This thesis is about the skills of practical writing for Tour Guide.In this article,the differences between English and Chinese are discussed.As a Tour Guide,one needs to grasp these characteristics of the two languag...This thesis is about the skills of practical writing for Tour Guide.In this article,the differences between English and Chinese are discussed.As a Tour Guide,one needs to grasp these characteristics of the two languages,and has ability of describing sceneries beautifully and accurately by writing.展开更多
Along with the extensive application of energy storage devices,the spent lithium-ion batteries(LIBs)are unquestionably classified into the secondary resources due to its high content of several valuable metals.However...Along with the extensive application of energy storage devices,the spent lithium-ion batteries(LIBs)are unquestionably classified into the secondary resources due to its high content of several valuable metals.However,current recycling methods have the main drawback to their tedious process,especially the purification and separation process.Herein,we propose a simplified process to recycle both cathode(LiCoO_(2))and anode(graphite)in the spent LIBs and regenerate newly high-performance anode material,CoO/CoFe2O4/expanded graphite(EG).This process not only has the advantages of succinct procedure and easy control of reaction conditions,but also effectively separates and recycles lithium from transition metals.The 98.43%of lithium is recovered from leachate when the solid product CoO/CoFe2O4/EG is synthesized as anode material for LIBs.And the product exhibits improved cyclic stability(890 mAh g^(-1) at 1 A g^(-1) after 700 cycles)and superior rate capability(208 mAh g^(-1) at 5 A g^(-1)).The merit of this delicate recycling design can be summarized as three aspects:the utilization of Fe impurity in waste LiCoO_(2),the transformation of waste graphite to EG,and the regeneration of anode material.This approach properly recycles the valuable components of spent LIBs,which introduces an insight into the future recycling.展开更多
As one of the most influential American writers in the 20th century, Hemingway pioneered a generation of writing style. He is famous for his unique writing style-iceberg theory. In this paper, the author firstly intro...As one of the most influential American writers in the 20th century, Hemingway pioneered a generation of writing style. He is famous for his unique writing style-iceberg theory. In this paper, the author firstly introduces the different views about Hemingway＇s iceberg theory among the critics. And then the author discusses the theory from the aspects of succinct words and symbolism. On the dimensions of describing scenery, portraying figures and describing psychology, Hemingway＇s style is seemingly rather simple and direct. On the other hand, the theme of Hemingway＇s works is symbolic and provides much room for thinking. Hemingway endowed his works with symbolic meanings by using the methods of pun and coda. Also, meanings of Christian symbolism are obvious in his works. Through discussion, the author refutes the critics＇ negative opinions towards iceberg theory.展开更多
Zero-knowledge succinct non-interactive arguments of knowledge(zk-SNARKs)are cryptographic protocols that ofer efcient and privacy-preserving means of verifying NP language relations and have drawn considerable atten‑...Zero-knowledge succinct non-interactive arguments of knowledge(zk-SNARKs)are cryptographic protocols that ofer efcient and privacy-preserving means of verifying NP language relations and have drawn considerable atten‑tion for their appealing applications,e.g.,verifable computation and anonymous payment protocol.Compared with the pre-quantum case,the practicability of this primitive in the post-quantum setting is still unsatisfactory,espe‑cially for the space complexity.To tackle this issue,this work seeks to enhance the efciency and compactness of lat‑tice-based zk-SNARKs,including proof length and common reference string(CRS)length.In this paper,we develop the framework of square span program-based SNARKs and design new zk-SNARKs over cyclotomic rings.Compared with previous works,our construction is without parallel repetition and achieves shorter proof and CRS lengths than previous lattice-based zk-SNARK schemes.Particularly,the proof length of our scheme is around 23.3%smaller than the recent shortest lattice-based zk-SNARKs by Ishai et al.(in:Proceedings of the 2021 ACM SIGSAC conference on computer and communications security,pp 212-234,2021),and the CRS length is 3.6×smaller.Our constructions follow the framework of Gennaro et al.(in:Proceedings of the 2018 ACM SIGSAC conference on computer and com‑munications security,pp 556-573,2018),and adapt it to the ring setting by slightly modifying the knowledge assumptions.We develop concretely small constructions by using module-switching and key-switching procedures in a novel way.展开更多
The famous zero-knowledge succinct non-interactive arguments of knowledge(zk-SNARK) was proposed by Groth in 2016.Typically, the construction is based on quadratic arithmetic programs which are highly efficient concer...The famous zero-knowledge succinct non-interactive arguments of knowledge(zk-SNARK) was proposed by Groth in 2016.Typically, the construction is based on quadratic arithmetic programs which are highly efficient concerning the proof length and the verification complexity. Since then, there has been much progress in designing zk-SNARKs, achieving stronger security,and simulated extractability, which is analogous to non-malleability and has broad applications. In this study, following Groth's pairing-based zk-SNARK, a simulation extractability zk-SNARK under the random oracle model is constructed. Our construction relies on a newly proposed property named target linearly collision-resistant, which is satisfied by random oracles under discrete logarithm assumptions. Compared to the original Groth16 zk-SNARK, in our construction, both parties are allowed to use such a random oracle, aiming to get the same random number. The resulting proof consists of 3 group elements and only 1 pairing equation needs to be verified. Compared to other related works, our construction is shorter in proof length and simpler in verification while preserving simulation extractability. The results also extend to achieve subversion zero-knowledge SNARKs.展开更多
文摘This thesis is about the skills of practical writing for Tour Guide.In this article,the differences between English and Chinese are discussed.As a Tour Guide,one needs to grasp these characteristics of the two languages,and has ability of describing sceneries beautifully and accurately by writing.
