检索结果-南通市图书馆

Inventory of aspen trees in spruce dominated stands in conserva-tion area

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2015年第2期2卷 143-154页

作者： Matti Maltamo Annukka Pesonen Lauri Korhonen Jari Kouki Mikko Vehmas Kalle Eerik?inen University of Eastern Finland School of Forest Science Blom Kartta oy City of Joensuu Natural Resources Institute Finland Joensuu Unit

Background： The occurrence of aspen trees increases the conservation value of mature conifer dominated forests. Aspens typically occur as scattered individuals among major tree species, and therefore the inventory of aspens is challenging. Methods： We characterized aspen populations in a boreal nature reserve using diameter distribution, spatial pattern, and forest attributes： volume, number of aspens, number of large aspen stems and basal area median diameter. The data were collected from three separate forest stands in Koli National Park, eastern Finland. At each site, we measured breast height diameter and coordinates of each aspen. The comparison of inventory methods of aspens within the three stands was based on simulations with mapped field data. We mimicked stand level inventory by locating varying numbers of fixed area circular plots both systematically and randomly within the stands. Additionally, we also tested if the use of airborne laser scanning （ALS） data as auxiliary information would improve the accuracy of the stand level inventory by applying the probability proportional to size sampling to assist the selection of field plot locations. Results： The results showed that aspens were always clustered, and the diameter distributions indicated different stand structures in the three investigated forest stands. The reliability of the volume and number of large aspen trees varied from relative root mean square error figures above 50% with fewer sample plots （5-10） to values of 25%-50% with ]0 or more sample plots. Stand level inventory estimates were also able to detect spatial pattern and the shape of the diameter distribution. In addition, ALS-based auxiliary information could be useful in guiding the inventories, but caution should be used when applying the ALS-supported inventory technique. Conclusions： This study characterized European aspen populations for the purposes of monitoring and management of boreal conservation areas. Our results suggest tha

关键词： Diameter distribution Historical continuity Inventory LiDAR Populus tremula L Simulation Spatial arrangement Stand characteristics

RESEARCH ANNOUNCEMENTS Galois Correspondence in Field Algebra of G-spin Mode

在线全文

学校读者我要写书评

暂无评论

数学进展 2003年第2期32卷 239-240页

作者：蒋立宁郭懋正 Department oy Applied Mathematics Beijing Institute oy TechnologyBeijing100081P.R.China LAMA School of MathematicsPeking UniversityBeijing100087P.R.China

A C*-system is a pair(B,G)consisting of a unital C*-algebra B and a continuotts

关键词：伽罗华对应 G-自旋模型群域代数 C代数

Stabilized Nickel-Rich-Layered Oxide Electrodes for High-Performance Lithium-Ion Batteries

在线全文

学校读者我要写书评

暂无评论

Energy & Environmental Materials 2024年第6期7卷 60-73页

作者： Zahra Ahaliabadeh Ville Miikkulainen Miia Mäntymäki Mattia Colalongo Seyedabolfazl Mousavihashemi Lide Yao Hua Jiang Jouko Lahtinen Timo Kankaanpää Tanja Kallio Department of Chemistry and Materials Science(CMAT) School of Chemical EngineeringAalto University02150 EspooFinland Department of Chemistry University of Helsinki00014 HelsinkiFinland Department of Applied Physics School of ScienceAalto University02150 EspooFinland Umicore Finland oy 67101 KokkolaFinland

This work made use of the Aalto University Otanano-Nanomicroscopy Center and RAMI *** support from Business Finland NextGenBat[grant number 211849]is greatly *** tomography experiment was performed at the beamline ID16B of the European Synchrotron Radiation Facility(ESRF),Grenoble,France,in the frame of proposal *** patent titled“Stabilized Positive Electrode Material to Enable High Energy and Power Density Lithium-Ion Batteries”(IPD3173)is pertinent to this *** was filed by Zahra Ahaliabadeh and Tanja Kallio,and the patent rights are held by Aalto University.

关键词： degradation mechanisms electrolyte decomposition hybrid coatings lithium-ion battery lithium-ion kinetics molecular layer deposition NMC811

Tackling boundaries of CCS in market deployment of second-generation oxy-fuel technology

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

Clean Energy 2018年第1期2卷 72-81页

作者： Kalle Nuortimo Timo Eriksson Reijo Kuivalainen Janne Härkönen Harri Haapasalo Timo Hyppänen Sumitomo SHI FW Energia oy P.O.Box 201 FI-78201 VarkausFinland Sumitomo SHI FW Energia oy P.O.Box 7FI-02130 EspooFinland Industrial Engineering and Management University of OuluP.O.Box 4610FI-90014Finland LUT school of Energy Systems PL 2053851 LappeenrantaFinland

