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effects of dust controls on respirable coal mine dust composition and particle sizes:case studies on auxiliary scrubbers and canopy air curtain

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International Journal of Coal Science & Technology 2024年第3期11卷 86-101页

作者： F.Animah C.Keles w.R.Reed e.Sarver Department of Mining and Minerals engineering Virginia Polytechnic Institute&State UniversityBlacksburgVAUSA National Institute of Occupational Safety and Health(NIOSH) PittsburghPAUSA

Control of dust in underground coal mines is critical for mitigating both safety and health *** decades,the National Institute of Occupational Safety and Health(NIOSH)has led research to evaluate the effectiveness of various dust control technologies in coal *** studies have included the evaluation of auxiliary scrubbers to reduce respirable dust downstream of active mining and the use of canopy air curtains(CACs)to reduce respirable dust in key operator *** detailed dust characterization was not a focus of such studies,this is a growing area of *** preserved filter samples from three previous NIOSH studies,the current work aims to explore the effect of two different scrubbers(one wet and one dry)and a roof bolter CAC on respirable dust composition and particle size *** this,the preserved filter samples were analyzed by thermogravimetric analysis and/or scanning electron microscopy with energy dispersive *** indicate that dust composition was not appreciably affected by either scrubber or the ***,the wet scrubber and CAC appeared to decrease the overall particle size *** an effect of the dry scrubber was not consistently observed,but this is probably related to the particular sampling location downstream of the scrubber which allowed for significant mixing of the scrubber exhaust and other return *** from the insights gained with respect to the three specific dust control case studies revisited here,this work demonstrates the value of preserved dust samples for follow-up investigation more broadly.

关键词： Respirable dust Dust control SeM–eDX Scrubber Canopy air curtain Silica

双色激光共振增强的气相C6H6分子的光电离谱

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光学学报 1987年第1期 1-10页

作者：范俊颖 G.MüLLeR J.L.LYMAN w.e.sohmid K.L.KOMPA 中国科学院上海光学精密机械研究所 Max-Planck-Institut für Quantenoptik D-8046 Garching b.München FRG Los Alamos National Laboratory New Mexico 87545 USA

本文给出了双色激光共振增强的气相苯的光电离谱结果。激发光子首先把分子从基态选择激发到s-1电子单态中一个确定的振动态,然后第二台激光器输出的离化光子把这个激发分子离化。实验证明离子的产额不但与中间电子能级1B2u的振动态有关... 详细信息

本文给出了双色激光共振增强的气相苯的光电离谱结果。激发光子首先把分子从基态选择激发到s-1电子单态中一个确定的振动态,然后第二台激光器输出的离化光子把这个激发分子离化。实验证明离子的产额不但与中间电子能级1B2u的振动态有关,且依赖于离化激光的波长。从所得到的离子谱的结构和强度可以求得离子的电子基态2e1g的振动频率及分子参数,精度较高。自离化里德堡能级对离化截面的贡献非常显著。某些自离化共振峰可以确认为是这些里德堡态的振动能级。

关键词：电子态跃迁 C6H6 激光双色共振增强气相

Supramolecular Polymerization of Hydrogen-Bonded Trimers in Bulk and Aqueous Medium

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CCS Chemistry 2024年第6期6卷 1458-1465页

作者： Freek V.de Graaf Stef A.H.Jansen Sandra M.C.Schoenmakers Bas van Genabeek Marle e.J.Vleugels Bart w.L.van den Bersselaar e.w.Meijer Ghislaine Vantomme Institute for Complex Molecular Systems Laboratory of Macromolecular and Organic ChemistryEindhoven University of Technology5600 MBEindhoven School of Chemistry and RNA Institute University of New South WalesSydneyNew South Wales 2052

Synthetic molecules that form functional noncovalent assemblies in water have received much attention for their potential applications as *** this work,we introduce a novel water-compatible monomer based on the phthalhydrazide moiety that assembles into hydrogen-bonded trimeric *** bulk,the material exhibits a cylindrical nanostructure in the liquid-crystalline phase at elevated temperatures,morphologically distinct from the crystalline lamellar *** water,these molecules effectively form cylinders in a one-dimensional fashion,yielding fibrous *** formation of these supramolecular polymers follows a cooperative mechanism,as evidenced by denaturation *** trimerized pattern represents a new category of aqueous su pramolecular polymers with future prospects for functional complex molecular systems.

