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A novel mesh-free poly-cell Galerkin method

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Acta Mechanica Sinica 2009年第4期25卷 517-527页

作者： c. Zheng X. h. Tang J. h. Zhang S. c. Wu State Key Laboratory of hydraulics and Mountain River Engineering Sichuan University State Key Laboratory of Digital Manufacturing and Equipment Technology Huazhong University of Science and Technology centre for Advanced computations in Engineering Science (AcES) Department of Mechanical EngineeringNational University of Singapore

A novel numerical method is explored and named as mesh-free poly-cell Galerkin method. An improved moving least-square （MLS） scheme is presented, which can avoid the matrix inversion in standard MLS and can be used to construct shape functions possessing delta Kronecher property. A new type of local support is introduced to ensure the alignment of integral domains with the cells of the back-ground mesh, which will reduce the difficult in integration. An intensive numerical study is conducted to test the accuracy of the present method. It is observed that solutions with good accuracy can be obtained with the present method.

关键词： MPG cO-MSL Mesh-free Meshless Voronoi diagram

Photo-induced Synthesis and characterization of Poly(methyl methacrylate) Grafted Sodium Salt of Partially carboxymethylated Guar Gum

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chinese Journal of Polymer Science 2014年第12期32卷 1690-1703页

作者： J.h.Trivedi M.D.Thaker h.c.Trivedi P.G. Department of chemistry Sardar Patel University

Photo-induced graft copolymerization of methyl methacrylate（MMA） onto sodium salt of partially carboxymethylated guar gum（Na-PcMGG, DS = 0.291） was carried out in an aqueous medium using ceric ammonium nitrate（cAN） as photoinitiator to synthesize a novel graft copolymer, Na-PcMGG-g-PMMA, which may find its potential application as a metal adsorbent. The influences of synthesis variables such as concentrations of photoinitiator（cAN）, nitric acid and monomer（MMA） as well as reaction time, temperature and amount of substrate on the grafting yields were studied and the reaction conditions for optimum photo-grafting were evaluated. At optimum concentration, the maximum values of the grafting yields achieved were G = 271.61% and GE = 63.89%. The experimental results were found to be in very good agreement with the proposed kinetic scheme. The photo-graft copolymerization of MMA onto Na-PcMGG（ DS = 0.291） was also carried out in the presence and absence of ultraviolet radiation for studying the efficiency of the photoinitiator. The influence of carboxymethyl groups introduced onto the guar gum molecules with regard to its behavior towards ultra-violet radiation induced grafting with MMA was also investigated. Photo-grafting process was confirmed and the products were characterized with the help of the spectroscopic（1h-NMR and FTIR） and SEM techniques.

关键词： Photo-induced grafting Methyl methacrylate Sodium salt of partially carboxymethylated guar gum Optimum reaction conditions characterization.

Neoadjuvant treatment of rectal cancer:where are we now?

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Gastroenterology Report 2016年第3期4卷 206-209,I0002页

作者： Aparna Kalyan Shaina Rozelle Al benson III Developmental Therapeutics Program of Division of hematology&Oncology Robert H.Lurie Comprehensive Cancer Center of Northwestern UniversityChicagoIL USA Division of hematology&Oncology Robert H.Lurie Comprehensive Cancer Center of Northwestern UniversityChicagoIL USA

Introduction colorectal cancer is the third leading cause of cancer-related mortality in the United States[1].Of this group of patients,approximately 39000 cases of rectal cancer were reported in the US in 20151].Treatment of rectal cancer truly requires combinatorial therapy with surgery,chemotherapy and radiation(RT),which now comprise the cornerstone of treatment for rectal cancer.

