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苍鹭鸟巢大小及用材量数量指标调查分析
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作者 刘双 《新农业》 2022年第20期34-35,共2页
辽宁努鲁儿虎山国家级自然保护区管理局成立苏家营子村苍鹭生活史和种群数量研究课题组,设立8个调查巢,对苍鹭巢进行调查,结果为平均外径51.6厘米、内径30.74厘米、巢高25.38厘米、巢深11.83厘米,枝条约505根计算,枝条总长度8700厘米。
关键词 苍鹭 鸟巢 用材量
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甘肃省天然林区森林资源蓄积量及用材林消长变化 被引量:2
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作者 熊奎山 《甘肃林业科技》 2005年第1期5-7,共3页
通过对甘肃省天然林区5次森林资源连续清查蓄积量及用材林蓄积量变化的分析,初步得出结论:1979~1988年甘肃省天然林区蓄积量为增长阶段,1988~1996年蓄积量属减少阶段,1996~2001年为增长阶段。通过对3个阶段的分析,说明甘肃省20多年来... 通过对甘肃省天然林区5次森林资源连续清查蓄积量及用材林蓄积量变化的分析,初步得出结论:1979~1988年甘肃省天然林区蓄积量为增长阶段,1988~1996年蓄积量属减少阶段,1996~2001年为增长阶段。通过对3个阶段的分析,说明甘肃省20多年来,天然林区蓄积量呈波浪式的增长、减少、再增长趋势,也充分说明了国家实施天保工程的正确性。 展开更多
关键词 天然林区 森林蓄积 用材林蓄积 变化
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干旱区杨树用材林土壤特性和林木生长对供水的响应 被引量:13
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作者 王葆芳 杨晓晖 +2 位作者 江泽平 郝玉光 张景波 《干旱区资源与环境》 CSSCI CSCD 北大核心 2006年第6期156-162,共7页
经过4年试验,结果表明,(1)供水对土壤水分调控作用明显,土壤各项含水指标均随供水量的增加而增加;(2)通过灌溉可改善土壤的三相比结构和土壤容重;灌溉对总孔隙度影响不明显;(3)灌溉对地下水位的影响显著,灌水前林地地下水... 经过4年试验,结果表明,(1)供水对土壤水分调控作用明显,土壤各项含水指标均随供水量的增加而增加;(2)通过灌溉可改善土壤的三相比结构和土壤容重;灌溉对总孔隙度影响不明显;(3)灌溉对地下水位的影响显著,灌水前林地地下水埋深为3.46m,而灌水期内地下水埋深在2.36~2.87m之间,在7500m^3/hm^2·a灌溉定额以下时,不会造成土地次生盐渍化;(4)不同供水量对林木生长的效应是不同的,随灌溉量增加而造成不同程度的正增长;(5)人工林的蒸腾耗水量随供水量的增加而增加;(6)河套灌区杨树速生丰产林的合理灌溉量为7500m^3/hm^2·a。 展开更多
关键词 内蒙河套灌区 用材林灌溉 蒸腾耗水 土壤水分指标 土壤物理性状
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扬溪林场林木资源结构动态分析
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作者 黄亚青 《安徽林业科技》 2003年第2期40-41,共2页
通过对扬溪林场1994年二类资源清查结果与2002年资源年报档案数据的对比分析。揭示了该场此间在林种结构、龄组结构、用材林单位面积蓄积量以及树种结构等方面的动态变化,并提出了几点经营建议。
关键词 扬溪林场 林木资源 结构 动态 二类资源清查 林种结构 龄组结构 用材林单位面积蓄积
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Regulation of applied-hormones on tension wood formation in Fraxinus mandshurica Rupr. var.japonica Maxim. seedlings gravitational response
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作者 JIANG Sha XU Ke REN Fan-ping ZHENG Shu-xin GU Song 《Journal of Life Sciences》 2008年第5期34-44,共11页
We investigated the role of GA3, uniconazole-P and IAA on tension wood formation, in particular the vessel features, in Fraxinu smandshurica seedlings. Ninety seedlings were used and treated with applications of GA3 a... We investigated the role of GA3, uniconazole-P and IAA on tension wood formation, in particular the vessel features, in Fraxinu smandshurica seedlings. Ninety seedlings were used and treated with applications of GA3 and/or IAA to the apical bud of the stem using a micropipette. Applications of GA3 or GA3 plus IAA with uniconazole-P strongly increased cell number of tension wood in comparison to that of no-uniconazole-P-applied, indicated that GA3 is more efficient than IAA on xylem cell production. Wood quality was also regulated by relative concentration ratio of GA3 to lAA, because of the vessel elements differentiation, density and size were controlled by GA3 and/or IAA on the different levels. These results suggested that the relative concentration ratio of GA3 to IAA and interactions of them are essential in regulating both wood quality and wood quantity, and tension wood formation in this species. 展开更多
关键词 Fraxinus mandshurica Rupr. var.japonica Maxim.Seedlings interaction PGR tension wood formation vesselfeatures
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A Universal Reduced Rupture Creep Approach for Failure Behavior of Aged Glass Polymers from the Rupture Creep Compliance by the Unified Master Prediction of Long Term Short Term Test of Curved Extrapolation
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作者 Guang-jun Song Da-ming Wu +2 位作者 Wei-yue Song Ming-shi Song Gui-xian Hu 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第5期552-562,I0003,共12页
The prediction of long term failure behaviors and lifetime of aged glass polymers from the short term tests of reduced rupture creep compliance (or strain) is one of difficult problems in polymer science and enginee... The prediction of long term failure behaviors and lifetime of aged glass polymers from the short term tests of reduced rupture creep compliance (or strain) is one of difficult problems in polymer science and engineering. A new "universal reduced rupture creep approach" with exact theoretical analysis and computations is proposed in this work. Failure by creep for polymeric material is an important problem to be addressed in the engineering. A universal equation on reduced extensional failure creep compliance for PMMA has been derived. It is successful in relating the