State estimation in roll dynamics for commercial vehicles

Accurate lateral load transfer estimation plays an important role in improving the performance of the active rollover prevention system equipped in commercial vehicles. This estimation depends on the accurate prediction of roll angles for both the sprung and the unsprung subsystems. This paper proposes a novel computational method for roll-angle estimation in commercial vehicles employing sensors which are already used in a vehicle dynamic control system without additional expensive measurement units. The estimation strategy integrates two blocks. The first block contains a sliding-mode observer which is responsible for calculating the lateral tyre forces, while in the second block, the Kalman filter estimates the roll angles of the sprung mass and those of axles in the truck. The validation is conducted through MATLAB/TruckSim co-simulation. Based on the comparison between the estimated results and the simulation results from TruckSim, it can be concluded that the proposed estimation method has a promising tracking performance with low computational cost and high convergence speed. This approach enables a low-cost solution for the rollover prevention in commercial vehicles.     

布达佩斯城市交通发展战略与启示

分别从概况、战略目标、实施策略等3个方面对布达佩斯城市交通发展的总体战略及公共交通、道路网络、静态交通、步行及自行车交通、交通管理等发展战略进行了阐述。由此得出,居民出行线路上任何一种交通方式的低效都将破坏整个交通链的效率,只有整个交通链所有交通环节的和谐发展,才能够使公共交通在运输服务上较小汽车具有竞争力;只有综合利用公共交通与私人交通,才能使城市交通与土地利用相协调。最后,结合布达佩斯和国内实践经验,总结提出了一种包含人口、经济、地理、环境、技术、制度等要素的“六棱形”城市交通发展战略规划模型。     

新加坡公共交通发展经验及启示

通过实际考察和走访咨询,系统地总结了新加坡的公共交通发展经验。首先介绍了新加坡对小汽车和公共交通发展采取的＂推、拉策略＂,以及新加坡公共交通的发展历程。在此基础上,对新加坡公共交通发展的成功经验进行了归纳和总结,包括管理机制、公共交通设施建设、公共交通运营系统、政策法规等方面的内容。结合我国城市交通发展的现状和特点,对城市公共交通的发展提出了措施和建议。     

高速公路景观设计初探

就高速公路景观设计进行了探讨.     

快速老化小鼠的学习记忆缺陷及其生化机制

目的用快速老化小鼠(SAMP8)模拟老年痴呆,观察其学习记忆能力,并探讨其学习记忆能力下降的可能机制。方法采用10月龄SAMP8,并用同龄抗快速老化小鼠(SAMR1)作为正常对照。用水迷路检测近记忆以及空间学习记忆能力。用生物化学方法检测大脑皮层线粒体膜电位和ATP酶活力,观察线粒体功能;检测皮层和海马胆碱乙酰基转移酶(ChAT)和乙酰胆碱酯酶(AChE)的活力,观察中枢胆碱能神经功能;检测血清超氧化物歧化酶(SOD)活力和丙二醛(MDA)含量,观察其全身性氧化应激状况。结果与SAMR1相比,SAMP8出现明显的衰老体征,其近记忆和空间学习记忆能力明显减弱,具有衰老和痴呆特征;皮层线粒体膜电位和ATP酶活力显著降低,海马ChAT活力显著下降,AChE活力显著升高,血清SOD活力稍有增高。结论SAMP8可以很好地模拟老年痴呆,其机制包括大脑皮层线粒体功能降低、海马胆碱能神经功能下降以及氧化应激等。     

QoS awared power and admission controls based on non-cooperative game theory in wireless networks

In order to better accommodate heterogeneous quality of service (QoS) in wireless networks, an algorithm called QeS-aware power and admission controls (QAPAC) is proposed. The system is modeled as u non- cooperative game where the users adjust their transmit powers to maximize the utility, thus restraining the interferences. By using adaptive utility functions and tunable pricing parameters according to QoS levels, this algorithm can well meet different QoS reqniremcnts and improve system capacity compared with those that ignore the QoS differ- ences.     

The role of interleukin-8 produced by tumor induced fibroblasts in the development of cutaneous melanoma

Objective To determine the role of interleukin-8 (IL-8) produced by tumor induced fibroblasts in the development of cutaneous melanoma. Methods B16 melanoma cells induced L929 fibroblasts phenotype was transdifferentiated to myofibroblasts (MF) by co-culture in vitro. MF was monitored by morphology and immunophenotype for a-SMA. The level of IL-8 was detected by ELISA. The effect on B16 cell proliferation rate was estimated using MIT method in vitro. Melanoma implanting model was constructed in C57 mice. Results L929 MF phenotype could be modulated by B16 melanoma cells-derived transforming growth factor-β1 (TGF-β1) and elevated the levels of IL-8. L929 MF did not influence the B16 melanoma cells viability in vitro, but shortened the time of tumor formation and increased the incidence rates of tumors in C57 implanting model mice. Conclusion Fibroblasts can be activated by tumor cells and produce IL-8, which acts as an inflammatory cytokine promoting the development of cutaneous melanoma.     

Study on T lymphocyte subsets and NK cells in patients with Graves＇ disease combined with type 2 diabetes

Objective To investigate changes in T lymphocyte subsets and NK cells in patients with simple Graves' disease (GD)and Graves' disease combined with type 2 diabetes mellitus (GD/T2DM). Methods Fifteen cases of GD/ T2DM were selected from our hospital from November 2001 to November 2004. Before and after therapy thyroid function, thyroglobulin antibody (TGA), thyroid microsomal antibody (TMA) and blood glucose level were measured, and T lymphocyte subsets (CD3, CD4, CD8, CD4/CD8) and NK cells (CD56) were measured by immunofluorescence double labeling monoclonal antibody and flow cytometry, respectively. At the same time, comparison was made with simple GD (15 cases), T2DM (15 cases) and healthy control (20 cases). Results Before therapy, CD4/CD8, CD4 and NK cells in GD/T2DM were less than normal, and there was no significant difference in comparison with simple GD (P<0.05). In T2DM group, only CD4/CD8 and CD4 were less than those of healthy controls (P<0.05). When thyroid function recovered after 1 to 3 months of methimazole treatment in both GD/T2DM and simple GD groups, various indexes recovered, which were more obvious in simple GD. Conclusion Immune hypofunction of GD may be the key to the immune abnormality of GD/T2DM, which is more significant than that of simple GD or T2DM. The recovery of thyroid function and immune abnormality is not consistent, and the recovery of GD is more significant than that of GD/T2DM.     

船舶上层建筑重量重心对其固有频率的影响

在船舶设计、建造过程中及船舶建造完成后,有时上层建筑的固有频率与主机、螺旋桨的激励频率相接近。想要通过一些简单有效的手段对船舶进行修改,使上层建筑的固有频率避开激励源频率以避免共振。本文利用大型通用有限元分析软件Ansys,以某300,000吨级原油船为研究对象,对上层建筑的重量和重心高度如何影响上层建筑的首阶横向、纵向固有频率进行灵敏度分析,以求找到简单有效的、适于工程实际中改变船舶上层建筑固有频率的方法。