Research for HIRFL new improvement project

According to the newest matching mode between the two cyclotrons at HIRFL, the beam obit properties were researched, especially for the harm of existing ‘over-magnetic shim’ in SSC as well as the trajectory in the new mode. The results obtained are encouraging.

固相反应制备的Pt/C催化剂对乙醇氧化的电催化活性

用固相反应法制备了Pt/C催化剂(Pt/C(s)),并研究了该催化剂对乙醇氧化的电催化活性。XRD和TEM测量表明,Pt/C(s)中Pt的平均粒径为3.8nm,结晶度为2.38,远小于用传统的液相还原方法制得的Pt/C催化剂(Pt/C(1))的平均粒径(8.5nm)和结晶度(5.56)。因此,Pt/C(s)对乙醇的电催化氧化性能远好于液相还原法制得的Pt/C(1)。

A hybrid coupled ocean-atmosphere model and ENSO prediction study

A hybrid coupled ocean-atmosphere model is designed, which consists of a global AGCM and a simple anomaly ocean model in the tropical Pacific. Retroactive experimental predictions initiated in each season from 1979 to 1994 are performed. Analyses indicate that: (1) The overall predictive capability of this model for SSTA over the central-eastern tropical Pacific can reach one year, and the error is not larger than 0.8 degrees C. (2) The prediction skill depends greatly on the season when forecasts start. However, the phenomenon of SPB (spring prediction barrier) is not found in the model. (3) The ensemble forecast method can effectively improve prediction results. A new initialization scheme is discussed.

牛山湖翘嘴鲌和红鳍原鲌的年龄与生长

于2002年4月~2003年3月研究了牛山湖翘嘴鲌(C luter alburnus)和红鳍原鲌(Cultrichthys erythropterus)的年龄组成与生长。研究结果表明,翘嘴鲌由5个年龄组组成,以2~4龄鱼为主;红鳍原鲌由3个年龄组组成,以2龄鱼为主。翘嘴鲌的平均体长和体重分别为367 mm和551 g;红鳍原鲌的平均体长和体重分别为141 mm和42 g。翘嘴鲌和红鳍原鲌的体长与体重关系式分别为W=0.00001L2.9902与W=0.000005L3.1941。牛山湖鱼类主要由适应静水生

有机氮的矿化进程及碳源添加的影响

本文运用室内恒温控湿好气培养试验研究了长期不同施肥制度培育的土壤有机N库的供氮能力；不同C／N比有机物料掺混土壤后有机N的矿化进程以及有机C源添加对其的影响。试验结果表明：长期不同施肥制度培育的土壤有机N库的供氮能力各不相同。与不施肥处理相比，长期施用化肥或有机肥均能提高土壤的供氮能力，但统计分析表明，长期单施化肥（150KgN·hm-2）与单施循环猪圈肥（约60Kg N·hm-2）处理土壤的供氮能力相似，说明有机培肥是保持和提高土壤氮素肥力的根本途径，而二者相结合可明显提高土壤供氮能力。掺混有机物料土壤中有机N的矿化进程与物料的C／N比密切相关，高C／N比的玉米秸粉能提供丰富的能源物质，但因其供应的氮素不足，微生物会固持土壤或空气中的氮而不发生有机N的净矿化释放，而低C／N比的大豆粉加入土壤后立刻会发生有机N的净矿化释放。有机C源的添加只能是暂时地抑制有机N的净矿化，但不能阻滞矿化过程的最终完成，土壤或有机物料中有机N的矿化分解是一个“持续进行、不可抑制的过程”。

WEPP模型的最新研究进展

WEPP(Water Soil Loss Equation)作为新一代水蚀预报模型,是指导水土保持措施优化配置、水土资源保护与持续利用的有效工具。近年来,遥感和GIS技术为WEPP快速获取所需资料、处理数据、图像编辑和输出等提供可靠的技术支撑;同时,区域化、尺度概念的引入,为WEPP应用于大尺度提供技术保障。为借鉴WEPP模型的优点,促进我国水蚀预报模型的发展,对WEPP模型的最新发展进行了详尽的介绍,并对WEPP应用到我国时可能存在的问题进行了初步分析。

