Isolation and Characterization of Psychrophilic Algae in Boron Enriched Pond on Boron Deposit of Qinghai     

KONG Fanjing  ZHENG Mianping  KONG Weigang  ZHANG Xuefei 《《地质学报》英文版》2014,88(Z1):80-81

正1 Introduction Cold environments on the planet occur in the Antarctic,the Arctic and high mountains which cover with ice and snow permanently.Microorganism adapted to cold habitats has been detected,but most of them were prokaryotes.(Morgan-Kiss et al,2006;jungbut et al,2012).Research on cold-adapted microorganism has  相似文献   

珠江三角洲地区城镇化与生态韧性的耦合协调研究     

WANG Shaojian  CUI Zitian  LIN Jingjie  XIE Jinyan  SU Kun 《地理学报(英文版)》2022,32(1):44-64

Urban resilience is an emerging research topic of urban studies, and its essence is described by the ability of cities to resist, recover, and adapt to uncertain disturbances. This paper constructs a "Size-Density-Morphology" urban ecological resilience evaluation system, uses a coupling coordination degree model to measure the degree of coupling coordination between urbanization and ecological resilience in the Pearl River Delta from 2000 to 2015, and conducts an in-depth discussion on its spatiotemporal characteristics. The results show the following.(1) From 2000 to 2015, the urbanization level of cities in the study area generally increased while the level of ecological resilience declined. The coupling coordination degree between the two systems decreased from basic coordination to basic imbalance.(2) In terms of spatial distribution, the coupling coordination degree between urbanization and ecological resilience of cities presented a circular pattern that centered on the cities at the estuary of the Pearl River and increased toward the periphery.(3) Ecological resilience sub-systems played variable roles in the coupling coordination between urbanization and ecological resilience. Specifically, size resilience mainly played a reverse blocking role;the influence of morphology resilience was generally positive and continued to increase over time;the effect of density resilience was positive and continued to decline and further became negative after falling below zero. The main pathways for achieving coordinated and sustainable development of future urbanization and ecological resilience in the Pearl River Delta include: leading the coordinated development of regions with new urbanization, improving ecological resilience by strictly observing the three areas and three lines, adapting to ecological carrying capacity, and rationally arranging urban green spaces.  相似文献   

生态重要性视角下东北林区县域生态安全格局研究——以呼伦贝尔市阿荣旗为例          下载免费PDF全文

李伊彤  荣丽华  李文龙  程磊 《干旱区地理》2022,45(5):1615-1625

县域生态安全格局构建对于保障我国生态安全、优化县域生态空间格局具有重要意义。基于内蒙古呼伦贝尔市阿荣旗生态系统服务功能重要性评价结果,利用景观形态空间格局分析 （MSPA）模型识别生态核心区作为生态源地,基于生态阻力因子与生态威胁因子构建阻力栅格,运用电路理论识别生态廊道、夹点以及改善区,构建阿荣旗综合生态安全格局。结果表明：（1） 阿荣旗生态极重要区面积4181.66 km²,占全旗面积的37.80%,生态重要区面积2174.50 km²,占全旗面积的19.80%,阿荣旗整体生态系统服务功能重要性较高。（2） 生态源地共有33块,占地面积1141.00 km²,主要分布于旗域北部区域,其中乔木林地是生态源地主要用地类型。（3） 构建生态廊道共73条,其中关键廊道62条,潜在廊道11条,总面积为1884.80 km²,生态廊道网络化结构完整,呈“北密南疏”分布状态。（4） 共识别夹点区面积71.25 km²,提取重要夹点38个,一级改善区面积176.65 km²,主要分布于旗域南部;二级改善区面积887.12 km²,主要分布于旗域南部与西北部。对各景观生态要素进行总体规划,宏观上形成“一屏两区,一网多点”的生态安全格局,为国土空间格局优化提供了现实路径和科学指引。  相似文献   

