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Effects of vegetation near-soil-surface factors on runoff and sediment reduction in typical grasslands on the Loess Plateau,China

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Journal of Arid Land 2022年第3期14卷 325-340页

作者： LI Panpan WANG Bing YANG Yanfen LIU Guobin State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYangling 712100China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China

Vegetation near-soil-surface factors can protect topsoil from erosion,however,their contributions to the reduction of soil erosion,especially under natural rainfall events,have not been systematically recognized.This study was performed to quantify the effects of near-soil-surface factors on runoff and sediment under natural rainfall events on grasslands dominated by Bothriochloa ischaemum(Linn.)Keng(BI grassland)and Artemisia gmelinii Thunb.(AG grassland)in two typical watersheds on the Loess Plateau,China in 2018.By successive removal of the plant canopy,litter,biological soil crusts(BSCs)and plant roots,we established five treatments including plant roots,plant roots+BSCs,plant roots+BSCs+litter,intact grassland and bare land in each grassland type.In total,twenty runoff plots(5 m×3 m)with similar slopes and aspects were constructed in the two types of grasslands.Results showed that plant canopy,litter and roots reduced runoff,while BSCs,which swelled in the presence of water,increased runoff.In contrast,all of these factors reduced sediment yield.In addition,the reductions in runoff and sediment yield increased with I30(maximum 30-min rainfall intensity)for each vegetation near-soil-surface factor except for BSCs.Among these factors,plant canopy had the largest contribution to runoff reduction,accounting for 48.8% and 39.9% in the BI and AG grasslands,respectively.The contributions of these vegetation near-soil-surface factors to sediment yield reduction were similar(21.3%-29.9%)in the two types of grasslands except for BSCs in the AG grassland(10.3%).The total reduction in runoff in the BI grassland(70.8%)was greater than that in the AG grassland(53.1%),while the reduction in sediment yield was almost the same in both grasslands(97.4%and 96.7%).In conclusion,according to the effects of different vegetation near-soil-surface factors on runoff and sediment production,our results may provide more complete insight and scientific basis into the effects of various vegetation related factors in controlling soil ero

关键词： vegetation near-soil-surface factor grassland arid and semi-arid soil erosion Loess Plateau

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Production,purific tion,characterization and application of two novel endoglucanases from buffalo rumen metagenome

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Journal of Animal Science and Biotechnology 2023年第3期14卷 1235-1251页

作者： Zhenxiang Meng Chengjian yang Jing Leng Weiyun Zhu yanfen Cheng Laboratory of Gastrointestinal Microbiology National Center for International Research On Animal Gut NutritionNanjing Agricultural UniversityNanjing 210095China Buffalo Research Institute Chinese Academy of AgriculturalNanning 530000China Key Laboratory of Animal Nutrition and Feed Science of Yunnan Province Yunnan Agricultural UniversityKunming 650000China

Background Lignocellulose biomass is the most abundant and renewable material in nature.The objectives of this study were to characterize two endoglucanases Trep Cel3 and Trep Cel4,and determine the effect of the combination of them(1.2 mg Trep Cel3,0.8 mg Trep Cel4)on in vitro rumen fermentation characteristics.In this study,three nature lignocellulosic substrates(rice straw,RS;wheat straw,WS;leymus chinensis,LC)were evaluated for their in vitro digestibility,gas,NH3-N and volatile fatty acid(VFA)production,and microbial protein(MCP)synthesis by adding enzymatic combination.Methods Two endoglucanases’genes were successfully expressed in Escherichia coli(E.coli)BL21(DE3),and enzymatic characteristics were further characterized.The combination of Trep Cel3 and Trep Cel4 was incubated with lignocellulosic substrates to evaluate its hydrolysis ability.Results The maximum enzymatic activity of Trep Cel3 was determined at p H 5.0 and 40℃,while Trep Cel4 was at p H 6.0 and 50℃.They were stable over the temperature range of 30 to 60℃,and active within the p H range of 4.0 to 9.0.The Trep Cel3 and Trep Cel4 had the highest activity in lichenan 436.9±8.30 and 377.6±6.80 U/mg,respectively.The combination of Trep Cel3 and Trep Cel4 exhibited the highest efficiency at the ratio of 60:40.Compared to maximum hydrolysis of Trep Cel3 or Trep Cel4 separately,this combination was shown to have a superior ability to maximize the saccharification yield from lignocellulosic substrates up to 188.4%for RS,236.7%for wheat straw WS,222.4%for LC and 131.1%for sugar beet pulp(SBP).Supplemental this combination enhanced the dry matter digestion(DMD),gas,NH3-N and VFA production,and MCP synthesis during in vitro rumen fermentation.Conclusions The Trep Cel3 and Trep Cel4 exhibited the synergistic relationship(60:40)and significantly increased the saccharification yield of lignocellulosic substrates.The combination of them stimulated in vitro rumen fermentation of lignocellulosic substrates.This combination has the potential to be a feed addit

