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Plant functional type approach for a functional interpretation of altitudinal vegetation zones in the Alborz Mts., Iran

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Journal of Mountain Science 2017年第11期14卷 2257-2269页

作者： Halime MORADI Farideh ATTAR jens OLDELAND Department of Plant Sciences School of Biology College of Science University of Tehran Biodiversity Ecology and Evolution of Plants Biocentre Klein Flottbek and Botanical Garden University of Hamburg

Mountains are an excellent system for evaluating ecological and biogeographical patterns. The obvious variations of the environmental factors along the altitude create different zones with adapted plant assemblages. However, few studies make use of plant functional type(PFT) for describing the variation of vegetation along altitudinal gradients. A PFT is a group of taxa with similar traits which respond similarly to the environmental gradients. In this study, we used PFTs as indicators describing five vegetation zones in the western Alborz Mt, Iran from 2000 – 4500 m. The plant trait data presented here covers six plant traits including growth form, stemleaf ratio, spinescence, hairiness, leaf consistency and plant height of 297 species. We considered altitude and soil factors to test the importance of environmental variables. We applied a multivariate analysis of three table ordination, i.e. environmental, species, and traits data to identify the PFTs. We further applied fourth-corner statistic to quantify trait-environment relationships. A constrained hierarchical clustering was used to detect five altitudinal zones and two zones of low and high nitrogen concentration. With regard to altitude wediscuss the distribution of species, traits and PFTs. Growth form, plant height and stem-leaf ratio were significantly related to altitude and nitrogen. We identified 19 PFTs from which 18 were significantly associated to one or more altitudinal zones. While the lower altitudinal zones contain a variety of PFTs higher altitudes contain less PFTs with the highest altitude containing only one single PFT, tiny rosette plants with soft mesomorphic leaves. We identified grazing and climatic harshness as well as rockiness as the most important drivers of the distribution of plant functional traits and types across the studied gradient.

关键词： Elevation Indicator Species Analysis Ordination Leaf traits Trait-environment relationships

Barriers to WHO Mental Health Action Plan updates to expand family and caregiver involvement in mental healthcare

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General Psychiatry 2022年第2期35卷 154-156页

作者： jens Peter Eckardt Research Unit Bedre PsykiatriCopenhagenDenmark

In 2021,the 74th World Health Assembly endorsed updates to the WHO's Comprehensive Mental Health Action Plan extending to 2030,including revised indicators to measure progress towards reaching defined targets and expa... 详细信息

关键词： expanded revised Action

Amine reclaiming technologies in post-combustion carbon dioxide capture

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Journal of Environmental Sciences 2015年第1期27卷 276-289页

作者： Tielin Wang Jon Hovland Klaus J.jens Telemark University College Tel-Tek Porsgrunn 3918 Norway

Amine scrubbing is the most developed technology for carbon dioxide（CO2） *** of amine solvents due to the presence of high levels of oxygen and other impurities in flue gas causes increasing costs and deterioration in long term performance,and therefore purification of the solvents is needed to overcome these problems. This review presents the reclaiming of amine solvents used for post combustion CO2capture（PCC）. Thermal reclaiming, ion exchange, and electrodialysis, although principally developed for sour gas sweetening, have also been tested for CO2 capture from flue *** three technologies all have their strengths and weaknesses, and further development is needed to reduce energy usage and costs. An expected future trend for amine reclamation is to focus on process integration of the current reclaiming technologies into the PCC process in order to drive down costs.

关键词： Carbon dioxide capture Amine reclaiming Distillation Ion exchange Electrodialysis

Influence of lubrication,tool steel composition,and topography on the high temperature tribological behaviour of aluminium

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Friction 2021年第1期9卷 155-168页

作者： Justine DECROZANT-TRIQUENAUX Leonardo PELCASTRE Braham PRAKASH jens HARDELL Machine Elements Lulea University of TechnologyLulea SE-97187Sweden Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China

