From August 14 to 16,the 52nd China Beijing International Gifts,Premium&Houseware Exhibition(hereinafter referred to as Beijing Gift&Home)was held at the China International Exhibition Center(Chaoyang Pavilion...From August 14 to 16,the 52nd China Beijing International Gifts,Premium&Houseware Exhibition(hereinafter referred to as Beijing Gift&Home)was held at the China International Exhibition Center(Chaoyang Pavilion)in Beijing,China.As the annual grand finale of the northern gift industry.展开更多
In order to reduce the ecological environmental pollution and economic losses caused by oil spill accidents from cross-river oil pipelines,this paper studies the structures of oil containment booms used for intercepti...In order to reduce the ecological environmental pollution and economic losses caused by oil spill accidents from cross-river oil pipelines,this paper studies the structures of oil containment booms used for intercepting oil spills in rapid rivers and proposes a new type of double-layer hole oil containment boom.By establishing a solid mechanics model,the geometric deformation and stress-strain distribution patterns of the double-layer hole oil containment boom under rapid flow velocities were analyzed.Additionally,the impact of the skirt angle,hole size,and porosity on themechanical properties of the newoil containment boomstructure was investigated,and the optimization range of the boom structure was determined.The results showed that,compared to the traditional single-layer oil containment boom,the optimized new boom reduced maximum tensile deformation by 91.1%and the maximum equivalent stress by 45.3%.Theresearch findings provide an effective reference for the rational design of oil containment booms in rapid rivers to ensure the safety of energy transportation and protect the ecological environment.展开更多
Bistable Deployable Composite Boom(Bi-DCB)can achieve bistable function by storing and releasing strain energy,which has a good application prospect in space field.For example,it serves as the main support section of ...Bistable Deployable Composite Boom(Bi-DCB)can achieve bistable function by storing and releasing strain energy,which has a good application prospect in space field.For example,it serves as the main support section of deployable structures(e.g.,solar arrays and antennas).This paper investigates folding stable state of Bi-DCB through the analytical method.Based on Archimedes’helix and energy principle,an analytical model for predicting folding stable state of Bi-DCB was presented.The failure index of Bi-DCB in folding stable state were analyzed using the Tsai-Hill criterion and the maximum stress criterion.Then,a 2400 mm long Bi-DCB was fabricated using autoclave method.The prediction results of the proposed model were compared with experiments and results of two other analytical models.It is shown that the proposed model shows good prediction accuracy.Finally,the effect of geometric parameters on folding stable state of Bi-DCB was further investigated with the aid of the proposed model.展开更多
[Objective] The aim of this study was to reveal the mechanism of Cu2+ hyper-accumulator in Setcreasea purpurea Boom from the angle of distribution characteristics and binding form of Cu2+ in tissue cells.[Method]The d...[Objective] The aim of this study was to reveal the mechanism of Cu2+ hyper-accumulator in Setcreasea purpurea Boom from the angle of distribution characteristics and binding form of Cu2+ in tissue cells.[Method]The distribution characteristics of Cu2+ in subcells of Setcreasea purpurea Boom was studied by the technique of differential centrifugation,and the binding form of Cu2+ in roots and leaves of Setcreasea purpurea Boom was also investigated by the sequential chemical extraction method and the enzymolysis method.[Result]Cu2+ in roots mainly distributed in the cell wall which is accounting for one third of the Total Cu2+ in roots,while Cu2+ in leaves mainly distributed in the chloroplast which is accounting for a quarter to the Total Cu2+ in leaves.Under the high concentration of Cu2+ or the extended treatment duration,the translocation of Cu2+ in root cells into the cell wall increased but the translocation of Cu2+ in root cells into the plastid decreased,while the translocation of Cu2+ in leaf cells into the chloroplast increased but the translocation of Cu2+ in leaf cells into the cell wall decreased.Cu2+ in leaves was mainly combined with amino acid,small molecular polymeric pigments,protein and polysaccharide,while Cu2+ in roots was mainly combined with cell wall substances such as cellulose and membrane-bound protein.[Conclusion]The distribution characteristics and binding form of Cu2+ in cells is possibly one of the dominant mechanisms for Cu2+ hyper-accumulator in Setcreasea purpurea Boom.展开更多
