Robust, accurate, and fast monitoring of residual plastic film (RPF) pollution in farmlands has great significance. Based on CBAM-DBNet, this study proposed a threshold-adaptive joint framework for identifying the RPF...Robust, accurate, and fast monitoring of residual plastic film (RPF) pollution in farmlands has great significance. Based on CBAM-DBNet, this study proposed a threshold-adaptive joint framework for identifying the RPF on farmland surfaces and estimating its coverage rate. UAV imaging was used to gather images of the RPF from several locations with various soil backgrounds. RPFs were manually labeled, and the degree of RPF pollution was defined based on the RPF coverage rate. Combining differentiable binarization network (DBNet) with the convolutional block attention module (CBAM), whose feature extraction module was improved. A dynamic adaptive binarization threshold formula was defined for segmenting the RPF’s approximate binary map. Regarding the RPF image detection branch, the CBAM-DBNet exhibited a precision (P) value of 85.81%, a recall (R) value of 82.69%, and an F1-score (F1) value of 84.22%, which was 1.09 percentage points higher than the DBNet in the comprehensive index F1 value. For the RPF image segmentation branch, using CBAM-DBNet to segment the RPF image combined with an adaptive binarization threshold formula. Subsequently, the mean absolute percentage error (MAPE), root mean square error (RMSE), and mean absolute error (MAE) of the prediction of RPF’s coverage rate were 0.276, 0.366, and 0.605, respectively, outperforming the DBNet and the Iterative Threshold method. This study provides a theoretical reference for the further development of evaluation technology for RPF pollution based on UAV imaging.展开更多
Plastic film mulch in agricultural production becomes essential to maintaining crop yields in arid and semiarid areas.However,the presence of residual film in farmland soil has also drawn much attention.In this study,...Plastic film mulch in agricultural production becomes essential to maintaining crop yields in arid and semiarid areas.However,the presence of residual film in farmland soil has also drawn much attention.In this study,three experiments were conducted.The first two experimental designs included 0,450,1350,and 2700 kg ha^(-1) of residual film pieces of approximately 5 cm side length added to field soil(0-20 cm soil depth)for seven years and added to pots for four years.In the third experiment,1350 kg ha^(-1)of the residual film with different side lengths(2-5,5-10,10-15,and 15-20 cm)was added to field soil for six years to explore the effect of residual film fragment size on soil nutrients,soil microorganisms,crop growth and yields.The residual film had little effect on the soil moisture at a field depth of 0-2(or 0-1.8)m.There were no significant effects on organic carbon,total nitrogen,inorganic nitrogen,total phosphorus or available phosphorus in the 0-20 cm soil layer.The presence of residual film decreased the richness and diversity of the bacterial community of the surface soil of the residual film,but it had no significant effect on the microbial community of the non-surface soil.The emergence rates of wheat and lentils occasionally decreased significantly with different amounts of residue fragments added to the field.At 450-2700 kg ha^(-1),the residual film reduced the plant height and stem diameter of maize and significantly reduced the shoot biomass of harvested maize by 11-19%.The average yields of maize and potato over the seven years decreased,but there were almost no significant statistical differences among the treatments.These results provide important data for a comprehensive scientific understanding of the effects of residual film on soil and crops in dryland farming systems.展开更多
This study investigated the residual film content and distribution at different soil depths in the Eighth Division of the Xinjiang Production and Construction Corps.Before spring plowing in 2019,representative fields ...This study investigated the residual film content and distribution at different soil depths in the Eighth Division of the Xinjiang Production and Construction Corps.Before spring plowing in 2019,representative fields in four areas(Anjihai,Shihezi suburbs,Mosuowan and Xiayedi)were selected for residual film collection.The average content of residual film in the Eighth Division was 104 kg/ha.The residual film content in the four areas decreased in the order Anjihai>Shihezi suburbs>Mosuowan>Xiayedi.The average amount of residual film collected from cotton fields was greater than that from corn fields.Residual film content in the cotton field at soil depths of 0~10 and 10~30 cm was higher than that in the corn field,whereas the residual film content at a 30–50 cm soil depth in the corn field was higher than that in the cotton field.The results showed that farmers do not consider the long-term benefits,the high cost and short time of recycling,and the easy recycling of surface residual film.The shallow that the higher content of residual film,the less water in the soil of cotton.The same time,the results showed that the quantity of residual film in cotton field had greater influence on cotton quality.展开更多
The effect of silicon doping on the residual stress of CVD diamond films is examined using both X-ray diffraction (XRD) analysis and Raman spectroscopy measurements. The examined Si-doped diamond films are deposited o...The effect of silicon doping on the residual stress of CVD diamond films is examined using both X-ray diffraction (XRD) analysis and Raman spectroscopy measurements. The examined Si-doped diamond films are deposited on WC-Co substrates in a home-made bias-enhanced HFCVD apparatus. Ethyl silicate (Si(OC2H5)4) is dissolved in acetone to obtain various Si/C mole ratio ranging from 0.1% to 1.4% in the reaction gas. Characterizations with SEM and XRD indicate increasing silicon concentration may result in grain size decreasing and diamond [110] texture becoming dominant. The residual stress values of as-deposited Si-doped diamond films are evaluated by both sin2ψ method, which measures the (220) diamond Bragg diffraction peaks using XRD, with ψ-values ranging from 0° to 45°, and Raman spectroscopy, which detects the diamond Raman peak shift from the natural diamond line at 1332 cm-1. The residual stress evolution on the silicon doping level estimated from the above two methods presents rather good agreements, exhibiting that all deposited Si-doped diamond films present compressive stress and the sample with Si/C mole ratio of 0.1% possesses the largest residual stress of ~1.75 GPa (Raman) or ~2.3 GPa (XRD). As the silicon doping level is up further, the residual stress reduces to a relative stable value around 1.3 GPa.展开更多
