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A Review on Cooperative Robotic Arms with Mobile or Drones Bases

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International Journal of Automation and computing 2021年第4期18卷 536-555页

作者： Larona Pitso Ramalepa Rodrigo S.Jamisola jr. Botswana International University of Science and Technology Palapye 10071Botswana

This review paper focuses on cooperative robotic arms with mobile or drone bases performing cooperative tasks. This is because cooperative robots are often used as risk-reduction tools to human life. For example, they are used to explore dangerous places such as minefields and disarm explosives. Drones can be used to perform tasks such as aerial photography, military and defense missions,agricultural surveys, etc. The bases of the cooperative robotic arms can be stationary, mobile(ground), or drones. Cooperative manipulators allow faster performance of assigned tasks because of the available "extra hand". Furthermore, a mobile base increases the reachable ground workspace of cooperative manipulators while a drone base drastically increases this workspace to include the aerial *** papers in this review are chosen to extensively cover a wide variety of cooperative manipulation tasks and industries that use *** cooperative manipulation, avoiding self-collision is one of the most important tasks to be performed. In addition, path planning and formation control can be challenging because of the increased number of components to be coordinated.

关键词： Cooperative arms mobile manipulator aerial manipulator mobile base drone base cooperative tasks

Very weak solutions to the two-dimensional Monge-Ampére equation Dedicated to Professor Jean-Yves Chemin on the Occasion of His 60th Birthday

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Science China Mathematics 2019年第6期62卷 1041-1056页

作者： Wentao Cao László Székelyhidi jr. Institut für Mathematik Universit?t Leipzig

In this short note we revisit the convex integration approach to constructing very weak solutions to the 2D Monge-Ampére equation with H?lder-continuous ?rst derivatives of exponent β < 1/5. Our approach is based on combining the approach of Lewicka and Pakzad(2017) with a new diagonalization procedure which avoids the use of conformal coordinates, which was introduced by De Lellis et al.(2018) for the isometric immersion problem.

关键词： Monge-Ampére equation convex integration weak solutions

Effect of induced shielding current transmission in longitudinal direction on levitation force of melt grown single-domain YBa_2Cu_3O_(7-x) cylindrical superconductor

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Science China(Physics,Mechanics & Astronomy) 2004年第2期47卷 146-153页

作者： R. Nicolsky R. de Andrade jr LASUP-DEE UFRJ Ilha do Fundao Cx.P.68515 21945-970 Rio de Janeiro RJ Brasil Correspondence should be addressed to Yang Wanmin LASUP-DEE UFRJ Ilha do Fundao Cx.P.68515 21945-970 Rio de Janeiro RJ Brasil Correspondence should be addressed to Yang Wanmin

A novel layer deletion method is used to experimentally investigate the effect of induced shielding current transmission (ISCT) in the longitudinal direction on the levitation force of a single-domain YBa2Cu3O7?x (YBCO) cylindrical superconductor (?30×7 mm). In the experiment the sample was gradually sliced into two equal sheets, at the middle height along a diameter with 5 mm every step. The experimental results show that the levitation force is closely related with the ISCT in the longitudinal direction. Any layer deletion, even a small piece of layer deletion can reduce the levitation force of the sample. After the whole layer was deleted the levitation force can diminish about 50%. It is also found that the levitation force is directly proportional to the effective factor of surface area, which is equal to the top surface area divided by the total surface area parallel to the top surface of the sample.

关键词： melt growth, single domain YBCO, levitation force, induced current distribution.

Synthesis and Molecular Structure of A Bimetallic Salen Complex Containing Zn and La: A Disordered Nitrate Group Dancing between Two Metal Centers

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Journal of Rare Earths 2005年第3期23卷 257-261页

作者： Leon Dyers jr Donald Van Derveer Xiu R Bu Department of Chemistry NASA Center for High Performance Polymers and Composites Clark Atlanta University Atlanta Georgia 30314 USADepartment of Chemistry Clemson University Clemson South Carolina 29634 USADepartment of Chemistry NASA Center for High Performance Polymers and Composites Clark Atlanta University Atlanta Georgia 30314 USA

A new bimetallic complex containing Zn and La was prepared from a salen ligand possessing methoxyl groups at the 3, 3′-positions. The structural feature is that one of nitrate groups is disordered and displaced between two metal centers. Crystal system: Triclinic space group:P-1, Z=2. a=0.82714(17) nm, b=1.3484(3) (1) nm, and c=1 3898(3) (1) nm, α=79.89(3)°, β=76.67(3)°, and γ=72.43(3)°. V=1 428 6(5) nm3, Dx=1.812 g·cm-3. (Δρ)max=1 510×10-3 enm3, (Δρ)min=-1.503×10-3 enm3. Accordingly, two water molecules occupy the metal centers in the apical positions via the syn-geometry.

