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Effect of cylinder wall parameters on the final packing density of mono-disperse spheres subject to three-dimensional vibrations Author links open overlay panel

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Particuology 2024年第8期91卷 211-225页

作者： jack R.Grogan Andrei L.Nicuşan Christopher R.K.Windows-Yule School of Chemical Engineering The University of BirminghamEdgbastonBirminghamB152TTUK

Achieving densely packed particles is desirable within the industries of ceramics,pharmaceuticals,defence and additive *** this work,we use the discrete element method(DEM)to determine the effect of wall parameters on the final packing density of mono-disperse spheres subject to 4 varying three-dimensional vibration and fill *** focus specifically on the impact of the container wall parameters on the particles'final packing *** on from the validation of the DEM simulation the particle-wall coefficient of restitution,the particle-wall coefficient of rolling friction and the particle-wall coefficient of sliding friction were varied individually and the effect on the final packing density *** relatively low particle-particle friction glass beads,the effect of these wall properties had no discernible effect on the final packing density *** on from these findings the particle-wall properties were varied at the extreme values of particle-particle coefficient of rolling friction and particle-particle coefficient of sliding *** a particle-particle coefficient of sliding friction=1,increases in particle-wall coefficient of restitution resulted in a minor increase in the final packing density of particles though this was not statistically *** a particle-particle coefficient of sliding friction=1,increases in particle-wall coefficient of rolling friction resulted in a minor decrease in the final packing density of the particles though again not to a degree where the trend can,with complete certainty,be distinguished from the random error across the ***,when the particle-particle coefficient of sliding friction=1,increases in particle-wall coefficient of sliding friction resulted in a significant decrease in the final packing density of *** decrease was attributed to the propagation of force chains throughout the *** significant decrease in final packing density with

关键词： Vibropacking Packing Densification Vibration Discrete element method Friction Wall friction Restitution

Application of the Shrinking Particle Model for the Evaluation of Molecular Recyclability of PET versus Semi-Aromatic Polyesters

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Open Journal of Physical Chemistry 2024年第2期14卷 21-35页

作者： jack van Schijndel Sanne de Krom Dennis Molendijk Koen van beurden Amarante böttger Research Group biopolymers/Green Chemistry Centre of Expertise Safe & Resilient Society Avans University of Applied Science Breda Netherlands New Materials and Their Applications Centre of Expertise Safe & Resilient Society Avans University of Applied Science Breda Netherlands Department of Materials Science and Engineering Delft University of Technology Delft Netherlands

The molecular recyclability of poly (ethylene terephthalate) (PET) and three semi-aromatic polyesters poly (phloretic acid) (poly-H), poly (dihydroferulic acid) (poly-G), and poly (dihydrosinapinic acid) (poly-S) is evaluated in this study. PET is an extensively used aromatic polyester, and poly-H, poly-G, and poly-S can be considered semi-aromatic poly (lactic acid) modifications. All these polyesters have been depolymerized at neutral pH and by acid- and base-catalyzed hydrolysis at two temperatures, i.e., 50˚C and 80˚C. base-catalyzed depolymerization of virgin PET leads to an isolated yield of 38% after 48 hours of reaction at 80˚C. Contrary to these results for PET, almost all the monomers of the semi-aromatic polyesters poly-H, poly-G, and poly-S are recovered with isolated yields larger than 90% at the same temperature after 15 minutes in a facile manner. A shrinking particle model used to determine the global kinetics of the base-catalyzed depolymerization showed that the rate rises with increasing temperature. Using the shrinking particle model, the intrinsic reaction rate constants were determined. It has been demonstrated that the rate coefficients of the depolymerization of the semi-aromatic polyesters poly-H, poly-G, and poly-S are between 2 and 3 orders of magnitude higher than those for PET.