甲醇对炭载铂和四羧基酞菁钴催化氧还原动力学的影响

运用旋转圆盘电极技术和线性扫描伏安方法研究比较了甲醇对炭载铂(Pt/C)和800℃热处理的炭载四羧基酞菁钴(CoPcTc/C)催化氧还原动力学的影响.结果表明,对于Pt/C催化剂,在大于0.64V和小于0.18V(vsSCE)的电位范围,甲醇的氧化和氧的还原互不影响,而在其它电位范围,甲醇使Pt/C催化氧还原的性能严重降低.对于800℃热处理的CoPcTc/C,在整个电位范围内,甲醇的存在对氧还原都没有影响,是一种活性较高、耐甲醇能力强的氧还原电催化剂.

直接甲醇燃料电池的耐甲醇阴极电催化剂炭载四羧基酞菁钴的研究

比较了甲醇对 Pt/C和炭载四羧基酞菁钴 (Co Pc Tc/C)催化氧还原性能的影响 .结果表明 ,甲醇使Pt/C催化氧还原的性能严重降低 ,而对经 80 0℃热处理的 Co Pc Tc/C(Co Pc Tc/C-80 0 )基本没有影响 ;并且Co Pc Tc/C-80 0催化氧还原的性能优于经其它温度热处理的 Co Pc Tc/C,Co Pc Tc/C-80 0是一种较好的直接甲醇燃料电池的耐甲醇阴极电催化剂 .XPS结果表明 ,Co Pc Tc/C-80 0的活性位可能是含 Co N4结构的物质和零价 Co的混合物.

石英砂在菱苦土磨具中的作用机理

本文利用物质结构与化学键的有关理论对石英砂的菱苦土磨具中的作用机理进行分析，并以实验对分析结果进行验证。结果表明：金刚砂晶体中Si-C共价键的离子性百分数仅为9％，石英晶体中Si-O共价键的离子性百分数为47％，因此，石英与主要以离子键结合的菱苦土结合剂之间有较强的静电作用力，石英与菱苦土的结合力强于金刚砂，可提高菱苦土磨具的耐磨性。

红原泥炭腐殖化度记录的全新世气候变化

腐殖化度作为气候代用指标首次用于我国泥炭的古气候研究,较好的记录了红原地区全新世的气候变化。对红原泥炭14 C 测年和腐殖化度分析,获得了距今12 000 年较高分辨率红原地区气候变化记录:11. 815～10. 9 kaB. P. ,气候干冷;10. 9～5. 6 kaB. P. ,气候湿暖;5. 6～3. 9 kaB. P. ,气候干冷;3. 9～1. 7 kaB. P. ,气候干冷、湿暖波动;1. 7～0 kaB. P. ,气候干冷。总体而言,大约5. 6 kaB. P. 是红原地区由早中全新世的湿暖气候向晚全新世干冷气候变化的转折点。同时,红原泥炭记录的降温事件在北半球具有普遍性,反映了青藏高原对全球气候变化的响应。

