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Dynamics and vibration reduction performance of asymmetric tristable nonlinear energy sink

Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 389-406页

作者： Hongyan CHEN Youcheng ZENG Hu DING Siukai lai Liqun CHEN School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechanoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200444China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityKowloonHong KongChina

With its complex nonlinear dynamic behavior,the tristable system has shown excellent performance in areas such as energy harvesting and vibration suppression,and has attracted a lot of *** this paper,an asymmetric tristable design is proposed to improve the vibration suppression efficiency of nonlinear energy sinks(NESs)for the first *** proposed asymmetric tristable NES(ATNES)is composed of a pair of oblique springs and a vertical ***,the three stable states,symmetric and asymmetric,can be achieved by the adjustment of the distance and stiffness asymmetry of the oblique *** governing equations of a linear oscillator(LO)coupled with the ATNES are *** approximate analytical solution to the coupled system is obtained by the harmonic balance method(HBM)and verified *** vibration suppression efficiency of three types of ATNES is *** results show that the asymmetric design can improve the efficiency of vibration reduction through comparing the chaotic motion of the NES oscillator between asymmetric steady *** addition,compared with the symmetrical tristable NES(TNES),the ATNES can effectively control smaller structural *** other words,the ATNES can effectively solve the threshold problem of TNES failure to weak ***,this paper reveals the vibration reduction mechanism of the ATNES,and provides a pathway to expand the effective excitation amplitude range of the NES.

关键词： asymmetric nonlinear energy sink(NES) tristable vibration control po-tential barrier

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Mechanical property of cylindrical sandwich shell with gradient core of entangled wire mesh

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Defence Technology（防务技术） 2024年第1期31卷 510-522页

作者： Xin Xue Chao Zheng Fu-qiang lai Xue-qian Wu Institute of Metal-rubber&Vibration Noise School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou350116China Fujian Metallurgical Industry Design Institute Fuzhou350116China

To explore the wide-frequency damping and vibration-attenuation performances in the application of aerospace components,the cylindrical sandwich shell structure with a gradient core of entangled wire mesh was proposed in this ***,the gradient cores of entangled wire mesh in the axial and radial directions were prepared by using an in-house Numerical Control weaving machine,and the metallurgical connection between skin sheets and the gradient core was performed using vacuum ***,to investigate the mechanical properties of cylindrical sandwich shells with axial or radial gradient cores,quasi-static and dynamic mechanical experiments were carried *** primary evaluations of mechanical properties include secant stiffness,natural frequency,Specific Energy Absorption(SEA),vibration acceleration level,and so *** results suggest that the vibration-attenuation performance of the sandwich shell is remarkable when the high-density core layer is at the end of the shell or abuts the inner *** axial gradient material has almost no influence on the vibration frequencies of the shell,whereas the vibration frequencies increase dramatically when the high-density core layer approaches the ***,compared to the conventional sandwich shells,the proposed functional grading cylindrical sandwich shell exhibits more potential in mass reduction,stiffness designing,and energy dissipation.

关键词： Entangled wire mesh Gradient cylindrical sandwich shell Vacuum brazing Secant stiffness Damping

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A booming field of large animal model research

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Zoological Research 2024年第2期45卷 311-313页

作者： Xiao-Jiang Li Liangxue lai Guangdong Key Laboratory of Non-human Primate Research Key Laboratory of CNS Regeneration(Ministry of Education)GHM Institute of CNS RegenerationJinan UniversityGuangzhouGuangdong 510632China State Key Laboratory of Bioactive Molecules and Druggability Assessment Jinan UniversityGuangzhouGuangdong 510632China CAS Key Laboratory of Regenerative Biology Guangdong Provincial Key Laboratory of Stem Cell and Regenerative MedicineGuangzhou Institutes of Biomedicine and HealthChinese Academy of SciencesGuangzhouGuangdong 510530China

Animal models are integral to the study of fundamental biological processes and the etiology of human *** animal models,especially those involving mice,have yielded abundant and significant insights,greatly enhancing ... 详细信息

关键词： mechanisms insight field

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Lacticaseibacillus rhamnosus Probio-M9 may be vertically transmitted from mother to infant during lactation based on faeces metagenomics

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Food Science and Human Wellness 2024年第2期13卷 721-728页

