珠三角港口改造引发的通航安全问题

以沙角B电厂煤码头水工结构加固改造工程为实例,对珠三角地区港口改造升级引发的水上通航安全问题进行探讨,提出了改造方案和水上安全生产对策,为港口码头改造升级服务.     

Comparative study on ghrelin level change and its related factors in hypertensive elders with psychological distress

Objective To investigate the change of plasma ghrelin level and explore the related factors of ghrelin alteration in elderly hypertensive patients with psychological distress. Methods A total of 300 elders, who were screened with Hamilton Anxiety Scale (HAMA), Hamilton Rating Scale for Depression (HAMD), and the Symptom Checklist-90 (SCL-90) for psychological stress and somato-psychological manifestations respectively, were divided into hypertension group (n=148) and non-hypertension group (n=152). Their blood samples were collected to measure the plasma level of ghrelin and total cortisol on the same day. Results The incidences of anxiety and depression were 27.7% and 11.7%, respectively, in all the enrolled elders. However, the rates of psychological distress, particularly anxiety, were significantly higher in the hypertensive elders than in the non-hypertensive ones (43.2% vs. 12.5%). Anxiety was positively related to the cortisol level but negatively related to the plasma ghrelin level, and the latter two were negatively correlated with each other. Conclusion Chronic increase of plasma cortisol induced by long-term anxiety can lead to the reduction of ghrelin level, which then adversely affects blood pressure in elders with psychological distress. Therefore, ghrelin might be a selective antihypertensive medicine for hypertensive elders with anxiety.     

Inhibitory action of docetaxel on the proliferation of HeLa and SiHa cells

Objective To study the inhibitory action of docetaxel (DOC) on the proliferation of HeLa and SiHa cells. Methods Cell morphological changes were observed with inverted phase contrast microscope. MTT was adopted to test and calculate the cell inhibition ratio. Flow cytometry was used to detect cell cycle. Results DOC had an obvious concentration-dependent inhibitory effect on the proliferation of both HeLa and SiHa cells. The inhibition ratio of DOC on SiHa was significantly higher than that on HeLa (P<0.05). DOC blocked HeLa at G2/M phase. Under the effect of DOC, the cell cycle of SiHa was not changed much. Conclusion DOC has an obvious inhibitory action on both HeLa and SiHa cells, which shows a promising prospect of DOC in clinical treatment of cervical cancer.     

采用马歇尔设计方法对旧沥青混合料进行热再生设计研究

该文介绍利用马歇尔试验方法进行旧沥青混合料热再生的设计研究,并对再生沥青混合料的路用性能进行了检测。     

高速公路桥面沥青混凝土防水层的设计方案

该文针对目前高速公路桥面渗水现象严重及其对桥梁的危害,对目前我国应用的聚氨酯防水涂料、乳化沥青、渗透结晶型DPS材料和渗透非结晶凝胶型SF材料等四种材料进行材料性能测试比较,并结合工程实践经验,得出选用渗透非结晶凝胶型SF材料作为沥青混凝土防水层是一种理想的方案。     

公路隧道围岩失稳概率计算中随机参数样本的修正

基于围岩变形破坏原理,建立了围岩稳定极限状态方程的普遍形式。研究了响应面方法求解该方程的过程,得出经典响应面方法仅仅适用于围岩物理力学参数随机分布曲线偏度系数为零的情况。针对围岩物理力学参数统计分布曲线的复杂性,利用统计矩参数对随机变量分布曲线形态特征的控制作用,提出了抽样样本修正方法和具体计算公式。归纳了修正后响应面算法的运行程序。以某公路隧道为例,分别采用经典算法和修正后算法计算了围岩稳定可靠度,然后与蒙特卡洛模拟结果进行了对照,经典方法计算结果与准精确解的绝对误差为1.017%,修正方法的计算结果与准精确解的相对误差为0.388%.     

斜坡路基沥青路面结构动力响应分析

斜坡地段公路的主要破坏形式是斜坡路基的稳定和沥青路面的纵向开裂。斜坡路基沥青路面的力学行为因其特殊的结构形式有其显著特点。现场调查表明轮载动力作用直接影响斜坡路基稳定及上承路面结构的响应。采用有限元软件ABAQUS建立了斜坡路基路面动力计算模型,分析了车辆荷载作用下斜坡路基动应力、路表弯沉以及基层层底拉应力的变化规律,重点研究了车辆轴载、行车速度、面层刚度、面层厚度、基层刚度、基层厚度、路基模量等外加荷载状态、路面层状组合与材料力学性能方面的参数对斜坡路基沥青路面结构动力响应的影响。分析认为斜坡路基填筑质量、基层厚度和动力作用对路面响应具有重要影响,设计、施工和管理中必需采取有针对性的措施以防止路面的早期破坏并保证路面的长期使用性能。     

223省道岩质高陡边坡稳定性的分析评价

针对广东省道223线岩质高陡边坡的稳定性问题,从其地形地貌、地层岩性、岩体结构等方面论证了对边坡稳定性的影响,并结合岩体质量分级及赤平极射投影法,对边坡的稳定性进行定性的工程地质分析。结果表明：岩质边坡整体上是稳定的,但应注意局部稳定性问题。     

基于仿真分析的汽车侧翻风险研究

侧翻事故是汽车产品缺陷可能引发的一种典型风险.文中应用ADAMS软件建立仿真模型,模拟车辆侧翻事故过程以研究其发生机理,并通过正交试验分析了侧翻风险与其主要影响因素之间的关系.     

Application of support vector machine to ship steering

System identification is an effective way for modeling ship manoeuvring motion and ship manoeuvrability prediction. Support vector machine is proposed to identify the manoeuvring indices in four different response models of ship steering motion, including the first order linear, the first order nonlinear, the second order linear and the second order nonlinear models. Predictions of manoeuvres including trained samples by using the identified parameters are compared with the results of free-running model tests. It is discussed that the different four categories are consistent with each other both analytically and numerically. The generalization of the identified model is verified by predicting different untrained manoeuvres. The simulations and comparisons demonstrate the validity of the proposed method.