摘要：The central solenoid(CS) is an important component of China Fusion Engineering Test Reactor, for producing, forming and stabilizing plasma in the superconducting tokamak. It is a complicated work to design and manufacture the large superconducting CS magnet, so it is meaningful to design a central solenoid model coil(CSMC) and analyze its electromagnetic properties in advance. In this paper, the structure, design parameters and magnetic field distribution of the CS model coil are discussed. The peak power of radial and axial turn conductors and time bucket loss are analyzed by using piecewise-linear method. The CSMC AC loss with different Nb3 Sn CICCs and AC loss of ITER CS coil are compared. The special electrometric method to measure AC loss of the CS model coil for future reference is presented.

摘要：指尖密封性能的量化表达和计算效率一直是设计人员关心的问题。针对指尖密封的工作特点,对其泄漏机理和磨损特性进行了分析。基于有限元分析构建了指尖密封性能量化表达的准动态性能模型,解决了理论设计中磨损和泄漏特性难以计算和计算工作量较大的问题。采用该方法的研究结果表明环境温度升高到300℃时,泄漏率较之27oC条件下降低了65%,磨损率升高了约4%;指尖片厚度从0.1mm增加到0.5mm时,泄漏率降低了70%,磨损率升高了28%;同时指尖曲梁个数、转子转速和压差对指尖密封性能同样具有重要影响。分析初步表明,提出的计算方法能够较好地反映指尖密封实际动态特性,为指尖密封性能设计提供了快捷高效计算方法。

摘要：为了避免在结构拓扑优化过程中杆件和节点的增删带来的奇异解,设计了一些启发式准则来产生结构可能的拓扑结构形式,再采用混合遗传算法———复合形遗传算法进行截面优化。把复合形法嵌入到遗传算法中,利用复合形法对群体中的可行个体和不可行个体分别进行处理,可提高遗传算法种群的质量,有利于最优解的搜索。该方法既有复合形法快速高效的特点,又有遗传算法全局性好的特点。算例的结果表明,该方法用于桁架结构拓扑优化设计是有效的。

摘要：在外界扰动出现时,含光伏的中压直流配电系统的母线电压会发生波动,给电力系统的稳定运行带来挑战。针对传统光伏恒压控制策略抗扰性不足的问题,提出了基于改进型线性自抗扰控制(linearactivedisturbance rejection control,LADRC)的光伏恒压控制策略。对于两级集成式的DC/DC变换器,采用基于微分反馈的线性扩张状态观测器(linear extended state observer,LESO),设计改进型LADRC结构,并详细分析了控制器的参数整定、抗扰性和稳定性。在仿真平台中将采用PI控制、传统LADRC和改进型LADRC的光伏恒压控制效果进行对比。结果表明,基于改进型LADRC的光伏恒压控制策略具有优秀的抗干扰能力,能够以更小的超调量和更快的响应速度使直流母线电压恢复稳定。

摘要：为提高永磁辅助同步磁阻电机(permanent magnet-assisted synchronous reluctance motor,PMa-SynRM)的输出性能,提出了基于核极限学习机(kernel extreme learning machine,KELM)和快速非支配排序遗传算法(nondominated sorting genetic algorithm,NSGA-II)相结合的外转子PMa-SynRM多目标优化设计方法。首先,对PMa-SynRM转子磁障进行初步设计并分析PMa-SynRM工作原理。其次,通过综合敏感性分析评估每个设计变量对优化目标的影响,选取主要优化参数。然后,以高输出转矩、高效率和低转矩脉动为优化目标,建立基于KELM的代理模型。最后,采用NSGA-II进行全局寻优,从NSGA-II生成的Pareto前沿中选择最优解,并通过有限元分析进行验证。仿真结果表明:优化后的电机较初始电机平均转矩提高了15.83%,转矩脉动降低了60.27%,且优化后电机效率较初始电机也有所提高,验证了本文优化设计方法的有效性。

摘要：非对称交酯合成效率低,开环聚合(ROP)产物分子量小,因此很少有研究报道聚非对称交酯的流变行为与力学性能.本研究采用N,N-二异丙基乙胺(DIPEA)作为缚酸剂,通过均相反应体系高效合成了多种非对称交酯,经ROP得到数均分子量70 kg/mol的聚非对称交酯;并对聚合物的化学结构、热学性能、流变行为和力学性能进行了表征.热学测试和力学性能测试结果表明5种聚酯材料均为非晶聚合物,在单体结构中引入高支化度饱和烷烃取代基和芳香族取代基可以提高聚合物玻璃化转变温度,而聚合物侧链的低支化度饱和烷烃取代基会降低其玻璃化转变温度并提高断裂伸长率.流变测试结果表明,不同取代基的聚非对称交酯的零切黏度均低于聚乳酸,并且聚合物的缠结分子量受取代基影响.本研究为聚酯材料结构设计与性能调控提供了有益参考.

