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Micromechanical characterization of microwave dielectric ceramic BaO-Sm_(2)O_(3)-5TiO_(2),by indentation and scratch methods

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Journal of Advanced Ceramics 2023年第6期12卷 1136-1165页

作者： Ming liu Zhitong Xu Fujian Provincial Key Laboratory of Terahertz Functional Devices and Intelligent Sensing School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou 350108China

Mechanical characterization of dielectric ceramics,which have drawn extensive attention in wireless communication,remains challenging.The micromechanical properties with the microstructures of dielectric ceramic BaO-Sm_(2)O_(3)-5TiO_(2)(BST)were assessed by nanoindentation,microhardness,and microscratch tests under different indenters,along with the X-ray diffraction(XRD),scanning electron microscopy(SEM),and Raman spectroscopy.Accurate determination of elastic modulus(Err)(i.e.,260 GPa)and indentation hardness(Hrr)(i.e.,16.2 GPa)of brittle BST ceramic by the instrumented indentation technique requires low loads with little indentation-induced damage.The elastic modulus and indentation hardness were analyzed by different methodologies such as energy-based approach,displacement-based approach,and elastic recovery of Knoop imprint.Consistent values(about 3.1 MPa·m^(1/2))of fracture toughness(Kc)of BST ceramic were obtained by different methods such as the Vickers indenter-induced cracking method,energy-based nanoindentation approaches,and linear elastic fracture mechanics(LEFM)-based scratch approach with a spherical indenter,demonstrating successful applications of indentation and scratch methods in characterizing fracture properties of brittle solids.The deterioration of elastic modulus or indentation hardness with the increase in indentation load(F)is caused by indentation-induced damage and can be used to determine the fracture toughness of material by energy-based nanoindentation approaches,and the critical void volume fraction(f^(*))is 0.27(or 0.18)if elastic modulus(or indentation hardness)of the brittle BST ceramic is used.The fracture work at the critical load corresponding to the initial decrease in elastic modulus or indentation hardness can also be used to assess the fracture toughness of brittle solids,opening new venues of the application of nanoindentation test as a means to characterize the fracture toughness of brittle ceramics.

关键词： brittle ceramics micromechanical properties instrumented indentation microscratch fracture toughness(K_(c)) grid nanoindentation

JIPB in 2010-A More Reader-Friendly International Journal

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Journal of Integrative Plant Biology 2010年第1期52卷 2-3页

作者： Chun-Ming liu, PhD Editor-in-Chief, JIPB 机构不详

Online publication and online reading are gradually becoming routine for scientists and students. Most researchers now follow the scientific development in their expertise area through PubMed, Google Scholar, E-alert and Faculty 1000, etc. This in turn will bring changes to the way of scientific publishing. In JIPB＇s case, we have seen a sharp increase of the number of downloads and online subscriptions during the last couple of years, compared to a rather stable hardcopy subscription rate for the same period.

关键词： Reader In 2010 JIPB in 2010-A More Reader-Friendly International Journal

Definition,prediction,prevention and management of patients with severe ischemic stroke and large infarction

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Chinese Medical Journal 2023年第24期136卷 2912-2922页

作者： Xing Hua Ming liu Simiao Wu Department of Neurology West China HospitalSichuan UniversityChengduSichuan 610041China Center of Cerebrovascular Diseases West China HospitalSichuan UniversityChengduSichuan 610041China

Severe ischemic stroke carries a high rate of disability and death.The severity of stroke is often assessed by the degree of neurological deficits or the extent of brain infarct,defined as severe stroke and large infarction,respectively.Critically severe stroke is a life-threatening condition that requires neurocritical care or neurosurgical intervention,which includes stroke with malignant brain edema,a leading cause of death during the acute phase,and stroke with severe complications of other vital systems.Early prediction of high-risk patients with critically severe stroke would inform early prevention and treatment to interrupt the malignant course to fatal status.Selected patients with severe stroke could benefit from intravenous thrombolysis and endovascular treatment in improving functional outcome.There is insufficient evidence to inform dual antiplatelet therapy and the timing of anticoagulation initiation after severe stroke.Decompressive hemicraniectomy(DHC)<48 h improves survival in patients aged<60 years with large hemispheric infarction.Studies are ongoing to provide evidence to inform more precise prediction of malignant brain edema,optimal indications for acute reperfusion therapies and neurosurgery,and the individualized management of complications and secondary prevention.We present an evidence-based review for severe ischemic stroke,with the aims of proposing operational definitions,emphasizing the importance of early prediction and prevention of the evolution to critically severe status,summarizing specialized treatment for severe stroke,and proposing directions for future research.

