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On the study of ricochet and penetration in sand,water and gelatin by spheres,7.62 mm APM2,and 25 mm projectiles

Defence Technology（防务技术） 2016年第2期12卷 159-170页

作者： John F.MOXNES ∅yvind fr∅yland Stian SKRIUDALEN Anne K.PRYTZ Jan A.TELAND Eva frIIS Gard ∅DEGARDSTUEN Land Systems Division Norwegian Defence Research EstablishmentP.O.Box 25N0-2027 KjellerNorway Nammo Raufoss AS P.O.Box 162N0-2831 RaufossNorway

We examine the ricochet and penetration behavior in sand, water and gelatin by steel spheres, 7.62 mm APM2 and 25 mm projectiles. A threshold impact angle(critical angle) exists beyond which ricochet cannot occur. The Autodyn simulation code with the smooth particle hydrodynamic(SPH) method and Impetus Afea Solver with the corpuscular model are used and the results are compared with experimental and analytical results. The resistance force in sand for spheres was proportional to a term quadratic in velocity plus a term linear in velocity. The drag coefficient for the quadratic term was 0.65. The Autodyn and Impetus Afea codes simulate too large penetration due to the lack of a linear velocity resistance force. Critical ricochet angles were consistent with analytical results in the literature. In ballistic gelatin at velocities of 50–850 m/s a drag coefficient of 0.30 fits the high speed camera recordings if a linear velocity resistance term is included. However, only a quadratic velocity resistance force with drag coefficient that varies with the Reynolds number also fits the measurements. The simulation of a sphere in water with Autodyn showed too large drag coefficient. The 7.62 mm APM2 core simulations in sand fit reasonable well for both codes. The 25 mm projectile ricochet simulations in sand show consistency with the high speed camera recordings. Computer time was reduced by one to two orders of magnitudes when applying the Impetus Afea Solver compared to Autodyn code due to the use of the graphics processing units(GPU).

关键词：明胶微球渗透行为炮弹光滑粒子流体动力学阻力系数模拟显示高速摄像机砂

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Strain rate dependency and fragmentation pattern of expanding warheads

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Defence Technology（防务技术） 2015年第1期11卷 1-9页

作者： John F.MOXNES Anne K.PRYTZ Фyvind fr?yland Stian SKRIUDALEN Steinar BФRVE Gard ФDEGARDSTUEN Land Systems Division Norwegian Defence Research Establishment (FFI) P.O.Box 25 NO-2027 Kjeller Norway Nammo Raufoss AS P.O.Box 162 NO-2831 Raufoss Norway

For the characterization of the behaviors of a metal material in events like expanding warheads, it is necessary to know its strength and ductility at high strain rates, around 104e105/s. The flyer plate impact testing produces the uniform stress and strain rates but the testing is expensive. The Taylor test is relatively inexpensive but produces non-uniform stress and strain fields, and the results are not so easily inferred for material modeling. In the split-Hopkinson bar(SHB), which may be used in compression, tension and torsion testing, the strain rates never exceeds 103/s. In the present work, we use the expanding ring test where the strain rate is 104e105/s. A streak camera is used to examine the expanding ring velocity, and a water tank is used to collect the fragments. The experimental results are compared with the numerical simulations using the hydrocodes AUTODYN, IMPETUS Afea and a regularized smooth particle(RSPH) software. The number of fragments increases with the increase in the expansion velocity of the rings. The number of fragments is similar to the experimental results. The RSPH software shows much the same results as the AUTODYN where the Lagrangian solver is used for the ring. The IMPETUS Afea solver shows a somewhat different fragmentation characteristic due to the node splitting algorithm that induces pronounced tensile splitting.

