期刊文献+
共找到17,358篇文章
< 1 2 250 >
每页显示 20 50 100
Atom substitution of the solid-state electrolyte Li_(10)GeP_(2)S_(12)for stabilized all-solid-state lithium metal batteries 被引量:1
1
作者 Zijing Wan Xiaozhen Chen +3 位作者 Ziqi Zhou Xiaoliang Zhong Xiaobing Luo Dongwei Xu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期28-38,I0002,共12页
Solid-state electrolyte Li_(10)GeP_(2)S_(12)(LGPS)has a high lithium ion conductivity of 12 mS cm^(-1)at room temperature,but its inferior chemical stability against lithium metal anode impedes its practical applicati... Solid-state electrolyte Li_(10)GeP_(2)S_(12)(LGPS)has a high lithium ion conductivity of 12 mS cm^(-1)at room temperature,but its inferior chemical stability against lithium metal anode impedes its practical application.Among all solutions,Ge atom substitution of the solid-state electrolyte LGPS stands out as the most promising solution to this interface problem.A systematic screening framework for Ge atom substitution including ionic conductivity,thermodynamic stability,electronic and mechanical properties is utilized to solve it.For fast screening,an enhanced model Dop Net FC using chemical formulas for the dataset is adopted to predict ionic conductivity.Finally,Li_(10)SrP_(2)S_(12)(LSrPS)is screened out,which has high lithium ion conductivity(12.58 mS cm^(-1)).In addition,an enhanced migration of lithium ion across the LSr PS/Li interface is found.Meanwhile,compared to the LGPS/Li interface,LSrPS/Li interface exhibits a larger Schottky barrier(0.134 eV),smaller electron transfer region(3.103?),and enhanced ability to block additional electrons,all of which contribute to the stabilized interface.The applied theoretical atom substitution screening framework with the aid of machine learning can be extended to rapid determination of modified specific material schemes. 展开更多
关键词 Atom substitution Solid-state electrolyte Machine learning Stabilized interface
下载PDF
Manure substitution improves maize yield by promoting soil fertility and mediating the microbial community in lime concretion black soil 被引量:1
2
作者 Minghui Cao Yan Duan +6 位作者 Minghao Li Caiguo Tang Wenjie Kan Jiangye Li Huilan Zhang Wenling Zhong Lifang Wu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第2期698-710,共13页
Synthetic nitrogen(N)fertilizer has made a great contribution to the improvement of soil fertility and productivity,but excessive application of synthetic N fertilizer may cause agroecosystem risks,such as soil acidif... Synthetic nitrogen(N)fertilizer has made a great contribution to the improvement of soil fertility and productivity,but excessive application of synthetic N fertilizer may cause agroecosystem risks,such as soil acidification,groundwater contamination and biodiversity reduction.Meanwhile,organic substitution has received increasing attention for its ecologically and environmentally friendly and productivity benefits.However,the linkages between manure substitution,crop yield and the underlying microbial mechanisms remain uncertain.To bridge this gap,a three-year field experiment was conducted with five fertilization regimes:i)Control,non-fertilization;CF,conventional synthetic fertilizer application;CF_(1/2)M_(1/2),1/2 N input via synthetic fertilizer and 1/2 N input via manure;CF_(1/4)M_(3/4),1/4 N input synthetic fertilizer and 3/4 N input via manure;M,manure application.All fertilization treatments were designed to have equal N input.Our results showed that all manure substituted treatments achieved high soil fertility indexes(SFI)and productivities by increasing the soil organic carbon(SOC),total N(TN)and available phosphorus(AP)concentrations,and by altering the bacterial community diversity and composition compared with CF.SOC,AP,and the soil C:N ratio were mainly responsible for microbial community variations.The co-occurrence network revealed that SOC and AP had strong positive associations with Rhodospirillales and Burkholderiales,while TN and C:N ratio had positive and negative associations with Micromonosporaceae,respectively.These specific taxa are implicated in soil macroelement turnover.Random Forest analysis predicted that both biotic(bacterial composition and Micromonosporaceae)and abiotic(AP,SOC,SFI,and TN)factors had significant effects on crop yield.The present work strengthens our understanding of the effects of manure substitution on crop yield and provides theoretical support for optimizing fertilization strategies. 展开更多
