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固体火箭超燃冲压发动机地面直连试验

航空兵器 2018年第4期25卷 57-61页

作者：赵翔夏智勋马立坤吕仲国防科技大学空天科学学院长沙410073 海军研究院北京100000

针对采用碳氢固体推进剂的固体火箭超燃冲压发动机开展了地面直连试验。介绍了试验系统,测量了推力、压力、温度和质量流量等参数,分析了试验结果,得到燃烧室的性能。燃烧室总压损失为74.1%,燃烧效率为84.0%,推力增益为0.718 k N,推力... 详细信息

针对采用碳氢固体推进剂的固体火箭超燃冲压发动机开展了地面直连试验。介绍了试验系统,测量了推力、压力、温度和质量流量等参数,分析了试验结果,得到燃烧室的性能。燃烧室总压损失为74.1%,燃烧效率为84.0%,推力增益为0.718 k N,推力增益比冲为3 726.9N·s/kg。

关键词：固体火箭超燃冲压发动机地面直连试验比冲碳氢固体推进剂燃烧室性能

Bionic soft robotic gripper with feedback control for adaptive grasping and capturing applications

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Frontiers of Mechanical Engineering 2024年第1期19卷 129-148页

作者： Tingke WU Zhuyong LIU Ziqi ma Boyang WANG Daolin ma Hexi YU Department of Engineering Mechanics School of Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China MOE Key Laboratory of Hydrodynamics Shanghai Jiao Tong UniversityShanghai 200240China

Robots are playing an increasingly important role in engineering *** robots have promising applications in several fields due to their inherent advantages of compliance,low density,and soft interactions.A soft gripper based on bio-inspiration is proposed in this *** analyze the cushioning and energy absorption mechanism of human fingertips in detail and provide insights for designing a soft gripper with a variable stiffness *** investigate the grasping modes through a large deformation modeling approach,which is verified through *** characteristics of the three grasping modes are quantified through testing and can provide guidance for robotics ***,the adaptability of the soft gripper is verified by grasping multi-scale and extremely soft ***,a cushioning model of the soft gripper is proposed,and the effectiveness of cushioning is verified by grasping extremely sharp objects and living ***,we validate the advantages of the variable stiffness of the soft gripper,and the results show that the soft robot can robustly complete assemblies with a gap of only 0.1 *** to the unstructured nature of the engineering environment,the soft gripper can be applied in complex environments based on the abovementioned experimental ***,we design the soft robotics system with feedback capture based on the inspiration of human catching *** feasibility of engineering applications is initially verified through fast capture experiments on moving *** design concept of this robot can provide new insights for bionic machinery.

关键词： soft bionic gripper variable stiffness structure large deformation modeling feedback control soft robotic system

冠心病患者外周血T细胞亚群和自然杀伤细胞的变化

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临床心血管病杂志 2009年第8期25卷 593-596页

作者：季亚娟丁晓梅马礼坤余华陈坷安徽省医科大学附属省立医院心内科安徽省心血管病研究所合肥230001

目的:探讨外周血CD4+T细胞、CD8+T细胞、CD4+CD25+调节性T细胞、自然杀伤细胞(NK细胞)水平与冠状动脉(冠脉)病变程度的关系。方法:选择收治的冠心病或疑诊为冠心病行冠脉造影的患者126例,按临床表现,冠脉造影诊断分为4组:急性心肌梗死(A... 详细信息

目的:探讨外周血CD4+T细胞、CD8+T细胞、CD4+CD25+调节性T细胞、自然杀伤细胞(NK细胞)水平与冠状动脉(冠脉)病变程度的关系。方法:选择收治的冠心病或疑诊为冠心病行冠脉造影的患者126例,按临床表现,冠脉造影诊断分为4组:急性心肌梗死(AMI)组34例、不稳定型心绞痛(UAP)组49例、稳定型心绞痛(SAP)组20例和冠脉造影正常胸痛综合征组(对照组)23例,采用流式细胞术测定4组患者外周血CD4+T细胞、CD8+T细胞、CD4+CD25+调节性T细胞(分为CD4+CD25+T细胞和CD4+CD25++T细胞)、NK(CD3-CD16+CD56+)细胞亚群占淋巴细胞的比例。同时分析各组T细胞亚群和NK细胞水平与Gensini积分相关性。结果:AMI组和UAP组CD4+T细胞较对照组显著升高,而CD8+T细胞、CD4+CD25+调节性T细胞、NK细胞显著降低(P<0.05);SAP组较对照组NK细胞显著升高(P<0.05)。CD8+T细胞,CD4+CD25+T细胞,CD4+CD25++T细胞与Gensini积分均呈负相关性(P<0.05)。结论:CD4+升高,CD8+T细胞、CD4+CD25+调节性T细胞、NK细胞降低可能反映了冠心病患者异常增强的免疫反应及免疫调节受损,其参与了动脉粥样硬化的发生发展。随着免疫调节受损加重,冠脉病变的数量和狭窄程度可能加重。

