Objective:The aim of this study was to investigate the mechanism of acupotomology(Apo)in the prevention of articular cartilage destruction via the promotion of chondrocyte proliferation and chondrocyte expression of c...Objective:The aim of this study was to investigate the mechanism of acupotomology(Apo)in the prevention of articular cartilage destruction via the promotion of chondrocyte proliferation and chondrocyte expression of cell cycle regulators,CyclinD1,CDK4 and CDK6 in a rabbit knee osteoarthritis(KOA)model.Methods:Twenty-eight rabbits were randomly divided into a control group,an OA(osteoarthritis)model group,an Apo(acupotomology)group and EA(electro-acupuncture)group(n Z 7).Improved Videman’s method was used to induce a rabbit model of KOA over 6 weeks.One week later,acupotomy and electro-acupuncture therapy was applied to animals in the respective groups and treatment lasted 4 weeks.Following these treatments,quantitative real-time PCR,immunohistochemical staining and western blotting were performed to assess the mRNA and protein levels of cell cycle regulators CyclinD1(Cell cycle protein D1),CDK4(Cyclin-dependent kinase 4)and CDK6(Cyclin-dependent kinase 6).Ethology measures and knee morphology were also compared among groups.Results:The Lequesne MG index score of morphology was increased(P<.01),and the passive range of motion(PROM)and the mRNA and protein levels of CyclinD1,CDK4,and CDK6 were significantly decreased(P<.01)in the OA model compared with the control group.The Lequesne MG index score and the morphology score were decreased in the Apo and EA group compared with the OA model group(P<.05 or P<.01),while the mRNA levels of CyclinD1,CDK4,and CDK6,and the protein levels of CDK4 were increased in the Apo and EA groups compared with the OA model group(P<.05 or P<.01).The PROM,and the protein levels of CyclinD1 and CDK6 were increased(P<.05)in the Apo group compared with the OA model group,while the PROM and the protein levels of CyclinD1 and CDK6 in the EA group were not significantly different(P>.05).Compared with the EA group,the morphology score was decreased in Apo group(P<.05).Conclusions:The mRNA levels of CyclinD1 and CDK4,and the protein level of CDK4 in chondrocytes are regulate by both Apo and EA.Apo is more effective than EA in regulating the protein levels of CyclinD1 and CDK6.According to the observed changes in morphology and cytokine levels,acupotomy can promote chondrocyte proliferation and can alleviate the destruction of articular cartilage in a model of KOA.展开更多
Limited information exists about the effects of antioxidants on sperm motility and DNA integrity during vitrification in humans. This study compared the effects of reduced glutathione (GSH) and monothioglycerol (MTG) ...Limited information exists about the effects of antioxidants on sperm motility and DNA integrity during vitrification in humans. This study compared the effects of reduced glutathione (GSH) and monothioglycerol (MTG) at different concentrations on post-thaw sperm motility and DNA integrity after vitrification in humans using 0.25 M trehalose as a cryoprotective agent, and found that supplementation of MTG or GSH at 0.5 mM resulted in significantly higher (P < 0.05) recovery rates of post-thaw total and progressive motilities. GSH was more powerful than MTG at the same concentration in cryoprotecting sperm motility (38.9% ± 3.6% vs 32.8% ± 2.4% compared to the control 26.8% ± 2.1% in recovery rate of progressive motility), but both had no significant influence on sperm DNA integrity during vitrification. It was concluded that sperm motility is more sensitive to oxidative stress during vitrification than sperm nuclear DNA, and supplementation of MTG or GSH in vitrification medium is beneficial in cryoprotecting sperm motility.展开更多
Objective:Panax notoginseng saponins (PNS),extracted from rhizome of the herb Radix et Rhizoma Notoginseng (Panax notoginseng (Burk.) F.H.Chen),was recently discovered to have beneficial effects against neurological d...Objective:Panax notoginseng saponins (PNS),extracted from rhizome of the herb Radix et Rhizoma Notoginseng (Panax notoginseng (Burk.) F.H.Chen),was recently discovered to have beneficial effects against neurological damage.This study investigated the effects of PNS on cerebral ischemia and elucidated the molecular mechanisms underlying these effects.Methods:Middle cerebral artery occlusion rats were treated with PNS (3.6 mg/100 g or 7.2 mg/100 g per day) for 7 days,the gene of LINGO-1 was measured and the expression of protein synaptophysin,postsynaptic density protein 95,LINGO-1 and p-EGFR/p-PI3K/p-AKT were investigated.The weight and mNSS score of Sprague-Dawley rats in each group were recorded every day during the 7 days.Results:PNS promoted middle cerebral artery occlusion rats' weight and the recovery of neural function.PNS significantly decreased ischemia-induced LINGO-1 protein expression.PNS also elevated EGFR/PI3K/AKT phosphorylation levels.Conclusion:PNS promoted cerebral recovery from ischemic injury by accelerating synapse reconstruction and inhibiting the neuron growth negative regulatory protein LINGO-1 and activating the epidermal growth factor receptor (EGFR)/PI3K/AKT signaling pathway in vivo.展开更多
