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Load dependent microstructural evolution in an as-cast 26%Cr high chromium cast iron during unlubricated sliding

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Friction 2022年第8期10卷 1258-1275页

作者： U.Pranav NAYAK Sebastian SUÁREZ Valentin PESNEL frank mücklich maría Agustina GUITAR Department of materials Science Saarland UniversitySaarbrücken 66123Germany materials Engineering Center Saarland Saarbrücken 66123Germany Ecole Européenne d’ingénieurs en Génie des matériaux Universitéde LorraineNancy 54000France

In the current study,an as-cast 26%Cr high chromium cast iron(HCCI)alloy was subjected to dry-sliding linear wear tests,under different *** loads were selected based on analytically computing the critical load(PC)i.e.,the load necessary to induce plastic *** PC was calculated to be 15 N and accordingly,a sub-critical load(5 N)and an over-critical load(20 N)were *** influence of increasing the load during the wear test was investigated in terms of the matrix microstructural behaviour and its ability to support the surrounding *** morphological aspects of the wear tracks,and the deformed matrix microstructure adjacent and underneath the track was analysed by confocal laser scanning microscope(CLSm)and scanning electron microscope(SEm),*** evidence of plastic deformation of the matrix was observed below *** the contrary,at loads equal to and higher than PC,the austenitic matrix plastically deformed as evidenced by the presence of slip *** backscattered diffraction(EBSD)measurements in terms of grain reference orientation deviation,and micro-Vickers hardness of the austenitic matrix indicated a deformation depth of about 40μm at the maximum applied load of 20 *** active wear mechanisms during sliding were a combination of both adhesive and abrasive wear,although increasing the load shifted the dominant mechanism towards *** was primarily attributable to the increased propensity for carbide cracking and fracturing,combined with the inability of the hardened austenitic matrix surface and sub-surface to adequately support the broken carbide ***,the shift in the dominant wear mechanism was also reflected in the wear volume and subsequently,the wear rate.

关键词： high chromium cast iron unlubricated sliding plastic deformation wear resistance carbide spallation matrix hardness

Influence of structural depth of laser-patterned steel surfaces on the solid lubricity of carbon nanoparticle coatings

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Friction 2023年第7期11卷 1276-1291页

作者： Timothy mACLUCAS Lukas DAUT Philipp GRÜTZmACHER maria Agustina GUITAR Volker PRESSER Carsten GACHOT Sebastian SUAREZ frank mücklich Chair of Functional materials Saarland UniversitySaarbrücken 66123Germany Institute for Engineering Design and Product Development TU WienWien 1060Austria INm–Leibniz Institute for New materials Saarbrücken 66123Germany Department of materials Science&Engineering Saarland UniversitySaarbrücken 66123Germany Saarene-Saarland Center for Energy materials and Sustainability Saarbrücken 66123Germany

Carbon nanoparticle coatings on laser-patterned stainless-steel surfaces present a solid lubrication system where the pattern's recessions act as lubricant-retaining *** study investigates the influence of the structural depth of line patterns coated with multi-walled carbon nanotubes(CNTs)and carbon onions(COs)on their respective potential to reduce friction and *** laser interference patterning(DLIP)with a pulse duration of 12 ps is used to create line patterns with three different structural depths at a periodicity of 3.5μm on AISI 304 steel ***,electrophoretic deposition(EPD)is applied to form homogeneous carbon nanoparticle coatings on the patterned *** ball-on-disc experiments are conducted on the as-described surfaces with an alumina counter body at a load of 100 *** results show that the shallower the coated structure,the lower its coefficient of friction(COF),regardless of the particle ***,with a minimum of just below 0.20,CNTs reach lower COF values than COs over most of the testing *** resulting wear tracks are characterized by scanning electron microscopy,transmission electron microscopy,and energy-dispersive X-ray *** friction testing,the CNTs remain in contact,and the immediate proximity,whereas the CO coating is largely *** of structural depth,no oxidation occurs on CNT-coated surfaces,whereas minor oxidation is detected on CO-coated wear tracks.

