检索结果-内蒙古大学图书馆

Magnitude,distribution and temporal trend of nitrous oxide emissions from China's natural soils over 1980–2022

science China Earth sciences 2025年第4期68卷 1074-1085页

作者： Songbai HONG Zimeng LI Mingsong TANG Fa LI Yitong YAO Yanzi YAN Mingzhu HE Xuhui WANG Hui ZENG Shilong PIAO School of Urban Planning and Design Shenzhen Graduate SchoolPeking UniversityShenzhen518055China Key Laboratory of Earth Surface System and Human-Earth Relations Ministry of Natural Resources of ChinaShenzhen Graduate SchoolPeking UniversityShenzhen518055China Institute of Carbon Neutrality Sino-French Institute for Earth System ScienceCollege of Urban and Environmental SciencesPeking UniversityBeijing100871China Department of Earth System Science Stanford UniversityStanfordCA94305USA Division of Geological and Planetary Sciences California Institute of TechnologyPasadenaCA91125USA Department of Soil and Environment Swedish University of Agricultural SciencesUppsala75007Sweden Joint International Research Laboratory of Catastrophe Simulation and Systemic Risk Governance Beijing Normal UniversityZhuhai519087China School of National Safety and Emergency Management Beijing Normal UniversityZhuhai519807China

Soils represent the largest contributor to global nitrous oxide(N_(2)O)***,current research efforts predominantly focus on N_(2)O emissions from agricultural soils,while studies on N_(2)O emissions from natural soils,another significant source,remain *** this study,we explored the magnitude,spatiotemporal dynamics,and drivers of N_(2)O emissions from China's natural soils over the period 1980–2022 via machine learning and a compiled novel dataset of 319 field *** results revealed that the N_(2)O flux per unit area was generally higher in the southeast compared to the northwest,and higher in forests than in *** spatial and biome heterogeneity was strongly regulated by local hydrothermal conditions and nitrogen *** averaged N_(2)O emissions over the study period were 646.2±27 Gg N_(2)O yr^(-1),with approximately equivalent contributions from forests and ***,there exhibited a significant and increasing trend from 1980 to 2022,with a rate of 2.7 Gg N_(2)O yr^(-2).Such an increase was primarily driven by the expansion of forested area and elevated nitrogen *** data-driven study presents a long-term and gridded estimate of N_(2)O emissions from China's natural soils,emphasizing the need for future research on changes of greenhouse gas emissions induced by land use change and nitrogen deposition.

关键词： Nitrous oxide Spatiotemporal dynamics Nitrogen deposition Forests Grasslands Data-driven estimates

来源：评论

学校读者我要写书评

暂无评论

In-situ SR-CT experimental study on rapid densification mechanisms of SiCw/Al composites: Orientation and structural arrangement of whisker

引用

Composites Part A: Applied science and Manufacturing 2025年 195卷

作者： Wang, Yuanjie Xiao, Yu Li, Yulong Hu, Xiaofang Xu, Feng CAS Key Laboratory of Mechanical Behaviour and Design of Materials Department of Modern Mechanics CAS Center for Excellence in Complex System Mechanics University of Science and Technology of China Anhui Hefei230027 China

For Al matrix composites, SiC whiskers (SiCw), as reinforcement, have a better ability to improve the strength and toughness of the material than particles. However, the current mechanical properties of SiCw/Al composites are still not up to expectations because of more complex factors such as whisker orientation and structure distribution. The key to achieve mechanical property optimization and breakthrough is to understand the relationship among the external field energy, microstructure and sintering process during the preparation of materials. In the present paper, the whole process of SiCw/Al composites microstructure evolution was observed accurately by in situ SR-CT experiment during microwave rapid sintering process. It was revealed that the densification effect of the sample was obviously better than that when the SiC whisker and Al particle neck are perpendicular to each other. It was found that the when the SiC whiskers located in the neck of Al particles were cross-distributed, the matrix density increased more. The angle between the cross-arranged whiskers had a key influence on the densification process of the material. It provided more understanding for the preparation of high performance SiCw/Al composites and raised the possibility for the preparation of more functional materials. © 2025 Elsevier Ltd

关键词： Densification

来源：评论

学校读者我要写书评

暂无评论

Simulation and analysis of the medical radioisotope 177Lu production based on a high-intensity DT neutron generator

引用

Applied Radiation and Isotopes 2025年 222卷 111880页

作者： Zhou, Chao Liu, Lu Mao, Jiale Qu, Ying Li, Baoqian Li, Yiguo He, Sanjun Wang, Xiaodong Zheng, Bo Feng, Song School of Nuclear Science and Technology University of South China Hengyang421001 China Division of Reactor Engineering Technology Research China Institute of Atomic Energy Beijing102413 China Key Laboratory of Advanced Nuclear Energy Design and Safety Ministry of Education Hengyang421001 China

