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Cortical activity in patients with high-functioning ischemic stroke during the Purdue Pegboard Test:insights into bimanual coordinated fine motor skills with functional near-infrared spectroscopy
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作者 Siyun Chen Mengchai Mao +4 位作者 Guangyue Zhu Yufeng Chen Yuqi Qiu Bin Ye dongsheng xu 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第5期1098-1104,共7页
After stroke,even high-functioning individuals may experience compromised bimanual coordination and fine motor dexterity,leading to reduced functional independence.Bilateral arm training has been proposed as a promisi... After stroke,even high-functioning individuals may experience compromised bimanual coordination and fine motor dexterity,leading to reduced functional independence.Bilateral arm training has been proposed as a promising intervention to address these deficits.However,the neural basis of the impairment of functional fine motor skills and their relationship to bimanual coordination performance in stroke patients remains unclear,limiting the development of more targeted interventions.To address this gap,our study employed functional near-infrared spectroscopy to investigate cortical responses in patients after stroke as they perform functional tasks that engage fine motor control and coordination.Twenty-four high-functioning patients with ischemic stroke(7 women,17 men;mean age 64.75±10.84 years)participated in this cross-sectional observational study and completed four subtasks from the Purdue Pegboard Test,which measures unimanual and bimanual finger and hand dexterity.We found significant bilateral activation of the sensorimotor cortices during all Purdue Pegboard Test subtasks,with bimanual tasks inducing higher cortical activation than the assembly subtask.Importantly,patients with better bimanual coordination exhibited lower cortical activation during the other three Purdue Pegboard Test subtasks.Notably,the observed neural response patterns varied depending on the specific subtask.In the unaffected hand task,the differences were primarily observed in the ipsilesional hemisphere.In contrast,the bilateral sensorimotor cortices and the contralesional hemisphere played a more prominent role in the bimanual task and assembly task,respectively.While significant correlations were found between cortical activation and unimanual tasks,no significant correlations were observed with bimanual tasks.This study provides insights into the neural basis of bimanual coordination and fine motor skills in high-functioning patients after stroke,highlighting task-dependent neural responses.The findings also suggest that patients who exhibit better bimanual performance demonstrate more efficient cortical activation.Therefore,incorporating bilateral arm training in post-stroke rehabilitation is important for better outcomes.The combination of functional near-infrared spectroscopy with functional motor paradigms is valuable for assessing skills and developing targeted interventions in stroke rehabilitation. 展开更多
关键词 bilateral arm training bimanual coordination cortical activity fine motor dexterity functional near-infrared spectroscopy(fNIRS) high-functioning Purdue Pegboard Test stroke
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A fiber Bragg grating based earth and water pressures transducer with three-dimensional fused deposition modeling for soil mass 被引量:4
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作者 Yue Qin Qiankun Wang +2 位作者 dongsheng xu Jiaming Yan Shanshan Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2022年第2期663-669,共7页
A novel fiber Bragg grating(FBG)sensor with three-dimensional(3D)fused deposition modeling(FDM)approach is proposed for effective stress measurement in soil mass.The three-diaphragm structure design is developed to me... A novel fiber Bragg grating(FBG)sensor with three-dimensional(3D)fused deposition modeling(FDM)approach is proposed for effective stress measurement in soil mass.The three-diaphragm structure design is developed to measure earth and water pressures simultaneously.The proposed transducer has advantages of small size,high sensitivity,low cost,immunity to electromagnetic interference and rapid prototyping.The working principle,design parameters,and manufacturing details are discussed.The proposed transducer was calibrated for earth and water pressures measurement by using weights and a specially designed pressure chamber,respectively.The calibration results showed that the wavelength of the transducer was proportional to the applied pressure.The sensitivity coefficients of the earth and water pressures were 12.633 nm/MPa and 6.282 nm/MPa,respectively.Repeated tests and error analysis demonstrated the excellent stability and accuracy of the earth and water pressure measurements.The performance of the proposed transducer was further verified by a model experimental test and numerical analysis,which indicated that the proposed transducer has great potential for practical applications. 展开更多
关键词 Fused deposition modeling(FDM) Fiber bragg-grating(FBG)sensor Earth pressure Water pressure
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An Improved Method Based on TODIM and TOPSIS for Multi-Attribute Decision-Making with Multi-Valued Neutrosophic Sets 被引量:4
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作者 dongsheng xu Lijuan Peng 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第11期907-926,共20页