Pollution of residual plastic film in arable lands is a severe problem in China. In this study, the status of residual film and influential factors were investigated using the methods of farm survey in combination wit...Pollution of residual plastic film in arable lands is a severe problem in China. In this study, the status of residual film and influential factors were investigated using the methods of farm survey in combination with questionnaires and quadrat sampling at a large number of field sites in Xinjiang Uygur Autonomous Region, China. The results showed that the amount of film utilization increased largely and reached to 1.8×10~5 t in 2013. Similarly, the mulching area also substantially increased in recent decades, and reached to 2.7×10~5 ha in the same year. According to the current survey, 60.7% of the sites presented a greater mulch residue than the national film residue standard(75 kg ha^(–1)), and the maximum residual amount reached 502.2 kg ha^(–1) in Turpan, Xinjiang. The film thickness, the mulching time and the crop type all influenced mulch residue. The thickness of the film had significantly negative correlation with the amount of residual film(P0.05), while the mulching years had significantly positive correlation with it(P0.05). The total amount of residual film in Xinjiang was 3.43×105 t in 2011, which accounted for 15.3% of the cumulative dosage of mulching. Among all the crops, the cotton fields had the largest residual amount of mulch film(158.4 kg ha^(–1)), and also the largest contribution(2.6×10~5 tons) to the total amount of residual film in Xinjiang.展开更多
TiNi thin films were sputter-deposited on circular single-crystal silicon substrates un-der various sputtering parameters. The crystal structure and residual stress of the as-deposited films were determined by X-ray d...TiNi thin films were sputter-deposited on circular single-crystal silicon substrates un-der various sputtering parameters. The crystal structure and residual stress of the as-deposited films were determined by X-ray diffraction and substrate-curvature method. The phenomenon of stress-suppressed martensitic transformation was observed. R is considered that the residual stresses in SMA thin films based on circular substrates act as balanced biaxial tensile stresses. The status of equilibrant delays the align-ment of self-accommodated variants and the volume shrinkage during the martensitic transformation.展开更多
The TiN films were deposited on 316 L stainless steel substrates at low temperature by arc ion plating. The influences of substrate bias voltage and temperature on microstructure, residual stress and mechanical proper...The TiN films were deposited on 316 L stainless steel substrates at low temperature by arc ion plating. The influences of substrate bias voltage and temperature on microstructure, residual stress and mechanical properties of the films were investigated by EDS, SEM, XRD and nanoindenter tester, respectively. The results showed that the TiN films were highly oriented in(111) orientation with a face-centered cubic structure. With the increase of substrate bias voltage and temperature, the diffraction peak intensity increased sharply with simultaneous peak narrowing, and the small grain sizes increased from 6.2 to 13.8 nm. As the substrate temperature increased from 10 to 300℃, the residual compressive stress decreased sharply from 10.2 to 7.7 GPa, which caused the hardness to decrease from 33.1 to 30.6 GPa, while the adhesion strength increased sharply from 9.6 to 21 N.展开更多
The influence of a gradient interlayer on the residual stress and cracking in TiN thin films was studied as a function of the thickness of gradient interlayer. Both X ray in situ tensile testing and grazing method wer...The influence of a gradient interlayer on the residual stress and cracking in TiN thin films was studied as a function of the thickness of gradient interlayer. Both X ray in situ tensile testing and grazing method were used to measure the residual stress in thin films. In TiN films, there exists a residual stress of 10 GPa, which can be remarkably decreased by a gradient interlayer between film and substrate. The cracking behavior of films after tension shows that the crack of film/substrate system begins at interface between film and substrate.展开更多
The relationship between texture and elastic properties of chemical vapor deposition (CVD) diamond films was analyzed based on the phenomenological theory, which reveals the influence of crystalline orientation and ...The relationship between texture and elastic properties of chemical vapor deposition (CVD) diamond films was analyzed based on the phenomenological theory, which reveals the influence of crystalline orientation and texture on the residual macro-strain and macro-stress. The phenomenological calculations indicated that the difference in Young's modulus could be 15% in single diamond crystals and 5% in diamond films with homogeneously distributed strong fiber texture. The experimentally measured residual strains of free-standing CVD diamond films were in good agreement with the correspondingly calculated Young's modulus in connection with the multi-fiber textures in the films, though the difference in Young's modulus induced by texture was only around 1%. It is believed that texture should be one of the important factors influencing the residual stress and strain of CVD diamond films.展开更多
In order to provide a theoretic basis for the research of Ti(C_xN_y) thinfilms, the thermodynamic database of Ti-C-N ternary system is established and the phase diagramsections are calculated. In addition to the asses...In order to provide a theoretic basis for the research of Ti(C_xN_y) thinfilms, the thermodynamic database of Ti-C-N ternary system is established and the phase diagramsections are calculated. In addition to the assessed thermodynamic properties of Ti-C-N system, theinfluence of the residual strain energy of Ti(C_xN_y) thin films on the phase equilibria isanalyzed. The classical formula for calculating the elastic strain energy is expressed into aRedlich-Kister form in order to perform the thermodynamic and equilibrium calculations using theThermo-Calc software. Isothermal sections at 900 and 1100 K are calculated with this database andcompared with those calculated without considering the residual stress. As a result, with theaddition of strain energy delta-fcc Ti(C_xN_y) phase area shrinks. It is therefore concluded thatwith the influence of the residual stress in Ti(C_xN_y) thin solid film, the precipitation of puredelta film requires more precise control of composition.展开更多
