30 resultados para 1316
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液滴操纵和控制是实现微全分析系统(μTAS)和芯片上的实验室(lab-on-a-chip)功能的基础,基于液滴操控的显示及微透镜已经成功应用。目前电润湿启动液滴方法简单、响应时间快,引起越来越多的关注。另一方面超疏水表面上的液滴具有低摩擦、低粘附的特性,借由这种原理制作的微流器件可以实现微量液体传输。为了更好的利用超疏水表面的特性,就需要研究液滴运动规律,以及表面特性的影响。
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IEECAS SKLLQG
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通过野外实地调查与相对干扰度计算,采用物种多样性指数及方差分析、相关分析等方法,对长白山北坡原始林(阔叶红松林)与2种次生林(杂木林与桦木林)的植物物种多样性进行了比较研究,并对影响物种多样性的可能因素进行了系统分析。结果表明:原始林共记录植物物种91种,分别隶属于46科72属;杂木林共记录植物物种128种,分别隶属于53科92属;桦木林共记录植物物种108种,分别隶属于52科87属。仅从Shannon-w iener多样性指数看,桦木林的乔木层、草本层和总体多样性均最小,而灌木层多样性最大;原始林在乔木层多样性小于杂木林,但是在灌木层、草本层和总体多样性均大于杂木林。原始林与次生林草本层的多样性较高,均大于相应的乔木层和灌木层。以原始林为参照,较大的干扰强度使乔木层多样性降低,而较小的干扰强度不仅不会降低乔木层多样性,反而可以增加其多样性;灌木、草本层的多样性受干扰的变化与乔木层相反。
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根据2006年Landsat TM影像,利用Erdas和ArcGIS软件,结合区划理论和聚落地理学,对辽宁省中部城市群的居民地分布格局进行了研究。结果表明:1)辽宁省中部城市群居民地在斑块数量上主要以小型斑块为主,斑块面积<1km2的斑块数量达斑块总数的96.38%,在斑块面积上以沈阳等几个大型城市的居民地占主要地位。2)依据居民地面积的空间比重将辽宁省中部城市群居民地划分为东部地区、沈阳地区和西部地区3个特征区域,其中沈阳地区平均斑块面积最大,城市化程度最高;西部地区斑块密度最大,居民地最为密集;东部地区平均斑块面积和斑块密度均最小,居民地发育程度低于另2个区域。3)尽管居民地在3个区域内都呈随机分布,但其指示参数——最邻近点指数还是体现出明显的区划差异。4)居民地分布受中心城市的影响显著,各中心城市的辐射范围不同,大小依次为沈阳>鞍山>铁岭>营口>辽阳>本溪>抚顺。
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植物根际沉积是一种重要的植物与土壤交换的界面过程,在土壤碳周转方面具有重要的作用;根际碳的沉积也是联系植物、土壤及微生物的桥梁.本文就近年来关于根际沉积中碳平衡、碳循环等相关研究,阐述了根际碳沉积的机制,探讨了相关试验中存在的问题,以及不同植物品种、种类和生育期根际沉积的差异和根际沉积物与土壤呼吸的关系,指出了根际沉积在植物-土壤体系中碳循环的重要作用.在此基础上,提出了未来的研究领域及方向.
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通过野外调查和室内分析,研究了新疆三工河流域平原绿洲耕地、人工林地、草地、灌木林地和盐碱地0~20 cm表层土壤盐渍化特征。结果表明:整个农业绿洲土壤盐分含量均值为9.33 g/kg,其中耕地平均值为6.9g/kg,超过75%耕地样点集中分布在低于2 g/kg的区间,而其它土地利用类型均高于10 g/kg,并且样点分散分布于各盐分等级中,自然和人为活动对不同土地利用类型盐分聚积均有显著作用;随地貌单元,自南向北盐分均值含量增加,在冲洪积扇中上部和地下水溢出带,盐分均值低于3.8 g/kg,而在冲洪积平原区,则高于10 g/kg;由于区域水资源的南北分布格局与利用差异,使得土壤盐分具有中等或强的空间变异性。
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本文对我国己发表的牡蛎作了详细的比较解剖学研究。在强蛎亚科(Pycnodonteinae)发现了第三个心耳--右上心耳和与其相连的第三条回心静脉--后静脉,这在双壳类中实属首次报道。第一次提出了牡蛎循环系统的两种类型,附心脏型和无附心脏型。两者之间的主要区别是:前者无肌套血管,其外套血液主要来自环外套动脉和附心脏,而后者由于无附心脏和环外套动脉,其外套血液主要来自肌套血管;前者是通过出鳃静脉和外套静脉分别将鳃前部和后部的血液送回心耳,而后者的外套静脉与外入鳃血管不通,鳃中的血液只能通过出鳃静脉回到心耳。根据外套腔的形态特点,本文将中国的牡蛎分为三种类型六个组。第一种类型,左右侧都具侧水腔,包括一个组;第二种类型,仅右侧具有侧水腔,包括四个组;第三种类型;不具侧水腔,包括一个组。在比较解剖学研究的基础上,文章还讨论了消化系统,神经系统,循环系统等一些主要系统的演化过程,并推测了现生牡蛎各属间的演化关系。提出了一些新的分类依据,发现了一个具有重要演化意义的单行属种,爪蛎属(Talonostrea),猫爪牡蛎(T. talonata)。澄清了目前世界上在舌骨蛎属(Hyotissa)、拟舌骨蛎属(Parahyotissa)、小蛎属(Saccostrea)和巨蛎属(Crassostrea)分类中的混乱。解决了我国牡蛎分类中存在己久的疑难问题,将己发表的20种牡蛎重新鉴定为15种,即舌骨牡蛎(Hyotissa hyotis),复瓦牡蛎(Parahyotissa imbricata)。中华牡蛎(P. sinensis),鸡冠牡蛎(Lopha cristagalli)。薄片牡蛎(Dendostren folium),缘齿牡蛎(D. cre-nulifera),褶牡蛎(Alectryonella plicatula),猫爪牡蛎(T. talonata),长牡蛎(Crassostrea gigas),近江牡(C. rivularis),拟近江牡蛎(Crassostrea sp.),僧帽牡蛎(Saccostrea cucullata),棘刺牡蛎(S. echinata),鹅掌牡蛎(Planostrea pestigris)和密鳞牡蛎(Ostrea denselamellosa)。它们分别隶属于二个科,曲蛎科(Grypheidae)和牡蛎科(Ostreidae);四个亚科,强蛎亚科(Pycnodonteinae)。冠蛎亚科(Pycnodonteinae),巨蛎亚科(Lopheinae)和牡蛎亚科(Crassostreinae)。