关键词： Depolymerization Molecular Recycling Poly-H Poly-G Poly-S PET Circular Polymers

Confirmation of a Sub-Saturn-size Transiting Exoplanet Orbiting a G Dwarf:TOI-1194 b and a Very Low Mass Companion Star: TOI-1251 b from TESS

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Research in Astronomy and Astrophysics 2024年第3期24卷 129-143页

作者： Jia-Qi Wang Xiao-Jun Jiang Jie Zheng Hanna Kellermann Arno Riffeser Liang Wang Karen A.Collins Allyson bieryla Lars A.buchhave steve b.Howell Elise Furlan Eric Girardin Joao Gregorio Eric Jensen Felipe Murgas Mesut Yilmaz Sam Quinn Xing Gao Ruo-Yu Zhou Frank Grupp Hui-Juan Wang CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy Of SciencesBeijing 10010China University of Chinese Academy of Sciences Beijing 100049China University Observatory Munich Scheinertrsse 1.D-81679 MunichGemany Max Planck Institute for Extraterrestrial Physics Giessenbachstr.1D-85748 GarchingGermany National Astronomical Observatories/Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing210042China CAS Key Laboratory of Astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China Center for Astrophysics Harvard&Smithsonian60 Garden Street.CambridgeMA 02138USA National Space Institute Technical University of DenmarkElektrovejDK-2800 KgsLyngbyDenmark NASA Ames Research Center Moffett FieldCA 94035USA NASA Exoplanet Science Institute Caltech/IPACMail Code 100-221200 E.California Blvd.PasadenaCA91125USA Grand Pra Observatory Switzerland Department of Physics Washington UniversitySt.LouisMO 63130.USA Department of Physics and Astronomy Swarthmore CollegeSwarthmorePA 19081USA Instituto de Astrofísica de Canarias(IAC) E-38205 La Laguna.TenerifeSpain Departamento de Astrofísica Universidad de La LagunaSpain Dept.of Astronomy and Space Sciences Ankara UniversityTandogan 06100AnkaraTurkey Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Urumqi No.1 Senior High School Urumqi 830002China Lijiang Gemini Observatory Lijiang 674199China

We report the confirmation of a sub-Saturn-size exoplanet,TOI-1194 b,with a mass of about 0.456+0.055-0.051M_(J),and a very low mass companion star with a mass of about 96.5±1.5 MJ,TOI-1251 *** candidates provided by the Transiting Exoplanet Survey Satellite(TESS)are suitable for further follow-up observations by ground-based telescopes with small and medium *** analysis is performed based on data from several telescopes worldwide,including telescopes in the Sino-German multiband photometric campaign,which aimed at confirming TESS Objects of Interest(TOIs)using ground-based small-aperture and medium-aperture telescopes,especially for long-period ***-1194 b is confirmed based on the consistent periodic transit depths from the multiband photometric *** measure an orbital period of 2.310644±0.000001 days,the radius is 0.767+0.045-0.041RJ and the amplitude of the RV curve is 69.4_(-7.3)^(+7.9)m s^(-1).TOI-1251 b is confirmed based on the multiband photometric and high-resolution spectroscopic data,whose orbital period is 5.963054+0.000002-0.000001days,radius is 0.947+0.035-0.033 R_(J) and amplitude of the RV curve is 9849_(-40)^(+42)ms^(-1).

关键词： planets and satellites fundamental parameters-planets and satellites gaseous planets-stars fundamental parameters-stars low-mass-methods data analysis-techniques photometric-techniques spectroscopic

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微塑料和纳米塑料威胁青藏高原环境

Science bulletin 2024年第5期69卷 589-592页

作者：张玉兰康世昌罗犀 Tanuj Shukla 高坛光 Deonie Allen steve Allen Melanie bergmann State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China College of Earth and Environmental Sciences Lanzhou UniversityLanzhou 730000China School of Geography Earth and Environmental SciencesUniversity of BirminghamBirmingham 200003UK Ocean Frontiers Institute Dalhousie UniversityHalifax B3H 4R2Canada Alfred-Wegener-Institut Helmholtz-Zentrum für Polar-und Meeresforschung Bremerhaven D-27515Germany University of Chinese Academy of Sciences Beijing 100049China

Plastic pollution is a planetary level threat which affects Earth’s environment and *** the poles to deep ocean basins,the growth of plastic waste has already exceeded its *** projected increase of plastic production and waste generation over the coming years makes the situation even more *** after stagnation in 2020 due to the COVID-19 pandemic,the global plastic production has also increased from 335 to 391 million metric tons(Mt)between 2016 and 2021(Fig.S1 online);yet currently post-consumer recycled and bio-based/attributed plastics only accounts~9%of the world’s plastic production[1].Statistically.

