This paper studies the evolutionary process of cooperative behavior in a public goods game model with heterogeneous investment strategies in square lattices.In the proposed model,players are divided into defectors,coo...This paper studies the evolutionary process of cooperative behavior in a public goods game model with heterogeneous investment strategies in square lattices.In the proposed model,players are divided into defectors,cooperators and discreet investors.Among these,defectors do not participate in investing,discreet investors make heterogeneous investments based on the investment behavior and cooperation value of their neighbors,and cooperators invest equally in each neighbor.In real life,heterogeneous investment is often accompanied by time or economic costs.The discreet investors in this paper pay a certain price to obtain their neighbors'investment behavior and cooperation value,which quantifies the time and economic costs of the heterogeneous investment process.The results of Monte Carlo simulation experiments in this study show that discreet investors can effectively resist the invasion of the defectors,form a stable cooperative group and expand the cooperative advantage in evolution.However,when discreet investors pay too high a price,they lose their strategic advantage.The results in this paper help us understand the role of heterogeneous investment in promoting and maintaining human social cooperation.展开更多
BACKGROUND Currently,pediatric surgeons are challenged by a lack of consensus on the optimal management strategy(conservative or surgical)for children with Bell’s stage II necrotizing enterocolitis(NEC).AIM To evalua...BACKGROUND Currently,pediatric surgeons are challenged by a lack of consensus on the optimal management strategy(conservative or surgical)for children with Bell’s stage II necrotizing enterocolitis(NEC).AIM To evaluate the clinical efficacy of peritoneal drainage in very-low-birth-weight(VLBW)neonates with modified Bell’s stage II NEC.METHODS This was a retrospective analysis of 102 NEC(modified Bell’s stage II)neonates born with VLBW who were treated at the Fujian Children’s Hospital(Fujian Branch of Shanghai Children’s Medical Center)between January 2017 and January 2020;these included 24 cases in the peritoneal drainage group,36 cases in the exploratory laparotomy group,and 42 cases in the conservative treatment group.RESULTS The general characteristics were comparable in the three groups(P>0.05).Compared with conservative treatment,peritoneal drainage was associated with significantly shorter fasting time,abdominal distension relief time,fecal occult blood(OB)negative conversion time,and reduced hospital length of stay(HLOS)(P<0.05 for all).Despite some advantages of peritoneal drainage over conservative treatment in terms of cure,conversion to laparotomy,intestinal perforation,intestinal stenosis,and abdominal abscess rates,the differences were not statistically significant(P>0.05).Compared to exploratory laparotomy,the fecal OB negative conversion time was significantly shorter in the peritoneal drainage group(P<0.05);similarly,the exploratory laparotomy group showed longer fasting time,abdominal distension relief time,HLOS,and higher complication rate compared to peritoneal drainage group,but the between-group differences were not statistically significant(P>0.05).CONCLUSION Peritoneal drainage,an easy-to-operate procedure,can improve the clinical symptoms of VLBW neonates with Bell’s stage II NEC and help reduce the HLOS.展开更多
Autophagy is a conserved intracellular degradation system that plays a dual role in cell death;thus,therapies targeting autophagy in cancer are somewhat controversial.Ferroptosis is a new form of regulated cell death ...Autophagy is a conserved intracellular degradation system that plays a dual role in cell death;thus,therapies targeting autophagy in cancer are somewhat controversial.Ferroptosis is a new form of regulated cell death featured with the iron-dependent accumulation of lethal lipid ROS.This pathway is morphologically,biochemically and genetically distinct from other forms of cell death.Accumulating studies have revealed crosstalk between autophagy and ferroptosis at the molecular level.In this review,we summarize the mechanisms of ferroptosis and autophagy,and more importantly,their roles in the drug resistance of cancer.Numerous connections between ferroptosis and autophagy have been revealed,and a strong causal relationship exists wherein one process controls the other and can be utilized as potential therapeutic targets for cancer.The elucidation of when and how to modulate their crosstalk using therapeutic strategies depends on an understanding of the fine-tuned switch between ferroptosis and autophagy,and approaches designed to manipulate the intensity of autophagy might be the key.展开更多
We hypothesized that RNA interference to silence Nogo-66 receptor gene expression in bone marrow mesenchymal stem cells before transplantation might further improve neurological function in rats with spinal cord trans...We hypothesized that RNA interference to silence Nogo-66 receptor gene expression in bone marrow mesenchymal stem cells before transplantation might further improve neurological function in rats with spinal cord transection injury. After 2 weeks, the number of neurons and BrdU-positive cells in the Nogo-66 receptor gene silencing group was higher than in the bone marrow mesenchymal stem cell group, and significantly greater compared with the model group. After 4 weeks, behavioral performance was signiifcantly enhanced in the model group. Af-ter 8 weeks, the number of horseradish peroxidase-labeled nerve ifbers was higher in the Nogo-66 receptor gene silencing group than in the bone marrow mesenchymal stem cell group, and signiifcantly higher than in the model group. The newly formed nerve ifbers and myelinated ner ve ifbers were detectable in the central transverse plane section in the bone marrow mesenchymal stem cell group and in the Nogo-66 receptor gene silencing group.展开更多