关键词： Warhead fragmentation Simulation fracture model Expanding ring

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Projected area and drag coefficient of high velocity irregular fragments that rotate or tumble

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Defence Technology（防务技术） 2017年第4期13卷 269-280页

作者： John F. Moxnes 0yvind fr0 yland Ivar J. 0ye Tom I. Brate Eva friis Gard 0degardstuen Tallak H. Risdal Norwegian Defence Research Establishment Land Systems Division P.O. Box 25 2027 Kjeller Norway Nammo Raufoss AS P.O. Box 162 2831 Raufoss Norway HPVisTech AS Bj0rnstadgutua 21 2092 Minnesund Norway

3 degrees of freedom(DOF)exterior ballistic computer models are used in fragment studies to calculate individual trajectories of each fragment based on drag coefficient and the projected(presented)area in the direction of velocity of center of *** expectation of a randomly distributed projected area is commonly used for fragments that tumble(random rotation)during *** forecast a model where the expected drag coefficient is dependent of shape and Mach *** or tumbling only affects the expected projected *** of projected areas during tumbling and rotation are *** examination of the data by Mc Cleskey(1988)indicates that the volume of the fragment to the power of2/3 is a better parameter to characterize the drag coefficient of the fragments than the maximum projected *** simulations are used to verify results and to study projected area and drag coefficient of fragments.

关键词： fragments Form factor Mach number Drag coefficient Cauchy area Tumbling

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Experimental and numerical study of the fragmentation of expanding warhead casings by using different numerical codes and solution techniques

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Defence Technology（防务技术） 2014年第2期10卷 161-176页

作者： John F.MOXNES Anne K.PRYTZ фyvind frфyland Siri KLOKKEHAUG Stian SKRIUDALEN Eva frIIS Jan A.TELAND Cato DФRUM Gard ФDEGARDSTUEN Land Systems Division.Norwegian Defence Research Establishment P.O.Box 25 Nammo Raufoss AS.P.O.Box 162

There has been increasing interest in numerical simulations of fragmentation of expanding warheads in *** there is a pressure on developers of leading commercial codes,such as *** and IMPETUS *** implement the reliable fracture models and the efficient solution *** applicability of the Johnson—Cook strength and fracture model is evaluated by comparing the fracture behaviour of an expanding steel casing of a warhead with *** numerical codes and different numerical solution techniques,such as Eulerian,*** particle hydrodynamics(SPH).and the corpuscular models recently implemented in IMPETUS Afea are *** the same solution techniques and material models we find that the codes give similar *** SPH technique and the corpuscular technique are superior to the Eulerian technique and the Lagrangian technique(with erosion) when it is applied to materials that have fluid like behaviour such as the explosive and the *** Eulerian technique gives much larger calculation time and both the Lagrangian and Eulerian techniques seem to give less agreement with our *** more correctly simulate the fracture behaviours of the expanding steel casing,we applied that ductility decreases with strain *** phenomena may be explained by the realization of adiabatic shear *** implemented node splitting algorithm in IMPETUS Afea seems very promising.

关键词：技术试验数字代码数值模拟弹头光滑粒子流体动力学 LS-DYNA 外壳数值求解方法

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Two imprinted genes primed by DEMETER in the central cell and activated by WRKY10 in the endosperm

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Journal of Genetics and Genomics 2024年第8期51卷 855-865页

作者： Ke Yang Yuling Tang Yue Li Wenbin Guo Zhengdao Hu Xuanpeng Wang frédéric Berger Jing Li College of Life Science and Technology Huazhong Agricultural UniversityWuhanHubei 430070China Sanya Institute of Breeding and Multiplication Hainan UniversitySanyaHainan 572025China School of Tropical Agriculture and Forestry Hainan UniversityHaikouHainan 570228China Hainan Yazhou Bay Seed Laboratory SanyaHainan 572025China Gregor Mendel Institute Austrian Academy of SciencesVienna BioCenter1030 ViennaAustria

The early development of the endosperm is crucial for balancing the allocation of maternal nutrients to *** process is believed to be evolutionarily associated with genomic imprinting,resulting in parentally biased allelic gene *** Fertilization Independent Seed(FIS)genes,the number of imprinted genes involved in early endosperm development and seed size determination remains *** study introduces early endosperm-expressed HAIKU(IKU)downstream Candidate F-box 1(ICF1)and ICF2 as maternally expressed imprinted genes(MEGs)in Arabidopsis *** these genes are also demethylated by DEMETER(DME)in the central cell,their activation differs from the direct DME-mediated activation seen in classical MEGs such as the FIS ***,ICF maternal alleles carry pre-established hypomethylation in their promoters,priming them for activation by the WRKY10 transcription factor in the *** the contrary,paternal alleles are predominantly suppressed by CG ***,we find that ICF genes partially contribute to the small seed size observed in iku *** discovery reveals a two-step regulatory mechanism that highlights the important role of conventional transcription factors in the activation of imprinted genes,which was previously not fully ***,the mechanism provides a new dimension to understand the transcriptional regulation of imprinting in plant reproduction and development.

