199 research outputs found

    Fission life-time calculation using a complex absorbing potential

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    A comparison between the semi-classical approximation and the full quantum calculation with a complex absorbing potential is made with a model of the fission of 258Fm. The potential barrier is obtained with the constrained Skyrme HF+BCS theory. The life-time obtained by the two calculations agree with each other the difference being only by 25%.Comment: 5 pages, 2 figures, Conference proceedings of CNR*15 workshop, Tokyo, October 2015 to be published in EPJ Web of Conference

    Design and measurements of the high gradient accelerating structures

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    The purpose of this thesis was to study on design and measurements of the high gradient accelerating structures. After introducing the main parameters to characterize Linacs we explained the application of the periodic accelerating structure. Then we studied TW accelerating structure operating at K-band frequency in order to linearize longitudinal space phase to increase beam brightness in the framework of the Compact Light XLS project in order to produce hard x-ray. We estimated group velocity as a function of frequency both analytically and numerically. Analytical results have a good agreement with the numerical results. The main parameters such as shunt impedance, quality factor (Geometric factor) and R/Q independently from the operating frequency for the TM010, TM110 and TM011 for a single cylindrical “pill-box” have been determined analytically as they provide accurate model for the accelerating structures. In order to characterize a normal conducting high accelerating structure with maximum gradients operating at X-band with extremely low probability of RF breakdown, an electroformed SW structures has been fabricated and characterized by SLAC and INFN with collaboration of other institute around the world at 11.424 GHz, coated with Au-Ni. We designed a gold plate RF high gradient structure operating at the X- band coated with Au-Ni. Bench measurements have been performed in the Department of SBAI of the University of Rome “La Sapienza”. The Slater method for the SW cavity has been employed in order to quantify the electric field inside the structure. Comparing the results with the results exposed from HFSS we report the features that have been quantified, showing good agreement. We continued working on the perturbation effect due to the aperture coupled between a waveguide and a cavity but for our application in SW multi-cell high gradient accelerating structure we studied on theoretical approach for reflection coefficient calculation in a SW cavity coupled to a waveguide. One method was based on circuit theory in which we found the overall Q of a resonant circuit for a cavity coupled to an external waveguide containing the RF generator. Q calculation led to the determining of the shunt impedance and consequently the reflection coefficient calculation. Comparison of the results shows a good agreement with the numerical results carried out by using the numerical code, HFSS. Another method of reflection coefficient calculation has been accomplished. We applied the modified Bethe’s theory presented by Collin and developed by De santis, Mostacci and L.Palumbo for TM01 mode cavities coupled by a small hole with a thickness size comparable to the wavelength. The amplitudes of forward and backward waves due to polarizabilites have been determined and we found equations for reflection and transmission coefficients. We demonstrated that our equation for reflection coefficient calculation is an analogous of the reflection coefficient obtained by Collin for TE10 using the circuit theory

    Predictive Study of Bubble Mean Diameter in Subcooled Flow Boiling

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    通道内截面汽泡平均直径是计算两相流相间界面传递方程以及计算汽液相界面浓度的重要参数。综合考虑过冷沸腾工况下汽泡动力学、两相热力学以及汽泡聚合效应; 对通道内汽泡尺寸的影响,提出过冷沸腾通道内截面汽泡平均直径预测模型。将该模型与实验数据进行比较,预测值与实验值偏差12.5%。Bubble mean diameter is a key parameter to calculate the interfacial; transfer equation of two phase flow and interfacial concentration.; Taking into account the effects of both the thermal, hydrodynamic; conditions and bubble coalescence rate on the mean bubble size in the; channel, a model has been developed. The proposed model agreed well with; the experimental data within the averaged relative deviation of 12.5%.福建省自然科学基

    Study on Hydrogen Production Activity of Klebsielal oxytoca HP1 and Stability of Its Soluble Hydrogenase under Atmosphere with O_2