A group of Cu(Zr)-based bulk metallic glasses (BMGs) with critical diameter (De) in the 12 to 18 mm range have been obtained using copper mould casting. In the Cu-Zr-Y-Al quaternary system, a new record of Dc=14...A group of Cu(Zr)-based bulk metallic glasses (BMGs) with critical diameter (De) in the 12 to 18 mm range have been obtained using copper mould casting. In the Cu-Zr-Y-Al quaternary system, a new record of Dc=14 mm was established for Cu-based compositions, and 16 mm for compositions based on equi-atomic CuZr. Additional partial substitution of Hf for Zr further elevated the Dc to 18 mm at Cu42Zr43Hf1.5Y3.5Al10.展开更多
Alzheimer's disease(AD) is the most common form of dementia in elderly with major symptoms of a general term for memory loss and other intellectual abilities impairment which are serious enough to interfere with d...Alzheimer's disease(AD) is the most common form of dementia in elderly with major symptoms of a general term for memory loss and other intellectual abilities impairment which are serious enough to interfere with daily life.While there is no treatment can prevent and revise the cognitive function impairment in AD,physical activity becomes a potential beneficia intervention for AD.Multiple evidences suggested that exercise in general plays beneficia roles in improving brain function.Most common mechanisms of exercise-induced enhancement of brain function are including alteration of neurogenesis,neuron plasticity,neuronal signaling and receptors,as well as neuronal networks.This mini review includes most recent clinical studies and focuses on the effects of physical exercise,cognitive stimulation,and combination of both physical and cognitive training on protection and rescue cognitive decline in people with AD.展开更多
The fully developed turbulence can be regarded as a nonlinear system,with wave coupling inside,which causes the nonlinear energy to transfer,and drives the turbulence to develop further or be suppressed.Spectral analy...The fully developed turbulence can be regarded as a nonlinear system,with wave coupling inside,which causes the nonlinear energy to transfer,and drives the turbulence to develop further or be suppressed.Spectral analysis is one of the most effective methods to study turbulence system.In order to apply it to the study of the nonlinear wave coupling process of edge plasma turbulence,an efficient algorithm based on spectral analysis technology is proposed to solve the nonlinear wave coupling equation.The algorithm is based on a mandatory temporal static condition with the nonideal spectra separated from the ideal spectra.The realization idea and programing flow are given.According to the characteristics of plasma turbulence,the simulation data are constructed and used to verify the algorithm and its implementation program.The simulation results and experimental results show the accuracy of the algorithm and the corresponding program,which can play a great role in the studying the energy transfer in edge plasma turbulences.As an application,the energy cascade analysis of typical edge plasma turbulence is carried out by using the results of a case calculation.Consequently,a physical picture of the energy transfer in a kind of fully developed turbulence is constructed,which confirms that the energy transfer in this turbulent system develops from lower-frequency region to higher-frequency region and from linear growing wave to damping wave.展开更多
Since microspeakers are widely used in mobile phones,high power is usually applied to obtain sufficient output sound pressure.However,the electric power is almost converted into heat,leading to the thermal problem in ...Since microspeakers are widely used in mobile phones,high power is usually applied to obtain sufficient output sound pressure.However,the electric power is almost converted into heat,leading to the thermal problem in microspeakers.Compared with large loudspeaker,microspeakers are smaller and the under yoke is relatively closed,causing the heat transfer more complex.In this study,a three-stage nonlinear thermal model was proposed for analyzing the thermal behavior in microspeakers.The inside air is a buffer area between the voice coil and magnet,and modeled as a middle stage of the heat transfer.The forced convection is still significant in microspeakers while the eddy current can be ignored.In order to obtain the thermal parameters of the model,a corresponding parameter identification method was put forward.The basic linear parameters and forced convection parameters were all obtained by measuring and fitting the temperature curves of voice coil at different single tones.A series of experiments were conducted to verify the proposed model and parameter identification method,and the results showed good aggrement between the measured and predicted temperature curves for different input signals.The proposed model was valid and accurate,and may be helpful for the design and application of microspeakers.展开更多
