To achieve the manufacturing of Thin-Wall and High-Rib Components(TWHRC)with high precision,a novel heavy load Multi-DOF Envelope Forming Press(MEFP)with Parallel Kinematic Mechanism(PKM),driven by six Permanent Magne...To achieve the manufacturing of Thin-Wall and High-Rib Components(TWHRC)with high precision,a novel heavy load Multi-DOF Envelope Forming Press(MEFP)with Parallel Kinematic Mechanism(PKM),driven by six Permanent Magnet Synchronous Motors(PMSMs),is developed.However,on account of the heavy forming load,the PMSM parameters are in great variation.Meanwhile,the PMSM is always in a transient state caused by fast time-varying forming load,resulting in low identification precision of varied PMSM parameters and control precision of PMSM under traditional parameter identification methods.To solve this problem,a novel Sliding Mode Control Method with Enhanced PMSM Parameter Identification(SMCMEPPI)for heavy load MEFP is proposed.Firstly,the kinematic model of MEFP is established.Secondly,the variation law of PMSM parameters under heavy load is revealed.Thirdly,an enhanced PMSM parameter identification method is proposed,in which the q axis current of PMSM is used to represent the changing rate of forming load and the adjustment factor is first proposed to remove improper input of PMSM parameter identification online.Fourthly,the Electromechanical Coupling Dynamic Model(ECDM)of MEFP,which includes identified PMSM parameters,is developed.Finally,based on the developed ECDM,a novel SMCMEPPI is proposed to realize the high-precision control of heavy load MEFP.The experimental results indicate that the proposed SMCMEPPI can significantly improve the control precision of heavy load MEFP.展开更多
As a class of cis-regulatory elements, enhancers were first identified as the genomic regions that are able to markedly increase the transcription of genes nearly 30 years ago. Enhancers can regulate gene expression i...As a class of cis-regulatory elements, enhancers were first identified as the genomic regions that are able to markedly increase the transcription of genes nearly 30 years ago. Enhancers can regulate gene expression in a cell-type specific and developmental stage specific manner. Although experimental technologies have been developed to identify enhancers genome-wide, the design principle of the regulatory elements and the way they rewire the transcriptional regulatory network tempo-spatially are far from clear. At present, developing predictive methods for enhanc- ers, particularly for the cell-type specific activity of enhancers, is central to computational biology. In this review, we survey the current computational approaches for active enhancer prediction and discuss future directions.展开更多
Introduction:A quadruplex digital polymerase chain reaction(dPCR)method was developed for the simultaneous detection of Salmonella spp.,Shigella spp.,Vibrio cholerae,and V.parahaemolyticus in wastewater to enhance pat...Introduction:A quadruplex digital polymerase chain reaction(dPCR)method was developed for the simultaneous detection of Salmonella spp.,Shigella spp.,Vibrio cholerae,and V.parahaemolyticus in wastewater to enhance pathogen identification velocity and efficiency.This study established detection limits for these bacterial pathogens and validated the method using environmental wastewater samples.Methods:Specific primers and probes were designed targeting the invA gene of Salmonella,ipaH gene of Shigella,tlh gene of V.parahaemolyticus,and cholera toxin gene ctxA of V.cholerae.The quadruplex dPCR assay underwent rigorous evaluation for analytical sensitivity and specificity.Detection limits were determined using spiked wastewater samples,and the method’s effectiveness was assessed through preliminary testing of 60 environmental wastewater samples.Results:The quadruplex dPCR assay was optimized at an annealing temperature of 58°C.In spiked wastewater samples,the detection limits were 390 CFU/100 mL for Salmonella,11 CFU/100 mL for Shigella,660 CFU/100 mL for V.cholerae,and 640 CFU/100 mL for V.parahaemolyticus.Analysis of 60 municipal wastewater samples revealed pathogen concentrations ranging from 100.9–14,560 copies/100 mL for Shigella,86.5–7,329 copies/100 mL for Salmonella,and 84.5–865.7 copies/100 mL for V.parahaemolyticus.Conclusions:The developed quadruplex dPCR assay demonstrates robust capability for comprehensive surveillance of intestinal bacterial pathogens in wastewater,offering reliable detection even at low concentrations.展开更多
