美国《芯片与科学法案》对我国半导体产业发展的影响及对策研究:基于创新链理论的视角

美国《芯片与科学法案》的出台反映了美国抢占半导体产业主导权、遏制我国半导体产业成长的战略意图。本文梳理出该法案出台背景和内容框架,提出美国半导体产业特征、支柱产业需求和两党政治斗争妥协是法案出台的直接原因。全球半导体产业链分为上中下游、支撑与终端应用等产业环节,其创新链通过四种双方和三种多方连接方式,连接企业、政府、高校及科研院所、金融机构和用户等主体。该法案差异化影响我国本土半导体上中下游、终端应用环节,中游制造受到威胁最高,上游设计其次,下游封测和终端应用最低。我国要遵循创新链开放性要求,在高水平开放格局下推动本土半导体产业创新发展;聚焦创新链治理权,构建本土企业作为领军企业的半导体产业创新链;加大创新链关键要素供给,推进半导体人才队伍建设。

聚碳酸酯二元醇的合成及应用研究进展

聚碳酸酯二元醇(PCDL)是制备聚碳酸酯型聚氨酯的重要原料,和传统的聚醚型聚氨酯和聚酯型聚氨酯相比,聚碳酸酯型聚氨酯表现出优异的耐水解性、力学性能和生物相容性。随着聚氨酯需求量的增长,聚碳酸酯二元醇的研究受到行业内的高度重视。本文先简要介绍了PCDL的合成方法,重点回顾了近十年来用于酯交换缩聚法制备PCDL的催化剂的研究进展,简述了PCDL在聚氨酯工业中的应用。未来开发非均相催化剂及高沸点的有机碱催化剂、制备不同结构的聚碳酸酯二元醇是PCDL的主要研究方向。

Synthesis of Polycarbonate Diols（PCDLs） via Two-step Process Using CH3COONa as an Effective Catalyst

Polycarbonate diols（PCDLs） with a number average molecular weight（M,） of 2800 and a narrow polydispersity index（PDI=1.33） were synthesized from dimethyl carbonate（DMC） and 1,4-butarlediol（BD） via a two-step process. The influences of the molar ratios of DMC to BD in the feedstock, polycondensation temperature and polycondensation time on the PCDLs preparation were studied. CH3COONa showed the best catalytic performance among the catalysts studied. The highest BD conversion of 73.8% and PCDLs yield of 64.7% were achieved under its optimum reaction conditions. Furthennore, based on the results of 1^H NMR, the relationships between the ratio of end groups （--OCH3/-OH） of oligomers, the Mn and chain-end constitute of resultant polycarbonates were also investigated. The results indicate that PCDLs can be synthesized when the oligomers mostly bear hydroxyl end groups. In contrast, it was impossible to prepare PCDLs when the oligomers were enriched with methyl carbonate end groups,