Agricultural Heritage Systems Tourism: definition,characteristics and development framework     

Mi Tian  Qing-wen Min  Wen-jun Jiao  Zheng Yuan  Anthony M. Fuller  Lun Yang  Yong-xun Zhang  Jie Zhou  Bing Cheng 《山地科学学报》2016,13(3):440-454

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Variations of bacterial and fungal communities along a primary successional chronosequence in the Hailuogou glacier retreat area (Gongga Mountain,SW China)     

Hong-yang Sun  Yan-hong Wu  Jun Zhou  Hai-jian Bing 《山地科学学报》2016,13(9):1621-1631

New terrestrial habitats have emerged and a primary succession has developed in the retreat area(29°34'N, 102°00'E, 2951–2886 m) after the retreat of the Hailuogou glacier. To investigate soil microbial changes along the primary successional chronosequence, mixed soil samples were collected at six sites at different ages(2 young sites, 2 mid-aged sites, and 2 old sites). The RNA was extracted and amplified. Bacterial 16 S r RNA and fungal 18 S r RNA were analyzed using high-throughput 454 pyrosequencing analysis. Overall, pyrosequencing showed that Proteobacteria, Acidobacteria, Bacteroidetes and Actinobacteria were the main bacterial phyla, and the fungal communities were strongly dominated by the phyla Ascomycota and Basidiomycota in the retreat area. The Shannon diversity index(Hshannon) of bacteria was 6.5 – 7.9, and that of fungi was 2.2 – 4.1 in these sites. For the bacterial communities, diversity and evenness values were highest on the mid-age sites and wererelatively low on the young and old sites. A similar trend was observed for the fungal communities. In contrast, soil properties showed significant linear distributional trends(increase or decrease) with the age of the site. Combining the linear change patterns of soil properties, the highest values of bacterial and fungal evenness and diversity in the mid-aged sites indicated that there was less environmental stress and more niches for microbial communities in the middle successional stage compare with other stages. In addition, our analysis showed that microbial communities were the main drivers that build a soil organic matter pool to expedite pedogenesis for ecosystem succession. This primary succession in the Hailuogou glacier retreat area is developing rapidly compared with that in other glacier retreats.  相似文献   

Scour development around submarine pipelines due to current based on the maximum entropy theory     

Jing?Zhang  Bing?ShiEmail author  Yakun?Guo  Weilin?Xu  Kejun?Yang  Enjin?Zhao 《中国海洋大学学报(英文版)》2016,15(5):841-846

This paper presents the results from laboratory experiments and theoretical analysis to investigate the development of scour around submarine pipeline under steady current conditions. Experiments show that the scour process takes place in two stages: the initial rapid scour and the subsequent gradual scour development stage. An empirical formula for calculating the equilibrium scour depth (the maximum scour depth) is developed by using the regression method. This formula together with the maximum entropy theory can be applied to establish a formula to predict the scour process for given water depth, diameter of pipeline and flow velocity. Good agreement between the predicted and measured scour depth is obtained.  相似文献   

Meiofauna Distribution in Intertidal Sandy Beaches Along China Shoreline(18?–40?N)     

Er Hua  Zhinan Zhang  Hong Zhou  Fanghong Mu  Jia Li  Ting Zhang  Bingqing Cong  Xiaoshou Liu 《中国海洋大学学报(英文版)》2016,15(1):19-27

In this study,the distribution pattern of meiofauna from nine sandy beaches at six latitudinal gradients along Chinese coast between 18 and 40?N was studied on their meiofauna abundance to examine the effect of latitudinal gradients.In general,meiofauna abundance was lower in four subtropical beaches in Xiamen(24?N) and Zhoushan(29?N) than that in other beaches.Meiofauna abundance differed little between tropical and temperate beaches.The taxonomic structure of meiofauna showed a dominance of nematode in colder area.The relative composition of turbellarians and polychaetes increased in warmer area.In addition to latitudinal gradient,salinity,oxygenation,sediment grain size affect also the meiofauna latitudinal distribution.As for horizontal distribution,the highest meiofauna abundance was found in low tidal zone at tropical beaches,and in middle tidal zone at temperate beaches.The horizontal distribution of meiofauna was controlled by both physical and biotic factors including feeding and anthropogenic activities.Although meiofauna abundance exhibited a horizontal difference,the composition of meiofaunal main taxa was unanimous horizontally at all beaches at the same sampling latitude.  相似文献   