关键词： Endoglucanase In vitro Lignocellulosic substrates Rumen fermentation

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Targeted Catalytic Cracking to Olefins(TCO):Reaction Mechanism,Production Scheme,and Process Perspectives

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Engineering 2023年第11期30卷 100-109页

作者： Youhao Xu yanfen Zuo Wenjie yang Xingtian Shu Wei Chen Anmin Zheng Research Institute of Petroleum Processing SinopecBeijing 100083China Economics and Development Research Institute SinopecBeijing 100029China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics National Center for Magnetic Resonance in WuhanKey Laboratory of Magnetic Resonance in Biological SystemsWuhan Institute of Physics and MathematicsInnovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China

Light olefins are important organic building blocks in the chemicals industry.The main low-carbon olefin production methods,such as catalytic cracking and steam cracking,have considerable room for improvement in their utilization of hydrocarbons.This review provides a thorough overview of recent studies on catalytic cracking,steam cracking,and the conversion of crude oil processes.To maximize the production of light olefins and reduce carbon emissions,the perceived benefits of various technologies are examined.Taking olefin generation and conversion as a link to expand upstream and downstream processes,a targeted catalytic cracking to olefins(TCO)process is proposed to meet current demands for the transformation of oil refining into chemical production.The main innovations of this process include a multiple feedstock supply,the development of medium-sized catalysts,and a diameter-transformed fluidizedbed reactor with different feeding schemes.In combination with other chemical processes,TCO is expected to play a critical role in enabling petroleum refining and chemical processes to achieve low carbon dioxide emissions.

关键词： Light olefins Steam cracking Catalytic cracking TCO process Oil processing revolution

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Characterization of a novel bifunctional enzyme from buffalo rumen metagenome and its effect on in vitro ruminal fermentation and microbial community composition

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Animal Nutrition 2023年第2期13卷 137-149页

作者： Zhenxiang Meng Jing Ma Zhanying Sun Chengjian yang Jing Leng Weiyun Zhu yanfen Cheng Laboratory of Gastrointestinal Microbiology National Center for International Research on Animal Gut NutritionNanjing Agricultural UniversityNanjing 210095China State Key Laboratory of Grassland Agro-Ecosystems Center for Grassland MicrobiomeCollege of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730000China Buffalo Research Institute Chinese Academy of AgriculturalNanning 530000China Key Laboratory of Animal Nutrition and Feed Science of Yunnan Province Yunnan Agricultural UniversityKunming 650000China

To efficiently use lignocellulosic materials in ruminants,it is crucial to explore effective enzymes,especially bifunctional enzymes.In this study,a novel stable bifunctional cellulase-xylanase protein from buffalo rumen metagenome was expressed and characterized,CelXyn2.The enzyme displayed optimal activity at pH 6.0 and 45℃.The residual endoglucanase and xylanase activities were 90.6%and 86.4%after a 60-min pre-incubation at 55℃.Hydrolysis of rice straw,wheat straw,sheepgrass and sugar beet pulp by CelXyn2 showed its ability to degrade both cellulose and hemicellulose polymers.Treatment with CelXyn2 improved the hydrolysis of agricultural residues with an evident increase in production of total gas,lactate and volatile fatty acids.The results of 16S rRNA and real-time PCR showed that the effect on in vitro ruminal microbial community depended on fermenta-tion substrates.This study demonstrated that CelXyn2 could strengthen lignocellulose hydrolysis and in vitro ruminal fermentation.These characteristics of CelXyn2 distinguish it as a promising candidate for agricultural application.

关键词： Bifunctional enzyme In vitro ruminal fermentation Lignocellulose Microbial communit

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Purification and Characterization of a Nonylphenol （NP）-degrading Enzyme from Bacillus cereus.Frankland

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Chinese Journal of Chemical Engineering 2011年第4期19卷 644-648页

作者： yang Ge ZHANG Ying BAI yanfen College of Textiles Tianjin Polytechnic University Tianjin 300160 China Key Lab of Biogeology and Environmental Geology of Ministry of Education China University of Geosciences Wuhan 430074 China

An extracellular NP-degrading enzyme secreted by Bacillus cereus.Frankland was purified to homogeneity by a combination of ammonium sulfate precipitation,Phenyl-Sepharose hydrophobic-interaction chromatography and DEAE anion-exchange chromatography.On SDS(sodium dodecyl sulfate)-polyacrylamide gel electrophoresis analysis,the purified enzyme showed a relative molecular mass of 58.3 kDa.The depolymerzation of subunits was accompanied with the loss of NP-degrading enzyme activity,and removing denaturing factors by dialysis could restore the dimer structure and enzymatic activity.The enzyme had an isoelectric point of 5.5 and an optimal temperature of 60℃,and was the most active at pH 6.0.The enzymatic activity was stable at pH 4-8 and inhibited by Cu2+.TenN-terminal amino acids were determined to be ASVNSIKIGY,demonstrating that the purified enzyme was a novel one.The hydrolysis pattern of the purified enzyme indicated that the NP-degrading enzyme was an endo NP-degrading enzyme.The extraordinary thermo-stability provided the enzyme with a good prospect to be used as a new tool for clean-production process for textile industry.