Transition metal sulfides(TMSs)have been regarded as greatly promising electrode materials for supercapacitors because of abundant redox electroactive sites and outstanding conductivity.Herein,we report a self-support...Transition metal sulfides(TMSs)have been regarded as greatly promising electrode materials for supercapacitors because of abundant redox electroactive sites and outstanding conductivity.Herein,we report a self-supported hierarchical Mn doped Co_(9)S_(8)@Co(OH)_(2) nanosheet arrays on nickel foam(NF)substrate by a one-step metal–organic-framework(MOF)engaged approach and a subsequent sulfurization process.Experimental results reveal that the introduction of manganese endows improved electric conductivity,enlarged electrochemical specific surface area,adjusted electronic structure of Co_(9)S_(8)@Co(OH)_(2) and enhanced interfacial activities as well as facilitated reaction kinetics of electrodes.The optimal Mn doped Co_(9)S_(8)@Co(OH)_(2) electrode exhibits an ultrahigh specific capacitance of 3745 F g^(-1) at 1 A g^(-1)(5.618 F cm^(-2) at 1.5 mA cm^(-2))and sustains 1710 F g^(-1) at 30 A g^(-1)(2.565 F cm^(-2) at 45 mA cm^(-2)),surpassing most reported values on TMSs.Moreover,a battery-type asymmetric supercapacitor(ASC)device is constructed,which delivers high energy density of 50.2 Wh kg^(-1) at power density of 800 W kg^(-1),and outstanding long-term cycling stability(94%capacitance retention after 8000 cycles).The encouraging results might offer an effective strategy to optimize the TMSs for energy-storage devices.展开更多
Rapid freezing and vitrification are becoming popular for human sperm cryopreservation;however, it remains unclear which method is better. The aims of the present study were to determine the optimal trehalose concentr...Rapid freezing and vitrification are becoming popular for human sperm cryopreservation;however, it remains unclear which method is better. The aims of the present study were to determine the optimal trehalose concentration and to compare the cryoprotective effects of rapid freezing and vitrification. The results showed that: 1) The optimal trehalose concentration was 0.25 mol/L;2) The post-thaw recovery rates of total and progressive sperm motilities after rapid freezing (38.6% ± 3.0% and 41.1% ± 5.0%) were significantly higher (P 0.05) than that after vitrification (26.1% ± 3.1% and 27.2% ± 1.3%) when 0.5 mL straws were used;3) However, the recovery rates of total and progressive motilities after rapid freezing in 0.5 mL straw (26.7% ± 9.6% and 26.8% ± 8.7%) were significantly lower (P 0.05) than that after vitrification in a novel straw-in-straw system (43.1% ± 4.2% and 41.8% ± 15.5%);and 4) The post-thaw sperm nuclear DNA damage level after rapid freezing in 0.5 mL straw (8.7% ± 2.8%) was not significantly different from that of sperm after vitrification in the straw-in-straw system (9.2% ± 2.5%). It was concluded that rapid freezing is superior to vitrification when using 0.5 mL straws;however, vitrification is superior to rapid freezing when using the straw-in-straw systems.展开更多
The graphene-based microsupercapacitors(MSCs)suffer from graphene aggregation issue in electrodes.It reduces the electrolyte ions transportation in the electrodes to degrade the charge storage ability of MSCs,hamperin...The graphene-based microsupercapacitors(MSCs)suffer from graphene aggregation issue in electrodes.It reduces the electrolyte ions transportation in the electrodes to degrade the charge storage ability of MSCs,hampering their practical application.Increasing the electrolyte ions transportation in the electrodes can boost the charge storage ability of MSCs.Herein,we design and experimentally realize pillar array structure of graphene electrodes for MSCs by direct ink writing technology.The graphene electrodes with pillar array structure increase the contact area with electrolyte and short the electrolyte ions transport path,facilitating electrolyte ions transport in electrodes.The MSCs exhibit high areal capacitance of 25.67 mF·cm^(−2),high areal energy density of 20.54μWh·cm^(−2),and high power density of 1.45 mW·cm^(−2).One single MSCs can power timer for 10 min and pressure sensor more than 160 min,showing high practical application possibility.This work provides a new avenue for developing high performance MSCs.展开更多
