A new identification method for five species of oysters in genus Crassostrea from China based on high-resolution melting analysis   总被引：2，自引：0，他引：2  

王家丰  许飞  李莉  张国范 《中国海洋湖沼学报》2014,32(2):419-425

The high phenotypic plasticity in the shell of oysters presents a challenge during taxonomic and phylogenetie studies of these economically important bivalves. However, because DNA can exhibit marked differences among morphologically similar species, DNA barcoding offers a potential means for oyster identification. We analyzed the complete sequences of the cytochrome oxidase subunit I （COI） of five common Crassostrea species in China （including Hong Kong oyster C. hongkongensis, Jinjiang oyster C. ariakensis, Portuguese oyster C. angulata, Kumamoto oyster C. sikamea, and Pacific oyster C. gigas） and screened for distinct fragments. Using these distinct fragments on a high-resolution melting analysis platform, we developed an identification method that does not rely on species-specific PCR or fragment length polymorphism and is efficient, reliable, and easy to visualize. Using a single pair of primers （Oyster- COI-1）, we were able to successfully distinguish among the five oyster species. This new method provides a simple and powerful tool for the identification of oyster species.  相似文献   

Quantitative assessment of remotely sensed global surface models using various land classes produced from Landsat data in Istanbul     

Naci Yastikli  Umut G. Sefercik  Fatih Esirtgen 《中国地理科学(英文版)》2014,24(3):307-316

Digital elevation model(DEM) is the most popular product for three-dimensional(3D) digital representation of bare Earth surface and can be produced by many techniques with different characteristics and ground sampling distances(GSD). Space-borne optical and synthetic aperture radar(SAR) imaging are two of the most preferred and modern techniques for DEM generation. Using them, global DEMs that cover almost entire Earth are produced with low cost and time saving processing. In this study, we aimed to assess the Satellite pour l'observation de la Terre-5(SPOT-5), High Resolution Stereoscopic(HRS), the Advanced Space-borne Thermal Emission and Reflection Radiometer(ASTER), and the Shuttle Radar Topography Mission(SRTM) C-band global DEMs, produced with space-borne optical and SAR imaging. For the assessment, a reference DEM derived from 1∶1000 scaled digital photogrammetric maps was used. The study is performed in 100 km2 study area in Istanbul including various land classes such as open land, forest, built-up land, scrub and rough terrain obtained from Landsat data. The analyses were realized considering three vertical accuracy types as fundamental, supplemental, and consolidated, defined by national digital elevation program(NDEP) of USA. The results showed that, vertical accuracy of SRTM C-band DEM is better than optical models in all three accuracy types despite having the largest grid spacing. The result of SPOT-5 HRS DEM is very close by SRTM and superior in comparison with ASTER models.  相似文献   

Optimization of fermentation conditions for 1,3-propanediol production by marine Klebsiella pneumonia HSL4 using response surface methodology     

李莉莉  周胜  吉华松  高任  秦启伟 《中国海洋湖沼学报》2014,32(5):1036-1045

The industrially important organic compound 1,3-propanediol(1,3-PDO) is mainly used as a building block for the production of various polymers. In the present study, response surface methodology protocol was followed to determine and optimize fermentation conditions for the maximum production of 1,3-PDO using marine-derived Klebsiella pneumoniae HSL4. Four nutritional supplements together with three independent culture conditions were optimized as follows: 29.3 g/L glycerol, 8.0 g/L K 2 HPO 4, 7.6 g/L(NH 4) 2 SO 4, 3.0 g/L KH 2 PO 4, pH 7.1, cultivation at 35°C for 12 h. Under the optimal conditions, a maximum 1,3-PDO concentration of 14.5 g/L, a productivity of 1.21 g/(L·h) and a conversion of glycerol of 0.49 g/g were obtained. In comparison with the control conditions, fermentation under the optimized conditions achieved an increase of 38.8% in 1,3-PDO concentration, 39.0% in productivity and 25.7% in glycerol conversion in flask. This enhancement trend was further confirmed when the fermentation was conducted in a 5-L fermentor. The optimized fermentation conditions could be an important basis for developing lowcost, large-scale methods for industrial production of 1,3-PDO in the future.  相似文献   

Creative industries agglomeration,regional innovation and productivity growth in China     

