Although the five-degree-of-freedom magnetic levitation system composed of two conical bearingless switched reluctance motors(CBSRMs)owns the simplest structure,the torque and levitation forces are coupled greatly.The...Although the five-degree-of-freedom magnetic levitation system composed of two conical bearingless switched reluctance motors(CBSRMs)owns the simplest structure,the torque and levitation forces are coupled greatly.Therefore,it is difficult to make the rotor rotate and be fully levitated simultaneously.To solve this problem,two different role division control strategies are proposed in this paper,i.e.individual role division and mutual role division control strategies.The difference between them is the selection of motor which controls the torque or the axial force.In order to understand the characteristics of control variables,the principle and mathematical model of CBSRM are introduced.After that,two control strategies are explained in detail.To verify the demonstrated performance,the simulations are completed with MATLAB/Simulink.展开更多
A digital photographic study of pool boiling with binary mixture Rll(CC13)-Rll3(CCl3CF3) was performed on a horizontal transparent heater at pressure of 0.1MPa. A high speed digital camera was applied to record th...A digital photographic study of pool boiling with binary mixture Rll(CC13)-Rll3(CCl3CF3) was performed on a horizontal transparent heater at pressure of 0.1MPa. A high speed digital camera was applied to record the bubble behaviors in boiling process. Strong effects of composition on bubble departure diameter, deparatre time, nucleation density were observed, which was attributed to the nature of the activation of the boiling surface and mass diffusion effects. The bubble departure diameter, departure period and nucleation density as functions of composition for binary mixtures R 11-R 113 were presented respectively. From the video images, it can be concluded that evaporation of microlayer is very important to the growth of bubble. It is also observed that there is not any liquid recruited into the microlayer below the bubble.展开更多
Dual-point composition control for a high-purity ideal heat integrated distillation column (HIDiC) is addressed in this work. Three measures are suggested and combined for overcoming process inherent nonlinearities:(1...Dual-point composition control for a high-purity ideal heat integrated distillation column (HIDiC) is addressed in this work. Three measures are suggested and combined for overcoming process inherent nonlinearities:(1) variable scaling; (2) multi-model representation of process dynamics and (3) feedforward compensation. These strategies can offer the developed control systems with several distinct advantages: (1) capability of dealing with severe disturbances; (2) tight tuning of controller parameters and (3) high robustness with respect to variation of operating conditions. Simulation results demonstrate the effectiveness of the proposed methodology.展开更多
Abstract--The time-optimal control design of the double integrator is extended to the finite-time stabilization design that compensates both input saturation and input delay. With the aid of the Artstein's transforma...Abstract--The time-optimal control design of the double integrator is extended to the finite-time stabilization design that compensates both input saturation and input delay. With the aid of the Artstein's transformation, the problem is reduced to assigning a saturated finite-time stabilizer. Index Terms--Finite-time stabilization, input delay, saturated design.展开更多
We study the attack vulnerability of network with duplication-divergence mechanism. Numerical results have shown that the duplication-divergence network with larger retention probability a is more robust against targe...We study the attack vulnerability of network with duplication-divergence mechanism. Numerical results have shown that the duplication-divergence network with larger retention probability a is more robust against target attack relatively. Furthermore, duplication-divergence network is broken down more quickly than its counterpart BA network under target attack. Such result is consistent with the fact of WWW and Internet networks under target attack. So duplication-divergence model is a more realistic one for us to investigate the characteristics of the world wide web in future. We also observe that the exponent γ of degree distribution and average degree are important parameters of networks, reflecting the performance of networks under target attack. Our results are helpful to the research on the security of network.展开更多
In the present paper, we introduce the notion of slant submanifolds of an almost hyperbolic contact metric manifolds. We have obtained some results on slant submanifolds of an almost hyperbolic contact metric manifold...In the present paper, we introduce the notion of slant submanifolds of an almost hyperbolic contact metric manifolds. We have obtained some results on slant submanifolds of an almost hyperbolic contact metric manifolds. We have given a necessary and sufficient condition for a slant submanifold of an almost hyperbolic contact metric manifolds.展开更多
