山东滨州市冰雹天气分型和预报方法研究

利用山东滨州市7个国家气象站与61个人影作业站点观测资料,结合高空观测及探空、ECMWF再分析等资料,对2001—2011年滨州降雹时空分布特征、天气系统和物理量特征、降雹形势分型和预报方法进行研究。得出:(1)降雹日数年均8.6次,总体呈现明显下降的年际变化特征;4—10月可降雹,6—7月降雹最多;降雹主要出现在14时—翌日02时;北部沿海相对较多。(2)降雹形势主要有5种类型:冷涡型降雹、低槽型降雹、横槽型降雹、西北气流型降雹、其他小范围降雹。根据冷涡中心位置冷涡型划分为两个关键区;低槽型可分为前倾槽、阶梯槽、较深低槽、与中低纬度共同作用的槽;横槽型降雹范围广、破坏性大;西北气流型存在连续性。(3)4类13种物理量具有不同分布特征和变异系数,均具有较好的代表性。不同月份、不同降雹影响程度和影响系统,物理量具有较明显差别。(4)0℃层高度在1370~5331m时,7种物理量可用于预报冰雹,K≥17℃、T850-500≥25℃、LI≤2℃、SRH≥0.1m^2·s^-2、SSI≥240、SWEAT≥100、Cape≥2J·kg^-1时可能降雹。6月、7—8月和其它月分别有3种、1种、3种物理量指标组合可用于预报冰雹,物理量的组合和数值有差异。     

Pushover analysis procedure for systems considering SSI effects based on capacity spectrum method

This paper presents a new procedure to transform an SSI system into an equivalent SDOF system using twice equivalence. A pushover analysis procedure based on the capacity spectrum method for buildings with SSI effects （PASSI） is then established based on the equivalent SDOF system, and the modified response spectrum and equivalent capacity spectrum are obtained. Furthermore, the approximate formulas to obtain the dynamic stiffness of foundations are suggested. Three steel buildings with different story heights （3, 9 and 20） including SSI effects are analyzed under two far-field and two near-field historical records and an artificial seismic time history using the two PASSI procedures and the nonlinear response history analysis （NLhRHA） method. The results are compared and discussed. Finally, combined with seismic design response spectrum, the nonlinear seismic response of a 9-story building with SSI effects is analyzed using the PASSI procedures, and its seismic performance is evaluated according to the Chinese ＇Code for Seismic Design of Buildings. The feasibility of the proposed procedure is verified.     

矿产地质勘查项目研判ABC

矿产地质勘查是高投入、高风险、高回报的投资活动,如何引进经济、优质的矿权是矿产地质勘查的先决条件和企业赖以发展的基础.对项目高效、快速、准确的研判是项目研发最重要的一步.文章把矿权分为3种矿权来源和4种项目类型.通过3种矿权来源点评和4种项目类型的剖析,探讨了项目研判的内容、研判的准则、研判的工作程序,把研判过程分为初判、普判、详判3个阶段.在此基础上研究了研判各阶段时间安排与具体工作内容,普判阶段编图方法、取样间距和取样方法,普判阶段工作量及费用概略估计,以及详判阶段的几个关键问题.     

CWRF对青藏高原气温和降水模拟效果的综合评估

利用CWRF(Climate-Weather Research and Forecasting model)对中国区域气候的31 a多物理集合模拟试验,分析了该模式对青藏高原气温和降水的模拟效果及其对水平分辨率和物理过程参数化方案的敏感性.结果表明:1)CWRF降尺度全面改善了全球模式对高原气温和降水的模拟,使气温年循...     

海洋动床物理模型试验地形制作技术

试验模型地形制作是物模试验的一个基本工作,模型制作的好坏直接关系到实验的精度.模型试验之前,需要根据相似理论,选取合适的材料,按照一定的几何比尺进行模型的制作.通过2个具体工程作为实例说明了模型制作的过程、制作的技术性问题和制作经验.     

Distribution of phytoplankton community in relation to environmental parameters in cage culture area of Sepanggar Bay,Sabah, Malaysia

This paper covers spatial and temporal variation in phytoplankton communities and physico-chemical water properties in the cage culture area of Sepanggar Bay, Sabah, Malaysia based on field measurement conducted during July 2005 to January 2006 to study the spatial and temporal variation in phytoplankton communities and physico-chemical water properties of the bay. Phytoplankton samples and water parameters data were collected from five different stations located inside the bay during Southwest, Interseasonal and Northeast monsoons. Forty phytoplankton genera, representatives of 23 families, were found in the study area with a mean abundance of 1.55 ± 1.19 × 10⁶ cells L⁻¹. Most of these genera belong to diatoms (82.17%), Dinoflagellates (17.55%) and cyanobacteria (0.29%). Three genera were found to be dominant (>10%) in phytoplankton abundance and these were Coscinodiscus spp. (36.38%), Chaetoceros spp (17.65%) and Bacteriastrum spp. (10.98%). The most dominant genus was Coscinodiscus spp. which showed high abundance during all monsoons and stations (except Station 3). Among the seven environmental parameters tested in this study, water temperature, pH and suspended sediment concentration were found to be significantly different between monsoons. On the other hand, no significant differences were found between stations for the studied physico-chemical parameters. A clear differences in phytoplankton densities were observed between monsoons and stations with higher mean abundances during interseasonal monsoon (2.40 ± 1.37 × 10⁶ cells L⁻¹) and at station five (2.05 ± 0.74 × 10⁶ cells L⁻¹), respectively. Conversely, the diversity indices, both Shannon–Wiener (H^′)$\left(H^{\prime }\right)$ and Pielou (J^′)$\left(J^{\prime }\right)$, showed no significant difference throughout stations and monsoons (except (H^′)$\left(H^{\prime }\right)$ for monsoons). Analysis of similarity (ANOSIM) results demonstrated temporal differences in phytoplankton community structure with highly diverse phytoplankton assemblage. Through cluster analysis five groups of phytoplankton were attained (at 40% similarity level) though no marked separation of the taxonomic classes pointed towards the constant pattern of the phytoplankton assemblage in the studied area.     

