检索结果-南通市图书馆

Stability assessment of tree ring growth of Pinus armandii Franch in response to climate change based on slope directions at the Lubanling in the Funiu Mountains,China

引用

Journal of Forestry Research 2024年第3期35卷 197-208页

作者： Jinkuan Li Jianfeng Peng Xiaoxu Wei Meng Peng Xuan Li Yameng Liu Jiaxin Li College of Geography and Environmental Science Henan UniversityKaifeng 475004People’s Republic of China key laboratory of Earth System observation and simulation of Henan Province Kaifeng 475004People’s Republic of China

Global warming will affect growth strategies and how trees will *** compare the response of tree radial growth to climate warming in different slope directions,samples of Pinus armandii Franch were collected and treering chronologies developed on northern and western slopes from the Lubanling in the Funiu *** analyses showed that two chronologies were mainly limited by temperatures in the previous June–August and the combination of temperatures and moisture in the current May–*** difference of the climate response to slopes was small but not *** growth of the LBL01 site on the northern slope was affected by the combined maximum and minimum temperatures,while that of the LBL02 site was affected by maximum *** regards to moisture,radial growth of the trees on the north slope was influenced by the relative humidity in the current May–July,while on the western slope,it was affected by the relative humidity in the previous June–August,the current May–July and the precipitation in the current May–*** the change in climate,the effects of the main limiting factors on growth on different slopes were visible to a certain extent,but the differences in response of trees on different slopes gradually decreased,which might be caused by factors such as different slope directions and the change in diurnal temperature *** results may provide information for forest protection and ecological construction in this region,and a scientific reference for future climate reconstruction.

关键词： Tree ring width Lubanling Pinus armandii Franch Slope direction Climate response

来源：

维普期刊数据库

同方期刊数据库

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

A mathematical model of calculating local tsunami wave source constraints and propagation

引用

Acta Oceanologica Sinica 2015年第5期34卷 103-109页

作者： LI Daming LI Yangyang State key laboratory of Hydraulic Engineering simulation and Safety Tianjin University

This paper presents a local tsunami simulation, including the initial displacement field model of tsunami source and tsunami wave propagation model. We deduced the tsunami wave equation; applied the matching of interior and exterior solutions method and water mass method to determine the initial displacement field in different bottom topography. Tsunami wave propagation model was based on the Boussinesq equation. Difference format was based on the ADI method which discretized in alternating direction in the form of implicit scheme. The open boundary of ADI had been revised considering the influence of wave propagation in the equation of motion. The local tsunami mathematical model was used in the simulation of 2011 Japan tsunami, and the results and the observation data match well.

关键词： local tsunami initial displacement field numerical simulation tsunami wave propagation

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

The Mg_(Ⅱ)absorption line systems in quasar spectra from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope

引用

Research in Astronomy and Astrophysics 2021年第4期21卷 119-128页

作者： Zhi-Fu Chen Huan-Chang Qin Yan-Chun Gao Run-Jin Gui Zhe-Geng Chen Ting-Ting Pang College of Mathematics and Physics Guangxi University for NationalitiesNanning 530006China School of Information Engineering Baise UniversityBaise 533000China key laboratory for ionospheric observation and simulation Guangxi University for NationalitiesNanning 530006China

Making use of quasar spectra from LAMOST,in the spectral data around the Mg_(Ⅱ)emission lines,research described in this paper has detected 217 Mg_(Ⅱ)narrow absorption lines(NALs)with W_(r)^(λ2796)≥3σ_(w)and W_(r)^(λ2803)≥2σ_(w)in a redshift range of 0.4554≤z_(abs)≤*** quasars observed by both LAMOST and SDSS,we find that 135 Mg_(Ⅱ)NALs were obviously observed in the LAMOST spectra,347 Mg_(Ⅱ)NALs were were apparent in the SDSS spectra,and 132 Mg_(Ⅱ)NALs were clearly present in both the SDSS and LAMOST *** missed Mg_(Ⅱ)NALs are likely ascribed to low signal-to-noise ratios of corresponding *** the Mg 11 NALs obviously observed in SDSS or LAMOST spectra,eight Mg 11 NALs were significantly changed with|ΔW_(r)^(λ2796)|≥3σw in time intervals ofΔMJD/(1+z_(em))=359-2819 d.

