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The Mixed-Mode Fatigue Crack Propagation Model of Piezoelectric Materials Under Electric Fatigue Loading by the jk-Integral

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Acta Mechanica Solida Sinica 2024年第4期37卷 634-641页

作者： Xianghua Chen Chunguang wang Qun Li The Institute of Xi’an Aerospace Solid Propulsion Technology Xi’an710025China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an710049China

The electric fatigue load has a significant effect on the crack propagation behavior and failure life of piezoelectric materials and devices. In this paper, an electrical mixed-mode fatigue crack propagation model for piezoelectric materials is proposed based on the piezoelectric jk-integral theory. The crack initiation, propagation, and life prediction criteria of piezoelectric materials under electric fatigue loading are given by this model, and the finite element simulation model is established to study the electrical mixed-mode crack propagation behavior of piezoelectric structures. Meanwhile, the electrical mixed-mode fatigue crack propagation model is applied to the fatigue crack propagation behavior of a piezoelectric typical defective structure, the crack–hole interference model. The mixed-mode crack propagation, fatigue life, and the interference behavior between the crack and hole at various hole locations of the crack–hole interference model are well recognized by this model. The crack propagation behavior under different electrical load intensities is also considered. The results show that the hole in front of the crack tip inhibits crack propagation to a certain extent, and the strength of electrical load affects the fatigue life of piezoelectric materials and structures. Therefore, the proposed electrical mixed-mode fatigue crack propagation model provides a reference for predicting the mixed-mode fatigue crack propagation behavior and fatigue life of piezoelectric structures under electric fatigue loading.

关键词： Configurational force j k-integral Piezoelectric Mixed-mode crack propagation Life prediction

Spatial diversion and coordination of flood water for an urban flood control project in Suzhou, China

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Water Science and Engineering 2024年第2期17卷 108-117页

作者： Yu Xu You-peng Xu Qiang wang Yue-feng wang Chao Gao Department of Geography and Spatial Information Techniques Ningbo UniversityNingbo 315211China State Key Laboratoryof Hydology Water Resources and Hydraulic Enginering Nanjing Hydraulic Research InstitueNanjing 210029China Laboratory of Sustainable Urban Drainage Ningbo UniversityNingbo 31521lChina Schol of Gegraphical and Oceanographic Sciences Nanjing UniversiyNanjing 210023China School of Geography and Tourism Chongqing Normal UniversityChongqing 401331China

Suzhou City,located in the Yangtze River Delta in China,is prone to flooding due to a complex combination of natural factors,including its monsoon climate,low elevation,and tidally influenced position,as well as intensive human *** Large Encirclement Flood Control Project(LEFCP)was launched to cope with serious floods in the urban *** project changed the spatiotemporal pattern of flood processes and caused spatial diversion of floods from the urban area to the outskirts of the ***,this study developed a distributed flood simulation model in order to understand this transition of flood *** results revealed that the LEFCP effectively protected the urban areas from floods,but the present scheduling schemes resulted in the spatial diversion of floods to the outskirts of the *** rainstorm frequencies of 10.0%to 0.5%,the water level differences between two representative water level stations(Miduqiao(MDQ)and Fengqiao(FQ))located inside and outside the LEFCP area,ranged from 0.75 m to 0.24 m and from 1.80 m to 1.58 m,*** addition,the flood safety margin at MDQ and the duration with the water level exceeding the warning water level at FQ ranged from 0.95 m to 0.43 m and from 4 h to 22 h,*** scheduling schemes for the hydraulic facilities of the LEFCP in extreme precipitation cases were developed ac-cording to food simulations under seven scheduling *** helps to regulate the spatial flood diversion caused by the LEFCP during extreme precipitation.

