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1.
基于熵权的北京城市生态系统健康模糊综合评价 总被引:51,自引:3,他引:51
采用基于熵权的模糊数学评价方法,借助于相对隶属度的概念评价了北京城市生态系统在某一特定时间内(1996~2003年)的相对健康状态。方法避免了主观判断城市生态系统健康标准的不确定性。评价结果表明:(1)1996~2003年,北京市相对健康状态整体呈上升趋势,最优年为2003年,最差年为1996年;(2)按照最大隶属度原则,人类健康要素的最大隶属度0.967(2002),生物群落的最大隶属度1.000(2003),社会的最大隶属度1.000(2003),经济的最大隶属度0.938(2003),人工环境的最大隶属度1.000(2003),自然环境的最大隶属度0.795(1998),自然与社会经济的相互作用的最大隶属度0.916(2002),对区域的影响的最大隶属度1.000(1996)。各评价要素的最大隶属度主要集中于2003年,其概率为37.5%。 相似文献
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健康青少年口腔优势菌对牙龈卟啉单胞菌拮抗作用的实验研究 总被引:1,自引:0,他引:1
目的分析健康青少年口腔优势菌(简称S.t2003)与牙龈卟啉单胞菌的相互关系。方法运用定量混合培养技术,以血链球菌标准株和变形链球菌作为对照。结果S.t2003与血链球菌标准株都对牙龈卟啉单胞菌有很强的抑制作用,但S.t2003的抑菌强度强于血链球菌的标准株;另外S.t2003和血链球菌标准株对牙龈卟啉单胞菌的抑制作用随其相对浓度的变化而改变,显示了S.t2003和血链球菌标准株与牙龈卟啉单胞菌的相互拮抗的关系。结论S.t2003对牙龈卟啉单胞菌具有较强的拮抗作用。 相似文献
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以内蒙古大兴安岭兴安落叶松林火烧迹地为研究对象,采用分层取样的方法对群落中植被进行了调查,分析比较了3种不同林型兴安落叶松林群落恢复过程中物种组成及多样性的差异。结果表明:不同林型兴安落叶松林群落各层α多样性指数总体表现为草本层灌木层乔木层。不同林型兴安落叶松林火烧迹地群落恢复12年后,草本层的Simpson和Shannon-Wiener指数均小于对照样地并呈现出草类-兴安落叶松林杜香-兴安落叶松林杜鹃-兴安落叶松林的趋势,而在灌木层则各指数均大于对照样地并呈现出草类-兴安落叶松林杜鹃-兴安落叶松林杜香-兴安落叶松林的趋势。 相似文献
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Between 1811 and 2003, the mean height of 17-year-old Estonian boys increased 18.4 cm (0.97 cm per decade). The increase was 5.2 cm (0.7 cm per decade) between 1811 and 1886, 12.3 cm (2.2 cm per decade) between 1922 and 1978, and 0.5 cm per decade between 1978 and 2003. Between 1922 and 2003, mean height increased 8.2% and mean weight increased 27.2%. Between 1956 and 2003, biacromial (shoulder) breadth increased more than bicristal (hip) breadth; relative chest depth diminished; chest circumference and upper thigh circumference both increased. A multidimensional body structure model is constructed from 1998 to 2003 data. 相似文献
5.
贵州下寒武统牛蹄塘生物群中海绵新材料 总被引:5,自引:1,他引:4
描述了贵州下寒武统牛蹄塘生物群中海绵化石1新属(Zunyispongiagen.nov.),2新种(Zunyispongiatriangulariagen.etsp.nov.,Choiafanensis.sp.nov.),通过对其形态功能的分析和讨论证实了寒武纪早期海绵动物的骨骼是由细小骨针向粗大骨针演变,骨架结构从不稳定型向稳定型发展。 相似文献
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A report on the eighth annual meeting of the Human Genome Organization (HGM2003), Cancun, Mexico, 27-30 April 2003. 相似文献
8.
SUZANNE SCHELD 《American anthropologist》2006,108(1):221-224
Crafting Gender: Women and Folk Art in Latin America and the Caribbean . Eli Barta, ed. Durham: Duke University Press, 2003. 244 pp.
Clothing the Pacific . Chloë Colchester. Oxford: Berg, 2003. 215 pp.
Wedding Dress across Cultures . Helen Bradley Foster and Donald Clay Johnson, eds. Oxford: Berg, 2003. 227 pp. 相似文献
Clothing the Pacific . Chloë Colchester. Oxford: Berg, 2003. 215 pp.
Wedding Dress across Cultures . Helen Bradley Foster and Donald Clay Johnson, eds. Oxford: Berg, 2003. 227 pp. 相似文献
9.
