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Response of Pinus taiwanensis growth to climate changes at its southern limit of Daiyun Mountain, China's Mainland Fujian Province

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Science China Earth Sciences 2016年第2期59卷 328-336页

作者： CHEN Dan FANG keyan LI YingJun DONG ZhiPeng ZHANG Yu ZHOU FeiFei Institute of Geography Key Laboratory of Humid Subtropical Eco-geographical Process (Ministry of Education)College of Geographical Sciences Fujian Normal University Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of Sciences Research Center for Scientific Development in Fenhe River Valley Taiyuan Normal University

The Pinus taiwanensis trees of a Chinese endemic species form pure forests at infertile sites in humid subtropical China, which can aid soil reservation and ecological resiliency at such sites. Herein, we used dendrochronological methods to investigate the growth patterns and their relationship with climate by analyzing 158 cores of 79 P. taiwanensis trees at 4 sites in their southernmost distribution in China's Mainland at Daiyun Mountain in Fujian Province. Tree growths at sites with favor- able conditions generally showed an age-related growth trend, which decreased from approximately 5 mm to 0.5 mm in about a century. Trees in moderately stressed environments established high growth in their juvenile periods but were highly suscep- tible to environmental stresses such as a sharp growth decline in the 1990s. The temperature in February and the moisture in July are the major limiting factors for most of the tree growths, except for a few extremely stressed P. taiwanensis trees. The growth of the dwarf P. taiwanensis trees, with all ring diameters of the first 20 years less than 4 ram, is mainly limited by the dry climate in May. Under the potential future warming trend, drought stress can be particularly threatening to these dwarf P. taiwanensis trees, which are likely to be the germplasm resources for this species in this region.

关键词： Daiyun Mountain Pinus taiwanensis Climate-growth relationships Drought Global warming

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The Impacts of Permafrost Change on NPP and Implications:A Case of the Source Regions of yangtze and Yellow Rivers

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Journal of Mountain Science 2011年第3期8卷 437-447页

作者： FANG Yiping QIN Dahe DING Yongjian yang Jianping XU keyan Institute of Mountain Hazards & Environment Chinese Academy of Sciences Chengdu 610041 China Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

This paper studies the relationship between net primary productivity (NPP) and annual average air temperature (GT) at 0cm above ground in permafrost regions by using revised Chikugo NPP model,cubic spline interpolating functions,and non-linear regression *** source regions of the yangtze and Yellow Rivers were selected as the research *** illustrate that:(1) There is significant non-linear relationship between NPP and GT in various typical years;(2) The maximum value of NPP is 6.17,5.87,7.73,and 5.41 DM·t·hm-2 ·a-1 respectively,and the corresponding GT is 7.1,10.0,21.2,and 8.9 o C respectively in 1980,1990,2000 and 2007;(3) In 1980,the sensitivity of NPP to GT is higher than in 1990,2000 and *** tendency shows that the NPP presents change from fluctuation to an adaptation process over time;(4) During 1980～2007,the accumulated NPP was reduced to 8.05,and the corresponding carrying capacity of theoretical livestock reduced by 11%;(5) The shape of the demonstration region of ecological compensation system,livelihood support system,and science appraisal system in the source regions of yangtze and Yellow Rivers are an important research for increasing the adaptation capacity and balancing protection and development.

关键词： The source regions of yangtze and Yellow Rivers Permafrost Ground temperature (GT) Net primary productivity (NPP) Policy adaptation

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Earthquakes as a potential contributing factor to climate change at multi-decadal scale

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Research in Cold and Arid Regions 2014年第2期6卷 131-138页

作者： keyan Fang Heikki Sepp Department of Geosciences and Geography PO Box 6400014 University of Helsinki

Climate changes at the multi-decadal scale are often associated with multi-decadal phase shifts of the dominant sea surface temperature （SST） pattern, such as the Pacific Decadal Oscillation （PDO）. The PDO may be associated with the North Pacific branch of the Thermohaline Circulation （THC）. Great earthquakes （M 〉8）, particularly along the route of the THC, might modulate the vertical mixing and bring deep, cold water to surface, contributing to multi-decadal changes in surface currents and the PDO. This may eventually lead to multi-decadal climate changes. We tested this hypothesis for the Pacific Ocean where great earthquakes have been frequently recorded. We found associations between the PDO and recurrent earthquakes along the route of the deep currents of the THC in the modern period since 1900, and relationships between hydroclimate change in Monsoonal Asia and historical earthquakes since 1300. However, it should be noted that this hypothesis is very preliminary and has many gaps that needs further evidences from more observational records and modeling studies.

