Triggered spark-gap switch is a popular discharge switch for pulse power systems.Previous studies have focused on planarizing this switch using thin film techniques in order to meet the requirements of compact size in...Triggered spark-gap switch is a popular discharge switch for pulse power systems.Previous studies have focused on planarizing this switch using thin film techniques in order to meet the requirements of compact size in the systems.Such switches are one-shot due to electrodes being too thin to sufficiently resist spark-erosion.Additionally,these switches did not employ any structures in securing internal gas composition,resulting in inconsistent performance under harsh atmospheres.In this work,a novel planar triggered spark-gap switch(PTS)with a hermetically sealed cavity was batched-prepared with printed circuit board(PCB)technology,to achieve reusability with low cost.The proposed PTS was inspected by micro-computed tomography to ensure PCB techniques meet the requirements of machining precision.The results from electrical experiments demonstrated that PCB PTS were consistent and reusable with lifespan over 20 times.The calculated switch voltage and circuit current were consistent with those derived from real-world measurements.Finally,PCB PTS was used to introduce hexanitrostilbene(HNS)pellets in a pulse power system to verify its performance.展开更多
The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,...The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,an integrated EFIs with enhanced energy efficiency was designed.Corresponding exploding foil initiator chips were fabricated in batch via micro electromechanical systems technology by integrating a unified foil,a flyer layer and a barrel on a glass substrate successively,meanwhile its package of the whole system was proposed at a volume of 2.194 cm^(3).The structural parameters were determined by predicted performance including flyer velocity,impact behavior and conduction property via the proposed theoretical models and the static electric field simulation.As expect,this integrated EFIs exhibited excellent functions,which could accelerate the flyer to a terminal velocity over 4 km/s and preeminently initiate HNS-IV pellet at a circuit of 0.24 μF/0.9 kV.Furthermore,the theoretical design,fabrication and performance test have been all included to validate the feasibility of this integrated EFIs that was beneficial for its commercial development in the future.展开更多
肌筋膜疼痛综合征（myofascial pain syndrome,MPS）是临床上的常见病和多发病,国外学者Travell及Simons在《Travell and Simons＇Myof-ascial Pain and Dysfunction–The Trigger Point Manual》一书中对激痛点理论进行了详细描述,代表...肌筋膜疼痛综合征（myofascial pain syndrome,MPS）是临床上的常见病和多发病,国外学者Travell及Simons在《Travell and Simons＇Myof-ascial Pain and Dysfunction–The Trigger Point Manual》一书中对激痛点理论进行了详细描述,代表了MPS的临床诊断和治疗的基础,然而由于很难确定激痛点,临床治疗很难收到满意的疗效。展开更多
In view of DC speed control system, this paper presents a predictive control algorithm to replace traditional PID control. System predictive model requires little information of the controlled object, and because it...In view of DC speed control system, this paper presents a predictive control algorithm to replace traditional PID control. System predictive model requires little information of the controlled object, and because it adopts rolling optimum method, system展开更多
Fuze is the information processing and control unit of the ammunition, so the quality of the fuze becomes one of the most important aspects of ammunition detection. Since using recoil force is a common method to the a...Fuze is the information processing and control unit of the ammunition, so the quality of the fuze becomes one of the most important aspects of ammunition detection. Since using recoil force is a common method to the arm fuze, its dynamic simulation test has always been the focus of the fuze test research. A new fuze recoil environmental simulation method is proposed based on the electromagnetic launcher. Then the trigger control characteristics of the fuze recoil simulation system and the influence of the trigger position on the recoil force are studied. The results of the study show that although the pulse width of the armature force curve can be changed by adjusting the trigger position, due to the limit of the range, there also exists the contradiction that the electromagnetic pulse width gets narrow with the increase of electromagnetic force peak. Thus, it cannot meet the requirements of the fuze launch recoil simulation. In order to make the recoil force close to the actual environment, the multi-stage trigger control characteristics are analyzed, and the influence of trigger position on recoil environmental force characteristics is studied. Then a fuze launch recoil environmental simulation platform is established and continuous electromagnetic force is achieved by using the trigger strategy. Finally, the experiment is performed to simulate the fuze launch recoil environment and show the feasibility and effectiveness of the proposed theoretical analysis. The major research work of this paper includes studying the composition and basic principle of the simulation system, establishing a launch model to analyze the single-stage and multi-stage coil fuze launch recoil characteristics, designing the test device to verify the correctness and validity of the research. This paper draws the conclusions that the feasibility of the fuze launch environmental simulation based on the electromagnetic launcher is verified, the trigger position has a great influence on force peak continuity, the problems of low maximum overload peak and short peak duration in the multi-stage coil fuze launch environmental simulation can be effectively solved through adjusting the trigger position, the system has creative and extensive application prospects.展开更多
