Acid rain is a problem of increasing agricultural, environmental, and ecological concerns worldwide. This study investigated impacts of simulated acid rain (SAR) on soil organic matter (SOM) and metal aluminum and iro...
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ISBN:
(纸本)9781845648251;9781845648244
Acid rain is a problem of increasing agricultural, environmental, and ecological concerns worldwide. This study investigated impacts of simulated acid rain (SAR) on soil organic matter (SOM) and metal aluminum and iron ions leaching from the red soil in central south China. Laboratory experiments were performed by leaching the soil columns with the SAR at a pH range from 2.5 to 5.6 over a 20-day period. Research results showed subjected to acid rain of different acidities, dissolved organic matter (DOM), Fe and Al ions were leached out from red soil into eluate, huge leaching loss tended to occur in the initial phase of the leaching and the higher the acidity of simulated acid rain was, the bigger the loss of them from red soil. There was a very good linear correlation between DOMs and dissolved Al and Fe in the eluates, squared correlation coefficient (R-2) were respectively 0.93839 and 0.9479. These results contributed to build the theoretical foundation for assessing the potential environmental risks of groundwater.
Defect imaging of composite plate is presented based on Reconstruction Algorithm for the Probabilistic Inspection of Damage（RAPID） and Omnidirectional Shear-horizontal wave Magnetostrictive Patch Transducer（OSH-MPT...
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Defect imaging of composite plate is presented based on Reconstruction Algorithm for the Probabilistic Inspection of Damage（RAPID） and Omnidirectional Shear-horizontal wave Magnetostrictive Patch Transducer（OSH-MPT） *** lowest shear-horizontal mode（SH0） can propagate in the composite plate through bonding *** can realize using the direct wave of SH0 mode to extract the damage *** is beneficial to detect composite plate in the case that the velocity of direct wave varies with the propagation direction.A small mass which is circular cylinder is bonded to simulate *** imaging results are achieved after eliminating the influence of the uneven probability distribution of *** OSH-MPT is a type of electromagnetic acoustic transducer（EMAT）.Due to the relatively low signal-to-noise characteristic of EMAT,the threshold is selected based on the Receiver Operating Characteristic（ROC） curve for improving RAPID-based imaging *** first OSH-MPT which mainly includes an annular magnetostrictive patch,a toroidal coil and a cylindrical permanent magnet was developed in recent years by Hong et al [1].Some parameters of OSH-MPT are modified to make it more suitable for the imaging in this *** RAPID with full summation method is defined as [2][3]P（x,y）=N∑n=1P_n（x,y）=N∑n=DI_nW_n[R_n（x,y）] The RAPID with full summation method is defined as P（x,y）=NΠn=1P_n（x,y）=NΠn={DI_nW_n[R_n（x,y）]+C} Two methods which are DI and DI are applied for calculatingn DI_*** DI is defined as DI（t）=(∫[V（t）-I（t）]dt/∫（t）dt) The DI is the signal difference coefficient（SDC） as SDC=1-C/σσ=t∑t=0[V（t）-μIt)-μ]/(t∑t=0[V（t）-μ_(V（t）]t∑t=0-μ])Eight OSH-MPT elements are bonded on the composite plate and the bonded mass simulates the discontinuity damage in 30 mm *** imaging area is set to 600 × 600 mm2 and the bottom left corner is the original point of *** mass is located at（339,315）.The problem of the uneven probability distribution exists i
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