It is with heavy hearts that we mourn the passing of Ning Cai, a luminary whose pioneering spirit illuminated the realms of network coding and beyond. On May 25, 2023, at the age of 75, Prof. Cai bid farewell, leaving behind a profound legacy that continues to resonate across generations of researchers. His contributions spanned a vast spectrum, from the groundbreaking explorations in network coding to the intricate realms of quantum information theory. Ning's indelible mark on the academic landscape is a testament to his unwavering dedication and relentless pursuit of knowledge. Among his many accolades, Ning's seminal works garnered widespread recognition, exemplified by the prestigious 2005 IEEE Information Theory Society Paper Award for his work "Linear Network Coding." Furthermore, his enduring impact was underscored by the 2018 ACM SIGMOBILE Test-of-Time Paper Award, bestowed upon his paper "Network Information Flow." In addition to his scholarly achievements, Ning's unwavering commitment to mentorship has left an indelible mark on countless aspiring scholars. His guidance and wisdom continue to inspire and guide future generations in their scholarly pursuits. As we bid farewell to a titan in the field, let us cherish the legacy of Ning Cai, whose brilliance and generosity of spirit will forever endure in the annals of academia.

翻译：我们怀着沉重的心情悼念蔡宁教授的逝世，这位先驱者的开拓精神照亮了网络编码乃至更广阔的领域。2023年5月25日，蔡教授与世长辞，享年75岁，留下了深刻影响数代研究者的宝贵学术遗产。他的贡献涵盖广泛领域，从网络编码的开创性探索到量子信息理论的复杂疆域。蔡宁在学术界留下的不可磨灭印记，印证了他对知识的坚定奉献与不懈追求。在其众多荣誉中，蔡宁的奠基性工作获得了广泛认可，例如其论文《线性网络编码》荣获2005年IEEE信息论学会最佳论文奖；其持久影响力亦体现于论文《网络信息流》所获的2018年ACM SIGMOBILE时间检验论文奖。除学术成就外，蔡宁对指导后学的坚定承诺亦在无数青年学者心中刻下永恒烙印。他的指引与智慧将持续激励并引领未来世代的学术探索。在告别这位领域巨擘之际，让我们珍视蔡宁教授留下的精神财富——其卓越才智与博大胸怀将永存于学术史册。