As a concept to describe development restrictions,resources and environment carrying capacity（RECC）research has developed over more than 100 years since it was first proposed at the beginning of the 20th century.It ...As a concept to describe development restrictions,resources and environment carrying capacity（RECC）research has developed over more than 100 years since it was first proposed at the beginning of the 20th century.It is now regarded as a significant factor in evaluating the level of cooperation between regional population,resources,and environment;and it is currently used as an effective and operational tool to guide regional sustainable development.This article first reviews the origin of RECC and its early headway.It then reviews the historical development of RECC from single factors,such as land resources carrying capacity,water resources carrying capacity and environmental carrying capacity（environmental capacity）,to more comprehensive research,such as comprehensive evaluation,emergy analysis,and ecological footprint analysis.In general,it appears that comprehensive research will become increasingly important in RECC research.However,there are several deficiencies in the current state of comprehensive research.Firstly,comprehensive RECC research lacks a common measurement standard,though some scholars have attempted to create one.Secondly,the RECC evaluation of open systems and dynamic studies should be strengthened.Thirdly,more attention should be paid to standardization,digitalization,and systematization to promote the applicability of RECC research to national practical demands.展开更多
Mine environmental evaluation is the key to mine environmental study. On the basis of the characteristics of the mine environmental problems, they are classified into （1） three wastes problem, （2） ground distortio...Mine environmental evaluation is the key to mine environmental study. On the basis of the characteristics of the mine environmental problems, they are classified into （1） three wastes problem, （2） ground distortion, （3） contradiction among mine drainage, water supply, ecological environment, （4） desertification, and （5） soil erosion. The evaluation is the basis of mine environmental problem classification and investigation, mine environmental rehabilitation, and the information system constructed can be used for subsequent research of evaluation techniques. A synthetic assessment of the 5 kinds of mine environmental problems can be divided into single-factor or multi-factor synthetic assessments; while by the viewpoint of time, the mine environmental assessment can be classified as the historical assessment, the current status assessment and the forecasting assessment.展开更多
The stripping and regeneration of the loaded organic phase of phosphorousmixer extractant (PPD) were studied. The mixed solutions (3 mol/L HCl +2 mol/L ZnC1_2) were used asthe stripping agent and more than 99 percent ...The stripping and regeneration of the loaded organic phase of phosphorousmixer extractant (PPD) were studied. The mixed solutions (3 mol/L HCl +2 mol/L ZnC1_2) were used asthe stripping agent and more than 99 percent of indium can be stripped after three-stage strippingwhen the volume ratio of organic phase to stripping agent is 1:1. The organic phase can he recycledto use alter regeneration with HCl. The parallel contrast experiments with D_2EHPA (di-2-ethyl hexylphosphoric acid) were carried out under the same conditions. The results show that the mixerextractant has good reusability and the stripping and regeneration of PPD are superior to those ofD_2EHPA.展开更多
[ Objective] This study aimed to investigate the optimal conditions for ultrasonic extraction of polysaccharides from Polyporus umbeUatus, thus providing a reliable basis for the development and utilization of P. umbe...[ Objective] This study aimed to investigate the optimal conditions for ultrasonic extraction of polysaccharides from Polyporus umbeUatus, thus providing a reliable basis for the development and utilization of P. umbellatus. [ Method ] By single-factor experiment, the ultrasonic extraction process of polyperus pelysac- charides was optimized. [Result] The optimal conditions for ultrasonic extraction of polysaccharides from P. umbeUatus were： solid-liquid ratio 1：40 （g： ml）, ex- traction duration 60 rain, extraction temperature 70 ℃, ultrasonic power 100 W. [ Conclusion] Compared with conventional water extraction method, ultrasonic ex- traction could significantly improve the content of polyporus polysaccharides with shorter extraction duration, lower solid-liquid ratio and lower extraction tempera-展开更多
Process integration method is used to establish a composite model to perform computations of hybrid models for water quality assessment of Haihe River, and a resolution is presented to clear the long-term obscurity ab...Process integration method is used to establish a composite model to perform computations of hybrid models for water quality assessment of Haihe River, and a resolution is presented to clear the long-term obscurity about the differences between single-factor assessment(SFA) and multifactor assessment(MFA) of water quality in this paper. Symbolic models were introduced to describe the types and orders of computations involved in SFA and such MFAs as Nemerow comprehensive index(NCI) and fuzzy comprehensive assessment(FCA). Facilitated by paired t-tests, the composite model of absolute distance(AD) was established to test the differences between SFA and MFAs on four water quality indicators(WQI). Matlab(R14) programs for these models were developed to perform integrative computations on 3 217 batches of water data obtained from seven monitoring sites of Haihe River from 2008 to 2017. Paired t-tests show that results of our SFA model(SFA-4) are not significantly different(p=0.926) from that of SFA based on all WQI, however, extremely significantly different from results of NCI(p=0) and FCA(p=0). SFA-4 is proved by AD model to be farther away from FCA(AD-S→F=1.075) than from NCI(AD-S→N=0.634). More than proving the deduction of SFA≥NCI≥FCA in most cases(p=0.885), the results from AD show that MFAs approach SFA when surface water becomes good(SFA=1) or worst(SFA=6), whereas depart to the farthest distance from SFA when surface water becomes worse(SFA=3). To sum up, the integrative computations involved in AD model on the water data are effective and efficient(improved by 44.2%). Furthermore, AD model shows the differences between SFA and MFAs clearly.