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Features and formulae of sediment incipient motion in vegetated flow environment

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Journal of Hydrodynamics 2024年第2期36卷 331-339页

作者： yu-xuan xu Wei-jie Wang Shi-bao Zhang Han-qing Zhao xue-kai Chen Hai-ping Zhang School of Water Conservancy North China University of Water Resources and Electric PowerZhengzhou450045China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing100038China China Three Gorges Corporation Wuhan430010China

Aquatic vegetation is a vital component of natural river ecosystems,playing a crucial role in maintaining ecological balance,providing habitat and improving water ***,the presence of vegetation results in increased resistance in vegetated channels compared with non-vegetated channels,rendering traditional sediment movement predictions inadequate for the ***,the concept of a vegetation influence factor,denoted by CDah,has been proposed by previous researchers to represent the effect of vegetation on sediment movement in *** this study,we focus on exploring the vegetation resistance coefficient(CD)among the vegetation influence factors,evaluating two different calculation methods for vegetation resistance coefficient,and presenting two expressions through genetic algorithm analysis to predict the incipient flow velocity of sediment in vegetated *** predicted values from the new formulae show excellent agreement with measured data,highlighting the high accuracy of the proposed methods in predicting the incipient flow velocity of *** results provide a solid theoretical basis for understanding the influence of aquatic vegetation on sediment particle movement.

关键词： Vegetation flow vegetation resistance coefficient genetic algorithm sediment initiation

Benchmark experiment on slab^(238)U with D-T neutrons for validation of evaluated nuclear data

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Nuclear Science and Techniques 2024年第2期35卷 145-159页

作者： Yan-Yan Ding Yang-Bo Nie yue Zhang Zhi-jie Hu Qi Zhao Huan-yu Zhang Kuo-Zhi xu Shi-yu Zhang Xin-Yi Pan Chang-Lin Lan jie Ren Xi-Chao Ruan Key Laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Institute of Fluid Physics China Academy of Engineering PhysicsMianyang 62100China

A benchmark experiment on^(238)U slab samples was conducted using a deuterium-tritium neutron source at the China Institute of Atomic *** leakage neutron spectra within energy levels of 0.8-16 MeV at 60°and 120°were measured using the time-of-flight *** samples were prepared as rectangular slabs with a 30 cm square base and thicknesses of 3,6,and 9 *** leakage neutron spectra were also calculated using the MCNP-4C program based on the latest evaluated files of^(238)U evaluated neutron data from CENDL-3.2,ENDF/B-Ⅷ.0,JENDL-5.0,and *** on the comparison,the deficiencies and improvements in^(238)U evaluated nuclear data were *** results showed the following.(1)The calculated results for CENDL-3.2 significantly overestimated the measurements in the energy interval of elastic scattering at 60°and 120°.(2)The calculated results of CENDL-3.2 overestimated the measurements in the energy interval of inelastic scattering at 120°.(3)The calculated results for CENDL-3.2 significantly overestimated the measurements in the 3-8.5 MeV energy interval at 60°and 120°.(4)The calculated results with JENDL-5.0 were generally consistent with the measurement results.

关键词： Leakage neutron spectra Uranium D-T neutron source Evaluated nuclear data

Influence of the penetration of adjacent X-section cast-in-place concrete(XCC)pile on the existing XCC pile in sand

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第7期25卷 557-572页

作者： Peng ZHOU Jianhui xu Changjie xu Guangwei CAO jie CUP xuanming DING School of Civil Engineering and Architecture State Key Laboratory of Performance Monitoring and Protecting of Rail Transit InfrastructureEast China Jiaotong UniversityNanchang330013China Guangdong Key Laboratory of Earthquake Engineering and Application Technology Earthquake Engineering Research&Test CenterGuangzhou UniversityGuangzhou510006China Key Laboratory of New Technology for the Construction of Cities in Mountain Areas College of Civil EngineeringChongqing UniversityChongqing400045China Zijin School of Geology and Mining Fuzhou UniversityFuzhou350116China

A series of small-scale 1g X-section cast-in-place concrete(XCC)pile-penetration model tests were conducted to study the effects of soil density and pile geometry on the lateral responses of an existing pile and the variations in surrounding soil *** results showed that the bending patterns of existing XCC piles varied with penetration *** lateral response of the existing pile was sensitive to the change in relative density and pile *** example,the bending moment of the existing pile increased along with these *** development of the radial stressσ′r/σ′v0 of the soil around an existing pile showed different trends at various depths during the penetration of the adjacent ***,the change in radial stress during the penetration of the XCC pile did not exhibit the“h/R effect”that was observed in the free-field soil,due to the shielding effect of the existing *** peak value of radial stressσ′r_max/σ′v0 decreased exponentially as the radial distance r/R *** attenuation ofσ′r_max/σ′v0 with r/R in the loose sand was faster than in the medium-dense or dense ***σ′r_max/σ′v0 at the same soil location increased with the cross-section geometry parameter.