关键词 FERTILIZATION manure substitution soil fertility maize yield bacterial community
下载PDF
Synthesis and Modulation of Low-Dimensional Transition Metal Chalcogenide Materials via Atomic Substitution 被引量:1
3
作者 Xuan Wang Akang Chen +3 位作者 XinLei Wu Jiatao Zhang Jichen Dong Leining Zhang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第9期49-94,共46页
In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterpart... In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterparts.The controllable synthesis and manipulation of these materials are crucial for tailoring their properties and unlocking their full potential in various applications.In this context,the atomic substitution method has emerged as a favorable approach.It involves the replacement of specific atoms within TMC structures with other elements and possesses the capability to regulate the compositions finely,crystal structures,and inherent properties of the resulting materials.In this review,we present a comprehensive overview on various strategies of atomic substitution employed in the synthesis of zero-dimensional,one-dimensional and two-dimensional TMC materials.The effects of substituting elements,substitution ratios,and substitution positions on the structures and morphologies of resulting material are discussed.The enhanced electrocatalytic performance and photovoltaic properties of the obtained materials are also provided,emphasizing the role of atomic substitution in achieving these advancements.Finally,challenges and future prospects in the field of atomic substitution for fabricating low-dimensional TMC materials are summarized. 展开更多
关键词 Transition metal chalcogenides Atomic substitution Ion exchange Low-dimensional materials Controllable synthesis
下载PDF
Effect of Rare-Earth Element Substitution in Superconducting R_(3)Ni_(2)O_(7) under Pressure
4
作者 Zhiming Pan Chen Lu +1 位作者 Fan Yang Congjun Wu 《Chinese Physics Letters》 SCIE EI CAS CSCD 2024年第8期77-81,共5页
Recently,high temperature(T_(c)≈80 K)superconductivity(SC)has been discovered in La_(3)Ni_(2)O_(7)(LNO)under pressure.This raises the question of whether the superconducting transition temperature T_(c) could be furt... Recently,high temperature(T_(c)≈80 K)superconductivity(SC)has been discovered in La_(3)Ni_(2)O_(7)(LNO)under pressure.This raises the question of whether the superconducting transition temperature T_(c) could be further enhanced under suitable conditions.One possible route for achieving higher T_(c) is element substitution.Similar SC could appear in the Fmmm phase of rare-earth(RE)R_(3)Ni_(2)O_(7)(RNO,R=RE element)material series under suitable pressure.The electronic properties in the RNO materials are dominated by the Ni 3d orbitals in the bilayer NiO_(2) plane.In the strong coupling limit,the SC could be fully characterized by a bilayer single 3d_(x^(2)−y^(2))-orbital t–J‖–J⊥ model.With RE element substitution from La to other RE element,the lattice constant of the Fmmm RNO material decreases,and the resultant electronic hopping integral increases,leading to stronger superexchanges between the 3d_(x^(2)−y^(2)) orbitals.Based on the slave-boson mean-field theory,we explore the pairing nature and the evolution of T_(c) in RNO materials under pressure.Consequently,it is found that the element substitution does not alter the pairing nature,i.e.,the inter-layer s-wave pairing is always favored in the superconducting RNO under pressure.However,the T_(c) increases from La to Sm,and a nearly doubled T_(c) could be realized in SmNO under pressure.This work provides evidence for possible higher T_(c) R_(3)Ni_(2)O_(7) materials,which may be realized in further experiments. 展开更多
关键词 ELEMENT substitution RARE
下载PDF
Impact of Co^(2+)substitution on structure and magnetic properties of M-type strontium ferrite with different Fe/Sr ratios
5
作者 Yang Sun Ruoshui Liu +1 位作者 Huayang Gong Baogen Shen 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期427-433,共7页
