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Sustainable conversion regenerated cellulose into cellulose oleate by sonochemistry

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Frontiers of Chemical Science and Engineering 2023年第8期17卷 1096-1108页

作者： De-Fa Hou pan-pan Yuan Zi-Wei Feng Meng An Pei-Yao Li can Liu Ming-Bo Yang National Joint Engineering Research Center for Highly-Efficient Utilization Technology of Forestry Resource Southwest Forestry UniversityKunming 650224China College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China

Derivatization has great potential for the high-value utilization of cellulose by enhancing its processability and functionality.However,due to the low reactivity of natural cellulose,it remains challenging to rapidly prepare cellulose derivatives with high degrees of substitution.The“cavitation effect”of ultrasound can reduce the particle size and crystalline index of cellulose,which provides a possible method for preparing cellulose derivatives.Herein,a feasible method was proposed for efficiently converting regenerated cellulose to cellulose oleate with the assistance of ultrasonic treatment.By adjusting the reaction conditions including ultrasonic intensity,feeding ratios of oleic acid,reaction time,and reaction solvent,a series of cellulose oleates with degrees of substitution ranging from 0.37 to 1.71 were synthesized.Additionally,the effects of different reaction conditions on the chemical structures,crystalline structures,and thermal behaviors were investigated thoroughly.Cellulose oleates with degrees of substitution exceeding 1.23 exhibited amorphous structures and thermoplasticity with glass transition temperatures at 159.8 to 172.6℃.This study presented a sustainable and practicable method for effectively derivatizing cellulose.

关键词： regenerated cellulose cellulose oleate sonochemistry degree of substitution thermoplasticity

An Improved Approach for Interaction of Wave with Floating Spheres and Its Applications

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China Ocean Engineering 2023年第1期37卷 115-130页

作者： LIU can DONG Zhi-yong pan Yun TONG Huan-huan YANG li-jing College of Civil Engineering Zhejiang University of TechnologyHangzhou 310023China School of Naval Architecture and Maritime Zhejiang Ocean UniversityZhoushan 316022China School of Marine Engineering Equipments Zhejiang Ocean UniversityZhoushan 316022China

To develop and utilize marine resources in the deep sea, the higher requirements for floating structures, which are operated in marine environment for a long term, have been put forward. Reasonable structure type and accurate force analysis are favorable guarantees to improve the survival performance and working performance of the floating structures. Floating spheres fastened by mooring cable were widely used in floating structures. In this paper, the wave forces of the floating sphere are efficiently and accurately calculated by solving the geometric relationship between the non-submerged floating sphere and wave surface. Combined with the hydrodynamic calculation of mooring cables based on the lumped mass method, the coupled motion model of multi-floating spheres fastened by multi-mooring cable was established under wave action. Furthermore, according to the floating structures fastened by mooring cable in the actual ocean engineering, the topological method of multi-mooring cables fastening the multifloating spheres was expounded from simple to complex. Finally, the modeling method and preliminarily hydrodynamic characteristics of the fastened floating structures, including the mooring system of renewable energy devices, ocean buoy, and coral nursery, were presented and analyzed in detail. The obtained results showed that the method for calculating the wave force on the floating sphere developed in this paper can accurately describe the motion process of the floating mooring sphere and the force on the mooring cable. Also, the topological method of multiple buoys and multiple mooring cables could efficiently establish various numerical hydrodynamic models of fastened buoys in ocean engineering.

关键词： floating sphere mooring cable wave forces hydrodynamic model ocean engineering

Catalyst-free Photochemical Bromination of Unprotected Aromatic Amino Acid Derivatives by Using a Rotating Ultraviolet Photoreactor

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Chemical Research in Chinese Universities 2022年第2期38卷 505-509页

作者： ZHANG Tingting LUO pan LAI can LIU Zheyi JIN Yan WANG Fangjun CAS Key Laboratory of Separation Sciences for Analytical Chemistry Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023P.R.China University of Chinese Academy of Sciences Beijing 100049P.R.China

Aromatic amino acid halides are valuable amino acid derivatives and fundamental building blocks that are used to various coupling reaction^1-3!,such as Heck,Suzuki and Ullmann reaction[4-7],and also important precurso... 详细信息

关键词： Catalyst-free Photochemistry Bromination 254 nm UV Unprotected aromatic amino acid derivative

Nano-TiO_(2) coate d nee dle carbon fib er reinforced phenolic aerogel composite with low density, excellent heat-insulating and infrared radiation shielding performance

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Journal of Materials Science & Technology 2023年第21期152卷 181-189页

作者： Yiwu pan Xiangyu Jin Hebing Wang He Huang can Wu Xiaojie Yan Changqing Hong Xinghong Zhang National Key Laboratory of Science and Technology on Advanced Composites in Special Environments Harbin Institute of TechnologyHarbin 150001China

