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Potential role of hippocampal neurogenesis in spinal cord injury induced post-trauma depression
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作者 ying ma Yue Qiao Xiang Gao 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第10期2144-2156,共13页
It has been reported both in clinic and rodent models that beyond spinal cord injury directly induced symptoms, such as paralysis, neuropathic pain, bladder/bowel dysfunction, and loss of sexual function, there are a ... It has been reported both in clinic and rodent models that beyond spinal cord injury directly induced symptoms, such as paralysis, neuropathic pain, bladder/bowel dysfunction, and loss of sexual function, there are a variety of secondary complications, including memory loss, cognitive decline, depression, and Alzheimer's disease. The largescale longitudinal population-based studies indicate that post-trauma depression is highly prevalent in spinal cord injury patients. Yet, few basic studies have been conducted to address the potential molecular mechanisms. One of possible factors underlying the depression is the reduction of adult hippocampal neurogenesis which may come from less physical activity, social isolation, chronic pain, and elevated neuroinflammation after spinal cord injury. However, there is no clear consensus yet. In this review, we will first summarize the alteration of hippocampal neurogenesis post-spinal cord injury. Then, we will discuss possible mechanisms underlie this important spinal cord injury consequence. Finally, we will outline the potential therapeutic options aimed at enhancing hippocampal neurogenesis to ameliorate depression. 展开更多
关键词 antidepressants chronic pain DEPRESSION EXERCISE hippocampal neurogenesis inflammation inhibition NEUROINFLAMMATION physical activity deficits social isolation spinal cord injury
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The effect of seismic action on stability of saline soil subgrade in cold region based on isothermal stratification method
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作者 Jie Cheng Yu Zhang +2 位作者 ying ma Xuerui Chen Ning An 《Earthquake Research Advances》 CSCD 2024年第3期66-81,共16页
With the change of seasons, the shear strength of saline soil subgrade filler will change with the change of external temperature, which will aggravate the adverse effects of seismic on the subgrade. To explore the in... With the change of seasons, the shear strength of saline soil subgrade filler will change with the change of external temperature, which will aggravate the adverse effects of seismic on the subgrade. To explore the influence of seismic action on the stability of saline soil subgrade under the influence of temperature on the strength of saline soil subgrade filler, this paper first carried out saline soil shear tests at different temperatures to obtain the influence of temperature on the shear strength of saline soil. Then, the temperature field of the saline soil subgrade was simulated, and then based on the subgrade isothermal stratification model and FLAC3D, the displacement and acceleration amplification effects of seismic action on the shady slope, sunny slope and subgrade of saline soil subgrade in different months were analyzed. The following conclusions were finally drawn: under the action of seismic, In the process of the change of subgrade temperature of Qarhan-Golmud Expressway between 7.7°C and 27°C, the change of saline soil cohesion is the main factor affecting the stability of subgrade slope, and the maximum and minimum values of subgrade surface settlement appear in September and June of each year,respectively. In August, the differences of settlement between the shady slope and the sunny slope shoulder of the subgrade were the largest, and the acceleration of the shady slope and the sunny slope and the inside of the subgrade changed most significantly in the vertical direction. Special attention should be paid to the seismic early warning in the above key months;In the range from both sides of the shoulder to the centerline of the roadbed,the acceleration amplification effect starts to increase significantly from about 3m from the centerline of the roadbed to the centerline, so it is necessary to pay attention to the seismic design of this range. 展开更多
关键词 Subgrade stability Saline soils Acceleration amplification effect Seismic design
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Characteristics and Trends of Urban Waterfront Human Settlements Based on CiteSpace
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作者 Binbin Zhang Jinghao Li +1 位作者 ying ma Nanwei Wu 《Journal of World Architecture》 2024年第2期146-153,共8页
