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Application of split Hopkinson tension bar technique to the study of dynamic fracture properties of materials

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Acta Mechanica Sinica 2012年第2期28卷 424-431页

作者： ze-jian xu Yu-Long Li Feng-Lei Huang State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology100081 BeijingChina School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China

A novel approach is proposed in determining dy- namic fracture toughness （DFT） of high strength steel, using the split Hopkinson tension bar （SHTB） apparatus, com- bined with a hybrid experimental-numerical method. The center-cracked tension specimen is connected between the bars with a specially designed fixture device. The fracture initiation time is measured by the strain gage method, and dynamic stress intensity factors （DSIF） are obtained with the aid of 3D finite element analysis （FEA）. In this approach, the dimensions of the specimen are not restricted by the connec- tion strength or the stress-state equilibrium conditions, and hence plane strain state can be attained conveniently at the crack tip. Through comparison between the obtained results and those in open publication, it is concluded that the ex- perimental data are valid, and the method proposed here is reliable. The validity of the obtained DFT is checked with the ASTM criteria, and fracture surfaces are examined at the end of paper.

关键词： Split Hopkinson tension bar Dynamic fracture toughness Hybrid experimental-numerical method High loading rate Failure mode

Mutual-structure weighted guided image filtering for depth map restoration

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Optoelectronics Letters 2025年第1期21卷 51-56页

作者： LIU Zijian SONG jian CHEN Quanmin xu jiangtao Tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology School of Microelectronics Tianjin University Spikesee Technology Co. Ltd.

Although guided image filtering(GIF) is known for preserving edges and fast computation, it may produce inaccurate outputs in depth map restoration. In this paper, a novel confidence-weighted GIF called mutual-structure weighted GIF(MSWGIF) is proposed, which replaces the mean filtering strategy in GIF during handling overlapping windows. The confidence value is composed of a depth term and a mutual-structure term, where the depth term is utilized to protect the edges of the output, and the mutual-structure term helps to select accurate windows during the structure characteristics of the guidance image are transferred to the output. Experimental results show that MSWGIF reduces the root mean square error(RMSE) by an average of 12.37%, and the average growth rate of correlation(CORR) is 0.07% on average. Additionally, the average growth rate of structure similarity index measure(SSIM) is 0.34%.

关键词： Wiener filtering

Preparation and Performance of Ternary Early Strength Agent and Quercetin Composite Cement Sealing Material

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 130-140页

作者： LIU jian CHEN Meiting JI Xiaoli xu Chao WANG Chunmei Department of Safety Science and Engineering Anhui University of Science and TechnologyHuainan 232001China Key Laboratory of Mine Safety and High Efficient Mining Jointly Built by Province and Education Ministry Anhui University of Science and TechnologyHuainan 232001China Department of Chemical Engineering and Explosives Anhui University of Science and TechnologyHuainan 232001China

A ternary early-strengthening agent consisting of calcium formate+triethanolamine+lithium sulfate was compounded with quercetin to shorten the setting time of cementitious materials while ensuring their early *** optimum ratio of the three early-strengthening agents was determined as 0.5%calcium formate+0.04%triethanolamine+0.4%lithium sulfate by response surface *** effects of the ternary early-strengthening agent composed of calcium formate+triethanolamine(TEA)+lithium sulfate on cementitious pore sealing materials under the synergistic effect of quercetin were studied by means of the performance tests of compressive strength,fluidity,and setting time,and the microstructural characterizations of X-ray powder diffractometer(XRD),thermogravimetry(TG-DSC)and scanning electron microscopy(SEM).The study shows that the synergistic effect of ternary early-strengthening agent and quercetin forms a multi-performance composite admixture for cementitious *** best performance was obtained with the compounding scheme of 0.5%calcium formate+0.04%triethanolamine+0.4%lithium sulfate ternary early-strengthening agent and 0.05%*** compressive strength of 1,3,7,and 28 d are 94.8%,39.8%,42%,and 28%higher than those of the blank group,*** initial time and final setting time are 41 and 57 minutes,*** to the microscopic analysis,the network and fibrous C-S-H gels generated by ternary early-strengthening agents are attached to the surface promoted by quercetin,which forms skeleton support while thickening and solidifying the cement slurry,which enhances the early compressive strength of the cement-based materials.

