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Gravity Change Caused by Heavy Rainfall Detected by A gPhone Gravimeter in Zhengzhou,China

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Journal of Earth Science 2024年第4期35卷 1273-1276页

作者： Lelin Xing Yufei Han Xiaowei niu Lei Bai Innovation Academy for Precision Measurement Science and Technology Chinese Academy of SciencesWuhan430077China Wuhan Geodesy National Observation and Research Station Wuhan430077China China Earthquake Networks Center Beijing100045China

The short-term effect of heavy rainfall on gPhone gravimeter observation at Zhengzhou Seismic Station is *** to the observation data during Jul.17–20,2021,the corrected gravity residual reflects the gravimetric response caused by heavy *** observed gravity change is dominated by the local effect considering topographic effect on *** deduced water depth near the observation station is about 300 mm.

关键词： gravity gravity change gravimeter heavy rain Zhengzhou

高校教师学术评价制度的历史流变、现实逻辑与改革图景

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黑龙江高教研究 2024年第5期42卷 34-40页

作者：牛风蕊福州大学福建福州350108

学术评价制度是高校学术管理的关键性制度,其从回归学术到“破五维”的嬗变过程体现了与国家宏观政策紧密耦合的特征。作为一种嵌入式的制度架构,教师学术评价是学术管理制度矩阵的核心要素,高校的分层发展格局、学科建设竞争、教师个... 详细信息

学术评价制度是高校学术管理的关键性制度,其从回归学术到“破五维”的嬗变过程体现了与国家宏观政策紧密耦合的特征。作为一种嵌入式的制度架构,教师学术评价是学术管理制度矩阵的核心要素,高校的分层发展格局、学科建设竞争、教师个体的职级晋升等多重逻辑的叠加效应,使教师学术评价制度呈现出异化现象。教师学术评价制度是高等教育管理制度体系的下位制度,其改革受到宏观制度“深层结构”的外生性动力影响,学术评价与资源的过度绑定、政府主导下的高校管理科层制、既定的学术评价制度产生的路径依赖,形塑着高校教师的学术偏好和学术秩序的重构过程。随着“破五维”改革推进,应从多个层面对教师学术评价制度进行优化:强化高校教师学术评价的多元主体治理,以科教融合为抓手增强高校教师学术评价制度的社会性导向,关注学科差异,实现“激励相容”。通过教师学术评价制度的供给侧结构性改革,引领高等教育高质量发展。

关键词：学术评价制度变迁绩效导向 “破五维” 高质量发展

UAV-assisted cooperative offloading energy efficiency system for mobile edge computing

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Digital Communications and Networks 2024年第1期10卷 16-24页

作者： Xue-Yong Yu Wen-Jin niu Ye Zhu Hong-Bo Zhu jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Nanjing210003China Engineering Research Centerof Health Service System Based on Ubiquitous Wireless Networks Ministry of EducationNanjng Universityof Posts and Telecommunications Nanjing210003China

Reliable communication and intensive computing power cannot be provided effectively by temporary hot spots in disaster areas and complex terrain ground *** this has greatly developed the application and integration of UAV and Mobile Edge Computing(MEC)to the Internet of Things(loT).However,problems such as multi-user and huge data flow in large areas,which contradict the reality that a single UAV is constrained by limited computing power,still *** to allowing UAV collaboration to accomplish complex tasks,cooperative task offloading between multiple UAVs must meet the interdependence of tasks and realize parallel processing,which reduces the computing power consumption and endurance pressure of *** the computing requirements of the user terminal,delay constraint of a computing task,energy constraint,and safe distance of UAV,we constructed a UAV-Assisted cooperative offloading energy efficiency system for mobile edge computing to minimize user terminal energy ***,the resulting optimization problem is originally nonconvex and thus,difficult to solve *** tackle this problem,we developed an energy efficiency optimization algorithm using Block Coordinate Descent(BCD)that decomposes the problem into three convex ***,we jointly optimized the number of local computing tasks,number of computing offloaded tasks,trajectories of UAV,and offloading matching relationship between multi-UAVs and multiuser *** results show that the proposed approach is suitable for different channel conditions and significantly saves the user terminal energy consumption compared with other benchmark schemes.

关键词： Computation offloading Internet of things(IoT) Mobile edge computing(MEC) Block coordinate descent(BCD)

Enhancing cut selection through reinforcement learning

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Science China Mathematics 2024年第6期67卷 1377-1394页

作者： Shengchao Wang Liang Chen Lingfeng niu Yu-Hong Dai Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing100190China Research Center on Fictitious Economy and Data Science Chinese Academy of SciencesBeijing100190China