Urban waterfront human settlements have gradually become a hot topic for research in recent years.Using CiteSpace,597 publications from 2017 to 2023 that were retrieved from the Web of Science were analyzed and sorted... Urban waterfront human settlements have gradually become a hot topic for research in recent years.Using CiteSpace,597 publications from 2017 to 2023 that were retrieved from the Web of Science were analyzed and sorted out,and the following characteristics were found:(1)The research hotspots transitioned from thermal comfort evaluation to the functional mechanism of water bodies,and then to the impact on the environment and residents’behavior.(2)The integration of disciplines has promoted the diversification of perspectives on urban waterfront human settlements,and the content has become more concentrated in interdisciplinary fields.Research on corresponding technology and methods of urban waterfront human settlement has improved,and so has the extensiveness of the experiments.(3)The research on urban waterfront human settlement from the perspective of ecology has been improving.The research focuses more on the harmonious coexistence of ecological and cultural values and human beings. 展开更多
关键词 Urban waterfront living environment Bibliometric analysis Urban thermal environment Ecological civilization construction Online publication:May 20 2024
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有机化学实验课教学质量提升的探索与实践
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作者 刘刚 张恒 +4 位作者 马莹 苑世领 宋其胜 徐政虎 孙继超 《大学化学》 CAS 2024年第4期70-74,共5页
本文介绍了有机化学实验教学过程中存在的一些问题,并从强化学生预习效果、加强教师技能培训、重视集体备课、强化实验过程的教师指导、增加课后的评价反思等方面介绍了我校提高有机化学实验教学质量的探索和实践。
关键词 有机化学实验 教学质量 实验教学
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Nuclear PLD1 combined with NPM1 induces gemcitabine resistance through tumorigenic IL7R in pancreatic adenocarcinoma
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作者 Danqi Fu Jingrui Yan +17 位作者 Zhaoyu Zhang Yang Liu Xiaoqing ma Jinsheng Ding Shengyu Yang Ran Zhao Antao Chang Chuntao Gao Jing Liu Tiansuo Zhao Xiuchao Wang Chongbiao Huang Song Gao ying ma Bo Tang Yukuan Feng Hongwei Wang Jihui Hao 《Cancer Biology & Medicine》 SCIE CAS CSCD 2023年第8期599-626,共28页
Objective:Pancreatic ductal adenocarcinoma(PDAC)is a highly malignant gastrointestinal cancer with a 5-year survival rate of only 9%.Of PDAC patients,15%-20%are eligible for radical surgery.Gemcitabine is an important... Objective:Pancreatic ductal adenocarcinoma(PDAC)is a highly malignant gastrointestinal cancer with a 5-year survival rate of only 9%.Of PDAC patients,15%-20%are eligible for radical surgery.Gemcitabine is an important chemotherapeutic agent for patients with PDAC;however,the efficacy of gemcitabine is limited due to resistance.Therefore,reducing gemcitabine resistance is essential for improving survival of patients with PDAC.Identifying the key target that determines gemcitabine resistance in PDAC and reversing gemcitabine resistance using target inhibitors in combination with gemcitabine are crucial steps in the quest to improve survival prognosis in patients with PDAC.Methods:We constructed a human genome-wide CRISPRa/dCas 9 overexpression library in PDAC cell lines to screen key targets of drug resistance based on sgRNA abundance and enrichment.Then,co-IP,ChIP,ChIP-seq,transcriptome sequencing,and qPCR were used to determine the specific mechanism by which phospholipase D1(PLD1)confers resistance to gemcitabine.Results:PLD1 combines with nucleophosmin 1(NPM1)and triggers NPM1 nuclear translocation,where NPM1 acts as a transcription factor to upregulate interleukin 7 receptor(IL7R)expression.Upon interleukin 7(IL-7)binding,IL7R activates the JAK1/STAT5 signaling pathway to increase the expression of the anti-apoptotic protein,BCL-2,and induce gemcitabine resistance.The PLD1 inhibitor,Vu0155069,targets PLD1 to induce apoptosis in gemcitabine-resistant PDAC cells.Conclusions:PLD1 is an enzyme that has a critical role in PDAC-associated gemcitabine resistance through a non-enzymatic interaction with NPM1,further promoting the downstream JAK1/STAT5/Bcl-2 pathway.Inhibiting any of the participants of this pathway can increase gemcitabine sensitivity. 展开更多
关键词 Gemcitabine resistance pancreatic ductal adenocarcinoma phospholipase D1 nucleophosmin 1 CRISPRa library
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Down-regulation of the Smad signaling by circZBTB46 via the Smad2-PDLIM5 axis to inhibit type I collagen expression
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作者 Jing YU Wen-Zhao YAN +10 位作者 Xin-Hua ZHANG Bin ZHENG Wen-Sen PAN Zhan YANG Hong ZHANG Zi-Yuan NIE ying ma Yang BAI Long ZHANG Dan-Dan FENG Jin-Kun WEN 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2023年第6期431-447,共17页