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The composition of the leaf oils from seven populations of J. sabina L., one population of Juniperus sabina var. arenaria (E. H. Wilson) Farjon were examined for their geographic variation. In addition, the leaf oils of J. chinensis L. and J. davurica Pall. were compared to J. sabina. Juniperus sabina var. arenarla, the sand loving juniper, oil was found to be very similar to that of J. davurica, Mongolia, and J. sabina, on sand dunes in Mongolia. This suggests that J. sabina var. arenaria might be conspecific with J. davurica. Farjon's move (2001) of J. sabina var. arenaria out of J. chinensis is supported. Considerable differentiation was found in populations of J. sabina from the Iberian peninsula. Cedrol, citronellol, safrole, trans-sabinyl acetate, terpinen-4-ol and beta-thujone were found to be polymorphic in several populations.
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In research field of oil geophysical prospecting, reservoir prediction is refers to forecasting physical properties of petroleum reservoir by using data of seismic and well logging, it is a research which can guide oil field development. Singularities of seismic and logging data are caused by the heterogeneity of reservoir physical property. It's one of important methods that using singularity characteristics of seismic and logging data to study the reservoir physical property in recently. Among them, realization of reservoir quantitative prediction by analyzing singularity of the data and enhancing transition description of data is difficulty in method research. Based on wavelet transform and the fractal theory, the paper studied the singularity judgment criterion for seismic and logging data, not only analyzed quantitative relation between singularity data and reservoir physical property, but also applied it in practical reservoir prediction. The main achievements are: 1. A new method which provides singular points and their strength information estimation at only one single scale is proposed by Herrmann (1999). Based on that, the dissertation proposed modified algorithm which realized singularity polarity detection. 2. The dissertation introduced onset function to generalize the traditional geologic boundaries variations model which used singularity characteristics to represent the abruptness of the lithologic velocity transition. We show that singularity analysis reveals generic singularity information conducted from velocity or acoustic impedance to seismogram based on the convolution seismic-model theory. Theory and applications indicated that singularity information calculated from seismic data was a natural attribute for delineating stratigraphy boundaries due to its excellent ability in detecting detailed geologic features. We demonstrated that singularity analysis was a powerful tool to delineate stratigraphy boundaries and inverse acoustic impedance and velocity. 3. The geologic significances of logging data singularity information were also presented. According to our analysis, the positions of singularities indicate the sequence stratigraphic boundary, and there is subtle relationship between the singularity strength and sedimentary environment, meanwhile the singularity polarity used to recognize stratigraphic base-level cycle. Based on all those above, a new method which provided sedimentary cycle analysis based on the singularity information of logging data in multiple scales was proposed in this dissertation. This method provided a quantitative tool for judging interface of stratum sequence and achieved good results in the actual application.