The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of trea...The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of treatment. How enterprises can make reasonable decisions on their water environment behavior based on the external environment and their own factors is of great significance for scientifically and effectively designing water environment regulation mechanisms. Based on optimal control theory, this study investigates the design of contractual mechanisms for water environmental regulation for small and medium-sized enterprises. The enterprise is regarded as an independent economic entity that can adopt optimal control strategies to maximize its own interests. Based on the participation of multiple subjects including the government, enterprises, and the public, an optimal control strategy model for enterprises under contractual water environmental regulation is constructed using optimal control theory, and a method for calculating the amount of unit pollutant penalties is derived. The water pollutant treatment cost data of a paper company is selected to conduct empirical numerical analysis on the model. The results show that the increase in the probability of government regulation and public participation, as well as the decrease in local government protection for enterprises, can achieve the same regulatory effect while reducing the number of administrative penalties per unit. Finally, the implementation process of contractual water environmental regulation for small and medium-sized enterprises is designed.展开更多
The original online version of this article (Zhao, S., Gu, H.B., Xue, L.F., Wang, D.S. and Huang, B. (2024) Contract Mechanism of Water Environment Regu-lation for Small and Medium Sized Enterprises Based on Optimal C...The original online version of this article (Zhao, S., Gu, H.B., Xue, L.F., Wang, D.S. and Huang, B. (2024) Contract Mechanism of Water Environment Regu-lation for Small and Medium Sized Enterprises Based on Optimal Control Theory. Journal of Water Resource and Protection, 16, 538-556. https://doi.org/10.4236/jwarp.2024.167030) unfortunately contains a mis-take. The second institution is “China Renewable Energy Engineering Insti-tute, Beijing, China”, not “China Renewable Engineering Institute, Beijing, China”.展开更多
For the porous‐membrane‐based osmotic energy generator,the potential synergistic enhancement mechanism of various key parameters is still controversial,especially because optimizing the trade‐off between permeabili...For the porous‐membrane‐based osmotic energy generator,the potential synergistic enhancement mechanism of various key parameters is still controversial,especially because optimizing the trade‐off between permeability and selectivity is still a challenge.Here,to construct a permeability and selectivity synergistically enhanced osmotic energy generator,the twodimensional porous membranes with tunable charge density are prepared by inserting sulfonated polyether sulfone into graphene oxide.Influences of charge density and pore size on the ion transport are explored,and the ionic behaviors in the channel are calculated by numerical simulations.The mechanism of ion transport in the process is studied in depth,and the fundamental principles of energy conversion are revealed.The results demonstrate that charge density and pore size should be matched to construct the optimal ion channel.This collaborative enhancement strategy of permeability and selectivity has significantly improved the output power in osmotic energy generation;compared to the pure graphene oxide membrane,the composite membrane presents almost 20 times improvement.展开更多
A 77-year-old female presented with shortness of breath and tightness of chest was admitted.Her past medical history included hypertension and she has been taking nifedipine regularly.Two years before,she was diagnose...A 77-year-old female presented with shortness of breath and tightness of chest was admitted.Her past medical history included hypertension and she has been taking nifedipine regularly.Two years before,she was diagnosed with pericardial effusion(Figure 1)and had pericardiocentesis drainage.On physical examination,her blood pressure was 151/100 mm-Hg and her pulse rate was 91 beats/min.展开更多
