Two field experiments were conducted to study the effects of 6-year plastic film mulching on bacterial diversity, organic matter of paddy soil and water use efficiency on different soils with great environmental varia...Two field experiments were conducted to study the effects of 6-year plastic film mulching on bacterial diversity, organic matter of paddy soil and water use efficiency on different soils with great environmental variabilities in Zhejiang Province, China, under non-flooding condition. The experiment started in 2001 at two sites with one rice crop annually. Three treatments included plastic film mulching with no flooding (PM), no plastic film mulching and no flooding (UM), and traditional flooding management (TF). Soil samples were collected and analyzed for bacterial diversity by DGGE and organic matter content, and water use efficiency (WUE) was calculated. The results showed that PM treatment favored the development of a more total bacterial community compared with TF management, the total number of bands was 33.3, 31.7 at tiller stage and heading stage (p < 0.05*). Hence, organic matter content was decreased by 36.7% and 51.4% under PM at two sites. PM also produced similar rice grain yield as TF at Duntou site and Dingqiao site, the average was 7924 kg?ha?1 and 7015 kg?ha?1 for PM and 8150 kg?ha?1 and 6990 kg?ha?1 for TF, respectively. Compared to TF, WUE and irrigation water use efficiency were increased significantly by 70.2% - 80.4% and 273.7% - 1300.0% for PM. It is essential to develop the water-saving agriculture.展开更多
In this study,rice straw(RS) was liquefied by ethylene carbonate(EC) using H_2SO_4 as a catalyst.The effects of various process conditions on the liquefaction characteristics were investigated by FT-IR and residue con...In this study,rice straw(RS) was liquefied by ethylene carbonate(EC) using H_2SO_4 as a catalyst.The effects of various process conditions on the liquefaction characteristics were investigated by FT-IR and residue content analysis.The results show that cellulose and lignin are degraded during the liquefaction process and large amounts of groups are generated.In addition,it is difficult to effectively liquefy RS by using EC alone as the liquefying agent without other additives.Compared to water addition on liquefaction,the residue content can be significantly reduced up to 30% by adding H_2O_2.It has also been proved that the liquor ratio(RS/EC,w/v) of 1∶5 with H_2O_2 as an additive at 145℃ for liquefaction time of 60 min in the presence of H_2SO_4 can accelerate the liquefaction process and high liquefaction yield can be obtained.展开更多
Considering the aim of carbon neutrality and reducing plastic pollution,lightweight porous materials with good thermal insulation and mechanical robustness derived from renewable resources are in high demand.Cellulose...Considering the aim of carbon neutrality and reducing plastic pollution,lightweight porous materials with good thermal insulation and mechanical robustness derived from renewable resources are in high demand.Cellulose-based pulp foams(PFs)offer considerable potential applications in many fields;however,the cost-effective manufacturing of PFs with satisfactory properties remains challenging.Herein,we demonstrate a simple and low-cost strategy to prepare a novel pulp/natural rubber(PNR)foam by combining wood pulp fiber and natural rubber latex through wet foaming and oven drying,eliminating traditional freeze-drying and solvent exchange processes.The obtained PNR foam exhibited high porosity(98.4%-99.1%),low density(14.1–24.0 mg/cm^(3)),and excellent water stability(without disintegration under magnetic stirring for 14 days).Moreover,montmorillonite(MMT)was easily incorporated into the PNR during the preparation process,improving the mechanical strength and heat insulation of the obtained PNRMMT foam.The optimized PNR-MMT foam could be compressed more than ten times without losing its resilience,exhibiting a compressive strength of 2.7 MPa at 80%strain,five times higher than that of pristine PF.Moreover,the PNR-MMT foam exhibited excellent flame retardant,good“spill”oil absorption,and good antibacterial properties towards Escherichia coli and Bacillus subtilis.Overall,this study provides a facile,sustainable,and low-cost route for manufacturing PNR-MMT foams with high resilience,good thermal insulation,excellent flame retardancy,and strong antibacterial properties,thus highlighting their usage potential in a broad range of applications.展开更多
We propose and demonstrate a polarization diversity two-dimensional grating coupler based on the lithium niobate on insulator platform, for the first time, to the best of our knowledge. The optimization design, perfor...We propose and demonstrate a polarization diversity two-dimensional grating coupler based on the lithium niobate on insulator platform, for the first time, to the best of our knowledge. The optimization design, performance characteristics,and fabrication tolerance of the two-dimensional grating coupler are thoroughly analyzed utilizing the three-dimensional finite-difference time-domain method. Experimentally,-7.2 d B of coupling efficiency is achieved with 1 d B bandwidth of64 nm. The polarization-dependent loss is about 0.4 d B around 1550 nm. Our work provides new polarization multiplexing approaches for the lithium niobate on insulator platform, paving the way for critical applications such as high-speed polarization multiplexed electro-optical modulators.展开更多
文摘Two field experiments were conducted to study the effects of 6-year plastic film mulching on bacterial diversity, organic matter of paddy soil and water use efficiency on different soils with great environmental variabilities in Zhejiang Province, China, under non-flooding condition. The experiment started in 2001 at two sites with one rice crop annually. Three treatments included plastic film mulching with no flooding (PM), no plastic film mulching and no flooding (UM), and traditional flooding management (TF). Soil samples were collected and analyzed for bacterial diversity by DGGE and organic matter content, and water use efficiency (WUE) was calculated. The results showed that PM treatment favored the development of a more total bacterial community compared with TF management, the total number of bands was 33.3, 31.7 at tiller stage and heading stage (p < 0.05*). Hence, organic matter content was decreased by 36.7% and 51.4% under PM at two sites. PM also produced similar rice grain yield as TF at Duntou site and Dingqiao site, the average was 7924 kg?ha?1 and 7015 kg?ha?1 for PM and 8150 kg?ha?1 and 6990 kg?ha?1 for TF, respectively. Compared to TF, WUE and irrigation water use efficiency were increased significantly by 70.2% - 80.4% and 273.7% - 1300.0% for PM. It is essential to develop the water-saving agriculture.
