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A model reduction approach for discrete-time linear time-variant systems with delayed inputs

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Science China(Information Sciences) 2024年第4期67卷 197-217页

作者： Ai-Guo WU Guang-ren DUAN Yu WANG jie ZHANG School of Mechanical Engineering and Automation Harbin Institute of Technology(Shenzhen) HIT Wuhu Robot Technology Research Institute Center for Control Science and Technology Southern University of Science and Technology

A model reduction approach is presented for discrete-time linear time-variant input-delayed systems. According to this proposed approach, a dynamical variable is constructed by taking advantage of the current state and historical information of input. It is revealed that the behavior of this dynamical variable is governed by a discrete-time linear delay-free system. It is worth noting that the presented variable transformation does not require the system matrix to be invertible. Based on the reduced delay-free models,stabilizing control laws can be easily obtained for the original delayed system. For the case with a single input delay, the constructed variable is an exact prediction for the future state, and thus the stabilizing control law could be designed by replacing the future state with its prediction. Finally, three discrete-time periodic systems with delayed input are employed to illustrate how to utilize the presented model reduction approaches.

关键词： reduction approach predictor-based feedback time-varying systems delayed input periodic system

Simplified quantitative analysis method and its application in the insitu synthesized copper-based azide chips

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Defence Technology（防务技术） 2024年第2期32卷 309-316页

作者： jie ren Yunfeng Li Mingyu Li Xingyu Wu Jiabao Wang Qingxuan Zeng State Key Laboratory of Explosion and Technology Beijing Institute of TechnologyBeijing 100081China

Copper-based azide(Cu(N_(3))2.or CuN_(3),CA)chips synthesized by in-situ azide reaction and utilized in miniaturized explosive systems has become a hot research topic in recent ***,the advantages of in-situ synthesis method,including small size and low dosage,bring about difficulties in quantitative analysis and differences in ignition capabilities of CA *** aim of present work is to develop a simplified quantitative analysis method for accurate and safe analysis of components in CA chips to evaluate and investigate the corresponding ignition *** this work,Cu(N_(3))2.and CuN_(3)components in CA chips were separated through dissolution and distillation by utilizing the difference in solubility and corresponding content was obtained by measuring N_(3)-concentration through *** spectrophotometry method was optimized by studying influencing factors and the recovery rate of different separation methods was studied,ensuring the accuracy and reproducibility of test *** optimized method is linear in range from 1.0-2..0 mg/L,with a correlation coefficient R^(2.=0.9998,which meets the requirements of CA chips with a milligram-level content *** with the existing ICP method,component analysis results of CA chips obtained by spectrophotometry are closer to real component content in samples and have satisfactory ***,as its application in miniaturized explosive systems,the ignition ability of CA chips with different component contents for direct ink writing CL-2. and the corresponding mechanism was *** study provided a basis and idea for the design and performance evaluation of CA chips in miniaturized explosive systems.

关键词： Copper-based azide chips Spectrophotometry Separation method Quantitative analysis Ignition ability

Effect of the sloping seabed on 3D soil-spudcan interaction using a material point-finite element(MPM-FEM)model

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1436-1454页

作者： Zhengda Lei Guangtian Zeng Huaihui ren Bisheng Wu Yuxin jie State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijingChina Key Laboratory of the Hydrosphere Sciences of the Ministry of Water Resources BeijingChina Institute of Ocean Engineering Tsinghua UniversityBeijingChina Longyuan (Beijing) Wind Power Engineering Technology Co. Ltd.BeijingChina

