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Science China Earth Sciences 2024年第9期67卷 2824-2844页

作者： Hongyu WANG Shuanhong ZHANG sen WANG Linghao KONG Yue ZHAO Qiqi ZHANG sen GAO Guohui HU Institute of Geomechanics Chinese Academy of Geological Sciences Key Laboratory of Paleomagnetism and Tectonic Reconstruction Ministry of Natural Resources SinoProbe Laboratory Chinese Academy of Geological Sciences School of Earth Science and Mineral Resources China University of Geosciences

The Great Oxidation Event（GOE） during the early Paleoproterozoic represents the first significant buildup in Earth's atmospheric oxygen and resulted in a series of significant changes in the Earth's surface environment. Among them is the 2.22（or 2.33）–2.06 Ga Lomagundi-Jatuli Event（LJE）, which is globally, the largest magnitude and longest duration, marine carbonate positive carbon isotope excursion(δ13CV-PDB>10‰) known. This event has attracted the attention of scholars all over the world. However, except for a high positive carbon isotope excursion(δ13CV-PDB>10‰) recently identified from marine carbonate rocks within the Daposhan Formation in the lower Fanhe Group（or the Sanchazi Group） in the Longgang Block in the northeast North China Craton（NCC）, Paleoproterozoic carbonates in the NCC are characterized by a low-amplitude positive carbon isotope excursion(δ13CV-PDB10‰） of marine carbonate rocks occurred at about 2.15 *** comparisons of different s

关键词： Lomagundi-Jatuli Event (LJE) Great Oxidation Event (GOE) Carbon-oxygen isotopes Liaohe Group Marine carbonate Jiao-Liao-Ji Belt North China Craton

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Multi-scale detector optimized for small target

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Optoelectronics Letters 2024年第4期20卷 243-248页

作者： ZHU Yongchang YANG sen TONG Jigang WANG Zenghui School of Electrical Engineering and Automation Tianjin University of TechnologyTianjin 300384China Center of Artificial Intelligence and Data Science University of South AfricaFlorida 1709South Africa Department of Electrical Engineering University of South AfricaFlorida 1709South Africa

The effectiveness of deep learning networks in detecting small objects is limited,thereby posing challenges in addressing practical object detection *** this research,we propose a small object detection model that operates at multiple *** model incorporates a multi-level bidirectional pyramid structure,which integrates deep and shallow networks to simultaneously preserve intricate local details and augment global ***,a dedicated multi-scale detection head is integrated into the model,specifically designed to capture crucial information pertaining to small *** comprehensive experimentation,we have achieved promising results,wherein our proposed model exhibits a mean average precision(mAP)that surpasses that of the well-established you only look once version 7(YOLOv7)model by 1.1%.These findings validate the improved performance of our model in both conventional and small object detection scenarios.

关键词： networks details thereby

Afforestation with an age-sequence of Mongolian pine plantation promotes soil microbial residue accumulation in the Horqin Sandy Land, China

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Journal of Arid Land 2024年第4期16卷 567-579页

作者： GUO Jingwen SONG Xueshu WANG Xiao DU Zhangliu LU sen State Key Laboratory of Efficient Production of Forest Resources Research Institute of ForestryChinese Academy of ForestryBeijing 100091China Co-Innovation Center for Sustainable Forestry in Southern China Nanjing Forestry UniversityNanjing 210037China College of Resources and Environmental Sciences China Agricultural UniversityBeijing 100193China

Land use change affects the balance of organic carbon(C)reserves and the global C *** residues are essential constituents of stable soil organic C(SOC).However,it remains unclear how microbial residue changes over time following *** this study,16-,23-,52-,and 62-year-old Mongolian pine stands and 16-year-old cropland were studied in the Horqin Sandy Land,*** analyzed changes in SOC,amino sugar content,and microbial parameters to assess how microbial communities influence soil C transformation and *** results showed that SOC storage increased with stand age in the early stage of afforestation but remained unchanged at about 1.27-1.29 kg/m2 after 52 ***,there were consistent increases in amino sugars and microbial residues with increasing stand *** stand age increased from 16 to 62 a,soil pH decreased from 6.84 to 5.71,and the concentration of total amino sugars increased from 178.53 to 509.99 mg/kg.A significant negative correlation between soil pH and the concentration of specific and total amino sugars was observed,indicating that the effects of soil acidification promote amino sugar stabilization during *** contrast to the Mongolian pine plantation of the same age,the cropland accumulated more SOC and microbial residues because of fertilizer *** Mongolian pine plantation with different ages,there was no significant change in calculated contribution of bacterial or fungal residues to SOC,suggesting that fungi were consistently the dominant contributors to SOC with increasing *** results indicate that afforestation in the Horqin Sandy Land promotes efficient microbial growth and residue accumulation in SOC stocks and has a consistent positive impact on SOC persistence.

