摘要：Based on coral proxies we reconstructed the western Pacific warm pool sea surface temperature (SST) since 1644 AD. High-frequency reconstructions are based on eight high-pass filtered coral series and raw reconstructions are derived from eight unfiltered coral series, respectively. Validation and comparison with other SST/temperature series show that the reconstructed warm pool SST is highly reliable. The leading periods of warm pool SST are ～2.1, ～2.3, ～2.9, ～3.6, ～3.8, and 80.7-year during the last ～360 years. The warm pool SST exhibits some obvious long-term trends: an upward trend of 0.04°C per century for the period of 1644–1825, while a decreasing trend of 0.24°C per century for the period of 1826–1885, and then a remarkable warming trend of 0.28°C per century taking place between 1886 and 2006. Especially, the SST shows the strongest trend of 0.67°C increase per century during the last 50 years, a warming unprecedented since 1644 AD. On interannual timescale, the connections between ENSO and the warm pool SST are robust during the reconstruction period. There are significant correlations between the warm pool SST and summer precipitation of the Yellow River basin and Huaihe River basin; the correlation coefficients are ?0.44 in reconstruction period (1880–1949 AD) and ?0.46 in instrumental period (1950–2005 AD) respectively. This relationship is also found between flood-drought index and the warm pool SST during the past 360 years, and their correlation coefficients are ?0.20 in reconstruction period and ?0.46 in instrumental period respectively, significant at the 0.01 level. On interdecadal timescale, this connection is more robust, and the correlation coefficient of the low-pass filtered components is ?0.42 during the whole period (1644–2000 AD). When the warm pool is warmer than normal, the precipitation is usually below the normal in the Yellow River and Huaihe River basin. On the contrary, when the warm pool is colder than the normal, there may be more

摘要：The North China Plain often su ers heavy haze pollution events in the cold season due to the rapid industrial development and urbanization in recent *** the winter of 2015,the megacity cluster of Beijing Tianjin Hebei experienced a seven-day extreme haze pollution episode with peak PM2.5(particulate matter(PM)with an aerodynamic diameter≤2.5μm)concentration of 727μg m *** the in uence of meteorological conditions on pollu-tant evolution,the e ects of varying initial conditions and lateral boundary conditions(LBCs)of the WRF-Chem model on PM2.5 concentration variation were investigated through ensemble methods.A control run(CTRL)and three groups of ensemble experiments(INDE,BDDE,INBDDE)were carried out based on difierent initial conditions and LBCs derived from ERA5 reanalysis data and its 10 ensemble *** CTRL run reproduced the meteorological conditions and the overall life cycle of the haze event reasonably well,but failed to capture the intense oscillation of the instantaneous PM2.5 ***,the ensemble forecasting showed a considerable advantage to some *** with the CTRL run,the root-mean-square error(RMSE)of PM2.5 concentration decreased by 4.33%,6.91%,and 8.44%in INDE,BDDE and INBDDE,respectively,and the RMSE decreases of wind direction(5.19%,8.89%and 9.61%)were the dominant reason for the improvement of PM2.5 concentration in the three ensemble *** on this case,the ensemble scheme seems an e ective method to improve the prediction skill of wind direction and PM2.5 concentration by using the WRF-Chem model.

摘要：建筑物防直击雷设计中,通常采用多支避雷针形成联合保护,多支不规则不等高避雷针的内部保护范围需要将避雷针分为3支一组,采用求解三元二次方程组的复杂方法,手算工作量大、效率低,编程实现也有相当的难度。利用AutoCAD带有的向量计算和坐标变换功能,巧妙利用几何方法解析出3支不等高避雷针内部的保护范围。

摘要：针对动态多元时间序列(MTS)上的状态转移模式(STAP)挖掘问题,提出一种准确高效的三支增量挖掘算法(3IU-STAP)。该算法根据原始数据、已有频繁STAP和增量数据构造出候选模式,使用频繁阈值将其划分至正域、负域以及边界域。仅边界域中的候选模式需要延迟决策,即通过扫描数据集来判断其是否频繁。准确性方面,设计了增量数据补齐技术,获得候选模式实际出现次数。效率方面,使用了向下封闭性质来控制候选模式数量,尽可能减少对数据的扫描。在4个真实数据集上的实验结果表明,与非增量方法相比,3IU-STAP可以得到准确结果,同时显著提高效率。