基金supported by the National Natural Science Foundation of China(31270633)State Key Laboratory of Pulp and Paper Engineering(201512)Hangzhou Qianjiang Distinguished Experts Programme of China
文摘In this study,rice straw(RS) was liquefied by ethylene carbonate(EC) using H_2SO_4 as a catalyst.The effects of various process conditions on the liquefaction characteristics were investigated by FT-IR and residue content analysis.The results show that cellulose and lignin are degraded during the liquefaction process and large amounts of groups are generated.In addition,it is difficult to effectively liquefy RS by using EC alone as the liquefying agent without other additives.Compared to water addition on liquefaction,the residue content can be significantly reduced up to 30% by adding H_2O_2.It has also been proved that the liquor ratio(RS/EC,w/v) of 1∶5 with H_2O_2 as an additive at 145℃ for liquefaction time of 60 min in the presence of H_2SO_4 can accelerate the liquefaction process and high liquefaction yield can be obtained.
基金supported by the National Natural Science Foundation of China(Nos.U22A20423,22208358)the International Partnership Program of the Chinese Academy of Sciences(No.323GJHZ2023019MI)+1 种基金as well as Qingdao Science and Technology Demonstration Projects(Nos.24–1–8-smjk-18-nsh,24–1–8-cspz-6-nsh)support from the China Scholarship Council(Nos.202207960008,202307960001).
文摘Considering the aim of carbon neutrality and reducing plastic pollution,lightweight porous materials with good thermal insulation and mechanical robustness derived from renewable resources are in high demand.Cellulose-based pulp foams(PFs)offer considerable potential applications in many fields;however,the cost-effective manufacturing of PFs with satisfactory properties remains challenging.Herein,we demonstrate a simple and low-cost strategy to prepare a novel pulp/natural rubber(PNR)foam by combining wood pulp fiber and natural rubber latex through wet foaming and oven drying,eliminating traditional freeze-drying and solvent exchange processes.The obtained PNR foam exhibited high porosity(98.4%-99.1%),low density(14.1–24.0 mg/cm^(3)),and excellent water stability(without disintegration under magnetic stirring for 14 days).Moreover,montmorillonite(MMT)was easily incorporated into the PNR during the preparation process,improving the mechanical strength and heat insulation of the obtained PNRMMT foam.The optimized PNR-MMT foam could be compressed more than ten times without losing its resilience,exhibiting a compressive strength of 2.7 MPa at 80%strain,five times higher than that of pristine PF.Moreover,the PNR-MMT foam exhibited excellent flame retardant,good“spill”oil absorption,and good antibacterial properties towards Escherichia coli and Bacillus subtilis.Overall,this study provides a facile,sustainable,and low-cost route for manufacturing PNR-MMT foams with high resilience,good thermal insulation,excellent flame retardancy,and strong antibacterial properties,thus highlighting their usage potential in a broad range of applications.
基金supported in part by the National Key R&D Program of China(Nos.2019YFB1803900 and 2019YFA0705000)the National Natural Science Foundation of China(Nos.11690031,11761131001,and 11904061)+6 种基金the Key R&D Program of Guangdong Province(No.2018B030329001)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01X121)the Project of Key Laboratory of Radar Imaging and Microwave Photonics,Ministry of Education(No.RIMP2019003)the Innovation Fund of WNLO(No.2018WNLOKF010),the Guangzhou Science and Technology Program(No.201707010096)the Guangxi Youth and Middle Aged Ability Promotion Project(No.2019KY0126)the BaGui Scholar Programof Guangxi Province(No.02304002022C)the China Postdoctoral Science Foundation(No.2020M673554XB).
文摘We propose and demonstrate a polarization diversity two-dimensional grating coupler based on the lithium niobate on insulator platform, for the first time, to the best of our knowledge. The optimization design, performance characteristics,and fabrication tolerance of the two-dimensional grating coupler are thoroughly analyzed utilizing the three-dimensional finite-difference time-domain method. Experimentally,-7.2 d B of coupling efficiency is achieved with 1 d B bandwidth of64 nm. The polarization-dependent loss is about 0.4 d B around 1550 nm. Our work provides new polarization multiplexing approaches for the lithium niobate on insulator platform, paving the way for critical applications such as high-speed polarization multiplexed electro-optical modulators.
