CsPbX_(3)-based(X=I,Br,Cl)inorganic perovskite solar cells(PSCs)prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability.However,the high trap state d...CsPbX_(3)-based(X=I,Br,Cl)inorganic perovskite solar cells(PSCs)prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability.However,the high trap state density and serious charge recombination between low-temperature processed TiO_(2)film and inorganic perovskite layer interface seriously restrict the performance of all-inorganic PSCs.Here a thin polyethylene oxide(PEO)layer is employed to modify TiO_(2)film to passivate traps and promote carrier collection.The impacts of PEO layer on microstructure and photoelectric characteristics of TiO_(2)film and related devices are systematically studied.Characterization results suggest that PEO modification can reduce the surface roughness of TiO_(2)film,decrease its average surface potential,and passivate trap states.At optimal conditions,the champion efficiency of CsPbI_(2)Br PSCs with PEO-modified TiO_(2)(PEO-PSCs)has been improved to 11.24%from 9.03%of reference PSCs.Moreover,the hysteresis behavior and charge recombination have been suppressed in PEO-PSCs.展开更多
Pattern analysis method was used to study DC breakdown characteristics of low-density polyethylene （LDPE） film and high-density polyethylene （HDPE） film, with particular attention paid to the breakdown phenomenon ...Pattern analysis method was used to study DC breakdown characteristics of low-density polyethylene （LDPE） film and high-density polyethylene （HDPE） film, with particular attention paid to the breakdown phenomenon identification. The breakdown pattern （BP） was recorded by a monocular-video-zoom microscope. The records showed that the effective area of BP was almost identical to the types of electrodes. The effective area od. The diameter was obtained by a mathematical was calculated by a mathematical integral methstatistic method. The study revealed that the DC breakdown voltage of LDPE was lower than that of HDPE. The diameter and effective area of LDPE were smaller than those of HDPE, but it is opposite for the condition of the needle-plane electrode with plane electrode grounded. As for the needle-plane electrode, the diameter and effective area with the films near the needle electrode were smaller than those near the plane electrode, and those in the middle of air gap were between them. As for the sphere-plane electrode, the diameter and effective area with the films near the plane electrode were smaller than those near the sphere electrode, and those in the middle of air gap were between them.展开更多
Hybrid materials were prepared using a silane coupling agent, tetraethoxysilane （ TEOS ） as the precursor, dilute hydrochloric acid as the catalyst, and epoxy as the matrices. The films coated with hybrid materials ...Hybrid materials were prepared using a silane coupling agent, tetraethoxysilane （ TEOS ） as the precursor, dilute hydrochloric acid as the catalyst, and epoxy as the matrices. The films coated with hybrid materials were expected to improve abrasion resistance and mechanical properties. The morphology, mechanical properties, adhesion, and abrasion resistance of the polyethylene terephthalate （PET） films were characterized using an atomic force microscope, a tensile testing machine, a bagger knife, and a reciprocating fabric abrasion tester. The result of research indicated that the modification significantly affected the abrasion resistance and roughness. The-tensile strength and abrasion resistance of the modified PET films increased by 40% and 50% respectively at 3 % TEOS mass fraction.展开更多
Lanthanum-rhodamine (6G and B) complexes were synthesized by Rheological Phase Reaction Method. Lanthanum-rhodamine (6G and B) complexes doped polyethylene films which have a function of lights-conversion were prepare...Lanthanum-rhodamine (6G and B) complexes were synthesized by Rheological Phase Reaction Method. Lanthanum-rhodamine (6G and B) complexes doped polyethylene films which have a function of lights-conversion were prepared. The emission and excitation spectra were measured. The experiments of growing seedling and culture were carried out in the shed built with doped and undoped polyethylene films. Lanthanum-rhodamine doped polyethylene films which have a function of lights-conversion can efficiently convert the green light in the sunlight to the red light for photosynthesis of crops, to promote the maturing of crops and raise the yield of crops.展开更多
The three stages in the hot-drawing process of ultrahigh-molecular-weight polyethylene gel films can be detected by x-ray diffraction, infrared spectroscopy, birefringence and scanning electron microscopy. In the firs...The three stages in the hot-drawing process of ultrahigh-molecular-weight polyethylene gel films can be detected by x-ray diffraction, infrared spectroscopy, birefringence and scanning electron microscopy. In the first stage of the drawing process, the lamellae in the gel films rotate and/or slip with the b-axis preferentially perpendicular to the drawing direction. With increased drawing, the c-axis of the lamellae become parallel to the stretching direction while unfolding of the chain begins, and the chains of the amorphous phase also orient along the drawing direction in the strain-chain domain. When the draw ratio is large enough, the lamellar structure is transformed into a fibrillar structure in a two-dimensional fashion.展开更多