Event prediction aims to predict the most possible following event given a chain of closely related context events.Previous methods based on event pairs or the entire event chain may ignore much structural and semanti...Event prediction aims to predict the most possible following event given a chain of closely related context events.Previous methods based on event pairs or the entire event chain may ignore much structural and semantic information.Current datasets for event prediction,naturally,can be used for supervised learning.Event chains are either from document-level procedural action flow,or from news sequences under the same column.This paper leverages graph structure knowledge of event triggers and event segment information for event prediction with general news corpus,and adopts the standard multiple choice narrative cloze task evaluation.The topic model is utilized to extract event chains from the news corpus to deal with training data bottleneck.Based on trigger-guided structural relations in the event chains,we construct trigger evolution graph,and trigger representations are learned through graph convolutional neural network and the novel neighbor selection strategy.Then there are features of two levels for each event,namely,text level semantic feature and trigger level structural feature.We design the attention mechanism to learn the features of event segments derived in term of event major subjects,and integrate relevance between event segments and the candidate event.The most possible next event is picked by the relevance.Experimental results on the real-world news corpus verify the effectiveness of the proposed model.展开更多
Cells actively modulate mechanobiological circuitry against external perturbations to stabilize whole cell/tissue physiology.The dynamic adaption of cells to mechanical force is critical for cells to perform vital bio...Cells actively modulate mechanobiological circuitry against external perturbations to stabilize whole cell/tissue physiology.The dynamic adaption of cells to mechanical force is critical for cells to perform vital biological functions,from single cell migration to embryonic development.Dysregulation of such dynamics has been associated with pathophysiological conditions in cardiovascular diseases,cancer,aging,and developmental disorders[1].Therefore,a direct understanding of cell’s biomechanical adaptive/maladaptive behaviors and the trigger factors causing the transformation of healthy adaption to maladaptation can help reveal the regulatory role of single cell mechanosensitive dynamics in the progression of various degenerative diseases and aging.However,current efforts for uncovering fundamental associations between disease and cell architecture have been focusing on'static'measurements of biophysical properties,which is limited by the requirement of large sample sizes to obtain statistically significant data.We therefore developed a single and highly integrated platform with mechanical stimulation and fine spatiotemporal sensing functions to probe the single cell mechanical dynamics at subcellular level to determine cell’s mechanophenotypes in healthy and disease conditions.We developed an integrated micromechanical system composed of an’ultrasound tweezer’stimulator[2]and a PDMS micropillar array [3] cellular force sensor to in situ noninvasively probe and monitor single cell mechanical dynamics.Vascular smooth muscle cells(VSMCs)from healthy mouse and mouse with induced abdominal aorta aneurysm(AAA)were used for cell mechanobiological study.An ultrasound transducer(V312-SM,Olympus)was used to generate ultrasound pulses to excite lipid-encapsulated microbubbles(Targeson)binding to cell membrane through an RGD-integrin linkage to apply a transient nanonewton force to VSMCs seeded on the PDMS micropillar array.PDMS micropillar array was fabricated and functionalized as previously described [3] and acts as the mechanical force sensor in our platform.Upon a 1 HZ and 10-second ultrasound stimulation,calcium influx was clearly detected in both healthy and AAA-VSMCs by using the fluo-4 calcium sensor,suggesting the microbubble-integrin-actin cytoskeleton(CSK)linkage can serve as a mechanosensory to sense the ultrasound stimulation.We then examined how healthy and AAA VSMCs would exhibit adaptions to mechanical stimulation at a global cellular scale.After the onset of a 10-second ultrasound stimulation,control and AAA-VSMCs displayed distinct dynamics of CSK tension within 30 mins,in which the CSK tension of healthy VSMCs increased within the reinforcement