关键词： line:identification quasars:absorption lines quasars:general

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

Preliminary Retrieval of Aerosol Optical Depth from All-sky Images

引用

Advances in Atmospheric Sciences 2010年第2期27卷 421-426页

作者：霍娟吕达仁 key laboratory for Atmosphere and Global Environment observation Chinese Academy of Sciences

The relationship between the radiance ratio （radiance at wavelength 450 nm to 650 nm） and aerosol optical depth （AOD） is analyzed in this paper by numerical simulation and a ＂LUT＂（look-up table） approach is then presented for the retrieval of AOD from the radiance ratio. In this LUT approach, the AOD retrieval error depends mainly on the assumption of aerosol types. From the preliminary simulation, a typical error of 15%–20% in AOD obtained from the radiance ratio is estimated, due to neglecting changes in the ground albedo and background atmosphere. At its worst, the AOD error reached a maximum of around 50%, which will be refined in the future. In the latter part of the paper, comparisons are made between AOD from the imager and from the CE-318 sun photometer, both located at Xianghe observatory in Hebei Province （39.75° N, 116.96° E）. This field experiment shows that AOD from the imager is highly correlated with AOD from the sun photometer, with a correlation coefficient of 0.95 and an average retrieval error of around 7%. A contrast experiment confirms the feasibility of retrieving AOD from all-sky images, but more analysis and future research are required to improve the accuracy.

关键词： all-sky image aerosol AOD radiance ratio

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

Application of high OLR-fed aerobic granules for the treatment of low-strength wastewater: Performance, granule morphology and microbial community

引用

Journal of Environmental Sciences 2013年第8期25卷 1549-1556页

作者： Jingyun Ma Xiangchun Quan Huai Li key laboratory of Water and Sediment Sciences of Ministry of Education/State key laboratory of Water Environment simulation School of Environment Beijing Normal University

Aerobic granules, pre-cultivated at the organic loading rate （OLR） of 3.0 kg COD/（m3 ·day）, were used to treat low-strength wastewater in two sequencing batch reactors at low OLRs of 1.2 and 0.6 kg COD/（m3 ·day）, respectively. Reactor performance, evolution of granule morphology, structure and microbial community at low OLRs under long-term operation （130 days） were investigated. Results showed that low OLRs did not cause significant damage to granule structure as a dominant granule morphology with size over 540 μm was maintained throughout the operation. Aerobic granules at sizes of about 750 μm were finally obtained at the low OLRs. The granule reactors operated at low OLRs demonstrated effective COD and ammonia removals （above 90%）, smaller granule sizes and less biomass. The contents of extracellular polymeric substances in the granules were decreased while the ratios of exopolysaccharide/exoprotein were increased （above 1.0）. The granules cultivated at the low OLRs showed a smoother surface and more compact structure than the seeded granules. A significant shift in microbial community was observed but the microbial diversity remained relatively stable. Confocal Laser Scanning Microscopy observation showed that the live cells were spread throughout the whole granule, while the dead cells were mainly concentrated in the outer layer of the granule, and the proteins, polysaccharides and lipids were mainly located in the central regime of the granule. In conclusion, granules cultivated at high OLRs show potential for treating low-strength organic wastewater steadily under long-term operation.

关键词： aerobic granule biodegradation low-strength wastewater organic loading rate microbial community

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 XCO_2 retrieval sensitivity using simulated Chinese Carbon Satellite(TanSat) measurements

引用

Science China Earth Sciences 2014年第8期57卷 1919-1928页

作者： CAI ZhaoNan LIU Yi YANG DongXu key laboratory of Middle Atmosphere and Global Environment observation Institute of Atmospheric PhysicsChinese Academy of Sciences

We present a study on the retrieval sensitivity of the column-averaged dry-air mole fraction of CO2(XCO2) for the Chinese carbon dioxide observation satellite(TanSat) with a full physical forward model and the optimal estimation technique. The forward model is based on the vector linearized discrete ordinate radiative transfer model(VLIDORT) and considers surface reflectance, gas absorption, and the scattering of air molecules, aerosol particles, and cloud particles. XCO2 retrieval errors from synthetic TanSat measurements show solar zenith angle(SZA), albedo dependence with values varying from 0.3 to 1 ppm for bright land surface in nadir mode and 2 to 8 ppm for dark surfaces like snow. The use of glint mode over dark oceans significantly improves the CO2 information retrieved. The aerosol type and profile are more important than the aerosol optical depth, and underestimation of aerosol plume height will introduce a bias of 1.5 ppm in XCO2. The systematic errors due to radiometric calibration are also estimated using a forward model simulation approach.

关键词： TanSat retrieval sensitivity retrieval error simulation XCO2

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

Progresses in the Atmospheric Electricity Researches in China during 2006-2010

引用

Advances in Atmospheric Sciences 2012年第5期29卷 993-1005页

作者：郄秀书 key laboratory of Middle Atmosphere and Global Environment observation Institute of Atmospheric PhysicsChinese Academy of Sciences

Atmospheric electricity is composed of a wide range of electric phenomena in the troposphere, strato- sphere, and even lower ionosphere. Research progress on atmospheric electricity in the past 5 years in China are briefly reviewed here. This research area has been greatly expanded through rocket-triggered lightning experiments and the increased use of high spatio-temporal resolution techniques for the detection and location of lightning. The main results described in this review are summarized in the following five aspects：（1） processes and parameters inferred from rocket-triggered lightning, （2） lightning physics and ef- fects （observations and theoretical study）, （3） lightning activities associated with different thunderstorms, （4） charge structure of thunderstorms （observations and simulation）, and （5） the VHF/UHF lightning location techniques and discharge channel mapping.

