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Research on a Monte Carlo global variance reduction method based on an automatic importance sampling method

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Nuclear Science and Techniques 2024年第5期35卷 200-215页

作者： Yi-Sheng Hao Zhen Wu Shen-Shen Gao Rui qiu Hui Zhang Jun-li li Department of Engineering Physics Tsinghua UniversityBeijing 100084China Key Laboratory of Particle and Radiation Imaging of Ministry of Education Beijing 100084China Nuctech Company limited Beijing 100084China

Global variance reduction is a bottleneck in Monte Carlo shielding *** global variance reduction problem requires that the statistical error of the entire space is *** study proposed a grid-AIS method for the global variance reduction problem based on the AIS method,which was implemented in the Monte Carlo program *** proposed method was validated using the VENUS-Ⅲ international benchmark problem and a self-shielding calculation *** results from the VENUS-Ⅲ benchmark problem showed that the grid-AIS method achieved a significant reduction in the variance of the statistical errors of the MESH grids,decreasing from 1.08×10^(-2) to 3.84×10^(-3),representing a 64.00% *** demonstrates that the grid-AIS method is effective in addressing global *** results of the selfshielding calculation demonstrate that the grid-AIS method produced accurate computational ***,the grid-AIS method exhibited a computational efficiency approximately one order of magnitude higher than that of the AIS method and approximately two orders of magnitude higher than that of the conventional Monte Carlo method.

关键词： Monte Carlo Global variance reduction Reactor shielding Automatic importance sampling

Colorimetric Detection of Acid Phosphatase and Malathion Using NiCo_(2)O_(4)Nanosheets as Peroxidase-Mimicking Activity

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Journal of Analysis and Testing 2024年第2期8卷 170-179页

作者： Jia Chen Zerong Long Yan li Hongdeng qiu Xinjiang Uygur Autonomous Product Quality Supervision and Inspection Institute Urumqi830000China CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou730000China

The establishment of a low-cost and facile approach for the assay of acid phosphatase(ACP)and its inhibitor is a research *** this paper,we successfully synthesized NiCo_(2)O_(4)nanosheets with peroxidase-mimicking activity in alkaline deep eutectic solvents(DESs)composed of NaOH and PEG-200,which can catalyze 3,3',5,5'-tetramethylbenzidine(TMB)to the oxidation state TMB(ox-TMB)in the presence of *** to L-ascorbic acid-2-phosphate can be hydrolyzed into ascorbic acid by ACP,the peroxidase-like activity of NiCo_(2)O_(4)nanosheets is ***,the addition of malathion,an inhibitor of ACP,can inhibit the activity of ACP and thus limit the production of ascorbic acid(AA).Therefore,a colorimetric approach can be established for highly sensitive and selective detection of ACP and malathion with detection limits of 0.032 U/L and 0.65 nmol/L,*** importantly,this method can be successfully applied to malathion detection in environmental samples tap water and food cucumber juice,indicating that it has potential application prospects in environmental and agricultural fields.

关键词： NiCo_(2)O_(4)nanosheets Acid phosphatase Malathion Peroxidase-mimicking activity Colorimetric

Self assembled electron blocking and lithiophilic interface towards dendrite-free solid-state lithium battery

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Chinese Chemical Letters 2024年第4期35卷 220-225页

作者： Caixia li Yi qiu Yufeng Zhao Wuliang Feng Institute for Sustainable Energy&College of Sciences Shanghai UniversityShanghai 200444China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin 300071China

The poor interfacial contact is one of the biggest challenges that solid-state lithium batteries suffer *** the solid-state electrolyte surface energy by transforming the interface from lithiophobic to lithiophilic is effective to promote the interfacial contact, but electronic conductive interphases usually increase the risk of electron attack, thus leading to uncontrollable li dendrite growth. Herein, we propose a self-assembled thermodynamic stable li I interphase to simultaneously improve the interfacial contact between the garnet electrolyte li_7La_(3)Zr_(2)O_(12)(LLZO) and li anode, and prohibit the electron attack. The direct contact between LLZO and li and the high temperature li melting process was ascribed to Zr4+reduction, which facilitated li dendrite formation and propagation. With the modification of the high lithiophilic I_(2) thin film, the area specific interfacial resistance of LLZO/li was reduced from 1525 Ω/cm^(2) to 57 Ω/cm^(2). More importantly, LLZO was protected from being reduced due to the outstanding electronic insulativity of the li I interphase, which leaded to a high critical current density of 1.2/7.0 m A/cm^(2) in the time/capacity-constant modes, respectively.

