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Temporal changes in mixing effects on litter decay and nitrogen release in a boreal riparian forest in northeastern China

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Journal of Forestry Research 2024年第2期35卷 33-41页

作者： Simin Wang bo Liu Rui Li Xiaoxin Sun Rong mao Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed College of ForestryJiangxi Agricultural UniversityNanchang 330045People’s Republic of China Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102People’s Republic of China Key Laboratory of Sustainable Forest Ecosystem Management of Ministry of Education School of ForestryNortheast Forestry UniversityHarbin 150040People’s Republic of China Heilongjiang Sanjiang Plain Wetland Ecosystem Research Station Fuyuan 156500People’s Republic of China

In riparian forests,litter decay provides essential energy and nutrients for both terrestrial and fluvial *** mixing effects(LMEs)are crucial in regulating litter decay and nutrient dynamics,yet how LMEs change over time is unclear in riparian *** this study,leaf litter of three common species(Alnus sibirica *** Turcz,Betula platyphylla Sukaczev,and Betula fruticosa Pall.)were mixed in an equal mass ratio and LMEs were measured for mass and nitrogen(N)remaining in whole litter mixtures over a 3-year period in a boreal riparian forest,northeastern *** were also assessed for component litter mass and N remaining by separating litter mixtures by *** the decay of litter mixtures,antagonistic effects on mass and N remaining were dominant after one and two years of decay,whereas only additive effects were observed after three *** correlated negatively with functional diversity after the first and two years of decay but disappeared after three *** sorting litter mixtures by species,non-additive LMEs on mass and N remaining decreased over incubation ***,non-additive LMEs were more frequent for litter of both *** and *** with lower N concentration than for *** litter with higher N *** results indicate that incubation time is a key determinant of litter mixing effects during decay and highlight that late-stage litter mixture decay may be predicted from single litter decay dynamics in boreal riparian forests.

关键词： Biodiversity Litter quality Litter mixtures Synergistic effects Functional diversity

A Multi-Token Sector Antenna Neighbor Discovery Protocol for Directional Ad Hoc Networks

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China Communications 2024年第7期21卷 149-168页

作者： Zhang Hang Li bo Yan Zhongjiang Yang mao Li Xinru School of Electronics and Information Northwestern Polytechnical UniversityXi’an 710072China The 54th Research Institute of CETC Shijiazhuang 050081China

In this paper,we propose a Multi-token Sector Antenna Neighbor Discovery(M-SAND)protocol to enhance the efficiency of neighbor discovery in asynchronous directional ad hoc *** central concept of our work involves maintaining multiple tokens across the *** prevent mutual interference among multi-token holders,we introduce the time and space non-interference ***,we propose a master-slave strategy between *** the master token holder(MTH)performs the neighbor discovery,it decides which 1-hop neighbor is the next MTH and which 2-hop neighbors can be the new slave token holders(STHs).Using this approach,the MTH and multiple STHs can simultaneously discover their neighbors without causing interference with each *** on this foundation,we provide a comprehensive procedure for the M-SAND *** also conduct theoretical analyses on the maximum number of STHs and the lower bound of multi-token generation ***,simulation results demonstrate the time efficiency of the M-SAND *** compared to the QSAND protocol,which uses only one token,the total neighbor discovery time is reduced by 28% when 6beams and 112 nodes are employed.

关键词： multi-token neighbor discovery SAND protocol sector antenna ad hoc network

Multi-machine collaboration realization conditions and precise and efficient production mode of intelligent agricultural machinery

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International Journal of Agricultural and Biological Engineering 2024年第2期17卷 27-36页

作者： bo Wang Xiaoxue Du Yana Wang Hanping mao Key Laboratory of Modern Agricultural Equipment and Technology Ministry of EducationJiangsu UniversityZhenjiang 212013JiangsuChina School of Agricultural Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina School of Optoelectronic Engineering Changzhou institute of technologyChangzhou 213032JiangsuChina

Multi-machine collaboration of agricultural machinery is one of the international frontier and hot research in the field of agricultural ***,the current domestic multi-machine collaborative operation of agricultural machinery is limited to the research of task goal planning and collaborative path optimization in a single production *** order to achieve the purpose of zero inventory of agricultural materials and precise and efficient production operations,a new technology of agricultural machinery multi-machine collaboration with multi-dimension and full chain was proposed,which takes into account the whole process of agricultural production,as well as agricultural machinery system and external supply chain,storage and transportation chain *** problems of data collaboration,process collaboration and organization collaboration were *** the realization conditions of new multi-machine cooperative technology were ***,the zero inventory mode and precise operation mode of agricultural materials under the background of multi-machine cooperation of intelligent agricultural machinery were ***,a precise and efficient agricultural production mode based on data-process-organization collaboration was *** results showed that the multi-machine cooperative technology mode of multi-dimensional and full-chain agricultural machinery could greatly improve the efficiency of agricultural machinery,operation quality,land utilization rate and reduce production cost.

