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On the time-independent Hamiltonian in real-time and imaginary-time quantum annealing

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Chinese Physics B 2020年第10期29卷 167-171页

作者： Jie Sun Songfeng Lu Hubei Engineering Research Center on Big Data Security School of Cyber Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China School of Internet Anhui UniversityHefei 230039China shenzhen huazhong university of science and technology Research institute Shenzhen 518063China

We present the analog analogue of Grover's problem as an example of the time-independent Hamiltonian for applying the speed limit of the imaginary-time Schrödinger equation derived by Okuyama and Ohzeki and the new class of energy-time uncertainty relation proposed by Kieu. It is found that the computational time of the imaginary-time quantum annealing of this Grover search can be exponentially small, while the counterpart of the quantum evolution driven by the real-time Schrödinger equation could only provide square root speedup, compared with classic search. The present results are consistent with the cases of the time-dependent quantum evolution of the natural Grover problem in previous works. We once again emphasize that the logarithm and square root algorithmic performances are generic in imaginary-time quantum annealing and quantum evolution driven by real-time Schrödinger equation, respectively. Also, we provide evidences to search deep reasons why the imaginary-time quantum annealing can lead to exponential speedup and the real-time quantum annealing can make square root speedup.

关键词： time-independent Hamiltonian imaginary-time quantum annealing quantum speed limit the energy-time uncertainty relation continuous Grover's search

Improved open-circuit voltage and ambient stability of CsPbI2Br perovskite solar cells by incorporating CH3NH3Cl

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Rare Metals 2020年第2期39卷 131-138页

作者： Chuan-Liang Chen Sha-Sha Zhang Tian-Lun Liu Shao-Hang Wu Zhi-Chun Yang Wei-Tao Chen Rui Chen Wei Chen Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan430074China China-EU institute for Clean and Renewable Energy Huazhong University of Science and TechnologyWuhan430074China shenzhen Key Laboratory of Nanobiomechanics Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Inorganic cesium metal halide perovskites have gained research interest as absorbers in perovskite solar cells due to their superior thermal *** these,CsPbI2Br,with a narrower band gap than CsPbBr3 and a better phase stability than CsPbI3,has received tremendous interest of the ***,CsPbI2 Br takes adverse phase transfer easily with an exposure to the water vapor in ambient air which not only brings inconvenience for researches but also puts forward very high requirement for ***,a dense and uniform film is obtained by incorporating hydrophobic CH3NH3Cl(MACl)into the precursor *** attributed to a good passivation effect,the defect density is decreased from3.12×1016 to 1.49×1016 cm-3 and the average photoluminescence lifetime is increased from 8.84 to 20.6 *** photovoltaic device achieves a high open-circuit voltage of 1.22 V based on optimized MACl-doped film and accordingly a higher power conversion efficiency(PCE) of 12.9% which is 21.7% higher than the pristine CsPbI2Br device with PCE of 10.6%.In addition,the ambient stability of MACl-doped device has been enhanced,which is greatly attributed to the hydrophobic properties of *** work provides a clue to improve ambient stability of inorganic perovskite solar cells and inspires toward further development of this material.

关键词： CsPbI2Br perovskite Passivation Ambient stability MACl

Resource investment for DDoS attack resistant SDN: a practical assessment

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science China(Information sciences) 2023年第7期66卷 112-129页

作者： Bin YUAN Fan ZHANG Jun WAN Huan ZHAO Shui YU Deqing ZOU Qiangsheng HUA Hai JIN School of Cyber science and Engineering Huazhong University of Science and Technology National Engineering Research Center for Big Data technology and System Services Computing technology and System Lab Hubei Engineering Research Center on Big Data Security shenzhen huazhong university of science and technology Research institute School of Computer science and technology Huazhong University of Science and Technology Cluster and Grid Computing Lab School of Computer science University of Technology Sydney

Software-defined networks(SDNs) present a novel network architecture that is widely used in various datacenters. However, SDNs also suffer from many types of security threats, among which a distributed denial of service(DDoS) attack, which aims to drain the resources of SDN switches and controllers,is one of the most common. Once the switch or controller is damaged, the network services can be *** defense schemes against DDoS attacks have been proposed from the perspective of attack detection;however, such defense schemes are known to suffer from a time consuming and unpromising accuracy, which could result in an unavailable network service before specific countermeasures are taken. To address this issue through a systematic investigation, we propose an elaborate resource-management mechanism against DDoS attacks in an SDN. Specifically, by considering the SDN topology, we leverage the M/M/c queuing model to measure the resistance of an SDN to DDoS attacks. Network administrators can therefore invest a reasonable number of resources into SDN switches and SDN controllers to defend against DDoS attacks while guaranteeing the quality of service(QoS). Comprehensive analyses and empirical data-based experiments demonstrate the effectiveness of the proposed approach.