展开更多
Abstract In the study of sequence stratigraphy and litho-paleogeography, quantitative analysis, precise calculation and detailed comparison of tremendous geological data, such as field profiles, logging records and se...Abstract In the study of sequence stratigraphy and litho-paleogeography, quantitative analysis, precise calculation and detailed comparison of tremendous geological data, such as field profiles, logging records and seismic curves from different areas, are the basic requirements. In order to obtain a more reliable and precise result, this paper presents a novel method that combines spatial database analysis with the single-factor mapping technology to establish sequence stratigraphical succession and to map the Ordovician litho-paleogeography of the Ordos Basin, one of the largest oil-gas bearing basins in North China Platform. By using this method, all of the related basic geological data can be quantitatively analyzed and effectively managed. Various attributes of the basic stratigraphic units and their characters, such as sequence thickness, penecontemporaneous dolostone content, shallow water parget content, and terrigenous material content, can be fully utilized statistically in facies analysis and in mapping. Based on this analysis, this paper has be exerted single-factor isopachous mapping quantitatively for each of the Ordovician sequences in the basin, and finally synthesized multiple factors to reconstruct the litho-paleogeography for each of the sequence intervals. The study shows that the proposed method is quite effective and has a much higher resolution in recognizing litho-paleogeographic subunits compared with traditional ways. For example, in one of the Middle Ordovician sequence intervals （SQ19 in the Lower Majiagou Formation） of the Ordos Basin, the authors have successfully developed a mathematical formula to divide the distribution of various facies units substantially, such as old lands, submarine uplifts, supratidal zones, intertidal zones and subtidal zones.展开更多
To address the serious pollution of heavy metals in AMD,the difficulty and the high cost of treatment,Fe_(3)O_(4)-L was prepared by the chemical co-precipitation method.Based on the single-factor and RSM,the effects o...To address the serious pollution of heavy metals in AMD,the difficulty and the high cost of treatment,Fe_(3)O_(4)-L was prepared by the chemical co-precipitation method.Based on the single-factor and RSM,the effects of particle size,total Fe concentration,the molar ratio of Fe^(2+)to Fe^(3+)and water bath temperature on the removal of AMD by Fe_(3)O_(4)-L prepared by chemical co-precipitation method were analyzed.Static adsorption experiments were conducted on Cu^(2+),Zn^(2+)and Pb^(2+)using Fe_(3)O_(4)-L prepared under optimal conditions as adsorbents.The adsorption properties and mechanisms were analyzed by combining SEM-EDS,XRD and FTIR for characterization.The study showed that the effects of particle size,total Fe concentration and the molar ratio of Fe^(2+)to Fe^(3+)are larger.Obtained by response surface optimization analysis,the optimum conditions for the preparation of Fe_(3)O_(4)-L were a particle size of 250 mesh,a total Fe concentration of 0.5 mol/L,and a molar ratio of Fe^(2+)to Fe^(3+)of 1:2.Under these conditions,the removal rates of Cu^(2+),Zn^(2+),and Pb^(2+)were 94.52%,88.49%,and 96.69%respectively.The adsorption of Cu^(2+),Zn^(2+)and Pb^(2+)by Fe_(3)O_(4)-L prepared under optimal conditions reached equilibrium at 180 min,with removal rates of 99.99%,85.27%,and 97.48%,respectively.The adsorption reaction of Fe_(3)O_(4)-L for Cu^(2+)and Zn^(2+)is endothermic,while that for Pb^(2+)is exothermic.Fe_(3)O_(4)-L can still maintain a high adsorption capacity after five cycles of adsorption-desorption experiments.Cu^(2+),Zn^(2+)and Pb^(2+)mainly exist as CuFe_(2)O_(4),Zn(OH)2,ZnFe_(2)O_(4)and PbS after being adsorbed by Fe_(3)O_(4)-L,which is the result of the combination of physical diffusion,ion exchange and surface complexation reaction.展开更多
The Fenton oxidation process was applied in the treatment of an actual high concentration nonylphenol Ethoxylates (NPEOs) wastewater. The effects of H2O2 dosage, molar ratio of H2O2/Fe2+ (Fe2+ dosage), pH value and re...The Fenton oxidation process was applied in the treatment of an actual high concentration nonylphenol Ethoxylates (NPEOs) wastewater. The effects of H2O2 dosage, molar ratio of H2O2/Fe2+ (Fe2+ dosage), pH value and reaction time on the degradation of NPEOs were investigated. The orthogonal experiment indicated that the order of degree of influence on the COD removal was molar ratio of H2O2/Fe2+, reaction time, dosage of H2O2, and initial pH. The single-factor tests were carried out to determine the optimal conditions, and the results were H2O2 dosage of 76.32 mmol/L, molar ratio of H2O2/Fe2+ of 3, pH value of 5 and reaction time of 2 h. Under the optimum operation conditions, the COD removal efficiency was 85.6% and the effluent could be mixed with other wastewater into the large-scale biological treatment system.展开更多
