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Can soil organic carbon sequestration and the carbon management index be improved by changing the film mulching methods in the semiarid region?

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Journal of Integrative Agriculture 2024年第5期23卷 1541-1556页

作者： Jialin Yang Liangqi ren Nanhai Zhang Enke Liu Shikun Sun Xiaolong ren Zhikuan Jia Ting Wei Peng Zhang College of Agronomy Northwest A&F UniversityYangling 712100China Key Laboratory of Crop Physi-Ecology and Tillage Science in Northwestern Loess Plateau Ministry of Agriculture and Rural AfairsNorthwest A&FUniversityYangling 712100China Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081China College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China

Plastic film mulching has been widely used to increase maize yield in the semiarid area of ***, whether long-term plastic film mulching is conducive to agricultural sustainability in this region remains controversial.A field experiment was initiated in 2013 with five different film mulching methods:(i) control method, flat planting without mulching (CK),(ii) flat planting with half film mulching (P),(iii) film mulching on ridges and planting in narrow furrows(S),(iv) full film mulching on double ridges (D), and (v) film mulching on ridges and planting in wide furrows (R).The effects on soil organic carbon (SOC) content, storage, and fractions, and on the carbon management index (CMI)were evaluated after nine consecutive years of plastic film *** results showed that long-term plastic film mulching generally maintained the initial SOC *** with no mulching, plastic film mulching increased the average crop yield, biomass yield, and root biomass by 48.38, 35.06, and 37.32%, respectively, which led to the improvement of SOC ***, plastic film mulching significantly improved CMI, and increased the SOC content by 13.59%, SOC storage by 7.47%and easily oxidizable organic carbon (EOC) by 13.78%on average,but it reduced the other labile *** sequestration and CMI were improved by refining the plastic film mulching *** S treatment had the best effect among the four mulching methods, so it can be used as a reasonable film mulching method for sustainable agricultural development in the semiarid area.

关键词： plastic film mulching soil organic carbon labile organic carbon fractions semiarid area

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Dynamic mechanical characteristics of deep Jinping marble in complex stress environments

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第2期16卷 630-644页

作者： Chendi Lou Heping Xie Ru Zhang Hai ren Hao Luo Kun Xiao Yuan Peng Qiang Tan Li ren Institute for Disaster Management and Reconstruction Sichuan UniversityChengdu610207China College of Water Resource&Hydropower Sichuan UniversityChengdu610065China MOE Key Laboratory of Deep Earth Science&Engineering Sichuan UniversityChengdu610065China Yalong River Hydropower Development Company Ltd.Chengdu610051China (Chongqing)International Engineering Technology Company Ltd.Chongqing401121China

To reveal the dynamic mechanical characteristics of deep rocks,a series of impact tests under triaxial static stress states corresponding to depths of 300-2400 m were *** results showed that both the strain rates and the stress environments in depth significantly affect the mechanical characteristics of *** sensitivity of strain rate to the dynamic strength and deformation modulus shows a negative correlation with depth,indicating that producing penetrative cracks in deep environments is more difficult when damage *** dynamic strength shows a tendency to decrease and then increase slightly,but decreases sharply *** demonstrates a similar trend as that of strength,whereas reflectivity indicates the opposite ***,two critical depths with high dynamically induced hazard possibilities based on the China Jinping Underground Laboratory(CJPL)were proposed for deep *** first critical depth is 600-900 m,beyond which the sensitivity of rock dynamic characteristics to the strain rate and restraint of circumferential stress decrease,causing instability of surrounding rocks under axial stress *** second one lies at 1500-1800 m,where the wave impedance and dynamic strength of deep surrounding rocks drop sharply,and the dissipation energy presents a negative *** suggests that the dynamic instability of deep surrounding rocks can be divided into dynamic load dominant and dynamic load induced types,depending on the second critical depth.