The flowers of ZhaoFen and RouFurong may contain essential oils with natural aromatic ingredients. In the present work, the chemical compositions of essential oil of Paeonia suffruticosa Andrews from the flowers of Zh...The flowers of ZhaoFen and RouFurong may contain essential oils with natural aromatic ingredients. In the present work, the chemical compositions of essential oil of Paeonia suffruticosa Andrews from the flowers of ZhaoFen and RouFurong grown only in China were investigated by GC-MS analysis. The results indicate that there are 27 constituents in ZhaoFen and 29 constituents in RouFurong, which account for 96.04% and 95.90% of the oils of ZhaoFen and RouFurong, respectively. The major components of the essential oils are character-rized by oxygenated terpenols, and their content is, respectively, 85.06% and 83.47%. The essential oil of Paeonia suffruticosa Andrews was reported for the first time on the aerial parts.展开更多
Chrysanthemum Fusarium wilt is a soil-borne disease that causes serious economic losses to the chrysanthemum industry.However,the molecular mechanism underlying the response of chrysanthemum WRKY to Fusarium oxysporum...Chrysanthemum Fusarium wilt is a soil-borne disease that causes serious economic losses to the chrysanthemum industry.However,the molecular mechanism underlying the response of chrysanthemum WRKY to Fusarium oxysporum infection remains largely unknown.In this study,we isolated CmWRKY6–1 from chrysanthemum‘Jinba’and identified it as a transcriptional repressor localized in the nucleus via subcellular localization and transcriptional activation assays.We found that CmWRKY6–1 negatively regulated resistance to F.oxysporum and affected reactive oxygen species(ROS)and salicylic acid(SA)pathways using transgenic experiments and transcriptomic analysis.Moreover,CmWRKY6–1 bound to the W-box element on the CmWRKY15-like promoter and inhibited its expression.Additionally,we observed that CmWRKY15-like silencing in chrysanthemum reduced its resistance to F.oxysporum via transgenic experiments.In conclusion,we revealed the mechanism underlying the CmWRKY6–1–CmWRKY15-like cascade response to F.oxysporum infection in chrysanthemum and demonstrated that CmWRKY6–1 and CmWRKY15-like regulates the immune system.展开更多
The dwarfing rootstocks-mediated high-density apple orchard is becoming the main practice management.Currently,dwarfing rootstocks are widely used worldwide,but their shallow root system and drought sensitivity necess...The dwarfing rootstocks-mediated high-density apple orchard is becoming the main practice management.Currently,dwarfing rootstocks are widely used worldwide,but their shallow root system and drought sensitivity necessitate high irrigation requirements.Here,the root transcriptome and metabolome of dwarfing(M9-T337,a drought-sensitive rootstock)and vigorous rootstocks(Malus sieversii,a drought-tolerant species,is commonly used as a rootstock)showed that a coumarin derivative,4-Methylumbelliferon(4-MU),was found to accumulate significantly in the roots of vigorous rootstock under drought condition.When exogenous 4-MU was applied to the roots of dwarfing rootstock under drought treatment,the plants displayed increased root biomass,higher root-to-shoot ratio,greater photosynthesis,and elevated water use efficiency.In addition,diversity and structure analysis of the rhizosphere soil microbial community demonstrated that 4-MU treatment increased the relative abundance of putatively beneficial bacteria and fungi.Of these,Pseudomonas,Bacillus,Streptomyces,and Chryseolinea bacterial strains and Acremonium,Trichoderma,and Phoma fungal strains known for root growth,or systemic resistance against drought stress,were significantly accumulated in the roots of dwarfing rootstock after 4-MU treatment under drought stress condition.Taken together,we identified a promising compound—4-MU,as a useful tool,to strengthen the drought tolerance of apple dwarfing rootstock.展开更多
