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Daubechies Wavelet Meshless Method for 2-D Elastic Problems

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Tsinghua Science and Technology 2008年第5期13卷 605-608页

作者：刘亚男刘应华岑章志 epartment of Engineering Mechanics Tsinghua University

This paper introduces a meshless method based on Daubechies （DB） wavelets for 2-D elastic problems. The scaling and wavelet functions of the DB wavelet are used as basis functions to approximate the unknown field functions, so there is no need to construct costly shape functions as in the finite element method （FEM） and other meshless methods. In addition, the properties of the DB wavelets facilitate implementation of the method. The new method is used to analyze the elastic problem of a plain plate with a circle hole, and the numerical results agree well with the FEM. This method is effective and can be extended to solve complicated two or three dimensional problems.

关键词： wavelet meshless method scaling function shape function

ON DOMINATING SEQUENCE METHOD IN THE POINT ESTIMATE AND SMALE THEOREM

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Science China Mathematics 1990年第2期33卷 135-144页

作者：王兴华韩丹夫 epartment of Methematics Hangzhou University

It can be optimized for the work of the point estimate on the Newton iteration, reported by Smale at the 20th Congress of Mathematicians in 1986. It has been proved that iffα(z,f) , for every analytic map f:E→F, z ∈ is an approximate zero of f,whereE and F are real or complex Banach spaces. In addition, if α,(z,f) , z is anapproximate zero of the second kind of f.

关键词： dominating sequence point estimate Newton iteration higher-order generalization approximate zero.

Intestinal obstruction in pregnancy with reverse rotation of the midgut:A case report

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World Journal of Clinical Cases 2020年第16期8卷 3553-3559页

作者： Xin-Yu Zhao Xin Wang Chun-Qiang Li Qi Zhang An-Qi He Gang Liu epartment of General Surgery Tianjin Medical University General HospitalTianjin 300052China

BACKGROUND Reverse rotation of the midgut is a rare type of intestinal *** of the right colon or entire midgut,stenosis of the transverse colon and obstruction of the duodenojejunal junction are common complications of reverse *** this study,we report the first case of intestinal obstruction associated with reverse rotation in *** SUMMARY A 31-year-old woman at 362+wk gestation presented to the emergency department with progressive abdominal cramping,nausea and bilious *** ultrasound scanning showed dilatation of the *** tomography scanning revealed features of reverse rotation of the midgut with intestinal *** consultation with the obstetrician,the pregnancy was terminated and exploratory abdominal surgery was ***-operatively,it was found that the mesentery of the colon and small intestine was insufficiently *** right colon and the small intestinal mesentery was twisted,and intestinal necrosis was *** duodenum and duodenojejunal junction were curved in front of the transverse colon,and the transverse colon passed through the tunnel behind the mesenteric *** reverse rotation with volvulus was *** necrotic intestine was resected and small intestine mesenteric reconstruction was *** patient recovered after *** leaving the hospital,the patient and her daughter remained well during an 8-month follow-up *** We report the diagnosis,treatment and etiology of a pregnant patient with intestinal obstruction due to reverse rotation of the *** similar cases,appropriate diagnosis and treatment should be carried out according to the condition of the fetus and pregnant woman.

关键词： Congenital intestinal malrotation Volvulus Reverse rotation of the midgut Intestinal obstruction Pregnancy Case report

Gravitation Without Singularity

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Chinese Physics Letters 2000年第2期17卷 82-84页

作者： CHEN Guang epartment of Electronics Shantou UniversityShantou 515063 East China Institute for Theoretical Physics Shanghai 200237

The coupled Einstein-scalar-vector field equations are found, and their static spherically symmetric solutions are derived under the consideration of self-gravitational interaction of scalar field and proved to be sin... 详细信息

关键词： energy scalar singularity

THERMAL POST-BUCKLING OF AN ELASTIC BEAMS SUBJECTED TO A TRANSVERSELY NON-UNIFORM TEMPERATURE RISING

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Applied Mathematics and Mechanics(English Edition) 2003年第5期24卷 514-520页

作者：李世荣程昌钧周又和 Department of Basic Science Gansu University to Technology epartment of Mechanics Shanghai University Department of Mechanics Lanzhou University

Based on the nonlinear geometric theory of axially extensible beams and by using the shooting method, the thermal post-buckling responses of an elastic beams,with immovably simply supported ends and subjected to a transversely non-uniformly distributed temperature rising, were investigated. Especially, the influences of the transverse temperature change on the thermal post-buckling deformations were examined and the corresponding characteristic curves were plotted. The numerical results show that the equilibrium paths of the beam are similar to what of an initially deformed beam because of the thermal bending moment produced in the beam by the transverse temperature change.

关键词： elastic beam transverse temperature change thermal post-buckling shooting method numerical solution

Leveraging machine learning for early recurrence prediction in hepatocellular carcinoma:A step towards precision medicine

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World Journal of Gastroenterology 2024年第5期30卷 424-428页

作者： Abhimati Ravikulan Kamran Rostami epartment of Gastroenterology Palmerston North HospitalPalmerston North 4442New Zealand

The high rate of early recurrence in hepatocellular carcinoma(HCC)post curative surgical intervention poses a substantial clinical hurdle,impacting patient outcomes and complicating postoperative *** advent of machine learning provides a unique opportunity to harness vast datasets,identifying subtle patterns and factors that elude conventional prognostic *** learning models,equipped with the ability to analyse intricate relationships within datasets,have shown promise in predicting outcomes in various medical *** the context of HCC,the application of machine learning to predict early recurrence holds potential for personalized postoperative care *** editorial comments on the study carried out exploring the merits and efficacy of random survival forests(RSF)in identifying significant risk factors for recurrence,stratifying patients at low and high risk of HCC recurrence and comparing this to traditional COX proportional hazard models(CPH).In doing so,the study demonstrated that the RSF models are superior to traditional CPH models in predicting recurrence of HCC and represent a giant leap towards precision medicine.

