A series of plate-experiments are carried out to acquire ultrapure aluminum （purity,. 99.999%） samples with damage. Based on the metallographic of all ＂soft-recovered＂ samples, the characteristics of damage evolut...A series of plate-experiments are carried out to acquire ultrapure aluminum （purity,. 99.999%） samples with damage. Based on the metallographic of all ＂soft-recovered＂ samples, the characteristics of damage evolution and spallation damage mechanism in ultrapure aluminum are analyzed in detail. Results show that the damage will increase regularly with increasing loading＂ strength. Most of voids appear in the grain boundary and grow alone under tensile loading＂ before they coalesce each other to form big irregular voids. These analysis results are helpful to understand the evolution process of ductile metal dynamic fracture and establish the damage evolution model.展开更多
This paper investigates how international cooperation for patent examination using Patent Prosecution Highway(PPH)agreements has affected the quality of firms'exports.Taking the PPH agreements signed between China...This paper investigates how international cooperation for patent examination using Patent Prosecution Highway(PPH)agreements has affected the quality of firms'exports.Taking the PPH agreements signed between China and the export destinations as a quasi-natural experiment,we established a difference-in-difference-in-differences model.We found that international cooperation for patent examination caused firms to increase export quality to PPH partners in patent-intensive industries to a greater extent.This effect was more profound among PPH partners with stronger intellectual property protection,diferentiated products and core products,and agreements along with the Patent Cooperation Treaty.We also found that PPH agreements increased the number of Chinese patent applications filed in PPH partners,patent applications by PPH partners in China,and the level of innovation,all of which constitute the major channels through which export quality to PPH partners increases.Our findings demonstrate that international patent cooperation has played an important role in promoting international trade quality.展开更多
基金Supported by the National Natural Science Foundation of China, the Fundamental Research Funds for the Central Universities and the National Natural Science Foundation of China under Grant Nos 10876014, 2010-1a-017and 11072119.
文摘A series of plate-experiments are carried out to acquire ultrapure aluminum （purity,. 99.999%） samples with damage. Based on the metallographic of all ＂soft-recovered＂ samples, the characteristics of damage evolution and spallation damage mechanism in ultrapure aluminum are analyzed in detail. Results show that the damage will increase regularly with increasing loading＂ strength. Most of voids appear in the grain boundary and grow alone under tensile loading＂ before they coalesce each other to form big irregular voids. These analysis results are helpful to understand the evolution process of ductile metal dynamic fracture and establish the damage evolution model.
基金the support from the National Natural Science Foundation of China(No.71903003)the National Social Science Fund of China(No.21CTJ015)+1 种基金the Strategic Economy and Civil-Military Integration Interdisciplinarity Program of Beijing Universities Advanced Disciplines Initiative(No.GJ2019163)the Program for Innovation Research in Central Universityof Financeand Economics。
文摘This paper investigates how international cooperation for patent examination using Patent Prosecution Highway(PPH)agreements has affected the quality of firms'exports.Taking the PPH agreements signed between China and the export destinations as a quasi-natural experiment,we established a difference-in-difference-in-differences model.We found that international cooperation for patent examination caused firms to increase export quality to PPH partners in patent-intensive industries to a greater extent.This effect was more profound among PPH partners with stronger intellectual property protection,diferentiated products and core products,and agreements along with the Patent Cooperation Treaty.We also found that PPH agreements increased the number of Chinese patent applications filed in PPH partners,patent applications by PPH partners in China,and the level of innovation,all of which constitute the major channels through which export quality to PPH partners increases.Our findings demonstrate that international patent cooperation has played an important role in promoting international trade quality.
