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A column study of the hydro-mechanical behavior of mature fine tailings under atmospheric drying

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International Journal of Mining Science and Technology 2017年第2期27卷 203-209页

作者： Anis Roshani Mamadou Fall Kevin Kennedy Department of Civil Engineering University of OttawaOttawa KIN 6N5Canada

In this paper, the hydro-mechanical behavior and physical properties of mature fine tailings(MFT) under atmospheric drying are investigated through a column study. In the study, evaporation takes place in the development of suction in the upper parts of the column and increasing suction leads to higher strength in the tailings. After 5 days, the suction in the first lift is around 17 k Pa in the upper part of the *** a second lift is added, the first lift initially loses strength but over a 30 days' period, the strength is recovered to its prior value and suction in the second lift reaches 500 k Pa. The vane shear strength values show a substantial increase in the strength of the MFT after 30 days under atmospheric drying and drainage. The 90% strength found in the column exceeds the threshold(5 k Pa). The hydraulic-mechanical properties of the deposited tailings are closely coupled due to several mechanisms, such as evaporation,drainage, self-consolidation, suction and crack development. The findings of this study will provide a better understanding of the placement behavior of multiple lifts of MFT and thus contribute to reclamation design standards and reduce the use of dedicated disposal areas.

关键词： Tailings Oil sand Environment Drying Multi-lift deposition

Optical Tamm States in Dielectric Photonic Crystal Heterostructure

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Chinese Physics Letters 2008年第6期25卷 2093-2096页

作者：郭继勇孙勇李宏强张冶文陈鸿 Pohl Institute of Solid State Physics Tongji University Shangha5 200092

We investigate one-dimensional dielectric photonic crystal and optical Tamm modes formed by superposition of two band gaps and find that this kind of mode can be explained by the single negative materials tunnelling effect. A finite-size dielectric photonic band gap can mimic one kind of effective single negative material and this property sensitively depends on the frequency location in stop-band regions and surface termination and so on. The effective impedance match and effective phase match give the precise position of the optical Tamm mode. Complete transparency via tunnelling is achieved by two opaque media and demonstrates the validity of our approach.

关键词： supernova explosion proto-neutron star shock wave

Recent, development in low-constraint fracture toughness testing for structural integrity assessment of pipelines

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Frontiers of Mechanical Engineering 2018年第4期13卷 546-553页

作者： Jidong KANG James A. GIANETTO William R. TYSON CanmetMATERIALS Hamilton L8P 0A5 Canada

Fracture toughness measurement is an integral part of structural integrity assessment of pipelines. Traditionally, a single-edge-notched bend （SE（B）） specimen with a deep crack is recommended in many existing pipeline structural integrity assessment procedures. Such a test provides high constraint and therefore conservative fracture toughness results. However, for girth welds in service, defects are usually subjected to primarily tensile loading where the constraint is usually much lower than in the three-point bend case. Moreover, there is increasing use of strain-based design of pipelines that allows applied strains above yield. Low-constraint toughness tests represent more realistic loading conditions for girth weld defects, and the corresponding increased toughness can minimize unnecessary conservatism in assessments. In this review, we present recent developments in low-constraint fracture toughness testing, specifically using single-edge- notched tension specimens, SENT or SE（T）. We focus our review on the test procedure development and automation, round-robin test results and some common concerns such as the effect of crack tip, crack size monitoring techniques, and testing at low temperatures. Examples are also given of the integration of fracture toughness data from SE（T） tests into structural integrity assessment.

关键词： fracture toughness constraint effect singleedge-notched tension test pipeline structural integrity assessment

A FURTHER INVESTIGATION ON THE PARAMETERS OF THE VDW TYPE EQUATION OF STATE

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Chinese Journal of Chemical Engineering 1996年第2期4卷 92-97页

作者：董军航徐南平王延儒时钧 Benjamin C.-Y. Lu Department of Chemical Engineering University of Ottawa Ontario KIN 6N5 Canada

1 INTRODUCTIONSince the days when Soave [1] and Peng and Robinson [2] disclosed their modifiedvan der Waals(vdW)equations of state(EOS),a large number of papers on the samesubject have been *** vdW type EOS are similar in structure,as they are de-rived from a generalized equation [3].Therefore,studies on vdW EOS are essentially fo-cused on the searching of the most rational parameters and the most appropriaterepresentation of these *** a lot of efforts were paid on this subject

关键词： EOS parameter characteristic factor generalization

Clinical observations on the treatment of prolapsing hemorrhoids with tissue selecting therapy

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World Journal of Gastroenterology 2015年第8期21卷 2490-2496页

作者： Zhi-Gang Wang Yong Zhang Xian-Dong Zeng Tie-Hui Zhang Qi-Dong Zhu De-Long Liu Yun-Yu Qiao Nan Mu Zhi-Tao Yin The 5~(th) Department of Anorectal Disease Shenyang Coloproctology Hospital