Due to the complexity of decision-making problems and the subjectivity of decision-makers in practical application,it is necessary to adopt different forms of information expression according to the actual situation o... Due to the complexity of decision-making problems and the subjectivity of decision-makers in practical application,it is necessary to adopt different forms of information expression according to the actual situation of specific decision-making problems and choose the best method to solve them.Multi-valued neutrosophic set,as an extension of neutrosophic set,can more effectively and accurately describe incomplete,uncertain or inconsistent information.TODIM and TOPSIS methods are two commonly used multi-attribute decision-making methods,each of which has its advantages and disadvantages.This paper proposes a new method based on TODIM and TOPSIS to solve multi-attribute decision-making problems under multi-valued neutrosophic environment.After introducing the related theory of multi-valued neutrosophic set and the traditional TODIM and TOPSIS methods,the new method based on a combination of TODIM and TOPSIS methods is described.And then,two illustrative examples proved the feasibility and validity of the proposed method.Finally,the result has been compared with some existing methods under the same examples and the proposed method’s superiority has been proved.This paper studies this kind of decision-making problem from algorithm idea,algorithm steps and decision-making influencing factors. 展开更多
关键词 Multi-valued neutrosophic set TODIM TOPSIS multi-attribute decision-making
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Determination of L-norvaline and L-tryptophan in dietary supplements by nano-LC using an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11- dihydroquinidine-silica hybrid monolithic column 被引量:1
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作者 dongsheng xu Elena Sanchez-Lopez +2 位作者 Qiqin Wang Zhengjin Jiang María Luisa Marina 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2020年第1期70-77,共8页
An analytical methodology based on an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine(MQD)-silica hybrid monolithic column was developed for the enantioseparation of 9-fluorenylmethoxycarbonyl(FMOC)deriv... An analytical methodology based on an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine(MQD)-silica hybrid monolithic column was developed for the enantioseparation of 9-fluorenylmethoxycarbonyl(FMOC)derivatized amino acids by nano-liquid chromatography.The mobile phase was optimized including the apparent pH,content of ACN,and concentration of the buffer to obtain a satisfactory enantioresolution performance.27 FMOC derivatized amino acids including 19 protein and 8 non-protein amino acids were tested,and 19 out of them were enantiomerically discriminated obtaining baseline separation for 11 of them.Analytical characteristics of the method were evaluated for norvaline and tryptophan in terms of linearity,precision,accuracy,limits of detection(LOD)and quantitation(LOQ)showing good performance to be applied to the enantiomeric determination of these amino acids in dietary supplements.LOD and LOQ values were 9.3 and 31 mM for norvaline enantiomers and 7.5 and 25 mM for tryptophan enantiomers,respectively.The contents of D-norvaline and D-tryptophan were below their respective LODs in all the analyzed samples.Quantitation of L-tryptophan and L-norvaline showed good agreement with the labeled contents except for one sample which did not show presence of L-norvaline,contrary to the label indication. 展开更多
关键词 9-Fluorenylmethoxycarbonyl Amino acids Chiral separation NANO-LC Quinidine-silica hybrid monolithic column
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Seismic Performance of Assembled Shear Wall with Defective Sleeve Connection
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作者 Hua Yan Bo Song +1 位作者 dongsheng xu Guodong Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2022年第4期199-217,共19页
In this paper,three kinds of shear walls with full sleeve grouting,fully defective sleeve and partially defective are designed for finite element analysis to analyze the influence of defects on the seismic performance... In this paper,three kinds of shear walls with full sleeve grouting,fully defective sleeve and partially defective are designed for finite element analysis to analyze the influence of defects on the seismic performance of shear walls.The research shows that at the beginning of loading(5 s),the three models begin to appear compressive damage at the bottom of the wall in all three models.The damage of the defect-free model develops rapidly,and the damage of the fully defective model is basically the same as that of the partially defective model.With the gradual increase of displacement control(15 s),the compressive damages at the foot of the wall in the defect-free and partially defective grouting model are obvious,with plastic hinge formed in the foot of the wall,and the phenomenon of development along the pier body showing up.When the structure is damaged,the overall compressive damages of the wall in the defect-free and partially defective models are obvious,and the damage on the defective side of the partially defective model is slightly deficient.While the maximum stress of pre-stressed reinforcement in the defect-freemodel is concentrated at the top of the sleeve,themaximumstress of the pre-stressed steel bar in the fully defective model appears at the end of the steel bar in the sleeve.The hysteresis curve shape of the non-defectmodel and partially defective model are basically the same,showing a“shuttle”shape with a sound energy dissipation effect.The hysteresis curve shape of the fully defective model appears an obvious“pinch”phenomenon.The yield displacement levels of the defect-free and partially defective models are smaller than that of the fully defective model structure.The stiffness degradation curves of the three models basically overlap with one another.Before the limit displacement,the stiffness results of the non-defect model and the partially defective model are greater than that of the fully defective model.When the displacement is loaded to 20 mm,the stiffness degradation of the three models is equivalent. 展开更多
关键词 Grouting sleeve DEFECTS shear wall finite element analysis seismic performance
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Is a Potential Therapeutic Strategy of Periodontal Intervention on Cardiovascular Disease, Yes or No?
