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Could natural phytochemicals be used to reduce nitrogen excretion and excreta‑derived N_(2)O emissions from ruminants?

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Journal of Animal Science and Biotechnology 2024年第2期15卷 490-508页

作者： Yuchao Zhao Ming Liu Linshu Jiang Leluo guan Beijing Key Laboratory of Dairy Cow Nutrition College of Animal Science and TechnologyBeijing University of AgricultureBeijing 102206China College of Animal Science and Technology China Agricultural UniversityBeijing 100193China Department of Agricultural Food and Nutritional ScienceUniversity of AlbertaEdmontonAB T6G 2R3Canada

Ruminants play a critical role in our food system by converting plant biomass that humans cannot or choose not to consume into edible high-quality ***,ruminant excreta is a significant source of nitrous oxide(N_(2)O),a potent greenhouse gas with a long-term global warming potential 298 times that of carbon *** phytochemicals or forages containing phytochemicals have shown the potential to improve the efficiency of nitrogen(N)utilization and decrease N_(2)O emissions from the excreta of *** inclusion of tannins can shift more of the excreted N to the feces,alter the urinary N composition and consequently reduce N_(2)O emissions from *** oils or saponins could inhibit rumen ammonia production and decrease urinary N *** grazed pastures,large amounts of glucosinolates or aucubin can be introduced into pasture soils when animals consume plants rich in these compounds and then excrete them or their metabolites in the urine or *** inhibitory compounds are excreted in the urine,they would be directly applied to the urine patch to reduce nitrification and subsequent N_(2)O *** phytochemicals’role in sustainable ruminant production is undeniable,but much uncertainty ***,transient effects,and adverse effects limit the effectiveness of these phytochemicals for reducing N *** this review,we will identify some current phytochemicals found in feed that have the potential to manipulate ruminant N excretion or mitigate N_(2)O production and deliberate the challenges and opportunities associated with using phytochemicals or forages rich in phytochemicals as dietary strategies for reducing N excretion and excreta-derived N_(2)O emissions.

关键词： Nitrogen metabolism Nitrous oxide Plant bioactive compounds Ruminant Urine patches

Design of Protograph LDPC-Coded MIMO-VLC Systems with Generalized Spatial Modulation

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China Communications 2024年第3期21卷 118-136页

作者： Dai Lin Fang Yi guan Yongliang Mohsen Guizani School of Information Engineering Guangdong University of TechnologyGuangzhou 51006China The State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710126China School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore Department of Machine Learning Mohamed Bin Zayed University of Artificial Intelligence(MBZUAI)Abu DhabiUnited Arab Emirates

This paper investigates the bit-interleaved coded generalized spatial modulation(BICGSM) with iterative decoding(BICGSM-ID) for multiple-input multiple-output(MIMO) visible light communications(VLC). In the BICGSM-ID scheme, the information bits conveyed by the signal-domain(SiD) symbols and the spatial-domain(SpD) light emitting diode(LED)-index patterns are coded by a protograph low-density parity-check(P-LDPC) code. Specifically, we propose a signal-domain symbol expanding and re-allocating(SSER) method for constructing a type of novel generalized spatial modulation(GSM) constellations, referred to as SSERGSM constellations, so as to boost the performance of the BICGSM-ID MIMO-VLC ***, by applying a modified PEXIT(MPEXIT) algorithm, we further design a family of rate-compatible P-LDPC codes, referred to as enhanced accumulate-repeat-accumulate(EARA) codes,which possess both excellent decoding thresholds and linear-minimum-distance-growth property. Both analysis and simulation results illustrate that the proposed SSERGSM constellations and P-LDPC codes can remarkably improve the convergence and decoding performance of MIMO-VLC systems. Therefore, the proposed P-LDPC-coded SSERGSM-mapped BICGSMID configuration is envisioned as a promising transmission solution to satisfy the high-throughput requirement of MIMO-VLC applications.

