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A novel control strategy based on a look-up table for optimal operation of MTDC systems in post-contingency conditions

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Protection and Control of Modern Power Systems 2022年第1期7卷 40-50页

作者： Seyed Mohsen alavi Reza Ghazi Department of Electrical Engineering Ferdowsi University of MashhadMashhadIran

Multi terminal VSC-HVDC systems are a promising solution to the problem of connecting offshore wind farms to AC *** power sharing and appropriate control of DC-link voltages are essential and must be maintained dur-ing the operation of VSC-MTDC systems,particularly in post-contingency *** traditional droop control methods cannot satisfy these requirements,and accordingly,this paper proposes a novel centralized control strategy based on a look-up table to ensure optimal power sharing and minimum DC voltage deviation immediately during post-contingency conditions by considering converter *** also reduces destructive effects(e.g.,frequency devia-tion)on onshore AC grids and guarantees the stable operation of the entire MTDC *** proposed look-up table is an array of data that relates operating conditions to optimal droop coefficients and is determined according to N-1 contingency analysis and a linearized system *** constraints and contingencies such as wind power changes,converter outage,and DC line disconnection are considered in its formation *** performed on a 4-terminal VSC-MTDC system in the MATLAB-Simulink environment validate the effectiveness and superiority of the proposed control strategy.

关键词： Optimal power sharing DC voltage deviation Adaptive droop control Multi-terminal HVDC(MTDC) Voltage source converter(VSC)

Optimum structural design of full-scale steel buildings using drift-tribe-charged system search

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Earthquake Engineering and Engineering Vibration 2022年第3期21卷 825-842页

作者： Siamak Talatahari Hedayat Veladi Mahdi Azizi Ali Moutabi-alavi Salar Rahnema Department of Civil Engineering University of TabrizTabriz 51666Iran Faculty of Engineering and Information Technology University of Technology SydneyUltimoNSW 2007Australia

In this paper,the potential of utilizing improved metaheuristic approaches in optimal design of building structures is *** this regard,the drift-tribe-charged system search algorithm is proposed that the position and velocity updating processes of the charged system search is developed by implementing the mathematical presentation of the free-electron model utilized for metal *** addition,the searching phase of the developed algorithm is also divided into three separate phases in order to improve the convergence capability of the *** means of these modifications,the exploitation and exploration rates of the standard algorithm are *** order to determine the ability of the proposed improved metaheuristic method considering some complex optimization problems,a 10-story steel building structure with 1026 structural members alongside a 60-story structure with 8272 members are utilized as numerical *** overall capability of the developed metaheuristic approach is compared with other metaheuristics.A total number of 30 independent runs have been conducted for each of the standard and proposed methods while a statistical analysis is also conducted for comparative *** obtained optimum results demonstrated that the proposed metaheuristic approach is capable of preparing better outcomes than other metaheuristics.

关键词： drift-tribe-charged system search optimum structural design full-scale steel building statistical analysis

Spatio-temporal suspended sediment fingerprinting under different land management practices

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International Journal of Sediment Research 2023年第4期38卷 481-493页

作者： Maziar Mohammadi Abdulvahed Khaledi Darvishan Nader Bahramifar Seyed Jalil alavi Department of Watershed Management Engineering Faculty of Natural Resources Tarbiat Modares University Department of Geography University of Zurich Department of Environmental Science Faculty of Natural Resources Tarbiat Modares University Department of Forestry Faculty of Natural Resources Tarbiat Modares University

