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Additive friction stir deposition of AZ31b magnesium alloy

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Journal of Magnesium and Alloys 2022年第9期10卷 2404-2420页

作者： Sameehan S.Joshi Shreyash M.Patil Sangram Mazumder Shashank Sharma Daniel A.Riley Shelden Dowden Rajarshi banerjee Narendra b.Dahotre Department of Materials Science and Engineering University of North Texas3940 N Elm StDentonTX 76207USA Center for Agile and Adaptive Additive Manufacturing University of North Texas3940 N Elm StDentonTX 76207USA

The current work explored additive friction stir deposition of AZ31b magnesium alloy with the aid of MELD?***31b magnesium bar stock was fed through a hollow friction stir tool rotating at constant velocity of 400 rpm and translating at linear velocity varied from 4.2 to 6.3 mm/s.A single wall consisting of five layers with each layer of 140×40×1 mm^(3)dimensions was deposited under each processing ***,phase,and crystallographic texture evolutions as a function of additive friction stir deposition parameters were studied with the aid of scanning electron microscopy including electron back scatter diffraction and X-ray *** feed material and additively produced samples consisted of theα-Mg *** additively produced samples exhibited a refined grain structure compared to the feed *** feed material appeared to have a weak basal texture,while the additively produced samples experienced a strengthening of this basal *** additively produced samples showed a marginally higher hardness compared to the feed *** current work provided a pathway for solid state additive manufacturing of Mg suitable for structural applications such as automotive components and consumable biomedical implants.

关键词： Additive friction stir deposition Magnesium alloys Additive manufacturing Thermomechanical processing Materials processing Solid state additive manufacturing

考虑地下水入侵导致土壤强度变化的沿海建筑地基韧性模型

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岩土力学 2023年第1期44卷 67-74页

作者：王草 AYYUb b.M KUMARI W.G.P 伍伦贡大学土木、采矿与环境学院澳大利亚伍伦贡马里兰大学土木与环境工程学院美国马里兰

海平面上升导致的地下水入侵沿海地区的建筑地基造成显著风险。提出了一个考虑地下水侵入导致土壤强度退化的沿海建筑地基韧性模型。该模型由地基的性能函数在服役期内的积分得到。考虑条形基础的韧性,其极限承载力由Terzaghi公式描述... 详细信息

海平面上升导致的地下水入侵沿海地区的建筑地基造成显著风险。提出了一个考虑地下水侵入导致土壤强度退化的沿海建筑地基韧性模型。该模型由地基的性能函数在服役期内的积分得到。考虑条形基础的韧性,其极限承载力由Terzaghi公式描述。韧性模型考虑气候变化背景下地下水位的上升对土壤强度的影响。通过一个算例,展示了所提出的韧性模型的适用性。结果表明,如果不考虑气候变化影响下地下水位的上升,则会得到不保守的结构韧性评估结果。结构全寿命周期内的韧性也取决于所采用的维护措施(即,修复受损的结构性能)。未来的研究中,还应考虑其他因素(如锈蚀)对沿海建筑地基性能退化的联合影响。

关键词：韧性模型沿海建筑地基土壤强度变化地下水入侵气候变化

Constraints on Neutrino Masses from baryon Acoustic Oscillation Measurements

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International Journal of Astronomy and Astrophysics 2018年第1期8卷 1-5页

作者： b. Hoeneisen Universidad San Francisco de Quito Quito Ecuador

From 21 independent baryon Acoustic Oscillation (bAO) measurements we obtain the following sum of masses of active Dirac or Majorana neutrinos: , where and . This result may be combined with independent measurements t... 详细信息

关键词： Neutrino Mass baryon Accoustic Oscillations Cosmology

Microwave assisted convenient synthesis of quino[2,3-b][1,5]benzoxazepines

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Chinese Chemical Letters 2009年第5期20卷 557-561页

作者： Swapnil S.Sonar Sandip A.Sadaphal Shivaji S.Pawar bapurao b.Shingate Murlidhar S.Shingare Department of Chemistry Dr. Babasaheb Ambedkar Marathwada UniversityAurangabad 431004MSIndia Department of Chemistry Vinayakrao Patil Mahavidyalaya VaijapurAurangabad 423701MSIndia National Chemical Laboratory Pune 411008MSIndia

A convenient synthesis of quino[2,3-b] [ 1,5]benzoxazepines from substituted 2-chloroquinoline-3-carbaldehyde and 2-hydroxy- aniline by using stable, non-toxic and inexpensive catalyst 1,8-diazabicyclo-undecan-7-ene （DbU）/silica gel is described. This method affords the quino[2,3-b][1,5]benzoxazepines under the influence of microwave irradiation （360 W） in solvent-free conditions within short reaction times （2-3 min）, giving high yields of products （93-96%）.

