给水管道腐蚀原因及防护措施探讨

给水管道在使用过程中很容易受到人为外力、管道材质、地下水、周围空气、土壤等因素的影响而腐蚀,影响了管道的使用质量和寿命,也带来较大的安全隐患。本文主要是从给水管道腐蚀原因出发,并探讨防护措施。     

面向智慧小镇建设的机房电气管线多目标优化布置方法

常规的管线布置优化方法难以在优化过程中得到全局搜索的最优解,导致安全性能无法得到保障,因此面向智慧小镇建设设计一个新的机房电气管线多目标优化布置方法。设置电气管线约束条件,将电压均值、单位时间内电流量、电气管线损耗恢复能力作为目标函数。优化管线布置全局搜索,使用交叉操作的方式不断得到更优解。建立多目标优化电气管线模型,得到电气管线多目标优化的数学模型。通过实验数据可知,该管线布置方法在算法测试中优于常规的3种算法,且在安全性能的检测中只与标准最优值相差6.22×10⁴,3个常规方法与标准最优值的差距为6.813×10⁴、7.6×10⁴、8.32×10⁴,因此可知该多目标优化的管线布置方法可以得到更优解。     

基于光谱尺度空间与管道滤波的红外目标检测

为了准确地从复杂干扰背景下检测出真实弱小目标，本文引入视觉显著性，设计了基于快速光谱尺度空间与动态管道滤波的红外目标检测算法。基于真实目标与背景内容之间的整体差异，引入快速光谱尺度空间与阈值分割技术，设计视觉显著性机制，对红外图像完成处理，输出全局显著性映射，以高效过滤干扰背景内容。考虑目标与背景的局部特征差异，构建自适应局部对比度增强机制，对粗检测结果实施处理，获取对应的局部显著性映射，改善视觉显著性区域内目标的对比度。引入高斯差分理论，通过估算每一帧红外图像中的目标像素直径，形成动态管道滤波，充分消除虚警，准确识别出弱小目标。多组实验数据显示：较已有的红外目标检测技术而言，在各种不同的复杂背景干扰下，所提算法呈现出更好的检测能力，拥有更理想的接收机工作特性ROC曲线。     

温州某公轨共建高架车站结构设计

为了解决城市廊道资源的紧张和公共交通发展需求的矛盾,出现了轨道交通和快速路的共建型式,即公轨共建的复合型交通模式,以温州市域铁路S2线一期工程的人民路站为例,研究公轨共建高架车站的结构设计要点。首先,为降低浅层气体对桩基的承载力及沉降影响,对遇到局部浅层气体发育的基础设计提供了合理的解决方案。然后针对公轨共建一体化车站分别进行了多遇和罕遇地震作用分析,研究表明构件及整体指标满足规范要求。最后针对工程的一些关键技术,如快速路桥面体系的选型、超长结构温度应力的控制措施、轨道梁挠度及应力的控制、快速路桥面振动对车站的影响等进行了分析,并给出了具体的解决方案和指导意见。     

海河平原区地下水累计可恢复超采量评价

地下水累计可恢复超采量评价对于地下水超采态势评判和超采综合治理实施都具有重要意义。本文以海河平原区为研究对象，提出超采量评价方法，旨在客观准确评价地下水累计可恢复超采量。针对浅层地下水超采量，提出生态临界水位作为传统“水位动态法”评价浅层地下水超采量的临界水位，据此得到研究区1959-2019年累计浅层超采量为869亿m³；针对深层地下水超采量，提出“不可恢复超采量”评价指标，采用地面沉降体积法评价深层地下水超采量，根据地面沉降体积计算深层承压含水层系统压密释水量体积，据此估算1970-2019年深层累计超采量为756亿m³；通过建立的一维非线性压密释水数值模型，模拟了深层承压含水层系统压密释水过程，计算得到非弹性压密释水量，评估研究区累计不可恢复超采量为558亿m³。因此本文认为，自1960年代以来，海河平原区地下水浅层和深层累计超采量1625亿m³，其中可恢复的超采量仅为1067亿m³。该研究结果可为未来地下水回补水量和南水北调规划调水量的确定提供参考。     

