Further study on the ultimate strength analysis of spherical pressure hulls

From a comparative study it is concluded that current design rules for the spherical pressure hull of manned submersible need to be updated and unified. In this paper, a series of spherical pressure hulls are calculated by nonlinear FEM. Based on these numerical results, the influence of critical arch length and the relationship of ultimate strength with t/R and structural imperfection are studied. Finally, empirical formulae for the ultimate strength of the titanium alloy spherical pressure hull of deep manned submersible based on numerical computations are given. The formulae can be used as the core equations to update current design rules.     

氯化镓对Walker256癌骨侵袭的抑制作用

目的　观察氯化镓 (GaCl3 )对Walker2 5 6癌骨侵袭大鼠的保护作用。方法　抽取SD大鼠的Walker 2 5 6癌腹水瘤 ,在大鼠右后肢胫骨内侧上 1/ 3处旁肌肉内接种 ,造成癌骨侵袭大鼠模型 ,从X线、生化、病理等方面 ,观察GaCl3 对Walker2 5 6癌骨侵袭的抑制作用。结果　在X线上显示GaCl3 对大鼠骨溶解有抑制作用 ;同时能显著降低血清中抗酒石酸酸性磷酸酶 (TrACP)的活性 ;镜下观察能减轻骨组织的病理学改变。结论　GaCl3 对Walker2 5 6癌骨侵袭大鼠有一定的抑制作用     

一类具稀疏效应食饵-捕食系统的分岔及混沌

得到了一类稀疏效应下的Predator—Prey系统发生静态分岔和Hopf分岔的条件，证明了此类系统存在混沌现象，完善了此类系统的研究工作。     

现代有轨电车在国内外的发展经验启示

现代有轨电车近年来以崭新的形象、舒适的服务、绿色环保、高效快速等特点受到市场的青睐,迅速发展。以法国部分城市为例,分析现代有轨电车在不同城市中的布局特点等,同时结合目前国内已经运营和正在规划的有轨电车城市的案例,总结有轨电车在城市公共交通系统中的定位和适用范围等,有助于有轨电车的规划建设。     

青岛城市轨道交通AFC系统读写器软件接口特点介绍

为了指导青岛城市轨道交通自动售检票系统的路网建设,规范技术标准,减少重复投资和设备维护及升级成本,青岛市地铁集团建设单位组织编制了AFC系统标准规范。研究和规范读写器的票卡处理单元(TPU)软件的接口,不仅可以提高车票处理速度、规避车票处理错误,还能实现线路间设备的互换性,并且可以减轻系统升级维护工作量和成本。从读写器软件的原理、架构和处理流程上,介绍了青岛城市轨道交通AFC系统票卡处理单元软件接口的特点。     

铁路新线引入枢纽有关问题的研究

铁路枢纽设计只有与时俱进,才能适应新时期铁路建设的需要。结合工程实践,对以往新线引入枢纽方案进行分析和总结,明确在设计中要充分分析影响方案的各种因素,充分考虑不同体制铁路引入的可能性;坚持"客内货外、客货分线"的原则;与其他公共走廊共通道,节约土地;结合长交路,规划货运直通线;根据车站类型及引入线路数量,分别采用"线路别引入、分场设置"和"方向别引入、合场设置"方案;统筹规划专用线,避免出现多头接入车站的情况;使用适宜类型的道岔;采取措施,软化客运站站前坡度,取消安全线。     

轨道交通电工电子设备的绝缘配合（上）

从绝缘配合的基本概念及TBff3251．1—2010《轨道交通绝缘配合第1部分：基本要求电工电子设备的电气间隙和爬电距离》的制定背景出发,阐述确定绝缘配合的因素,包括额定绝缘电压、过电康类别、污染等级、绝缘材料及海拔等,以及获得所需电气间隙和爬电距离的步骤,说明过电压防护仿真的作用和参数,解释绝缘试验中的实际问题,以便理解和执行TB/T3251．1—2010。     

高填方路基压实度测试技术的研究

就瑞雷波法检测高填方路基压实进行了研究,并在河北省京秦高速公路高填方路基施工检测中进行试验,验证了其可行性和可靠性.此项技术可在国内高速公路高填方路基施工检测中推广应用.     

One-dimensional model on fuel penetration in diesel sprays with gas flow

In diesel engine, spray penetration is usually changed by in-cylinder gas flow. Accurate prediction on diesel spray with gas flow is important to the optimal design of diesel fuel injection system. This paper presents a theory investigation focusing on the penetration of diesel spray with gas flow. In order to understand the effect of gas flow on the penetration of diesel spray, a one-dimensional spray model is developed from an idealized diesel spray, which is able to predict the spray behavior under different gas flow conditions. The ambient gas flow is simplified as ideal flow that has only constant flow velocity along x-axial and y-axial directions of spray. The x-axial and y-axial directions are respectively defined as along and vertical spray directions. The main assumption is that the y-axial direction gas flow has no effect on the penetration of spray along x-axial direction. The principles of conservation of mass and momentum are used in the derivation. Momentum of in-cylinder air flow is also taken into consideration. Validation of the model at stable condition is achieved by comparing model predictions with experimental measurements of diesel spray without gas flow from Naber's experiments. Furthermore, CFD simulations on penetration of diesel spray with gas flow were performed with the commercial code AVL-fire. The onedimensional model is validated by the penetration results with gas flow from CFD calculation. Results show that a reasonable estimation of the spray evolution can be obtained for both with and without ambient gas flow conditions.     

细节决定成败的安全思考

安全发展是企业发展的基础,而精细化管理是实现安全发展的重要保障。2010年7月20日,中国油运安全论坛开幕,中海发展股份有限公司油轮公司(中海油运)总经理茅士家作了题为"从海因法则看油轮安全管理精细化"的主旨演讲。演讲结束后,本刊记者就油轮安全的精细化管理专访了茅士家总经理。