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Optically levitated micro gyroscopes with an MHz rotational vaterite rotor

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Microsystems & Nanoengineering 2024年第3期10卷 219-227页

作者： kai zeng Xiangming Xu Yulie Wu Xuezhong Wu Dingbang Xiao College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China College of Information and Communication National University of Defense TechnologyWuhan 430000China Key Laboratory of Satellite Navigation Technology National University of Defense TechnologyChangsha 410073China

The field of levitated optomechanics has experienced significant advancements in manipulating the translational and rotational dynamics of optically levitated particles and exploring their sensing *** concept of using optically levitated particles as gyroscopes to measure angular motion has long been explored but has not yet been proven either theoretically or *** this study,we present the first rotor gyroscope based on optically levitated high-speed rotating *** gyroscope is composed of a micrometer-size ellipsoidal vaterite particle that is driven to rotate at MHz frequencies in a vacuum *** an external angular velocity is input,the optical axis deviates from its initial position,resulting in changes in the frequency and amplitude of the rotational *** analyzing these changes,the angular velocity of the input can be accurately detected,making it the smallest rotor gyroscope in the *** angular rate bias instability of the gyroscope is measured to be 0.08°/s and can be further improved to as low as 10^(−9)°/h theoretically by cooling the motion and increasing the angular moment of the levitated *** work opens a new application paradigm for levitated optomechanical systems and may pave the way for the development of quantum rotor gyroscopes.

关键词： particles rotational angular

Bubble model analysis on the cell formation of a green alga

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International Journal of Biomathematics 2020年第5期13卷 21-31页

作者： Yuandi Wang Nanjun Yan Zhigang Zhou kai zeng Department of Mathematics Shanghai University Shanghai 200444 P.R.China College of A qua-life Sciences and Technology Shanghai Ocean University Shanghai 201306 P.R.China

Mathematical simulation for cell and division,a complex process resulting from a series of major morphological evolution and biological mechanisms,is shown by using variational *** of differential equation systems with boundary conditions for the cell walls satisfying come out from analysis on minimally total *** bubble model for cell geometric formation is found and a mechanism for tri-bubble model is also investigated *** interesting fact is that every angle between any two tangent lines at the same intersections of cell edges for both double bubble and tri-bubble is equal to 27r/*** addition to the derivation of these differential equation models,these theories are also applied to the specific experimental data analysis,and it is found that the model is very consistent with the experimental results.

关键词： Green algae cell mathematical model bubble differential equation variational principle

Short communication Solvothermal synthesis of trigonal selenium with butterfly-like microstructure

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Particuology 2013年第5期11卷 614-617页

作者： kai zeng Shuguang Chen Yande Song Haibin Li Fujin Li Peng Liu School of Physics and Electronic Science Changsha University of Science & Technology

We present a facile synthesis of trigonal selenium with butterfly-like microstructure from elemental sele- nium via a solvothermal and aging route. By using X-ray diffraction and scanning electron microscopy to characterize the products, a possible growth mechanism is proposed. The solvothermal process pro- motes the dissolution of selenium in ethylenediamine to form a brown homogeneous [Se（en）x] solution. By introducing acetone into this [Se（en）x] solution, amorphous selenium nanoparticles were produced which then transformed into trigonal selenium, which further assembled along the c-axis to form hexag- onal rods. Owing to stereo hindrance as well as to development of opposite lateral sides of the hexagonal rod in opposing directions, a butterfly-like microstructure consisting of two long outside rods and a short inner rod was obtained.