Jin Hong  Wentao Yu  Xiumei Guo  Dingtao Zhao 《中国地理科学(英文版)》2014,24(2):258-268

This paper falls into the broad area of economic geography and economics of creativity,and it presents an alternative approach to explain why total factor productivity(TFP)growth is different across China′s regions.It establishes an empirical model to estimate the spatial agglomeration effects of creative industries on regional TFP growth,using China′s provincial panel data during the period of 2003 to 2010.We found that the creative industries agglomeration(CIA)has significant and positive impact on regional TFP growth.The result also implies that the CIA can facilitate regional TFP growth through promoting regional innovation instead of improving regional efficiency.Therefore,we argue that policy makers should take some measures to retain and establish more creative zones.  相似文献   

Surface modification of ZrO2 nanoparticles with styrene coupling agent and its effect on the corrosion behaviour of epoxy coating     

赵霞  刘栓  王秀通  侯保荣 《中国海洋湖沼学报》2014,32(5):1163-1171

The surface of ZrO2 nanoparticles was modified by styrene coupling grafting method to improve the dispersion and interaction of the nanoparticles with the epoxy coating in which the modified ZrO2 nanoparticles were used as an additive. The grafting performance and microstructure of the nano- ZrO2/epoxy coating were analyzed by Fourier transformation infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The corrosion behavior of the nano-ZrO2/epoxy coating on mild steel was evaluated in neutral 3.5 wt% NaC1 solution using electrochemical impedance spectroscopy （EIS）. Both the coating capacitance and coating resistance fitted by the equivalent circuit from EIS were used to evaluate the protective performance of the coating towards the mild steel. The results show a superior stability and efficient corrosion protection by the modified ZrO2 nanoparticles. The epoxy coating containing 2 wt% modified ZrO2 nanoparticles exhibited the best corrosion performance among all the coating specimens. This research may provide an insight into the protection of mild steel using modified epoxy coatings.  相似文献   

Carbon sequestration effects of shrublands in Three-North Shelterbelt Forest region,China   总被引：5，自引：1，他引：4  

Wenhui Liu  Jiaojun Zhu  Quanquan Jia  Xiao Zheng  Junsheng Li  Xuedong Lou  Lile Hu 《中国地理科学(英文版)》2014,24(4):444-453

Three-North Shelterbelt Forest(TSF) program, is one of six key forestry programs and has a 73-year construction period, from 1978 to 2050. Quantitative analysis of the carbon sequestration of shrubs in this region is important for understanding the overall function of carbon sequestration of the forest and other terrestrial ecosystems in China. This study investigated the distribution area of shrubland in the TSF region based on remote sensing images in 1978 and 2008, and calculated the carbon density of shrubland in combination with the field investigation and previous data from published papers. The carbon sequestration quantity and rate from 1978 to 2008 was analyzed for four sub-regions and different types of shrubs in the TSF region. The results revealed that: 1) The area of shrubland in the study area and its four sub-regions increased during the past thirty years. The area of shrubland for the whole region in 2008 was 1.2 × 10~7 ha, 72.8% larger than that in 1978. The Inner Mongolia-Xinjiang Sub-region was the largest shrubland distribution area, while the highest coverage rate was found in the North China Sub-region. 2) In decreasing order of their carbon sequestration, the four types of shrubs considered in this study were Hippophae rhamnoides, Caragana spp., Haloxylon ammodendron and Vitex negundo var. heterophylla. The carbon sequestration of H. rhamnoides, with a maximum mean carbon density of 16.5 Mg C/ha, was significantly higher than that of the other three species. 3) The total carbon sequestration of shrubland in the study region was 4.5×10~7 Mg C with a mean annual carbon sequestration of 1.5 ×10~6 Mg C. The carbon density in the four sub-regions decreased in the following order: the Loess Plateau Sub-region, the North China Sub-region, the Northeast China Sub-region and the Inner Mongolia-Xinjiang Sub-region. The paucity of studies and data availability on the large-scale carbon sequestration of shrub species suggests this study provides a baseline reference for future research in this area.  相似文献   

Soil carbon stock and flux in plantation forest and grassland ecosystems in Loess Plateau,China   总被引：1，自引：1，他引：0  

Chanjuan Hu  Guohua Liu  Bojie Fu  Liding Chen  Yihe Lyu  Lei Guo 《中国地理科学(英文版)》2014,24(4):423-435