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作者 Tie-Lou Chen Xinhai Zhang +1 位作者 dongsheng xu Juehui Li 《Surgical Science》 2017年第1期52-64,共13页
Aims: Cardiovascular disease (CVD) and periodontitis are both chronic inflammatory disorders which are highly prevalent in populations. Bacteria involved in the periodontal disease have been found to be cardiovascular... Aims: Cardiovascular disease (CVD) and periodontitis are both chronic inflammatory disorders which are highly prevalent in populations. Bacteria involved in the periodontal disease have been found to be cardiovascular risk markers. Periodontal pathogens may contribute to the atheroma pathogenesis. Severe periodontitis is correlated with the prevalence of bacteraemia, and poor periodontal status is an important risk factor for CVD. However, the association is unclear. If the association is causal, the periodontal therapy will lead to an attenuation of the effects on CVD. The study aimed to study if the periodontal intervention therapy presented therapeutic effects on CVD. Methods: English language literature on periodontal intervention therapy on CVD is causal or not. The literature revealed 62 papers associated with this study to investigate the relationship between periodontitis and CVD. Results: The literature supported the idea that periodontal infections had been associated with CVD. Certain periodontal therapy is associated with bacteraemia, and the prevalence of bacteraemia may arise from periodontal therapy and poor oral hygiene practices. Periodontal therapy not only presented therapeutic effects by reducing cytokine activity and C-response protein (CRP), but also caused bacteraemia transitorily. Effective antibiotic prophylaxis pre- or post-periodontal therapy presented some beneficial effects on bacteraemia or CVD. Conclusion: Severe periodontitis causes systemic inflammation and endothelial dysfunction, and goes beyond the oral cavity. Periodontal intervention would contribute to the prevention of atherosclerosis, and antibiotic prophylaxis would be helpful to decrease bacteraemia and reduce the onset of CVD. 展开更多
关键词 PERIODONTAL DISEASE Cardiovascular DISEASE PERIODONTAL INTERVENTION Antibiotic PROPHYLAXIS YES or NO
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Refinement of α′Martensite by Oxygen in Selective Laser Melted Ti-6Al-4V
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作者 Hasfi FNurly Jinhu Zhang +8 位作者 Dechun Ren Yusheng Cai Haibin Ji dongsheng xu Zhicheng Dong Hao Wang Qingmiao Hu Jiafeng Lei Rui Yang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2024年第5期777-792,共16页
Oxygen is crucial in influencing the microstructure evolution of selective laser melted(SLMed)Ti–6Al–4V,significantly impacting its applicability in various sectors.Therefore,this study investigates the influnce of ... Oxygen is crucial in influencing the microstructure evolution of selective laser melted(SLMed)Ti–6Al–4V,significantly impacting its applicability in various sectors.Therefore,this study investigates the influnce of oxygen on microstructure evolution,particularlyα′martensite transformation and refinement mechanisms.Four alloys,Ti–6Al–4V–xO(x=0.11,0.16,0.21,and 0.25 wt%),were fabricated by the SLM process.The martensite start temperature(M_(s))of Ti–6Al–4V,as evaluated by computation,is 656.8°C,and oxygen was found to increase the M_(s) by about 10°C per 0.1 wt%.The SLMed alloy samples exhibit[001]_(β)growth texture along the build direction.Crystallographic analysis of martensite morphology suggests internal twinning on{1011}planes as the lattice invariant strain,which becomes more predominant with increasing oxygen content.Refinement of α′martensite plates by oxygen is due to increased lattice distortion,reduced prior β grain size,and oxygen segregation toβgrain boundaries.Our findings contribute to improving the understanding of the effect of oxygen on the transformation mechanism ofα′martensite during SLM of Ti–6Al–4V. 展开更多
关键词 Selective laser melting α′Martensite Martensite start temperature OXYGEN TI-6AL-4V
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Nerve root magnetic stimulation regulates the synaptic plasticity of injured spinal cord by ascending sensory pathway
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作者 Ya Zheng Lingyun Cao +7 位作者 Dan Zhao Qi Yang Chunya Gu Yeran Mao Guangyue Zhu Yulian Zhu Jing Zhao dongsheng xu 《Neural Regeneration Research》 2025年第12期3564-3573,共10页