BACKGROUND Abnormal type I collagen(COL1)expression is associated with the development of many cardiovascular diseases.The TGF-beta/Smad signaling pathway and circRNAs have been shown to regulate COL1 gene expression,... BACKGROUND Abnormal type I collagen(COL1)expression is associated with the development of many cardiovascular diseases.The TGF-beta/Smad signaling pathway and circRNAs have been shown to regulate COL1 gene expression,but the underlying molecular mechanisms are still not fully understood.METHODS Gain-and loss-of-function experiments were prformed to study the effect of circZBTB46 on the expression of alpha 2 chain of type I collagen(COL1A2).Co-immunoprecipitation assay was performed to observe the interaction between two proteins.RNA immunoprecipitation assay and biotin pull-down assay were performed to observe the interaction of circZBTB46 with PDLIM5.RESULTS In this study,we investigated the role of circZBTB46 in regulating COL1A2 expression in human vascular smooth muscle cells(VSMCs).We found that circZBTB46 is expressed in VSMCs and that TGF-beta inhibits circZBTB46 formation by downregulating KLF4 expression through activation of the Smad signaling pathway.CircZBTB46 inhibits the expression of COL1A2 induced by TGF-beta.Mechanistically,circZBTB46 mediates the interaction between Smad2 and PDLIM5,resulting in the inhibition of Smad signaling and the subsequent downregulation of COL1A2 expression.Furthermore,we found that the expression of TGFbeta and COL1A2 is decreased,while circZBTB46 expression is increased in human abdominal aortic aneurysm tissues,indicating that circZBTB46-mediated regulation of TGF-beta/Smad signaling and COL1A2 synthesis in VSMCs plays a crucial role in vascular homeostasis and aneurysm development.CONCLUSIONS CircZBTB46 was identified as a novel inhibitor of COL1 synthesis in VSMCs,highlighting the importance of circZBTB46 and PDLIM5 in regulating TGF-beta/Smad signaling and COL1A2 expression. 展开更多
关键词 PDLIM5 SMAD2 HOMEOSTASIS
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Sea-Land Segmentation of Remote Sensing Images Based on SDW-UNet
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作者 Tianyu Liu Pengyu Liu +3 位作者 Xiaowei Jia Shanji Chen ying ma Qian Gao 《Computer Systems Science & Engineering》 SCIE EI 2023年第5期1033-1045,共13页
Image segmentation of sea-land remote sensing images is of great importance for downstream applications including shoreline extraction,the monitoring of near-shore marine environment,and near-shore target recognition.... Image segmentation of sea-land remote sensing images is of great importance for downstream applications including shoreline extraction,the monitoring of near-shore marine environment,and near-shore target recognition.To mitigate large number of parameters and improve the segmentation accuracy,we propose a new Squeeze-Depth-Wise UNet(SDW-UNet)deep learning model for sea-land remote sensing image segmentation.The proposed SDW-UNet model leverages the squeeze-excitation and depth-wise separable convolution to construct new convolution modules,which enhance the model capacity in combining multiple channels and reduces the model parameters.We further explore the effect of position-encoded information in NLP(Natural Language Processing)domain on sea-land segmentation task.We have conducted extensive experiments to compare the proposed network with the mainstream segmentation network in terms of accuracy,the number of parameters and the time cost for prediction.The test results on remote sensing data sets of Guam,Okinawa,Taiwan China,San Diego,and Diego Garcia demonstrate the effectiveness of SDW-UNet in recognizing different types of sea-land areas with a smaller number of parameters,reduces prediction time cost and improves performance over other mainstream segmentation models.We also show that the position encoding can further improve the accuracy of model segmentation. 展开更多
关键词 Sea-land segmentation UNet depth-wise separable convolution squeeze-excitation position encoding
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表面活性剂溶致液晶的表征及相图绘制
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作者 姜渝凯 王一涵 +3 位作者 张云恺 尉云平 马莹 杜娜 《大学化学》 CAS 2024年第4期114-118,共5页
该实验以离子型表面活性剂C_(14)TAB-水二元体系为研究对象,通过偏光显微镜和目视观察法详细研究体系的各向同(异)性、双折射、偏光织构等光学性质和相行为,利用小角X射线散射(SAXS)技术表征溶致液晶相的结构和参数,并绘制其二元相图。... 该实验以离子型表面活性剂C_(14)TAB-水二元体系为研究对象,通过偏光显微镜和目视观察法详细研究体系的各向同(异)性、双折射、偏光织构等光学性质和相行为,利用小角X射线散射(SAXS)技术表征溶致液晶相的结构和参数,并绘制其二元相图。该实验在原有综合化学实验的基础上拓展研究体系,降低实验成本,提升实验准确性,可帮助学生在了解溶致液晶表观性质的基础上,进一步认识其微观结构,掌握表征技术的原理和方法,激发学生对物理化学实验的兴趣,有助于学生科学逻辑思维的拓展和实验技能的提高。 展开更多
关键词 溶致液晶 表面活性剂 双折射 小角X射线散射
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Prevalence and risk factors of diabetes mellitus among elderly patients in the Lugu community 被引量:1
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作者 Li-Zhen Zhao Wei-Min Li ying ma 《World Journal of Diabetes》 SCIE 2024年第4期638-644,共7页
