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Classification of knowledge graph completeness measurement techniques

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Journal of Systems Engineering and Electronics 2024年第1期35卷 154-162页

作者： zhang Ying XIAO gang Institute of Systems Engineering Academy of Military SciencesBeijing 100107China

At present,although knowledge graphs have been widely used in various fields such as recommendation systems,question and answer systems,and intelligent search,there are always quality problems such as knowledge omissions and *** assessment and control,as an important means to ensure the quality of knowledge,can make the applications based on knowledge graphs more complete and more accurate by reasonably assessing the knowledge graphs and fixing and improving the quality problems at the same ***,as an indispensable part of the knowledge graph construction process,the results of quality assessment and control determine the usefulness of the knowledge *** them,the assessment and enhancement of completeness,as an important part of the assessment and control phase,determine whether the knowledge graph can fully reflect objective phenomena and reveal potential connections among *** this paper,we review specific techniques of completeness assessment and classify completeness assessment techniques in terms of closed world assumptions,open world assumptions,and partial completeness *** purpose of this paper is to further promote the development of knowledge graph quality control and to lay the foundation for subsequent research on the completeness assessment of knowledge graphs by reviewing and classifying completeness assessment techniques.

关键词： quality assessment completeness assessment closed world assumptions open world assumption partial completeness assumption

Tunability of Band Gaps in Two-Dimensional Phononic Crystals with Magnetorheological and Electrorheological Composites

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Acta Mechanica Solida Sinica 2021年第1期34卷 40-52页

作者： gang zhang Yuanwen Gao Key Laboratory of Mechanics on Environment and Disaster in Western China The Ministry of Education of ChinaLanzhou UniversityLanzhou730000China Department of Mechanics and Engineering Science College of Civil Engineering and MechanicsLanzhou UniversityLanzhou730000China

The elastic wave propagation properties of phononic crystals(PnCs)composed of an elastic matrix embedded in magnetorheological and electrorheological elastomers are studied in this *** tunable band gaps and transmission spectra of these materials are calculated using the finite element method and supercell *** variations in the band gap characteristics with changes in the electric/magnetic fields are *** numerical results show that the electric and magnetic fields can be used in combination to adjust the band gaps *** start and stop frequencies of the band gap are obviously affected by the electric field,and the band gap width is regulated more significantly by the magnetic *** widest and highest band gap can be obtained by combined application of the electric and magnetic *** addition,the band gaps can be moved to the low-frequency region by drilling holes in the PnC,which can also open or close new band *** results indicate the possibility of multi-physical field regulation and design optimization of the elastic wave properties of intelligent PnCs.

关键词： Phononic crystal.Band gap Magnetic field Electric field Combined adjustment

Fast calculation method for mission opportunities in orbital interception and rendezvous problems

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Chinese Journal of Aeronautics 2023年第6期36卷 201-212页

作者： Huidong MA gang zhang Research Center of Satellite Technology Harbin Institute of TechnologyHarbin 150080China

This paper proposes a fast calculation method to solve all mission opportunities for orbital interception and orbital rendezvous under the impulse-magnitude *** from the existing search methods,the proposed method does not need to solve Lambert's problem in the whole *** cases are considered for either departure time or transfer time being free,or both being *** fixed departure time,the feasible windows of transfer time are obtained by solving a single-variable nonlinear equation only of terminal true ***,for fixed interception(or rendezvous)time,the feasible windows of departure time are *** free departure time and free transfer time,all mission opportunities are obtained by using a onedimensional search *** hyperbolic-transfer and the multiple-revolution cases are also *** results show that the proposed method is superior to the typical pork-chop plot method and the two-dimensional launch window method in computational time.

关键词： Mission opportunity Impulse-magnitude constraint Orbital interception Orbital rendezvous Pork-chop plot

Fabrication of segregated poly(arylene sulfide sulfone)/graphene nanoplate composites reinforced by polymer fibers for electromagnetic interference shielding

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Nano Materials Science 2022年第3期4卷 285-293页

作者： Cheng-gong Chang Jia-cao Yang gang zhang Sheng-ru Long Xiao-jun Wang Jie Yang College of Polymer Science and Engineering Sichuan UniversityChengdu610065China Analytical and Testing Center Sichuan UniversityChengdu610064China State Key Laboratory of Polymer Materials Engineering Sichuan UniversityChengdu610065China Jiangsu JITRI Advanced Polymer Materials Research Institute Co. LtdChina

