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Dynamic modeling and parameter identification of a gun saddle ring

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Defence Technology（防务技术） 2020年第2期16卷 325-333页

作者： Tong lin lin-fang qian qiang Yin Shi-yu Chen Tai-su Liu School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China

In this study,a theoretical nonlinear dynamic model was established for a saddle ring based on a dynamic force analysis of the launching process and the structure according to contact-impact *** ADAMS software was used to build a parameterized dynamic model of the saddle ring.A parameter identification method for the ring was proposed based on the particle swarm optimization algorithm.A loading test was designed and performed several times at different elevation *** response histories of the saddle ring with different loads were then *** parameters of the saddle ring dynamic model were identified from statistics generated at a 500 elevation angle to verify the feasibility and accuracy of the proposed *** actual loading history of the ring at a 70°elevation angle was taken as the model *** response histories of the ring under these working conditions were obtained through a *** simulation results agreed with the actual ***,the effectiveness and applicability of the proposed dynamic model were verified,and it provides an effective method for modeling saddle rings.

关键词： Gun saddle ring Dynamic response Parameter identification Particle swarm optimization

A phenomenological model for plastic flow behavior of rotating band material with a large temperature range

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Defence Technology（防务技术） 2023年第7期25卷 121-133页

作者： Yi-cheng Zhu Jia-wei Fu lin-fang qian Jing-hua Cao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094JiangsuChina Northwest Institute of Mechanical and Electrical Engineering Xianyang712099ShaanxiChina School of Materials Science and Engineering Nanjing University of Science and TechnologyNanjing210094China

The plastic flow behavior of the rotating band material is investigated in this paper. The rotating band material is processed from H96 brass alloy, which is hardened to a much higher yield strength compared to the annealed one. The dynamically uniaxial compression behavior of the material is tested using the split Hopkinson pressure bar(SHPB) with temperature and strain rate ranging from 297 to 1073 K and500 to 3000 s^(-1), respectively, and a phenomenological plastic flow stress model is developed to describe the mechanical behavior of the material. The material is found to present noticeable temperature sensitivity and weak strain-rate sensitivity. The construction of the plastic flow stress model has two steps. Firstly, three univariate stress functions, taking plastic strain, plastic strain rate and temperature as independent variable, respectively, are proposed by fixing the other two variables. Then, as the three univariate functions describe the special cases of flow stress behavior under various conditions, the principle of stress compatibility is adopted to obtain the complete flow stress function. The numerical results show that the proposed plastic flow stress model is more suitable for the rotating band material than the existing well-known models.

关键词： Rotating band Plastic flow behavior Large temperature range Phenomenological model

Barrier Lyapunov functions-based dynamic surface control with tracking error constraints for ammunition manipulator electro-hydraulic system

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Defence Technology（防务技术） 2021年第3期17卷 836-845页

作者： Shou-Cheng Nie lin-fang qian Long-Miao Chen ling-Fei Tian Quan Zou School of Mechanical Engineering Nanjing University of Science and TechnologyNanjingChina

This paper focuses on the dynamic tracking control of ammunition manipulator system. A standard state space model for the ammunition manipulator electro-hydraulic system(AMEHS) with inherent nonlinearities and uncertainties considered was established. To simultaneously suppress the violation of tracking error constraints and the complexity of differential explosion, a barrier Lyapunov functionsbased dynamic surface control(BLF-DSC) method was proposed for the position tracking control of the ammunition manipulator. Theoretical analysis prove the stability of the closed-loop overall system and the tracking error converges to a prescribed neighborhood asymptotically. The effectiveness and dynamic tracking performance of the proposed control strategy is validated via simulation and experimental results.

关键词： Ammunition manipulator Electro-hydraulic system Error constraints Tracking control

Fluorine-doped carbon quantum dots with deep-red emission for hypochlorite determination and cancer cell imaging

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Chinese Chemical Letters 2024年第6期35卷 433-438页

作者： Boran Cheng Lei Cao Chen Li fang-Yi Huo qian-fang Meng Ganglin Tong Xuan Wu lin-lin Bu Lang Rao Shubin Wang Department of Oncology Shenzhen Key Laboratory of Gastrointestinal Cancer Translational ResearchCancer InstitutePeking University Shenzhen HospitalShenzhen-Peking University-Hong Kong University of Science and Technology Medical CenterShenzhen 518036China Institute of Biomedical Health Technology and Engineering Shenzhen Bay LaboratoryShenzhen 518132China The State Key Laboratory Breeding Base of Basic Science of Stomatology(Hubei-MOST)&Key Laboratory of Oral Biomedicine Ministry of Education School&Hospital of StomatologyWuhan UniversityWuhan 430079China