关键词： Rock mechanics Split-Hopkinson pressure bar Coupled static‒dynamic loading Different depths Holmquist-Johnson-Cook(HJC)model

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Effects of the nozzle structure and fluidized gas composition on the gas-particle two-phase jet characteristic in a powder fuel scramjet

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Particuology 2024年第9期92卷 166-179页

作者： Changfei Zhuo Hongming Ding Xiaobin ren Hanyu Deng Xiong Chen School of Mechanical and Engineering Key Laboratory of Special Engine TechnologyMinistry of EducationNanjing University of Science and TechnologyNanjing210094China Department of Mechanical Engineering National University of Singapore9 Engineering Drive 1Singapore117576 Shanxi North Xing'an Chemical Industry Co. Ltd.Taiyuan030008China

The interaction between nozzle design and fluidization gas composition significantly influences the dynamics within a powder fuel scramjet's combustion *** investigate this relationship,an experimental study utilized high-speed shadow imaging technology to explore the macroscopic aspects of powder fuel *** investigation examined various convergence angles,nozzle throat lengths,and fluidized gas *** findings include:During jet development,powder fuel initially concentrates near the axis,with non-convergence angle nozzles exhibiting longer concentrated distribution periods than convergence angle *** nozzle convergence angles lead to increased penetration distance,frontal velocity,and radial diffusion distance during the initial stages of jet ***,stable jet shapes show larger divergence angles as nozzle convergence angle decreases,with the largest divergence angle observed atα=60°.In the initial 0-7 ms of jet development,the powder fuel jet demonstrates greater penetration distance and frontal velocity under certain ***,penetration distance and frontal velocity increase with throat length from 7 to 20 ms,accompanied by changes in divergence ***,at a throat length(l)of 2 mm,the near-field divergence angle measures 46.50°,and the far-field divergence angle is 22.25°.Conversely,at l=8mm,the near-field divergence angle is 33.49°,and the far-field divergence angle is 23.21°.The fluidization gas composition minimally affects jet penetration distance and frontal velocity during the initial 0-3 ***,due to hydrogen's low density,hydrogen/powder fuel jets exhibit shorter distances and velocities compared to nitrogen/powder fuel *** fluidization also results in larger divergence angles,particularly in the near *** findings underscore the importance of nozzle design and fluidization gas composition in optimizing scramjet performance and efficiency.

关键词： Multiphase flows Gas-particle two-phase jet Nozzle contraction angle Powder fuel scramjet

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A blockchain-empowered authentication scheme for worm detection in wireless sensor network

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Digital Communications and Networks 2024年第2期10卷 265-272页

作者： Yuling Chen Xiong Yang Tao Li Yi ren Yangyang Long State Key Laboratory of Public Big Data College of Computer Science and TechnologyGuizhou UniversityGuiyang550025China School of Computing Science University of East AngliaNorwichNR57TJUK

Wireless Sensor Network(WSN)is a distributed sensor network composed a large number of nodes with low cost,low performance and *** special structure of WSN brings both convenience and *** example,a malicious participant can launch attacks by capturing a physical ***,node authentication that can resist malicious attacks is very important to network ***,blockchain technology has shown the potential to enhance the security of the Internet of Things(IoT).In this paper,we propose a Blockchain-empowered Authentication Scheme(BAS)for *** our scheme,all nodes are managed by utilizing the identity information stored on the ***,the simulation experiment about worm detection is executed on BAS,and the security is evaluated from detection and infection *** experiment results indicate that the proposed scheme can effectively inhibit the spread and infection of worms in the network.

