检索结果-南通市图书馆

Patterns and ecological determinants of woody plant height in eastern Eurasia and its relation to primary productivity

引用

Journal of Plant Ecology 2019年第5期12卷 791-803页

作者： Zhiheng Wang Yaoqi Li Xiangyan Su Shengli Tao Xiao Feng Qinggang Wang Xiaoting Xu Yunpeng Liu Sean T.Michaletz Nawal Shrestha Markku Larjavaara Brian J.Enquist Institute of Ecology and key laboratory for Earth surface processes of the Ministry of Education College of Urban and Environmental SciencesPeking UniversityBeijing 100871China Department of Ecology and Evolutionary Biology University of ArizonaTucsonAZ 85721USA LaboratoireÉvolution et DiversitéBiologique(EDB)UMR 5174 31062Toulouse Cedex 9France Institute of the Environment University of ArizonaTucsonAZ 85721USA Department of Ecology College of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China key laboratory of Bio-Resource and Eco-Environment of Ministry of Education College of Life SciencesSichuan UniversityChengdu 610065SichuanChina Biosphere 2 University of ArizonaTucsonAZ 85721USA Department of Botany and Biodiversity Research Centre University of British ColumbiaVancouverBC V6T 1Z4Canada The Santa Fe Institute Santa FeNM 87501USA

Aims Plant height is a key functional trait related to aboveground bio-mass,leaf photosynthesis and plant ***,large-scale geographical patterns in community-average plant height(cAPH)of woody species and drivers of these patterns across different life forms remain hotly ***,whether cAPH could be used as a predictor of ecosystem primary productivity is *** We compiled mature height and distributions of 11422 woody spe-cies in eastern Eurasia,and estimated geographic patterns in cAPH for different taxonomic groups and life *** we evaluated the effects of environmental(including current climate and historical climate change since the Last Glacial Maximum(LGM))and evolutionary factors on ***,we compared the predictive power of cAPH on primary productivity with that of LiDAR-derived canopy-height data from a global *** Findings Geographic patterns of cAPH and their drivers differed among taxonomic groups and life *** strongest predictor for cAPH of all woody species combined,angiosperms,all dicots and deciduous dicots was actual evapotranspiration,while temperature was the strongest pre-dictor for cAPH of monocots and tree,shrub and evergreen dicots,and water availability for *** climate change since the LGM had only weak effects on *** phylogenetic signal was detected in family-wise average height,which was also unrelated to the tested environmental ***,we found a strong correlation between cAPH and ecosystem primary *** productivity showed a weaker relationship with cAPH of the tallest species within a grid cell and no relationship with LiDAR-derived canopy height reported in the global *** findings suggest that current climate rather than historical climate change and evolutionary history determine the geographical patterns in ***,the relative effects of climatic factors representing environmental energy and water availability on s

关键词： annual evapotranspiration ecosystem primary productivity environmental factors historical climate change phylogenetic signals community-average plant height woody plants

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effects of river damming on biogenic silica turnover:implications for biogeochemical carbon and nutrient cycles

引用

Acta Geochimica 2017年第4期36卷 626-637页

作者： Nan Ma Zhaoliang Song Baoli Wang Fushun Wang Xiaomin Yang Xiaodong Zhang Qian Hao Yuntao Wu Institute of the surface-Earth System Science Research Tianjin University School of Environmental and Chemical Engineering Shanghai University

Rivers link terrestrial ecosystems and marine ecosystems, and they transport large amounts of substances into oceans each year, including several forms of silicon(Si), carbon(C), and other nutrients. However, river damming affects the water flow and biogeochemical cycles of Si, C, and other nutrients through biogeochemical interacting processes. In this review, we first summarize the current understanding of the effects of river damming on the processes of biogeochemical Si cycle, especially the source, composition, and recycling process of biogenic silica(BSi). Then, we introduce dam impacts on the cycles of C and some other nutrients. Dissolved silicon in rivers is mainly released from phytolith dissolution and silicate weathering. BSi in suspended matter or sediments in most rivers mainly consists of phytoliths and mainly originates from soil erosion. However, diatom growth and deposition in many reservoirs formed by river interception may significantly increase the contribution of diatom Si to total BSi, and thus significantly influence the biogeochemical Si,C, and nutrient cycles. Yet the turnover of phytoliths and diatoms in different rivers formed by river damming is still poorly quantified. Thus, they should be further investigated to enhance our understanding about the effects of river damming on global biogeochemical Si, C and nutrient cycles.

