东亚夏季风指数的年际变化与东亚大气环流

文中从夏季东亚热带、副热带环流系统特点出发 ,定义了能较好表征东亚夏季风环流年际变化的特征指数 ,并分析了东亚夏季风指数的年际变化与东亚大气环流及夏季中国东部降水的关系。文中定义的东亚夏季风指数既反映了夏季东亚大气环流风场的变化特征 ,也较好地反映了夏季中国东部降水的年际变化特征。此外 ,还探讨了东亚夏季风指数变化的先兆信号     

中-吉-乌铁路(中国段)设计洪水的研究

根据中—吉—乌铁路(中国段)沿线近10个水文观测站40多年(建站一2000年)最大洪峰流量资料，对中—吉—乌铁路(中国段)最大洪峰流量设计值进行系统的研究。应用统计学导出的P—Ⅲ分布，预测了中—吉—乌铁路(中国段)最大洪峰流量不同概率设计值。这对于中—吉—乌铁路(中国段)工程设计和施工及未来铁路养护等具有重要的科学意义和工程价值。     

Addressing regional disparities in allowance allocation in China’s national emissions trading scheme

China's national emissions trading scheme (ETS) is expected to be operational in 2017. Effectively addressing regional disparities at the provincial level in allowance allocation will greatly affect the acceptance of the allocation approach and thus deserves careful consideration. This article aims to explore possible approaches for addressing regional disparities, by introducing regional adjustment factors (RAF) in free allowance allocation. Based on the principle of ‘national unified rules?+?stricter adjustment by provincial authorities’, four single factorial and three multi-factorial methods are proposed to calculate the RAFs, through a normalization process. These methods are associated with the most acknowledged factors dealing with regional disparities, including per-capita GDP; per-capita CO₂ emissions; industrial sector contribution to GDP; economy-wide emissions control targets and CO₂ emissions per unit GDP, per unit power and heat output and per unit industrial added value. A comparative analysis is made for the seven methods, in regard to value distribution and level of matching regional political demand.

Key policy insights

• ‘Allowing stricter regional adjustment’ represents a dominant feature for China's national ETS, which aims to address regional disparities and government demands.

• How the adjustment plan is designed will have a major influence on the operation of the national ETS and regional business competitiveness. Provincial governments need to consider the trade-off between auction revenue and local business competitiveness.

• Applying the different methods leads to more scattered results for some regions, for whom the choice of adjustment approach will therefore have a greater impact.

• Based on the analysis, four adjustment methods that generate similar results – the per-capita GDP-based method, the intensity reduction target-based method, the 12th FYP target-based method and intensity-based grandfathering – are recommended for most provincial-level regions, with some exceptions.

     

含变时滞输入的挠性航天器姿态复合控制

对含变时滞输入的挠性航天器姿态复合控制问题进行了研究,主要是通过设计一个时滞依赖的H_∞控制和干扰观测器（DOBC）相结合的复合分层控制结构,实现姿态角和姿态角速度的稳定控制.本文所提方法的优势为：1）对振动引起的干扰进行精确补偿,减少了干扰对控制效果的影响;2）设计了时滞依赖的状态控制器,降低了时滞对姿态的影响;3）在泛函求解过程中引入了时滞积分不等式分解系数,从而降低了设计的保守性.最后,通过数值仿真验证了本文设计的控制方法的有效性,并分析了时滞量及时滞积分不等式分解系数对闭环系统性能的影响.     

Sediment transport for desert watersheds in erodible materials

Sediment transport for five small watersheds in arid southern Israel, eroded into shales, chalks, anhydrites and alluvium is studied. Analysis includes data from three large watersheds in the southern United States. Results indicate that floodwater heavily laden with suspended load (10-60 per cent, by weight) is characteristic of watersheds cut in erodible materials. No correlation was found between environmental characteristics such as lithology, catchment area, angle of slope or rainfall intensity and suspended-sediment concentration or texture. The carrying capacity for sands, derived both from hillslopes and channel alluvium is greatly increased by high suspended silt concentration, the trend being (where R = ratio, % fines/% sand; C_s = suspended load concentration, per cent by weight). The high concentration of fine sediment effectively causes more sand transport than would normally occur. This is also true for transport of coarser clastics; higher velocities, typical of highly concentrated silt suspensions, increased competence for transporting pebbles and boulders. The action of a large variety of processes (splash, wash, rilling, gullying, sliding, mudflow) combine with low infiltration and high credibility to render every rainstorm erosionally effective, and high concentrations of washload increase both the capacity and competence of coarse clastic transport. Whole basins are thus subjected to high rates of denudation (2-10 mm/yr).     

