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Protein crystallization with DNA templates

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Particuology 2024年第3期86卷 262-268页

作者： Bo Zhang Jia Yu Zhe Pu Wenhui Guo Ruoqi Yang Yu Wen Zhijiang Rong Hui Wang Xiaoli Wu Bo Wang Hongyan Sun School of Environment and Resources Taiyuan University of Science and TechnologyTaiyuan030024China School of Chemical Engineering and technology Taiyuan University of Science and TechnologyTaiyuan030024China

Protein crystallization plays a significant role in three-dimensional structural analysis and protein *** is important to increase the crystallization efficiency,which is possible by adding hetero-geneous templates in crystallization *** is biologically compatible and artificially designable polymer,which is easy to *** this study,single-and double-stranded DNA of precise sequences were designed and used as templates to promote protein crystallization of lysozyme and ***-fluence of DNA,single-stranded DNA with 10,20,40 bases and double-stranded DNA with 10,20,40 base pairs,were *** success rate of obtaining crystals of lysozyme and catalase in equal period was significantly improved with the addition of DNA comparing without templates ***-stranded DNA led to higher nucleation rate than that with single-stranded *** promotion of nucleation was more obvious at low concentration of protein solution and with longer chain DNA *** number and crystallization rate was enhanced with addition of long double-stranded DNA *** the results confirm that DNA is an effective polymer additive to enhance protein crystallization,especially for the application of the scarce protein crystallization.

关键词： DNA Polymer Additive Protein Crystallization

Investigation of high rate mechanical flow followed by ignition for high-energy propellant under dynamic extrusion loading

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Defence technology（防务技术） 2024年第2期32卷 336-347页

作者： Liying Dong Yanqing Wu Kun Yang Xiao Hou State Key Laboratory of Explosion Science and technology Beijing Institute of TechnologyBeijing 100081China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

Investigating the ignition response of nitrate ester plasticized polyether(NEPE) propellant under dynamic extrusion loading is of great significant at least for two cases. Firstly, it helps to understand the mechanism and conditions of unwanted ignition inside charged propellant under accident ***, evaluates the risk of a shell crevice in a solid rocket motor(SRM) under a falling or overturning scene. In the present study, an innovative visual crevice extrusion experiment is designed using a dropweight apparatus. The dynamic responses of NEPE propellant during extrusion loading, including compaction and compression, rapid shear flow into the crevice, stress concentration, and ignition reaction, have been firstly observed using a high-performance high-speed camera. The ignition reaction is observed in the triangular region of the NEPE propellant sample above the crevice when the drop weight velocity was 1.90 m/s. Based on the user material subroutine interface UMAT provided by finite element software LS-DYNA, a viscoelastic-plastic model and dual ignition criterion related to plastic shear dissipation are developed and applied to the local ignition response analysis under crevice extrusion conditions. The stress concentration occurs in the crevice location of the propellant sample, the shear stress is relatively large, the effective plastic work is relatively large, and the ignition reaction is easy to occur. When the sample thickness decreases from 5 mm to 2.5 mm, the shear stress increases from 22.3 MPa to 28.6 MPa, the critical value of effective plastic work required for ignition is shortened from 1280 μs to 730 μs, and the triangular area is easily triggering an ignition reaction. The propellant sample with a small thickness is more likely to stress concentration, resulting in large shear stress and effective work, triggering an ignition reaction.

关键词： NEPE propellant Crevice extrusion Shear flow Sample thickness Ignition reaction

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Scalable graphene foam with ultrahigh conductivity for stabilizing Pt towards efficient hydrogen evolution

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Nano Research 2024年第8期17卷 6968-6976页

作者： Ming Zhao Meng Huang Huihui Jin Dayin He Wei Qian Zixin Zhang Daping He State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Hubei Engineering Research Center of RF-Microwave technology and Application Wuhan University of TechnologyWuhan 430070China School of Information Engineering Wuhan University of TechnologyWuhan 430070China School of Chemistry and Materials Science University of Science and Technology of ChinaHefei 230026China Sanya Science and Education Innovation Park of Wuhan University of technology Sanya 572000China

For the carbon-based catalyst to be active and stable,especially in harsh electrochemical environments,the key is to decrease the concentration of defects and raise the degree of graphitization of the carbon ***,we develop a highly graphitized graphene foam with multiplicated structure to fabricate self-supporting Pt-based catalysts for efficient and stable hydrogen evolution reaction(HER)*** foam(GO-2850)is obtained through an ultra-high temperature treatment at 2850℃,with perfect graphene structure and extremely low defect,ensuring high electrical conductivity and corrosion ***,its multiplicated structure provides an inherently favorable environment for the dispersion of Pt nanoparticles(Pt NPs)and offers abundant channels for electrolyte infiltration during the catalytic *** a result,the as-prepared Pt/GO-2850 is far active and stable than the Pt NPs supported on commercial carbon paper(Pt/CP)counterpart toward catalyzing HER,exhibiting an outstanding activity and long-term durability(300 h@10 mA·cm^(−2))in acidic/alkaline/seawater *** can be attributed to the stronger interaction between the lower-defect GO-2850 substrate and Pt,as evidenced by characterization and theoretical *** work extends further insight into the design self-supporting catalysts of high activity and stability with promising prominent application toward green energy devices.