At present,GNSS-Acoustic(GNSS-A)combined technology is widely used in positioning for seafloor geodetic stations.Based on Sound Velocity Profiles(SVPs)data,the equal gradient acoustic ray-tracing method is applied in ...At present,GNSS-Acoustic(GNSS-A)combined technology is widely used in positioning for seafloor geodetic stations.Based on Sound Velocity Profiles(SVPs)data,the equal gradient acoustic ray-tracing method is applied in high-precision position inversion.However,because of the discreteness of the SVPs used in the forementioned method,it ignores the continuous variation of sound velocity structure in time domain,which worsens the positioning accuracy.In this study,the time-domain variation of Sound Speed Structure(SSS)has been considered,and the cubic B-spline function is applied to characterize the perturbed sound velocity.Based on the ray-tracing theory,an inversion model of“stepwise iteration&progressive corrections”for both positioning and sound speed information is proposed,which conducts the gradual correction of seafloor geodetic station coordinates and disturbed sound velocity.The practical data was used to test the effectiveness of our method.The results show that the Root Mean Square(RMS)errors of the residual values of the traditional methods without sound velocity correction,based on quadratic polynomial correction and based on cubic B-spline function correction are 1.43 ms,0.44 ms and 0.21 ms,respectively.The inversion model with sound velocity correction can effectively eliminate the systematic error caused by the change of SSS,and significantly improve the positioning accuracy of the seafloor geodetic stations.展开更多
A multiwavelength tunable ring-cavity erbium-doped fiber laser(EDFL)based on a Lyot filter was presented.For the proposed Lyot filter,a comb filter consisting of an EDF-polarization-maintaining fiber(EDF-PMF),a polari...A multiwavelength tunable ring-cavity erbium-doped fiber laser(EDFL)based on a Lyot filter was presented.For the proposed Lyot filter,a comb filter consisting of an EDF-polarization-maintaining fiber(EDF-PMF),a polarization controller(PC),and a circulator with four ports was used to suppress the mode competition.The light transmission direction was guaranteed by the circulator.For the proposed fiber laser,tunable single,dual,triple,quadruple,quintuple,sextuple,and septuple wavelengths were realized.A single-wavelength laser output with an optical signal-to-noise ratio(SNR)of up to30.56 dB was realized,and a tuning range of 1590.54 nm to 1599.54 nm was achieved by tuning the PC.The stability of the single,dual,triple,and quadruple-wavelength center power fluctuations was less than 0.05 dB,0.98 dB,5.07 dB,and7.71 dB respectively.When the laser was operated in the multiwavelength condition,the SNR was more than 20.97 dB.The proposed erbium-doped fiber laser is suitable for fiber-sensing system applications.展开更多
Petroleum-based materials,such as plastic,are characterized by adverse environmental pollution;as a result,researchers have sought alternative degradable plastics that are environmentally friendly,such as polylactic a...Petroleum-based materials,such as plastic,are characterized by adverse environmental pollution;as a result,researchers have sought alternative degradable plastics that are environmentally friendly,such as polylactic acid(PLA).PLA has shown great potential to replace petroleum-based plastics.In this study,seven different samples of unmodified Pueraria lobata root powder(PRP)with different contents(i.e.,0,5,10,15,20,25,and 30 wt%)and three different modified PRPs(i.e.,treated with NaOH,NaOH-KH-550,and Formic)were used to reinforce polylactic acid(PLA)via solution casting process.These prepared PRP/PLA composite films were characterized using SEM,FTIR,UV-visible spectra analysis,TG,DSC,weight loss measurement(wt%),and mechanical measurements.The results showed that the PRP modified with KH-550(PRPK)intensified the interaction in the interface region between the PRP and the PLA matrix,thus increasing the tensile strength(54.5 MPa),elongation at break(2.8%),and Young’s modulus(3310 MPa)of the PRPK/PLA biofilms.Contact angle measurement showed that the PRP treatments contributed to the hydrophobicity of films.The transparency of PRP-10/PLA film atλ_(800)was 11.09%,and its UVA and UVB transmittance were 3.28 and 1.16,respectively.After blending PLA with PRP,the PRP/PLA composite films exhibited excellent biodegradability.In summary,PRPK improved the mechanical properties of PLA and prevented the films from ultraviolet light,suggesting that PRPK-5/PLA film could be used as packaging materials.展开更多