关键词： intelligent agricultural machinery multi-machine collaboration multi-dimensional whole chain zero inventory precise and efficient production mode

Impact and mechanism of bisphosphonate depressant 1-hydroxypropane-1,1-diphosphonic acid on flotation decalcification of dolomite-rich magnesite ore

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International Journal of Mining Science and Technology 2024年第7期34卷 1017-1032页

作者： Wengang Liu Xudong Chen Wenbao Liu Naixu Zhang Yong mao ying Guo School of Resources&Civil Engineering Northeastern UniversityShenyang 110819China

Given the depletion of high-quality magnesite deposits and the rising demand for high-end magnesium materials,the separation and utilization of high-calcium magnesite ores have become ***,the similar surface properties and solubility of semi-soluble salt-type minerals,pose significant challenges for the utilization of dolomite-rich magnesite *** this study,1-hydroxypropane-1,1-di phosphonic acid(HPDP)was identified for the first time as a high-performance depressant for *** tests,including contact angle measurements,ζ potential analysis,X-ray photoelectron spectroscopy,and atomic force microscopy,were conducted to elucidate the interfacial interaction mechanisms of HPDP on the surfaces of the two minerals at different ***,molecular modeling calculations were used to detail the spatial matching relationship between HPDP and the crystal faces of the two *** was emphasized that HPDP specifically adsorbed onto the dolomite surface by forming calcium phosphonate,ensuring that the dolomite surface remained hydrophilic and ***,it was found that the adsorption strength of HPDP on the mineral surfaces depended on the activity of the metal sites and their spatial *** findings provide a theoretical foundation for the molecular design of flotation reagents for high-calcium magnesite ores.

关键词： Depressant Interfacial mechanism Magnesite Dolomite DFT Decalcification

Metal-free Optical Pressure Sensor with High Sensitivity and Extensive Range

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1291-1300页

作者： mao Ji Meng Huang Haomin Lyu Sheng Shi bo Qi Chengrong Li State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China IEEE CSEE

Pressure monitoring of a transformer oil tank can grasp the pressure change process caused by gas production when severe internal defects occur and take timely measures to ensure the safe operation of the *** pressure sensors generally use metal encapsulation or have an air cavity structure,threatening the transformer’s insulation if it is directly used inside the *** this end,this paper proposes a method for developing a high-sensitivity,large-range,and metallizationfree optical pressure sensing device with temperature *** grating is encapsulated by fluorosilicone rubber and supplemented by an epoxy resin shielding shell on the *** the same time,a double-grating vertical arrangement is adopted to improve pressure measurement sensitivity,further avoiding the influence of temperature rise caused by a defect of the transformer on the measurement result of the *** addition,by optimizing the geometric structure of the internal sensitizing element,pre-stretching length of the fiber grating,gap distance,and other parameters,probe size can be reduced while ensuring the sensor’s *** show the proposed method can meet the requirements of sensor fabrication with different sensitivities and ranges,and to a certain extent,both high sensitivity and extensive ranges can be taken into *** sensitivity of the fabricated prototype is 15 pm/kPa,and the range is about 0.2 *** the same time,the metal-free feature of the sensor makes it suitable for use in various oil-immersed power *** records oil pressure changes caused by oil discharge breakdown,making it sensitive to small pressure changes in early failures.

关键词： Highly sensitive extensive range optical sensing no metallization pressure perception temperature compensation transformer

Influence of friction-lubrication characteristics varying with rolling speed on instability of chatter and slip in cold tandem rolling process

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Journal of Iron and Steel Research International 2024年第4期31卷 894-908页

作者： Yan-li Xin Zhi-ying Gao bo Tian Qing-dong Zhang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China

In the high-speed cold tandem rolling process of thin plate,chatter or slip instability gives rise to the deterioration of equipment and product *** instability behavior is closely related to interfacial friction-lubrication con-dition which is generally characterized by the friction ***,with higher and higher speed requirements,the commonly used model of friction coefficient is no longer applicable and accurate.A novel approach is suggested to calculate the speed-dependent friction coefficient,in which the viscosity-pressure-temperature effects of the lubricant,surface roughness states of work rolls and rolled piece are comprehensively involved and the mixed flm lubrication theory is ***,the influences of friction coefficient on the instability of slip and chatter are investigated for a five-stand cold tandem rolling *** one side,the critical friction coefficient for each stand is determined by calculating the corresponding slip factor;on the other hand,the friction coefficient varying with rolling speed is combined with the model of theoretical critical rolling speed presented under constant friction coefficient,so that the speed threshold is ***,the stable and unstable regions corresponding to the rear three stands are individually discussed,and the technical strategies are proposed to suppress both slip and chatter frequently occurring in the actual rolling process.