关键词： SeleniumSolution-phaseButterfly-likeCrystal growthMicrostructure

Effects of INA on postharvest blue and green molds and anthracnose decay in citrus fruit

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Journal of Integrative Agriculture 2020年第5期19卷 1396-1406页

作者： JING Jia-yi ZHANG Hong-yan XUE Yao-bi zeng kai-fang College of Food Science Southwest UniversityChongqing 400715P.R.China Food Storage and Logistics Research Center Southwest UniversityChongqing 400715P.R.China

As a synthetic functional analog of salicylic acid, 2,6-dichloroisonicotinic acid(INA) is effective in inducing the host disease resistance of a plant against a pathogen. The effects of INA on controlling postharvest blue and green molds and anthracnose decay and defense-related enzymes on citrus fruits were investigated, and the ascorbic acid of naturally infected citrus flavedo was also measured. Results showed that 1.0 mmol L^(–1) INA treatments significantly reduced blue and green molds and anthracnose decay development on both wound-inoculated fruit and naturally-infected fruit compared with the control fruit. The treatment effectively enhanced the β-1,3-glucanase(GLU), chitinase(CHI), phenylalanine ammonia-lyase(PAL) and peroxidase(POD) activities and the polyphenol oxidase(PPO) in flavedo. The results presented here suggest that INA might be used as a chemical fungicide substitution to control postharvest diseases in citrus fruits.

关键词： postharvest citrus fruit INA induced resistance

Multispectral point cloud superpoint segmentation

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Science China(Technological Sciences) 2024年第4期67卷 1270-1281页

作者： WANG QingWang WANG MingYe ZHANG ZiFeng SONG Jian zeng kai SHEN Tao GU YanFeng Faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming 650500China Yunnan Key Laboratory of Computer Technologies Application Kunming 650500China School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China

The multitude of airborne point clouds limits the point cloud processing *** are grouped based on similar points,which can effectively alleviate the demand for computing resources and improve processing ***,existing superpoint segmentation methods focus only on local geometric structures,resulting in inconsistent spectral features of points within a *** feature inconsistencies degrade the performance of subsequent ***,this study proposes a novel Superpoint Segmentation method that jointly utilizes spatial Geometric and Spectral Information for multispectral point cloud superpoint segmentation(GSI-SS).Specifically,a similarity metric that combines spatial geometry and spectral information is proposed to facilitate the consistency of geometric structures and object attributes within segmented *** the formation of the primary superpoints,an intersuperpoint pointexchange mechanism that maximizes feature consistency within the final superpoints is *** are conducted on two real multispectral point cloud datasets,and the proposed method achieved higher recall,precision,F score,and lower global consistency and feature classification *** experimental results demonstrate the superiority of the proposed GSI-SS over several state-of-the-art methods.

关键词： multispectral point cloud superpoint segmentation over-segmentation spatial-spectral joint metric

Transfer-based Approximate Dynamic Programmingfor Rolling Security-constrained Unit Commitment with Uncertainties

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Protection and Control of Modern Power Systems 2024年第5期9卷 42-53页

作者： Jianquan Zhu kai zeng Jiajun Chen Wenmeng Zhao Wenhao Liu Wenkai Zhu School of Electric Power Engineering South China University of TechnologyGuangzhou 510640China Electric Power Research Institute China Southern Power GridGuangzhou 510700China

This paper studies the rolling security-constrained unit commitment(RSCUC)problem with AC power flow and *** this NP-hard problem,it is modeled as a Markov decision process,which is then solved by a transfer-based approximate dynamic programming(TADP)algorithm proposed in this *** from traditional approximate dynamic programming(ADP)algorithms,TADP can obtain the commitment states of most units in advance through a decision transfer technique,thus reducing the action space of TADP ***,compared with traditional ADP algorithms,which require to determine the commitment state of each unit,TADP only needs determine the unit with the smallest on-state probability among all on-state units,thus further reducing the action *** proposed algorithm can also prevent the iter-ative update of value functions and the reliance on rolling forecast information,which makes more sense in the rolling decision-making process of ***,nu-merical simulations are carried out on a modified IEEE 39-bus system and a real 2778-bus system to demonstrate the effectiveness of the proposed algorithm.

