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Chinese Journal of Chemistry 2021年第6期39卷 1503-1510页

作者： Chandra s Azad Pratibha shukla mark A Olson Anudeep K Narula Institute for Molecular Design and synthesis School of Pharmaceutical Science&TechnologyHealth Science PlatformTianjin University92 Weijin RoadNankai DistrictTianjin 300072China "Hygeia" Centre of Excellence in Pharmaceutical SciencesGuru Gobind Singh Indraprostho UniversitySector 16-CDwarkaNew Delhi 110078India Department of Chemistry Northwestern University2145 Sheridan RoodEvanstonIL 60208USA

A catalytic two-component three-centered(2C3C)Ugi-type reaction was developed for the synthesis of L-1-deoxynojirimycin(DNJ)isomers using a chiron *** new and quite mild catalytic system,comprised of phenylphosphinic ... 详细信息

关键词： Azasugars Multicomponent reactions Nitrilium ion Isocyanide Reductive cyclization

Compressive and cyclic flexural response of double-hooked-end steel fiber reinforced concrete

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Frontiers of structural and Civil Engineering 2022年第9期16卷 1104-1126页

作者： Demewoz W.MENNA Aikaterini s.GENIKOMsOU mark F.GREEN Department of Civil Engineering Queen’s UniversityKingstonON K7L 3N6Canada

Recent developments on high-performance double-hooked-end steel fibers have enhanced the wide applications of steel fiber reinforced concrete(sFRC).This study presents the compressive properties and the cyclic flexural performance of the sFRC that were experimentally *** different double-hooked-end steel fibers at 0.25%,0.5%,0.75%,and 1%volume fractions were *** fiber types had similar length to diameter ratios,while the first two fiber types had similar anchorage mechanisms(4D)and tensile strength and the third type had different anchorage mechanism(5D)and a higher tensile *** increased volumetric ratio of the fibers increased the post-peak compressive strain(ductility),the tensile strength,and the cyclic flexural strength and cumulative energy dissipation characteristics of the *** the 4D fibers,the mixtures with the larger steel fibers showed higher flexural strength and more energy dissipation compared to the sFRCs with smaller size *** 1%steel fiber dosage,4D and 5D specimens showed similar cyclic flexural ***,a 3D finite element model that can predict the monotonic and cyclic flexural responses of the double-hooked-end sFRC was *** calibration process considered the results obtained from the inverse analysis to determine the tensile behavior of the sFRC.

关键词： steel fiber reinforced concrete fiber geometry cyclic loading energy dissipation finite element modeling inverse analysis

Bleeder entry evaluation using condition mapping and numerical modeling

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International Journal of Mining science and Technology 2021年第1期31卷 137-143页

作者： Ted M.Klemetti mark A.Van Dyke Gabriel s.Esterhuizen National Institute for Occupational safety and Health Pittsburgh Mining Research DivisionPittsburghPA 15236USA

One of the most common critical areas of longwall mining in terms of ground stability are the gateroad and bleeder *** critical entries provide much-needed safe access for miners and allow for adequate ventilation required for dilution of hazardous airborne contaminants and must remain open during mining of a multi-panel *** paper is focused on the stability of the longwall entries subjected to a single abutment load such as bleeders,first tailgate,and last *** tailgate and last headgate are also referred to as blind headgate and tailgate.A study of a longwall district through conditions mapping,support evaluations,and numerical modeling was conducted and evaluated by researchers from the National Institute for Occupational safety and Health(NIOsH).The condition mapping and support evaluations were performed on entries that spanned the previous five years of mining and relied on a diverse selection of supports to maintain the functionality of the *** modeling was also conducted to evaluate various support types with further investigation and comparison to the condition *** study demonstrated the importance of the abutment load decay versus distance from the gob edge,the potential for a reduction in material handling related injuries,as well as optimal usage of secondary and standing support.