关键词： li_7La_(3)Zr_(2)O_(12) liI interphase Interfacial contact li dendrite Thermodynamic stable

Robust-augmentation nonlinear dynamic inversion control of over-actuated coaxial high-speed helicopter in transition mode

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Chinese Journal of Aeronautics 2024年第8期37卷 404-420页

作者： Yuqing qiu Yan li Jinxi LANG Yuxian liU Zhong WANG School of Automation Northwestern Polytechnical UniversityXi’an 710129China

As the elevator and rudder can be used actively for control,in addition to the rotors,Coaxial High-speed Helicopters(CHHs)have the problems of control redundancy and changing control authority in the transition *** paper presents a robust-augmentation transitioning flight control design for a CHH under the adverse conditions of parametric uncertainties and external ***,based on control characteristic analysis,an Adaptive Filtered Nonlinear Dynamic Inversion(AFNDI)controller is proposed for the angular rate to handle the effect of unknown unstructured uncertainties and external *** analysis proves that the presented angular rate controller can guarantee steady-state and transient ***,the attitude angle and velocity controllers are also ***,an Incremental-based Nonlinear Prioritizing Control Allocation(INPCA)method is designed to take into account control surface transition and changing control authority,which efficiently distributes the required moments between coaxial rotors and aero-surfaces,and avoids the control reversal problem of the yaw *** the proposed control architecture,the low-pass filter is introduced to alleviate the adverse influence of time delay and measurement ***,the effectiveness of the proposed controller is demonstrated through nonlinear numerical simulations,and is compared with existing *** results show that the proposed control law can improve both capabilities of disturbance rejection and fast response,and works satisfactorily for the CHH transitioning control characteristic.

关键词： Coaxial high-speed helicopter Transition mode Attitude control Control allocation Robust adaptive control

Structural variations of a new fertility restorer gene,Rf20,underlie the restoration of wild abortive-type cytoplasmic male sterility in rice

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Molecular Plant 2024年第8期17卷 1272-1288页

作者： Shufeng Song Yixing li Mudan qiu Na Xu Bin li Longhui Zhang Lei li Weijun Chen Jinglei li Tiankang Wang Yingxin qiu Mengmeng Gong Dong Yu Hao Dong Siqi Xia Yi Pan Dingyang Yuan li li State Key Laboratory of Hybrid Rice Hunan Hybrid Rice Research CenterHunan Academy of Agricultural SciencesChangsha 410125China College of Agronomy Hunan Agricultural UniversityChangsha 410128China College of Plant Protection Hunan Agricultural UniversityChangsha 410128China College of Tropical Crops Hainan UniversityHaikou 570228China Longping Branch College of BiologyHunan UniversityChangsha 410125China

The discovery of a wild abortive-type(WA)cytoplasmic male sterile(CMS)line and breeding its restorer line have led to the commercialization of three-line hybrid rice,contributing considerably to global food ***,the molecular mechanisms underlyingfertility abortion and the restoration of CMs-WA lines remain largely *** this study,we cloned a restorer gene,Rf2o,following a genome-wide association study analysis of the core parent lines of three-line hybrid *** found that Rf20 was present in all core parental lines,but different haplotypes and structural variants of its gene resulted in differences in Rf2o expression levels between sterileand restored ***20 could restorepollen fertility in the CMS-WA line and was found to be responsible for fertility restoration in some CMs lines under high *** addition,we found that Rf20 encodes a pentatricopeptide repeat protein that competes with WA352 for binding with *** interaction enhances Cox11's function as a scavenger of reactive oxygen species,which in turn restores ***,ourstudysuggestsanewactionmodeforpentatricopeptide repeatproteins inthe fertilityrestorationofCMs lines,providing an essential theoretical basisforbreedingrobustrestorer lines and for overcoming high temperature-induced fertility recovery of some CMS lines.

关键词： COX11 cytoplasmic male sterility rf20 WA352 wild abortion

An Imbalanced Data Classification Method Based on Hybrid Resampling and Fine Cost Sensitive Support Vector Machine

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Computers, Materials & Continua 2024年第6期79卷 3977-3999页

作者： Bo Zhu Xiaona Jing Lan qiu Runbo li College of Mechanical and Electrical Engineering Kunming University of Science&TechnologyKunming650500China

When building a classification model,the scenario where the samples of one class are significantly more than those of the other class is called data *** imbalance causes the trained classification model to be in favor of the majority class(usually defined as the negative class),which may do harm to the accuracy of the minority class(usually defined as the positive class),and then lead to poor overall performance of the model.A method called MSHR-FCSSVM for solving imbalanced data classification is proposed in this article,which is based on a new hybrid resampling approach(MSHR)and a new fine cost-sensitive support vector machine(CS-SVM)classifier(FCSSVM).The MSHR measures the separability of each negative sample through its Silhouette value calculated by Mahalanobis distance between samples,based on which,the so-called pseudo-negative samples are screened out to generate new positive samples(over-sampling step)through linear interpolation and are deleted finally(under-sampling step).This approach replaces pseudo-negative samples with generated new positive samples one by one to clear up the inter-class overlap on the borderline,without changing the overall scale of the *** FCSSVM is an improved version of the traditional *** considers influences of both the imbalance of sample number and the class distribution on classification simultaneously,and through finely tuning the class cost weights by using the efficient optimization algorithm based on the physical phenomenon of rime-ice(RIME)algorithm with cross-validation accuracy as the fitness function to accurately adjust the classification *** verify the effectiveness of the proposed method,a series of experiments are carried out based on 20 imbalanced datasets including both mildly and extremely imbalanced *** experimental results show that the MSHR-FCSSVM method performs better than the methods for comparison in most cases,and both the MSHR and the FCSSVM played significan

