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Two 8-node quadrilateral spline elements by B-net method

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Acta Mechanica Sinica 2012年第6期28卷 1620-1629页

作者： Juan Chen chong-Jun Li School of Mathematics and Quantitative Economics Dongbei University of Finance and Economics School of Mathematical Sciences Dalian University of Technology

Isoparametric quadrilateral elements are widely used in the finite element method, but the accuracy of the isoparametric quadrilateral elements will drop obviously deteriorate due to mesh distortions. Spline functions have some properties of simplicity and conformality. Two 8-node quadrilateral elements have been developed using the trian- gular area coordinates and the B-net method, which can ex- actly model the quadratic field for both convex and concave quadrangles. Some appropriate examples are employed to evaluate the performance of the proposed elements. The nu- merical results show that the two spline elements can obtain solutions which are highly accurate and insensitive to mesh distortions.

关键词： Spline finite element B-net method Quadri-lateral element - Bivariate spline interpolation The secondorder completeness

The cross-ratio distortion of integrably asymptotic affine homeomorphism of unit circle

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Science China Mathematics 2012年第3期55卷 625-632页

作者： WU chong Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China

Let QS* (S 1) be the space of quasisymmetric homeomorphisms of the unit circle such that the corresponding subspace of the universal Teichmu¨ller space has Weil-Petersson *** this paper we give a necessary condition ... 详细信息

关键词： universal Teichm/iller space quasisymmetric homeomorphism Weil-Petersson metric cross-ratio

Development of quadrilateral spline thin plate elements using the B-net method

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Acta Mechanica Sinica 2013年第4期29卷 567-574页

作者： Juan Chen chong-Jun Li School of Mathematics and Quantitative Economics Dongbei University of Finance and Economics School of Mathematical Sciences Dalian University of Technology

The quadrilateral discrete Kirchhoff thin plate bending element DKQ is based on the isoparametric element Q8, however, the accuracy of the isoparametric quadrilateral elements will drop significantly due to mesh distortions. In a previous work, we constructed an 8-node quadrilateral spline element L8 using the triangular area coordinates and the B- net method, which can be insensitive to mesh distortions and possess the second order completeness in the Cartesian co- ordinates. In this paper, a thin plate spline element is devel- oped based on the spline element L8 and the refined tech- nique. Numerical examples show that the present element indeed possesses higher accuracy than the DKQ element for distorted meshes.

关键词： Spline finite element ~ Refined quadrilateral el-ement ~ Discrete Kirchhoff plate element ~ Triangular areacoordinates ~ B-net method

Gender preference and implications for screening colonoscopy:Impact of endoscopy nurses

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World Journal of Gastroenterology 2012年第27期18卷 3590-3594页

作者： Vui Heng chong Division of Gastroenterology and Hepatology Department of MedicineRaja Isteri Pengiran Anak Saleha HospitalBandar Seri BegawanBA 1710Brunei Darussalam

AIM： TO assess the gender preferences, specifically the gender of the nursing staff （endoscopy assistants） and the impact on acceptance for screening colonoscopy （SC）. METHODS： Patients or relatives attending the clinics or health care workers working in a tertiary center were invited to participate in this questionnaire study. The questionnaire enquired on the general demographics （1） age, gender, ethnicity, education level, and employ- ment status, previous history of colonoscopy, family or personal history of colonic pathologies, personal and family history of any cancers; （2） subjects were asked if they would go for an SC if they had appropriate indi- cations （age over 50 years, family history of colorectal cancer （CRC）, fecal occult blood positive, anemia espe- cially iron deficiency anemia, bleeding per rectum with or without loss of appetite, weight loss and abdominal pain） with and without symptoms attributable to CRC; and （3） preferences for the gender of the endoscopists and assistants and whether they would still undergo SC even if their preferences were not met. RESULTS： Eighty-four point seven percent （470/550） completed questionnaire were analysed. More female subjects expressed gender preferences for the endos- copists [overall 70%; female （67.7%） and male （2.3%）] compared to male subjects [overall 62.8%; male （56%） and female （6.8%）, P = 0.102]. Similarly, more female subjects expressed gender preferences for the assis- tants [overall 74.5%; female （73.4%） and male （1.1%）] compared to male subjects [overall 58%, male （49.3%） and female （8.7%）, P 〈 0.001]. Overall, a third would decline an SC, despite having appropriate indications, if their preferences were not met. On univariate analysis, male gender, non-Malay ethnicity （Chinese and others） and previous colonoscopy experience were more likely to undergo an SC, even if their preferences were not met （all P 〈 0.05）. Gender and previous experience fodds ratio （OR） 1.68, 95% confidence interval （CI） 1.

关键词： Colorectal cancer Screening colonoscopy Gender preference Patient satisfaction Endoscopy

Esophageal rupture due to Sengstaken-Blakemore tube misplacement

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World Journal of Gastroenterology 2005年第41期11卷 6563-6565页

作者： Chee-Fah chong Emergency Department Shin-Kong Wu Ho-Su Memorial Hospital TaipeiTaiwanChina

The author presents three cases of esophageal rupture during the treatment of massive esophageal variceal bleeding with Sengstaken-Blakemore (SB) tube. In each case, simple auscultation was used to guide SB tube insertion, with chest radiograph obtained only after complete inflation of the gastric balloon. Two patients died of hemorrhagic shock and one died of *** author suggests that confirmation of SB tube placement by auscultation alone may not be *** chest radiographs should be obtained before and after full inflation of the gastric balloon to confirm tube position and to detect tube dislocation.