关键词： noncovalent chemistry supramolecular polymers hydrogen bonding cooperativity nanostructure

Superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： H.T.Jeong S.w.Lee w.J.Kim Department of Materials Science and engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the HCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

Association between baseline levels of muscular strength and risk of stroke in later life:The Cooper Center Longitudinal Study

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Journal of Sport and Health Science 2024年第5期13卷 642-649页

作者： Stephen w.Farrell David Leonard Qing Li Carolyn e.Barlow Kerem Shuval Jarett D.Berry Andjelka Pavlovic Laura F.DeFina Research Division The Cooper InstituteDallasTX 75230USA Department of Internal Medicine University of Texas at Tyler School of MedicineTylerTX 75799USA

Background:Muscular strength is an important component of physical *** evaluated the relationship between baseline muscular strength and risk of stroke among adults who were aged≥65 years during ***:we included 7627 healthy adults(mean age=43.9 years,86.0%male)underwent a baseline physical examination between 1980 and *** strength was determined by 1-repetition maximum measures for bench press and leg press and categorized into age-and sex-specific tertiles for each *** fitness(CRF)was assessed via a maximal treadmill exercise *** enrolled in fee-for-service Medicare from 1999 to 2019 were included in the *** between baseline strength and stroke outcomes were estimated using a modified Cox proportional hazards *** a secondary analysis,we examined stroke risk by categories of CRF where Quintile 1=low,Quintiles 2-3=moderate,and Quintiles 4-5=high CRF based on age and ***:After 70,072 person-years of Medicare follow-up,there were 1211 earliest indications of incident *** multivariable analyses,the hazard ratio(95%confidence interval(95%CI))for stroke across bench press categories were 1.0(referent),0.96(0.83-1.11),and 0.89(0.77-1.04),respectively(p trend=0.14).The trend across categories of leg press was also non-significant(p trend=0.79).Adjusted hazard ratio(95%CI)for stroke across ordered CRF categories were 1.0(referent),0.90(0.71-1.13),and 0.72(0.57-0.92)(p trendwhile meeting public health guidelines for muscular strengthening activities is likely to improve muscular strength as well as many health outcomes in older adults,performing such activities may not be helpful in preventing ***,meeting guidelines for aerobic activity is likely to improve CRF and lower stroke risk.

关键词： Cardiorespiratory fitness Medicare Muscular strength Stroke

Pervasive Attentive Neural Network for Intelligent Image Classification Based on N-CDe’s

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Computers, Materials & Continua 2024年第4期79卷 1137-1156页

作者： Anas w.Abulfaraj Department of Information Systems Faculty of Computing and Information TechnologyKing Abdulaziz UniversityRabigh21911Saudi Arabia

The utilization of visual attention enhances the performance of image classification *** attentionbased models have demonstrated notable performance,but many of these models exhibit reduced accuracy when confronted with inter-class and intra-class similarities and ***-Controlled Differential equations(N-CDe’s)and Neural Ordinary Differential equations(NODe’s)are extensively utilized within this ***’s possesses the capacity to effectively illustrate both inter-class and intra-class similarities and differences with enhanced *** this end,an attentive neural network has been proposed to generate attention maps,which uses two different types of N-CDe’s,one for adopting hidden layers and the other to generate attention *** distinct attention techniques are implemented including time-wise attention,also referred to as bottom N-CDe’s;and element-wise attention,called topN-CDe’***,a trainingmethodology is proposed to guarantee that the training problem is sufficiently *** classification tasks including fine-grained visual classification andmulti-label classification,are utilized to evaluate the *** proposedmethodology is employed on five publicly available datasets,including CUB-200-2011,ImageNet-1K,PASCAL VOC 2007,PASCAL VOC 2012,and MS *** obtained visualizations have demonstrated that N-CDe’s are better appropriate for attention-based activities in comparison to conventional NODe’s.