In order to analyze the stress and deformation of different permeability of residual oil film in the complex pore, which are affected by the viscous-elasticity of the fluid, the hydrodynamic displacement mechanism is ...In order to analyze the stress and deformation of different permeability of residual oil film in the complex pore, which are affected by the viscous-elasticity of the fluid, the hydrodynamic displacement mechanism is explored from the stand-point of hydrodynamics, that is, the residual oil film displaced by alternating injection of different concentrations of the polymer solution, viscous-elastic fluid flow equation is established in the complex pore by choosing continuity equation, motion equation and the upper convected Maxwell constitutive equation. The flow field is computed by using the method of numerical analysis. Not only the stress and deformation of residual oil film on the different permeability of micro pores, but also the analysis of the flooding mechanism of alternating injection of different concentrations of the polymer solution is got. The results show that the larger the viscous-elasticity of polymer solution is, the bigger the normal deviatoric stress acting on the residual oil film is;the distribution of normal deviatoric stress has the abrupt change. The stronger the viscous-elasticity of the polymer solution is, the bigger the horizontal stress difference acting on the residual oil film is and the more obvious the deformation is;the high-concentration polymer solution is suitable for high-permeability micro pores. Low-concentration polymer solution is suitable for medium and low-permeability micro pores. Alternating injection of polymer solution can improve Volumetric Sweep Efficiency and increase the deformation of residual oil film, which is conducive to enhancing oil recovery.展开更多
Before spring ploughing in 2019,the representative fields of the 8^(th) Division were selected,and residual film at different depths of soil in three areas of the 8^(th) Division was collected. Through the analysis on...Before spring ploughing in 2019,the representative fields of the 8^(th) Division were selected,and residual film at different depths of soil in three areas of the 8^(th) Division was collected. Through the analysis on the weight and amount of residual film at different depths of soil,it was found that the average content of residual film in the 8^(th) Division was 104 kg/hm^2. From high to low,the content sequence of residual film in the three areas was Anjihai area,Mosuowan area and Xiayedi area. The average amount of residual film collected from the cotton field in the three areas was greater than that from the corn field. In the three areas,the content of residual film in the cotton field at the depth of 0-10 and 11-30 cm was higher than that in the corn field,while the content of residual film at the depth of 31-50 cm in the corn field was higher than that in the cotton field.展开更多
[Objectives]This study was conducted to explore the characteristics of soil residual film pollution load in cotton fields in the Yellow River Delta,so as to effectively control soil film pollution.[Methods]Cotton fiel...[Objectives]This study was conducted to explore the characteristics of soil residual film pollution load in cotton fields in the Yellow River Delta,so as to effectively control soil film pollution.[Methods]Cotton field mulching film survey and residue monitoring were conducted in the Yellow River Delta area.[Results]The amount of mulching film residues in cotton fields in the Yellow River Delta was 37.7-128.7 kg/hm^(2),which had a significant increase compared with 5 years ago,and the differences between plots were large;and after straw was returned to the field,the soil residual film obviously gathered in the 20-30 cm soil layer.The residual film blocks with a size of more than 25 cm^(2) accounted for 62.6%,which was a relatively high proportion,indicating that soil pollution can be caused easily,and it is difficult to control.During a certain period of time,the soil residual film pollution may have a tendency to aggravate,and the ecological risk is higher.[Conclusions]This study has important theoretical and practical significance for improving soil quality in the region and ensuring the safety of cotton field ecosystem and environmental health.展开更多
Residual films on the sowing layer produced after mulching in Xinjiang farmland,harm the sowing quality and root growth of crops.In this study,a sowing layer residual film recovery machine based on a radial plate arc-...Residual films on the sowing layer produced after mulching in Xinjiang farmland,harm the sowing quality and root growth of crops.In this study,a sowing layer residual film recovery machine based on a radial plate arc-shaped nail-tooth roller structure was designed.Meanwhile,the key device structures were designed and the main working parameters were analyzed.Then,taking the working depth,the forward speed of the machine and the rotation speed of the nail tooth roller as the test factors,and the film collection rate and film intertwining rate as the test indicators,the single factor tests and the Box-Behnken response surface tests were carried out to evaluate the performance of the sowing layer residual film recovery machine.Consequently,the results showed that the order of significant factors was the working depth,the forward speed of the machine,and the rotation speed of the nail tooth roller.Besides,the optimal working parameters were determined,which the working depth,the forward speed of the machine,and the rotation speed of the nail tooth roller were 100 mm,4.8 km/h,and 49.3 r/min,respectively.Moreover,the predicted value of the film collection rate was 69.20%.Finally,the verification test was taken with the optimal working parameter,and the results showed that the film collection rate was 66.84%,and the film intertwining rate was 1.39%.The relative error between the test value and the predicted value of the film collection rate was 3.40%.It indicated that the machine can perform the collection of sowing layer residual films.This study can provide a theoretical basis and reference for the design of new sowing layer residual film machines.展开更多
Water quality within water distribution system may vary with both location and time. Water quality models are used to predict the spatial and temporal variation of water quality throughout water system. A model of res...Water quality within water distribution system may vary with both location and time. Water quality models are used to predict the spatial and temporal variation of water quality throughout water system. A model of residual chlorine decay in water pipe has been developed, given the consumption of chlorine in reactions with chemicals in bulk water, bio films on pipe wall, in corrosion process, and the mass transport of chlorine from bulk water to pipe wall. Analytical methods of the flow path from water sources to the observed point and the water age of every observed node were proposed. Model is used to predict the decay of residual chlorine in an actual distribution system. Good agreement between calculated and measured values was obtained.展开更多