关键词： solid lubricant coatings carbon nanotubes carbon onions direct laser interference patterning(DLIP)surface structuring electrophoretic deposition(EPD)

Decoding complexity: the need to enhance precision and streamline spatial understanding in neuroscience

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Neural Regeneration Research 2025年第3期20卷 801-802页

作者： Sameehan mahajani Armita Salahi Brenda Gonzalez Charlotte Nelson frank Hsiung Biology&Applications Division NodexusSan JoseCAUSA

Neuroscience is the ultimate frontier in our quest for a comprehensive understanding of human behavior. Since its launch in 2009, the Human Connectome Project has emerged as a pioneering force, making heroic strides i... 详细信息

关键词： behavior frontier dating

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TeV astronomy

Frontiers of physics 2013年第6期8卷 714-747页

作者： frank m. Rieger max-Planck-Institut fiir Kernphysik P.O. Box 103980 69029 Heidelberg Germany Institut de Ciencies de L'Espai (IEEC-CSIC) Campus UAB Torte C5 08193 Bellaterra Spain Dublin Institute for Advanced Studies 31 Fitzwilliam Place Dublin 2 Ireland European Associated Laboratory for Gamma-Ray Astronomy jointly supported by CNRS and MPG

With the successful realization of the current-generation of ground-based detectors, TeV Astronomy has entered into a new era. We review recent advances in VHE astronomy, focusing on the potential of Imaging Atmospheric Cherenkov Telescopes （IACTs）, and highlight astrophysical implications of the results obtained within recent years.

关键词： TeV astronomy gamma-rays Cherenkov telescopes high-energy astrophysics

Influence of groundwater depth on species composition and community structure in the transition zone of Cele oasis

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Journal of Arid Land 2010年第4期2卷 235-242页

作者： frank m. THOmAS Department of Geobotany University of Trier Behringstraβe 21 54296 Trier Germany

The paper analyzes the hypothesis that the distribution of dominant plant species and characteristics of plant communities are related to groundwater depth. The results showed that variations of groundwater depth impacted distributions and characteristics of dominant plant communities. However, besides groundwater depth, the community composition and species diversity were also influenced by physiognomy of the habitat. Based on the similarity coefficient, the differences between dominant plant communities were significant at different groundwater depths. Compared with other results relating to desert vegetation and groundwater depth, variations of community distribution were similar at the large spatial scale. However, in this extremely arid region, there were significant differences in community type and community succession when compared with other arid regions, especially in relationship to deep groundwater depth. With groundwater depth from deep to shallow, communities transformed with the sequence of Alhagi communities, Tamarix spp. communities, Populus communities, Phragmites communities, and Sophora communities. At groundwater depth of less than 6.0 m, the community type and composition changed, and the species diversity increased. Among these dominant species, Tamarix exhibited the biggest efficiency in resource utilization according to niche breadth, which means it possessed the best adaptability to environmental conditions at the oasis margins.

关键词： groundwater depth community characteristic niche breadth oases Taklamakan desert

HIV protease:late action to prevent immune detection

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Signal Transduction and Targeted Therapy 2021年第5期6卷 1408-1409页

作者： Konstantin m.J.Sparrer frank Kirchhoff Institute of molecular Virology Ulm University Medical CenterUlmGermany

A recent study published in Science by Wang and colleagues shows that premature activation of the HIV-1 protease leads to caspase activation and recruitment domain 8(CARD8)inflammasome-mediated pyroptosis of infected macrophages and CD4+T cells(Fig.1).These findings might help to improve approaches aiming to eliminate the latent viral reservoirs upon HIV-1 *** invading viral pathogens trigger the innate immune system and are usually rapidly controlled and eventually *** sense viral intruders via so-called pattern recognition receptors(PRRs)capable of detecting pathogen-associated molecular patterns(PAmPs)allowing discrimination between self and *** many cases,these patterns are viral nucleic acids that show pathogen-specific structures or emerge at the wrong localization in the ***,activation of PRRs by their respective ligands leads to the induction of various anti-viral signaling cascades,among them the inflammasome.

关键词： eventually action eliminate

Endoscopic papillectomy: Data of a prospective observational study

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World Journal of Gastroenterology 2013年第27期19卷 4316-4324页

作者： Uwe Will Anne-Kathrin müller frank Fueldner Igor Wanzar frank meyer Department of Gastroenterology Municipal Hospital Department of Surgery University Hospital