Amidst the inefficiencies of traditional job-seeking approaches in the recruitment ecosystem, the importance of automated job recommendation systems has been magnified. However, existing models optimized to maximize u...Amidst the inefficiencies of traditional job-seeking approaches in the recruitment ecosystem, the importance of automated job recommendation systems has been magnified. However, existing models optimized to maximize user clicks for general product recommendations prove inept in addressing the unique challenges of job recommendation, namely reciprocity and competition. Moreover, sparse data on online recruitment platforms can further negatively impact the performance of existing job recommendation algorithms. To counteract these limitations, we propose a bilateral heterogeneous graph-based competition iteration model. This model comprises three integral components: 1) two bilateral heterogeneous graphs for capturing multi-source information from people and jobs and alleviating data sparsity, 2) fusion strategies for synthesizing attributes and preferences to produce mutually beneficial job matches, and 3) a competition-enhancing strategy for dispersing competition realized through a two-stage optimization algorithm. Augmented by granular attention mechanisms for enhanced interpretability, the model’s efficacy, competition dispersion, and interpretability are validated through rigorous empirical evaluations on a real-world recruitment platform.展开更多
With the aid of different types of mechanoreceptors,human is capable of perceiving stimuli from surrounding environments and manipulating various objects dexterously.In this paper,a bio-inspired tactile fingertip is d...With the aid of different types of mechanoreceptors,human is capable of perceiving stimuli from surrounding environments and manipulating various objects dexterously.In this paper,a bio-inspired tactile fingertip is designed mimicking human fingertip in both structures and functionalities.Two pairs of strain gages and(Polyvinylidene Fluoride)PVDF films are perpendicularly arranged to simulate the Fast-Adapting(FA)and Slowly Adapting(SA)type mechanoreceptors in human hands,while silicones,Polymethyl Methacrylate(PMMA),and electronic wires are applied to mimic the skin,bone and nerve fibers.Both static and dynamic forces can be perceived sensitively.A preprocessing electric circuit is further designed to transform the resistor changes into voltages,and then filter and amplify the four-channel signals.In addition to strong robustness due to the embedded structure,the developed fingertip is found sensitive to deformations via a force test experiment.Finally,two robotic experiments explore its recognition ability of contact status and object surface.Excellent performance is found with high accuracy of 99.72%achieved in discriminating six surfaces that are ubiquitous in daily life,which demonstrates the effectiveness of our designed tactile sensor.展开更多
Regulating flow direction of photo-excited electrons from interior to active sites in surface is critical to enhance the photocatalytic performance. Herein, photoinduced chemical reduction process was utilized to pinp...Regulating flow direction of photo-excited electrons from interior to active sites in surface is critical to enhance the photocatalytic performance. Herein, photoinduced chemical reduction process was utilized to pinpoint deposit CdS and NiS nanodots sequentially onto g-C_(3)N_(4)nanosheets. The resulted hybrid composite NiS/CdS/g-C_(3)N_(4)was much more active under visible light, and eventually boosted the hydrogen evolution rate of 3015 μmol g^(-1)h^(-1), to be 2.4 folds better than that of g-C_(3)N_(4). Because of the relative low content of CdS(around 3.0 wt%), the enhanced activity is due to the favoring band overlapping and promoting charge separation rather than increasing light absorption. Femto-second time-resolved transient absorption spectroscopy(fs-TAS) clearly reveals that the photo-excited electrons are from g-C_(3)N_(4),and then migrate unidirectionally to CdS and finally to NiS, which is caused by the precisely regulate the position of CdS and NiS on g-C_(3)N_(4)surface. This study elucidates the electron transfer kinetics and processes in multi-component system and affords a new avenue to construct stable photocatalysts with high activity.展开更多
Autonomous vehicles(AVs)are a promising emerging technology that is likely to be widely deployed in the near future.People's perception on AV safety is critical to the pace and success of deploying the AV technolo...Autonomous vehicles(AVs)are a promising emerging technology that is likely to be widely deployed in the near future.People's perception on AV safety is critical to the pace and success of deploying the AV technology.Existing studies found that people's perceptions on emerging technologies might change as additional information was provided.To investigate this phenomenon in the AV technology context,this paper conducted real-world AV experiments and collected factors that may associate with people's initial opinions without any AV riding experience and opinion change after a successful AV ride.A number of ordered probit and binary probit models considering data heterogeneity were employed to estimate the impact