关键词： bit-interleaved coded modulation generalized spatial modulation multiple-input multipleoutput protograph LDPC codes visible light communication

Quantitative assessment of the supply,demand and flows of ecosystem services in the Yangtze River Basin,China

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Frontiers of Earth Science 2024年第2期18卷 422-445页

作者： Dongjie guan Xiaofeng FAN Lilei ZHOU Kangwen ZHU School of Smart City Institute Chongqing Jiaotong UniversityChongqing 400074China

Ecosystem service flow is essential for transporting,transforming,and maintaining ecosystem services and connecting supply and *** study attempted to quantitatively assess the supply and demand flows of ecosystem services in the Yangtze River Basin in 2000,2010,and 2020;assess the evolution of the spatial patterns of ecosystem service flow at the provincial,watershed and urban agglomeration scales;and design a zoning standard for ecosystem service *** results showed as follows.1)Between 2000 and 2020,the Yangtze River had a progressive drop in its freshwater supply,water conservation service and carbon sequestration service *** decline rates for these services were measured at 10.90%,11.11%,and 5.17%,*** climate regulation service flow exhibited a pattern of initial fall followed by a subsequent increase,characterized by a decline rate of 35.53%.2)The lowest was the ecosystem service flow in the lower reaches of the Yangtze River and the Yangtze River Delta urban *** supply service flow and water conservation service flow were the highest in the upper reaches of the Yangtze River and the Chengdu-Chongqing urban *** sequestration service flow and climate regulation service flow were the highest in the middle reaches of the Yangtze River Basin and the urban agglomeration in the middle reaches of the Yangtze River.3)From 2000 to 2020,the change ratios of the area proportion of the confluence,flow,and outflow areas in the Yangtze River Basin were 1.06,3.17,and 0.86,*** results of this research could offer decision support for regulating ecosystem services in the Yangtze River Basin,promoting sustainable regional development and achieving rational use of the basin resources.

关键词： Yangtze River Basin ecosystem services supply and demand service flow quantitative assessment spatial matching

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Optics-driven drone

Science China(Information Sciences) 2024年第2期67卷 322-324页

作者： Xuelong LI guan HUANG Zhigang WANG Bin ZHAO School of Artificial Intelligence OPtics and Electro Nics (iOPEN)Northwestern Polytechnical University Shanghai Artificial Intelligence Laboratory

In the field of vicinagearth security, low-altitude flying vehicles such as drones play an indispensable role in aerial remote sensing, intelligent search and rescue, etc. [1]. It can be foreseen that the autonomous and intelligent execution of complex tasks by drones is an inevitable trend for future development.

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1.42-fold enhancement of formate selectivity by linker conversion on the Zn-based metal organic framework catalyst

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Journal of Energy Chemistry 2024年第3期90卷 183-190,I0006页

作者： Yayu guan Yuyu Liu Fanghua Ning Jin Yi Jiujun Zhang Institute for Sustainable Energy College of SciencesShanghai UniversityShanghai 200444China

Electro-reduction of carbon dioxide(ERCO_(2)) is considered an effective method to alleviate the greenhouse effect and produce value-added *** the dominant selectivity of Zn-based catalysts for formate remains a *** this article,the ZnIn-E_(12) catalyst is successfully prepared by solvent assisted ligand exchange(SALE) method to convert organic ligands,achieving a Faradaic efficiency of 72.28% for formate at-1.26 V ***(V_(RHE)),which is 1.42 times higher than the original *** shows that the successful conversion of organic ligands can transform the catalyst from the original large size polyhedron to cross-linked network of particles with a diameter of about 30 *** increased specific surface area can expose more active sites and facilitate the electrocatalytic conversion of CO_(2) to *** work is expected to provide inspiration for the regulation of formate selectivity and catalyst size in Zn-based catalysts.

关键词： Electrocatalyst Carbon dioxide Formate Linker conversion

A GMDA clustering algorithm based on evidential reasoning architecture

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Chinese Journal of Aeronautics 2024年第1期37卷 300-311页

作者： Haibin WANG Xin guan Xiao YI shuangming LI Guidong SUN Naval Aviation University Yantai 264001China Unit 92941 of PLA Huludao 125001China Institute of Systems Engineering Beijing 100082China

The traditional clustering algorithm is difficult to deal with the identification and division of uncertain objects distributed in the overlapping region,and aimed at solving this problem,the Evidential Clustering based on General Mixture Decomposition Algorithm(GMDA-EC)is ***,the belief classification of target cluster is carried out,and the sample category of target distribution overlapping region is ***,on the basis of General Mixture Decomposition Algorithm(GMDA)clustering,the fusion model of evidence credibility and evidence relative entropy is constructed to generate the basic probability assignment of the target and achieve the belief division of the ***,the performance of the algorithm is verified by the synthetic dataset and the measured *** experimental results show that the algorithm can reflect the uncertainty of target clustering results more comprehensively than the traditional probabilistic partition clustering algorithm.

