基于地理国情普查的海绵城市下沉式绿地的分析研究——以武汉市江汉区为例     

尹言军  周立翔  张茜  梁武卫 《地理信息世界》2017,24(3)

海绵城市是城市建设的新理念,全国正在推进海绵城市建设,为解决城市内涝,缓解城市建设对城市水文、环境的负面影响,在技术层面为海绵城市提供服务。文章采用现势性最强的地理国情普查数据,采用空间数据分析方法,通过定量计算分析了海绵城市建设中的下沉式绿地的现状与分布,为海绵城市建设的研究提供了技术支撑,同时也为地理国情普查更好地服务社会提供了可靠、准确、权威的地理信息服务。  相似文献   

Genetic changes from artificial propagation of Pacific salmon affect the productivity and viability of supplemented populations   总被引：7，自引：1，他引：6  

Reisenbichler  R. R.; Rubin  S. P. 《ICES Journal of Marine Science》1999,56(4):459-466

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Construction of a metagenomic DNA library of sponge symbionts and screening of antibacterial metabolites   总被引：1，自引：0，他引：1  

CHEN Juan ZHU Tianjiao LI Dehai CUI Chengbin FANG Yuchun LIU Hongbing LIU Peipei GU Qianqun ZHU Weiming 《中国海洋大学学报(英文版)》2006,5(2):119-122

To study the bioactive metabolites produced by sponge-derived uncultured symbionts, a metagenomic DNA library of the symbionts of sponge Gelliodes gracilis was constructed. The average size of DNA inserts in the library was 20 kb. This library was screened for antibiotic activity using paper disc assaying. Two clones displayed the antibacterial activity against Micrococcus tetragenus. The metabolites of these two clones were analyzed through HPLC. The result showed that their metabolites were quite different from those of the host E. coli DH5α and the host containing vector pHZ132. This study may present a new approach to exploring bioactive metabolites of sponge symbionts.  相似文献   

Population statistics study of radio and gamma-ray pulsars in the Galactic plane     

Peter L. Gonthier  Sarah A. Story  Brian D. Clow  Alice K. Harding 《Astrophysics and Space Science》2007,309(1-4):245-251

We present results of our pulsar population synthesis of normal and millisecond pulsars in the Galactic plane. Over the past several years, a program has been developed to simulate pulsar birth, evolution and emission using Monte Carlo techniques. We have added to the program the capability to simulate millisecond pulsars, which are old, recycled pulsars with extremely short periods. We model the spatial distribution of the simulated pulsars by assuming that they start with a random kick velocity and then evolve through the Galactic potential. We use a polar cap/slot gap model for γ-ray emission from both millisecond and normal pulsars. From our studies of radio pulsars that have clearly identifiable core and cone components, in which we fit the polarization sweep as well as the pulse profiles in order to constrain the viewing geometry, we develop a model describing the ratio of radio core-to-cone peak fluxes. In this model, short period pulsars are more cone-dominated than in our previous studies. We present the preliminary results of our recent study and the implications for observing these pulsars with GLAST and AGILE.   相似文献   

Conservation aspects of natural populations and captive-bred stocks of turbot (Scophthalmus maximus) and Dover sole (Solea solea) using estimates of genetic diversity     

Exadactylos  Athanasios; Rigby  Mark J.; Geffen  Audrey J.; Thorpe  John P. 《ICES Journal of Marine Science》2007,64(6):1173-1181

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A review of the biology and genetics of sea lice   总被引：5，自引：0，他引：5  

Boxaspen  Karin 《ICES Journal of Marine Science》2006,63(7):1304-1316

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Cambrian Reefs in the Western North China Platform, Wuhai, Inner Mongolia     

LEE Jeong-Hyun  KIM Byeong-Jun  LIANG Kun  PARK Tae-Yoon S.  CHOH Suk-Joo  LEE Dong-Jin  WOO Jusun 《《地质学报》英文版》2016,90(6):1946-1954

