检索结果-南通市图书馆

Constraint on the focal mechanism of the 2011 Tohoku earthquake from the radial modes

在线全文

学校读者我要写书评

暂无评论

Geodesy.and Geody.amics 2024年第1期15卷 27-32页

作者： Weikun chen hao Ding School of Geodesy.and Geomatics Hubei LuoJia LaboratoryWuhan UniversityWuhan 430079China

Different from other normal modes of the Earth’s free oscillation that depend on all the six components(M_(rr),M_(tt),M_(pp),M_(rt),M_(rp),and M_(tp))of the centroid moment tensor,the amplitudes of the radial modes depend on the M_(rr)component(e.g.,scalar moment(M_(0)),dip(δ),and slip(λ))and hy.ocenter depth of the focal mechanism,and hence can be easily.used to constrain these parameters of the focal *** this study.we use the superconducting gravimeter(SG)records after the 2011 Tohoku earthquake to analy.e the radial modes_(0)S_(0)and_(1)S_(0).Based on the solutions of the focal mechanism provided by.the GCMT and USGS,we can obtain the theoretical amplitudes of these two radial *** the theoretical amplitudes with the observation amplitudes,it is found that there are obvious differences between the former and the latter,which means that the GCMT and USGS focal mechanisms cannot well represent the real focal mechanism of the 2011 *** the GCMT solution as a reference and changing the depth and the three parameters of the M_(rr)moment,the scalar moment(M_(0))and the dip(δ)have significant influences,but the effects of the slip(λ)and the depth are *** comparisons,we provide a new constraint(M_(0)=5.8±0.09×10^(22)N·m,δ=10.1±0.08°,λ=88°,and depth=20 km)for the focal mechanism of the 2011 *** addition,we further determine the center frequency.1.631567±2.6e^(-6)mHz)and quality.factor(2046.4±50.1)of the_(1)S_(0)mode.

关键词： Focal mechanism Radial modes Gravity.observation

Very.long wave infrared quantum dot photodetector up to 18μm

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2024年第4期13卷 772-782页

作者： Xiaomeng Xue Qun hao Menglu chen School of Optics and Photonics Beijing Institute of TechnologyBeijing 100081China. Westlake Institute for Optoelectronics FuyangHangzhou 311421China. Phy.ics Department Changchun University of Science and TechnologyChangchun 130022China

Colloidal quantum dots(CQDs)are of interest for optoelectronic devices because of the possibility.of high-throughput solution processing and the wide energy.gap tunability.from ultraviolet to infrared *** may.question about the upper limit on the CQD wavelength *** date,although the CQD absorption already.reaches terahertz,the practical photodetection wavelength is limited within mid-wave *** figure out challenges on CQD photoresponse in longer wavelength,would reveal the ultimate property.on these ***’s more,it motivates interest in bottom-up infrared photodetection with less than 10%cost compared with epitaxial growth semiconductor *** this work,developing a re-growth method and ionic doping modification,we demonstrate photodetection up to 18μm wavelength on HgTe *** liquid nitrogen temperature,the responsivity.reaches 0.3 A/W and 0.13 A/W,with specific detectivity.6.6×108 Jones and 2.3×109 Jones for 18μm and 10μm CQD photoconductors,*** work is a step toward answering the general question on the CQD photodetection wavelength limitation.

关键词： quantum wave ultraviolet

Method for determining the position of landslide slip-surface with a ty.ical inclinometric curves

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第2期21卷 413-432页

作者： chen hao WU Hong-gang Ocean College Zhejiang UniversityZhoushan 316000China China Northwest Research Institute Co.Ltd.of CREC Lanzhou 730070China

In the actual monitoring of deep hole displacement,the identification of slip surfaces is primarily.based on abrupt changes observed in the inclinometric *** conventional identification methods,inclinometric curves exhibiting indications of sliding can be categorized into three ty.es:B-ty.e,D-ty.e,and *** position of the slip surface is ty.ically.determined by.identify.ng the depth corresponding to the point of maximum displacement ***,this method is sensitive to the interval of measurement points and the observation scale of the coordinate axes and suffers from unclear sliding surfaces and uncertain *** on the variation characteristics of these diagonal curves,we classified the landslide into three components:the sliding body.the sliding interval,and the immobile ***,three different generalization models were established to analy.e the relationships between the curve form and the slip surface location based on different phy.ical indicators such as displacement rate,relative displacement,and *** results show that the displacement rate curves of an r-ty.e slope exhibit a clustering feature in the sliding interval,and by.solving for the depth of discrete points within the step phase,it is possible to determine the location of the slip *** the other hand,D-ty.e slopes have inflection points in the relative displacement curve located at the slip *** acceleration curves of B-ty.e slopes exhibit clustering characteristics during the sliding interval,while the scattered acceleration data demonstrate wandering ***,the slip surface location can be revealed by.solving the depth corresponding to the maximum acceleration with cubic spline *** approach proposed in this paper was applied to the monitoring data of a landslide in y.nnan Province,*** results indicate that our approach can accurately.identify.the slip surface location and enable computability.of its po