摘要：“一五”时期,我国广大农村组建了青年突击队。农村青年突击队的产生与当时的农业发展目标、农业生产面临的现实困境、城市青年突击队的成功经验密切相关。农村青年突击队的发展壮大,是多种举措形成合力的结果,包括因势利导提供政策支持、有针对性地开展宣传动员、建立分工明确且相互配合的协同机制、因时因地制宜设计多种突击队类型等。农村青年突击队这一组织形式提高了农村青年的生产技术能力、涵养了农村青年的集体主义精神、有力地开辟了组织动员农村青年的新路径、培育了青年干部人才。新时代新征程,总结农村青年突击队的成功经验对组织动员广大青年投身乡村振兴具有重要的借鉴价值。

摘要：随着国家老龄化的加剧,人们开始聚焦老年人的生活是否便捷。城市家具是构筑于城市公众区域内,具有实际使用功效的、有别于建筑实体的小型设施的整体称呼,包括交通、休闲、通信等方面的设施,整体而言,公园是城市特色和文化内涵的核心体验。本研究以西安曲江池遗址公园为研究对象,通过问卷调查与实地考察法,对老年人进行西安曲江池遗址公园内城市家具满意度调查,并对西安曲江池遗址公园内的各项设施与空间进行统计,分析现状问题,从老年人直接接触的适老性城市家具、植被设置方面,提出适宜老年人使用较多的曲江池遗址公园优化设计策略。

摘要：在深水井进行测试作业时,旋转坐封测试管柱因平台升沉,封隔器坐封困难,且旋转坐封容易损坏水下树脐带缆,导致井下防喷屏障失效,影响作业安全和时效。采用上下活动管柱坐封的新型非旋转坐封封隔器和井下声波无线遥测式直读压力温度计,优化改进测试管柱设计和操作程序,形成了一套适用于深水的非旋转高效APR测试管柱。该测试管柱利用电缆测量地层伽马、套管及钻杆放射性标记校正射孔深度,通过非旋转坐封封隔器和管柱内灌入轻质液垫或留空实现负压射孔,采用管柱内加压或投棒方式点火,在南海东部X井现场应用达到了测试目的和取样要求。该管柱设计为深水井提供了一种安全高效的测试技术。

摘要：针对高速铁路安全运行的重要性,分析了输电线路跨(钻)越高速铁路的现状、跨(钻)越方式的选择,并重点阐述了输电线路的设计技术,力图使设计人员能够较准确地掌握输电线路跨(钻)越高速铁路的技术要求,做好设计工作,确保输电线路安全可靠地跨(钻)越高速铁路。

摘要：天然气水合物作为当下备受关注的潜在新型清洁能源资源,绝大部分赋存于水深大于300 m的海底沉积层中,日本与中国相继应用深水钻井船和半潜式平台进行了海域天然气水合物的试采实践,均取得一定成果。中国南海海域天然气水合物储量丰富,进一步探究行之有效的方法与工艺,实现安全、稳定、高效的商业化开采,对于解决日益严峻的能源紧缺及环境恶化问题具有重要意义。通过国内外技术调研,对降压、注热、注剂等开采方法进行研究,结合日本海域天然气水合物的试采实践,对其试采的前期准备、设计准则与难点、工艺方案、生产测试系统关键组成部分以及存在的气液分离效率、出砂、流动保障等问题进行深入分析,并提出了相关的优化改进建议,为后续海域天然气水合物试采设计和施工提供借鉴。

摘要：选取2014年11月6—11日一次典型污染过程,以北京城区为重点关注的目标区域,基于印痕分析技术判别对该区域影响较大的敏感源区,设计重点区域减排试验和敏感源区逐日动态减排试验,利用区域化学传输模式WRFChem进行模拟对比。结果显示:上述两种方案对源强较高的减排当地PM_(2.5)浓度降低均有明显的改善作用,且在传输作用下会辐射影响到下游地区;但仅就目标区域而言,敏感源区减排方案的减排效率要远远高于重点区域减排方案。为了验证基于敏感源分析的动态减排方法的适用性,进一步开展了不同季节以及不同背景浓度的个例模拟。结果表明:基于敏感源区分析结果制定动态逐日减排措施,可降低削减成本、提高减排效率,以达到最具经济环境效益的减排效果。