Background: Previous studies suggested that supplementation of lactating sows with β-hydroxy-β-methylbutyrate(HMB) could improve the performance of weaning pigs, but there were little information in the muscle fi...Background: Previous studies suggested that supplementation of lactating sows with β-hydroxy-β-methylbutyrate(HMB) could improve the performance of weaning pigs, but there were little information in the muscle fiber type transformation of the offspring and the subsequent performance in pigs from weaning through finishing in response to maternal HMB consumption. The purpose of this study was to determine the effect of supplementing lactating sows with HMB on skeletal muscle fiber type transformation and growth of the offspring during d 28 and180 after birth. A total of 20 sows according to their body weight were divided into the control(CON, n = 10) or HMB groups(HMB, n = 10). Sows in the HMB group were supplemented with β-hydroxy-β-methylbutyrate calcium(HMB-Ca) 2 g/kg feed during d 1 to 27 of lactation. After weaning, 48 mixed sex piglets were blocked by sow treatment and fed standard diets for post-weaning, growing, finishing periods. Growth performance was recorded during d 28 to 180 after birth. Pigs were slaughtered on d 28(n = 6/treatment) and 180(n = 6/treatment) postnatal and the longissimus dorsi(LD) was collected, respectively.Results: The HMB-fed sows during lactation showed increased HMB concentration(P &lt; 0.05) in milk and LD of weaning piglets(P &lt; 0.05). In addition, offsprings in HMB group had a higher finishing BW and lean percentage than did pigs in CON group(P &lt; 0.05), meanwhile, compared with pigs from sows fed the CON diet, pigs from sows fed HMB diet showed higher type Ⅱ muscle fiber cross-sectional area(CSA), elevated myosin heavy chain(MyHC) Ⅱb and Sox6 mRNA, and fast-MyHC protein levels in LD(P &lt; 0.05).Conclusions: HMB supplemented to sow diets throughout lactation increases the levels of HMB in maternal milk and skeletal muscle of pigs during d 28 after birth and promotes subsequent performance of pigs between d 28 and 180 of age by enhancing glycolytic muscle fiber transformation.展开更多
Based on relativistic wave functions from multiconfiguration Dirac-Hartree-Fock and configuration interaction cal- culations, E2 and M1 transition probabilities of 2p3 4S3/2-2p3 2D3/2,5/2 are investigated in the nitro...Based on relativistic wave functions from multiconfiguration Dirac-Hartree-Fock and configuration interaction cal- culations, E2 and M1 transition probabilities of 2p3 4S3/2-2p3 2D3/2,5/2 are investigated in the nitrogen-like sequence with 7 〈 Z 〈 16. The contributions of the electron correlations, Breit interaction, and the quantum electrodynamic (QED) effects on the transition properties are analyzed. The present results can be used for diagnosing plasma. In addition, several N-like ions can also be recommended as a promising candidate for a highly charged ion (HCI) clock with a quality factor (Q) of trnnsition as hitch as 1020.展开更多
Based on the multiconfiguration Dirac-Hartree-Fock(MCDHF)method,similar models are employed to simultaneously calculate the first-order and second-order Zeeman coefficients as well as the hyperfine interaction constan...Based on the multiconfiguration Dirac-Hartree-Fock(MCDHF)method,similar models are employed to simultaneously calculate the first-order and second-order Zeeman coefficients as well as the hyperfine interaction constants of the related energy levels of ^(27)Al^(+)and its logical ions ^(9)Be^(+)and^(25)Mg^(+)in the^(27)Al^(+)optical clock.With less than 0.34%deviations from experimental values in Zeeman coefficients of^(27)Al^(+),these calculated parameters will be of great help for better evaluation of the systematic uncertainty.We also calculate the isotope shift parameters of the related energy levels,which could extend our knowledge and understanding of nuclear properties of these ions.展开更多
A lot of work has focused on compensating nonlinear distortions ofthe microspeaker under large excitation, yet it is unclear at which levelthe effect of nonlinear distortion is imperceptible or not annoying. Inthis st...A lot of work has focused on compensating nonlinear distortions ofthe microspeaker under large excitation, yet it is unclear at which levelthe effect of nonlinear distortion is imperceptible or not annoying. Inthis study virtual listening tests were performed to evaluate thedeterioration of sound quality in music signals with different levels ofnonlinear distortion by a microspeaker. Binaural recordings of themusic played by the microspeaker were made at different voltagelevels, adjusted to the same RMS power, and afterwards reproducedby a low distortion reference headphone. The “double-blind triple-stimuluswith hidden reference” method was used in the listening tests. Listenerswere required to not only discern the distortion, but also rank theseverity of the distortion. The effects of several factors includingsubject, program material and distortion level on the perceiveddistortion are discussed.展开更多