斑石鲷消化系统形态学与组织学观察     

陈宵  肖志忠  肖永双  姬广磊  邓钦有  李旋  王雨福  马玉婷  李军  刘相全  连昌  连亚明  杨理忠 《海洋科学》2022,46(7):70-77

为探明斑石鲷(Oplegnathus punctatus)消化系统的形态特征和组织学结构,助力斑石鲷的人工繁育及养殖技术研发,作者采用形态解剖学和组织学切片技术对斑石鲷消化系统进行了实验研究。研究发现斑石鲷的消化道共由6部分组成,从头至尾依次是口咽腔、食道、胃、幽门盲囊、小肠、直肠。斑石鲷的口咽腔内部空间大,颌齿内部彼此连接、外部愈合,呈现典型的鹦鹉喙状,咽齿呈扁平的圆盾状,于上下颌齿内侧上下对称分布,这样复合结构(喙状颌齿与圆盾状咽齿)使得斑石鲷能够轻易地碾碎甲壳动物的外壳,进而完成摄食。斑石鲷的食道短粗,黏膜层密布具纵褶,内部含有丰富的杯状细胞,能够协助斑石鲷吞咽食物。胃部呈典型的不对称V型,黏膜层下分布着密集的胃腺,幽门部拥有整个消化道最厚实的肌肉层,摄取的食物将在这里完成消化和分解。斑石鲷的小肠分为前肠、中肠、后肠3部分,管径大小逐次递减,黏膜层上肠绒毛的密度和长度也遵同样的规律,从结构可以推断出斑石鲷肠道吸收功能主要集中于前中肠。直肠管径与小肠前肠段接近,长度很短仅为小肠的1/7,相比小肠部分,肠绒毛更加稀疏,绒毛长度也更短,主要承担消化残留物的压缩排泄和水分与微量元素的重吸收,相对简单结构对应着相对简单的功能。  相似文献   

2010—2020及影响因素分析年青岛海滩剖面稳定性     

梁伟强  王永红  王凯伟 《海洋通报》2022,(1)

海滩的稳定性及其演变是砂质海滩研究的重要内容。在全球砂质海滩普遍遭受侵蚀的背景下,分析部分稳定海滩的特征和原因可以为海滩维护和科学管理提供重要参考。本文基于近 11 年 （2010—2020 年） 青岛第一、第三和石老人海水浴场共 8 条典型剖面的实地监测高程数据,对海滩滩肩宽度和单宽体积进行计算对比,研究表明,除石老人海水浴场一个剖面变化较大外,其他剖面的滩肩宽度只变化了 0~14 m,是 11 年前的 0%~23.3%;单宽体积变化了 8.5~46.5 m3,是 11 年前的1.0%~9.4%;海滩剖面垂向扰动范围一般在 30~60 cm 范围内。海滩存在局部小尺度淤积或侵蚀,剖面形态总体较为稳定。海平面变化、台风和风暴潮等自然因素是海岸轻微侵蚀或调整的重要影响因素,但对海滩的优化管理 （包括定期监测海滩、适度展开养护、制定完善的管理政策和加强执行力度等人为因素） 可以应对这些海滩变化,并且已成为近年来该研究海滩保持稳定的关键因素。  相似文献   

Road extraction based on fuzzy logic and mathematical morphology from pan-sharpened ikonos images   总被引：2，自引：0，他引：2  

Ali  Mohammadzadeh  Ahad  Tavakoli  Mohammad J.  Valadan Zoej 《The Photogrammetric Record》2006,21(113):44-60

  相似文献   

Spectro-morphology of galaxies     

S. Lauger  D. Burgarella  V. Buat 《Astrophysics and Space Science》2003,284(2):969-972

We present a quantitative method of classification of the multi-wavelength morphology of galaxies, elaborated from the nearby galaxies and usable to high redshift objects. We use the morphological parameters of concentration of light at the galaxy center and 180^°-rotationnal asymmetry, computed in several wavelengths, from ultraviolet (UV) to R band. The variation of these indices with λ reflects the proportion of young and old stellar populations in galaxies, that is characteristic of every morphological type: elliptical/lenticular, spiral and irregular. We need to elaborate some templates of these variation spectra from the study of nearby objects, for an application to distant galaxies. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Measurements of sea ice thickness and its subice morphology analysis using ice-penetration radar in the Arctic Ocean     

