江西省应对气候变化政策

为应对全球气候变化,各级政府纷纷提出应对气候变化的战略和政策。以江西气候变化和影响事实为基础,分析和总结了目前江西省应对气候变化所采取的政策,包括农业政策、林业政策、水资源管理政策及防灾减灾政策等,得出了政府是应对气候变化的领导者、组织者和政策的制定者的结论,认为政府在应对气候变化行动中具有重要的引导作用。     

基于数据驱动高阶学习律的轮式移动机器人轨迹跟踪控制

轮式机器人执行巡逻、播种和工业生产等任务是一个强非线性的间歇过程.针对重复运行的轮式机器人轨迹跟踪问题,本文提出了一种基于数据驱动的高阶迭代学习控制算法.首先,对轮式移动机器人的模型进行推导设计,并对推导得到的状态空间形式的离散时间模型利用基于状态转移的迭代动态线性化方法,将轮式机器人系统转化为线性输入输出数据模型;其次,设计高阶迭代优化目标函数得到控制律,并利用参数更新律估计线性输入输出数据模型中的未知参数.控制器的设计和分析只使用系统的输入输出数据,不包含任何显式的模型信息.通过采用高阶学习控制方法,在控制律中利用更多之前迭代的控制输入信息,提高了控制性能.最后,仿真结果验证了该方法在轮式机器人轨迹跟踪控制中的有效性.     

黔西南一次中β尺度强对流天气分析

2020年5月2日,黔西南出现中β尺度的强对流天气,安龙钱相出现42m/s灾害性大风,最大冰雹直径普安罗汉25mm,最大小时雨强册亨站66mm/h。对常规地面观测资料、高空观测资料、多普勒天气雷达资料以及NOAA的HYSPLIT模式同期驱动资料等分析,结果表明：(1)本次过程主要受高空槽、中低层切变线、地面辐合线、云南热低压等系统共同影响;(2)大气不稳定层结明显,零度层高度和-20℃层高度利于降雹,0-6km垂直风切变和干暖盖指数利于大风,水汽条件好利于短时强降水,后向轨迹模式HYSPLIT模拟出四条兴仁站水汽输送路径：本地、西、西南、东北路径;(3)过程中卫星红外云图上为椭圆形雹暴云团发展移动,TBB中心低于-60℃,对流云顶伸展较高;(4)三条回波路径均为西北-东南方向;大冰雹发生时,雷达回波呈现“钩状”、三体散射长钉、回波悬垂、风暴顶强辐散、垂直液态含水量跃增、高回波顶高等特征;短时强降水发生时,存在回波质心低、低层强烈径向辐合、雷达产品雨强大等特点;(5)安龙钱相发生42m/s灾害性大风时,65dBz反射率因子核位于6km,回波梯度大,反射率因子核迅速下降,存在侧向入流槽口、径向正负速度对、深厚中层径向辐合、风暴顶强烈辐散、明显旋转等特征,正速度模糊达35m/s;特殊地形的“狭管效应”对产生本次灾害性大风有增幅作用。     

松南油伴生CO2气的成因及其对油气藏的影响

以松辽盆地南部长岭断陷油伴生气和含片钠铝石砂岩为对象,研究松南伴生CO2气的成因,并在此基础上,讨论幔源-岩浆CO2混入对油气动态成藏的影响。通过对伴生气组分,碳、氧及氦同位素数据的分析,发现松南油伴生CO2气的体积分数为1.57%～75.25%,主体在20%以上,δ13 CCO2值为-9.90‰～-4.00‰,R/Ra为0.95～4.46,说明松南油伴生气中CO2的体积分数很高,伴生CO2气主体为幔源-岩浆成因。如果幔源-岩浆CO2气大量混入油藏,将发生CO2驱油,形成次生油气藏。由松南油气藏的典型剖面特征及片钠铝石中原生烃类包裹体的发现,证实松南存在幔源-岩浆CO2驱油的事实。在幔源-岩浆CO2与油气混合成藏地区,寻找幔源-岩浆CO2充注驱油成因的次生油气藏已成为新的勘探思路。     

Groundwater dewatering optimization in the Shengli no. 1 open-pit coalmine, Inner Mongolia, China

Impacted by groundwater, faults, lithology, and other factors, the slope of the Shengli no. 1 open-pit coalmine has been in a state of instability. Among these factors, groundwater in the quaternary aquifer is considered primary. Thus, an optimum design for dewatering well pumping rates is presented in this paper. A two-dimensional groundwater simulation model is built to characterize the groundwater flow of the study area. A steady-state model was applied to the observed data (head and discharge) to verify and calibrate the groundwater model. The pilot point method, with a regularization option provided by parameter estimation, was used to identify the hydraulic conductivity field. Afterward, a groundwater optimization model is integrated with the calibrated simulation model to realize groundwater dewatering optimization in the studied open-pit coalmine, and an optimization method called modified Pareto dominance-based real-coded genetic algorithm is adopted. Taking into account the safety of the mine, slope and dewatering wells, seepage discharge is added to objective function and the maximum aquifer saturated thickness is set as the constraint condition in the optimization model. The results indicate that the dewatering optimization procedure developed in this paper can serve as a useful template and framework for solving mining related water problems.     