The ocean accounts for approximately 71%of the total area of the Earth.Whether it is studying the shape of the Earth itself through geodesy or the future development of earth system science,strengthening the construct...The ocean accounts for approximately 71%of the total area of the Earth.Whether it is studying the shape of the Earth itself through geodesy or the future development of earth system science,strengthening the construction of ocean geodesy disciplines and innovating ocean geodetic observation technologies have evident theoretical and practical significance.In recent years,the discipline of ocean geodesy in China has been continuously developing and growing,and notable breakthroughs have been made in ocean satellite geodesy and seafloor geodetic observation technology.Research on ocean geodetic observation models and algorithms has also made great progress.展开更多
According to the boundary condition with the zero,negative,or positive velocity,the initial boundary problem for compressible multi-phase flow with the Dirichlet-type boundary condition can be classified into three ca...According to the boundary condition with the zero,negative,or positive velocity,the initial boundary problem for compressible multi-phase flow with the Dirichlet-type boundary condition can be classified into three cases:impermeable problem,inflow problem,or outflow problem.In this paper,we review the recent progress on the existence and nonlinear stability of the stationary solution to the outflow/inflow problems for viscous multi-phase flow.展开更多
目的:系统评价曲伏前列素滴眼液与噻吗洛尔滴眼液治疗中国成人原发性开角型青光眼(POAG)的血流动力学、散光度及细胞因子的变化。方法:检索PubMed,EMbase,Cochrane Library,Web of Science,中国期刊全文数据库(CNKI),中国生物医学文献...目的:系统评价曲伏前列素滴眼液与噻吗洛尔滴眼液治疗中国成人原发性开角型青光眼(POAG)的血流动力学、散光度及细胞因子的变化。方法:检索PubMed,EMbase,Cochrane Library,Web of Science,中国期刊全文数据库(CNKI),中国生物医学文献数据库(CBM),维普数据库及万方数据库2015-01-01/2020-12-31收录的有关曲伏前列素与噻吗洛尔治疗中国成人POAG的随机对照试验(RCTs)和回顾性队列研究。按照纳入与排除标准筛选文献,用Cochrane风险评估工具对RCTs进行质量评价,用NOS量表对回顾性队列研究进行质量评价。采用Review Manager 5.4软件进行Meta分析并生成加权均数差(WMD)为效应量对比曲伏前列素与噻吗洛尔在视网膜中央动脉(CRA)和睫状后短动脉(PCA)的收缩期峰值血流速度(PSV)、舒张末期血流速度(EDV)及血管阻力指数(RI)、散光度、血浆内皮素-1(ET-1)、血清基质金属蛋白酶(MMP)、房水基质金属蛋白酶抑制因子-2(TIMP-2)、血清TIMP-2中的差异。结果:共纳入8项RCTs,4项回顾性队列研究,合计1192例患者。Meta分析结果显示:曲伏前列素组较噻吗洛尔组更能提高CRA和PCA的PSV(WMD=2.40,95CI:2.12~2.68,P<0.00001;WMD=3.76,95%CI:3.30~4.22,P<0.00001)、EDV(WMD=0.81,95%CI:0.70~0.91,P<0.00001;WMD=0.90,95%CI:0.72~1.09,P<0.00001)以及降低CRA和PCA的RI(WMD=-0.07,95%CI:-0.10~-0.04,P<0.00001;WMD=-0.07,95%CI:-0.08~-0.05,P<0.00001);曲伏前列素降低散光度(WMD=-1.34,95%CI:-1.62~-1.06,P<0.00001)效果更优;曲伏前列素较噻吗洛尔更能降低血浆ET-1(WMD=-5.14,95%CI:-7.08~-3.20,P<0.00001)、血清MMP(WMD=-12.48,95%CI:-24.27~-0.69,P=0.04),而对房水TIMP-2(WMD=-1.40,95%CI:-5.51~2.71,P=0.51)、血清TIMP-2(WMD=1.69,95%CI:-30.03~33.41,P=0.92)的影响差异不明显。结论:曲伏前列素治疗POAG较噻吗洛尔在改善血流动力学指标以及降低散光度方面更具优势。展开更多
文摘The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of treatment. How enterprises can make reasonable decisions on their water environment behavior based on the external environment and their own factors is of great significance for scientifically and effectively designing water environment regulation mechanisms. Based on optimal control theory, this study investigates the design of contractual mechanisms for water environmental regulation for small and medium-sized enterprises. The enterprise is regarded as an independent economic entity that can adopt optimal control strategies to maximize its own interests. Based on the participation of multiple subjects including the government, enterprises, and the public, an optimal control strategy model for enterprises under contractual water environmental regulation is constructed using optimal control theory, and a method for calculating the amount of unit pollutant penalties is derived. The water pollutant treatment cost data of a paper company is selected to conduct empirical numerical analysis on the model. The results show that the increase in the probability of government regulation and public participation, as well as the decrease in local government protection for enterprises, can achieve the same regulatory effect while reducing the number of administrative penalties per unit. Finally, the implementation process of contractual water environmental regulation for small and medium-sized enterprises is designed.