关键词： Severe stroke Large infarction Malignant brain edema Critically severe stroke Definition Prediction Prevention Management

Attitude Regulation With Bounded Control in the Presence of Large Disturbances With Bounded Moving Average

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IEEE/CAA Journal of Automatica Sinica 2022年第5期9卷 834-846页

作者： Ang Li Alessandro Astolfi Ming liu School of Astronautics Harbin Institute of TechnologyHarbin 150080China Department of Electrical and Electronic Engineering Imperial College LondonLondon SW72AZUK Dipartimento di Ingegneria Civile e Ingegneria Informatica University of Rome Tor VergataRoma 00133Italy IEEE

The attitude regulation problem with bounded control for a class of satellites in the presence of large disturbances,with bounded moving average,is solved using a Lyapunov-like design.The analysis and design approaches are introduced in the case in which the underlying system is an integrator and are then applied to the satellite attitude regulation problem.The performance of the resulting closed-loop systems are studied in detail and it is shown that trajectories are ultimately bounded despite the effect of the persistent disturbance.Simulation results on a model of a small satellite subject to large,but bounded in moving average,disturbances are presented.

关键词： control cubeSats robust attitude regulation ultimate boundedness

One-against-all-based Hellinger distance decision tree for multiclass imbalanced learning

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Frontiers of Information Technology & Electronic Engineering 2022年第2期23卷 278-290页

作者： minggang DONG Ming liu Chao JING School of Information Science and Engineering Guilin University of TechnologyGuilin 541004China Guangxi Key Laboratory of Embedded Technology and Intelligent System Guilin 541004China Guangxi Key Laboratory of Trusted Software Guilin University of Electronic TechnologyGuilin 541004China

Since traditional machine learning methods are sensitive to skewed distribution and do not consider the characteristics in multiclass imbalance problems,the skewed distribution of multiclass data poses a major challenge to machine learning algorithms.To tackle such issues,we propose a new splitting criterion of the decision tree based on the one-against-all-based Hellinger distance(OAHD).Two crucial elements are included in OAHD.First,the one-against-all scheme is integrated into the process of computing the Hellinger distance in OAHD,thereby extending the Hellinger distance decision tree to cope with the multiclass imbalance problem.Second,for the multiclass imbalance problem,the distribution and the number of distinct classes are taken into account,and a modified Gini index is designed.Moreover,we give theoretical proofs for the properties of OAHD,including skew insensitivity and the ability to seek a purer node in the decision tree.Finally,we collect 20 public real-world imbalanced data sets from the Knowledge Extraction based on Evolutionary Learning(KEEL)repository and the University of California,Irvine(UCI)repository.Experimental and statistical results show that OAHD significantly improves the performance compared with the five other well-known decision trees in terms of Precision,F-measure,and multiclass area under the receiver operating characteristic curve(MAUC).Moreover,through statistical analysis,the Friedman and Nemenyi tests are used to prove the advantage of OAHD over the five other decision trees.

关键词： Decision trees Multiclass imbalanced learning Node splitting criterion Hellinger distance One-against-all scheme

The combined effect of bromadiolone and ivermectin (iBr) in controlling both rodents and their fleas

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Integrative Zoology 2024年第1期19卷 156-164页

作者： Ming liu Xinrong WAN Wei liu Xingan MA Zhibin ZHANG State Key Laboratory of Integrated Pest Management Institute of ZoologyChinese Academy of SciencesBeijingChina CAS Center for Excellence in Biotic Interactions University of Chinese Academy of SciencesBeijingChina Inner Mongolia Minzu University TongliaoInner MongoliaChina International Society of Zoological Sciences BeijingChina

Rodent pests not only cause severe agricultural loss but also spread zoonotic pathogens to human beings.Antico-agulant rodenticides are widely used to decrease the population densities of rodents but often lead to the spillover of ectoparasites becausefleas and ticks may gather on surviving rodents.Therefore,it is necessary to killfleas and ticks before culling rodents to minimize the risk of pathogen transmission.In this study,we used a mixture of ivermectin(an antiparasitic drug)and bromadiolone(an anticoagulant rodenticide)to control both rodent andflea/tick abundances.We found that in a laboratory test,0.01%ivermectin bait was not lethal for greater long-tailed hamsters after 7 days of treatment,while 0.1%ivermectin bait was lethal for approximately 33%of treated rodents.In afield test,bait containing 0.001%,0.005%,0.01%,and 0.05%ivermectin decreased the number offleas per vole of Brandt’s voles to 0.42,0.22,0.12,and 0.2,respectively,compared with 0.77 in the control group,indicating that 0.01%ivermectin bait performed best in removingfleas.In another laboratory test,bait containing a 0.01%ivermectin and 0.005%bromadiolone mixture caused the death of all voles within 6–14 days after the intake of the bait.In thefield test,the bait containing 0.01%ivermectin and 0.005%bromadiolone reduced the average number offleas per vole to 0.35,which was significantly lower than the 0.77 of the control group.Our results indicate that a 0.01%ivermectin and 0.005%bromadiolone mixture could be used to control both rodents andfleas to minimize the spillover risk of disease transmission when using traditional rodenticides.