reduced extensional failure creep compliance with aging time, temperature, levels of stress, the average growth dimensional number and the parameter in K-W-W function. Based on the universal equation, a method for the prediction of failure behavior, failure strain criterion, failure time of PMMA has been developed which is named as a universal "reduced rupture creep approach". The results show that the predicted failure strain and failure time of PMMA at different aging times for different levels of stress are all in agreement with those obtained directly from experiments, and the proposed method is reliable and practical. The dependences of reduced extensional failure creep compliance on the conditions of aging time, failure creep stress, the structure of fluidized-domain constituent chains are discussed. The shifting factor, exponent for time-stress superposition at different levels of stress and the shifting factor, exponent for time-time aging superposition at different aging time are theoretically defined respectively. 展开更多
关键词 Reduced extensional failure creep compliance Extensional failure Predictionof failure strain and time PMMA Shifting factor Shifting exponent
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Analysis of the Power System from an Electron Beam Accelerator and the Correlation with the Theoretical Dosimetry for Radiation Processing
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作者 Samir Luiz Somessari Elizabeth S. Ribeiro Somessari Carlos Gaia da Silveira Wilson Aparecido Parejo Calvo 《Journal of Physical Science and Application》 2015年第5期356-366,共11页
Dynamitron DC1500/25/04 type EBA (Electron beam accelerator), model JOB 188, was manufactured by IBA Industrial (Radiation Dynamics, Inc.) and installed at IPEN-CNEN/SP, in 1978. The technical specifications of th... Dynamitron DC1500/25/04 type EBA (Electron beam accelerator), model JOB 188, was manufactured by IBA Industrial (Radiation Dynamics, Inc.) and installed at IPEN-CNEN/SP, in 1978. The technical specifications of the EBA are: energy 0.5 to 1.5 MeV; beam current: 0.3 to 25.0 mA; beam scanning: 60 to 120 cm; beam width: 25.4 mm and frequency: 100 Hz. Nowadays, this accelerator has been used for innumerable applications, such as: For sterilization of medical, pharmaceutical and biological products, treatment of industrial and domestic effluents and sludge, preservation and disinfestations of foods and agricultural products. Other important application are lignocellulosic material irradiation as a pre-treatment to produce ethanol bio-fuel, decontamination of pesticide packing, solid residues remediation, organic compounds removal from wastewater, treatment of effluent from petroleum production units, crosslinking of foams, wires and electric cables. Electron accelerator JOB 188 is, also, very important composite and nanocomposite materials and carbon fibers irradiation, irradiated grafting ion-exchange membranes for fuel cells application, natural polymers and multilayer packages irradiation and biodegradable blends production. The energy of the electron beam is calculated as a function of the current in the accelerator high-voltage divisor, taking into account the thickness and density of the material to be irradiated. This energy is calculated considering the electron through the entire material and the distance from the titanium foil window, so that the absorbed doses at the points of entrance and exit are equivalent on the material. The dose is directly proportional to the beam current and the exposure time of the material under the electron beam and inversely proportional to the scan width. The aim of this paper is to analyze the power system parameters of the EBA Dynamitron DC 1500/25/04, such as, voltage and RMS (Root-mean-square) current in the oscillator system, high voltage generator and waveform. For this purpose software developed in the Radiation Technology Center at IPEN/CNEN-SP to simulate the energy efficiency of this industrial accelerator. Finally, it is also targeted to compare theoretical dosimetry using parameters of energy and beam current with data from the accelerator power system. This knowledge and technology will be very useful and essential for the control system upgrade of EBA, mainly Dynamitron DC 1500/25/04 taking into consideration that radiation processing technology for industrial and environmental applications has been developed and used worldwide. 展开更多
关键词 Electron beam accelerator industrial dosimetry radiation processing accelerator power system Dynamitron DC 1500/25/04 accelerator.