关键词： rectal cancer neoadjuvant chemoradiation 5-fluorouracil local recurrence

Longwall top coal caving design for thick coal seam in very poor strength surrounding strata

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International Journal of coal Science & Technology 2021年第4期8卷 641-658页

作者： h.Jangara c.Atilla Ozturk Mining Engineering Department Faculty of MinesIstanbul Technical UniversityIstanbulTurkey

Alpu lignite field is an important coal deposit with nearly 2 billion tons of coal resources located in the middle of *** mine deposit consists of three main *** thickness of two of them vary from 4 to 30 *** surrounding rock mass is very poor in terms of *** high clay content and weak rock mass make mechanized mining *** this research,applicability of the longwall top coal caving method was *** very weak strength behavior of the coal and the surrounding strata increases the importance of research in the mine site in terms of ground *** aim is to design the mechanized longwall mine based on ground control *** of all,classification of the roof,coal,inter-burden,and floor strata were classified based on geotechnical ***,cavability index,shield,and floor bearing capacity were *** methods were applied to understand the limitations of a mechanized system that is very critical due to the very low strength *** to the main results,roof strata was classified as immediately caving while mining height was calculated as 5-6 ***,the relations among geotechnical characterizations of roof and floor strata,cutting and caving heights,and required shield capacity were presented based on analytical and numerical *** proposed approach can be used as a ground control method for the applicability as well as the limitations of mechanized longwall mining design in weak strata conditions.

关键词： coal Geotechnics Ground control Longwall mining Numerical methods

Laser additive manufacturing of biodegradable Mg-based alloys for biomedical applications: A review

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Journal of Magnesium and Alloys 2022年第4期10卷 915-937页

作者： c.L.Wu W.J.Xie h.c.Man Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina

Metallic implants are widely used in internal fixation of bone fracture in surgical *** are mainly used for providing mechanical support and stability during bone reunion,which usually takes a few months to *** implants made of stainless steels,Ti-based alloys and cocrMo alloys have been widely used for orthopedic reconstruction due to their high strength and high corrosion *** metallic implants will remain permanently inside the body after implantation,and a second surgery after bone healing is needed because the long-term presence of implant will lead to various *** implant removal surgery not only incurs expenditure,but also risk and psychological *** a consequence,studies on the development of biodegradable implants,which would degrade and disappear in vivo after bone reunion is completed,have drawn researchers’*** this connection,Mg-based alloys have shown great potentials as promising implant materials mainly due to their low density,inherent biocompatibility,biodegradability and mechanical properties close to those of ***,the high degradation rate of Mg-based implants in vivo is the biggest hurdle to *** from materials selection,a fixation implant is ideally tailor-made in size and shape for an individual case,for best surgical ***,laser additive manufacturing(LAM),with the advent of sophisticated laser systems and software,is an ideal process to solve these *** this paper,we reviewed the progress in LAM of biodegradable Mg-based alloys for biomedical *** effect of powder properties and laser processing parameter on the formability and quality was thoroughly *** microstructure,phase constituents and metallurgical defects formed in the LAMed samples were *** mechanical properties,corrosion resistance,biocompatibility and antibacterial properties of the LAMed samples were summarized and compared with samples fabricated by

关键词： Laser additive manufacturing Magnesium alloys Implant Biomedical applications Mechanical properties Biodegradability

cO_2 laser-micro plasma arc hybrid welding for galvanized steel sheets

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Transactions of Nonferrous Metals Society of china 2011年第A1期21卷 47-53页

作者： c.h.KIM Y.N.AhN J.h.KIM Advance Welding & Joining Research Group Korea Institute of Industrial Technology Incheon 406-840 South Korea

A laser lap welding process for zinc-coated steel has a well-known unsolved problem-porosity formation. The boiling temperature of coated zinc is lower than the melting temperature of the base metal, which is steel. In the autogenous laser welding, the zinc vapor generates from the lapped surfaces expels the molten pool and the expulsion causes numerous weld defects, such as spatters and blow holes on the weld surface and porosity inside the welds. The laser-arc hybrid welding was suggested as an alternative method for the laser lap welding because the arc can preheat or post-beat the weldment according to the arrangement of the laser beam and the arc. cO2 laser-micro plasma hybrid welding was applied to the lap welding of zinc-coated steel with zero-gap. The relationships among the weld quality and process parameters of the laser-arc arrangement, and the laser-arc interspacing distance and arc current were investigated using a full-factorial experimental design. The effect of laser-arc arrangement is dominant because the leading plasma arc partially melts the upper steel sheets and vaporizes or oxidizes the coated zinc on the lapped surfaces. compared with the result from the laser-TIG hybrid welding, the heat input from arc can be reduced by 40%.