177Lu is one of the medical radioisotopes with wide application prospects. To explore the 177Lu production besides using reactors, a concept of utilizing high-enriched cylindrical 176Lu based on a high-intensity DT neutron generator via the direct neutron capture reaction has been proposed. The production of 177Lu in a176Lu2O3 solid shell target has been simulated considering layers of neutron multiplier, moderator, and reflector around itself. Materials used as multipliers, moderators, and reflectors have been investigated and analyzed for neutronics optimization. The combinations and thicknesses of different layers have been calculated using the response surface methodology (RSM), and the three layers were found almost independently for the 177Lu production. Both the activity and the specific activity of produced 177Lu were improved significantly using the RSM. According to the calculations, about 13.5 Ci 177Lu can be produced after 40 days of irradiation with a stable neutron yield of 5 × 1011 n/s. © 2025 Elsevier Ltd

关键词： Neutron irradiation apparatus

来源：评论

学校读者我要写书评

暂无评论

The role of secondary phases on SCC initiation of Alloy 718 in simulated PWR primary water

引用

Corrosion science 2025年 252卷

作者： Zhu, Tianyu Wang, Jiamei Song, Miao Ren, Quanyao Qiu, Xi Li, Yuanming Tang, Chuanbao Yi, Hongpu Zhang, Jing Tian, Wenxi Ang, Y.U. Guo, Xianglong School of Nuclear Science and Engineering Shanghai Jiao Tong University No. 800 Dongchuan Road Shanghai200240 China Ministry of Education China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China School of Energy and Power Engineering Xi'an Jiao Tong University Xi'an710049 China Baimtec Material Co. Ltd Beijing100095 China

Stress corrosion cracking (SCC) initiation behavior of Alloy 718 with different precipitates was studied by slow strain rate tensile testing (SSRT) in a simulated pressurized water reactor (PWR) primary water environment. It was found that both nano-precipitates (γ', γ'' phases) and δ phases enhanced the SCC susceptibility. Nano-precipitates significantly suppressed the interior slip and increased the local stress concentration at grain boundaries (GBs), thus promoting the initiation of intergranular (IG) cracks. GBs oriented perpendicular to the loading direction favored IG crack propagation. Preferential oxidation of the δ phases and the δ/γ interface were precursors to crack initiation, thereby increasing the SCC susceptibility. The shape of δ phases affected the oxidation degree, and more severe oxidation was observed on needle-like δ phases. © 2025 Elsevier Ltd

关键词： Stress corrosion cracking

来源：评论

学校读者我要写书评

暂无评论

Online Flow Scheduling in Virtualized Time-Sensitive Networks: A Joint Admission Control and VNF Embedding Approach

引用

IEEE Transactions on Mobile Computing 2025年第6期24卷 4651-4667页

作者： Zhang, Yajing Chen, Cailian Li, Mingyan You, Chaoqun Guan, Xinping Quek, Tony Q. S. Shanghai Satellite Network Research Institute Co. Ltd. Shanghai200120 China Shanghai Jiao Tong University Department of Automation Shanghai200240 China Ministry of Education of China Key Laboratory of System Control and Information Processing Shanghai200240 China Shanghai Engineering Research Center of Intelligent Control and Management Shanghai200240 China Chongqing University College of Computer Science Chongqing400044 China Fudan University School of Computer Science Shanghai200433 China Singapore University of Technology and Design 487372 Singapore

Time-sensitive networking (TSN) is proposed to satisfy the increasingly stringent demands of Industrial 4.0 for deterministic transmission. This is achieved by generating a series of centrally configured gate control lists to strictly restrict the forwarding time of arriving flows. However, such a centralized scheme requires prior information of all flows, severely impeding TSN from providing an online response to dynamic industrial applications. To solve this problem, we innovatively propose to use admission control (AC) to realize deterministic transmission in the virtualized TSN network. In this approach, AC is distributively executed on each node and link, whereby flows of applications are served by passing through a series of virtual network functions (VNFs). This distributed AC execution is regarded as a VNF embedding (VNE) process. Specifically, we propose a two-stage online framework, Smart Admission Control (SmartAC), to cater to dynamic applications. The first stage, referred to as the static stage, obtains a deterministic VNE solution by synthesizing AC decisions of individual TSN nodes and links. The second stage, referred to as the dynamic stage, fine-tunes VNE solutions obtained from the static stage to adapt to the harsh environment with insufficient resources or limited VNF migration budgets. Simulation results demonstrate the effectiveness of SmartAC in improving response rate and resource utilization ratio. Notably, SmartAC reduces runtime by 90% compared to existing algorithms and exhibits robustness across different network topologies. © 2002-2012 IEEE.

