检索结果-南通市图书馆

Digitally determining forest inventory units with an ecological classification system

在线全文

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2006年第z1期49卷 118-127页

作者： TANG Una, wang qingli, Guofan Shao,{2., wang shunzhong, LI Xiufen & XU Dong institute of applied ecology, chinese academy of Sciences, shenyang 110016, china Graduate University of chinese academy of Sciences, Beijing 100101, china Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN 47907, USA institute of applied {2. Chinese Academy of Sciences

Management-level forest resource data in china were obtained with a combination of two forest inventories. However, inconsistencies in the spatial attributes of forest data vary between the two inventory types and between two inventories of the same type. The inconsistencies make it inconvenient for long-term forest management planning with digital technologies. Ecological Land Types (ELTs) and Ecological Land Type Phases (ELTPs) have been mapped in selected forestry regions in northeast china, where important forest industries are located. The boundaries of ELTs are determined by geomorphic conditions, which are quantified by Digital Elevation Models (DEM); ELTPs are classified by overlaying ELTs with forest vegetation data layers that are obtained with both remotely sensed and ground data. The ELTPs represent the divisions of land in terms of both natural and human-induced forest conditions, and therefore they are reliable units for forest inventories and management. This paper introduces a case study for digitally determining forest inventory units in Benxi City, Liaoning Province, northeast china. The general objective of the study was to explain how a compatible forest inventory system should be designed and why the compatible forest inventory system was significant to digital forestry in china.

关键词： forest inventory, ecological classification, ELT mapping, ELTP mapping, geographic information systems, forest management.

Quantifying soil erosion with GIS-based RUSLE under different forest management options in Jianchang Forest Farm

在线全文

学校读者我要写书评

暂无评论

中国科学：技术科学英文版 2006年第z1期49卷 160-166页

作者： zhang hengming, {2. qingli, dai limin, Guofan Shao, TANG Una, wang shunzhong & GU Huiyan institute of applied ecology, chinese academy of Sciences, shenyang 110016,{12. Graduate University of chinese academy of Sciences, Beijing 100101,{12. Department of Forestry and Natural Resources, Purdue University, Lafayette IN47901, USA Northeast Forestry University, Harbin 150040,{12. institute of applied {2. Chinese Academy of Sciences Graduate University of chinese academy of Sciences

Quantitatively estimating soil erosion with an integration of geographic information system (GIS) and the revised universal soil loss equation (RUSLE) under four different exposed soil proportion scenarios caused by forest management practices was studied at Jianchang Forest Farm. The GIS provided means of input data generation required by RUSLE model and allowed a spatial assessment of the erosion hazard over the study area. Four exposed soil proportion scenarios of 5%, 10%, 2.% and 30% were tested with the GIS-based RUSLE model to evaluate soil erosion hazard. The predicted soil erosion potentials were classified into five categories in order to provide valuable aids for management planning.

关键词： geographic information system, RUSLE, soil erosion, forest management.

In-situ warming does not change soil priming effect induced by glucose addition in a temperate forest

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2024年第4期34卷 759-769页

作者： Xiaohan DONG Yunting FANG Dongwei liu Xin GUAN Kai HUANG Yuqi liu Qingkui {2. Silong {2. Weidong zhang Huitong Experimental Station of Forest ecology CAS Key Laboratory of Forest Ecology and ManagementInstitute of Applied EcologyShenyang 110016China University of chinese academy of Sciences Beijing 101408China Hunan Key Laboratory for Structure and Ecosystem Service of Subtropical Forest Huitong National Research Station of Forest EcosystemHuitong 418307China Qingyuan Forest chinese Ecosystem Research Network(CERN) National Observation and Research StationShenyang 110016China Key Laboratory of Forest ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016(China)f Key Laboratory of Stable Isotope Techniques and ApplicationsShenyang 110016China Key Laboratory of Terrestrial Ecosystem Carbon Neutrality Shenyang 110016China

Priming effect(PE)on soil organic carbon(SOC)decomposition caused by the addition of organic carbon(C)is an important ecological process in regulating soil C ***,most priming studies are confined to laboratory trials,while the assessment of soil PE under field conditions with variable weather conditions is *** study assessed the direct effects of glucose addition and in-situ warming on the extent of PE under field conditions in a temperate *** evaluated soil PE using 13C-glucose labelling,a simple and novel technique,based on the Keeling plot *** addition significantly enhanced native SOC decomposition and induced strong ***,the effect of in-situ warming on the extent of PE was not *** study confirms the importance of PE in regulating SOC turnover under field conditions.