关键词： lightning physics thunderstorm electricity lightning meteorology lightning climatology light- ning effects

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

Effect of acicular ferrite on banded structures in low-carbon microalloyed steel

引用

International Journal of Minerals,Metallurgy and Materials 2014年第12期21卷 1167-1174页

作者： Lei Shi Ze-sheng Yan Yong-chang Liu Xu Yang Cheng Zhang Hui-jun Li State key laboratory of Hydraulic Engineering simulation and Safety School of Materials Science and Engineering Tianjin University

The effect of acicular ferrite （AF） on banded structures in low-carbon microalloyed steel with Mn segregation during both iso- thermal transformation and continuous cooling processes was studied by dilatometry and microscopic observation. With respect to the iso- thermal transformation process, the specimen isothermed at 550℃ consisted of AF in Mn-poor bands and martensite in Mn-rich bands, whereas the specimen isothermed at 450℃ exhibited two different morphologies of AF that appeared as bands. At a continuous cooling rate in the range of 4 to 50℃/s, a mixture of AF and martensite formed in both segregated bands, and the volume fraction of martensite in Mn-rich bands was always higher than that in Mn-poor bands. An increased cooling rate resulted in a decrease in the difference of martensite volume fraction between Mn-rich and Mn-poor bands and thereby leaded to less distinct microstrucmral banding. The results show that Mn segregation and cooling rate strongly affect the formation of AF-containing banded structures. The formation mechanism of microstructural banding was also discussed.

关键词： low-carbon microalloyed steel acicular ferrite microstructure manganese segregation

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

simulation of influence of multi-defects on long-term working performance of high arch dam

引用

Science China(Technological Sciences) 2011年第S1期54卷 1-8页

作者： ZHANG GuoXin ,LIU Yi,ZHENG CuiYing & FENG Fan State key laboratory of simulation and Regulation of Water Cycle in River Basin,Beijing 100038,China China Institute of Water Resources and Hydropower Research,Beijing 100038,China State key laboratory of simulation and Regulation of Water Cycle in River Basin Beijing China

As an integrated structure,an arch dam is assumed to bear loads in its design ***,multi-defects,such as cracks and the opening of transverse joints,are unavoidable during construction and ***-defects will reduce the structural integrity and stiffness of the dam and affect its working performance and degree of *** the current paper,a numerical model of defects and a simulation method of a high arch dam are *** Chencun arch dam is analyzed as a case *** entire course simulation analysis of the Chencun arch dam from construction to operation is carried out,through which the opening of the transverse and longitudinal joints,formation of cracks,and their influence on deformation and stress of the dam are *** to the results of the analysis,appropriate measures should be adopted to prevent the development of cracks,and observation should be strengthened for a more timely discovery of risks.

关键词： high arch dam crack multi-defects working performance

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

Influence of mantle convection to the crustal movement pattern in the northeastern margin of the Tibetan Plateau based on numerical simulation

引用

Science China Earth Sciences 2018年第11期61卷 1644-1658页

作者： Aiyu ZHU Dongning ZHANG Tao ZHU Yingxing GUO Institute of Geophysics China Earthquake Administration key laboratory of Seismic observation and Geophysical Imaging Institute of GeophysicsChina Earthquake Administration

Based on the recent observations about the movement and rheological structure of the lithosphere and deformation pattern of the crust, we developed a three-dimensional finite element model for the northeastern margin of the Tibetan *** model considered the impacts of both external and internal conditions, including mantle convection, gravitational potential energy and block interactions. We compared the simulated surface movement rates to the observed GPS velocities, and the results revealed that crustal movement gradually decreased toward the edge of the plateau. The factors controlling this pattern are the interactions of adjacent blocks, gravitational potential energy of the plateau, and also mantle convection as well. Additionally,according to the observation that there was an apparent difference between the horizontal movement rate of the lithosphere and convective velocity of the underlying mantle, and also based on the results of seismic anisotropy studies that suggest different strengths and deformation regimes of the lithosphere in different tectonic blocks, we proposed that the impact of mantle convection on the lithosphere may have varied in space, and introduced a parameter named mantle convection intensity factor in numerical simulations. Our simulation results show consistent surface movement rates with GPS observations, which further supports the viewpoint of seismic anisotropy studies, i.e., the degree of coupling between the crust and mantle varies significantly among different blocks.

关键词： Northeastern margin of the Tibetan Plateau Crustal movement Mantle convection Numerical simulation

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：