一次超级单体雹暴观测分析和成雹区识别研究

利用多普勒雷达资料,结合探空和常规资料,对2011 年4 月17 日一次超级单体雹暴的流场和回波结构演变特征进行了详细研究,主要结果:该雹暴是在条件性不稳定和垂直风切变较大的环境条件下产生的右移风暴。雹云初生发展阶段,垂直剖面显示逐渐形成有组织化的斜上升气流促进雹云发展。成熟降雹阶段,雹云内形成一支强的斜上升气流和深厚的中气旋,主上升气流对应雹云的弱回波区。雹云维持典型的弱回波区—悬挂回波—回波墙特征结构。根据雷达径向速度和雹云移速订正得出的“零线”演变发现,随着雹云的发展,“零线”逐渐向悬挂回波靠近,并穿过悬挂回波,“零线”的走向为上翘式,附近“穴道”的汇集力较强,有利于降雹。通过对“零线”位置的判断可分析有利成雹的区域。根据高低空两层强回波的水平错位,利用两高度强中心连线所作剖面能快速准确得出特征剖面,并将0℃ 层以上6 km 高度处降雹潜势达到100%的45 dBZ 的区域识别为成雹区,与降雹实况对比发现识别效果良好。     

海洋地震资料相位控制处理——东海研究实例

为了满足定量解释的需要,地震资料处理必须是高分辨率、振幅保持和相位控制的.面向海洋地震资料的相位控制处理技术包括利用远场信号进行确定性零相位化、Q补偿、预测反褶积及剩余相位校正等.利用模拟远场信号求取确定性去气泡及零相位化算子.此文基于相位控制处理,讨论了海洋地震资料的相位和极性判别方法,探讨了大于24 ms算子长度的预测反褶积对于保持信号形状的必要性,介绍了东海三维地震资料相位控制流程.     

Combining CLUE-S and SWAT models to forecast land use change and non-point source pollution impact at a watershed scale in Liaoning Province,China

Non-point source （NPS） pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. In this study, NPS pollution load was simulated in urban planning, historic trends and ecological protection land use scenarios based on the Conversion of Land Use and its Effect at Small regional extent （CLUE-S） and Soil and Water Assessment Tool （SWAT） models applied to Hunhe-Taizi River Watershed, Liaoning Province, China. Total nitrogen （TN） and total phosphorus （TP） were chosen as NPS pollution indices. The results of models validation showed that CLUE-S and SWAT models were suitable in the study area. NPS pollution mainly came from dry farmland, paddy, rural and urban areas. The spatial distribution of TN and TP exhibited the same trend in 57 sub-catchments. The TN and TP had the highest NPS pollution load in the western and central plains, which concentrated the urban area and farm land. The NPS pollution load would increase in the urban planning and historic trends scenarios, and would be even higher in the urban planning scenario. How- ever, the NPS pollution load decreased in the ecological protection scenario. The differences observed in the three scenarios indicated that land use had a degree of impact on NPS pollution, which showed that scientific and ecologically sound construction could effec- tively reduce the NPS pollution load in a watershed. This study provides a scientific method for conducting NPS pollution research at the watershed scale, a scientific basis for non-point source pollution control, and a reference for related policy making.     

东海西部陆架海域水团的季节特征分析

On the basis of the CTD data and the modeling results in the winter and summer of 2009, the seasonal characteristics of the water masses in the western East China Sea shelf area were analyzed using a cluster analysis method. The results show that the distributions and temperature-salinity characteristics of the water masses in the study area are of distinct seasonal difference. In the western East China Sea shelf area, there are three water masses during winter, i.e., continental coastal water（CCW）, Taiwan Warm Current surface water（TWCSW） and Yellow Sea mixing water（YSMW）, but four ones during summer, i.e., the CCW, the TWCSW, Taiwan Warm Current deep water（TWCDW） and the YSMW. Of all, the CCW, the TWCSW and the TWCDW are all dominant water masses. The CCW, primarily characterized by a low salinity, has lower temperature, higher salinity and smaller spatial extent in winter than in summer. The TWCSW is warmer, fresher and smaller in summer than in winter, and it originates mostly from the Kuroshio surface water（KSW） northeast of Taiwan, China and less from the Taiwan Strait water during winter, but it consists of the strait water and the KSW during summer. The TWCDW is characterized by a low temperature and a high salinity, and originates completely in the Kuroshio subsurface water northeast of Taiwan.     