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Comparison of Procedures to Evaluate the Cyclic Stress-Strain Curve from Incremental Step Test
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作者 Giovanni Zonfrillo Duccio Nappini 《Journal of Mechanics Engineering and Automation》 2015年第6期362-369,共8页
The design of structural components in low-cycle fatigue field often requires the knowledge of the cyclic properties of the material, which are commonly described by the classical relation of Ramberg-Osgood. In order ... The design of structural components in low-cycle fatigue field often requires the knowledge of the cyclic properties of the material, which are commonly described by the classical relation of Ramberg-Osgood. In order to obtain the cyclic curve using experimental data from incremental step tests, four methodologies are described and critically discussed. Three methods differ in the procedure of evaluation of the elastic modulus, while in the last one the experimental data are interpolated with a single non-linear regression. The various techniques were applied to data obtained from tests carried out on stainless steel specimens, and the resulting differences were analysed and quantified. An average behaviour was evaluated considering the total set of data obtained from experimental tests. The choice of the most suitable method is related to both the strain range of interest and the goal for which the results are used. 展开更多
关键词 Cyclic curve incremental step test Ramberg-Osgood stainless steel.
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Review of research and measurement for application properties of HTS tapes 被引量:3
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作者 WANG YinShun ZHENG YiBo 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第8期1568-1577,共10页
Research and development of high-temperature superconducting(HTS)apparatus are ongoing in the world with the great progress on the HTS tapes in recent years.The most attractive applications require the HTS tapes to pe... Research and development of high-temperature superconducting(HTS)apparatus are ongoing in the world with the great progress on the HTS tapes in recent years.The most attractive applications require the HTS tapes to perform well upon the application of an alternative current(AC)and/or an AC magnetic field.The electromagnetic properties of the HTS tapes including anisotropy,uniformity,alternative current(AC losses)and stability as well as mechanical characteristics are important fundamental parameters for these applications.This paper summarizes and focuses on several typical measurement principles and methods as well as apparatuses of those characteristic parameters except for their stability developed in past several years in China. 展开更多
关键词 critical current N-VALUE mechanical characteristics ANISOTROPY AC losses contact-free
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Template-directed fabrication of 3D graphene-based composite and their electrochemical energy-related applications 被引量:8
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作者 Hua-Jun Qiu Li Liu Yu Wang 《Science Bulletin》 SCIE EI CAS CSCD 2016年第6期443-450,共8页
Graphene shows great potentials in electrochemical energy-related areas.To enhance its properties and corresponding electrochemical performance,recently,three-dimensional(3D)graphene-based materials especially monolit... Graphene shows great potentials in electrochemical energy-related areas.To enhance its properties and corresponding electrochemical performance,recently,three-dimensional(3D)graphene-based materials especially monolithic porous graphene with encapsulated functional nanomaterials have arisen much research interest for electrochemical catalysis,lithium ion batteries(LIBs),lithium–sulfur batteries,supercapacitors,etc.With the enhanced structure properties such as interconnected graphene network,high volume-specific surface area and electronic conductivity,3D monolithic graphene is more suitable for the fabrication of composite electrode materials in real devices.In this article,we discuss recent development in fabricating monolithic 3D graphene and their composites using template-directed methods and their applications in electrochemical energy-related areas. 展开更多
关键词 Nanoporous graphene Templatedirected synthesis COMPOSITE ELECTROCATALYSIS Lithium ion batteries
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Biomass-derived carbon materials with structural diversities and their applications in energy storage 被引量:19
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作者 江丽丽 盛利志 范壮军 《Science China Materials》 SCIE EI CSCD 2018年第2期133-158,共26页
Currently, carbon materials, such as graphene,carbon nanotubes, activated carbon, porous carbon, have been successfully applied in energy storage area by taking advantage of their structural and functional diversity. ... Currently, carbon materials, such as graphene,carbon nanotubes, activated carbon, porous carbon, have been successfully applied in energy storage area by taking advantage of their structural and functional diversity. However, the development of advanced science and technology has spurred demands for green and sustainable energy storage materials.Biomass-derived carbon, as a type of electrode materials, has attracted much attention because of its structural diversities,adjustable physical/chemical properties, environmental friendliness and considerable economic value. Because the nature contributes the biomass with bizarre micro structures,the biomass-derived carbon materials also show naturally structural diversities, such as OD spherical, 1D fibrous, 2D lamellar and 3D spatial structures. In this review, the structure design of biomass-derived carbon materials for energy storage is presented. The effects of structural diversity, porosity and surface heteroatom doping of biomass-derived carbon materials in supercapacitors, lithium-ion batteries and sodium-ion batteries are discussed in detail. In addition, the new trends and challenges in biomass-derived carbon materials have also been proposed for further rational design of biomass-derived carbon materials for energy storage. 展开更多
