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Chebyshev polynomial-based Ritz method for thermal buckling and free vibration behaviors of metal foam beams

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 891-910页

作者： n.D.nGUYEn t.n.nGUYEn Faculty of Civil Engineering Ho Chi Minh City University of Technology and EducationHo Chi Minh City 71309Viet Nam Faculty of Engineering and technology Kien Giang UniversityChau Thanh 92000Viet Nam

this study presents the Chebyshev polynomials-based Ritz method to examine the thermal buckling and free vibration characteristics of metal foam *** analyses include three models for porosity distribution and two scenarios for thermal *** material properties are assessed under two conditions,i.e.,temperature dependence and temperature *** theoretical framework for the beams is based on the higher-order shear deformation theory,which incorporates shear deformations with higher-order *** governing equations are established from the Lagrange equations,and the beam displacement fields are approximated by the Chebyshev *** simulations are performed to evaluate the effects of thermal load,slenderness,boundary condition(BC),and porosity distribution on the buckling and vibration behaviors of metal foam *** findings highlight the significant influence of temperature-dependent(tD)material properties on metal foam beams'buckling and vibration responses.

关键词： Ritz method Chebyshev function buckling vibration metal foam beam higher-order beam theory(HOBt)

Bioinspired nanocomposites with self-adaptive mechanical properties

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nano Research 2024年第2期17卷 633-648页

作者： grant Kitchen Bohan Sun Sung Hoon Kang 13400 n Charles St Department of Materials Science and EngineeringJohns Hopkins UniversityBaltimore 21218USA 23400 n Charles St Department of Mechanical EngineeringJohns Hopkins UniversityBaltimore 21218USA 33400 n Charles St Hopkins Extreme Materials InstituteJohns Hopkins UniversityBaltimore 21218USA

Conventional synthetic materials have fixed mechanical properties and suffer defects,damage,and degradation over *** makes them unable to adapt to changing environments and leads to limited ***,self-adaptive materials inspired by natural materials have emerged as a solution to address these *** the ability to change their mechanical properties based on changing mechanical environments,repairing defects,and maintaining their mechanical properties,these materials can lead to improved performance while decreasing *** this review,we explore self-adaptive phenomena found in nature that have inspired the development of synthetic self-adaptive materials,and the mechanisms that have been employed to create the next generation of *** potential applications of these materials,the challenges that existing approaches face,and future research opportunities are also discussed.

关键词： nanocomposites self-adaptive materials bioinspired materials force-activated resilience

nonlinear-Optical Analogies in nuclear-Like Soliton Reactions:Selection Rules,nonlinear tunneling and Sub-Barrier Fusion–Fission

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Chinese Physics Letters 2024年第8期41卷 1-7页

作者： t.L.Belyaeva V.n.Serkin Universidad Autonoma del Estado de Mexico Av.Instituto Literario 100C.P.50000TolucaMexico Benemerita Universidad Autonoma de Puebla Av.4 Sur 104C.P.72001PueblaMexico

the main goal of our study is to reveal unexpected but intriguing analogies arising between optical solitons and nuclear physics,which still remain hidden from *** consider the main cornerstones of the concept of nonlinear optics of nuclear reactions and the well-dressed repulsive-core *** the base of this model,we reveal the most intriguing properties of the nonlinear tunneling of nucleus-like solitons and the soliton selfinduced sub-barrier transparency *** describe novel interesting and stimulating analogies between the interaction of nucleus-like solitons on the repulsive barrier and nuclear sub-barrier *** main finding of this study concerns the conservation of total number of nucleons(or the baryon number)in nuclear-like soliton *** show that inelastic interactions among well-dressed repulsive-core solitons arise only when a“cloud”of“dressing”spectral side-bands appears in the frequency spectra of the *** property of nucleus-like solitons is directly related to the nuclear density distribution described by the dimensionless small shape-squareness *** the Fourier spectra of nucleus-like solitons are similar to the nuclear form *** show that the nuclear-like reactions between well-dressed solitons are realized by“exchange”between“particle-like”side bands in their spectra.