文摘The original online version of this article (Zhao, S., Gu, H.B., Xue, L.F., Wang, D.S. and Huang, B. (2024) Contract Mechanism of Water Environment Regu-lation for Small and Medium Sized Enterprises Based on Optimal Control Theory. Journal of Water Resource and Protection, 16, 538-556. https://doi.org/10.4236/jwarp.2024.167030) unfortunately contains a mis-take. The second institution is “China Renewable Energy Engineering Insti-tute, Beijing, China”, not “China Renewable Engineering Institute, Beijing, China”.
基金Natural Science Foundation of Jilin Province,Grant/Award Number:YDZJ202101ZYTS002National Natural Science Foundation of China,Grant/Award Number:52003099+1 种基金Capital Construction Fund of Jilin Province,Grant/Award Number:2021C039‐1Fundamental Research Funds for the Central Universities。
文摘For the porous‐membrane‐based osmotic energy generator,the potential synergistic enhancement mechanism of various key parameters is still controversial,especially because optimizing the trade‐off between permeability and selectivity is still a challenge.Here,to construct a permeability and selectivity synergistically enhanced osmotic energy generator,the twodimensional porous membranes with tunable charge density are prepared by inserting sulfonated polyether sulfone into graphene oxide.Influences of charge density and pore size on the ion transport are explored,and the ionic behaviors in the channel are calculated by numerical simulations.The mechanism of ion transport in the process is studied in depth,and the fundamental principles of energy conversion are revealed.The results demonstrate that charge density and pore size should be matched to construct the optimal ion channel.This collaborative enhancement strategy of permeability and selectivity has significantly improved the output power in osmotic energy generation;compared to the pure graphene oxide membrane,the composite membrane presents almost 20 times improvement.
基金funded by the Tianjin Natural Science Foundation (No. 21JCYBJC01740 and 21JCYBJC01460)the Tianjin Key Medical Discipline (Specialty) Construction Project+1 种基金the Tianjin Key Medical Discipline (Specialty) Construction Project(TJYXZDXK-029A)Science Foundation of The Tianjin Education Commission (No.2023ZD007)
文摘A 77-year-old female presented with shortness of breath and tightness of chest was admitted.Her past medical history included hypertension and she has been taking nifedipine regularly.Two years before,she was diagnosed with pericardial effusion(Figure 1)and had pericardiocentesis drainage.On physical examination,her blood pressure was 151/100 mm-Hg and her pulse rate was 91 beats/min.
文摘The flowers of ZhaoFen and RouFurong may contain essential oils with natural aromatic ingredients. In the present work, the chemical compositions of essential oil of Paeonia suffruticosa Andrews from the flowers of ZhaoFen and RouFurong grown only in China were investigated by GC-MS analysis. The results indicate that there are 27 constituents in ZhaoFen and 29 constituents in RouFurong, which account for 96.04% and 95.90% of the oils of ZhaoFen and RouFurong, respectively. The major components of the essential oils are character-rized by oxygenated terpenols, and their content is, respectively, 85.06% and 83.47%. The essential oil of Paeonia suffruticosa Andrews was reported for the first time on the aerial parts.
基金This research was supported by National Natural Science Foundation of China(32072603)China Agriculture Research System(CARS-23-A18)+1 种基金The JBGS Project of Seed Industry Revitalization in Jiangsu Province[JBGS(2021)094]Jiangsu Agriculture Science and Technology Innovation Fund[CX(22)2033].