关键词：层析纯化降解酶 NP 芽孢杆菌壬基酚十二烷基硫酸钠表征蜡样芽胞杆菌

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Make U-Net Greater: An Easy-to-Embed Approach to Improve Segmentation Performance Using Hypergraph

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Computer Systems Science & Engineering 2022年第7期42卷 319-333页

作者： Jing Peng Jingfu yang Chaoyang Xia Xiaojie Li yanfen Guo Ying Fu Xinlai Chen Zhe Cui Chengdu Institute of Computer Application University of Chinese Academy of SciencesChengdu610041China School of Computer Science Chengdu University of Information TechnologyChengdu610225China University of Chinese Academy of Sciences Beijing100049China Department of Experimental Rheumatology Nijmegen6525GANetherlands

semantics information while maintaining spatial detail con-texts.Long-range context information plays a crucial role in this scenario.How-ever,the traditional convolution kernel only provides the local and small size of the receptiveﬁeld.To address the problem,we propose a plug-and-play module aggregating both local and global information(aka LGIA module)to capture the high-order relationship between nodes that are far apart.We incorporate both local and global correlations into hypergraph which is able to capture high-order rela-tionships between nodes via the concept of a hyperedge connecting a subset of nodes.The local correlation considers neighborhood nodes that are spatially adja-cent and similar in the same CNN feature maps of magnetic resonance(MR)image;and the global correlation is searched from a batch of CNN feature maps of MR images in feature space.The inﬂuence of these two correlations on seman-tic segmentation is complementary.We validated our LGIA module on various CNN segmentation models with the cardiac MR images dataset.Experimental results demonstrate that our approach outperformed several baseline models.

关键词： Convolutional neural network semantic segmentation hypergraph neural network LGIA module

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Green and efficient degradation of cefoperazone sodium by Bi_(4)O_(5)Br_(2) leading to the production of non-toxic products:Performance and degradation pathway

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Journal of Environmental Sciences 2021年第2期33卷 203-215页

作者： Yingying Chen Ruiping Li Yan Gu Hailin Tian Yingping Huang Junsong Chen yanfen Fang Changying yang College of Biology and Pharmacy China Three Gorges UniversityYichang443002China College of Hydraulic and Enuironmental Engineering China Three Gorges UniversityYichang443002China Engineering Research Center of Eco-environment in Three Gorges Reservoir Region Ministry of EducationChina Three Gorges UniversityYichang443002China

Photocatalytic process represents a promising approach to overcome the pollution challenge associated with the antibiotics-containing wastewater.This study provides a green,efficient and novel approach to remove cephalosporins,particularly cefoperazone sodium(CFP).Bi_(4)O_(5)Br_(2) was chosen for the first time to systematically study its degradation for CFP,including the analysis of material structure,degradation performance,the structure and toxicity of the transformation products,etc.The degradation rate results indicated that Bi_(4)O_(5)Br_(2) had an excellent catalytic activity leading to 78%CFP removal compared with the pure BiOBr(38%)within 120 min of visible light irradiation.In addition,the Bi_(4)O_(5)Br_(2) presents high stability and good organic carbon removal efficiency.The effects of the solution p H(3.12-8.75)on catalytic activity revealed that CFP was mainly photocatalyzed under acidic conditions and hydrolyzed under alkaline conditions.Combined with active species and degradation product identification,the photocatalytic degradation pathways of CFP by Bi_(4)O_(5)Br_(2) was proposed,including hydrolysis,oxidation,reduction and decarboxylation.Most importantly,the identified products were all hydrolysis rather than oxidation byproducts transformed from the intermediate ofβ-lactam bond cleavage in CFP molecule,quite different from the mostly previous studies.Furthermore,the final products were demonstrated to be less toxic through the toxicity analysis.Overall,this study illustrates the detailed mechanism of CFP degradation by Bi_(4)O_(5)Br_(2) and confirms Bi_(4)O_(5)Br_(2) to be a promising material for the photodegradation of CFP.

