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Phenomenological theory of surface effects in ferroelectrics and its relationship with transverse Ising model

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Science China Mathematics 1997年第1期40卷 67-75页

作者：钟维烈王玉国张沛霖曲保东 epartment of Physics Shandong University Jinan 250100 Chinaepartment of Physics Shandong University Jinan 250100 Chinaepartment of Physics Shandong University Jinan 250100 Chinaepartment of Physics Shandong University Jinan 250100 China

The relationship between the transverse field Ising model and the Landau phenomenological theory for ferroelectrics is analyzed, and the Landau free energy expression for ferroelectrics having surfaces is derived. It is pointed out that the traditional expression in which the surface integral has only a term of the square polarization is valid only for special cases, in general a term of the polarization to the four should be included as well. By use of the newly derived free energy expression, the thickness-dependence of the spontaneous polarization and Curie temperature of ferroelectric films is calculated; thereby some experimental results incompatible with the traditional phenomenological theory are successfully explained.

关键词： surface effects in ferroelectrics Landau theory transverse field Ising model ferroelectric phase transition.

Synthesis, crystal structure and forming mechanism of two novel copper (Ⅱ) α-methacrylate complexes with benzimidazole

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Science China chemistry 1999年第4期42卷 363-372页

作者：王尧宇时茜杨秉勤史启祯高忆慈周忠远 epartment of chemistry Northwest University Xi’an China Department of chemistry Lanzhou University Lanzhou China Chengdu Institute of Organis chemistry Chinese Acaderny of Sciences Chengdu China

Two copper (Ⅱ) a-methacrylate complexes with benzimidazole, Cu[CH2 =C(CH3)-COO]2(C7H6N2)2(1) and Cu2[CH2 = C(CH3)-COO]4(C7H6N2)2(2) , have been prepared and characterized by elemental analyses, IR and electronic reflectance spectroscopies. The single crystal X-ray diffraction study of the two complexes shows that complex 1 has a square planar configuration, while complex 2 has a binuclear cage structure. The crystal structural analyses show that both complexes 1 and 2 are monoclinic, with space group P21/c, a = 0.924 16(8) nm, b = 1.233 02(13) nm, c = 0.989 1(3) nm, β = 91.912(13)°, Dc = 1.386g/cm3, Z = 2, R = 0.0339 for the former; and a= 0.9057(2) nm, b = 2.252 1(5) nm, c = 1.623 5(4) nm, β = 90.11(2)°, Dc = 1.411 g/cm3, Z =4, R =0.056 8, Cu-Cu = 0.266 21 nm for the latter. Different structural types of complexes 1 and 2 were produced simultaneously in the reaction of copper (Ⅱ) α-methacrylate with benzimidazole in methanol solution. The forming mechanism of the complexes has been summarized .

关键词： copper (Ⅱ) complex α-methacrylate benzimidazole crystal structure forming mechanism.

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

Crystal Structure and Bioactivity of Complex [Gd（C10H9N2O4）（C10H8N2O4）（H2O）3]2·phen·4H2O

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Chinese Journal of chemistry 2005年第9期23卷 1198-1202页

作者：何水样杨锐武望婷史启祯王大奇安德荣 D epartment of chemistry Northwest University and Shaanxi Key Laboratory of Physico-lnorganic Chemistry Xi'an Shaanxi 710069 China College of chemistry and Chemical Engineering LiaochengUniversity Liaocheng 252059 China Institute of Plant Protection Northwest Science and Technology University of Agriculture and Forestry Yangling Shaanxi 712100 China

A novel gadolinium（Ⅲ） complex with N-（2-propionic acid）-salicyloyl hydrazone （C10H10N2O4, H3L） and 1,10-phenanthroline （C12H8N2, phen） was prepared and characterized. The crystal structure of [Gd（H2L）（HL）- （H2O）3]2·phen·4H2O was determined by X-ray single crystal diffractometry. The crystal complex crystallizes in the triclinic system with space group P-1. There are two 9-coordinated structure units in every complex molecule, in which Gd（Ⅲ） is coordinated by two tridentate ligands （H2L and HL forms） and three water molecules and both the structural units take a distorted monocapped square antiprism. There is a free 1,10-phenanthroline connecting with coordinated water by hydrogen bonds in the crystal. The bioactivity tests indicate that the complex is an inhibitor against three bacteria.

关键词： gadolinium(Ⅲ) complex N-(2-propionic acid)-salicyloyl hydrazone 1,10-phenanthroline crystal structure bioactivity

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

Improving the stability and bioavailability of tea polyphenols by encapsulations:a review

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Food Science and Human Wellness 2022年第3期11卷 537-556页

作者： Zhiya Yin Ting Zheng Chi-Tang Ho Qingrong Huang Qingli Wu Man Zhang Department of Food Science Rutgers UniversityNJ 08901USA New Use Agriculture and Natural Plant Products Program epartment of Plant BiologyRutgers UniversityNJ 08901USA Department of medicinal chemistry Rutgers UniversityNJ 08854USA Center for Agricultural Food Ecosystems The New Jersey Institute for FoodNutrition and HealthRutgers UniversityNJ 08901USA

Tea polyphenols(TPPs)have attracted significant research interest due to their health ***,TPPs are sensitive to certain environmental and gastrointestinal conditions and their oral bioavailability was found to be very *** systems made of food-grade materials have been reported to improve the shelf-life,bioavailability and bioefficacy of *** review discusses the chemistry of TPPs;the setbacks of TPPs for application;and the strategies to counteract application limitations by rationally designing delivery *** overview of different formulations used to encapsulate TPPs is provided in this study,such as emulsion-based systems(liposome,nanoemulsion,double emulsion,and Pickering emulsion)and nano/microparticles-based systems(protein-based,carbohydrate-based,and bi-polymer based).In addition,the stability,bioavailability and bioactivities of encapsulated TPPs are evaluated by various in vitro and in vivo *** current findings provide scientific insights in encapsulation approaches for the delivery of TPPs,which can be of great value to TPPs-fortified food *** explorations are needed for the encapsulated TPPs in terms of their applications in the real food industry as well as their biological fate and functional pathways in vivo.

关键词： Tea polyphenols Encapsulation Stability Bioavailability Bioefficacy