of these factors on people's initial opinions and opinion change.The study found that people's initial opinions toward AV safety are significantly associated with people's age,personal income,monthly fuel cost,education experience,and previous AV experience.Further,the factors dominating people's opinion change after a successful AV ride include people's age,personal income,monthly fuel cost,daily commute time,driving alone indicator,willingness to pay for AV technology,and previous AV experience.These results provide important references for future implementations of the AV technology.Additionally,based on the inconsistent effects for variables across different models,suggestions for future transportation survey designs are provided.展开更多
High-granularity vehicle trajectory data can help researchers develop traffic simulation models,understand traffic flow characteristics,and thus propose insightful strategies for road traffic management.This paper pro...High-granularity vehicle trajectory data can help researchers develop traffic simulation models,understand traffic flow characteristics,and thus propose insightful strategies for road traffic management.This paper proposes a novel vehicle trajectory extraction method that can extract high-granularity vehicle trajectories from aerial videos.The proposed method includes video calibration,vehicle detection and tracking,lane marking identification,and vehicle motion characteristics calculation.In particular,the authors propose a Monte-Carlo-based lane marking identification approach to identify each vehicle's lane.This is a challenging problem for vehicle trajectory extraction,especially when the aerial videos are taken from a high altitude.The authors applied the proposed method to extract vehicle trajectories from several high-resolution aerial videos recorded from helicopters.The extracted dataset is named by the High-Granularity Highway Simulation(HIGH-SIM)vehicle trajectory dataset.To demonstrate the effectiveness of the proposed method and understand the quality of the HIGHSIM dataset,we compared the HIGH-SIM dataset with a well-known dataset,the NGSIM US-101 dataset,regarding the accuracy and consistency aspects.The comparison results showed that the HIGH-SIM dataset has more reasonable speed and acceleration distributions than the NGSIM US-101 dataset.Also,the internal and platoon consistencies of the HIGH-SIM dataset give lower errors compared to the NGSIM US-101 dataset.To benefit future research,the authors have published the HIGH-SIM dataset online for public use.展开更多
基金the National Natural Science Foundation of China program(No.81574067).
文摘Objective:The aim of this study was to investigate the mechanism of acupotomology(Apo)in the prevention of articular cartilage destruction via the promotion of chondrocyte proliferation and chondrocyte expression of cell cycle regulators,CyclinD1,CDK4 and CDK6 in a rabbit knee osteoarthritis(KOA)model.Methods:Twenty-eight rabbits were randomly divided into a control group,an OA(osteoarthritis)model group,an Apo(acupotomology)group and EA(electro-acupuncture)group(n Z 7).Improved Videman’s method was used to induce a rabbit model of KOA over 6 weeks.One week later,acupotomy and electro-acupuncture therapy was applied to animals in the respective groups and treatment lasted 4 weeks.Following these treatments,quantitative real-time PCR,immunohistochemical staining and western blotting were performed to assess the mRNA and protein levels of cell cycle regulators CyclinD1(Cell cycle protein D1),CDK4(Cyclin-dependent kinase 4)and CDK6(Cyclin-dependent kinase 6).Ethology measures and knee morphology were also compared among groups.Results:The Lequesne MG index score of morphology was increased(P<.01),and the passive range of motion(PROM)and the mRNA and protein levels of CyclinD1,CDK4,and CDK6 were significantly decreased(P<.01)in the OA model compared with the control group.The Lequesne MG index score and the morphology score were decreased in the Apo and EA group compared with the OA model group(P<.05 or P<.01),while the mRNA levels of CyclinD1,CDK4,and CDK6,and the protein levels of CDK4 were increased in the Apo and EA groups compared with the OA model group(P<.05 or P<.01).The PROM,and the protein levels of CyclinD1 and CDK6 were increased(P<.05)in the Apo group compared with the OA model group,while the PROM and the protein levels of CyclinD1 and CDK6 in the EA group were not significantly different(P>.05).Compared with the EA group,the morphology score was decreased in Apo group(P<.05).Conclusions:The mRNA levels of CyclinD1 and CDK4,and the protein level of CDK4 in chondrocytes are regulate by both Apo and EA.Apo is more effective than EA in regulating the protein levels of CyclinD1 and CDK6.According to the observed changes in morphology and cytokine levels,acupotomy can promote chondrocyte proliferation and can alleviate the destruction of articular cartilage in a model of KOA.
