Catalogue of this issue
2. China University of Science and Technology New progress has been made in the precise construction of mono/divalent ion selective separation membranes
3. China University of Science and Technology Guangshouhong research group reveals the regulation of nucleolar RNA interference pathway Molecular mechanism of ribosomal RNA level
4. China University of Science and Technology completed high spatial resolution imaging based on color erasure intensity interference
5. China University of Science and Technology analyzed the tubular transport channel protein of Mycobacterium
6. The University of Science and Technology of China has made important progress in improving the efficiency of superconducting qubit reading by machine learning
Recently, the Guo Guangcan academician team of the University of Science and Technology of China has made important progress in the research of high-dimensional quantum communication. The team Li Chuanfeng, Liu Biheng's research group and the Austrian Professor Marcus Huber collaborated to achieve this in a high-noise environment In order to achieve efficient high-dimensional quantum communication. The results were published in the internationally renowned journal " Physical Review Letters " on September 10.
In recent years, the research groups of Li Chuanfeng and Liu Biheng have devoted themselves to the experimental research of high-dimensional quantum communication networks, and have made a series of progress in the preparation and transmission of high-dimensional entanglement, including the preparation of the world’s highest fidelity 32-dimensional quantum The entangled state realizes the effective transmission of the high-dimensional entangled state in the 11 km fiber.
Experimental device diagram
In this experiment, the research results show that: when the noise is small, high-dimensional full-space coding can achieve the best coding efficiency.Specifically, using 4-dimensional entangled states and 8-dimensional entangled states, and after post-processing such as error correction and confidentiality amplification, each pair of entangled photons can still obtain a key greater than 1 bit, which is beyond the reach of a two-dimensional bit system. limit. As the noise increases, the use of high-dimensional partial subspace encoding is more resistant to the impact of noise, and the experimental results are significantly better than the two-dimensional bit system, thus ensuring that efficient high-dimensional quantum communication can still be achieved in a high-noise environment .
This achievement experiment verified the advantages of high-dimensional quantum communication, and provided a feasible way to achieve efficient high-dimensional quantum communication under different noise environments.
Link to the paper: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.110505
Read more:
http://news.ustc.edu.cn/info/1048/76687.htm
02
NEWS
China University of Science and Technology of China has made new progress in the precision construction of primary/divalent ion selective
separation membranes
Recently, the team of Professor Xu Tongwen from the University of Science and Technology of China's primary/divalent ion selective separation membrane precision A breakthrough has been made in construction, and a sub-2-nm covalent organic framework (COFs) membrane is reported, which exhibits a high monovalent cation penetration rate and a very low divalent cation penetration rate. Efficient ion transmission and separation. The research results were published in the internationally renowned journal Advanced Materials.
Professor Tongwen Xu’s team proposed a new strategy for building and regulating ion-selective transport channels by regulating the secondary interactions of the side chain of and by using the properties of molecular self-assembly. In-situ polymerization on the surface is used to realize the construction of nano-tapered holes in the ultra-thin separation layer, shorten the ion mass transfer path, and strengthen the mass transfer behavior of ions in the membrane. In order to deeply study the mass transfer behavior and separation mechanism of ions in confined pores, the team proposed a porous framework material with regular pore structure and clear framework structure parameters as a model.Under the precision of , the precise customization of ion transmission channels and the precise regulation of channel properties are realized, and the effect of high efficiency and precise separation of ions is achieved. The key structural parameters of the channels are quantified, and the ion confinement mass transfer mechanism is initially revealed.
Sub2-nm COFs membrane uses hydrogen bonding to achieve high-efficiency ion screening
Research shows that the construction of a COFs porous membrane with abundant hydrogen bonding sites can significantly improve ion selectivity while maintaining ion permeability . This work not only provides a theoretical basis for the transport mechanism of ions in sub2-nm confined spaces, but also provides theoretical guidance for the structural design and regulation of polymer-based ion selective separation membranes.