关键词： X-section cast-in-place concrete(XCC)pile Test Penetration Sand Lateral response Radial stress

First Digit Distributions of Gamma-Ray Bursts

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Research in Astronomy and Astrophysics 2024年第5期24卷 70-75页

作者： Hou-yu Lai Jun-jie Wei Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China

The occurrence of the first significant digits from real world sources is usually not equally distributed,but is consistent with a logarithmic distribution instead,known as Benford’s *** this work,we perform a comprehensive investigation on the first digit distributions of the duration,fluence,and energy flux of gamma-ray bursts (GRBs) for the first *** a complete GRB sample detected by the Fermi satellite,we find that the first digits of the duration and fluence adhere to Benford’s ***,the energy flux shows a significant departure from this law,which may be due to the fact that a considerable part of the energy flux measurements is restricted by lack of spectral *** on the conventional duration classification scheme,we also check if the durations and fluences of long and short GRBs (with duration T_(90)>2 s and T_(90)≤2 s,respectively) obey Benford’s *** find that the fluences of both long and short GRBs still agree with the Benford distribution,but their durations do not follow Benford’s *** results hint that the long–short GRB classification scheme does not directly represent the intrinsic physical classification scheme.

关键词： (stars:)gamma-ray burst general-methods statistical-astronomical databases miscellaneous

A Simple Proof of ACC for Minimal Log Discrepancies for Surfaces

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Acta Mathematica Sinica,English Series 2024年第2期40卷 425-434页

作者： Jing Jun HAN yu jie LUO Shanghai Center for Mathematical Sciences Fudan UniversityJiangwan CampusShanghai 200438P.R.China Department of Mathematics Johns Hopkins UniversityBaltimoreMD 21218USA

Following Shokurov's idea,we give a simple proof of the ACC conjecture for minimal log discrepancies for surfaces.

关键词： Ascending chain condition minimal log discrepancies minimal model program surface

Blockchain-based immunization against kleptographic attacks

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Science China(Information Sciences) 2024年第7期67卷 172-183页

作者： Changsong JIANG Chunxiang xu jie CHEN Kefei CHEN School of Computer Science and Engineering University of Electronic Science and Technology of China Yangtze Delta Region Institute (Huzhou) University of Electronic Science and Technology of China Department of Mathematics Hangzhou Normal University

Adversarial implementations of cryptographic primitives called kleptographic attacks cause the leakage of secret information. Subliminal channel attacks are one of the kleptographic attacks. In such attacks, backdoors are embedded in implementations of randomized algorithms to elaborately control randomness generation, such that the secrets will be leaked from biased outputs. To thwart subliminal channel attacks, double-splitting is a feasible solution, which splits the randomness generator of a randomized algorithm into two independent generators. In this paper, we instantiate double-splitting to propose a secure randomness generation algorithm dubbed SRG using two physically independent generators: ordinary and public randomness generators. Based on public blockchains, we construct the public randomness generator,which can be verified publicly. Hashes of a sufficient number of consecutive blocks that are newly confirmed on a blockchain are used to produce public randomness. In SRG, outputs from the two generators are taken as inputs of an immunization function. SRG accomplishes immunization against subliminal channel ***, we discuss the application strategies of SRG for symmetric and public-key encryption.