文摘Limited information exists about the effects of antioxidants on sperm motility and DNA integrity during vitrification in humans. This study compared the effects of reduced glutathione (GSH) and monothioglycerol (MTG) at different concentrations on post-thaw sperm motility and DNA integrity after vitrification in humans using 0.25 M trehalose as a cryoprotective agent, and found that supplementation of MTG or GSH at 0.5 mM resulted in significantly higher (P < 0.05) recovery rates of post-thaw total and progressive motilities. GSH was more powerful than MTG at the same concentration in cryoprotecting sperm motility (38.9% ± 3.6% vs 32.8% ± 2.4% compared to the control 26.8% ± 2.1% in recovery rate of progressive motility), but both had no significant influence on sperm DNA integrity during vitrification. It was concluded that sperm motility is more sensitive to oxidative stress during vitrification than sperm nuclear DNA, and supplementation of MTG or GSH in vitrification medium is beneficial in cryoprotecting sperm motility.
基金funding from the National Natural Science Foundation of China(Grant Nos.81573926 and 81173235).
文摘Objective:Panax notoginseng saponins (PNS),extracted from rhizome of the herb Radix et Rhizoma Notoginseng (Panax notoginseng (Burk.) F.H.Chen),was recently discovered to have beneficial effects against neurological damage.This study investigated the effects of PNS on cerebral ischemia and elucidated the molecular mechanisms underlying these effects.Methods:Middle cerebral artery occlusion rats were treated with PNS (3.6 mg/100 g or 7.2 mg/100 g per day) for 7 days,the gene of LINGO-1 was measured and the expression of protein synaptophysin,postsynaptic density protein 95,LINGO-1 and p-EGFR/p-PI3K/p-AKT were investigated.The weight and mNSS score of Sprague-Dawley rats in each group were recorded every day during the 7 days.Results:PNS promoted middle cerebral artery occlusion rats' weight and the recovery of neural function.PNS significantly decreased ischemia-induced LINGO-1 protein expression.PNS also elevated EGFR/PI3K/AKT phosphorylation levels.Conclusion:PNS promoted cerebral recovery from ischemic injury by accelerating synapse reconstruction and inhibiting the neuron growth negative regulatory protein LINGO-1 and activating the epidermal growth factor receptor (EGFR)/PI3K/AKT signaling pathway in vivo.
基金financial support from Natural Science Foundation of Zhejiang Province(LY21B030005)National Natural Science Foundation of China(51702287).
文摘Transition metal sulfides(TMSs)have been regarded as greatly promising electrode materials for supercapacitors because of abundant redox electroactive sites and outstanding conductivity.Herein,we report a self-supported hierarchical Mn doped Co_(9)S_(8)@Co(OH)_(2) nanosheet arrays on nickel foam(NF)substrate by a one-step metal–organic-framework(MOF)engaged approach and a subsequent sulfurization process.Experimental results reveal that the introduction of manganese endows improved electric conductivity,enlarged electrochemical specific surface area,adjusted electronic structure of Co_(9)S_(8)@Co(OH)_(2) and enhanced interfacial activities as well as facilitated reaction kinetics of electrodes.The optimal Mn doped Co_(9)S_(8)@Co(OH)_(2) electrode exhibits an ultrahigh specific capacitance of 3745 F g^(-1) at 1 A g^(-1)(5.618 F cm^(-2) at 1.5 mA cm^(-2))and sustains 1710 F g^(-1) at 30 A g^(-1)(2.565 F cm^(-2) at 45 mA cm^(-2)),surpassing most reported values on TMSs.Moreover,a battery-type asymmetric supercapacitor(ASC)device is constructed,which delivers high energy density of 50.2 Wh kg^(-1) at power density of 800 W kg^(-1),and outstanding long-term cycling stability(94%capacitance retention after 8000 cycles).The encouraging results might offer an effective strategy to optimize the TMSs for energy-storage devices.