AIM:To compare the effects and postoperative complications between tissue selecting therapy stapler(TST)and Milligan-Morgan hemorrhoidectomy(M-M).METHODS:Four hundred and eighty patients with severe prolapsing hemorrhoids,who were admitted to the Shenyang Coloproctology Hospital between 2009and 2012,were randomly divided into observation(n=240)and control(n=240)*** were performed with TST in the observation group and with the M-M technique in the control *** therapeutic effects,operation security,and postoperative complications in the two groups were *** immediate and long-term complications were assessed according to corresponding *** was assessed on a visual analogue *** efficacy was assessed by specialized *** follow-up was conducted one year after the ***:The total effective rates of the observation and control groups were 99.5%(217/218)and 98.6%(218/221)respectively;the difference was not statistically significant(P=0.322).Their were significant differences between observation and control groups in intraoperative blood loss(5.07±1.14 vs 2.45±0.57,P=0.000),pain(12 h after the surgery:5.08±1.62 vs 7.19±2.01,P=0.000;at first dressing change:2.64±0.87 vs 4.34±1.15,P=0.000;first defecation:3.91±1.47 vs 5.63±1.98,P=0.001),urine retention(n=22 vs n=47,P=0.001),anal pendant expansion after the surgery(2.35±0.56 vs 5.16±1.42,P=0.000),operation time(18.3±5.6 min vs 29.5±8.2 min,P=0.000),and the length of hospital stay(5.3±0.6 d vs 11.4±1.8 d,P=0.000).Moreover TST showed significant reductions compared to M-M in the rates of long-term complications such as fecal incontinence(n=3 vs n=16,P=0.003),difficult bowel movement(n=1 vs n=9,P=0.011),intractable pain(n=2 vs n=12,P=0.007),and anal discharge(n=3 vs n=23,P=0.000).CONCLUSION:TST for severe prolapsing hemorrhoids is a satisfactory technique for more rapid recovery,lower complication rates,and higher operation security.

关键词： Complication rate Milligan-Morgan hemorrhoidectomy

Effect of Different Types of Wing-Wing Interactions in Flapping MAVs

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Journal of Bionic Engineering 2017年第1期14卷 60-74页

作者： Wee Beng Tay Temasek Laboratories National University of Singapore 5A Engineering Drive 1 117411 Singapore

Wing-Wing Interaction （WWI）, such as the Clap and Fling Motion （CFM）, occurs when two wings are flapping close together, improving performance. We intend to design a hovering Flapping Micro Aerial Vehicle （FMAV） which makes use of WWI. We investigate the effects of flexibility, kinematic motions, and two- to six-wing flapping configurations on the FMAV through numerical simulations. Results show that a rigid spanwise and flexible chordwise wing produces the highest lift with minimum power. The smoothly varying sinusoidal motion, which is visually similar to the CFM, produces similar lift in comparison to the CFM, while having lower peak power requirement. Lastly, lift produced by each wing of the two-, four-, six-wing configurations is approximately equal. Hence more wings generate higher total lift force, but at the expense of higher drag and power requirement. These results will be beneficial in the understanding of the underlying aerodynamics of WWI, and in improving the performance of our FMAV.

关键词： flapping wings MAV immersed boundary methods clap and fling

Twisted double incidence algebras of type A_n

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Science China Mathematics 2000年第11期43卷 1164-1173页

作者：邓邦明 Department of Mathematics Beijing Normal University Beijing 10087a5 China

This paper gives a complete classification of (Δ)-finite twisted double incidence algebras of posets in the case where the Hasse quivers of posets are of type An.

关键词： twisted double incidence algebra quasi-hereditary algebra good module category F(Δ)-finiteness

INVERSE PROBLEM STABILITY OF A CONTINUOUS-IN-TIME FINANCIAL MODEL

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Acta Mathematica Scientia 2019年第5期39卷 1423-1439页

作者： Tarik CHAKKOUR Piaf INRA Site de Crou?l 5Chemin de Beaulieu

In this work, we study the inverse problem stability of the continuous-in-time model which is designed to be used for the finances of public institutions. We discuss this study with determining the Loan measure from algebraic spending measure in Radon measure space M([tI,Θmax]), and in Hilbert space L2([tI,Θmax]) when they are density measures. For this inverse problem we prove the uniqueness theorem, obtain a procedure for constructing the solution and provide necessary and sufficient conditions for the solvability of the inverse problem in L2([tI,Θmax]).

关键词： inverse problem stability mathematical model Fredholm operator

Linear and Nonlinear Anderson Localization in a Curved Potential

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Chinese Physics Letters 2014年第3期31卷 27-29页

作者： Claudio Conti Department of Physics University Sapienza Piazzale Aldo Moro 5 Rome 00185 Italy

Disorder induced localization in the presence of nonlinearity and curvature is investigated. The time-resolved three-dimensional expansion of a wave packet in a bent cigar shaped potential with a focusing Kerr-like interaction term and Gaussian disorder is numerically analyzed. A self-consistent analytical theory, in which randomness, nonlinearity and geometry are determined by a single scaling parameter, is reported, and it is shown that curvature enhances localization.

关键词： WAVE packets RESEARCH NONLINEAR theories CURVATURE LOCALIZATION (Mathematics) PHYSICS research