关键词： Urban flooding Urban flood control project Rainstorm fregue ncy Flood simulation model Suzhou City

Deactivation mechanisms and anti-deactivation strategies of molecular sieve catalysts for NO_(x)reduction

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Chinese Chemical Letters 2024年第3期35卷 8-18页

作者： Fuli wang Penglu wang jin zhang Dengchao Peng Mengmeng Wei Dengsong zhang School of Environmental and Chemical Engineering State Key Laboratory of Advanced Special SteelInternational Joint Laboratory of Catalytic ChemistryCollege of SciencesShanghai UniversityShanghai 200444China

Molecular sieve catalysts,owing to their unique chemical properties,are widely used as catalysts among various catalytic *** Br?nsted acid sites in molecular sieve catalysts usually enable active components to disperse well on the catalyst surface,and help to adsorb a large number of gas molecules to achieve maximum catalytic ***,a variety of molecular sieve catalysts have been developed and used in the selective catalytic reduction of NO_(x)by NH_(3)(NH_(3)-SCR).For example,Cu molecular sieve catalysts such as Cu-SSz-13 and Cu-SAPO-34 with wide temperature windows and stable structure are considered and applied as commercial catalysts for NO_(x)removal in diesel vehicles for a long *** molecular sieve catalysts possess many advantages,they still cannot avoid the serious deactivation caused by various factors in practical *** this review,reasons leading to the deactivation of molecular sieve catalysts for NO_(x)reduction in actual working conditions were *** deactivation mechanisms of molecular sieve catalysts for NO_(x)reduction were analyzed and the corresponding anti-deactivation strategies were ***,challenges and prospects of molecular sieve catalysts for NO_(x)reduction were also proposed.

关键词： Environmental catalysis NO_(x) reduction Molecular sieve catalysts Deactivation mechanism Anti-deactivation

Optimization of chemistry and process parameters for control of intermetallic formation in Mg sludges

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journal of Magnesium and Alloys 2024年第4期12卷 1431-1448页

作者： Y.Fu G.G.wang A.Hu Y.Li K.B.Thacker j.P.Weiler H.Hu Department of Mechanical Automotive and Materials EngineeringUniversity of Windsor401 Sunset AveWindsorOntario N9B 3P4Canada Global Technology Centre Meridian Lightweight Technologies25 MacNab AveStrathroyOntario N7G 4H6Canada

Intermetallic formation in sludge during magnesium(Mg)melting,holding and high pressure die casting practices is a very important ***,very often it is overlooked by academia,original equipment manufacturers(OEM),metal ingot producers and even die *** aim of this study was to minimize the intermetallic formation in Mg sludge via the optimization of the chemistry and process *** Al8Mn5 intermetallic particles were identified by the microstructure analysis based on the Al and Mn *** design of experiment(DOE)technique,Taguchi method,was employed to minimize the intermetallic formation in the sludge of Mg alloys with various chemical compositions of Al,Mn,Fe,and different process parameters,holding temperature and holding *** sludge yield(SY)and intermetallic size(IS)was selected as two *** optimum combination of the levels in terms of minimizing the intermetallic formation were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,690℃ for the holding temperature and holding at 30 mins for the holding time,*** best combination for smallest intermetallic size were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,630℃ for the holding temperature and holding at 60 mins for the holding time,*** groups of sludge factors,Chemical Sludge(CSF),Physical Sludge(PSF)and Comprehensive Sludge Factors(and CPSF)were established for prediction of sludge yields and intermetallic sizes in Al-containing Mg *** CPSF with five independent variables including both chemical elements and process parameters gave high accuracy in prediction,as the prediction of the PSF with only the two processing parameters of the melt holding temperature and time showed a relatively large deviation from the experimental *** Chemical Sludge Factor was primarily designed for small ingot producers and die casters with a limited melting and holding capacity,of which process parameters could be fixed *** Physical Sludge Factor could be used f

关键词： Magnesium sludge Al-Mn intermetallic Optimization Taguchi method Sludge factor Chemical composition Process parameter

Numerical Investigations on the Resonance Errors of Multiscale Discontinuous Galerkin Methods for One-Dimensional Stationary Schrödinger Equation

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Communications on Applied Mathematics and Computation 2024年第1期6卷 311-324页

作者： Bo Dong Wei wang Department of Mathematics University of Massachusetts DartmouthNorth DartmouthMA02747USA Department of Mathematics and Statistics Florida International UniversityMiamiFL33199USA

In this paper,numerical experiments are carried out to investigate the impact of penalty parameters in the numerical traces on the resonance errors of high-order multiscale discontinuous Galerkin(DG)methods(Dong et *** j Sci Comput 66:321–345,2016;Dong and wang in j Comput Appl Math 380:1–11,2020)for a one-dimensional stationary Schrödinger *** work showed that penalty parameters were required to be positive in error analysis,but the methods with zero penalty parameters worked fine in numerical simulations on coarse *** this work,by performing extensive numerical experiments,we discover that zero penalty parameters lead to resonance errors in the multiscale DG methods,and taking positive penalty parameters can effectively reduce resonance errors and make the matrix in the global linear system have better condition numbers.