关键词： lue lblling tchnquegbal wamingrmingt hppidfaty ai solganmattermineralisatn oezme respiration

Evolutionary Variational YOLOv8 Network for Fault Detection in Wind Turbines

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第7期80卷 625-642页

作者： Hongjiang wang Qingze Shen Qin dai Yingcai Gao Jing Gao Tian {2. College of Information Shenyang Institute of EngineeringShenyang110136China Graduate School Shenyang Institute of EngineeringShenyang110136China College of Software Northeastern UniversityShenyang110169China

Deep learning has emerged in many practical applications,such as image classification,fault diagnosis,and object *** recently,convolutional neural networks(CNNs),representative models of deep learning,have been used to solve fault ***,the current design of CNNs for fault detection of wind turbine blades is highly dependent on domain knowledge and requires a large amount of trial and *** this reason,an evolutionary YOLOv8 network has been developed to automatically find the network architecture for wind turbine blade-based fault ***8 is a CNN-backed object detection ***,to reduce the parameter count,we first design an improved FasterNet module based on the Partial Convolution(PConv)***,to enhance convergence performance,we improve the loss function based on the efficient complete intersection over the *** on this,a flexible variable-length encoding is proposed,and the corresponding reproduction operators are *** experimental results confirmthat the proposed approach can achieve better fault detection results and improve by 2.6%in mean precision at 50(mAP50)compared to the existing ***,compared to training with the YOLOv8n model,the YOLOBFE model reduces the training parameters by 933,937 and decreases the GFLOPS(Giga Floating Point Operations Per Second)by 1.1.

关键词： Neural architecture search YOLOv8 evolutionary computation fault detection

Investigation of Material Properties Based on 3D Graphite Morphology for Compacted Graphite Iron

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1077-1086页

作者： Chenglu Zou Yan Zhao Gang Zhu Jianchao Pang Shaogang wang Yangzhen liu Feng liu Shouxin Li Zhefeng zhang institute of Metal Research Chinese Academy of SciencesShenyang110016China School of Mechanical Engineering Liaoning Petrochemical UniversityFushun113001China institute of Advance Wear and Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou510632China Jihua Laboratory Foshan528200China Key Laboratory of Pressure Systems and Safety Ministry of EducationSchool of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai200237China

The strength and thermal conductivity of compacted graphite iron(CGI)are crucial performance indicators in its engineering *** presence of graphite in CGI significantly influences the two *** the previous studies,graphite in CGI was often described using two-dimensional(2.)*** this study,the three-dimensional(3D)size,shape,and distribution of graphite in CGI were analyzed using X-ray *** on this,a new method is introduced to calculate the 3D vermicularity and compare it with the 2. vermicularity in terms of tensile properties and thermal *** results demonstrate that vermicular graphite exhibits greater connectivity in 3D observation compared to 2. ***,the calculation method of 3D vermicularity is determined by considering the surface area and volume of the connected *** a linear relationship between 3 and 2. vermicularity has been *** comparing the correlation coefficient,it has been found that the 3D vermicularity offers a more accurate method to establish the relationship among graphite morphology,thermal conductivity and tensile property of CGI.

关键词： Compacted graphite iron 3D graphite morphology X-ray tomography Thermal conductivity Tensile property

Multilevel Micro Structures of the Clam Make the Sealing Even Tighter

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第3期21卷 1442-1452页

作者： Daobing Chen Xiaolong zhang Junqiu zhang Zhiwu Han Ruteng {2. Zhen Lin Yifeng Lei Longjian Xue Sheng liu The institute of Technological Science Wuhan UniversityWuhan430072China School of Power and Mechanical Engineering Wuhan UniversityWuhan430072China The Key Laboratory of Bionic Engineering(Ministry of Education) Jilin UniversityChangchun130022China institute of Structured and Architected Materials Liaoning Academy of MaterialsShenyang110167China

Excellent fluid sealing performance is crucial to ensuring the safety of important equipment,especially in aerospace field,such as space capsule and fuel *** frequently opening and closing of the sealing devices is particularly *** by this background,clams(Mactra chinensis)which can open and close their double shells with superior sealing performance,are studied in this ***,we show that the clam’s sealing ability is the result of its unique multilevel intermeshing microstructures,including hinge teeth and *** microstructures,which resemble gear teeth,engage with each other when the shell closes,forming a tight structure that prevents the infiltration of water from the ***,the presence of micron blocks prevents the penetration of finer *** simulation results of the bionic end seal components show that the multilevel microstructure has a superior sealing *** research is expected to be applied to undersea vehicles that require frequent door opening and closing.