关键词： bromadiolone flea iBr ivermectin rodent synergistic control

Antifertility effects of EP-1 (quinestrol and levonorgestrel) on Pacific rats (Rattus exulans)

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Integrative Zoology 2024年第1期19卷 127-142页

作者： Jing liu Feiyun TU Ming liu Jichao WANG Zhibin ZHANG Ministry of Education Key Laboratory for Ecology of Tropical Islands Key Laboratory of Tropical Animal and Plant Ecology of Hainan ProvinceCollege of Life SciencesHainan Normal UniversityHaikouHainanChina Secretariat Office International Society of Zoological Science and Society and Journal OfficeInstitute of ZoologyChinese Academy of SciencesBeijingChina State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijingChina CAS Center for Excellence in Biotic Interactions University of Chinese Academy of SciencesBeijingChina

Pest rodents pose a serious threat to island biodiversity.Fertility control could be an alternative approach to control the impact of rodents on these islands.In this study,we examined the antifertility effects of EP-1 baits containing quinestrol(E)and levonorgestrel(P)using a dose of 50 ppm E and P at three different ratios(E:P ratio=1:2,1:1,and 2:1)on Pacific rats(Rattus exulans)in the Xisha Islands,Hainan,China.Compared to the control group,all animals in EP-1 treatment groups showed significantly decreased food intake and body weight.In treated males,there were obvious abnormalities in testis structure and a significant decrease of relative seminal vesicle weight,but no significant effect on relative uterine and ovarian weights(g kg-1 body weight),or ovarian structure in females.Adding 8%sucrose to the original 50-ppm baits(E:P ratio=1:1)significantly increased bait palatability for males and females.This dose induced uterine edema and abnormalities of ovarian structure in females but had no significant negative effect on the relative testis,epididymis,and seminal vesicle weights(g kg-1 body weight)or sperm density in males.In summary,50-ppm EP-1(1:1)baits have the potential to disrupt the fertility of females,and 8%sucrose addition to the EP-1 baits(E:P ratio=1:1)could improve bait palatability.This dose disrupted the testis structure in males.Future studies are needed to improve bait acceptance and assess the antifertility effects of EP-1(1:1)on Pacific rats in captive breeding trials and underfield conditions.

关键词： EP-1 fertility control island biodiversity conservation levonorgestrel quinestrol Rattus exulans

Adaptive fuzzy backstepping control for attitude stabilization of flexible spacecraft with signal quantization and actuator faults

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Science China(Information Sciences) 2021年第5期64卷 135-150页

作者： Qiuhong liu Ming liu Guangren DUAN Research Institute of Intelligent Control Systems Harbin Institute of Technology Research Center of Satellite Technology Harbin Institute of Technology Center for Control Theory and Guidance Technology Harbin Institute of Technology

In this study, the fault-tolerant attitude control of flexible spacecraft is investigated over digital communication channels, where a uniform quantizer is considered with respect to the sensor signals and controller indexes. Further, an adaptive fuzzy backstepping control strategy has been developed for the considered attitude stabilization issue, where the adaptive fuzzy logic method is used to approximate the rigid-flexible coupled nonlinearity of the spacecraft. In this design, the online adjusting quantizer parameters are injected into the controller gains to simultaneously compensate for the quantization errors and timevarying actuator faults. In the proposed control method, the attitude stabilization task is achieved in the presence of external disturbances, time-varying actuator faults, and signal quantization. Finally, the practical examples are compared to demonstrate the effectiveness of the proposed control strategy.

关键词： fault-tolerant control attitude stabilization signal quantization adaptive fuzzy control backstepping control

Trotter–Kato Approximations of Impulsive Neutral SPDEs in Hilbert Spaces

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Acta Mathematica Sinica,English Series 2024年第5期40卷 1229-1243页

作者： Ming liu Xia ZHANG Ling Fei DAI School of Mathematical Sciences Tiangong UniversityTianjin 300387P.R.China

This paper studies a class of impulsive neutral stochastic partial differential equations in real Hilbert spaces.The main goal here is to consider the Trotter-Kato approximations of mild solutions of such equations in the pth-mean(p≥2).As an application,a classical limit theorem on the dependence of such equations on a parameter is obtained.The novelty of this paper is that the combination of this approximating system and such equations has not been considered before.

关键词： Impulsive neutral stochastic partial diferential equation Trotter-Kato approximations classical limit theorem