The use of automated systems to record the identity of individual penguins and their movements in and out of a colony can provide an effective means of studying penguin biology remotely. A new gateway installed at the macaroni penguin colony at Fairy Point (513 breeding pairs in 2003) on Bird Island, South Georgia in February 2003 and the implantation of passive integrated transponders for identifying individuals is described. The reliability of the system in recording penguin arrival and departure during the end of the 2002/2003 breeding season and over the complete 2003/2004 breeding season was tested using an independent method of radio telemetry. Results from two seasons of trials indicated that there was only a 3.7% probability of the gateway missing a penguin in 2002/2003 (185 total logged crossings) and 3.9% in 2003/2004 (1,309 total logged crossings); this compared with probabilities of 16.2 and 7.9% using radio telemetry, both differences being highly significant. This automatic logging gateway is therefore shown to be a more reliable means of recording the transit of penguins between the colony and sea and, over the longer term, elucidating colony attendance and survival rates of this species at South Georgia. 相似文献
10.
Sarah Hake 《Genome biology》2004,5(1):302
A report of the American Society for Plant Biologists' meeting 'Plant Genetics 2003: Mechanisms of Genetic Variation', Snowbird, Utah, USA, 22-24 October 2003. 相似文献
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An indicator of quantifying eco-environmental vulnerability was established by synthesizing 12 variables, mainly retrieved from satellite data with incorporation of analytical hierarchy process (AHP). Six vulnerability levels of potential, slight, light, medium, heavy, and very heavy were graded to depict changes of vulnerability over temporal and spatial scales. The proposed approach was employed to study spatiotemporal eco-environmental vulnerability with Landsat data acquired in 1989, 2003, and 2014 for the Thua Thien – Hue Province, Vietnam. Over the time periods of 1989–2003 and 2003–2014, both heavy and very heavy vulnerability levels exhibit an increasing trend in both magnitude and spatial size: The former raised from 5.9% in 1989, to 7.9% in 2003, and 15% in 2014; and the later increased from 1.2% in 1989, to 3.2% in 2003, and 7.3% in 2014. Both levels mainly appeared on urbanized area, bare land, semi-bare land, agricultural land, and sparse forests. In contrast, there was a significant decline in potential vulnerability level with 36.4% in 1989, 30.9% in 2003, and 19.2% in 2014, while the remaining vulnerability levels slight, light, and medium fluctuated slightly, increased in 2003 and decreased in 2014. Supporting reasons for such changes include: (1) deforestation, agriculture intensification, construction of three hydro-electric projects during the period 2003–2014; and (2) significant expansion of urbanized area leading to differences in thermal signatures in urban areas as compared with rural areas. The findings demonstrate that eco-environmental vulnerability is primarily exaggerated by anthropogenic activities through land use/land cover (LULC) changes and further enhanced by natural processes including disasters in the Thua Thien – Hue Province of Vietnam. The correlation between land surface temperature (LST) and Normalized Difference Built-up Index (NDBI) is found to be positively correlated with 0.87, 0.89, and 0.84 for 1989, 2003, and 2014, respectively. In contrast, LST-Normalized Difference Vegetation Index (NDVI) is found negatively correlated with respect to the spatiotemporal trend of environmental vulnerability with −0.81, −0.81, and −0.76 in 1989, 2003, and 2014, respectively. In addition, areas having potential, slight, and medium thermal environmental levels are decreased from 1989 to 2003 to 2003–2014. At the regional scale, increased anthropogenic activities through land’s modification have intensified the eco-environmental vulnerability in the study area. The currently proposed methodology is feasible for evaluating long-term eco-environmental changes processes by using remote sensing data, and valid for the other regions. 相似文献
13.
Hake S 《Genome biology》2003,5(1):302
A report of the American Society for Plant Biologists' meeting 'Plant Genetics 2003: Mechanisms of Genetic Variation', Snowbird,
Utah, USA, 22-24 October 2003. 相似文献
14.
Traffic control: p120-catenin acts as a gatekeeper to control the fate of classical cadherins in mammalian cells 总被引:4,自引:0,他引:4
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Proteins of the p120 family have been implicated in the regulation of cadherin-based cell adhesion, but their relative importance in this process and their mechanism of action have remained less clear. Three papers in this issue suggest that p120 plays a key role in maintaining normal levels of cadherin in mammalian cells, and that it may do so by regulating cadherin trafficking (Chen et al., 2003; Davis et al., 2003; Xiao et al., 2003). 相似文献
15.
Annual spawning of the hydrothermal vent mussel, Bathymodiolus azoricus, under controlled aquarium, conditions at atmospheric pressure 总被引:1,自引:0,他引:1
A. Colaço I. Martins L. Pires C. Prieto H. Lopes P.R. Dando 《Journal of experimental marine biology and ecology》2006,333(2):166-171
Dense macrofaunal communities of modioliform mussels are a major component of many hydrothermal vent and cold seep ecosystems. The hydrothermal vent mussel Bathymodiolus azoricus, that dominates hydrothermal vent communities near the Azores Triple Junction, can be maintained in aquaria at atmospheric pressure. Cages containing these mussels were placed over diffuse vent outlets and recovered at different times. Cages recovered in January 2003 contained mussels with ripe gonads while those recovered in July, August and November 2001 and in April 2003 did not. Mussels collected post-spawning in April 2003 spawned in the aquaria in January 2004. Young mussels recruited to the cages in April 2003. The data support a main single period of spawning and of juvenile recruitment for B. azoricus. 相似文献
16.