In this study,an ultrasonic assisted natural deep eutectic solvent(DES)was used to extract hydroxytyrosol(HT)from olive leaves.The optimal extraction conditions of the MaPa-4 concentration,extraction time and solid-li...In this study,an ultrasonic assisted natural deep eutectic solvent(DES)was used to extract hydroxytyrosol(HT)from olive leaves.The optimal extraction conditions of the MaPa-4 concentration,extraction time and solid-liquid ratio were obtained by single factor experiments.The formation mechanism of MaPa and its interaction with HT were analyzed by FTIR,^(1)H-NMR and density functional theory(DFT)calculation.Then,MaPa-4 and water extracts obtained under the optimal extraction conditions were selected for a series of efficacy tests.MaPa-4 extract demonstrated low cytotoxicity,good biocompatibility,and excellent antiinflammatory and bacteriostatic properties.Overall,MaPa-4,as an environmentally friendly and efficient solvent,was combined with ultrasound treatment to develop an efficient,green and feasible method to extract HT from olive leaves.展开更多
To determine proper flight parameters of an unmanned helicopter for tea plantation frost protection,field experiments were conducted to study the impact of flight height,speed and interval on airflow disturbance and t...To determine proper flight parameters of an unmanned helicopter for tea plantation frost protection,field experiments were conducted to study the impact of flight height,speed and interval on airflow disturbance and temperature rise around tea canopies based on the analysis and simulation of frost protection with a certain helicopter.The relationship between temperature rise after flight and the above flight parameters was established through a regression orthogonal experiment,based on which the optimal combination of flight parameters was obtained through the single-factor golden section method.The results showed that wind speed around tea canopies decreased with the increase of flight height when flight speed was constant.There was a multivariate linear relationship between temperature rise and flight parameters,and the sequence of flight parameters’influence on frost protection effect was flight interval,flight height,flight speed.The optimal combination of flight parameters were flight height of 4.0 m,flight speed of 6.0 m/s and flight interval of 20 min.After the flight with the above parameters air temperature around tea canopies increased 1.6℃ when background thermal inversion strength was 3.8℃.展开更多
Since the resin-based composite materials are of essential importance in many key engineering fields,the manufacture processes are highly worth studying and optimizing for satisfying quality control at the highest pos...Since the resin-based composite materials are of essential importance in many key engineering fields,the manufacture processes are highly worth studying and optimizing for satisfying quality control at the highest possible production rate.In this paper,combined with the impregnation theory,the flow-thermal-mechanical multiphysics coupling model is built to characterize,investigate and optimize the osmotic flow process of hot-melt resin in fiber fabrics with the uniformity and adequacy of resin impregnation as the evaluation criteria.First,the osmotic flow process is characterized by the osmotic flow front of resin,which is tracked by the phase-field method.Then,the influencing factors of roller clearance,temperature and speed are comprehensively investigated.After that,the simulation data of resin impregnation degree are fitted by polynomial curves,with accuracy up to 96.13%,for further investigation of interaction between influencing factors.Finally,based on the above results,the operation parameter combination for impregnation process is optimized with the response surface method and provided as the guidance for practical application.展开更多
基金The National Key Research and Development Program of China(2016YFC0503500)National Science and Technology Major Project(Z2016C01G01)
文摘As a concept to describe development restrictions,resources and environment carrying capacity（RECC）research has developed over more than 100 years since it was first proposed at the beginning of the 20th century.It is now regarded as a significant factor in evaluating the level of cooperation between regional population,resources,and environment;and it is currently used as an effective and operational tool to guide regional sustainable development.This article first reviews the origin of RECC and its early headway.It then reviews the historical development of RECC from single factors,such as land resources carrying capacity,water resources carrying capacity and environmental carrying capacity（environmental capacity）,to more comprehensive research,such as comprehensive evaluation,emergy analysis,and ecological footprint analysis.In general,it appears that comprehensive research will become increasingly important in RECC research.However,there are several deficiencies in the current state of comprehensive research.Firstly,comprehensive RECC research lacks a common measurement standard,though some scholars have attempted to create one.Secondly,the RECC evaluation of open systems and dynamic studies should be strengthened.Thirdly,more attention should be paid to standardization,digitalization,and systematization to promote the applicability of RECC research to national practical demands.