植物稳定同位素多尺度、高分辨率古气候信息综合辨识-以安图红松和红原泥炭为例

植物稳定同位素气候学因其具有坚实的理论基础，在古气候研究中倍受关注。同位素“语言”对气候变化的记录是一种“精确”记录。近30多年来，大量科学家不懈努力，提出并完善了植物C、H、O同位素分馏模型，为全球气候变化提供了理想的研究手段。古气候研究面临空前的机遇和挑战；不论是气候规律的发掘以及气候驱动机制的探讨，均需要大力加强。作者利用植物同位素气候学这一理想的研究“工具”，分别选取树轮和泥炭气候历史档案库作为信息载体，开展了中国全新世以来高分辨率、多时间尺度的气候信息综合辨识。我的工作表明：植物稳定同位素组成是理想的气候代用指标。树轮、泥炭档案库相结合，可以获得多尺度（年际、代际、百年以及千年时间尺度）、高分辨率气候信息，对于认识全球气候变化规律以及深入探讨全球气候动力学机制是十分重要的。1、安图红松树轮同位素气候代用记录研究（1）安图红松树轮同位素组成受多种气象因子的联合作用，因而单一地将某一同位素指标与某一气象因子做回归分析所得结果不甚理想。本论文构建了“温度一湿度”复合气候指标，取得了理想的结果。研究发现，不论是树轮δ13C还是δ18O，均与5-8月温湿复合指标显著相关。重建的气候变化与《安图县志》记录的气候变化事件大多吻合。证明这种新的研究方案是可行的，值得在以后的工作中进一步加强。（2）安图红松树轮δ13C灵敏地记录了该区过去200年来5-7月低云量变化。综合分析各种气象要素之间的相关关系以及气象要素与树轮δ13C之间的相关关系，作者认为，低云量对树轮δ13C的影响是一种间接影响。低云量非常显著地影响日照强度以及降雨量等气象因子，进而借助于日照强度及降雨量等气象因子在树轮δ13C中留下自身的变化“印记”。（3）功率谱分析证明，安图红松树轮δ13C、δ18O序列均包含了显著的准2年周期、准4年周期、准10-8年周期。分别是对东亚夏季风准两年振荡（QBO），ENSO准4年周期，太阳活动准11年周期的响应。（4）作者在传统树轮氢、氧同位素分馏模型基础上，同时引入“交换因子”和“蒸腾因子”两个新参数，改进了树轮氢、氧同位素分馏模型。改进的模型能利用树轮H、O同位素组成较准确模拟大气降水H、O同位素组成。改进的模型采用“自适应”方式，具有很大的灵活性，可望用于“用泥炭同位素组成模拟大气降水同位素组成”这项研究中。2、红原泥炭氧同位素气候代用记录研究（1）过去6000年来，红原温度变化趋势与金川、敦德温度变化趋势有很好的相似性，证明中国大多地区温度变化趋势是一致的。6000～4000aBP平均温度水平较低；4000-1500 aBP平均温度水平较高；1500aBP至今平均温度水平相对较低。4000aBP和1500aBP是近6000年温度变化序列中两个显著的转折点。（2）红原温度变化序列中记录到一系列低温突变，这些突变事件与金川、敦德、格陵兰、北大西洋，等等，广泛区域内温度突变事件具有很好的一致性。特别地，每当一次低温突变事件发生，通常有相应的社会结构重整、社会崩溃、古文明坍塌等重大历史事件与之对应。这进一步证实，气候变化（特别是气候突变）对整个社会经济和文明的冲击是十分明显的。（3）近6000年红原、金川温度变化趋势与大气14C变化趋势非常相似，暗示中国地区温度变化的主要驱动力来自太阳活动。功率谱分析进一步证实了这一结论。功率谱分析中最显著的周期信号是88-yr和123-127-yr年周期，体现了一种典型的世纪尺度温度变化特征。3、综合讨论（1）“红原-金川”平均温度变化趋势显示，近千年中国平均温度变化与经典的太阳活动极小期，如Darton极小、Maunder极小、sp6rer极小、oort极小，等等，表现一致。表明中国气温变化主要驱动力来自太阳活动。大约在1050-1250AD期间，中国温度水平较高。而同期大气14C，南极冰心10Be以及模拟的总太阳辐射等均表明太阳活动处于较高水平。大量树轮记录也表明近百年中国并无异常升温。这些资料表明，最近百年气温变化可能并未超出自然变率。（2）提出了“大洋温盐环流一季风”概念模型。这一模型能很好解释北大西洋温度突变与印度洋夏季风突变的一致性、中国东北和西南长期降雨趋势的反相性、北太平洋（温盐环流上翻区）温度记录与北大西洋温度记录的“跷跷板”效应（seesaw effect），等等。大洋温盐环流可能是主宰印度洋夏季风区、东亚夏季风区长期干湿变迁的主要因素。

