大型充泥袋结构在黄骅港一期工程引堤工程中的应用

重点介绍黄骅港引堤工程采用大型充泥袋结构方案的研究应用情况,并对设计、施工中的某些技术问题进行探讨并提出建议。     

坞门吊装吊索受力计算

本文以定距双吊钩起吊门为例,在考虑偏心的情况下,提出了一套有针对性的计算方法,并对吊索内力计算结果、现场实测结果和不同的计算方法做了分析比较。     

设计模式在对准数据采集处理系统中的应用

对准数据采集处理系统作为丰富动态条件下舰载系统对准检测手段的一次尝试,必须具备高度可复用性和灵活性．支持基于该系统软件进行的扩充和再开发。设计模式代表了成功的可复用的优秀设计经验,在系统设计中引人设计模式将有效的提高系统的可扩展性和可维护性。文章在对准数据采集处理系统中引入了设计模式,介绍了设计模式的概念及使用,并结合该系统软件的开发流程中设计模式的应用实践,阐述了基于设计模式的对准数据采集处理系统的优点及特点。     

软土地基桥台设计与受力分析

软土地基是桥台工程施工中重要的环节之一,对于整体桥梁的正常运行有着重要的影响。然而,由于很多设计人员在对软土地基桥台进行设计过程中,常常忽视了对软土地基的加固工作,导致桥台频繁出现塌陷、开裂的现象,甚至还会引发重大的安全事故,造成人员伤亡,严重危及人们的生命财产安全。因此,本文针对软土地基桥台设计进行研究探讨,并以实例分析软土地基桥台受力情况,以供参考。     

Effect of ulinastatin on hepatic ischemia-reperfusion injury in rats

Objective To investigate the effect of ulinastatin (UTI) on hepatic ischemia-reperfusion injury in rats. Methods Totally 24 adult Sprague-Dawley rats were randomly divided into 3 groups: sham-operated control group (SO group), ischemia-reperfusion group (I/R group) and ulinastatin group (UTI group). Liver in I/R group underwent 1 h of reperfasion after 30 min of ischemia. In UTI group, UTI (2×104 U/kg) was administered to rats 30 min before modeling. The levels of alanine aminotransferase, aspartate aminotransferase and tumor necrosis factor-alpha (TNF-α) in serum were measured and the levels of nitric oxide and malondialdehyde in liver were determined. The histological changes of liver were observed. Results The levels of alanine aminotransferase, aspartate aminotransferase and TNF-α in serum were significantly increased in I/R group compared with those in UTI group (P<0.05). The levels of nitric oxide and malondialdehyde in liver were significantly higher in I/R group than in UTI group (P<0.05).Histological examination of liver indicated that the damages were more severe in I/R group than in UTI group.Conclusion UTI has the ability to inhibit the production of TNF-α and oxyradical, and ameliorate microcirculatory dysfunction in rats with hepatic ischemia-reperfasion injury.     

A hybrid firefly algorithm for optimizing fractional proportional-integral-derivative controller in ship steering

In this paper, a new algorithm which integrates the powerful firefly algorithm(FA) and the ant colony optimization(ACO) has been used in tracking control of ship steering for optimization of fractional-order proportional-integral-derivative(FOPID) controller gains. Particle swarm optimization(PSO) algorithm is also used to optimize FOPID controllers, and their performances are compared. It is found that FA optimized FOPID controller gives better performance than others. Sensitivity analysis has been carried out to see the robustness of optimum FOPID gains obtained at nominal conditions to wide changes in system parameters, and the optimum FOPID gains need not be reset for wide changes in system parameters.     

从大莱龙铁路投标谈如何提高报价内涵质量

通过复核工程数量、合理计算运杂费和灵活编制补充单价,以及在认真检查计算过程中存在的问题等方面,简述提高报价内涵质量.     

斜交框构桥计算方法对比

通过有限元模型从理论上分析探讨斜交框构桥的受力情况,并将平面框架和三维块单元模型的计算结果进行比较,证明随着框架宽度及斜交角度的加大,两种方法的计算结果相差越大。     

轿车等速驱动轴传动效率的试验研究

针对国产某型轿车采用的两种等速驱动轴,利用试验方法对该驱动轴的传动效率进行了试验研究,探讨了万向节夹角、使用工况和转速等对其传动效率的影响.试验结果表明,驱动轴的传动效率随万向节夹角的增大而减小,而且两侧万向节夹角相等时驱动轴整体的传动效率会有所改善;挡位(转速和转矩)对驱动轴传动效率的影响不明显,但是在大夹角状态下,传动效率随挡位升高有增大趋势;在外侧万向节夹角较大的条件下,如果转矩不变而转速降低,则传动效率明显减小.     

模糊控制变增益在曲柄箱油雾浓度检测系统中的应用

由于曲柄箱油雾浓度变化范围很大，在计算机控制系统中，必须根据油雾浓度变化而改变增益，以保证A／D转换精度，本文介绍了采用模糊算法控制增益的方法。