基金China National Natural Science Foundation（Grant No.40572149,40772162）；National Key Project of Scientific and Technical Supporting Programs （2007BAK24B01,2006BAB16B04）；the “973” Project(Grant No.2006CB202205）the Key Projects of Ministry of Education of P.R.China（Grant No.2004-295）.
文摘Mine environmental evaluation is the key to mine environmental study. On the basis of the characteristics of the mine environmental problems, they are classified into （1） three wastes problem, （2） ground distortion, （3） contradiction among mine drainage, water supply, ecological environment, （4） desertification, and （5） soil erosion. The evaluation is the basis of mine environmental problem classification and investigation, mine environmental rehabilitation, and the information system constructed can be used for subsequent research of evaluation techniques. A synthetic assessment of the 5 kinds of mine environmental problems can be divided into single-factor or multi-factor synthetic assessments; while by the viewpoint of time, the mine environmental assessment can be classified as the historical assessment, the current status assessment and the forecasting assessment.
基金The project is financially supported by the "95" National Key Research Project (96-119-03-03-02-A)
文摘The stripping and regeneration of the loaded organic phase of phosphorousmixer extractant (PPD) were studied. The mixed solutions (3 mol/L HCl +2 mol/L ZnC1_2) were used asthe stripping agent and more than 99 percent of indium can be stripped after three-stage strippingwhen the volume ratio of organic phase to stripping agent is 1:1. The organic phase can he recycledto use alter regeneration with HCl. The parallel contrast experiments with D_2EHPA (di-2-ethyl hexylphosphoric acid) were carried out under the same conditions. The results show that the mixerextractant has good reusability and the stripping and regeneration of PPD are superior to those ofD_2EHPA.
基金Supported by Practical Innovation Program for College Students in Jiangsu ProvinceSocial Development Project of Taizhou City(TS019)
文摘[ Objective] This study aimed to investigate the optimal conditions for ultrasonic extraction of polysaccharides from Polyporus umbeUatus, thus providing a reliable basis for the development and utilization of P. umbellatus. [ Method ] By single-factor experiment, the ultrasonic extraction process of polyperus pelysac- charides was optimized. [Result] The optimal conditions for ultrasonic extraction of polysaccharides from P. umbeUatus were： solid-liquid ratio 1：40 （g： ml）, ex- traction duration 60 rain, extraction temperature 70 ℃, ultrasonic power 100 W. [ Conclusion] Compared with conventional water extraction method, ultrasonic ex- traction could significantly improve the content of polyporus polysaccharides with shorter extraction duration, lower solid-liquid ratio and lower extraction tempera-
基金Supported by the National Natural Science Foundation of China(61872147,61761023).