关键词： soil organic matter stand age biomarker amino sugars microbial residues

Complex granular flows of sticky-wet material on flip-flow screens:Calibration of discrete element simulations

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Particuology 2024年第1期84卷 290-308页

作者： Ningning Xu sen Tang Dongdong Lin Runhui Geng Xinwen Wang Xihui Liang School of Chemical and Environmental Engineering China University of Mining and Technology(Beijing)Beijing100083China Department of Mechanical Engineering University of ManitobaWinnipegManitobaR3T 5V6Canada

Discrete element method(DEM)is an effective approach for studying the screening process of flip-flow ***,there have been few studies focusing on the thick layer of sticky-wet particles on flip-flow *** achieve accurate simulations of the thick layer of sticky-wet particles on a flip-flow screen,firstly,the movement law of particle flow was studied,and a multi-regime combination cali-bration method based on characteristics of particle flow regimes was *** on the Plackett-Burman experiment,the curse of dimensionality caused by multi-state and multi-contact parameters was ***,the lifting cylinder,rotating drum,and trampoline tests were carried out to obtain macroscopic reference values under various granular flow *** calibration results were then determined using the response surface method and climbing ***,the calibration results were tested at both macroscopic and mesoscopic scales and compared with a commonly used calibration *** results demonstrate that the calibration method,which considers the multi-state characteristics,improves simulation accuracy by 2%-10%and reduces the simulation error to less than 10%,thus meeting the requirements for engineering optimization of flip-flow screens.

关键词： DEM Complex granular flow Parameter calibration Flip-flow screen Sticky-wet particles Thick layer

Design Framework of Unsourced Multiple Access for 6G Massive IoT

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China Communications 2024年第1期21卷 1-12页

作者： Chunlin Yan Siying Lyu sen Wang Yuhong Huang Xiaodong Xu China Mobile Communication Research Institute Beijing 100053China ZGC Institute of Ubiquitous-X Innovation and Applications Beijing 100080China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

In this paper,ambient IoT is used as a typical use case of massive connections for the sixth generation(6G)mobile communications where we derive the performance requirements to facilitate the evaluation of technical solutions.A rather complete design of unsourced multiple access is proposed in which two key parts:a compressed sensing module for active user detection,and a sparse interleaver-division multiple access(SIDMA)module are simulated side by side on a same platform at balanced signal to noise ratio(SNR)operating *** a proper combination of compressed sensing matrix,a convolutional encoder,receiver algorithms,the simulated performance results appear superior to the state-of-the-art benchmark,yet with relatively less complicated processing.

关键词： channel coding compressed sensing massive Internet-of-Things(IoT) sparse interleaverdivision multiple access(SIDMA) the sixth generation(6G)mobile communications unsourced multiple access

Method of fabricating artificial rock specimens based on extrusion free forming(EFF)3D printing

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1455-1466页

作者： Xiaomeng Shi Tingbang Deng sen Lin Chunjiang Zou Baoguo Liu Key Laboratory for Urban Underground Engineering of the Ministry of Education Beijing Jiaotong UniversityBeijing100044China School of Civil Engineering Beijing Jiaotong UniversityBeijing100044China Department of Civil Engineering Monash UniversityMelbourne3800Australia

Three-dimensional(3D)printing technology has been widely used to create artificial rock samples in rock *** 3D printing can create complex fractures,the material still lacks sufficient similarity to natural *** free forming(EFF)is a 3D printing technique that uses clay as the printing material and cures the specimens through high-temperature *** this study,we attempted to use the EFF technology to fabricate artificial rock *** results show the physico-mechanical properties of the specimens are significantly affected by the sintering temperature,while the nozzle diameter and layer thickness also have a certain *** specimens are primarily composed of SiO_(2),with mineral compositions similar to that of natural *** density,uniaxial compressive strength(UCS),elastic modulus,and tensile strength of the printed specimens fall in the range of 1.65–2.54 g/cm3,16.46–50.49 MPa,2.17–13.35 GPa,and 0.82–17.18 MPa,*** is capable of simulating different types of rocks,especially mudstone,sandstone,limestone,and ***,the simulation of hard rocks with UCS exceeding 50 MPa still requires validation.