Near-Field Drives Long-Lived Shallow Trapping of Polymeric C3N4 for Efficient Photocatalytic Hydrogen Evolution

Undesired photoelectronic dormancy through active species decay is adverse to photoactivity enhancement. An insufficient extrinsic driving force leads to ultrafast deep charge trapping and photoactive species depopulation in carbon nitride (g-C₃N₄). Excitation of shallow trapping in g-C₃N₄ with long-lived excited states opens up the possibility of pursuing high-efficiency photocatalysis. Herein, a near-field-assisted model is constructed consisting of an In₂O₃-cube/g-C₃N₄ heterojunction associated with ultrafast photodynamic coupling. This In₂O₃-cube-induced near-field assistance system provides catalytic “hot areas”, efficiently enhances the lifetimes of excited states and shallow trapping in g-C₃N₄ and this favors an increased active species density. Optical simulations combined with time-resolved transient absorption spectroscopy shows there is a built-in charge transfer and the active species lifetimes are longer in the In₂O₃-cube/g-C₃N₄ hybrid. Besides these properties, the estimated overpotential and interfacial kinetics of the In₂O₃-cube/g-C₃N₄ hybrid co-promotes the liquid phase reaction and also helps in boosting the photocatalytic performance. The photocatalytic results exhibit a tremendous improvement (34-fold) for visible-light-driven hydrogen production. Near-field-assisted long-lived active species and the influences of trap states is a novel finding for enhancing (g-C₃N₄)-based photocatalytic performance.     

现代市政道路给排水管道工程的设计与施工探讨

市政道路给排水管道工程设计与施工是一个综合性的过程,要考虑各个方面的影响因素,其工程质量关系着城市运行的稳定性,具有非同寻常的作用。在市政道路给排水工程施工中,需要涉及到多个工艺环节,要合理调控各个环节的连接关系,保证工程的有序施工,严格管控工程质量。     

Flow modeling of high-viscosity fluids in pipeline infrastructure of oil and gas enterprises

Today, the issues related to solving the problem of finding an effective distribution of oil flows through the system of oil pipelines in order to reduce the total energy consumption are relevant. The solution to this problem is connected with selection of rational pumping modes for various technological sections of oil pipelines using modern methods of mathematical programming or new techniques for improving the energy and transport characteristics of oil.Reducing energy consumption during pumping of crude through oil trunk pipelines can be achieved by various methods. Numerous investigations in this direction are mainly carried out to save energy on separate single-line pipelines. However, due to the development of the network of trunk oil pipelines in the world over the past decades, the issues of energy efficient management of oil flows throughout the entire oil pipeline system of oil and gas enterprises become urgent.This paper analyses parameters for pipeline transport of high-viscosity and heavy oils. The article proposes a method for assessing the rheological properties of oil for further planning of pumping taking into account the preservation of oil quality and an increase in energy and transport characteristics. The proposed solutions and tasks for predicting changes in the viscosity-temperature characteristics of the flow for blends of different oil types are especially relevant in the current conditions of an increase in the share of oil production with complex rheological characteristics. Results of the presented investigations may be used for planning the measures of efficient transportation of high-viscosity and heavy oils.     

The corrosion behavior and mechanism of X65 steel induced by iron‐oxidizing bacteria in the seawater environment

The corrosion behavior and mechanism of iron‐oxidizing bacteria (IOB) on X65 steel in seawater are studied. This study uses the methods of weight loss, electrochemical measurements, and surface analysis. The results show that the IOB increases the corrosion damage degree of steel. Pittings are observed in the medium with IOB. The potentiodynamic polarization curves show that the anodic reaction rate is accelerated in the corrosion process of IOB. The synergies in corrosion between the metal surface, abiotic corrosion products, and bacterial cells, and the pitting corrosion mechanism of X65 steel are discussed.