Ion substitution has significantly improved the performance of ferrite magnets,and cobalt remains a key area of research.Studies on the mechanism of Co^(2+)in strontium ferrite,especially SrFe_(2n-x)Co_(x)O_(19-d)(n=6... Ion substitution has significantly improved the performance of ferrite magnets,and cobalt remains a key area of research.Studies on the mechanism of Co^(2+)in strontium ferrite,especially SrFe_(2n-x)Co_(x)O_(19-d)(n=6.1-5.4;x=0.05-0.20)synthesized using the ceramic method,showed that Co^(2+)preferentially enters the lattice as the Fe/Sr ratio decreases.This results in a decrease in the lattice constants a and c due to oxygen vacancies and iron ion deficiency.The impact of Co substitution on morphology is minor compared to the effect of the Fe/Sr ratio.As the Fe/Sr ratio decreases and the Co content increases,the saturation magnetization decreases.The magnetic anisotropy field exhibits a nonlinear change,generally increasing with higher Fe/Sr ratios and Co content.These changes in the performance of permanent magnets are attributed to the absence of Fe^(3+)ions at the 12k+2a and 2b sites and the substitution of Co^(2+)at the 2b site.This suggests that by adjusting the Fe/Sr ratio and appropriate Co substitution,the magnetic anisotropy field of M-type strontium ferrite can be effectively optimized. 展开更多
关键词 HEXAFERRITE Co substitution Raman spectra magnetic properties
下载PDF
Spray pyrolysis feasibility of tungsten substitution for cobalt in nickel-rich cathode materials
6
作者 Zihan Hou Lisheng Guo +8 位作者 Xianlong Fu Hongxian Zheng Yuqing Dai Zhixing Wang Hui Duan Mingxia Dong Wenjie Peng Guochun Yan Jiexi Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第10期2244-2252,共9页
Cobalt(Co)serves as a stabilizer in the lattice structure of high-capacity nickel(Ni)-rich cathode materials.However,its high cost and toxicity still limit its development.In general,it is possible to perform transiti... Cobalt(Co)serves as a stabilizer in the lattice structure of high-capacity nickel(Ni)-rich cathode materials.However,its high cost and toxicity still limit its development.In general,it is possible to perform transition metal substitution to reduce the Co content.However,the traditional coprecipitation method cannot satisfy the requirements of multielement coprecipitation and uniform distribution of elements due to the differences between element concentration and deposition rate.In this work,spray pyrolysis was used to prepare LiNi_(0.9)Co_(0.1-x)W_(x)O_(2)(LNCW).In this regard,the pyrolysis behavior of ammonium metatungstate was analyzed,together with the substitu-tion of W for Co.With the possibility of spray pyrolysis,the Ni-Co-W-containing oxide precursor presents a homogeneous distribution of metal elements,which is beneficial for the uniform substitution of W in the final materials.It was observed that with W substitution,the size of primary particles decreased from 338.06 to 71.76 nm,and cation disordering was as low as 3.34%.As a consequence,the pre-pared LNCW exhibited significantly improved electrochemical performance.Under optimal conditions,the lithium-ion battery assembled with LiNi_(0.9)Co_(0.0925)W_(0.0075)O_(2)(LNCW-0.75mol%)had an improved capacity retention of 82.7%after 200 cycles,which provides insight in-to the development of Ni-rich low-Co materials.This work presents that W can compensate for the loss caused by Co deficiency to a cer-tain extent. 展开更多
关键词 lithium-ion batteries Ni-rich LOW-COBALT W substitution spray pyrolysis
下载PDF
Atomically Substitutional Engineering of Transition Metal Dichalcogenide Layers for Enhancing Tailored Properties and Superior Applications
7
作者 Zhaosu Liu Si Yin Tee +1 位作者 Guijian Guan Ming‑Yong Han 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第5期248-284,共37页
