117 resultados para 417


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IEECAS SKLLQG

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IEECAS SKLLQG

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报道了一种在束测量β+ 延发粒子的方法。由新建成的兰州放射性次级束流线 (RIBLL )提供的2 0 Na次级束 ,利用飞行时间 (TOF)和能损 (ΔE)符合的方法实现 2 0 Na次级束流的在束鉴别与调制。将数据获取过程分为有束和停束两个获取时段 ,分别完成对次级束流和β+ 延发粒子的记录。同时利用脉冲发生器和计数器实现2 0 Na延发粒子衰变半衰期的测量

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用同位旋相关的Boltzmann Langevin方程研究了在入射能量为2 8 7MeV/u下 ,不同弹核 14O ,16 O和 18O轰击不同靶核 7Be和 9Be的反应 ,计算了生成碎片的产生截面 ,发现用丰中子 (缺中子 )炮弹或丰中子 (缺中子 )靶进行反应 ,所得到的产物均有丰中子 (缺中子 )的碎片出现 .同位素分布宽度和峰位与入射体系密切相关 ,产生碎片的电荷数越接近入射弹核的电荷数 ,则同位素分布的宽度越大 ,峰位偏离β稳定线值越远 ,其同位旋效应越明显 .

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This study reports a method for high-frequency shoot organogenesis and plant establishment of Potentilla potaninii Wolf. Hypocotyl and cotyledon explants of P. potaninii were cultured on Murashige and Skoog (MS) medium supplemented with various concentrations of benzyladenine (BA) and alpha-naphthaleneacetic acid (NAA) to induce adventitious shoot formation for micropropagation. The highest frequency of adventitious shoot regeneration was achieved from hypocotyl and cotyledon explants grown on MS medium supplemented with 5.0 mg l(-1) BA and 1.0 mg l(-1) NAA. The regenerated shoots rooted most efficiently on half-strength MS medium supplemented with 1.0 mg l(-1) NAA and 0.5 mg l(-1) indole-3-acetic acid or indole-3-butyric acid. The acclimatized plants with normal morphology and growth characters flowered and set seeds in the following year.

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在HIRFL-CSR(兰州重离子冷却储存环)电源控制系统中,Kicker电源需要控制器提供高压充电电压基准电压信号和触发信号,采集基准电压信号,将电源充电电压与期望值进行比较,如果有偏差,则进行修正,使实际值与期望值一致。为Kicker电源设计的电源控制器采用DSP作为处理器,采用串行DAC为电源提供基准电压波形,基准电压信号回读用并行ADC来完成。论文首先简要介绍了Kicker电源系统,根据控制器的设计要求,选用TI公司的TMS320VC5402芯片,给出了控制器的总体设计。其次,具体介绍了TMS320VC5402的结构、外围设备,给出了电路设 计原理图,以及与存储器连接电路图,并分别介绍了硬件系统各个部分的电路设计以及FPGA部分设计。再次,介绍了DSP编程环境CCS,给出了FLASH擦写过程以及二次下载原理,并详细论述了基准电压信号发送的编写,并对回读的基准电压信号进行了滤波处理。最后,对电源控制器的设计进行了总结。论文完成了Kicker磁铁电源控制器的硬件设计和底层软件设计,为以后在该硬件平台上下一步工作打下了坚实的基础

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Natl Chiao Tung Univ, Dept Comp Sci

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According to two times investigation on Scarabaeoidea of Huitong secondary Cunninghamia lanceolata forest in early spring,summer, the number of species Scarabaeoidea in early spring,and summer is 23 and 24,respectively; the Shannon diversity index is 2.067 and 2.417, respectivety; the Shannon evenness is 0.659 and 0.761.In early spring, the dominant species are Malatera horosericea,Melolontha frater and Granida albosparsa.In summer, The dominant species are Anomala vividana, Anomala alabopilosa and Anomala lucens.The species abundance distribution of Scarabaeoidea in two different seasons is fitted in to logarithmic series distribution. A small number of species often become dominant in different seasons.

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概述了国际全球变化研究计划(ESSP、IGBP、WCRP、IHDP、DIVERSITAS)新近的研究战略调整和研究重点,在对国际全球变化研究成果综合分析的基础上,总结了全球变化研究的阶段性理论进展,归纳了全球变化研究的特点和趋势。

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Cinnabar, an important traditional Chinese mineral medicine, has been widely used as a Chinese patent medicine ingredient for sedative therapy. However, the pharmaceutical and toxicological effects of cinnabar, especially in the whole organism, were subjected to few investigations. In this study, an NMR-based metabolomics approach has been applied to investigate the toxicological effects of cinnabar after intragastrical administration (dosed at 0.5, 2 and 5 g/kg body weight) on male Wistar rats.

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The elastic anisotropy of the potential low compressible and hard materials OsB2 and RuB2 were studied by first-principles investigation within density functional theory. The structure, elastic constants, bulk modulus, shear modulus, Poisson's ratio and Debye temperature have been calculated within both local density approximation (LDA) and generalized gradient approximation (GGA). The results indicated that the calculated bulk modulus and shear modulus were in good agreement with the experimental and previous theoretical studies.

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In general, the reduction of Eu3+ to Eu2+ in solids needs an annealing Process in a reducing atmosphere. in this paper, it is of great interest and importance to find that the reduction of Eu3+ to Eu2+ can be realized in a series of alkaline-earth metal aluminum silicates MAl2Si2O8 (M = Ca, Sr, Ba) just in air condition. The Eu2+-doped MAl2Si2O8 (M = Ca, Sr, Ba) powder samples were prepared in air atmosphere by Pechini-type sol-gel process. It was found that the strong hand emissions of 4f(6)5d(1)-4f(7) from Eu2+ were observed at 417, 404 and 373 nm in air-annealed CaAl2Si2O8, SrAl2Si2O8 and BaAl2Si2O8, respectively, under ultraviolet excitation although the Eu3+ precursors were employed. In addition, under low-voltage electron beam excitation, Eu2+-doped MAl2Si2O8 also shows strong blue or ultraviolet emission corresponding to 4f(6)5d(1)-4f(7) transition.

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Chitosan(chitin)/cellulose composites as biodegradable biosorbents were prepared under an environment-friendly preparation processes using ionic liquids. Infrared and X-ray photoelectron spectra indicated the stronger intermolecular hydrogen bond between chitosan and cellulose, and the hydroxyl and amine groups were believed to be the metal ion binding sites. Among the prepared biosorbents, freeze-dried composite had higher adsorption capacity and better stability. The capacity of adsorption was found to be Cu(II) (0.417 mmol/g) > Zn(II) (0.303 mmol/g) > Cr(VI) (0.251 mmol/g) > Ni(II) (0.225 mmol/g) > Ph(II) (0.127 mmol/g) at the same initial concentration 5 mmol L-1. In contrast to some other chitosan-type biosorbents, preparation and component of the biosorbent were obviously more environment friendly. Moreover, adsorption capacity of chitosan in the blending biosorbent could be fully shown.

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对Cyanex923(925)/[C8mim][PF6]和TBP/[A336][NO3]两个离子液基体系在萃取Sc(Ⅲ)中的应用进行了研究。实验表明,由于空间位阻较小,Cyanex923在[C8mim][PF6]中对Sc(Ⅲ)的萃取能力明显优于Cyanex925。温度对Cyanex923/[C8mim][PF6]体系萃取Sc(Ⅲ)的影响较小。与[C8mim][PF6]相反,[A336][NO3]在水中的浓度随酸度增加逐步减少。TBP/[A336][NO3]对Sc(Ⅲ)具有较高的萃取率。