F. Natali L. Cecchi T. Torrigiani Malaspina F. Barbano S. Orlandini 《Aerobiologia》2013,29(3):399-406
The aim of this study was to assess the current aerobiological situation and to investigate the influence of the hot and dry summer 2003 on pollen season (onset, end and duration of the pollen season, peak pollen day and value, total seasonal amount of pollen grains) of herbaceous family as Poaceae, Urticaceae and Compositeae. Heat wave of 2003 influenced the phenology of the main pollen families in Tuscany: the high temperatures occurred during 2003 affected pollen season of different family with different responses. This study confirms the role that the climate has on the flora species and in particular on herbaceous species phenology and the high variability of the pollination among different places, during extreme events. In general, high spring temperature induces an advance of the flowering period and a release of higher pollen quantity of Urticaceae and Poaceae; however, exceptional weather conditions (i.e., summer 2003) could exert an opposite effect, resulting in an impairment of flowering of Urticaceae during autumn. Compositeae species produced a low amount of pollen in 2003, even if the peak value was higher than the average in some stations. 相似文献
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1997—2003年广州市土地利用变化遥感监测研究及动态分析 总被引:2,自引:2,他引:2
分析了前人在土地利用研究中所用到的技术方法的基础上,利用广州市1997年和2003年的Landsat TM影像,在遥感和地理信息系统软件的支持下对广州市1997~2003年的土地利用/土地覆盖信息进行了提取并进行了统计分析,同时从土地利用变化的数量、速度、空间转移和区域差异等几个方面探讨广州市这6年来的土地利用变化规律以及其转化机理。通过本研究可以得出:(1)广州市1997~2003年间的土地利用变化状况处于一个平稳变化的阶段,其变化速度和强度都相对比较弱;(2)广州市各类土地利用类型变化存在着明显的区域差异,同时各类土地利用类型之间的转化强度不是很明显。 相似文献
18.
Crepidulospora nom. nov. is a replacement generic name for the genus Crepidula Simakova, Pankova et Issi, 2003 based on the type species Crepidula beklemishevi Simakova, Pankova et Issi, 2003 (Microsporida) from Anopheles beklemishevi. The name proposed by Simakova et al., 2003 is a preoccupied name, because it was already used for the gastropode Crepidula Lamarque 1899 (Echinospirida, Calibraeidae), a parasite of Mytilus. A valid name of the type species of the genus is now Crepidulospora beklemishevi (Simakova, Pankova, Issi, 2003) comb. n. Crepidulospora Simakova, Pankova et Issi nom. non. Type species: Crepidula beklemishevi Simakova, Pankova, Issi, 2003. Diagnosis. Sporogony is octosporoblastic. Sporogonal stages are in direct contact with host cell cytoplasm. 8 uninucleate spores, 4.2 x 2.2 mkm, are sandals-like. Polar tube is anisofilar, with 6-7 coils (2 + 4-5). Polaroplast is three-partite, with broad vesicular, vesicular and lamellar compartments. Microsporidia ilnfects larval adipose tissues. Type host: Anopheles beklemishevi (Diptera, Culicidae). 相似文献
19.
Iyer VR 《Genome biology》2003,4(6):324
A report on the Genomics, Proteomics and Bioinformatics Thematic Meeting during the 2003 American Society for Biochemistry and Molecular Biology (ASBMB) Annual Meeting, San Diego, USA, 11-15 April 2003. 相似文献
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从山东各地疑似流感发病猪分离到10株流感病毒,经国家流感中心鉴定均为A型流感病毒H9N2亚型。将其中一株Sw/SD/1/2003(H9N2)的血凝素全基因(HA)进行克隆与测序,与GenBank收录的其它猪流感和禽流感H9N2亚型的HA基因进行比较,发现Sw/SD/1/2003(H9N2)的血凝素基因在核苷酸序列方面同广西1999年分离的禽流感毒株Ck/GX/99(H9N2)和2000年云南分离的禽流感毒株Ck/YN/2000(H9N2)的同源性最高;进化树分析表明Sw/SD/1/2003(H9N2)起源于禽源的H9N2亚型流感病毒;Sw/SD/1/2003的HA氨基酸裂解位点与其他H9N2亚型不问,Sw/SD/1/2003的HA氨基酸裂解位点是R-S-L-R-G,而其它猪流感和禽流感H9N2亚型都是R-S-S-R-G。 相似文献