We present a family of the solutions of two-component Bose-Einstein condensates with time-dependentscattering length by means of multiple-scale method.Our numerical calculations show that the collision properties (the...We present a family of the solutions of two-component Bose-Einstein condensates with time-dependentscattering length by means of multiple-scale method.Our numerical calculations show that the collision properties (theposition,the time,and the frequency of the collision) between two solitons can be controlled by the time-dependentinterspecies scattering length.Meanwhile,we also find that the amplitude of the solitons is close related to the timedependentinterspecies scattering length.展开更多
Safety-critical applications such as the independently driving systems of electric vehicle (EV) require a high degree of reliability. The controller area network (CAN) is used extensively in the control sectors. A...Safety-critical applications such as the independently driving systems of electric vehicle (EV) require a high degree of reliability. The controller area network (CAN) is used extensively in the control sectors. A new real-time and reliable scheduling algorithm based on time-triggered scheduler with a focus on the CAN-based distributed control systems for independently driving EV is exploited. A distributed control network model for a dual-wheel independendy driving EV is established. The timing and reliabili- ty analysis in the worst case with the algorithm is used to evaluate the predictability and dependability and the simulation based on the algorithm with CANoe software is designed. The results indicate the algorithm is more predicable and dependable.展开更多
Diallel cross analysis among seven diverse pure lines of maize, (IK8, IK58, ZP-707, OH40, UN44052, DKI7 and HS) with their nonreciprocal 21 crosses, were carried out for estimating the nature and magnitude of gene e...Diallel cross analysis among seven diverse pure lines of maize, (IK8, IK58, ZP-707, OH40, UN44052, DKI7 and HS) with their nonreciprocal 21 crosses, were carried out for estimating the nature and magnitude of gene effects through component and graphic analysis for characters: number of days to tasseling, number of days to silking, plant height, ear height, number of rows per ear, number of grains per row, 300 grain weight and grain yield per plant. The results showed highly significant mean square of genotypes for all studied characters. Additive and dominance variances were found to be significant from zero for all the eight characters except number of days to tasseling and silking for which additive genetic variance was no significant. Dominance variance estimation was relatively higher than the additive variance for all characters. The graphic analysis suggested the presence of epistatic gene effects (non-allelic interaction) for number of days to tasseling, number of days to silking, plant height, number of grains per row and grain yield per plant. The estimates of narrow sense heritability varied from 1.85% for 300 grain weight to 49.88% for ear height, it was moderate in case of ear height and low for the remainder characters.展开更多
Based on planar Si dual-base transistor conception, a novel mesa dual-base heterojunc- tion bipolar transistor ( HBT) is designed and fabricated. Molecule beam extension. selective wet chemical etching, common contact...Based on planar Si dual-base transistor conception, a novel mesa dual-base heterojunc- tion bipolar transistor ( HBT) is designed and fabricated. Molecule beam extension. selective wet chemical etching, common contact photolithography and metal lift-off technique are adopted in the process. The device has particular and distinct voltage-controlled negative differential resistance (NDR) and photo-controlled NDR. The highest peak-to-vally current rate of the voltage-controlled NDR is larger than 148 and the peak current varies with the increase of collector voltage. The device features high speed and high frequency characteristics derived from HBT and intrinsic bistability and self-latching characteristics due to NDR. A single dual-base HBT can be seen as an integration of NDR device, HBT and photoconductive device. Compared with common HBT.the groove is the key factor producing NDR.展开更多
The DC microgrid is connected to the AC utility by parallel bidirectional power converters (BPCs) to import/export large power, whose control directly affects the performance of the grid-connected DC microgrid. Much...The DC microgrid is connected to the AC utility by parallel bidirectional power converters (BPCs) to import/export large power, whose control directly affects the performance of the grid-connected DC microgrid. Much work has focused on the hierarchical control of the DC, AC, and hybrid microgrids, but little has considered the hierarchical control of multiple parallel BPCs that directly connect the DC microgrid to the AC utility. In this paper, we propose a hierarchical control for parallel BPCs of a grid-connected DC mierogrid. To suppress the potential zero-sequence circulating cm-cent in the AC side among the parallel BPCs and realize feedback linearization of the voltage control, a d-q-O control scheme instead of a conventional d-q control scheme is proposed in the inner current