文摘Chrysanthemum Fusarium wilt is a soil-borne disease that causes serious economic losses to the chrysanthemum industry.However,the molecular mechanism underlying the response of chrysanthemum WRKY to Fusarium oxysporum infection remains largely unknown.In this study,we isolated CmWRKY6–1 from chrysanthemum‘Jinba’and identified it as a transcriptional repressor localized in the nucleus via subcellular localization and transcriptional activation assays.We found that CmWRKY6–1 negatively regulated resistance to F.oxysporum and affected reactive oxygen species(ROS)and salicylic acid(SA)pathways using transgenic experiments and transcriptomic analysis.Moreover,CmWRKY6–1 bound to the W-box element on the CmWRKY15-like promoter and inhibited its expression.Additionally,we observed that CmWRKY15-like silencing in chrysanthemum reduced its resistance to F.oxysporum via transgenic experiments.In conclusion,we revealed the mechanism underlying the CmWRKY6–1–CmWRKY15-like cascade response to F.oxysporum infection in chrysanthemum and demonstrated that CmWRKY6–1 and CmWRKY15-like regulates the immune system.
基金National Key Research and Development Project(2019YFD1000100)China Postdoctoral Science Foundation(2022 M712612)supported this work.
文摘The dwarfing rootstocks-mediated high-density apple orchard is becoming the main practice management.Currently,dwarfing rootstocks are widely used worldwide,but their shallow root system and drought sensitivity necessitate high irrigation requirements.Here,the root transcriptome and metabolome of dwarfing(M9-T337,a drought-sensitive rootstock)and vigorous rootstocks(Malus sieversii,a drought-tolerant species,is commonly used as a rootstock)showed that a coumarin derivative,4-Methylumbelliferon(4-MU),was found to accumulate significantly in the roots of vigorous rootstock under drought condition.When exogenous 4-MU was applied to the roots of dwarfing rootstock under drought treatment,the plants displayed increased root biomass,higher root-to-shoot ratio,greater photosynthesis,and elevated water use efficiency.In addition,diversity and structure analysis of the rhizosphere soil microbial community demonstrated that 4-MU treatment increased the relative abundance of putatively beneficial bacteria and fungi.Of these,Pseudomonas,Bacillus,Streptomyces,and Chryseolinea bacterial strains and Acremonium,Trichoderma,and Phoma fungal strains known for root growth,or systemic resistance against drought stress,were significantly accumulated in the roots of dwarfing rootstock after 4-MU treatment under drought stress condition.Taken together,we identified a promising compound—4-MU,as a useful tool,to strengthen the drought tolerance of apple dwarfing rootstock.
基金National Natural Science Foundation of China(Nos.41931076,42174020)Laoshan Laboratory(No.LSKJ202205101)State Key Laboratory of Geo-Information Engineering(No.SKLGIE2020-M-1-1)。
文摘At present,GNSS-Acoustic(GNSS-A)combined technology is widely used in positioning for seafloor geodetic stations.Based on Sound Velocity Profiles(SVPs)data,the equal gradient acoustic ray-tracing method is applied in high-precision position inversion.However,because of the discreteness of the SVPs used in the forementioned method,it ignores the continuous variation of sound velocity structure in time domain,which worsens the positioning accuracy.In this study,the time-domain variation of Sound Speed Structure(SSS)has been considered,and the cubic B-spline function is applied to characterize the perturbed sound velocity.Based on the ray-tracing theory,an inversion model of“stepwise iteration&progressive corrections”for both positioning and sound speed information is proposed,which conducts the gradual correction of seafloor geodetic station coordinates and disturbed sound velocity.The practical data was used to test the effectiveness of our method.The results show that the Root Mean Square(RMS)errors of the residual values of the traditional methods without sound velocity correction,based on quadratic polynomial correction and based on cubic B-spline function correction are 1.43 ms,0.44 ms and 0.21 ms,respectively.The inversion model with sound velocity correction can effectively eliminate the systematic error caused by the change of SSS,and significantly improve the positioning accuracy of the seafloor geodetic stations.
基金Beijing Great Wall Scholars Program(Grant No.CIT&TCD20190323)Beijing Youth Talent Support Program(Grant No.Z2019042)the National Natural Science Foundation of China(Grant No.61875237).