Understanding spatio-temporal suspended sediment dynamics is more important in large watersheds due to the decisive role of local source apportionment in sediment transport and yield. The Talar River with a large mountainous watershed in northern Iran, which plays a vital role in water supply for agriculture and drinking, recently has faced quality degradation. The current study explores the relative contribution of suspended sediment sources using geochemical tracers and fingerprinting techniques in high and low flow periods along this river. Soil samples were collected from four major land uses including rangeland, forest, rainfed agriculture, and irrigated agriculture, as well as riverbanks and riparian zones along the main river. Furthermore, suspended sediment was sampled at four sampling points along the main river in two seasons. Land use apportionment in suspended sediment yield was calculated using an unmixing model included in a newly developed package(Finger Pro) in high flow and low flow, separately. The fingerprinting results showed a highly spatio-temporal dynamic for sediment source contribution along the main river in high and low flow periods. Natural land uses(forest and rangeland) in upstream reaches and agricultural land uses and riverbank sources in downstream reaches showed higher contributions to suspended sediment yield. The mean contribution of various land uses for both high and low flow periods indicated substantial contributions from forest(34%-41%) and riverbanks(31%-33%). The significant difference in sediment geochemical properties for the two flow seasons highlights the important role of the prevailing climatic-hydrologic condition on river ***, this issue indicates that sediment source contributions and transfer mechanisms are highly dynamic in Talar River watershed. The current study outcomes provide essential knowledge to create a robust strategy for mitigation of river sediment pollution.

关键词： Land use River water quality Sediment fingerprinting Sustainability Unmixing model

Spatial variability of soil microbial indices in common alder COMMON ALDER(Alnus glutinosa) stands using a geostatistical approach in northern Iran

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Journal of Forestry Research 2019年第2期30卷 679-688页

作者： Neda Ghorbanzadeh Ali Salehi hassan Pourbabaei Ali Ashraf Soltani Tolarod Seyed Jalil alavi Department of Forestry Faculty of Natural ResourcesUniversity of Guilan Department of Soil Science Faculty of Agriculture and Natural Resources University of Mohaghegh Ardabili Department of Forestry Faculty of Natural Resources and Marine Sciences University of Tarbiat Modares

Microbial indices and their spatial patterns are strongly affected by environmental factors. Spatial variability of soil properties is one of the most important causes of variability in soil microbial indices. This research was conducted in the Caspian forest to assess spatial variabilities and frequency distributions of microbial *** soil samples were taken using a grid sampling design 40 9 40 m. Microbial indices, organic carbon,nitrogen and pH were determined. Soil variable distributions showed that microbial indices had abnormal distributions. Logarithmic transformation produced normal distribution. Spatial continuity using geostatistical(variogram) was studied and maps obtained by point *** variograms revealed the presence of spatial autocorrelation. The results indicate that spatial dependence of soil microbial indices was affected by non-intrinsic factors and forest management procedures. The maps show that soil microbial indices and soil properties have spatial variability. The spatial pattern of microbial indices was correlated to organic carbon and nitrogen.

关键词： Variograms Soil microbial indices Spatial distribution Natural forest Iran

Cluster decay half-lives using asymmetry dependent densities

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Chinese Physics C 2022年第4期46卷 131-140页

作者： V.Dehghani S.A.alavi R.Razavi A.Soylu F.Koyuncu Department of Physics University of Sistan and BaluchestanZahedanIran Physics Department Faculty of ScienceImam Hossein Comprehensive UniversityTehranIran Department of Physics Nigdeomer Halisdemir UniversityNigde 51240Turkey Program of Opticianry Golhisar Vocational School of Health ServicesBurdur Mehmet Akif Ersoy University15400GolhisarBurdurTurkey

By adopting different neutron and proton density distributions,cluster decay half-lives were investigated using double-folding potentials with constant and nuclear asymmetry dependent sets of nuclear density *** adopted asymmetry dependent sets of parameters were fitted based on microscopic calculations,and they were calculated based on the neutron skin/halo-type nuclei assumption and by employing experimental rms charge radii.A bulk agreement between theory and experiment was obtained for all sets of parameters using a calculated cluster preformation *** differences were observed between the skin and halo-type ***,the notable role of the asymmetry parameter was observed in the relatively large differences between the skin and skintype with zero thickness.