文摘Process integration method is used to establish a composite model to perform computations of hybrid models for water quality assessment of Haihe River, and a resolution is presented to clear the long-term obscurity about the differences between single-factor assessment(SFA) and multifactor assessment(MFA) of water quality in this paper. Symbolic models were introduced to describe the types and orders of computations involved in SFA and such MFAs as Nemerow comprehensive index(NCI) and fuzzy comprehensive assessment(FCA). Facilitated by paired t-tests, the composite model of absolute distance(AD) was established to test the differences between SFA and MFAs on four water quality indicators(WQI). Matlab(R14) programs for these models were developed to perform integrative computations on 3 217 batches of water data obtained from seven monitoring sites of Haihe River from 2008 to 2017. Paired t-tests show that results of our SFA model(SFA-4) are not significantly different(p=0.926) from that of SFA based on all WQI, however, extremely significantly different from results of NCI(p=0) and FCA(p=0). SFA-4 is proved by AD model to be farther away from FCA(AD-S→F=1.075) than from NCI(AD-S→N=0.634). More than proving the deduction of SFA≥NCI≥FCA in most cases(p=0.885), the results from AD show that MFAs approach SFA when surface water becomes good(SFA=1) or worst(SFA=6), whereas depart to the farthest distance from SFA when surface water becomes worse(SFA=3). To sum up, the integrative computations involved in AD model on the water data are effective and efficient(improved by 44.2%). Furthermore, AD model shows the differences between SFA and MFAs clearly.
基金Supported by the National Natural Science Foundation of China for the Innovation Group Project(No. 40621002)
文摘Abstract In the study of sequence stratigraphy and litho-paleogeography, quantitative analysis, precise calculation and detailed comparison of tremendous geological data, such as field profiles, logging records and seismic curves from different areas, are the basic requirements. In order to obtain a more reliable and precise result, this paper presents a novel method that combines spatial database analysis with the single-factor mapping technology to establish sequence stratigraphical succession and to map the Ordovician litho-paleogeography of the Ordos Basin, one of the largest oil-gas bearing basins in North China Platform. By using this method, all of the related basic geological data can be quantitatively analyzed and effectively managed. Various attributes of the basic stratigraphic units and their characters, such as sequence thickness, penecontemporaneous dolostone content, shallow water parget content, and terrigenous material content, can be fully utilized statistically in facies analysis and in mapping. Based on this analysis, this paper has be exerted single-factor isopachous mapping quantitatively for each of the Ordovician sequences in the basin, and finally synthesized multiple factors to reconstruct the litho-paleogeography for each of the sequence intervals. The study shows that the proposed method is quite effective and has a much higher resolution in recognizing litho-paleogeographic subunits compared with traditional ways. For example, in one of the Middle Ordovician sequence intervals （SQ19 in the Lower Majiagou Formation） of the Ordos Basin, the authors have successfully developed a mathematical formula to divide the distribution of various facies units substantially, such as old lands, submarine uplifts, supratidal zones, intertidal zones and subtidal zones.
基金This work was supported by the National Natural Science Foundation of China(41672247)Liaoning Province’s“Program for Promoting Liaoning Talents”(XLYC1807159)+1 种基金the Discipline Innovation Team of Liaoning Technical University(LNTU20TD-21)the Liaoning Provincial Department of Education(LJKZ0324).
文摘To address the serious pollution of heavy metals in AMD,the difficulty and the high cost of treatment,Fe_(3)O_(4)-L was prepared by the chemical co-precipitation method.Based on the single-factor and RSM,the effects of particle size,total Fe concentration,the molar ratio of Fe^(2+)to Fe^(3+)and water bath temperature on the removal of AMD by Fe_(3)O_(4)-L prepared by chemical co-precipitation method were analyzed.Static adsorption experiments were conducted on Cu^(2+),Zn^(2+)and Pb^(2+)using Fe_(3)O_(4)-L prepared under optimal conditions as adsorbents.The adsorption properties and mechanisms were analyzed by combining SEM-EDS,XRD and FTIR for characterization.The study showed that the effects of particle size,total Fe concentration and the molar ratio of Fe^(2+)to Fe^(3+)are larger.Obtained by response surface optimization analysis,the optimum conditions for the preparation of Fe_(3)O_(4)-L were a particle size of 250 mesh,a total Fe concentration of 0.5 mol/L,and a molar ratio of Fe^(2+)to Fe^(3+)of 1:2.Under these conditions,the removal rates of Cu^(2+),Zn^(2+),and Pb^(2+)were 94.52%,88.49%,and 96.69%respectively.The adsorption of Cu^(2+),Zn^(2+)and Pb^(2+)by Fe_(3)O_(4)-L prepared under optimal conditions reached equilibrium at 180 min,with removal rates of 99.99%,85.27%,and 97.48%,respectively.The adsorption reaction of Fe_(3)O_(4)-L for Cu^(2+)and Zn^(2+)is endothermic,while that for Pb^(2+)is exothermic.Fe_(3)O_(4)-L can still maintain a high adsorption capacity after five cycles of adsorption-desorption experiments.Cu^(2+),Zn^(2+)and Pb^(2+)mainly exist as CuFe_(2)O_(4),Zn(OH)2,ZnFe_(2)O_(4)and PbS after being adsorbed by Fe_(3)O_(4)-L,which is the result of the combination of physical diffusion,ion exchange and surface complexation reaction.