关键词： Multilevel micro structures Opening and closing components Clam Sealing Bionic

A study of novel real-time power balance strategy with virtual asynchronous machine control for regional integrated electric-thermal energy systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science china(Technological Sciences) 2024年第7期67卷 2074-2086页

作者： wang Rui LI Ming-Jia wang YiBo SUN QiuYe {2. PinJia College of Information Science and Engineering Northeastern UniversityShenyang 110819China School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Department of Electrical Engineering Tsinghua UniversityBeijing 100084China

The development of regional integrated electric-thermal energy systems(RIETES) is considered a promising direction for modern energy supply systems. These systems provide a significant potential to enhance the comprehensive utilization and efficient management of energy resources. Therein, the real-time power balance between supply and demand has emerged as one pressing concern for system stability operation. However, current methods focus more on minute-level and hour-level power optimal scheduling methods applied in RIETES. To achieve real-time power balance, this paper proposes one virtual asynchronous machine(VAM) control using heat with large inertia and electricity with fast response speed. First, the coupling timescale model is developed that considers the dynamic response time scales of both electric and thermal energy systems. Second, a real-time power balance strategy based on VAM control can be adopted to the load power variation and enhance the dynamic frequency response. Then, an adaptive inertia control method based on temperature variation is proposed, and the unified expression is further established. In addition, the small-signal stability of the proposed control strategy is validated. Finally, the effectiveness of this control strategy is confirmed through MATLAB/Simulink and HIL(Hardware-in-the-Loop) experiments.

关键词： regional integrated electric-thermal energy systems real-time power balance virtual asynchronous machine adaptive inertia small-signal stability

Fatigue and Corrosion Fatigue Properties of Mg-Zn-Zr-Nd Alloys in Glucose-Containing Simulated Body Fluids

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1533-1550页

作者： Xue Han Dan zhang Song zhang Mohammed R.I.Abueida Lili Tan Xiaopeng Lu Qiang {2. Huanye liu School of Materials Science and Engineering Shenyang University of TechnologyShenyang110870China School and Hospital of Stomatology China Medical UniversityShenyang110001China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China shenyang National Laboratory for Materials Science Northeastern UniversityShenyang110819China

Medical bone implant magnesium(Mg)alloys are subjected to both corrosive environments and complex loads in the human *** increasing number of hyperglycemic and diabetic patients in recent years has brought new challenges to the fatigue performance of Mg ***,it is significant to study the corrosion fatigue(CF)behavior of medical Mg alloys in glucose-containing simulated body fluids for their clinical ***,the corrosion and fatigue properties of extruded Mg-Zn-Zr-Nd alloy in Hank’s balanced salt solution(HBSS)containing different concentrations(1 g/L and 3 g/L)of glucose were *** average grain size of the alloy is about 5μm,which provides excellent overall mechanical *** conditional fatigue strength of the alloy was 12. MPa in air and 88 MPa and 70 MPa in HBSS containing 1 g/L glucose and 3 g/L glucose,*** crack initiation points for alloys in air are oxide inclusions and in solution are corrosion *** corrosion rate of the alloy is high at the beginning,and decreases as the surface corrosion product layer thickens with the increase of immersion *** corrosion products of the alloy are mainly Mg(OH)_(2.,MgO and a small amount of Ca-P *** electrochemical results indicated that the corrosion rate of the alloys gradually decreased with increasing immersion time,but the corrosion tendency of the alloy was greater in HBSS containing 3 g/L *** the one hand,glucose accelerates the corrosion process by adsorbing large amounts of aggressive Cl^(-)*** the other hand,glucose will be oxidized to form gluconic acid,and then reacts with Mg(OH)_(2. and MgO to form Mg gluconate,which destroys the corrosion product film and leads to the aggravation of corrosion and the accumulation of fatigue damage.

关键词： Mg alloys Corrosion fatigue Glucose Gluconic acid Corrosion product

Effect of land use on soil nematode community composition and co-occurrence network relationship

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第8期23卷 2807-2819页

作者： Xiaotong liu Siwei Liang Yijia Tian Xiao wang Wenju Liang Xiaoke {2. institute of applied {2. Chinese Academy of SciencesShenyang 110016China Tillage and Cultivation Research institute Liaoning Academy of Agricultural SciencesShenyang 110161China University of chinese academy of Sciences Beijing 100049China Key Lab of Conservation Tillage and Ecological Agriculture in Liaoning Province Shenyang 110016China

Land use influences soil biota community composition and diversity,and then belowground ecosystem processes and *** characterize the effect of land use on soil biota,soil nematode communities in crop land,forest land and fallow land were investigated in six regions of northern *** richness,diversity,abundance and biomass of soil nematodes was the lowest in crop *** richness and diversity of soil nematodes were 2..8and 15.1%higher in fallow land than in crop land,*** significant differences in soil nematode indices were found between forest land and fallow land,but their network keystone genera composition was *** the keystone genera,50%of forest land genera were omnivores-predators and 36%of fallow land genera were *** proportion of fungivores in forest land was 2..8%lower than in fallow *** network complexity and the stability were lower in crop land than forest land and fallow *** pH,NH_(4)^(+)-N and NO_(3)^(–)-N were the major factors influencing the soil nematode community in crop land while soil organic carbon and moisture were the major factors in forest *** nematode communities in crop land influenced by artificial management practices were more dependent on the soil environment than communities in forest land and fallow *** use induced soil environment variation and altered network relationships by influencing trophic group proportions among keystone nematode genera.

关键词： soil nematode trophic groups community composition co-occurrence network land use