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Radiogenic Source Identification for the Helium Production-Diffusion Equation

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Communications in Computational Physics 2013年第6期14卷 1-20页

作者： Gang Bao todd A.Ehlers Peijun Li Department of Mathematics Zhejiang UniversityHangzhou 310027China Department of Mathematics Michigan State UniversityEast LansingMI 48824USA Department of Geosciences Wilhelmstrasse 56Universitat TubingenD-72074TubingenGermany Department of Mathematics Purdue UniversityWest LafayetteIN 47907USA

Knowledge of helium diffusion kinetics is critical for materials in which helium measurements are made,particulary for *** most cases the helium ages were younger than expected,an observation attributes to diffusive loss of helium and the ejection of high energy alpha *** it is important to accurately calculate the distribution of the source term within a *** this paper,the prediction of the helium concentrations as function of a spatially variable source term are *** the forward and inverse solutions are *** the assumption of radially symmetric geometry,an analytical solution is deduced based on the eigenfunction *** regularization methods,the Tikhonov regularization and the spectral cutoff regularization,are considered to obtain the regularized *** estimates with optimal convergence order are shown between the exact solution and the regularized *** examples are presented to illustrate the validity and effectiveness of the proposed methods.

关键词： Inverse source problem production-diffusion equation Tikhonov regularization

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The Troupe(Excerpt)

Frontiers of Literary Studies in China-Selected Publications from Chinese Universities 2018年第4期12卷 645-673页

作者： WANG Anyi todd Foley 不详 Department of East Asian Studies & Comparative Literature New York UniversityNew YorkNY 10003USA

*** OperaIn its previous life,this regional Cultural Workers' Troupe of ours had been a Liuzi opera *** being displaced by the 'new culture,' Liuzi opera seemed to be in full decline—an ancient and rare dramatic form that had become *** had never seen it ourselves,or even heard a line of it *** said it had its origins as palace entertainment,possessing a subtle richness and lofty style that made it a truly elite form,though too elite to gain the popularity needed to withstand the test of *** explanation always sounded a little overblown.

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Effect of longwall-induced subsurface deformations on shale gas well casing stability under deep covers

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International Journal of Mining Science and Technology 2019年第1期29卷 3-8页

作者： Daniel W.H.Su Peter Zhang Mark Van Dyke todd Minoski Center for Disease Control and Prevention(CDC) National Institute for Occupational Safety and Health(NIOSH)Pittsburgh Mining Research Division(PMRD)

This paper presents the results of a 2017 study conducted by the National Institute for Occupational Safety and Health(NIOSH), Pittsburgh Mining Research Division(PMRD), to evaluate the effects of longwall-induced subsurface deformations within a longwall abutment pillar under deep cover. The 2017 study was conducted in a southwestern Pennsylvania coal mine, which extracts 457 m-wide longwall panels under 361 m of cover. One 198 m-deep, in-place inclinometer monitoring well was drilled and installed over a 45 m by 84 m center abutment pillar. In addition to the monitoring well, surface subsidence measurements and underground coal pillar pressure measurements were conducted as the 457 m-wide longwall panel on the south side of the abutment pillar was being mined. Prior to the first longwall excavation, a number of simulations using FLAC3D^(TM) were conducted to estimate surface subsidence, increases in underground coal pillar pressure, and subsurface horizontal displacements in the monitoring well. Comparisons of the pre-mining FLAC3D simulation results and the surface, subsurface,and underground instrumentation results show that the measured in-place inclinometer casing deformations are in reasonable agreement with those predicted by the 3D finite difference models. The measured surface subsidence and pillar pressure are in excellent agreement with those predicted by the 3D *** from this 2017 research clearly indicate that, under deep cover, the measured horizontal displacements within the abutment pillar are approximately one order of magnitude smaller than those measured in a 2014 study under medium cover.