关键词： Artificial rock 3D printing Extrusion free forming(EFF) Similarity analysis Mechanical properties

Conceptual design of a 714-MHz RFQ for compact proton injectors and development of a new tuning algorithm on its aluminium prototype

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Nuclear Science and Techniques 2024年第1期35卷 45-58页

作者： Yi-Xing Lu Wen-Cheng Fang Yu-sen Guo Zhen-Tang Zhao Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800China University of Chinese Academy of Sciences Beijing 101408China Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201204China Shanghai Key Laboratory of Cryogenics&Superconducting RF Technology Shanghai 201800China ShanghaiTech University Shanghai 201210China

Radio frequency quadrupoles(RFQs),which are crucial components of proton injectors,significantly affect the performance of proton accelerator *** RFQ with a high frequency of 714 MHz dedicated to compact proton injectors for medi-cal applications is designed in this *** RFQ is designed to accelerate proton beams from 50 keV to 4 MeV within a short length of 2 m and can be matched closely with the downstream drift tube linac to capture more particles through a preliminary *** develop an advanced RFQ,challenging techniques,including fabrication and tuning method,must be evaluated and verified using a *** aluminium prototype is derived from the conceptual design of the RFQ and then redesigned to confirm the radio frequency performance,fabrication procedure,and feasibility of the tuning ***,a new tuning algorithm based on the response matrix and least-squares method is developed,which yields favorable results based on the prototype,i.e.,the errors of the dipole and quadrupole components reduced to a low level after several tuning *** from the conceptual design and techniques obtained from the prototype,the formal mechanical design of the 2-m RFQ is ready for the next manufacturing step.

关键词： Compact proton injector RFQ IH-DTL High gradient Tuning

Experimental study of the damage characteristics of rocks containing non-penetrating cracks under cyclic loading

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International Journal of Mining Science and Technology 2024年第2期34卷 197-210页

作者： Jun Xu Xiaochun Xiao Lu Ma sen Luo Jiaxu Jin Baijian Wu School of Mechanics and Engineering Liaoning Technical UniversityFuxin 123000China School of Civil Engineering Liaoning Technical UniversityFuxin 123000China Department of Engineering Mechanics Southeast UniversityNanjing 211189China

The damage evolution process of non-penetrating cracks often causes some unexpected engineering *** specimens containing non-penetrating crack(s)are used to study the damage evolution and characteristics under cyclic *** results show that under cyclic loading,the relationship between the number of non-penetrating crack(s)and the characteristic parameters(cyclic number,peak stress,peak strain,failure stress,and failure strain)of the pre-cracked specimens can be represented by a decreasing linear *** damage evolution equation is fitted by calibrating the accumulative plastic strain for each cycle,and the damage constitutive equation is proposed by the concept of effective ***,non-penetrating cracks are more likely to cause uneven stress distribution,damage accumulation,and local failure of *** local failure can change the stress distribution and relieve the inhibition of non-penetrating crack extension and eventually cause a dramatic destruction of the ***,the evolution process caused by non-penetrating cracks can be regarded as one of the important reasons for inducing *** results are expected to improve the understanding of the process of spalling formation and rockburst and can be used to analyze the stability of rocks or rock structures.

关键词： Damage characteristics Constitutive model Fissured rocks Non-penetrating crack Cyclic loading

Relationship among Parkinson’s disease, constipation, microbes, and microbiological therapy

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World Journal of Gastroenterology 2024年第3期30卷 225-237页

作者： Xin-Yang Yuan Yu-sen Chen Zhou Liu Department of Neurology Affiliated Hospital of Guangdong Medical UniversityZhanjiang 524000Guangdong ProvinceChina Institute of Neurology Guangdong Key Laboratory of Age-Related Cardiac and Cerebral DiseasesZhanjiang 524000Guangdong ProvinceChina

This comprehensive review elucidates the complex interplay between gut microbiota and constipation in Parkinson’s disease(PD),a prevalent non-motor symptom contributing significantly to patients’morbidity.A marked alteration in the gut microbiota,predominantly an increase in the abundance of Proteobacteria and Bacteroidetes,is observed in PD-related *** treatments,although safe,have failed to effectively alleviate symptoms,thereby necessitating the development of novel therapeutic *** interventions such as prebiotics,probiotics,and fecal microbiota transplantation(FMT)hold therapeutic *** prebiotics improve bowel movements,probiotics are effective in enhancing stool consistency and alleviating abdominal *** shows potential for significantly alleviating constipation symptoms by restoring gut microbiota balance in patients with *** promising developments,the causal relationship between changes in gut microbiota and PD-related constipation remains elusive,highlighting the need for further research in this expanding field.

关键词： Parkinson disease Constipation Gut microbiota Prebiotics Probiotics Fecal microbiota transplantation

Rice Variety Classification Based on Optimized Near-Infrared Spectral Classification Model

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Rice science 2024年第1期31卷 6-9,I0009-I0012页

作者： YANG sen WANG Zhenmin ZHANG Houqing SONG Wenlong College of Computer and Control Engineering Northeast Forestry UniversityHarbin 150040China The 49th Research Institute of China Electronics Technology Group Corporation Harbin 150000China

Accurate classification of rice variety is essential to ensure the brand value of high-quality rice *** the impact of sample state on modeling optimization algorithms,rice samples after grinding and sealing were *** enhance the accuracy of rice variety classification,we introduced a spectral characteristic wavelength selection method based on adaptive sliding window permutation entropy(ASW-PE).

关键词： sealing Infrared grinding