文摘Rapid freezing and vitrification are becoming popular for human sperm cryopreservation;however, it remains unclear which method is better. The aims of the present study were to determine the optimal trehalose concentration and to compare the cryoprotective effects of rapid freezing and vitrification. The results showed that: 1) The optimal trehalose concentration was 0.25 mol/L;2) The post-thaw recovery rates of total and progressive sperm motilities after rapid freezing (38.6% ± 3.0% and 41.1% ± 5.0%) were significantly higher (P 0.05) than that after vitrification (26.1% ± 3.1% and 27.2% ± 1.3%) when 0.5 mL straws were used;3) However, the recovery rates of total and progressive motilities after rapid freezing in 0.5 mL straw (26.7% ± 9.6% and 26.8% ± 8.7%) were significantly lower (P 0.05) than that after vitrification in a novel straw-in-straw system (43.1% ± 4.2% and 41.8% ± 15.5%);and 4) The post-thaw sperm nuclear DNA damage level after rapid freezing in 0.5 mL straw (8.7% ± 2.8%) was not significantly different from that of sperm after vitrification in the straw-in-straw system (9.2% ± 2.5%). It was concluded that rapid freezing is superior to vitrification when using 0.5 mL straws;however, vitrification is superior to rapid freezing when using the straw-in-straw systems.
基金financially supported by the National Natural Science Foundation of China(No.52072297)Key R&D Plan of Shaanxi Province(No.2021GXLH-Z-068)Young Talent Support Plan of Xi’an Jiaotong University.
文摘The graphene-based microsupercapacitors(MSCs)suffer from graphene aggregation issue in electrodes.It reduces the electrolyte ions transportation in the electrodes to degrade the charge storage ability of MSCs,hampering their practical application.Increasing the electrolyte ions transportation in the electrodes can boost the charge storage ability of MSCs.Herein,we design and experimentally realize pillar array structure of graphene electrodes for MSCs by direct ink writing technology.The graphene electrodes with pillar array structure increase the contact area with electrolyte and short the electrolyte ions transport path,facilitating electrolyte ions transport in electrodes.The MSCs exhibit high areal capacitance of 25.67 mF·cm^(−2),high areal energy density of 20.54μWh·cm^(−2),and high power density of 1.45 mW·cm^(−2).One single MSCs can power timer for 10 min and pressure sensor more than 160 min,showing high practical application possibility.This work provides a new avenue for developing high performance MSCs.
基金supported by the National Natural Science Foundation of China(Grant No.72172070).
文摘Amidst the inefficiencies of traditional job-seeking approaches in the recruitment ecosystem, the importance of automated job recommendation systems has been magnified. However, existing models optimized to maximize user clicks for general product recommendations prove inept in addressing the unique challenges of job recommendation, namely reciprocity and competition. Moreover, sparse data on online recruitment platforms can further negatively impact the performance of existing job recommendation algorithms. To counteract these limitations, we propose a bilateral heterogeneous graph-based competition iteration model. This model comprises three integral components: 1) two bilateral heterogeneous graphs for capturing multi-source information from people and jobs and alleviating data sparsity, 2) fusion strategies for synthesizing attributes and preferences to produce mutually beneficial job matches, and 3) a competition-enhancing strategy for dispersing competition realized through a two-stage optimization algorithm. Augmented by granular attention mechanisms for enhanced interpretability, the model’s efficacy, competition dispersion, and interpretability are validated through rigorous empirical evaluations on a real-world recruitment platform.
基金funded by National Natural Science Foundation of China under Grant No.52205009Natural Science Foundation of Jiangsu Province under Grant No.BK20210233Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems.
文摘With the aid of different types of mechanoreceptors,human is capable of perceiving stimuli from surrounding environments and manipulating various objects dexterously.In this paper,a bio-inspired tactile fingertip is designed mimicking human fingertip in both structures and functionalities.Two pairs of strain gages and(Polyvinylidene Fluoride)PVDF films are perpendicularly arranged to simulate the Fast-Adapting(FA)and Slowly Adapting(SA)type mechanoreceptors in human hands,while silicones,Polymethyl Methacrylate(PMMA),and electronic wires are applied to mimic the skin,bone and nerve fibers.Both static and dynamic forces can be perceived sensitively.A preprocessing electric circuit is further designed to transform the resistor changes into voltages,and then filter and amplify the four-channel signals.In addition to strong robustness due to the embedded structure,the developed fingertip is found sensitive to deformations via a force test experiment.Finally,two robotic experiments explore its recognition ability of contact status and object surface.Excellent performance is found with high accuracy of 99.72%achieved in discriminating six surfaces that are ubiquitous in daily life,which demonstrates the effectiveness of our designed tactile sensor.