Distribution and potential sources of organochlorine pesticides in the karst soils of a tiankeng in southwest China

This research was conducted in an attempt to assess the concentration levels and potential sources of organochlorine pesticides (OCPs) in the karst soils of Dashiwei tiankeng, southwest China. The tiankeng is a karst surface expression that can act as a focal point for introduction of contaminants to groundwater system, which may serve as condenser and receiver for semi-volatile persistent organic pollutants such as OCPs. In this study, surface soil samples from Dashiwei tiankeng were collected and 23 organochlorine pesticide compounds were analyzed. The results showed that the concentration was 0.019–3.605 ng/g for DDTs (sum of p,p’-DDD, p,p’-DDE, o,p’-DDT, p,p’-DDT), 0.001–0.218 ng/g for HCHs (sum of α-, β-, γ-, δ-HCH), 0.003–0.290 ng/g for CHLs (sum of heptachlor, heptachlor epoxide, TC, CC and trans-nonachlor), 0.001–0.064 ng/g for endosulfan (sum of α-endosulfan and β-endosulfan), 0.008–1.630 ng/g for HCB and 0.023–0.928 ng/g for other OCPs (sum of aldrin, dieldrin, methoxychlor, endrin, endrin aldehyde and endrin ketone). The total OCPs concentrations varied from 0.055 to 5.216 ng/g. The ratio of DDT/(DDE + DDD) in the floor soils of Dashiwei tiankeng ranged from 0.434 to 0.797, suggesting a mostly historical residue of technical DDT contamination. However, the ratio of DDT/(DDE + DDD) in the upper rim soils was higher than one, which that there was fresh DDT application nearby. Both the floor and upper rim soils of Dashiwei tiankeng had high ratios of o,p’-DDT/p,p’-DDT (range of 0.016–10.833 with mean of 5.424 and 4.667–7.714 with mean of 5.723, respectively), which implied that the primary source of DDTs was probably from dicofol-type DDT products. The average ratios of α-/γ-HCH were 24.435 in the floor soils and 1.067 in the upper rim soils, together with the averaged percentages of β-HCH among the total HCH isomers (accounting for 33.772 %), indicating that the HCHs were a dominant contribution from technical HCH usage in the past.     

Comparison of Cone Model Parameters for Halo Coronal Mass Ejections

Halo coronal mass ejections (HCMEs) are a major cause of geomagnetic storms, hence their three-dimensional structures are important for space weather. We compare three cone models: an elliptical-cone model, an ice-cream-cone model, and an asymmetric-cone model. These models allow us to determine three-dimensional parameters of HCMEs such as radial speed, angular width, and the angle [γ] between sky plane and cone axis. We compare these parameters obtained from three models using 62 HCMEs observed by SOHO/LASCO from 2001 to 2002. Then we obtain the root-mean-square (RMS) error between the highest measured projection speeds and their calculated projection speeds from the cone models. As a result, we find that the radial speeds obtained from the models are well correlated with one another (R > 0.8). The correlation coefficients between angular widths range from 0.1 to 0.48 and those between γ-values range from ?0.08 to 0.47, which is much smaller than expected. The reason may be the different assumptions and methods. The RMS errors between the highest measured projection speeds and the highest estimated projection speeds of the elliptical-cone model, the ice-cream-cone model, and the asymmetric-cone model are 376 km?s^?1, 169 km?s^?1, and 152 km?s^?1. We obtain the correlation coefficients between the location from the models and the flare location (R > 0.45). Finally, we discuss strengths and weaknesses of these models in terms of space-weather application.     

基于实测数据的综合脉冲星时研究

介绍了脉冲星计时在几个重要方面的应用,给出了脉冲星时间尺度的简要定义.基于澳大利亚PARKES天文台的毫秒脉冲星实测计时数据,建立了基于4颗毫秒脉冲星的综合脉冲星时,并将其稳定度σz与原子时进行比较,最后分析了影响综合脉冲星时的几个重要因素及其对脉冲星计时精度的影响与应用.     

甘肃及邻区GPS连续站时间序列地震预报效能评估

1 研究背景 地震预测方法或手段的效能评价,是寻找有效的预报方法、选择科学的预报判据,也是进行综合地震预测的重要基础.1989年许绍燮(1989)提出R值评分方法,后经郑兆苾等(2001)、罗兰格(2015)等学者们不断完善而日趋成熟,逐渐成为地震预测领域认可度较高的常规地震效能评价方法之一.