Transition metal dichalcogenides(TMDs)are a promising class of layered materials in the post-graphene era,with extensive research attention due to their diverse alternative elements and fascinating semiconductor behav... Transition metal dichalcogenides(TMDs)are a promising class of layered materials in the post-graphene era,with extensive research attention due to their diverse alternative elements and fascinating semiconductor behavior.Binary MX2 layers with different metal and/or chalcogen elements have similar structural parameters but varied optoelectronic properties,providing opportunities for atomically substitutional engineering via partial alteration of metal or/and chalcogenide atoms to produce ternary or quaternary TMDs.The resulting multinary TMD layers still maintain structural integrity and homogeneity while achieving tunable(opto)electronic properties across a full range of composition with arbitrary ratios of introduced metal or chalcogen to original counterparts(0–100%).Atomic substitution in TMD layers offers new adjustable degrees of freedom for tailoring crystal phase,band alignment/structure,carrier density,and surface reactive activity,enabling novel and promising applications.This review comprehensively elaborates on atomically substitutional engineering in TMD layers,including theoretical foundations,synthetic strategies,tailored properties,and superior applications.The emerging type of ternary TMDs,Janus TMDs,is presented specifically to highlight their typical compounds,fabrication methods,and potential applications.Finally,opportunities and challenges for further development of multinary TMDs are envisioned to expedite the evolution of this pivotal field. 展开更多
关键词 Transition metal dichalcogenides Atomic substitution Tailored structure Tunable bandgap Enhanced applications
下载PDF
Quantitative lithium substitution of carboxyl hydrogens in polyacrylic acid binder enables robust SiO electrodes with durable lithium storage stability
8
作者 Weihua Wang Wenyi Li +7 位作者 Siyi Jing Huiping Yang Huiqun Wang Ling Huang Yuxiang Mao Xikun Pang Yudai Huang Li Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第10期352-360,I0007,共10页
The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH g... The design of advanced binders plays a critical role in stabilizing the cycling performance of large-volume-effect silicon monoxide(SiO)anodes.For the classic polyacrylic acid(PAA)binder,the self-association of-COOH groups in PAA leads to the formation of intramolecular and intermolecular hydrogen bonds,greatly weakening the bonding force of the binder to SiO surface.However,strengthening the binder-material interaction from the perspective of binder molecular regulation poses a significant challenge.Herein,a modified PAA-Li_(x)(0.25≤x≤1)binder with prominent mechanical properties and adhesion strength is specifically synthesized for SiO anodes by quantitatively substituting the carboxylic hydrogen with lithium.The appropriate lithium substitution(x=0.25)not only effectively increases the number of hydrogen bonds between the PAA binder and SiO surface owing to charge repulsion effect between ions,but also guarantees moderate entanglement between PAA-Li_x molecular chains through the ion-dipole interaction.As such,the PAA-Li_(0.25)/SiO electrode exhibits exceptional mechanical properties and the lowest volume change,as well as the optimum cycling(1237.3 mA h g^(-1)after 100cycles at 0.1 C)and rate performance(1000.6 mA h g^(-1)at 1 C),significantly outperforming the electrode using pristine PAA binder.This work paves the way for quantitative regulation of binders at the molecular level. 展开更多
关键词 Polyacrylic acid binder SiO anode Quantitative lithium substitution Charge repulsion effect Adhesion strength
下载PDF
Design of low-alloying and high-performance solid solution-strengthened copper alloys with element substitution for sustainable development
9
作者 Jiaqiang Li Hongtao Zhang +2 位作者 Jingtai Sun Huadong Fu Jianxin Xie 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期826-832,共7页
Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-... Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-speed rail contact wires,electronic component connectors,and other devices.Overcoming the contradiction between low alloying and high performance is an important challenge in the development of solid solution-strengthened copper alloys.Taking the typical solid solution-strengthened alloy Cu-4Zn-1Sn as the research object,we proposed using the element In to replace Zn and Sn to achieve low alloying in this work.Two new alloys,Cu-1.5Zn-1Sn-0.4In and Cu-1.5Zn-0.9Sn-0.6In,were designed and prepared.The total weight percentage content of alloying elements decreased by 43%and 41%,respectively,while the product of ultimate tensile strength(UTS)and electrical conductivity(EC)of the annealed state increased by 14%and 15%.After cold rolling with a 90%reduction,the UTS of the two new alloys reached 576 and 627MPa,respectively,the EC was 44.9%IACS and 42.0%IACS,and the product of UTS and EC(UTS×EC)was 97%and 99%higher than that of the annealed state alloy.The dislocations proliferated greatly in cold-rolled alloys,and the strengthening effects of dislocations reached 332 and 356 MPa,respectively,which is the main reason for the considerable improvement in mechanical properties. 展开更多
