汶川地震断裂带科学钻探项目WFSD-3孔施工技术与体会

WFSD-3孔是汶川地震科学钻探项目的系列钻孔之一,历经2年多的施工,攻克了世界罕见的复杂地层钻进、大直径原状样取心和高地应力下钻孔护壁重重技术难关,圆满完成了施工任务。重点介绍了WFSD-3孔施工技术与经验,并对施工若干技术问题提出探讨与认识。

Water and nitrogen transport characteristics of single-line interference infiltration under film hole irrigation with muddy water and fertilizer

Based on the experimental data,this study investigated the effect of sand content of muddy water on water and nitrogen transport characteristics of the single-line interference infiltration under film hole irrigation with muddy water and fertilizer.The relationship between the single-line interference infiltration parameters,the sand content,the wetting front movement distances,and the sand content were all established.The model of the cumulative infiltration volume of per unit film pore area,the vertical and horizontal wetting front movement distance of the free surface,and the wetting front movement distance of the interference center with sand content and infiltration time were proposed.Reveal the law of the change of soil water content and the distribution of NO_(3)^(-)-N content based on different muddy water sand content.The results indicate that at the same infiltration time,as the muddy water sand content increases,the cumulative infiltration volume per unit pore area decreases.The infiltration index of the free infiltration and the single-line interference vary little when the sand content increases,mainly are around 0.64 and 0.58.The relationship between infiltration parameters a,b and the sand content is linear function.At the same location,the more the sand content,the smaller the wetting front movement distance in free surface and the single-line interference surface,the less the NO_(3)^(-)-N content.

Fabrication of Z-Scheme WO3/KNbO3 Photocatalyst with Enhanced Separation of Charge Carriers

Z-Schemc photocatalysts as a research locus pertomi strong redox capability and high photocatalytic peribnnance.WO3/KNbO3 photocatalysts were fabricated by ball milling method,and performed higlier photocatalytic activity in liquid degradation(rhodamine B,methylene blue and bisphenol A),compared with WO3 or KNbO3 monomer.This is due to that Z-scheme heterojunction is lonned between WO3 and KNbO3,and the holes photo-excited in valence band of KNbO?are quickly combined with the electrons in conduction band of WO3.The electrons accumulated in conduction band of KNbO3 show high reducibility,thereby reducing O2 to·O 2-,and the holes in valence band of WO3 show high oxidative to oxidize H2O to·OH,respectively.Furthermore,it is proved by means of electron spin resonaiice(ESR)spectra,terephthalic acid photolumiiiescence probing technique(TA・PL),and UV-Vis absorption spectra of nitroblue tetrazolium.This work indicates that the iabrication of Z-scheme structure can improve the photocatalytic activity by efficiently separating the photogenerated electrons and holes in the photocatalytic reaction system,which is helpful to deeply understand the migration mechanism of photoexcited cairier(band-band transfer and Z-scheme transfer)in heterojunction photocatalysts.

Distinguishing the observational signatures of hot spots orbiting Reissner-Nordström spacetime

This paper investigates observable signatures of hot spots orbiting Reissner-Nordström(RN)black holes and naked singularities.For an RN black hole,we find two discernible lensing image tracks in time integrated images,capturing a complete orbit of hot spots and a image shadow within the critical curve where photons with a small impact parameter fall into the event horizon.Conversely,in RN singularities,additional image tracks can be found within the critical curve,originating from photons reflected by the infinitely high effective potential well.Moreover,we find incomplete and converging tracks from the time integrated images of hot spot orbiting RN singularities that have no photon sphere.The presence of these additional image tracks significantly influences temporal magnitudes at their local maxima,enabling us to differentiate between RN black holes and RN naked singularities.