关键词： cluster decay double-folding charge radii density

非对称N-(亚水杨基)二亚乙基三胺铜(Ⅱ)配合物的合成、结构分析和催化活性评价(英文)

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催化学报 2013年第7期34卷 1456-1461页

作者： hassan HOSSEINI-MONFARED Sohaila alavi Milosz SICZEK Department of Chemistry University of Zanjan Faculty of Chemistry University of Wroclaw

A new copper(Ⅱ) complex of a non‐symmetric Schiff base, [CuII(saldien)(H2O)]+(1), has been synthesized and characterized by elemental analysis and several other spectroscopic methods (Hsaldien = N‐(salicylidene)diethylenetriamine). The crystal structure of 1 has also been determined by X‐ray crystallography. The geometry of the complex cation in 1 was found to be distorted square pyramidal with the mononegative Schiff base coordinating to the copper in a tetradentate mode via the O,N,N', and N''‐donor atoms. The remaining coordination site was occupied by the O atom of a H2O molecule in the axial position. The catalytic potential of 1 was tested in the oxidation reactions of cyclooctene and cyclohexene with aqueous 30% H2O2/NaHCO3 in acetonitrile. These reactions proceeded smoothly to give the corresponding epoxides with selectivity levels greater than 99%. This catalytic system also showed high levels of activity and selectivity towards the oxidation of cyclohexane (i.e., cyclohexanol 37% and cyclohexanone 54%) in comparison with most of the other Cu‐based systems reported in the literature.

关键词：三胺配合物催化活性亚水杨基非对称结构分析合成 Schiff碱亚乙基

One—Dimensional Potentials in q Space

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Chinese Physics Letters 2003年第1期20卷 8-11页

作者： S.A.alavi HighEnergyPhysicsDivision DepartmentofPhysicsUniversityofHelsinkiandHelsinkiInstituteofPhysicsFIN-0

We study one-dimensional potentials in q space and the new features that arise. In particular, we show that the probability of tunnelling of a particle through a barrier or potential step is less than that of the same particle with the same energy in ordinary space which is somehow unexpected. We also show that the tunnelling time for a particle in q space is less than that of the same particle in ordinary space.

关键词： DEFORMED QUANTUM-MECHANICS YANG-BAXTER EQUATION UNCERTAINTY RELATION HARMONIC-OSCILLATOR HEISENBERG ALGEBRA DYNAMICS ANALOG

Berry‘’s Phase in Noncommutative Spaces

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Chinese Physics Letters 2003年第5期20卷 605-607页

作者： S.A.alavi HighEnergyPhysicsDivision DepartmentofPhysicsUniversityofHelsinkiFinlandHelsinkiInstituteofPhysicsFIN-00014HelsinkiFinland

We discuss the perturbative aspects of noncommutative quantum mechanics. Then we study Berry's phase within the framework of noncommutative quantum mechanics. The results show deviations from the usual quantum mechani... 详细信息

关键词：贝里相位量子力学非交换空间扰动

General Noncommuting Curvilinear Coordinates and Fluid Mechanics

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Chinese Physics Letters 2006年第10期23卷 2637-2639页

作者： S.A.alavi Department of Physics Sabzevar University of Tarbiat Moallem Sabzevar PO Box 397 Iran Sabzevar House of Physics Asrar Laboratories of Physics Laleh Square Sabzevar Iran

We show that restricting the states of a charged particle to the lowest Landau level introduces noncommutativity between general curvilinear coordinate operators. The Cartesian, circular cylindrical and spherical polar coordinates are three special cases of our quite general method. The connection between U（1） gauge fields defined on a general noncommuting curvilinear coordinates and fluid mechanics is explained. We also recognize the Seiberg-Witten map from general noncommuting to commuting variables as the quantum correspondence of the Lagrange-to-Euler map in fluid mechanics.

关键词： SCATTERING SPACES