High-performance thermal protection materials(TPMs)for spacecraft are becoming current research hotspots.Lightweight polymer-based ablators are considered to be the most promising candidates for TPMs due to their excellent designability and versatility.In this study,a unique nano-TiO_(2) coated needled carbon fiber felt/phenolic resin aerogel composite(TiCF/PR)is reported.Wherein the anatase nano-TiO_(2) was in-situ coated on the surface of carbon fibers uniformly through the sol-gel and calcination method,then,the phenolic resin aerogel was in-situ synthesized in the nano-TiO_(2) coated needled carbon fiber felt(TiCF)preform through vacuum impregnation and solvothermal method.The as-prepared aerogel com-posite possesses a low density(0.30–0.32 g/cm^(3)),low thermal conductivity(0.034 and 0.312 W/(m K)in the z and xy directions),and excellent thermal stability with 13.86%residual weight at 1300℃ in air.It is worthwhile to note that the TiCF/PR composite exhibits excellent antioxidant ablation and infrared(IR)radiation shielding properties in a high-temperature heating environment.With an oxygen-acetylene blaze heating of 1.5 MW/m^(2) for 150 s,the linear ablation rates decreased by 13.4%,and the backside temperature reduced from 322.3 to 179.1℃ compared to that of the sample without nano-TiO_(2) coating.The experimental and theoretical analysis showed that the present TiCF/PR nanocomposite has competitive and potential application prospects in the field of future TPMs.

关键词： Carbon fiber Opacifier Mechanical properties Thermal properties Ablation performance

Fast-Tracker 2.0:Improving autonomy of aerial tracking with active vision and human location regression

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IET Cyber-Systems and Robotics 2021年第4期3卷 292-301页

作者： Neng pan Ruibin Zhang Tiankai Yang can Cui Chao Xu Fei Gao State Key Laboratory of Industrial Control Technology Zhejiang UniversityHangzhouChina Huzhou Institute of Zhejiang University HuzhouChina

In recent years,several progressive studies promote the development of aerial tracking.One of the representative studies is our previous work Fast-Tracker which is applicable to various challenging tracking scenarios.However,it suffers from two main drawbacks:(1)the oversimplification in target detection by using artificial markers and(2)the contradiction between simultaneous target and environment perception with limited onboard vision.In this study,we upgrade the target detection in Fast-Tracker to detect and localise a human target based on deep learning and non-linear regression to solve the former problem.For the latter one,we equip the quadrotor system with 360°active vision on a customised gimbal camera.Furthermore,we improve the tracking trajectory planning in Fast-Tracker by incorporating an occlusion-aware mechanism that generates observable tracking trajectories.Comprehensive real-world tests confirm the proposed system's robustness and real-time capability.Benchmark comparisons with Fast-Tracker validate that the proposed system presents better tracking performance even when performing more difficult tracking tasks.

关键词： autonomous aerial vehicles motion planning navigation path planning

Corrosion Behavior of 316L Stainless Steels Exposed to Salt Lake Atmosphere of Western China for 8 years

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Acta Metallurgica Sinica(English Letters) 2021年第4期34卷 555-564页

作者： Mingxiao Guo Junrong Tang Tianzhen Gu can Peng Qiaoxia Li Chen pan Zhenyao Wang Institute of Metal Research Chinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China University of Chinese Academy of Sciences Beijing100049China

The evolution of corrosion behavior of 316 L stainless steels exposed to salt lake atmosphere for 8 years was investigated.The results showed that the stainless steel in salt lake atmosphere had a greater corrosion rate during the initial exposure time and relatively lower corrosion rate during the subsequent exposure time.Dust depositions accumulated on the downward surface caused severe local corrosion of stainless steel.As exposure time prolonged,the relative amount of Croxide and Feoxidein the corrosion products gradually increased,which may directly affect the corrosion rate of stainless steels.Moreover,the maximum pit depth followed a power function with respect to exposure time.

关键词： Atmospheric corrosion Salt lake atmosphere Stainless steel X-ray photoelectron spectroscopy(XPS) Electrochemical impedance spectroscopy(EIS)

Sex and Death:Identification of Feedback Neuromodulation Balancing Reproduction and Survival

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Neuroscience Bulletin 2020年第12期36卷 1429-1440页

作者： can Gao Chao Guo Qionglin Peng Jie Cao Galit Shohat-Ophir Dong Liu Yufeng pan The Key Laboratory of Developmental Genes and Human Disease School of Life Science and TechnologySoutheast UniversityNanjing 210096China School of Life Sciences Nantong UniversityNantong 226019China The Mina&Everard Goodman Faculty of Life Sciences and Susan Gonda Multidisciplinary Brain Research Center Bar-Ilan UniversityRamat-Gan 5290002Israel Co-innovation Center of Neuroregeneration Nantong UniversityNantong 226019China