loop, and the square of the DC voltage is adopted in the inner voltage loop. DC side droop control is applied to realize DC current sharing among multiple BPCs at the primary control level, and this induces DC bus voltage deviation. The quantified relationship between the current sharing error and DC voltage deviation is derived, indicating that there is a trade-off between the DC voltage deviation and current sharing error. To eliminate the current sharing error and DC voltage deviation simultaneously, slope-adjusting and voltage-shifting approaches are adopted at the secondary control level. The pro- posed tertiary control realizes precise active and reactive power exchange through parallel BPCs for economical operation. The proposed hierarchical control is applied for parallel BPCs of a grid-connected DC microgrid and can operate coordinately with the control for controllable/uncontrollable distributional generation. The effectiveness of the proposed control method is verified by corresponding simulation tests based on Matlab/Simulink, and the performance of the hierarchical control is evaluated for prac- tical applications.展开更多
In nature, bacteria must sense copper and tightly regulate gene expression to evade copper toxicity. Here,we identify a new copper-responsive two-component system named DsbRS in the important human pathogen Pseudomona...In nature, bacteria must sense copper and tightly regulate gene expression to evade copper toxicity. Here,we identify a new copper-responsive two-component system named DsbRS in the important human pathogen Pseudomonas aeruginosa;in this system, DsbS is a sensor histidine kinase, and DsbR, its cognate response regulator, directly induces the transcription of genes involved in protein disulfide bond formation(Dsb)(i.e., the dsbDEG operon and dsbB). In the absence of copper, DsbS acts as a phosphatase toward DsbR, thus blocking the transcription of Dsb genes. In the presence of copper, the metal ion directly binds to the sensor domain of DsbS, and the Cys82 residue plays a critical role in this process. The copperbinding behavior appears to inhibit the phosphatase activity of DsbS, leading to the activation of DsbR.The copper resistance of the dsbRS knock-out mutant is restored by the ectopic expression of the dsbDEG operon, which is a DsbRS major target. Strikingly, cognates of the dsbRS-dsbDEG pair are widely distributed across eubacteria. In addition, a DsbR-binding site, which contains the consensus sequence 5’-TTA-N8-TTAA-3’, is detected in the promoter region of dsbDEG homologs in these species. These findings suggest that the regulation of Dsb genes by DsbRS represents a novel mechanism by which bacterial cells cope with copper stress.展开更多
In trauma, infection and hemorrhagic shock derived stress, primary and secondary injury may result in severe derangement in the internal environment. The abnormal changes of immune-mediated inflammation interfere its ...In trauma, infection and hemorrhagic shock derived stress, primary and secondary injury may result in severe derangement in the internal environment. The abnormal changes of immune-mediated inflammation interfere its pathogenesis and development directly. In recent years, various aspects of neuroendocrine responses, especially the regulatory effects of hypothalamic-pituitary-adrenal and sympathetico-adrenomedullary axes in inflammatory diseases have been the focus of research. Most importantly,corticotropin-releasing hormone (CRH) acts as a key player in the regulation of interactions between neuroendocrine and immunity both directly and indirectly. The paper summarized the recent development of CRH in the immune-mediated inflammation.展开更多
Dual-phase high-entropy alloys(DP-HEAs)with excellent strength-ductility combinations have attracted scientific interests.In the present study,the microstructures of AlCrCuFeNi3.0DP-HEA fabricated via selective laser ...Dual-phase high-entropy alloys(DP-HEAs)with excellent strength-ductility combinations have attracted scientific interests.In the present study,the microstructures of AlCrCuFeNi3.0DP-HEA fabricated via selective laser melting(SLM)are rationally adjusted and controlled.The mechanisms engendering the hierarchical microstructures are revealed.It is found that the AlCrCuFeNi3.0fabricated by SLM at the scanning speed of 400 mm s-1falls into the eutectic coupled zone,and increasing the scanning speed will make this composition deviate away from the eutectic coupled zone due to the increased cooling rate.The enrichment of Cr and Fe solutes with large growth restriction values ahead of the solid/liquid interface can develop a constitutional supercooling zone,thus facilitating the heterogeneous nucleation and nearequiaxed grain formation.The synergy of the near-eutectic DP nano-structures and near-equiaxed grains instead of columnar ones effectively suppresses cracking for the as-built DP-HEA.During the tensile deformation,the intergranular back stress hardening similar to the grain-boundary strengthening is discovered.Meanwhile,the near-eutectic microstructures comprised of soft face-centered cubic and hard ordered bodycentered cubic(B2)DP nano-structures lead to plastic strain incompatibility within grains,thus producing the intragranular back stress.The Cr-rich nano-precipitates inside the B2 phase are found to be sheared by dislocation gliding and can complement the back stress.Additionally,multiple strengthening mechanisms are physically evaluated,and the back stress strengthening contributes obviously to the high performances of the as-built DP-HEA.展开更多
