Neutron and proton diffusion in fusion reactions for the synthesis of superheavy nuclei

The restriction of the one dimensional (1D) master equation (ME) with the mass number of the projectile-like fragment as a variable is studied, and a two-dimensional (2D) master equation with the neutron and proton numbers as independent variables is set up, and solved numerically. Our study showed that the 2D ME can describe the fusion process well in all projectile-target combinations. Therefore the possible channels to synthesize super-heavy nuclei can be studied correctly in wider possibilities. The available condition for employing 1D ME is pointed out.

SARS起源于污染对病毒进化的加速诱导

针对当前广为流传的SARS病毒“太空起源说”和“野生动物来源说”两种理论 ,本文根据污染进化生态学原理和SARS病毒发病传染特征 ,以有关实验结果为科学依据 ,阐述了SARS病毒的起源问题 ,指出 :我国当前环境日益严重的复合污染为SARS致病病毒的产生提供了适宜的外部生态条件和物质基础 ,SARS致病病毒可能起源于多个病毒的基因重组或融合 ,更可能是一种来自于感冒病毒进化而形成的超级感冒病毒 .可以预料 ,这一推断将为彻底解决SARS的病源提供有价值的理论指导

Separation of enantiomers by nanoliquid chromatography and capillary electrochromatography using a bonded cellulose trisphenylcarbamate stationary phase

A cellulose trisphenylcarbamate-bonded chiral stationary phase was applied to nano-liquid chromatography (nano-LC) and capillary electrochromatography (CEC) with nonaqueous and aqueous solutions as the mobile phases. Several chiral compounds were successfully resolved on the prepared phase by nano-LC. The applicability of nonaqueous CEC on a cellulose derivative stationary phase was investigated with the organic solvents methanol, hexane, 2-propanol, and tetrahydrofuran (THF) containing acetic acid, as well as triethylamine as the mobile phases. Enantiomers of warfarin and praziquantel were baseline-resolved with plate numbers of 82 300 and 38 800 plates/m, respectively, for the first eluting enantiomer. The influence of applied voltage, concentration of nonpolar solvent, apparent pH, and buffer concentration in the mobile phase on the electroosmotic flow (EOF) and the mobility of the enantiomers was evaluated. Enantioseparations of traps-stilbene oxide and praziquantel were also achieved in aqueous CEC with plate numbers of 111 100 and 107 400 plates/m, respectively, for the first eluting enantiomer. A comparison between nonaqueous CEC and aqueous CEC based on a cellulose trisphenylcarbamate stationary phase was discussed. Pressure-assisted CEC was examined for the chiral separation of praziquantel and faster analysis with high enantioselectivity was acquired with the proper pressurization of the inlet vial.

中国黄土地区耕作侵蚀模拟(英文)

耕作侵蚀是国际上新近开展的一个研究领域。为了对中国黄土地区的耕作侵蚀规律进行定量描述 ,采用施放小立方块作为示踪材料进行耕作试验及测量来示踪和监测土壤运动 ,并通过相关分析与理论推导 ,对该地区的耕作侵蚀进行了模拟 ,获得了能够直接计算出坡面剖面任何一点净侵蚀模数的耕作侵蚀模型 ,结果表明 ,在采用当地由动物牵引的传统犁在坡面上自下而上进行往返横坡等高向下翻土耕作方式下 :1)一次耕作导致的耕层土壤朝坡向方向平均水平运动距离随坡度的变化表现为线性相关 ;2 )一次耕作导致的坡面剖面任何位置耕层断面的净侵蚀模数 ,受土壤容重、耕作深度、土壤与耕作条件决定的系数和地形曲率的影响。

Room-temperature synthesis and luminescence properties of Eu3+/Tb3+-doped La(1,3,5-BTC)(H2O)(6)

The facile, rapid, and effective synthesis of coordination polymer La(1,3,5-BTC)(H2O)(6) has been realized via direct precipitation at room temperature. It is found that the crystal structure is of monoclinic, space group Cc. The doped Eu3+ or Tb3+ ions samples have the same phase and exhibit red and green emissions under UV light excitation, respectively.

