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Photoswitchable Spiropyridine Enabled Photoactuation of Polymeric Hydrogels under Physiological pH Conditions

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Chinese Journal of Polymer science 2024年第10期42卷 1602-1609页

作者： Cong Liao Meng-Qi Du Chuang Li key laboratory of Precision and Intelligent Chemistry Department of Polymer Science and Engineering University of Science and Technology of China

The incorporation of molecular switches into polymer networks has been a powerful approach for the development of functional polymer materials that display macroscopic actuation and function enabled directly by molecular changes. However, such materials sometimes require harsh conditions to perform their functions, and the design of new molecular photoswitches that can function under physiological conditions is highly needed. Here, we report the design and synthesis of a spiropyridine-based photoswitchable hydrogel that exhibits light-driven actuation at physiological pH. Owing to its high p Ka, spiropyridine maintains its ring-open protonated form at neutral pH, and the resulting hydrogel remains in a swollen state. Upon irradiation with visible light, the ring closure of spiropyridine leads to a decrease in the charge and a reduction in the volume of the hydrogel. The contracted gel could spontaneously recover to its expanding state in the dark, and this process is highly dynamic and reversible when the light is switched on and off. Furthermore, the hydrogel shows switchable fluorescence in response to visible light. Bending deformation is observed in the hydrogel thin films upon irradiation from one side. Importantly, the independence of this spiropyridine hydrogel from the acidic environment makes it biotolerant and shows excellent biocompatibility. This biocompatible spiropyridine hydrogel might have important biorelated applications in the future.

关键词： Biocompatibility Photoactuation Physiological pH Polymer hydrogel Spiropyridine photowitch

Highly sensitive CO_(2)-LITES sensor based on a self-designed low-frequency quartz tuning fork and fiber-coupled MPC

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Chinese Optics Letters 2024年第7期22卷 105-110页

作者： Jinfeng Hou Xiaonan Liu Yahui Liu Ying He Weijiang Zhao Yufei Ma National key laboratory of science and technology on Tunable Laser Harbin Institute of TechnologyHarbin 150001China

A highly sensitive carbon dioxide(CO_(2))sensor based on light-induced thermoelastic spectroscopy(LITES)utilizing a selfdesigned low-frequency quartz tuning fork(QTF)and a fiber-coupled multipass cell(MPC)is reported in this *** QTF with a low resonant frequency of 8675 Hz and a high Q factor of 11,675.64 was used to improve its energy accumulation time and the sensor’s signal *** MPC with the fiber-coupled structure and optical length of 40 m was adopted to significantly increase the gas absorbance and reduce the optical alignment difficulty as well as improve the robustness of the sensor system.A distributed feedback(DFB),near-infrared diode laser with an emission wavelength of 1.57μm was used as an excitation *** experimental results showed that this CO_(2)-LITES sensor had an excellent linear response to CO_(2) *** minimum detection limitation(MDL)of this CO_(2)-LITES sensor was obtained to be 445.91 ppm,and it could be improved to 47.70 ppm(parts per million)when the integration time of the system reached 500 *** improvement methods for the detection performance of such sensors were also discussed.

关键词： carbon dioxide quartz tuning fork multipass cell light-induced thermoelastic spectroscopy

Selective core-shell doping enabling high performance 4.6 V-LiCoO2

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Journal of Energy Chemistry 2024年第8期95卷 684-693页

作者： Yueming Xia Jianrui Feng Jinhui Li Yan Li Zhengfeng Zhang Xiaoqi Wang Jianli Shao Manling Sui Pengfei Yan Beijing key laboratory of Microstructure and Property of Solids College of Materials Science & Engineering Beijing University of Technology Petro China Research Institute of Petroleum Exploration & Development State key laboratory of Explosion science and technology Beijing Institute of Technology

Constructing robust surface and bulk structure is the prerequisite for realizing high performance high voltage LiCoO2（LCO）.Herein,we manage to synthesize a surface Mg-doping and bulk Al-doping coreshell structured LCO,which demonstrates excellent cycling ***-cell shows 94.2% capacity retention after 100 cycles at 3.0-4.6 V（***/Li+） cycling,and no capacity decay after 300 cycles for fullcell test（3.0-4.55 V）.Based on comprehensive microanalysis and theoretical calculations,the degradation mechanisms and doping effects are systematically *** the undoped LCO,high voltage cycling induces severe interfacial and bulk degradations,where cracks,stripe defects,fatigue H2 phase,and spinel phase are identified in grain *** the doped LCO,Mg-doped surface shell can suppress the interfacial degradations,which not only stabilizes the surface structure by forming a thin rock-salt layer but also significantly improves the electronic conductivity,thus enabling superior rate *** Al-doping can suppress the lattice "breathing" effect and the detrimental H3 to H1-3 phase transition,which minimizes the internal strain and defects growth,maintaining the layered structure after prolonged *** theoretical calculations,this work deepens our understanding of the doping effects of Mg and Al,which is valuable in guiding the future material design of high voltage LCO.