The bilevel programming is applied to solve hierarchical intelligence control problems in such fields as industry, agriculture, transportation, military, and so on. This paper presents a quadratic objective penalty fu...The bilevel programming is applied to solve hierarchical intelligence control problems in such fields as industry, agriculture, transportation, military, and so on. This paper presents a quadratic objective penalty function with two penalty parameters for inequality constrained bilevel programming. Under some conditions, the optimal solution to the bilevel programming defined by the quadratic objective penalty function is proved to be an optimal solution to the original bilevel programming. Moreover, based on the quadratic objective penalty function, an algorithm is developed to l^nd an optimal solution to the original bilevel programming, and its convergence proved under some conditions. Furthermore, under the assumption of convexity at function without lower level problems is defined and lower level problems, a quadratic objective penalty is proved equal to the original bilevel programming.展开更多
Voltage-controlled quantum dynamics of two quantum-dot molecules (QDMs) embedded in two separated photonic crystal cavities are theoretically investigated. We show numerically that generation of entangled states and...Voltage-controlled quantum dynamics of two quantum-dot molecules (QDMs) embedded in two separated photonic crystal cavities are theoretically investigated. We show numerically that generation of entangled states and population transfer between the two QDMs can be realized with the same coupling parameters. The effects of parameters deviation and dissipations on generation entangled states be used for realization of new-type of solid state quantum and populations transfer are also discussed. The results may devices and integrated electro-optical devices,展开更多
Metallic nanostructures have underpinned plasmonic-based advanced photonic devices in a broad range of research fields over the last decade including physics, engineering, material science and bioscience, The key to r...Metallic nanostructures have underpinned plasmonic-based advanced photonic devices in a broad range of research fields over the last decade including physics, engineering, material science and bioscience, The key to realizing functional plasmonie resonances that can manipulate light at the optical frequencies relies on the creation of conductive metallic structures at the nanoscale with low structural defects. Currently, most plasmonic nanostructures are fabricated either by electron beam lithography (EBL) or by focused ion beam (FIB) milling, which are expensive, complicated and time-consuming. In comparison, the direct laser writing (DLW) technique has demonstrated its high spatial resolution and cost-effectiveness in three-dimensional fabrication of micro/nanostrucmres. Furthermore, the recent breakthroughs in superresolution nanofabrication and parallel writing have significantly advanced the fabrication resolution and throughput of the DLW method and made it one of the promising future nanofabrication technologies with low-cost and scalability. In this review, we provide a comprehensive summary of the state-of-the-art DLW fabrication technology for nanometer scale metallic structures. The fabrication mechanisms, different material choices, fabrication capability, including resolution, conductivity and structure surface smoothness, as well as the characterization methods and achievable devices for different applications are presented. In particular, the development trends of the field and the perspectives for future opportunities and challenges are provided at the end of the review. It has been demonstrated that the quality of the metallic structures fabricated using the DLW method is excellent compared with other methods providing a new and enabling platform for functional nanophotonic device fabrication.展开更多
基金supported by the National Natural Science Foundations of China (Nos. 51877107,51577087,51477074)
文摘Although the five-degree-of-freedom magnetic levitation system composed of two conical bearingless switched reluctance motors(CBSRMs)owns the simplest structure,the torque and levitation forces are coupled greatly.Therefore,it is difficult to make the rotor rotate and be fully levitated simultaneously.To solve this problem,two different role division control strategies are proposed in this paper,i.e.individual role division and mutual role division control strategies.The difference between them is the selection of motor which controls the torque or the axial force.In order to understand the characteristics of control variables,the principle and mathematical model of CBSRM are introduced.After that,two control strategies are explained in detail.To verify the demonstrated performance,the simulations are completed with MATLAB/Simulink.