基金supported by the National Natural Science Foundation of China (No. 21902143)。
文摘Regulating flow direction of photo-excited electrons from interior to active sites in surface is critical to enhance the photocatalytic performance. Herein, photoinduced chemical reduction process was utilized to pinpoint deposit CdS and NiS nanodots sequentially onto g-C_(3)N_(4)nanosheets. The resulted hybrid composite NiS/CdS/g-C_(3)N_(4)was much more active under visible light, and eventually boosted the hydrogen evolution rate of 3015 μmol g^(-1)h^(-1), to be 2.4 folds better than that of g-C_(3)N_(4). Because of the relative low content of CdS(around 3.0 wt%), the enhanced activity is due to the favoring band overlapping and promoting charge separation rather than increasing light absorption. Femto-second time-resolved transient absorption spectroscopy(fs-TAS) clearly reveals that the photo-excited electrons are from g-C_(3)N_(4),and then migrate unidirectionally to CdS and finally to NiS, which is caused by the precisely regulate the position of CdS and NiS on g-C_(3)N_(4)surface. This study elucidates the electron transfer kinetics and processes in multi-component system and affords a new avenue to construct stable photocatalysts with high activity.
基金sponsored by Susan A.Bracken Faculty Fellowship and National Science Foundation Grants CMMI#1558887 and#1932452.
文摘Autonomous vehicles(AVs)are a promising emerging technology that is likely to be widely deployed in the near future.People's perception on AV safety is critical to the pace and success of deploying the AV technology.Existing studies found that people's perceptions on emerging technologies might change as additional information was provided.To investigate this phenomenon in the AV technology context,this paper conducted real-world AV experiments and collected factors that may associate with people's initial opinions without any AV riding experience and opinion change after a successful AV ride.A number of ordered probit and binary probit models considering data heterogeneity were employed to estimate the impact of these factors on people's initial opinions and opinion change.The study found that people's initial opinions toward AV safety are significantly associated with people's age,personal income,monthly fuel cost,education experience,and previous AV experience.Further,the factors dominating people's opinion change after a successful AV ride include people's age,personal income,monthly fuel cost,daily commute time,driving alone indicator,willingness to pay for AV technology,and previous AV experience.These results provide important references for future implementations of the AV technology.Additionally,based on the inconsistent effects for variables across different models,suggestions for future transportation survey designs are provided.
基金supported in part by the United States National Science Foundation Grant#1932452 and Federal Highway Administration Grant#DTFH6116D00030.
文摘High-granularity vehicle trajectory data can help researchers develop traffic simulation models,understand traffic flow characteristics,and thus propose insightful strategies for road traffic management.This paper proposes a novel vehicle trajectory extraction method that can extract high-granularity vehicle trajectories from aerial videos.The proposed method includes video calibration,vehicle detection and tracking,lane marking identification,and vehicle motion characteristics calculation.In particular,the authors propose a Monte-Carlo-based lane marking identification approach to identify each vehicle's lane.This is a challenging problem for vehicle trajectory extraction,especially when the aerial videos are taken from a high altitude.The authors applied the proposed method to extract vehicle trajectories from several high-resolution aerial videos recorded from helicopters.The extracted dataset is named by the High-Granularity Highway Simulation(HIGH-SIM)vehicle trajectory dataset.To demonstrate the effectiveness of the proposed method and understand the quality of the HIGHSIM dataset,we compared the HIGH-SIM dataset with a well-known dataset,the NGSIM US-101 dataset,regarding the accuracy and consistency aspects.The comparison results showed that the HIGH-SIM dataset has more reasonable speed and acceleration distributions than the NGSIM US-101 dataset.Also,the internal and platoon consistencies of the HIGH-SIM dataset give lower errors compared to the NGSIM US-101 dataset.To benefit future research,the authors have published the HIGH-SIM dataset online for public use.