Pyrolysis Characteristics and Thermal Kinetics of Degradable Films

Developing degradable films is an important means for resolving the problem of film pollution; however, in recent years, there have been only few studies related to the thermal analysis of degradable plastic films. This research detailed the composition and pyrolysis of one kind of ordinary and three kinds of degradable plastic films using the differential thermal analysis （DTA） technique. The results showed that degradable films and ordinary film had similar DTA curves, which reflected their similar compositions; however, small differences were measured, which were due to the added constituents of the degradable films. The pyrolysis reaction orders of each film were about 0.93. The pyrolysis activation energies and pre-exponential factors followed the order of ordinary film 〉 photodegradable film 〉 photodegradable calcium carbonate film 〉 biodegradable film. The results of this research laid the foundation for new theories for harnessing soil pollution caused by plastic films.

Effects of degradable films with different degradation cycles on soil temperature,moisture and maize yield

Photo biodegradable film is an ideal degradable mulch film with synergistic effect of photo-degradability and biodegradability.To examine the covering effects of different films,maize was cultivated in the field with three kinds of degradable films(DF)mulching which had different degradation cycles(DF No.1,No.2 and No.3),with common plastic film mulching and no filming mulching(open ground)as comparison.The degradation rates and degrees of degradable films were examined,and the effects of different films on soil temperature,soil moisture,maize yield and relevant characteristics in each treatment were analyzed.The results indicated that the degradable films had good degradability,and the weight loss rate in 100 d for DF No.1,No.2,and No.3 were 22.31%,19.46%,and 15.63%,which were 4.16,3.63,and 2.92 times of the plastic film,respectively.In the early period of maize growth,the degradable films had good warming effects on soil,which were similar with the plastic film.The effect of DF No.2 on soil water conservation was slightly better than that of DF No.1 or No.3,similar with that of the plastic film.The soil water contents in 0-140 cm depths were significantly higher for DF No.2 than that for the open ground(p<0.05).The degradable films could significantly promote the ear development of maize,improve the ear characteristics,shorten the bald tip,and increase kernel number per plant(KNP)and 1000-kernel weight(TKW).The grain yields(GYs)for DF No.2,No.1,and No.3 were significantly improved,with 35.15%,31.35%,and 30.07%higher than that the open ground respectively(p<0.05).With no significant difference between DF and the plastic film,the GY was increased more for DF No.2 than that for DF No.1 and No.3.The degradable films fulfilled successfully all the functions of the plastic film,thus they were recommended as viable option to the plastic film due to their good degradability.

Degradation Mechanism of the Superconducting Transition Temperature in Nb Thin Films

Systemic measurements show that there is no 3D to 2D crossover in the reduction of the superconducting transition temperature Tc in Nb thin films. This result is consistent with all previous measurements while it is contrary to the prevailing understanding based on the interplay between proximity, localization, and lifetime broadening. Our study indicates that the decrease of Tc can be interpreted by the combined effects of electron-phonon coupling parameter λ and the defect scattering rate pw, being uniquely determined by their ratio λ/ρw. Other factors such as film thickness and irradiation do not produce additional effects beyond these two parameters.

Degradation of sulfadiazine antibiotics by water falling film dielectric barrier discharge

A new water falling film dielectric barrier discharge was applied to the degradation of sulfadiazine in the aqueous solution. The various parameters that affect the degradation of sulfadiazine and the proposed evolutionary process were investigated. The results indicated that the inner concentrations of 10 mg/L sulfadiazine can be all removed within 30 min. The optimum pH value was 9.10 and both strong acidic and alkaline solution conditions were not suitable for the degradation. The degradation of sulfadiazine can be enhanced by the addition of hydrogen radical scavengers, but be inhibited by adding hydroxyl radical scavengers. The water falling film dielectric barrier discharge was rather ineffective in mineralization, because of the intermediates were recalcitrant to be degraded. The existence of Fe2＋ and CCI4 in the liquid phase can promote the degradation and mineralization of sulfadiazine. It was found that the degradation of SDZ was enhanced by CC14 was mainly because of the increase of＇OH due to the reaction of CC14 with ＊H that reduce the chances of their recombination with ＂OH. Based on the 8 intermediate products identified by LC-MS, the proposed evolution of the degradation process was investigated.

ANFIS-based approach to studying subthreshold behavior including the traps effect for nanoscale thin-film DG MOSFETs

A fuzzy framework based on an adaptive network fuzzy inference system（ANFIS） is proposed to evaluate the relative degradation of the basic subthreshold parameters due to hot-carrier effects for nanoscale thin-film double-gate（DG） MOSFETs.The effect of the channel length and thickness on the resulting degradation is addressed, and 2-D numerical simulations are used for the elaboration of the training database.Several membership function shapes are developed,and the best one in terms of accuracy is selected.The predicted results agree well with the 2-D numerical simulations and can be efficiently used to investigate the impact of the interface fixed charges and quantum confinement on nanoscale DG MOSFET subthreshold behavior.Therefore,the proposed ANFIS-based approach offers a simple and accurate technique to study nanoscale devices,including the hot-carrier and quantum effects.

In-situ synthesis of TiO_2 rutile/anatase heterostructure by DC magnetron sputtering at room temperature and thickness effect of outermost rutile layer on photocatalysis

TiO2 rutile/anatase heterostructure thin films with varying rutile thickness have been in-situ synthesized via DC magnetron sputtering with Ar gas at room temperature. The crystal texture, surface morphology, energy gap and optical properties of the films have been investigated by X-ray diffraction meter, grazing incidence X-ray diffraction meter, Raman spectroscopy, scanning electron microscopy, and UV–visible spectrophotometer, which indicates that the rutile/anatase heterostructure films are successfully fabricated. The further degradation experiments display that the photocatalytic activity can be dramatically affected by the thickness of the outmost rutile layer and the 100 nm thickness exhibits the best performance in all of the TiO2 thin films. With the increase of the outmost rutile layer, the optical band gap of TiO2 film displays a systematic decrease slightly. However,the change in photocatalytic activity does not coincide with that in the band gap. The photoresponse and electrochemical properties of the thin films have been characterized to understand the mechanism of the varied photocatalytic activity.