基金Supported by the National Natural Science Foundation of China (No.10355001) and the Century Programme of ChineseAcademy of Sciences.
文摘A digital photographic study of pool boiling with binary mixture Rll(CC13)-Rll3(CCl3CF3) was performed on a horizontal transparent heater at pressure of 0.1MPa. A high speed digital camera was applied to record the bubble behaviors in boiling process. Strong effects of composition on bubble departure diameter, deparatre time, nucleation density were observed, which was attributed to the nature of the activation of the boiling surface and mass diffusion effects. The bubble departure diameter, departure period and nucleation density as functions of composition for binary mixtures R 11-R 113 were presented respectively. From the video images, it can be concluded that evaporation of microlayer is very important to the growth of bubble. It is also observed that there is not any liquid recruited into the microlayer below the bubble.
基金Supported by the New-Energy and Industry Technology Development Organization (NEDO) through the Energy Conservation Center of Japan.
文摘Dual-point composition control for a high-purity ideal heat integrated distillation column (HIDiC) is addressed in this work. Three measures are suggested and combined for overcoming process inherent nonlinearities:(1) variable scaling; (2) multi-model representation of process dynamics and (3) feedforward compensation. These strategies can offer the developed control systems with several distinct advantages: (1) capability of dealing with severe disturbances; (2) tight tuning of controller parameters and (3) high robustness with respect to variation of operating conditions. Simulation results demonstrate the effectiveness of the proposed methodology.
基金partially supported by the National Natural Science Foundation of China(61374024,61321003,61325309)the Natural Science Foundation of Hunan Province(14JJ2016)the Teacher Research Foundation of Central South University(2013JSJJ023)
文摘Abstract--The time-optimal control design of the double integrator is extended to the finite-time stabilization design that compensates both input saturation and input delay. With the aid of the Artstein's transformation, the problem is reduced to assigning a saturated finite-time stabilizer. Index Terms--Finite-time stabilization, input delay, saturated design.
基金The project supported by National Natural Science Foundation of China under Grant No. 10375022Acknowledgment We thank Prof. Tang Yi for helpful discussions.
文摘We study the attack vulnerability of network with duplication-divergence mechanism. Numerical results have shown that the duplication-divergence network with larger retention probability a is more robust against target attack relatively. Furthermore, duplication-divergence network is broken down more quickly than its counterpart BA network under target attack. Such result is consistent with the fact of WWW and Internet networks under target attack. So duplication-divergence model is a more realistic one for us to investigate the characteristics of the world wide web in future. We also observe that the exponent γ of degree distribution and average degree are important parameters of networks, reflecting the performance of networks under target attack. Our results are helpful to the research on the security of network.
文摘In the present paper, we introduce the notion of slant submanifolds of an almost hyperbolic contact metric manifolds. We have obtained some results on slant submanifolds of an almost hyperbolic contact metric manifolds. We have given a necessary and sufficient condition for a slant submanifold of an almost hyperbolic contact metric manifolds.