关键词 element substitution copper alloy solid solution strengthening microstructure and performance
下载PDF
Mitigation of N_(2)O emissions in water-saving paddy fields:Evaluating organic fertilizer substitution and microbial mechanisms
10
作者 Delei Kong Xianduo Zhang +5 位作者 Qidong Yu Yaguo Jin Peikun Jiang Shuang Wu Shuwei Liu Jianwen Zou 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第9期3159-3173,共15页
Water-saving irrigation strategies can successfully alleviate methane emissions from rice fields,but significantly stimulate nitrous oxide(N_(2)O)emissions because of variations in soil oxygen level and redox potentia... Water-saving irrigation strategies can successfully alleviate methane emissions from rice fields,but significantly stimulate nitrous oxide(N_(2)O)emissions because of variations in soil oxygen level and redox potential.However,the relationship linking soil N_(2)O emissions to nitrogen functional genes during various fertilization treatments in water-saving paddy fields has rarely been investigated.Furthermore,the mitigation potential of organic fertilizer substitution on N_(2)O emissions and the microbial mechanism in rice fields must be further elucidated.Our study examined how soil N_(2)O emissions were affected by related functional microorganisms(ammonia-oxidizing archaea(AOA),ammonia-oxidizing bacteria(AOB),nirS,nirK and nosZ)to various fertilization treatments in a rice field in southeast China over two years.In this study,three fertilization regimes were applied to rice cultivation:a no nitrogen(N)(Control),an inorganic N(Ni),and an inorganic N with partial N substitution with organic manure(N_(i)+N_(o)).Over two rice-growing seasons,cumulative N_(2)O emissions averaged 0.47,4.62 and 4.08 kg ha^(−1)for the Control,Ni and N_(i)+N_(o)treatments,respectively.In comparison to the Ni treatment,the N_(i)+N_(o)fertilization regime considerably reduced soil N_(2)O emissions by 11.6%while maintaining rice yield,with a lower N_(2)O emission factor(EF)from fertilizer N of 0.95%.Nitrogen fertilization considerably raised the AOB,nirS,nirK and nosZ gene abundances,in comparison to the Control treatment.Moreover,the substitution of organic manure for inorganic N fertilizer significantly decreased AOB and nirS gene abundances and increased nosZ gene abundance.The AOB responded to N fertilization more sensitively than the AOA.Total N_(2)O emissions significantly correlated positively with AOB and nirS gene abundances while having a negative correlation with nosZ gene abundance and the nosZ/nirS ratio across N-fertilized plots.In summary,we conclude that organic manure substitution for inorganic N fertilizer decreased soil N_(2)O emissions primarily by changing the soil NO_(3)^(−)-N,pH and DOC levels,thus inhibiting the activities of ammonia oxidation in nitrification and nitrite reduction in denitrification,and strengthening N_(2)O reduction in denitrification from water-saving rice paddies. 展开更多
关键词 organic manure substitution inorganic fertilizer N_(2)O functional microbe rice paddy
下载PDF
Atomic Ni directional-substitution on ZnIn_(2)S_(4) nanosheet to achieve the equilibrium of elevated redox capacity and efficient carrier-kinetics performance in photocatalysis
11
作者 Haibin Huang Guiyang Yu +5 位作者 Xingze Zhao Boce Cui Jinshi Yu Chenyang Zhao Heyuan Liu Xiyou Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期272-281,I0007,共11页