period(0-5 min)and restored to their ground state with the relaxation period(5-10 min);yet AAA-VSMCs displayed compromised dynamics of such CSK tension upon calcium influx.Quantitative analysis and theoretical modelling revealed the critical roles of myosin motor contraction,F-actin filament polymerization in regulating cell mechanosensitive dynamics in response to a transient mechanical perturbation.The distinct force and CSK dynamics in healthy and AAA conditions indicates that the force-dependent CSK molecular kinetics is a critical factor governing the distinct mechanosensitive dynamics of cells under pathologically dysfunctional conditions.Our results reveal that the mechanical adaptive process of cells to mechanical stimulus can measure the cellular mechanobiological phenotypes featured in both pathologically healthy and diseased context.We demonstrated that an altered mechanobiological phenotype,i.e.AAA-VSMCs with distinct actomyosin-CSK properties potentiates a mechanical maladaptation that reflects progressive accumulation of cellular damage and dysfunction.This may further reveal the pathogenic contexts and their physical mediators featuring biophysical dysregulation in cardiovascular diseases.展开更多
OBJECTIVE To investigate the role of triggering receptor expressed on myeloid cells-2(TREM2) in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP) model mice with Parkinson disease(PD) and explore the underlying s...OBJECTIVE To investigate the role of triggering receptor expressed on myeloid cells-2(TREM2) in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP) model mice with Parkinson disease(PD) and explore the underlying signaling pathway that mediate TREM2 function.METHODS TREM2 adenovirus were stereologically injected into the right striatum.Two weeks later,MPTP was intraperitoneally injected to produce the acute MPTP mouse model of PD.Mice were sacrificed at different time points following MPTP for biochemical or histological study.RESULTS Overexpression of TREM2 remarkably reduced MPTP-induced neuropathology including the dopaminergic neurodegeneration and neuroinflammation in vivo.Further study revealed that TREM2 may inhibit neuroinflammation by negatively regulating the TRAF6/TLR4-mediated activation of the MAPK and NF-κB signaling pathways.CONCLUSION TREM2 may have important neuroprotective effects against PD by critical y modulating neuroinflammatory responses.展开更多
为加强中国热带农业科学院（简称中国热科院）草业科学一级学科的建设．应中国热科院品种资源研究所（简称乩资所）、中国热带作物学会牧草与饲料作物专业委员会的邀请，美国弗古尼亚理工大学赵炳宁副教授于6月27日来品资所进行学术交...为加强中国热带农业科学院（简称中国热科院）草业科学一级学科的建设．应中国热科院品种资源研究所（简称乩资所）、中国热带作物学会牧草与饲料作物专业委员会的邀请，美国弗古尼亚理工大学赵炳宁副教授于6月27日来品资所进行学术交流，并作了题为“Acidovorax citrulli type Ⅲ effector Aave-2166 interacts with WRKY 70 to trigger defense responses in host and non—host plants”的学术报告。展开更多
基金We gratefully acknowledge support from the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20151486).
文摘Triggered spark-gap switch is a popular discharge switch for pulse power systems.Previous studies have focused on planarizing this switch using thin film techniques in order to meet the requirements of compact size in the systems.Such switches are one-shot due to electrodes being too thin to sufficiently resist spark-erosion.Additionally,these switches did not employ any structures in securing internal gas composition,resulting in inconsistent performance under harsh atmospheres.In this work,a novel planar triggered spark-gap switch(PTS)with a hermetically sealed cavity was batched-prepared with printed circuit board(PCB)technology,to achieve reusability with low cost.The proposed PTS was inspected by micro-computed tomography to ensure PCB techniques meet the requirements of machining precision.The results from electrical experiments demonstrated that PCB PTS were consistent and reusable with lifespan over 20 times.The calculated switch voltage and circuit current were consistent with those derived from real-world measurements.Finally,PCB PTS was used to introduce hexanitrostilbene(HNS)pellets in a pulse power system to verify its performance.
基金National Natural Science Foundation of China (Grant No.11872013) to provide fund for conducting experiments。
文摘The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,an integrated EFIs with enhanced energy efficiency was designed.Corresponding exploding foil initiator chips were fabricated in batch via micro electromechanical systems technology by integrating a unified foil,a flyer layer and a barrel on a glass substrate successively,meanwhile its package of the whole system was proposed at a volume of 2.194 cm^(3).The structural parameters were determined by predicted performance including flyer velocity,impact behavior and conduction property via the proposed theoretical models and the static electric field simulation.As expect,this integrated EFIs exhibited excellent functions,which could accelerate the flyer to a terminal velocity over 4 km/s and preeminently initiate HNS-IV pellet at a circuit of 0.24 μF/0.9 kV.Furthermore,the theoretical design,fabrication and performance test have been all included to validate the feasibility of this integrated EFIs that was beneficial for its commercial development in the future.