关键词： River damming Biogenic silica Biogeochemical cycles River ecosystem

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of multiple dynamic processes on chlorophyll variation in the Luzon Strait in summer 2019 based on glider observation

引用

Journal of Oceanology and Limnology 2023年第2期41卷 469-481页

作者： Xiangpeng WANG Yan DU Yuhong ZHANG Tianyu WANG State key laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China College of Marine Science University of Chinese Academy of SciencesBeijing 100049China Guangdong key laboratory of Ocean Remote Sensing South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China

Luzon Strait is the main channel connecting the South China Sea(SCS)and the western Pacific,with complex atmospheric and oceanic dynamic *** on 44 days of glider measurements and satellite observations,we investigated the temporal and vertical variations of chlorophyll-a(Chl-a)concentration in the Luzon Strait from July 25 to September 6,*** Chl a was mainly distributed above 200 m and concentrated in the subsurface chlorophyll maximum(SCM)*** depth of SCM ranged between 50 m and 110 m,and the magnitude of SCM varied from 0.42 mg/m3 to 1.12 mg/*** variation of Chl a was identified with three stages responding to different dynamic *** the influence of Kuroshio intrusion,the SCM depth sharply deepened,and its magnitude decreased in Stage ***,a prominent Chl-a bloom was observed in the SCM layer from August 6 to August *** Chl-a bloom in Stage 2 was related to the influence of a cyclonic eddy,which uplifted of the thermocline and thus the deep *** Stage 3,prolonged heavy rainfall in the northeastern SCS resulted in a significant salinity decrease in the upper *** convergence of upper water deepened the thermocline and the mixed ***,the Chl a decreased in the SCM layer but increased in the surface *** particular,a typhoon passed through the Luzon Strait on August 24,which induced the Chl a increase in the upper 50 ***,there was little change in the depth-integrated Chl a(0-200 m),indicating that the Chl a increase in the surface layer was likely associated with physical entrainment of SCM caused by strong mixing,rather than the phytoplankton bloom in the upper water *** gliders provide frequent autonomous observations that help us understand the regional ocean’s complex dynamic processes and biological responses.

关键词： Luzon Strait glider observations chlorophyll a Kuroshio cyclonic eddy typhoon

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fluctuations of water Table Level in a Subtropical Peatland,Central China

引用

Journal of Earth Science 2022年

作者： Guang Yang Yiming Zhang Xianyu Huang State key laboratory of Biogeology and Environmental Geology China University of Geosciences Hubei key laboratory of Critical Zone Evolution School of Geography and Information Engineering China University of Geosciences

water level is the overriding control on carbon cycles in peatlands, which are important for global carbon cycles and ecosystem services. To date, our knowledge of the pattern of water level fluctuations in peatlands and the influence of precipitation and air temperature on them in the subtropical remains poor. In this study, we conducted continuous high-resolution monitoring of water levels from 2014 to 2021 in the Dajiuhu peatland, a typically subtropical peatland in central China. Monitoring results showed that the water level had strong annual(370 days) and seasonal(130 days) oscillations in the Dajiuhu peatland. The annual oscillation is associated with both precipitation and temperature, while the seasonal oscillation is mainly controlled by precipitation. In addition, the depth of peat surface to the water table(DWT) has weak but significant correlations with precipitation and temperature on the daily and weekly scales(r = 0.1–0.21, P water table fluctuation cumulation, the correlation coefficients increase apparently(r = 0.47–0.69, P water level and have the potential to improve the interpretation of water-level related paleoenvironmental proxies and the understanding of the relationship between water level and biogeochemical processes.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Observations of marine snow and fecal pellets in a sediment trap mooring in the northern South China Sea

引用

Acta Oceanologica Sinica 2020年第3期39卷 141-147页

作者： Meng Gao Baoqi Huang Zhifei Liu Yulong Zhao Yanwei Zhang School of Earth and Space Sciences Peking UniversityBeijing 100871China State key laboratory of Marine Geology Tongji UniversityShanghai 200092China

Sediment traps are an important tool for studying the source, composition and sedimentation processes of sinking particulate matter in the ocean. An in situ observational mooring(TJ-A-1) is located in the northern South China Sea(20.05°N, 117.42°E) at a water depth of 2 100 m and equipped with two sediment traps deployed at 500 m and 1 950 m. Samples were collected at 18-day intervals, and 20 samples were obtained at both depths from May 2014 to May 2015. Large amounts of fecal matter and marine snow were collected in the lower trap. The fluxes of marine snow and fecal pellets exhibited a fluctuating decrease between May 2014 and early August 2014 and then stabilized at a relatively low level. Scanning electron microscopy observations revealed that the main components of the marine snow and fecal pellets were diatoms, coccolithophores, radiolarians, and other debris, all of which are planktons mostly produced in photic zone. Used in conjunction with the particle collection range estimates from the lower trap and data on ocean surface chlorophyll, these marine snow and fecal pellets were related to the lateral transport of deep water and not vertical migrations from overlying water column. Moreover, the source area might be southwest of Taiwan.

