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Defence Technology（防务技术） 2024年第5期35卷 18-46页

作者： Man xu Nanxi Xiang Ping Yin qi Lai Siping Pang School of Materials Science&Engineering Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

From the standpoint of chemical structures,the organic backbones of energetic materials can be classified into aromatic rings,nonaromatic rings,and open *** the category of aromatic energetic compounds exhibits several advantages in the regulation of energetic properties,the nonaromatic heterocycles,assembling nitramino explosophores with simple alkyl bridges,still have prevailed in benchmark *** methylene bridge plays a pivotal role in the constructions of the classic nonaromatic heterocycle-based energetic compounds,e.g.,hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX)and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX),whereas ethylene bridge is the core moiety of state-of-the-art explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20).In this context,it is of great interest to employ simple and practical bridges to assemble aromatic and nonaromatic nitrogen-rich heterocycles,thereby expanding the structural diversity of energetic materials,e.g.,bridged and fused nitrogen-rich ***,alkyl-bridged poly-heterocycles highlight the potential for the open chain type of energetic *** this review,the development of alkyl bridges in linking nitrogen-rich heterocycles is presented,and the perspective of the newly constructed energetic backbones is summarized for the future design of advanced energetic materials.

关键词： Energetic materials Alkyl bridge strategy Nitrogen-rich azoles Fused heterocycles Azoles

Research progress of tumor-associated macrophages in immune checkpoint inhibitor tolerance in colorectal cancer

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World Journal of Gastrointestinal Oncology 2024年第10期16卷 4064-4079页

作者： qi Fan Zheng-wei Fu Ming xu Feng Lv Jia-Song Shi qi-qi Zeng De-Hai Xiong Intestinal Center Chongqing University Three Gorges HospitalChongqing 404000China Department of Gastroenterology Nanjing Drum Tower HospitalThe Affiliated Hospital of Nanjing University Medical SchoolNanjing 210008Jiangsu ProvinceChina

The relevant mechanism of tumor-associated macrophages(TAMs)in the treatment of colorectal cancer patients with immune checkpoint inhibitors(ICIs)is discussed,and the application prospects of TAMs in reversing the treatment tolerance of ICIs are discussed to provide a reference for related *** a class of drugs widely used in clinical tumor immunotherapy,ICIs can act on regulatory molecules on cells that play an inhibitory role-immune checkpoints-and kill tumors in the form of an immune response by activating a variety of immune cells in the immune *** sensitivity of patients with different types of colorectal cancer to ICI treatment varies *** phenotype and function of TAMs in the colorectal cancer microenvironment are closely related to the efficacy of *** can regulate the phenotypic function of TAMs,and TAMs can also affect the tolerance of colorectal cancer to ICI *** play an important role in ICI resistance,and making full use of this target as a therapeutic strategy is expected to improve the immunotherapy efficacy and prognosis of patients with colorectal cancer.

关键词： Colorectal cancer Immune checkpoint inhibitor resistance Tumor microenvironment Tumor-associated macrophages Review

Post-synthetic modifications of MOFs by different bolt ligands for controllable release of cargoes

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Chinese Chemical Letters 2024年第10期35卷 404-407页

作者： Hao Wang Meng-qi Pan Ya-Fei Wang Chao Chen Jian xu Yuan-Yuan Gao Chuan-Song qi wei Li Xian-He Bu College of New Materials and Chemical Engineering Beijing Key Lab of Special Elastomeric Composite MaterialsBeijing Institute of Petrochemical TechnologyBeijing 102617China School of Materials Science and Engineering National Institute for Advanced MaterialsTKL of Metal and Molecule-Based Material ChemistryNankai UniversityTianjin300350China College of Chemical Engineering Inner Mongolia University of TechnologyHohhot 010051China

Post-synthetic modifications(PSM)have drawn great attention as a vigoroso tool to tune or enhance the performance of metal-organic frameworks(MOFs).However,the current PSM method usually have to sacrifice the porosity of MOFs to enrich their functionality,such as pore space partition(PSP)and postsynthetic elimination and insertion(PSE&I),causing a trade-off in this *** address this issue,we herein propose a new PSM strategy of using the size-matching ligands as the bolts to lock MOFs'pores,which could be anchored onto open metal sites(OMSs)after guest loading through a stepwise *** a result,the loaded cargoes undergo a controlled releasing process with respect to different bolt *** proposed strategy provides a promising way to balance the functionality and porosity of MOFs.