关键词： galvanized steel cO2 laser micro plasma hybrid welding

Analysis of electron energy distribution function in a magnetically filtered complex plasma

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chinese Physics B 2013年第4期22卷 324-329页

作者： M K Deka h Bailung N c Adhikary Physical Sciences Division Institute of Advanced Study in Science and Technology Vigyan Path Paschim Boragaon Garchuk Guwahati-781035 Assam India

The electron energy distribution function （EEDF） for a magnetically filtered dusty plasma is studied in a dusty double plasma device where the electron energy can be varied from 0.15 eV to ～ 2.8 eV and plasma density from 10 6 cm-3 to 10 9cm-3 . The characteristics of EEDF for these ranges of plasma parameters are investigated in a pristine plasma as well as in a dusty plasma. The results show that in the presence of dust, there is a drastic modification in EEDF patterns in a plasma with higher electron temperature and density than those in a low temperature and low density plasma produced by the magnetic filter.

关键词： dusty plasma magnetic filter electron energy distribution function

circatidal rhythms of locomotion in the American horseshoe crab Limulus polyphemus: Underlying mechanisms and cues that influence them

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current Zoology 2010年第5期56卷 499-517页

作者： christopher c.chABOT Winsor h.WATSON Ⅲ Department of Biological Sciences Plymouth State University Department of Biological Sciences University of New Hampshire

While eye sensitivity in the American horseshoe crab Limulus polyphemus has long been known to be under the control of an endogenous circadian clock, only recently has horseshoe crab locomotion been shown to be controlled by a separate clock system. In the laboratory, this system drives clear activity rhythms throughout much of the year, not just during the mating season when horseshoe crabs express clear tidal rhythms in the field. Water temperature is a key factor influencing the expression of these rhythms： at 17~c tidal rhythms are expressed by most animals, while at I l^c expression of circatidal rhythms is rarely seen, and at 4~c rhythms are suppressed. Neither long （16：8 Light：Dark） nor short （8：16） photoperiods modify this behavior at any of these temperatures. Synchronization of these circatidal rhythms can be most readily effeeted by water pressure cycles both in situ and in the lab, while temperature and current cycles play lesser, but possibly contributory, roles. Interestingly, Light：Dark cycles appear to have synchronizing as well as ＂masking＂ effects in some individuals. Evidence that each of two daily bouts of activity are independent suggests that the Limulus circatidal rhythm of locomotion is driven by two （circalunidian） clocks, each with a period of 24.8h. While the anatomical locations of either the circadian clock, that drives fluctuations in visual sensitivity, or the circatidal clock, that controls tidal rhythms of locomotion, are currently unknown, preliminary molecular analyses have shown that a 71 kD protein that reacts with antibodies directed against the Drosophila PERIOD （PER） protein is found in both the pro- tocerebrum and the subesophageal ganglion

关键词： circatidal circadian circalunidian Rhythms Behavior PER Tides Locomotion

high resolution tracking of adult horseshoe crabs Limulus polyphemus in a New hampshire estuary using fixed array ultrasonic telemetry

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current Zoology 2010年第5期56卷 599-610页

作者： Winsor h.WATSON Ⅲ christopher c.chABOT Department of Biological Sciences University of New Hampshire Department of Biology Plymouth State University

While several studies have documented the large-scale, seasonal movements of horseshoe crabs, little is known about their fine-scale, daily movement patterns. In this study we used a fixed array ultrasonic telemetry system to track the movements of 12 male and 16 female horseshoe crabs in the Great Bay estuary, New hampshire. Data were obtained during the mating season, as well as during the remainder of the summer and fall, in the years 2005-2008. During the mating season animals were often, but not always, active during the high tides when they were approaching and leaving the spawning beaches. On average, both males and females approached mating beaches during 33% of the high tides they experienced and they most often made the tran- sition from being inactive to active during the last two hours of an incoming tide. From April-October horseshoe crabs were significantly more active during high tide periods vs low tide periods, with no clear preference for diurnal vs nocturnal activity. After the mating season ended horseshoe crabs continued to move into shallower water at high tide and then return to deeper water at low tide. Observations by ScUBA divers suggest that during these excursions into the mudflats horseshoe crabs were digging pits in the sediment while foraging for food. Thus, the tidal rhythm of activity that has been so well documented during the mating season probably persists into the fall, and primarily involves foraging activities

关键词： Telemetry Tracking Movements Mating Foraging Estuary