The sloping seabed affects the bearing capacity and failure mechanism of soil,which may compromise the stability and safety of offshore structures such as jack-up *** paper employs a coupled model combining the material point method and finite element method(MPM-FEM)to analyze the impact of sloping seabeds on the three-dimensional soil-spudcan *** MPM-FEM model implements the B¯approach to solve the challenge of volumetric locking due to the incompressibility constraints imposed by yield *** is validated against the centrifuge *** effects of sloping seabeds on penetration resistance,soil flow pattern,lateral response,stress distribution,and failure mechanism are *** soil mainly undergoes overall failure when the ratio of penetration depth to spudcan diameter(i.e.D P/D)is between 0 and *** the slope angle increases,the soil on the side of lower slope is expelled further,resulting in an asymmetric stress distribution and a larger horizontal sliding force of *** D P/D increases to 0.75,the soil transitions to localized plastic flow failure,and the range of soil flow affected by the spudcan penetration *** results show that,when the slope angle increases,the lateral displacement and stress distribution on the lower slope of a sloping seabed is significantly larger than that of a horizontal seabed,impacting the spudcan and surrounding soil *** study suggests that the seabed slope significantly affects the range of soil flow and failure at shallow penetration,indicating that the slope angle should be taken into account in the design and installation of offshore jack-up rigs,particularly in areas with sloping seabeds.

关键词： Soil-spudcan interaction Centrifuge tests MPM-FEM model B—approach Sloping seabeds Offshore structures

Synthesis of porous flower-like SnO_(2./CdSnO_(3) microstructures with excellent sensing performances for volatile organic compounds

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Frontiers of Materials Science 2024年第1期18卷 45-57页

作者： jie Wan Gang Wang Haibo ren Jiarui Huang Sang Woo Joo School of Materials Science and Engineering Anhui Polytechnic UniversityWuhu 241000China Key Laboratory of Functional Molecular Solids of the Ministry of Education College of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China School of Mechanical Engineering Yeungnam UniversityGyeongsanGyeoungbuk 712749Republic of Korea

Porous flower-like SnO_(2./CdSnO_(3) microstructures self-assembled by uniform nanosheets were synthesized using a hydrothermal process followed by calcination,and the sensing performance was measured when a gas sensor,based on such microstructures,was exposed to various volatile organic compound(VOC)*** response value was found to reach as high as 100.1 when the SnO_(2./CdSnO_(3) sensor was used to detect 100 ppm formaldehyde gas,much larger than those of other tested VOC gases,indicating the high gas sensitivity possessed by this sensor especially in the detection of formaldehyde ***,the response/recovery process was fast with the response time and recovery time of only 13 and 2. s,*** excellent gas sensing performance derive from the advantages of SnO_(2./CdSnO_(3),such as abundant n-n heterojunctions built at the interface,high available specific surface area,abundant porosity,large pore size,and rich reactive oxygen species,as well as joint effects arising from SnO_(2. and CdSnO_(3),suggesting that such porous flower-like SnO_(2./CdSnO_(3) microstructures composed of nanosheets have a high potential for developing gas sensors.

关键词： SnO_(2./CdSnO_(3) porous flower-like microstructure volatile organic gas sensingproperty gas sensor

Interpretability of Neural Networks Based on Game-theoretic Interactions

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Machine Intelligence Research 2024年第4期21卷 718-739页

作者： Huilin Zhou jie ren Huiqi Deng Xu Cheng Jinpeng Zhang Quanshi Zhang School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China XLAB The Second Academy of China Aerospace Science and Industry CorporationBeijing 100854China

This paper introduces the system of game-theoretic interactions,which connects both the explanation of knowledge encoded in a deep neural networks(DNN)and the explanation of the representation power of a *** this system,we define two gametheoretic interaction indexes,namely the multi-order interaction and the multivariate *** crucially,we use these interaction indexes to explain feature representations encoded in a DNN from the following four aspects:(1)Quantifying knowledge concepts encoded by a DNN;(2.Exploring how a DNN encodes visual concepts,and extracting prototypical concepts encoded in the DNN;(3)Learning optimal baseline values for the Shapley value,and providing a unified perspective to compare fourteen different attribution methods;(4)Theoretically explaining the representation bottleneck of ***,we prove the relationship between the interaction encoded in a DNN and the representation power of a DNN(e.g.,generalization power,adversarial transferability,and adversarial robustness).In this way,game-theoretic interactions successfully bridge the gap between“the explanation of knowledge concepts encoded in a DNN”and"the explanation of the representation capacity of a DNN"as a unified explanation.

