检索结果-南通市图书馆

Cooperative guidance law with maneuverability awareness:A decentralized solution

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第7期37卷 450-457页

作者： Shuyang XU xun song Chaoyong LI College of Electrical Engineering Zhejiang UniversityHangzhou 310027China Beijing Institute of Electronic System Engineering Beijing 100074China

In this paper,we propose a cooperative guidance law aimed to achieve coordinated impact angles with limited observation on target *** primary challenge lies in establishing an appropriate communication graph among all missiles and devising an algorithm to estimate target acceleration information during *** address this,we propose a specific communication topology and employ a numerical integration-based estimation ***,a distributed algorithm is introduced to facilitate consensus on target acceleration *** upon these foundations,we design an optimal-control-based distributed guidance law for each *** of the proposed guidance law is validated through numerical simulations.

关键词： Cooperative guidance Target maneuver estimation Distributed estimation Consensus Optimal control

Geochronological and geochemical constraints on the petrogenesis and geodynamic process of Hemler,Vlinder,and Il'ichev seamount lavas in NW Pacific

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第6期67卷 1856-1871页

作者： xun WEI Yan ZHANG Xuefa shi Hui ZHANG Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine Geology Qingdao Marine Science and Technology CenterQingdao 266237China Shandong Key Laboratory of Deep Sea Mineral Resources Development(Preparatory) Qingdao 266061China

Oceanic intraplate volcanoes with linear age progressions are usually accepted to be derived from melting of an upwelling mantle *** seamount groups in NW Pacific,however,show complex age-distance relationships that are difficult to explain using the classic“mantle plume hypothesis”,and thus their origins are *** this study,we present ^(40)Ar-^(39)Ar age,geochemical,and Sr-Nd-Pb-Hf isotopic data of lavas from Hemler,Vlinder,and Il’ichev seamounts in NW Pacific,to elucidate their petrogenesis and geodynamic *** lavas from Hemler,Vlinder,and Il’ichev seamounts are classified as alkali basalt,basanite/nephelinite,and *** with Mg O>8 wt.%exhibit high contents of CaO,FeO^(T),and TiO_(2),similar to the composition of melts formed from reaction between carbonated eclogite-derived melts and fertile *** lavas have elevated Zr/Hf ratios(40.6-45.2)and negative Zr and Hf anomalies,indicating the presence of a carbonate component in the mantle *** are enriched in incompatible trace elements and have enriched mantle 1(EM1)-like SrNd-Pb-Hf isotopic *** isotopic compositions of Vlinder,Il’ichev basanite,and Hemler lavas in this study are similar to the Rarotonga *** occurring at the same seamount,the Il’ichev alkali basalts display more depleted SrNd-Hf isotopic compositions compared to Il’ichev *** to plate tectonic reconstruction results,the ages of Hemler(100.1 Ma),Vlinder pre-(100.2 Ma)and post-shield(87.5 Ma),and Il’ichev(56.4 Ma)lavas clearly deviate from the Macdonald,Arago,Rarotonga,and Samoa hotspot tracks,indicating that they cannot directly originate from mantle *** propose that in the mid-Cretaceous,when the Pacific plate passed over Rarotonga hotspot,melting of Rarotonga plume formed the Vlinder(main-shield stage),Pako,and Ioah *** Rarotonga(and possibly Samoa)plume materials would have been dispersed into the surrounding asthenosphere by mantle conve

关键词： Mantle plume Magellan seamount trail Carbonated mantle component Hotspot Lithosphere extension

Increase of chiral sensing ability in host-guest chemistry by magnetic anisotropy

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第8期67卷 2775-2782页

作者： Jia-Liang Chen Bin Li Feng Yang Tiesheng shi xun-Cheng Su State Key Laboratory of Elemento-organic Chemistry Tianjin Key Laboratory of Biosensing and Molecular RecognitionCollege of ChemistryNankai UniversityTianjin 300071China College of Chemistry Chemical Engineering and Materials ScienceZaozhuang UniversityZaozhuang 277160China

Enantiomeric molecules generally play distinct functions in chemistry,biology,and *** physical and chemical properties of chiral analytes lay difficulty in discrimination and quantification of the *** report herein an efficient approach of increasing the chiral sensing ability ofβ-cyclodextrin(β-CD),a widely used host molecule,in the hostguest chemistry by magnetic anisotropy.A rigid and chiral lanthanide binding tag was attached to theβ-CD to amplify the changes of nuclear magnetic resonance(NMR)signals in the host-guest recognition *** installation of the paramagnetic lanthanide ion inβ-CD greatly enhances the enantiomeric discrimination up to 30-fold in comparison with the diamagneticβ-CD *** addition,the magnitude of the paramagnetic effects is tunable according to the diverse range of paramagnetic strength of the lanthanide *** reported method significantly increases the chiral sensing ability ofβ-CD,which can be applied to other host *** transferred paramagnetic effects,pseudocontact shifts(PCSs)and paramagnetic relaxation enhancements(PREs),from the host to the guest molecules,are valuable structural restraints to determine the absolute stereochemistry of the chiral *** strategy does not need modification of the analytes and is complementary to the reported analytical methods that rely on the functionalization of the chiral analytes.