Fingerprinting hydrothermal fluids in porphyry Cu deposits using K and Mg isotopes

In this study, we performed an integrated investigation of K and Mg isotopes in hydrothermally altered rocks from the giant Dexing porphyry Cu deposit in China. Both the altered porphyry intrusion and the surrounding wall rocks exhibit large variations in K and Mg isotope compositions, with δ41K values ranging between-1.02‰ and 0.38‰, and δ26Mg values ranging between-0.49‰ and 0.32‰. The δ41K and δ26Mg values of the majority of altered samples are higher than the isotopic baseline values for upper continental crust. We attribute the general increase in δ41 K and δ26Mg in altered rocks to hydrothermal alteration,which caused preferential incorporation of heavy K and Mg isotopes in alteration products, particularly phyllosilicates. However,a few altered samples show anomalously low δ41K and δ26Mg values. The δ41K and δ26Mg values do not correlate with K and Mg concentrations, or mineralogy of altered samples. The variable K-Mg isotope data likely reflect fluids of different physicalchemical properties, or different isotopic compositions. Based on the combined K-Mg isotope data, at least three groups of hydrothermal fluids are distinguished from the Dexing porphyry deposit. Therefore, K-Mg isotopes are potentially a novel tracer for fingerprinting fluids in complex hydrothermal systems.     

正压大气中的波流相互作用及Sine-Gordon方程

从正压涡度方程出发,利用截谱方法,讨论波动与基本流之间的相互作用,得到了波流之间能量转换的条件。在引入时空缓变量后,导出Sine-Gordon方程,并求得了孤立子解。     

全球大气再分析实时资料前处理关键技术研制

针对全球实时气象数据,重点研制面向全球大气再分析的观测资料前处理关键技术,主要包括实现大量实时文件快速解析分类的数据分拣技术,实现多类气象观测要素并行解码的信息提取技术,满足同化数据格式需求和实现分级分类有效存储的自定义模板统一编码技术。关键技术已于2019年6月在国家气象信息中心业务应用,为我国第一代全球大气和陆面再分析业务提供着稳定的实时观测数据支撑。     

再分析资料和陆面数据同化资料土壤湿度产品在中国北方地区的适用性评估

土壤湿度是地球系统模拟的重要参数之一,准确获得其时空分布和变化特征是研究陆-气相互作用的基础。再分析资料和陆面数据同化资料均可提供全球或区域高分辨率土壤湿度产品,但在使用前需要对其进行评估分析。利用土壤湿度观测数据,计算ERA5、ERA5-Land、NCEP-DOE R2、CRA40再分析资料和GLDAS-Noah、GLDAS-CLSM、CLDAS陆面数据同化资料土壤湿度产品与观测数据的中位数、模拟偏差、相关系数等统计指标,并分季节和气候区讨论不同土壤湿度产品在中国北方地区的模拟效果。结果表明：整体来看,CRA40与观测值的相关性最好,ERA5和ERA5-Land分别对干中心、湿中心模拟效果更好,GLDAS-Noah对于较干土壤地区模拟略偏湿,CLDAS对较湿土壤地区模拟结果以系统性偏干为主,NCEP-DOE R2和GLDAS-CLSM模拟效果较差;ERA5、ERA5-Land、NCEP-DOE R2、GLDAS-Noah和CLDAS在所有季节均为模拟正偏差,春季模拟效果较好的是CRA40、ERA5-Land,夏季和秋季ERA5-Land、ERA5和CRA40与观测值相关性较好,不同产...     

新中国气象科技人才培训历程

有时夜里出现不常见的云状,张乃召会立即训练学员晚上对云的辨认。军委参谋长叶剑英亲自出席训练队结业典礼并表示这批学员是我党我军的第一批气象工作者,是我党气象事业诞生的标志,并鼓励学员到各地去完成气象观测任务。