关键词： Evidential clustering Credal partition Evidential reasoning Mixed decomposition Gaussian mixture model

Atomically Substitutional Engineering of Transition Metal Dichalcogenide Layers for Enhancing Tailored Properties and Superior Applications

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Nano-Micro Letters 2024年第5期16卷 248-284页

作者： Zhaosu Liu Si Yin Tee Guijian guan Ming‑Yong Han Institute of Molecular Plus Tianjin UniversityTianjin 300072People’s Republic of China Institute of Materials Research and Engineering A*STARSingapore 138634Singapore

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 *** 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 *** 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 *** review comprehensively elaborates on atomically substitutional engineering in TMD layers,including theoretical foundations,synthetic strategies,tailored properties,and superior *** emerging type of ternary TMDs,Janus TMDs,is presented specifically to highlight their typical compounds,fabrication methods,and potential ***,opportunities and challenges for further development of multinary TMDs are envisioned to expedite the evolution of this pivotal field.

关键词： Transition metal dichalcogenides Atomic substitution Tailored structure Tunable bandgap Enhanced applications

Elastic buckling analysis and optimization of thin-walled bamboo-like pipe beam subjected to pure bending

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Chinese Journal of Aeronautics 2024年第3期37卷 133-152页

作者： Yayun YU Dongli MA Liang ZHANG Xiaopeng YANG Hao guan School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China

In this paper,a stiffening design imitating the bamboo node is proposed for weight reduction of the long composite pipe beam subjected to bending *** distribution of bamboo nodes can efficiently suppress the ovalization of the section,thus significantly improving the bending resistance of the *** on this principle,ring stiffeners are proposed to be fixed to the pipe beam,making the long beam equivalent to the combination of a series of short pipes that suffered less section ovalization.A database of the optimal laminate orientations for different normalized lengths is obtained through optimizations,where the discreteness of the ply count is *** on this database,weight optimizations are conducted,and the optimal designs of beams with and without stiffeners are obtained and *** comparison results show that the proposed bamboo-like stiffened beam not only regains a near-linear load–displacement relationship,but also reduces the weight by up to 16%under the same buckling *** addition,it is found that for the pipe beams with radius-to-thickness ratios of more than 18,increasing the radius leads to a decrease in elastic buckling resistance when the weight remains a constant,which is opposite to the design for strength and *** model and database developed in this paper can provide a reference for weight reduction design and weight estimation for composite pipe beams.

关键词： Composite beam Buckling Thin-walled structure Unmanned aerial vehicles Bamboo

Multiscale analysis-based peridynamic simulation of fracture in porous media

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 1-13页

作者： Zihao YANG Shangkun SHEN Xiaofei guan Xindang HE Junzhi CUI School of Mathematics and Statistics Northwestern Polytechnical UniversityXi’an 710072China School of Mathematical Sciences Tongji UniversityShanghai 200092China School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an 710072China LSEC ICMSECAcademy of Mathematics and Systems ScienceCASBeijing 100190China

The simulation of fracture in large-scale structures made of porous media remains a challenging *** techniques either assume a homogeneous model,disregarding the microstructure characteristics,or adopt a micro-mechanical model,which incurs an intractable computational cost due to its complex stochastic geometry and physical properties,as well as its nonlinear and multiscale *** this study,we propose a multiscale analysis-based dual-variable-horizon peridynamics(PD)model to efficiently simulate macroscopic structural *** influence of microstructures in porous media on macroscopic structural failure is represented by two PD parameters:the equivalent critical stretch and *** equivalent critical stretch is calculated using the microscale PD model,while the equivalent micro-modulus is obtained through the homogenization method and energy density equivalence between classical continuum mechanics and PD *** examples of porous media with various microstructures demonstrate the validity,accuracy,and efficiency of the proposed method.

关键词： porous media multiscale variable-horizon peridynamic equivalent critical stretch equivalent micro-modulus