BACKGROUND Age is a significant risk factor of diabetes mellitus(DM).With the develop of population aging,the incidence of DM remains increasing.Understanding the epidemiology of DM among elderly individuals in a cert... BACKGROUND Age is a significant risk factor of diabetes mellitus(DM).With the develop of population aging,the incidence of DM remains increasing.Understanding the epidemiology of DM among elderly individuals in a certain area contributes to the DM interventions for the local elderly individuals with high risk of DM.AIM To explore the prevalence of DM among elderly individuals in the Lugu community and analyze the related risk factors to provide a valid scientific basis for the health management of elderly individuals.METHODS A total of 4816 elderly people who came to the community for physical examination were retrospectively analyzed.The prevalence of DM among the elderly was calculated.The individuals were divided into a DM group and a non-DM group according to the diagnosis of DM to compare the differences in diastolic blood pressure(DBP)and systolic blood pressure(SBP),fasting blood glucose,body mass index(BMI),waist-to-hip ratio(WHR)and incidence of hypertension(HT),coronary heart disease(CHD),and chronic kidney disease(CKD).RESULTS DM was diagnosed in 32.70%of the 4816 elderly people.The BMI of the DM group(25.16±3.35)was greater than that of the non-DM group(24.61±3.78).The WHR was 0.90±0.04 in the non-DM group and 0.90±0.03 in the DM group,with no significant difference.The left SBP and SBP in the DM group were 137.9 mmHg±11.92 mmHg and 69.95 mmHg±7.75 mmHg,respectively,while they were 126.6 mmHg±12.44 mmHg and 71.15 mmHg±12.55 mmHg,respectively,in the non-DM group.These findings indicate higher SBP and lower DBP in DM patients than in those without DM.In the DM group,1274 patients were diagnosed with HT,accounting for 80.89%.Among the 3241 non-DM patients,1743(53.78%)were hypertensive and 1498(46.22%)were nonhypertensive.The DM group had more cases of HT than did the non-DM group.There were more patients with CHD or CKD in the DM group than in the non-DM group.There were more patients who drank alcohol more frequently(≥3 times)in the DM group than in the non-DM group.CONCLUSION Older adults in the Lugu community are at a greater risk of DM.In elderly individuals,DM is closely related to high BMI and HT,CHD,and CKD.Physical examinations should be actively carried out for elderly people to determine their BMI,SBP,DBP,and other signs,and sufficient attention should be given to abnormalities in the above signs before further diagnosis. 展开更多
关键词 Diabetes mellitus Type 2 diabetes mellitus ELDERLY Risk factors
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Identification and hazard analysis of landslides triggered by earthquakes and rainfall
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作者 Lei Li Yu Zhang +4 位作者 Yunlong Hou Bingbing Han Ning An Hui Zhang ying ma 《Earthquake Research Advances》 CSCD 2024年第3期42-54,共13页
This study aims to utilize the Small Baseline Subset Interferometric Synthetic Aperture Radar(SBAS-In SAR)technique and Google Earth optical remote sensing images to analyze the area within 20 km around the epicenter ... This study aims to utilize the Small Baseline Subset Interferometric Synthetic Aperture Radar(SBAS-In SAR)technique and Google Earth optical remote sensing images to analyze the area within 20 km around the epicenter of a M 3.9, earthquake that occurred in Tanchang County, Gansu Province, on December 28, 2020. The objective is to identify potential earthquake-induced landslides, assess their scale, and determine their impact range. The study results reveal the successful identification of two potential landslides in the 20 km radius around the epicenter. Through time-series deformation analysis, it was observed that these potential landslides were significantly influenced by both the earthquake and rainfall. Further estimation of these potential landslides indicates maximum depths of 7.4 m and 14.1 m for the failure surfaces, with volumes of 9.02 × 10~4m~3and 25.5 ×10~4m~3, respectively. Finally, based on the simulation analysis of Massflow software, the maximum thickness of soil accumulation in the final accumulation area after sliding of the potential landslide in Shangyaai is 12 m, the area of the final accumulation area is 1.75 × 10~4m~2, and the farthest movement distance is 1124 m. The maximum thickness of soil accumulation in the final accumulation area after sliding of the potential landslide in Wangshancun is 8 m, the area of the final accumulation area is 7.89 × 10~4m~2, and the farthest movement distance is 742 m. 展开更多
关键词 SBAS-InSAR technology EARTHQUAKE Deformation monitoring LANDSLIDE Massflow Hazard analysis
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Effects of electrical parameters and their interactions on plasma electrolytic oxidation coatings on aluminum substrates 被引量:12
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作者 Ling-yun AN ying ma +2 位作者 Xiao-xu YAN Sheng WANG Zhan-ying WANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第4期883-895,共13页
