二维边坡滑动面及稳定性弹塑性有限元分析

通过理论推导和证明,提出了岩土潜在滑线(面)确定潜在滑移线面的理论。该理论根据弹塑性有限元的应力分析结果,用数值积分方法得出岩土潜在滑移线(面),是确定岩土潜在滑移面的通用方法。当岩土应力达到破坏状态时,确定的潜在滑移面将转为真正的滑移面。通过大量的边坡算例和实例分析得出,本文所提出潜在滑移线(面)理论是正确的,分析边坡稳定确定潜在滑面具有优越性。常规边坡稳定性分析与本文方法所得到的最危险潜在滑移线(面)形状和位置、边坡稳定安全系数均相差较大;常规法所得到的结果与实际也相差较大;岩土的变形参数变化对潜在滑移线(面)的形状影响较大,而对边坡最危险潜在滑移线(面)的形状、位置及平均稳定安全系数影响不大;填土容重变化对潜在滑移线(面)的形状及位置影响不大;对边坡稳定安全系数影响较大。     

无线网络自适应带宽预留的准入控制技术研究

未来无线网络不仅向用户提供非实时的数据业务同时也提供实时的诸如话音、视频等多媒体业务，这就要求无线网络必需向用户提供不同要求的服务质量保证。提出一种基于自适应带宽预留的呼叫准入控制方案，该方案不仅考虑了切换呼叫优先于新呼叫，还考虑到实时业务对非实时业务的优先级，并将实时业务的掉线概率控制在预定的门限值以下，有效地保证各类业务的服务质量。     

Ship appearance optimal design on RCS reduction using response surface method and genetic algorithms

Radar cross section (RCS) reduction technologies are very important in survivability of the militarynaval vessels. Ship appearance shaping as an effective countermeasure of RCS reduction redirects the scatteredenergy from one angular region of interest in space to another region of little interest. To decrease the scatteringelectromagnetic signals from ship scientifically, optimization methods should be introduced in shaping design.Based on the assumption of the characteristic section design method, mathematical formulations for optimalshaping design were established. Because of the computation-intensive analysis and singularity in shapingoptimization, the response surface method (RSM) combined genetic algorithm (GA) was proposed. The poly-nomial response surface method was adopted in model approximation. Then genetic algorithms were employedto solve the surrogate optimization problem. By comparison RCS of the conventional and the optimal design,the superiority and effectiveness of proposed design methodology were verified.Ky words: radar cross section (RCS); characteristic section design method; response surface method; genetic algorithm (GA) was proposed. The polynomial response surface method was adopted in model approximation. Then genetic algorithms were employed to solve the surrogate optimization problem. By comparison RCS of the conventional and the optimal design, the superiority and effectiveness of proposed design methodology were verified.     

多抗乙素对小鼠S_(180)肉瘤中免疫活性细胞浸润的影响

曾经证明多抗乙素有明显的抑瘤作用。本文以小鼠实验性S_(180)肉瘤为模型观察了多抗乙素对肿瘤组织内和肿瘤周围Mφ、L_3T_4~- 及Lyt_2~-细胞的影响,同时观察了肿瘤坏死组织周围中性粒细胞浸润及小血管内血栓形成的改变。结果提示:Pb治疗组,肿瘤周围及肿瘤内浸润的L_3T_4~-和Lyt_2~-细胞显著增多,说明Pb可诱导肿瘤组织中淋巴细胞浸润;肿瘤组织的坏死灶周围明显充血、小血管血栓形成显著增加,并有带状中性粒细胞浸润。这些改变与TNF介导的肿瘤组织损伤相符,提示Pb的抑瘤作用主要是通过免疫活性细胞产生的TNF实现的。     

P_(53)蛋白和增殖细胞核抗原在肾癌中表达的临床意义

采用免疫组织化学方法检测40例肾癌组织中P53蛋白和增殖细胞核抗原（PC-NA）的表达。发现P53蛋白阳性表达者共10例（25％）。P53蛋白表达与肿瘤病理分级、临床分期及预后无相关性。肾癌组织的PCNA增殖指数随肿瘤病理分级的上升而增加，PC－NA高表达组（增殖指数＞10％）预后不良，特别是临床早期但PCNA高表达者预后也很差。结果提示P53蛋白表达在肾癌生物学行为及预后评估中无重要意义，而PCNA可作为肾癌恶性度及预后评估指标。P53蛋白和PCNA表达无相关性。     

基于B／S体系结构的铁路电务段管理信息系统的研究

主要介绍基于B/S（Browser/Server)体系结构的铁路电务段管理信息系统的构建，对系统的特点及基于ASP的数据库开发过程进行了分析。     

丘陵及山地城市建设用地竖向规划方法研究

该文针对丘陵及山地城市的特点,重点从地形地貌评价、防洪排涝规划及竖向管理措施等三个方面对山地城市竖向规划方法及一般技术路线进行了论证及总结,并简要介绍了ArcGIS技术在竖向规划中的应用。     

中新天津生态城市政配套工程中创新理念的应用

该文阐述了在中新天津生态城市政道路及排水工程设计中,所采用的生态、节能、环保的设计理念和思路,对其他市政工程的建设具有借鉴意义。     

长纤维增强热塑性复合材料在汽车前端模块中的应用

世界汽车材料技术发展的主要方向是轻量化和环保化。汽车塑料相对密度低,以塑代钢制作外装件可减轻汽车自重,达到节能减排目的。文章介绍了长纤维增强热塑性复合材料(简称LFT)在国内外汽车行业的应用情况以及在汽车前端模块的应用状态。对LFT的力学性能等方面也做了比较详细的介绍,并就传统钣金焊接和LFT制作的前端模块进行了各个方面的对比分析,从中得出了LFT材料在该零件开发中的应用前景是令人期盼的。最后对前端模块应用复合材料的设计开发提供了一些建议。     

Effective assessment of tyre–road friction coefficient using a hybrid estimator

Vehicle stability and active safety control depend heavily on tyre forces available on each wheel of a vehicle. Since tyre forces are strongly affected by the tyre–road friction coefficient, it is crucial to optimise the use of the adhesion limits of the tyres. This study presents a hybrid method to identify the road friction limitation; it contributes significantly to active vehicle safety. A hybrid estimator is developed based on the three degrees-of-freedom vehicle model, which considers longitudinal, lateral and yaw motions. The proposed hybrid estimator includes two sub-estimators: one is the vehicle state information estimator using the unscented Kalman filter and another is the integrated road friction estimator. By connecting two sub-estimators simultaneously, the proposed algorithm can effectively estimate the road friction coefficient. The performance of the proposed estimation algorithm is validated in CarSim/Matlab co-simulation environment under three different road conditions (high-μ, low-μ and mixed-μ). Simulation results show that the proposed estimator can assess vehicle states and road friction coefficient with good accuracy.