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Many-objective optimization for coordinated operation of integrated electricity and gas network

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Journal of Modern Power Systems and Clean Energy 2017年第3期5卷 350-363页

作者： Y.n.KOU J.H.ZHEnG Zhigang LI q.H.WU School of Electric Power Engineering South China University of TechnologyGuangzhou 510640China Department of Electrical Engineering and Electronics The University of LiverpoolLiverpool L693GJUK

This paper develops a many-objective optimization model, which contains objectives representing the interests of the electricity and gas networks, as well as the distributed district heating and cooling units, to coordinate the benefits of all parties participated in the integrated energy system(IES). In order to solve the many-objective optimization model efficiently, an improved objective reduction(IOR) approach is proposed, aiming at acquiring the smallest set of objectives. The IOR approach utilizes the Spearman’s rank correlation coefficient to measure the relationship between objectives based on the Pareto-optimal front captured by the multi-objective group search optimizer with adaptive covariance and Lévy flights algorithm, and adopts various strategies to reduce the number of objectives gradually. Simulation studies are conducted on an IES consisting of a modified IEEE 30-bus electricity network and a 15-node gas network. The results show that the many-objective optimization problem is transformed into a bi-objective formulation by the IOR. Furthermore,our approach improves the overall quality of dispatch solutions and alleviates the decision making burden.

关键词： Integrated energy system Gas network Electricity network Many-objective optimization Objective reduction

Analytical and numerical studies for seiches in a closed basin with various geometric shapes of longitudinal section

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Theoretical & Applied Mechanics Letters 2021年第3期11卷 151-156页

作者： I.Magdalena n.Karima H.q.Rif’atin Faculty of Mathematics and natural Sciences Bandung Institute of TechnologyBandungIndonesia

Seiches are long-period standing waves with a unique period called a natural resonant period,during which the phenomenon of resonance *** occurrence of resonance in coastal areas can cause destruction to surrounding natural and man-made *** determining the resonant period of a given basin,we can pinpoint the conditions that allow waves to achieve *** this study,a mathematical model is developed from the shallow water equations to examine seiches and resonances in various types of closed *** developed model is solved analytically using the separation of variables method to determine the seiches’fundamental resonant *** between the analytical solutions and experimental measurements for resonant periods are also *** is shown that the analytical resonant period confirms the experimental data for closed basin of various geometric *** a finite volume method on a staggered grid,the model is solved numerically to simulate the wave profile when resonance phenomenon *** those numerical simulations,we also obtain the fundamental resonant period for each basin which agrees with the derived analytical period.

关键词： Seiches Fundamental resonant period Closed basin Shallow water equations Finite volume method

Reliability of quasi integrable and non-resonant Hamiltonian systems under fractional Gaussian noise excitation

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Acta Mechanica Sinica 2020年第4期36卷 902-909页

作者： q.F.Lu W.q.Zhu M.L.Deng Department of Mechanics State-Key Laboratory of Fluid Power and Mechatronic SystemsZhejiang UniversityHangzhou 310027China

The reliability of quasi integrable and non-resonant Hamiltonian system under fractional Gaussian noise(fGn)excitation is *** rather flat fGn power spectral density(PSD)in most part of frequency band,the fGn is innovatively regarded as a wide-band ***,the stochastic averaging method for quasi integrable Hamiltonian systems under wide-band noise excitation is applied to reduce 2n-dimensional original system into n-dimensional averaged ltd stochastic differential equations(SDEs).Reliability function and mean first passage time are obtained by solving the associated backward Kolmogorov equation and Pontryagin *** validity of the proposed procedure is tested by applying it to an example and comparing the numerical results with those from Monte Carlo simulation.

关键词： Reliability Fkst passage time quasi integrable and non-resonant Hamiltonian systems Fractional Gauss noise

Increasing secondary bacterial infections with Enterobacteriaceae harboring bla_(CTX-M-15) and bla_(CMY-6) in patients with bronchogenic carcinoma:an emerging point of concern

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Asian Pacific Journal of Tropical Medicine 2011年第1期4卷 5-12页

作者： Mohammed Shahid Abida malik Rakesh Bhargava Section of Bacteriology & Molecular Biology Department of Medical MicrobiologyJN Medical College & HospitalAligarh Muslim UniversityAligarh-202 002U.P.India T.B.& Chest Diseases Jawaharlal Nehru Medical College & HospitalAligarh Muslim UniversityAligarh-202002Uttar PradeshIndia

