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Finite Groups with Some Bounded Codegrees

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Acta Mathematica Sinica,English Series 2024年第7期40卷 1778-1784页

作者： Dong fang YANG Yu ZENG Heng LV School of Mathematics and Statistics Southwest UniversityChongqing400715P.R.China Department of Mathematics Changshu Institute of TechnologyChangshu215500P.R.China

For a characterχof a finite group G,the number cod(χ) := ∣G:ker(χ)∣/χ(1)is called the codegree ofχ.In this paper,we give a solvability criterion for a finite group G depending on the minimum of the ratioχ(1)^(... 详细信息

关键词： Finite group codegree degree simple group

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Discontinuous phase diagram of amorphous carbons

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National Science Review 2024年第4期11卷 164-171页

作者： YinBo Zhu ZhouYu fang ZhongTing Zhang HengAn Wu CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of China State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences

The short-range order and medium-range order of amorphous carbons demonstrated in experiments allow us to rethink whether there exist intrinsic properties hidden by atomic disordering. Here we presented six representative phases of amorphous carbons（0.1–3.4 g/cm3）, namely, disordered graphene network（DGN）, high-density amorphous carbon（HDAC）, amorphous diaphite（a-DG）, amorphous diamond（a-D）, paracrystalline diamond（p-D）, and nano-polycrystalline diamond（NPD）, respectively, classified by their topological features and microstructural characterizations that are comparable with experiments. To achieve a comprehensive physical landscape for amorphous carbons, a phase diagram was plotted in the sp3/sp2versus density plane, in which the counterintuitive discontinuity originates from the inherent difference in topological microstructures, further guiding us to discover a variety of phase transitions among different amorphous carbons. Intriguingly, the power law, log（sp3/sp2） ∝ ρn, hints at intrinsic topology and hidden order in amorphous carbons, providing an insightful perspective to reacquaint atomic disorder in non-crystalline carbons.

关键词： amorphous carbons disordered carbons phase diagram microstructural topology phase transition

Data-driven discovery of linear dynamical systems from noisy data

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Science China(Technological Sciences) 2024年第1期67卷 121-129页

作者： WANG YaSen YUAN Ye fang HuaZhen DING Han School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China State Key Lab of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074China Department of Mechanical Engineering University of KansasLawrence 66045USA

In modern science and engineering disciplines,data-driven discovery methods play a fundamental role in system modeling,as data serve as the external representations of the intrinsic mechanisms within ***,empirical data contaminated by process and measurement noise remain a significant obstacle for this type of *** this study,we have developed a data-driven method capable of directly uncovering linear dynamical systems from noisy *** method combines the Kalman smoothing and sparse Bayesian learning to decouple process and measurement noise under the expectation-maximization framework,presenting an analytical method for alternate state estimation and system ***,the discovered model explicitly characterizes the probability distribution of process and measurement noise,as they are essential for filtering,smoothing,and stochastic *** have successfully applied the proposed algorithm to several simulation *** results demonstrate its potential to enable linear dynamical system discovery in practical applications where noise-free data are intractable to capture.

关键词： system identification sparse Bayesian learning Kalman smoothing process and measurement noise

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Grain size effect on the assembly quality of micro-scaled barrel formed by microforming

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Advances in Manufacturing 2024年第1期12卷 19-32页

作者： Dien Hu Jieyichen fang Feng Zeng Ming-Wang Fu Department of Mechanical Engineering Research Institute of Advanced ManufacturingThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongPeople’s Republic of China Xiamen Yulong Machinery Co.Ltd. Xiamen361023FujianPeople’s Republic of China

In this research,a method employing micro-extrusion was designed to produce the micro-scaled barrel-shaped parts with complex geometrical features to study the feasibility of the proposed microforming method and its grain size effect on the formability of the complicated internal features in terms of deformation behavior,material evolution,accuracy of dimensions and final components *** results reveal that the deformation behavior is highly affected by grain size and becomes unpredictable with increased grain *** addition,assembly parameters including feature dimension,tolerance and coaxiality also vary with grain size,and the variation of grain size needs to be accommodated by different assembly types,viz.,clearance fit or transition *** the microstructural evolution aspect,it was identified there were two dead zones and four shear bands,and the formation of these deformation zones was barely affected by the variation in grain *** bulges,cracks,and fracture induced voids were observed on the surface of the final components,tailoring the microstructure of the working material with finer grains could significantly avoid these *** study advances the understanding of forming microparts by extrusion processes and provides guidance for microforming of similar microparts.

关键词： Microformed part Size effect Extrusion Microstructural evolution Dimensions Assembly accuracy

Surface engineering with ionic polymers on membranes for boron removal

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 61-69页

作者： Xiting Zhang Chenyi fang J Paul Chen Sui Zhang Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore 117576Singapore Department of Civil and Environmental Engineering National University of SingaporeSingapore 119260Singapore College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China

Removal of boric acid from seawater and wastewater using reverse osmosis membrane technologies is imperative and yet remains inadequately addressed by current commercial *** research efforts performed post-modification of reverse osmosis membranes to enhance boron rejection,which is usually accompanied by substantial sacrifice in water *** study delves into the surface engineering of low-pressure reverse osmosis membranes,aiming to elevate boron removal efficiency while maintaining optimal salt rejection and water *** were modified by the self-polymerization and co-deposition of dopamine and polystyrene sulfonate at varying ratios and *** surfaces became smoother and more hydrophilic after *** optimum membrane exhibited a water permeability of 9.2±0.1 L·m^(-2)·h^(-1)·bar^(-1),NaCl rejection of 95.8%±0.3%,and boron rejection of 49.7%±0.1% and 99.6%±0.3% at neutral and alkaline pH,*** water permeability is reduced by less than 15%,while the boron rejection is 3.7 times higher compared to the blank *** research provides a promising avenue for enhancing boron removal in reverse osmosis membranes and addressing water quality concerns in the desalination process.