关键词： Post-synthetic modifications Metal-organic frameworks Bolting ligand Control release Cargo

Experimental investigation on weak shock wave mitigation characteristics of flexible polyurethane foam and polyurea

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Defence Technology（防务技术） 2024年第1期31卷 179-191页

作者： Shiyu Jia Cheng Wang Wenlong xu Dong Ma Fangfang qi State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China Institute for Advanced Technology Shandong UniversityJinan250061China

In recent years,explosion shock wave has been considered as a signature injury of the current military *** strong shock wave is lethal to the human body,weak shock wave can cause many more lasting *** investigate the protection ability and characteristics of flexible materials and structures under weak shock wave loading,the blast wave produced by TNT explosive is loaded on the polyurethane foam with the density of 200.0 kg/m3(F-200)and 400.0 kg/m3(F-400),polyurea with the density of 1100.0 kg/m^(3)(P-1100)and structures composed of the two materials,which are intended for individual *** results indicate that the shock wave is attenuated to weak pressure disturbance after interacting with the flexible materials which are not *** shock wave protective capability of single-layer materials is dependent on their thickness,density and microscopic *** overpressure,maximum pressure rise rate and impulse of transmitted wave decrease exponentially with increase in sample *** the same thickness,F-400 provides better protective capability than F-200 while P-1100 shows the best protective capability among the three *** this study,as the materials are not destroyed,F-200 with a thickness more than10.0 mm,F-400 with a thickness more than 4.0 mm,and P-1100 with a thickness more than 1.0 mm can attenuate the overpressure amplitude more than 90.0%.Further,multi-layer flexible composites are *** layer layouts of designed structures and layer thickness of the single-layer materials can affect the protective *** the research range,the structure in which polyurea is placed on the impact side shows the optimal shock wave protective performance,and the thicknesses of polyurea and polyurethane foam are 1.0 mm and 4.0 mm *** overpressure attenuation rate reached maximum value of 93.3%and impulse attenuation capacity of this structure are better than those of s

关键词： Free-field explosion Weak shock wave mitigation Polyurea Polyurethane foam Multi-layered composites

High-Order Decoupled and Bound Preserving Local Discontinuous Galerkin Methods for a Class of Chemotaxis Models

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Communications on Applied Mathematics and Computation 2024年第1期6卷 372-398页

作者： wei Zheng Yan xu School of Mathematical Sciences University of Science and Technology of ChinaHefei230026AnhuiChina

In this paper,we explore bound preserving and high-order accurate local discontinuous Galerkin(LDG)schemes to solve a class of chemotaxis models,including the classical Keller-Segel(KS)model and two other density-dependent *** use the convex splitting method,the variant energy quadratization method,and the scalar auxiliary variable method coupled with the LDG method to construct first-order temporal accurate schemes based on the gradient flow structure of the *** semi-implicit schemes are decoupled,energy stable,and can be extended to high accuracy schemes using the semi-implicit spectral deferred correction *** bound preserving DG discretizations are only worked on explicit time integration methods and are difficult to get high-order *** overcome these difficulties,we use the Lagrange multipliers to enforce the implicit or semi-implicit LDG schemes to satisfy the bound constraints at each time *** bound preserving limiter results in the Karush-Kuhn-Tucker condition,which can be solved by an efficient active set semi-smooth Newton *** numerical experiments illustrate the high-order accuracy and the effect of bound preserving.