关键词 biomass-derived carbon materials supercapacitors lithium-ion batteries sodium-ion batteries
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Numerical simulation of deposit in confluence zone of debris flow and mainstream 被引量:8
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作者 CHEN RiDong LIU XingNian +1 位作者 CAO ShuYou GUO ZhiXue 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第10期2618-2628,共11页
Abundant solid materials were formed as a result of landslide and collapse due to Wenchuan earthquake.The solid source around mountains would form a debris flow when appropriate rain condition occurs.Such a debris flo... Abundant solid materials were formed as a result of landslide and collapse due to Wenchuan earthquake.The solid source around mountains would form a debris flow when appropriate rain condition occurs.Such a debris flow is structurally very large and strong,and the river flow can hardly wash away the deposit when the debris flow enters into the mainstream.As a result,the deposit on the river bed due to debris flow will cause a series of hazards.Based on the previous researches and relevant data,this paper simplified the interaction between debris flow and current of the main river,and adopted the finite element characteristic-based-split algorithm which is favorable to the stabilization of dealing with the convection.Finally,the numerical model of the confluence of debris flow deposit and main river was developed,and the deposit progress of the mega-debris flow from Wenjiagou in Mianyuan river was reproduced.Furthermore,the influence of the deposit on the flow route of the main river,and distribution of velocity and water depth were analyzed.The results showed that the simulation deposit terrain qualitatively agreed with the field data through comparison,including the deposit area and depth distribution.Furthermore,the improvement of the model in future was discussed. 展开更多
关键词 torrential flood debris flow confluence zone FEM
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Glyconanomaterials: Emerging applications in biomedical research 被引量:2
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作者 Xuan Chen Olof Ramstrom Mingdi Yan 《Nano Research》 SCIE EI CAS CSCD 2014年第10期1381-1403,共23页
Carbohydrates constitute the most abundant organic matter in nature, serving as structural components and energy sources, and mediating a wide range of cellular activities. The emergence of nanomaterials with distinct... Carbohydrates constitute the most abundant organic matter in nature, serving as structural components and energy sources, and mediating a wide range of cellular activities. The emergence of nanomaterials with distinct optical, magnetic, and electronic properties has witnessed a rapid adoption of these materials for biomedical research and applications. Nanomaterials of various shapes and sizes having large specific surface areas can be used as multivalent scaffolds to present carbohydrate ligands. The resulting glyconanomaterials effectively amplify the glycan-mediated interactions, making it possible to use these materials for sensing, imaging, diagnosis, and therapy. In this review, we summarize the synthetic strategies for the preparation of various glyconanomaterials. Examples are given where these glyconanomaterials have been used in sensing and differentiation of proteins and cells, as well as in imaging glycan-medicated cellular responses. 展开更多
关键词 glyconanomaterials carbohydrates IMAGING THERAPY
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Characterization the Reaction of Isocyanate and Cellulose by XPS
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作者 GAOZhenhua GUJiyou LIZhiguo 《Chinese Forestry Science and Technology》 2004年第2期41-48,共8页
The X-ray photoelectron spectroscopy (XPS) technique was used to study the reaction ofphenyl isocyanate and cellulose with different moisture contents (MC). The C1S XPS peak of cellulose isonly one symmetrical contrib... The X-ray photoelectron spectroscopy (XPS) technique was used to study the reaction ofphenyl isocyanate and cellulose with different moisture contents (MC). The C1S XPS peak of cellulose isonly one symmetrical contribution at 285.95 eV. While the C1S XPS peaks of N,N-dibenzylurea, thereaction resultant of phenyl isocyanate and water, have two contributions at 288.6±0.1 eV and 284.7±0.1 eV corresponding to the carbonyl group and phenyl ring group, respectively. Their area ratio isbetween 11.88 and 11.98 that is quite neat to the theoretical value of 12.0. With the moisture content (MC)of cellulose increased, the proportion of isocyanate reacted with water increased. When the MC reaches 9.78%, 92.98% of all consumed isocyanate will react with water. By spattering analysis, it reveals that thereaction resultants of benzyl isocyanate distribute mainly on the surface of cellulose. 展开更多
关键词 benzyl isocyanate CELLULOSE moisture content competitive reaction ESCA analysis
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