关键词： sealing material ternary early-strengthening agent quercetin synergetic effect response surface methodology

Observation of topological charge transformations in acoustic vortex using passive periodic systems

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 140-147页

作者： Di-Chao Chen Xie Liu Changqing xu Da-jian Wu Ying Cheng Xiao-Jun Liu School of Physics and Technology Nanjing Normal University Key Laboratory of Modern Acoustics School of Physics Nanjing University

Vortex transmutation utilizes a periodic system, which not only enables the alteration of the topological charge(TC) of unstable input vortices but also facilitates their transformation into stable structures. This approach is crucial for investigating the characteristics of vortices in various wave systems. Here, we achieve acoustic vortex TC transmutation by employing a welldesigned dual-structured plate external system(DPES). The interactions between the acoustic vortex and the finite-order discrete rotational symmetry lead to the transformation of its topological charge when complete rotational symmetry is broken to Nthorder discrete symmetry. Our results experimentally demonstrate the acoustic vortex TC transmutation based on passive artificial structures, enabling numerous applications in particle manipulation and information multiplexing as well as advancing our understanding and control over free-space acoustic vortices.

关键词： acoustic vortex topological charge transformation artificial structure

Recent Advances in Fibrous Materials for Hydroelectricity Generation

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Nano-Micro Letters 2025年第2期17卷 109-133页

作者： Can Ge Duo xu Xiao Feng Xing Yang Zheheng Song Yuhang Song Jingyu Chen Yingcun Liu Chong Gao Yong Du Zhe Sun Weilin xu jian Fang College of Textile and Clothing Engineering Soochow UniversitySuzhou 215123People’s Republic of China National Engineering Laboratory for Modern Silk Soochow UniversitySuzhou 215123People’s Republic of China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200People’s Republic of China Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123People’s Republic of China Department of Electrical and Computer Engineering University of MassachusettsAmherstMA 01003USA Department of Materials Imperial College LondonSouth Kensington CampusLondon SW72AZUK College of Textile Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018People’s Republic of China School of Materials Science and Engineering Shanghai Institute of Technology100 Haiquan RoadShanghai 201418People’s Republic of China

Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable *** generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy *** materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first ***,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are ***,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in ***,the potential applications including power supply,energy storage,electrical sensor,and information expression are also ***,some existing challenges are considered and prospects for future development are sincerely proposed.

关键词： Hydroelectricity Fibrous material Streaming potential Ion diffusion

Insights into spinal muscular atrophy from molecular biomarkers

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Neural Regeneration Research 2025年第7期20卷 1849-1863页

作者： Xiaodong Xing Xinzhu Liu Xiandeng Li Mi Li Xian Wu Xiaohui Huang Ajing xu Yan Liu jian Zhang Department of Clinical Pharmacy Xinhua HospitalShanghai Jiao Tong University School of MedicineShanghaiChina College of Pharmacy Chongqing Medical UniversityChongqingChina

Spinal muscular atrophy is a devastating motor neuron disease characterized by severe cases of fatal muscle *** is one of the most common genetic causes of mortality among infants aged less than 2 *** research is currently receiving more attention,and new candidate biomarkers are constantly being *** review initially discusses the evaluation methods commonly used in clinical practice while briefly outlining their respective pros and *** also describe recent advancements in research and the clinical significance of molecular biomarkers for spinal muscular atrophy,which are classified as either specific or non-specific *** review provides new insights into the pathogenesis of spinal muscular atrophy,the mechanism of biomarkers in response to drug-modified therapies,the selection of biomarker candidates,and would promote the development of future ***,the successful utilization of biomarkers may facilitate the implementation of gene-targeting treatments for patients with spinal muscular atrophy.