关键词： northern South China Sea sediment trap marine snow fecal pellets

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Quasi-3-yr cycle of Rainy Season Precipitation in Tibet related to Different Types of ENSO during 1981–2015

引用

Journal of Meteorological Research 2018年第2期32卷 181-190页

作者： Chunxue WANG Zhenfeng MA Climate Center of Sichuan Province Chengdu 610072 key laboratory of Sichuan Province for Heavy Rain and Drought-Hood Disasters in Plateau and Basin Chengdu 610072

The rainy season precipitation in Tibet（RSPT） is a direct cause for local floods/droughts. It also indirectly affects the thermal conditions of the Tibetan Plateau, which can result in anomalous patterns of atmospheric circulation over East Asia. The interannual variability of the RSPT is often linked with the El Ni？o–Southern Oscillation（ENSO）, but the relevant mechanisms are far from being understood, particularly for different types of ENSO events. We investigated the interannual variation of the RSPT in association with different types of ENSO. A quasi-3-yr period of the RSPT（less–more–more precipitation） was significant at the 95% confidence level. A joint multi-taper method with singular value decomposition analysis of the coupled field between the RSPT and the sea surface temperature（SST）revealed that the developing eastern Pacific type El Ni？o was accompanied by a decrease in the RSPT. The shift from the central Pacific type El Ni？o to the eastern Pacific La Ni？a was accompanied by an increase in the RSPT. Weakening of the central Pacific La Ni？a was accompanied by an increase in the RSPT. Analysis of the mechanism of this coupling, using the same analysis method but other climatic factors, indicated that the gradually strengthening eastern Pacific El Ni？o can inhibit the Walker circulation, weakening the South Asian summer monsoon, and resulting in transport of less water vapor from the Bay of Bengal to Tibet. The change from the central Pacific El Ni？o to the eastern Pacific La Ni？a led to continued strengthening of the Walker circulation with westward movement of the ascending area. This enhanced the South Asian summer monsoon over the Arabian Sea and transported more water vapor to Tibet. The decreasing central Pacific La Ni？a accompanied by persistent cooling of SSTs in the equatorial Pacific led to a strong eastern North Pacific summer monsoon, causing an anomaly in the easterly transport of water vapor from the Sea of Japan to Tibet and increased RSPT

关键词： Tibet multi-taper method with singular value decomposition E1 Nifio-Southern Oscillation period

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Highly efficient catalytic performances of nitro compounds via hierarchical PdNPs-loaded MXene/polymer nanocomposites synthesized through electrospinning strategy for wastewater treatment

引用

Chinese Chemical Letters 2020年第4期31卷 992-995页

作者： Juanjuan Yin Fangke Zhan Tifeng Jiao Huizhen Deng Guodong Zou Zhenhua Bai Qingrui Zhang Qiuming Peng State key laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004China Hebei key laboratory of Applied Chemistry School of Environmental and Chemical EngineeringYanshan UniversityQinhuangdao 066004China National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao 066004China

The problem of water pollution has become increasingly serious,and it has already threatened the survival of mankind and has become an obstacle to the healthy development of human ***,we prepared a novel polyvinyl alcohol(PVA)/polyacrylic acid(PAA)/MXene fiber membrane by *** heat treatment of film and subsequent modification with Pd nanoparticles,PVA/PAA/MXene@PdNPs composite nanofiber membrane with high specific surface area and excellent catalytic performance was finally *** uniform distribution of MXene sheets in the composite fiber membrane not only solves the problem that the MXene sheet is not easy to be monolayerized,but also can grow the self-reduced Pd nanoparticles on the MXene *** addition,the composite nanofiber membrane exhibits excellent catalytic ability and cycle stability for 4-nitrophenol(4-NP)and 2-nitrophenol(2-NA),providing new strategy for the study of catalytic composite materials related to degradation of wastewater.

