A new record of ponyfish <Emphasis Type="Italic">Deveximentum megalolepis</Emphasis> (Perciformes: Leiognathidae) in Beibu Gulf of China     

Yuman Ju  Na Song  Guobao Chen  Dianrong Sun  Zhiqiang Han  Tianxiang Gao 《中国海洋大学学报(英文版)》2017,16(3):468-472

A new record ponyfish, Deveximentum megalolepis Mochizuki and Hayashi, 1989, was documented based on its morphological characteristics and DNA barcode. Fifty specimens were collected from Beibu Gulf of China and identified as D. megalolepis by morphological characterization. The coloration, meristic traits, and morphometric measurements were consistent with previously published records. In general, it is a silver-white, laterally compressed and deep bodied ponyfish with 6–9 rows of scales on cheek; scale rows above lateral line 6–8; scale rows below lateral line 14–17. Mitochondrial cytochrome oxidase I subunit (COI) gene fragment was sequenced for phylogenetic analysis. There is no sequence variation of COI gene between the specimens collected in this study. The genetic distances between D. megalolepis and other congeneric species range from 3.6% to 14.0%, which were greater than the threshold for fish species delimitation. The COI sequence analysis also supported the validity of D. megalolepis at genetic level. However, the genetic distance between Chinese and Philippine individuals was about 1.2% and they formed two lineages in gene tree, which may be caused by the geographical distance.  相似文献   

Micromorphological features of diagnostic horizons in several soils in southwest China: Implication for soil taxonomic classification   总被引：1，自引：0，他引：1  

Xiangming Xu  Yurong He  Chengmin Huang  Donghong Xiong 《山地科学学报》2010,7(1):73-82

The comparative studies on micromorphological features in diagnostic horizons of Stagnic Anthrosols, Ustic Ferrosols and Ustic Vertosols in southwestern China were conducted to underpin the rationale for Chinese Soil Taxonomy. The following findings were explored: (1) Stagnic Anthrosols had the specific micromorphological features, e.g., the humic formation in anthrostagnic epipedon, the platy structures in plow subhorizon, the secondary formation of ferromanganese and the weakly optical-orientation clay do...  相似文献   

Study of a comprehensive assessment method of the environmental quality of soil in industrial and mining gathering areas   总被引：1，自引：0，他引：1  

Yang Guan  Chaofeng Shao  Qingbao Gu  Meiting Ju  Xueju Huang 《Stochastic Environmental Research and Risk Assessment (SERRA)》2016,30(1):91-102

Industrial and mining activities have been recognized as major sources of heavy metal contamination in soil. Here, we developed a comprehensive assessment method for the soil environment in industrial and mining gathering areas based on the pressure–state–response model. Using this method, we assessed the environmental quality of soil in a typical industrial and mining gathering area in Tianjin City, China. The results are as follows: (1) The comprehensive environmental quality index of the soil in the study area was 0.532, which corresponds to an alert state and shows that the soil environment is generally poor. (2) The pressure, state, and response indexes were 0.609, 0.634, and 0.163, respectively, which suggests that the pressure in the soil environment of the study area is barely acceptable, and the state is merely passable. Furthermore, the response measures are not ideal. (3) The low response index scores indicate poor production processes, low pollutant treatment level, and unsatisfactory level of management by the enterprises in the study area. (4) The distribution of soil risks was found to be inseparably related to that of contamination sources and land use types. Furthermore, the distribution was uneven to a certain degree. Finally, we propose recommendations for the optimization, adjustment, and management of typical industrial and mining gathering areas with petrochemical, metallurgy, and other heavily polluting enterprises.  相似文献   

Global Warming Potential in an Intensive Vegetable Cropping System as Affected by Crop Rotation and Nitrogen Rate   总被引：3，自引：0，他引：3       下载免费PDF全文

Ju Min  Kouping Lu  Haijun Sun  Longlong Xia  Hailin Zhang  Weiming Shi 《洁净——土壤、空气、水》2016,44(7):766-774

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Q系统法在甘肃北山岩体质量评价中的应用研究——以BS03号孔为例     

