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Your search keyword '"Cao, Zhengwen"' showing total 194 results
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194 results on '"Cao, Zhengwen"'

1. Mask-coding-assisted continuous-variable quantum direct communication with orbital angular momentum multiplexing

Author

Cao, Zhengwen, Wang, Yujie, Chai, Geng, Chen, Xinlei, and Lu, Yuan

Subjects
Quantum Physics, Physics - Optics
Abstract

Quantum secure direct communication (QSDC) is a approach of communication to transmit secret messages base on quantum mechanics. Different from the quantum key distribution, secret messages can be transmitted directly on quantum channel with QSDC. Higher channel capacity and noise suppression capabilities are key to achieving long-distance quantum communication. Here we report a continuous-variable QSDC scheme based on mask-coding and orbital angular momentum, in which the mask-coding is employed to protect the security of the transmitting messages and to suppression the influence of excess noise. And the combination of orbital angular momentum and the information block transmission can effectively improve the secrecy capacity. In the 800 information blocks * 1310 bits length 10-km experiment, the results show that the statistical average of bit error rate has decreased by 36% and reached 0.38% comparing to existing solutions, and the system excess noise is 0.0184 SNU, and the final secrecy capacity is 6.319 * 106 bps. Therefore, this scheme reduces error bits while increasing secrecy capacity, providing a solution for long-distance large-scale quantum communication.

Published
2024

5. Machine Learning assisted excess noise suppression for continuous-variable quantum key distribution

Author

Liang, Kexin, Chai, Geng, Cao, Zhengwen, Wang, Qing, Wang, Lei, and Peng, Jinye

Subjects
Quantum Physics
Abstract

Excess noise is a major obstacle to high-performance continuous-variable quantum key distribution (CVQKD), which is mainly derived from the amplitude attenuation and phase fluctuation of quantum signals caused by channel instability. Here, an excess noise suppression scheme based on equalization is proposed. In this scheme, the distorted signals can be corrected through equalization assisted by a neural network and pilot tone, relieving the pressure on the post-processing and eliminating the hardware cost. For a free-space channel with more intense fluctuation, a classification algorithm is added to classify the received variables, and then the distinctive equalization correction for different classes is carried out. The experimental results show that the scheme can suppress the excess noise to a lower level, and has a significant performance improvement. Moreover, the scheme also enables the system to cope with strong turbulence. It breaks the bottleneck of long-distance quantum communication and lays a foundation for the large-scale application of CVQKD.

Published
2022

21. Amorphization Engineering of Bimetallic Metal‐Organic Frameworks to Identify Volcano‐Type Trend toward Oxygen Evolution Reaction.

Author

Zhou, Jian, Qiao, Fei, Ren, Zhichu, Hou, Xianbiao, Chen, Zongkun, Dai, Shuixing, Su, Ge, Cao, Zhengwen, Jiang, Heqing, and Huang, Minghua

Subjects
METAL-organic frameworks, OXYGEN evolution reactions, AMORPHIZATION, STRUCTURE-activity relationships, CATALYTIC activity, ENGINEERING
Abstract

Amorphous metal‐organic frameworks (MOFs) with aperiodic atomic arrangements, featuring high intrinsic activity and rich active sites, have emerged as promising oxygen evolution reaction (OER) catalysts. However, the quantitative structure‐activity relationships (SARs) that determine the OER activity, the key to a rational catalyst design, remain unresolved. Inspired by controllable amorphization engineering, the amorphous MOF structures are rationally constructed as an ideal platform to explore the SAR in catalyzing OER. The mechanistic studies show that the OER activity could be volcano‐shape correlated with either constant adsorption energy difference between OOH* and O* (ΔGOOH* − ΔGO*) or the position of the d band center. The amorphous MOF (Ni8Co2‐BDC), situated close to the volcano summit, possesses an appropriate Ed energy level, which exhibits the balanced intermediates adsorption/desorption ability and consequently results in the boosted catalytic activity and long‐term stability. This work supplies new perspectives to investigate the SAR in amorphous MOF structures, thereby guiding the rational design of advanced OER catalysts. [ABSTRACT FROM AUTHOR]

Published
2024
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39. Membrane Catalysis: N2O Decomposition over La0.2Sr0.8Ti0.2Fe0.8O3–δ Membrane with Oxygen Permeability.