[Objective] This study was to investigate the expression of the specific protein in Setcreasea purpurea Boom under copper stress, with the aim to clarify the copper tolerance mechanism of S. purpurea. [Method] Methods...[Objective] This study was to investigate the expression of the specific protein in Setcreasea purpurea Boom under copper stress, with the aim to clarify the copper tolerance mechanism of S. purpurea. [Method] Methods of water culture, elec- trophoresis and chromatography were used to analyze the molecular weight of the specific protein in the copper hyperaccumulator S. purpurea, as well as its expression time and the minimum copper concentration for the expression. And the specific protein was isolated and purified. [Result] Under copper stress, the minimum concentra- tion of copper to induce the expression of the specific protein from S. purpurea was 50 umol/L, and the expression time of the protein was in the 4th week with the molecular weight of 89.4 kDa. [Conclusion] The results show that the copper tolerance of S. purpurea is closely related with the expression of the specific protein.展开更多
[Objective] The aim was to explore biological function of related genes in Setcreasea purpurea Boom under copper stress and to study the mechanism of its copper-resistance from standpoint of molecular biology in order...[Objective] The aim was to explore biological function of related genes in Setcreasea purpurea Boom under copper stress and to study the mechanism of its copper-resistance from standpoint of molecular biology in order to solve the problem of copper pollution. [Method] Setcreasea purpurea Boom was taken as experimental material which enjoys enrichment ability to cupric ion. About 90 fragments of differential expression were obtained by cDNA-AFLP and silver staining technique, among which, 17 fragments were amplified. After purification and identification, sequences of 6 differential fragments were got and used for BLAST X contrast. [Result] Six differential expressed fragments may play roles when Setcreasea purpurea Boom was under copper stress. The homology achieved 49% between differential sequences of E5MG-3 and of Arabidopsis thaliana mRNA （accession numbers： AAM62956.1）, homology was 53% between sequences of E4MB-2 and Solanum tuberosum mRNA （accession numbers： A5A717.1）, and 65% between sequences of E6MG-1 and Colocasia esculenta （L.） Schott mRNA （accession numbers： AAO62313.1）. It can be concluded that differential expressed genes are related to cell signaling, antioxidation, metabolism and protein modification. [Conclusion] The study has laid foundation for further exploration of regulatory network about response of Setcreasea purpurea Boom to copper stress.展开更多
After the last flight of the Concorde in 2003,sonic boom has been one of the obstacles to the return of a supersonic transport aircraft to service.To reduce the sonic boom intensity to an acceptable level,it is of gre...After the last flight of the Concorde in 2003,sonic boom has been one of the obstacles to the return of a supersonic transport aircraft to service.To reduce the sonic boom intensity to an acceptable level,it is of great significance to study the effect of lift distribution on far-field sonic boom,since lift is one of the most important contributors to an intense sonic boom.Existing studies on the longitudinal lift distribution used low-fidelity methods,such as Whitham theory,and in turn,only preliminary conclusions were obtained,such as that extending the lift distribution can reduce sonic boom.This paper uses a newly developed high-fidelity prediction method