Poly(arylene sulfide sulfone)/graphene nanoplate(PASS/GNP) composites with segregated structure based on continuous polymer fiber skeletons were fabricated by coating a thin conductive layer on the PASS fibers and then performing compression molding. The formation of a unique segregated conductive network endowed the PASS/GNP composites with high electrical conductivity and excellent electromagnetic interference(EMI) shielding effectiveness(SE), reaching 17.8 S/m and 30.1 d B, respectively, when the content of the GNPs in the conductive layer was 20 wt%. The PASS/GNP composites also exhibited outstanding mechanical properties, which was attributed to the continuous PASS fiber skeletons that could withstand large loads and the strong interfacial interaction between the conductive layers and the PASS fibers that could provide good stress transfer. This approach is suitable for most soluble polymers.

关键词： Segregated structure EMI shielding Interfacial interaction Mechanical properties

On Exact Solutions to Partial Differential Equations by the Modified Homotopy Perturbation Method

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Acta Mathematicae Applicatae Sinica 2012年第1期28卷 91-98页

作者： gang YANG ru-yun CHEN Luo-gen YAO School of Information Hunan University of CommerceChangsha 410205China School of Science Guangdong Ocean UniversityZhanjiang 524088China

Based on the modified homotopy perturbation method （MHPM）, exact solutions of certain partial differential equations are constructed by separation of variables and choosing the finite terms of a series in p as exact solutions. Under suitable initial conditions, the PDE is transformed into an ODE. Some illustrative examples reveal the efficiency of the proposed method.

关键词： homotopy perturbation method modified homotopy perturbation method analytic solution Fokker-Planck equation

Quantum uncertainty relations of Tsallis relative α entropy coherence based on MUBs

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Communications in Theoretical Physics 2022年第1期74卷 31-39页

作者： Fu-gang zhang School of Mathematics and Information Science Nanchang Hangkong UniversityNanchang 330063China

In this paper,we discuss quantum uncertainty relations of Tsallis relative α entropy coherence for a single qubit system based on three mutually unbiased *** α∈[1/2,1)U(1,2],the upper and lower bounds of sums of coherence are ***,the above results cannot be verified directly for any α∈(0,1/2).Hence,we only consider the special case of α=1/n+1,where n is a positive integer,and we obtain the upper and lower *** comparing the upper and lower bounds,we find that the upper bound is equal to the lower bound for the special α=1/2,and the differences between the upper and the lower bounds will increase as α ***,we discuss the tendency of the sum of coherence,and find that it has the same tendency with respect to the different θ or φ,which is opposite to the uncertainty relations based on the Rényi entropy and Tsallis entropy.

关键词： quantum uncertainty relation Tsallis relativeαentropy of coherence the upper and lower bounds single qubit state MUB

Microstructure and Wear Properties of Fe-based Amorphous Coatings Deposited by High-velocity Oxygen Fuel Spraying

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Journal of Iron and Steel Research International 2016年第7期23卷 699-704页

作者： gang WANG Ping XIAO Zhong-jia HUANG ru-jie HE Remanufacturing Surface Engineering Technology Research Center Anhui Polytechnic University Institute of Advanced Structure Technology Beijing Institute of Technology

Fe-based powder with a composition of Fe_（42.87）Cr_（15.98）Mo_（16.33）C_（15.94）B_（8.88）（at.%）was used to fabricate coatings by high-velocity oxygen fuel *** effects of the spraying parameters on the microstructure and the wear properties of the Fe-based alloy coatings were systematically *** results showed that the obtained Fe-based coatings with a thickness of about 400μm consisted of a large-volume amorphous phase and some *** increasing the fuel and oxygen flow rates,the porosity of the obtained coatings *** coating deposited under optimized parameters exhibited the lowest porosity of 2.8%.The excellent wear resistance of this coating was attributed to the properties of the amorphous matrix and the presence of nanocrystals homogeneously distributed within the *** wear mechanism of the coatings was discussed on the basis of observations of the worn surfaces.