关键词： solitons soliton nonlinear

Evaluation of slope stability through rock mass classification and kinematic analysis of some major slopes along nH-1A from Ramban to Banihal, north Western Himalayas

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 167-182页

作者： Amit Jaiswal A.K.Verma t.n.Singh Department of Civil and Environmental Engineering Indian Institute of Technology PatnaPatna801106India

the network of Himalayan roadways and highways connects some remote regions of valleys or hill slopes,which is vital for India’s socio-economic *** to natural and artificial factors,frequency of slope instabilities along the networks has been increasing over last few *** of stability of natural and artificial slopes due to construction of these connecting road networks is significant in safely executing these roads throughout the *** rock mass classification methods are generally used to assess the strength and deformability of rock *** study assesses slope stability along the nH-1A of Ramban district of north Western *** structurally and non-structurally controlled rock mass classification systems have been applied to assess the stability conditions of 14 *** evaluating the stability of these slopes,kinematic analysis was performed along with geological strength index(GSI),rock mass rating(RMR),continuous slope mass rating(CoSMR),slope mass rating(SMR),and Q-slope in the present *** SMR gives three slopes as completely unstable while CoSMR suggests four slopes as completely *** stability of all slopes was also analyzed using a design chart under dynamic and static conditions by slope stability rating(SSR)for the factor of safety(FoS)of 1.2 and 1 respectively.Q-slope with probability of failure(PoF)1%gives two slopes as stable *** slope angle has been determined based on the Q-slope safe angle equation and SSR design chart based on the *** value ranges given by different empirical classifications were RMR(37-74),GSI(27.3-58.5),SMR(11-59),and CoSMR(3.39-74.56).Good relationship was found among RMR&SSR and RMR&GSI with correlation coefficient(R 2)value of 0.815 and 0.6866,***,a comparative stability of all these slopes based on the above classification has been performed to identify the most critical slope along this road.

关键词： Rock mass classification Kinematic analysis Slope stability Himalayan road Static and dynamic conditions

Stability Analysis and Performance Evaluation of Additive Mixed-Precision Runge-Kutta Methods

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Communications on Applied Mathematics and Computation 2024年第1期6卷 705-738页

作者： Ben Burnett Sigal Gottlieb Zachary J.grant Center for Scientific Computing and Data Science Research UMass DartmouthNorth DartmouthMassachusettsUSA CSME Michigan State UniversityEast LansingMichiganUSA

Additive Runge-Kutta methods designed for preserving highly accurate solutions in mixed-precision computation were previously proposed and *** specially designed methods use reduced precision for the implicit computations and full precision for the explicit *** this work,we analyze the stability properties of these methods and their sensitivity to the low-precision rounding errors,and demonstrate their performance in terms of accuracy and *** develop codes in FORtRAn and Julia to solve nonlinear systems of ODEs and PDEs using the mixed-precision additive Runge-Kutta(MP-ARK)*** convergence,accuracy,and runtime of these methods are *** show that for a given level of accuracy,suitably chosen MP-ARK methods may provide significant reductions in runtime.

关键词： Mixed precision Runge-Kutta methods Additive methods Accuracy

the neurovascular unit-on-a-chip:modeling ischemic stroke to stem cell therapy

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neural Regeneration Research 2024年第7期19卷 1431-1432页

作者： Seonghun Kim Minjun Kim Gerald A.grant Wonjae Lee Department of neurosurgery Duke University School of MedicineDurhamNCUSA Department of neurobiology Duke University School of MedicineDurhamNCUSA Duke Institute for Brain Sciences Duke University School of MedicineDurhamNCUSA Duke Cancer Institute Duke University School of MedicineDurhamNCUSA

the neurovascular unit and stem cell therapy in ischemic stroke:Ischemic stroke,accounts for approximately 85% of all stroke incidents and is a major global health *** is the leading cause of disability and death worldwide,posing immense societal and economic challenges due to the long-term care required for stro ke survivors and the significant healthcare costs associated with its treatment and management(Amarenco et al.,2009).

关键词： death unit

new trends in diagnosis and management of gallbladder carcinoma

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World Journal of Gastrointestinal Oncology 2024年第1期16卷 13-29页

作者： Efstathios t Pavlidis Ioannis n Galanis theodoros E Pavlidis ^(nd)Propedeutic Department of Surgery Hippokration General HospitalSchool of MedicineAristotle University of ThessalonikiThessaloniki 54642Greece