With the rapid development of artificial intelligence in recent years,applying various learning techniques to solve mixed-integer linear programming(MILP)problems has emerged as a burgeoning research *** from constructing end-to-end models directly,integrating learning approaches with some modules in the traditional methods for solving MILPs is also a promising *** cutting plane method is one of the fundamental algorithms used in modern MILP solvers,and the selection of appropriate cuts from the candidate cuts subset is crucial for enhancing *** to the reliance on expert knowledge and problem-specific heuristics,classical cut selection methods are not always transferable and often limit the scalability and generalizability of the cutting plane *** provide a more efficient and generalizable strategy,we propose a reinforcement learning(RL)framework to enhance cut selection in the solving process of ***,we design feature vectors to incorporate the inherent properties of MILP and computational information from the solver and represent MILP instances as bipartite ***,we choose the weighted metrics to approximate the proximity of feasible solutions to the convex hull and utilize the learning method to determine the weights assigned to each ***,a graph convolutional neural network is adopted with a self-attention mechanism to predict the value of weighting ***,we transform the cut selection process into a Markov decision process and utilize RL method to train the *** experiments are conducted based on a leading open-source MILP solver *** on both general and specific datasets validate the effectiveness and efficiency of our proposed approach.

关键词： reinforcement learning mixed-integer linear programming cutting plane method cut selection

A Study on the Impact of Chemical Structure on the Evolution of Aggregate Structure in Fiber-shaped High Density Polyethylene Vitrimer

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Chinese Journal of Polymer Science 2024年第10期42卷 1557-1565页

作者： Bing Wang Yuan-Chu Gao Hai Wang Hui niu State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of Technology

Vitrimers have emerged as a prominent research area in the field of polymer materials. Most of the studies have focused on synthesizing polymers with versatile dynamic crosslinking structures, while the impact of chemical structure on aggregate structure of vitrimers, particularly during polymer processing, remains insufficiently investigated. The present study employed commercial maleic anhydride-grafted-high density polyethylene (M-g-HDPE) as the matrix and hexanediol as the crosslinker to facilely obtain fiber-shaped HDPE vitrimers through a reaction extrusion and post-drawing process. Through chemical structure characterization, morphology observation, thermal and mechanical properties investigation, as well as aggregate structure analysis, this work revealed the influence of dynamic bonds on the formation of aggregate structures during fiber-shaped vitrimers processing. A small amount of dynamic bonds in HDPE restricts the motion of PE chain during melt-extruding and post-drawing, resulting in a lower orientation of the PE chains. However, lamellar growth and fibril formation during post-drawing at high temperature are enhanced to some extent due to the competition between dynamic bond and chain relaxation. The uneven morphology of fibershaped HDPE vitrimers can be attributed to the stronger elastic effect brought by dynamic bonding, which plays a more dominant role in determining the mechanical properties of fiber-shaped vitrimers compared to aggregate *** Vitrimers have emerged as a prominent research area in the field of polymer *** of the studies have focused on synthesizing polymers with versatile dynamic crosslinking structures,while the impact of chemical structure on aggregate structure of vitrimers,particularly during polymer processing,remains insufficiently *** present study employed commercial maleic anhydride-grafted-high density polyethylene (M-g-HDPE) as the matrix and hexanediol as the crosslinker to facile

关键词： Aggregate structures Fiber-shaped High density polyethylene vitrimer Transesterification reaction

Peptide drugs: a new direction in cancer immunotherapy

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Cancer Biology & Medicine 2024年第3期21卷 198-203页

作者： Xinghua Sui Xiaoshuang niu Xiuman Zhou Yanfeng Gao School of Pharmaceutical Sciences(Shenzhen) Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107China

Cancer immunotherapy has emerged as a promising approach in cancer treatment and is considered a major advancement after surgical interventions, radiotherapy, chemotherapy, and targeted therapy. The clinical use of im... 详细信息

关键词： drugs immunotherapy cancer

An Arecibo follow-up study of seven pulsars discovered by Five-hundred-meter Aperture Spherical radio Telescope(FAST)

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Research in Astronomy and Astrophysics 2021年第10期21卷 97-107页

作者： Shen Wang Wei-Wei Zhu Di Li Zhi-Chen Pan Pei Wang James MCordes Shami Chatterjee Ju-Mei Yao Lei Qian You-Ling Yue Lei Zhang Ru-Shuang Zhao Shuang-Qiang Wang jia-rui niu Mao Yuan Chen-Chen Miao Xiao-Yao Xie Zhi-Jie Liu Xu-Hong Yu Shan-Ping You Ling-Qi Meng FAST Collaboration National Astronomical Observatories Chinese Academy of Sciences20A Datun RoadChaoyang DistrictBeijing 100101China College of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China NAOC-UKZN Computational Astrophysics Centre University of KwaZulu-NatalDurban 4000South Africa Department of Astronomy Cornell UniversityIthacaNY 14853USA Cornell Center for Astrophysics and Planetary Science Cornell UniversityIthacaNY 14853USA Xinjiang Astronomical Observatories Chinese Academy of Sciences150Science 1-StreetUrumqi 830011China Guizhou Normal University Guiyang 550001China