基金Supported by National Natural Science Foundation of China under Grant No. 11074212the Foundation for the Author of National Excellent Doctoral Dissertation of China under Grant No. 200726the Foundation of Key Laboratory of QET of the Education Bureau of Hunan Province of China under Grant No. 09QNET05
文摘We present a family of the solutions of two-component Bose-Einstein condensates with time-dependentscattering length by means of multiple-scale method.Our numerical calculations show that the collision properties (theposition,the time,and the frequency of the collision) between two solitons can be controlled by the time-dependentinterspecies scattering length.Meanwhile,we also find that the amplitude of the solitons is close related to the timedependentinterspecies scattering length.
基金Supported by the National High Technology Research and Development Programme of China (No. (2008AA11 A146 ), China Postdoctoral Science Foundation (20090450298).
文摘Safety-critical applications such as the independently driving systems of electric vehicle (EV) require a high degree of reliability. The controller area network (CAN) is used extensively in the control sectors. A new real-time and reliable scheduling algorithm based on time-triggered scheduler with a focus on the CAN-based distributed control systems for independently driving EV is exploited. A distributed control network model for a dual-wheel independendy driving EV is established. The timing and reliabili- ty analysis in the worst case with the algorithm is used to evaluate the predictability and dependability and the simulation based on the algorithm with CANoe software is designed. The results indicate the algorithm is more predicable and dependable.
文摘Diallel cross analysis among seven diverse pure lines of maize, (IK8, IK58, ZP-707, OH40, UN44052, DKI7 and HS) with their nonreciprocal 21 crosses, were carried out for estimating the nature and magnitude of gene effects through component and graphic analysis for characters: number of days to tasseling, number of days to silking, plant height, ear height, number of rows per ear, number of grains per row, 300 grain weight and grain yield per plant. The results showed highly significant mean square of genotypes for all studied characters. Additive and dominance variances were found to be significant from zero for all the eight characters except number of days to tasseling and silking for which additive genetic variance was no significant. Dominance variance estimation was relatively higher than the additive variance for all characters. The graphic analysis suggested the presence of epistatic gene effects (non-allelic interaction) for number of days to tasseling, number of days to silking, plant height, number of grains per row and grain yield per plant. The estimates of narrow sense heritability varied from 1.85% for 300 grain weight to 49.88% for ear height, it was moderate in case of ear height and low for the remainder characters.
基金Supported by "973" National Key Basic Research Program ( No. 2002CB311905) andYoung Teacher Foundation of Tianjin University.
文摘Based on planar Si dual-base transistor conception, a novel mesa dual-base heterojunc- tion bipolar transistor ( HBT) is designed and fabricated. Molecule beam extension. selective wet chemical etching, common contact photolithography and metal lift-off technique are adopted in the process. The device has particular and distinct voltage-controlled negative differential resistance (NDR) and photo-controlled NDR. The highest peak-to-vally current rate of the voltage-controlled NDR is larger than 148 and the peak current varies with the increase of collector voltage. The device features high speed and high frequency characteristics derived from HBT and intrinsic bistability and self-latching characteristics due to NDR. A single dual-base HBT can be seen as an integration of NDR device, HBT and photoconductive device. Compared with common HBT.the groove is the key factor producing NDR.
基金Project supported by the National Natural Science Foundation of China (No. 51377142), the National High-Tech R&D Program (863) of China (No. 2014AA052001), the Zhejiang Provincial Natural Science Foundation of China (No. LY16E070002), and the Zhejiang Province Key R&D Project (No. 2017C01039)
文摘The DC microgrid is connected to the AC utility by parallel bidirectional power converters (BPCs) to import/export large power, whose control directly affects the performance of the grid-connected DC microgrid. Much work has focused on the hierarchical control of the DC, AC, and hybrid microgrids, but little has considered the hierarchical control of multiple parallel BPCs that directly connect the DC microgrid to the AC utility. In this paper, we propose a hierarchical control for parallel BPCs of a grid-connected DC mierogrid. To suppress the potential zero-sequence circulating cm-cent in the AC side among the parallel BPCs and realize feedback linearization of the voltage control, a d-q-O control scheme instead of a conventional d-q control scheme is proposed in the inner current loop, and the square of the DC voltage is adopted in the inner voltage loop. DC side droop control is applied to realize DC current sharing among multiple BPCs at the primary control level, and this induces DC bus voltage deviation. The quantified relationship between the current sharing error and DC voltage deviation is derived, indicating that there is a trade-off between the DC voltage deviation and current sharing error. To eliminate the current sharing error and DC voltage deviation simultaneously, slope-adjusting and voltage-shifting approaches are adopted at the secondary control level. The pro- posed tertiary control realizes precise active and reactive power exchange through parallel BPCs for economical operation. The proposed hierarchical control is applied for parallel BPCs of a grid-connected DC microgrid and can operate coordinately with the control for controllable/uncontrollable distributional generation. The effectiveness of the proposed control method is verified by corresponding simulation tests based on Matlab/Simulink, and the performance of the hierarchical control is evaluated for prac- tical applications.