In this paper we demonstrate that the residual stress introduced by several different surface finishes affects the critical current density for passivation and the passive current density in the anodic polarization cu...In this paper we demonstrate that the residual stress introduced by several different surface finishes affects the critical current density for passivation and the passive current density in the anodic polarization curve of austenitic stainless steel and that those critical current densities can be reduced by controlling the residual stress by applying a cavitating jet to the backs of specimens. The results show that the current density either increased or decreased depending on the surface finish, and that was decreased by introducing compressive residual stress for all surface finishes.展开更多
In order to study current situation of application,recycling and residue pollution of mulching films in Xinjiang,and accurately grasp pollution degree of residue of mulching films,this paper made an empirical analysis...In order to study current situation of application,recycling and residue pollution of mulching films in Xinjiang,and accurately grasp pollution degree of residue of mulching films,this paper made an empirical analysis on residue of mulching films in 31 typical counties and cities in Xinjiang. Results indicate that( i) use of mulching films in Xinjiang is wide and there is great difference in use and residue recycling between cities and counties. Planting area and planting structure jointly influence use of mulching films,and the use of mulching films is significantly correlated with recycling of mulching films,but not correlated with recycling rate of mulching films.( ii) There are significant differences in distribution of residue of mulching films,highest in North Xinjiang and South Xinjiang,followed by East Xinjiang,and the lowest in West Xinjiang.( iii) There are significant differences in distribution of residue of mulching films between different crop fields. Residue of mulching films in cotton field is the key problem of pollution.展开更多
In this study, soybean residues were treated with HCl and soybean residue cellulose was extracted, which was used to prepare cellulose nanofiber (CNF) using the high-pressure homogenization method. The maximum yield o...In this study, soybean residues were treated with HCl and soybean residue cellulose was extracted, which was used to prepare cellulose nanofiber (CNF) using the high-pressure homogenization method. The maximum yield of CNF, the reaction temperature, reaction time, and HCl concentration were optimized. The optimum HCl concentration for acid treatment was 6%, the reaction time was 60 min, the reaction temperature was 80℃, and the maximum yield of soybean residue cellulose was 78.8%. The different CNF films were then prepared;the color, mechanical property, and light transmittance of the CNF films were studied. Compared to the properties of the CNF film prepared with the soybean residue cellulose by high-pressure homogenization 15 times (HGT-15 film), the mechanical properties of the CNF film with soybean residue cellulose by decolorizing treatment decreased, but the light transmittance increased. The film prepared by adding HGT- 15 CNF to whey protein was investigated for its mechanical property, light transmittance, and solubility. Unlike the pure whey protein film, addition of 2.0% CNF to the whey protein enhanced the mechanical property and water vapor transmission rate (WVT) of the film. With the increase in CNF content, the solubility of the whey protein film decreased, and then stabilized.展开更多
In order to get a clear picture of distribution characteristics of mulching plastic film residue in cotton fields in the Yellow River Delta and make scientific pollution prevention and control strategies, an investiga...In order to get a clear picture of distribution characteristics of mulching plastic film residue in cotton fields in the Yellow River Delta and make scientific pollution prevention and control strategies, an investigation was conducted in Dongying City. Five typical cotton fields were chosen, and then the number, distri- bution density and area of residual film were measured. The results showed that the residual film was 18. 84-53. 53 kg/hm^2 in cotton fields for more than 20 years, and the differences between fields were larger. The residual density was 225-340 thousand per hectare. There were great differences among residual pieces. The proportion of residual pieces over 25 cm^2 was 94. 1%, that between 100 cm^2 and 500 cm^2 was more than 50. 0%, and that bigger than 500 cm^2 was about 21. 0%. In the Yellow River Delta cotton region, large, thin and difficult to recovery were the main characteristics of mulching plastic film residue, and it had the possibility of mi- grating to deep soil. Thus, the ecological risk of mulching plastic film residue was higher. Key words The Yellow River Delta; Cotton field; Residue of mulching plastic film; Distribution characteristic展开更多
In this paper, we investigate the effect of layer thickness on the residual stresses of copper indium gallium diselenide (CIGS) solar cells with polyimide substrate caused by CIGS layer deposition at 400?C and then co...In this paper, we investigate the effect of layer thickness on the residual stresses of copper indium gallium diselenide (CIGS) solar cells with polyimide substrate caused by CIGS layer deposition at 400?C and then cooling down to room temperature using the Finite Element Method (FEM). Moreover, we also examined the effect of layer thickness on residual stress of CIGS solar cells after cooling down to room temperature from the hotspot temperatures of 200?C, 300?C, and 400?C. Our simulated CIGS is composed of five layers: ZnO, CdS, CIGS, Mo, and PI substrate. We were able to quantify the effect of each layer’s thickness and hotspot temperature on the average stresses of each layer for the CIGS solar cells. We found that the PI substrate layer has the most significant effect on the residual stress of CIGS solar cells. Our simulation results reveal that the stress type (tensile vs. compressive) and the magnitude of stress of the CIGS layer (main absorber layer) can be controlled by changing the thickness of the PI substrate while applying a heat to CIGS solar cells. Quantitative analysis of relationship between layer thickness and thermo-mechanical stress of thin film solar cells can help solar cell manufacturers design more robust and reliable solar cells. For example, fabricating PI layer thickness less than 17 μm can improve the performance of CIGS solar cells by nullifying the compressive residual stress in the CIGS absorber layer.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.32060288)the National Natural Science Foundation of China(Grant No.32160300)+1 种基金the Bingtuan Science and Technology Program(Grant No.2019AB007)the Science and Technology Planning Project of the first division of Alaer city(Grant No.2022XX06).