关键词： Imbalanced data classification Silhouette value Mahalanobis distance RIME algorithm CS-SVM

Vibration Reduction by a Partitioned Dynamic Vibration Absorber with Acoustic Black Hole Features

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Chinese Journal of Mechanical Engineering 2024年第4期37卷 120-134页

作者： Xiaoning Zhao Chaoyan Wang Hongli Ji Jinhao qiu li Cheng State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China Nanjing Institute of Information Technology Nanjing 210016China Department of mechanical Engineering Hong Kong Polytechnic UniversityKowloon 999077Hong KongChina

Vibration quality is a vital indicator for assessing the progress of modern *** dynamic vibration absorber(DVA)based on the acoustic black hole(ABH)feature is a new passive control method that manipulates *** offers efficient energy focalization and broad-spectrum vibration suppression,making it highly promising for applications in large equipment such as aircraft,trains,and *** previous advancements in ABH-DVA development,certain challenges remain,particularly in ensuring effective coupling with host structures during *** address these issues,this study proposes a partitioned ABH-featured dynamic vibration absorber(PABH-DVA)with partitions in the radial direction of the *** employing a plate as the host structure,simulations and experiments were conducted,demonstrating that the PABH-DVA outperforms the original symmetric ABH-DVA in terms of damping *** study also calculated and compared the coupling coefficients of the two ABH-DVAs to uncover the mechanism behind the enhanced *** results revealed that the PABH-DVA exhibits more coupled modes,occasionally with lower coupling coefficients than the symmetric *** influence of frequency ratio and modal mass was further analyzed to explain the reasons behind the PABH-DVA's superior damping ***,the study discussed the impact of the number of slits and their *** research further explains the coupling mechanism between the ABH-DVA and the controlled structure,and provides new ideas for the further application of ABH in engineering.

关键词： Acoustic black hole Vibration control Dynamic vibration absorber Coupling analysis

Wood use and forest management by Neolithic millet farmers at the Xinglong site,northern China

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Science China Earth Sciences 2024年第6期67卷 1910-1921页

作者： Hui SHEN Zhenwei qiu Keliang ZHAO Xinying ZHOU Xiaoqiang li Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China National Museum of China Beijing 100006China University of Chinese Academy of Sciences Beijing 100049China

The origin and development of agriculture and its relationship with climate change are hotly debated topics among environmental *** this study,we analyzed wood charcoal materials from the Neolithic Xinglong site in northern China in order to understand the woody vegetation around the site and how early millet farmers shaped local *** results suggest that the area around the Xinglong sites during 8700-7000 yr BP was primarily woodlands,including Prunus sibirica shrubs,Ulmus and Acer forests,and Populus stands near *** 8000 to 7000 yr BP,the warm and humid climate probably contributed to the expansion of Acer,Rhamnus,and Juniperus,and may have facilitated the development of early millet *** these ancient wood fragments that we studied,the high percent of Prunus charcoal appears to indicate an abundance of fruit trees,which might have constituted the main component of local ***,the wood taxa illustrate the existence of a variety of ecological habitats,and it is logical to assume that people made full use of the locally available wood ***,Populus and Ulmus were the dominant sources of *** results of tree-ring curvature analyses indicate that people mainly collected trunks or large branches of Ulmus,Populus,Acer,and Juniperus *** interpret the increasing use of Prunus twigs and the declining percentage of Prunus charcoal in the period between 8000-7000 yr BP as indicating that people started to protect and manage wild fruit *** may have started pruning to acquire more food resources as part of the cultural responses and adaptation strategies employed by these early millet cultivators.

关键词： Xinglong site Wood charcoal Wood use Woodland management

Extracorporeal membrane oxygenation as a bridging therapy for patients with thiamine deficiency-induced pulmonary arterial hypertension

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World Journal of Emergency Medicine 2024年第2期15卷 147-149页

作者： Fangfang qiu Weixing Dai Tengyue Huang Min li Department of Intensive Care Unit the Fourth Affiliated Hospital of Zhejiang University School of MedicineYiwu 322000China Department of Intensive Care Unit the Second Affiliated Hospital of Zhejiang University School of MedicineHangzhou 310009China

Thiamine deficiency is characterized by a deficiency of thiamine(vitamin B1),lactic acidosis,pulmonary arterial hypertension(PAH),right-sided heart failure,and peripheral nerve *** deficiency is easily misdiagnosed and missed during clinical practice and is associated with death in severe cases.[1,2]Here we reported a patient who was admitted to the hospital with severe metabolic acidosis and pulmonary hypertension and finally diagnosed with thiamine deficiency by detecting plasma vitamin B1 *** clinically obvious thiamine deficiency is rare,and cases of thiamine deficiency requiring extracorporeal membrane oxygenation(ECMO)treatment are rarer,we believe that our case will be helpful for emergency clinicians.

关键词： vitamin hypertension arterial