Experimental results of helicon sources

Helicon plasma source is known as an efficient generator of uniform and high density plasma. A helicon plasma source was developed for the investigation of plasma striping and plasma lens at the Institute of Modern Physics, CAS. In this paper, the characteristics of helicon plasma have been studied by using Langmuir four-probe and a high plasma density up to 3.9×1013 /cm3 has been achieved with the Nagoya type III antenna. In the experiment, several important phenomena have been found: (1) for a given magnetic induction intensity, the plasma density became greater with the increase of RF power; (2) the helicon mode appeared at the RF power between 300 W and 400 W; (3) the plasma density gradually tended to saturation as the RF power increased to the higher power; (4) a higher plasma density can be obtained by a good matching between the RF power and the magnetic field distribution. The key issue is how to optimize the matching between the RF power and the magnetic field. Moreover, some tests on the extraction of ion beam were performed, and the preliminary results were given. The problems which existed in the helicon ion source will be discussed and the increase in beam density will be expected by extraction system optimum.

VIC068A在电源控制系统中的应用

VME总线为单处理器或多处理器的高速并行传输建立了标准体系规范,利用桥接芯片VIC068A的硬件逻辑连接实现网络处理芯片与VME背板总线之间的通讯,将后台计算机数据库及前端设备通过网络和VME总线紧密地连接起来,实现数据的快速获取与给定。

萨拉乌苏河流域mgs3地层段腹足类动物化石种类及气候环境

IEECAS SKLLQG

平顶波加速对束流纵向相空间的影响

介绍了平顶波加速技术的基本思想 ,并研究了在回旋加速器中 ,平顶波加速腔各主要参数 ,如其频率、电压及其稳定度等对束流纵向相空间的影响 .

海洋微生物生物活性物质研究

海洋微生物以其分类的多样性和遗传背景的特殊性而具有产生新型生物活性物质的巨大潜力 .本文对海洋微生物产生的生物活性物质的研究进展进行了综述 .从报道的研究结果看 ,占海洋微生物主导地位的海洋细菌产生的活性物质种类最为丰富 ;海洋真菌和海洋放线菌虽非海洋微生物中的主要菌群 ,但其产生新型生物活性物质的潜能不可低估 .此外 ,目前研究主要局限于那些在常规条件下易于培养的微生物类群 ,今后的趋势之一是对于非可培养海洋微生物产生的生物活性物质的探索 .我国应充分利用国内海洋微生物资源优势加强这一领域的研究 .

几种酸性土壤供氮力测定方法的综合评价

模拟旱地条件进行黑麦草盆栽试验,对不同供氮力指标与黑麦草吸氮量相关性进行研究,结果表明,短期好气培养法测定的可矿化氮与吸氮量相关系数为0.820;氯化钾与氯化钙浸提的硝态氮与黑麦草吸氮量的相关系数分别为0.892和0.916,表明硝态氮含量作为土壤供氮能力指标具有一定的稳定性;微生物量氮的测定结果不够稳定且与黑麦草吸氮量相关性不高(r=0.751)。分析表明,氯仿熏蒸-浸提全氮与吸氮量的相关性最好,相关系数可达0.941,是一个较好的供氮力指标。

Effect of silver nanoparticles on luminescent properties of europium complex in di-ureasil hybrid materials

Organic-inorganic hybrids containing luminescent lanthanide complex Eu(tta)(3)Phen (tta = thenoyltrifluoroaceton, phen = 1,10-phenanthroline) and silver nanoparticles have been prepared via mixing rare earth complex and nanoparticles with the precursors of di-ureasil using a sol-gel process. The obtained hybrid materials with transparent and elastomeric features were characterized by transmission electron microscope, solid-state Si-29 magic-angle spinning NMR spectra, diffuse reflectance, UV-visible absorption and photoluminescence spectroscopies. The effect of the silver nanoparticles on the luminescence properties was investigated. The experimental results showed that the luminescence intensity of the Eu(tta)(3)phen complex could be enhanced by less than ca. 9.5 nM of silver nanoparticles with the average diameter of 4 nm, and reached its maximum at the concentration of ca. 3.6 nM. Further increasing the concentration of the silver nanoparticles (> 9.5 nM) made the luminescence quenched. The enchancement and quench mechnism was discussed.

微过氧化物酶-8与Eu~(3+)相互作用的机理

用紫外 -可见 ( UV-Vis)吸收光谱和电化学方法研究 Eu3+ 与微过氧化物酶 -8( MP-8)相互作用的机理 ,发现 Eu3+优先与 MP-8中血红素基团的 2个丙酸基的羧基氧发生强的配位作用 ,导致 MP-8分子中血红素基团的非平面性、暴露程度和电化学可逆性的增加 .过剩的 Eu3+与 MP-8分子中肽链上的含氧基团发生弱的相互作用 ,对血红素基团结构的影响较小

Hydrothermal synthesis and structure of [Ni(en)(2)V6O14](n)

A new complex [Ni (en)(2)V6O14](n) was hydrothermally synthesized and characterized by 2-dimensional vanadium oxide framework pillared by Ni(en)(2)group. Single crystal X-ray analysis indicates that this compound crystallizes in monoclinic system, space group P2(1)/c with a=0. 892 17(18) nm, b = 1. 711 1(3) nm, c=0. 662 73(13) nm, beta=111. 58(3)degrees, V=0.940 8(3) nm(3), Z=2, D-c=2.501 g/cm(3), R=0. 042 3, omegaR=0. 060 9, S=1. 006.

Syntheses and structures of Na-2[Zn-II(ida)(2)].7H(2)O and Na-4[Hg-II(nta)(2)].7H(2)O

The title complexes were synthesized and the crystal structures of their salts were determined by single-crystal X-ray structure analyses. Na-2[Zn-I(ida)(2)]. 7H(2)O: Triclinic, P1, a=0.523 4(2) nm, b=0.897 10(10) nm, c=1.069 10(10) nm, alpha=85.910(10)degrees, beta= 76.380(10)degrees, gamma=83.52(2)degrees, V=0.484 2(2) nm(3), Z=1. The complex anion [Zn-I (ida)(2)](2-) has a pseudo-octahedral structure in which the two N atoms: are in a trans configuration. Na-4[Hg-I(nta)(2)]. 7H(2)O: Monoclinic, C-c, a = 1.795 0(4) nm, b = 0.892 9(2)nm, c = 1.575 4(2) nm, beta = 92.78 (3)degrees, V = 2.526 2(9) nm(3), Z = 4. The complex anion [Hg-I (nta)(2)](4-) has a pseudo-bicapped-octahedral structure in which the two N atoms are in a trans configuration.

双环己基18冠6对水/硝基苯界面离子的促进传输

Li~-和H~-因较强的亲水性,较难穿越液/液界面进行传输。本文报道了冠醚双环已基18冠6对Li~+,Na~+,Rb~-和H~-在水/硝基苯界面的促进传输行为,求得了相应促进传输过程的一系列参数,并对被传输离子在传输过程中的形态变化进行了初步的探讨。