The development of cost-effective electrocatalysts with high efficiency and long durability for hydrogen evolution reaction(HER)remains a great challenge in the field of water splitting.Herein,we design an ultrafine a...The development of cost-effective electrocatalysts with high efficiency and long durability for hydrogen evolution reaction(HER)remains a great challenge in the field of water splitting.Herein,we design an ultrafine and highly dispersed Ru nanoparticles stabilized on porous V_(8)C_(7)/C matrix via pyrolysis of the metal-organic frameworks V-BDC(BDC:1,4-benzenedicarboxylate).The obtained Ru-V_(8)C_(7)/C composite exhibits excellent HER performance in all p H ranges.At the overpotential of 40 mV,its mass activity is about 1.9,4.1 and 9.4 times higher than that of commercial Pt/C in acidic,neutral and alkaline media,respectively.Meanwhile,Ru-V_(8)C_(7)/C shows the remarkably high stability in all p H ranges which,in particular,can maintain the current density of 10 m A cm^(-2)for over 150 h in 1.0 mol L^(-1)phosphate buffer saline(PBS).This outstanding HER performance can be attributed to the high intrinsic activity of Ru species and their strong interface interactions to the V_(8)C_(7)/C substrate.The synergistic effect of abundant active sites on the surface and the formed Ru-C-V units at the interface promotes the adsorption of reaction intermediates and the release of active sites,contributing the fast HER kinetics.This work provides a reference for developing versatile and robust HER catalysts by surface and interface regulation for pH tolerance.展开更多
The 3D location and dipole orientation of light emitters provide essential information in many biological,chemical,and physical systems.Simultaneous acquisition of both information types typically requires pupil engin...The 3D location and dipole orientation of light emitters provide essential information in many biological,chemical,and physical systems.Simultaneous acquisition of both information types typically requires pupil engineering for 3D localization and dual-channel polarization splitting for orientation deduction.Here we report a geometric phase helical point spread function for simultaneously estimating the 3D position and dipole orientation of point emitters.It has a compact and simpler optical configuration compared to polarization-splitting techniques and yields achromatic phase modulation in contrast to pupil engineering based on dynamic phase,showing great potential for single-molecule orientation and localization microscopy.展开更多
Sensors with a small footprint and real-time detection capabilities are crucial in robotic surgery and smart wearable equipment.Reducing device footprint while maintaining its high performance is a major challenge and...Sensors with a small footprint and real-time detection capabilities are crucial in robotic surgery and smart wearable equipment.Reducing device footprint while maintaining its high performance is a major challenge and a significant limitation to their development.Here,we proposed a monolithic integrated micro-scale sensor,which can be used for vector force detection.This sensor combines an optical source,four photodetectors,and a hemispherical silicone elastomer component on the same sapphire-based AlGaInP wafer.The chip-scale optical coupling is achieved by employing the laser lift-off techniques and the flip-chip bonding to a processed sapphire substrate.This hemispherical structure device can detect normal and shear forces as low as 1mN within a measurement range of 0–220 mN for normal force and 0–15 mN for shear force.After packaging,the sensor is capable of detecting forces over a broader range,with measurement capabilities extending up to 10 N for normal forces and 0.2 N for shear forces.It has an accuracy of detecting a minimum normal force of 25 mN and a minimum shear force of 20 mN.Furthermore,this sensor has been validated to have a compact footprint of approximately 1.5 mm^(2),while maintaining high real-time response.We also demonstrate its promising potential by combining this sensor with fine surface texture perception in the fields of compact medical robot interaction and wearable devices.展开更多
Diterpenoid alkaloids(DAs) have been often utilized in clinical practice due to their analgesic and anti-infammatory properties. Natural DAs are prevalent in the family Ranunculaceae, notably in the Aconitum genus. Ne...Diterpenoid alkaloids(DAs) have been often utilized in clinical practice due to their analgesic and anti-infammatory properties. Natural DAs are prevalent in the family Ranunculaceae, notably in the Aconitum genus. Nevertheless, the evolutionary origin of the biosynthesis pathway responsible for DA production remains unknown.In this study, we successfully assembled a highquality, pseudochromosome-level genome of the DA-rich species Aconitum vilmorinianum(A.vilmorinianum)(5.76 Gb). An A. vilmorinianumspecific whole-genome duplication event was discovered using comparative genomic analysis,which may aid in the evolution of the DA biosynthesis pathway. We identified several genes involved in DA biosynthesis via integrated genomic, transcriptomic, and metabolomic analyses. These genes included enzymes encoding target ent-kaurene oxidases and aminotransferases, which facilitated the activation of diterpenes and insertion of nitrogen atoms into diterpene skeletons, thereby mediating the transformation of diterpenes into DAs. The divergence periods of these genes in A. vilmorinianum were further assessed, and it was shown that two major types of genes were involved in the establishment of the DA biosynthesis pathway. Our integrated analysis offers fresh insights into the evolutionary origin of DAs in A.vilmorinianum as well as suggestions for engineering the biosynthetic pathways to obtain desired DAs.展开更多
基金Project supported by the Open Foundation of Key Laboratory of Software Engineering of Yunnan Province(Grant Nos.2020SE308 and 2020SE309).