基金supported by the National Key R&D Program of China(2016YFA0501503)the National Mega-project for Innovative Drugs of China(2019ZX09721001-004-003)+2 种基金the National Natural Science Foundation of China(31670136 31870127 and 81861138047)the Science and Technology Commission of Shanghai Municipality(19JC1416400)the State Key Laboratory of Drug Research(SIMM2003ZZ-03).
文摘In nature, bacteria must sense copper and tightly regulate gene expression to evade copper toxicity. Here,we identify a new copper-responsive two-component system named DsbRS in the important human pathogen Pseudomonas aeruginosa;in this system, DsbS is a sensor histidine kinase, and DsbR, its cognate response regulator, directly induces the transcription of genes involved in protein disulfide bond formation(Dsb)(i.e., the dsbDEG operon and dsbB). In the absence of copper, DsbS acts as a phosphatase toward DsbR, thus blocking the transcription of Dsb genes. In the presence of copper, the metal ion directly binds to the sensor domain of DsbS, and the Cys82 residue plays a critical role in this process. The copperbinding behavior appears to inhibit the phosphatase activity of DsbS, leading to the activation of DsbR.The copper resistance of the dsbRS knock-out mutant is restored by the ectopic expression of the dsbDEG operon, which is a DsbRS major target. Strikingly, cognates of the dsbRS-dsbDEG pair are widely distributed across eubacteria. In addition, a DsbR-binding site, which contains the consensus sequence 5’-TTA-N8-TTAA-3’, is detected in the promoter region of dsbDEG homologs in these species. These findings suggest that the regulation of Dsb genes by DsbRS represents a novel mechanism by which bacterial cells cope with copper stress.
基金This work was supported by the Special Funds for Major State Basic Research Projects (2005CB522600), the Eleventh Five-Year Science and Technology Project of PLA (06G080), and Natural Science Foundation Project of CQCSTC (2009BB5316)
文摘In trauma, infection and hemorrhagic shock derived stress, primary and secondary injury may result in severe derangement in the internal environment. The abnormal changes of immune-mediated inflammation interfere its pathogenesis and development directly. In recent years, various aspects of neuroendocrine responses, especially the regulatory effects of hypothalamic-pituitary-adrenal and sympathetico-adrenomedullary axes in inflammatory diseases have been the focus of research. Most importantly,corticotropin-releasing hormone (CRH) acts as a key player in the regulation of interactions between neuroendocrine and immunity both directly and indirectly. The paper summarized the recent development of CRH in the immune-mediated inflammation.
