检索结果-南通市图书馆

Fourier transform technique in variational treatment of two-electron parabolic quantum dot

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2009年第8期18卷 3508-3516页

作者： S.Sakiroglu a.yιldιz .Dogan K.Akgngr H.Epik y.Ergn H.Sarι .Skmen Physics Department Dokuz Eyll University Physics Department Anadolu University Physics Department Cumhuriyet University

In this work, we propose an efficient method of reducing the computational effort of variational calculation with a Hylleraas-like trial wavefunction. The method consists of introducing integral transforms for the terms as r12^κ exp （-λτ12） which provide the calculation of the expectation value of energy and the relevant matrix elements to be done ana.ytically over single-electron coordinates instead of Hylleraas coordinates. We have used this method to calculate the ground state energy of a two-electron system in a spherical dot and a disk-like quantum dot separately. Under parabolic confinement potential and within effective mass approximation size and shape effects of quantum dots on the ground state energy of two electrons have been investigated. The calculation shows that our results even with a small number of basis states are in good agreement with previous theoretical results.

关键词： two-electron quantum dot parabolic confinement variational method Hylleraas coor- dinates

Effect of relative humidity on the desulfurization performance of calcium-based desulfurizer

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 179-188页

作者： Juan lǖ yu Fu Ha.yan yu HuanWang Zhe Wang Ha.yan Chen School of Environment and Resource Southwest University of Science and TechnologyMianyang 621010China Guangyuan Emergency Management bureau Guangyuan 628000China

low desulfurization efficiency impedes the wide application of dry desulfurization technology,which is a low-cost and simple process,and one significant solution is the development and manufacture of high-performance *** this study,firstly,a steam jet mill was used to digest quicklime;then,we utilized numerical simulation to study the flow field distribution and ana.yze the driving factors of quicklime digestion;and lastly,the desulfurization performance of the desulfurizer was evaluated under different relative *** results show that the desulfurizer prepared via the steam jet mill had better apparent activity than traditional ***,the entire jet flow field of the steam jet mill is in a supersonic and highly turbulent flow state,with high crushing intensity and good particle acceleration *** contact with the nascent surface maximizes the formation of slaked *** experiments demonstrated that the operating time with 100%desulfurization efficiency and the“break-through”time for the desulfurizer prepared via the steam jet mill is longer than that of traditional desulfurizers,and has significant advantages,especially at low flue gas relative *** with traditional desulfurizers,the desulfurizer prepared via steam jet mill expands the range of acceptable flue gas temperature,and the failure temperature is 1.625 times that of traditional *** work breaks through the technical bottleneck of low dry desulfurization efficiency,which is an important step in pushing forward the application of dry desulfurization.

关键词： Dry desulfurization Relative humidity Desulfurization efficiency High-efficiency desulfurizer Quicklime digestion

Control Policy learning Design for Vehicle Urban Positioning via BeiDou Navigation

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第1期37卷 114-135页

作者： QIN yahang ZHANG Chengye CHEN Ci XIE Shengli lEWIS Frank l School of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong Key laboratory of IoT Information Technology Guangzhou 510006China. Center for Intelligent Batch Manufacturing Based on IoT Technology Key laboratory of Intelligent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint laboratory for Smart Discrete Manufacturing Guangzhou 510006China Key laboratory of Intelligent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a learning-based control policy design for point-to-point vehicle positioning in the urban environment via BeiDou *** navigating in urban ca.yons,the multipath effect is a kind of interference that causes the navigation signal to drift and thus imposes severe impacts on vehicle localization due to the reflection and diffraction of the BeiDou ***,the authors formulated the navigation control system with unknown vehicle dynamics into an optimal control-seeking problem through a linear discrete-time system,and the point-to-point localization control is modeled and handled by leveraging off-policy reinforcement learning for feedback *** proposed learning-based design guarantees optimality with prescribed performance and also stabilizes the closed-loop navigation system,without the full knowledge of the vehicle *** is seen that the proposed method can withstand the impact of the multipath effect while satisfying the prescribed convergence rate.A case study demonstrates that the proposed algorithms effectively drive the vehicle to a desired setpoint under the multipath effect introduced by actual experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation multipath effect prescribed convergence rate reinforcement learning urban localization.