关键词： Longwall Deformations Shale gas wells Casing Safety and health

Interactions between background matching and disruptive colouration： Experiments using human predators and virtual crabs

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Current Zoology 2015年第4期61卷 718-728页

作者： Peter A. todd Huijia PHUA Kok Ben TOH Experimental Marine Ecology Laboratory Department of Biological Sciences National University of Singapore 14 Science Drive 4 Blk S3 #02-05 Singapore 117543

Interactions between disruptive colouration and the match between prey and background spot size were manipulated in two experiments that used time taken by human ＇predators＇ to find artificial prey （virtual crab morphs） against heterogeneous backgrounds as a measure of the their camouflage. Experiment 1, in which the spots and their placement imitated the arrangement on the crab Carcinus maenas, tested whether high and low contrast spots touching the body outline （disruptive ＇edge＇ morphs） made the artificial prey more difficult to detect than when the spots did not touch the outline （non-disruptive ＇inner＇ morphs） against three different backgrounds：＇small＇, ＇middle＇ and ＇large＇ spot size. In Experiment 2, the range of spot sizes and their positions （＇edge＇ and ＇inner＇） on the crab morphs were varied to determine the most effective combination against the ＇mid- dle＇ background. Altogether, 640 volunteers participated in these computer trials, representing a high degree of independent replication. All patterned morphs were significantly harder to detect than plain morphs, indicating that possessing at least some degree of background matching can provide camouflage. Both experiments demonstrated that various morphs, though not having the same spot sizes as the background, had similar or better survivorship as those with matching spot sizes--indicating that opti- mal camouflage did not come from background matching alone. In Experiment 2, edge-disrupted morphs consistently took longer to find than their non-disruptive counterparts. The relative effects of edge disruption, contrast, and background/prey spot size are clearly context-dependent, highlighting the complexity of prey concealment [Current Zoology 61 （4）： 718-728, 2015].

关键词： Background matching Camouflage Carcinus maenas Crypsis Disruptive colouration Predation

ERCP for the treatment of bile leak after partial hepatectomy and fenestration for symptomatic polycystic liver disease

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World Journal of Gastroenterology 2012年第28期18卷 3705-3709页

作者： Nayantara Coelho-Prabhu David M Nagorney todd H Baron Mayo Clinic College of Medicine Rochester MN 55905 United States

AIM: To describe endoscopic treatment of bile leaks in these patients and to identify risk factors in these patients which can predict the development of bile leaks. METHODS: Retrospective case-control study examining consecutive patients who underwent partial hepatectomy for polycystic liver disease (PLD) and developed a postoperative bile leak managed endoscopically over a ten year period. Each case was matched with two controls with PLD who did not develop a postoperative bile leak. RESULTS: Ten cases underwent partial hepatectomy with fenestration for symptoms including abdominal distention, pain and nausea. Endoscopic retrograde cholangiopancreatography (ERCP) showed anatomic abnormalities in 1 case. A biliary sphincterotomy was performed in 4 cases. A plastic biliary stent was placed with the proximal end at the site of the leak in 9 cases; in 1 case two stents were placed. The overall success rate of ERCP to manage the leak was 90%. There were no significant differences in age, gender, comorbidities, duration of symptoms, history of previous surgery or type of surgery performed between cases and controls. CONCLUSION: ERCP with stent placement is safe and effective for management of post-hepatectomy bile leak in patients with PLD.

关键词： Polycystic liver Hepatectomy Bile leak Endoscopic retrograde cholangiopancreatography

Analysis of Oxides Formed on the Surface of the Alloy 690 in Hydrogenated Supercritical Water

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Acta Metallurgica Sinica(English Letters) 2016年第8期29卷 774-781页

作者： Jin Gao Fa-rong Wan Guo-ping Cao Kumar Sridharan todd Allen School of Materials Science and Engineering University of Science and Technology Beijing Department of Materials Science and Engineering University of Wisconsin-Madison

The oxides formed on the surface of the alloy 690 in hydrogenated supercritical water at 400℃ for 1000 h were investigated using scanning electron microscopy,transmission electron microscopy,scanning transmission electron microscopy and energy-dispersive X-ray *** oxides on me surface of the alloy 690 exhibited multi-layer structure：an outer layer consisted of granular crystallites（NiO and NiFe_2O_4） and a compact inner layer（spinel and Cr_2O_3）.Chemical analysis indicated that the outer layer was enriched in nickel but depleted in chromium,whereas the inner layer was enriched in chromium and iron but depleted in *** inner layer was also characterized as layered structure by Fe-rich spinel on top of continuous Cr_2O_3 ***,Cr_2O_3 nodules were readily observed at the oxides/alloy interface.