关键词：微塑料 attributed plastics

Principles to Support Modular Software Construction

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Journal of Computer Science & Technology 2017年第1期32卷 3-10页

作者： jack b. Dennis Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge MA 02139 U.S.A.

The construction of large software systems is always achieved through assembly of independently written components -- program modules. For these software components to work together, they must share a common set of data types and principles for representing structured data such as arrays of values and files. This common set of tools for creating and operating on data objects is provided by the infrastructure of the computer system： the hardware, operating system and runtime code. because the nature and properties of these tools are crucial for correct operation of software components and their inter-operation, it is essential to have a precise specification that may be used for verifying correctness of application software on one hand, and to verify correctness of system behavior on the other. We call such a specification a program execution model （PXM）. It is evident that the properties of the PXM implemented by a computer system can have serious impact on the ability of application programmers to practice modular software construction. This paper discusses the concept of program execution models and presents a set of principles that a PXM must satisfy to provide a sound basis for modular software construction. because parallel program execution on computer systems with many processing units is an essential part of contemporary computing environments, the expression of parallelism and modular software construction using components involving parallel operations is included in this treatment. The conclusion is that it is possible to build computer systems that implement a PXM within which any parallel program may be used, unmodified, as a component for building more substantial parallel programs.

关键词： program execution model data flow model codelet abstract architecture parallel computing

Emphysematous Cystitis: Report of Two Cases and Review of the Literature

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Health 2024年第4期16卷 309-318页

作者： Roland bertile banga-Mouss Nestor Ghislain Andzouana Mbamognoua Yanick Dimi Nyanga Armel Melvin Atipo Ondongo steve Aristid Ondziel-Opara Raïssa Laure Mayanda Ohouanda Nick Arnaud Monabeka Evariste bouenizabila Anani Séverin Wences Odzébé Prosper Alain bouya Urology Department University Hospital of Brazzaville Brazzaville Republic of the Congo Faculty of Health Sciences Marien Ngouabi University Brazzaville Republic of the Congo Department of Metabolic and Endocrine Diseases University Hospital of Brazzaville Brazzaville Republic of the Congo

Emphysematous cystitis is a rare complication of lower urinary tract infection whose prognosis is conditioned by the delay in treatment. The predisposition of diabetic patients to urinary infections caused by gas-producing bacteria is considered one of the most common factors in the occurrence of emphysematous cystitis. The currently recommended diagnostic test is CT scanning, which has definite value in assessing gas accumulation in the bladder wall and lumen. The authors report the observations of two patients aged 68 and 80 who were treated for emphysematous cystitis complicating diabetes mellitus. The evolution was favorable under treatment with antibiotic therapy, insulin therapy and bladder drainage.

关键词： Emphysematous Cystitis Computed Tomography Lower Urinary Tract Infection Diabetes Mellitus

Management of Testicular Cancers in brazzaville

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Open Journal of Urology 2024年第5期14卷 324-332页

作者： Roland bertile banga-Mouss Yanick Dimi Nyanga brice Nkoua Epala Armel Melvin Atipo Ondongo steve Aristid Ondziel-Opara Eliane Ndounga Alexis bolenga Louis Constant Mbele Mantsouaka Judith Nsonde Malanda Aanani Séverin Wencesl Odzébé Prosper Alain bouya Departement of Urology and Andrology University Hospital of Brazzaville Brazzaville Republic of the Congo Departement of Medicale Oncology and Radiotherapy University Hospital of Brazzaville Brazzaville Republic of the Congo

Introduction: Testicular cancer accounts for 5% of urological tumors, predominantly affecting young men. The aim of our study was to report the diagnostic and evolutionary aspects of testicular cancer cases treated in our center. Patients and Methods: A retrospective study conducted over a 15-year period involving 12 patients treated for testicular cancer at the University Hospital of brazzaville. Results: The median age was 31 years (range 11 to 49 years), with a median consultation delay of 10.6 months (range 3 to 27 months). Scrotal mass was the most common reason for consultation. Cancer was bilateral in two patients. Two patients were admitted with metastatic disease. Histopathological examination favored germ cell tumors in 7 cases, two cases of non-Hodgkin’s malignant lymphoma, and one case of epididymo-testicular adenocarcinoma. Adjuvant chemotherapy resulted in complete remission in patients with germ cell tumors. However, neoadjuvant chemotherapy was not effective in patients admitted with advanced-stage disease. Conclusion: Testicular cancer is a rare condition that is curable in the majority of cases, but its management is often complicated in our setting due to delayed diagnosis caused by taboos surrounding genital organ pathologies.