Carbon sequestration occurs when cultivated soils are re-vegetated. In the hilly area of the Loess Plateau, China, black locust(Robinia pseudoacacia) plantation forest and grassland were the two main vegetation types used to mitigate soil and water loss after cultivation abandonment. The purpose of this study was to compare the soil carbon stock and flux of these two types of vegetation which restored for 25 years. The experiment was conducted in Yangjuangou catchment in Yan′an City, Shaanxi Province, China. Two adjacent slopes were chosen for this study. Six sample sites were spaced every 35–45 m from summit to toe slope along the hill slope, and each sample site contained three sampling plots. Soil organic carbon and related physicochemical properties in the surface soil layer(0–10 cm and 10–20 cm) were measured based on soil sampling and laboratory analysis, and the soil carbon dioxide(CO2) emissions and environmental factors were measured in the same sample sites simultaneously. Results indicated that in general, a higher soil carbon stock was found in the black locust plantation forest than that in grassland throughout the hill slope. Meanwhile, significant differences in the soil carbon stock were observed between these two vegetation types in the upper slope at soil depth 0–10 cm and lower slope at soil depth 10–20 cm. The average daily values of the soil CO2 emissions were 1.27 μmol/(m2·s) and 1.39 μmol/(m2·s) for forest and grassland, respectively. The soil carbon flux in forest covered areas was higher in spring and less variation was detected between different seasons, while the highest carbon flux was found in grassland in summer, which was about three times higher than that in autumn and spring. From the carbon sequestration point of view, black locust plantation forest on hill slopes might be better than grassland because of a higher soil carbon stock and lower carbon flux.  相似文献   

Evaluation of the biological toxicity of lfuorine in Antarctic krill     

ZHANG Ling  LU Xiaoqi  WANG Zhangmin  QIN Liqiang  LIN Zhiqin  YUAN Linxi  ZHANG Wen  YIN Xuebin 《极地研究(英文版)》2014,(1):38-45

Antarctic krill is a potentially nutritious food source for humans, but lfuorine （F） toxicity is a matter of concern. To evaluate the toxicity of F in Antarctic krill, 30 Wistar rats were divided into three groups with different dietary regimens：a control group, a krill treatment group （150 mg＆#183;kg-1 F）, and a sodium lfuoride （NaF） treatment group （150 mg＆#183;kg-1 F）. After three months, F concentrations in feces, plasma, and bone were determined, and the degree of dental and skeletal lfuorosis was assessed. The F concentrations in plasma and bone from the krill treatment group were 0.167 0＆#177;0.020 4 mg.L-1 and 2 709.8＆#177;301.9 mg＆#183;kg-1, respectively, compared with 0.043 8＆#177;0.005 5 mg＆#183;L-1 and 442.4＆#177;60.7 mg＆#183;kg-1, respectively, in samples from the control group. Concentrations of F in plasma and bone in the krill treatment group were higher than in the control group, but lower than in the NaF treatment group. The degree of dental lfuorosis in the krill treatment group was moderate, compared with severe in the NaF treatment group and normal in the control group. The degree of skeletal lfuorosis did not change signiifcantly in any group. These results showed that the toxicity of F in Antarctic krill was lower than for an equivalent concentration of F in NaF, but it was toxic for rats consuming krill in large quantities. To conclude, we discuss possible reasons for the reduced toxicity of F in Antarctic krill. The present study provides a direct toxicological reference for the consideration of Antarctic krill for human consumption.  相似文献   

一种基于Harris角点检测的SVG转换可视化效果评价方法     

王艳慧  李跃 《地球信息科学学报》2014,(3):368-375

SVG作为移动互联时代获得各种丰富图形信息的有效表达方法,已成为LBS中空间信息表达与描述的热点应用之一,但目前的研究大多没有考虑多源数据格式向SVG格式转换后的图像质量评价问题。针对多源空间数据向SVG格式转换方法和转换效果评价技术,本文设计了栅格数据和矢量数据向SVG格式转换的表达方法,分别利用直接载入栅格图像和编程实现矢量数据转换的方法实现了多源空间数据向SVG格式的有效转换;从定性与定量相结合的角度分析了转换前后的图像质量,设计了角点检测评价指标和流程,提出了基于Harris角点检测的SVG转换前后图形几何质量的评价方法。实验证明:SVG格式比较适用于位置服务中对空间数据尤其是矢量数据的表达,经过SVG转换后的图像,无论是栅格数据还是矢量数据都具有较高的图像质量,且栅格数据的转换效果相对略差于矢量数据;验证了一种基于SVG的移动位置空间服务信息表达和组织模式,对普及和强化SVG在位置服务系统中的应用具有一定的推动作用。  相似文献   

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甘雨  隋立芬  肖国锐  段宇  戚国宾 《大地测量与地球动力学》2014,34(3):129-132

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