Mesozooplankton biomass and grazing responses to Cyclone Opal, a subtropical mesoscale eddy

As part of E-Flux III cruise studies in March 2005, plankton net collections were made to assess the effects of a cyclonic cold-core eddy (Cyclone Opal) on the biomass and grazing of mesozooplankton. Mesozooplankton biomass in the central region of Cyclone Opal, an area of uplifted nutricline and a subsurface diatom bloom, averaged 0.80±0.24 and 1.51±0.59 g DW m⁻², for day and night tows, respectively. These biomass estimates were about 80% higher than control (OUT) stations, with increases more or less proportionately distributed among size classes from 0.2 to >5 mm. Though elevated relative to surrounding waters south of the Hawaiian Islands (Hawai’i lee), total biomass and size distribution in Cyclone Opal were almost exactly the same as contemporary measurements made at Stn. ALOHA, 100 km north of the islands, by the HOT (Hawaii Ocean Time-series) Program. Mesozooplankton biomass and community composition at the OUT stations were also similar to ALOHA values from 1994 to 1996, preceding a recent decadal increase. These comparisons may therefore provide insight into production characteristics or biomass gradients associated with decadal changes at Stn. ALOHA. Gut fluorescence estimates were higher in Opal than in ambient waters, translating to grazing impacts of 0.11±0.02 d⁻¹ (IN) versus 0.03±0.01 d⁻¹ (OUT). Over the depth-integrated euphotic zone, mesozooplankton accounted for 30% of the combined grazing losses of phytoplankton to micro- and meso-herbivores in Opal, as compared to 13% at control stations. Estimates of active export flux by migrating zooplankton averaged 0.81 mmol C m⁻² d⁻¹ in Cyclone Opal and 0.37 mmol C m⁻² d⁻¹ at OUT stations, 53% and 24%, respectively, of the carbon export measured by passive sediment traps. Migrants also exported 0.18 mmol N m⁻² d⁻¹ (117% of trap N flux) in Cyclone Opal compared to 0.08 mmol N m⁻² d⁻¹ (51% of trap flux) at control stations. Overall, the food-web importance of mesozooplankton increased in Cyclone Opal both in absolute and relative terms. Diel migrants provided evidence for enhanced export flux in the eddy that was missed by sediment trap and ²³⁴Th techniques, and migrant-mediated flux was the major export term in the observed bloom-perturbation response and N mass balance of the eddy.     

民俗中的婴儿体貌美及其文化意蕴

中国民俗中对婴儿体貌的审美是以婴儿的生理特征为基础,认为身体白胖、脸庞丰满、额部高宽、头部圆大是形成婴儿体貌美的因素。这种婴儿的体貌美是一种趋向变形、夸张的美,是融合优美和滑稽美的审美形态。也是一种象征意义的美,具有深厚的中国民俗文化意蕴。反映了中国人特有的追求平安、健康的在世理想,以及特殊的求福、祈福文化和审美心理。     

Summer fast ice evolution off Zhongshan Station,Antarctica

Based on the field data acquired in the program of fast ice observation off Zhongshan Station, Prydz Bay, East Antarctica during the austral summer 2005/ 2006, physical properties evolution of fast ice during the ice ablation season is analyzed in detail. Results show that the annual maximum ice thickness in 2005 occurred in later November, and then ice started to reek, and the ablation duration was 62 days; sea water under the ice became warmer synchronously; corresponding to the warming sea ice temperature, a ＂relative cold mid-layer＂ appeared in sea ice; the fast ice marginal line recoiled back to the shore observably, and the recoil distance was 20.9 km from 18 December 2005 through 14 January 2006. In addition, based on the data of sea ice thickness survey along the investigation course of MV Xuelong on December 18 of 2005, the ice thickness distribution paten in the marginal ice zone have been described ： sea ice thickness increased, but the diversity of floe ice thick-ness decreased from open water to fast ice zone distinctly.     

迭代逼近科学方法在速度估算中的作用

以地球物理中的速度为题 ,在详细描述了速度参数重要作用、各类速度基本概念及其应用范围、影响速度估算的各种因素的基础上 ,以模型和处理流程的叠加速度分析为例 ,在两个层面上展现了迭代逼近方法。又以剩余层速度分析为例 ,说明了具有反馈控制思想的迭代逼近算法 ,从而指出该方法在速度估算中的重要作用