Feasibility of achieving net-zero energy performance in high-rise buildings using solar energy

在线全文

学校读者我要写书评

暂无评论

Energy and Built Environment 2024年第6期5卷 946-956页

作者： Mehrdad Shirinbakhsh l.D.Danny Harvey University of Toronto 100St.George StreetTorontoONM5S 3G3Canada

As part of a broad strategy to reach net-zero greenhouse gas emissions and limit global warming,ma.y countries are requiring all new buildings to have net-zero energy *** requires that on-site energy use not exceed on-site generation of renewable energy(taken here to be solar energy),or equivalently,that the building Energy Use Intensity(EUI,kWh/m^(2)a)not exceed the supply of on-site solar energy(electricity and heat)per m^(2)of floor area per *** this basis,we find that achieving net-zero energy performance in an archetype 40-story square building in 16 different cities of North America requires EUI of 17–24 kWh/m^(2)a using PV panels,and 19–28 kWh/m^(2)a using PVT *** building orientation to a non-square floor shape can improve maximum permitted EUI by up to 50%in PV and 60%in PVT ***,the best-performing residential and commercial buildings have EUIs of 50–75 kWh/m^(2)*** if building heights are limited to 5–10 floors does the available solar energy,and thus the permitted EUI,reach 50–75 kWh/m^(2)***,we recommend that policymakers not require high-rise buildings to be net-zero energy,unless they are prepared to limit building heights to 5–10 floors.

关键词： High-rise net-zero energy buildings Building geometry Building height Solar NZEB

Multi-criteria decision-making method for evaluation of investment in enhanced geothermal systems projects

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and AI 2024年第3期17卷 143-167页

作者： Sara Raos Josipa Hranić Ivan Rajšl University of Zagreb Faculty of Electrical Engineering and Computing Unska 310000 ZagrebCroatia GE Vernova 58 Charles StreetCambridgeMassachusettsUSA

Deep geothermal energy presents large untapped renewable energy potential could significantly contribute to global energy needs. However, developing geothermal projects involves uncertainties regarding adequate geothermal brine extraction and huge costs related to preparation phases and consequently drilling and stimulation activities. Therefore, evaluating utilization alternatives of such projects is a complex decision-making problem effectively addressed using multi-criteria decision-making (MCDM) methods. This study introduces the MCDM method utilizing ana.ytic hierarchy process (AHP) and weighted decision matrix (WDM) to assess different utilization alternatives (electricity generation, direct heat use and cogeneration). The AHP method determines the weight of each criterion and sub-criterion, while the WDM calculates the final project grade. Five criteria groups - technological, geological, economic, societal and environmental – comprising twenty-eight influencing factors were selected and used for the assessment of investment in Enhanced Geothermal Systems (EGS) projects. The AHP-WDM method was used by 38 experts from six categories: industry, educational institution, research and technology organization (RTO), small- and medium-sized enterprises (SME), local community and other. These diverse expert inputs aimed to capture va.ying perspectives and knowledge influence investment decisions in geothermal energy. The results were ana.ysed accordingly. The results underscore the importance of incorporating different viewpoints to develop robust, credible, and effective investment strategies for EGS projects. Therefore, this method will contribute to more efficient EGS project development, enabling thus a greater penetration of the EGS into the market. Additionally, the proposed AHP-WDM method was implemented for a case study examining two locations. locations were assessed and compared on scenario-based evaluation. The results confirmed the method's adequa.y for a

关键词： Deep geothermal energy Enhanced geothermal systems(EGS) Multi-criteria decision-making(MCDM)method Ana.ytic hierarchy process(AHP) Weighted decision matrix(WDM)

Two-Stream Approximation to the Radiative Transfer Equation:A New Improvement and Comparative Accura.y with Existing Methods

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2024年第2期41卷 278-292页

作者： F.Momo TEMGOUA l.Akana NGUIMDO DNJOMO Environmental Energy Technologies laboratory(EETl) Faculty of SciencesUniversity of YaoundéPO Box 812 YaoundéCameroon Department of Electrical and Electronic Engineering Faculty of Engineering and TechnologyUniversity of BueaPO Box 63 BueaCameroon

Mathematical modeling of the interaction between solar radiation and the Earth's atmosphere is formalized by the radiative transfer equation(RTE), whose resolution calls for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the RTE with the development of the phase function and the intensity into a third-order series of legendre polynomials. This new approach, which adds one more term in the expression of the intensity and the phase function, allows in the conditions of a plane parallel atmosphere a new mathematical formulation of γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined Delta Function and Modified Eddington, and second-order approximation methods with reference to the Discrete Ordinate(Disort) method(δ –128 streams), considered as the most precise. This work also determines the conversion function of the proposed New Method using the fundamental definition of two-stream approximation(F-TSA) developed in a previous work. Notably,New Method has generally better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, New Method shows very good precision for wide domains of the zenith angle μ 0, but tends to deviate from the Disort method with the zenith angle, especially for high values of optical thickness. In spite of this divergence in reflectance for high values of optical thickness, very strong correlation with the Disort method(R ≈ 1) was obtained for most cases of optical thickness in this study. An ana.ysis of the legendre polynomial series for simple functions shows that the high precision is due to the fact that the approximated functions ameliorate the accura.y when the order of approximation increases, although it has been proven that there is a limit order depending on the function from which the precision is lost. This observation indicates that increasing the order of app