关键词： biomarkers disease progression gene-targeting therapy neurofilaments Nusinersen spinal muscular atrophy(SMA) survival motor neuron therapeutic evaluation treatment outcomes

Identification of a dual functional betulinic acid analog for the treatment of osteoarthritis by phenotypic screening

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Science China Life Sciences 2025年第1期68卷 300-302页

作者： ze-Min Lin Mai Xiang Wen-Hui Wei Shu-Hui Fan Li Chen Jie Wang Xiao-Qian Yang Chun-Hao Yang Shi-Jun He jian-Ping Zuo Laboratory of Immunopharmacology State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of Sciences School of Pharmacy University of Chinese Academy of Sciences School of Pharmacy Nanjing University of Chinese Medicine State Key Laboratory of Drug Research Department of Medicinal ChemistryShanghai Institute of Materia MedicaChinese Academy of Sciences Innovation Research Institute of Traditional Chinese Medicine Shanghai University of Traditional Chinese Medicine Experiment Center for Science and Technology Shanghai University of Traditional Chinese Medicine

Dear Editor, Phenotypic drug discovery, which observes compound effects on physiology,has given way to targeting specific molecules, but has revived by using modern methods to find drugs based on therapeutic outcomes in disease models(Vincent et al., 2022). Osteoarthritis(OA) is a prevalent chronic joint disorder, primarily affecting knee joints, with osteoclast activation due to low-grade inflammation resulting in increased bone resorption and structural changes in the joint(Katz et al.,2021).

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Modular assembly of complex C-alkyl glycoside enabled via cooperative NHC and photoredox catalysis

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Science China Chemistry 2025年

作者： Rui-Qiang Jiao Ming Li Xi Chen Mei-ze xu Tian Ding Xiao-Ping Gong Zhuo-Mei Li xue-Yuan Liu Yong-Min Liang State Key Laboratory of Applied Organic Chemistry Lanzhou University College of Chemistry and Chemical Engineering Northwest Normal University

C-Alkyl glycosides are found in natural products and are indispensable in drug development programs,owing to their diverse range of medicinal ***-component reactions involving glycosyl radical addition are well documented and proved efficient for the C-alkyl glycosides ***,multicomponent reactions for the rapid and controllable construction of structurally diversified C-alkyl glycosides in a single step remains a significant challenge due to the issues associated with balancing reactivity,compatibility,and ***,we report an NHC and photoredox co-catalyzed three-component method to access complex and valuable C-alkyl *** protocol exhibits broad substrate scope and excellent chemoand ***,nine types of sugars are compatible with this *** addition,the generality of this catalytic strategy was further highlighted by the potential for scalable production,the feasibility of further modifications of the products and its successful application in the late-stage functionalization of pharmaceutical skeletons.

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Optimization Method for Cross-regional Maximum Power Purchase Capacity in Regional Power Grids Ensuring Supply Scenarios

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Dianwang Jishu/Power System Technology 2025年第1期49卷 232-241页

作者： xu, Hao Jia, Longwen Liu, Zhicheng xu, jian Huang, Yanbo Liao, Siyang Central China Branch of State Grid Corporation of China Hubei Province Wuhan 430077 China School of Electrical Engineering and Automation Wuhan University Hubei Province Wuhan 430072 China

As multiple levels of electricity markets become intertwined and coupled across different time scales, regional power grids, while serving as hubs for trading channels, also face a series of operational risks, such as network congestion and ensuring security and reliability of supply. In response to the supply security scenario under market-oriented models, based on the analysis of intra-provincial transmission section blocking, an optimization method for inter-regional and inter-provincial power supply capability in the electricity spot market is proposed. Firstly, based on the correlation model of inter-provincial trading channels, inter-provincial physical interconnections, and intra-provincial transmission sections, the mechanism of intra-provincial network congestion formation is analyzed. Secondly, the Gradient Boosting Decision Tree algorithm predicts intra-provincial transmission section blocking, identifying critical sections that form the boundary for electricity purchases in the spot market. Finally, to maximize electricity purchases through inter-regional channels while considering constraints on DC power injection stability, the power supply capability of the target province is optimized. The proposed method is validated by analyzing it based on actual provincial networks. © 2025 Power System Technology Press. All rights reserved.

关键词： Power markets