Read more:
http://news.ustc.edu.cn/info/1048/76608.htm
Link to the paper:
https://onlinelibrary.wiley.com/doi/10.1002/adma.202104404
03
NEWS
China University of Science and Technology of China Guangshouhong Research Group
reveals the nucleolar RNA interference pathway
regulates the molecular mechanism of ribosomal RNA levels
Recently, the Chinese University of Science and Technology Department of Life Sciences and Medicine and the First Affiliated Hospital Researcher Feng Xuezhu and Professor Guang Shouhong’s research team used the model organism Caenorhabditis elegans as a model and discovered the phenomenon of nucleolar RNA interference: that is, antisense ribosomal small interfering RNA (risiRNA) can induce NRDE complexes to enter the nucleolus and bind to ribose. Somatic RNA precursor; by inhibiting the transcription activity of RNA polymerase I, and then regulating the synthesis level of ribosomal RNA , inhibiting the accumulation of false ribosomal RNA metabolism. The research results were published on Nucleic Acids Research.
siRNA is a type of small non-coding RNA with a length of about 22 nucleotides and long.It is widely found in animals and plants, and it performs important functions in the growth and development of the body, reproductive genetics and immune defense. It is also an excellent drug molecule. Guangshouhong’s research group has used Caenorhabditis elegans as the research object for many years. Through forward and reverse genetic screening, a series of SUSI factors that inhibit the production of endogenous siRNA have been identified. These factors are widely involved in ribose in cells. The process of body RNA processing and degradation. When the function of SUSI factor is defective, incorrectly processed ribosomal RNA fragments will accumulate in the cell. These fragments interact with RNA-dependent RNA polymerase to further induce the production of risiRNA. risiRNAs complement the ribosomal RNA sequence and regulate the level of ribosomal RNA by activating the nuclear RNA interference pathway.
In this study, the research team confirmed that any functional defects in the subunit of RNA exonucleosomes can cause the accumulation of risiRNA. risiRNA induces nuclear RNA interference key factors NRDE-2 and NRDE-3 to enter the nucleolus, bind to the ribosomal RNA precursor, and then inhibit the transcription activity of RNA polymerase I. The study also found that RNA exonucleosomes can respond to the homeostasis of nuclear ribosomal RNA through changes in subcellular localization. RNA exonucleosomes perform important functions in the processing and metabolism of various RNAs, and are mainly located in the nucleolus of cells. The imbalance of RNA homeostasis in the cell's ribosomal RNA will cause RNA exonucleosomes to move from the nucleolus to the nucleoplasm. The correct subcellular localization of RNA exonucleosomes plays an important role in inhibiting the production of risiRNA.
Read more:
http://news.ustc.edu.cn/info/1048/76572.htm
Link to the paper:
https://academic.oup.com/nar/advance-article/doi /10.1093/nar/gkab662/6345473
04
NEWS
China University of Science and Technology has completed high spatial resolution imaging based on color erasure
intensity interference
Recently, Pan Jianwei, Zhang Qiang, etc. and their collaborators used Jinan Institute of Quantum Technology to develop a periodic polarization lithium niobate waveguide to build a color erasing intensity interferometer and successfully distinguish 1.43km Two light sources with different wavelengths (1063.6nm and 1064.4 nm) at a distance of 4.2mm from the outside have verified that the color erasing intensity interference technology has high spatial resolution imaging capabilities with a result that exceeds the diffraction limit of a single telescope by 40 times, and expands the intensity of the intensity interference technology. The scope of application is expected to be applied to the fields of astronomical observation, space remote sensing and space debris detection. The relevant results are published in the internationally renowned academic journal "Physics Review Letters".
interferometers are widely used in various high spatial resolution imaging technologies to break through the resolution limit (diffraction limit) under the finite aperture of a single lens. In 2016, the American physicist and Nobel Prize winner Frank Wilczek and his colleagues theoretically proposed that the introduction of a color erasing detector based on the principle of frequency conversion into an intensity interferometer can make photons of different wavelengths entering the detector_ span4span also interferes and extracts phase information. They named this new technology color erasing intensity interference technology. Subsequently, Pan Jianwei's group used the periodic polarization lithium niobate waveguide independently developed by Jinan Quantum Institute to build the color erasing single-photon detection for the first time, and based on this principle, demonstrated the intensity interference technology in the laboratory.