In water deficit area, judicious use of water is essential for increasing area under crop production with limited water supply. Film Mulching has been advocated as an effective means for conserving soil moisture in ri...In water deficit area, judicious use of water is essential for increasing area under crop production with limited water supply. Film Mulching has been advocated as an effective means for conserving soil moisture in rice production. The effects of high density polyethylene (HDPE) film on increasing rice production, controlling weeds and residue amount of plastic were studied under five treatments, including 5, 10, 15 and 20 μm thickness as well as bare cultivation (CK). The results indicated that the HDPE film mulching mode had significant effects on weed control, soil temperature, soil moisture, photosynthetic rate, seedling biomass, yield and residues of plastic film. Combined with economic effect, it showed that the HDPE film of 10 μm is the best option for rice production.展开更多
Low density polyethylene film surface-grafted resorcinol was prepared by a sequential process.Firstly, acrylic acid was grafted to the surface of low density polyethylene by UV photo-grafting.Secondly, the carboxylic ...Low density polyethylene film surface-grafted resorcinol was prepared by a sequential process.Firstly, acrylic acid was grafted to the surface of low density polyethylene by UV photo-grafting.Secondly, the carboxylic groups in poly（acrylic acid） chains were transferred to acyl chloride groups by the reaction of carboxylic groups with thionyl chloride.The stability of acyl chloride groups in several solvents（alcohol, water, acetone, aqueous NaOH and in N2 atmosphere） was investigated, and N2 atmosphere and acetone were appropriate media to protect acyl chloride groups from side reaction.Finally, resorcinol monomer reacted with acyl chloride to append to the poly（acrylic acid）chains at room temperature.FT-IR-ATR was used to characterize the change of carbonyl groups during each step of the grafting process.Furthermore, by the experimental data of gravimetric analysis the grafted resorcinol monomer on the surface of low density polyethylene film was verified to have undergone condensation with acetone further in the resorcinol/acetone solution at 56℃, which might be a useful feature for synthesizing a thermoplastic/thermosetting composition.展开更多
High-density polyethylene(HDPE)film leakage location detection is frequently accomplished using the double-electrode technique.The electric potential and potential difference are the main physical parameters in the do...High-density polyethylene(HDPE)film leakage location detection is frequently accomplished using the double-electrode technique.The electric potential and potential difference are the main physical parameters in the double-electrode approach.Due to the impact of the complex geoelectric environment,the electric potential and the electric potential difference are not sensitive enough to respond to minimal leakage.The tiny leaking area cannot be precisely located using the electric potential and electric potential difference.Using the COMSOL Multiphysics software,this study created a standard geoelectric model of the double-electrode method.We calculated a new parameter—the G parameter through secondary electric potential difference—based on the response characteristics of the electric potential and the electric potential difference while the HDPEfilm is leaking.The experiment demonstrates that the G parameter is more sensitive than the electric potential and electric potential difference for detecting the leaking area of HDPE film.The G parameter is more effective at detecting leakage than the electric potential and electric potential difference.The results of this study can be used to locate HDPEfilm leakage areas in a landfill.展开更多
基金financially supported by the Guangzhou Basic and Applied Basic Research Foundation,China(No.303523)。
文摘CsPbX_(3)-based(X=I,Br,Cl)inorganic perovskite solar cells(PSCs)prepared by low-temperature process have attracted much attention because of their low cost and excellent thermal stability.However,the high trap state density and serious charge recombination between low-temperature processed TiO_(2)film and inorganic perovskite layer interface seriously restrict the performance of all-inorganic PSCs.Here a thin polyethylene oxide(PEO)layer is employed to modify TiO_(2)film to passivate traps and promote carrier collection.The impacts of PEO layer on microstructure and photoelectric characteristics of TiO_(2)film and related devices are systematically studied.Characterization results suggest that PEO modification can reduce the surface roughness of TiO_(2)film,decrease its average surface potential,and passivate trap states.At optimal conditions,the champion efficiency of CsPbI_(2)Br PSCs with PEO-modified TiO_(2)(PEO-PSCs)has been improved to 11.24%from 9.03%of reference PSCs.Moreover,the hysteresis behavior and charge recombination have been suppressed in PEO-PSCs.