关键词： Model interpretability and transparency explainable AI game theory interaction deep learning.

Acaricidal effect of the antimicrobial metabolite xenocoumacin 1 on spider mite control

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Journal of Integrative Agriculture 2024年第3期23卷 948-959页

作者： Jiaxing Wei Hong Yan jie ren Guangyue Li Bo Zhang Xuenong Xu Institute of Plant Protection Chinese Academy of Agricultural SciencesBeijing 100193China State Key Laboratory for Biology of Plant Diseases and Insect Pests Beijing 100193China Key Laboratory of Natural Enemies Insects Ministry of Agriculture and Rural AffairsBeijing 100193China

The two-spotted spider mite,Tetranychus urticae Koch,is one of the most harmful pests in many agroecosystems *** effectively manage this pest,there is an urgent need to develop novel bio-active acaricides that support integrated pest management strategies targeting *** this study,we explored the acaricidal effects of xenocoumacin 1 (Xcn1) on *** and its predator Neoseiulus californicus using the highly puri?ed ***1 was extracted and purified from the cell-free supernatant of the Xenorhabdus nematophila CB6 mutant constructed by the easy promoter activated compound identi?cation (easyPACId) *** the concentration of Xcn1 exceeded 100μg mL~(–1),the survival rate of spider mite adults declined to below 40%and the fecundity was decreased by 80%at six days *** concentrations of 2. and 50μg mL~(–1),Xcn1 signi?cantly impeded spider mite development by inhibiting the ***,neither concentration had any adverse effects on the survival or reproduction of the predatory mite *** results from laboratory and semi-?eld experiments consistently demonstrated the effectiveness of the antimicrobial metabolite Xcn1 in controlling pest mites at both the molecular and physiological *** study offers a promising possibility that combines the compatible biocontrol agents of Xcn1 and predatory mites for integrated pest mite control.

关键词： pest management predatory mite Xcn1 morphology developmental inhibition transcriptome

Calcium-based polymers for suppression of soil acidification by improving acid-buffering capacity and inhibiting nitrification

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Journal of Environmental Sciences 2024年第5期139卷 138-149页

作者： Fei Kang Yunshan Meng Yanning Ge Yun Zhang Haixiang Gao Xueqin ren jie Wang Shuwen Hu Beijing Key Laboratory of Farmland Soil Pollution Prevention-control and Remediation College of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China Department of Applied Chemistry China Agricultural UniversityBeijing 100193China

Soil acidification is a major threat to agricultural sustainability in tropical and subtropical *** and environmentally friendly materials,such as calcium lignosulfonate(CaLS),calcium poly(aspartic acid)(PASP-Ca),and calcium polyγ-glutamic acid(γ-PGA-Ca),are known to effectively ameliorate soil ***,their effectiveness in inhibiting soil acidification has not been *** study aimed to evaluate the effect of CaLS,PASP-Ca,andγ-PGA-Ca on the resistance of soil toward acidification as directly and indirectly(i.e.,via nitrification)caused by the application of HNO_(3)and urea,*** comparison,Ca(OH)_(2.and lignin were used as the inorganic and organic controls,*** the materials,γ-PGA-Ca drove the substantial improvements in the pH buffering capacity(pHBC)of the soil and exhibited the greatest potential in inhibiting HNO_(3)-induced soil acidification via protonation of carboxyl,complexing with Al~(3+),and cation exchange *** acidification induced by urea,CaLS was the optimal one in inhibiting acidification and increasing exchangeable acidity during ***,the sharp reduction in the population sizes of ammonia-oxidizing bacteria(AOB)and ammonia-oxidizing archaea(AOA)confirmed the inhibition of nitrification via CaLS ***,compared to improving soil pHBC,CaLS may play a more important role in suppressing indirect ***,γ-PGA-Ca was superior to PASP-Ca and CaLS in enhancing the soil pHBC and the its resistance to acidification induced by HNO_(3) addition,whereas CaLS was the best at suppressing urea-driven soil acidification by inhibiting *** conclusion,these results provide a reference for inhibiting soil re-acidification in intensive agricultural systems.