文摘肌筋膜疼痛综合征（myofascial pain syndrome,MPS）是临床上的常见病和多发病,国外学者Travell及Simons在《Travell and Simons＇Myof-ascial Pain and Dysfunction–The Trigger Point Manual》一书中对激痛点理论进行了详细描述,代表了MPS的临床诊断和治疗的基础,然而由于很难确定激痛点,临床治疗很难收到满意的疗效。
文摘In view of DC speed control system, this paper presents a predictive control algorithm to replace traditional PID control. System predictive model requires little information of the controlled object, and because it adopts rolling optimum method, system
文摘Fuze is the information processing and control unit of the ammunition, so the quality of the fuze becomes one of the most important aspects of ammunition detection. Since using recoil force is a common method to the arm fuze, its dynamic simulation test has always been the focus of the fuze test research. A new fuze recoil environmental simulation method is proposed based on the electromagnetic launcher. Then the trigger control characteristics of the fuze recoil simulation system and the influence of the trigger position on the recoil force are studied. The results of the study show that although the pulse width of the armature force curve can be changed by adjusting the trigger position, due to the limit of the range, there also exists the contradiction that the electromagnetic pulse width gets narrow with the increase of electromagnetic force peak. Thus, it cannot meet the requirements of the fuze launch recoil simulation. In order to make the recoil force close to the actual environment, the multi-stage trigger control characteristics are analyzed, and the influence of trigger position on recoil environmental force characteristics is studied. Then a fuze launch recoil environmental simulation platform is established and continuous electromagnetic force is achieved by using the trigger strategy. Finally, the experiment is performed to simulate the fuze launch recoil environment and show the feasibility and effectiveness of the proposed theoretical analysis. The major research work of this paper includes studying the composition and basic principle of the simulation system, establishing a launch model to analyze the single-stage and multi-stage coil fuze launch recoil characteristics, designing the test device to verify the correctness and validity of the research. This paper draws the conclusions that the feasibility of the fuze launch environmental simulation based on the electromagnetic launcher is verified, the trigger position has a great influence on force peak continuity, the problems of low maximum overload peak and short peak duration in the multi-stage coil fuze launch environmental simulation can be effectively solved through adjusting the trigger position, the system has creative and extensive application prospects.
基金supported by the National Natural Science Foundation of China(71731002,71971190).
文摘Event prediction aims to predict the most possible following event given a chain of closely related context events.Previous methods based on event pairs or the entire event chain may ignore much structural and semantic information.Current datasets for event prediction,naturally,can be used for supervised learning.Event chains are either from document-level procedural action flow,or from news sequences under the same column.This paper leverages graph structure knowledge of event triggers and event segment information for event prediction with general news corpus,and adopts the standard multiple choice narrative cloze task evaluation.The topic model is utilized to extract event chains from the news corpus to deal with training data bottleneck.Based on trigger-guided structural relations in the event chains,we construct trigger evolution graph,and trigger representations are learned through graph convolutional neural network and the novel neighbor selection strategy.Then there are features of two levels for each event,namely,text level semantic feature and trigger level structural feature.We design the attention mechanism to learn the features of event segments derived in term of event major subjects,and integrate relevance between event segments and the candidate event.The most possible next event is picked by the relevance.Experimental results on the real-world news corpus verify the effectiveness of the proposed model.