关键词： Electrospinning MXene sheet Self-reduction Palladium nanoparticle Catalyst

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Spatiotemporal features and possible mechanisms of seasonal changes in sea surface height south of Japan

引用

Chinese Journal of Oceanology and Limnology 2014年第4期32卷 933-945页

作者：马利斌 key laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of Sciences Center for Earth System Model Nanjing University of Information Science & Technology

Variations of sea surface height （SSH） in the Kuroshio south of Japan are addressed by analyzing 19-year （1993-2011） altimetry data from AVISO. Regionally averaged time series of observed SSH had a rising linear trend at 2.64＋0.72 mrn/a in this period. By analyzing the power spectra, several periods were recognized in temporal SSH variations, including those around 90 and 360 days. The seasonal cycle of SSH was minimum in winter （February） and maximum in summer （August）, with peak-to-peak amplitude about 20.0 cm. The spatial distribution of linear trends was inhomogeneous, with a rising linear trend along the coastline and a tripole structure offshore. Spatial distributions of standard deviation of seasonal SSH show very dynamic activities in the southeast of Kyushu and south of Honshu. Seasonal variations of observed SSH are partially explained by surface buoyancy forcing, local wind forcing and the steric component related to subsurface water beneath the mixed layer. Results show different spatial distributions of correlation coefficient and estimation skill between seasonally observed and modeled SSH, which are calculated from surface buoyancy flux, local wind forcing and the steric component related to subsurface water. Of those three, the surface buoyancy flux has a greater contribution to variations of observed SSH on the seasonal time scale south of Japan.

关键词： spatiotemporal variation net surface heat flux wind stress subsurface water

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of clouds, sea surface temperature, and its diurnal variation on precipitation efficiency

引用

Chinese Physics B 2013年第9期22卷 456-464页

作者：沈新勇庆涛李小凡 key laboratory of Meteorological Disaster of Ministry of Education Nanjing University of Information Science and Technology NOAA/NESDIS/Center for Satellite Applications and Research College ParkMaryland 20740USA

The effects of clouds, sea surface temperature, and its diurnal variation on precipitation efficiency are investigated us ing grid-scale data from nine equilibrium sensitivity cloud-resolving model experiments driven without large-scale vertical velocity. The precipitation efficiencies are respectively defined in surface rainfall, cloud, and rain microphysical budgets. We mathematically and physically demonstrate the relationship between these precipitation efficiencies. The 2 ℃ increases in spatiotemporal invariant sea surface temperature （SST） from 27 ℃ to 29 ℃ and from 29 ℃ to 31 ℃, and the inclusion of diurnal SST difference 1 ℃ and the 1℃ increase in diurnal SST difference generate opposite changes in the precipitation efficiency by changing ice cloud-radiation interactions. The radiative and microphysical processes of ice clouds have opposite effects on the precipitation efficiency because of the rainfall increase associated with the reduction in the saturation mixing ratio caused by the exclusion of radiative effects and the decrease in rainfall related to the reduction in net condensation caused by the exclusion of deposition processes. The radiative effects of water clouds on the precipitation efficiency are statistically insensitive to the radiative effects of ice clouds.

关键词： sea surface temperature diurnal variations clouds precipitation efficiency

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analysis of interaction between surface and sewer pipe system based on computational fluid dynamics

引用

Journal of Southeast University(English Edition) 2020年第2期36卷 198-205页

作者： Geng Yanfen Mao Jiandong Wang Zhili Guo Huaqiang School of Transportation Southeast University Nanjing 211189 China State key laboratory of Hydrology-water Resources and Hydraulic Engineering Nanjing Hydraulic Research Institute Nanjing 210024 China

To verify the accuracy of weir and orifice formula and analyze the hydraulic characteristics of exchange flow in a manhole,a three-dimensional numerical model was proposed to assess the exchange flow rate between the surface and sewer pipe systems based on the real-world scale *** hydrodynamic model is based on the three-dimensional Navier-Stokes equations including the standard k-εmodel for turbulence processes,and the volume of fluid(VOF)method for capturing the free *** results of the computational fluid dynamics(CFD)simulation are compared with the conventional overflow equations,showing that the weir and orifice formula is appropriate to determine the exchange flow rate between two systems in this specific study *** and velocity contours at the center profile under both the inflow and surcharge conditions show that the exchange flow is directly related to the water level on the surface and the junction area between the manhole and right *** results demonstrate the potential application of CFD in analyzing the interaction of urban flood flows,which can provide much clearer details of the interaction process.

关键词： computational fluid dynamics(CFD) exchange flow rate urban flood model weir and orifice formula

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：