关键词： Calcium-based polymer Soil acidification pH buffering capacity Nitrification inhibition

Rotational Doppler effect of composite vortex beams with tailored OAM spectra

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Photonics Research 2024年第8期12卷 1665-1672页

作者： YUTIAN LIANG RUIJIAN LI jie ZHAO XINGYUAN LU TONG LIU ZHENGLIANG LIU YUAN ren CHENGLIANG ZHAO Department of Aerospace Science and Technology Space Engineering UniversityBeijing 101416China School of Physical Science and Technology Soochow UniversitySuzhou 215006China Department of Basic Course Space Engineering UniversityBeijing 101416China

There recently has been increasing interest in the research and application of the rotational Doppler effect(RDE),which paves a promising way to detect rotating objects *** order to obtain more information about the rotating object from the rotational Doppler signal,composite vortex beams by coaxial superposition of orbital angular momentum(OAM)modes are often used as the probe ***,to the best of our knowledge,the RDE of composite vortex beams with arbitrary OAM spectra has not yet been comprehensively *** this paper,the correspondence between the OAM spectrum of a probe beam and the frequency spectrum of a rotational Doppler signal is theoretically *** is explicitly revealed that the RDE frequency spectrum of scattered light is related to the product of two autocorrelation functions:one from the OAM spectrum of probe beam and the other from the spiral spectrum of rotating *** the basis of this relation,one can regulate the RDE frequency spectrum on demand via tailoring the OAM spectrum of the probe *** a proof of concept we design a special composite vortex beam to eliminate the broadening of the RDE spectrum induced by *** findings are of practical value in applications such as remote sensing and optical metrology.

关键词： OAM composite rotating

Tuning the cross-linked structure of basic poly(ionic liquid)to develop an efficient catalyst for the conversion of vinyl carbonate to dimethyl carbonate

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Chinese Journal of Chemical Engineering 2024年第8期72卷 106-116页

作者： Zhaoyang Qi Shiquan Zhong Huiyun Su Changshen Ye Limei ren Ting Qiu jie Chen College of Chemical Engineering Fuzhou UniversityFuzhou 350108China Department of Chemical Engineering Shijiazhuang UniversityShijiazhuang 050035China Qingyuan Innovation Laboratory Quanzhou 362801China Fuzhou University International Joint Laboratory of Thermochemical Conversion of Biomass Fuzhou UniversityFuzhou 350108China

Dimethyl carbonate(DMC)is a crucial chemical raw material widely used in organic synthesis,lithiumion battery electrolytes,and various other *** current primary industrial process employs a conventional sodium methoxide basic catalyst to produce DMC through the transesterification reaction between vinyl carbonate and ***,the utilization of this catalyst presents several challenges during the process,including equipment corrosion,the generation of solid waste,susceptibility to deactivation,and complexities in separation and *** address these limitations,a series of alkaline poly(ionic liquid)s,i.e.[DVBPIL][PHO],[DVCPIL][PHO],and[TBVPIL][PHO],with different crosslinking degrees and structures,were synthesized through the construction of cross-linked polymeric monomers and *** poly(ionic liquid)s exhibit cross-linked structures and controllable cationic and anionic *** was conducted to investigate the effect of the cross-linking degree and structure on the catalytic performance of transesterification in synthesizing *** was discovered that the appropriate cross-linking degree and structure of the[DVCPIL][PHO]catalyst resulted in a DMC yield of up to 80.6%.Furthermore,this catalyst material exhibited good stability,maintaining its catalytic activity after repeated use five times without significant *** results of this study demonstrate the potential for using alkaline poly(ionic liquid)s as a highly efficient and sustainable alternative to traditional catalysts for the transesterification synthesis of DMC.

关键词： Poly(ionic liquid) Cross-linking degree Dimethyl carbonate production Transesterification reaction Mechanism