基金Supported by the Doctoral Foundation from Education Ministry of China (No. 20040056037).
文摘Pattern analysis method was used to study DC breakdown characteristics of low-density polyethylene （LDPE） film and high-density polyethylene （HDPE） film, with particular attention paid to the breakdown phenomenon identification. The breakdown pattern （BP） was recorded by a monocular-video-zoom microscope. The records showed that the effective area of BP was almost identical to the types of electrodes. The effective area od. The diameter was obtained by a mathematical was calculated by a mathematical integral methstatistic method. The study revealed that the DC breakdown voltage of LDPE was lower than that of HDPE. The diameter and effective area of LDPE were smaller than those of HDPE, but it is opposite for the condition of the needle-plane electrode with plane electrode grounded. As for the needle-plane electrode, the diameter and effective area with the films near the needle electrode were smaller than those near the plane electrode, and those in the middle of air gap were between them. As for the sphere-plane electrode, the diameter and effective area with the films near the plane electrode were smaller than those near the sphere electrode, and those in the middle of air gap were between them.
基金Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education of China(No.2005-383)
文摘Hybrid materials were prepared using a silane coupling agent, tetraethoxysilane （ TEOS ） as the precursor, dilute hydrochloric acid as the catalyst, and epoxy as the matrices. The films coated with hybrid materials were expected to improve abrasion resistance and mechanical properties. The morphology, mechanical properties, adhesion, and abrasion resistance of the polyethylene terephthalate （PET） films were characterized using an atomic force microscope, a tensile testing machine, a bagger knife, and a reciprocating fabric abrasion tester. The result of research indicated that the modification significantly affected the abrasion resistance and roughness. The-tensile strength and abrasion resistance of the modified PET films increased by 40% and 50% respectively at 3 % TEOS mass fraction.
文摘Lanthanum-rhodamine (6G and B) complexes were synthesized by Rheological Phase Reaction Method. Lanthanum-rhodamine (6G and B) complexes doped polyethylene films which have a function of lights-conversion were prepared. The emission and excitation spectra were measured. The experiments of growing seedling and culture were carried out in the shed built with doped and undoped polyethylene films. Lanthanum-rhodamine doped polyethylene films which have a function of lights-conversion can efficiently convert the green light in the sunlight to the red light for photosynthesis of crops, to promote the maturing of crops and raise the yield of crops.
文摘The three stages in the hot-drawing process of ultrahigh-molecular-weight polyethylene gel films can be detected by x-ray diffraction, infrared spectroscopy, birefringence and scanning electron microscopy. In the first stage of the drawing process, the lamellae in the gel films rotate and/or slip with the b-axis preferentially perpendicular to the drawing direction. With increased drawing, the c-axis of the lamellae become parallel to the stretching direction while unfolding of the chain begins, and the chains of the amorphous phase also orient along the drawing direction in the strain-chain domain. When the draw ratio is large enough, the lamellar structure is transformed into a fibrillar structure in a two-dimensional fashion.
文摘In water deficit area, judicious use of water is essential for increasing area under crop production with limited water supply. Film Mulching has been advocated as an effective means for conserving soil moisture in rice production. The effects of high density polyethylene (HDPE) film on increasing rice production, controlling weeds and residue amount of plastic were studied under five treatments, including 5, 10, 15 and 20 μm thickness as well as bare cultivation (CK). The results indicated that the HDPE film mulching mode had significant effects on weed control, soil temperature, soil moisture, photosynthetic rate, seedling biomass, yield and residues of plastic film. Combined with economic effect, it showed that the HDPE film of 10 μm is the best option for rice production.