Mid to late Cambrian thrombolites and maze-like maceriate reefs from the western North China Platform, Wuhai, Inner Mongolia, northwestern China, occur in the middle of a succession dominated by thin-bedded lime mudstone-shale/marlstone alternations, and are laterally surrounded by limestone conglomerate and/or grainstone. Thrombolite, characterized by meter-scale lenticular mounds composed of millimeter- to centimeter-scale mesoclots and wackestone matrix, occurs in the lower middle part of the sequence. Thrombolite mesoclots are composed of microstromatolites with alternating dark gray and light gray micritic laminae. The maze-like maceriate reefs occur in the middle to the upper part of the sequence, commonly forming lenticular mounds up to 1 m thick. They are characterized by centimeter- to decimeter-scale branched maze-like structures, whose biogenic portions (maceria) are selectively dolomitized. The maceriae are composed of poorly preserved microstromatolites and siliceous sponges. Inter-macerial sediments consist of lime mud and scattered bioclasts. These Wuhai reefs are generally similar to but older than various other Cambrian reefs previously reported from the Shandong region, northeastern China.  相似文献   

Temporal dynamics and persistence of sponge assemblages in a Central Pacific atoll lagoon          下载免费PDF全文

Ingrid S.S Knapp  Gareth J. Williams  James J. Bell 《Marine Ecology》2016,37(5):1147-1153

Sponges are important components of coral reef fauna, although little is known of their temporal dynamics. Sponges dominate the lagoon system at Palmyra Atoll in the Central Pacific, which may not be its natural state. Here we examined the temporal variability and recruitment rates of these sponge assemblages to determine if they are stable and examined the evidence that a recent transition has occurred from a coral‐ to sponge‐dominated system. We found 24 sponge species in permanent quadrats in the lagoon between 2009 and 2011, and 11 species on our recruitment panels. The sponge assemblage composition and abundance did not vary significantly between years and appear stable. Many sponge recruits were found in both years that the panels were examined although higher rates were recorded in the second year of the study. While it seems very possible that a change to a sponge‐dominated lagoon is associated with declining environmental quality at Palmyra as a result of modifications over 70 years ago, without pre‐modification data on reef assemblage composition this remains speculative. Our observations of short‐term temporal stability in the sponge assemblages at Palmyra highlight the potential for sponge‐dominated reef states to be maintained in degraded reef environments that are seemingly unsuitable for coral survival.  相似文献   

基于流域GIS空间建模的雨洪模拟方法     

徐晗  徐建刚 《地理空间信息》2022,20(2):33-38,92

基于多层次GIS空间分析模型技术,系统地建立了从流域雨洪过程相关影响因子栅格化处理到产汇流过程模型的集成化模拟方法,首次实现了对流域内任意栅格单元内河道断面的径流过程线的可视化测算。同时还对于模型中单元水流长度与河道单元流速率定方法进行了优化改进。实例分析结果表明:模型结构更为严谨、参数设置更为科学,改进的技术方法对于福建汀江十年一遇洪水场次的模拟结果精度有明显提高,能够满足相关海绵城市规划应用需求。  相似文献   

The resolved red giant branches of E/S0 galaxies     

Regina E. Schulte-Ladbeck  Igor O. Drozdovsky  Michèle Belfort  Ulrich Hopp 《Astrophysics and Space Science》2003,284(2):909-912

Formation paradigms for massive galaxies have long centered around two antipodal hypotheses – the monolithic-collapse and the accretion/merger scenarios. Empirical data on the stellar contents of galaxy halos is crucial in order to develop galaxy formation and assembly scenarios which have their root in observations, rather than in numerical simulations. The Hubble Space Telescope (HST) has enabled us to study directly individual stars in the nearby E/S0 galaxies Cen A, NGC 3115, NGC 5102, and NGC 404. We here present and discuss HST single-star photometry in V and I bands. Using color-magnitude diagrams and stellar luminosity functions, we gauge the galaxies' stellar contents. This can be done at more than one position in the halo, but data with deeper limiting magnitudes are desired to quantify the variation of metallicity with galactocentric radius. We here compare the color distributions of red giant stars with stellar isochrones, and we intercompare the galaxies' halo populations, noting that their total absolute V magnitudes cover the range from about –21.5 to –17.5. In the future, we plan to model the stellar metallicity distributions with the aim to constrain chemical enrichment scenarios, a step towards unravelling the evolutionary history of elliptical and lenticular galaxies. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献