摘要：党的二十届三中全会强调要提升产业链供应链韧性和健全安全制度,打造自主可控、安全可靠的产业链供应链。在此背景下,研究我国产业链供应链安全发展的逻辑、障碍与路径,可以为实现我国产业链供应链安全发展提供重要的理论基础。产业链供应链安全发展的逻辑,是实现产业链供应链安全需要确保主体要素和结构要素的安全。通过对大宗原料、规模化制造、高新技术、生产性服务四大重点产业的八家典型企业的多案例研究,基于主体要素和结构要素的安全逻辑,识别我国重点产业的产业链供应链安全障碍。进而构建产业链供应链安全发展的路径,包括维护路径和阶跃路径两个维度。维护路径强调从主体要素和结构要素两个视角展开。阶跃路径强调以社会引领、技术驱动、制度辅助为核心要素。为实现维护路径和阶跃路径的有效实施,对于维护路径,需要启动我国重要产业链供应链的韧性战略设计和完善本土产业链供应链安全预警机制;对于阶跃路径,需要通过产业集群和搭建产业信息服务体系支持本土企业深度参与全球产业链供应链重构,通过改革科技创新体制加快突破产业链供应链的关键核心技术,通过构建全国统一大市场推动产业链供应链增加需求活力。

摘要：目的探讨陀螺式钴-60立体放射治疗系统产生的轫致辐射的屏蔽及对环境的影响。方法以一台陀螺式钴-60立体放射治疗系统为例,运用剂量估算法进行屏蔽防护设计及核实。结果依据陀螺式钴-60立体放射治疗系统运行上限参数,对射线初级和次级屏蔽层以及加速器防护门的屏蔽能力等进行估算和分析。机房的相应屏蔽层厚度设计可以满足防护设计要求。结论建设此类设施,只要加强辐射防护,陀螺式钴-60立体放射治疗系统产生的轫致辐射对周围环境的影响是可接受的。

摘要：In the context of global climate change and urbanization,urban flooding is an important type of natural disaster that affects urban development,especially in China,which is experiencing rapid *** the past 10 years,urban flooding events have caused huge disaster losses in Chinese *** has resulted in significant negative effects on the urban infrastructure,socioeconomic systems,and urban residents,thus causing widespread *** have confirmed the change in extreme rainstorms is due to the changing environments in many cities *** studies on the impact of these rainstorms with different characteristics for urban flooding is valuable for coping with unfavorable *** addition,numerical simulations provide an economical and viable means to perform these *** paper presents a numerical model of Xiamen Island in *** were conducted for 12 design rainstorm events with different return periods,rain patterns,and *** results indicate that,in the case of an equal rainfall amount,the rainfall intensity is the key factor that affects the inundated area,depth,and ***,the rainfall intensity is not the only determining factor;the rainfall pattern also affects the *** regard to the rainfall pattern,a higher rainfall peak coefficient usually leads to severe urban inundation and *** a result,the lag time would be shorter,which may further exacerbate the impact of urban flood *** results of this study provide insights into managing flood risks,developing urban flood prevention strategies,and designing flood prevention measures.

摘要：In this paper, a novel idea for rate allocation combining both vertical coupling and horizontal coupling constraints is proposed, and a unified utility function to balance two paradoxical issues: efficiency and fairness, revenue and cost is elaborated in WCDMA networks. Then, the optimal rate allocation problem is formulated as a network utility maximization(NUM) model based on cross-layer design and end-to-end congestion control, aiming at exploring the impacts of wired networks and the characteristics of radio access networks(RANs) on rate allocation. Furthermore, a distributed algorithm is derived, which can effectively match load states between RANs and wired networks, followed by a detailed illustration of the practical implementations. Numerical results demonstrate a signifi cant performance improvement in the end-to-end throughput.