鲁西北地区一次秋季强对流天气的雷达识别分析

利用SA雷达探测和高空探空资料,结合防雹作业数据和灾情信息,对2016年9月11日发生在鲁西北地区的强对流天气过程中两个对流单体进行雷达识别分析。结果表明:两个对流单体发展迅速,在4-7个体扫(约25-45min)内,垂直液态水含量(VIL)分别跃增了27kg·m^-2、16kg·m^-2,达到64kg·m^-2、57kg·m^-2;在反射率因子图上都具有典型的冰雹回波特征:存在较明显的强回波墙、回波穹窿、有界弱回波区;实施防雹作业后,对流单体回波顶高、VIL、风暴质心高度、冰雹概率、强冰雹概率等指标持续下降,进一步证实了开展防雹作业可有效地减小降雹灾害。     

不同的酸雨处理对冬小麦净光合速率的影响

以冬小麦(皖麦68)为研究对象,采用大田及盆栽的培育方式,按照不同浓度将酸雨分为CK(pH5.6)、T1(pH4.0)、T2(p H2.5)三组,探究酸雨对小麦不同生育期净光合速率的影响。结果表明,随着模拟酸雨p H值的减小,小麦净光合速率受到抑制加强。整个小麦生长周期中T2处理下小麦净光合速率较CK处理降幅均显著,其中开花期的降幅达到极显著,而T1处理较CK处理净光合速率虽然有所降低,但不显著。小麦生长期间,中午时段会出现"光合午休"现象,此时会有效抑制小麦的净光合速率。     

2017年2月下旬浙江省一次冷锋引起的大风天气过程分析

利用常规地面气象观测资料和NCEP再分析资料,对2017年2月20—21日浙江省中西部地区的一次冷空气大风天气过程进行分析。结果表明：西伯利亚冷高压与东亚大槽共同作用形成的强气压梯度是此次大风天气过程的重要成因;高空槽槽后动量下传是此次区域性大风超出一般冷锋大风强度的关键因素;200 hPa高空西风急流入流区的辐合下沉运动与冷锋前的上升运动叠加形成的次级环流是此次大风天气出现的增强条件。     

挑战与冲突下的景区修建性详细规划对策探析——以临潭县冶木峡景区为例

以临潭县冶木峡景区招标项目的旅游修建性详细规划为例,以景区发展的外部环境和内部条件的分析和评价为基础,通过对规划中面临的挑战和冲突的把握和认识,经过多次"头脑风暴"的不断搜寻、验证和思考,逐步明确为若干个相对清晰的规划目标和规划理念.并从景区发展的总体定位、空间结构、用地竖向、道路系统、传统建筑风格与风貌、生态环境保护等方面,针对上述挑战和冲突,提出了规划对策.最后,针对景区修建性详细规划中面临的普遍问题,提出通过"规划预研究"的形式解决景区上位规划和相关规划缺失的矛质;并对设计中对待传统文化和建筑风格的基本态度提出了看法.     

Characterization and quantification of within-year variation of snow-cover elevation in mountainous regions, eastern Tibet

Fluctuating snow-covered elevation (FSCE) was conceptualized and proposed to characterize within-year variation of the border between snow-covered and snow-free area in mountainous regions. Two parameters, namely median of snow free period (T_m) and snow free duration (ΔT), were defined to quantify FSCE. A regression model of FSCE was developed for the Lhasa River Basin, Niyang River Basin, and Changdu region in eastern Tibet. Statistical analysis of the snow-products data with a spatial resolution of 25km×25km shows that: (1) T_m correlates weakly with geographical and topographic factors, having the yearly mean value of July 31; (2) ΔT correlates significantly with the average elevation of the snow-products cell, having the yearly mean value of nearly five months (i.e., 151 days); (3) the region begins snow disappearance in late April and finishes snow coverage in mid November, being snow-free from late June to mid September and snow-covered from December to March in the next year. In addition, snow-products with higher spatial resolution will be helpful to characterize FSCE in smaller spatial scales.     

GESE: a small UV space telescope to conduct a large spectroscopic survey of z∼1 Galaxies

One of the key goals of NASA’s astrophysics program is to answer the question: How did galaxies evolve into the spirals and elliptical galaxies that we see today? We describe a space mission concept called Galaxy Evolution Spectroscopic Explorer (GESE) to address this question by making a large spectroscopic survey of galaxies at a redshift, z～1 (look-back time of ～8 billion years). GESE is a 1.5-m space telescope with an ultraviolet (UV) multi-object slit spectrograph that can obtain spectra of hundreds of galaxies per exposure. The spectrograph covers the spectral range, 0.2–0.4 μm at a spectral resolving power, R～500. This observed spectral range corresponds to 0.1–0.2 μm as emitted by a galaxy at a redshift, z=1. The mission concept takes advantage of two new technological advances: (1) light-weighted, wide-field telescope mirrors, and (2) the Next-Generation MicroShutter Array (NG-MSA) to be used as a slit generator in the multi-object slit spectrograph.     

THE DISTRIBUTION REGULARITY OF HIGHER CATEGORIES IN CHINESE SOIL TAXONOMY

SoildaSSificationPlays~rolesinsoilsUrVey,soilmappingandagriculturaltechnologytranSferinthelightoflocalconditions.ItisalsothemediumofsoilsciencecornmunicationamongdomesticandinternationalscholarS.MOber,thesurveyandevaluationoftricultUralnatalsoarealways~onthesoilclaSSification:firstly,theproperties,typeSanddistributionSofAmsmustbesurveyed;thenthesoiladaptationandproductionPOtentialcanbeevaluated.This'isoneofthemostimportantandbasicworkintheinvestigatignofagricultUralsituation.I.~~or~occu…     

DISTRIBUTION OF THE MAIN CROP GERMPLASM RESOURCES IN CHINA

Cropgermplasmresourcesaretheindispensablematerialbaseforcropbreedingandagriculturalproduction.Theresearchondistributionofcropgermplasmr~urcesisofgreatimportanceinstudyingonorigin,evolutionandclassificationofcrops,expeditingandcollectinggermplasm,ascertainingofcentersofdiversity,protectinggermplasmr~urcesandmakingagriculturalproductiondivision.Since1949,researchesofexploration,collection,preservation,cha-racterizationandevaluationofcropgermplasmresourceshavebeendoneinChina.Atpresent,thenational…     

遥感影像上线状目标自动提取研究现状与思考

自动识别遥感影像上的目标，快速、准确地获取所需信息是遥感数据处理的主要发展方向。从分析遥感影像上道路的基本特征出发，探讨了道路提取的基本思想，总结了国内外关于道路半自动提取的现状，综述了常用的提取算法，提出了对该问题的思考和进一步研究的设想。     

关于利用一维波动理论计算土层地震反映传递函数的讨论

对利用一维波动理论计算土层地震反应时，将基岩假定为具有自由边界的半无限空间，输入地震记录、计算传递函数，进而计算土层地表的地震反应这一方法步骤的合理性进行了讨论。理论推演表明，从基岩面输入地震记录和计算传递函数时，应当考虑基岩和上覆土层的相互作用影响。数值算例表明，考虑与不考虑基岩和上覆土层相互作用的影响，算得的土层地面地震反应，无论加速度时程、峰值和反应谱，均存在不可忽视的差异。