to quantitatively study the effect of longitudinal lift distribution on the sonic boom of a Canard-Wing-Stabilator-Body(CWSB)configuration.This high-fidelity prediction method combines near-feld CFD simulation with far-field propagation by solving the augmented Burgers equation.A multipole analysis method is employed for the extraction of near-field waveform in order to reduce computational cost.Seven configurations with the same total lift but different distributions are studied,and the quantitative relationship between the longitudinal lift distribution and far-field sonic boom intensity is investigated.It is observed that a small lift generated by the stabilator can prevent aft-stabilator and aft-fuselage shocks from merging,while the balanced lift generated by the canard and wing can effectively keep the corresponding shocks further apart,which is beneficial for reducing both the on-track and off-track sonic boom.In turn,the acoustic level perceived at the ground can be reduced by 5.9 PLdB on-track and 5.4 PLdB off-track,on average.展开更多
BOOMBOX译码器在黄土塬地区施工中，采用多井组合激发时，由于激发网络电阻增大，致使拒爆、丢炮和丢失验证时断信号（confirmation time break，CTB）的现象频发，严重制约了地震生产。针对该译码器的激发能力问题，分别从点火电压、...BOOMBOX译码器在黄土塬地区施工中，采用多井组合激发时，由于激发网络电阻增大，致使拒爆、丢炮和丢失验证时断信号（confirmation time break，CTB）的现象频发，严重制约了地震生产。针对该译码器的激发能力问题，分别从点火电压、充电时间、点火电流和CTB产生信号原理等方面进行了详尽的分析研究，并通过电路改进和现场试验，找到了提高其激发能力的一种较为便捷的方法。通过现场使用，取得了较好效果。展开更多
The purpose of this paper is to demonstrate and investigate the concepts of new deployable boom systems, which consist of the BCON （braid coated bi-convex tape） boom and the SMA-BCON （braid coated bi-shape memory a...The purpose of this paper is to demonstrate and investigate the concepts of new deployable boom systems, which consist of the BCON （braid coated bi-convex tape） boom and the SMA-BCON （braid coated bi-shape memory alloy convex tape） boom. Both booms are developed for the deployable membrane structures such as solar sails, thin membrane solar array panels, deorbit mechanisms for small satellites and reflectors of space solar power satellite, etc. BCON booms can store around polygonal or cylindrical center hub, and the booms can deploy by the stepwise manner by releasing a constraint mechanism which pins the boons into two or three points for the total length. SMA-BCON booms are mainly developed for a square center body systems, and SMA is adapted on the bent po^nts of the booms where stored around each edge of the center hub. Through the deployment experiments of both booms, the stepwise deployment behavior and its tendency are obtained. The design concept of BCON boom and SMA-BCON hnnm i~ demonstrated through this study.展开更多
文摘From August 14 to 16,the 52nd China Beijing International Gifts,Premium&Houseware Exhibition(hereinafter referred to as Beijing Gift&Home)was held at the China International Exhibition Center(Chaoyang Pavilion)in Beijing,China.As the annual grand finale of the northern gift industry.
文摘In order to reduce the ecological environmental pollution and economic losses caused by oil spill accidents from cross-river oil pipelines,this paper studies the structures of oil containment booms used for intercepting oil spills in rapid rivers and proposes a new type of double-layer hole oil containment boom.By establishing a solid mechanics model,the geometric deformation and stress-strain distribution patterns of the double-layer hole oil containment boom under rapid flow velocities were analyzed.Additionally,the impact of the skirt angle,hole size,and porosity on themechanical properties of the newoil containment boomstructure was investigated,and the optimization range of the boom structure was determined.The results showed that,compared to the traditional single-layer oil containment boom,the optimized new boom reduced maximum tensile deformation by 91.1%and the maximum equivalent stress by 45.3%.Theresearch findings provide an effective reference for the rational design of oil containment booms in rapid rivers to ensure the safety of energy transportation and protect the ecological environment.
基金supported by the National Natural Science Foundation of China(No.52275231)the National Defense Basic Scientific Research Program of China(No.JCKY2019205C002).