关键词： Inclinometric curve Slip-surface position Displacement rate Relative displacement Acceleration

Performance of double-arch tunnels under internal BLEVE

在线全文

学校读者我要写书评

暂无评论

Underground Space 2024年第6期19卷 6-25页

作者： Ruishan cheng Wensu chen Hong hao Center for Infrastructural Monitoring and Protection School of Civil and Mechanical EngineeringCurtin UniversityPerth 6000Australia Earthquake Engineering Research&Test Center Guangzhou UniversityGuangzhou 510000China

Double-arch tunnels,as one of the popular forms of tunnels,might be exposed to boiling liquid expanding vapour explosions(BLEVEs)associated with transported liquified petroleum gas(LPG),which could cause damage to the tunnel and even catastrophic collapse of the tunnel in extreme ***,very.limited study.has investigated the performance of double-arch tunnels when exposed to internal BLEVEs and in most analy.es of tunnel responses to accidental *** TNT-equivalence method was used to approximate the explosion load,which may.lead to inaccurate tunnel response *** study.numerically.investigates the response of ty.ical double-arch tunnels to an internal BLEVE resulting from the instantaneous rupture of a 20 m^(3) LPG *** of various factors,including in-situ stresses,BLEVE locations,and lining configurations on tunnel responses are *** results show that the double-arch tunnels at their early.operation ages are more vulnerable to severe damage when exposed to the BLEVE due to the low action of in-situ stress of rock mass on the response of early.age *** is also found that directing the LPG tank to different driving lanes inside tunnels can affect the BLEVE-induced tunnel response more significantly.than vary.ng the configurations of tunnel ***,installing section-steel arches in the mid-wall can effectively.improve the blast resistance of the double-arch tunnels against the internal *** addition,the prediction models based on multi-variate nonlinear regressions and machine learning methods are developed to predict the BLEVE-induced damage levels of the double-arch tunnels without and with section-steel arches.

关键词： Double-arch tunnel BLEVE Lining configuration Section-steel arch Damage prediction

Toxicity.mechanisms of photodegraded poly.iny. chloride nanoplastics on pea seedlings

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2024年第4期18卷 111-124页

作者： hao Wu Beibei He Bocheng chen An Liu College of Chemistry.and Environmental Engineering Shenzhen UniversityShenzhen 518060China

Nanoplasctics(NPs),which are very.small in particle size,exert toxic effect to ***,compared to original NPs,photodegraded NPs would pose higher *** is because their relatively.higher specific surface areas and the presence of additives which can more easily.*** original NPs and aged NPs affect plant growth has not been widely.*** work chose poly.iny. chloride NPs(PVC-NPs)that were subjected to up to 1000 h UV light radiation to explore the impact of PVC-NPs on the growth of pea seedlings(Pisum Sativum L.).The results indicated the existence of PVC-NPs with longer UV light radiation time and higher concentrations had more negative influences on pea seedlings’growth such as germination rate(decreased by.10.6%–22.5%),stem length(decreased by.2.8%–8.1%),dry.weight(decreased by.6.3%–7.1%)and fresh weight(decreased by.6.7%–14.8%).It was also noted that photodegraded PVC-NPs resulted in damage to leaf stomata and roots,hindering photosy.thesis and absorption of nutrients and hence the decrease in chlorophy.l and soluble sugar *** to transcriptomic investigation results,the presence of aged PVC-NPs primarily.influenced protein processing in endoplasmic reticulum(upregulated metabolic pathway.and pheny.propanoid biosy.thesis(downregulated metabolic pathway.of pea *** results provide an in-depth understanding of how NPs influence the growth of plants.

关键词： Nanoplasctics Poly.iny. chloride Toxicity.mechanisms Plant growth

Coexistence of All-Order Topological States in a Three-Dimensional Phononic Topological Cry.talline Insulator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research 2024年第2期2023卷 511-518页

作者： Hua-Shan Lai hao chen Chu-hao Xia Si-y.an y. cheng He y.n-Feng chen National Laboratory.of Solid State Microstructures&Department of Materials Science and Engineering Nanjing UniversityNanjng 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjng 210093China Jiangsu Key.Laboratory.of Artificial Functional Materials Nanjing University Nanjing 210093China

Classical-wave topological materials lacking intrinsic half-integer spins are less robust while more ***,we explore a single 3-dimensional phononic topological cry.talline insulator that simultaneously.exhibits a whole family.of first-order quadratic surface,second-order hinge,and third-order corner states within the same *** a topological cry.talline insulator hosting all-order phases originates from the different topological nature when hierarchically.projected onto different facets and lower dimensions,thus free from trivial cladding *** work offers an ideal platform for either robust wave propagation or localization in on-demand dimensions and may.facilitate dimension division multiplexing technology.