基金supported by the Pre-research Fund Project of Ministry of Equipment and Development of China(61409230301)the Fundamental Research Funds for the Central Universities(2019kfyXMPY005 and 2019kfyXKJC042)。
文摘Dual-phase high-entropy alloys(DP-HEAs)with excellent strength-ductility combinations have attracted scientific interests.In the present study,the microstructures of AlCrCuFeNi3.0DP-HEA fabricated via selective laser melting(SLM)are rationally adjusted and controlled.The mechanisms engendering the hierarchical microstructures are revealed.It is found that the AlCrCuFeNi3.0fabricated by SLM at the scanning speed of 400 mm s-1falls into the eutectic coupled zone,and increasing the scanning speed will make this composition deviate away from the eutectic coupled zone due to the increased cooling rate.The enrichment of Cr and Fe solutes with large growth restriction values ahead of the solid/liquid interface can develop a constitutional supercooling zone,thus facilitating the heterogeneous nucleation and nearequiaxed grain formation.The synergy of the near-eutectic DP nano-structures and near-equiaxed grains instead of columnar ones effectively suppresses cracking for the as-built DP-HEA.During the tensile deformation,the intergranular back stress hardening similar to the grain-boundary strengthening is discovered.Meanwhile,the near-eutectic microstructures comprised of soft face-centered cubic and hard ordered bodycentered cubic(B2)DP nano-structures lead to plastic strain incompatibility within grains,thus producing the intragranular back stress.The Cr-rich nano-precipitates inside the B2 phase are found to be sheared by dislocation gliding and can complement the back stress.Additionally,multiple strengthening mechanisms are physically evaluated,and the back stress strengthening contributes obviously to the high performances of the as-built DP-HEA.
基金supported by the National Natural Science Foundation of China under Grant Nos.11271329 and 10971193
文摘The bilevel programming is applied to solve hierarchical intelligence control problems in such fields as industry, agriculture, transportation, military, and so on. This paper presents a quadratic objective penalty function with two penalty parameters for inequality constrained bilevel programming. Under some conditions, the optimal solution to the bilevel programming defined by the quadratic objective penalty function is proved to be an optimal solution to the original bilevel programming. Moreover, based on the quadratic objective penalty function, an algorithm is developed to l^nd an optimal solution to the original bilevel programming, and its convergence proved under some conditions. Furthermore, under the assumption of convexity at function without lower level problems is defined and lower level problems, a quadratic objective penalty is proved equal to the original bilevel programming.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11004001 and 11105001the Key Project of Chinese Ministry of Education under Grant No.212076the Anhui Provincial Natural Science Foundation under Grant No.1208085QA09
文摘Voltage-controlled quantum dynamics of two quantum-dot molecules (QDMs) embedded in two separated photonic crystal cavities are theoretically investigated. We show numerically that generation of entangled states and population transfer between the two QDMs can be realized with the same coupling parameters. The effects of parameters deviation and dissipations on generation entangled states be used for realization of new-type of solid state quantum and populations transfer are also discussed. The results may devices and integrated electro-optical devices,
基金supported by the Australian Research Council through the Discovery Early Career Researcher Award Scheme(Grant No.DE120100291)the Discovery Project Scheme(Grant No.DP150102972)
文摘Metallic nanostructures have underpinned plasmonic-based advanced photonic devices in a broad range of research fields over the last decade including physics, engineering, material science and bioscience, The key to realizing functional plasmonie resonances that can manipulate light at the optical frequencies relies on the creation of conductive metallic structures at the nanoscale with low structural defects. Currently, most plasmonic nanostructures are fabricated either by electron beam lithography (EBL) or by focused ion beam (FIB) milling, which are expensive, complicated and time-consuming. In comparison, the direct laser writing (DLW) technique has demonstrated its high spatial resolution and cost-effectiveness in three-dimensional fabrication of micro/nanostrucmres. Furthermore, the recent breakthroughs in superresolution nanofabrication and parallel writing have significantly advanced the fabrication resolution and throughput of the DLW method and made it one of the promising future nanofabrication technologies with low-cost and scalability. In this review, we provide a comprehensive summary of the state-of-the-art DLW fabrication technology for nanometer scale metallic structures. The fabrication mechanisms, different material choices, fabrication capability, including resolution, conductivity and structure surface smoothness, as well as the characterization methods and achievable devices for different applications are presented. In particular, the development trends of the field and the perspectives for future opportunities and challenges are provided at the end of the review. It has been demonstrated that the quality of the metallic structures fabricated using the DLW method is excellent compared with other methods providing a new and enabling platform for functional nanophotonic device fabrication.