关键词： Imprinting Epigenetics DNAmethylation Seedsize Endosperm

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Parallelization of frequency domain quantum gates:manipulation and distribution of frequency-entangled photon pairs generated by a 21 GHz silicon microresonator

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Advanced Photonics 2024年第3期6卷 60-69页

作者： Antoine Henry Dario A.Fioretto Lorenzo M.Procopio Stéphane Monfray frédéric Boeuf Laurent Vivien Eric Cassan Carlos Alonzo-Ramos Kamel Bencheikh Isabelle Zaquine Nadia Belabas Institut Polytechnique de Paris LTCI Université Paris-Saclay CNRS Centre for Nanosciences and Nanotechnology Weizmann Institute of Science STMicroelectronics SAS

Harnessing the frequency dimension in integrated photonics offers key advantages in terms of scalability, noise resilience, parallelization, and compatibility with telecom multiplexing *** ring resonators have been used to generate frequency-entangled states through spontaneous four-wave mixing. However, state-of-the-art integrated resonators are limited by trade-offs among size,spectral separation, and efficient photon pair generation. We have developed silicon ring resonators with a footprint below 0.05 mm2providing more than 70 frequency channels separated by 21 GHz. We exploit the narrow frequency separation to parallelize and independently control 34 single qubit-gates with a single set of three off-the-shelf electro-optic devices. We fully characterize 17 frequency-bin maximally entangled qubit pairs by performing quantum state tomography. We demonstrate for the first time, we believe, a fully connected five-user quantum network in the frequency domain. These results are a step towards a generation of quantum circuits implemented with scalable silicon photonics technology, for applications in quantum computing and secure communications.

关键词： frequency domain integrated photonics quantum gates quantum networks

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Dynamic of Scalar Bosons in Aharonov-Bohm Magnetic Field

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Journal of Applied Mathematics and Physics 2024年第1期12卷 268-276页

作者： frédéric D. Y. Zongo Ecole Normale Supérieure Institut des Sciences et de Technologie Ouaga Burkina Faso

We study the dynamic of scalar bosons in the presence of Aharonov-Bohm magnetic field. First, we give the differential equation that governs this dynamic. Secondly, we use variational techniques to show that the following Schrödinger-Newton equation: , where A is an Aharonov-Bohm magnetic potential, has a unique ground-state solution.

关键词： Scalar Boson Aharonov-Bohm Magnetic Field Schrödinger-Newton Equation Ground-State Solution

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Pathological and Clinical Correlation European Union-Thyroid Imaging Reporting and Data System (EU-TIRADS) Classification of Thyroid Nodules in Two University Hospitals in Cotonou

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Open Journal of Endocrine and Metabolic Diseases 2024年第2期14卷 15-25页

作者： Annelie Kerekou Hode Hubert Dedjan fréjus Alamou Department of Endocrinology Metabolism Nutrition of National University Hospital Center-Hubert Koutoukou Maga Cotonou Bénin Department of Medicine and Medical Specialties of the Departemental University Hospital Center of Ouémé/Plateau Porto-Novo Bénin

Introduction: Since its creation in 2017 by the European community, the EU-TIRADS classification has enjoyed an excellent reputation in several countries around the world. Indeed, several studies conducted in these countries testify to the effectiveness of this tool for the management of nodular thyroid pathology. However, in Benin, the contribution of this classification has not yet been evaluated. It is therefore to overcome this inadequacy that we undertook this study. Objective: Participate in improving the diagnostic and therapeutic management of thyroid nodules at the CNHU HKM in Cotonou and at the CHUZ in Suru-Léré. Methods: This is a cross-sectional study with retrospective data collection spread over a period of 3 years 5 months, from January 2019 to May 2022 and carried out jointly in the Endocrinology Metabolism Nutrition and ORL-CCF departments of the CNHU HKM of Cotonou and in the ORL-CCF department of the CHUZ of Suru-Léré. The study population consisted of patients who consulted the University Clinic of Endocrinology Metabolism Nutrition, the University Clinic of ORL-CCF of the CNHU-HKM and the University Clinic of ORL-CCF of the CHUZ of Suru-Léré for thyroid nodule and who have had surgery. The study data was collected from patients hospitalization records using a survey form. Results: On ultrasound, according to the EU-TIRADS classification, 56.8% of nodules presented a low risk of malignancy (EU-TIRADS 3) compared to respectively 19.8%;23% and 2.5% of nodules with zero (EU-TIRADS 2), intermediate (EU-TIRADS 4) and high (EU-TIRADS 5) risk of malignancy. Regarding the performance of this classification, it is sensitive in 37.5% of cases and has a specificity of 78.5% with a PPV (Positive Predictive Value) and a NPV (Negative Predictive Value) respectively of 6.6 % and 91.6%. Furthermore, the bivariate correlations revealed that the size of the nodule was significantly associated with the malignancy of the nodule (p = 0.014) and the calculated value o