The use of high strength aluminium alloys,such as 6 XXX and 7 XXX series,is continuously increasing for automotive applications in view of their good strength-to-weight *** formability at room temperature is limited and they are thus often formed at high temperatures to enable production of complex *** challenges during hot forming of aluminium are the occurrence of severe adhesion and material transfer onto the forming *** negatively affects the tool life and the quality of the produced *** general,the main mechanisms involved in the occurrence of material transfer of aluminium alloys at high temperature are still not clearly ***,this study is focussed on understanding of the friction and wear behaviour during interaction of Al6016 alloy and three different tool steels in as-received and polished *** tribotests were carried out under dry and lubricated conditions,with two distinct lubricants,using a reciprocating friction and wear *** worn surfaces were analysed using scanning electron microscopy(SEM)and energy dispersive X-ray spectroscopy(EDS).The results showed a high dependence of friction and wear behaviour on the tool steel roughness as well as on the stability of the lubricant *** were found to develop in the contact zone and their capacity to improve the tribological behaviour is seen to be drastically impacted by the surface roughness of the tool *** the tribolayers failed,severe adhesion took place and led to high and unstable friction as well as material transfer to the tool steel.

关键词： friction wear high temperature tribology aluminium lubrication tribolayer

How green composite materials could benefit aircraft construction

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Science China(Technological Sciences) 2019年第8期62卷 1478-1480页

作者： SOUTIS Constantinos YI XiaoSu BACHMANN jens Aerospace Research Institute University of Manchester Manchester Ml 3 9PL UK Faculty of Science and Engineering University of Nottingham Ningbo China Ningbo 315100 China DLR German Aerospace Center Institute of Composite Structures and Adaptive Systems Lilienthalplatz 7 Braunschweig 38108 Germany

Aeronautical composite materials can be typically characterized by their excellent mechanical properties, light weight and high performance when compared to the more conventional materials, and the ability to tailor t... 详细信息

关键词： typically characterized excellent mechanical properties conventional materials

Modeling and optimization of a spherical triboelectric generator

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Nano Research 2023年第9期16卷 11925-11931页

作者： jens Gravesen Morten Willatzen Jiajia Shao Zhong Lin Wang DTU Compute Technical University of DenmarkKgs.LyngbyDK-2800Denmark Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China Georgia Institute of Technology AtlantaGeorgia 30332USA

A detailed geometric analysis of spherical triboelectric nanogenerators is *** comparison with earlier works on spherical triboelectric generators,the general case where the moving dielectric rolls on the inside surface of the larger sphere of the TENG is discussed in terms of maximum energy *** optimization analysis of geometrical parameters allows various cases of electrode geometry,either in the form of a spherical circle,spherical ellipse,spherical rectangle,or spherical isosceles trapezium,to be *** analytical insight and computational effective models provided by differential geometry make the mathematical model superior compared to standard three-dimensional(3D)numerical methods.

关键词： spherical triboelectric nanogenerator differential geometry analysis electrode shape study modeling and optimization

Perforated midgut diverticulitis:Revisited

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World Journal of Gastroenterology 2012年第34期18卷 4714-4720页

作者： Milan Spasojevic jens Marius Naesgaard Dejan Ignjatovic Department of Gastrointestinal Surgery Vestfold Hospital3103 TonsbergNorway Department of Digestive Surgery Akershus University HospitalUniversity of Oslo1478 LorenskogNorway

AIM:To study and provide data on the evolution of medical procedures and outcomes of patients suffering from perforated midgut diverticulitis. METHODS:Three data sources were used:the Medline and Google search engines were searched for case reports on one or more patients treated for perforated midgut diverticulitis (Meckel's diverticulitis excluded) that were published after 1995. The inclusion criterion was sufficient individual patient data in the article. Both indexed and non-indexed journals were used. Patients treated for perforated midgut diverticulitis at Vestfold Hospital were included in this group. Data on symptoms, laboratory and radiology results, treatment modalities, surgical access, procedures, complications and outcomes were collected. The Norwegian patient registry was searched to find patients operated upon for midgut diverticulitis from 1999 to 2007. The data collected were age, sex, mode of access, surgical procedure performed and number of patients per year. Historical controls were retrieved from an article published in 1995 containing pertinent individual patient data. Statistical analysis was done with SPSS ***:GroupⅠ:106 patients (48 men) were found. Mean age was 72.2 ± 13.1 years (mean ± SD). Age or sex had no impact on outcomes (P = 0.057 and P = 0.771, respectively). Preoperative assessment was plain radiography in 53.3% or computed tomography (CT) in 76.1%. Correct diagnosis was made in 77.1% with CT, 5.6% without (P = 0.001). Duration of symptoms before hospitalization was 3.6 d (range:1-35 d), but longer duration was not associated with poor outcome (P = 0.748). Eighty-six point eight percent of patients underwent surgery, 92.4% of these through open access where 90.1% had bowel resection. Complications occurred in 19.2% of patients and 16.3% underwent reoperation. Distance from perforation to Treitz ligament was 41.7 ± 28.1 cm. At surgery, no peritonitis was found in 29.7% of patients, local peritonitis in 47.5%, and dif