关键词： Doping effect Electron microscopy Failure mechanism High-voltage LiCoO2 Lithium-ion battery

Achieving Narrowed Bandgaps and Blue-Light Excitability in Zero-Dimensional Hybrid Metal Halide Phosphors via Introducing Cation-Cation Bonding

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Energy & Environmental Materials 2024年第1期7卷 298-304页

作者： Pengfei Fu Shining Geng Ruixiang Mi Ranyun Wu Guangya Zheng Binbin Su Zhiguo Xia Guangda Niu Jiang Tang Zewen Xiao Wuhan National laboratory for Optoelectronics Huazhong University of Science and Technology The State key laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied TechniquesSchool of Materials Science and Technology South China University of Technology School of Optical and Electronic Information Huazhong University of Science and Technology

Zero-dimensional(0D) hybrid metal halides,which consist of organic cations and isolated inorganic metal halide anions,have emerged as phosphors with efficient broadband ***,these materials generally have too wide bandgaps and thus cannot be excited by blue light,which hinders their applications for efficient white light-emitting diodes(WLEDs).

关键词： blue-light-excitable cation–cation bonding hybrid metal halide phosphor zero-dimensional

Effects of Rosa roxburghii&edible fungus fermentation broth on immune response and gut microbiota in immunosuppressed mice

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Food science and Human Wellness 2024年第1期13卷 154-165页

作者： Dechang Xu Jielun Hu Yadong Zhong Yanli Zhang Wenting Liu Shaoping Nie Mingyong Xie State key laboratory of Food science and technology China-Canada Joint Laboratory of Food Science and Technology(Nanchang)Key Laboratory of Bioactive Polysaccharides of Jiangxi ProvinceNanchang UniversityNanchang 330047China

With the rise of probiotics fermentation in food industry,fermented foods have attracted worldwide *** this study,protective effects of Rosa roxburghii&edible fungus fermentation broth(REFB)on immune function and gut health in Cyclophosphamide induced immunosuppressed mice were *** showed that REFB could improve the immune organ index,and promote the proliferation and differentiation of splenic T *** addition,it attenuated intestinal mucosal damage and improved intestinal cellular *** administration also up-regulated the expression of IL-4,INF-γ,TNF-α,T-bet and GATA-3 mRNA in small ***,administration of REFB modulated gut microbiota composition and increased the relative abundance of beneficial genus,such as *** also increased the production of fecal short-chain fatty *** indicate that REFB has the potential to improve immunity,alleviate intestinal injury and regulate gut microbiota in immunosuppressed mice.

关键词： Fermented foods Immunosuppressed mice Immune response Gut microbiota Short-chain fatty acids

EmotionIC: emotional inertia and contagion-driven dependency modeling for emotion recognition in conversation

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science China(Information sciences) 2024年第08期67卷 130-146页

作者： Yingjian LIU Jiang LI Xiaoping WANG Zhigang ZENG School of Artificial Intelligence and Automation Huazhong University of Science and Technology Hubei key laboratory of Brain-inspired Intelligent Systems Huazhong University of Science and Technology key laboratory of Image Processing and Intelligent Control (Huazhong University of science and technology) Ministry of Education Institute of Artificial Intelligence Huazhong University of Science and Technology

Emotion recognition in conversation(ERC) has attracted growing attention in recent years as a result of the advancement and implementation of human-computer interface technologies. In this paper,we propose an emotional inertia and contagion-driven dependency modeling approach(EmotionIC) for ERC tasks. Our EmotionIC consists of three main components, i.e., identity masked multi-head attention(IMMHA), dialogue-based gated recurrent unit(DiaGRU), and skip-chain conditional random field(SkipCRF).Compared to previous ERC models, EmotionIC can model a conversation more thoroughly at both the feature-extraction and classification levels. The proposed model attempts to integrate the advantages of attention-and recurrence-based methods at the feature-extraction level. Specifically, IMMHA is applied to capture identity-based global contextual dependencies, while Dia GRU is utilized to extract speaker-and temporal-aware local contextual information. At the classification level, SkipCRF can explicitly mine complex emotional flows from higher-order neighboring utterances in the conversation. Experimental results show that our method can significantly outperform the state-of-the-art models on four benchmark *** ablation studies confirm that our modules can effectively model emotional inertia and contagion.

