检索结果-南通市图书馆

In Situ Reconfiguration of Assembling Pattern for Modular Continuum Robots

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第4期21卷 1695-1706页

作者： Jie Zhang Jiannan cai Ke ma Jinzhao Yang Zhigang Wu Haijun Peng Jianing Wu School of Mechanical Engineering Dalian University of TechnologyDalian116024People’s Republic of China School of Advanced manufacturing Sun Yat-Sen UniversityShenzhen518107People’s Republic of China School of Aeronautics and Astronautics Sun Yat-Sen UniversityShenzhen518107People’s Republic of China

Modular continuum robots possess significant versatility across various scenarios;however,conventional assembling methods typically rely on linear connection between *** limitation can impede the robotic interaction capabilities,especially in specific engineering ***,inspired by the assembling pattern between the femur and tibia in a human knee,we proposed a multidirectional assembling *** strategy encompasses linear,oblique,and orthogonal connections,allowing a two-module continuum robot to undergo in-situ reconfiguration into three distinct initial *** anticipate the final configuration resulting from diverse assembling patterns,we employed the positional formulation finite element framework to establish a mechanical model,and the theoretical results reveal that our customizable strategy can offer an effective route for robotic *** showcased diverse assembling patterns for coping with interaction *** experimental results indicate that our modular continuum robot not only reconfigures its initial profile in situ but also enables on-demand regulation of the final *** capabilities provide a foundation for the future development of modular continuum robots,enabling them to be adaptable to diverse environments,particularly in unstructured surroundings.

关键词： Assembling patterns Continuum robot In-situ reconfiguration Tensegrity structure Varying stiffness

A DNA tetrahedron-based ferroptosis-suppressing nanoparticle: superior delivery of curcumin and alleviation of diabetic osteoporosis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bone Research 2024年第1期12卷 227-239页

作者： Yong Li Zhengwen cai Wenjuan ma Long Bai En Luo Yunfeng Lin State Key Laboratory of Oral Diseases&National Center for Stomatology&National Clinical Research Center for Oral Diseases West China Hospital of StomatologySichuan UniversityChengduSichuan 610041PR China Department of Oral and maxillofacial Surgery Affiliated Stomatological HospitalSouthwest Medical UniversityLuzhouSichuan 646000PR China Sichuan Provincial Engineering Research Center of Oral Biomaterials ChengduSichuan 610041China

Diabetic osteoporosis(DOP)is a significant complication that poses continuous threat to the bone health of patients with diabetes;however,currently,there are no effective treatment *** patients with diabetes,the increased levels of ferroptosis affect the osteogenic commitment and differentiation of bone mesenchymal stem cells(BMSCs),leading to significant skeletal *** address this issue,we aimed to target ferroptosis and propose a novel therapeutic approach for the treatment of *** synthesized ferroptosis-suppressing nanoparticles,which could deliver curcumin,a natural compound,to the bone marrow using tetrahedral framework nucleic acid(tFNA).This delivery system demonstrated excellent curcumin bioavailability and stability,as well as synergistic properties with *** in vitro and in vivo experiments revealed that nanoparticles could enhance mitochondrial function by activating the nuclear factor E2-related factor 2(NRF2)/glutathione peroxidase 4(GPX4)pathway,inhibiting ferroptosis,promoting the osteogenic differentiation of BMSCs in the diabetic microenvironment,reducing trabecular loss,and increasing bone *** findings suggest that curcumin-containing DNA tetrahedron-based ferroptosissuppressing nanoparticles have a promising potential for the treatment of DOP and other ferroptosis-related diseases.

