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Frontiers of Architectural Research 2024年第4期13卷 712-728页

作者： Mine Hamamcıoğlu-Turan Engin Aktaș Özge Deniz Toköz Faculty of Architecture İzmir Institute of TechnologyİzmirTürkiye Faculty of Engineering İzmir Institute of TechnologyİzmirTürkiye

This study aims to contribute to the understanding of the evolution of art and construction in the early settlements established by Turkish communities on the far west Asian coast by focusing on two developed examples in Urla *** surveying and evaluation techniques of architectural restoration and civil engineering were *** findings include the understanding of the hierarchy of rural settlements in the studied landscape:old C¸esme the most developed village of peninsula in the 16th *** was positioned along a valley in distance to coast,but in control of harbor that played significant role in commerce between Europe and *** mosque and tomb,dated to late 14th e early 15th centuries,used to crown *** minaret tower of mosque,domed tomb tower on a cubical base and squinch in the transition zone of mosque are evidences for Central Asian *** of local lime stone,re-usage of andesite blocks,framing of the stone blocks with bricks,and pendentive in tomb refer to Roman-Byzantine *** study presents the development of Turkish art and construction on the far west Asian coast in the 14th‒15th *** will be a guide for related conservation management in similar contexts.

关键词： Mosque Tomb Central Asia Western Anatolia Mediterranean Conservation

Transient Characteristics and Accommodative Current Limiting strategy for Bidirectional Interlinking Converters in Hybrid AC/DC Microgrids

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CsEE Journal of Power and Energy systems 2024年第4期10卷 1575-1588页

作者： Xia shen zhikang shuai Wen Huang Chao shen Yang shen z.John shen College of Electrical and Information Engineering Hunan UniversityChangsha 410082China Department of Electrical and Computer Engineering Illinois Institute of TechnologyChicagoIL 60616 USA

Bidirectional interlinking converter(BIC)is the core equipment in a hybrid AC/DC microgrid connected between AC and DC ***,the variety of control modes and flexible bidirectional power flow complicate the influence of AC faults on BIC itself and on DC sub-grid,which potentially threaten both converter safety and system *** study first investigates AC fault influence on the BIC and DC bus voltage under different BIC control modes and different pre-fault operation states,by developing a mathematical model and equivalent sequence ***,based on the analysis results,a general accommodative current limiting strategy is proposed for BIC without limitations to specific mode or operation *** amplitude is predicted and constrained according to the critical requirements to protect the BIC and relieving the AC fault influence on the DC bus *** with conventional methods,potential current limit failure and distortions under asymmetric faults can also be ***,experiments verify feasibility of the proposed method.

关键词： Bidirectional interlinking converter current limiting fault characteristic hybrid AC/DC microgrid variation/oscillation of DC bus voltage

Research on Fine-Grained RecognitionMethod for sensitive Information in social Networks Based on CLIP

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Computers, Materials and Continua 2024年第1期81卷 1565-1580页

作者： zhang M. shan F. Liu M. Wang z. school of Computer science Zhongyuan University of Technology Zhengzhou 450007 China Henan Key Laboratory of Cyberspace situation Awareness Zhengzhou 450001 China

With the emergence and development of social networks, people can stay in touch with friends, family, and colleaguesmore quickly and conveniently, regardless of their location. This ubiquitous digital internet environment has also ledtolarge-scaledisclosureof personal *** tothe complexity andsubtletyof sensitive information, traditional sensitive information identification technologies cannot thoroughly address the characteristics of each piece of data, thus weakening the deep connections between text and images. In this context, this paper adopts the CLIP model as a modality discriminator. By using comparative learning between sensitive image descriptions and images, the similarity between the images and the sensitive descriptions is obtained to determine whether the images contain sensitive information. This provides the basis for identifying sensitive information using different modalities. specifically, if the original data does not contain sensitive information, only single-modality text-sensitive information identification is performed; if the original data contains sensitive information, multimodality sensitive information identification is conducted. This approach allows for differentiated processing of each piece of data, thereby achieving more accurate sensitive information identification. The aforementioned modality discriminator can address the limitations of existing sensitive information identification technologies, making the identification of sensitive information from the original data more appropriate and precise. © 2024 The Authors. Published by Tech science Press.