This article discusses the market potential estimation results at different stages of second-generation oxy-fuel technology for carbon capture and storage,where oxygen content is increased in order to increase efficiency and product life *** article highlights the challenges to commercializing an energy technology with long development lead *** related to external market environment,regulations and market price for carbon dioxide(CO_(2))also need to be *** study is based on a second-generation oxy-CFB technology evaluation,SWOT analysis and product life-cycle *** commercialization of second-generation oxy-fuel technology,estimated as a basis of oxy-CFB technology,is largely found to be dependent on technical,sociological and economical aspects related to the energy market *** CO_(2) price in European Union(EU)emissions trading is currently below 10€/ton,which does not favour investment in ***_(2) storage also faces public opposition and EU directive *** CO_(2) price needs to be in the range of 30€/ton by 2030,the estimated time of *** development or subsidies would also be required for the second-generation oxy-CFB power production concept to become *** is one of the critical factors in market deployment as the price development is influenced by several external factors,including the EU’s environmental policy,politics and public acceptance.

关键词： Second generation oxyfuel technology market deployment CFB technology tackling boundary of CCS

Wear Behavior and Mechanism of Spheroidal Graphite Cast Iron

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

Journal of Iron and Steel Research International 2013年第10期20卷 81-86页

作者： YANG Zi-run LI Dong-sheng WANG Lan WANG Shu-qi WEI Min-xian school of Materials Engineering Yancheng Institute of Technology school of Materials Science and Engineering Jiangsu University

Wear behavior and mechanism of spheroidal graphite cast iron were studied on a pin on-disk elevated tem- perature wear tester. The phase and morphology of worn surfaces were examined by X ray diffraction and scanning electron microscopy. Results show that with an increase of load, wear rate of spheroidal graphite cast iron gradually increases under low loads, rapidly increases or potentially increases under high loads; wear rate increases with in- creasing ambient temperature. At 25 200 ℃, adhesive wear prevails; oxidative wear and adhesive wear coexist at 400 ℃. As load surpasses 150 N at 400 ℃, extrusive wear appears. The elevated-temperature wear of spheroidal graphite cast iron is a physical and chemical process including the following reactions： xFe＋y/2O2-Fexoy , 2C＋ O2- 2CO and Fex oy ＋yCO-xFe＋yCO2. Hence, at 400 ℃, the amount of graphite and tribo oxides are substan- tially reduced because of reductive function of graphite. It can be suggested that wear reduced effect of graphite and tribo-oxides is impaired.

关键词： spheroidal graphite cast iron wear behavior wear mechanism tribo oxide microstructure

Evidence of refilled chamber gas pressure enhancing cooling rate during melt spinning of a Zr_(50)Cu_(40)Al_(10) alloy

在线全文

学校读者我要写书评

暂无评论

China Foundry 2015年第4期12卷 299-304页

作者： Hong-wang Yang Peng Zhang M.J.Tan Yuan Ge Wan-ping Tian Rui-chun Wang Rong-de Li school of Materials Science and Engineering Shenyang University of Technology school of Mechanical and Aerospace Engineering Nanyang Technological University

The influence of the refilled gas pressure on the glass forming behaviour of one of the best ternary glass forming alloys Zr50Cu40Al10 was studied for the melt spinning process. The amorphicity of as-quenched ribbons was characterized by X-ray diffraction （XRD） and differential scanning calorimetry （DSC）. The refilled chamber atmospheric pressure is crucial to the cooling rate of melt spinning. At high vacuum, at pressure less than 0.0001 atm, fully crystalline fragments are obtained. Monolithic amorphous ribbons were only obtained at a gas pressure of 0.1 atm or higher. The extended contact length between thecribbons and the copper wheel contributes to the high cooling rate of melt spinning. Higher chamber gas pressure leads to more turbulence of liquid metal beneath the nozzle; therefore, lower pressure is preferable at practical melt spinning processes once glass forming conditions are fulfilled.

关键词： metallic glass amorphous alloy melt spinning glass forming behaviour

Corrosion behavior of Mg-Zn-Ca amorphous alloys with Nd addition in simulated body fluids

在线全文

学校读者我要写书评

暂无评论

China Foundry 2014年第6期11卷 503-509页

作者： Qin Chunling Xiao Tongna Li Yongyan Wang Zhifeng Liu Li Xiong Hanqing Zhao Weimin school of Materials Science and Engineering Hebei University of Technology school of Materials Science and Engineering Central South University

The effects of Nd addition on corrosion behavior of Mg66Zn30Ca4 amorphous alloys in simulated body fluids （SBF） were studied in this paper. Electrochemical properties of the samples before and after corrosion were determined. Surface morphologies of samples after immersion in SBF at 37 ℃ for different times were observed under scanning electron microscope （SEM）. Results show that the corrosion resistance of Mg-based alloys in SBF is improved with the addition of Nd element. The electrochemical properties indicate that microalloying Nd element to the alloys leads to an ennoblement in the open circuit potentials of the alloys and a decrease in the anodic current density in SBF, especially for the Mgee66-xZn30Ca4Ndx alloys with Nd content of 1.0at.%-1.5at.%. It was observed that the surface morphologies of the alloys immersed in SBF change with the Nd addition. A flake- like structure parallel to the alloy substrate formed on the surface of 1.0at.% Nd-containing alloy immersed in SBF for 7 days improves the corrosion resistance of the amorphous alloys by blocking the corrosion liquid from attacking the alloys.