It is a challenge to coordinate carrier-kinetics performance and the redox capacity of photogenerated charges synchronously at the atomic level for boosting photocatalytic activity.Herein,the atomic Ni was introduced ... It is a challenge to coordinate carrier-kinetics performance and the redox capacity of photogenerated charges synchronously at the atomic level for boosting photocatalytic activity.Herein,the atomic Ni was introduced into the lattice of hexagonal ZnIn_(2)S_(4) nanosheets(Ni/ZnIn_(2)S_(4))via directionalsubstituting Zn atom with the facile hydrothermal method.The electronic structure calculations indicate that the introduction of Ni atom effectively extracts more electrons and acts as active site for subsequent reduction reaction.Besides the optimized light absorption range,the elevation of Efand ECBendows Ni/ZnIn_(2)S_(4) photocatalyst with the increased electron concentration and the enhanced reduction ability for surface reaction.Moreover,ultrafast transient absorption spectroscopy,as well as a series of electrochemical tests,demonstrates that Ni/ZnIn_(2)S_(4) possesses 2.15 times longer lifetime of the excited charge carriers and an order of magnitude increase for carrier mobility and separation efficiency compared with pristine ZnIn_(2)S_(4).These efficient kinetics performances of charge carriers and enhanced redox capacity synergistically boost photocatalytic activity,in which a 3-times higher conversion efficiency of nitrobenzene reduction was achieved upon Ni/ZnIn_(2)S_(4).Our study not only provides in-depth insights into the effect of atomic directional-substitution on the kinetic behavior of photogenerated charges,but also opens an avenue to the synchronous optimization of redox capacity and carrier-kinetics performance for efficient solar energy conversion. 展开更多
关键词 ZnIn_(2)S_(4) substitution Carrier kinetics Redox capacity PHOTOCATALYSIS
下载PDF
Effects of long-term partial substitution of inorganic fertilizer with pig manure and/or straw on nitrogen fractions and microbiological properties in greenhouse vegetable soils
12
作者 Shuo Yuan Ruonan Li +5 位作者 Yinjie Zhang Hao'an Luan Jiwei Tang Liying Wang Hongjie Ji Shaowen Huang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第6期2083-2098,共16页
Partial substitution of inorganic fertilizers with organic amendments is an important agricultural management practice.An 11-year field experiment(22 cropping periods)was carried out to analyze the impacts of differen... Partial substitution of inorganic fertilizers with organic amendments is an important agricultural management practice.An 11-year field experiment(22 cropping periods)was carried out to analyze the impacts of different partial substitution treatments on crop yields and the transformation of nitrogen fractions in greenhouse vegetable soil.Four treatments with equal N,P_(2)O_(5),and K_(2)O inputs were selected,including complete inorganic fertilizer N(CN),50%inorganic fertilizer N plus 50%pig manure N(CPN),50%inorganic fertilizer N plus 25%pig manure N and 25%corn straw N(CPSN),and 50%inorganic fertilizer N plus 50%corn straw N(CSN).Organic substitution treatments tended to increase crop yields since the 6th cropping period compared to the CN treatment.From the 8th to the 22nd cropping periods,the highest yields were observed in the CPSN treatment where yields were 7.5-11.1%greater than in CN treatment.After 11-year fertilization,compared to CN,organic substitution treatments significantly increased the concentrations of NO_(3)^(-)-N,NH_(4)^(+)-N,acid hydrolysis ammonium-N(AHAN),amino acid-N(AAN),amino sugar-N(ASN),and acid hydrolysis unknown-N(AHUN)in soil by 45.0-69.4,32.8-58.1,49.3-66.6,62.0-69.5,34.5-100.3,and 109.2-172.9%,respectively.Redundancy analysis indicated that soil C/N and OC concentration significantly affected the distribution of N fractions.The highest concentrations of NO_(3)^(-)-N,AHAN,AAN,AHUN were found in the CPSN treatment.Organic substitution treatments increased the activities ofβ-glucosidase,β-cellobiosidase,N-acetyl-glucosamidase,L-aminopeptidase,and phosphatase in the soil.Organic substitution treatments reduced vector length and increased vector angle,indicating alleviation of constraints of C and N on soil microorganisms.Organic substitution treatments increased the total concentrations of phospholipid fatty acids(PLFAs)in the soil by 109.9-205.3%,and increased the relative abundance of G^(+)bacteria