新一代天气雷达故障维修典型案例

针对新一代天气雷达（CINRAD/CB/CD）在内蒙古业务运行过程中所出现的一些典型故障,文章归纳总结了新一代天气雷达发射机故障、伺服系统故障、接收机噪声系数超标等几类典型故障的故障定位与故障排除方法,对雷达的日常维护和维修工作具有一定的参考价值。     

藏东南帕隆藏布现今河流地貌特征 及其晚第四纪演化

河流沉积与地貌对构造与气候的变化极为敏感,可记录区域构造活动、气候变化和环境演变等多方面的丰富信息。由于独特的构造背景与气候条件,帕隆藏布不仅成为雅鲁藏布水系水量最大的支流,而且其流域在藏东南地区占有重要的地位。帕隆藏布流域内地表过程活跃且河流地貌演化过程快速,是揭示青藏高原东南部构造地貌演化的重要载体。通过对该河流地貌的形态学和沉积学分析发现,帕隆藏布河流形态具有明显的线状特征,其干流近似直线展布,而主要支流呈羽状分布,两者多呈直角交汇,表明河流形态明显受到嘉黎断裂带的构造形迹控制。进一步利用光释光和¹⁴C定年方法,对帕隆藏布的晚第四纪河流地貌演化,尤其是干流和东久河支流的晚第四纪河流阶地进行研究后发现,末次冰期以来的气候变化导致帕隆藏布的晚第四纪河流地貌呈现出典型的分段式特征,根据海拔高度主要可划分为3段：1）海拔2 600 m以下的河谷地貌呈V形峡谷,河谷比降大,阶地沉积年龄均在9.0～2.0 kaBP间,沉积属性以河流相和坡积相为主,表明是全新世以来气候变暖条件下形成的;2）海拔2 600～3 300 m的中游段河谷呈冰蚀围谷盆地、U形槽谷等,河谷比降小,河岸谷坡坡度小,主谷两岸冰碛垄发育,存留了古冰缘地貌遗迹,阶地沉积属性以古湖相、冰水相及河流相为主,测年结果在29.8～10.9 kaBP和50.9～39.8 kaBP间,显示其曾经为末次冰期和冰消期冰缘湖泊体系,后被现今的帕隆藏布所贯通;3）海拔3 300 m以上河流地貌为典型的冰川U形槽谷,谷底平坦,发育现代冰湖,仅发育Ⅰ级阶地并上面覆有冰碛物堆积体,有末次冰期的冰缘地貌遗迹,但主要受周围海洋性冰川作用,呈现现代冰缘地貌特征。整体上看,帕隆藏布的现今河流地貌上、下游两端年轻,主要形成于全新世期间;中游的河流地貌出现较早,残留了末次冰期和冰消期的冰缘地貌特征,并保留了广泛的古冰湖相沉积物。因此,帕隆藏布现今的河流形态主要出现在末次冰期以来。     

Origins of heavy oils in the Erlian Basin, ne China

The Erlian Basin is located in the Central Asia-Mongolian fold belt between the Siberian and Sino-Korean Cratons. It is a Mesozoic continental rift basin composed of 52 individual fault-depressions. The main phase of rifting took place during the Early Cretaceous when a series of fluvial-lacustrine sediments were deposited. Each depression forms an independent sedimentary system and behaves as an independent petroleum system. Hydrocarbon source rocks are found in the upper Arshan and lower Tengger Formations. These are mainly type II source rocks and are mainly located in oil generation window at the present day. A series of oilfields and commercial oil flows have been found in the basin, highlighting its good petroleum potential. Many of these oils are heavy.Six oil samples from the Anan and ten from the Jirgalangtu Depressions have been subjected to routine geochemical analytical techniques in order to evaluate the origins. The methods used include gas chromatography of the saturated and aromatic hydrocarbon fractions, gas-chromatography-mass-spectrometry of the saturated hydrocarbon fraction and stable carbon isotope analyses. The trace metal elements of the biodegraded oils from the Jirgalangtu Depression were also analysed by atomic absorption spectroscopy.Two types of heavy oils : primary and biodegraded were identified on the basis of these data. The former includes both immature and mature heavy oils. A filtering-and-spill process was proposed to explain the origin of primary mature heavy oils (or tar-mat) in the Anan Depression. The biodegraded oils from the Jirgalangtu Depression were ranked and classified in terms of the degree of biodegradation, using a series of geochemical parameters based on the gas chromatographic concentrations and biomarker fingerprints of gas-chromatography-mass-spectrometry of the saturated hydrocarbon fraction. The relationship between oil saturation and porosity indicates that the heavy oils in the Jirgalangtu Depression were biodegraded after they accumulated.     