文摘This paper studies the evolutionary process of cooperative behavior in a public goods game model with heterogeneous investment strategies in square lattices.In the proposed model,players are divided into defectors,cooperators and discreet investors.Among these,defectors do not participate in investing,discreet investors make heterogeneous investments based on the investment behavior and cooperation value of their neighbors,and cooperators invest equally in each neighbor.In real life,heterogeneous investment is often accompanied by time or economic costs.The discreet investors in this paper pay a certain price to obtain their neighbors'investment behavior and cooperation value,which quantifies the time and economic costs of the heterogeneous investment process.The results of Monte Carlo simulation experiments in this study show that discreet investors can effectively resist the invasion of the defectors,form a stable cooperative group and expand the cooperative advantage in evolution.However,when discreet investors pay too high a price,they lose their strategic advantage.The results in this paper help us understand the role of heterogeneous investment in promoting and maintaining human social cooperation.
文摘BACKGROUND Currently,pediatric surgeons are challenged by a lack of consensus on the optimal management strategy(conservative or surgical)for children with Bell’s stage II necrotizing enterocolitis(NEC).AIM To evaluate the clinical efficacy of peritoneal drainage in very-low-birth-weight(VLBW)neonates with modified Bell’s stage II NEC.METHODS This was a retrospective analysis of 102 NEC(modified Bell’s stage II)neonates born with VLBW who were treated at the Fujian Children’s Hospital(Fujian Branch of Shanghai Children’s Medical Center)between January 2017 and January 2020;these included 24 cases in the peritoneal drainage group,36 cases in the exploratory laparotomy group,and 42 cases in the conservative treatment group.RESULTS The general characteristics were comparable in the three groups(P>0.05).Compared with conservative treatment,peritoneal drainage was associated with significantly shorter fasting time,abdominal distension relief time,fecal occult blood(OB)negative conversion time,and reduced hospital length of stay(HLOS)(P<0.05 for all).Despite some advantages of peritoneal drainage over conservative treatment in terms of cure,conversion to laparotomy,intestinal perforation,intestinal stenosis,and abdominal abscess rates,the differences were not statistically significant(P>0.05).Compared to exploratory laparotomy,the fecal OB negative conversion time was significantly shorter in the peritoneal drainage group(P<0.05);similarly,the exploratory laparotomy group showed longer fasting time,abdominal distension relief time,HLOS,and higher complication rate compared to peritoneal drainage group,but the between-group differences were not statistically significant(P>0.05).CONCLUSION Peritoneal drainage,an easy-to-operate procedure,can improve the clinical symptoms of VLBW neonates with Bell’s stage II NEC and help reduce the HLOS.
基金supported by the National Natural Science Foundation of China (Grant No. 81602471, 81672729, 81672729, 81874380 and 81672932)Zhejiang Provincial Natural Science Foundation of China under Grants (Grant No. LY19H160055, LY19H160059)+5 种基金by Zheng Shu Medical Elite Scholarship Fundby grant from sub-project of China National Program on Key Basic Research Project (973 Program) (Grant No. 2014CB744505)Zhejiang Provincial Natural Science Foundation of China for Distinguished Young Scholars (Grant No. LR18H160001)Zhejiang Province Medical Science and Technology Project (Grant No. 2017RC007)Talent Project of Zhejiang Association for Science and Technology (Grant No. 2017YCGC002)Zhejiang Province Science and Technology Project of TCM (Grant No. 2019ZZ016)
文摘Autophagy is a conserved intracellular degradation system that plays a dual role in cell death;thus,therapies targeting autophagy in cancer are somewhat controversial.Ferroptosis is a new form of regulated cell death featured with the iron-dependent accumulation of lethal lipid ROS.This pathway is morphologically,biochemically and genetically distinct from other forms of cell death.Accumulating studies have revealed crosstalk between autophagy and ferroptosis at the molecular level.In this review,we summarize the mechanisms of ferroptosis and autophagy,and more importantly,their roles in the drug resistance of cancer.Numerous connections between ferroptosis and autophagy have been revealed,and a strong causal relationship exists wherein one process controls the other and can be utilized as potential therapeutic targets for cancer.The elucidation of when and how to modulate their crosstalk using therapeutic strategies depends on an understanding of the fine-tuned switch between ferroptosis and autophagy,and approaches designed to manipulate the intensity of autophagy might be the key.
文摘We hypothesized that RNA interference to silence Nogo-66 receptor gene expression in bone marrow mesenchymal stem cells before transplantation might further improve neurological function in rats with spinal cord transection injury. After 2 weeks, the number of neurons and BrdU-positive cells in the Nogo-66 receptor gene silencing group was higher than in the bone marrow mesenchymal stem cell group, and significantly greater compared with the model group. After 4 weeks, behavioral performance was signiifcantly enhanced in the model group. Af-ter 8 weeks, the number of horseradish peroxidase-labeled nerve ifbers was higher in the Nogo-66 receptor gene silencing group than in the bone marrow mesenchymal stem cell group, and signiifcantly higher than in the model group. The newly formed nerve ifbers and myelinated ner ve ifbers were detectable in the central transverse plane section in the bone marrow mesenchymal stem cell group and in the Nogo-66 receptor gene silencing group.