and fungi taxa,but decreased the relative abundance of G-bacteria,total bacteria,and actinomycetes.Overall,long-term organic substitution management increased soil OC concentration,C/N,and the microbial population,the latter in turn positively influenced soil enzyme activity.Enhanced microorganism numbers and enzyme activity enhanced soil N sequestration by transforming inorganic N to acid hydrolysis-N(AHN),and enhanced soil N supply capacity by activating non-acid hydrolysis-N(NAHN)to AHN,thus improving vegetable yield.Application of inorganic fertilizer,manure,and straw was a more effective fertilization model for achieving sustainable greenhouse vegetable production than application of inorganic fertilizer alone. 展开更多
关键词 organic substitution management greenhouse vegetable production N fractions microbial community composition extracellular enzyme activity enzyme stoichiometry coefficients
下载PDF
Development and characterization of wheat–Aegilops kotschyi 1U^(k)(1A)substitution line with positive dough quality parameters
13
作者 JIANG Yun WANG De-li +2 位作者 HAO Ming ZHANG Jie LIU Deng-cai 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第4期999-1008,共10页
Exploring novel high molecular weight glutenin subunits(HMW-GSs)from wild related species is a strategy to improve wheat processing quality.The objective of the present investigation was to identify the chromosomes of... Exploring novel high molecular weight glutenin subunits(HMW-GSs)from wild related species is a strategy to improve wheat processing quality.The objective of the present investigation was to identify the chromosomes of the wheatalien introgression line N124,derived from the hybridization between Triticum aestivum with Aegilops kotschyi,and characterize the effects on quality-related traits.Fluorescence in situ hybridization karyotypes showed that N124 is a disomic 1U^(k)(1A)substitution line.Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE)and reversedphase high-performance liquid chromatography verified N124 expressed two HMW-GSs of the Ae.kotschyi parent.PacBio RNA sequencing and phylogenetic analysis confirmed that the two HMW-GSs were U^(k)x and U^(k)y.Compared to the wheat parent,the substitution line had no obvious agronomic defects except fewer grains per spike but improved several major quality parameters.It can be served as a donor or bridge material for wheat quality improvement. 展开更多
关键词 Aegilops kotschyi common wheat 1Uk(1A)substitution line HMW-GS processing quality
下载PDF
基于管柱动力学的特深井通井组合刚度评价方法与应用 被引量:2
14
作者 祝效华 李文哲 +5 位作者 李柯 陈力力 孟鐾桥 沈欣宇 罗伟 贺明敏 《钻采工艺》 CAS 北大核心 2024年第2期51-58,共8页
我国特深井钻井正处于快速发展阶段,受井眼尺寸大和深度深的影响,钻井过程中极易出现微井斜、扩径缩径和井壁台阶等,导致套管下入困难,因此通井钻具组合评价尤为重要。目前,现场使用的评价方法常忽略了管柱下入过程中与井壁的碰撞和变形... 我国特深井钻井正处于快速发展阶段,受井眼尺寸大和深度深的影响,钻井过程中极易出现微井斜、扩径缩径和井壁台阶等,导致套管下入困难,因此通井钻具组合评价尤为重要。目前,现场使用的评价方法常忽略了管柱下入过程中与井壁的碰撞和变形,导致通井效果时好时坏。为了辅助现场施工,文章基于全井管柱动力学模型和HHT-α数值计算方法提出了一种能够模拟管柱下入的动态过程的通井钻具组合的评价方法,该方法考虑了实测井眼轨迹、井眼扩大率和下入阻力等要素。通过某特深井三开下套管前的钻具组合进行实例计算分析,表明井眼扩大率和套管串下入阻力对通井能力和套管下入影响较大,当井眼扩大率较小且套管串下入阻力较大时,需要使用刚度较大的多扶正器通井钻具组合。本方法可以实现实测井况条件下比较精准的刚度对比模拟,也成功指导了案例井?486 mm套管的安全下入。 展开更多
关键词 特深井 通井钻具组合 管柱动力学模型 刚度比 井眼扩大率 下入阻力
下载PDF
Securing Healthcare Data in IoMT Network Using Enhanced Chaos Based Substitution and Diffusion
15
作者 Musheer Ahmad Reem Ibrahim Alkanhel +3 位作者 Naglaa FSoliman Abeer D.Algarni Fathi E.Abd El-Samie Walid El-Shafai 《Computer Systems Science & Engineering》 SCIE EI 2023年第11期2361-2380,共20页
Patient privacy and data protection have been crucial concerns in Ehealthcare systems for many years.In modern-day applications,patient data usually holds clinical imagery,records,and other medical details.Lately,the ... Patient privacy and data protection have been crucial concerns in Ehealthcare systems for many years.In modern-day applications,patient data usually holds clinical imagery,records,and other medical details.Lately,the Internet of Medical Things(IoMT),equipped with cloud computing,has come out to be a beneficial paradigm in the healthcare field.However,the openness of networks and systems leads to security threats and illegal access.Therefore,reliable,fast,and robust security methods need to be developed to ensure the safe exchange of healthcare data generated from various image sensing