Performance of rectangular closed diaphragm walls in gently sloping liquefiable deposits subjected to different earthquake ground motions

The performance of rectangular closed diaphragm walls(RCDW) subjected to earthquake ground motions is extremely complicated in gently sloping liquefiable deposits and requires further investigation. A nonlinear finite element(FE) model was developed to investigate the seismic performance of an RCDW in the OpenSees platform. Initially, the feasibility of the FE model to simulate the seismic behavior of the RCDW was validated by comparing the numerical results with the experimental data. The numerical results agree well with the centrifuge test data. Then, the calibrated model was used to study the seismic performance of the RCDW subjected to different ground motions in gently sloping liquefiable deposits.The numerical results indicate that the soil-RCDW system under near-fault ground motions is more likely to be damaged than that under far-fault ground motions. The difference between the maximum and minimum(D_(max-min)) the RCDW displacement and the maximum excess pore pressure in the soil core increased as the Arias intensity increased. The seismic response of the soil-RCDW system was strongly affected by the frequency content, durations, energy distribution and initial directions of the ground motions. Moreover, the modified specific energy density(MSED) has a good linear relationship with the D_(max-min) of the RCDW displacement.     

深度贫困地区农户脱贫稳定性测度及影响机理研究

农户脱贫稳定性研究可为深度贫困地区巩固脱贫攻坚成果和乡村振兴有效衔接提供重要的理论依据。论文基于可持续生计视角进一步厘定了“农户脱贫稳定性”概念,从自然资本、物质资本、社会资本、人力资本和金融资本5个维度构建了农户脱贫稳定性评价指标体系,选取地处深度贫困地区的贵州省天柱县为研究区,测算1295户样本农户脱贫稳定性指数,基于不同方法共同识别影响因素并探究影响机理,提出构建稳定脱贫的长效机制。结果表明：(1)研究区农户脱贫稳定性指数整体水平偏高,脱贫稳定性较强,但农户个体差异性显著,其中物质资本和自然资本维度的脱贫稳定性较高,金融资本其次,人力资本和社会资本维度的脱贫稳定性较低,返贫风险较大;(2)农户脱贫稳定性类型主要以一般型或稳定型为主,脱贫稳定性综合指数中各类型占比分布从高到低大致呈“水滴”特征,有12.44%的样本农户处于临界型,返贫风险较大;(3)技能培训、外出务工人口占比、土地流转、转移性收入占比、到乡镇政府距离和到主干道距离是影响研究区农户脱贫稳定性的主要影响因素;(4)构建了能力提升、产业培育、激发动力、完善基础设施和拓展就业“五位一体”的深度贫困地区农户脱贫稳定性长效机制...     

对流云人工增雨效果检验技术方法及应用

对流云降水时空变差较大,利用WoodleyRosenfeld提出的建立在雷达资料基础上的移动目标单元法对对流云增雨作业进行效果评估。利用塘沽、北京及秦皇岛3部雷达资料,对其进行插值处理,确定移动目标单元识别和跟踪方法,然后在移动目标单元中确定催化单元和对比单元,记录每个单元的物理参量,利用Z-R关系反演降水量,对物理参量和反演降水量做统计分析,定量计算增雨效果的同时提供人工增雨的物理证据。应用该方法对2011年7月24日对流云人工增雨作业效果进行评估,结果表明:催化剂进入云中后使得最大回波强度增强,回波顶高增加,从物理角度证明了催化对增加降水起到了一定作用。利用降雨率对增雨作业进行定量效果分析,结果表明该次作业相对增雨7.69%,显著度检验值0.043,增雨效果较为显著。     

