How is a nation’s embrace of snow and ice shaping a new cultural identity and igniting a multi-trillion-yuan economic boom?ADRIAAN Smit now cannot imagine a life without snowboarding,a passion that has become central...How is a nation’s embrace of snow and ice shaping a new cultural identity and igniting a multi-trillion-yuan economic boom?ADRIAAN Smit now cannot imagine a life without snowboarding,a passion that has become central to his world.He is excited to witness how winter sports are fostering a new winter culture in China.Listening to Smit speaking so enthusiastically about the slopes,one might assume he was raised in a region where snow sports are a way of life,but the fact is quite the contrary.展开更多
Wavelength tunable and directly modulated distributed Bragg reflector （DBR） lasers with butt-joint technology are designed, fabricated and characterized. The DBR laser consists of a gain section and a DBR section. T...Wavelength tunable and directly modulated distributed Bragg reflector （DBR） lasers with butt-joint technology are designed, fabricated and characterized. The DBR laser consists of a gain section and a DBR section. To increase the electrical isolation between the gain section and the DBR section, parts of a p-doped material in the isolation region are etched off selectively. Over 2kΩ isolation resistance is realized ultimately without the need of ion implantation, which simplifies the fabrication process. The laser exhibits high speed modulation with a large tunable range. The 3dB direct modulation bandwidth of the device is over 8GHz in a 12nm tunable range. This widely tunable DBR laser with the simple structure is promising as a colorless light source for the next-generation time and wavelength division multiplexed passive optical network （TWDM-PON） systems.展开更多
Compared with a conventional single section two-phase closed thermosyphon （TPCT） wellbore, a two-section TPCT wellbore has better heat transfer performance, which may improve the temperature distribution of fluid in...Compared with a conventional single section two-phase closed thermosyphon （TPCT） wellbore, a two-section TPCT wellbore has better heat transfer performance, which may improve the temperature distribution of fluid in wellbores, increase the temperature of fluid in wellheads and even more effectively reduce the failure rate of conventional TPCT wellbores. Heat transfer performance of two-section TPCT wellbores is affected by working medium, combination mode and oil flow rate. Different working media are introduced into the upper and lower TPCTs, which may achieve a better match between the working medium and the temperature field in the wellbores. Interdependence exists between the combination mode and the flow rate of the oil, which affects the heat transfer performance of a two-section TPCT wellbore. The experimental results show that a two-section TPCT wellbore, with equal upper and lower TPCTs respectively filled with Freon and methanol, has the best heat transfer performance when the oil flow rate is 200 L/h.展开更多
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
[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
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
文摘How is a nation’s embrace of snow and ice shaping a new cultural identity and igniting a multi-trillion-yuan economic boom?ADRIAAN Smit now cannot imagine a life without snowboarding,a passion that has become central to his world.He is excited to witness how winter sports are fostering a new winter culture in China.Listening to Smit speaking so enthusiastically about the slopes,one might assume he was raised in a region where snow sports are a way of life,but the fact is quite the contrary.
基金Supported by the National Key Project under Grant No 2016YFB0402301the National High Technology Research and Development Program of China under Grant No 2013AA014502the National Natural Science Foundation of China under Grant Nos 61635010,61320106013,61474112,61321063 and 61274071
文摘Wavelength tunable and directly modulated distributed Bragg reflector （DBR） lasers with butt-joint technology are designed, fabricated and characterized. The DBR laser consists of a gain section and a DBR section. To increase the electrical isolation between the gain section and the DBR section, parts of a p-doped material in the isolation region are etched off selectively. Over 2kΩ isolation resistance is realized ultimately without the need of ion implantation, which simplifies the fabrication process. The laser exhibits high speed modulation with a large tunable range. The 3dB direct modulation bandwidth of the device is over 8GHz in a 12nm tunable range. This widely tunable DBR laser with the simple structure is promising as a colorless light source for the next-generation time and wavelength division multiplexed passive optical network （TWDM-PON） systems.
基金the financial support from the National Natural Science Foundation of China (No. 50674096)PetroChina Scientific & Technological Risk Innovation Project (No. 060511-2-1)
文摘Compared with a conventional single section two-phase closed thermosyphon （TPCT） wellbore, a two-section TPCT wellbore has better heat transfer performance, which may improve the temperature distribution of fluid in wellbores, increase the temperature of fluid in wellheads and even more effectively reduce the failure rate of conventional TPCT wellbores. Heat transfer performance of two-section TPCT wellbores is affected by working medium, combination mode and oil flow rate. Different working media are introduced into the upper and lower TPCTs, which may achieve a better match between the working medium and the temperature field in the wellbores. Interdependence exists between the combination mode and the flow rate of the oil, which affects the heat transfer performance of a two-section TPCT wellbore. The experimental results show that a two-section TPCT wellbore, with equal upper and lower TPCTs respectively filled with Freon and methanol, has the best heat transfer performance when the oil flow rate is 200 L/h.
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(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.
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。