关键词： Quino[2,3-b][1.,5]benzoxazepines DbU/silica gel Microwave irradiation Solvent-free

Numerical modeling of the transmission dynamics of drug-sensitive and drug-resistant HSV-2

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Communications in Nonlinear Science and Numerical Simulation 2001年第1期6卷 23-27页

作者： A. b. GUMEL(Department of Mathematics, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada ) Department of Mathematics University of Manitoba Winnipeg Manitoba R3T 2N2 Canada

A competitive finite-difference method will be constructed and used to solve a modified deterministic model for the spread of herpes simplex virus type-2 (HSV-2) within a given population. The model monitors the transmission dynamics and control of drug-sensitive and drug-resistant HSV-2. Unlike the fourth-order Runge-Kutta method (RK4), which fails when the discretization parameters exceed certain values, the novel numerical method to be developed in this paper gives convergent results for all parameter values.

关键词： HSV-2 finite-difference initial-value problem numerical instabilities positivity

Linguo-Combinatorial Simulation of Complex Systems

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Journal of Mathematics and System Science 2012年第1期2卷 58-66页

作者： Mikhail b. lgnatyev St-Petersburg State University of Aerospace Instrumentation St-Petersburg 190000 Russia

Contemporary world is developing system and we must have the new models. Any complex system interacts with its changing environment and its viability depends on its adaptability. The number of arbitrary coefficients in the structure of equivalent equations of complex system changes in the process of learning. In systems with more than six variables, the number of arbitrary coefficients increases first, and then, passing through the maximum, begins to decrease. This phenomenon makes it possible to explain the processes of system growth, complication and death in biological, economical and physical-engineering systems. The author uses the Linguo-combinatorial method of investigation of complex systems, in taking key words for building equivalent equations. This phenomenon is able to increase the adaptability of different systems.

关键词： Adaptability combinatorial simulation uncertainty appearance essence general systems theory,physics biology. social-economics.

DEEP WELLS IN THE PEKING AREA

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地质学报 1924年第2期 127-138+197页

作者： G.b.bARbOUR Department of Geology Yenching University Peking

The underground water-supply of the plain of North Chihli is of sufficient importance to geologists and civil engineers to warrant the placing in readily available form of some data till now not easily accessible.

关键词： DEEP WELLS IN THE PEKING AREA down

Controlling hyperchaotic complex systems with unknown parameters based on adaptive passive method

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Chinese Physics b 2013年第6期22卷 268-276页

作者： Gamal M.Mahmoud Emad E.Mahmoud Ayman A.Arafa Department of Mathematics Faculty of ScienceTaibah UniversityAl-Madeenah Al-MunawwarahP.O.Box 344Kingdom of Saudi Arabia Department of Mathematics Faculty of ScienceSohag UniversitySohag 82524Egypt College of Applied Medical Sciences TurabahTaif UniversityKingdom of Saudi Arabia

The aim of this paper is to study the control of hyperchaofic complex nonlinear systems with unknown parameters using passive control theory. An approach is stated to design the passive controller and estimate the unknown parameters based on the property of the passive system. The feasibility and effectiveness of the proposed approach is demonstrated through its application to the hyperchaotic complex Lu system, as an example. The estimated values of the unknown parameters are calculated. The analytical form of the complex controller is derived and used in the numerical simulation to control the hyperchaotic attractors of this example. block diagrams of this example using Matlab/Simulink are constructed after and before the control to ensure the validity of the analytical results. Other examples of hyperchaotic complex nonlinear systems can be similarly treated.

关键词： control passive control hyperchaotic complex

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双层协同对地观测卫星星座设计

华中科技大学学报（自然科学版） 2018年第2期46卷 100-105页

作者：王茂才罗鑫宋志明戴光明中国地质大学计算机学院湖北武汉430074 中国地质大学智能地学信息处理湖北省重点实验室湖北武汉430074

针对日益增长的卫星对地观测需求,提出了一种双层卫星星座设计方案.首先,分析了我国目前对地观测卫星的覆盖性能,以时间分辨率和空间分辨率作为对地观测星座的评价指标;然后,通过优化卫星轨道高度,得到满足任务要求的最优轨道;最后,通... 详细信息

针对日益增长的卫星对地观测需求,提出了一种双层卫星星座设计方案.首先,分析了我国目前对地观测卫星的覆盖性能,以时间分辨率和空间分辨率作为对地观测星座的评价指标;然后,通过优化卫星轨道高度,得到满足任务要求的最优轨道;最后,通过设置轨道相位使得整个星座构成全连通链路,单个地面站与卫星相连便可以与整个星座相连,从而摆脱了对中继卫星的依赖.该方案充分结合了中轨星座时间分辨率高、低轨星座空间分辨率高的优点,相对于传统的单层卫星组网方案,双层星座能够以高空间分辨率和时间分辨率对全球任意目标1 d观测多次,并实现遥测指令与观测数据的实时传输.

关键词：对地观测卫星协同观测双层星座共地面轨迹低轨卫星