关键词： SDN security DDoS attacks resource management queueing theory QoS

Recent progress of nanotechnology-based theranostic systems in cancer treatments

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Cancer Biology & Medicine 2021年第2期18卷 336-351页

作者： Ying Xue Yuting Gao Fanling Meng Liang Luo National Engineering Research Center for Nanomedicine College of Life Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory of Bioinorganic Chemistry and Materia Medica School of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074China Research institute of huazhong university of science and technology in shenzhen Shenzhen 518057China

Theranostics that integrates therapy and diagnosis in one system to achieve accurate cancer diagnosis and treatment has attracted tremendous interest,and has been recognized as a potential breakthrough in overcoming the challenges of conventional *** are ideal candidates as carriers for theranostic agents,which is attributed to their extraordinary physicochemical properties,including nanoscale sizes,functional properties,prolonged blood circulation,active or passive tumor targeting,specific cellular uptake,and in some cases,excellent optical properties that ideally meet the needs of phototherapy and imaging at the same ***,with the development of nanotechnology,theranostics has become a reality,and is now in the transition stage of"bench to bedside."In this review,we summarize recent progress on nanotechnology-based theranostics,i.e.,nanotheranostics,that has greatly assisted traditional therapies,and has provided therapeutic strategies emerging in recent decades,as well as"cocktail"theranostics mixing various treatment modalities.

关键词： Theranostics cancer therapy diagnosis nanoparticles nanotechnology

Sufficient and necessary conditions for global stability of genetic regulator networks with time delays

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science China(Information sciences) 2016年第1期59卷 175-187页

作者： Guopeng ZHOU Jinhua HUANG Fengxia TIAN Xiaoxin LIAO School of Electrical and Electronic Engineering Huazhong University of Science and Technology institute of Engineering and technology Hubei University of Science and Technology Department of Electric and Electronic Engineering Wuhan Institute of Shipbuilding Technology College of Automation Huazhong University of Science and Technology

This paper is concerned with the global stability of the nonlinear model for genetic regulator networks(GRNs) with time delays. Four new sufficient and necessary conditions for global asymptotic stability and global exponential stability of the equilibrium point of GRNs are derived. Specifically, using comparing theorem and Dini derivation method, three weak sufficient conditions for global stability of GRNs with constant time delays are proposed. Finally, a general GRN model is used to illustrate the effectiveness of the proposed theoretical results. Compared with the previous results, some sufficient and necessary conditions for Lyapunov stability of GRNs are proposed, which are not seen before.

关键词： genetic regulator networks time delay global asymptotic stable global exponential stable comparing theorem Dini derivative

Quasi-Physical Algorithm of an Off-Lattice Model for Protein Folding Problem

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Journal of Computer science & technology 2007年第4期22卷 569-574页

作者：刘景发黄文奇 Computer and Software institute Nanjing University of Information Science and Technology School of Computer science and technology Huazhong University of Science and Technology

Protein folding problem is one of the most prominent problems of bioinformatics. In this paper, we study a three-dimensional off-lattice protein AB model with two species of monomers, hydrophobic and hydrophilic, and present a heuristic quasi-physical algorithm. By elaborately simulating the movement of the smooth elastic balls in the physical world, the algorithm finds low-energy configurations for a given monomer chain. A subsequent ＂off-trap＂ strategy is proposed to trigger a jump for a stuck situation in order to get out of local minima. The methods have been tested in the off-lattice AB model. The computational results show promising performance. For all sequences with 13 to 55 monomers, the algorithm finds states with lower energy than previously proposed putative ground states. Furthermore, for the sequences with 21, 34 and 55 monomers, new putative ground states are found, which are different from those given in present literature.