关键词： Chest radiograph Esophageal rupture Sengstaken-Blakemore tube

Escape and Stand of the Pluto Atmosphere

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Communications in Theoretical Physics 2002年第7期38卷 125-127页

作者： GAO chong-Yi School of Physical Science and Technology Lanzhou University Lanzhou 730000 China

Molar mass μmin of the lightest gas, which will exist "forever" in the atmosphere at the planet surface,can be evaluated by Jeans rule. The μmin of Pluto is 17.3 g@ mol-1. It is evident that both N2 and CO can be major atmospheric composition at the Pluto surface, and will exist "forever". CH4 can only be escaping slowly from Pluto atmosphere, and still holds quite a proportion in current Pluto atmosphere. However, it will not escape from Titan (or Jupiter, Saturn) atmosphere largely, and will exist "forever". Given the quantitylevelof partial pressure of CH4 in Pluto and Titan (or Jupiter, Saturn) original atmosphere is the same, it will be clear that the current partial pressure of CH4 in Pluto surface atmosphere is 10-3 Pa.

关键词： planet atmosphere, Pluto atmosphere, Jeans rule, atmospheric composition, escape

Bioleaching and biosorption behavior of vanadium-bearing stone coal by Bacillus mucilaginosus

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International Journal of Minerals,Metallurgy and Materials 2023年第2期30卷 283-292页

作者： Yingbo Dong Shijia chong Hai Lin School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants Beijing 100083China

The recovery of vanadium(V)from stone coal by bioleaching is a promising *** bioleaching experiments and the biosorption experiments were carried out,aiming to explore the adsorption characteristics of Bacillus mucilaginosus(***)on the surface of vanadium-bearing stone coal,and the related mechanisms have been *** bioleaching at 30℃ for 28 d,the cumulative leaching rate of V reached 60.2%.The biosorption of *** on stone coal was affected by many *** the pH value of leaching system is 5.0,strong electrostatic attraction between bacteria and stone coal promoted *** in the logarithmic growth phase had mature and excellent biosorption *** initial bacterial concentration of 3.5×10^(8) CFU/mL was conducive to adhesion,with 38.9%adsorption rate and 3.6×10^(7) CFU/g adsorption *** adsorption of *** on the stone coal conformed to the Freundlich model and the pseudo-second-order kinetic *** surface carried functional groups(-CH_(2),-CH_(3),-NH_(2),etc.),which were highly correlated with the adsorption *** addition,biosorption changed the surface properties of stone coal,resulting in the isoelectric point(IEP)approaching the *** results could provide an effective reference for the adsorption laws of bacteria on minerals.

关键词： Bacillus mucilaginosus vanadium-bearing stone coal bioleaching biosorption

Toward tunable shape memory effect of NiTi alloy by grain size engineering:A phase field study

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Journal of Materials Science & Technology 2024年第1期168卷 276-289页

作者： Bo Xu chong Wang Qingyuan Wang Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan ProvinceSichuan UniversityChengdu 610065China Department of Mechanical Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China Key Laboratory of Deep Underground Science and Engineering (Sichuan University)Ministry of EducationChengdu 610065China

The inelastic deformations of shape memory alloys(SMAs)always show poor controllability due to the avalanche-like martensite transformation,and the effective control for the deformation of precision de-vices has been not yet *** this work,the phase field method was used to investigate the shape memory effects(SMEs)of NiTi SMAs undergoing grain size(GS)engineering,to obtain tunable one-way and stress-assisted two-way SMEs(OWSME and SATWSME).The OWSME and SATWSME of the systems with various gradient-nanograin structures and bimodal grain structure,as well as that with geometric gradients were *** simulated results indicate that due to the GS dependences of martensite transformation and reorientation,the occurrence and expansion of martensite reorientation,martensite transformation and its reverse can be efficaciously controlled via the GS *** combining the GS engineering and geometric gradient design,since the effects of GS and stress gradient can be su-perimposed or competing,and the responses of martensite reorientation,martensite transformation and its reverse to this are different,the OWSME and SATWSME of the geometrically graded systems with various nanograin structures can exhibit different improvements in *** short,the reorienta-tion hardening modulus during OWSME is increased and the transformation temperature window during SATWSME is widened by GS engineering,indicating the improved controllability of *** optimal GS engineering schemes revealed in this work provide the basic reference and guidance for designing tun-able SMEs and producing NiTi-based driving devices catering to desired functional performance in various engineering fields.

关键词： Phase field NiTi Shape memory effect Grain size engineering Geometric gradient

True polar wander in the Earth system

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Science China Earth Sciences 2023年第6期66卷 1165-1184页

作者： chong WANG Ross N.MITCHELL State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

True polar wander(TPW),or planetary reorientation,is the rotation of solid Earth(crust and mantle)about the liquid outer core in order to stabilize Earth’s rotation due to mass *** TPW is well-documented on Earth presently with satellites and for multiple planets and moons in the Solar System,the prevalence of TPW in Earth history remains *** a history of controversy,both the physical plausibility of TPW on Earth and an empirical basis for it are now *** resistance to the old idea likely stems from the fact that,like plate tectonics,TPW may influence much of the Earth system,thus acknowledging its existence requires rethinking how many different datasets are *** review summarizes the development of TPW as a concept and provides a framework for future research that no longer regards TPW like a ghost process that may or may not exist,but as an integral part of the Earth system that can relate shallow and deep processes that are otherwise only mysteriously ***,we focus on the temporal regularity of large TPW,and discuss its relationship with the supercontinent-megacontinent cycle based on previous *** suggest the assembly of megacontinents has a close linkage to large ***,supercontinent tenure and breakup have a close linkage to fast *** effects of TPW on sea level changes,paleoclimate,biological diversity,and other facets of the Earth system are presented and require interdisciplinary tests in the future.

关键词： True polar wander(TPW) Planetary reorientation Apparent polar wander(APW) Mantle convection Supercontinent cycle Megacontinent