关键词： earthquake climate change Thermohaline Circulation PDO

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Magnetic dipole band in 113In

Magnetic dipole band in 113In

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第十四届全国核物理大会暨第十届会员代表大会

作者： MA keyan1, yang Dong1, LU JingBin1, WANG LieLin3,WANG HuiDong1, LIU YunZuo1, MA YingJun1, LIU GongYe1, LI Li1, ZHU LiHua2, WU XiaoGuang2, LI GuangSheng2, LIU Shan1, HE ChuangYe2, LI XueQin2 1 Department of Physics, Jilin University, Changchun 130023, China 2 China Institute of Atomic Energy, Beijing 102413, China 3 Southwest University of Science and Technology, sichuan 621010, China

High spin states in the nucleus 113In have been investigated using the reaction 110Pd(7Li,4n)at a beam energy of *** positive parity dipole band with the configurati

关键词： High spin states tilted axis cranking model shears band collective rotational energy

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In-situ Synthesis and Characterization of Poly(vinyl alcohol)/Hydroxyapatite Composite Hydrogel by Freezing-thawing Method

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Chemical Research in Chinese Universities 2019年第3期35卷 521-529页

作者： MENG Deyue ZHOU Xiuqing ZHENG keyan MIAO Chong SHENG Ye ZOU Haifeng College of Chemistry Jilin UniversityChangchun 130012P.R.China JA Biotech Co. Ltd.Changchun 130103P.R.China

Poly(vinyl alcohol)/hydroxyapatite(PVA/HA) composite hydrogel was successfully in-situ synthesized via three cycles of freezing-thawing. The composition and structure of products were investigated by X-ray diffraction( XRD), Fourier transformed infrared spectroscopy(FTIR) and scanning electron microscopy(SEM). The influence of different preparation methods and contents of material on the mechanical properties of PVA/HA composite hydrogel was discussed through tensile and compressive tests. The template of PVA could avoid the agglomeration of HA particles, which improves the mechanical properties of the composite hydrogel effectively. The tensile strength, modulus and compressive performances of the PVA/HA composite hydrogel prepared by the in-situ synthesis method were better than those of hydrogel obtained by the simple blend metliod. In addition, the effect of the content of PVA, HA, and the pH value on tlie properties of tlie PVA/HA composite hydrogel has been discussed in detail.

关键词： Composite hydrogel In-situ synthesis Tensile property Compressive property

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Spatiotemporal phase change materials for thermal energy long-term storage and controllable release

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Journal of Energy Chemistry 2023年第5期80卷 228-236,I0006页

作者： yangeng Li Yan Kou keyan Sun Jie Chen Chengxin Deng Chaohe Fang Quan Shi Thermochemistry Laboratory Liaoning Province Key Laboratory of Thermochemistry for Energy and MaterialsDalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China College of Petroleum Engineering Liaoning Petrochemical UniversityFushun 113000LiaoningChina CNPC Research Institute of Petroleum Exploration&Development Bejing 100083China

Phase change materials(PCMs)have attracted much attention in the field of solar thermal utilization recently,due to their outstanding thermal energy storage ***,PCMs usually release their stored latent heat spontaneously as the temperature below the phase transition temperature,rendering thermal energy storage and release uncontrollable,thus hindering their practical application in time and ***,we developed erythritol/sodium carboxymethylcellulose/tetrasodium ethylenediaminetetraacetate(ERY/CMC/EDTA-4Na)composite PCMs with novel spatiotemporal thermal energy storage properties,defined as spatiotemporal PCMs(STPCMs),which exhibit the capacity of thermal energy long-term storage and controllable *** results show that the composite PCMs are unable to lose latent heat due to spontaneous crystallization during cooling,but can controllably release thermal energy through cold crystallization during *** cold-crystallization temperature and enthalpy of composite PCMs can be adjusted by proportional addition of EDTA-4Na to the *** the mass fractions of CMC and EDTA-4Na are both 10%,the composite PCMs can exhibit the optical coldcrystallization temperature of 51.7℃ and enthalpy of 178.1 J/*** supercooled composite PCMs without latent heat release can be maintained at room temperature(10-25℃)for up to more than two months,and subsequently the stored latent heat can be controllably released by means of thermal triggering or heterogeneous *** findings provide novel insights into the design and construction of new PCMs with spatiotemporal performance of thermal energy long-term storage and controllable release,and consequently open a new door for the development of advanced solar thermal utilization techniques on the basis of STPCMs.

关键词： Phase change materials Long-term thermal storage Controllable release Erythritol

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Ag/TiO_(2)/WO_(3)nanoparticles with efficient visible light photocatalytic activity

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Optoelectronics Letters 2022年第1期18卷 1-5页

作者： LI Yujie HAI Guangyuan DING Guilin WANG keyan ZHANG Dequan Physical Department Tianjin Ren’ai CollegeTianjin 301636China School of Material Science and Engineering Tiangong UniversityTianjin 300387China Tianjin SYP Engineering Glass Company Tianjin 300409China

A simple strategy for synthesizing Ag decorated TiO_(2)/WO_(3)composite nanoparticles by sol-gel method used as recyclable photocatalyst is *** photocatalytic efficiency to the degradation of methyl blue(MB)by Ag/TiO_(2)/WO_(3)nanoparticles is studied under ultraviolet-visible(UV-Vis)light *** shows that the photocatalytic efficiency of Ag/TiO_(2)/WO_(3)photocatalyst achieves 96%in 20 min,which is 16 times higher than that of pristine TiO;at the same *** Ag/TiO_(2)/WO_(3)photocatalyst can still reach the degradation rate of 90%in the fifth degradation experiment,indicating a good stability and photocatalytic activity.