关键词： membrane low-pressure reverse osmosis boron surface engineering

Pijx confers broad-spectrum seedling and panicle blast resistance by promoting the degradation of ATP b subunit and OsRbohC-mediated ROS burst in rice

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Molecular Plant 2024年第4期17卷 672-675页

作者： ning Xiao Yunyu Wu Xiaoxiang Zhang Zeyun Hao Zichun Chen Zefeng Yang Yue Cai Ruyi Wang Ling Yu Zhiping Wang Yue Lu Wei Shi Cunhong Pan Yuhong Li Changhai Zhou Jianju Liu Niansheng Huang Guangqing Liu Hongjuan Ji Shuhao Zhu Shuai fang Yuese ning Aihong Li 不详

(Molecular Plant 16,1832-1846,November 62023)The originally published version of this manuscript contained several small mistakes in the labels and legends of main and supplemental figures,along with a few small mistakes in the main text,that have now been ***,in Figure 6G,the label“NILGY31^(Pijx)”has been corrected to“NIL^(Pijx)”,and in the legend of Figure 6H,“PPL^(Pijx Piz-t)”and“PPL^(Pijx Pigm)”have been corrected to“NIL^(Piz-t Pijx)”and“PPL^(Pigm Pijx).”In Figure S8A。

关键词： seedling Figure panicle

Earth vitality:An integrated framework for tracking Earth sustainability

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A comparison of statistical learning of naturalistic textures between DCNNs and the human visual hierarchy

地理学与可持续性（英文） 2024年第1期5卷 96-107页

作者： Chuanglin fang Zhitao Liu Institute of Geographical Sciences and Resources Chinese Academy of SciencesBeijing 100101China School of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

The Anthropocene era is characterized by the escalating impact of human activities on the environment,as well as the increasingly complex interactions among various components of the Earth *** factors greatly affect the Earth's evolutionary *** notable strides in sustainable development practices worldwide,it remains unclear to what extent we have achieved Earth ***,there is a pressing need to enhance conceptual and methodological frameworks to measure sustainability progress *** address this need,we developed an Earth Vitality Framework that aids in tracking the Earth sustainability progress by considering interactions between spheres,recognizing the equal relationship between humans and nature,and presenting a threshold scheme for all *** applied this framework at global and national scales to demonstrate its *** findings reveal that the current Earth Vitality Index is 63.74,indicating that the Earth is in a"weak"*** social institutions,unsatisfactory life experiences and the poor state of the biosphere and hydrosphere have remarkably affected the Earth ***,inequality exists between high-income and low-income *** most of the former exhibit poor human-nature interaction,all of them enjoy good human well-being,while the opposite is true for the ***,we summarize the challenges and possible options for enhancing the Earth vitality in terms of coping with spillover effects,tipping cascades,feedback,and heterogeneity.

关键词： Multi-sphere Human-nature interaction Sustainability Earth vitality framework

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Science China Technological Sciences 2024年第8期67卷 2310-2318页

作者： LU XinCheng YUAN ZiQi ZHANG YiChi AI HaiLin CHENG SiYuan GE YiRan fang fang CHEN NiHong Department of Psychological and Cognitive Sciences Tsinghua University Department of Computer Science and Technology Tsinghua University School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health Peking University Key Laboratory of Machine Perception (Ministry of Education) Peking University Peking-Tsinghua Center for Life Sciences Peking University IDG/McGovern Institute for Brain Research Peking University State Key Laboratory of Brain and Cognitive Science Institute of Psychology Chinese Academy of Sciences IDG/McGovern Institute for Brain Research Tsinghua University

The visual system continuously adapts to the statistical properties of the environment. Existing evidence shows a close resemblance between deep convolutional neural networks(CNNs) and primate visual stream in neural selectivity to naturalistic textures above the primary visual processing stage. This study delves into the mechanisms of perceptual learning in CNNs,focusing on how they assimilate the high-order statistics of natural textures. Our results show that a CNN model achieves a similar performance improvement as humans, as manifested in the learning pattern across different types of high-order image statistics. While L2 was the first stage exhibiting texture selectivity, we found that stages beyond L2 were critically involved in learning. The significant contribution of L4 to learning was manifested both in the modulations of texture-selective responses and in the consequences of training with frozen connection weights. Our findings highlight learning-dependent plasticity in the mid-to-high-level areas of the visual hierarchy. This research introduces an AI-inspired approach for studying learning-induced cortical plasticity, utilizing DCNNs as an experimental framework to formulate testable predictions for empirical brain studies.

关键词： CNN perceptual learning naturalistic texture psychophysics

Interface engineering enabled sintering-resistant metal nanocatalysts via reverse Ostwald ripening

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Science China Chemistry 2024年第9期67卷 2789-2791页

作者： Ying Sun Wenhui fang Jieshan Qiu Institute of Clean Energy Chemistry Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials of Liaoning Province College of Chemistry Liaoning University State Key Laboratory of Chemical Resource Engineering College of Chemical Engineering Beijing University of Chemical Technology

The design and fabrication of advanced nanocatalysts with the high activity, selectivity, and superior durability remains a big challenge in industrial catalysis [1,2]. The sintering of nanocatalysts under the thermally and/or chemically triggered conditions is a bottle-neck issue, which seriously decreases the amount of the exposed active sites and changes the original electronic structure of catalysts, resulting in the irreversible catalyst deactivation and high capital and time cost in industrial operation [3].

关键词： CHEMISTRY

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