Based on orthogonal experiments,the effects of voltage,frequency,duty ratio and their interactions on the thickness and corrosion resistance of coatings prepared by plasma electrolytic oxidation(PEO)on aluminum in an ... Based on orthogonal experiments,the effects of voltage,frequency,duty ratio and their interactions on the thickness and corrosion resistance of coatings prepared by plasma electrolytic oxidation(PEO)on aluminum in an alkaline silicate-containing electrolyte were investigated.The thicknesses of these coatings were obtained by measuring their cross-section using Image J software.Their corrosion resistances were evaluated in HCl and NaCl media through spot test and electrochemical test.The results show that the experimental design of this study is the key to investigate the interactions among these electrical parameters.Additionally,not only each independent factor,but also their interactions exhibit a remarkable influence on the coatings.The combination of high voltage,low frequency and large duty ratio significantly increases the coating thickness and content of the corrosion resistance phase,and thus improves the corrosion resistance of the coating in HNO3 medium.Conversely,the coating possessing the densest microstructure and best corrosion resistance in NaCl medium is obtained when low voltage and high frequency match with a small duty ratio. 展开更多
关键词 ALUMINUM plasma electrolytic oxidation VOLTAGE FREQUENCY duty ratio interaction orthogonal experiments corrosion resistance
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Effects of melt treatment temperature and isothermal holding parameter on water-quenched microstructures of A356 aluminum alloy semisolid slurry 被引量:7
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作者 Ming LI Yuan-dong LI +3 位作者 Guang-li BI Xiao-feng HUANG Ti-jun CHEN ying ma 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第3期393-403,共11页
The semisolid slurry of the A356 aluminum alloy was prepared by self-inoculation method(SIM),the effects of melt treatment temperatures and isothermal holding parameters on water-quenched microstructures of A356 alumi... The semisolid slurry of the A356 aluminum alloy was prepared by self-inoculation method(SIM),the effects of melt treatment temperatures and isothermal holding parameters on water-quenched microstructures of A356 aluminum alloy semisolid slurry were investigated,and the solidification behavior of the remaining liquid phase(secondary solidification)was analyzed.The results indicate that the melt treatment temperature has significant effects on the final semisolid microstructures.The semisolid slurry which is suitable for the rheological forming can be produced when the melt treatment temperature is between 680 and 690°C.During the isothermal holding process,the growth rate of the primary particles conforms to the dynamic equation of Dt 3-Do3=Kt,and the coarsening rate of the primary particles is the fastest when the isothermal holding temperature is 600°C.Additionally,the isothermal holding time also has obvious effect on the secondary solidification microstructures.The secondary particles are the smallest and roundest when the isothermal holding time is 3 min.The amount of the secondary particles gradually increases with the increase of isothermal holding temperature,and the eutectic reaction therefore is confined into small intergranular areas,contributing to the compactness of the final solidified eutectic structures. 展开更多
关键词 aluminum alloy SEMISOLID self-inoculation method secondary solidification primary particles eutectic structure
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Obstacle Avoidance and Multitarget Tracking of a Super Redundant Modular Manipulator Based on Bezier Curve and Particle Swarm Optimization 被引量:6
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作者 Li Chen ying ma +1 位作者 Yu Zhang Jinguo Liu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2020年第5期101-119,共19页
A super redundant serpentine manipulator has slender structure and multiple degrees of freedom.It can travel through narrow spaces and move in complex spaces.This manipulator is composed of many modules that can form ... A super redundant serpentine manipulator has slender structure and multiple degrees of freedom.It can travel through narrow spaces and move in complex spaces.This manipulator is composed of many modules that can form different lengths of robot arms for different application sites.The increase in degrees of freedom causes the inverse kinematics of redundant manipulator to be typical and immensely increases the calculation load in the joint space.This paper presents an integrated optimization method to solve the path planning for obstacle avoidance and discrete trajectory tracking of a super redundant manipulator.In this integrated optimization,path planning is established on a Bezier curve,and particle swarm optimization is adopted to adjust the control points of the Bezier curve with the kinematic constraints of manipulator.A feasible obstacle avoidance path is obtained along with a discrete trajectory tracking by using a follow-the-leader strategy.The relative distance between each two discrete path points is limited to reduce the fitting error of the connecting rigid links to the smooth curve.Simulation results show that this integrated optimization method can rapidly search for the appropriate trajectory to guide the manipulator in obtaining the target while achieving obstacle avoidance and meeting joint constraints.The proposed algorithm is suitable for 3D space obstacle avoidance and multitarget path tracking. 展开更多