关键词： Radiative Transfer Equation two-stream method legendre polynomial optical thickness moments of specific intensity conversion function transmittance reflectance

Improved Reall-Santos method for AdS black holes in general 4-derivative gravities

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 74-86页

作者： Peng-Ju Hu liang Ma Hong lü yi Pang Center for Joint Quantum Studies and Department of Physics School of ScienceTianjin UniversityTianjin 300350China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China Peng Huanwu Center for Fundamental Theory Hefei 230026China

For a.ymptotically flat black holes,Reall-Santos method is a convenient tool to compute leading higher derivative corrections to the thermodynamic quantities without actually solving the modified field ***,there are subtleties in its generalization to a.ymptotically AdS black holes with general higher derivative *** of all,it is necessa.y to know all the higher derivative holographic counterterms and the surface terms implementing the variational principle and subtracting the *** then needs to solve for the modified AdS radius and rescale the time coordinate in an appropriate way such that the induced metric on the conformal bounda.y of AdS black hole is not *** observe that Reall-Santos method can be directly applied to a particular 4-derivative gravity model,known as the Einstein-Weyl gravity,which does not modify the AdS radius and requires only the Gibbons-Hawking-york term and holographic counterterms for the 2-derivative *** thus suggest that to compute the thermodynamic quantities of AdS black holes in general 4-derivative theories of gravity,one simply needs to transform it to a Einstein-Weyl gravity with identical thermodynamic variables by appropriate field *** explicitly verify this proposal with spherically-symmetric and static charged black holes in Einstein-Maxwell theory extended with generic 4-derivative interactions.

关键词： black holes thermodynamics higher-derivative corrections effective theories higher dimensional black holes quantum gravity

Zassenhaus lemma,Schreier Refinement Theorem,and Jordan–Hölder Theorem for Gyrogroups

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2024年第2期31卷 323-332页

作者： Prathomjit Khachorncharoenkul Rasimate Maungchang Teerapong Suksumran l.A.Bokut School of Science Walailak UniversityNakhon Si Thammarat 80160Thailand Department of Mathematics Faculty of ScienceChiang Mai University Chiang Mai 50200Thailand 不详

In this article,we extend the Zassenhaus lemma(also called the butterfly lemma)and the Schreier refinement theorem to the case of *** addition,we use these results to prove the Jordan–Hölder theorem for gyrogroups as... 详细信息

关键词： Zassenhaus lemma Schreier refinement theoremg yrogroup subgyrogroup diagram normal subgyrogroup

Simultaneous removal of critical rare earth elements and chalcogen oxyanions by anaerobic granular sludge

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4595-4611页

作者： Chiara Belloni Mohanakrishnan logan Stefano Papirio Piet N.l.lens University of Galway Galway H91 TK33Ireland Department of Civil Architectural and Environmental EngineeringUniversity of Naples Federico II80125 NaplesItaly

Conventional mining of economically and strategically important critical rare earth elements(REEs)(such as neodymium,lanthanum and dysprosium),and chalcogens(such as selenium and tellurium)are associated with a huge economic and environmental ***,the need to recover REEs as well as chalcogens from different waste streams including wastewaters is becoming *** assays on synthetic chalcogen/REE-laden wastewater showed that the presence of REEs significantly improved the tellurite removal rate(>80%)and enhanced selenate removal by 66%±10%.Three 3.9 l continuous upflow anaerobic granular sludge bed(UASB)reactors were operated at a hydraulic retention time of 24 h and30℃.Selenate reduction was achieved with a removal efficiency of~98%with an influent p H of 4.0 for more than 28 *** effect of REEs on tellurite removal in the UASB bioreactor could not be clearly established since a soluble tellurium removal efficiency of more than 98%was observed alrea.y before the addition of REEs at elevated tellurite *** complete REE removal in both batch assays and UASB reactors at higher pH(7.0±0.5)was attributed to precipitation,whereas chalcogen oxyanions removal was due to microbial ***,at acidic p H,biosorption was responsible for REE's removal,and the Se-enriched sludge exhibited a superior REE's removal efficiency than the non-enriched and Te-enriched sludge.

关键词： Rare earth elements Selenium Tellurium Bioreduction Adsorption