关键词： Cold tandem rolling:Oil film thickness Speed-dependent friction coefficient-Slip:Chatter

Small RNAs in plant defense

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Small RNAs in plant defense

λ/20-Thick cavity for mimicking electromagnetically induced transparency at telecommunication wavelengths

第九届全国核糖核酸学术讨论会

作者：陈晓亚 Chang-Qing Yang ying-bo mao 中国科学院植物生理与生态研究所

In defense against herbivores and pathogens,plants have developed specialized(secondary)metabolic pathways and *** of secondary metabolites is often regulated by both developmental programs and stimulation *** found t...

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Advanced Photonics 2024年第3期6卷 42-50页

作者： Hua Lu Shouhao Shi Dikun Li Shuwen bo Jianxu Zhao Dong mao Jianlin Zhao Northwestern Polytechnical University School of Physical Science and TechnologyMOE Key Laboratory of Material Physics and Chemistry under Extraordinary ConditionsKey Laboratory of Light-Field Manipulation and Information AcquisitionMinistry of Industry and Information TechnologyShaanxi Key Laboratory of Optical Information TechnologyXi’anChina

Optical cavities play crucial roles in enhanced light-matter interaction,light control,and optical communications,but their dimensions are limited by the material property and operating *** planar cavities are urgently in demand for large-area and integrated optical ***,extremely reducing the planar cavity dimension is a critical challenge,especially at telecommunication ***,we demonstrate a type of ultrathin cavities based on large-area grown Bi_(2)Te_(3)topological insulator(TI)nanofilms,which present distinct optical resonance in the near-infrared *** result shows that the Bi_(2)Te_(3)TI material presents ultrahigh refractive indices of>6 at telecommunication *** cavity thickness can approach 1/20 of the resonance wavelength,superior to those of planar cavities based on conventional Si and Ge high refractive index ***,we observed an analog of the electromagnetically induced transparency(EIT)effect at telecommunication wavelengths by depositing the cavity on a photonic *** EIT-like behavior is derived from the destructive interference coupling between the nanocavity resonance and Tamm *** spectral response depends on the nanocavity thickness,whose adjustment enables the generation of obvious Fano *** experiments agree well with the *** work will open a new door for ultrathin cavities and applications of TI materials in light control and devices.

关键词： topological insulator optical nanocavity photonic crystal electromagnetically induced transparency-like effect

The influences of perforating phase and bedding planes on the fracture deflection in laminated shale

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Petroleum Science 2024年第2期21卷 1221-1230页

作者： Ming-Zhe Gu mao Sheng Xiao-ying Zhuang Xin-Yi Li Gen-Sheng Li National Key Laboratory of Petroleum Resources and Engineering China University of PetroleumBeijing102249China College of Petroleum Engineering China University of PetroleumBeijing102249China College of Civil Engineering Tongji UniversityShanghai200092China

The perforating phase leads to complex and diverse hydraulic fracture propagation behaviors in laminated shale formations. In this paper, a 2D high-speed imaging scheme which can capture the interaction between perforating phase and natural shale bedding planes was proposed. The phase field method was used to simulate the same conditions as in the experiment for verification and hydraulic fracture propagation mechanism under the competition of perforating phase and bedding planes was *** results indicate that the bedding planes appear to be no influence on fracture propagation while the perforating phase is perpendicular to the bedding planes, and the fracture propagates along the perforating phase without deflection. When the perforating phase algins with the bedding planes, the fracture initiation pressure reserves the lowest value, and no deflection occurs during fracture propagation. When the perforating phase is the angle 45°, 60°and 75°of bedding planes, the bedding planes begin to play a key role on the fracture deflection. The maximum deflection degree is reached at the perforating phase of75°. Numerical simulation provides evidence that the existence of shale bedding planes is not exactly equivalent to anisotropy for fracture propagation and the difference of mechanical properties between different shale layers is the fundamental reason for fracture deflection. The findings help to understand the intrinsic characteristics of shale and provide a theoretical basis for the optimization design of field perforation parameters.

关键词： Shale Propagation Perforating Bedding Structure