关键词：冠状动脉疾病外周血CD4^+T细胞 CD8^+T细胞 CD4^+CD25^+调节性T细胞自然杀伤细胞

Tuning Surface Molecular Design of Porous Carbon for Blue Energy Harvesting

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Research 2024年第1期2023卷 651-662页

作者： Jian Yu Zhong-Lin Wang Tianwei ma Department of Civil and Environmental Engineering University of Hawaii at MānoaHonoluluHI 96822USA Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China College of Engineering Texas A&M University-Corpus ChristiCorpus ChristiTX 78412USA

Capacitive mixing is a promising blue energy technology due to its membrane-free electricity generation and long electrode life ***,because of limited performance,existing systems do not lend themselves to practical *** it is a crucial factor directly influencing electrode behavior,surface chemistry has largely been overlooked in capacitive ***,we show that manipulating surface functionalization alone can tune the responses of electrodes to produce a high voltage rise without altering the pore structure of the *** findings reveal that the spontaneous electrode potential of a surface-modified carbon electrode shifts negatively proportional to the surface charge due to the surface groups,which explains why and how manipulating the surface chemistry can improve the power generation capacity.

关键词： electrode Porous mixing

Deployment analysis of composite thin-walled lenticular tubes with effect of storage time and temperature

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Chinese Journal of Aeronautics 2024年第1期37卷 162-172页

作者： Jinfeng DENG Ning AN Qilong JIA Xiaofei ma School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065China State Key Laboratory for Strength and Vibration of Mechanical Structures School of AerospaceXi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China Xi’an Institute of Space Radio Technology Xi’an 710100China

Composite Thin-walled Lenticular Tube(CTLT)is increasingly utilized in small satellites missions as a lightweight,foldable,and rollable structural material that facilitates the construction of large deployable *** CTLT is initially flattened and coiled around a central hub for storage before launch,during which elastic energy is stored as deformation energy,allowing it to be self-deployed on demand for use in *** work presents a comprehensive investigation into the coiling,storage and deployment behaviors of CTLT that wraps around a central hub.A nonlinear explicit dynamic finite element model was developed with both deformable CTLT and rigidbodies mechanisms including the central hub and guide rollers,as well as the complex interactions among *** coiling mechanics characteristics such as stored strain energy and rotational moment were presented and validated against experimental data in the ***,the dynamic deployment behaviors were analyzed in terms of two different deployment methods,namely,controlled deployment and free *** effect of material property change during storage was also discussed through numerical experiments.

关键词： Composite deployable structures Deployment dynamics Finite element method Stress relaxation Thin-walled booms

Deciphering and integrating invariants for neural operator learning with various physical mechanisms

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National Science Review 2024年第4期11卷 111-122页

作者： Rui Zhang Qi Meng Zhi-Ming ma Academy of mathematics and Systems Science Chinese Academy of Sciences(CAS) Microsoft Research

Neural operators have been explored as surrogate models for simulating physical systems to overcome the limitations of traditional partial differential equation(PDE) solvers. However, most existing operator learning methods assume that the data originate from a single physical mechanism, limiting their applicability and performance in more realistic scenarios. To this end, we propose the physical invariant attention neural operator(PIANO) to decipher and integrate the physical invariants for operator learning from the PDE series with various physical mechanisms. PIANO employs self-supervised learning to extract physical knowledge and attention mechanisms to integrate them into dynamic convolutional *** to existing techniques, PIANO can reduce the relative error by 13.6%–82.2% on PDE forecasting tasks across varying coefficients, forces or boundary conditions. Additionally, varied downstream tasks reveal that the PI embeddings deciphered by PIANO align well with the underlying invariants in the PDE systems, verifying the physical significance of PIANO.