Promoting synaptic plasticity and inducing functional reorganization of residual nerve fibers hold clinical significance for restoring motor function following spinal cord injury.Neuromagnetic stimulation targeting th... Promoting synaptic plasticity and inducing functional reorganization of residual nerve fibers hold clinical significance for restoring motor function following spinal cord injury.Neuromagnetic stimulation targeting the nerve roots has been shown to improve motor function by enhancing nerve conduction in the injured spinal cord and restoring the synaptic ultrastructure of both the sensory and motor cortex.However,our understanding of the neurophysiological mechanisms by which nerve root magnetic stimulation facilitates motor function recovery in the spinal cord is limited,and its role in neuroplasticity remains unclear.In this study,we established a model of spinal cord injury in adult male Sprague–Dawley rats by applying moderate compression at the T10 vertebra.We then performed magnetic stimulation on the L5 nerve root for 3 weeks,beginning on day 3 post-injury.At day 22 post-injury,we observed that nerve root magnetic stimulation downregulated the level of interleukin-6 in the injured spinal cord tissue of rats.Additionally,this treatment reduced neuronal damage and glial scar formation,and increased the number of neurons in the injured spinal cord.Furthermore,nerve root magnetic stimulation decreased the levels of acetylcholine,norepinephrine,and dopamine,and increased the expression of synaptic plasticity-related m RNA and proteins PSD95,GAP43,and Synapsin II.Taken together,these results showed that nerve root magnetic stimulation alleviated neuronal damage in the injured spinal cord,regulated synaptic plasticity,and suppressed inflammatory responses.These findings provide laboratory evidence for the clinical application of nerve root magnetic stimulation in the treatment of spinal cord injury. 展开更多
关键词 dendrite inflammation magnetic stimulation nerve root neurological function neuronal damage neurotransmitter spinal cord injury synaptic plasticity synaptic transmission
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Ti-Al合金γ/α_2界面结构及拉伸变形行为的分子动力学模拟 被引量:4
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作者 涂爱东 滕春禹 +4 位作者 王皞 徐东生 傅耘 任占勇 杨锐 《金属学报》 SCIE EI CAS CSCD 北大核心 2019年第2期291-298,共8页
采用分子动力学方法,通过考察共格和半共格界面,发现体系总能量随两相厚度比变化,得到2种界面相互转变的临界片层厚度;对不同片层厚度的Ti-Al合金进行垂直界面的拉伸加载,发现共格界面的屈服强度高于半共格界面,断裂行为随γ和α_2相的... 采用分子动力学方法,通过考察共格和半共格界面,发现体系总能量随两相厚度比变化,得到2种界面相互转变的临界片层厚度;对不同片层厚度的Ti-Al合金进行垂直界面的拉伸加载,发现共格界面的屈服强度高于半共格界面,断裂行为随γ和α_2相的厚度比变化。塑性变形首先发生在γ相一侧,形成Shockley偏位错,进而通过剪切传递方式穿过γ/α_2界面,激活a2相的锥面层错;γ/α_2界面为后续的位错和孪生提供形核点。 展开更多
关键词 TIAL 界面 塑性变形 力学行为 分子动力学
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Dynamic recrystallization behavior of GH4169G alloy during hot compressive deformation 被引量:16
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作者 Dan Jia Wenru Sun +1 位作者 dongsheng xu Fang Liu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2019年第9期1851-1859,共9页
The microstructure evolutions and nucleation mechanisms of GH4169G alloy were studied by optical microscope, electron backscatter diffraction (EBSD) and transmission electron microscope (TEM). The hot compression test... The microstructure evolutions and nucleation mechanisms of GH4169G alloy were studied by optical microscope, electron backscatter diffraction (EBSD) and transmission electron microscope (TEM). The hot compression tests were performed different imposed reductions in the range of true strain from 0.12 to 1.2 at the temperatures of 930 °-1050 ° with strain rates of 0.01 s^-1-l s^-1. It is found that cumulative and local misorientation increase firstly and then decrease when the strain is increased due to the progress of dynamic recrystallization (DRX). The low angle boundaries (LAGBs) rapidly develop to high angle boundaries (HAGBs) at relatively high deformation temperature or the low strain rate. There are three DRX mechanisms observed for GH4169 G alloy during hot deformation. Discontinuous dynamic recrystallization (DDRX) as the dominant mechanism for GH4169 G alloy is characterized by typical necklace structures and bulged-original boundaries. Besides, different deformation bands with dislocation cells formed in deformed matrix at low temperature and large strain, which indicates that continuous dynamic recrystallization (CDRX) contributed to the DRX process. The twin boundaries lost their coherent characteristics and provide sites for nucleation, which also accelerates the nucleation of DRX. 展开更多
关键词 GH4169G ALLOY Dynamic RECRYSTALLIZATION NUCLEATION MECHANISM
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Gold nanoflowers for 3D volumetric molecular imaging of tumors by photoacoustic tomography 被引量:8
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作者 Yuanyuan Jiang Zijian Deng +5 位作者 Dan Yang Xin Deng Qi Li Yinlin Sha Changhui Li dongsheng xu 《Nano Research》 SCIE EI CAS CSCD 2015年第7期2152-2161,共10页