文摘A multiwavelength tunable ring-cavity erbium-doped fiber laser(EDFL)based on a Lyot filter was presented.For the proposed Lyot filter,a comb filter consisting of an EDF-polarization-maintaining fiber(EDF-PMF),a polarization controller(PC),and a circulator with four ports was used to suppress the mode competition.The light transmission direction was guaranteed by the circulator.For the proposed fiber laser,tunable single,dual,triple,quadruple,quintuple,sextuple,and septuple wavelengths were realized.A single-wavelength laser output with an optical signal-to-noise ratio(SNR)of up to30.56 dB was realized,and a tuning range of 1590.54 nm to 1599.54 nm was achieved by tuning the PC.The stability of the single,dual,triple,and quadruple-wavelength center power fluctuations was less than 0.05 dB,0.98 dB,5.07 dB,and7.71 dB respectively.When the laser was operated in the multiwavelength condition,the SNR was more than 20.97 dB.The proposed erbium-doped fiber laser is suitable for fiber-sensing system applications.
基金This research was funded by the Xiaohe Talent Project of Zhangjiajie City(No.2022xhrc01)the Research Foundation of Hunan Provincial Education Department(Nos.20A412+1 种基金19C1541)the Natural Science Research Project of Jishou University(No.Jd19005).
文摘Petroleum-based materials,such as plastic,are characterized by adverse environmental pollution;as a result,researchers have sought alternative degradable plastics that are environmentally friendly,such as polylactic acid(PLA).PLA has shown great potential to replace petroleum-based plastics.In this study,seven different samples of unmodified Pueraria lobata root powder(PRP)with different contents(i.e.,0,5,10,15,20,25,and 30 wt%)and three different modified PRPs(i.e.,treated with NaOH,NaOH-KH-550,and Formic)were used to reinforce polylactic acid(PLA)via solution casting process.These prepared PRP/PLA composite films were characterized using SEM,FTIR,UV-visible spectra analysis,TG,DSC,weight loss measurement(wt%),and mechanical measurements.The results showed that the PRP modified with KH-550(PRPK)intensified the interaction in the interface region between the PRP and the PLA matrix,thus increasing the tensile strength(54.5 MPa),elongation at break(2.8%),and Young’s modulus(3310 MPa)of the PRPK/PLA biofilms.Contact angle measurement showed that the PRP treatments contributed to the hydrophobicity of films.The transparency of PRP-10/PLA film atλ_(800)was 11.09%,and its UVA and UVB transmittance were 3.28 and 1.16,respectively.After blending PLA with PRP,the PRP/PLA composite films exhibited excellent biodegradability.In summary,PRPK improved the mechanical properties of PLA and prevented the films from ultraviolet light,suggesting that PRPK-5/PLA film could be used as packaging materials.
基金National Natural Science Foundation of China(No.41931076)Laoshan Laboratory(No.LSKJ202205105)+1 种基金National Key R&D Program of China(No.2020YFB0505802)State Key Laboratory of Geo-information Engineering(No.SKLGIE2020-M-1-1)。
文摘The ocean accounts for approximately 71%of the total area of the Earth.Whether it is studying the shape of the Earth itself through geodesy or the future development of earth system science,strengthening the construction of ocean geodesy disciplines and innovating ocean geodetic observation technologies have evident theoretical and practical significance.In recent years,the discipline of ocean geodesy in China has been continuously developing and growing,and notable breakthroughs have been made in ocean satellite geodesy and seafloor geodetic observation technology.Research on ocean geodetic observation models and algorithms has also made great progress.
基金supported by the National Natural Science Foundation of China(nos.11931010,11871047)the key research project of Academy for Multidisciplinary Studies,Capital Normal University,and by the Capacity Building for Sci-Tech Innovation-Fundamental Scientific Research Funds(no.007/20530290068).
文摘According to the boundary condition with the zero,negative,or positive velocity,the initial boundary problem for compressible multi-phase flow with the Dirichlet-type boundary condition can be classified into three cases:impermeable problem,inflow problem,or outflow problem.In this paper,we review the recent progress on the existence and nonlinear stability of the stationary solution to the outflow/inflow problems for viscous multi-phase flow.