Author

Liu, Mengke, Cao, Zhengwen, Liang, Wenyuan, Zhang, Yan, and Jiang, Heqing

Subjects
*MEMBRANE permeability (Biology), *CATALYSIS, *HETEROGENEOUS catalysis, *NITROUS oxide, *PEROVSKITE, *OXYGEN
Abstract

Compared to conventional heterogeneous catalysis, membrane catalysis can facilitate in situ removal of inhibiting species on a catalyst, therefore effectively increases the reaction rate. Herein, kinetically controlled decomposition of N2O was studied employing a La0.2Sr0.8Ti0.2Fe0.8O3–δ (LSTF) perovskite membrane, and the direct catalytic N2O decomposition over membrane surface was compared with membrane catalysis of N2O decomposition involving in situ oxygen removal. In the case of membrane catalysis, oxygen produced from N2O conversion can be in situ removed by using a LSTF oxygen‐permeable membrane, thus increasing the amount of surface active sites for N2O decomposition. By sweeping hydrogen at one side of the membrane to consume the permeated oxygen from the other side N2O conversion was improved. [ABSTRACT FROM AUTHOR]

Published
2022
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41. Efficient Quantum Private Communication Based on Dynamic Control Code Sequence

Author

Cao Zhengwen, Zeng Guihua, Xiao-Yi Feng, Jinye Peng, and Jin Qi

Subjects
Scheme (programming language), Sequence, Theoretical computer science, Physics and Astronomy (miscellaneous), Computer science, General Mathematics, 01 natural sciences, 010309 optics, CHAOS (operating system), Systematic code, Transmission (telecommunications), 0103 physical sciences, Code (cryptography), Constant-weight code, 010306 general physics, Algorithm, Quantum, computer, computer.programming_language
Abstract

Based on chaos and quantum properties, we propose a quantum private communication scheme with dynamic control code sequence. The initial sequence is obtained via chaotic systems, and the control code sequence is derived by grouping, XOR and extracting. A shift cycle algorithm is designed to enable the dynamic change of control code sequence. Analysis shows that transmission efficiency could reach 100 % with high dynamics and security.

Published
2016
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46. Flexibilization of Biorefineries: Tuning Lignin Hydrogenation by Hydrogen Partial Pressure.

Author

Cao, Zhengwen, Xu, Yun, Lyu, Pengbo, Dierks, Michael, Morales‐García, Ángel, Schrader, Wolfgang, Nachtigall, Petr, and Schüth, Ferdi

Subjects
PARTIAL pressure, LIGNINS, HYDROGEN, ALIPHATIC hydrocarbons, HYDROGENATION, HYDROGEN storage
Abstract

The present study describes an interesting and practical catalytic system that allows flexible conversion of lignin into aromatic or aliphatic hydrocarbons, depending on the hydrogen partial pressure. A combination of experiment and theory shows that the product distribution between aromatics and aliphatics can be simply tuned by controlling the availability of hydrogen on the catalyst surface. Noticeably, these pathways lead to almost complete oxygen removal from lignin biomass, yielding high‐quality hydrocarbons. Thus, hydrogen–lignin co‐refining by using this catalytic system provides high flexibility in hydrogen storage/consumption towards meeting different regional and temporal demands. [ABSTRACT FROM AUTHOR]

Published
2021
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47. Quantum Secure Direct Communication Scheme in the Non-symmetric Channel with High Efficiency and Security

Author

Jinye Peng, Zeng Guihua, Xiao-Fei Qi, Xiao-Yi Feng, and Cao Zhengwen

Subjects
Classical capacity, Quantum network, Theoretical computer science, Physics and Astronomy (miscellaneous), General Mathematics, Quantum operation, Quantum algorithm, Quantum capacity, Quantum channel, Quantum information, Topology, Amplitude damping channel, Mathematics
Abstract

By analyzing the basic properties of a class of three-particle W states, we show how to establish a non-symmetric channel to realize a quantum dense code scheme, each quantum pair can carry log2 18 bits of classical message by employing different kinds of unitary transformation in three-dimensional Hilbert space, which can improve the transmission efficiency of classical message. Based on this quantum dense code, we propose a novel quantum secure direct communication scheme. The security of the scheme is also discussed in detail, and the error rate for eavesdropper is 50 %.

Published
2014
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