关键词： chiral recognition nuclear magnetic resonance host-guest chemistry magnetic anisotropy lanthanide ions

同方期刊数据库

On the Quantum Cohomology of Blow-ups of Four-dimensional Quadrics

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第1期40卷 313-328页

作者： Jian xun HU Hua Zhong KE Chang Zheng LI Lei song School of Mathematics Sun Yat-sen UniversityGuangzhou 510275P.R.China

We propose a conjecture relevant to Galkin’s lower bound conjecture,and verify it for the blow-ups of a four-dimensional quadric at a point or along a projective *** also show that Conjecture O holds in these two cases.

关键词： Quantum cohomology blow-up quadric hypersurface

Study on a probabilistic algorithm for the forming and 3D characterization of special-shaped surfaces under profile grinding

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第2期12卷 288-299页

作者： Zhao-Qing Zhang Kai-Ning shi Yao-Yao shi Yi-Hui song Zhe He Ya-song Pu School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an710072People’s Republic of China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an710072People’s Republic of China Engineering Research Center of Advanced Manufacturing Technology for Aero Engine(Northwestern Polytechnical University) Ministry of EducationXi’an710072People’s Republic of China

Profile grinding is the most crucial method for the ultra-precision machining of special-shaped ***,profile grinding produces a unique machining profile,and many random factors in the machining process lead to complex surface *** this study,the structural and probabilistic characteristics of the profile grinding of a special-shaped surface were analyzed,and a probabilistic algorithm for the forming and 3D characterization of special-shaped surfaces under profile grinding was *** forming process of a GH738 blade tenon tooth surface was considered as an example to demonstrate the *** comparison results showed that the simulation results had similar surface characteristics to the measurement results,and the relative error range of the 3D roughness parameter was 0.21%–19.76%,indicating an accurate prediction and characterization of the complex special-shaped surface under the action of multiple factors.

关键词： Special-shaped surface Profile grinding Surface morphology 3D characterization

Associations of Sarcopenia, Handgrip Strength and Calf Circumference with Cognitive Impairment among Chinese Older Adults

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2021年第11期34卷 859-870页

作者： WU Bing LYU Yue Bin CAO Zhao Jin WEI Yuan shi Wan Ying GAO Xiang ZHOU Jin Hui KRAUS Virginia Byers ZHAO Feng CHEN Xin LU Feng ZHANG Ming Yuan LIU Ying Chun TAN Qi Yue song shi xun QU Ying Li ZHENG Xu Lin SHEN Chong MAO Chen shi Xiao Ming Center for Global Health School of Public HealthNanjing Medical UniversityNanjing 211166JiangsuChina China CDC Key Laboratory of Environment and Population Health National Institute of Environmental HealthChinese Center for Disease Control and PreventionBeijing 100021China School of Public Health Jilin UniversityChangchun 130012JilinChina Department of Nutritional Sciences Pennsylvania State UniversityUniversity ParkPA19019USA Duke Molecular Physiology Institute and Department of Medicine Duke University School of MedicineDurhamNorth Carolina27701USA Beijing Municipal Health Commission Information Center Beijing 100034China Division of Epidemiology School of Public HealthSouthern Medical UniversityGuangzhou 510515GuangdongChina

Objective To evaluate the associations of sarcopenia,handgrip strength and calf circumference with cognitive impairment among Chinese older *** Totally 2,525 older adults were recruited from the Healthy Aging and Biomarkers Cohort *** impairment was assessed by the Chinese Mini-Mental State *** strength was calculated from the means of the right and left hand *** circumference was measured at the site of maximum circumference of the non-dominant *** formula developed by Ishii was used to define *** logistic regression was performed to evaluate the associations of sarcopenia,handgrip strength,and calf circumference with cognitive *** The prevalence of cognitive impairment was 34.36%.The adjusted odds ratio(OR)for cognitive impairment in individuals with sarcopenia was 2.55[95% confidence interval(95%CI):1.86-3.50].Compared with individuals in the first quartile(Q1)of calf circumference,the adjusted ORs in the second,third,and fourth quartiles(Q_(2),Q_(3),and Q_(4))were 0.75(95% CI:0.58-0.96),0.59(95% CI:0.44-0.79),and 0.62(95% CI:0.45-0.8),*** with individuals in Q1 of handgrip strength,the adjusted ORs for Q_(2),Q_(3),and Q_(4) were 0.49(95%CI:0.38-0.62),0.31(95% CI:0.23-0.41),and 0.30(95%CI:0.21-0.44),*** Sarcopenia,identified by low handgrip strength and low calf circumference,was positively associated with cognitive impairment.

