Ramp-up experiments by means of lower hybrid wave on HT-7 superconducting tokamak have been performed and analyzed. A ramp-up rate of over 300 kA/s is obtained and a conversion efficiency of over 1.0% has been achieve...Ramp-up experiments by means of lower hybrid wave on HT-7 superconducting tokamak have been performed and analyzed. A ramp-up rate of over 300 kA/s is obtained and a conversion efficiency of over 1.0% has been achieved during the ramp-up phase. The study of the dependence of conversion efficiency on plasma density shows that the conversion efficiency is affected by the driven current, which is mainly dominated by the competition of impurity concentration with wave accessibility condition. In addition, the effect of current profile may play an important role in determining the conversion efficiency.展开更多
The power conversion efficiency （PCE） of poly（3-hexylthiophene） （P3HT） and [6,6]-phenyl C61-butyric acid methyl ester （P061BM） based organic solar cells （OSCs） is significantly improved by using benzyl aceta...The power conversion efficiency （PCE） of poly（3-hexylthiophene） （P3HT） and [6,6]-phenyl C61-butyric acid methyl ester （P061BM） based organic solar cells （OSCs） is significantly improved by using benzyl acetate （BA）, an organic compound without any halogen or sulphur atom, as a processing additive to control the blend morphology. The solar cells show PCE of 3.85% with a fill factor （FF） of 65.22%, which are higher than those of the common thermal annealing device （PCE 3.30%, FF 60.83%）. The overall increased PCE depends upon the enhanced crystallinity of P3HT and good carriers transport, with a high balanced charge carrier mobility.展开更多
Adaptive cluster sampling (ACS) has been a very important tool in estimation of population parameters of rare and clustered population. The fundamental idea behind this sampling plan is to decide on an initial sample ...Adaptive cluster sampling (ACS) has been a very important tool in estimation of population parameters of rare and clustered population. The fundamental idea behind this sampling plan is to decide on an initial sample from a defined population and to keep on sampling within the vicinity of the units that satisfy the condition that at least one characteristic of interest exists in a unit selected in the initial sample. Despite being an important tool for sampling rare and clustered population, adaptive cluster sampling design is unable to control the final sample size when no prior knowledge of the population is available. Thus adaptive cluster sampling with data-driven stopping rule (ACS’) was proposed to control the final sample size when prior knowledge of population structure is not available. This study examined the behavior of the HT, and HH estimator under the ACS design and ACS’ design using artificial population that is designed to have all the characteristics of a rare and clustered population. The efficiencies of the HT and HH estimator were used to determine the most efficient design in estimation of population mean in rare and clustered population. Results of both the simulated data and the real data show that the adaptive cluster sampling with stopping rule is more efficient for estimation of rare and clustered population than ordinary adaptive cluster sampling.展开更多
The HTS current leads of superconducting magnets for large scale fusion devices and high energy particle colliders can reduce the power consumption for cooling by 2/3 compared with conventional leads. The resistive se...The HTS current leads of superconducting magnets for large scale fusion devices and high energy particle colliders can reduce the power consumption for cooling by 2/3 compared with conventional leads. The resistive sections of high-rated current leads are usually made of a heat exchanger cooled by gas flow. The supply of the cooling mass flow incurs more than 90% of the cooling cost for the HTS leads. The mass flow rate requirement depends not only on the length and material of the resistive heat exchanger, but also on the heat transfer coefficient and HEX surface, the joint resistance at the cold end of a sheet-stack HEX with a larger specific presented in the paper. The test results of efficiency can be achieved. and its cooling approach. The design and operation surface and a much smaller hydraulic diameter are an HTS lead optimized for 8 kA show that a 98.4%展开更多
针对定向凝固镍基高温合金DZ125叶片榫齿，采用电镀成型CBN砂轮对其进行了高效深切磨削（High efficieney deep grinding，HEDG）试验，对磨削比能及工件表面完整性进行了分析。结果显示，在保持速比（Us／‰）不变时，提高磨削速度饥...针对定向凝固镍基高温合金DZ125叶片榫齿，采用电镀成型CBN砂轮对其进行了高效深切磨削（High efficieney deep grinding，HEDG）试验，对磨削比能及工件表面完整性进行了分析。结果显示，在保持速比（Us／‰）不变时，提高磨削速度饥可有效降低磨削比能，提高平均材料去除率。磨削比能表现出“尺寸效应”，其值最终稳定在40～60J／mm^3之间；在相同的平均材料去除率下，磨削比能随着磨削深度的增大而上升；在相同的单颗磨粒切厚下，磨削深度的差异对磨削比能的影响较小。对试验中最大平均材料去除率下获得的工件表面质量进行分析发现，已加工工件表面不同区域磨削纹理均很清晰，无皱叠及犁沟两侧翻起等现象；表层金相显微组织基本无变化，未发现相变、撕裂及晶粒扭曲现象；工件表层加工硬化程度为7．7％～19％，深度为40μm。结果显示了HEDG在高效磨削DZ125叶片榫齿中推广应用的潜力，并为其实际生产中磨削参数的选择提供了参考。展开更多