文摘Robust, accurate, and fast monitoring of residual plastic film (RPF) pollution in farmlands has great significance. Based on CBAM-DBNet, this study proposed a threshold-adaptive joint framework for identifying the RPF on farmland surfaces and estimating its coverage rate. UAV imaging was used to gather images of the RPF from several locations with various soil backgrounds. RPFs were manually labeled, and the degree of RPF pollution was defined based on the RPF coverage rate. Combining differentiable binarization network (DBNet) with the convolutional block attention module (CBAM), whose feature extraction module was improved. A dynamic adaptive binarization threshold formula was defined for segmenting the RPF’s approximate binary map. Regarding the RPF image detection branch, the CBAM-DBNet exhibited a precision (P) value of 85.81%, a recall (R) value of 82.69%, and an F1-score (F1) value of 84.22%, which was 1.09 percentage points higher than the DBNet in the comprehensive index F1 value. For the RPF image segmentation branch, using CBAM-DBNet to segment the RPF image combined with an adaptive binarization threshold formula. Subsequently, the mean absolute percentage error (MAPE), root mean square error (RMSE), and mean absolute error (MAE) of the prediction of RPF’s coverage rate were 0.276, 0.366, and 0.605, respectively, outperforming the DBNet and the Iterative Threshold method. This study provides a theoretical reference for the further development of evaluation technology for RPF pollution based on UAV imaging.
基金funded by the National Natural Science Foundation of China (31470496)the Fundamental Research Funds for the Central Universities, China (lzujbky-2021-sp42)the ‘111’ Programme 2.0, China (BP0719040)。
文摘Plastic film mulch in agricultural production becomes essential to maintaining crop yields in arid and semiarid areas.However,the presence of residual film in farmland soil has also drawn much attention.In this study,three experiments were conducted.The first two experimental designs included 0,450,1350,and 2700 kg ha^(-1) of residual film pieces of approximately 5 cm side length added to field soil(0-20 cm soil depth)for seven years and added to pots for four years.In the third experiment,1350 kg ha^(-1)of the residual film with different side lengths(2-5,5-10,10-15,and 15-20 cm)was added to field soil for six years to explore the effect of residual film fragment size on soil nutrients,soil microorganisms,crop growth and yields.The residual film had little effect on the soil moisture at a field depth of 0-2(or 0-1.8)m.There were no significant effects on organic carbon,total nitrogen,inorganic nitrogen,total phosphorus or available phosphorus in the 0-20 cm soil layer.The presence of residual film decreased the richness and diversity of the bacterial community of the surface soil of the residual film,but it had no significant effect on the microbial community of the non-surface soil.The emergence rates of wheat and lentils occasionally decreased significantly with different amounts of residue fragments added to the field.At 450-2700 kg ha^(-1),the residual film reduced the plant height and stem diameter of maize and significantly reduced the shoot biomass of harvested maize by 11-19%.The average yields of maize and potato over the seven years decreased,but there were almost no significant statistical differences among the treatments.These results provide important data for a comprehensive scientific understanding of the effects of residual film on soil and crops in dryland farming systems.
基金This study was funded by“Strong youth”key talents of scientific and technological innovation of the Xinjiang Construction Crops(No.2021CB040)“Science and Technology Project of the Eighth Division(No.2022NY03)”.
文摘This study investigated the residual film content and distribution at different soil depths in the Eighth Division of the Xinjiang Production and Construction Corps.Before spring plowing in 2019,representative fields in four areas(Anjihai,Shihezi suburbs,Mosuowan and Xiayedi)were selected for residual film collection.The average content of residual film in the Eighth Division was 104 kg/ha.The residual film content in the four areas decreased in the order Anjihai>Shihezi suburbs>Mosuowan>Xiayedi.The average amount of residual film collected from cotton fields was greater than that from corn fields.Residual film content in the cotton field at soil depths of 0~10 and 10~30 cm was higher than that in the corn field,whereas the residual film content at a 30–50 cm soil depth in the corn field was higher than that in the cotton field.The results showed that farmers do not consider the long-term benefits,the high cost and short time of recycling,and the easy recycling of surface residual film.The shallow that the higher content of residual film,the less water in the soil of cotton.The same time,the results showed that the quantity of residual film in cotton field had greater influence on cotton quality.