关键词： neural operator PDE solver contrastive learning physical invariants

Theoretical study of aromaticity reversal in dimethyldihydropyrene derivatives

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Chinese Journal of Structural Chemistry 2024年第5期43卷 8-10页

作者： Fangwen Peng Zhen Luo Yingjin ma Haibo ma School of Chemistry and Chemical Engineering Nanjing UniversityNanjing210023China Computer Network Information Center Chinese Academy of SciencesBeijing100190China Qingdao Institute for Theoretical and Computational Sciences School of Chemistry and Chemical EngineeringShandong UniversityQingdaoShandong266237China

Aromaticity has always been an intriguing chemistry topic,which is considered to have close relations with materials'stability and chemical reactivity due to special energy *** conjugated cycles,Hückel's rule,proposed in 1931,suggests that annulenes having[4n+2]and[4n]πelectrons present aromatic and antiaromatic characters with closed and open electronic configurations,respectively[1].

关键词： Hückel aromatic reactivity

急性心肌梗死患者院内心源性休克风险列线图预测模型的构建

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临床心血管病杂志 2021年第5期37卷 421-427页

作者：周晓娟马礼坤魏艳张理想赵梅安徽医科大学合肥230022 中国科学技术大学附属第一医院心血管内科

目的:分析急性心肌梗死(AMI)患者术后院内心源性休克(CS)的风险因素,依此建立预测AMI患者院内CS发生风险的列线图模型。方法:通过胸痛中心数据库及医院信息系统回顾性分析我院心内科住院且接受急诊冠状动脉(冠脉)介入治疗的327例AMI患... 详细信息

目的:分析急性心肌梗死(AMI)患者术后院内心源性休克(CS)的风险因素,依此建立预测AMI患者院内CS发生风险的列线图模型。方法:通过胸痛中心数据库及医院信息系统回顾性分析我院心内科住院且接受急诊冠状动脉(冠脉)介入治疗的327例AMI患者的临床资料,依据患者住院期间CS的发生情况将受试对象分为CS组(52例)和非CS组(275例),利用LASSO回归模型和多因素Logistic回归分析AMI患者发生院内CS的风险因素,并建立个性化的CS预测模型。结果:LASSO回归结果提示,白细胞计数、肌酐、尿素氮、尿酸、氨基末端脑钠肽前体、左室射血分数及合并新发心房颤动为AMI患者发生院内CS的重要风险因素(P<0.05)。利用上述7个预测指标构建了列线图模型。内部验证后,列线图预测AMI患者发生院内CS的AUC值为0.888(95%CI:0.840~0.922),灵敏度为0.832,特异度为0.782。校准曲线提示列线图模型的偏差校正曲线与理想曲线具有较好的一致性。临床决策曲线分析法提示列线图模型的预测概率阈值处于0~0.8时,患者的临床净收益水平最高。结论:本研究依据院内CS发生的重要风险因素构建了个性化的CS发生风险预测模型,经相关指标证实该预测模型具有较好的预测效率和临床适用性,能准确、有效地预测AMI患者院内CS的发生风险,从而协助临床医护人员筛选高CS风险患者,制定针对性的干预措施,降低AMI患者术后CS的发生率。

关键词：急性心肌梗死心源性休克列线图临床决策

Armoring lithium metal anode with soft±rigid gradient interphase toward high-capacity and long-life all-solid-state battery

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Green Energy & Environment 2024年第8期9卷 1279-1289页

作者： Rui Zhang Biao Chen Yuhan ma Yue Li Junwei Sha Liying ma Chunsheng Shi Naiqin Zhao School of materials Science and Engineering and Tianjin Key Laboratory of Composite and Functional materials Tianjin University Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Department of Chemical and Biomolecular Engineering National University of Singapore Collaborative Innovation Centre of Chemical Science and Engineering

Solid polymer electrolytes （SPEs） are highly promising for realizing high-capacity,low-cost,and safe Li metal ***,the Li dendritic growth and side reactions between Li and SPEs also plague these ***,a fluorinated lithium salt coating （FC） with organicinorganic gradient and soft-rigid feature is introduced on Li surface as an artificial protective layer by the in-situ reaction between Li metal and fluorinated carboxylic *** FC layer can improve the interface stability and wettability between Li and SPEs,assist the transport of Li ions,and guide Li nucleation,contributing to a dendrite-free Li deposition and long-lifespan Li metal *** symmetric cell with FC-Li anodes exhibits a high areal capacity of 1 mah cm-2at 0.5 ma cm-2,and an ultra-long lifespan of 2000 h at a current density of 0.1 m A ***,the full cell paired with the LiFePO4cathode exhibits improved cycling stability,remaining 83.7%capacity after 500 cycles at 1 *** matching with the S cathode,the FC layer can prevent the shuttle effect,contributing to stable and high-capacity Li-S *** work provided a promising way for the construction of stable all-solid-state lithium metal batteries with prolonged lifespan.

关键词： All-solid-state battery Solid polymer electrolyte Li metal anode Li nucleation Interface stability