numerical model of mortar fluidity test was successfully established by DEM.The increase in flake particle content leads to greater elongation of machined sand.High flaky particle content can lead to poor flowability of mortar.There is a correlation between the aggregate shape parameters and the ...
compared with bare slope, the E/U(effective particles/ultimate particles) value of clay in the erosion and sediment particles in 0-5 min was reduced by 36%, 64% and 58% respectively, and that of silt was reduced by 48%, 69%, 63% respectively when the thickness of sand was 0.5, 1.0...
of lost soil concentrated in 0~40μm,of which the loss of fine particles with sizes of 1.8~24.0μm was the largest.The loss of fine particles in farmland soils resulted in the increase of sand and gravel in farmland soils by 7% and 75%,respectively,also the averaged particle size of ...
particles to coarse particles and concentration of Ca2+ was high.Meanwhile,concentrations of K+,EC and OC in PM2.5 were high due to the straw burning in Yangtze Delta.Therefore,together with local emission control,the control of secondary fine particulate matter and its precursors should be also...
This study was conducted to investigate seasonal distributions of fine particles (PM 2.5 ) and associated polycyclic aromatic hydrocarbons (PAHs) at three cities. PM 2.5 samples were collected on glass fiber filters at urban (Chuncheon), metropolitan (Seoul), and industrial complex sites (Ulsan) fr...
(2) The enrichment capacity of selenium varied in different land utilization and soil types. The absorption capacity of selenium in soil decreased due to human agricultural activities. Clayey particles or iron oxides in the yellow-brown loam layer were easy to combine and enrich selenium. The ...
This lithofacies is mainly developed in the central part of the basin and is mostly composed of grey and brownish grey medium-thick fine-grained sandstone. The sandstone as a whole is uniformly massive (Fig. 5-a, d) with well-sorted particles and locally contains irregular mudstone tearing deb...
This study focused on the pollution characteristics of fine particles in the aerosol in Beijing city,analyzed the correlation between variation of mass concentration and various kinds of natural factors.Tracing and tracking the particulates have been done with HYSPLIT model of the U.S.Air Resources ...
Analysis of lithology and grain size show that, the section is fluvial deposit with typical binary structure, which can be further divided into channel deposit and floodplain deposit. The channel deposits are mainly medium-coarse sand containing mica fragments, with oblique bedding. Frequency curves ...
Wind-shield walls decrease the velocity of wind-drift sand flow in transit. This results in sand accumulating in the wind-shadow zone of both windshield wall and track line, causing severe sand sediment hazard. This study reveals the characteristics of s