In order to verify that the technology has high spatial resolution imaging capabilities, the team carried out field experiments in Shanghai. As shown in the figure, they used two different wavelengths of pump light to pump two PPLN waveguides connected in parallel to achieve a color erasing detector that could not distinguish the difference between 1063.6nm and 1064.4nm photons, and used two such detectors. An intensity interferometer with a baseline length of 80cm was built to measure two light sources with different wavelengths at a distance of 1.43km and a distance of 4.2mm. After obtaining the experimental data, they theoretically proposed a phase fitting algorithm to obtain the angular distance between the two light sources. The result exceeded the diffraction limit of the single 10.9mm telescope used in the experiment by 40 times.Successfully verified the high spatial resolution imaging capability of the system. "Physics Review Letters" magazine reviewer comments "This work provides a new and interesting imaging method that goes beyond the traditional diffraction limit determined by the aperture size.
Read more:
http://news.ustc.edu .cn/info/1048/76551.htm
Link to the paper:
https://doi.org/10.1111/poms.13366https://link.aps.org/doi/10.1103/PhysRevLett.127.103601
05
NEWS
The Chinese University of Science and Technology has analyzed the
tubular transport channel protein
of mycobacteria. Mycobacteria have a very complex envelope structure and are a natural barrier for mycobacteria to resist external pressure. Due to this unique complexity The envelope structure, the material transport between mycobacteria and the external environment or host has unique properties. And the channels on the mycobacterial envelope can secrete virulence factors and promote the efflux of antibiotics, thereby helping the mycobacteria to cause disease. Therefore, it is a good therapeutic target. However, the material transport pathways on the cell wall and capsule of mycobacteria are still poorly understood.
The research team led by Professor Zhou Zhenghong of span4span has determined the unknown functional protein Rv3705c in Mycobacterium tuberculosis and its homologous protein in Mycobacterium smegmatis by X-ray crystallography and cryo-electron microscopy method. According to the three-dimensional structure of MSMEG_6251, it was found that these two proteins can self-assemble into a tubular structure in vitro. A series of molecular biology and biochemical experiments show that the protein acts as a channel on the outer membrane of mycobacteria. Therefore, this The protein was named TiME. The results were published online in the internationally renowned academic journal Science Advances.
This study was the first to discover material transport channels in the mycobacterial capsule.It provides new clues and ideas for studying the material transport mechanism of pathogenic mycobacteria and developing new drug targets.
Read more:
http://news.ustc.edu.cn/info/1048/76552.htm
Link to the paper:
https://advances.sciencemag.org/content/7/34/eabg5656
06
NEWS
The University of Science and Technology of China has made important progress in machine learning to improve the efficiency of superconducting qubits
Recently, the team of Academician Guo Guangcan of the University of Science and Technology of China is working on machine learning to improve the efficiency of superconducting qubits. Significant progress has been made. The team's Professor Guoping Guoping's research group cooperated with the Quanyuan Quantum Computing Company to study the influence of crosstalk on the state reading of qubits on the Quanyuan "Kwafu" 6 bit superconducting quantum chip, and made innovations It is proposed to use a shallow neural network to identify and read the state information of qubits, thereby greatly suppressing the influence of crosstalk and further improving the fidelity of multi-bit reading. The results were published in the form of a long research article in the well-known international journal of applied physics "Physical Review Applied".
The high-fidelity measurement of the qubit state is a key part of quantum computing. Due to the existence of various forms of stray coupling, the state of adjacent bits may affect the measurement result of the target bit, thereby reducing the fidelity of the measurement, thereby reducing the success rate of the quantum algorithm. With the further expansion of quantum chips, in order to further improve the reading fidelity, how to solve the above-mentioned crosstalk problem will become a major challenge for researchers.
The traditional qubit reading scheme and the influence of crosstalk
Professor Guo Guoping's research group proposed a new qubit reading scheme through the abstraction and simulation of the qubit information extraction process: through training based on digital signal processing The shallow neural network built by the process,Realize the precise identification and classification of the qubit state. Researchers applied this scheme to the original "Kwafu" 6-bit superconducting quantum chip. The experiment found that the new reading scheme not only effectively improved the 6-bit reading fidelity, but also greatly suppressed reading crosstalk. effect. At the same time, because the data processing in the new solution can be further simplified to a single-step matrix operation, it can be directly transferred to the FPGA in the future, so as to realize the zero delay judgment of the qubit state and the real-time feedback control of the qubit. This scheme is not only suitable for superconducting quantum computing, but also suitable for other quantum computing physics implementation schemes.
Read more:
http://news.ustc.edu.cn/info/1048/76553.htm
Link to the paper:
https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied .16.024063
Source: University of Science and Technology of China
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