银川部分污灌区生产大米铅含量分析

采用电感耦合等离子体-原子发射光谱(ICP-AES),测定分析了银川地区紫金花造纸厂污灌区生产大米的铅的质量分数.分析结果显示:该污灌区生产大米中铅的质量分数平均值为4.5mg/kg(n=5),RSD<1%,超过国家对食品中铅的质量分数规定的最高限定值10倍,说明该大米已不能食用;由于尚未超过国家对动物饲料规定的铅的质量分数的最高限定值,因此它尚可作为饲料,但已接近临界状态.     

液态软包装锂离子蓄电池的研制

应用软包装技术成功开发出053048型液态软包装锂离子蓄电池。对液态软包装锂离子蓄电池制造工艺流程作了简单介绍,选用优质包装膜,采用冲壳成型技术与热板粘结技术,并对极耳进行技术处理,实现了电池的封装。电池性能测试结果表明,0.2 C、0.5 C和1 C放电容量均达到500 mAh以上,1 C循环300次后容量保持在90%左右,环境适应性、高低温性能、短路性能、自放电性能均达到或超过了国家标准。液态软包装锂离子蓄电池具有价格、性能及工艺的竞争优势和广阔的市场前景。     

铜接地体技术在GIS变电站工程中的探索与实践

本文通过阐述铜接地体技术的基本原理,结合广东省江门市220kV新会变电站和广东省台山电厂220kV铜鼓升压站等GIS配电装置变电站工程实例,分析铜接地体与常规接地体的优劣与互补性,探索出一套适用于GIS变电站的铜接地体技术。     

感耦等离子体原子发射光谱法测定高纯铅中杂质元素的干扰研究

文章介绍了用ＩＣＰ－ＡＥＳ法测定高纯铅中杂质元素时，Ｐｂ对分析元素的干扰情况。Ｐｂ对Ｇｅ、Ｍｏ、Ｐ、Ａｓ、Ｆｅ、Ｂｉ、Ｍｎ有背景影响，对Ｓｂ产生谱线干扰。１０ｍｇ／ｍｌ的Ｐｂ分别产生相当于０．２３５μｇ／ｍｌＡｓ、０．７５０μｇ／ｍｌＰ、０．３３５μｇ／ｍｌＭｏ和３．９５０μｇ／ｍｌＳｂ的信号。     

液氮传导冷却型高温超导电流引线研制

80 A和200 A液氮传导冷却型高温超导(HTS)电流引线由铜引线段、中间过渡段和高温超导段组成,HTS热端采用液氮传导冷却,HTS冷端采用液氦传导冷却。铜引线段工作在室温到中间温度(~80 K),高温超导段工作温区6—80 K。介绍该传导冷却型电流引线的结构设计和低温性能测试。实验结果表明,中间过渡段温度~78 K,高温超导热端温度77 K;80 A、200 A电流引线液氦下稳态测试电流分别为100 A和250 A。     

Price and lead time differentiation,capacity strategy and market competition

We study a duopoly market in which customers are heterogeneous, and can be segmented as price or time sensitive. Each firm tailors (differentiates) its products/services for the two customer classes solely based on guaranteed lead time and the corresponding price. Our objective is to understand how competition affects price and lead time differentiation of the firms in the presence of different operations strategy (shared versus dedicated capacity), product substitution and asymmetry between the competing firms. Our results suggest that when firms use dedicated resources to serve the two market segments, pure price competition always tends to decrease individual prices as well as price differentiation, irrespective of the market behaviour. Further, the effect of competition is more pronounced when customers are allowed to self-select, thereby introducing substitutability between the two product options. On the other hand, when firms compete in time, in addition to price, the effect of competition on product differentiation depends crucially on the behaviour of the market. Our results further suggest that the firm with a larger market base should always maintain a larger price and lead time differentiation between the two market segments. Similarly, the firm with a capacity cost advantage should also maintain a larger lead time differentiation.     

Enhancement of energy storage density in antiferroelectric PbZrO3 films via the incorporation of gold nanoparticles

In this work, antiferroelectric Au–PbZrO₃ (Au–PZO) nanocomposite thin films were prepared by chemical solution deposition (CSD), and the effects of Au concentration on the antiferroelectric properties and the recoverable energy density were investigated. The results showed that the optimal Au concentration in the Au–PZO nanocomposite thin films was about 1 mol% for structural and electric properties. In the Au–PZO nanocomposite thin films with 1 mol% Au, Au nanoparticles (NPs) were distributed uniformly in the perovskite PZO matrix. Moreover, the recoverable energy density was 10.8 J/cm³ at 600 kV/cm, which is 42% higher than that of the pure PZO films. The results demonstrate that adding an appropriate amount of noble metal NPs in antiferroelectric thin films is an effective method to improve the energy storage properties.