关键词： metallic glass high-velocity oxygen fuel Fe-based amorphous coating micro-hardness wear resistance

Efficacy of scraping therapy on blood pressure and sleep quality in stage Ⅰ and Ⅱ essential hypertension: A systematic review and meta-analysis

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Journal of Integrative Medicine 2024年第1期22卷 12-21页

作者： Zheng-gang Zhu Jian-ru Wang Xiao-yan Pan School of Nursing Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina School of Health Sciences Universiti Sains MalaysiaKubang Kerian 16150KelantanMalaysia Department of Cardiovascular Medicine the First Affiliated Hospital of Henan University of Chinese MedicineZhengzhou 450000Henan ProvinceChina

Background Scraping therapy is widely used in treating stage I and II essential hypertension in ***,there has been no systematic evaluation of the efficacy of scraping therapy on blood pressure and sleep quality in stage I and II essential *** strategy Seven electronic databases(PubMed,Scopus,Cochrane Library,Web of Science,EBSCO,China National Knowledge Infrastructure and Wanfang Data electronic databases)were searched from inception to December *** on the principle of combining subject words with text words,the search strategy was constructed around search terms for“scraping therapy,”“scraping,”“Guasha,”“Gua sha,”“hypertension,”and“high blood pressure”during the database *** criteria Randomized controlled trials(RCTs)were included if they recruited patients with stage I and II essential hypertension and included a scraping therapy *** intervention group received antihypertensive drugs and scraping therapy,while the control group only took antihypertensive *** extraction and analysis Review Manager 5.4.0 and STATA 15.1 were used to enter all the relevant outcome variables to conduct the *** quality of the selected RCTs was assessed using the PEDro *** sensitivity analysis was carried out by iteratively excluding individual studies and repeating the analysis to determine the stability of the findings and identify any studies with greater influence on the *** analysis was performed to find the source of *** plots were used to evaluate the publication bias of included *** Nine RCTs including 765 participants were ***-analysis showed that scraping therapy combined with medication had an advantage over the use of medication alone in lowering systolic blood pressure(mean difference[MD]=?5.09,95%confidence interval[CI]=?6.50 to?3.67,P<0.001)and diastolic blood pressure(MD=?2.66,95%CI=?3.17 to?2.14,P<0.001).Subgroup analysis showed tha

关键词： Scraping therapy Essential hypertension Efficacy Blood pressure Sleep quality Systematic review Meta-analysis

Biological sources, paleoenvironment, and organic matter enrichment in source rocks of the Ordovician Majiagou Formation, Ordos Basin, China:Evidence from biomarkers,microfossils, and inorganic geochemical analyses

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Journal of Palaeogeography 2024年第1期13卷 92-115页

作者： Jing-Jing Cao Wen-Zhe gang Shang-ru Yang State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Bejing)Beijing 102249China College of Geosciences China University of Petroleum(Bejing)Beijing 102249China Oil and Gas Technology Research Institute PetroChina Changqing Oifield CompanyXi'an 710018Shaanxi ProvinceChina

Carbonate deposits in the Ordovivian Majiagou Formation are significant source rocks for natural gas generation in the Ordos Basin, northwestern China. Previous studies mainly focused on the organic matter enrichment mechanism of shales rather than carbonate rocks. The biological sources and paleoenvironment of carbonate source rocks, and the main controlling factors of organic matter enrichment in the carbonate source rocks were studied in this paper in combination with evidence from biomarkers, microfossils and inorganic geochemistry analysis. The results show that four types of microfacies were identified in the Majiagou Formation, respectively as: mud flat microfacies, mud-dolomite flat microfacies, dolomite flat microfacies, and open marine microfacies. The biological sources of organic matter are chiefly planktonic algae, followed by bacteria. The mud flat and mud-dolomite flat contain a high abundance of terrigenous detrital inputs, as indicated by the high content of Al_(2)O_(3), TiO_(2), Th, and Zr. The low Sr/Cu and high Rb/Sr values reveal warm and humid paleoclimate conditions in the mud flat and mud-dolomite flat, whereas the dolomite flat and open marine were likely formed in hot and arid paleoclimate conditions. The mud flat and mud-dolomite flat deposits were characterized by high paleoproductivity of the Majiagou Formation. Low Sr/Ba values were found in the mud flat samples, indicating fresh to brackish water condition, whereas samples of other facies have a relatively high degree of salinity. Based on U_(auth), Mo_(auth), Cr_(auth), Co_(auth), δCe, and δEu values, the mud flat microfacies was formed in a suboxic and anoxic environment, whereas the mud-dolomite flat, dolomite flat and open marine microfacies were within dysoxic to oxic conditions. A model of organic matter enrichment in the Majiagou Formation is thus established. The level of terrigenous detrital inputs is the principal factor of organic matter enrichment in the Majiagou Formation,

关键词： Biological source Microfacies Trace elements Organic matter Majiagou Formation Ordos Basin