关键词： stability assessment Bleeder entry Abutment loading Condition mapping Longwall Ground control

Protecting miners from coal bursts during development above historic mine workings in Harlan County,KY

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International Journal of Mining science and Technology 2021年第1期31卷 111-116页

作者： Christopher mark Mine safety and Health Administration PittsburghPA 15236USA

In order to reach a large,untapped reserve of high-quality coal,D8 Cloverlick Mine proposed to mine a corridor nearly 600 m deep beneath the Benham spur of Black Mountain,Kentucky’s highest peak.D8 Cloverlick Mine was extracting the Owl seam,but the corridor’s route lay approximately 20 m above century-old mine workings in the C–(Darby)*** to the concern,three serious coal bursts had recently occurred in nearby Owl seam *** of the old workings seemed to indicate that the underlying C–seam had been fully ***,two of the coal bursts had occurred above areas where the C–seam was also shown as mined *** safety and Health Administration(MsHA)Technical support therefore investigated the records of past mining to better understand the old mine *** conditions observed in current Owl seam workings were also compared with the maps of the old C–seam *** study concluded that the presence of hazardous underlying remnants could not be ruled *** mitigate the burst risk,D8 Cloverlick Mine adopted a strategy of stress probe drilling.A self-propelled coal drill was used to auger 11.5-m-long,small diameter holes in advance of *** each hole was drilled,the cuttings were measured to detect the presence of highly stressed *** the crossing was successfully completed without incident.

关键词： Coal bursts Underground mining Room-and-pillar Destressing

An updated empirical model for ground control in *** coal mines

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International Journal of Mining science and Technology 2021年第2期31卷 163-174页

作者： Christopher mark Mine safety and Health Administration PittsburghPA 15217USA

Multiple seam interactions are a major source of ground instability in several *** methods are well suited for this problem,because while the mechanics multiple seam interactions are very complex and poorly understood,many mining case histories are available for *** study makes use of an updated database that includes 356 multiseam case histories,including 67 unsuccessful *** paper describes in detail the process used to design the study,collect the data,conduct the statistical analysis,and develop the quantitative *** model can be used for mine planning in multiple seam situations,and has been made available as a module within the Analysis of Coal Pillar stability(ACPs)computer program.

关键词： Underground Coal Multiseam Ground control Pillar design Empirical

Recurrent hepatitis C after liver transplant

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World Journal of Gastroenterology 2014年第31期20卷 10668-10681页

作者： Andrew s deLemos Paul A schmeltzer mark W Russo Department of Medicine Center for Liver Diseases and Transplantation Carolinas Medical Center

End stage liver disease from hepatitis C is the most common indication for liver transplantation in many parts of the world accounting for up to 40% of liver transplants. Antiviral therapy either before or after liver transplantation is challenging due to side effects and lower efficacy in patients with cirrhosis and liver transplant recipients, as well as from drug interactions with immunosuppressants. Factors that may affect recurrent hepatitis C include donor age, immunosuppression, IL28 B genotype, cytomegalovirus infection, and metabolic syndrome. Older donor age has persistently been shown to have the greatest impact on recurrent hepatitis C. After liver transplantation, distinguishing recurrent hepatitis C from acute cellular rejection may be difficult, although the development of molecular markers may help in making the correct diagnosis. The advent of interferon free regimens with direct acting antiviral agents that include Ns3/4A protease inhibitors, Ns5 B polymerase inhibitors and Ns5 A inhibitors holds great promise in improving outcomes for liver transplant candidates and recipients.

关键词： Hepatitis C Liver transplant Donor risk factors Immunosuppression Protease inhibitors Fibrosing cholestatic hepatitis C Acute cellular rejection Cytomegalovirus

Daoism and the German Mission in Martin Heidegger's“The Thing”

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Frontiers of Philosophy in China 2019年第4期14卷 570-592页

作者： mark Kevin s.Cabural Division of Humanities Hong Kong University of Science and TechnologyHong KongChina

In this article,I examine Martin Heidegger’s 1950 lecture/essay“The Thing”(Das Ding)in two ***,as a piece influenced by chapter 11 of the *** second,as a postwar writing which can be interpreted vis-a-vis the Black Notebooks and his other *** are instances in“The Thing”which are analogous to his statements found in the Black Notebooks and his other writings which describe and clarify his controversial political *** brief,I suggest here that Heidegger’s articulation of the concept of wu 無 of chapter 11 of the Daodejing as the void of the jug in“The Thing”may potentially describe his controversial engagement with German National socialism as part of his response to the call for German ***,the fundamentality of the void of the jug is comparable to the exclusivity and exceptionality of the Germans in their mission;and the use of the void of the jug as outpouring is an interesting way to emphasize his disagreement with the regime by pointing out that his support to German National socialism is not to the extent of brutally annihilating the Jews.