基金supported by the National Natural Science Foundation of China under Grants Nos.50671105 and 50621091.
文摘A group of Cu(Zr)-based bulk metallic glasses (BMGs) with critical diameter (De) in the 12 to 18 mm range have been obtained using copper mould casting. In the Cu-Zr-Y-Al quaternary system, a new record of Dc=14 mm was established for Cu-based compositions, and 16 mm for compositions based on equi-atomic CuZr. Additional partial substitution of Hf for Zr further elevated the Dc to 18 mm at Cu42Zr43Hf1.5Y3.5Al10.
文摘Alzheimer's disease(AD) is the most common form of dementia in elderly with major symptoms of a general term for memory loss and other intellectual abilities impairment which are serious enough to interfere with daily life.While there is no treatment can prevent and revise the cognitive function impairment in AD,physical activity becomes a potential beneficia intervention for AD.Multiple evidences suggested that exercise in general plays beneficia roles in improving brain function.Most common mechanisms of exercise-induced enhancement of brain function are including alteration of neurogenesis,neuron plasticity,neuronal signaling and receptors,as well as neuronal networks.This mini review includes most recent clinical studies and focuses on the effects of physical exercise,cognitive stimulation,and combination of both physical and cognitive training on protection and rescue cognitive decline in people with AD.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFE0301200)the National Natural Science Foundation of China(Grant Nos.12075077 and 12175055)the Science and Technology Project of Sichuan Pprovince,China(Grant No.2020YJ0464)。
文摘The fully developed turbulence can be regarded as a nonlinear system,with wave coupling inside,which causes the nonlinear energy to transfer,and drives the turbulence to develop further or be suppressed.Spectral analysis is one of the most effective methods to study turbulence system.In order to apply it to the study of the nonlinear wave coupling process of edge plasma turbulence,an efficient algorithm based on spectral analysis technology is proposed to solve the nonlinear wave coupling equation.The algorithm is based on a mandatory temporal static condition with the nonideal spectra separated from the ideal spectra.The realization idea and programing flow are given.According to the characteristics of plasma turbulence,the simulation data are constructed and used to verify the algorithm and its implementation program.The simulation results and experimental results show the accuracy of the algorithm and the corresponding program,which can play a great role in the studying the energy transfer in edge plasma turbulences.As an application,the energy cascade analysis of typical edge plasma turbulence is carried out by using the results of a case calculation.Consequently,a physical picture of the energy transfer in a kind of fully developed turbulence is constructed,which confirms that the energy transfer in this turbulent system develops from lower-frequency region to higher-frequency region and from linear growing wave to damping wave.
基金The National Natural Science Foundation of China(Grant No.11274172)supported this work.
文摘Since microspeakers are widely used in mobile phones,high power is usually applied to obtain sufficient output sound pressure.However,the electric power is almost converted into heat,leading to the thermal problem in microspeakers.Compared with large loudspeaker,microspeakers are smaller and the under yoke is relatively closed,causing the heat transfer more complex.In this study,a three-stage nonlinear thermal model was proposed for analyzing the thermal behavior in microspeakers.The inside air is a buffer area between the voice coil and magnet,and modeled as a middle stage of the heat transfer.The forced convection is still significant in microspeakers while the eddy current can be ignored.In order to obtain the thermal parameters of the model,a corresponding parameter identification method was put forward.The basic linear parameters and forced convection parameters were all obtained by measuring and fitting the temperature curves of voice coil at different single tones.A series of experiments were conducted to verify the proposed model and parameter identification method,and the results showed good aggrement between the measured and predicted temperature curves for different input signals.The proposed model was valid and accurate,and may be helpful for the design and application of microspeakers.