关键词： Mg alloy amorphous alloy corrosion behavior SBF electrochemical measurements

Geochemistry of Late Archaean shaly BIF formed by oxic exogenic processes: an example from Ramagiri schist belt,Dharwar Craton, India

在线全文

学校读者我要写书评

暂无评论

Chinese Journal Of Geochemistry 2015年第3期34卷 362-378页

作者： Meenal Mishra school of Sciences Indira Gandhi National Open University

The central block of the auriferous Ramagiri schist belt, in the Eastern Dharwar Craton, India consists of bimodal volcanics(mafic-felsic), shaly BIF and metasedimentary rocks. Geochemical studies of the associated shaly BIF have indicated the enrichment of the major and trace elements such as Si O2, Al2O3, Ti O2, K2 O, Mg O, Fe2O3(T),Zr, Y, Cr, Ni, alkali and alkaline earth elements indicates that the clastic component of the shaly BIF had their contribution from the contemporaneous bimodal *** concave chondrite normalized REE patterns share ubiquitously anomalous positive cerium anomaly, absence of positive europium anomaly and the overall HREE enrichment. The REE patterns resemble those from the modern day sea water, except for positive Ce anomaly. The data suggests that arc related bimodal volcanism had been the plausible source of Fe, silica, REE and other trace elements. The coherent behaviour of Fe, Ti, Mn and P with the REEs indicates that they got incorporated from Fe–Ti–Mn bearing primary minerals and secondary products like clays. The variability of REE patterns in the BIF formation samples probably results from the differences in scavenging efficiency. The BIF bears signatures of mixing of the contemporaneous clastic and chemical processes, as well as the changes accompanying diagenesis and *** precipitation of Fe did not stop during the sedimentation in an island arc related tectonic setting. The BIF strongly lacks the signatures from hydrothermal input. The presence of positive cerium anomalies and the absence of positive europium anomalies in the shaly banded ironformations imply that iron oxidation during BIF deposition took place in shallow waters rather than at depth, at oxicanoxic boundary.

关键词：地球化学二氧化硅克拉通晚太古代岩带印度力作用双峰式火山岩

Clinically relevant human temporal bone measurements using novel high-resolution cone-beam CT

在线全文

学校读者我要写书评

暂无评论

Journal of Otology 2017年第1期12卷 9-17页

作者： Jing Zou Jaakko Laahelma Antti Arnisalo Ilmari Pyykko Department of Otolaryngology-Head and Neck Surgery Center for Otolaryngology-Head & Neck Surgery of Chinese PLA Changhai Hospital Second Military Medical University Shanghai China Hearing and Balance Research Unit Field of Oto-laryngology School of Medicine University of Tampere Tampere Finland Planmeca oy Helsinki Finland Department of Otorhinolaryngology-Head and Neck Surgery Helsinki University Central Hospital Helsinki Finland

Objective: To test the feasibility of measuring fine temporal bone structures using a newly established cone-beam computed tomography(CBCT)*** and methods: Six formalin-fixed human cadaver temporal bones were imaged using a high-resolution CBCT system that has 900 frames and copper t aluminum filtration. Fine temporal bone structures, including those of the facial nerve canal and vestibular structures, were identified and ***: The fine structures of the middle ear, including the tympanic membrane, tendon of the tensor tympani, cochleariform process of the semicanal of the tensor tympani, pyramidal eminence, footplate of the stapes, full path of the facial nerve within the temporal bone, supralabyrinthine space, semicircular canals, pathway of the subarcuate canal, and full path of the vestibular aqueduct, were clearly demonstrated. The vestibular aqueduct has a midpoint width of 0.4 ± 0.0 mm and opercular width of 0.5 ± 0.1 mm(mean ± SD). The length of the internal acoustic meatus was 10.6 ± 1.2 mm(mean ± SD), and the diameter of the internal acoustic meatus was 3.7 ± 0.3 mm(mean ± SD).Conclusion: This novel high-resolution CBCT system has potentially broad applications in the diagnosis of inner ear disease and in monitoring associated pathological changes, surgical planning, navigation for the ear surgery, and temporal bone training.

关键词： CT Temporal bone anatomy Vestibule Facial nerve