基金the financial support from the American Heart Association ( 16SDG31020038)
文摘Cells actively modulate mechanobiological circuitry against external perturbations to stabilize whole cell/tissue physiology.The dynamic adaption of cells to mechanical force is critical for cells to perform vital biological functions,from single cell migration to embryonic development.Dysregulation of such dynamics has been associated with pathophysiological conditions in cardiovascular diseases,cancer,aging,and developmental disorders[1].Therefore,a direct understanding of cell’s biomechanical adaptive/maladaptive behaviors and the trigger factors causing the transformation of healthy adaption to maladaptation can help reveal the regulatory role of single cell mechanosensitive dynamics in the progression of various degenerative diseases and aging.However,current efforts for uncovering fundamental associations between disease and cell architecture have been focusing on'static'measurements of biophysical properties,which is limited by the requirement of large sample sizes to obtain statistically significant data.We therefore developed a single and highly integrated platform with mechanical stimulation and fine spatiotemporal sensing functions to probe the single cell mechanical dynamics at subcellular level to determine cell’s mechanophenotypes in healthy and disease conditions.We developed an integrated micromechanical system composed of an’ultrasound tweezer’stimulator[2]and a PDMS micropillar array [3] cellular force sensor to in situ noninvasively probe and monitor single cell mechanical dynamics.Vascular smooth muscle cells(VSMCs)from healthy mouse and mouse with induced abdominal aorta aneurysm(AAA)were used for cell mechanobiological study.An ultrasound transducer(V312-SM,Olympus)was used to generate ultrasound pulses to excite lipid-encapsulated microbubbles(Targeson)binding to cell membrane through an RGD-integrin linkage to apply a transient nanonewton force to VSMCs seeded on the PDMS micropillar array.PDMS micropillar array was fabricated and functionalized as previously described [3] and acts as the mechanical force sensor in our platform.Upon a 1 HZ and 10-second ultrasound stimulation,calcium influx was clearly detected in both healthy and AAA-VSMCs by using the fluo-4 calcium sensor,suggesting the microbubble-integrin-actin cytoskeleton(CSK)linkage can serve as a mechanosensory to sense the ultrasound stimulation.We then examined how healthy and AAA VSMCs would exhibit adaptions to mechanical stimulation at a global cellular scale.After the onset of a 10-second ultrasound stimulation,control and AAA-VSMCs displayed distinct dynamics of CSK tension within 30 mins,in which the CSK tension of healthy VSMCs increased within the reinforcement period(0-5 min)and restored to their ground state with the relaxation period(5-10 min);yet AAA-VSMCs displayed compromised dynamics of such CSK tension upon calcium influx.Quantitative analysis and theoretical modelling revealed the critical roles of myosin motor contraction,F-actin filament polymerization in regulating cell mechanosensitive dynamics in response to a transient mechanical perturbation.The distinct force and CSK dynamics in healthy and AAA conditions indicates that the force-dependent CSK molecular kinetics is a critical factor governing the distinct mechanosensitive dynamics of cells under pathologically dysfunctional conditions.Our results reveal that the mechanical adaptive process of cells to mechanical stimulus can measure the cellular mechanobiological phenotypes featured in both pathologically healthy and diseased context.We demonstrated that an altered mechanobiological phenotype,i.e.AAA-VSMCs with distinct actomyosin-CSK properties potentiates a mechanical maladaptation that reflects progressive accumulation of cellular damage and dysfunction.This may further reveal the pathogenic contexts and their physical mediators featuring biophysical dysregulation in cardiovascular diseases.
基金Shandong Province Science and Technology Program (2016GSF201061).
文摘OBJECTIVE To investigate the role of triggering receptor expressed on myeloid cells-2(TREM2) in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP) model mice with Parkinson disease(PD) and explore the underlying signaling pathway that mediate TREM2 function.METHODS TREM2 adenovirus were stereologically injected into the right striatum.Two weeks later,MPTP was intraperitoneally injected to produce the acute MPTP mouse model of PD.Mice were sacrificed at different time points following MPTP for biochemical or histological study.RESULTS Overexpression of TREM2 remarkably reduced MPTP-induced neuropathology including the dopaminergic neurodegeneration and neuroinflammation in vivo.Further study revealed that TREM2 may inhibit neuroinflammation by negatively regulating the TRAF6/TLR4-mediated activation of the MAPK and NF-κB signaling pathways.CONCLUSION TREM2 may have important neuroprotective effects against PD by critical y modulating neuroinflammatory responses.
文摘为加强中国热带农业科学院（简称中国热科院）草业科学一级学科的建设．应中国热科院品种资源研究所（简称乩资所）、中国热带作物学会牧草与饲料作物专业委员会的邀请，美国弗古尼亚理工大学赵炳宁副教授于6月27日来品资所进行学术交流，并作了题为“Acidovorax citrulli type Ⅲ effector Aave-2166 interacts with WRKY 70 to trigger defense responses in host and non—host plants”的学术报告。