关键词： Budget control

来源：评论

学校读者我要写书评

暂无评论

Thermal–Mechanical Coupling Model of a Double-Piece Inner Ring Ball Bearing Based on ADAMS Secondary Development

引用

Lubricants 2025年第4期13卷 154-154页

作者： Xue, Yujun Meng, Fanjing Yu, Yongjian Cai, Haichao School of Mechanical and Electrical Engineering Henan University of Science and Technology Luoyang471003 China Longmen Laboratory Luoyang471003 China Henan Key Laboratory for Machinery Design and Transmission System Henan University of Science and Technology Luoyang471003 China Henan Collaborative Innovation Center for High-End Bearings Luoyang471003 China

The double-piece inner ring ball bearing is an important part of an aero-engine. An excessive bearing temperature leads to bearing thermal expansion, lubricating oil performance degradation, and other problems that seriously affect the service life and reliability of the bearing. Thus, it is important to study the temperature field of a double-piece inner ring ball bearing. In this study, considering the heat exchange of lubricant circulating in the oil tank–tubing–bearing and the influence of the flow field in the bearing chamber on the bearing’s temperature rise, a modified transient thermal network equation for an oil tank–tubing–bearing system was established. Based on ADAMS software and considering the thermal–mechanical coupling effect on the bearing’s contact force, a thermal–mechanical coupling dynamic model for double-piece inner ring ball bearings was established. Combined with the bearing dynamics and modified transient thermal network equation, a thermal–mechanical coupling transient temperature field model for double-piece inner ring ball bearings was constructed. A temperature rise test was carried out on a double-piece inner ring ball bearing, and the accuracy of the bearing temperature rise simulation model was verified by the test results. The model can simulate the oil temperature change process, calculate the heat absorbed by the lubricating oil more accurately, and provide a theoretical basis for the design of bearing and lubrication systems. © 2025 by the authors.

关键词： Ball bearings

来源：评论

学校读者我要写书评

暂无评论

Stabilization of zinc anode by trace organic corrosion inhibitors for long lifespan

引用

Chinese Chemical Letters 2025年第3期36卷 538-543页

作者： Wenfeng Shao Chuanlin Li Chenggang Wang Guangsen Du Shunshun Zhao Guangmeng Qu Yupeng Xing Tianshuo Guo Hongfei Li Xijin Xu School of Physics and Technology University of JinanJi’nan 250022China State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China School of Chemistry and Chemical Engineering Shandong UniversityJi’nan 250100China School of System Design and Intelligent Manufacturing Southern University of Science and TechnologyShenzhen 518000China

Aqueous zinc-ion batteries are highly favored for their enhanced safety and reduced ***,there exist challenges including zinc dendrite,hydrogen evolution,and surface corrosion to be *** electrolyte additives is a highly convenient approach to solving zinc anode-related *** by industrial corrosion protection,a trace amount of the corrosion inhibitor urotropine(URT)is used as an electrolyte additive to protect the zinc *** calculation and experimental analysis confirm the adsorption of URT molecules onto the surface of Zn,which inhibits hydrogen *** adsorption further leads to the formation of an inorganic-organic bilayer solid electrolyte interface(SEI)on the surface of the zinc anode,effectively protecting the Zn anode from corrosion,hydrogen evolution and zinc *** presence of SEI enables symmetrical Zn//Zn cells to exhibit a long cycling performance of 1750 h at 1mA/cm^(2)and an average coulombic efficiency of 99.0%at 1mA/cm^(2)in Zn//Cu *** being coupled with polyaniline(PANI),the Zn//PANI full battery displays excellent cycle stability and specific capacity.