关键词： protein folding off-lattice model quasi-physical algorithm off-trap strategy NP-hard problem

Precision forging technology for aluminum alloy

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Frontiers of Mechanical Engineering 2018年第1期13卷 25-36页

作者： Lei DENG Xinyun WANG Junsong JIN Juchen XIA State Key Laboratory of Materials Processing and Die & Mouldtechnology Huazhong University of Science and Technology Wuhan430074 China Research institute of huazhong university of science and technology inshenzhen Shenzhen 518057 China

Aluminum alloy is a preferred metal material for lightweight part manufacturing in aerospace, auto- mobile, and weapon industries due to its good physical properties, such as low density, high specific strength, and good corrosion resistance. However, during forging processes, underfilling, folding, broken streamline, crack, coarse grain, and other macro- or microdefects are easily generated because of the deformation characteristics of aluminum alloys, including narrow forgeable temperature region, fast heat dissipation to dies, strong adhesion, high strain rate sensitivity, and large flow resistance. Thus, it is seriously restricted for the forged part to obtain precision shape and enhanced property. In this paper, progresses in precision forging technologies of aluminum alloy parts were reviewed. Several advanced precision forging technologies have been developed, including closed die forging, isothermal die forging, local loading forging, metal flow forging with relief cavity, auxiliary force or vibration loading, casting-forging hybrid forming, and stamping-forging hybrid forming. High-precision alumi- num alloy parts can be realized by controlling the forging processes and parameters or combining precision forging technologies with other forming technologies. The development of these technologies is beneficial to promote the application of aluminum alloys in manufacturing of lightweight parts.

关键词： precision forging aluminum alloy closed dieforging flow control forging hybrid-forming technology

Evaporated potassium chloride for double-sided interfacial passivation in inverted planar perovskite solar cells

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Journal of Energy Chemistry 2021年第3期30卷 493-500页

作者： Shasha Zhang Xiaobo Yan Zonghao Liu Hongmei Zhu Zhichun Yang Yuqian Huang Sanwan Liu Di Wu Ming Pan Wei Chen Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074HubeiChina China-EU institute for Clean and Renewable Energy Huazhong University of Science and TechnologyWuhan 430074HubeiChina shenzhen Key Laboratory of Nanobiomechanics Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055GuangdongChina Henan institute of Advanced technology Zhengzhou UniversityZhengzhou 450001HenanChina

Defect-induced charge carrier recombination at the interfaces between perovskite and adjacent charge transport layers restricts further improvements in the device performance of perovskite solar cells(PSCs).Defect passivation at these interfaces can reduce trap states and inhibit the induced nonradiative ***,we report a double-sided interfacial passivation via simply evaporating potassium chloride(DIP-KCl)at both the hole transport layer(HTL)/perovskite and perovskite/electron transport layer(ETL)interfaces in inverted planar *** demonstrate that the bottom KCl layer at the HTL/perovskite interface not only reduces the interfacial defects and improves the interfacial contact,but also leads to increased perovskite crystallinity,while the top KCl layer at the perovskite/ETL interface efficiently passivates the perovskite top surface defects and facilitates electron extraction at this ***,suppressed nonradiative recombination and faster charge extraction at both interfaces close to the perovskite layer can be achieved by using our DIP-KCl *** a result,inverted PSCs based on DIP-KCl present an increased efficiency from 17.1% to 19.2% and enhanced stability,retaining over 90% of their initial efficiency after aging at maximum power point tracking for 1000 *** work provides a simple and efficient way for defect passivation to further increase the efficiency and stability of PSCs.

关键词： Double-sided interfacial passivation KCl Defect passivation Nonradiative recombination Perovskite solar cells

Dwell Time of Particles in Tunneling Barriers of Arbitrary Shape

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Chinese Physics Letters 1998年第12期15卷 862-864页

作者： BAI Er-juan SHU Qi-qing institute of Applied Nuclear technology Shenzhen UniversityShenzhen 518060 School of science Shenzhen UniversityShenzhen 518060

For a one-dimensional barrier of arbitrary shape,an expression of the dwell time of tunneling particles has been obtained by subdividing it into infinitesimal rectangular barrier elements and then summing the dwell times spent by particles inside the barrier elements,and the dwell times in a parabolic potential barrier were *** results show that the dwell times are almost independent of the barrier width as it is greater than a characteristic width *** can be ascribed that in the width range beyond Wc,the tunneling probabilities through the barrier elements are very small,thus the times taken to tunnel through them make little contribution to the summation of the dwell times in all the barrier elements.

关键词： barrier tunneling beyond