关键词： graphene foam high graphitization Pt nanoparticles hydrogen evolution reaction long-term stability

Sensitivity of ghost imaging compared to conventional imaging [Invited]

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Chinese Optics Letters 2024年第6期22卷 15-32页

作者： Long-Kun Du Shuai Sun Yao-Kun Xu Hui-Zu Lin Ning-Yi Leng Wei-Tao Liu Institute for Quantum Science and technology College of ScienceNational University of Defense TechnologyChangsha 410073China Interdisciplinary Center of Quantum Information National University of Defense TechnologyChangsha 410073China Hunan Key Laboratory of Mechanism and technology of Quantum Information Changsha 410073China College of Electronic Science and technology National University of Defense TechnologyChangsha 410073China Department of Mathematics College of ScienceNational University of Defense TechnologyChangsha 410073China

Ghost imaging has been attracting more and more attention, which provides a way to obtain images of objects with only a single-pixel detector. Considering possible applications, it becomes urgent to clarify the sensitivity of ghost imaging. Due to the unique characteristics of single-pixel detectors, which collect photons without distributing them to multiple pixels,often outperforming array sensors, ghost imaging is believed to be more sensitive than conventional imaging. However,a systematic analysis on the sensitivity of ghost imaging is yet to be completed. In this paper, we present a method for quantitatively assessing the sensitivity of ghost imaging. A detailed comparison is provided between ghost imaging and conventional imaging, taking into account the particle nature of photons and the noise of detection. With the settings of the two imaging methods being the same to the most extent, the minimal required number of detected photons for images of a certain quality is considered. For the thermal source version, ghost imaging demonstrates enhanced sensitivity under practical situations, with noise *** an entangled source, ghost imaging surpasses conventional imaging techniques in terms of sensitivity obviously. In one word, ghost imaging promises higher sensitivity at low photon flux and noisy situations.

关键词： sensitivity ghost imaging conventional imaging

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Dual-microcomb generation via a monochromatically pumped dual-mode microresonator

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Photonics Research 2024年第1期12卷 163-171页

作者： RUNLIN MIAO KE YIN CHAO ZHOU CHENXI ZHANG ZHUOPEI YU XIN ZHENG TIAN JIANG National Innovation Institute of Defense technology Academy of Military Sciences PLA ChinaBeijing 100071China Beijing Institute for Advanced Study National University of Defense TechnologyBeijing 100000China College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China College of Electronic Science and technology National University of Defense TechnologyChangsha 410073China Institute for Quantum Science and technology College of ScienceNational University of Defense TechnologyChangsha 410073China

Microcombs have enabled a host of cutting-edge applications from metrology to communications that have garnered significant attention in the last ***,due to the thermal instability of the microresonator,additional control devices like auxiliary lasers are indispensable for single-soliton generation in some ***,the increased system complexity would be too overwhelming for dual-microcomb ***,we put forward a novel approach to mitigate the thermal instability and generate the dual-microcomb using a compact *** process is akin to mode-division multiplexing,as the dual-microcombs are generated by pumping the dual-mode of a single Si_(3)N_(4) microresonator with a continuous-wave *** numerical simulations and experimental measurements indicate that this innovative technique could offer a straightforward way to enlarge the soliton existence range,allowing entry into the multistability regime and triggering another microcomb alongside the main soliton *** outcome not only shines new light on the interaction mechanism of microresonator modes but also provides an avenue for the development of dual-microcomb-based ranging and low phase noise microwave generation.

关键词： resonator pumped pumping

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Hybrid effect on mechanical properties and high-temperature performance of copper matrix composite reinforced with micro-nano dual-scale particles

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Journal of Materials Science & technology 2024年第5期172卷 94-103页

作者： Xingde Zhang Yihui Jiang Fei Cao Tian Yang Fan Gao Shuhua Liang School of Materials Science and Engineering Xi’an University of TechnologyXi’an 710048China Engineering Research Center of Conducting Materials and Composite technology Ministry of EducationXi’an University of TechnologyXi’an 710048China Shaanxi Province Key Laboratory of Electrical Materials and Infiltration technology Xi’an University of TechnologyXi’an 710048China