基金supported by the National Special Research Fund for Non-Profit Sector(Agriculture)(No.201203015)Academy of Kechuang Feed Industry in Sichuan(2013NZ0056)+1 种基金Research Team of Youth Scientific and Technical Innovation of Sichuan(13CXTD0004)the Program for Changjiang Scholars and Innovative Research Team in University(IRT13083)
文摘Background: Previous studies suggested that supplementation of lactating sows with β-hydroxy-β-methylbutyrate(HMB) could improve the performance of weaning pigs, but there were little information in the muscle fiber type transformation of the offspring and the subsequent performance in pigs from weaning through finishing in response to maternal HMB consumption. The purpose of this study was to determine the effect of supplementing lactating sows with HMB on skeletal muscle fiber type transformation and growth of the offspring during d 28 and180 after birth. A total of 20 sows according to their body weight were divided into the control(CON, n = 10) or HMB groups(HMB, n = 10). Sows in the HMB group were supplemented with β-hydroxy-β-methylbutyrate calcium(HMB-Ca) 2 g/kg feed during d 1 to 27 of lactation. After weaning, 48 mixed sex piglets were blocked by sow treatment and fed standard diets for post-weaning, growing, finishing periods. Growth performance was recorded during d 28 to 180 after birth. Pigs were slaughtered on d 28(n = 6/treatment) and 180(n = 6/treatment) postnatal and the longissimus dorsi(LD) was collected, respectively.Results: The HMB-fed sows during lactation showed increased HMB concentration(P &lt; 0.05) in milk and LD of weaning piglets(P &lt; 0.05). In addition, offsprings in HMB group had a higher finishing BW and lean percentage than did pigs in CON group(P &lt; 0.05), meanwhile, compared with pigs from sows fed the CON diet, pigs from sows fed HMB diet showed higher type Ⅱ muscle fiber cross-sectional area(CSA), elevated myosin heavy chain(MyHC) Ⅱb and Sox6 mRNA, and fast-MyHC protein levels in LD(P &lt; 0.05).Conclusions: HMB supplemented to sow diets throughout lactation increases the levels of HMB in maternal milk and skeletal muscle of pigs during d 28 after birth and promotes subsequent performance of pigs between d 28 and 180 of age by enhancing glycolytic muscle fiber transformation.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11604385 and 91436103)
文摘Based on relativistic wave functions from multiconfiguration Dirac-Hartree-Fock and configuration interaction cal- culations, E2 and M1 transition probabilities of 2p3 4S3/2-2p3 2D3/2,5/2 are investigated in the nitrogen-like sequence with 7 〈 Z 〈 16. The contributions of the electron correlations, Breit interaction, and the quantum electrodynamic (QED) effects on the transition properties are analyzed. The present results can be used for diagnosing plasma. In addition, several N-like ions can also be recommended as a promising candidate for a highly charged ion (HCI) clock with a quality factor (Q) of trnnsition as hitch as 1020.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11604385 and 91536106)the Natural Science Foundation of Hunan Province,China(Grant No.2019JJ50743)the Research Project of the National University of Defense Technology(Grant No.ZK17-03-11)。
文摘Based on the multiconfiguration Dirac-Hartree-Fock(MCDHF)method,similar models are employed to simultaneously calculate the first-order and second-order Zeeman coefficients as well as the hyperfine interaction constants of the related energy levels of ^(27)Al^(+)and its logical ions ^(9)Be^(+)and^(25)Mg^(+)in the^(27)Al^(+)optical clock.With less than 0.34%deviations from experimental values in Zeeman coefficients of^(27)Al^(+),these calculated parameters will be of great help for better evaluation of the systematic uncertainty.We also calculate the isotope shift parameters of the related energy levels,which could extend our knowledge and understanding of nuclear properties of these ions.
文摘A lot of work has focused on compensating nonlinear distortions ofthe microspeaker under large excitation, yet it is unclear at which levelthe effect of nonlinear distortion is imperceptible or not annoying. Inthis study virtual listening tests were performed to evaluate thedeterioration of sound quality in music signals with different levels ofnonlinear distortion by a microspeaker. Binaural recordings of themusic played by the microspeaker were made at different voltagelevels, adjusted to the same RMS power, and afterwards reproducedby a low distortion reference headphone. The “double-blind triple-stimuluswith hidden reference” method was used in the listening tests. Listenerswere required to not only discern the distortion, but also rank theseverity of the distortion. The effects of several factors includingsubject, program material and distortion level on the perceiveddistortion are discussed.
基金supported by the Overseas High-level Talents Plan of China and Guangdong Provincethe 100 Talents Plan Foundation of Sun Yat-sen University+4 种基金the Fundamental Research Funds for the Central Universitiesthe Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2017ZT07C069)the National Natural Science Foundation of China(22075321,21821003,21890380,and 22375223)the Guangdong Basic Research Center of Excellence for Functional Molecular Engineeringthe Natural Science Foundation of Guangdong Province(2021A1515010068)。
文摘The development of cost-effective electrocatalysts with high efficiency and long durability for hydrogen evolution reaction(HER)remains a great challenge in the field of water splitting.Herein,we design an ultrafine and highly dispersed Ru nanoparticles stabilized on porous V_(8)C_(7)/C matrix via pyrolysis of the metal-organic frameworks V-BDC(BDC:1,4-benzenedicarboxylate).The obtained Ru-V_(8)C_(7)/C composite exhibits excellent HER performance in all p H ranges.At the overpotential of 40 mV,its mass activity is about 1.9,4.1 and 9.4 times higher than that of commercial Pt/C in acidic,neutral and alkaline media,respectively.Meanwhile,Ru-V_(8)C_(7)/C shows the remarkably high stability in all p H ranges which,in particular,can maintain the current density of 10 m A cm^(-2)for over 150 h in 1.0 mol L^(-1)phosphate buffer saline(PBS).This outstanding HER performance can be attributed to the high intrinsic activity of Ru species and their strong interface interactions to the V_(8)C_(7)/C substrate.The synergistic effect of abundant active sites on the surface and the formed Ru-C-V units at the interface promotes the adsorption of reaction intermediates and the release of active sites,contributing the fast HER kinetics.This work provides a reference for developing versatile and robust HER catalysts by surface and interface regulation for pH tolerance.