作者： Lan Yang lai-Yu Kwok Zhihong Sun Heping Zhang Key Laboratory of Dairy Biotechnology and Engineering Ministry of EducationInner Mongolia Agricultural UniversityHohhot 010018China Key Laboratory of Dairy Products Processing Ministry of Agriculture and Rural AffairsInner Mongolia Agricultural UniversityHohhot 010018China Inner Mongolia Key Laboratory of Dairy Biotechnology and Engineering Inner Mongolia Agricultural UniversityHohhot 010018China

Probiotics exert beneficial effects on the *** study aimed to investigate whether maternally ingested Lacticaseibacillus rhamnosus Probio-M9 during pregnancy could access and colonize the infant *** study recruited one pregnant woman,who ingested Probio-M9 daily from 35 weeks of gestation to *** of the mother-infant pair were regularly collected from one month before delivery to 6 months of infant's age for metagenomic ***-M9 genomes were mappable to all infant fecal samples,suggesting the ingested probiotics could be vertically transmitted from mother to ***-or mother-specific differential metabolic pathways were found between the maternal and infant's gut microbiome,implicating apparent differences in the intestinal metagenomic potential/function between the mother and the *** conclusion,maternal ingestion of Probio-M9 during the final weeks of gestation could deliver to the infant *** findings provided novel insights into shaping infant's gut microbiota.

关键词： Metagenomic analysis Lacticaseibacillus rhamnosus Gut microbiome Mother Infant

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Optimal Strategy for Aircraft Pursuit-evasion Games via Self-play Iteration

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Machine Intelligence Research 2024年第3期21卷 585-596页

作者： Xin Wang Qing-lai Wei Tao Li Jie Zhang State Key Laboratory of Management and Control for Complex Systems Institute of AutomationChinese Academy of SciencesBeijing100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing100049China Institute of Systems Engineering Macao University of Science and TechnologyMacao999078China

In this paper,the pursuit-evasion game with state and control constraints is solved to achieve the Nash equilibrium of both the pursuer and the evader with an iterative self-play *** the condition where the Hamiltonian formed by means of Pontryagin’s maximum principle has the unique solution,it can be proven that the iterative control law converges to the Nash equilibrium ***,the strong nonlinearity of the ordinary differential equations formulated by Pontryagin’s maximum principle makes the control policy difficult to figured *** the system dynamics employed in this manuscript contains a high dimensional state vector with *** practical applications,such as the control of aircraft,the provided overload is ***,in this paper,we consider the optimal strategy of pursuit-evasion games with constant constraint on the control,while some state vectors are restricted by the function of the *** address the challenges,the optimal control problems are transformed into nonlinear programming problems through the direct collocation ***,two numerical cases of the aircraft pursuit-evasion scenario are given to demonstrate the effectiveness of the presented method to obtain the optimal control of both the pursuer and the evader.

关键词： Differential games pursuit-evasion games nonlinear control optimal control Nash equilibrium solution

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Cr-catalyzed allylic C(sp^(3))–H addition to aldehydes enabled by photoinduced ligand-to-metal charge transfer

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Science China Chemistry 2024年第5期67卷 1589-1595页

作者： Xianrong Zeng Feng-Hua Zhang Runchen lai Xiaoyu Lin Zhaobin Wang Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province Department of ChemistrySchool of Science and Research Center for Industries of the FutureWestlake UniversityHangzhou 310030China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province Instrumentation and Service Center for Molecular SciencesWestlake UniversityHangzhou 310024China

Photoinduced ligand-to-metal charge transfer(LMCT) has emerged as an effective strategy for synthesizing organic molecules in a sustainable manner. However, the majority of existing reports on selective C(sp^(3))–H bond functionalization via photoinduced LMCT focus on the use of late transition metals or rare-earth metals for radical additions or cross-couplings. In contrast, the utilization of photoinduced LMCT with 3d early transition metals poses a significant challenge. Herein, we describe an unprecedented approach to allylic C(sp^(3))–H addition to aldehydes, employing chromium(Cr) complexes as catalysts through visible-light-induced LMCT. By investigating the reaction pathway through various mechanistic studies, including radical trapping, kinetic isotope effect(KIE) analysis, and transient absorption spectroscopy, valuable insights have been gained. The proposed mechanism suggests the intermediacy of bromine radicals through homolysis of the Cr–Br bond. Notably, this protocol expands our understanding of the photochemical properties of earth-abundant Cr complexes.