关键词： Chemotaxis models Local discontinuous Galerkin(LDG)scheme Convex splitting method Variant energy quadratization method Scalar auxiliary variable method Spectral deferred correction method

High-Order Two-Scale Asymptotic Paradigm for the Elastodynamic Homogenization of Periodic Composites

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Acta Mechanica Solida Sinica 2024年第1期37卷 124-138页

作者： wei-Zhi Luo Mu He Liang Xia qi-Chang He State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China Laboratoire Modélisation et Simulation Multi-Echelle MSME UMR 8208 CNRSUniversite Gustave Eiffel77454 Marne-la-ValléeFrance

The classical two-scale asymptotic paradigm provides macroscopic and microscopic analyses for the elastodynamic homogenization of periodic composites based on the spatial or/and temporal variable,which offers an approximate framework for the asymptotic homogenization analysis of the motion ***,in this framework,the growing complexity of the homogenization formulation gradually becomes an obstacle as the asymptotic order *** such a context,a compact,fast,and accurate asymptotic paradigm is *** work reviews the high-order spatial two-scale asymptotic paradigm with the effective displacement field representation and optimizes the implementation by symmetrizing the tensor to be ***,the modified implementation gets rid of the excessive memory consumption required for computing the high-order tensor,which is demonstrated by representative one-and two-dimensional *** numerical results show that(1)the contrast of the material parameters between media in composites directly affects the convergence rate of the asymptotic results for the homogenization of periodic composites,(2)the convergence error of the asymptotic results mainly comes from the truncation error of the modified asymptotic homogenized motion equation,and(3)the excessive norm of the normalized wavenumber vector in the two-dimensional inclusion case may lead to a non-convergence of the asymptotic results.

关键词： Composites Homogenization Asymptotic analysis Dynamics Dispersion

Emergency management capacity assessment for urban rail transit-an example of Beijing Metro Line 13

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Transportation Safety and Environment 2024年第1期6卷 109-115页

作者： Jiao Liu Yun qi wei Wang School of Emergency Management and Safety Engineering China University of Mining&Technology(Beijing)Beijing 100083China China Safety Science Journal Editorial Department China Occupational Safety and Health AssociationBeijing 100011China College of mechanical engineering and automation Liaoning University of TechnologyJinzhou 121001LiaoningChina

In order to improve the emergency management capability of urban rail transit system and reduce accidents during metro operation,an emergency management capability evaluation method combining analytic hierarchy process(AHP)and technique for order preference by similarity to ideal solution(TOPSIS)is *** on the Prevention Preparation Response Recovery(PPRR)model,factors influencing the emergency management capability of the urban rail transit system are summarized from the perspective of‘human,machine,environment and management’.Then,an emergency management capability evaluation index system containing of 20 secondary indicators is constructed in four stages:emergency prevention,emergency preparation,emergency response and emergency *** weights of indicators are calculated using the AHP method,and the closeness of each indicator to the optimal solution is analysed with the TOPSIS ***,take the Beijing Metro Line 13 as an example to investigate the level of emergency management capability of urban rail *** results show that the emergency management capability of Beijing’s urban rail transit system is‘well’,among which hazard prevention measures(0.31)and emergency response team(0.34)have a greater weight on the emergency management capability of rail *** model can more accurately assess the emergency management capability of urban rail transit and provide a basis for emergency management.

关键词： urban rail transit emergency management capability analytic hierarchy process(AHP) technique for order preference by similarity to ideal solution(TOPSIS) prevention preparation response recovery(PPRR)model

Effects of nitrogen deposition on the carbon budget and water stress in Central Asia under climate change

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Journal of Arid Land 2024年第8期16卷 1118-1129页

作者： HAN qifei xu wei LI Chaofan School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing 210044China