文摘The Fenton oxidation process was applied in the treatment of an actual high concentration nonylphenol Ethoxylates (NPEOs) wastewater. The effects of H2O2 dosage, molar ratio of H2O2/Fe2+ (Fe2+ dosage), pH value and reaction time on the degradation of NPEOs were investigated. The orthogonal experiment indicated that the order of degree of influence on the COD removal was molar ratio of H2O2/Fe2+, reaction time, dosage of H2O2, and initial pH. The single-factor tests were carried out to determine the optimal conditions, and the results were H2O2 dosage of 76.32 mmol/L, molar ratio of H2O2/Fe2+ of 3, pH value of 5 and reaction time of 2 h. Under the optimum operation conditions, the COD removal efficiency was 85.6% and the effluent could be mixed with other wastewater into the large-scale biological treatment system.
基金financially supported by the National Natural Science Foundation of China(21905069,U21A20307),the Shenzhen Science and Technology Innovation Committee(Grant No.ZDSYS20190902093220279,KQTD20170809110344233,GXWD20201230155427003-20200821181245001,GXWD20201230155427003-20200821181809001,ZX20200151)the Department of Science and Technology of Guangdong Province(Grant No.2020A1515110879).
文摘In this study,an ultrasonic assisted natural deep eutectic solvent(DES)was used to extract hydroxytyrosol(HT)from olive leaves.The optimal extraction conditions of the MaPa-4 concentration,extraction time and solid-liquid ratio were obtained by single factor experiments.The formation mechanism of MaPa and its interaction with HT were analyzed by FTIR,^(1)H-NMR and density functional theory(DFT)calculation.Then,MaPa-4 and water extracts obtained under the optimal extraction conditions were selected for a series of efficacy tests.MaPa-4 extract demonstrated low cytotoxicity,good biocompatibility,and excellent antiinflammatory and bacteriostatic properties.Overall,MaPa-4,as an environmentally friendly and efficient solvent,was combined with ultrasound treatment to develop an efficient,green and feasible method to extract HT from olive leaves.
基金The authors are grateful to the financial support by National High Technology Research and Development Program of China(2012AA10A508)National Natural Science Foundation of China(31101089)Priority Academic Program Development of Jiangsu Higher Education Institutions(2014-37)。
文摘To determine proper flight parameters of an unmanned helicopter for tea plantation frost protection,field experiments were conducted to study the impact of flight height,speed and interval on airflow disturbance and temperature rise around tea canopies based on the analysis and simulation of frost protection with a certain helicopter.The relationship between temperature rise after flight and the above flight parameters was established through a regression orthogonal experiment,based on which the optimal combination of flight parameters was obtained through the single-factor golden section method.The results showed that wind speed around tea canopies decreased with the increase of flight height when flight speed was constant.There was a multivariate linear relationship between temperature rise and flight parameters,and the sequence of flight parameters’influence on frost protection effect was flight interval,flight height,flight speed.The optimal combination of flight parameters were flight height of 4.0 m,flight speed of 6.0 m/s and flight interval of 20 min.After the flight with the above parameters air temperature around tea canopies increased 1.6℃ when background thermal inversion strength was 3.8℃.
基金financially supported by the National Natural Science Foundation of China(52176202)。
文摘Since the resin-based composite materials are of essential importance in many key engineering fields,the manufacture processes are highly worth studying and optimizing for satisfying quality control at the highest possible production rate.In this paper,combined with the impregnation theory,the flow-thermal-mechanical multiphysics coupling model is built to characterize,investigate and optimize the osmotic flow process of hot-melt resin in fiber fabrics with the uniformity and adequacy of resin impregnation as the evaluation criteria.First,the osmotic flow process is characterized by the osmotic flow front of resin,which is tracked by the phase-field method.Then,the influencing factors of roller clearance,temperature and speed are comprehensively investigated.After that,the simulation data of resin impregnation degree are fitted by polynomial curves,with accuracy up to 96.13%,for further investigation of interaction between influencing factors.Finally,based on the above results,the operation parameter combination for impregnation process is optimized with the response surface method and provided as the guidance for practical application.