关键词： Solid electrolyte interface Aqueous zinc-ion battery Corrosion inhibitors Electrolyte additive Zinc anode

来源：评论

学校读者我要写书评

暂无评论

DeepSeek: Paradigm Shifts and Technical Evolution in Large AI Models

引用

IEEE/CAA Journal of Automatica Sinica 2025年第5期12卷 841-858页

作者： Luolin Xiong Haofen Wang Xi Chen Lu Sheng Yun Xiong Jingping Liu Yanghua Xiao Huajun Chen Qing-Long Han Yang Tang Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of Education and the Engineering Research Center of Process System Engineering Ministry of Education East China University of Science and Technology Shanghai China College of Design and Innovation Tongji University Shanghai China Shanghai Key Laboratory of Data Science School of Computer Science Fudan University Shanghai China School of Software Beihang University Beijing China School of Information Science and Engineering East China University of Science and Technology Shanghai China AZFT Joint Laboratory for Knowledge Engine Hangzhou Innovation Center College of Computer Science and Technology Zhejiang University Hangzhou China School of Science Computing and Engineering Technologies Swinburne University of Technology Melbourne VIC Australia

DeepSeek, a Chinese artificial intelligence (AI) startup, has released their V3 and R1 series models, which attracted global attention due to their low cost, high performance, and open-source advantages. This paper begins by reviewing the evolution of large AI models focusing on paradigm shifts, the mainstream large language model (LLM) paradigm, and the DeepSeek paradigm. Subsequently, the paper highlights novel algorithms introduced by DeepSeek, including multi-head latent attention (MLA), mixture-of-experts (MoE), multi-token prediction (MTP), and group relative policy optimization (GRPO). The paper then explores DeepSeek's engineering breakthroughs in LLM scaling, training, inference, and system-level optimization architecture. Moreover, the impact of DeepSeek models on the competitive AI landscape is analyzed, comparing them to mainstream LLMs across various fields. Finally, the paper reflects on the insights gained from DeepSeek's innovations and discusses future trends in the technical and engineering development of large AI models, particularly in data, training, and reasoning.

关键词： Training Technological innovation Foundation models Large language models Reinforcement learning Prediction algorithms Market research Cognition Inference algorithms Optimization

来源：评论

学校读者我要写书评

暂无评论

Lattice Boltzmann method for simulation of time-dependent neutral particle transport

引用

Nuclear science and Techniques 2017年第3期28卷 74-84页

作者： Ya-Hui Wang Li-Ming Yan Bang-Yang Xia Yu Ma School of Energy Science and Engineering Harbin Institute of Technology Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China

In this paper, a novel model is proposed to investigate the neutron transport in scattering and absorbing medium. This solution to the linear Boltzmann equation is expanded from the idea of lattice Boltzmann method(LBM) with the collision and streaming process. The theoretical derivation of lattice Boltzmann model for transient neutron transport problem is proposed for the first *** fully implicit backward difference scheme is used to ensure the numerical stability, and relaxation time and equilibrium particle distribution function are obtained. To validate the new lattice Boltzmann model, the LBM formulation is tested for a homogenous media with different sources, and both transient and steady-state LBM results get a good agreement with the benchmark solutions.

关键词： Transient neutron transport Lattice Boltzmann method Linear Boltzmann equation

来源：评论

学校读者我要写书评

暂无评论

GNN-Assisted BiG-AMP: Joint Channel Estimation and Data Detection for Massive MIMO Receiver

引用

IEEE Transactions on Wireless Communications 2025年

作者： Liu, Zishen Wu, Nan He, Dongxuan Yuan, Weijie Li, Yonghui Quek, Tony Q. S. School of Information and Electronics Beijing Institute of Technology Beijing100081 China School of System Design and Intelligent Manufacturing Shenzhen Key Laboratory of Robotics and Computer Vision Southern University of Science and Technology Shenzhen518055 China School of Electrical and Information Engineering The University of Sydney SydneyNSW2008 Australia Singapore University of Technology and Design 487372 Singapore Department of Electronic Engineering Kyung Hee University Yongin17104 Korea Republic of

In this paper, we develop a graph neural network (GNN)-assisted bilinear inference approach to enhance the receiver performance of the MIMO system through message passing-based joint channel estimation and data detection (JCD). Specifically, based on the bilinear generalized approximate message passing (BiG-AMP) framework and conditional correlation of signal, we propose a GNN-assisted BiG-AMP (GNN-BiGAMP) approach, which integrates a GNN module into the data-detection-loop to compensate the inaccurate marginal likelihood approximation. By leveraging the coupling between the channel and received symbols, a bilinear GNN-assisted BiG-AMP (BiGNN-BiGAMP) JCD receiver is further proposed. This method incorporates two GNNs with similar graph representation into the bilinear posterior estimation loops, which not only compensates for approximation errors but also alleviates performance loss due to premature variance convergence, thereby enhancing the receiver performance significantly. To fully exploit the supervised information from channel estimation and data detection, we propose a multitask learning based training scheme, which coordinates GNNs with different tasks in two loops. Simulation results show that our proposed GNN-assisted JCD receivers significantly outperform other JCD counterparts in terms of both channel estimation and data detection. © 2025 IEEE. All rights reserved.

关键词： Graph neural networks

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：