Atmospheric deposition of nitrogen(N)plays a significant role in shaping the structure and functioning of various terrestrial ecosystems ***,the magnitude of N deposition on grassland ecosystems in Central Asia still remains highly *** this study,a multi-data approach was adopted to analyze the distribution and amplitude of N deposition effects in Central Asia from 1979 to 2014 using a process-based denitrification decomposition(DNDC)*** showed that total vegetation carbon(C)in Central Asia was 0.35(±0.09)Pg C/a and the averaged water stress index(WSI)was 0.20(±0.02)for the whole *** N deposition led to an increase in the vegetation C of 65.56(±83.03)Tg C and slightly decreased water stress in Central *** of this study will expand both our understanding and predictive capacity of C characteristics under future increases in N deposition,and also serve as a valuable reference for decision-making regarding water resources management and climate change mitigation in arid and semi-arid areas globally.

关键词： carbon dynamics climate change grassland ecosystems nitrogen deposition water stress index

Multi-objective optimization of a high speed on/off valve for dynamic performance improvement and volume minimization

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Chinese Journal of Aeronautics 2024年第10期37卷 435-444页

作者： qi ZHONG Junxian WANG Enguang xu Cheng YU Yanbiao LI College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310023China

Hydraulic circuits with high speed on/off valve(HSV)for servo control have become commonplace in ***,the individual valve that is not volume-optimized results in a large total size of hydraulic control system,diminishing the *** address this issue,the high-precision equivalent reluctance model of the HSV is established by employing an equivalent magnetic circuit,on which the dynamic characteristic of the HSV,as well as the effects of structural parameters on switching behaviour,are *** on this model,multi-objective optimization is adopted to design an HSV with faster dynamic performance and smaller volume,NSGA-II genetic algorithm is applied to obtain the Pareto front of the desired *** assess the impact before and after optimization,an HSV based on the optimized structure is manufactured and *** experimental results show that the optimized HSV reduces 47.1%of its solenoid volume while improving opening and closing dynamic performance by 14.8%and 43.0%respectively,increasing maximum switching frequency by 6.2%,and expanding flow linear control area by 6.7%.These results validate the optimized structure and indicate that the optimization method provided in the paper is beneficial for developing superior HSV.

关键词： High speed on/off valve Dynamic response Volume Multiobjective optimization NSGA-II genetic algorithm

LMR-CBT: learning modality-fused representations with CB-Transformer for multimodal emotion recognition from unaligned multimodal sequences

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Frontiers of Computer Science 2024年第4期18卷 39-47页

作者： Ziwang FU Feng LIU qing xu Xiangling FU Jiayin qi School of Computer Science(National Pilot Software Engineering School) Beijing University of Posts and TelecommunicationsBeijing 100876China Key Laboratory of Trustworthy Distributed Computing and Service(BUPT) Beijing 100876China Shanghai International School of Chief Technology Officer East China Normal UniversityShanghai 200062China School of Computer Science and Technology East China Normal UniversityShanghai 200062China School of Cyberspace Security Guangzhou UniversityGuangdong 510006China

Learning modality-fused representations and processing unaligned multimodal sequences are meaningful and challenging in multimodal emotion *** approaches use directional pairwise attention or a message hub to fuse language,visual,and audio ***,these fusion methods are often quadratic in complexity with respect to the modal sequence length,bring redundant information and are not *** this paper,we propose an efficient neural network to learn modality-fused representations with CB-Transformer(LMR-CBT)for multimodal emotion recognition from unaligned multi-modal ***,we first perform feature extraction for the three modalities respectively to obtain the local structure of the ***,we design an innovative asymmetric transformer with cross-modal blocks(CB-Transformer)that enables complementary learning of different modalities,mainly divided into local temporal learning,cross-modal feature fusion and global self-attention *** addition,we splice the fused features with the original features to classify the emotions of the ***,we conduct word-aligned and unaligned experiments on three challenging datasets,IEMOCAP,CMU-MOSI,and *** experimental results show the superiority and efficiency of our proposed method in both *** with the mainstream methods,our approach reaches the state-of-the-art with a minimum number of parameters.

关键词： modality-fused representations cross-model blocks multimodal emotion recognition unaligned multimodal sequences computational affection