关键词： kleptographic attacks subliminal channel blockchain immunization randomized algorithm

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Real-time Operation Optimization in Active Distribution Networks Based on Multi-agent Deep Reinforcement Learning

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 886-899页

作者： jie xu Hongjun Gao Renjun Wang Junyong Liu the College of Electrical Engineering Sichuan UniversityChengduChina

The increasing integration of intermittent renewable energy sources(RESs)poses great challenges to active distribution networks(ADNs),such as frequent voltage *** paper proposes a novel ADN strategy based on multiagent deep reinforcement learning(MADRL),which harnesses the regulating function of switch state transitions for the realtime voltage regulation and loss *** deploying the calculated optimal switch topologies,the distribution network operator will dynamically adjust the distributed energy resources(DERs)to enhance the operation performance of ADNs based on the policies trained by the MADRL *** to the model-free characteristics and the generalization of deep reinforcement learning,the proposed strategy can still achieve optimization objectives even when applied to similar but unseen ***,integrating parameter sharing(PS)and prioritized experience replay(PER)mechanisms substantially improves the strategic performance and *** framework has been tested on modified IEEE 33-bus,IEEE 118-bus,and three-phase unbalanced 123-bus *** results demonstrate the significant real-time regulation capabilities of the proposed strategy.

关键词： Reconfiguration active distribution network distributed energy resource real-time control deep reinforcement learning parameter sharing scalability

Supramolecular Biomaterials for Cancer Immunotherapy

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Research 2024年第2期2023卷 491-509页

作者： Huan Liang Qingqing Lu jie Yang Guocan yu College of Science Nanjing Forestry UniversityNanjing 210037P.R.China Key Laboratory of Bioorganic Phosphorus Chemistry&Chemical Biology Department of ChemistryTsinghua UniversityBeijing 100084P.R.China

Cancer immunotherapy has achieved tremendous successful clinical results and obtained historic victories in tumor ***,great limitations associated with feeble immune responses and serious adverse effects still cannot be neglected due to the complicated multifactorial etiology and pathologic microenvironment in *** rapid development of nanomedical science and material science has facilitated the advanced progress of engineering biomaterials to tackle critical *** supramolecular biomaterials with flexible and modular structures have exhibited unparalleled advantages of high cargo-loading efficiency,excellent biocompatibility,and diversiform immunomodulatory activity,thereby providing a powerful weapon for cancer *** past decades,supramolecular biomaterials were extensively explored as versatile delivery platforms for immunotherapeutic agents or designed to interact with the key moleculars in immune system in a precise and controllable *** this review,we focused on the crucial role of supramolecular biomaterials in the modulation of pivotal steps during tumor immunotherapy,including antigen delivery and presentation,T lymphocyte activation,tumor-associated macrophage elimination and repolarization,and myeloid-derived suppressor cell *** on extensive research,we explored the current limitations and development prospects of supramolecular biomaterials in cancer immunotherapy.

关键词： biomaterials limitations thereby

Double-nylon purse-string suture in closing postoperative wounds following endoscopic resection of large(≥3 cm)gastric submucosal tumors

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World Journal of Gastroenterology 2024年第9期30卷 1143-1153页

作者： Shan-Shan Wang Meng-Yao Ji xu Huang Yan-Xia Li Shi-jie yu yu Zhao Lei Shen Department of Gastroenterology Renmin Hospital of Wuhan UniversityWuhan 430000Hubei provinceChina

BACKGROUND Endoscopic full-thickness resection(EFTR)of gastric submucosal tumors(SMTs)is safe and effective;however,postoperative wound management is equally *** on suturing following EFTR for large(≥3 cm)SMTs is scarce and *** To evaluate the efficacy and clinical value of double-nylon purse-string suture in closing postoperative wounds following EFTR of large(≥3 cm)*** We retrospectively analyzed the data of 85 patients with gastric SMTs in the fundus of the stomach or in the lesser curvature of the gastric body whose wounds were treated with double-nylon purse-string sutures after successful tumor resection at the Endoscopy Center of Renmin Hospital of Wuhan *** operative,postoperative,and follow-up conditions of the patients were *** All tumors were completely resected using EFTR.36(42.35%)patients had tumors located in the fundus of the stomach,and 49(57.65%)had tumors located in the body of the *** patients underwent suturing with double-nylon sutures after EFTR without laparoscopic assistance or further surgical *** fever and stomach pain were reported in 13(15.29%)and 14(16.47%)patients,*** serious adverse events occurred during the intraoperative or postoperative periods.A postoperative review of all patients revealed no residual or recurrent *** Double-nylon purse-string sutures can be used to successfully close wounds that cannot be completely closed with a single nylon suture,especially for large(≥3 cm)EFTR wounds in SMTs.

关键词： Endoscopic full-thickness resection Purse-string suture Postoperative wounds Submucosal tumors