关键词： Cr catalysis photoinduced ligand-to-metal charge transfer hydrogen-atom transfer carbonyl addition

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Primary hyperparathyroidism-induced acute pancreatitis in pregnancy:A systematic review with a diagnostic-treatment algorithm

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World Journal of Gastroenterology 2024年第32期30卷 3755-3765页

作者： Goran Augustin Quirino lai Maja Cigrovski Berkovic Department of Surgery University Hospital Centre Zagreb and School of Medicine University of ZagrebZagreb 10000Croatia General Surgery and Organ Transplantation Unit Department of SurgerySapienza University of RomeRome 00018Italy Department for Sport and Exercise Medicine Faculty of KinesiologyUniversity of ZagrebZagreb 10000Croatia

BACKGROUND Primary hyperparathyroidism(PHPT)-induced acute pancreatitis(AP)during pregnancy has rarely been *** to this rarity,there are no diagnostic or treatment algorithms for pregnant *** To determine appropriate diagnostic methods,therapeutic options,and factors related to maternal and fetal outcomes for PHPT-induced AP in *** A literature search of articles in English,Japanese,German,Spanish,and Italian was performed using PubMed(1946-2023),PubMed Central(1900-2023),and Google *** Preferred Reporting Items for Systematic reviews and Meta-Analyses(PRISMA)protocol was *** search terms included“pancreatite acuta,”“iperparatiroidismo primario,”“gravidanza,”“travaglio,”“puerperio,”“postpartum,”“akute pankreatitis,”“primärer hyperparathyreoidismus,”“Schwangerschaft,”“Wehen,”“Wochenbett,”“pancreatitis aguda,”“hiperparatiroidismo primario,”“embarazo,”“parto,”“puerperio,”“posparto,”“acute pancreatitis,”“primary hyperparathyroidism,”“pregnancy,”“labor,”“puerperium,”and“postpartum.”Additional studies were identified by reviewing the reference lists of retrieved ***,imaging,surgical,obstetric,and outcome data were *** Fifty-four cases were collected from the 51 *** median maternal age was 29 ***-induced AP starts at the 20th gestational week;higher gestational weeks were seen in mothers who died(mean gestational week 28).Median values of amylase(1399,Q1-Q3=519-2072),lipase(2072,Q1-Q3=893-2804),serum calcium(3.5,Q1-Q3=3.1-3.9),and parathormone(PTH)(384,Q1-Q3=123-910)were *** 46 cases,adenoma was the cause of PHPT,followed by 2 cases of carcinoma and 1 case of *** the remaining 5 cases,the diagnosis was not *** ultrasound was positive in 34 cases,whereas sestamibi was performed in 3 cases,and neck computed tomography or magnetic resonance imaging was performed in 9 cases(the enlarged parathyroid gland was not localized in 3 cases).Surgery was the prefer

关键词： Primary hyperparathyroidism Acute pancreatitis Pregnancy Diagnosis Maternal mortality Fetal mortality Algorithm

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Dynamical distribution of continuous service time model involving non-Maxwellian collision kernel and value functions

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Chinese Physics B 2024年第9期33卷 340-348页

作者： Minfang Zhao Lingting Kong Miao Liu Shaoyong lai School of Mathematics and Statistics Yili Normal UniversityYining 835000China Institute of Applied Mathematics Yili Normal UniversityYining 835000China School of Mathematics Southwestern University of Finance and EconomicsChengdu 611130China

The distribution of continuous service time in call centers is investigated.A non-Maxwellian collision kernel combining two different value functions in the interaction rule are used to describe the evolution of continuous service time,*** the statistical mechanical and asymptotic limit methods,Fokker–Planck equations are derived from the corresponding Boltzmann-type equations with non-Maxwellian collision *** steady-state solutions of the Fokker–Planck equation are obtained in exact *** experiments are provided to support our results under different parameters.