Thermo- and pH-sensitive poly(vinylmethyl ether)/carboxymethylchitosan hydrogels crosslinked using electron beam irradiation or using glutaraldehyde as a crosslinker

BACKGROUND: Stimuli-sensitive or intelligent hydrogels have been investigated for many biomedical and pharmaceutical applications. Those hydrogels with dual sensitivity will have more extensive potential applications. The aim of the work presented was to prepare a series of thermo- and pH-sensitive hydrogels based on poly(vinylmethyl ether) (PVME) and carboxymethylchitosan (CMCS). The hydrogels were crosslinked using electron beam irradiation (EB) or using glutaraldehyde (GA) as a crosslinker at room temperature.

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.

混合稀土中单一稀土元素的化学分析

本文提出以2-乙基己基膦酸-2-乙基己脂(P507)萃取柱色谱分离,EDTA络合滴定混合稀土中单一稀土元素,并应用于多种混合稀土氧化物中单一稀土的全分析。本方法所需设备简单,分析结果准确可靠。

馆养海豚的饲养、疾病防治研究及海洋哺乳动物环境标本库的建立

以馆养北太平洋宽吻海豚为研究对象，在海豚馆和水族馆等场所开展了大量的现场实验和行为学研究；通过出海考察、“调查卡”统计、整理历史资料等方式，总结了中国海洋哺乳动物的资源现状，并对我国典型海域中的海洋哺乳动物标本通过目前较为先进的中子活化(INAA)等技术进行了一系列的分析研究。主要结果如下： 1通过对海豚馆的先后10头海豚进行的长达5年的现场实验，首次提出并建立了适合海豚生长的水质标准体系，其中，盐度范围是29-32，PH值范围是7.8-8.2，氯浓度范围是0.3—1.5mg／L，溶解氧范围为5.0—8.8×10~(-6)，大肠菌群不超过200MPN等等，这为国内各地海兽馆中的海兽饲养提供了参照标准，为我国海兽饲养业的发展提供了可靠的基础资料。2 通过对海豚的每一批饵料鱼体营养成分的测定分析(粗蛋白、粗脂肪、灰分、水分和总细菌数)，进而通过对海豚的食性、日食量及食前反应、食后反应等方面的研究，发现了海豚的季节性饮食喜好规律，即海豚在冬天喜欢采食鲐鱼等高能量型鱼类，在夏天喜1欢采食带鱼等低能量型鱼类，首次建立了海豚的饵料投喂、营养补充物质的适量添加及定期进行驱虫、接种疫苗和体格检查等科学饲养管理方法体系。3通过对北太平洋宽吻海豚进行的500余头次的生理指标的测定(直接获得有关数据9000多个)，在国内首次建立了多头宽吻海豚的生理指标档案和数据库，主要包括血常规指标、血液生化指标、体温、呼吸频率等45个指标。4在宽吻海豚生理指标档案和数据库基础上，运用了适当的计算方法，结合相应的生理学意义，统计归纳出了宽吻海豚各生理指标的正常阈值和范围，如白细胞的正常阈值为3.797×10~9个／L-11.56×10~9个／L等等，此生理指标阈值范围体系是准确了解海豚机体的生理状况、疾病诊断及治疗的关键依据。5 发现了海豚各生理指标间的相关关系及生理指标与海豚疾病诊断间的关系规律，基本形成了宽吻海豚常见疾病的诊断和防治方法体系，如海豚血液指标中的K~+值降低，白蛋白与球蛋白比值 (A／G)下降，表明海豚机体脱水，电解质代谢紊乱；海豚血液中 的谷草转氨酶、谷丙转氨酶大幅升高，中性粒细胞值上升，胆红素值升高，表明海豚的肝脏功能异常等等。其中，治愈铜绿假单孢菌感染经查新属国际领先水平。6 总结了中国海洋哺乳动物的资源现状，并通过中子活化技术、等离子体耦合原子发射谱技术和原子发射谱技术，对日本下关海豚、秦皇岛海豚、莱州湾海豚和秦皇岛江豚的肌肉、肝脏、肾脏、心脏和肺等样品进行了多元素的测定分析，测出了其中的27种元素的含量，初步建立了中国海洋哺乳动物环境标本库。7 通过对所测海洋哺乳动物器官样品中的元素含量的比较，发现海洋哺乳动物的不同器官富集元素的能力明显不同，各器官的富集能力基本是肝脏 > 肾脏 > 心脏 > 肺 > 肌肉，海兽肌肉不适合作为环境标本库的样品，而肝脏和肾脏较为适合作为海洋哺乳动物环境标本库的样品。8 所测海兽器官样品中的大多元素的含量值与阿拉斯加环境标本库的结果相似，只有Zn、Cu、Pb和Hg的含量远远高于阿拉斯加环境标本库的结果，而与中国人体肝脏的相应元素的含量基本相似。日本下关海豚肝脏中的Cd、Co、Cr、Cu、Pb、V和Zn元素的含量高于秦皇岛海豚和莱州湾海豚肝脏中对应元素的含量，而秦皇岛海豚肝脏中的As、Cu、和Ni的含量又高于莱州湾海豚肝脏中的相应元素的含量。

