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Plastic deformation of a Zr-based bulk metallic glass fabricated by selective laser melting

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Journal of Materials Science & Technology 2021年第1期60卷 139-146页

作者： l.Deng K.Kosiba R.limbach l.Wondraczek u.Kühn S.Pauly IFW Dresden Institute for Complex MaterialsHelmholtzstraße 20D-01069DresdenGermany Otto Schott Institute of Materials Research University of JenaFraunhoferstraße 6D-07743JenaGermany university of Applied Sciences Aschaffenburg Würzburger Straße 45D-63743AschaffenburgGermany

Fully amorphous Zr_(52.5)Cu_(17.9)Ni_(14.6)Al_(10)Ti_(5) bulk metallic glass(BMG) samples with a relative density exceeding 98% were fabricated via selective laser melting(SlM).High fracture stresses of around1700 MPa and a reproducible plastic strain of about 0.5% were obtained for cylindrical SlM *** analysis of the observed serrations during compressive loading implies that the shear-band dynamics in the additively manufactured samples distinctly differ from those of the as-cast *** phenomenon appears to originate from the presence of uniformly dispersed spherical pores as well as from the more pronounced heterogeneity of the glass itself as revealed by instrumented *** these heterogeneities,the shear bands are straight and form in the plane of maximum shear *** manufacturing,hence,might not only allow for producing large BMG samples with complex geometries but also for manipulating their deformation behaviour through tailoring porosity and structural heterogeneity.

关键词： Powder bed fusion Selective laser melting Bulk metallic glass Serrated flow Heterogeneity

Recent advances in the understanding and management of chronic pancreatitis pain

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Journal of Pancreatology 2024年第1期7卷 35-44页

作者： Jessica Walker Olivia l.Babyok Jami l.Saloman Anna Evans Phillips Department of Internal Medicine University of Pittsburgh Medical CenterPittsburghPAUnited States Division of Gastroenterology Hepatology and NutritionDepartment of MedicineSchool of MedicineUniversity of PittsburghPittsburghPAUnited States Center for Pain Research Center for NeuroscienceSchool of MedicineUniversity of PittsburghPittsburghPAUnited States

Abdominal pain is the most common symptom of chronic pancreatitis(CP)and is often debilitating for patients and very difficult to *** date,there exists no cure for the *** strategies focus on symptom management and on mitigation of disease progression by reducing toxin exposure and avoiding recurrent inflammatory *** treatment protocols start with medical management followed by consideration of procedural or surgical intervention on selected patients with severe and persistent *** incorporation of adjuvant therapies to treat comorbidities including psychiatric disorders,exocrine pancreatic insufficiency,mineral bone disease,frailty,and mal.utrition,are in its early *** clinical studies and animal models have been designed to improve investigation into the pathophysiology of CP pain,as well as to improve pain *** the array of tools available,many therapeutic options for the management of CP pain provide incomplete *** still remains much to discover about the neural regulation of pancreas-related *** this review,we will discuss research from the last 5 years that has provided new insights into novel methods of pain phenotyping and the pathophysiology of CP *** discoveries have led to improvements in patient selection for optimization of outcomes for both medical and procedural management,and identification of potential future therapies.

关键词： Central sensitization Chronic pancreatitis Pain phenotyping Peripheral sensitization

Identification of Hammerstein systems with asymmetric dead-zone nonlinearities using canonical parameterized model

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控制理论与应用（英文版） 2012年第4期10卷 511-516页

作者： Xiaohua lü Xuemei REN School of Automation Beijing Institute of Technology

A non-iterative identification method with parameterization of the unknown dead-zone is proposed for Hammerstein systems in presence of asymmetric dead-zone nonlinearities. The canonical parameterized model which is a single expression without segmentation is utilized to describe the dead-zone, based on which a universal-type parametric model can be established to approximate the entire system. This model can be established without separating the nonlinear part from the linear part. The dead-zone parameters and the coefficients in the linear transfer function can be estimated simultaneously according to the proposed algorithm. Numerical experiments are presented to il.ustrate the effectiveness of the proposed scheme.

关键词： Hammerstein systems Asymmetric dead-zone nonlinearity Canonical parameterized model System identification

Teaching and learning Chinese through Immersion:A Case Study from the North American Context

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Frontiers of Education in China 2020年第1期15卷 99-141页

作者： Chan lÜ Department of Asian languages&literature University of WashingtonSeattleWA 98195-3521USA

With the promise of achieving bilingualism,biliteracy,and cul.ural pluralism,Chinese immersion programs for students from kindergarten to 12th grade(K-12)in North America,especially the uS,have been proliferating in the past two *** on this rapidly growing population of non-native Chinese learners is also *** research synthesis focuses on 35 selected studies published in recent years on Chinese immersion in both Chinese and English language journals and *** review found that researchers are exploring a wide range of issues with respect to language and literacy development in Chinese immersion programs,including academic achievement in English,language and literacy acquisition in Chinese,instructional strategies and classroom interaction,as well as learners’language use and its sociolinguistic *** studies reflect a growing interest in and demand for learning more about the lesser-researched Chinese foreign language(CFl)learner population,and this review concludes with suggestions for future research on Chinese immersion based on its curricular features as well as specific considerations for conducting research with young,emergent bilingual and biliterate learners.