文摘Bistable Deployable Composite Boom(Bi-DCB)can achieve bistable function by storing and releasing strain energy,which has a good application prospect in space field.For example,it serves as the main support section of deployable structures(e.g.,solar arrays and antennas).This paper investigates folding stable state of Bi-DCB through the analytical method.Based on Archimedes’helix and energy principle,an analytical model for predicting folding stable state of Bi-DCB was presented.The failure index of Bi-DCB in folding stable state were analyzed using the Tsai-Hill criterion and the maximum stress criterion.Then,a 2400 mm long Bi-DCB was fabricated using autoclave method.The prediction results of the proposed model were compared with experiments and results of two other analytical models.It is shown that the proposed model shows good prediction accuracy.Finally,the effect of geometric parameters on folding stable state of Bi-DCB was further investigated with the aid of the proposed model.
基金Supported by the National Natural Science Foundation(30760021)Natural Science Foundation of Jiangxi Province(0530016)Project of the Education Department of Jiangxi Province(Jiangxi Education&Tech-nology No.[2007]151)~~
文摘[Objective] The aim of this study was to reveal the mechanism of Cu2+ hyper-accumulator in Setcreasea purpurea Boom from the angle of distribution characteristics and binding form of Cu2+ in tissue cells.[Method]The distribution characteristics of Cu2+ in subcells of Setcreasea purpurea Boom was studied by the technique of differential centrifugation,and the binding form of Cu2+ in roots and leaves of Setcreasea purpurea Boom was also investigated by the sequential chemical extraction method and the enzymolysis method.[Result]Cu2+ in roots mainly distributed in the cell wall which is accounting for one third of the Total Cu2+ in roots,while Cu2+ in leaves mainly distributed in the chloroplast which is accounting for a quarter to the Total Cu2+ in leaves.Under the high concentration of Cu2+ or the extended treatment duration,the translocation of Cu2+ in root cells into the cell wall increased but the translocation of Cu2+ in root cells into the plastid decreased,while the translocation of Cu2+ in leaf cells into the chloroplast increased but the translocation of Cu2+ in leaf cells into the cell wall decreased.Cu2+ in leaves was mainly combined with amino acid,small molecular polymeric pigments,protein and polysaccharide,while Cu2+ in roots was mainly combined with cell wall substances such as cellulose and membrane-bound protein.[Conclusion]The distribution characteristics and binding form of Cu2+ in cells is possibly one of the dominant mechanisms for Cu2+ hyper-accumulator in Setcreasea purpurea Boom.
基金Supported by the National Natural Science Foundation of China (30760021)the Natural Science Foundation of Jiangxi Province,China (0530016)the Program of Education Bureau of Jiangxi Province,China (ganjiaojizi[2007]No.151)~~
文摘[Objective] This study was to investigate the expression of the specific protein in Setcreasea purpurea Boom under copper stress, with the aim to clarify the copper tolerance mechanism of S. purpurea. [Method] Methods of water culture, elec- trophoresis and chromatography were used to analyze the molecular weight of the specific protein in the copper hyperaccumulator S. purpurea, as well as its expression time and the minimum copper concentration for the expression. And the specific protein was isolated and purified. [Result] Under copper stress, the minimum concentra- tion of copper to induce the expression of the specific protein from S. purpurea was 50 umol/L, and the expression time of the protein was in the 4th week with the molecular weight of 89.4 kDa. [Conclusion] The results show that the copper tolerance of S. purpurea is closely related with the expression of the specific protein.