基金Project (51005154) supported by the National Natural Science Foundation of ChinaProject (12CG11) supported by the Chenguang Program of Shanghai Municipal Education Commission, ChinaProject (201104271) supported by the China Postdoctoral Science Foundation
文摘The effect of silicon doping on the residual stress of CVD diamond films is examined using both X-ray diffraction (XRD) analysis and Raman spectroscopy measurements. The examined Si-doped diamond films are deposited on WC-Co substrates in a home-made bias-enhanced HFCVD apparatus. Ethyl silicate (Si(OC2H5)4) is dissolved in acetone to obtain various Si/C mole ratio ranging from 0.1% to 1.4% in the reaction gas. Characterizations with SEM and XRD indicate increasing silicon concentration may result in grain size decreasing and diamond [110] texture becoming dominant. The residual stress values of as-deposited Si-doped diamond films are evaluated by both sin2ψ method, which measures the (220) diamond Bragg diffraction peaks using XRD, with ψ-values ranging from 0° to 45°, and Raman spectroscopy, which detects the diamond Raman peak shift from the natural diamond line at 1332 cm-1. The residual stress evolution on the silicon doping level estimated from the above two methods presents rather good agreements, exhibiting that all deposited Si-doped diamond films present compressive stress and the sample with Si/C mole ratio of 0.1% possesses the largest residual stress of ~1.75 GPa (Raman) or ~2.3 GPa (XRD). As the silicon doping level is up further, the residual stress reduces to a relative stable value around 1.3 GPa.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest from the Ministry of Agriculture,China(201003014)
文摘Pollution of residual plastic film in arable lands is a severe problem in China. In this study, the status of residual film and influential factors were investigated using the methods of farm survey in combination with questionnaires and quadrat sampling at a large number of field sites in Xinjiang Uygur Autonomous Region, China. The results showed that the amount of film utilization increased largely and reached to 1.8×10~5 t in 2013. Similarly, the mulching area also substantially increased in recent decades, and reached to 2.7×10~5 ha in the same year. According to the current survey, 60.7% of the sites presented a greater mulch residue than the national film residue standard(75 kg ha^(–1)), and the maximum residual amount reached 502.2 kg ha^(–1) in Turpan, Xinjiang. The film thickness, the mulching time and the crop type all influenced mulch residue. The thickness of the film had significantly negative correlation with the amount of residual film(P0.05), while the mulching years had significantly positive correlation with it(P0.05). The total amount of residual film in Xinjiang was 3.43×105 t in 2011, which accounted for 15.3% of the cumulative dosage of mulching. Among all the crops, the cotton fields had the largest residual amount of mulch film(158.4 kg ha^(–1)), and also the largest contribution(2.6×10~5 tons) to the total amount of residual film in Xinjiang.
基金This work was supported by the Doctoral Research Foundation(No.98024838) of National Education Ministry.
文摘TiNi thin films were sputter-deposited on circular single-crystal silicon substrates un-der various sputtering parameters. The crystal structure and residual stress of the as-deposited films were determined by X-ray diffraction and substrate-curvature method. The phenomenon of stress-suppressed martensitic transformation was observed. R is considered that the residual stresses in SMA thin films based on circular substrates act as balanced biaxial tensile stresses. The status of equilibrant delays the align-ment of self-accommodated variants and the volume shrinkage during the martensitic transformation.
基金Projects(51401128,51275095) supported by the National Natural Science Foundation of ChinaProject(SKLRS-2013-MS-03) supported by the Open Fund from the State Key Laboratory of Robotics and System,China
文摘The TiN films were deposited on 316 L stainless steel substrates at low temperature by arc ion plating. The influences of substrate bias voltage and temperature on microstructure, residual stress and mechanical properties of the films were investigated by EDS, SEM, XRD and nanoindenter tester, respectively. The results showed that the TiN films were highly oriented in(111) orientation with a face-centered cubic structure. With the increase of substrate bias voltage and temperature, the diffraction peak intensity increased sharply with simultaneous peak narrowing, and the small grain sizes increased from 6.2 to 13.8 nm. As the substrate temperature increased from 10 to 300℃, the residual compressive stress decreased sharply from 10.2 to 7.7 GPa, which caused the hardness to decrease from 33.1 to 30.6 GPa, while the adhesion strength increased sharply from 9.6 to 21 N.
文摘The influence of a gradient interlayer on the residual stress and cracking in TiN thin films was studied as a function of the thickness of gradient interlayer. Both X ray in situ tensile testing and grazing method were used to measure the residual stress in thin films. In TiN films, there exists a residual stress of 10 GPa, which can be remarkably decreased by a gradient interlayer between film and substrate. The cracking behavior of films after tension shows that the crack of film/substrate system begins at interface between film and substrate.
基金This work was financially supported by the National Natural Science Foundation of China (No.50372007).
文摘The relationship between texture and elastic properties of chemical vapor deposition (CVD) diamond films was analyzed based on the phenomenological theory, which reveals the influence of crystalline orientation and texture on the residual macro-strain and macro-stress. The phenomenological calculations indicated that the difference in Young's modulus could be 15% in single diamond crystals and 5% in diamond films with homogeneously distributed strong fiber texture. The experimentally measured residual strains of free-standing CVD diamond films were in good agreement with the correspondingly calculated Young's modulus in connection with the multi-fiber textures in the films, though the difference in Young's modulus induced by texture was only around 1%. It is believed that texture should be one of the important factors influencing the residual stress and strain of CVD diamond films.
基金This work was financially supported by the National Natural Science Foundation of China(No.50071008).