关键词 Super redundant manipulator Multi target tracking Follow-the-leader Obstacle avoidance Bezier curve PSO
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Investigation of mutual effects among additives in electrolyte for plasma electrolytic oxidation on magnesium alloys 被引量:9
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作者 Lingyun An ying ma +2 位作者 Le Sun Zhanying Wang Sheng Wang 《Journal of Magnesium and Alloys》 SCIE 2020年第2期523-536,共14页
Plasma electrolytic oxidation(PEO)coatings were prepared on AZ91D magnesium alloys in alkaline silicate-based electrolyte with and without additives.The mutual effects among additives including TiC particles,dispersan... Plasma electrolytic oxidation(PEO)coatings were prepared on AZ91D magnesium alloys in alkaline silicate-based electrolyte with and without additives.The mutual effects among additives including TiC particles,dispersant polyethylene glycol 6000(PEG6000)and anionic surfactant sodium dodecyl sulfate(SDS)were studied based on orthogonal experiment.The content and distribution of TiC deposited in the coatings were measured by EPMA and EDS.The thicknesses,phase compositions,microstructures and corrosion resistances of the codlings were cAarnined by using TT260 eddy current tuickncss gage,XRD,SEM and clcctrochcniical test,respectively.The results show that the experiment design of this study is the key to study the mutual effects among these additives.Each additive and their interactions all remarkably influence TiC content and corrosion resistance of the coatings.Smaller size TiC is much easier to migrate towards the anode,and the interaction between PEG6000 and SDS both effectively prevents its agglomeration and increases the number of its negative surface charges,which further increase the migration rate and the deposited uniformity of TiC and make TiC have more opportunity to deposit in the discharge channel.Thus,when smaller size TiC,PEG6000 and SDS are all added into the electrolyte,they could improve the anti-corrosion property of the coating to the largest extent attributed to higher TiC content and the densest microstructure of the coating. 展开更多
关键词 Magnesium alloys Plasma electrolytic oxidation ADDITIVES Mutual effects Orthogonal experiment Corrosion resistance
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Effect of mixing rate and temperature on primary Si phase of hypereutectic Al-20Si alloy during control ed diffusion solidification(CDS) process 被引量:5
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作者 Yuan-dong Li Xin-long Zhang +3 位作者 ying ma Diran Apelian Hong-wei Zhou Xing-hai Liu 《China Foundry》 SCIE CAS 2015年第3期173-179,共7页
Controlled Diffusion Solidification(CDS) is a promising process relied on mixing two liquid alloys of precisely controlled chemistry and temperature in order to produce a predetermined alloy composition. In this study... Controlled Diffusion Solidification(CDS) is a promising process relied on mixing two liquid alloys of precisely controlled chemistry and temperature in order to produce a predetermined alloy composition. In this study, the CDS was employed to prepare hypereutectic Al-20%Si(mass fraction) alloy using Al-30%Si and pure Al of different temperatures. The mixing rate was controlled using three small crucibles with a hole of different diameters in their bottom. The effect of mixing rate and temperature on the microstructure of the primary Si-phase during the mixing of molten Al and Al-30%Si was studied. The results showed that when the diameter of the small crucible bottom hole is 16 mm, a higher mass mixing rate 0.217 kg·s-1 would results in a lower stream velocity 0.414 m·s-1. Conversely a lower mass mixing rate 0.114 kg·s-1(the diameter of the small crucible bottom hole is 8 mm) would result in a higher fluid stream velocity 0.879 m·s-1. A lower mass mixing rate would be better to refine the primary Si than a higher mass mixing rate. Meanwhile, the morphology and distribution of primary Si could also be improved. Especially, when Al-30%Si alloy at 820 °C was mixed with pure Al at 670 °C in the case of a mass mixing rate of 0.114 kg·s-1 and a pouring temperature of 680 °C, the average size of the primary Si phase would be only 18.2 μm. Its morphology would mostly be octahedral and the primary Si would distribute uniformly in the matrix microstructure. The lower mass mixing rate(0.114 kg·s-1) will enhance the broken tendency of Al-30%Si steam and the mixing agitation of resultant melt, so the primary Si phase can be better refined. 展开更多