Objective:To look for secondary bacterial infections in bronchogenic carcinoma（BCA） with resistant organisms harboring bla genes considering the paucity of relevant ***: A total of 137 confirmed cases of BCA and 34 healthy volunteers were studied for the occurrence and prevalence of blaCTX-M and and blaAmpC harboring-enterobacteriaceae.A subset of these patients（n=69） was previously reported for the secondary infection with the Aspergillus species. Bronchoalveolar lavages（BAL） were subjected for bacterial and fungal cultures and the bacterial isolates were screened by multiplex PCRs for the presence of blaCTX-M and blaAmpC.The isolates were also screened for the association of insertion sequence（IS26） by PCR and characterized by RAPD for any clonal ***:A total of 143 bacterial isolates were obtained from 137 BAL specimens of BC,*** Enterobacteriaceae-isolates were multidrug-resistant showing concomitant resistance to fluoroquinolones and *** blaCTX-M and blaAmpC of CIT family were detected in 77.4%and 27.4%isolates,*** revealed the presence of blaCTX-M-15 and blaCMY-6.Twenty one percent of the isolates were simultaneously harboring blaampC and blaCTX-M-15.IS26 PCR and RAPD typing revealed the presence of diverse bacterial population but no predominant clone was *** present study also suggests strong association of aspergillosis with lung cancer and further strengthens the potential use of non-validated serological tests suggested ***:We emphasize that all patients of bronchogenic carcinoma should also be screened for secondary bacterial infections,along with secondary fungal infections,so as to introduce early and specific antimicrobial therapy and to prevent unwanted deaths.

关键词： Bronchogenic carcinoma Secondary bacterial infections CTX-M AmpC Enterobacteriaceae

High strength Al-Cu-Mg based alloy with synchronous improved tensile properties and hot-cracking resistance suitable for laser powder b e d fusion

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Journal of Materials Science & Technology 2023年第10期141卷 155-170页

作者： q.Z.Wang n.Kang X.Lin M.EL Mansori W.D.Huang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Arts et Metiers Institute of Technology MSMPHESAM UniversitéChâlons-en-Champagne F-51006France Key Laboratory of Metal High Performance Additive Manufacturing and Innovative Design MIIT ChinaNorthwestern Polytechnical UniversityXi’an 710072China Texas A&M Engineering Experiment Station Institute for Manufacturing SystemsCollege StationTX 77843USA

In present work,a novel crack-free Al-Cu-Mg-Si-Ti alloy with synchronous improved tensile properties and hot-cracking resistance was proposed and successfully manufactured by laser powder bed fusion(LPBF).The microstructure evolution behaviors and the corresponding strengthening mechanisms were investigated in *** LPBF-processed Al-Cu-Mg-Si-Ti alloy presents a heterogeneous microstructure consisting of ultrafine equiaxed grains(UFGs)at the boundary and coarse columnar grains(CGs)at the center of the single molten ***-precipitated D022-Al 3 Ti particles were found to act as the nuclei to refine the grains at the boundary of the molten pool during solidification process,which is attributed to the low cooling rate providing the sufficient incubation time for the precipitation of D022-Al 3 *** are two orientation relationships(ORs)betweenα-Al and D022-Al 3 Ti,i.e.[001]α-Al//[001]D022-Al3Ti,(200)α-Al//(200)D022-Al3Ti and[1¯1¯2]α-Al//[¯111]D022-Al3Ti,(1¯11)α-Al//(¯11¯2)D022-Al3Ti,which are two of the eight ORs predicted with the E2EM *** grains in present alloy,no matter for UFGs or CG,exhibited high critical hot-cracking stress,which means a strong hot-cracking ***-nanoprecipitation of Cu-,Mg-,and Si-rich q’and S’phases was introduced to enhance the mechanical performance ofα-Al *** as-built sample exhibits superior tensile properties,with the yield strength(YS)of 473±8 MPa,ultimate tensile strength(UTS)of 541±2 MPa and elongation(EI)of 10.9%±1.2%.

关键词： Laser powder bed fusion High strength Al-Cu-Mg alloys Duplex microstructure Precipitation Tensile properties

nonlinear mechanics of a ring structure subjected to multi-pairs of evenly distributed equal radial forces

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Acta Mechanica Sinica 2017年第5期33卷 942-953页

作者： q. Chen F. Sun Z. Y. Li L. Taxis n. Pugno Biomechanics Laboratory School of Biological Science and Medical Engineering Southeast University State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics School of Chemistry Physics and Mechanical EngineeringQueensland University of Technology (QUT) Laboratory of Bio-Inspired and Graphene nanomechanics Department of Civil Environmental and Mechanical Engineering University of Trento School of Engineering and Materials Science Queen Mary University of London Ket Lab Italian Space Agency Via del Politecnico snc

Combining the elastica theory, finite element (FE) analysis, and a geometrical topological experiment, we studied the mechanical behavior of a ring subjected to multi-pairs of evenly distributed equal radial forces by looking at its seven distinct states. The results showed that the theoretical predictions of the ring deformation and strain energy matched the FE results very well, and that the ring deformations were comparable to the topological experiment. Moreover, no matter whether the ring was compressed or tensioned by n-pairs of forces, the ring always tended to be regular polygons with 2n sides as the force increased, and a proper compressive force deformed the ring into exquisite flower-like patterns. The present study solves a basic mechanical problem of a ring subjected to lateral forces, which can be useful for studying the relevant mechanical behavior of ring structures from the nano- to the macro-scale.