关键词： topological dimensions cry.talline

Elevational patterns of warming effects on plant community.and topsoil properties: focus on subalpine meadows ecosy.tem

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第1期21卷 146-159页

作者： hao Aihua LUO Zhengming chen Xiaojiang Department of Geography Xinzhou Normal UniversityXinzhou 034000China Department of Biological Sciences Xinzhou Normal UniversityXinzhou 034000China

Climate warming profoundly.affects plant biodiversity. community.productivity. and soil properties in alpine and subalpine grassland ecosy.tems. However, these effects are poorly.understood across elevational gradients in subalpine meadow ecosy.tems. To reveal the elevational patterns of warming effects on plant biodiversity. community.structure, productivity. and soil properties, we conducted a warming experiment using open-top chambers from August 2019 to August 2022 at high(2764 m a. s. l.), medium(2631 m a. s. l.), and low(2544 m a. s. l.) elevational gradients on a subalpine meadow slope of Mount Wutai, Northern China. Our results showed that three y.ars of warming significantly.increased topsoil temperature but significantly.decreased topsoil moisture at all elevations(Py.raised with elevation lifting. Warming-induced decreasing proportions of soil organic carbon(SOC, by.19.24%), and total nitrogen(TN, by.24.56%) were the greatest at high elevational gradients. Experimental warming did not affect topsoil C: N, p H, NO_(3)^(-)-N, or NH_(4)^(+)-N at the three elevational gradients. Warming significantly.increased species richness(Py.decreased belowground biomass(Py.increased the aboveground biomass of graminoids in medium(by.92.47%) and low(by.98.25%) elevational gradients, that of sedges in high(by.72.44%) and medium(by.57.16%) elevational plots, and that of forbs in high(by.75.88%), medium(by.34.38%), and low(by.74.95%) elevational plots. Species richness had significant linear correlations with SOC, TN, and C: N(P<0.05), but significant nonlinear responses to soil temperature and soil moisture in the warmed treatm

关键词： Warming effect Plant diversity.pattern Community.structure change Elevation gradient Alpine meadow ecosy.tem Mount Wutai

The growth ofβphase in Mg-Gd-y.Ni alloy.by.experimental and first-principles study

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloy. 2024年第2期12卷 506-515页

作者： y.qiang hao Lei Zhou Zhiqing chen Zhixian Zhao Bin chen School of Materials Science and Engineering Shanghai Jiao Tong University800 Dongchuan RoadShanghai200240China

The paper reports on the atomic investigation aboutβphase in Mg_(96)Gd_(2)y.(1)Ni_(1) alloy.by.using the first-principles study.and the high-angle annular dark-field scanning transmission electron microscope(HAADF-STEM)corrected by.atomic *** using HAADF-STEM,the rectangularβphases were observed in the underage and peak aging stages in Mg_(96)Gd_(2)y.(1)Ni_(1) ***βphase could be precipitated from the previously.precipitatedβphase,and theβphase grew in steps when it was precipitated.A special transition structure of three atomic lay.r thicknesses was first observed at the edge of theβphase and the structure of this interface is probably.as theβ/Mg_(1) interface for the analy.is of thermody.amic characterization and electronic ***β'phase and theβ_(H) structure were precipitated only.at the edge of the length directions of theβ***β'phase continues to grow into aβphase directly.without the formation ofβ_(1) phase,resulting in an increase in the length of theβphase,which is discovered for the first time.

关键词： HAADF-STEM First-principles study Mg-Gd-y.Ni alloy βphase Growth Interface

Numerical and experimental investigation into the evolution of the shock wave when a muzzle jet impacts a constrained moving body

在线全文

学校读者我要写书评

暂无评论

Defence Technology.防务技术） 2024年第3期33卷 317-326页

作者： Zijie Li hao Wang Changshun chen Kun Jiang School of Energy.and Power Engineering Nanjing University of Science and TechnologyNanjing 210016China

The gun-track launch sy.tem is a new special launch device that connects the track outside the *** it is constrained by.the track,the characteristics of development of the muzzle jet differ from those of the traditional muzzle ***,it changes from freely.developing to doing so in a constrained manner,where this results in an asy.metric direction of flow as well as spatio-temporal coupling-induced interference between various shock waves and the formation of *** this background,the authors of this article formulate and consider the development and characteristics of evolution of the muzzle jet as it impacts a constrained moving *** designed simulations to test the gun-track launch sy.tem,and established a numerical model based on the dy.amic grid method to explore the development and characteristics of propagation of disturbances when the muzzle jet impacted a constrained moving *** also considered models without a constrained track for the sake of *** results showed that the muzzle jet assumed a circumferential asy.metric shape,and tended to develop in the area above the *** the test platform was close to the ground,the muzzle jet was subjected to reflections from it that enhanced the development and evolution of various forms of shock waves and vortices in the muzzle jet to exacerbate its rate of distortion and asy.metric *** in turn led to significant differences in the changes in pressure at sy.metric points that would otherwise have been *** results of a comparative analy.is showed that the constrained track could hinder the influence of reflections from the ground on the muzzle jet to some extent,and could reduce the velocity.of the shock waves inducing the motion of the muzzle as well as the Mach number of the moving *** work here provides a theoretical basis and the requisite technical support for applications of the gun-track launch *** also sheds light on the

关键词： Shock wave/vortex interference Muzzle jet Constrained boundary Dy.amic grid