文摘In order to provide a theoretic basis for the research of Ti(C_xN_y) thinfilms, the thermodynamic database of Ti-C-N ternary system is established and the phase diagramsections are calculated. In addition to the assessed thermodynamic properties of Ti-C-N system, theinfluence of the residual strain energy of Ti(C_xN_y) thin films on the phase equilibria isanalyzed. The classical formula for calculating the elastic strain energy is expressed into aRedlich-Kister form in order to perform the thermodynamic and equilibrium calculations using theThermo-Calc software. Isothermal sections at 900 and 1100 K are calculated with this database andcompared with those calculated without considering the residual stress. As a result, with theaddition of strain energy delta-fcc Ti(C_xN_y) phase area shrinks. It is therefore concluded thatwith the influence of the residual stress in Ti(C_xN_y) thin solid film, the precipitation of puredelta film requires more precise control of composition.
文摘In order to analyze the stress and deformation of different permeability of residual oil film in the complex pore, which are affected by the viscous-elasticity of the fluid, the hydrodynamic displacement mechanism is explored from the stand-point of hydrodynamics, that is, the residual oil film displaced by alternating injection of different concentrations of the polymer solution, viscous-elastic fluid flow equation is established in the complex pore by choosing continuity equation, motion equation and the upper convected Maxwell constitutive equation. The flow field is computed by using the method of numerical analysis. Not only the stress and deformation of residual oil film on the different permeability of micro pores, but also the analysis of the flooding mechanism of alternating injection of different concentrations of the polymer solution is got. The results show that the larger the viscous-elasticity of polymer solution is, the bigger the normal deviatoric stress acting on the residual oil film is;the distribution of normal deviatoric stress has the abrupt change. The stronger the viscous-elasticity of the polymer solution is, the bigger the horizontal stress difference acting on the residual oil film is and the more obvious the deformation is;the high-concentration polymer solution is suitable for high-permeability micro pores. Low-concentration polymer solution is suitable for medium and low-permeability micro pores. Alternating injection of polymer solution can improve Volumetric Sweep Efficiency and increase the deformation of residual oil film, which is conducive to enhancing oil recovery.
基金Supported by the Shihezi Science and Technology Plan of the Eighth Division(2018RK01)。
文摘Before spring ploughing in 2019,the representative fields of the 8^(th) Division were selected,and residual film at different depths of soil in three areas of the 8^(th) Division was collected. Through the analysis on the weight and amount of residual film at different depths of soil,it was found that the average content of residual film in the 8^(th) Division was 104 kg/hm^2. From high to low,the content sequence of residual film in the three areas was Anjihai area,Mosuowan area and Xiayedi area. The average amount of residual film collected from the cotton field in the three areas was greater than that from the corn field. In the three areas,the content of residual film in the cotton field at the depth of 0-10 and 11-30 cm was higher than that in the corn field,while the content of residual film at the depth of 31-50 cm in the corn field was higher than that in the cotton field.
基金Supported by Coarse Cereals Innovation Team of Shandong Province Modern Agricultural Industry Technology System(SDAIT-15-11)Cotton Innovation Team(SDAIT-15-07)。
文摘[Objectives]This study was conducted to explore the characteristics of soil residual film pollution load in cotton fields in the Yellow River Delta,so as to effectively control soil film pollution.[Methods]Cotton field mulching film survey and residue monitoring were conducted in the Yellow River Delta area.[Results]The amount of mulching film residues in cotton fields in the Yellow River Delta was 37.7-128.7 kg/hm^(2),which had a significant increase compared with 5 years ago,and the differences between plots were large;and after straw was returned to the field,the soil residual film obviously gathered in the 20-30 cm soil layer.The residual film blocks with a size of more than 25 cm^(2) accounted for 62.6%,which was a relatively high proportion,indicating that soil pollution can be caused easily,and it is difficult to control.During a certain period of time,the soil residual film pollution may have a tendency to aggravate,and the ecological risk is higher.[Conclusions]This study has important theoretical and practical significance for improving soil quality in the region and ensuring the safety of cotton field ecosystem and environmental health.
基金the National Natural Science Foundation of China(Grant No.52175240)the Major Scientific and Technological Projects of Xinjiang Production and Construction Corps(2018AA001/03)the Graduate Education Innovation Project of Xinjiang Uygur Autonomous Region(Grant No.XJ2022G083).
文摘Residual films on the sowing layer produced after mulching in Xinjiang farmland,harm the sowing quality and root growth of crops.In this study,a sowing layer residual film recovery machine based on a radial plate arc-shaped nail-tooth roller structure was designed.Meanwhile,the key device structures were designed and the main working parameters were analyzed.Then,taking the working depth,the forward speed of the machine and the rotation speed of the nail tooth roller as the test factors,and the film collection rate and film intertwining rate as the test indicators,the single factor tests and the Box-Behnken response surface tests were carried out to evaluate the performance of the sowing layer residual film recovery machine.Consequently,the results showed that the order of significant factors was the working depth,the forward speed of the machine,and the rotation speed of the nail tooth roller.Besides,the optimal working parameters were determined,which the working depth,the forward speed of the machine,and the rotation speed of the nail tooth roller were 100 mm,4.8 km/h,and 49.3 r/min,respectively.Moreover,the predicted value of the film collection rate was 69.20%.Finally,the verification test was taken with the optimal working parameter,and the results showed that the film collection rate was 66.84%,and the film intertwining rate was 1.39%.The relative error between the test value and the predicted value of the film collection rate was 3.40%.It indicated that the machine can perform the collection of sowing layer residual films.This study can provide a theoretical basis and reference for the design of new sowing layer residual film machines.