关键词： Deep learning multi-modal fusion sensitive information recognition social networks

High-secured Image LsB steganography Using AVL-Tree with Random RGB Channel substitution

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Computers, Materials and Continua 2024年第1期81卷 183-211页

作者： Njoum M. sulaiman R. shukur z. Qamar F. Center of Cyber security Faculty of Information Science and Technology Universiti Kebangsaan Malaysia Selangor Bangi 43600 Malaysia Computer science and Cyber security Faculty of Engineering and Information Technology BirZeit University Ramallah P.O. Box 14 BirZeit Palestine

Random pixel selection is one of the image steganography methods that has achieved significant success in enhancing the robustness of hidden data. This property makes it difficult for steganalysts’ powerful data extraction tools to detect the hidden data and ensures high-quality stego image generation. However, using a seed key to generate non-repeated sequential numbers takes a long time because it requires specific mathematical equations. In addition, these numbers may cluster in certain ranges. The hidden data in these clustered pixels will reduce the image quality, which steganalysis tools can detect. Therefore, this paper proposes a data structure that safeguards the steganographic model data and maintains the quality of the stego image. This paper employs the Adelson-Velsky and Landis (AVL) tree data structure algorithm to implement the randomization pixel selection technique for data concealment. The AVL tree algorithm provides several advantages for image steganography. Firstly, it ensures balanced tree structures, which leads to efficient data retrieval and insertion operations. secondly, the self-balancing nature of AVL trees minimizes clustering by maintaining an even distribution of pixels, thereby preserving the stego image quality. The data structure employs the pixel indicator technique for Red, Green, and Blue (RGB) channel extraction. The green channel serves as the foundation for building a balanced binary tree. First, the sender identifies the colored cover image and secret data. The sender will use the two least significant bits (2-LsB) of RGB channels to conceal the data’s s.z. and associated information. The next step is to create a balanced binary tree based on the green channel. Utilizing the channel pixel indicator on the LsB of the green channel, we can conceal bits in the 2-LsB of the red or blue channel. The first four levels of the data structure tree will mask the data s.z., while subsequent levels will conceal the remaining digits of s

关键词： AVL tree capacity Image steganography imperceptibility peak signal-to-noise ratio (PsNR) pixel random selection (PRs)

Rational molecular design of efficient yellow-red dendrimer TADF for solution-processed OLEDs: a combined effect of substitution position and strength of the donors

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science China Chemistry 2024年第5期67卷 1613-1623页

作者： Changfeng si Dianming sun Tomas Matulaitis David B.Cordes Alexandra M.z.slawin Eli zysman-Colman Organic semiconductor Centre EaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsKY169STUK

The development of high-performance solution-processed red organic light-emitting diodes(OLEDs) remains a challenge,particularly in terms of maintaining efficiency at high luminance. Here, we designed and synthes.z.d four novel orange-red thermally activated delayed fluorescence(TADF) dendrimers that are solution-processable: 2GCz BP, 2DPACz BP, 2FBP2GCz and 2FBP2DPACz. We systematically investigated the effect of substitution position and strength of donors on the optoelectronic properties. The reverse intersystem crossing rate constant(kRIsC) of the emitters having donors substituted at positions 11and 12 of the dibenzo[a,c]phenazine(BP) is more than 10-times faster than that of compounds substituted having donors substituted at positions 3 and 6. Compound 2DPACz BP, containing stronger donors than 2GCz BP, exhibits a red-shifted emission and smaller singlet-triplet energy splitting, ΔE_(sT), of 0.01 e V. The solution-processed OLED with 10 wt% 2DPACz BP doped in m CP emitted at 640 nm and showed a maximum external quantum efficiency(EQE_(max)) of 7.8%, which was effectively maintained out to a luminance of 1,000 cd m-2. such a device's performance at relevant display luminance is among the highest for solution-processed red TADF OLEDs. The efficiency of the devices was improved significantly by using 4Cz IPN as an assistant dopant in a hyperfluorescence(HF) configuration, where the 2DPACz BP HF device shows an EQEmaxof 20.0% at λEL of 605 nm and remains high at 11.8% at a luminance of 1,000 cd m-2, which makes this device one of the highest efficiency orange-to-red HF sP-OLEDs to date.