关键词： Differential equations neural-controlled De image classification attention maps N-CDe’s

Barosinusitis due to routine weather changes:A cross-sectional analysis of public websites

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world Journal of Otorhinolaryngology-Head and Neck Surgery 2024年第1期10卷 18-23页

作者： James C.Campbell Julia e.Canick Philip G.Chen Ralph Abi Hachem David w.Jang Department of Head and Neck Surgery&Communication Sciences Duke University School of MedicineDurhamNorth CarolinaUSA Duke University School of Medicine DurhamNorth CarolinaUSA Department of Otolaryngology-Head and Neck Surgery University of Texas Health Science Center San AntonioSan AntonioTexasUSA

Background:Sinusitis is a common diagnosis that can be erroneously associated with routine weather‐related barometric pressure *** actuality,these pressure changes likely exacerbate migraine headaches,which can cause facial pain and pressure rather than true sinus ***:The present study sought to characterize the representation of both sinusitis and migraine in association with barometric pressure changes across websites on the ***:An Internet search for relevant terms was conducted,and content of the resulting pages was assessed for associations between weather‐related pressure changes and either sinusitis or *** in reported results across different subtypes of Internet sources were *** primary outcomes measured were(1)whether a given media source associated barometric weather changes with sinusitis,(2)whether that source associated barometric weather changes with migraine,and(3)treatment options offered by that ***:Of the 116 included webpages,36(31.03%)associated sinusitis and routine barometric pressure *** these,10(27.77%)were otolaryngology practice ***‐seven webpages(57.76%)associated migraine and routine barometric pressure *** these,nonotolaryngology webpages were more likely to report this ***:Otolaryngology practice sites were observed to be the most frequent professional medical resource reporting the unsubstantiated claim that routine barometric pressure changes are associated with *** sources were more likely to link weather‐related pressure changes to *** results suggest that opportunities exist for otolaryngology practice sites to educate patients about nonrhinogenic headache etiologies.

关键词： acute rhinosinusitis balloon sinus dilation headache migraine sinusitis

The quasi-Gramian solution of a non-commutative extension of the higher-order nonlinear Schr?dinger equation

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Communications in Theoretical Physics 2024年第3期76卷 51-61页

作者： H w A Riaz J Lin Department of Physics Zhejiang Normal UniversityJinhua 321004China

The nonlinear Schr?dinger(NLS)equation,which incorporates higher-order dispersive terms,is widely employed in the theoretical analysis of various physical *** this study,we explore the non-commutative extension of the higher-order NLS *** treat real or complex-valued functions,such as g_(1)=g_(1)(x,t)and g_(2)=g_(2)(x,t)as non-commutative,and employ the Lax pair associated with the evolution equation,as in the commutation *** derive the quasi-Gramian solution of the system by employing a binary Darboux *** soliton solutions are presented explicitly within the framework of *** visually understand the dynamics and solutions in the given example,we also provide simulations illustrating the associated ***,the solution can be used to study the stability of plane waves and to understand the generation of periodic patterns within the context of modulational instability.

关键词： integrable systems Darboux transformation solitons

Highly enhanced UV absorption and light emission of monolayer wS_(2)through hybridization with Ti_(2)N MXene quantum dots and g-C_(3)N_(4)quantum dots

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Opto-electronic Advances 2024年第6期7卷 31-39页

作者： Anir S.Sharbirin Rebekah e.Kong wendy B.Mato Trang Thu Tran eunji Lee Jolene w.P.Khor Afrizal L.Fadli Jeongyong Kim Department of energy Science Sungkyunkwan UniversitySuwon 16419Republic of Korea

Two-dimensional(2D)transition metal dichalcogenides(TMD)are atomically thin semiconductors with promising optoelectronic applications across the visible ***,their intrinsically weak light absorption and the low photoluminescence quantum yield(PLQY)restrict their performance and potential use,especially in ultraviolet(UV)wavelength light *** dots(QD)derived from 2D materials(2D/QD)provide efficient light absorption and emission of which energy can be tuned for desirable light *** this study,we greatly enhanced the photon absorption and PLQY of monolayer(1L)tungsten disulfide(wS_(2))in the UV range via hybridization with 2D/QD,particularly titanium nitride MXene QD(Ti_(2)N MQD)and graphitic carbon nitride QD(GCNQD).with the hybridization of MQD or GCNQD,1LwS_(2)showed a maximum PL enhancement by 15 times with 300 nm wavelength excitation,while no noticeable enhancement was observed when the excitation photon energy was less than the bandgap of the QD,indicating that UV absorption by the QD played a crucial role in enhancing the light emission of 1L-wS_(2)in our 0D/2D hybrid *** findings present a convenient method for enhancing the photo-response of 1L-wS_(2)to UV light and offer exciting possibilities for harvesting UV energy using 1L-TMD.

关键词： monolayer TMD wS_(2) 2D-derived quantum dots UV absorption energy transfer