基金Supported by National Natural Science Foundation of China(30760021)Natural Science Foundation of Jiangxi Province(0530016)Project from Education Bureau of Jiangxi Province([2007]151)~~
文摘[Objective] The aim was to explore biological function of related genes in Setcreasea purpurea Boom under copper stress and to study the mechanism of its copper-resistance from standpoint of molecular biology in order to solve the problem of copper pollution. [Method] Setcreasea purpurea Boom was taken as experimental material which enjoys enrichment ability to cupric ion. About 90 fragments of differential expression were obtained by cDNA-AFLP and silver staining technique, among which, 17 fragments were amplified. After purification and identification, sequences of 6 differential fragments were got and used for BLAST X contrast. [Result] Six differential expressed fragments may play roles when Setcreasea purpurea Boom was under copper stress. The homology achieved 49% between differential sequences of E5MG-3 and of Arabidopsis thaliana mRNA （accession numbers： AAM62956.1）, homology was 53% between sequences of E4MB-2 and Solanum tuberosum mRNA （accession numbers： A5A717.1）, and 65% between sequences of E6MG-1 and Colocasia esculenta （L.） Schott mRNA （accession numbers： AAO62313.1）. It can be concluded that differential expressed genes are related to cell signaling, antioxidation, metabolism and protein modification. [Conclusion] The study has laid foundation for further exploration of regulatory network about response of Setcreasea purpurea Boom to copper stress.
基金sponsored by the National Natural Science Foundation of China(Nos.12072285,U20B2007)the Shaanxi Science Fund for Distinguished Young Scholars,China(No.2020JC-13)the Natural Science Funding of Shaanxi Province,China(No.2020JM-127).
文摘After the last flight of the Concorde in 2003,sonic boom has been one of the obstacles to the return of a supersonic transport aircraft to service.To reduce the sonic boom intensity to an acceptable level,it is of great significance to study the effect of lift distribution on far-field sonic boom,since lift is one of the most important contributors to an intense sonic boom.Existing studies on the longitudinal lift distribution used low-fidelity methods,such as Whitham theory,and in turn,only preliminary conclusions were obtained,such as that extending the lift distribution can reduce sonic boom.This paper uses a newly developed high-fidelity prediction method to quantitatively study the effect of longitudinal lift distribution on the sonic boom of a Canard-Wing-Stabilator-Body(CWSB)configuration.This high-fidelity prediction method combines near-feld CFD simulation with far-field propagation by solving the augmented Burgers equation.A multipole analysis method is employed for the extraction of near-field waveform in order to reduce computational cost.Seven configurations with the same total lift but different distributions are studied,and the quantitative relationship between the longitudinal lift distribution and far-field sonic boom intensity is investigated.It is observed that a small lift generated by the stabilator can prevent aft-stabilator and aft-fuselage shocks from merging,while the balanced lift generated by the canard and wing can effectively keep the corresponding shocks further apart,which is beneficial for reducing both the on-track and off-track sonic boom.In turn,the acoustic level perceived at the ground can be reduced by 5.9 PLdB on-track and 5.4 PLdB off-track,on average.
文摘BOOMBOX译码器在黄土塬地区施工中，采用多井组合激发时，由于激发网络电阻增大，致使拒爆、丢炮和丢失验证时断信号（confirmation time break，CTB）的现象频发，严重制约了地震生产。针对该译码器的激发能力问题，分别从点火电压、充电时间、点火电流和CTB产生信号原理等方面进行了详尽的分析研究，并通过电路改进和现场试验，找到了提高其激发能力的一种较为便捷的方法。通过现场使用，取得了较好效果。
文摘The purpose of this paper is to demonstrate and investigate the concepts of new deployable boom systems, which consist of the BCON （braid coated bi-convex tape） boom and the SMA-BCON （braid coated bi-shape memory alloy convex tape） boom. Both booms are developed for the deployable membrane structures such as solar sails, thin membrane solar array panels, deorbit mechanisms for small satellites and reflectors of space solar power satellite, etc. BCON booms can store around polygonal or cylindrical center hub, and the booms can deploy by the stepwise manner by releasing a constraint mechanism which pins the boons into two or three points for the total length. SMA-BCON booms are mainly developed for a square center body systems, and SMA is adapted on the bent po^nts of the booms where stored around each edge of the center hub. Through the deployment experiments of both booms, the stepwise deployment behavior and its tendency are obtained. The design concept of BCON boom and SMA-BCON hnnm i~ demonstrated through this study.