By binding molecular probes that target tumor cells, gold nanoparticles (AuNPs) with superior characteristics have shown great potential in tumor molecular imaging studies. The non-invasive, high-resolution, and thr... By binding molecular probes that target tumor cells, gold nanoparticles (AuNPs) with superior characteristics have shown great potential in tumor molecular imaging studies. The non-invasive, high-resolution, and three-dimensional imaging of the targeted AuNPs within the tumor is desirable for both diagnosis and therapy. In this study, gold nanoflowers (AuNFs) are presented as a novel contrast agent for photoacoustic tomography (PAT). By binding to folic acid, the molecular probe, the tail-vein injected AuNFs concentrated within the tumor site in mice; this was clearly visualized by three-dimensional (3D) PAT imaging. In addition, toxicity assay proved that AuNFs were harmless to living cells and animals. Our results demonstrate that AuNFs have great potential in tumor molecular imaging. 展开更多
关键词 nanoparticles gold nanoflowers contrast agents photoacoustic tomography tumor imaging molecular IMAGING
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Flow behavior and processing map for hot deformation of ATI425 titanium alloy 被引量:12
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作者 Qinggang Meng Chunguang Bai dongsheng xu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2018年第4期679-688,共10页
Flow behavior and processing map play important roles in the hot deformation process of titanium alloys. In this research, compression Gleeble tests have been carried out to investigate the stress-strain relationship ... Flow behavior and processing map play important roles in the hot deformation process of titanium alloys. In this research, compression Gleeble tests have been carried out to investigate the stress-strain relationship at temperatures ranging from 700 to 1000 ℃ and strain rates ranging from 0.001 to 1 s-1 for ATI 425 titanium alloy. Arrhenius type constitutive equation was obtained to describe the compressive flow behavior with modification of additional deformation dead zone, friction model, temperature model and strain rate. The introduction of novel calculation method for α value in Arrhenius equation gives more accurate fitting than traditional one. Processing maps were drawn based on the distribution of dissipator co-content, and optimized deformation temperature and strain rate range obtained. It is proven to be accurate and effective through the experimental results. The microstructure analysis shows that more dynamic recrystallization can be achieved in the area with larger ηvalue on the processing map. 展开更多
关键词 Titanium alloy Flow stress Constitutive equation Processing map
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Cobalt-based hydroxide nanoparticles @ N-doping carbonic frameworks core-shell structures as highly efficient bifunctional electrocatalysts for oxygen evolution and oxygen reduction reactions 被引量:6
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作者 Shiqiang Feng Cheng Liu +2 位作者 Zhigang Chai Qi Li dongsheng xu 《Nano Research》 SCIE EI CAS CSCD 2018年第3期1482-1489,共8页
The development of highly efficient and earth-abundant oxygen evolution/ reduction reaction (OER/ORR) catalysts is essential for rechargeable metal-air batteries. Herein, cobalt-based hydroxide nanoparticles @ N-dop... The development of highly efficient and earth-abundant oxygen evolution/ reduction reaction (OER/ORR) catalysts is essential for rechargeable metal-air batteries. Herein, cobalt-based hydroxide nanoparticles @ N-doping carbonic framework (CoOHCat@NCF) core-shell structures have been designed as highly stable and efficient OER/ORR bifunctional catalysts. The obtained composite shows enhanced catalytic activities and excellent stability in alkaline media. In the OER, a high turnover frequency (2.03 s^-1 at an overpotential of 0.36 V), low overpotential at high current density (100 mA.cm-2 requiring an overpotential of 0.38 V), and excellent stability (100 mA·cm^-2 for one week with no activity loss) have been achieved. Furthermore, although cobalt species-based catalysts are known as good ORR catalysts, their hybridization with NCF obtained from metal organic frameworks successfully enhanced their ORR activities. The efficient activity of CoOHCat@NCF as a bifunctional oxygen electrocatalyst can be ascribed to the core-shell structures stabilizing the active catalytic sites and the porous shell structure favoring electrocatalysis-related mass transport. 展开更多
关键词 core-shell structure cobalt-based hydroxidenanoparticles @ N-dopingcarbonic framework(CoOHCat@NCF) bifunctional electrocatalyst oxygen evolution reaction oxygen reduction reaction
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A high-sensitivity H2S gas sensor based on optimized ZnO-ZnS nano-heterojunction sensing material 被引量:6