Some semelparous organisms in nature mate as many times as they can in a single reproductive episode before death,while most iteroparous species including humans avoid such suicidal reproductive behavior.Animals naturally pursue more sex and the possible fatal consequence of excessive sex must be orchestrated by negative feedback signals in iteroparous species,yet very little is known about the regulatory mechanisms.Here we used Drosophila male sexual behavior as a model system to study how excessive sex may kill males and how the nervous system reacts to prevent death by sex.We found that continuous sexual activity by activating the fruitlessexpressing neurons induced a fixed multi-step behavioral pattern ending with male death.We further found negative feedback in the fly brain to prevent suicidal sexual behavior by expression changes of the neurotransmitters acetylcholine and gamma-aminobutyric acid,and neuropeptide F.These findings are crucial to understand the molecular underpinnings of how different organisms choose reproductive strategies and balance reproduction and survival.

关键词： Drosophila Reproduction Survival NPF GABA Acetylcholine

Optimal readout of superconducting qubits exploiting high-level states

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Fundamental Research 2021年第1期1卷 16-21页

作者： can Wang Ming-Cheng Chen Chao-Yang Lu Jian-Wei pan Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics University of Science and Technology of ChinaHefeiAnhui 230026China CAS Centre for Excellence and Synergetic Innovation Centre in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefeiAnhui 230026China

High-fidelity initialization,manipulation,and measurement of qubits are important in quantum computing.For the Google’s Sycamore processor,the gate fidelity of single-and two-qubit logic operations has improved to>99.6%,whereas single-shot measurement fidelity remains at the level of 97%,which severely limits the ap-plication of the superconducting approach to large-scale quantum computing.The current measurement scheme relies on the dispersive interaction between the qubit and the readout resonator,which was proposed back in 2004.However,the measurement fidelity is limited by the trade-offbetween the state separation and relax-ation time of the two-level system.Recently,an exciting phenomenon was observed experimentally,wherein the separation-decay limit could be alleviated by exploiting the cascade decay nature of the higher levels;however,the mechanism and effectiveness of this phenomenon are still unclear.Herein,we present a theoretical tool to extract different types of errors in high-level states encoding dispersive measurement.For the realistic parame-ters of Google’s Sycamore processor,the use of state|2>is sufficient to suppress 92%of the decay readout error on average,where the total readout error is dominated by the background thermal excitation.We also show counter-intuitively that,the assistance of high-level states is effective in the measurement of logic 0,where there is no decay process.

关键词： Dispersive measurement Transmon Superconducting qubit Quantum computation

Reducing host aldose reductase activity promotes neuronal differentiation of transplanted neural stem cells at spinal cord injury sites and facilitates locomotion recovery

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Neural Regeneration Research 2022年第8期17卷 1814-1820页

作者： Kun Zhang Wen-can Lu Ming Zhang Qian Zhang pan-pan Xian Fang-Fang Liu Zhi-Yang Chen Chung Sookja Kim Sheng-Xi Wu Hui-Ren Tao Ya-Zhou Wang Department of Neurobiology and Institute of Neurosciences School of Basic MedicineFourth Military Medical UniversityXi’anShaanxi ProvinceChina Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration Tongji UniversityShanghaiChina Department of Spine Surgery Shenzhen University General HospitalShenzhenGuangdong ProvinceChina Department of Neurology Hainan Hospital of Chinese PLA General HospitalSanyaHainan ProvinceChina Department of Anesthesiology Tangdu HospitalFourth Military Medical UniversityXi’anShaanxi ProvinceChina Faculty of Medicine Macao University of Science and TechnologyMacao Special Administrative RegionChina

Neural stem cell(NSC)transplantation is a promising strategy for replacing lost neurons following spinal cord injury.However,the survival and differentiation of transplanted NSCs is limited,possibly owing to the neurotoxic inflammatory microenvironment.Because of the important role of glucose metabolism in M1/M2 polarization of microglia/macrophages,we hypothesized that altering the phenotype of microglia/macrophages by regulating the activity of aldose reductase(AR),a key enzyme in the polyol pathway of glucose metabolism,would provide a more beneficial microenvironment for NSC survival and differentiation.Here,we reveal that inhibition of host AR promoted the polarization of microglia/macrophages toward the M2 phenotype in lesioned spinal cord injuries.M2 macrophages promoted the differentiation of NSCs into neurons in vitro.Transplantation of NSCs into injured spinal cords either deficient in AR or treated with the AR inhibitor sorbinil promoted the survival and neuronal differentiation of NSCs at the injured spinal cord site and contributed to locomotor functional recovery.Our findings suggest that inhibition of host AR activity is beneficial in enhancing the survival and neuronal differentiation of transplanted NSCs and shows potential as a treatment of spinal cord injury.

关键词： aldose reductase functional recovery inflammation macrophage microglia neural stem cell transplantation neuronal differentiation polarization spinal cord injury