Gallbladder(GB)carcinoma,although relatively rare,is the most common biliary tree cholangiocarcinoma with aggressiveness and poor *** is closely associated with cholelithiasis and long-standing large(>3 cm)gallstones in up to 90%of *** other main predisposing factors for GB carcinoma include molecular factors such as mutated genes,GB wall calcification(porcelain)or mainly mucosal microcalcifications,and GB polyps≥1 cm in *** is made by ultrasound,computed tomography(Ct),and,more precisely,magnetic resonance imaging(MRI).Preoperative staging is of great importance in decisionmaking regarding therapeutic *** staging is based on MRI findings,the leading technique for liver metastasis imaging,enhanced three-phase Ct angiography,or magnetic resonance angiography for major vessel *** is also necessary to use positron emission tomography(PEt)-Ct or ^(18)F-FDG PEt-MRI to more accurately detect metastases and any other occult deposits with active metabolic *** laparoscopy may detect dissemination not otherwise found in 20%-28.6%of *** treatment is needed,including surgical resection,targeted therapy by biological agents according to molecular testing gene mapping,chemotherapy,radiation therapy,and *** is of great importance to understand the updated guidelines and current treatment *** extent of surgical intervention depends on the disease stage,ranging from simple cholecystectomy(t1a)to extended resections and including extended cholecystectomy(t1b),with wide lymph node resection in every case or IV-V segmentectomy(t2),hepatic trisegmentectomy or major hepatectomy accompanied by hepaticojejunostomy Roux-Y,and adjacent organ resection if necessary(t3).Laparoscopic or robotic surgery shows fewer postoperative complications and equivalent oncological outcomes when compared to open surgery,but much attention must be paid to avoiding *** addition to surgery,novel targe

关键词： Biliary tract neoplasms Extrahepatic cholangiocarcinoma Gallbladder carcinoma Gallbladder diseases Biliary tree diseases Gastrointestinal malignancies

Management of obstructed colorectal carcinoma in an emergency setting:An update

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 598-613页

作者： Efstathios t Pavlidis Ioannis n Galanis theodoros E Pavlidis 2nd Propedeutic Department of Surgery Hippokration General HospitalSchool of MedicineAristotle University of ThessalonikiThessaloniki 54642Greece

Colorectal carcinoma is common,particularly on the left *** 20%of patients,obstruction and ileus may be the first clinical manifestations of a carcinoma that has advanced(stage II,III or even IV).Diagnosis is based on clinical presentation,plain abdominal radiogram,computed tomography(Ct),Ct colonography and positron emission tomography/*** best management strategy in terms of short-term operative or interventional and long-term oncological outcomes re-mains *** the most common left-sided obstruction,the first choice should be either emergency surgery or endoscopic decompression by self-expen-dable metal stents or *** operative plan should be either one-stage or two-stage ***-stage resection with on-table bowel decompression and irrigation can be accompanied or not accompanied by proximal defunctioning stoma(colostomy or ileostomy).Primary anastomosis is more convenient but has increased risks of anastomotic leakage and ***-stage resection(Hart-mann’s procedure)is safer and the most widely used despite temporally affecting quality of *** control surgery in high-risk frail patients is less frequently performed since it can be successfully substituted with endoscopic stenting or *** the less common right-sided obstruction,one-stage surgical resection is more beneficial than endoscopic *** role of minimally invasive surgery(laparoscopic or robotic)is a subject of *** laparoscopic-assisted management is advantageous to some extent but requires much expertise due to inherent difficulties in dissecting the distended colon and the risk of rup-ture and subsequent septic *** decompressing stent as a bridge to elective surgery more substantially decreases the risks of morbidity and mortality than emergency surgery for decompression and has equivalent medium-term overall survival and disease-free survival *** combination with neoadjuvant chemotherapy or radiation may have a p

关键词： Acute abdomen Obstructive ileus Colorectal carcinoma Emergency surgery Colectomy Intraluminal metal stents

Current considerations on intraductal papillary neoplasms of the bile duct and pancreatic duct

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World Journal of Gastroenterology 2024年第10期30卷 1461-1465页

作者： Efstathios t Pavlidis Ioannis n Galanis theodoros E Pavlidis 2^(nd) Propedeutic Department of Surgery Hippokration General HospitalSchool of MedicineAristotle University of ThessalonikiThessaloniki 54642Greece

Pancreatobiliary intraductal papillary neoplasms(IPns)represent precursors of pancreatic cancer or bile duct cholangiocarcinoma that can be detected and *** advances in diagnostic methods,identifying these premalignant lesions is still challenging for treatment *** imaging,biomarkers and molecular tests for genomic alterations can be used for diagnosis and *** intervention in combination with new chemotherapeutic agents is considered the optimal treatment for malignant *** balance between the risk of malignancy and any risk of resection guides management policy;therefore,treatment should be individualized based on a meticulous preoperative assessment of high-risk *** of the bile duct is more aggressive;thus,early diagnosis and surgery are *** conservative management of low-risk pancreatic branch-duct lesions is safe and effective.

关键词： Biliary tree diseases Pancreatic cystic neoplasms Biliary tract neoplasms Extrahepatic cholangiocarcinoma Pancreatic adenocarcinoma