徐健  王驹  马艳  钟霞 《铀矿地质》2009,25(6):366-372,379

利用岩体质量评价Q系统的特点,对Q系统各参数进行赋值,根据Q值对BS03号孔附近岩体进行质量分级,给出定性结论。与利用RQD值所得岩体质量评价结果对比,一致性良好。  相似文献   

煤岩构造变形与动力变质作用   总被引：1，自引：0，他引：1       下载免费PDF全文

琚宜文  林红  李小诗  范俊佳 《地学前缘》2009,16(1):158

煤岩是一种对温度、压力等地质环境因素十分敏感的有机岩,地质演化过程中的各种构造-热事件必然导致煤岩发生一系列物理与化学结构的变化,并形成不同类型的构造煤。在构造应力作用下,煤岩不仅发生脆性和韧性变形,而且还产生不同程度的动力变质作用。因而,关于煤岩构造变形与动力变质作用的研究不仅具有重要的科学意义,而且在煤层气资源评价以及煤与瓦斯突出危险性预测方面也具有重要的实际意义。文中在已有研究成果基础上,通过对构造煤系列Ro,max、XRD和NMR(CP/MAS+TOSS)等测试和实验方法的对比研究,深入分析了煤岩不同构造变形和动力变质特征,进一步探讨了构造应力下煤岩动力变质作用的机理。研究成果表明,在构造应力作用下,煤岩脆性变形主要是通过破裂面上快速机械摩擦转化为热能而引起煤岩化学结构与其成分的改变;而韧性变形煤主要是通过局部区域应变能的积累而引起煤岩化学结构的破坏,从而发生不同机制的动力变质作用。  相似文献   

甘肃地区近震震级的量规函数研究   总被引：5，自引：4，他引：1  

陈继锋  尹欣欣  董宗明  姚海东  蒲举 《中国地震》2013,29(3):327-334

采用甘肃测震台网“十五”宽频带数字地震记录资料,选取自2009 年1 月～ 2012 年12 月所记录的13086 次地震事件,通过震级残差统计方法计算了各台站单台震级与台网平均震级的偏差、平均偏差和标准偏差,分析了震级偏差频次分布和定量统计,修正了ML量规函数,得到了代表甘肃地区的地方性均匀震级量规函数。  相似文献   

Component-based topological data model for three-dimensional geology modeling     

Hou Enke  Wu Lixin  Wu Yuhua  Ju Tianyi 《地球空间信息科学学报》2013,16(2):122-127

On the study of the basic characteristics of geological objects and the special requirement for computing 3D geological model, this paper gives an object-oriented 3D topologic data model. In this model, the geological objects are divided into four object classes: point, line, area and volume. The volume class is further divided into four subclasses: the composite volume, the complex volume, the simple volume and the component. Twelve kinds of topological relations and the related data structures are designed for the geological objects.  相似文献   

Impacts of Boundary-Layer Structure and Turbulence on the Variations of PM2.5 During Fog–Haze Episodes     

Ju  Tingting  Wu  Bingui  Zhang  Hongsheng  Wang  Zhaoyu  Liu  Jingle 《Boundary-Layer Meteorology》2022,183(3):469-493

Boundary-Layer Meteorology - The precise cause of PM2.5 (fine particular matter with a diameter smaller than 2.5&nbsp;μm) explosive growth and the contribution of intermittent turbulence...  相似文献   

浙江桐庐县刘家奥陶纪剖面生物地层学初步研究   总被引：2，自引：0，他引：2  

张元动  张举  汪建国  宋妍妍  汪隆武  俞国华  黎康清 《地层学杂志》2012,(1):1-12

新发现的浙江桐庐刘家剖面位于马金一乌镇断裂与球川一萧山断裂之间,是浙西北地区以碎屑岩沉积为主的代表性奥陶纪地层剖面。根据所获得的宁国组和胡乐组的笔石化石,初步建立了该层段的笔石生物地层序列,自下而上包括Tetragraptusapproximatus带、Corymbograptusdeflexus带、Azygograp...  相似文献