钙华非经典沉积的纳米生长过程与调控机制初探——以九寨沟—黄龙钙华形成为例

钙华是自然界重要的岩溶碳酸盐沉淀之一,其形成过程往往受到生命活动的影响,弄清钙华生物沉积作用有助于更好地理解钙华微岩相结构和地球化学特征的气候环境指示意义。本文以黄龙-九寨沟钙华形成为例,阐述黄龙-九寨沟现代钙华纳米结晶特征、纳米钙华的生长和集合体形态,分析模拟实验中生物有机质对钙华生长和形貌的调控原因,揭示了生物活动和代谢产物对纳米钙华成核、生长及钙华晶体形貌的调控两途径四阶段机制;为探究钙华成因、碳酸钙生长调控机制、钙华退化的因素及其保护和可持续利用钙华景观具有重要的科学价值。      

延伸期预报中大气初值与海温边值的相对作用

初始条件记忆和下垫面条件是延伸期可预报性的主要来源,它们在不同时段、不同区域的相对作用存在明显不同。利用中国国家气候中心最新一代大气环流模式BCC_AGCM,设计了由4组不同大气初值与海温边值构成的组合试验,研究了（大气）初值与（海温）边值对全球不同区域延伸期预报的相对作用。结果显示,模式预测技巧在3周以内强烈依赖于初值。在相同的边值条件强迫下,不同初值在月内尺度上的预测技巧差异非常明显,且在更长的时间尺度上,初值仍然能够提供一定的预测信息。从全球来看,边值强迫对预测技巧的影响从一周左右开始。在低层的850 hPa高度场上,边值的作用在热带地区于第4-5候与初值相当,其他区域的边值影响达到与初值相当的时间滞后于热带地区;在北半球500 hPa高度场上,边值的作用在热带地区第5候前后达到与初值作用相当,其他区域这个时间则推迟至第6候前后,比对低层的影响时间滞后1-2候;对于东亚地区而言,边值的贡献在第2候就已显现,对预测技巧产生了明显的改进。在延伸期尺度上,边值强迫主要作用的区域为低纬度区域,且对500 hPa高度场的影响更为稳定,在该区域第5候以后有较为明显的改进。初值与边值对延伸期预报都具有相当重要的作用,认识初、边值条件的相对作用能够为延伸期预报的改进奠定基础。     

雷达发射机灯丝电源故障维修

灯丝电源是一个交流稳压电源,通过灯丝中间变压器和位于油箱中的脉冲变压器及灯丝变压器,为速调管灯丝供电.2011年7月18日,内蒙古气象局通辽天气雷达站的CINRAD/CB雷达发射机反复出现灯丝电源故障,且无法加高压导致雷达停机,经分析和排查故障原因,最终排除了雷达故障.就此次故障的出现,分析其原因,举一反三,对雷达台站在今后的工作中加强备件的管理和测试数据的管理有一定的启示.     

Reactivity at (nano)particle-water interfaces,redox processes,and arsenic transport in the environment

Massive deleterious impacts to human health are resulting from the use of arsenic-bearing groundwaters in South-East Asia deltas and elsewhere in the world for drinking, cooking and/or irrigation. In Bangladesh alone, a fifth of all deaths are linked to arsenicosis. In the natural and engineered subsurface environment, the fate of arsenic is, to a large extent, controlled by redox potential, pH, as well as total iron, sulfur and carbonate content, via sorption and coprecipitation on a variety of natural and engineered (nano)particles. In the present article, we address: (1) new insights in the sorption mechanisms of As on Fe(II) and Fe(III) nanophases recognized to play an important role in the microbial cycling of As and Fe; (2) artifacts often encountered in field and laboratory studies of As speciation due to the extreme redox sensitivity of the Fe-As-O-H phases; and (3) as a conclusion, the implications for water treatment. Indeed the specific reactivity of nanoparticles accounts not only for the As bioavailability within soils and aquifers, but also opens new avenues in water treatment.