关键词： Ring structures Mechanical properties Shape Strain energy

Zinc Oxide-Based q-Switched Erbium-Doped Fiber Laser

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Chinese Physics Letters 2017年第4期34卷 43-45页

作者： n.A.Aziz A.A.Latiff M.q.Lokman E.Hanafi S.W.Harun Department of Electrical Engineering Faculty of Engineering University of Malaya Kuala Lumpur 50603 Malaysia Photonics Research Centre University of Malaya Kuala Lumpur 50603 Malaysia

We demonstrate a q-switched erbium-doped fiber laser （EDFL） using a newly developed zinc oxide- （ZnO） based saturable absorber （SA）. The SA is fabricated by embedding a prepared ZnO powder into a poly（vinyl alcohol） film. A small piece of the film is then sandwiched between two fiber ferrules and is incorporated in an EDFL cavity for generating a stable q-switching pulse train. The EDFL operates at 1560.4nm with a pump power threshold of 11.8mW, a pulse repetition rate tunable from 22.79 to 61.43kHz, and the smallest pulse width of 7.00 μs. The q-switching pulse shows no spectral modulation with a peak-to-pedestal ratio of 62 dB indicating the high stability of the laser. These results show that the ZnO powder has a great potential to be used for pulsed laser applications.

关键词： Zinc Oxide-Based q-Switched Erbium-Doped Fiber Laser SA ZnO

novel Photoinitiated Synthesis, Characterization, Thermal Kinetics, and Mechanism of Complex of Potassium Hexacyanoferrate with Imidazole

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Chemical Research in Chinese Universities 2009年第2期25卷 138-142页

作者： MAJID Kowsar AHMAD Siraj malik Mukhtar Ahmad Department of Chemistry National Institute of Technology

Photoinitiated substitution complex of [Fe（Cn）6]^4- with imidazole has been synthesized and characterized. On the basis of elemental analysis, the empirical molecular formula of the complex is K4[Fe（Cn）5（C3H4n2）]·4H2O. The substitution of aquo ligand produced as a result of photoexcitation by imidazole has been confirmed by various spectroscopic thechniques like UV-Vis, FTIR, nMR, and SEM techniques. The characteristic FTIR and nMR absorption peaks for different entities present support the assigned formula. The presence of cyanide and imidazole ligands is shown by FTIR absorption peaks at 2046 cm^-1 due to v（C≡n） and at 1447 and 1619 cm^-1 due to v（C=n） and v（C=C） stretching vibration of the aromatic ring of imidazole, hence, confirming the assigned formula and photoinitiated substitution process. ^1HnMR also shows the peaks for aromatic hydrogen confirming again the presence of imidazole in the complex, further supporting the successful photoinitiated process. The water outside the coordination sphere has been confirmed from FTIR peaks and thermal analysis. Thermal kinetics and mechanistic studies have also been carried out by TG and DSC, Thermodynamics parameters such as activation energy（Ea）, preexponential factor（A）, and entropy of activation（Aft） have been calculated for each step via different methods like Doyle＇s, Coats, and Redfern and Arrehenius.

关键词： Photochemistry Potassium he.xacyanoferrate Imidazole Photosubstitution FTIR

EFFECT OF Mo AnD Mo_2C On THE MICROSTRUCTURE AnD PROPERTIES OF THE CERMETS BASED On Ti(C,n)

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Acta Metallurgica Sinica(English Letters) 2008年第3期21卷 211-219页

作者： S.q. Zhou W. Zhao W.H. Xiong Y.n. Zhou School of Materials Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China The University of Waterloo Waterloo ON N2L3G1 Canada

Effect of Mo and Mo2 C on the microstructure and properties of Ti（C,n）-based cermets was investigated in this article. The results have indicated that the weight percentage of Mo from 5 to 10 can reduce Ti（C,n） grain diameter and thickness of the rim, and Ti（C,n） grain can be wetted by ni-Cu-Mo liquid so as to get small contiguity of Ti（C,n） grain. In that way, the transverse rupture strength of Ti（C,n）-based cermets has reached 1800-1900 MPa; the fracture toughness has been due to 16-18 MPa.m1/2. But 15 wt pct Mo was not more effective on Ti（C,n）-based cermets, because the thickness of the rim becomes larger. In the circumstance of Mo2 C, 5 wt pct Mo2 C was good for microstructure and properties of Ti（C,n）-based cermets, but 11 wt pct Mo2C has resulted in larger contiguity of Ti（C,n） grain and big Ti（C,n） grain diameter so as to reduce transverse rupture strength and fracture toughness. So that, the effect of Mo on Ti（C,n）-based cermets is better than Mo2C.

关键词： Cermet Transverse rupture strength (TRS) Contiguity Fracture toughness