基金supported by the National Natural Science Foundation of China(Nos.62105368,62275268,and 62375284)the Science and Technology Innovation Program of Hunan Province(No.2023RC3010)。
文摘The 3D location and dipole orientation of light emitters provide essential information in many biological,chemical,and physical systems.Simultaneous acquisition of both information types typically requires pupil engineering for 3D localization and dual-channel polarization splitting for orientation deduction.Here we report a geometric phase helical point spread function for simultaneously estimating the 3D position and dipole orientation of point emitters.It has a compact and simpler optical configuration compared to polarization-splitting techniques and yields achromatic phase modulation in contrast to pupil engineering based on dynamic phase,showing great potential for single-molecule orientation and localization microscopy.
基金support from the National Key R&D Program of China under Grant No.2023YFB2806800Fundamental and Applied Fundamental Research Fund of Guangdong Province(2021B1515130001,Z.L.)+4 种基金The Shenzhen Science and Technology Program(JCYJ20220818100603007,Z.L.)National Natural Science Foundation of China(62275117,X.C.)Shenzhen Excellent Youth Program(RCYX20221008092900001,X.C.)Guangdong Major Talent Project(2019QN01C177,X.C.)The Guangdong Major Talent Project(2019CX01×014,T.W.).
文摘Sensors with a small footprint and real-time detection capabilities are crucial in robotic surgery and smart wearable equipment.Reducing device footprint while maintaining its high performance is a major challenge and a significant limitation to their development.Here,we proposed a monolithic integrated micro-scale sensor,which can be used for vector force detection.This sensor combines an optical source,four photodetectors,and a hemispherical silicone elastomer component on the same sapphire-based AlGaInP wafer.The chip-scale optical coupling is achieved by employing the laser lift-off techniques and the flip-chip bonding to a processed sapphire substrate.This hemispherical structure device can detect normal and shear forces as low as 1mN within a measurement range of 0–220 mN for normal force and 0–15 mN for shear force.After packaging,the sensor is capable of detecting forces over a broader range,with measurement capabilities extending up to 10 N for normal forces and 0.2 N for shear forces.It has an accuracy of detecting a minimum normal force of 25 mN and a minimum shear force of 20 mN.Furthermore,this sensor has been validated to have a compact footprint of approximately 1.5 mm^(2),while maintaining high real-time response.We also demonstrate its promising potential by combining this sensor with fine surface texture perception in the fields of compact medical robot interaction and wearable devices.
基金supported by the National Key Plan for Scientific Research and Development of China(2020YFA0509304 and 2021YFA0805300)the Chinese Academy of Sciences(XDB39000000)+3 种基金the National Natural Science Foundation of China(82030034,32121002,and 81971123)CAMS Innovation Fund for Medical Sciences(2021-I2M-C&T-B-012)the Fundamental Research Funds for the Central Universities(YD9110002027)the Guangzhou Key Research Program on Brain Science(202007030008)。
基金supported by funding from the CAS “Pioneer Hundred Talents” Program and Strategic Priority Research Program of the Chinese Academy of Sciences (XDB31000000) to Y.C.National Natural Science Foundation of China (Nos. 31960082, 32270395, and 31960096)Yunnan Fundamental Research Projects (No. 202101AS070021) to D.Z。
文摘Diterpenoid alkaloids(DAs) have been often utilized in clinical practice due to their analgesic and anti-infammatory properties. Natural DAs are prevalent in the family Ranunculaceae, notably in the Aconitum genus. Nevertheless, the evolutionary origin of the biosynthesis pathway responsible for DA production remains unknown.In this study, we successfully assembled a highquality, pseudochromosome-level genome of the DA-rich species Aconitum vilmorinianum(A.vilmorinianum)(5.76 Gb). An A. vilmorinianumspecific whole-genome duplication event was discovered using comparative genomic analysis,which may aid in the evolution of the DA biosynthesis pathway. We identified several genes involved in DA biosynthesis via integrated genomic, transcriptomic, and metabolomic analyses. These genes included enzymes encoding target ent-kaurene oxidases and aminotransferases, which facilitated the activation of diterpenes and insertion of nitrogen atoms into diterpene skeletons, thereby mediating the transformation of diterpenes into DAs. The divergence periods of these genes in A. vilmorinianum were further assessed, and it was shown that two major types of genes were involved in the establishment of the DA biosynthesis pathway. Our integrated analysis offers fresh insights into the evolutionary origin of DAs in A.vilmorinianum as well as suggestions for engineering the biosynthetic pathways to obtain desired DAs.