关键词： Testicular Cancer Germ Cell Tumor Cisplatin Testicular Lymphoma Testicular Adenocarcinoma

The impact of attractants on pocket gopher trapping

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Current Zoology 2014年第4期60卷 472-478页

作者： Roger A. bALDWIN Ryan MEINERZ steve b. ORLOFF Department of Wildlife Fish and Conservation Biology University of California-Davis Davis CA 95616 USA University of California Cooperative Extension 1655 South Main Street Yreka CA 96097 USA

Pocket gophers （Geomyidae） have an extensive impact on both natural and agricultural systems. Trapping is a tech- nique often used to sample and manage these populations. The identification of an attractant that increases capture rates of pocket gophers would greatly assist researchers and pest management professionals alike. Therefore, we tested the attractiveness of four attractants （peanut butter, anise, grapefruit attractant, and carrot） plus a control （no attractant） using uncovered and covered trap sets to determine what impact they have on visitation and capture rates of pocket gophers. We also determined how the impact of cover status and attractants differ across varying weights and gender of pocket gophers. We found no direct effect of any attracrant on visitation and capture rates of pocket gophers, nor on the gender of captured individuals. However, when no attractant was used, the mtmber of pocket gophers captured per 100 trap nights was greater when trap sets were uncovered vs. when covered, and capture rates were generally high and consistent when using peanut butter as an attractant. Additionally, we noted that covered trap sets that were baited with peanut butter yielded heavier pocket gopher captures than uncovered trap sets using this same attractant. This is key, given the difficulty associated with capturing older, more experienced individuals. Combined with data from a previous investigation, this suggests that there is no advantage to using any attractant when utilizing uncovered trap sets, but there is likely some benefit to using peanut butter in covered trap sets [Current Zoology 60 （4）： 472-478, 2014].

关键词： Attractant Demographics Pocket gopher Thomomys bottae Thomomys talpoides Trapping

New Opportunities for Lanthanide Luminescence

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Journal of Rare Earths 2007年第3期25卷 257-274页

作者： Jean-Claude G. bünzli steve Comby Anne-Sophie Chauvin Caroline D. b. Vandevyver Laboratory of Lanthanide Supramolecular Chemistry Ecole Polytechnique Fédérale de Lausanne BCH 1402 CH-1015 Lausanne Switzerland

Trivalent lanthanide ions display fascinating optical properties. The discovery of the corresponding elements and their first industrial uses were intimately linked to their optical properties. This relationship has been kept alive until today when many high-technology applications of lanthanide-containing materials such as energy-saving lighting devices, displays, optical fibers and amplifiers, lasers, responsive luminescent stains for biomedical analyses and in cellulo sensing and imaging, heavily rely on the brilliant and pure-color emission of lanthanide ions. In this review we first outlined the basics of lanthanide luminescence with emphasis on f-f transitions, the sensitization mechanisms, and the assessment of the luminescence efficiency of lanthanide-containing emissive molecular edifices. Emphasis was then put on two fast developing aspects of lanthanide luminescence： materials for telecommunications and light emitting diodes, and biomedical imaging and sensing. Recent advances in NIR-emitting materials for plastic amplifiers and waveguides were described, together with the main solutions brought by researchers to minimize non-radiative deactivation of excited states. The demonstration in 1999 that erbium tris（8-hydroxyquinolinate） displayed a bright green emission suitable for organic light emitting diodes （OLEDs） was followed by realizing that in OLEDs, 25% of the excitation energy leads to singlet states and 75% to triplet states. Since lanthanide ions are good triplet quenchers, they now also play a key role in the development of these lighting devices. Luminescence analyses of biological molecules are among the most sensitive analytical techniques known. The long lifetime of the lanthanide excited states allows time-resolved spectroscopy to be used, suppressing the sample autofluorescence and reaching very low detection limits. Not only visible lanthanide sensors are now ubiquitously provided in medical diagnosis and in cell imaging, but the feasibili

关键词： lanthanide luminescence sensitization near infrared telecommunications organic light emitting diode (OLED) time-resolved luminescence in cellulo sensing cell imaging rare earths