关键词： Wireless Sensor Network(WSN) Node authentication Blockchain Tangle Worm detection

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区块链分布式技术在电力需求侧响应管理中的应用

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电信科学 2019年第5期35卷 155-160页

作者：任昊文杨雅琪鼎信信息科技有限责任公司广东广州510623 广州致讯信息科技有限责任公司广东广州510032

研究了分散式区块链机制的理论,提出一种将区块链分布式技术应用于智能电网需求侧响应计划管理的方法。该方法基于区块链防篡改的分布式记账技术,存储从IoT智能计量设备收集的能量消耗信息,以编程方式定义每个消费者级别的自我执行智能... 详细信息

研究了分散式区块链机制的理论,提出一种将区块链分布式技术应用于智能电网需求侧响应计划管理的方法。该方法基于区块链防篡改的分布式记账技术,存储从IoT智能计量设备收集的能量消耗信息,以编程方式定义每个消费者级别的自我执行智能合约,保障交易的灵活性。区块链分布式技术提供相关奖励或惩罚以平衡能源需求与电网能源生产的规则。基于共识的验证将用于检验需求响应计划,并为灵活的供应商提供适当的财务结算方式。结果表明,基于区块链分布式技术的电力需求侧管理可用于智能电网条件下的能源需求和生产匹配,需求响应信号精确度高,但收敛所需的灵活性减少。

关键词：区块链分布式技术需求侧响应智能电网

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Boosting the self-trapped exciton emission in vacancy-ordered double perovskites via supramolecular assembly

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Chinese Journal of Structural Chemistry 2024年第6期43卷 1-2页

作者： Xingwen Cheng Haoran ren Jiangshan Luo Institute of Quantum and Sustainable Technology(IQST) School of Chemistry and Chemical EngineeringJiangsu UniversityZhenjiang212013China

All-inorganic 3D lead-free vacancy-ordered double perovskites(DPs)in the A_(2)MX_(6)phase have garnered significant attention in the fields of photovoltaics and light-emitting diodes(LED)due to their exceptional optoelectronic properties[1].These properties encompass a high optical absorption coefficient,tunable bandgap,and long carrier diffusion dis-tance.

关键词： optoelectronic vacancy double

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Afforestation increases microbial diversity in low-carbon soils

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Journal of Forestry Research 2024年第2期35卷 14-22页

作者： Xuesen Pang Chuankuan Wang Chengjie ren Zhenghu Zhou Center for Ecological Research Key Laboratory of Sustainable Forest Ecosystem Management‑Ministry of EducationNortheast Forestry UniversityHarbin 150040People’s Republic of China Northeast Asia Biodiversity Research Center Northeast Forestry UniversityHarbin 150040People’s Republic of China State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F UniversityYangling 712100People’s Republic of China

Afforestation has an important role in biodiversity conservation and ecosystem function improvement.A meta-analysis was carried out in China,which has the largest plantation area globally,to quantify the effects of plantings on soil microbial *** results showed that the overall effect of afforestation on soil microbial diversity was positive across the *** forest algorithm suggested that soil carbon was the most important factor regulating microbial diversity and the positive response was only found with new plantings on low-carbon bare lands but not on high-carbon farmlands and *** addition,afforestation with broadleaved species increased microbial diversity,whereas planting with conifers had no effect on microbial *** study clarified the effects of plantings on soil microbial diversity,which has an important implication for establishing appropriate policies and practices to improve the multiple functionalities(e.g.,biodiversity conservation and climate change mitigation)during plantation establishment.

关键词： Afforestation Microbial diversity Soil microbial communities Species-energy theory Plantations

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In-situ UV-Vis Spectroscopy of Trisulfur Radicals in Lithium-Sulfur Batteries

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Chemical Research in Chinese Universities 2024年第2期40卷 279-286页

作者： DOU renju WANG Qin ren Xiaoyan LU Lehui School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026P.R.China State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022P.R.China