关键词： curcumin osteoporosis diabetic

Diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging parameters and serum tumor markers in rectal carcinoma prognosis

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第5期16卷 1796-1807页

作者： Ren-Qi Mu Jun-Wei Lv cai-Yun ma Xiao-Hui ma Dong Xing Hou-Sheng ma Department of Radiology Yantai Mountain HospitalYantai 264001Shandong ProvinceChina Department of Radiology Yantai Yuhuangding HospitalYantai 264000Shandong ProvinceChina Department of Gynaecology Yantai Yuhuangding HospitalYantai 264000Shandong ProvinceChina The First Clinical Medical College Xinjiang Medical UniversityUrumqi 830011Xinjiang Uygur Autonomous RegionChina

BACKGROUND Rectal carcinoma(RC),one of the most common malignancies globally,presents an increasing incidence and mortality year by year,especially among young people,which seriously affects the prognosis and quality of life of *** present,dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)parameters and serum carbohydrate antigen 19-9(CA19-9)and CA125 Levels have been used in clinical practice to evaluate the T stage and differentiation of ***,the accuracy of these evaluation modalities still needs further *** study explores the application and value of these methods in evaluating the T stage and differentiation degree of *** To analyze the diagnostic performance of DCE-MRI parameters combined with serum tumor markers(TMs)in assessing pathological processes and prognosis of RC *** A retrospective analysis was performed on 104 RC patients treated at Yantai Yuhuangding Hospital from may 2018 to January *** were categorized into stages T1,T2,T3,and T4,depending on their T stage and differentiation *** addition,they were assigned to low(L group)and moderate-high differentiation(M+H group)groups based on their differentiation *** levels of DCE-MRI parameters and serum CA19-9 and CA125 in different groups of patients were *** addition,the value of DCE-MRI parameters[volume transfer constant(Ktrans),rate constant(Kep),and extravascular extracellular volume fraction(Ve)in assessing the differentiation and T staging of RC patients was ***,the usefulness of DCE-MRI parameters combined with serum CA19-9 and CA125 Levels in the evaluation of RC differentiation and T staging was *** Ktrans,Ve,CA19-9 and CA125 were higher in the high-stage group and L group than in the low-stage group and M+H Group,respectively(P2 and 0

关键词： Rectal carcinoma Volume transfer constant Rate constant Extravascular extracellular volume fraction Serum carbohydrate antigen 19-9 Serum carbohydrate antigen 125

One-step construction of strongly coupled Co_(3)V_(2)O_(8)/Co_(3)O_(4)/MXene heterostructure via in-situ Co-F bonds for high performance all-solid-state asymmetric supercapacitors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第2期43卷 682-691页

作者： Ji Zhou Bin-Bin Liu Hu Zheng Wen-Qing ma Qian Li cai-Xia Xu Institute for Advanced Interdisciplinary Research(iAIR) Collaborative Innovation Center of Technology and Equipment for Biological Diagnosis and Therapy in Universities of ShandongSchool of Chemistry and Chemical EngineeringUniversity of JinanJinan250022China

Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x) composite was easily synthesized via one-step succinct-operated hydrothermal *** interconnected Co_(3)V_(2)O_(8)/Co_(3)O_(4) nanowires network can in-situ grow and anchor on the surface of Ti_(3)C_(2)T_(x) via the strong Co-F bonds and contribute tremendously to depress Ti_(3)C_(2)T_(x) *** from the synergistically interplayed effect among the multiple interfaces and high conductivity of Ti_(3)C_(2)T_(x) as well as outstanding stability of the as-designed nanostructure,the optimum Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x)electrode reaches a commendable specific capacitance(up to 3800 mF·cm^(−2)),great rate capability(80%capacitance retention after 20-times current increasing),and preeminent cycling stability(95.4%/85.5%retention at 7000th/20,000th cycle).Moreover,the all-solid-state asymmetric supercapacitor based on Co_(3)V_(2)O_(8)/Co_(3)O_(4)/Ti_(3)C_(2)T_(x) and active carbon can deliver a high energy density of 84.0μWh·cm^(−2) at the power energy of 3.2 mW·cm^(−2),and excellent cycling durability with 87.0%of initial capacitance retention upon 20,000 *** work provides a practicable pathway to tailor MXene-based composites for high-performance supercapacitor.