关键词： Discontinuous Galerkin(DG)method Multiscale method Resonance errors One-dimensional Schrödinger equation

Advances in regional nodal management of early-stage breast cancer

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Chinese journal of Cancer Research 2024年第2期36卷 215-225页

作者： zhao Bi Yongsheng wang Breast Cancer Center Shandong Cancer Hospital and InstituteShandong First Medical University and Shandong Academy of Medical SciencesJinan 250017China

With the continuous improvement of systemic treatment, reasonable local regional control of early-stage breast cancer can be translated into survival benefits. The optimization of regional nodal management in patients with limited sentinel lymph node(SLN) metastasis needs to be weighed by surgical complications, regional recurrence risk, and lymph node status, as well as other escalating treatment(systemic/radiotherapy) that may result from deescalating surgery. With the effective support and supplementation of systemic therapy and radiotherapy, the management of axillary surgery is developing in a de-escalating trend. The widespread application of neoadjuvant therapy has contributed to optimizing the management of patients with clinically node-negative/imaging nodepositive disease. In clinical practice, it is necessary to consider the residual tumor burden of regional lymph nodes when formulating the optimal irradiation fields in patients with limited positive SLN without axillary lymph node dissection. The combined application of genomic tests and American College of Surgeons Oncology Group z0011/AMAROS criteria could provide patients with a better strategy of dual de-escalation treatment, which includes the de-escalation of both axillary surgery and systemic treatment. In the era of sentinel lymph node biopsy(SLNB), the regional nodal management of breast cancer should adhere to the concept of “updating ideas, making bold assumptions, and carefully seeking proof”, make full use of the benefits of systemic therapy and radiotherapy to reduce the scope of surgery and complications, and expand the “net benefit” of efficacy and quality of life. This review discusses the optimization of regional nodal management in the era of SLNB, in order to provide reference information for clinicians.

关键词： Breast cancer sentinel lymph node biopsy internal mammary lymph node radiotherapy surgery

CRBFT:A Byzantine Fault-Tolerant Consensus Protocol Based on Collaborative Filtering Recommendation for Blockchains

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Computers, Materials & Continua 2024年第7期80卷 1491-1519页

作者： Xiangyu Wu Xuehui Du Qiantao Yang Aodi Liu Na wang Wenjuan wang He’nan Province Key Laboratory of Information Security Information Engineering UniversityZhengzhou450000China School of Cyber Science Engineering Zhengzhou UniversityZhengzhou450000China

Blockchain has been widely used in finance,the Internet of Things(IoT),supply chains,and other scenarios as a revolutionary *** protocol plays a vital role in blockchain,which helps all participants to maintain the storage state ***,with the improvement of network environment complexity and system scale,blockchain development is limited by the performance,security,and scalability of the consensus *** address this problem,this paper introduces the collaborative filtering mechanism commonly used in the recommendation system into the Practical Byzantine Fault Tolerance(PBFT)and proposes a Byzantine fault-tolerant(BFT)consensus protocol based on collaborative filtering recommendation(CRBFT).Specifically,an improved collaborative filtering recommendation method is designed to use the similarity between a node’s recommendation opinions and those of the recommender as a basis for determining whether to adopt the recommendation *** can amplify the recommendation voice of good nodes,weaken the impact of cunningmalicious nodes on the trust value calculation,andmake the calculated resultsmore *** addition,the nodes are given voting power according to their trust value,and a weight randomelection algorithm is designed and implemented to reduce the risk of *** experimental results show that CRBFT can effectively eliminate various malicious nodes and improve the performance of blockchain systems in complex network environments,and the feasibility of CRBFT is also proven by theoretical analysis.

