浅谈C50混凝土配合比设计

对C50混凝土配合比设计中值得注意的几个问题进行分析,并提出相应的防治措施。     

平均排队长度差最小的单交叉口在线Q学习模型

为改善交叉口排队长度管理,避免交叉口某个方向排队长度过长,采用强化学习理论建立了以平均排队长度差最小为优化目标的在线Q学习模型.针对控制性能指标相对于邻近的配时方案不敏感的特点,提出了以平均排队长度差作为基本单位重新构造奖励函数,目的是拉大各行为对应的Q值差距,提高模型的收敛速度和鲁棒性.集成Excel VBA,Vissim,Matlab建立了在线仿真平台,作为计算环境对算例进行了计算.算例中利用GPS数据对Vissim软件中车辆加减速度曲线进行了标定.计算结果表明以平均排队长度差作为优化目标能够提高各个方向排队长度的平衡性,优化整个交叉口的时空资源;建立的在线Q模型具有学习能力和较快的计算速度,模型能否收敛受到周期取值和可选行为数量的影响.     

复杂海况下基于强化学习的USV局部路径规划方法研究（英文）

Conducting hydrodynamic and physical motion simulation tests using a large-scale self-propelled model under actual wave conditions is an important means for researching environmental adaptability of ships. During the navigation test of the self-propelled model, the complex environment including various port facilities, navigation facilities, and the ships nearby must be considered carefully, because in this dense environment the impact of sea waves and winds on the model is particularly significant. In order to improve the security of the self-propelled model, this paper introduces the Q learning based on reinforcement learning combined with chaotic ideas for the model's collision avoidance, in order to improve the reliability of the local path planning. Simulation and sea test results show that this algorithm is a better solution for collision avoidance of the self navigation model under the interference of sea winds and waves with good adaptability.     

Local path planning method of the self-propelled model based on reinforcement learning in complex conditions

Conducting hydrodynamic and physical motion simulation tests using a large-scale self-propelled model under actual wave conditions is an important means for researching environmental adaptability of ships. During the navigation test of the self-propelled model, the complex environment including various port facilities, navigation facilities, and the ships nearby must be considered carefully, because in this dense environment the impact of sea waves and winds on the model is particularly significant. In order to improve the security of the self-propelled model, this paper introduces the Q learning based on reinforcement learning combined with chaotic ideas for the model＇s collision avoidance, in order to improve the reliability of the local path planning. Simulation and sea test results show that this algorithm is a better solution for collision avoidance of the self navigation model under the interference of sea winds and waves with good adaptability.     

混凝土回弹强度差异的原因分析与控制要点

针对某高速公路某标段40 m T梁28 d回弹强度较低的情况进行了因素分析。从影响混凝土强度的养护、配合比、原材料、施工组织因素四大方面进行论述。文章论述的同时强调了混凝土强度的控制要点,强调了试验室要与现场实际情况结合并做到动态控制。     

焊后处理工艺对Q345E低合金钢焊接接头疲劳性能的影响

通过对K型坡口Q345E低合金钢T型角接接头三点弯曲疲劳试验,研究了焊趾不处理、焊趾打磨、焊趾喷丸、焊趾打磨+喷丸处理对焊接接头疲劳性能的影响.结果表明,焊接接头焊后细节处理工艺对接头疲劳性能的影响十分显著,焊趾打磨和焊趾喷丸均是提高焊接接头疲劳性能的重要手段,而焊趾打磨+喷丸处理综合处理时效果最佳.     

基于DSP的50Hz相敏轨道电路接收器的设计与实现

50Hz相敏轨道电路被广泛应用于城市轨道交通的轨道电路系统,其接收端所采用二元二位继电器存在诸多不安全因素,给轨道交通的正常运营埋下了较大隐患。介绍所设计的一种微电子式的相敏轨道电路接收器,选用TI公司的TMS320LF2407A作为控制CPU,采用双DSP架构的硬件冗余设计,并执行双套软件,利用数字信息处理技术对轨道电路信息进行识别,从软件和硬件上提高设备的安全性。     

Q345qD桥梁钢对接焊缝疲劳裂纹扩展性能试验研究

为采用断裂力学方法对既有钢桥焊接细节进行疲劳评估,对6.1,10.0和23.5 mm的Q345q D桥梁钢对接焊缝进行疲劳裂纹扩展速率试验和疲劳裂纹扩展门槛值测定试验,基于两种数据处理方法得到了不同厚度、不同应力比下的疲劳裂纹扩展速率参数。试验结果表明:在通常的应力强度因子幅值范围(10~70 MPa·m0.5)内,基于单试件数据点的处理结果对应的裂纹扩展速率明显高于基于成组数据点的处理结果;Q345q D对接焊缝的疲劳裂纹扩展速率随应力比增加而增加;本批次的Q345q D对接焊缝的疲劳裂纹扩展性能优于BS7910中给出的通用钢材疲劳裂纹扩展性能;Q345q D对接焊缝疲劳扩展门槛值随应力比增加而降低,并给出了门槛值随应力比变化的公式。     

洛美沙星葡萄糖注射液的药效学研究

报道了洛美沙星葡萄糖注射液的体内、体外抗菌活性，并与其口服制剂及环丙沙星注射液进行了比较。结果表明：洛美沙星注射液是一种广谱、高效、作用迅速的抗菌药物，对革兰氏阳性茵的MIC为0．31～20mg／L，对革兰氏阴性菌的MIC为0．005～10mg／L。杀菌实验表明：对金葡菌、大肠杆菌、痢疾杆菌、肺炎杆菌及绿脓杆菌为杀菌作用。抗菌效果基本不受PH、接种菌量和血清蛋白结合的影响。体内效果（ED50）优于口服制剂。体内、外抗菌活性近似于环丙沙星。     

THE CLINICAL SIGNIFICANCE OF MONITORING CARBOHYDRATE ANTIGEN CA50 IN COLORECTAL CARCINOMA

AntigenssuchasQ-fetoproteinandcarcinoembryonicantigenhavebeenusedasmarkersforthediagnosisandpostoperativeevaluationofpatientswithmalignanttumors.Lindholmetaldetectedamalignanttumorcelllinebyusinghybridomatechniquein1983,themonoclonalantibodiessecretedbythecelllineweredefinedasC50.TheantigenrecognizedbyC50monoclonalantibodywasnamedCA50.Itwasraisedagainstacolorectaladenocarcinomacellline.CA50antigenexistsonthecellsurfaceintheformoflipidorlipoproteincomplex,belongingtothemarkerofsphingoglycoli…