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作者 Pei Ding dongsheng xu +4 位作者 Nan Dong Ying Chen Pengcheng xu Dan Zheng Xinxin Li 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第8期2050-2054,共5页
This paper reports a high-performance H2S gas sensing material that is made of ZnO nanowires(NWs)modified by an optimal amount of ZnS to form nano-hete rojunctions.Compared with the intrinsic ZnONWs,the three differen... This paper reports a high-performance H2S gas sensing material that is made of ZnO nanowires(NWs)modified by an optimal amount of ZnS to form nano-hete rojunctions.Compared with the intrinsic ZnONWs,the three differently modified nano-heterostructure material ZnO-ZnS-x(x=5,10,15)shows significant improvement in sensing performance to H2S at the working temperatures of 100-400℃,especially in the low temperature range(<300℃).The chemiresistive sensor with ZnO-ZnS-10 sensingmaterial exhibits the largest response signal to H2S among all the other ZnO-ZnS-x(x=5,10,15,20)sensors.Its response signal to 5 ppm H2S at 150℃is about 2.7 times to that of the ZnO-NWs sensor.Besides,the ZnO-ZnS-10 sensor also features satisfactory selectivity and repeatability at 150℃.With the technical advantage attributed to the reduction of the redesigned band gap at the interface between ZnO and ZnS,the ZnO-ZnS hete ro structure sensor rather than the traditional ZnO-NWs sensor can be used for high-sensitivity application at low working temperature. 展开更多
关键词 ZnO-ZnS heterojunction Hydrogen sulfide Gas sensor Sensitivity detection SELECTIVITY Band gap
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Effects of heating rate on the alloy element partitioning and mechanical properties in equiaxedα+βTi-6Al-4V alloy 被引量:3
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作者 Jinhu Zhang Hongtao Ju +8 位作者 Haisheng xu Liang Yang Zhichao Meng Chen Liu Ping Sun Jianke Qiu Chunguang Bai dongsheng xu Rui Yang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第35期1-9,共9页
The effects of heating rate on the alloy element partitioning and mechanical properties during the phase transformation ofα→βin Ti-6Al-4 V alloy under solution treatment have been investigated by the experiments an... The effects of heating rate on the alloy element partitioning and mechanical properties during the phase transformation ofα→βin Ti-6Al-4 V alloy under solution treatment have been investigated by the experiments and phase field simulations,which reveal the evolutions of microstructure and compositions at the non-equilibrium state and well verify the experimental results.The specific results indicate that the compositions measured through electron probe micro-analysis(EPMA)under a lower heating rate are close to the equilibrium ones corresponding to the solution temperature.Heating up to the target solution temperature,as the heating rate increases,the Al content decreases and V increases in the primaryα(α_(p))grain with a larger size,the volume fraction ofα_(p)increases and the composition gradient betweenα_(p)andβphases gets steeper.The interrelated relationship among the diffusion,compositions,solution temperature and free energy of the system has been discussed in detail.Moreover,increasing the heating rate(~20.0 K/min)may help to improve the mechanical properties of the alloy by mainly adjusting theα_(p)/β;volume fractions,α_(p)particle size and secondaryα(α_(p))size during the process of heating up to the solution temperature.These results may shed some light on the optimization of the knowledge-based heat treatment route. 展开更多
关键词 Heating rate Alloying element partitioning Microstructure morphology Mechanical properties
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MD simulation of asymmetric nucleation and motion of h011] superdislocations in TiAl 被引量:2
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作者 dongsheng xu Hao Wang +1 位作者 Rui Yang Anil K.Sachdev 《Chinese Science Bulletin》 SCIE EI CAS 2014年第15期1725-1737,共13页
The nucleation and propagation of h011]superdislocations in intermetallic TiAl were investigated using molecular dynamics simulations and static energetics calculation,as part of our systematic effort to understand th... The nucleation and propagation of h011]superdislocations in intermetallic TiAl were investigated using molecular dynamics simulations and static energetics calculation,as part of our systematic effort to understand the twining and dislocation behavior of alloys based on c-TiAl.It was found that compared to ordinary dislocations in disordered crystals,superdislocations in ordered TiAl lattice behave differently when sheared in the two opposite senses along[0"11]direction.This difference is due to the lower L10lattice symmetry