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    目的:考察产酸克雷伯氏菌(Klebsielal oxytoca HP1)耐氧产氢特性及其可溶性氢酶的氧耐受特性。方法:研究K.oxytoca HP1在不同气相氧浓度条件下利用葡萄糖(1%,m/v)、丙酮酸钠(0.5%,m/v)及甲酸(0.1%,v/v)等底物产氢活性的以及K.oxyto-ca HP1可溶性氢酶在空气及氧饱和溶液中催化产氢活性。结果:K.oxytoca HP1在葡萄糖(1%,m/v)底物中具有较高耐氧产氢活性,6h内在气相氧浓度为5%、10%和21%条件下的氢产量分别为厌氧条件下的20.9%、13.7%、8.3%;K.oxytoca HP1可溶性氢酶在空气中孵育12h后,其活性残余85.4%,在氧饱和溶液中活性损失一半约3h。结论:试验结果提示K.oxytoca HP1具有耐氧产氢特性,其可溶性氢酶具有较高氧耐受性,在氢能源的开发中具有潜在的应用前景。Objective: To study the hydrogen production activity of K. oxytoca HP1 under condition with oxygen stress and the oxygen tolerance ability of its soluble hydrogenase. Method: The hydrogen production activity of K. oxytoca HP1 incubated in glucose (1%,m/v), sodium pyruvate (0.5%,m/v)or formate (0.1%,v/v) under atmosphere with 0%,5%,10% and 21% O2 were studied on, and the remain activity of its soluble hydrogenase incubated in air or pure O2 during 0-12h were studied on. Result: The results show that K. oxytoca HP1 has high hydrogen production activity in glucose (1%,m/v) substrate under atmosphere with oxygen. Compared to in anaerobic condition, the hydrogen production of K. oxytoca HP1 under atmosphere with 5%, 10% and 21% oxygen was 20.9%,13.7% and 8.3% respectively in 6h. The soluble hydrogenase from K. oxytoca HP1 exhibits considerable oxygen toleration ability, the remain activity was 85.4% after the hydrogenase exposure to air 12h and its activity lost half after the hydrogenase exposed to oxygen 3h. Conclusion:These results suggest that K. oxytoca HP1 and its soluble hydrogenase have potential to be applied in hydrogen production and application.福建省青年科技人才创新项目资助(No.12005J003

    金属氧化物SPC簇模型方法——嵌入簇点电量的确定

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    探讨和比较了确定金属氧化物晶体点电荷量的几种自洽条件的优劣 ,并使用abinitioHF方法对在不同点电荷量嵌入环境下MgO簇电子性质进行了研究 .计算结果表明 :点电荷量的大小会明显影响嵌入簇的电子性质 ;即使MgO被通常认为是纯的离子型氧化物 ,点电荷量取为表观化合价± 2 ,仍过高地估计了Madelung势 ,嵌入簇与点电荷之间应满足一定的自洽条件 ;使用点电荷为嵌入环境时 ,即使达到电荷自洽、偶极矩自洽或势自洽 ,簇模型计算结果仍与固体性质存在一定的偏差 ;将点电荷进行球谐展开 ,赋予其连续变化的电荷密度分布后 ,得到了一个对固体整体性质描述较好的SPC簇模型

    Rapid determination of 1,2-propylene glycol and glycerol in refill fluids for electronic cigarettes by Raman spectroscopy

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    为实现电子烟烟液主要成分的简便快速检测,建立了同时测定电子烟烟液中1,2-丙二醇和丙三醇含量的拉曼光谱分析方法,利用该方法测定了17个电子烟烟液; 样品,并与气质联用法进行了结果比较。结果表明:①1,2-丙二醇和丙三醇分别在0.125~0.956和0.106~1.120; g/mL时,以522和671 cm~(-1)特征信号峰强度绘制的标准工作曲线线性关系良好(R~2>; 0.999),单样本和独立样本t检验结果证实方法的准确性较高。②17个电子烟烟液样品中,1,2-丙二醇和丙三醇的含量分别为0.533~0.766; 和0.182~0.476; g/mL。该方法与气质联用法检测结果的配对样本t检验结果表明,在95%置信概率下,两种方法的定量结果一致。该方法不需进行样品前处理,更适用于批量; 电子烟烟液中1,2-丙二醇和丙三醇的快速定量分析。A simple and rapid Raman spectroscopy method for simultaneous; determination of 1,2-propylene glycol and glycerol in refill fluids for; electronic cigarettes was developed. Samples of 17 refill fluids were; analyzed by a portable Raman spectrometer,and the data were compared; with those determined by GC-MS. The results showed that: 1) The standard; curves of 1,2-propylene glycol and glycerol determined at the Raman; intensity of 522 and 671 cm~(-1) possessed good correlation coefficients; (R~2 above 0.999) in the content range of 0.125-0.956 and 0.106-1.120; g/mL,respectively. The results of one sample t-test and independent; sample t-test indicated that the Raman method was accurate. 2) The; contents of 1,2-propylene glycol and glycerol in 17 refill fluids were; in the range of 0.533-0.766 and 0.182-0.476 g/mL, respectively. The; result of paired sample t-test showed that the data determined by Raman; spectroscopy were consistent with those obtained by GC-MS at a; confidence level of 95%. Without sample pretreatment, Raman spectroscopy; method is simple to operate and more suitable for the rapid quantitative; determination of 1,2-propylene glycol and glycerol in batches of refill; fluids for electronic cigarettes.浙江中烟工业有限责任公司科技项

    点焊薄片应变传感器的数值分析与实验研究

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    工程实际中,许多现场环境不适合应变片的粘贴、密封、养护以及工期要求等,需要将应变粘贴、养护及密封工作提前到实验室进行。点焊薄片应变传感器能够保证焊接过程中不产生引起应变片损坏的热量。通过对电阻点焊和氩弧点焊两种薄片应变传感器进行试验研究和数值分析,证明了点焊薄片应变传感器具有很好的传递性能和疲劳性能,可以应用于复杂环境情况下的应变测量
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