等离子光量计测定稀土矿中的稀土元素

本法采用P507淋洗萃取树脂富集稀土离子,在低酸度下解脱稀土元素。控制酸度在0.6MHCI下定容,采用自制新型可拆卸的循环雾化系统,以等离子光量计分别测定15个稀土分量,实验结果表明,稀土总量在毫克量级的各稀土回收率在96.48～97.5％之间,满足矿石中测定稀土元素的要求,相对标准偏差为±0.6～6.5％。     

N′,N″-三(对甲苯磺酰)-三氨乙基胺(L)的合成和抗肿瘤活性研究

合成了一个三齿配体,并对其抗肿瘤活性进行了测试.     

强烈磁暴影响地电测量的探讨

本文探讨强烈磁暴对地电测量的影响问题。首先从麦克斯韦方程组出发、求解地球对磁暴环流的电磁感应问题、得出地面一点的分量解，进而得到地面上的磁暴效应。其次，由磁暴效应对地电网络的作用得出两个效果，最后根据对固原台资料的分析得到两点认识、可作为地电观测中干扰识别与排除的依据之一。     

热连轧轧制力计算精度模拟软件的开发

开发一种提高轧制力计算精度的软件。该软件可方便地引入操作者的经验及现场测量数据，在工程应用中能有针对性地校正轧制力模型，且简便实用。     

增压流化床（PFBC）烟气流量测量

增压流化床（ＰＦＢＣ）烟气流量测量蔡瑞洪，蒋守国，王双群，贾玉琴（东南大学热能所，南京２１００１８）为了估算烟气轮机的热效率，必须测量含尘烟气流量，ＰＦＢＣ含尘烟气经多级除尘后可使含尘浓度在２００ｍｓ／ｍ‘以下，尘粒粒径在１０ｕｒｎ以下，这种含尘烟气...     

逐步熔融凝固加工

介绍逐步熔融加工的原理，即向非诱导性的成形模内连续提供诱导性的颗粒或粉末状的原材料，利用高频加热使模内的材料熔化并保持一个较窄的区域，通过成形模与加热源的相对移动，使材料自下而上逐步地熔融和凝固，达到一次成形的目的，此外还介绍了它适应范围宽及制品的优良的物理和力学性能等优点。     

CBA甲A联赛三人裁判与两人裁判执法的比较研究

对CBA甲A联赛三人裁判与两人裁判临场执法的情况作了调研分析，对2000－2001年赛季三人裁判制与1997－1998年赛季两人裁判制的各5场比赛的临场执法情况进行了比较研究。     

生态旅游环境问题与环境承载力刍议

简要分析了生态旅游的发展现状与生态旅游环境问题的成因，在此基础上，重点探讨了生态旅游环境承载力的内涵、组成体系、指标体系，提出了提高环境承载力的对策与措施。     

Marrow mesenchymal stem cells transduced with TPO/FL genes as support for ex vivo expansion of hematopoietic stem/progenitor cells

A new marrow-derived mesenchymal stem cell (hMSC) line that could support expansion of hematopoietic stem/progenitor cells (HSPCs) was developed. Primary hMSCs were infected with retrovirus containing Flt-3 ligand and thrombopoietin genes. CD34+ cells from cord blood were expanded with primary hMSCs or transduced hMSCs. The expansion of total nucleated cells, CD34+ cells and mixed colonies containing erythroid and myeloid cells and megakaryocytes for 2 weeks coculture with transduced hMSCs was remarkably increased. The outputs of long-term culture-initiating cells for 2 and 4 weeks coculture with transduced hMSCs were also largely increased. The expansion rates of HSPCs with transduced hMSCs were unchanged for 6 weeks. In contrast, the expansion rates of HSPCs with primary hMSCs declined drastically through 6 weeks. SCID-repopulating cell expansion with transduced hMSCs for 4 weeks was significantly higher than that of uncultured CD34+ cells and HSPCs expanded with primary hMSCs. Received 21 June 2005; received after revision 30 July 2005; accepted 24 August 2005