关键词： K-12 education Chinese immersion programs Chinese as a foreign language(CFl) academic achievement bilingual and biliteracy acquisition instructional strategies classroom interaction learner language

Observation about the Classical Electromagnetic Gauge Transformation and Its Quantum Correspondence

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Journal of Modern Physics 2024年第4期15卷 474-479页

作者： Gustavo V. lópez Jorge A. lizarraga Departamento de Física Universidad de Guadalajara Guadalajara Mexico

using the landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transformation does not correspond to a one-dimensional.unitary group transformation u(1) of the wave function for the quantum case. In addition, with the re-examination of the relation between the magnetic field B and its vector potential A, we found that, in order to have a consistent formulation of the dynamics of the charged particle with both expressions, we must have that B=∇×A if and only if B≠0.

关键词： Gauge Transformation Harmonic Oscillator Quantum Hall Effect Electromagnetic Potentials

Geological reservoir and resource potential(10^(13)m^(3))of gas hydrates in the South China Sea

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China Geology 2024年第3期7卷 422-444页

作者： Pi-bo Su Wei Wei Yun-bao Sun Yao-yao lü Huai Cheng Wei-feng Han Wei Zhang Jin-qiang liang National Engineering Research Center for Gas Hydrate Exploration and Development Guangzhou 511458China Sanya Institute of South China Sea Geology Guangzhou Marine Geological SurveySanya 572025China Central laboratory of Geological Sciences Research Institute of Petroleum Exploration and DevelopmentLangfang 065007China Qingdao Institute of Marine Geology Qingdao 266237China laboratory for Marine Mineral Resources Qingdao Marine Science and Technology CenterQingdao 266237China

A detailed understanding of the distribution and potential of natural gas hydrate(NGHs)resources is crucial to fostering the industrialization of those resources in the South China Sea,where NGHs are *** this study,this study analyzed the applicability of resource evaluation methods,including the volumetric,genesis,and analogy methods,and estimated NGHs resource potential in the South China Sea by using scientific resource evaluation methods based on the factors controlling the geological accumulation and the reservoir characteristics of ***,this study compared the evaluation results of NGHs resource evaluations in representative worldwise sea areas via rational *** results of this study are as follows:(1)The gas hydrate accumulation in the South China Sea is characterized by multiple sources of gas supply,multi-channel migration,and extensive accumulation,which are significantly different from those of oil and gas and other unconventional resources.(2)The evaluation of gas hydrate resources in the South China Sea is a highly targeted,stratified,and multidisciplinary evaluation of geological resources under the framework of a multi-type gas hydrate resource evaluation system and focuses on the comprehensive utilization of multi-source heterogeneous data.(3)Global NGHs resources is n×10^(15)m^(3),while the NGHs resources in the South China Sea are estimated to be 10^(13)m^(3),which is comparable to the abundance of typical marine NGHs deposits in other parts of the *** the South China Sea,the NGHs resources have a broad prospect and provide a substantial resource base for production tests and industrialization of NGHs.

关键词： Reservoir characteristics Natural gas hydrates Gas migration Resource potential Resource evaluation methods Hierarchical evaluation system Volumetric method South China Sea Clean energy exploration engineering

DataCon:面向安全研究的多领域大规模竞赛开放数据

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信息安全学报 2024年第1期9卷 123-136页

作者：郑晓峰段海新陈震宇应凌云何直泽汤舒俊郑恩南刘保君陆超逸沈凯文张甲陈卓林子翔清华大学网络科学与网络空间研究院北京100084 奇安信科技集团北京100088

网络安全数据是开展网络安全研究、教学的重要基础资源,尤其基于实战场景下的安全数据更是科研教学成果更符合安全实践的保障。然而,由于网络安全的技术变化快、细分领域多、数据敏感等原因,寻找合适的网络安全数据一直是研究者们进行... 详细信息