关键词： Sarcopenia Cognitive impairment Handgrip strength Calf circumference Older adults

Hierarchical multihead self-attention for time-series-based fault diagnosis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第6期70卷 104-117页

作者： Chengtian Wang Hongbo shi Bing song Yang Tao Key Laboratory of Smart Manufacturing in Energy Chemical Process of the Ministry of Education East China University of Science and TechnologyShanghai 200237China

Fault diagnosis is important for maintaining the safety and effectiveness of chemical *** the multivariate,nonlinear,and dynamic characteristic of chemical process,many time-series-based data-driven fault diagnosis methods have been developed in recent ***,the existing methods have the problem of long-term dependency and are difficult to train due to the sequential way of *** overcome these problems,a novel fault diagnosis method based on time-series and the hierarchical multihead self-attention(HMSAN)is proposed for chemical ***,a sliding window strategy is adopted to construct the normalized time-series ***,the HMSAN is developed to extract the time-relevant features from the time-series process *** improves the basic self-attention model in both width and *** the multihead structure,the HMSAN can pay attention to different aspects of the complicated chemical process and obtain the global dynamic ***,the multiple heads in parallel lead to redundant information,which cannot improve the diagnosis *** the hierarchical structure,the redundant information is reduced and the deep local time-related features are further ***,a novel many-to-one training strategy is introduced for HMSAN to simplify the training procedure and capture the long-term ***,the effectiveness of the proposed method is demonstrated by two chemical *** experimental results show that the proposed method achieves a great performance on time-series industrial data and outperforms the state-of-the-art approaches.

关键词： Self-attention mechanism Deep learning Chemical process Time-series Fault diagnosis

Regulation and application of supramolecular gel with circularly polarized luminescence

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第6期67卷 1865-1880页

作者： Shen song Yulong shi Liangliang Zhu Bingbing Yue School of Materials and Chemistry&Institute of Bismuth and Rhenium University of Shanghai for Science and TechnologyShanghai200093China State Key Laboratory of Molecular Engineering of Polymers Fudan UniversityShanghai200438China

Supermolecular gel is a three-dimensional network structure assembled by small molecules or polymers in solvents through noncovalent *** emergence of system complexity occurs spontaneously during the molecular self-assembly process.A multitude of chiral molecular self-assembly systems have been engineered,facilitating the achievement of circularly polarized luminescence(CPL)through the amalgamation of chiral entities with *** bonding,π-πstacking,and noncovalent forces,such as host-guest interactions and Van der Waals'forces,confer upon supramolecular gels the capacity to react to diverse *** to the flexibility of supramolecular assembly,the CPL properties of supramolecular gels have rich controllability and can be used in various *** this review,we summarized the examples of CPL-active supramolecular gel assembly,and further summarized the assembly environment factors and external ***,the versatility of CPL applications in supramolecular gels is demonstrated,ranging from optical devices,information encryption,biosensing and chemical sensing,and other practical *** conclusion,the study provides insights into the multicultural factors influencing CPL in supramolecular gels,describes their applications in various domains,and presents future perspectives in the field.

关键词： supramolecular gels circularly polarized luminescence self-assembly chirality stimuli-response

Combining TDLAS and multi-fusion algorithms for methane gas concentration detection

在线全文

学校读者我要写书评

暂无评论

Optoelectronics Letters 2024年第6期20卷 353-359页

作者： shi Guojun song Xinmin DONG Taiji School of Information&Electrical Engineering Heilongjiang Bayi Agricultural UniversityDaqing 163319China College of Electrical and Information Engineering Northeast Petroleum UniversityDaqing 163318China

High-precision methane gas detection is of great importance in industrial safety, energy production and environmental protection, etc. However, in the existing measurement techniques, the methane gas concentration information is susceptible to noise, which leads to its useful signal being drowned by noise. A fusion algorithm of variational modal decomposition(VMD) and improved wavelet threshold filtering is proposed, which is used in combination with tunable diode laser absorption spectroscopy(TDLAS) to implement a non-contact, high-resolution methane gas concentration detection. The fusion algorithm can perform noise reduction and further segmentation of the methane gas detection signal. And the simulation and experiment verify the effectiveness of the fusion algorithm, and the experimental results show that for the detection of air containing 10 ppm, 30 ppm, 60 ppm, 80 ppm, and 99 ppm methane, the errors are 12.75%, 8.18%, 3.37%, 2.46%, and 1.78%, respectively.

关键词： Combining TDLAS and multi-fusion algorithms for methane gas concentration detection TDLAS