孙波  邓新生  康建成  罗宇忠  温家洪  李院生 《极地研究(英文版)》2003,14(1)

1　IntroductionSeaice ,asanimportantcomponentoftheArcticclimatesystem ,hasdrawnsignifi cantscientificinterest.Seaicethicknessanditsmorphologyhavedramaticimpactsono cean atmosphere iceinteractions(Wadhams 1 994;Barryetal.1 993 ;Dickson 1 999;PadhamsandNorman 2 0 0 0 ) ,whichdirectlyaffecttheexchangeprocessandspeedofheatandmassbetweentheoceanandtheatmosphere ,dominatethephysicalmechanicsfea turesofseaice ,andaffecttheseaicemovement&deformationaswellasicefreezing&meltingprocess(Hollandetal.1 99…  相似文献   

Dust Morphology Of The Inner Coma Of C/1995 O1 (Hale-Bopp)     

Warell  Johan  LAGERKVIST  CLAES-INGVAR  Lageros  JOHAN S. V. 《Earth, Moon, and Planets》1997,78(1-3):197-203

Dust continuum imaging of comet C/1995 O1 (Hale-Bopp) was carried out with the Swedish Vacuum Solar Telescope (SVST)on La Palma in April, 1997. Images were reduced according to standard procedure, aligned, averaged, navigated and enhanced with azimuthal renormalization, rotational derivative, temporal derivative and unsharp masking processing. The rotational period of the nucleus was determined to 11.5 h and the mean projected dust outflow velocity to 0.41 km s⁻¹. Shell envelopes in the sunward side of the coma were separated by a projected distance of ∼15 000–20 000 km and spiralling inwards towards smaller radii in the direction of local evening. Small scale inhomogeneities of size 1 000–2 000 km, interpreted as correlated with variations in dust emission activity, were seen at radii ≤20 000 km. Two overlapping shell systems with a relative lag angle of ∼55° were evident at the time. The north pole of the nucleus was directed towards the Earth. The dust emission pattern is very complex and may be due to several active areas. The shape of the incomplete spiral shell pattern indicates that the angle between the line-of-sight and the rotational axis of the nucleus was not large. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

冀东金矿带中生代岩浆作用及其成矿意义——来自锆石矿物学证据     

张岱岳  王树志  曹冲  王涛  郭志华 《地质论评》2022,68(4):1361-1374

冀东金厂峪金矿被认为与青山口花岗岩体侵入有关,而同样距离矿区较近的腰岭子花岗闪长岩体则研究较少,由于两岩体在岩性、构造背景等方面有很大的相似性,因此有必要探讨两成矿条件和成矿潜力差异的可能原因。本文对腰岭子和青山口岩体中的锆石进行透射光和阴极发光（CL）图像分析、晶体形态学以及统计学分析,结果显示两岩体的形成温度相差不大,分别为650～800℃和650～850℃。较高的岩浆热水含量和富碱环境可能是青山口岩体成矿的必要条件。应用LA- ICP- MS方法对腰岭子花岗闪长岩中的锆石进行U- Pb年代学测试,其结晶年龄为161.5±0.9 Ma,与峪耳崖金矿区内的闪长岩脉年龄相近,且两者在含矿岩体特征方面有很大的相似性,因此认为腰岭子岩体的成金潜力较大。两岩体稀土元素地球化学特征显示轻稀土相对亏损而重稀土相对富集。同时,有明显的Ce正异常和微弱的Eu负异常,结合野外地质观察,认为两岩体可能经历了壳幔混合作用。结合前人对青山口岩体年龄的测试结果及大地构造背景认为两岩体可能为来自同一岩浆房不同阶段侵位的产物。  相似文献