基金the National Science and Technology Major Project of China(No.2019-Ⅶ-0017-0158)the National Natural Science Foundation of China(Nos.U2037204,U21A20131)the Innovative Research Team Development Program of Ministry of Education of China(No.IRT17R83)for the support given to this research。
文摘To achieve the manufacturing of Thin-Wall and High-Rib Components(TWHRC)with high precision,a novel heavy load Multi-DOF Envelope Forming Press(MEFP)with Parallel Kinematic Mechanism(PKM),driven by six Permanent Magnet Synchronous Motors(PMSMs),is developed.However,on account of the heavy forming load,the PMSM parameters are in great variation.Meanwhile,the PMSM is always in a transient state caused by fast time-varying forming load,resulting in low identification precision of varied PMSM parameters and control precision of PMSM under traditional parameter identification methods.To solve this problem,a novel Sliding Mode Control Method with Enhanced PMSM Parameter Identification(SMCMEPPI)for heavy load MEFP is proposed.Firstly,the kinematic model of MEFP is established.Secondly,the variation law of PMSM parameters under heavy load is revealed.Thirdly,an enhanced PMSM parameter identification method is proposed,in which the q axis current of PMSM is used to represent the changing rate of forming load and the adjustment factor is first proposed to remove improper input of PMSM parameter identification online.Fourthly,the Electromechanical Coupling Dynamic Model(ECDM)of MEFP,which includes identified PMSM parameters,is developed.Finally,based on the developed ECDM,a novel SMCMEPPI is proposed to realize the high-precision control of heavy load MEFP.The experimental results indicate that the proposed SMCMEPPI can significantly improve the control precision of heavy load MEFP.
基金supported by grants from the National Natural Science Foundation of China(NSFC, Grant No. 31271398 and 91131012)100 Talents Project to ZZ, NSFC(Grant No.91019016)National Basic Research Program of China(NBRPC, Grant No. 2012CB316503) to MQZ
文摘As a class of cis-regulatory elements, enhancers were first identified as the genomic regions that are able to markedly increase the transcription of genes nearly 30 years ago. Enhancers can regulate gene expression in a cell-type specific and developmental stage specific manner. Although experimental technologies have been developed to identify enhancers genome-wide, the design principle of the regulatory elements and the way they rewire the transcriptional regulatory network tempo-spatially are far from clear. At present, developing predictive methods for enhanc- ers, particularly for the cell-type specific activity of enhancers, is central to computational biology. In this review, we survey the current computational approaches for active enhancer prediction and discuss future directions.
基金Supported by the National Key Research and Development Program(2022YFC3201704-01)from the Ministry of Science and Technology of the People’s Republic of Chinathe Key Project of the Capital’s Funds for Health Improvement and Research,China(2022-1G-4231).
文摘Introduction:A quadruplex digital polymerase chain reaction(dPCR)method was developed for the simultaneous detection of Salmonella spp.,Shigella spp.,Vibrio cholerae,and V.parahaemolyticus in wastewater to enhance pathogen identification velocity and efficiency.This study established detection limits for these bacterial pathogens and validated the method using environmental wastewater samples.Methods:Specific primers and probes were designed targeting the invA gene of Salmonella,ipaH gene of Shigella,tlh gene of V.parahaemolyticus,and cholera toxin gene ctxA of V.cholerae.The quadruplex dPCR assay underwent rigorous evaluation for analytical sensitivity and specificity.Detection limits were determined using spiked wastewater samples,and the method’s effectiveness was assessed through preliminary testing of 60 environmental wastewater samples.Results:The quadruplex dPCR assay was optimized at an annealing temperature of 58°C.In spiked wastewater samples,the detection limits were 390 CFU/100 mL for Salmonella,11 CFU/100 mL for Shigella,660 CFU/100 mL for V.cholerae,and 640 CFU/100 mL for V.parahaemolyticus.Analysis of 60 municipal wastewater samples revealed pathogen concentrations ranging from 100.9–14,560 copies/100 mL for Shigella,86.5–7,329 copies/100 mL for Salmonella,and 84.5–865.7 copies/100 mL for V.parahaemolyticus.Conclusions:The developed quadruplex dPCR assay demonstrates robust capability for comprehensive surveillance of intestinal bacterial pathogens in wastewater,offering reliable detection even at low concentrations.