文摘Low density polyethylene film surface-grafted resorcinol was prepared by a sequential process.Firstly, acrylic acid was grafted to the surface of low density polyethylene by UV photo-grafting.Secondly, the carboxylic groups in poly（acrylic acid） chains were transferred to acyl chloride groups by the reaction of carboxylic groups with thionyl chloride.The stability of acyl chloride groups in several solvents（alcohol, water, acetone, aqueous NaOH and in N2 atmosphere） was investigated, and N2 atmosphere and acetone were appropriate media to protect acyl chloride groups from side reaction.Finally, resorcinol monomer reacted with acyl chloride to append to the poly（acrylic acid）chains at room temperature.FT-IR-ATR was used to characterize the change of carbonyl groups during each step of the grafting process.Furthermore, by the experimental data of gravimetric analysis the grafted resorcinol monomer on the surface of low density polyethylene film was verified to have undergone condensation with acetone further in the resorcinol/acetone solution at 56℃, which might be a useful feature for synthesizing a thermoplastic/thermosetting composition.
基金supported by the National Key Research and Development Program of China (Grant Nos. 2019YFC1510802 and 2019YFC1804302)the National Natural Science Foundation of China (Grant No. 41504081)the Fundamental Research Funds for the Central Universities (Grant No. 2019B17214)。
文摘High-density polyethylene(HDPE)film leakage location detection is frequently accomplished using the double-electrode technique.The electric potential and potential difference are the main physical parameters in the double-electrode approach.Due to the impact of the complex geoelectric environment,the electric potential and the electric potential difference are not sensitive enough to respond to minimal leakage.The tiny leaking area cannot be precisely located using the electric potential and electric potential difference.Using the COMSOL Multiphysics software,this study created a standard geoelectric model of the double-electrode method.We calculated a new parameter—the G parameter through secondary electric potential difference—based on the response characteristics of the electric potential and the electric potential difference while the HDPEfilm is leaking.The experiment demonstrates that the G parameter is more sensitive than the electric potential and electric potential difference for detecting the leaking area of HDPE film.The G parameter is more effective at detecting leakage than the electric potential and electric potential difference.The results of this study can be used to locate HDPEfilm leakage areas in a landfill.
文摘为探究不同厚度低密度聚乙烯保鲜膜对采后葡萄质构品质及贮藏特性的影响,以‘巨峰’葡萄为试材,分别用0(无包装组,CK)、0.02、0.03、0.04、0.05 mm和0.06 mm厚度的LDPE保鲜膜袋包装,于(1±1)℃低温下贮放42 d,每隔7 d测定其贮藏期质构品质及贮藏特性指标,进行相关性分析,并采用主成分分析法确定最佳保鲜膜厚度。结果表明:与CK组相比,不同厚度LDPE保鲜膜均能延缓葡萄掉粒率及失重率的上升,较好地保持葡萄色泽和亮度,同时能抑制水分、可溶性糖和可溶性蛋白含量的下降,延缓果皮和果肉硬度的降低。CK组、0.05 mm和0.06 mm LDPE组分别在贮藏28 d、35 d和35 d时失去商品价值,而0.02 mm、0.03 mm和0.04 mm LDPE组能将葡萄保鲜期延长至42 d。相关性分析显示,葡萄贮藏期间质构、感官和营养各指标之间密切相关。PCA结果显示,0.03 mm LDPE组置信圈较窄小,保鲜效果最好。综上,0.03 mm LDPE能较好地保持‘巨峰’葡萄的贮藏品质。
文摘为延长‘红丰’梨采后贮藏保鲜期,提升果实贮藏品质,该试验采用不同厚度聚乙烯膜包装经0.4μL/L 1-甲基环丙烯(1-methylcyclopropene,1-MCP)保鲜剂处理后的‘红丰’梨果实,于冷藏期间测定果实相关指标,探索适宜聚乙烯膜包装厚度。结果表明,0.015 mm聚乙烯(polyethylene,PE)膜包装可有效维持果实硬度,延缓果皮转黄,延缓可溶性固形物和可滴定酸含量的增加,有效抑制总酚含量降低,降低果肉褐变指数,有效抑制丙二醛含量和相对电导率的增加,抑制多酚氧化酶活性,促进抗氧化关键酶活性。因此,0.015 mm PE膜包装可通过一定程度上维持细胞膜完整性,降低膜脂氧化程度,提高果实抗氧化能力从而延缓1-MCP处理果实衰老和果肉褐变。该试验为‘红丰’梨采后贮藏保鲜方式研究奠定了理论基础。
