Heavy-ion conformal irradiation in the shallow-seated tumor therapy terminal at HIRFL

Basic research related to heavy-ion cancer therapy has been done at the Institute of Modern Physics (IMP), Chinese Academy of Sciences since 1995. Now a plan of clinical trial with heavy ions has been launched at IMP. First, superficially placed tumor treatment with heavy ions is expected in the therapy terminal at the Heavy Ion Research Facility in Lanzhou (HIRFL), where carbon ion beams with energy up to 100 MeV/u can be supplied. The shallow-seated tumor therapy terminal at HIRFL is equipped with a passive beam delivery system including two orthogonal dipole magnets, which continuously scan pencil beams laterally and generate a broad and uniform irradiation field, a motor-driven energy degrader and a multi-leaf collimator. Two different types of range modulator, ripple filter and ridge filter with which Guassian-shaped physical dose and uniform biological effective dose Bragg peaks can be shaped for therapeutic ion beams respectively, have been designed and manufactured. Therefore, two-dimensional and three-dimensional conformal irradiations to tumors can be performed with the passive beam delivery system at the earlier therapy terminal. Both the conformal irradiation methods have been verified experimentally and carbon-ion conformal irradiations to patients with superficially placed tumors have been carried out at HIRFL since November 2006.

Characterization of complex hydrocarbons in cigarette smoke condensate by gas chromatography-mass spectrometry and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry

Gas chromatography-mass spectrometry with electron ionization and positive-ion chemical ionization and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC x GC-TOF-MS) were applied for the characterization of the chemical composition of complex hydrocarbons in the non-polar neutral fraction of cigarette smoke condensates. Automated data processing by TOF-MS software combined with structured chromatograms and manual review of library hits were used to assign the components from GC x GC-TOF-MS analysis. The distributions of aliphatic hydrocarbons and aromatics were also investigated. Over 100 isoprenoid hydrocarbons were detected, including carotene degradation products, phytadiene isomers and carbocyclic diterpenoids. A total of 1800 hydrocarbons were tentatively identified, including aliphatic hydrocarbons, aromatics, and isoprenoid hydrocarbons. The identified hydrocarbons by GC x GC-TOF-MS were far more than those by GC-MS. (C) 2004 Elsevier B.V. All rights reserved.

水分胁迫对抗旱性不同小麦品种叶片光合及根呼吸等生理特性的影响

以两个抗旱性不同的小麦品种西农1043、陕253为材料,采用盆栽与水培试验相结合的方式,研究水分亏缺对小麦不同生育期叶片光合及根呼吸速率等生理指标的影响。结果表明:相同水分处理下,抗旱品种西农1043与水分敏感品种陕253相比,具有较高的光合和根呼吸速率、以及相对较高的保护酶活性;水分胁迫下,两个小麦品种叶片光合和根呼吸速率及苗期叶保护酶活性均降低;两种水分处理下抗旱性强的西农1043根呼吸所占光合的比例相对高于陕253。

黄土区退果还耕对黑垆土硝态氮积累和迁移的影响

在黄土高原沟壑区王东沟小流域,针对塬面、梁地和坡地三种地形,分别选取了盛果期果园、老果园和退果还耕地等,研究了退果还耕条件下,三种地貌类型土壤剖面中水分含量变化及NO_3~--N、NH_4~+-N积累和迁移规律。结果表明,无论塬面、梁地或者坡地上,果园土壤水分含量显著降低(10%～14%);果园退耕后,土壤水分开始缓慢恢复。盛果期,塬面NO_3~--N峰值主要处于100—200 cm之间,退果还耕后,100 cm以上土层中NO_3~--N含量降低,100cm以下NO_3~--N积累量在增加,并且峰值不断向下移动。盛果期果园NO_3~--N积累量为631～3032 kg/hm~2;退果还耕地、老果园NO_3~--N积累量都显著高于盛果期果园。盛果期40%以上的NO_3~--N积累在100—200 cm土层,但退果还耕地上50%左右集中分布在200—300 cm土层。土地利用与管理方式的变化对NH_4~+-N分布特征的影响并不明显。

黄土高原地区雨水集蓄利用技术发展评述

通过对黄土高原地区雨水集蓄利用技术发展现状的全面分析 ,指出了目前该地区雨水集蓄利用技术推广应用中存在的主要问题 ,最后提出了发展本地区先进、高效、适用雨水集蓄利用技术的具体对策

Two dimensional nuclear magnetic resonance analysis of bis(2,2 '-bipyridine)(2,2 '-bipyridine-4,4 '-dicarboxylic acid)ruthenium(II) hexafluorophosphate

The H-1 and C-13 nuclear magnetic resonance(NMR) spectra are reported for bis(2, 2'-bipyridine)(2, 2'-bipyridine-,4,4'-dicarboxylic acid) ruthenium(II) hexafluoruphosphate that has been used as a tagged molecule of electrochemiluminescent immunoassay. Because of the effect of Ru atom on ligands, it is difficult to assign its NMR spectra. BS' means of two dimensional H-1-H-1 COSY and H-1-C-13 COSY techniques, the H-1 and C-13 NMR spectra of bis (2, 2'-bipylidine) (2, 2'-bipyridine-4, 4-dicarboxylic acid) ruthenium(II) hexafluorophosphate are assigned completely. This provides a basis for NMR characterization of the nerv similar tagged molecules.

六氟磷酸二(2,2’-联吡啶)(2,2’-联吡啶-4,4’-二羧酸)合钌(Ⅱ)的二维核磁共振谱分析

利用核磁共振氢谱和碳谱研究了电化学探针六氟磷酸二(2,2＇-联吡啶)(2,2＇-联吡啶-4,4’-二羧酸)合钌(Ⅱ)的立体结构,并通过二维~1H~1同核相关及~1H-~(13)C异核相关技术对其氢谱和碳谱进行了归属.

SENSITIVE AMPEROMETRIC DETECTION OF GLUCOSE BY REVERSED PHASE LIQUID-CHROMATOGRAPHY AT A PRUSSIAN BLUE CHEMICALLY MODIFIED ELECTRODE OF NOVEL CONSTRUCTION

A new liquid chromatography electrochemical (LCEC) scheme for glucose sensing has been developed on the basis of a Prussian Blue chemically modified electrode (CME) of novel construction and characterized in terms of various experimental parameters by the flow injection analysis (FIA) technique. Unique hydrodynamic voltammograms were obtained for the first time at the CME in the flow-through amperometric detection of glucose, and subsequently both anodic and cathodic peaks could be expected on monitoring the operating potential in the modest positive or negative region. The unique pH dependence on the CME response towards glucose makes it perfectly compatible with conventional reversed phase liquid chromatography systems. On the basis of these features, practical application in glucose LCEC detection has been effectively performed; a linear response range over three orders of magnitude and a detection limit of subpicomole level were readily obtained. The capability of the established LCEC mode in the direct sensing of urinary glucose has been demonstrated.

有机共沉淀-石墨炉原子吸收光谱法测定高纯氧化镧、氧化钇中微量钴和镍

本文系用吡咯啶二硫代氨基甲酸铵(APDC)在0.3mol/L硝酸介质中共沉淀、石墨炉原子吸收法测定了高纯氧化镧、氧化钇中微量钴和镍、对于钴和镍的相对标准偏差分别为1.9～3.0％和3.9～4.1％;回收率分别为100～103％和95～100％;检出限分别为9.6×10~-(10)g和9.9×10~-(10)g。