关键词： bimetallic complex zinc lanthannm rare earths

Can a multistage approach improve individual tree mortality predictions across the complex mixed-species and managed forests of eastern North America?

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Forest Ecosystems 2023年第1期10卷 21-30页

作者： Cen Chen John Kershaw jr Aaron Weiskittel Elizabeth McGarrigle Center for Research on Sustainable Forests University of MaineOronoME04469USA Faculty of Forestry&Environmental Management University of New BrunswickFrederictonNBE3B 5A3Canada Nova Scotia Department of Natural Resources HalifaxNSB3J 3M8Canada

Tree mortality plays a fundamental role in the dynamics of forest ecosystems,yet it is one of the most difficult phenomena to accurately *** modeling strategies have been developed to improve individual tree mortality *** less explored strategy is the use of a multistage modeling *** improvements from this approach have remained largely *** this study,we developed a novel multistage approach and compared its performance in individual tree mortality predictions with a more conventional approach using an identical individual tree mortality model *** permanent plot data(n=9442)covering the Acadian Region of North America and over multiple decades(1965–2014)were used in this *** results indicated that the model behavior with the multistage approach better depicted the observed mortality and showed a notable improvement over the conventional *** difference between the observed and predicted numbers of dead trees using the multistage approach was much smaller when compared with the conventional *** addition,tree survival probabilities predicted by the multistage approach generally were not significantly different from the observations,whereas the conventional approach consistently underestimated mortality across species and overestimated tree survival probabilities over the large range of DBH in the *** new multistage approach also predictions of zero mortality in individual plots,a result not possible in conventional ***,the new approach was more tolerant of modeling errors because it based estimates on ranked tree mortality rather than error-prone predicted ***,this new multistage approach deserves to be considered and tested in future studies.

关键词： Tree mortality modeling Mortality disaggregation Mixed effect model Annualization Mixed forests

Synthesis and Luminescent Properties of Planar-tip and Tapered-tip ZnO Nanorod Arrays

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Journal of Materials Science & Technology 2008年第4期24卷 633-636页

作者： Chun-wen WANG jr-hau HE Lih-juann CHEN Department of Materials Science and Engineering National Tsing-Hua University Hsinchu City 30013 Taiwan China Institute of Photonics and Optoelectronics and Department of Electrical Engineering National Taiwan UniversityTaipei 106 Taiwan China

Vertically aligned ZnO nanorods were synthesized on a-plane sapphire via a metal catalyzed vapor phase transport and condensation process in a two-zone vacuum furnace. Planar-tip and tapered-tip ZnO nanorods were successfully synthesized by utilizing different source materials under the same growth conditions. The growth mechanisms were proposed to be vapor-liquid-solid （VLS） process for planar-tip ZnO nanorods and a combination of VLS and self-catalyzed processes for tapered-tip ZnO nanorods, From cathodoluminescence （CL） measurements, tapered-tip ZnO nanorods have more intense green emission than planar-tip ZnO nanorods, and therefore possess higher oxygen vacancy concentration than planar-tip ZnO nanorods. From CL characteristics, well-aligned planar-tip ZnO nanorods shall serve effectively as laser source, while well-aligned tapered-tip ZnO nanorods are suitable for direction-related optical applications.