AIm:To investigate the clinical value of endoscopic papillectomy indicated by feasibility and safety of the procedure in various diseases of the papilla in a representative number of patients in a setting of daily clinical and endoscopic practice and care by means of a systematic prospective observational study. mETHODS:Through a defined time period, all consecutive patients with tumor-like lesions of the papilla, who were considered for papillectomy, were enrolled in this systematic bicenter prospective observational study, and subdivided into 4 groups according to endoscopic and endoscopic ultrasonography (EUS) findings as well as histopathological diagnosis:adenoma; carcinoma/ neuroendocrine tumor (NET)/lymphoma; papilla into which catheter can not be introduced; adenomyomatosis, respectively. Treatment results and outcome were characterized by R0 resection, complication, recurrence rates and tumor-free ***:Over a 7-year period, 58 patients underwent endoscopic papillectomy. main symptoms prompting to diagnostic measures were unclear abdominal pain in 50% and cholestasis with and without pain in 44%. Overall, 54/58 patients [inclusion rate, 93.1%; sex ratio, males/females = 25/29 (1:1.16); mean age, 65 (range, 22-88) years] were enrolled in the study. Prior to papillectomy, EUS was performed in 79.6% (n = 43/54). Group 1 (adenoma, n = 24/54; 44.4%):91.6% (n = 22/24) with R0 resection; tumor-free survival after a mean of 18.5 mo, 86.4% (n = 19/22); recurrence, 13.6% (n = 3/22); minor complications, 12.5% (n = 3/24). Group 2 (carcinoma/NET/lymphoma, n = 18/54; 33.3%):75.0% (n = 10/18) with R0 resection; tumor-free survival after a mean of 18.5 (range, 1-84) mo, 88.9% (n = 8/9); recurrence, 11.1% (n = 1/9). Group 3 (adenomyomatosis, n = 4/54; 7.4%). Group 4 (primarily no introducible catheter into the papilla, n = 8; 14.8%). The overall complication rate was 18.5% (n = 10/54; 1 subject with 2 complications):Bleeding, n = 3; pancreatitis, n = 7; perforat

关键词： Papilla of Vater Papillectomy Endoscopic ultrasonography Adenoma Carcinoma Carcinoid-like tumor Adenomyomatosis

Selective Suspension in Aqueous Sodium Dodecyl Sulfate According to Electronic Structure Type Allows Simple Separation of metallic from Semiconducting Single-Walled Carbon Nanotubes

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Nano Research 2009年第8期2卷 599-606页

作者： Kai moshammer frank Hennrich manfred m.Kappes Forschungszentrum Karlsruhe Institut für NanotechnologieD-76021 KarlsruheGermany Institut für Physikalische Chemie Universität KarlsruheD-76128 KarlsruheGermany

Both density gradient centrifugation and gel electrophoresis have been reported to allow high throughput separation of metallic from semiconducting single-walled carbon nanotubes(SWNTs)when using aqueous sodium dodecyl sulphate(SDS)*** show here that both methods rely on an initial dispersion-by-sonication step,which is already selective with respect to electronic structure *** corresponding aqueous SDS“starting”suspensions obtained after sonication and purifi cation by simple centrifugation(70,000 g,1 h)contain semiconducting SWNTs primarily in the form of small bundles whereas metallic SWNTs are predominantly suspended as individual *** gradient centrifugation then separates the bundles from the individual tubes on the basis of differences in their overall buoyant *** electrophoresis separates the longer bundles from the shorter individual tubes on the basis of their different *** also demonstrate that such starting suspensions can be fractionated according to electronic structure type by even simpler techniques such as size exclusion chromatography or gel fi ltration,thus opening the way for simple scale-up.

关键词： Single-walled carbon nanotubes metallic–semiconducting separation electrophoresis density gradient centrifugation size exclusion chromatography

From basic properties to the mott design of correlated delafossites

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npj Computational materials 2021年第1期7卷 1084-1100页

作者： frank Lechermann European XFEL SchenefeldGermany Center for Computational Quantum Physics Flatiron InstituteNew YorkNYUSA

The natural-heterostructure concept realized in delafossites highlights these layered *** metallic,band-or mott-insulating character may be associated with individual layers,inter-layer coupling still plays a decisive *** review the correlated electronic structure of PdCoO_(2),PdCrO_(2),and AgCrO_(2),showing that layer-entangled electronic states can deviate from standard classifications of interacting *** finding opens up possibilities for materials design in a subtle mott-critical *** Hidden-mott physics,correlation-induced semimetallicity,or Dirac/flat-band dispersions in a mott background are emerging *** with achievements in the experimental preparation,this inaugurates an exciting research field in the arena of correlated materials.

关键词： materials metallic showing