关键词： thermally activated delayed fluorescence solution-processing red OLEDs dibenzo[a,c]phenazine dendrimers

Decorating crystalline YFe_(2-x)Al_(x) on the Mg_(60)La_(10)Ni_(20)Cu_(10) amorphous alloy as “hydrogen pump” to realize fast de/hydrogenation

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Journal of Materials science & Technology 2024年第6期173卷 72-79页

作者： L.J.Huang H.Wang L.z.Ouyang M.zhu H.J.Lin school of Materials science and Engineering Key Laboratory of Advanced Energy Storage Materials of Guangdong ProvinceSouth China University of TechnologyGuangzhou 510641China Institute of Advanced Wear&Corrosion Resistance and Functional Materials Jinan UniversityGuangzhou 510632China

Mg-based amorphous alloys are one of the potential hydrogen storage materials but suffer from sluggish dehydrogenation/hydrogenation(de/hydrogenation)*** this work,as a new strategy,a hydrogen pump is built on the surface of amorphous alloys to solve this *** milling crystalline YFe_(2-x)Al_(x) hydrogen storage alloy with Mg_(60)La_(10)Ni_(20)Cu_(10) amorphous alloy,fine crystalline particles were seeded on amorphous alloy powder to form a“strawberry”*** to the TEM observation,a metallurgical bonding boundary formed between the Mg-based amorphous matrix and the Y-Fe-Al crystalline *** microstructure and de/hydrogenation kinetics investigation,the“hydrogen pump”effect of the seeded crystalline alloy was confirmed,which makes it much easier for the hydrogen to dissociate on and diffuse through the surface of the Mg-based amorphous *** such effect,the H absorption rate of Mg_(60)La_(10)Ni_(20)Cu_(10) amorphous alloy became almost eight times faster and it absorbs ~2.8 wt.% in 1 h at 130℃ under 4.5 MPa-H_(2).Further,fast hydrogenation can even achieve at 70℃ and the low-temperature dehydrogenation kinetics of the amorphous hydride can be also greatly *** present work proves that surface modification is of great importance for obtaining Mg-based amorphous alloy with ideal hydrogen storage performance.

关键词： Hydrogen storage Mg-based amorphous alloy Hydrogen pump Composite structure

Microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with different prestrain levels

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Journal of Materials science & Technology 2024年第4期171卷 80-93页

作者： Y.H.zhang H.Li z.W.Yang X.Liu Q.F.Gu state Key Laboratory of solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory alloy(sMA)is a promising material in the aerospace field due to its wide transformation *** application of shape memory effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to ***-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of sMA ***,microstructure evolution and deformation mechanisms of Ni_(47)Ti_(44)Nb_(9)sMA subjected to vari-ous prestrain levels are still *** this end,microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by the dislocation slip of the NiTi matrix andβ-Nb *** stageⅢ,in addition to the higher density of dislocations and further growth of stress-induced martensite variants(sIMVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,after subsequent unloading and heating,a higher density of{114}austenite twins form in the specimen with a larger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(T)upon heating increases first and then ***ε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(T)can be attributed to the formation of new sIMVs,the further growth of existing sIMVs,and the recoverable(001)compound *** the decrease ofε_(re)^(T)is mainly associated with the irrecoverable strain by{20−1}martensite *** effe

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory alloy Wide transformation hysteresis Thermomechanical loading Microstructure evolution shape memory behaviors stress-induced martensitic transformation Deformation twinning

Electromagnetic Performance Analysis of Variable Flux Memory Machines with series-magnetic-circuit and Different Rotor Topologies

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CEs Transactions on Electrical Machines and systems 2024年第1期8卷 3-11页

作者： Qiang Wei z.Q.zhu Yan Jia Jianghua Feng shuying Guo Yifeng Li shouzhi Feng Department of Electronic and Electrical Engineering The University of SheffieldSheffield S13JDU.K. IEEE the CRRC zhuzhou Institute Company Ltd. Zhuzhou 412001China

In this paper,the electromagnetic performance of variable flux memory(VFM)machines with series-magnetic-circuit is investigated and compared for different rotor *** on a V-type VFM machine,five topologies with different interior permanent magnet(IPM)arrangements are evolved and optimized under same *** on two-dimensional(2-D)finite element(FE)method,their electromagnetic performance at magnetization and demagnetization states is *** reveals that the iron bridge and rotor lamination region between constant PM(CPM)and variable PM(VPM)play an important role in torque density and flux regulation(FR)***,the global efficiency can be improved in VFM machines by adjusting magnetization state(Ms)under different operating conditions.