关键词： ZnO Well-aligned Nanorods Cathodoluminescence

Alternative expressions for stand diameter in complex forests

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Forest Ecosystems 2023年第3期10卷 328-336页

作者： Mark J.Ducey John A.Kershaw jr. Department of Natural Resources and the Environment University of New HampshireDurhamNHUSA Faculty of Forestry and Environmental Management University of New BrunswickFrederictonNBCanada

Quadratic mean diameter is the most frequently reported descriptor of the diameter distribution of *** such,it is often used as an indicator of forest stand structure,developmental stage,and ecological and economic ***,quadratic mean diameter can be heavily influenced by the presence or absence of large numbers of small stems in lower canopy strata,and it is also sensitive to left-truncation of the diameter distribution,making its interpretation across inventories with different protocols ***,we examine three alternative expressions of stand diameter:the arithmetic and quadratic mean diameter of the thickest 100 trees per hectare,and the basal area-weighted mean *** data from the United States Forest Inventory and Analysis program for New York and New England,these alternative expressions showed closer correlation with multiple stand structural variables than did quadratic mean diameter,including merchantable cubic and board foot volume per hectare,aboveground live tree carbon per hectare,and total number of live and dead standing trees greater than 40 cm diameter at breast height per hectare(previously proposed as an index of old-growth structure).Arithmetic and quadratic mean diameter of the thickest 100 trees per hectare showed nearly identical performance,and the strongest correlations across the *** develop closed-form expressions for these variables when the diameter distribution is a Weibull,and illustrate their behavior relative to quadratic mean diameter for that *** the reasons for prevalence of quadratic mean diameter as an indicator remain valid,we suggest that these alternative measures should be more widely reported and analyzed to give a more informative depiction of stand structure and development in complex forests.

关键词： Forest structure Diameter at breast height Weibull distribution

Climate pledges versus commitment: Are policy actions of Middle-East and North African countries consistent with their emissions targets?

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Advances in Climate Change Research 2022年第4期13卷 612-621页

作者： Hermas ABUDU Presley K.WESSEH jr Boqiang LIN School of Management China Institute for Studies in Energy PolicyCollaborative Innovation Center for Energy Economics and Energy PolicyXiamen UniversityFujian361005China Belt and Road Research Institute Xiamen UniversityFujian361005China

Carbon emission is inevitable,and changes with energy consumption and economic development,presents policy options toward sustainable development ***,there is little assurance from policymakers in committing to climate change pledges:taking the Middle-East and North African(MENA)region as a specific case with using 2019 as a cut-off *** conducted an interim assessment of the Paris Agreement to ascertain whether climate actions are in tandem with emissions reduction *** use of difference-in-difference technique as a quasiexperiment supported by fixed-effects and placebo treatment models,the results point to evidence of less than 1%effective CO_(2) emissions reduction as of 2019 compared to the 2015 *** current carbon emissions reduction commitment level is far-reaching contrary to the Nationally Determined Contributions(NDCs)pledged(16.43%on average by 2030 compared to the 2015 level).The analysis suggests that achieving NDCs commitments are currently major burden on policymakers since the economic development is highly linked with nonrenewable energy ***,a more comprehensive framework when accounting for all available renewable and clean energy projects shows reduction levels in the range of 30%-40%from 2020 to *** results suggest that the Paris Agreement in MENA countries may be more effective from 2020,thus underscore the importance of capturing ongoing projects(involving renewable and clean energy technologies)into interim policy *** shared implication is that greater efforts are demanded from the region and at country levels to further decrease emissions through the use of negative emissions technologies particularly in the electricity generation sector.

关键词： Paris Agreement Carbon emissions reduction potential Carbon effciency:Climate change policy quasi-experiment MENA climate change performance

Symptomatic male with subclinical varicocele found on ultrasound evaluation

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Asian Journal of Andrology 2016年第2期18卷 313-314页

作者： Ahmad Majzoub Edmund Sabanegh jr. Department of Urology Glickman Urological and Kidney Institute Cleveland Clinic Foundation CLeveland Ohio USA.

Scrotal pain is a commonly encountered complaint in urology practice. It occurs in around 2%-10% of patients with *** a relatively common association, the effect ofvaricocele on pain is much less investigated than its relation with infertility. Biggers and Soderdahl were the first to explore surgical treatment for pain attributed to a clinical varicocele in 1981, reporting an improvement rate of 48% after surgery.

关键词： SCROTAL CONTENT PAIN INTERNAL SPERMATIC VEIN CHRONIC ORCHIALGIA CORD MICRODENERVATION DENERVATION LIGATION