网络安全数据是开展网络安全研究、教学的重要基础资源,尤其基于实战场景下的安全数据更是科研教学成果更符合安全实践的保障。然而,由于网络安全的技术变化快、细分领域多、数据敏感等原因,寻找合适的网络安全数据一直是研究者们进行科研和老师开展实践教学时关注的重要问题。本文总结并分析了多个领域的经典公开安全数据集,发现其在研究应用时存在数据旧、规模小、危害大等不足;克服安全数据领域选择、大规模实战数据获取、安全隐私开放等困难,构造了更符合当前科研需求DataCon安全数据集。数据集大规模覆盖DNS、恶意软件、加密恶意流量、僵尸网络、网络黑产等多个领域,且均来自实战化场景,并基于DataCon竞赛平台将其开放给参赛者和科研人员。目前,DataCon数据集涵盖了已成功举办四届的“DataCon大数据安全分析大赛”的全部数据,大赛被国家教育部评为优秀案例,并进入多所高校研究生加分名单,数据内容也一直随着真实网络环境中攻防场景的变化而持续更新。目前,DataCon数据集涵盖了已成功举办四届的“DataCon大数据安全分析大赛”的全部数据,大赛被国家教育部评为优秀案例,并进入多所高校研究生加分名单,数据内容也一直随着真实网络环境中攻防场景的变化而持续更新。数据集持续收到科研人员、学术的数据使用申请,支撑了多篇学术论文的发表,充分说明了其有效性和可用性。我们希望DataCon数据及竞赛能够对网络安全领域产、学、研结合有所帮助和促进。

关键词： DataCon 安全研究开放数据竞赛

A New Proof for Congruent Number’s Problem via Pythagorician Divisors

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Advances in Pure Mathematics 2024年第4期14卷 283-302页

作者： léopold Dèkpassi Keuméan François Emmanuel Tanoé uFR Mathematics and Computer Science F&#233lix Houphou&#235t Boigny University Abidjan Cote d&#8217Ivoire

Considering Pythagorician divisors theory which leads to a new parameterization, for Pythagorician triplets ( a,b,c )∈ ℕ 3∗ , we give a new proof of the well-known problem of these particular squareless numbers n∈ ℕ ∗ , called congruent numbers, characterized by the fact that there exists a right-angled triangle with rational sides: ( A α ) 2 + ( B β ) 2 = ( C γ ) 2 , such that its area Δ= 1 2 A α B β =n;or in an equivalent way, to that of the existence of numbers u 2 , V 2 , W 2 ∈ ℚ 2∗ that are in an arithmetic progression of reason n;Problem equivalent to the existence of: ( a,b,c )∈ ℕ 3∗ prime in pairs, and f∈ ℕ ∗ , such that: ( a−b 2f ) 2 , ( c 2f ) 2 , ( a+b 2f ) 2 are in an arithmetic progression of reason n;And this problem is also equivalent to that of the existence of a non-trivial primitive integer right-angled triangle: a 2 + b 2 = c 2 , such that its area Δ= 1 2 ab=n f 2 , where f∈ ℕ ∗ , and this last equation can be written as follows, when using Pythagorician divisors: (1) Δ= 1 2 ab= 2 S−1 d e ¯ ( d+ 2 S−1 e ¯ )( d+ 2 S e ¯ )=n f 2;Where ( d, e ¯ )∈ ( 2ℕ+1 ) 2 such that gcd( d, e ¯ )=1 and S∈ ℕ ∗ , where 2 S−1 , d, e ¯ , d+ 2 S−1 e ¯ , d+ 2 S e ¯ , are pairwise prime quantities (these parameters are coming from Pythagorician divisors). When n=1 , it is the case of the famous impossible problem of the integer right-angled triangle area to be a square, solved by Fermat at his time, by his famous method of infinite descent. We propose in this article a new direct proof for the numbers n=1 (resp. n=2 ) to be non-congruent numbers, based on an particular induction method of resolution of Equation (1) (note that this method is efficient too for general case of prime numbers n=p≡a ( ( mod8 ) , gcd( a,8 )=1 ). To prove it, we use a classical proof by induction on k , that shows the non-solvability property of any of the following systems ( t=0 , corresponding to case n=1 (resp. t=1 , corresponding to case n=2 )): ( Ξ t,k ){ X 2 + 2 t ( 2 k Y ) 2 = Z 2 X 2 + 2

关键词： Prime Numbers-Diophantine Equations of Degree 2 & 4 Factorization Greater Common Divisor Pythagoras Equation Pythagorician Triplets Congruent Numbers Inductive Demonstration Method Infinite Descent BSD Conjecture

Sustainable graywater reuse for residential landscape irrigation-a critical review

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Chinese Journal of Population,Resources and Environment 2015年第3期13卷 250-264页

作者： u.Pinto B.l.Maheshwari School of Science & Health University of Western Sydney

The demand for potable water is rising rapidly due to an ever-increasing population,economic activities,and dwindling water *** provide adequate water supplies in the future,understanding the issues and challenges in the reuse of water and developing appropriate strategies for reuse will be *** way to augment water supplies for residential.use is to reuse graywater- the wastewater from kitchens,bathrooms,and *** this article,we critically review the evolution of water reuse,the definition of graywater,graywater reuse practices,volumes and flow in different situations,and graywater *** then examine the issues associated with different graywater treatment methods and how using graywater for irrigation around homes affects soil quality and plant *** study concludes that graywater treatment costs,human health risks,and its effect on soil quality are some of the challenges that need to be addressed in the future for widespread and sustainable reuse of graywater for irrigation around homes.

关键词： water reuse graywater irrigation sustainability urban water water treatment