A dual-scale hybrid HfB_(2)/Cu-Hf composite with HfB_(2) microparticles and Cu_(5) Hf nanoprecipitates was designed and *** contribution of the hybrid effect to the mechanical properties and high-temperature performances was studied from macro and micro perspectives,*** hybrid of dual-scale particles can make the strain distribution of the composite at the early deformation stage more uniform and delay the strain concentration caused by the HfB_(2) *** dislocation pinning of HfB_(2) particles and the coherent strengthening of Cu_(5) Hf nanoprecipitates simultaneously play a strengthening role,but the strength of the hybrid composite is not a simple superposition of two strengthening *** addition,both Cu_(5) Hf nanoprecipitates and HfB_(2) microparticles contribute to the high-temperature performance of the composite,the growth and phase transition of nanoprecipitates at high temperature will reduce their contribution to strength,while the stable HfB_(2) particles can inhibit the coarsening of matrix grains and maintain the high-density geometrically necessary dislocations(GNDs)in the matrix,which ensures more excellent high-temperature resistance of the hybrid *** a result,the hy-brid structure can simultaneously possess the advantages of multiple reinforcements and make up for the shortcomings of each ***,a copper matrix composite with high strength,high conductivity,and excellent high-temperature performance is displayed.

关键词： Copper matrix composite HfB 2 particles Hybrid effect High strength and high conductivity High-temperature performance

Passive neutron multiplicity device for^(240)Pu measurement based on FPGA

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Nuclear Science and Techniques 2024年第9期35卷 141-154页

作者： Yan Zhang Hao-Ran Zhang Ren-Bo Wang Ming-Yu Li Rui Chen Hai-Tao Wang Xiang-Ting Meng Shu-Min Zhou Bin Tang Fundamental Science on Radioactive Geology and Exploration technology Laboratory East China University of TechnologyNanchang 330013China Engineering Research Center for Nuclear technology Application Ministry of EducationEast China University of TechnologyNanchang 330013China Pan China Detect technology Co.Ltd. Nanchang 330013China

A passive neutron multiplicity measurement device,FH-NCM/S1,based on field-programmable gate arrays(FPGAs),is developed specifically for measuring the mass of plutonium-240(^(240)Pu)in mixed oxide ***-NCM/S1 adopts an inte-grated approach,combining the shift register analysis mode with the pulse-position timestamp mode using an *** optimal effective length of the^(3)He neutron detector was determined to be 30 cm,and the thickness of the graphite reflector was ascertained to be 15 cm through MCNP *** fabricating the device,calibration measurements were per-formed using a^(252)Cf neutron source;a detection efficiency of 43.07%and detector die-away time of 55.79μs were *** samples of plutonium oxide were measured under identical conditions using the FH-NCM/S1 in shift register analysis mode and a plutonium waste multiplicity *** obtained double rates underwent corrections for detection efficiency(ε)and double gate fraction(f_(d)),resulting in corrected double rates(D_(c)),which were used to validate the accuracy of the shift register analysis ***,the device exhibited fluctuations in the measurement results,and within a single 20 s measurement,these fluctuations remained below 10%.After 30 cycles,the relative error in the mass of^(240)Pu was less than 5%.Finally,correlation calculations confirmed the robust consistency of both measurement *** study holds specific significance for the subsequent design and development of neutron multiplicity devices.

关键词： Spent fuel Non-destructive assay Neutron multiplicity ^(240)Pu FPGA

A mixed Nash equilibrium solution for visibility-based pursuit-evasion game with multiple obstacles

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Science China(Information Sciences) 2024年第09期67卷 330-332页

作者： Shaoming BU Li LIANG Youqing WANG College of Information Science and technology Beijing University of Chemical Technology

This study primarily investigates a visibility-based pursuitevasion game with multiple obstacles. The pursuer aims to maintain surveillance over the evader as long as possible, while the evader's objective is to escape the pursuer's surveillance as quickly as possible. We use the explicit strategy method to analyze the winning conditions and optimal strategy of the player in the case of corner obstacles and propose a 'Present-Future-Past'(PFP) loop structure to extend the strategy to the case of multiple obstacles.

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Vector field path following for a micro flapping-wing robot

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Science China(Information Sciences) 2024年第6期67卷 442-444页

作者： Haifeng HUANG Yingte LIU Tao NIU Chang WANG Yao ZOU Wei HE School of Intelligence Science and technology University of Science and Technology Beijing Institute of Artificial Intelligence University of Science and Technology Beijing Key Laboratory of Intelligent Bionic Unmanned Systems Ministry of EducationUniversity of Science and Technology Beijing

Flapping-wing robots mimic the flight patterns of natural flying creatures,granting them natural *** hold promising applications in the military reconnaissance,urban surveillance,and various other fields[1–3].However,the current limitations in size often restrict the suitability of existing bird-like flapping-wing robots,

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