关键词： Ti_(3)C_(2)T_(x) Co_(3)V_(2)O_(8)/Co_(3)O_(4) Heterostructure Cathode Supercapacitor

Braille Character Segmentation Algorithm Based on Gaussian Diffusion

在线全文

学校读者我要写书评

暂无评论

Computers, materials & Continua 2024年第4期79卷 1481-1496页

作者： Zezheng Meng Zefeng cai Jie Feng Hanjie ma Haixiang Zhang Shaohua Li School of Computer Science and Technology Zhejiang Sci-Tech UniversityHangzhou310018China

Optical braille recognition methods typically employ existing target detection models or segmentation modelsfor the direct detection and recognition of braille characters in original braille images. However, these methodsneed improvement in accuracy and generalizability, especially in densely dotted braille image environments. Thispaper presents a two-stage braille recognition framework. The first stage is a braille dot detection algorithmbased on Gaussian diffusion, targeting Gaussian heatmaps generated by the convex dots in braille images. Thisis applied to the detection of convex dots in double-sided braille, achieving high accuracy in determining thecentral coordinates of the braille convex dots. The second stage involves constructing a braille grid using traditionalpost-processing algorithms to recognize braille character information. Experimental results demonstrate that thisframework exhibits strong robustness and effectiveness in detecting braille dots and recognizing braille charactersin complex double-sided braille image datasets. The framework achieved an F1 score of 99.89% for Braille dotdetection and 99.78% for Braille character recognition. Compared to the highest accuracy in existing methods,these represent improvements of 0.08% and 0.02%, respectively.

关键词： Computer vision image recognition optical braille recognition

Wavefield Separation of Distributed Acoustic Sensing Vertical Seismic Profile Data Based on Multichannel Vector Median Filtering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年第2期35卷 712-716页

作者： Zijuan ma Jun Lu Feng Zhang Pinbo Ding Zhidong cai Key Laboratory of Intraplate Volcanoes and Earthquakes Ministry of EducationChina University of GeosciencesBeijing 100083China College of Geophysics China University of PetroleumBeijing 102249China New Resources Geophysical Exploration Division BGP Inc.CNPCZhuozhouHebei 072751China

INTRODUCTION Distributed acoustic sensing(DAS)is a novel and popular technology for vertical seismic profile(VSP)data acquisition because of its many advantages,including full vertical coverage,high sampling density,low cost,and resistance to stressors(high temperature and pressure).The current industrial application of DAS in borehole exploration acquires single-mode *** records strain rates,which are then converted to particle velocities by the modem before being written to the disk.

关键词： Seismic Vertical borehole

Research on casing deformation prevention technology based on cementing slurry system optimization

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 1231-1240页

作者： Yan Yan Meng cai Wen-Hai ma Xiao-Chuan Zhang Li-Hong Han Yong-Hong Liu State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment materials CNPC Tubular Goods Research InstituteXi©an710077ShaanxiChina College of Mechanical and Electrical Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province Chengdu610095SichuanChina CNPC Daqing Oilfield Company Daqing163453HeilongjiangChina

The casing deformation prevention technology based on the optimization of cement slurry is proposed to reduce the casing deformation of shale oil and gas wells during hydraulic fracturing. In this paper, the fracture mechanism of hollow particles in cement sheath was firstly analyzed by discrete element method, and the effect of hollow particles in cement on casing deformation was investigated by laboratory experiment method. Finally, field test was carried out to verify the improvement effect of the casing deformation based on cement slurry modification. The results show that the formation displacement can be absorbed effectively by hollow particles inside the cement transferring the excessive deformation away from casing. The particles in the uncemented state provide deformation space during formation slipping. The casing with diameter of 139.7 mm could be passed through by bridge plug with the diameter of 99 mm when the mass ratio of particle/cement reaches 1:4. According to the field test feedback, the method based on optimization of cement slurry can effectively reduce the risk of casing deformation, and the recommended range of hollow microbeads content in the cement slurry is between 15% and 25%.