We present Arecibo 327 MHz confirmation and follow-up studies of seven new pulsars discovered by the Five-hundred-meter Aperture Spherical radio Telescope(FAST).These pulsars are discovered in a pilot program of the Commensal Radio Astronomy FAST Survey(CRAFTS)with the ultra-widebandwidth commissioning *** of them are normal pulsars and two are extreme nulling slow *** J2111+2132’s dispersion measure(DM:78.5 pc cm^(-3))is above the upper limits of the two Galactic free electron density models,NE2001 and YMW16,and PSR J2057+2133’s position is out of the Scutum-Crux Arm,making them uniquely useful for improving the Galactic free electron density model in their *** present a detailed single pulse analysis for the slow nulling *** show evidence that PSR J2323+1214’s main pulse component follows a non-Poisson distribution and marginal evidence for a sub-pulse-drift or recurrent period of 32.3±0.4 rotations from PSR J0539+*** discuss the implication of our finding to the pulsar radiation mechanism.

关键词： methods:observational pulsars:general stars:neutron

Sliding behaviors of the trapezoidal roof rock block under a lateral dynamic disturbance

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 741-760页

作者： Feng Dai Wancheng Zhu Min Ren Shunchuan Wu Leilei niu Faculty of Land Resources Engineering Kunming University of Science and TechnologyKunming650093China Center for Rock Instability and Seismicity Research Department of Mining EngineeringSchool of Resource and Civil EngineeringNortheastern UniversityShenyang110819China

The surrounding rock of underground space is always affected by external dynamic disturbance from the side position,such as blasting vibration from a stope at the same level or seismic waves from adjacent strata.A series of laboratory tests,numerical simulations and theoretical analyses were carried out in this study to disclose the sliding mechanism of roof rock blocks under lateral ***,the experiments on trapezoidal key block under various clamping loads and disturbance were conducted,followed by numerical simulations using the fast Lagrangian analysis of continua(FLAC3D).Then,based on the conventional wave propagation model and the classical shear-slip constitutive model,a theoretical model was proposed to capture the relative displacement between blocks and the sliding displacement of the key *** results indicate that the sliding displacement of the key block increased linearly with the disturbance energy and decreased exponentially with the clamping load when the key block was disturbed to slide(without instability).Meanwhile,when the key block was disturbed to fall,two types of instability process may appear as immediate type or delayed *** addition,the propagation of stress waves in the block system exhibited obvious low-velocity and lowfrequency characteristics,resulting in the friction reduction effect appearing at the contact interface,which is the essential reason for the sliding of rock *** results can be applied to practical underground engineering and provide valuable guidance for the early detection and prevention of rockfalling disasters.

关键词： Lateral dynamic disturbance Trapezoidal rock block system Low-velocity and low-frequency wave Friction reduction effect Instability mode

Sustainable Intensification and Large-scale Operation of Cultivated Land Use at the Farmers’ Scale:A Case Study of Shandong Province,China

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Chinese Geographical Science 2024年第1期34卷 149-167页

作者： LI Li LYU Xiao ZHANG Anlu niu Shandong PENG Wenlong School of Public Administration Huazhong Agricultural UniversityWuhan430070China Department of Geography University of ZurichZurich8057Switzerland School of Humanities and Law Northeastern UniversityShenyang110169China School of Geography and Tourism Qufu Normal UniversityRizhao276800China

Sustainable intensification of cultivated land use(SICLU) and large-scale operations(LSO) are widely acknowledged strategies for enhancing agricultural ***,the existing literature has faced challenges in precisely defining SICLU and constructing comprehensive indicators,which has hindered the exploration of factors influencing LSO within the SICLU *** address this gap,we integrated self-efficacy theory into the design of an index framework for evaluating *** subsequently employed econometric models to analyze the significant factors that impact *** findings reveal that SICLU can be divided into four key dimensions:intensive management,efficient output,resource conservation,and ecological environment ***,it is crucial to incorporate belief-based cognitive factors into the index system,as farmers’ understanding of fertilizer and pesticide application significantly influences their willingness to engage in ***,we identify grain market turnover as the most influential factor in promoting LSO,with single-factor contribution rates reaching 70.9% for cultivated land transfer willingness and 62.5% for the total planting ***,unlike irrigation and agricultural machinery inputs,increased labor inputs correspond to larger planting areas for *** trend may be attributed to reduced labor availability because of rural labor migration,whereas the reduction in irrigation and agricultural input is contingent on innovations in production practices and the transfer of cultivated land management ***,SICLU dynamically influences LSO,with each index related to SICLU having an optimal range that fosters *** insights offer valuable guidance for policymakers,emphasizing farmers as their central focus,with the adjustment of input and output factors as a means to achieve LSO as the ultimate *** conclusion,we propose research avenues for further enriching the SICLU framework to ensur

关键词： sustainable intensification of cultivated land use(SICLU) self-efficacy status quo bias input and output Boosted Regression Tree willingness to transfer cultivated land cultivated land planting areas Shandong,China