关键词： conditions. visible photocatalytic

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Slip-Control Strategy of Dual Independent Electric Drive Tracked Vehicle

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Journal of Beijing Institute of Technology 2019年第4期28卷 715-724页

作者： Shuyang Zhang Yunan Zhang keyan Ning Nanming Yan Qingfeng Fang Weaponry and Control Department Army Academy of Armored ForcesBeijing 100072China China North Vehicle Research Institute Beijing 100072China

In order to improve the brake performance of a dual independent electric drive tracked vehicle,a dynamic model for braking situation was ***,a sliding model controller(SMC)with an auxiliary system was designed to control the slip and its effectiveness was proved.A hardware-in-loop simulation through MATLAB/XPC was compared with the normal SMC and normal integral sliding mode controller(ISMC),the results show that SMC with the auxiliary system has a better performance:a smaller overshoot and steady state *** disturbance is suppressed *** the initial speed of ***/h,the brake distance was shortened by 3.4%and 6.8%compared with the other two methods,***,initial speeds of ***/h tests was carried out on a flat soil *** with a no-control brake,the displacement was shortened by *** demonstrates the effectiveness of the slip-control *** the same situation,the error between the simulation and test is 18.1%,which validates the accuracy of models.

关键词： tracked vehicle electric drive braking slip sliding model control

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Geochemical Features and Metallogenic Prediction of the Caixiashan-Weiquan Area in the East Tianshan Region

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Acta Geologica Sinica(English Edition) 2012年第4期86卷 885-893页

作者： LU Lu ZHU Lixin XIAO keyan MA Shengming YIN Jiangning XU Mingzuan Chinese Academy of Geological Sciences Institute of Mineral Resources Chinese Academy of Geological Sciences Institute of Geophysical and Geochemical Exploration CAGS Jiangsu Provincial Institute of Geological Prospecting Techniques

The Caixiashan-Weiquan area is an important ore concentration area in the eastern Tianshan metallogenic belt. Firstly, this paper studies geochemical features of 1564 samples of 1：200000 stream sediments of the Matoutan mapsheet, where the Caixiashan and Weiquan deposits are located. Processing, analysis and explanation of exploration geochemical data play an important role in the procedure of finding the ore, which are related to whether the measured elements content of geochemical samples can effectively guide the work of mineral exploration. As a highly nonlinear dynamical system, the neural network is more analogous to the human brains in terms of principles and features compared with conventional geochemical approaches. It can adapt itself to the environment, sum up laws, complete pattern recognition. Secondly, the authors used the Kohonen neural network to classify all samples based on 10 mineralization elements of stream sediment samples in order to determine possible mineral ores, reduce the scope of ore targets and study indicator elements of the ninth group of samples, which is the mostly closest to the deposit. The results show that the neural network can delineate metallogenic prospective areas and is effective in the discovery of deep geochemical information.

关键词： Regional exploration geochemistry Pb-Zn deposits neural network metallogenic prediction

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Single-element Anomaly Mapping from Stream Sediment Geochemical Landscapes Aided by Digital Terrain Analysis

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Acta Geologica Sinica(English Edition) 2023年第1期97卷 149-162页

作者： XIANG Jie XIA Peng XIAO keyan Emmanuel John M.CARRANZA CHEN Jianping International Mining Research Center China Geological SurveyBeijing 100037China China Mining News China Geological SurveyBeijing 100037China Institute of Advanced Studies China University of GeosciencesWuhan 430074China MNR Key Laboratory of Metallogeny and Mineral Resource Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China Department of Geology University of the Free StateBloemfonteinSouth Africa School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China

The identification of anomalies within stream sediment geochemical data is one of the fastest developing areas in mineral *** various means used to achieve this objective make use of either continuous or discrete field models of stream sediment geochemical *** map anomalies in a discrete field model of such data,two corrections are required:background correction and downstream dilution *** and geomorphology are important factors in variations of element content in stream ***,few studies have considered,through the use of digital terrain analysis,the influence of geomorphic features in downstream dilution correction of stream sediment geochemical *** study proposes and demonstrates an improvement to the traditional downstream dilution correction equation,based on the use of digital terrain analysis to map single-element anomalies in stream sediment geochemical ***,this study compares the results of analyses using discrete and continuous field models of stream sediment geochemical data from the Xincang area,*** efficiency of the proposed methodology was validated against known mineral *** results indicate that catchment-based analysis outperforms interpolation-based analysis of stream sediment geochemical data for anomaly ***,the proposed modified downstream dilution correction equation proved more effective than the original ***,further testing of this modified downstream dilution correction is needed in other areas,in order to investigate its efficiency further.

关键词： stream sediment sample catchment basin digital terrain analysis downstream dilution correction background correction

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