compared with the face-centered cubic(fcc)lattice that it based on,with different yield stress and strain,and dislocation core dissociation and motion.Superdislocations nucleated in the form of loops dissociated in a planar manner into four Shockley partials separated by three kinds of faults:superlattice intrinsic stacking fault(SISF),anti-phase domain boundary(APB)and complex stacking fault(CSF),with partial separations depending on the sense of shearing and dislocation character.During loop expansion,the dislocation core changes both in width and dissociation manner depending on the character of the segment in the loop.The core contains four partials close to edge orientation,gradually changing to three fold near 60°,and finally into twofold dissociationaround 30°character.Superdislocations may have multiple critical resolved shear stresses(CRSS)for motion depending on dissociation and shearing sense even for the same slip system,with lower critical stress for the motion when SISF is in leading position. 展开更多
关键词 MD模拟 TIAI Γ-TIAL基合金 对称核 分子动力学模拟 普通位错 剪切应力 故障分离
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Pollution of hazardous substances in industrial construction and demolition wastes and their multi-path risk within an abandoned pesticide manufacturing plant 被引量:2
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作者 Sheng Huang Xin Zhao +6 位作者 Yanqiu Sun Jianli Ma Xiaofeng Gao Tian Xie dongsheng xu Yi Yu Youcai Zhao 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2017年第1期123-135,共13页
Exploration of heavy metals and organic pollutants, their leaching capacity along with health and environmental risks in contaminated industrial construction and demolition waste (ICDW) within a pesticide manufactu... Exploration of heavy metals and organic pollutants, their leaching capacity along with health and environmental risks in contaminated industrial construction and demolition waste (ICDW) within a pesticide manufacturing plant were investigated. A maximum content of 90.8 mg·kg-1 Cd was found present in the wastes, which might originate from phosphorus rocks and industrial sulfuric acid used in pesticide production processes. An average concentration of 979.8 mg·kg-1 dichlorovos and other 11 organophosphorus pesticide were also detected. Relatively high leaching rates of around 4.14‰ were obtained from laboratory simulated ICDW using both glacial acetic acidsodium hydroxide and deionized water. Pesticide pollutants had the strongest tendency to retaining on dry bricks (leaching rate 1.68 9‰) compared to mortar-coatings, etc. due to their different physical characteristics and octanol-water partioning coefficient. Mobility of pesticide from on-site ICDW by water was spatially correlated to waste types, process sections and human activities, with a flux of leaching rate between 5.9‰ to 27.4%. Risk-based corrective action (RBCA) model was used to simulate the risk of contaminated ICDW debris randomly scattered. Oral and demlal ingestion amount by local workers was 9.8 × 10-3 and 1.9 × 10-2 mg.(kg-d)-1, respectively. Potential leaching risk to aquatic systems exceeded the limit for nearly 75% waste. Environmental and health risk exceedance was found in most ICDW, while the risk value of the most severely contaminated brick waste was 660 times beyond critical level. Implications for waste management involving construction and deconstruction work, waste transferring and regulation supplying were also provided. 展开更多
关键词 Industrial demolition wastes Heavy metals PESTICIDES Leaching characteristics Risk assessment Waste management
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Direct reprogramming of induced neural progenitors: a new promising strategy for AD treatment 被引量:4
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作者 Siqiang Lai Min Zhang +4 位作者 dongsheng xu Yiying Zhang Lisha Qiu Changhai Tian Jialin Charlie Zheng 《Translational Neurodegeneration》 SCIE CAS 2015年第1期48-53,共6页
Alzheimer’s disease(AD)is a prominent form of dementia,characterized by aggregation of the amyloidβ-peptide(Aβ)plaques and neurofibrillary tangles,loss of synapses and neurons,and degeneration of cognitive function... Alzheimer’s disease(AD)is a prominent form of dementia,characterized by aggregation of the amyloidβ-peptide(Aβ)plaques and neurofibrillary tangles,loss of synapses and neurons,and degeneration of cognitive functions.Currently,although a variety of medications can relieve some of the symptoms,there is no cure for AD.Recent breakthroughs in the stem cell field provide promising strategies for AD treatment.Stem cells including embryonic stem cells(ESCs),neural stem cells(NSCs),mesenchymal stem cells(MSCs),and induced pluripotent stem cells(iPSCs)are potentials for AD treatment.However,the limitation of cell sources,safety issues,and ethical issues restrict their applications in AD.Recently,the direct reprogramming of induced neural progenitor cells(iNPCs)has shed light on the treatment of AD.In this review,we will discuss the latest progress,challenges,and potential applications of direct reprogramming in AD treatment. 展开更多