关键词： Blockchain consensus byzantine fault-tolerant collaborative filtering trust

Solid particle size characterization by a high-frequency collision response in pneumatic particulate flow

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Particuology 2024年第3期86卷 39-54页

作者： Kai wang Yichen Li ziang Chang Min Qin Guangming Fu Bangtang Yin Gang wang jiaqi Tian School of Petroleum Engineering China University of Petroleum(East China)Qingdao266580China Key Laboratory of Unconventional Oil&Gas Development China University of Petroleum(East China)Ministry of EducationQingdao266580China National Engineering Research Center of Oil&Gas Drilling and Completion Technology Qingdao266580China Shock and Vibration of Engineering Materials and Structures Key Lab ofSichuan Province Southwest University of Science and TechnologyMianyang621000China

A novel triaxial vibration method is developed for the real-time characterization of the solid particle size distribution(PsD)in pneumatic particulate flow,which is critical for chemical *** this work,the particle-wall collision and friction behaviours were analysed by the time-domain statistical and timefrequency joint methods to narrow the high-frequency response range by the initial experiment of free fall for a single particle,interparticle,and multiple ***,verification experiments of PSD characterization in pneumatic flow were ***,the quantitative triaxial energy response model that considers the particle size,shape,and mass factors were ***,a good agreement of the particle number identification was found between the triaxial vibration energy and mean particle size of 150-550μ***,the performance with the best accuracy was focused on a range of 42-43 kHz in the x-axis and z-axis and 36.8-38.8 kHz in the ***,the individual particle energy was inversely analysed by the triaxial vibration response within the optimized frequency bands,and the PSD was characterized in real-time by a low error rate,that is,5.2% from the Xz-axis direction of sand(42-43 kHz)and 5.6% from the XYz-axis of glass(30.9-33.9 kHz,46.2-47.2 kHz,38.3-41.3 kHz for each axis response).Therefore,this research complements the existing approaches for PsD characterization in particulate multiphase flow.

关键词： Solid particulate flow Triaxial vibration High-frequency response Particle wall Particle size distribution

Permian ridge subduction-related magmatism in the Chinese Altai: Insights from geochronology and geochemistry of the jiangjunshan pluton

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journal of Earth Science 2024年

作者： Shi-Heng Bai Ru-Xiong Lei Matthew j.Brzozowski zhenhua wang Wei wang Chang-zhi Wu Laboratory of Mineralization and Dynamics， School of Earth Science and Resources， Chang'an University Xinjiang Natural Resources and Ecological Environment Research Center

The Chinese Altai is an important constituent of the Central Asian Orogenic Belt， a prominent Phanerozoic accretionary orogenic belt. Oceanic-continental subduction processes during the Cambrian–Carboniferous and intracontinental extension from the Triassic onwards have been well constrained in the Chinese Altai， the southwestern portion of the CAOB. Characterizing the petrogenetic evolution of the Chinese Altai during the Permian has， therefore， been considered critical to enhancing our understanding of the tectonic transformations that occurred in this region. Despite this， the tectonic environment of the Chinese Altai during this period remains equivocal. To address this deficiency， this contribution characterizes the age of formation and geochemical composition of the jiangjunshan pluton located in the southern portion of the Chinese Altai. zircon U-Pb geochronology demonstrates that the gabbro and two-mica alkali feldspar granite， which comprise the main body of the jiangjunshan pluton， formed at ca. 272 ± 3.5 and 272 ± 1.6 Ma， respectively. Geochemically， the gabbro is depleted in light rare earth elements （LREE）， has low Nb/Yb （0.39–0.46） and Ti/V （23.7–25.3） ratios， exhibits trace-element characteristics resembling normal mid-ocean ridge basalts （N-MORB）， but is depleted in Nb and Ta similar to island arc basalts. The depleted Hf and Nd isotope compositions (εHf（t） = +0.60 to +4.63， εNd（t） = +6.32 to +7.80) of the gabbro， coupled with the weak correlation between εNd（t） values and SiO2contents， suggest that the magma from which it crystallized was slightly contaminated by crustal material during its evolution. Based on the Sm， Yb， and La contents， it is inferred that the melt from which the gabbro crystallized originated from approximately 8–20% partial melting of spinel lherzolite mantle. The depleted Hf and Nd isotope compositions (εHf（t） = +6.81 to +9.10， εNd（t） = +0.79 to +1.45) of the granite， combined with petrographic observations （e.g.， absent of the

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