关键词： Martin Heidegger Daodejing German mission nothing void emptiness

A comparative study of the mechanical properties, fracture behavior, creep, and shrinkage of chemically based self-consolidating concrete

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Frontiers of structural and Civil Engineering 2014年第1期8卷 36-45页

作者： Mahdi AREZOUMANDI mark EZZELL Jeffery s VOLZ Department of Civil Architectural and Environmental Engineering Missouri University of Science and Technology Missouri MO 65409 USA U s Army Corps of Engineers 1222 Spruce St. St. Louis Missouri MO 63103 USA school of Civil Engineering and Environmental science University of Oklahoma Norman OK 73019-1024 USA

This study presents the results of an experimental investigation that compares the mechanical properties, fracture behavior, creep, and shrinkage of a chemically-based self-consolidating concrete （sCC） mix with that of a corresponding conventional concrete （CC） mix. The CC and sCC mix designs followed conventional proportioning in terms of aggregate type and content, cement content, air content, water-cementitiuos materials （w/cm） ratio, and workability. Then, using only chemical admixtures, the authors converted the CC mix to an sCC mix with all of the necessary passing, filling, flowability, and stability requirements typically found in sCC. The high fluidity was achieved with a polycarboxylate-based high-range water-reducing admixture, while the enhanced stability was accomplished with an organic, polymer-based viscosity-modifying admixture. The comparison indicated that the sCC and CC mixes had virtually identical tensile splitting strengths, flexural strengths, creep, and shrinkage. However, the sCC mix showed higher compressive strengths and fracture energies than the corresponding CC mix.

关键词： admixture conventional concrete (CC) creep fracture mechanic mechanical Properties self-consolidatingconcrete (sCC) shrinkage

Predicting excavation damage zone depths in brittle rocks

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第1期8卷 60-74页

作者： Matthew A.Perras mark s.Diederichs Queen’s University Miller Hall36 Union StreetKingstonOntarioK7L 3N6Canada swiss Federal Institute of Technology Sonneggstrasse 5ZurichCH-8092Switzerland

During the construction of an underground excavation, damage occurs in the surrounding rock mass due in large part to stress changes. While the predicted damage extent impacts profile selection and support design, the depth of damage is a critical aspect for the design of permeability sensitive excavations, such as a deep geological repository(DGR) for nuclear waste. Review of literature regarding the depth of excavation damage zones(EDZs) indicates three zones are common and typically related to stress induced damage. Based on past developments related to brittle damage prediction using continuum modelling, the depth of the EDZs has been examined numerically. One method to capture stress induced damage in conventional engineering software is the damage initiation and spalling limit(DIsL) approach. The variability of depths predicted using the DIsL approach has been evaluated and guidelines are suggested for determining the depth of the EDZs around circular excavations in brittle rock masses. Of the inputs evaluated, it was found that the tensile strength produces the greatest variation in the depth of the EDZs. The results were evaluated statistically to determine the best fit relation between the model inputs and the depth of the EDZs. The best correlation and least variation were found for the outer EDZ and the highly damaged zone(HDZ) showed the greatest variation. Predictive equations for different EDZs have been suggested and the maximum numerical EDZ depths, represented by the 68% prediction interval, agreed well with the empirical evidence. This suggests that the numerical limits can be used for preliminary depth prediction of the EDZs in brittle rock for circular excavations.

关键词： Excavation damage zones(EDZs) Deep geological repository(DGR) Empirical depth prediction Numerical depth prediction Damage depth sensitivity Damage initiation and spalling limit(DIsL)

Biomimicry and Theory of structures-Design Methodology Transfer from Trees to Moment Frames

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Journal of Bionic Engineering 2014年第4期11卷 638-648页

作者： mark Grigorian MGA structural Engineering Inc. 111 N. Jackson st. Glendale CA. 91206 USA

Currently, there are only three classical and a handful of emerging design methodologies available to structural engineers worldwide. None of these methodologies can explain the design concepts involved in the realization of natural structures such as trees, nor can they fully address the design needs of contemporary engineering structures. The recently developed Performance Control （PC） incorporates both the essence of the classical concepts and the newer procedures and addresses the observed performance of the structure during its known history of loading, PC attempts to mimic nature by applying the known theories of structures to the design of case-specific frameworks, rather than investigating their results for compliance against prescriptive criteria. Parametric examples have been provided to illustrate the applications of the conceptual design similarities between trees and manmade moment frames. It has been shown that an understanding of the structural performance of trees can enhance the structural design of moment frames, and that bioinspired PC can lead to minimum weight moment frames under lateral loading. The analogous performances of the natural and manmade structures may help explain the structural response of trees to similar loading scenarios.

关键词： performance control biomimetics trees moment frames lateral loading