Molecular weight controllable degradation of <Emphasis Type="Italic">Laminaria japonica</Emphasis> polysaccharides and its antioxidant properties     

ZHA Shenghua  ZHAO Qingsheng  ZHAO Bing  OUYANG Jie  MO Jianling  CHEN Jinjin  CAO Lili  ZHANG Hong 《中国海洋大学学报(英文版)》2016,15(4):637-642

In this study, molecular weight controllable degradation of algal Laminaria japonica polysaccharides（LPS） was investigated by ultrasound combined with hydrogen peroxide. Three main factors, i.e., ultrasonic power（A）, ultrasonic time（B）, and H₂O₂ concentration（C） were chosen for optimizing parameters by employing three-factors, three-levels BBD. The influence of degradation on structure change and antioxidant activities was also investigated. A second-order polynomial equation including molecular weight（Y） of Laminaria japonica polysaccharides and each variable parameter, i.e., ultrasonic power（A）, ultrasonic time（B）, and H₂O₂ concentration（C）, was established: Y=20718.67-4273.13A-4000.38B-1438.75C+2333.25AB+1511.00AC+873.00BC+2838.29A² + 2490.79B²+873.04C². The equation regression coefficient value（R² = 0.969） indicated that this equation was valid. The value of the adjusted determination coefficient（adjusted R² = 0.914） also confirmed that the model was highly significant. The results of selected experimental degradation conditions matched with the predicted value. FT-IR spectra revealed that the structures of LPS before and after degradation were not significantly changed. Antioxidant activities of LPS revealed that low Mws possessed stronger inhibitory than the original polysaccharides. The scavenging effects on superoxide radicals was the highest when IC50 of crude LPS was 4.92 mg mL^-1 and IC50 of Mw 18.576 KDa was 1.02 mg mL^-1, which was fourfold higher than initial polysaccharide.  相似文献   

An Analytical Model for Assessing Stability of Pre-Existing Faults in Caprock Caused by Fluid Injection and Extraction in a Reservoir     

Lei Wang  Bing Bai  Xiaochun Li  Mingze Liu  Haiqing Wu  Shaobin Hu 《Rock Mechanics and Rock Engineering》2016,49(7):2845-2863

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人为热释放:全球分布的估算及其气候效应的探索   总被引：1，自引：0，他引：1  

陈兵  陈良富  董理  石广玉 《大气科学》2016,40(2):289-295

人类生产和生活中大量消费各种形式的能源,除了向大气里排放温室气体和气溶胶外,还释放大量热量。人为热释放伴随着人类社会发展而长期存在,随着全球人口增长和经济发展,其影响效应不断加剧。人为热释放具有典型地域集中、不均匀分布的特征:虽然全球平均人为热释放通量仅约为0.03 W m-2,在人口密集的城市地区,人为热释放可高达每平方米数百瓦,足以影响局地气候。伴随全球经济的发展,人口的增长及城市化进程的加剧,人为热释放分布更集中,影响气候的范围逐步扩大,其对气候的影响能力逐步增强。全球气候模式的结果表明:人为热释放能够对全球大气环流产生影响,进而影响到全球气候变化。人为热释放可以导致全球地表温度增温约0.06 K,500 hPa温度场平均升温约0.04 K,尤其对北半球中高纬度升温效应明显。研究结果表明,人为热释放虽然没有温室气体如二氧化碳等影响因子对全球气候的影响那么显著,但是其仍然能够对全球气候产生影响,是全球气候变化不可忽视的影响因子。  相似文献   

Grain boundary wetness of partially molten dunite     

Shangshang Mu  Ulrich H. Faul 《Contributions to Mineralogy and Petrology》2016,171(5):40

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Mechanisms involved in sorption of metals by chemically treated waste biomass from irrigation pond     

J. M. Lezcano  F. González  A. Ballester  M. L. Blázquez  J. A. Muñoz 《Environmental Earth Sciences》2016,75(10):852

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Microbial diversity in lake–river ecotone of Poyang Lake,China     

Xiaolan Huang  Baoqing Hu  Peng Wang  Xiaoling Chen  Bing Xu 《Environmental Earth Sciences》2016,75(11):965

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