An inventory of forest relicts in the pastures of Southern Tibet (Xizang AR, China)

An inventory of isolated tree stands surrounded by desert pastures in Southern Tibet (A.R. Xizang, China) revealed more than 50 sites with vigorous trees of Juniperus convallium Rehder & E.H. Wilson and Juniperus tibetica Kom and additional more than 10 records where juniper trees had been destroyed between 1959-1976. The tree stands are not restricted to any specific habitat, and occur within an area stretching 650 km westwards from the current forest border of Southern Tibet. The trees are religious landmarks of the Tibetan Buddhists. The highest trees were found at an elevation of 4,860 m. Vegetation records, rainfall correlations and temperature data collected by local climate stations and successful reforestation trials since 1999 indicate that forest relicts fragmented through human interference could regenerate if current cattle grazing and deforestation practices are halted. The drought line of Juniperus forests in Southern Tibet is approximately 200-250 mm/a. A first pollen diagram from Lhasa shows forest decline associated with the presence of humans since at least 4,600 yr BP. The currently degraded commons developed in the last 600 yr. To date, no findings of remains of ancient forests in the Central Tibetan Highlands of the Changtang have been reported.

澳大利亚阿德莱德地区大气重力波的气辉观测研究

气辉是研究中高层大气及电离层高度的重力波的传播特性的一种重要手段。本文利用澳大利亚阿德莱德地区一个三镜头气辉仪7年的OH和OI气辉观测数据，结合同一地区中频雷达所测日平均风场数据，采用最大熵谱分析方法，分析研究了该地区上空中层顶区域重力波的统计传播特性，并研究了重力波在中层顶区域的垂直传播特征。结果表明: （1）在中层顶气辉观测区，通过OH和OI分别探测到49个和28个周期大于40分钟的重力波事件。统计结果表明，在OH和OI两个高度上观测到的较大尺度重力波主要集中在周期为68分钟，水平相速度为36米/秒。同时这些重力波接近水平方向传播，具有东南向的优势传播方向。OH仰角平均为10度，OI为8度。表明传播到中层顶气辉层区域的这些重力波可能产生于相距观测点很远的地方，并且受到背景风场的方向滤波和拉伸的作用。 （2）在1999年1月12日晚上的气辉观测中， 我们通过OH和OI气辉在两个不同高度上观测到了同一次重力波事件，根据两个高度上观测到的扰动时序相位差， 我们判断该重力波为上行波。然而，我们所得到的大部分事例中，符合在两个高度上观测到的重力波事例之间具有明显相关性的极少。分析表明，由于该气辉仪及其观测方法本身存在固有的误差，同时也因为重力波在中层顶高度受到强烈的风剪切作用而导致传播相位的改变，使得我们很少能在两个气辉探测高度上观测到同一个重力波事件。

Proposta para classificação de organossolos em níveis inferiores com base nas frações húmicas.

Este estudo foi desenvolvido com base em 19 perfis de Organossolos e solos afins descritos e coletados em diferentes regiões do Brasil. As amostras foram caracterizadas para fins de classificação e tiveram sua matéria orgânica fracionada nas frações ácidos fúlvicos, ácidos húmicos e humina. A partir desses valores foram calculados os índices FAH/FAF e EA/HUM. As variaáveis obtidas pelo fracionamento das substâncias húmicas apresentarm correlação significativa com diferentes atibutos dos Organossolos. Com base nos teores absolutos das frações ácidos fúlvicos, ácidos húmicos e na relação EA/HUM, foram propostos índices para separação dos Organossolos. Com base nos teores absolutos das frações ácidos fúlvicos, ácidos húmicos e na relação EA/HUM, foram propostos índices para separação dos Organossolos nos 5o. e 6o. níveis categóricos.

Apocryffa Si?n Cent

Bryant-Quinn, M. (2004). Apocryffa Si?n Cent. Cyfres Beirdd yr Uchelwyr, 26. Aberystwyth: Canolfan Uwchefrydiau Cymreig a Cheltaidd Prifysgol Cymru.