high efficiency and clean exhaust, experimental engines built to date emit more hydrocarbons (HCs) and carbon monoxide (CO) than the conventional machines. These compounds are not only strictly controlled components of the exhaust gas of road vehicles but are also an energy loss indicator. The prime objective of this study was to investigate the major sources of the HCs formed in the combustion chamber of an experimental PCCI engine in order to suggest some effective technologies for HC reduction. In this study, to explore the dominant sources of HC emissions in both operation modes, a single cylinder engine was prepared such that it could operate using either conventional diesel combustion or PCCI combustion. Specifically, the contributions of the top-ring crevice volume in the combustion chamber and the bulk quenching of the lean mixture were investigated. To understand the influence of the shape and magnitude of the crevice on HC emissions, the engine was operated with 12 specially prepared pistons with different top-ring crevices installed one after another. The engine emitted proportionally more HCs as the depth of the crevice increased as long as the width remained narrower than the prevailing quench distance. The top-ring-crevice-originated exhaust HCs comprised approximately 31% of the total HC emissions in the baseline condition. In a series of tests to estimate the effects of bulk quench on exhaust HC emissions, intake air was heated from 300K to 400K in steps of 25K. With the intake air heated, HC and CO emissions decreased with a gradually diminishing rate to zero at 375K. In conclusion, the most dominant sources of HC emissions in PCCI engines were the crevice volumes in the combustion chamber and the bulk quenching of the lean mixtures. The key methods for reducing HC emissions in PCCI engines are minimizing crevice volume in the combustion chamber and maximizing intake air temperature allowed based on the permissible NOx level.     

New lead-acid battery management system based on generator regulation

A novel regulation system for a vehicle generator and lead-acid battery is proposed in this paper. By integrating the regulation method, the output voltage of the generator is determined and controlled by the algorithm to save electrical energy and protect the lead-acid battery. The regulation algorithm is implemented in Matlab/Simulink, and the logic function of the system is verified using the dSPACE/AutoBox workbench. The experimental results show that the new algorithm improves the performance of the fuel economy of the vehicle and the battery state-of-health compared to the traditional control method.