增强国际合作共创图学辉煌

结合在巴西萨尔瓦多（Salvador）召开的第12届几何与图学国际会议以及近年来参加国际交流与合作的体会,论述近年来国际上几何与图学的研究与进展,特别是在理论图学,应用图学和图学教育方面的动态和最新成就。介绍南美国家特别是巴西的研究成果,表明了他们在几何,造型,图形图像处理,计算机辅助设计和图学教育改革方面与我国相似的发展和状况。这种相似性说明在科学技术上的国际影响是何等高效地改变着世界的进程。     

International comparison of thermal noise-temperature measurementsat 2, 4, and 12 GHz

We discuss an international comparison of thermal noise-power measurements (GTRF-92-2), which has recently been completed under the auspices of the Consultative Committee for Electricity and Magnetism (CCEM). The noise temperatures of two solid-state sources with GPC-7 connectors were measured at 2, 4, and 12 GHz at the national laboratories in France, Germany, the United Kingdom, and the United States. Good agreement was found among the results from the different laboratories, with all results agreeing within the expanded uncertainties, which ranged from approximately 0.5% to 2.9%. The comparison was performed in accordance with the guidelines recently adopted by the Bureau International des Poids et Mesures (BIPM)     

The Second International Symposium on Refractories Beijing, China, October 30-November 2, 1992

The 2nd International Symposium on Refrac-toties jointly organized by the Chinese Ceramic So-ciety and the Chinese Society for Metals was heldin Beijing, China, On October 30-Novemeber 2,1992. The Technical Association of Refractories,Japan, the American Ceramic Society, the Refrac-tories Association of Great Britain, the GermanRefractories Association, the Australian Ceramic     

国际资讯

英国塑料联合会(BPF)发布了第一份可持续发展报告,介绍了整个行业的相关举措。塑料供应链中的可持续性发展突出了该行业对当前环境问题所作的积极贡献,包括生产实践、行业对可持续性的具体贡献和报废管理。新报告以2018年出版的《塑料:循环经济的愿景》为基础,探讨了BPF及其成员可以积极影响可持续发展成果并致力于实现英国循环经济的领域。它展示了塑料行业如何为加强二次塑料材料市场、减少塑料加工中的能源消耗以及制定新的国际标准做出的贡献。