基金TheNationalNaturalScienceFoundationofChina (No .5 96 780 18)
文摘Water quality within water distribution system may vary with both location and time. Water quality models are used to predict the spatial and temporal variation of water quality throughout water system. A model of residual chlorine decay in water pipe has been developed, given the consumption of chlorine in reactions with chemicals in bulk water, bio films on pipe wall, in corrosion process, and the mass transport of chlorine from bulk water to pipe wall. Analytical methods of the flow path from water sources to the observed point and the water age of every observed node were proposed. Model is used to predict the decay of residual chlorine in an actual distribution system. Good agreement between calculated and measured values was obtained.
文摘In this paper we demonstrate that the residual stress introduced by several different surface finishes affects the critical current density for passivation and the passive current density in the anodic polarization curve of austenitic stainless steel and that those critical current densities can be reduced by controlling the residual stress by applying a cavitating jet to the backs of specimens. The results show that the current density either increased or decreased depending on the surface finish, and that was decreased by introducing compressive residual stress for all surface finishes.
文摘In order to study current situation of application,recycling and residue pollution of mulching films in Xinjiang,and accurately grasp pollution degree of residue of mulching films,this paper made an empirical analysis on residue of mulching films in 31 typical counties and cities in Xinjiang. Results indicate that( i) use of mulching films in Xinjiang is wide and there is great difference in use and residue recycling between cities and counties. Planting area and planting structure jointly influence use of mulching films,and the use of mulching films is significantly correlated with recycling of mulching films,but not correlated with recycling rate of mulching films.( ii) There are significant differences in distribution of residue of mulching films,highest in North Xinjiang and South Xinjiang,followed by East Xinjiang,and the lowest in West Xinjiang.( iii) There are significant differences in distribution of residue of mulching films between different crop fields. Residue of mulching films in cotton field is the key problem of pollution.
基金supported by the foundation of State Key Laboratory of Pulp and Paper Engineering (201819)the project of Shaanxi Provincial Department of Education Key Laboratory Research Open Fund (Grant No. 17JS017)the project of Shaanxi University of Science and Technology Research Initial Fund (Grant No. BJ15-29)
文摘In this study, soybean residues were treated with HCl and soybean residue cellulose was extracted, which was used to prepare cellulose nanofiber (CNF) using the high-pressure homogenization method. The maximum yield of CNF, the reaction temperature, reaction time, and HCl concentration were optimized. The optimum HCl concentration for acid treatment was 6%, the reaction time was 60 min, the reaction temperature was 80℃, and the maximum yield of soybean residue cellulose was 78.8%. The different CNF films were then prepared;the color, mechanical property, and light transmittance of the CNF films were studied. Compared to the properties of the CNF film prepared with the soybean residue cellulose by high-pressure homogenization 15 times (HGT-15 film), the mechanical properties of the CNF film with soybean residue cellulose by decolorizing treatment decreased, but the light transmittance increased. The film prepared by adding HGT- 15 CNF to whey protein was investigated for its mechanical property, light transmittance, and solubility. Unlike the pure whey protein film, addition of 2.0% CNF to the whey protein enhanced the mechanical property and water vapor transmission rate (WVT) of the film. With the increase in CNF content, the solubility of the whey protein film decreased, and then stabilized.
基金Supported by Cotton Innovation Team of Modern Agriculture Technology System of Shandong Province(SDAIT-07)Special Fund for Independent Innovation Achievement Transformation(2013ZHZX2A0402)~~
文摘In order to get a clear picture of distribution characteristics of mulching plastic film residue in cotton fields in the Yellow River Delta and make scientific pollution prevention and control strategies, an investigation was conducted in Dongying City. Five typical cotton fields were chosen, and then the number, distri- bution density and area of residual film were measured. The results showed that the residual film was 18. 84-53. 53 kg/hm^2 in cotton fields for more than 20 years, and the differences between fields were larger. The residual density was 225-340 thousand per hectare. There were great differences among residual pieces. The proportion of residual pieces over 25 cm^2 was 94. 1%, that between 100 cm^2 and 500 cm^2 was more than 50. 0%, and that bigger than 500 cm^2 was about 21. 0%. In the Yellow River Delta cotton region, large, thin and difficult to recovery were the main characteristics of mulching plastic film residue, and it had the possibility of mi- grating to deep soil. Thus, the ecological risk of mulching plastic film residue was higher. Key words The Yellow River Delta; Cotton field; Residue of mulching plastic film; Distribution characteristic
文摘In this paper, we investigate the effect of layer thickness on the residual stresses of copper indium gallium diselenide (CIGS) solar cells with polyimide substrate caused by CIGS layer deposition at 400?C and then cooling down to room temperature using the Finite Element Method (FEM). Moreover, we also examined the effect of layer thickness on residual stress of CIGS solar cells after cooling down to room temperature from the hotspot temperatures of 200?C, 300?C, and 400?C. Our simulated CIGS is composed of five layers: ZnO, CdS, CIGS, Mo, and PI substrate. We were able to quantify the effect of each layer’s thickness and hotspot temperature on the average stresses of each layer for the CIGS solar cells. We found that the PI substrate layer has the most significant effect on the residual stress of CIGS solar cells. Our simulation results reveal that the stress type (tensile vs. compressive) and the magnitude of stress of the CIGS layer (main absorber layer) can be controlled by changing the thickness of the PI substrate while applying a heat to CIGS solar cells. Quantitative analysis of relationship between layer thickness and thermo-mechanical stress of thin film solar cells can help solar cell manufacturers design more robust and reliable solar cells. For example, fabricating PI layer thickness less than 17 μm can improve the performance of CIGS solar cells by nullifying the compressive residual stress in the CIGS absorber layer.