关键词： conditional random field emotion recognition in conversation emotional inertia and contagion gated recurrent unit multi-head attention

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Tribological Behaviors of Electroless Nickel-Boron Coating on Titanium Alloy Surface

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 309-320页

作者： Yao Jia Jianping Lai Jiaxin Yu Huimin Qi Yafeng Zhang Hongtu He key laboratory of Testing technology for Manufacturing Process in Ministry of Education State Key Laboratory of Environment-Friendly Energy MaterialsSouthwest University of Science and TechnologyMianyang 621010China

Titanium alloys are excellent structural materials in engineering fields,but their poor tribological properties limit their further *** plating is an effective method to enhance the tribological performance of alloys,but it is difficult to efficiently apply to titanium alloys,due to titanium alloy’s strong chemical *** this work,the electroless Nickel-Boron(Ni-B)coating was successfully deposited on the surface of titanium alloy(Ti-6AL-4V)via a new pre-treatment ***,linearly reciprocating sliding wear tests were performed to evaluate the tribological behaviors of titanium alloy and its electroless Ni-B *** was found that the Ni-B coatings can decrease the wear rate of the titanium alloy from 19.89×10^(−3)mm^(3)to 0.41×10^(−3)mm^(3),which attributes to the much higher hardness of Ni-B *** heat treatment,the hardness of Ni-B coating further increases corresponding to coating crystallization and hard phase ***,heat treatment does not improve the tribological performance of Ni-B coating,due to the fact that higher brittleness and more severe oxidative wear exacerbate the damage of heat-treated ***,the Ni-B coatings heat-treated both in air and nitrogen almost present the same tribological *** finding of this work on electroless coating would further extend the practical applications of titanium alloys in the engineering fields.

关键词： Electroless coating Titanium alloy Tribology Wear Heat treatment Nanoindentation

Al/Hf ratio-dependent mechanisms of microstructure and mechanical property of nearly fully dense Al—Hf reactive material

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Defence technology（防务技术） 2024年第1期31卷 230-241页

作者： Junbao Li Weibing Li Xiaoming Wang ZNDY of Ministerial key laboratory Nanjing University of Science and TechnologyNanjing 210094China

This study proposed three types of Al—Hf reactive materials with particle size ratios(a),which were almost completely dense(porosity of<5.40%)owing to their preparation using hot-pressing *** characteristics and phase composition were analyzed,and the influence of particle size ratios on dynamic mechanical behavior and damage mechanism were *** prepared sample with a=0.1 exhibited continuous wrapping of the Hf phase by the Al ***—Hf contact(continuous Hf phase)within the sample gradually increased with increasing a,and a small amount of fine Hf appeared for the sample with a=*** reactive materials exhibited clear strain-rate sensitivity,with flow stressσ0.05and failure strainεfincreasing approximately linearly with increasing strain rate.ε.It is found that the plastic deformation of the material increased with increasing strain *** a increased from 0.1 to 1,the flow stress gradually *** failure of the material was dominated by ductile fracture with a large Al phase plastic deformation band for lower a,while brittle fracture with crushed Hf particles occurred at higher ***,a constitutive model based on BP neural network was proposed to describe the stress-strain relationships of the materials,with an average relative error of 2.22%.

关键词： Reactive material Particle size Split Hopkinson pressure bar test Stressestrain relationship Impact failure BP neural network

GS-orthogonalization OMP method for space target detection via bistatic space-based radar

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Chinese Journal of Aeronautics 2024年第7期37卷 333-351页

作者： Shuyu ZHENG Libing JIANG Qingwei YANG Yingjian ZHAO Zhuang WANG National key laboratory of science and technology on Automatic Target Recognition College of Electronic Science and TechnologyNational University of Defense TechnologyChangsha 410073China

A space-based bistatic radar system composed of two space-based radars as the transmitter and the receiver respectively has a wider surveillance region and a better early warning capability for high-speed targets,and it can detect focused space targets more flexibly than the monostatic radar system or the ground-based radar ***,the target echo signal is more difficult to process due to the high-speed motion of both space-based radars and space *** be specific,it will encounter the problems of Range Cell Migration(RCM)and Doppler Frequency Migration(DFM),which degrade the long-time coherent integration performance for target detection and localization *** solve this problem,a novel target detection method based on an improved Gram Schmidt(GS)-orthogonalization Orthogonal Matching Pursuit(OMP)algorithm is proposed in this ***,the echo model for bistatic space-based radar is constructed and the conditions for RCM and DFM are ***,the proposed GS-orthogonalization OMP method is applied to estimate the equivalent motion parameters of space ***,the RCM and DFM are corrected by the compensation function correlated with the estimated motion ***,coherent integration can be achieved by performing the Fast Fourier Transform(FFT)operation along the slow time direction on compensated echo *** simulations and real raw data results validate that the proposed GS-orthogonalization OMP algorithm achieves better motion parameter estimation performance and higher detection probability for space targets detection.

关键词： Bistatic space-based radar High-speed maneuvering space targets detection Range Cell Migration(RCM) Doppler Frequency Migration(DFM) Gram Schmidt(GS)-orthogonalization Orthogonal Matching Pursuit(OMP)algorithm