文摘Ramp-up experiments by means of lower hybrid wave on HT-7 superconducting tokamak have been performed and analyzed. A ramp-up rate of over 300 kA/s is obtained and a conversion efficiency of over 1.0% has been achieved during the ramp-up phase. The study of the dependence of conversion efficiency on plasma density shows that the conversion efficiency is affected by the driven current, which is mainly dominated by the competition of impurity concentration with wave accessibility condition. In addition, the effect of current profile may play an important role in determining the conversion efficiency.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61405209,61107090,21172187,51273168,20102139 and 51173199the National Basic Research Program of China under Grant Nos 2014CB643501 and 2010DFA52310+3 种基金the Shandong Provincial Natural Science Foundation under Grant No ZR2011BZ007the Key Project of Hunan Province Education Department under Grant No 13A102the Innovation Group and Xiangtan Joint Project of Hunan Natural Science Foundation under Grant Nos 12JJ7002 and 12JJ8001the Scientific Research Fund of Hunan Provincial Education Department under Grant Nos 11CY023 and 12B123
文摘The power conversion efficiency （PCE） of poly（3-hexylthiophene） （P3HT） and [6,6]-phenyl C61-butyric acid methyl ester （P061BM） based organic solar cells （OSCs） is significantly improved by using benzyl acetate （BA）, an organic compound without any halogen or sulphur atom, as a processing additive to control the blend morphology. The solar cells show PCE of 3.85% with a fill factor （FF） of 65.22%, which are higher than those of the common thermal annealing device （PCE 3.30%, FF 60.83%）. The overall increased PCE depends upon the enhanced crystallinity of P3HT and good carriers transport, with a high balanced charge carrier mobility.
文摘Adaptive cluster sampling (ACS) has been a very important tool in estimation of population parameters of rare and clustered population. The fundamental idea behind this sampling plan is to decide on an initial sample from a defined population and to keep on sampling within the vicinity of the units that satisfy the condition that at least one characteristic of interest exists in a unit selected in the initial sample. Despite being an important tool for sampling rare and clustered population, adaptive cluster sampling design is unable to control the final sample size when no prior knowledge of the population is available. Thus adaptive cluster sampling with data-driven stopping rule (ACS’) was proposed to control the final sample size when prior knowledge of population structure is not available. This study examined the behavior of the HT, and HH estimator under the ACS design and ACS’ design using artificial population that is designed to have all the characteristics of a rare and clustered population. The efficiencies of the HT and HH estimator were used to determine the most efficient design in estimation of population mean in rare and clustered population. Results of both the simulated data and the real data show that the adaptive cluster sampling with stopping rule is more efficient for estimation of rare and clustered population than ordinary adaptive cluster sampling.
文摘The HTS current leads of superconducting magnets for large scale fusion devices and high energy particle colliders can reduce the power consumption for cooling by 2/3 compared with conventional leads. The resistive sections of high-rated current leads are usually made of a heat exchanger cooled by gas flow. The supply of the cooling mass flow incurs more than 90% of the cooling cost for the HTS leads. The mass flow rate requirement depends not only on the length and material of the resistive heat exchanger, but also on the heat transfer coefficient and HEX surface, the joint resistance at the cold end of a sheet-stack HEX with a larger specific presented in the paper. The test results of efficiency can be achieved. and its cooling approach. The design and operation surface and a much smaller hydraulic diameter are an HTS lead optimized for 8 kA show that a 98.4%
文摘针对定向凝固镍基高温合金DZ125叶片榫齿，采用电镀成型CBN砂轮对其进行了高效深切磨削（High efficieney deep grinding，HEDG）试验，对磨削比能及工件表面完整性进行了分析。结果显示，在保持速比（Us／‰）不变时，提高磨削速度饥可有效降低磨削比能，提高平均材料去除率。磨削比能表现出“尺寸效应”，其值最终稳定在40～60J／mm^3之间；在相同的平均材料去除率下，磨削比能随着磨削深度的增大而上升；在相同的单颗磨粒切厚下，磨削深度的差异对磨削比能的影响较小。对试验中最大平均材料去除率下获得的工件表面质量进行分析发现，已加工工件表面不同区域磨削纹理均很清晰，无皱叠及犁沟两侧翻起等现象；表层金相显微组织基本无变化，未发现相变、撕裂及晶粒扭曲现象；工件表层加工硬化程度为7．7％～19％，深度为40μm。结果显示了HEDG在高效磨削DZ125叶片榫齿中推广应用的潜力，并为其实际生产中磨削参数的选择提供了参考。