关键词 Alzheimer’s disease Stem cell-based therapy Induced neural progenitor cells
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Phase field simulation of the stress-inducedαmicrostructure in Ti–6Al–4 V alloy and its CPFEM properties evaluation 被引量:2
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作者 Jinhu Zhang xuexiong Li +9 位作者 dongsheng xu Chunyu Teng Hao Wang Liang Yang Hongtao Ju Haisheng xu Zhichao Meng Yingjie Ma Yunzhi Wang Rui Yang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第31期168-182,共15页
Variant selection under specific applied stresses during precipitation of a plates from prior-βmatrix in Ti-6 Al-4 V was investigated by 3 D phase field simulations.The model incorporates the Burgers transformation p... Variant selection under specific applied stresses during precipitation of a plates from prior-βmatrix in Ti-6 Al-4 V was investigated by 3 D phase field simulations.The model incorporates the Burgers transformation path fromβto a phase,with consideration of interfacial energy anisotropy,externally applied stresses and elastic interactions among a variants andβmatrix.The Gibbs free energy and atomic mobility data are taken from available thermodynamic and kinetic databases.It was found that external stresses have a profound influence on variant selection,and the selection has a sensitive dependence,as evidenced by both interaction energy calculations and phase field simulations.Compared with normal stresses,shear stresses applied in certain directions were found more effective in accelerating the transformation,with a stronger preference to fewer variants.The volume fractions of various a variants and the final microstructure were determined by both the external stress and the elastic interaction among different variants.The a clusters formed by variants with Type2 misorientation([11-20]/60°)relation were found more favored than those with Type4([-1055-3]/63.26°)under certain applied tensile stress such as along<111>β.The mechanical properties of different microstructures from our phase field simulation under different conditions were calculated for different loading conditions,utilizing crystal plastic finite element simulation.The mechanical behavior of the various microstructures from phase field simulation can be evaluated well before the alloys are fabricated,and therefore it is possible to select microstructure for optimizing the mechanical properties of the alloy through thermomechanical processing based on the two types of simulations. 展开更多
关键词 Titanium alloy Phase transformation MICROTEXTURE Mechanical evaluation Phase field Crystal plasticity finite element
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Seeded growth of Ti-46Al-8Nb polysynthetically twinned crystals with an ultra-high elongation 被引量:2
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作者 Hao Jin Qing Jia +4 位作者 Quangang Xian Ronghua Liu Yuyou Cui dongsheng xu Rui Yang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2020年第19期190-195,共6页
Large size polysynthetically twinned crystals of Ti-46 Al-8 Nb alloy with a parallel lamellar microstructure were successfully prepared using a Ti-43 Al-3 Si seed by our new operation.A large amount of columnar B2 pha... Large size polysynthetically twinned crystals of Ti-46 Al-8 Nb alloy with a parallel lamellar microstructure were successfully prepared using a Ti-43 Al-3 Si seed by our new operation.A large amount of columnar B2 phase paralleling to the growth direction was found in the final lamellar microstructure.Higher growth rate(>30 mm/h)led to the failure of seeding process.Based on these results,a new mechanism is proposed to describe the seeding process of the hypo-peritectic Ti Al alloys.The peritecticαphase is suggested to directly nucleate from the melt,and then act as nucleus for transformedαphase in the subsequentβtoαtransformation.At the higher growth rate,the appearance ofβphase secondary dendrites and homogeneous nucleation lead to the failure of seeding process.High Nb addition leads to a large amount of residualβphase,and theseβdendrites finally evolve into B2 phase.The room temperature tensile elongation was measured to be 11.9-18.5%for Ti-46 Al-8 Nb PST crystals,which is the highest ever reported value for Ti Al based alloys. 展开更多
关键词 TiAl alloys Polysynthetically twinned crystals Peritectic solidification Seeded growth DUCTILITY
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