基金This work was supported by National Natural Science Foundation of China(51902347,51822812,51772334,51778627).
文摘Along with the extensive application of energy storage devices,the spent lithium-ion batteries(LIBs)are unquestionably classified into the secondary resources due to its high content of several valuable metals.However,current recycling methods have the main drawback to their tedious process,especially the purification and separation process.Herein,we propose a simplified process to recycle both cathode(LiCoO_(2))and anode(graphite)in the spent LIBs and regenerate newly high-performance anode material,CoO/CoFe2O4/expanded graphite(EG).This process not only has the advantages of succinct procedure and easy control of reaction conditions,but also effectively separates and recycles lithium from transition metals.The 98.43%of lithium is recovered from leachate when the solid product CoO/CoFe2O4/EG is synthesized as anode material for LIBs.And the product exhibits improved cyclic stability(890 mAh g^(-1) at 1 A g^(-1) after 700 cycles)and superior rate capability(208 mAh g^(-1) at 5 A g^(-1)).The merit of this delicate recycling design can be summarized as three aspects:the utilization of Fe impurity in waste LiCoO_(2),the transformation of waste graphite to EG,and the regeneration of anode material.This approach properly recycles the valuable components of spent LIBs,which introduces an insight into the future recycling.
文摘As one of the most influential American writers in the 20th century, Hemingway pioneered a generation of writing style. He is famous for his unique writing style-iceberg theory. In this paper, the author firstly introduces the different views about Hemingway＇s iceberg theory among the critics. And then the author discusses the theory from the aspects of succinct words and symbolism. On the dimensions of describing scenery, portraying figures and describing psychology, Hemingway＇s style is seemingly rather simple and direct. On the other hand, the theme of Hemingway＇s works is symbolic and provides much room for thinking. Hemingway endowed his works with symbolic meanings by using the methods of pun and coda. Also, meanings of Christian symbolism are obvious in his works. Through discussion, the author refutes the critics＇ negative opinions towards iceberg theory.
基金supported by the National Key R&D Program of China under Grant 2020YFA0712303Zhedong Wang is supported by National Natural Science Foundation of China(Grant No.62202305)Shanghai Pujiang Program under Grant 22PJ1407700.
文摘Zero-knowledge succinct non-interactive arguments of knowledge(zk-SNARKs)are cryptographic protocols that ofer efcient and privacy-preserving means of verifying NP language relations and have drawn considerable atten‑tion for their appealing applications,e.g.,verifable computation and anonymous payment protocol.Compared with the pre-quantum case,the practicability of this primitive in the post-quantum setting is still unsatisfactory,espe‑cially for the space complexity.To tackle this issue,this work seeks to enhance the efciency and compactness of lat‑tice-based zk-SNARKs,including proof length and common reference string(CRS)length.In this paper,we develop the framework of square span program-based SNARKs and design new zk-SNARKs over cyclotomic rings.Compared with previous works,our construction is without parallel repetition and achieves shorter proof and CRS lengths than previous lattice-based zk-SNARK schemes.Particularly,the proof length of our scheme is around 23.3%smaller than the recent shortest lattice-based zk-SNARKs by Ishai et al.(in:Proceedings of the 2021 ACM SIGSAC conference on computer and communications security,pp 212-234,2021),and the CRS length is 3.6×smaller.Our constructions follow the framework of Gennaro et al.(in:Proceedings of the 2018 ACM SIGSAC conference on computer and com‑munications security,pp 556-573,2018),and adapt it to the ring setting by slightly modifying the knowledge assumptions.We develop concretely small constructions by using module-switching and key-switching procedures in a novel way.
基金supported by the National Key R&D Program of China(Grant No.2019YFB2101703)the National Natural Science Foundation of China(Grant Nos.62272107 and U19A2066)+1 种基金the Innovation Action Plan of Shanghai Science and Technology(Grant No.21511102200)the Key R&D Program of Guangdong Province(Grant No.2020B0101090001)。
文摘The famous zero-knowledge succinct non-interactive arguments of knowledge(zk-SNARK) was proposed by Groth in 2016.Typically, the construction is based on quadratic arithmetic programs which are highly efficient concerning the proof length and the verification complexity. Since then, there has been much progress in designing zk-SNARKs, achieving stronger security,and simulated extractability, which is analogous to non-malleability and has broad applications. In this study, following Groth's pairing-based zk-SNARK, a simulation extractability zk-SNARK under the random oracle model is constructed. Our construction relies on a newly proposed property named target linearly collision-resistant, which is satisfied by random oracles under discrete logarithm assumptions. Compared to the original Groth16 zk-SNARK, in our construction, both parties are allowed to use such a random oracle, aiming to get the same random number. The resulting proof consists of 3 group elements and only 1 pairing equation needs to be verified. Compared to other related works, our construction is shorter in proof length and simpler in verification while preserving simulation extractability. The results also extend to achieve subversion zero-knowledge SNARKs.