关键词： Bi_(4)O_(5)Br_(2) Cefoperazone sodium Photocatalytic activity Degradation products

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Oxidation behavior of ferritic/martensitic steels in flowing supercritical water

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Journal of Materials Science & Technology 2021年第5期64卷 114-125页

作者： Quanqiang Shi Wei Yan yanfen Li Naiqiang Zhang Yiyin Shan Ke yang Hiroaki Abe Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Laboratory of Condition Monitoring and Control for Power Plant Equipment of Ministry of Education North China Electric Power UniversityBeijing 102206China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Engineering The University of TokyoTokaiIbaraki319-1188Japan

The oxidation behavior of two Ferritic/Martensitic(F/M)steels including novel SIMP steel and commercial P91 steel were investigated by exposure to flowing deaerated supercritical water(SCW)at 700℃for up to 1000 h.The kinetic weight gain curves follow parabolic and near-cubic rate equations for SIMP and P91 steels,respectively.X-Ray Diffraction analysis showed the presence of magnetite and a spinel phase in flowing SCW for both steels.The morphology and structure of the oxide scales formed on these two steels were analyzed.The relationship between the microstructure and oxidation behavior and the reason that SIMP steel showed better oxidation resistance than P91 steel were discussed.

关键词： Ferritic/martensitic steel Supercritical water Oxidation Oxide scale SIMP steel

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On Laves phase in a 9Cr3W3CoB martensitic heat resistant steel when aged at high temperatures

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Journal of Materials Science & Technology 2021年第26期85卷 129-140页

作者： Ye Liang Wei Yan Xianbo Shi yanfen Li Quanqiang Shi Wei Wang Yiyin Shan Ke yang Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

9Cr3W3 CoB steels are developed to serve at the temperature range of 620-650℃,and have been recognized as the most promising martensitic heat-resistant steels for supercritical power plants.Due to the high W and Co contents,the Fe_(2)W Laves phase in such 9Cr3W3 CoB steel possesses some specialties in thermodynamics.In the present research,it was found that even when aged at 800℃in the 9Cr3W3 CoB steel,instead of dissolving,Laves phase formed after 50 h and kept on increasing in size and number density until 1000 h,indicating that the Laves phase was marching for the thermodynamic equilibrium during aging.In this thermodynamic process,the W-rich M_(3)B_(2)borides in as-received steel and M23C6 carbides were revealed to dissolve,supporting the growth of Laves phase.SEM investigation indicates that Laves phase tended to form clusters,and finally grow as a unit bulk Laves phase with an irregular shape.Besides,Laves phase nucleated next to M23C6 carbides and enwrapped them inside at 800℃.In addition,the growth processes of Laves phase and M23C6 carbides were a competitive procedure,the coarsening of M23C6 carbides was prior to the growth of Laves phase at 750℃while the growth of Laves phase was prior to the coarsening of M23C6 carbides at 800℃.

关键词： 9Cr3W3Co steel Aging Laves phase Cobalt M23C6 carbides

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Antimicrobial power of biosynthesized Ag nanoparticles using refined Ginkgo biloba leaf extracts

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Frontiers of Materials Science 2022年第2期16卷 109-118页

作者： Wenbo ZHUANG Dafeng HU Xudong ZHANG Kai XIONG Xiao DING Jian LU Yong MAO Peng yang Chao LIU yanfen WAN National Center for International Research on Photoelectric and Energy Materials Advanced Computing CenterMaterials Genome InstituteSchool of Materials and EnergyYunnan UniversityKunming 650091China Kunming Institute of Botany Chinese Academy of SciencesKunming 650201China Department of Nuclear Medicine Yunnan Cancer Hospital&The Third Affiliated Hospital of Kunming Medical UniversityKunming 650118China

Silver nanoparticles(Ag NPs),relative to existing antibacterial agents,are more effective,less toxic and more economical,and have shown enormous potential for the nanomedicine application.In this work,we report a‘green’method for the rapid and efficient synthesis of Ag NPs using Ginkgo biloba extracts as reducing agent and capping agent.The properties of Ag NPs against fungi and bacteria were investigated.The results showed that the Ginkgo biloba extracts are crucial for the preparation of uniform and monodispersed Ag NPs.The prepared Ag NPs exhibited remarkable antibacterial activities.The minimum inhibitory concentrations of Ag NPs for Escherichia coli and Pseudomonas aeruginosa were 0.044 and 0.088μg·mL−1,respectively.Moreover,Ag NPs exhibited excellent bactericidal performance against MDR-Pseudomonas aeruginosa.It was found that the effect of the antibacterial activity of Ag NPs on Escherichia coli and Staphylococcus aureus was tightly related to the reactive oxygen species accumulation.This research provides guidelines for the efficient green synthesis of Ag NPs and its antibacterial applications.

关键词： Ginkgo biloba extract silver nanoparticle green synthesis antibacterial application

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