关键词： Intestinal Small bowel Jejunum Ileum Perforation Diverticulitis Conservative treatment

Study of the wall adhesive tensile contact of moist iron ore bulk solids

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Particuology 2020年第3期18卷 67-75页

作者： Tao Fang Wei Chen jens Plinke Craig Wheeler Alan Roberts School of Civil Engineering East China Jiaotong UniversityNanchang 330013China School of Engineering The University of NewcastleCallaghan 2308Australia

The adhesive tensile stress between moist bulk iron ore solids and wall surfaces are critical to control and avoid blockage in large throughput material handling *** this study,an experimental system was designed to investigate the adhesive tensile contact between a range of iron ore materials and wall lining *** contact mechanism between the material specimen and the wall surface was initially *** experimental results indicated that the adhesive tensile stress is dependent on both the moisture content and the applied major consolidation stress,with the former exhibiting more significant contribution to increasing the magnitude of *** surface roughness of the wall showed a negligible effect in determining the adhesive tensile ***,the iron ore sample with a higher fines content was observed to be able to achieve a higher adhesive tensile stress compared to the coarse ***,the insights resulting from the study demonstrated practical applicability through measures such as blending and/or beneficiation,which reduce the adhesive tensile stress and minimise blockages.

关键词： Wet sticky material Adhesive tensile stress Wall linings Liquid bridge force Capillary stress Soil texture

Novel Traveling Wave Sandwich Piezoelectric Transducer with Single Phase Drive:Theoretical Modeling,Experimental Validation,and Application Investigation

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Chinese Journal of Mechanical Engineering 2021年第5期34卷 206-225页

作者： Liang Wang Fushi Bai Viktor Hofmann Jiamei Jin jens Twiefel State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China Institute of Dynamics and Vibration Research Leibniz University Hannover30167 HannoverGermany School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710072ShaanxiChina

Most of traditional traveling wave piezoelectric transducers are driven by two phase different excitation signals,leading to a complex control system and seriously limiting their applications in *** overcome these issues,a novel traveling wave sandwich piezoelectric transducer with a single-phase drive is proposed in this *** waves are produced in two driving rings of the transducer while the longitudinal vibration is excited in its sandwich composite beam,due to the coupling property of the combined *** results in the production of elliptical motions in the two driving rings to achieve the drive *** analytical model is firstly developed using the transfer matrix method to analyze the dynamic behavior of the proposed *** vibration characteristics are measured and compared with computational results to validate the effectiveness of the proposed analytical ***,the driving concept of the transducer is investigated by computing the motion trajectory of surface points of the driving ring and the quality of traveling wave of the driving ***,application example investigations on the driving effect of the proposed transducer are carried out by constructing and assembling a tracked mobile *** results indicated that 1)the assembled tracked mobile system moved in the driving frequency of 19410 Hz corresponding to its maximum mean velocity through frequency sensitivity experiments;2)motion characteristic and traction performance measurements of the system prototype presented its maximum mean velocity with 59 mm/s and its maximum stalling traction force with 1.65 N,at the excitation voltage of 500 V_(RMS).These experimental results demonstrate the feasibility of the proposed traveling wave sandwich piezoelectric transducer.

关键词： Traveling wave Sandwich piezoelectric transducer Single phase excitation Transfer matrix method Ultrasonic motor