关键词： Memory machine Permanent magnet Rotor topologies series magnetic circuit Variable flux

Communication-less Management strategy for Electric Vehicle Charging in Droop-controlled Islanded Microgrids

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Journal of Modern Power systems and Clean Energy 2024年第4期12卷 1227-1238页

作者： Abdullah Azhar Al-Obaidi Mohammed zaki El-sharafy Hany E.z.Farag saifullah shafiq Ali Al-Awami Independent Electricity system Operator(IEsO) MississaugaCanada Department of Electrical Engineering and Computer science York UniversityTorontoCanada University of Queensland StLucia QLD 4067Australia Department of Electrical Engineering King Fahd University of Petroleum&MineralsDhahranSaudi Arabia

Adopting high penetration levels of electric vehicles(EVs)necessitates the implementation of appropriate charging management systems to mitigate their negative impacts on pow-er distribution ***,most of the proposed Ev charging management techniques rely on the availability of high-bandwidth communication *** techniques are far from realization due to①the lack of utility-grade communica-tion systems in many cases such as secondary(low-voltage)pow-er distribution systems to which EVs are connected,rural ar-eas,remote communities,and islands,and②existing fears and concerns about the data privacy of EV users and cyber-physical *** these cases,appropriate local control schemes are needed to ensure the adequate management of EV charging without violating the grid operation ***,this paper introduces a new communication-less management strategy for EV charging in droop-controlled islanded *** proposed strategy is autonomous,as it is based on the measurement of system frequency and local bus *** proposed strategy implements a social charging fairness policy during periods when the microgrid distributed genera-tors(DGs)are in short supply by allocating more system capaci-ty to the EVs with less charging in the ***,a novel communication-less EV load shedding scheme is incorpo-rated into the management strategy to provide relief to the mi-crogrid during events of severe undervoltage or underfrequency occurrences due to factors such as high loading or DG *** simulations demonstrate the superiority of the pro-posed strategy over the state-of-the-art controllers in modulat-ing the EV charging demand to counteract microgrid instability.

关键词： Charging battery management communication-less control droop control electric vehicle islanded microgrid

RECIPROCATING EXTRUsION OF IN sITU Mg_2si REINFORCED Mg-Al BAsED COMPOsITE

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Acta Metallurgica sinica(English Letters) 2008年第3期21卷 169-177页

作者： z.M. zhang C.J. Xu X.F. Guo s.z. Jia school of Materials science ＆ Engineering Xi＇an University of Technology Xi＇an 710048 China

M92si reinforced Mg-Al based composite with high amount o/silicon was prepared by permanent mould casting, and then extruded by reciprocating extrusion （RE） after the composite was processed by homogenization heat treatment. The effect of RE processing on the morphology and s.z. of M92si and the mechanical properties of the com- posite were investigated, to develop new ways to refine the M928i phase and improve its shape. The result showed that RE was very useful in refining the M92si phase. The more the RE processing passes, the better the refining effect would be. Moreover, the uniform distribution of M928i phases would be more in the composite. After the composite was processed by RE for 12 passes, most M92si phases were equiaxed, with granular diameter below 20 μm, and distributed uniformly in the matrix of the composite. The mechanical properties of the composite could be increased prominently by RE processing, and were much higher than that in the as-cast state. As the temperature rises, the tensile strength is reduced. For the composite RE processed for 12 passes, the tensile strength, yield strength, and elongation are 325.9 MPa, 211.4 MPa, and 3.3% at room temperature, whereas, 288.2 MPa, ,207.7 MPa, and 7.8%, respectively, at 150℃. In comparison with the properties at room temperature, the tensile strength and yield strength are high and only decrease by 11.6% and 1.8% at 150℃. The M928i reinforced Mg-Al based composite possesses good heat resistance at 150℃. The excellent resistance to effect of heat is attributed to the high melting tempera- ture and good thermal stability of fine Mg2si phases, which are distributed uniformly in the composite, and effectively hinder the grain boundary gliding and dislocation movement.

关键词： Reciprocating extrusion Magnesium alloy In situ composite Elevated temperature property