煤炭地质勘查相关规范执行过程的中常见问题分析

煤炭是我国最主要的矿产资源之一,目前煤炭矿产资源勘查、煤质评价、煤炭资源储量报告评审及煤炭矿井建设等工作依据的主要技术标准,为指导相关工作的开展做出了突出的贡献。然而,在相关规范的实际执行过程中,常会遇到诸如煤炭可采性区块的界定依据、资源储量控制程度、含煤系数的计算标准、局部可采煤层的稳定性评价、最低可采煤层厚度指标、不可采煤层的计量、高硫煤的处理方式等问题。通过分析上述问题在规范执行中的局限及矛盾,提出了相应的修订建议。     

Cold–wet spells in mainland China during 1951–2011

Two types of persistent extreme weather events, the cold–wet spell (CWS) and the persistent wet-freezing event (PWFE), are defined by considering the persistence of both extreme low temperature (ELT) and precipitation. Regional CWS and PWFE are identified based on temporal persistence and spatial contiguity of single-station-based CWS event and PWFE, respectively. Relevant factors are further discussed to reveal the features of spatial distribution and temporal variability of such events. The results indicate that: (1) station-based CWSs are mostly observed in southern China, especially in eastern part of southwest China and south China. PWFEs are relatively frequently observed immediate south of middle reach of the Yangtze River. Both CWS and PWFE of longer duration are frequently observed in the northern part of the Yunnan–Guizhou Plateau. Further analyses indicate that the occurrence of these events in southern China is positively related to elevation. (2) A total of 48 regional CWSs and 21 regional PWFEs are identified during cold season over 1951–2011 in China. The long-lasting ELT and rainy (snowy)/freezing condition render the event in southern China in 2008, the most severe one in the last five decades. (3) Precipitation is the limitation condition for the occurrence of CWS and PWFE in northern China, while ELT is the dominant factor for CWS and PWFE in southern China.     

STUDIES ON ENVIRONMENTAL BACKGROUND VALUES IN CHINA

An investigation on environmental background values was made in an area of about 1,140,000 km2, which included temperate and subtropical zones of China. The environmental background values of 142 soil environment units, 18 main soil types, 87 surface water environment units, 8 aquatic organism environment units and 20 underground water environment units were obtained. The rules, causes and effecting factors of regional differentiation of the environmental background values were deduced from over 200,000 various data.     

Screening and molecular classification of low-temperature protease from Antarctic microorganism and its characterization

107 strains producing protease were screened from 260 strains of Antarctic psychrophilic bacteria, among which proteolytic activity of five strains was more than 45 U ml^-1. The 16S rRNA gcne sequences homology and phylogcnetic analysis of five Antarctic psychrophillc bacteria showed that NJ276, NJS-9, NJ16-70,NJ345 belonged tO the described genus Pseudoalteromonas and NJ341 belonged to the genus Colwellia. The growth and the protease characteristic of four Antarctic psychrophilic bacteria had been studied, and the result showed that the 6ptimal temperature for growth and protease-produeing of four strains was about 10℃. Their growth and protease-produeing were still high during incubatlng 2-5 days. The maximum proteolytic activity occurred at pH 9 for four Antarctic psychrophilic bacteria. The optimal temperature of protease action of both strains NJ276 and NJ5-9 was about 50℃, however, the optimal temperature of protease aetlon of both strains NJ341 and NJ345 was about 40 ℃, and their proteolytic activity under 0℃ exhibited nearly 30% of the maximum activity, but their thermal stabilities were weaker. These results indicated that proteases from NJ341 and NJ345 were low-temperature proteases.     

弱磁场及甚强磁场下奇异夸克物质Urca过程的中微子能量损失率

研究了磁场对奇异星模型中夸克直接Urca过程的中微子能量损失率的影响,首先改进了弱场条件下的近似计算方法,这一方法可以推广到其他弱作用过程．在甚强磁场下,严格地计算Urca过程的中微子能量损失率,结果显示辐射率强烈地依赖于磁场,与磁场的二次方成正比,更重要的是对温度的依赖关系不同于弱场及没有磁场时的情形．     

绿地信息提取研究

城市绿地作为城市结构中的主要元素,在城市中起着一个重要的作用。本文基于TM遥感影像,对大连市城市绿地专题信息进行提取,并对绿地格局进行研究和探讨。通过计算各组成分分量和归一化植被指数ND-VI之间的相关系数来进行波段组合,提高了遥感影像的分类精度。结果显示该方法可以准确地得到绿地信息。