三代压水堆内陆厂址放射性流出物排放问题及改进建议

由于内陆厂址受纳水体容量有限,使得核电内陆厂址面临的一个关键问题就是液态流出物排放。本文通过对比分析三代压水堆内陆厂址液态流出物排放与现有排放国家标准要求,发现三代压水堆两项指标不能满足内陆厂址要求,即除氚、¹⁴C外其他放射性核素和氚排放均不能满足内陆厂址要求。针对除氚、¹⁴C外其他放射性核素排放,建议增加化学絮凝、离子交换床和反渗透装置以满足100 Bq/L的排放要求。针对氚排放,通过调整排放方式能满足2台机组氚排放要求,使得下游1 km处氚浓度不超过71 Bq/L;多机组内陆电厂的氚排放建议利用联合电解催化交换(CECE)和水精馏(WD)技术,以达到分离氚的目的。     

一种基于实时几何测距的船桥主动防撞方法

本文提出一种基于实时几何测距的船桥主动防撞方法。该方法对船的改动量甚微,仅需维持多项距离矩阵,通过告警逻辑矩阵进行展示与告警,能起到很好的船桥防撞提示效果。     

Global stable tracking control of underactuated ships with input saturation

In this paper, tracking control of underactuated ship in the presence of input saturation is addressed. By dividing the tracking error dynamic system into a cascade of two subsystems, the torques in surge and yaw axes are designed separately using the backstepping technique. More specifically, we design the yaw axis torque in such a way that its corresponding subsystem is finite time stable, which makes it to be de-coupled from the second subsystem after a finite time. This enables us to design the torque in the surge axis independently. It is shown that the closed-loop system is stable and the mean-square tracking errors can be made arbitrarily small by choosing design parameters. Simulation results also verify the effectiveness of the proposed scheme.     

舰船综合业务传输设备的EMC设计

阐述了舰船综合业务传输设备的EMC设计思想,提出了具体解决方案.实践证明该方法可以有效地屏蔽各种电磁信号的干扰,保证设备正常工作.     

Upgrading of Sewerage Assets to Comply with New Legislation: A Lothian Regional Viewpoint

The EC bathing water Directive and the recent EC urban waste water treatment Directive have provided, and will continue to provide, a strong stimulus for the provision of environmental improvement through the upgrading of sewerage assets. The positive response by Lothian Regional Council to necessary improvements in the last fifteen years, and the proposed improvements in the next fifteen years, are reviewed against the background of financial constraints. It is suggested that parts of the urban waste water treatment Directive relating to estuarial and coastal discharges are not appropriate or necessary in the context of conditions in Lothian Region.     

Impact in Scotland of UK and EC Sewage Legislation

The EC Directive (91/271/EEC) concerning urban waste water treatment has far-reaching financial and technological implications for local authorities in Scotland which are responsible for sewerage. Increased capital consent limits and additional financial assistance from central government are essential if the requirements of the legislation are to be met.
Although the Directive is welcomed in general terms, the sections of the legislation dealing with the identification of sensitive waters and the provision of primary treatment for coastal discharges to less sensitive waters are of limited environmental significance in Scotland.
The elimination of sewage sludge disposal at sea will create severe difficulties for Scottish authorities as a high percentage of sewage sludge is currently disposed of at sea. Each of the main alternative disposal options presents environmental, financial and technical problems and, in the case of incineration, the certainty of widespread unpopularity with the public.     

近代内陆自建公园营造的“自在”与 “自为”——以西安莲湖公园为例

西安莲湖公园是近代西北地区最早进行系统建设的 自建公园之一，其早期持续的营建活动不仅是近代内陆园林转 型历程的一个缩影，也展现出不同于沿海开埠地区城市公园的 鲜明特色。为探求近代内陆自建公园营造在“西风东渐”文化 冲击下的自主探索与能动受纳，引入“自在”与“自为”这一 对概念，系统梳理近代时期莲湖公园由整备、营造、修葺到重 建4个阶段中“自在”的营建特征和“自为”的主导观念，借 此总结近代自建公园营建之客观内涵背后的能动本质，以史为 鉴反思近代公园建设发展的经验教训，也为新时代的公园更新 提供更多参照。     

空间视角下的温瑞塘河保护规划

在快速城市化的背景下,对温瑞塘河进行了保护规划,针对其存在的问题,从空间的角度,以用地管制为主要手段,确定了保护主体的范围,明确了用地控制和管理权限,从而起到确保流域生态安全的作用,这是对城市内河水网保护途径的一种新尝试。     

一种贝叶斯目标选择算法

为了解决多假目标干扰环境下的舰艇编队目标选择问题,在线性高斯假设下,建立了编队目标运动模型和量测模型,并基于贝叶斯方法推导了复合假设后验概率,提出了一种反舰导弹目标选择算法。该算法充分利用了导弹导航位置误差、编队机动和队形等信息,并且适用于量测噪声方差不同的实际情况。同时,为了降低算法的计算复杂度,设计了基于队形的预滤波器,大大削减了复合假设数量。算例仿真表明,该算法具有优良的性能,显著提高了编队目标正确选择概率。     

内河船舶柴油机排放法规及应对措施试验研究

介绍了我国内河船舶柴油机气态污染物排放控制法规。选取某型内河船用主推进柴油机开展原机排放台架测试试验。基于法规限值要求,制定了降低该柴油机排放措施,即加装选择性催化还原系统。试验结果表明:该型柴油机在加装了SCR后处理系统后,排气污染物中CO、HC+NO_x比排放满足法规限值要求,且对柴油机油耗率、压降等性能影响较小。最后,对柴油机颗粒物排放处理措施进行了探讨,可为内河船舶柴油机排放治理技术路线的选择提供参考。