Propofol facilitates the development of long-term depression (LTD) and impairs the maintenance of long-term potentiation (LTP) in the CA1 region of the hippocampus of anesthetized rats

Memory is sensitive to the short-acting anesthetic (2,6-diisopropylphenol) propofol, but the underlying mechanism is little known. Here, we have examined the effects of propofol on synaptic plasticity in the CA1 region of the hippocampus of anesthetized rats. We found that low dose of propofol (20 mg/kg, i.p.) did not affect the basal transmission, but enhanced prominently the development of long-term depression (LTD) and impaired the maintenance of long-term potentiation (LTP). The impairment of LTP maintenance and enhancement of LTD development may contribute to propofol-induced deficits in memory following propofol anesthesia. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.

Maintenance of Multifemale Social Organization in a Group of Nomascus concolor at Wuliang Mountain, Yunnan, China

Many short-term studies have reported groups of black crested gibbons containing >= 2 adult females (Nomascus concolor). We report the stability of multifemale groups in this species over a period of 6 yr. Our focal group and 2 neighboring groups included 2 breeding females between March 2003 and June 2009. We also habituated 1 multifemale group to observers and present detailed information concerning their social relationships over a 9-mo observation period. We investigated interindividual distances and agonistic behavior among the 5 group members. The spatial relationship between the 3 adult members (1 male, 2 females) formed an equilateral triangle. A subadult male was peripheral to the focal group, while a juvenile male maintained a closer spatial relationship with the adult members. We observed little agonistic behavior among the adult members. The close spatial relationship and lack of high rates of agonistic behavior among females suggest that the benefits of living in a multifemale group were equal to or greater than the costs for both females, given their ecological and social circumstances. The focal group occupied a large home range that was likely to provide sufficient food sources for the 2 females and their offspring. Between March 2003 and June 2009, 1 adult female gave 2 births and the other one gave 1 birth. All individuals in the focal group survived to June 2009. A long-term comparative study focused on females living in multifemale groups and females living in pair-living groups would provide insight into understanding the evolutionary mechanisms of the social system in gibbons.

Compensatory growth response in three-spined stickleback in relation to feed-deprivation protocols

Different protocols of food deprivation were used to bring two groups of juvenile three-spined sticklebacks Gaslerosteus aculeatus to the same reduced body mass in comparison with a control group fed daily ad libitum. One group experienced I week or deprivation then 2 weeks on maintenance rations. The second group experienced I week of ad lithium feeding followed by 2 weeks of deprivation. The deprived groups were reduced to a mean mass ore. 80% of controls. The compensatory growth response shown when ad libitum feeding was resumed was independent of the trajectory by which the three-spined sticklebacks had reached the reduced body mass. The compensatory response was Sufficient to return the deprived groups to the mass and length trajectories shown by the control group within 4 weeks. There was full compensation for dry mass and total lipid, but incomplete compensation for lipid-free dry mass. Hyperphagia and increased growth efficiency were present in the re-feeding phase, but there was a lag of a week before the hyperphagia was established. The consistency of the compensatory response of immature three-spined sticklebacks provides a potential model system for the analysis and prediction of appetite and growth in teleosts. (C) 2003 The Fisheries Society of the British isles.

Simultaneous genotyping of multiplex single nucleotide polymorphisms of the K-ras gene with a home-made kit

Accurate and fast genotyping of single nucleotide polymorphisms (SNPs) is important in the human genome project. Here an automated fluorescent method that can rapidly and accurately genotype multiplex known SNPs was developed by using a homemade kit, which has lower cost but higher resolution than commercial kit. With this method, oncogene K-ras was investigated, four known SNPs of K-ras gene exon 1 in 31 coloerctal cancer patients were detected. Results indicate that mutations were present in 8(26%) of 31 patients, and most mutations were localized in codon 12. The presence of these mutations is thought to be a critical step and plays an important role in human colorectal carcinogenesisas. (C) 2003 Elsevier B.V. All rights reserved.