[Objective] This study aimed to solve the mulch plastic film pollution problems in Xinjiang, in order to provide reliable theoretical basis for the research on the degradation mechanism of biodegradable plastic films....[Objective] This study aimed to solve the mulch plastic film pollution problems in Xinjiang, in order to provide reliable theoretical basis for the research on the degradation mechanism of biodegradable plastic films. [Method] The effect of illumination intensity on the decomposition of decomposable mulching films was investigated through simulating the field condition in laboratory. Regression analysis was employed to fit the processes of film decompositions. [Result] The weight loss ratios of different types of plastic films were closely related with the illumination. There was no sundry produced during the degradation process, but the weight was reduced, indicating that degradation produced gas, thus, ultraviolet rays had destructive effect on mulch plastic films. Different types of plastic films showed significant differences in the degradation speeds, and under the same conditions, the degradation speed of S4# with the induction period of 30 d was the fastest. With the extension of uv illumination time, the degradation became cumulative degradation process. [Conclusion] Under the uv rays, the weight loss ratio and illumination hours is regarded as a positive correlation relationship. The significant inspection shows that the data fitted degradation model can be described by the logistic model of Y = a/（1＋b×e -ct）, and all the parameters show significant differences （P0.01）.展开更多
hin films of ZnO were prepared using the double photobeams ultraviolet laserinduced-metallorganic chemical vapour deposition (MOCVD)technique. The struc-ture and transparent photoconductive properties of these films w...hin films of ZnO were prepared using the double photobeams ultraviolet laserinduced-metallorganic chemical vapour deposition (MOCVD)technique. The struc-ture and transparent photoconductive properties of these films were investigated us-ing X-ray diffraction (XRD) , reflecting electron diffraction (RED) .scanning elec-tron microscopy (SEM) and ultraviolet visible absorption spectrometry (UV) .Theexperiments showed that the technique produced superior quality films of polycrys-tal ZnO_(1-x) (the O-vacancies in the ZnO lattice) , and possessed higher depositionrate, lower growth temperature conipared with CVD or MOCVD technique and thethin films had far better transparent photoconductive properties than tliose grownby the conventional CVD or MOCVD technique.展开更多
We have selected four mouse cell mutantshypersensitive to the lethal effect ofionizing radiation.They show cross-sensitivity to bleomycin and otherchemicals but not to ultraviolet light.
基金Supported by the National Key Technology R&D Program (2007BAC20B01)the Fund for Postgraduate of Tarim University (TDZKSS06004)~~
文摘[Objective] This study aimed to solve the mulch plastic film pollution problems in Xinjiang, in order to provide reliable theoretical basis for the research on the degradation mechanism of biodegradable plastic films. [Method] The effect of illumination intensity on the decomposition of decomposable mulching films was investigated through simulating the field condition in laboratory. Regression analysis was employed to fit the processes of film decompositions. [Result] The weight loss ratios of different types of plastic films were closely related with the illumination. There was no sundry produced during the degradation process, but the weight was reduced, indicating that degradation produced gas, thus, ultraviolet rays had destructive effect on mulch plastic films. Different types of plastic films showed significant differences in the degradation speeds, and under the same conditions, the degradation speed of S4# with the induction period of 30 d was the fastest. With the extension of uv illumination time, the degradation became cumulative degradation process. [Conclusion] Under the uv rays, the weight loss ratio and illumination hours is regarded as a positive correlation relationship. The significant inspection shows that the data fitted degradation model can be described by the logistic model of Y = a/（1＋b×e -ct）, and all the parameters show significant differences （P0.01）.
文摘hin films of ZnO were prepared using the double photobeams ultraviolet laserinduced-metallorganic chemical vapour deposition (MOCVD)technique. The struc-ture and transparent photoconductive properties of these films were investigated us-ing X-ray diffraction (XRD) , reflecting electron diffraction (RED) .scanning elec-tron microscopy (SEM) and ultraviolet visible absorption spectrometry (UV) .Theexperiments showed that the technique produced superior quality films of polycrys-tal ZnO_(1-x) (the O-vacancies in the ZnO lattice) , and possessed higher depositionrate, lower growth temperature conipared with CVD or MOCVD technique and thethin films had far better transparent photoconductive properties than tliose grownby the conventional CVD or MOCVD technique.
文摘We have selected four mouse cell mutantshypersensitive to the lethal effect ofionizing radiation.They show cross-sensitivity to bleomycin and otherchemicals but not to ultraviolet light.
