Trace elements in human transitory milk. Variation caused by biological attributes of mother and infant

Multielement analysis was performed on human milk collected on 5-9-d postpartum from 51 Japanese females using inductively coupled plasma (ICP) mass spectrometry (MS), ICP atomic emission spectrometry (ICP-AES) and fluorometry. Thirty-one elements were detected by these analytical methods in milk. Twelve elements (Na, Mg, P, S, K, Ca, Cu, Zn, Se, Sr, Rb, and Mo) were detected in all of the samples. Al, Cs, and Ba were the elements detected by ICP-MS in more than half of the samples. Multiple regression analysis extracted biological attributes of mother and infant, such as maternal stature, maternal wt, or infant's birth wt, as statistically significant factors contributing to the variation in elemental concentration in milk. However, the rates of contribution were small in all cases. It was concluded that the biological attributes of mother and infant examined in this study were not the major factors that contribute to elemental variation in human milk.     

热处理工艺对冲击曲线的影响

通过ＳＡ５１５Ｇｒ．７０钢的不同温度正火和１３ＭｎＮｉＭｏＮｂＲ钢正火不同温度回火试样的示波冲击试验，研究了不同热处理工艺对冲击曲线的影响。     

电子商务环境下企业资源计划(ERP)的新进展

分析了在电子商务环境下企业资源计划 (ERP)需求的新特点 ,并结合ERP发展和实际应用中存在的问题 ,论述了ERP与电子商务集成化的发展方向 ,提出了企业关系管理 (ERM )的基本框架和建立商业网络 (BN)的必要性。同时 ,还论述了ERP系统在网络化、模块化和智能化的发展方向和最新进展。     

分离有机/有机混合物的PVA、CA系列膜及其渗透汽化性能研究(Ⅱ) 成膜条件对渗透汽化性能的影响

用溶剂完全蒸发法制备了PVA复合膜 .经对MTBE/MeOH混合物的分离实验得到了PVA复合膜的最佳成膜条件 ,即 :铸膜液中PVA、马来酸浓度分别为 7%、3% ,热处理温度130～ 15 0℃ .在 1%～ 2 %丙酮水溶液中浸泡处理 4～ 8h ,CTA中空纤维RO膜被改性成渗透汽化膜 .CTA中空纤维膜的分离性能优于其它醋酸纤维素系列膜 ,PVA/CA复合膜的性能优于PVA/PAN复合膜和CA/PAN复合膜     

5ZV25J-10160窄V胶带失效原因及改进措施

对川南矿区使用的5ZV25J－10160联组窄V胶带的损坏情况进行了观察分析，主要损坏原因有：胶带V形夹角与带轮轮槽夹角不一致，胶带顶部宽度与带轮轮槽开口宽度不符合要求，在传递动力中造成带轮顶部与胶带联结层接触而单根胶带悬空；胶带硫化质量差、配组不当；胶带及带轮安装、调校未达到要求。对此提出如下改进措施：规定胶带V形夹角和带轮轮槽夹角均为40°，单根胶带顶部宽25mm，带轮轮槽开口宽23．4mm；胶带必须严格按规定配组、安装、调校。实践证明，经改进后胶带传动平稳，无异常损坏。     

基于窗口的面向对象的GUI设计

文中讨论了一种基于窗口的对象用户界面设计思想及方法，详细描述了各种类的定义。在ＤＯＳ环境下运用ＷａｔｃｏｍＣ＋＋语言在微机上开发运行。它可以使用户方便地进行再开发工作，界面运用事件处理方式由窗口、弹出菜单、图标、按钮等组成。效果良好。     

Variable-gain up-converter with current reuse for 5-GHz WLAN applications

A variable-gain up-conversion mixer for 5-GHz WLAN applications is presented, whose input stage is based on a novel variable gain transconductor. The proposed topology features reduced power consumption by exploiting dc current reuse for mixer biasing. Moreover, a new low-consumption control circuit is introduced, which achieves a temperature-stable and linear-in-dB characteristic, providing a 40-dB dynamic range within ±1 dB gain error.