关键词 Controlled Diffusion Solidification(CDS) hypereutectic Al-Si alloy mass mixing rate stream velocity primary Si
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Molybdenum carbide clusters for thermal conversion of CO2 to CO via reverse water-gas shift reaction 被引量:4
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作者 ying ma Zhanglong Guo +3 位作者 Qian Jiang Kuang-Hsu Wu Huimin Gong Yuefeng Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第11期37-43,共7页
Molybdenum carbides are highly active for CO2 conversion to CO via the reverse water-gas shift(RWGS)reaction, however the large grain size up to micrometers renders its relatively lower active sites utilization effici... Molybdenum carbides are highly active for CO2 conversion to CO via the reverse water-gas shift(RWGS)reaction, however the large grain size up to micrometers renders its relatively lower active sites utilization efficiency while generating CH4 as a by-product. In this work, a homogeneously dispersed molybdenum carbide hybrid catalyst with sub-nanosized cluster(the average size as small as 0.5 nm) is prepared via a facile carbothermal treatment for highly selective CO2-CO reduction. The partially disordered Mo2C clusters are characterized by synchrotron high-resolution XRD and atomic resolution HAADF-STEM analysis, for which the source cause of the disorder is pinpointed by XAFS analysis to be the nitrogen intercalants from the carbonaceous precursor. The partially disordered Mo2C clusters show a RWGS rate as high as 184.4 μmol gMo2C-1s-1 at 400 ℃ with a superior selectivity toward CO(> 99.5%). This work 2 highlights a facile strategy for fabricating highly dispersed and partially disordered Mo2C clusters at a sub-nano size with beneficial N-doping for delivering high catalytic activity and operational stability. 展开更多
关键词 Co2 conversion Reverse water-gas-shift reaction Molybdenum carbide cluster Sub-nanosize CO selectivity
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Effects of Cu addition on microstructureand mechanical properties of as-cast Mg-6Znmagnesium alloy 被引量:3
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作者 Yu Zhang Xiao-feng Huang +3 位作者 ying ma Ti-jun Chen Yuan-dong Li Yuan Hao 《China Foundry》 SCIE 2017年第4期251-257,共7页
The application of Mg-Zn binary alloys is restricted due to their developed dendritic microstructure and poor mechanical properties. In this study, an alloying method was used to improve the mechanical properties of M... The application of Mg-Zn binary alloys is restricted due to their developed dendritic microstructure and poor mechanical properties. In this study, an alloying method was used to improve the mechanical properties of Mg-Zn alloy. The Mg-6Zn magnesium alloys microalloyed with varying Cu content(0, 0.8, 1.5, 2.0 and 2.5wt.%) were fabricated by permanent mould casting, and the effects of Cu content on the microstructure and mechanical properties of as-cast Mg-6Zn alloys were studied using OM, SEM, XRD and tensile tests at room temperature. The obtained results show that the addition of Cu not only can refine the grains effectively, but also can modify the eutectic morphology and improve the mechanical properties of the alloys. The main phases of the studied alloys include α-Mg, MgZn_2, Mg_2Cu and CuMgZn. When the content of Cu exceeds 0.8wt.%, Mg_2Cu phase appears. Meanwhile, the eutectic morphology is modified into dendritic shape or lamellar structure, which has an adverse effect on the tensile properties. Furthermore, among the investigated alloys, the alloy containing 0.8% Cu shows an optimalultimate tensile strength of 196 MPa, while the alloy with 1.5wt.% Cu obtains an excellent elongation of 7.22%. The experimental alloys under different Cu contents show distinguishing fracture behaviors: the fracture of the alloy with 0.8wt.% Cu reveals a mixed mode of inter-granular and quasi-cleavage, while in other investigated alloys, the fracture behaviors are dominated by cleavage fracture. 展开更多
关键词 MG-ZN magnesium ALLOY CU ADDITION microstructure MECHANICAL property fracture mode
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Computer Simulation of Cathode Materials for Lithium Ion and Lithium Batteries: A Review 被引量:2
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作者 ying ma 《Energy & Environmental Materials》 SCIE EI CAS 2018年第3期148-173,共26页
Driven by the increasing demand for electrochemical energy storage,lithium ion and lithium batteries have been the subject of tremendous scientific endeavors for decades.However,limited energy density,which is bottlen... Driven by the increasing demand for electrochemical energy storage,lithium ion and lithium batteries have been the subject of tremendous scientific endeavors for decades.However,limited energy density,which is bottlenecked by available high-density cathode materials,has become a critical issue to be solved. 展开更多