关键词： Machine learning Artificial intelligence Hepatocellular carcinoma Hepatology Early recurrence Liver resection

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Advances in Manufacturing 2016年第4期4卷 287-295页

作者： G. Buffa M. De Lisi E. Sciortino L. Fratini epartment of Chemical Management Computer and Mechanical Engineering University of Palermo Viale delle Scienze 90128 Palermo Italy

Dissimilar stir welding （FSW） lap joints were produced by friction out of Ti6A14V titanium alloy and AA2024 aluminum alloy sheets. The joints, welded with varying tool rotation and feed rate, were studied by ana- lyzing the maximum shear strength, Vickers microhardness and optical observations. A dedicated numerical model, able to take into account the presence of the two different alloys, was used to highlight the effects of the process parameters on temperature distribution, strain distribution, and material flow. The combined analysis of experimental measurements and numerical predictions allowed explaining the effects of tool rotation and feed rate on the material flow. It was found that tool rotation had a larger impact on the joint effectiveness with respect to feed rate. A competition between material mixing and heat input occurs with increasing tool rotation, resulting in higher joint strength when lower values of tool rotation are used.

关键词： Finite element method (FEM) Ti6A14V AA2024 Friction stir welding (FSW) Lap joint

Meniscus behaviors and capillary pressures in capillary channels having various cross-sectional geometries

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Chinese Journal of Chemical Engineering 2018年第10期26卷 2014-2022页

作者： Yicun Tang Jingchun Min Xuan Zhang Guiling Liu Department of Engineering Mechanics Tsinghua University Beijing 100084 China epartment of Energy and Power Engineering Tsinghua University Beijing 100084 China

A numerical study has been conducted to simulate the liquid/gas interface(meniscus) behaviors and capillary pressures in various capillary channels using the volume of fluid(VOF) method. Calculations are performed for four channels whose cross-sectional shapes are circle, regular hexagon, square and equilateral triangle and for four solid/liquid contact angles of 30°, 60°, 120° and 150°. No calculation is needed for the contact angle of 90° because the liquid/gas interface in this case can be thought to be a plane surface. In the calculations, the liquid/gas interface in each channel is assumed to have a flat surface at the initial time, it changes towards its due shape thereafter, which is induced by the combined action of the surface tension and contact angle. After experiencing a period of damped oscillation, it stabilizes at a certain geometry. The interface dynamics and capillary pressures are compared among different channels under three categories including the equal inscribed circle radius, equal area, and equal circumscribed circle radius. The capillary pressure in the circular channel obtained from the simulation agrees well with that given by the Young–Laplace equation, supporting the reliability of the numerical model. The channels with equal inscribed circle radius yield the closest capillary pressures, while those with equal circumscribed circle radius give the most scattered capillary pressures,with those with equal area living in between. A correlation is developed to calculate the equivalent radius of a polygonal channel, which can be used to compute the capillary pressure in such a channel by combination with the Young–Laplace equation.

关键词： Capillary phenomenon Polygonal channel Meniscus shape Capillary pressure

Influence of ^(12)C^(6+) ion irradiation on mutant avermitilis

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Chinese Physics C 2012年第11期36卷 1140-1144页

作者：王曙阳陈积红李文建梁剑平薄永恒马晓琪刘敬 epartment of Biology Physics Institute of Modern PhysicsChinese Academy of Sciences Lanzhou University Gansu Agricultural University

The effects of 12C＋6 ion irradiation on colony morphology and mycelia morphology, as well as on mutation rate have been studied in the B1a high-product strains （ZJAV-Y1-203） mutated by heavy ion irradiation and compared with that in the original strain （ZJAV-A-1）. After irradiating the rate of a straw hat colony type having a high ability of producing B1a in ZJAV-Y1-203 strains was higher than that found in ZJAV-A-1 strains. When strains were cultured in a liquid medium for 24 hours, the mycelium becoming thinner could be observed in all of the irradiated ZJAV- Y1-203 groups, but only in the ZJAV-A-1 groups irradiated at the dose of 50 Gy or more. The early growth of mycelium was inhibited in the ZJAV- Y1-203 group irradiated with a high dose. The highest positive mutation rate （23.5%） of ZJAV - Y1 - 203 was reached at the lower dose of 30 Gy while the highest positive mutation rate of 34.2% in ZJAV-A-1 appeared at 50 Gy. These results indicate that the effects of heavy ion irradiation still exist even in the mutated Streptomyces avermitilis, and only the dose is lower and the effects not so strong compared with the one that is first irradiated with optimized heavy ion doses. This is evidence of the one directional mutation being controlled by many more factors in a organism.

关键词： Streptomyces avermitilis 12C+6 ion beam progress irradiation influence