关键词： kinetic theory service time Fokker–Planck equation value function

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Highly reversible Zn anode enabled by anticatalytic carbon layer with suppressed hydrogen evolution

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Rare Metals 2024年第7期43卷 3044-3054页

作者： Wen-Duo Zhang Chuang Sun Yu-Xuan Zhu Feng Gao Chao lai School of Chemistry and Materials Science Jiangsu Normal UniversityXuzhou221116China

Aqueous zinc-ion batteries(AZIBs)have emerged as a promising high-efficiency energy storage system due to the high energy density,low-cost and environmental ***,the practical application of AZIBs is severely restricted by the challenges faced by the Zn anode,which include uncontrollable dendrite growth,corrosion and hydrogen evolution ***,a simple and convenient physical vapor deposition(PVD)method is reported for fabricating uniform graphite as a protection layer on the surface of Zn *** high conductivity graphite layer on Zn anode(denoted as Zn@C)not only benefits the uniform distribution of the electric field,but also provides numerous Zn nucleation sites to regulate and navigate Zn-ion stripping/plating ***,the graphite layer with a poor catalytic activity endows the Zn@C anode with a highly suppressed hydrogen ***,a hydrogen and dendrite free anode is achieved with artificial anticatalytic carbon layer on Zn anode,exhibiting a high reversibility and excellent cycling stability over 2600 h at the current density of 5 mA·cm^(-2)with a capacity of 2.5 mAh·cm^(-2)and longtime cycling stability for assembled full *** work strategically designs the properties of the artificial interface layer to effectively address various challenges simultaneously,which presents insights for the future development of high-performance rechargeable AZIBs.

关键词： Zn metal anode Artificial anticatalytic layer Hydrogen suppression Dendrite free

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Oils with different degree of saturation:effects on ileal digestibility of fat and corresponding additivity and bacterial community in growing pigs

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Journal of Animal Science and Biotechnology 2024年第4期15卷 1657-1668页

作者： Lu Wang Yifan Chen Yuansen Yang Nuo Xiao Changhua lai State Key Laboratory of Animal Nutrition Ministry of Agriculture and Rural Affairs Feed Industry CentreChina Agricultural UniversityNo.2 Yuanmingyuan West RoadHaidian DistrictBeijing 100193China College of Animal Science and Technology Hebei Agricultural UniversityHebei 071000China

Background Oils are important sources of energy in pig *** combination of oils with different degree of saturation contributes to improve the utilization efficiency of the mixed oils and may reduce the cost of oil *** experiment was conducted to evaluate the effects of oils with different degree of saturation on the fat digestibility and corresponding additivity and bacterial community in growing *** Eighteen crossbred(Duroc×Landrace×Yorkshire)barrows(initial body weight:29.3±2.8 kg)were surgically fitted with a T-cannula in the distal *** experimental diets included a fat-free basal diet and 5 oil-added *** 5 oil-added diets were formulated by adding 6%oil with different ratio of unsaturated to saturated fatty acids(U:S)to the basal *** 5 oils were palm oil(U:S=1.2),canola oil(U:S=12.0),and palm oil and canola oil were mixed in different proportions to prepare a combination of U:S of 2.5,3.5 and 4.5,*** The apparent and standardized ileal digestibility(AID and SID)of fat and fatty acids increased linearly(P<0.05)as the U:S of dietary oils increased except for SID of fat and C18:*** AID and SID of fat and fatty acids differed among the dietary treatments(P<0.05)except for SID of unsaturated fatty acids(UFA)and C18:*** one-slope broken-line analyses for the SID of fat,saturated fatty acids(SFA)and UFA indicated that the breakpoint for U:S of oil was 4.14(R^(2)=0.89,P<0.01),2.91(R^(2)=0.98,P<0.01)and 3.84(R^(2)=0.85,P<0.01),*** determined SID of fat,C18:1,C18:2 and UFA in the mixtures was not different from the calculated SID of fat,C18:1,C18:2 and ***,the determined SID of C16:0,C18:0 and SFA in the mixtures were greater than the calculated SID values(P<0.05).The abundance of Romboutsia and Turicibacter in pigs fed diet containing palm oil was greater than that in rapeseed oil treatment group,and the two bacteria were negatively correlated with SID of C16:0,C18:0 and SFA(P<0.05).

关键词： Additivity Bacterial community Fat and fatty acids Growing pigs Ratio of unsaturated to saturated fatty acids Standardized ileal digestibility

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