关键词： Alloy 690 Supercritical water Oxides Corrosion

FunnelCloud:a cloud-based system for exploring tornado events

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International Journal of Digital Earth 2017年第10期10卷 1030-1054页

作者： Jie Lian Michael P.McGuire todd W.Moore Department of Computer and Information Sciences Towson UniversityTowsonMDUSA Department of Geography and Environmental Planning Towson UniversityTowsonMDUSA

Recent research has shown an increase in the number of extreme tornado outbreaks per *** characterization of the spatio-temporal pattern of tornado events is therefore a critical task in the analysis of meteorological ***,there are a large number of available meteorological datasets that can be used for such ***,much of these data are distributed across multiple websites and are not accessible in a central *** poses a significant challenge for a scientist who is interested in exploring meteorological patterns associated with tornado *** paper presents a novel system which uses cloud-based technology for integrating,storing,exploring,analyzing,and visualizing meteorological data associated with tornado *** system employs a novel NoSQL database schema and web services architecture for data integration and provides a user friendly interface that allows scientists to explore the spatio-temporal pattern of tornado ***,scientists can use this interface to analyze the relationship between different meteorological variables and properties of tornado outbreaks using a number of spatio-temporal statistical and data mining *** efficacy of the system is demonstrated on a use case centered on the analysis of climatic indicators of large spatio-temporally clustered tornado outbreaks.

关键词： tornado data warehouse cloud-based system NoSQL data integration spatio-temporal clustering web-mapping

Influence of varying bedding thickness of underclay on floor stability

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International Journal of Mining Science and Technology 2017年第3期27卷 517-523页

作者： Jessu Kashi Vishwanath Kostecki todd Ray Spearing Anthony John Spencer Zhang Jixiong Western Australia School of Mines Curtin University Kalgoorlie 6430 Australia Southern Illinois University Carhondale 62901 USA The State Key Laboratory of Coal Resources and Safe Mining China University of Mining & Technology Xuzhou 221116 China

The variation in bedding thickness of the weak immediate floor has long been a challenge in the lllinois basin coal mines when it comes to floor stability. The vertical thickness of the immediate floor is not constant throughout the mines and can vary over short horizontal distances. The biggest misconception from a design standpoint is to use the maximum or average thickness found from core logs taken from various locations on the mine property. The result of this practice is oversized pillars in the areas where the weak immediate floor has thinned vertically. This over-design leaves coal in situ which could have otherwise been extracted. This paper presents a plane strain numerical model to illustrate the effect of a change in bedding thickness of a weak immediate floor across one or two coal pillars. The floor bearing capacity of the variable floor below each pillar where then compared to the consistent floor. The results show that the varying bedding thickness of weak underclay has an impact on the bearing capacity of the floor. Geometrically with the decrease in bedding thickness for constant pillar width, the B/H ratio increases exponentially. The influence of varying bedding thickness on the floor bearing capacity is apparent at higher B/H ratios. The floor bearing capacity under a single pillar is in variable floor model if the average thickness remains constant. For single pillar, the average of the bedding thickness can be considered and for pillars in a panel, and a safety factor has been proposed to take into account this change in bedding thickness.

关键词： Bedding thickness klnderclay Fireclay Illinois Basin Floor bearing capacity Floor safety factor

Successful endoscopic treatment of colonic gallstone ileus using electrohydraulic lithotripsy

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World Journal of Gastroenterology 2010年第12期16卷 1533-1536页

作者： Martin D Zielinski Lincoln E Ferreira todd H Baron Division of Trauma Critical Care and General Surgery Department of Medicine Federal University of Juiz de Fora Department of Gastroenterology and Hepatology

The surgical management of gallstone ileus is complex and potentially highly *** management requires enterolithotomy and is generally followed by fistula resection at a later *** have been reports of gallstone extraction using various endoscopic modalities to relieve the obstruction,however,to date,there has never been a published case of endoscopic stone extraction from the colon using electrohydraulic *** this report,we present the technique employed to successfully perform an electrohydraulic lithotripsy for removal of a large gallstone impacted in the sigmoid colon.A cavity was excavated in an obstructing 4.1 cm lamellated stone in the sigmoid colon using electrohydraulic lithotripsy.A screw stent retractor and stent extractor bored a larger lumen which allowed for guidewire advancement and stone fracture via serial pneumatic balloon *** stone fragments were *** lithotripsy is a safe and effective method to treat colonic obstruction in the setting of gallstone ileus.

关键词： Gallstone ileus Endoscopy Electrohydraulic lithotripsy Bowel obstruction Colon