关键词 atomistic simulations CATHODE lithium ion battery
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Effects of Sm addition on microstructural evolution of Mg-6Zn-0.4Zr alloy during semi-solid isothermal heat treatment 被引量:6
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作者 Yu Zhang Xiao-feng Huang +2 位作者 ying ma Ti-jun Chen Yuan Hao 《China Foundry》 SCIE 2017年第2期85-92,共8页
The application of segmental semi-solid thixoforming of magnesium alloys is confined due to the dimensional distinction existing in solid particles of the alloy billet from edge to center zones. In the present study, ... The application of segmental semi-solid thixoforming of magnesium alloys is confined due to the dimensional distinction existing in solid particles of the alloy billet from edge to center zones. In the present study, the effects of Sm addition on the microstructural evolution of Mg-6Zn-0.4Zr and Mg-6Zn-4Sm-0.4Zr alloys by semi-solid isothermal heat treatment were investigated, to obtain optimum semi-solid microstructures for the subsequently thixoforming. The results indicate that the grains of the Sm-bearing alloy are evidently refined and gradually evolve from dendritic to globular and elliptic particles. In addition, the distinctly dimensional effect of the Mg-6Zn-0.4Zr alloy is eliminated with 4% Sm addition; the particle sizes in all zones from center to the edge of the billet are almost identical. With the increment of isothermal heat treatment temperature, the dendritic microstructures completely disappear, and meanwhile, the irregular and globular particles gradually form. The size, morphology and the distribution of solid particles mainly depend on the formation and permeation of the liquid phase in the process of isothermal heat treatment. As the isothermal temperature increases from 570 °C to 610 °C, the average size and shape factor of solid particles of both the alloys with and without Sm addition gradually decrease while the liquid fraction gradually increases. 展开更多
关键词 Mg-Zn-Zr magnesium alloy dimensional effect Sm semi-solid isothermal heat treatment non-dendritic microstructure
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Investigation of anti-corrosion property of hybrid coatings fabricated by combining PEC with MAO on pure magnesium 被引量:1
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作者 Le Sun ying ma +2 位作者 Binfeng Fan Sheng Wang Zhanying Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2022年第10期2875-2888,共14页
Novel hybrid coatings on pure magnesium were prepared by combining plasma electrolytic carburizing(PEC)with micro-arc oxidation(MAO)to further enhance the anti-corrosion property in this paper.Scanning electron micros... Novel hybrid coatings on pure magnesium were prepared by combining plasma electrolytic carburizing(PEC)with micro-arc oxidation(MAO)to further enhance the anti-corrosion property in this paper.Scanning electron microscopy(SEM)was used to observe the microstructure of the coatings,meanwhile,energy dispersive spectrometry(EDS)and X-ray diffraction(XRD)were separately used to investigate the elemental as well as phase compositions of the coatings.The anti-corrosion property of the coatings was evaluated by potentiodynamic polarization curves as well as electrochemical impedance spectroscopy(EIS).The results show that PEC process is closely related with the effects of adsorption as well as diffusion of the activated carbon atoms,and it can provide a favorable pretreatment surface with predesigned chemical composition to obtain a new kind of phase,namely Si C with superior corrosion resistance and chemical stability,in the following PEC+MAO hybrid coatings.Meanwhile,PEC preprocessing also can afford an excellent micro-structure to increase the coating thickness as well as to improve the compactness of the PEC+MAO hybrid coatings.During the fabrication process of the PEC+MAO hybrid coatings,an overlapping phenomenon in regard to coating thickness can be observed instead of heaping up layer by layer.Compared with both single PEC surface modification layers as well as single MAO coatings,the PEC+MAO hybrid coatings exhibit more superior anti-corrosion property.Especially,the EIS data reveal that the PEC+MAO hybrid coatings can act as an effective protection system to provide relatively excellent long-range anti-corrosion protection.Note also that employing same MAO technique for both single MAO treatment as well as PEC+MAO combining procedure is the key to this research. 展开更多
关键词 Pure magnesium Plasma electrolytic carburizing Micro-arc oxidation Surface modification layers Hybrid coatings Anti-corrosion property
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