and other IoMT-driven devices in the IoMT network.This paper presents an image protection scheme for healthcare applications to protect patients’medical image data exchanged in IoMT networks.The proposed security scheme depends on an enhanced 2D discrete chaotic map and allows dynamic substitution based on an optimized highly-nonlinear S-box and diffusion to gain an excellent security performance.The optimized S-box has an excellent nonlinearity score of 112.The new image protection scheme is efficient enough to exhibit correlation values less than 0.0022,entropy values higher than 7.999,and NPCR values around 99.6%.To reveal the efficacy of the scheme,several comparison studies are presented.These comparison studies reveal that the novel protection scheme is robust,efficient,and capable of securing healthcare imagery in IoMT systems. 展开更多
关键词 Secure communication healthcare data encryption Internet of Medical Things(IoMT) discrete chaotic map substitution box(S-box)
下载PDF
欧盟PFAS限制提案解读及其对制冷空调行业影响与应对 被引量:2
16
作者 安青松 侯佳鑫 +1 位作者 史琳 戴晓业 《制冷学报》 CAS CSCD 北大核心 2024年第2期22-29,共8页
在《〈关于消耗臭氧层物质的蒙特利尔议定书〉基加利修正案》的履约和“双碳”目标的双重驱动下,制冷剂替代是制冷空调领域最为关注的热点之一。采用热物性相近的低GWP的HFOs制冷剂和天然制冷剂作为替代品,实现HFCs的削减被认为是较为... 在《〈关于消耗臭氧层物质的蒙特利尔议定书〉基加利修正案》的履约和“双碳”目标的双重驱动下,制冷剂替代是制冷空调领域最为关注的热点之一。采用热物性相近的低GWP的HFOs制冷剂和天然制冷剂作为替代品,实现HFCs的削减被认为是较为合适的替代技术路线;但随着2023年2月欧盟出台的PFAS限制提案,引发了对HFOs制冷剂替代前景的担忧,这可能影响全球制冷剂替代发展。因此,首先对PFAS物质进行了介绍,分析了含氟制冷剂与PFASs的关系,并对PFAS法案的形成脉络和关键内容进行了解读,总结了不同领域对此的观点,希望对未来制冷剂替代方案的制定提供一定思辨意义和参考价值。 展开更多
关键词 制冷剂替代 欧盟PFAS法案 PFASs HFOs 基加利修正案
下载PDF
自体骨移植与骨替代物手术治疗胫骨平台骨折的Meta分析 被引量:1
17
作者 郭华 黄凌岸 +3 位作者 李皓乾 郭丽 李鹏翠 卫小春 《中国骨伤》 CAS CSCD 2024年第3期300-305,共6页
目的:通过Meta分析系统评价自体骨移植和骨替代物治疗胫骨平台骨折的临床疗效。方法:计算机检索2005年1月至2022年8月PubMed、Web of Science、中国知网、万方等数据库已发表的关于自体骨移植和骨替代物治疗胫骨平台骨折的病例对照研究... 目的:通过Meta分析系统评价自体骨移植和骨替代物治疗胫骨平台骨折的临床疗效。方法:计算机检索2005年1月至2022年8月PubMed、Web of Science、中国知网、万方等数据库已发表的关于自体骨移植和骨替代物治疗胫骨平台骨折的病例对照研究文献。根据纳排标准进行文献筛选及数据提取,对入选的随机对照研究(randomized controlled trial,RCT)采用Cochrane手册中的干预性Meta分析标准进行质量评价。采用RevMan 5.3软件对两种方法的关节凹陷、关节面二次塌陷率、失血量、手术时间和感染率进行Meta分析。结果:共纳入7项RCT研究,424例患者,其中骨替代物组296例,自体骨移植组128例。两组手术时间[MD=-16.79,95%CI(-25.72,-7.85),P=0.0002],出血量[MD=-70.49,95%CI(-79.34,-61.65),P<0.00001]比较,差异有统计学意义。而关节凹陷[MD=-0.17,95%CI(-0.91,0.58),P=0.66],关节面二次塌陷率[RR=-0.74,95%CI(0.35,1.57),P=0.43],感染率[RR=1.21,95%CI(0.31,4.70),P=0.78]比较,差异无统计学意义。结论:骨替代物与自体骨移植治疗胫骨平台骨折在关节凹陷、关节面二次塌陷率和感染率方面疗效相近。但骨替代物较自体骨移植,能减少失血量,缩短手术时间。 展开更多
关键词 胫骨平台骨折 自体骨移植 骨替代物 META分析
下载PDF
新能源汽车对成品油替代的区域性研究 被引量:2
18
作者 韩冰 齐超 于献策 《国际石油经济》 2024年第1期85-91,共7页
2023年,中国新能源汽车已进入全面市场拓展期。目前,中国新能源汽车正处于“两高一强”的发展阶段,对成品油的替代呈现“一家独大”的现状。将全国分为东北、西北、西南、华东、华南、华北六个区域,构建“长期看保有,中期看销量,短期看... 2023年,中国新能源汽车已进入全面市场拓展期。目前,中国新能源汽车正处于“两高一强”的发展阶段,对成品油的替代呈现“一家独大”的现状。将全国分为东北、西北、西南、华东、华南、华北六个区域,构建“长期看保有,中期看销量,短期看运营车”的分析框架,从短期、中期、长期三个维度对不同区域、不同省份的新能源汽车的成品油替代作用展开细化分析研究。建议成品油销售企业根据各区域新能源汽车发展特色制定油品销售规划,分区域推进综合能源服务站的布局与建设,同时助力公共领域新能源汽车的应用推广工作,以应对新能源汽车对成品油的替代,加快世界一流综合性国际能源公司的建设。 展开更多
关键词 新能源汽车 成品油替代 油品销售 区域性研究
下载PDF
我国航运业绿色低碳发展的需求、路径与展望 被引量:1
19
作者 范爱龙 严新平 +1 位作者 李忠奎 张海颖 《船海工程》 北大核心 2024年第4期1-5,12,共6页
为探讨航运业在综合运输体系中的重要性,并针对加速航运业绿色低碳发展对实现交通运输行业双碳战略目标的意义展开分析。通过考察航运业当前的碳排放状况,分析我国在绿色低碳发展方面存在的问题,对国内外绿色航运政策需求及其对航运业... 为探讨航运业在综合运输体系中的重要性,并针对加速航运业绿色低碳发展对实现交通运输行业双碳战略目标的意义展开分析。通过考察航运业当前的碳排放状况,分析我国在绿色低碳发展方面存在的问题,对国内外绿色航运政策需求及其对航运业的影响进行综合评估。在此基础上,研究我国航运业绿色低碳发展的路径,包括总体思路、基本原则,以及相应的策略与实施措施,展望航运业绿色低碳发展的技术创新方向,提出从能源替代和运营管理两个方面促进航运业绿色低碳发展。 展开更多
关键词 航运业 绿色低碳 能源替代 能效提升
下载PDF
数据要素、新型基础设施与产业结构调整路径 被引量:4
20
作者 朱晓武 魏文石 王靖雯 《南方经济》 北大核心 2024年第1期107-123,共17页
数据要素和新型基础设施在各个产业发挥日益重要的作用。不同产业对数据要素和新型基础设施的应用方式和利用效率存在差异,影响产业结构调整路径。文章构建包含两个生产部门的动态一般均衡模型,用于代表不同产业或同一产业内的不同企业... 数据要素和新型基础设施在各个产业发挥日益重要的作用。不同产业对数据要素和新型基础设施的应用方式和利用效率存在差异,影响产业结构调整路径。文章构建包含两个生产部门的动态一般均衡模型,用于代表不同产业或同一产业内的不同企业。每个部门将数据作为新生产要素、将新型基础设施作为数据扩展型技术,与传统生产要素结合形成新的生产函数。不同部门的数据产出弹性、数据和传统要素的替代弹性存在差异,这是影响产业结构调整路径的重要因素。通过理论模型推导和数值模拟研究,文章发现:在不同产业之间,由于产品替代弹性较低,提高数据要素和新型基础设施的数量会导致数据产出弹性较高、数据和传统要素的替代弹性较高的产业产出提高,但其产品价格和名义产出降低,促使资本和劳动力流向数据利用效率低的产业。这一过程将改变资本和劳动力的价格,影响劳动收入份额。在同一产业内部,由于不同企业间的产品替代弹性较高,数据要素和新型基础设施导致资本和劳动力流向数据利用效率高的企业,优化生产要素配置,推动整个产业的数字化转型。新型基础设施建设对产业结构调整的推动作用受到数据要素的调节,且最终的影响方向和路径与数据要素一致,可以通过调整需求结构引导更具针对性和长效的产业结构调整。最后,文章提出数据要素、新型基础设施建设的相关政策建议,并对产业结构调整可能导致的问题提出对策。 展开更多
关键词 数据要素 新型基础设施 产业结构调整 替代弹性
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部