煤炭生产、消费与工业SO2排放关系计量研究——以西部8省为例

研究目的：探究工业SO₂排放与煤炭生产、消费存在必然的联系。研究方法：相关分析方法和改进的物理学重心模型。研究结果表明：(1)时序特征显示:西部煤炭生产、煤炭消费量和工业SO₂排放量整体都呈现上升趋势,三者增长率均呈现多波峰“M”状波动。2)重心轨迹显示:工业SO₂排放轨迹呈现为“倒L”型,煤炭生产和消费轨迹呈现为“J”型。(3)综合对比发现:煤炭生产从源头上影响工业SO₂排放,煤炭消费从空间上影响工业SO₂排放,为消减工业SO₂排放改善生态环境,必须在优先减少煤炭消费增加清洁能源比重的同时,更应该关注对煤炭生产过程的管控。     

陈四楼煤矿岩巷综合机械化掘进探索

为提高岩巷单进水平，减轻职工劳动强度，在“多上设备少上人”的理念指导下，陈四楼煤矿一直在探索着岩巷快速掘进技术，先后在不同地点、不同条件下实践了6条不同设备配套形式的岩巷作业线，通过对不同岩巷作业线优缺点的对比，在探索中不断改进，使得在不同条件下的岩巷作业线形式逐渐清晰、成熟，最终总结出了适合陈四楼煤矿较为成熟的岩巷作业线，车场、联络巷等较短或拐弯较多的巷道采用耙装机+胶带输送机+采区矸石仓岩巷作业线形式，主要大巷采用液压钻车+挖掘装载机+胶带输送机+采区矸石仓岩巷作业线，与传统的人工打眼、耙矸机+矿车出矸系统比较，采用岩巷作业线平均单进水平由传统工艺的60 m/月提高到90 m/月，施工人员由12人减少到8人，极大地提升了岩巷单进水平、提高工效，降低工人劳动强度。     

一种使用多维度直方图匹配的图像风格迁移算法

在传统的基于直方图匹配的图像风格迁移算法的基础上，提出一种新的基于多维度直方图匹配的图像风格迁移算法。通过构建关于原图像的不同维度的直方图，然后进行原图像和目标图像的匹配，分别得到原图像在不同维度直方图下的风格迁移图像，最后对这些风格迁移后的图像进行融合生成最终的结果。在保持原图像与目标图像整体风格上尽量相似的情形下，同时又使原图像的局部细节尽可能保留，实现整体风格相似却又保留局部细节的平衡。     

超宽带大功率合成器设计北大核心CSCD

在80 MHz~1 GHz频段,单个功率管输出功率能达到100 W以上,为研制输出功率400 W的功率放大器,文中设计了四路功率合成器。该合成器需要实现功率容量大、工作频带宽、体积小的设计目标。在功率容量方面,文中采用悬置带状线结构,其功率容量远远大于微带线结构;在工作频带方面,采用切比雪夫九节阻抗变换器,将工作带宽拓宽为80 MHz~1 GHz;在体积方面,文中合成器的功率合成部分采用Y型节级联实现四路功率合成,阻抗变换部分采用切比雪夫阻抗变换器进行阻抗变换,该结构相较于磁环巴伦功率合成器,不但具有损耗小、平坦度高的优点,而且通过将阻抗变换器设计成曲折的形状,进一步缩小了合成器体积。仿真与实测结果显示该合成器在80 MHz~1 GHz范围内还具有较高的平坦度,合成效率可达90%以上。     

Water leakage due to the welding defect and improvement to reach 1-MW beam operation in the mercury target of J-PARC

ABSTRACT

Neutron flux per pulse reached world record at neutron source in Japan Proton Accelerator Research Complex (J-PARC). In the J-PARC, mercury target system is used as a spallation neutron source. A target vessel has a multi-walled protection system that comprises a mercury vessel enclosed with a double-walled water shroud. This is to prevent the leakage of the mercury outside the target vessel. The multi-walled structure needed to be complicated with a lot of welding lines. However, during the operation, we faced an unscheduled shutdown due to water leakage to the intermediate layer between the mercury vessel and water shroud. An investigation on the cause of the leakage was carried out. It is deduced that the leakage path was formed due to the crack propagation from welding defects that are caused by the complicated multi-walled structure. The crack propagation is attributed to the repeated stress by pressure waves generated in the mercury target. Based on the investigation results, the design was improved to remove the welding line on the complicated structure and to realize the stable operation with 1 MW proton beam, which is the final design value of the neutron source in J-PARC.     

Optimal cost design of flow lines with reconfigurable machines for batch production

Modular reconfigurable machines offer the possibility to efficiently produce a family of different parts. This paper formalises a cost optimisation problem for flow lines equipped with reconfigurable machines which carry turrets, machining modules and single spindles. The proposed models take into account constraints related to: (i) design of machining modules, turrets, and machines, (ii) part locations, and (iii) precedence relations among operations. The goal is to minimise equipment cost while reaching a given output and satisfying all the constraints. A mixed integer programming model is developed for the considered optimisation problem. The approach is validated through an industrial case study and extensive numerical experiments.     

Optimised memory allocation for less false abortion and better performance in hardware transactional memory

ABSTRACT

This paper introduces and tackles a special performance hazard in Hardware Transactional Memory (HTM): false abortion. False abortion causes many unnecessary transaction abortions in HTM and can greatly impact the performance, making HTM not that useful when it is adopted as a fast path for Software Transactional Memory. By introducing a new memory allocator design, we are able to put objects that are likely to be accessed together from different threads into different cache lines and thus avoid conflicts of hardware transactions in different threads. Experiments show that our method can reduce 47% of transaction abortion and achieve a speedup of up to 1.67× (averagely 22%), yet only consume 14% more memory, showing great potential to enhance current HTM technology.     

飞机电子系统线路的故障维修分析

飞机电子线路在飞行过程中的运行状态会对飞机飞行性能造成直接影响。电子线路在实际工作中会产生一些故障,此种故障较为常见,并且故障表现形式会存在一定差异。本文能对飞机线路维修方法进行简单阐述,对线路故障检修措施进行简单分析,最后提出线路故障预防措施。     

地铁列车-嵌入式轨道系统动力学性能研究I：理论建模、试验分析及验证

嵌入式轨道作为一种减振降噪轨道结构型式，通常是基于城市街道路面的低地板有轨电车系统设计的，而嵌入式轨道的连续支承特性及其减振降噪优点使其在地铁中具有较好的应用前景。嵌入式轨道在地铁中应用，将面临更高运行速度、更大轴重、更复杂线路条件等挑战，地铁列车-嵌入式轨道系统的动力学行为有待研究。建立地铁列车-嵌入式轨道系统的动力学模型，模型包括轨道系统模型、列车系统模型以及轮轨相互作用模型。其中，轨道子系统为嵌入式轨道系统，是建模和研究的重点。模型考虑了TIMOSHENKO钢轨模型、等效弹簧-阻尼单元支承的柔性轨道板模型、以及钢轨周围的填充材料模型，填充材料模型采用考虑质量的黏弹性弹簧-阻尼单元来模拟以考虑填充材料的惯性、弹性和阻尼特性。在我国首例运用于地铁的嵌入式轨道试验线开展了动力学性能试验研究，基于试验分析了动力学性能并通过试验验证了动力学模型的有效性，建立的分析模型和相关结论为嵌入式轨道结构在我国地铁的应用提供了理论基础和参考。