关键词： Cement slurry Hollow ceramsite Casing deformation Formation slip Field test

Effects of arbuscular mycorrhizal fungi on zinc uptake,translocation and accumulation in winter wheat during whole plant growth stages

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2024年第2期34卷 374-384页

作者： Jing YANG Chuangye ZHANG Yifan LIU Yuanzhe ma Xiangyao WU Jun cai Fuyong WU College of Natural Resources and Environment Northwest A&F UniversityYangling 712100China Key Laboratory of Plant Nutrition and Agricultural Environment of Northwest of Ministry of Agriculture Yangling 712100China

Although arbuscular mycorrhizal fungi(AMF)could play important roles in zinc(Zn)uptake in host plants,the effects of AMF on Zn uptake and transport in winter wheat during the whole growth stages remain unclear.A pot experiment was conducted to investigate the effects of Funneliformis mosseae(Fm)and Claroideoglomus etunicatum(Ce)on Zn absorption,transport,and accumulation in winter wheat growing in soils spiked with different Zn levels(0,2.5,and 25 mg kg^(-1)).The results showed that there was a significant correlation between mycorrhizal colonization rate and Zn absorption efficiency in winter wheat roots during the post-anthesis period,but there was no significant correlation during the pre-anthesis *** mycorrhizal fungi significantly increased Zn concentrations(0.56–1.58 times)in wheat grains under 0 mg kg^(-1)Zn level,but decreased Zn concentrations in wheat grains under 25 mg kg^(-1)Zn ***,at the filling and maturity stages,AMF increased Zn absorption rate and the contribution of root Zn uptake to grain Zn by 3–14 and 0.36–0.64 times,respectively,under 0 mg kg^(-1)Zn level and 0.21–1.02 and 0.27–0.37 times,respectively,under 2.5 mg kg^(-1)Zn ***,AMF decreased root Zn absorption rate(0.32–0.61 times)and increased the contribution of Zn remobilization in vegetative tissues to grain Zn(1.69–2.01 times)under 25 mg kg^(-1)Zn *** study would complement the mechanisms and effects of AMF on Zn absorption and transport in winter wheat and provide a potential method for the application of AMF to enrich wheat grain Zn.

关键词： grain Zn source mycorrhizal response post-anthesis period Zn absorption rate Zn remobilization

Testing method of rock structural plane using digital drilling

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2563-2578页

作者： Qi Wang Yuncai Wang Bei Jiang Hongke Gao Fenglin ma Dahu Zhai Songlin cai State Key Laboratory for Tunnel Engineering China University of Mining and Technology(Beijing)Beijing100083China

The rock mass consists of rock blocks and structural planes,which can reduce its integrity and ***,accurately obtaining the characteristics of the rock mass structural plane is a prerequisite for evaluating stability and designing supports in underground ***,there are no effective testing methods for the characteristic parameters of the rock mass structural plane in underground *** paper presents the digital drilling technology as a new testing method of rock mass structural *** rock specimens with cracks of varying widths and angles were used to simulate the rock mass structural planes,and the multifunctional rock mass digital drilling test system was employed to carry out the digital drilling *** analysis focuses on the variation laws of drilling parameters,such as drilling pressure and drilling torque,affected by the characteristics of prefabricated cracks,and clarifies the degradation mechanism of rock equivalent compressive ***,an identification model for the characteristic parameters of rock mass structural planes during drilling is *** test results indicate that the average difference of the characteristics of prefabricated cracks identified by the equivalent compressive strength is 2.45°and 0.82 mm,*** identification model while drilling is verified to be correct due to the high identification *** on this,a method for testing the characteristic parameters of the surrounding rock structural plane while drilling is *** research offers a theoretical and methodological foundation for precise in situ identification of structural planes of the surrounding rock in underground engineering.

关键词： Structural planes in the rock mass Digital drilling Drilling parameters Equivalent compressive strength Testing method