关键词： Thyroid Nodules EU-TIRADS Classification Malignancy

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A study on wildfire impacts on greenhouse gas emissions and regional air quality in South of Orléans,france

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Journal of Environmental Sciences 2024年第1期135卷 521-533页

作者： Chaoyang Xue Gisèle Krysztofiak Yangang Ren Min Cai Patrick Mercier frédéric Le Fur Corinne Robin Benoit Grosselin Véronique Daele Max RMcGillen Yujing Mu Valéry Catoire Abdelwahid Mellouki Laboratoire de Physique et Chimie de l’Environnement et de l’Espace(LPC2E) CNRS–UniversitéOrléans–CNES(UMR 7328)Orléans Cedex 245071France Institut de Combustion AérothermiqueRéactivitéEnvironnement(ICARE)CNRSOrléans Cedex 245071France Research Centre for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Lig’Air-Association de surveillance de la qualitéde l’air en région Centre-Val de Loire Saint-Cyr-en-Val 45590France Mohammed V University RabatMorocco

Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global *** September 2020,a small wildfire(burned area:36.3 ha)event occurred in Souesmes(Loiret-Cher,Sologne,france),and its plume spread out over 200 km on the following day as observed by the MODIS *** on measurements at a suburban site(~50 km northwest of the fire location)in Orléans and backward trajectory analysis,young wildfire plumes were *** increases in gaseous pollutants(CO,CH_(4),N_(2)O,VOCs,etc.)and particles(including black carbon)were found within the wildfire plumes,leading to a reduced air *** factors,defined as EF(X)=ΔX/ΔCO(where,X represents the target species),of various trace gases and black carbon within the young wildfire plumes were determined accordingly and compared with previous *** in the ambient ions(such as ammonium,sulfate,nitrate,chloride,and nitrite in the particle-and gasphase)and aerosol properties(e.g.,aerosol water content,aerosol p H)were also quantified and ***,we estimated the total carbon and climate-related species(e.g.,CO_(2),CH_(4),N_(2)O,and BC)emissions and compared them with fire emission *** biomass burning emission inventories have uncertainties in estimating small fire burned areas and *** instance,we found that the Global Fire Assimilation System(GFAS)may underestimate emissions(e.g.,CO)of this small wildfire while other inventories(GFED and FINN)showed significant *** that it is the first time to record wildfire plumes in this region,related atmospheric implications are presented and discussed.

关键词： Wildfire Air quality Emission factor Emission inventory VOLTAIRE supersite

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Existence of Entropy Solution for Degenerate Parabolic-Hyperbolic Problem Involving p(x)-Laplacian with Neumann Boundary Condition

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Applied Mathematics 2024年第7期15卷 455-463页

作者： Mohamed Karimou Gazibo Duni Yegbonoma frédéric Zongo Laboratoire de Mathmatiques Fondamentales et Applications (LMFA) Dpartement de Mathmatiques cole Normale Suprieure Universit Abdou Moumouni de Niamey Niamey Niger Laboratoire Interdisciplinaire de Recherche en Sciences Appliques (LIRSA) cole Normale Suprieure Burkina Faso

We consider a strongly non-linear degenerate parabolic-hyperbolic problem with p(x)-Laplacian diffusion flux function. We propose an entropy formulation and prove the existence of an entropy solution.

关键词： Lebesgue and Sobolev Spaces with Variable Exponent Weak Solution Entropy Solution Degenerate Parabolic-Hyperbolic Equation Conservation Law Leray Lions Type Operator Neumann Boundary Condition Existence Result

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