As a type of new carbon-based nanomaterials,carbon dots(CDs)possess exceptional optical properties,making them highly desirable for use in fluorescent ***,the CDs with deep-red(DR)or near-infrared(NIR)emission have rarely been *** this work,we prepared deep-red emissive fluorine-doped carbon quantum dots(F-CDs)by introducing a precursor simultaneously containing fluorine and *** synergistic effect of nitrogen doping and D-π-A pattern production contributed to the maximum emission of F-CDs at 636 nm with an absolute quantum yield of 36.00%±0.68%.Moreover,we designed an F-CDs-based fluorescence assay to determine the content of hypochlorite(ClO^(-)),with a limit of detection(LOD)as low as 15.4 nmol/L,indicating the high sensitivity of F-CDs to ClO^(-).In real samples,the F-CDs-based fluorescent sensor exhibited excellent sensitivity and selectivity in the detection of ClO^(-),with an error below 2%,suggesting their great potential in daily *** cancer cell imaging,the F-CDs not only demonstrated high sensitivity to ClO^(-)but also exhibited excellent mitochondria targeting,as evidenced by the high Pearson's correlation coefficient(PCC)of 0.93 in colocalization *** work presented here suggests the great potential of replacing commercial dyes with F-CDs for highly specific mitochondria labeling and cell imaging.

关键词： Carbon dots Near-infrared Cell imaging Mitochondria labeling Hypochlorite determination

Experimental distillation of tripartite quantum steering with an optimal local filtering operation

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Photonics Research 2024年第3期12卷 552-562页

作者： qian-XI ZHANG XIAO-XU fang HE LU School of Physics State Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China Shenzhen Research Institute of Shandong University Shenzhen 518057China

Multipartite Einstein-Podolsky-Rosen(EPR)steering admits multipartite entanglement in the presence of uncharacterized verifiers,enabling practical applications in semi-device-independent *** applications generally require stronger steerability,while the unavoidable noise weakens steerability and consequently degrades the performance of quantum information ***,we propose the local filtering operation that can maximally distill genuine tripartite EPR steering from N copies of three-qubit generalized Greenberger-Horne-Zeilinger states,in the context of two semi-device-independent *** optimal filtering operation is determined by the maximization of assemblage *** and numerical results indicate the advantage of the proposed filtering operation when N is finite and the steerability of initial assemblages is ***,a proof-of-principle demonstration of two-copy distillation is realized with the optical *** advantage of the optimal local filtering operation is confirmed by the distilled assemblage in terms of higher assemblage fidelity with perfectly genuine tripartite steerable assemblages,as well as the greater violation of the inequality to witness genuine tripartite steerable *** results benefit the distillation of multipartite EPR steering in practice,where the number of copies of initial assemblages is generally finite.

关键词： filtering distillation optimal

Comparative analysis between single-train passing and double-train intersection in a tunnel

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第5期25卷 429-442页

作者： Jianming DU qian fang Xuan ZHANG Hualao WANG Bridge and Tunnel Research Center Research Institute of Highway Ministry of TransportBeijing 100088China Tunnel and Underground Engineering Research Center of Ministry of Education Beijing Jiaotong UniversityBeijing 00044China

Aerodynamic pressure significantly impacts the scientific evaluation of tunnel service *** aerodynamic pressure of two trains running in a double-track tunnel is considerably more complicated than that of a single *** used the numerical method to investigate the difference in aerodynamic pressure between a single train and two trains running in a double-track ***,the numerical method was verified by comparing the results of numerical simulation and on-site ***,the characteristics of aerodynamic pressure were ***,the influence of various train-tunnel factors on the characteristics of aerodynamic pressure was *** results show that the aerodynamic pressure variation can be divided into stage I:irregular pressure fluctuations before the train tail leaves the tunnel exit,and stage II:periodic pressure declines after the train tail leaves the tunnel *** addition,the aerodynamic pressure simultaneously jumps positively or drops negatively for a single train or two trains running in double-track tunnel *** pressure amplitude in the two-train case is higher than that for a single *** maximum positive peak pressure difference(P_(STP))and maximum negative peak pressure difference(P_(STN))increase as train speed rises to the power from 2.256 to 2.930 in stage *** P_(STP) and P_(STN) first increase and then decrease with the increase of tunnel length in stage *** P_(STP) and P_(STN) increase as the blockage ratio rises to the power from 2.032 to 2.798 in stages I and II.

关键词： Railway tunnel Aerodynamic effect Pressure characteristic Train speed Tunnel length Blockage ratio

A Generic Strategy to Create Mechanically Interlocked Nanocomposite/Hydrogel Hybrid Electrodes for Epidermal Electronics

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Nano-Micro Letters 2024年第5期16卷 120-133页

作者： qian Wang Yanyan Li Yong lin Yuping Sun Chong Bai Haorun Guo Ting fang Gaohua Hu Yanqing Lu Desheng Kong College of Engineering and Applied Sciences National Laboratory of Solid State Microstructureand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210023People’s Republic of China State Key Laboratory of Analytical Chemistry for Life Science and Jiangsu Key Laboratory of Artificial Functional MaterialsNanjing UniversityNanjing 210023People’s Republic of China College of Chemical Engineering and Technology Engineering Research Center of Seawater Utilization Technology of Ministry of EducationState Key Laboratory of Reliability and Intelligence of Electrical EquipmentHebei University of TechnologyTianjin 300130People’s Republic of China Key Laboratory of Intelligent Optical Sensing and Manipulation Nanjing UniversityNanjing 210093People’s Republic of China

Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human *** the primary compliant conductors used in these devices,metallic nanostructure/elastomer composites often struggle to form conformal contact with the textured *** electrodes have been consequently developed based on conductive nanocomposite and soft hydrogels to establish seamless skin-device ***,chemical modifications are typically needed for reliable bonding,which can alter their original *** overcome this limitation,this study presents a facile fabrication approach for mechanically interlocked nanocomposite/hydrogel hybrid *** this physical process,soft microfoams are thermally laminated on silver nanowire nanocomposites as a porous interface,which forms an interpenetrating network with the *** microfoam-enabled bonding strategy is generally compatible with various *** resulting interlocked hybrids have a 28-fold improved interfacial toughness compared to directly stacked *** electrodes achieve firm attachment to the skin and low contact impedance using tissue-adhesive *** have been successfully integrated into an epidermal sleeve to distinguish hand gestures by sensing mus-cle *** nanocomposite/hydrogel hybrids reported here offer a promising platform to combine the benefits of both materials for epidermal devices and systems.

关键词： Stretchable electronics Epidermal electronics Silver nanowire Conductive nanocomposites Hydrogel

Selective N-Methylation of N-Methylaniline with CO_(2) and H_(2) over Cu/In_(2)O_(3) Catalyst

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Chinese Journal of Chemistry 2024年第3期42卷 276-282页

作者： Huan Zheng Bo qian lin He State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhouGansu730000 China University of Chinese Academy of Sciences Beijing100049 China

N-Methylation of amines with CO_(2) and H2 is a potential approach for CO_(2) utilization because N-methylated amines can be used as solvents and organic intermediates. In_(2)O_(3)-supported Cu (Cu/In_(2)O_(3)) acts as an effective heterogeneous catalyst for N-methylation reaction of N-methylaniline (MA) with CO_(2) and H_(2),showing higher N,N-dimethylaniline (DMA) selectivity than other supported Cu catalysts. On one hand,the dispersion of Cu can be improved by the defective In_(2)O_(3) support. On the other hand,In_(2)O_(3) support is active in the dissociative adsorption of CO_(2) through C—O bond breaking. In addition,the H_(2) dissociation ability of In_(2)O_(3) can also be enhanced by Cu. The combination of Cu and In_(2)O_(3) is effective in the activation of CO_(2),the adsorption of intermediate N-methylformanilide (MFA),the hydrogenation of MFA to DMA and the prohibition of C—N bond cleavage side reactions,thereby enhancing the reaction rate of MA conversion and the selectivity to DMA.

关键词： N-Methylation CO_(2) Cu/In_(2)O_(3) Supported catalysts Heterogeneous catalysis

Revealing Al-O/Al-F reaction dynamic effects on the combustion of aluminum nanoparticles in oxygen/fluorine containing environments:A reactive molecular dynamics study meshing together experimental validation

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Defence Technology（防务技术） 2024年第4期34卷 313-327页

作者： Gang Li Chuande Zhao qian Yu fang Yang Jie Chen Institute of Chemical Materials China Academy of Engineering Physics(CAEP)P.O.Box 919-311Mianyang 621900SichuanChina

Improving the energy conversion efficiency in metallic fuel(e.g.,Al)combustion is always desirable but challenging,which often involves redox reactions of aluminum(Al)with various mixed oxidizing *** instance,Al-O reaction is the most common pathway to release limited energy while Al-F reaction has received much attentions to enhance Al combustion ***,microscopic understanding of the Al-O/Al-F reaction dynamics remains unsolved,which is fundamentally necessary to further improve Al combustion *** this work,for the first time,Al-O/Al-F reaction dynamic effects on the combustion of aluminum nanoparticles(n-Al)in oxygen/fluorine containing environments have been revealed via reactive molecular dynamics(RMD)simulations meshing together combustion *** RMD simulation systems of Al core/O_(2)/HF,n-Al/O_(2)/HF,and n-Al/O_(2)/CF4 with oxygen percentage ranging from 0%to 100%have been *** n-Al combustion in mixed O_(2)/CF_4 environments have been conducted by constant volume combustion *** results show that Al-O reaction exhibits kinetic benefits while Al-F reaction owns thermodynamic benefits for n-Al *** n-Al/O_(2)/HF,Al-O reaction gives faster energy release rate than Al-F reaction(1.1 times).The optimal energy release efficiency can be achieved with suitable oxygen percentage of 10%and 50%for n-Al/O_(2)/HF and n-Al/O_(2)/CF_4,*** combustion experiments,90%of oxygen percentage can optimally enhance the peak pressure,pressurization rate and combustion ***,Al-O reaction prefers to occur on the surface regions while Al-F reaction prefers to proceed in the interior regions of n-Al,confirming the kinetic/thermodynamic benefits of Al-O/Al-F *** synergistic effect of Al-O/Al-F reaction for greatly enhancing n-Al combustion efficiency is demonstrated at atomicscale,which is beneficial for optimizing the combustion performance of metallic fuel.

关键词： Al-O/Al—F reaction Kinetic benefits Thermodynamic benefits Molecular dynamics Combustion