Here we employ in-situ UV-Vis spectroscopy to monitor the sulfur redox reaction with oxygen-containing molecules as an additive,for example,biphenyl-4,4′-dicarboxylic acid(BDC).Furthermore,Raman spectrum,electron paramagnetic resonance(EPR),and electrospray ionization-mass spectrometry(ESI-MS)measurements reveal that the formation of BDC-S_(3)•^(‒)complexes can establish the long-term stability of polysulfide radicals,change the kinetics of sulfur redox reaction,and then generate decent capacity retention and rate *** to the density functional theory(DFT)analysis,S_(3)•^(‒)radicals are the underlying product of S_(6)^(2‒)cleavage,owing to the decreased chemical energy and the increased stability of S_(3)•^(‒)radicals through Lewis acid-base *** assembled Li-S batteries with BDC additive deliver a high reversible capacity of 420 mA·h·g^(−1)over 200 cycles with over 98%Coulombic efficiency,under the current density of 0.2 C.

关键词： Radical Polysulfide In-situ UV-Vis Spectroscopy Electrolyte additive Lithium-sulfur battery

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Effects of pressure relief holes on coal burst:Insights from true-triaxial unloading tests

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第9期16卷 3378-3394页

作者： Fuqiang ren Murat Karakus Giang Nguyen Thomas Bruning School of Civil Engineering University of Science and Technology LiaoningAnshan114051China Mining and Petroleum Engineering The University of AdelaideAdelaideSouth Australia5005Australia State Key Laboratory for Geomechanics&Deep Underground Engineering China University of Mining and TechnologyBeijing100083China School of Architecture and Civil Engineering The University of AdelaideSouth Australia5005Australia

Drilling pressure relief is one of the methods to reduce the risk of coal bursts in deep ***,the effect of the drill hole orientations has not been studied well enough to understand their impact on the burst failure *** this study,we investigated two designs of drill hole *** first design includes drill holes located on the upper free face of the rectangular samples and labelled as upper hole(UH)and centre hole(CH)e the long axes of the drill holes are aligned with minor principal stress,s3,*** second design includes drill holes at the top(TH)and the side(SH)of the rectangular samples in which the long axes of the drill holes are aligned with the maximum,s1,and intermediate principal stress,s2,directions,*** coal samples with the proposed drill hole orientations were subjected to the true-triaxial unloading coal burst *** results show that the drill holes reduce the risk of coal ***,we found that the intensity of coal burst was significantly reduced with the SH-type,followed by the *** also observed that the coal burst intensity is reduced better for the CH,UH,TH,and SH-type drilling ***,it was found that the orientations of drill holes have little influence on the failure mode(splitting).The acoustic emission(AE)activities for coal with drill holes noticeably decreased,especially for the UH and CH *** drill holes reduced the upper limit of the AE entropy(chaos of microcracks generation).However,regarding reducing the coal burst risk,the TH and SH are less effective than UH and CH.

关键词： Coal burst Triaxial unloading Drilling orientation Ejection characteristic Acoustic emission(AE)

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A model reduction approach for discrete-time linear time-variant systems with delayed inputs

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Science China(Information Sciences) 2024年第4期67卷 197-217页

作者： Ai-Guo WU Guang-ren DUAN Yu WANG Jie ZHANG School of Mechanical Engineering and Automation Harbin Institute of Technology(Shenzhen) HIT Wuhu Robot Technology Research Institute Center for Control Science and Technology Southern University of Science and Technology

A model reduction approach is presented for discrete-time linear time-variant input-delayed systems. According to this proposed approach, a dynamical variable is constructed by taking advantage of the current state and historical information of input. It is revealed that the behavior of this dynamical variable is governed by a discrete-time linear delay-free system. It is worth noting that the presented variable transformation does not require the system matrix to be invertible. Based on the reduced delay-free models,stabilizing control laws can be easily obtained for the original delayed system. For the case with a single input delay, the constructed variable is an exact prediction for the future state, and thus the stabilizing control law could be designed by replacing the future state with its prediction. Finally, three discrete-time periodic systems with delayed input are employed to illustrate how to utilize the presented model reduction approaches.

关键词： reduction approach predictor-based feedback time-varying systems delayed input periodic system

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