关键词： Rolling security-constrained unit com-mitment approximate dynamic programming decision transfer probability-based decision priority criterion uncertainty

Polypropylene crisper and 1-MCP delay the softening,lignification and transcription levels of related enzyme genes of golden needle mushrooms(Flammulina velutipes)

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Journal of Integrative Agriculture 2022年第1期21卷 249-260页

作者： WANG Wen-jun LI Yao LI Fu-hua zeng kai-fang MING Jian College of Food Science Southwest UniversityChongqing 400715P.R.China Research Center of Food Storage&Logistics Southwest UniversityChongqing 400715P.R.China

The fresh postharvest golden needle mushroom(Flammulina velutipes) sporocarp has a high moisture content and crisp texture, but it still has high physiological activity and respiration, leading to senescence and quality *** with 1-methylcyclopropene(1-MCP) and polypropylene(PP) crispers were used to study the changes of lignification and softening of F. velutipes during storage. The main findings were as follows: the crisper packaging could effectively prolong the storage time of F. velutipes;either the 1-MCP treatment, crisper packaging or the combination of the two treatments could significantly inhibit the accumulation of lignin and the decreases in the contents of cellulose and pectin, and had certain inhibitory effects on the activities of enzymes involved in lignification and softening including phenylalanine ammonia-lyase(PAL), cinnamyl alcohol dehydrogenase(CAD), cellulase(Cx), pectin methylesterase(PME) and polygalacturonase(PG). Among them, the inhibitory effect of the crisper packaging was higher than the 1-MCP treatment, while the combination of the two treatments was the best. The results of transmission electron microscopy(TEM) and scanning electron microscopy(SEM) showed that the crisper packaging in combination with the 1-MCP treatment could effectively maintain the integrity and stability of the F. velutipes cellular structure and inhibit the emergence of plasmolysis to prevent cell membrane rupture. The transcription levels showed that the crisper packaging and the combination of the 1-MCP treatment and crisper packing could effectively affect the expression of genes for enzymes related to lignification and softening of F. velutipes. In conclusion, 1-MCP and PP crispers could delay the lignification and softening of F. velutipes during storage.

关键词： Flammulina velutipes polypropylene crisper 1-MCP softening and lignification transcription levels

Effects of methionine treatment on storage quality and antioxidant activity of postharvest jujube fruit

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Journal of Integrative Agriculture 2023年第9期22卷 2893-2904页

作者： LIU Yao LEI Xing-meng GUO Yu-xiao YAO Shi-xiang zeng kai-fang College of Food Science Southwest UniversityChongqing 400715P.R.China Food Storage and Logistics Research Center Southwest UniversityChongqing 400715P.R.China National Citrus Engineering Research Center Chongqing 400712P.R.China

Jujube fruits usually suffer from physiological disorders or infectious diseases during storage,leading to quality deterioration,softening,or ***,this study aims to investigate the effect of methionine soaking treatment on the postharvest jujube fruit decay rate and storage *** treatment significantly reduced the decay rate of postharvest jujube fruit and effectively maintained fruit color and titratable *** treatment effectively delayed the decrease of firmness,soluble solids,ascorbic acid,and lignin contents in jujube *** treatment reduced the content of alanine and phenylalanine,and increased the content of glycine in jujube fruit,but displayed no significant effect on total amino acid *** addition,jujube fruits in the methionine treatment group had a higher total phenolic and flavonoid content and antioxidant capacity,both in free and bound *** with the control,methionine treatment also significantly increased the content of individual phenolic acid fractions(gallic acid,vanillic acid,and syringic acid)and flavonoid fractions(catechin,epicatechin,rutin)in free form as well as individual phenolic acid fractions in bound form(gallic acid and ferulic acid)in jujube ***,this study suggested that the methionine treatment could be used as a prospective preservative to reduce the postharvest decay of jujube fruit and alleviate its nutritional quality deterioration during cold storage at 4°C.

关键词： methionine jujube decay rate sensory quality nutritional value

The effect of interfacial diffusion on device performance of polymer solar cells: a quantitative view by active-layer doping

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Science China Chemistry 2015年第2期58卷 317-322页

作者： Li Nian Jiadong Zhou kai zeng Xiaoyan Wu Linlin Liu zengqi Xie Fei Huang Yuguang Ma Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology

The diffusion of constituent materials at interfaces is one of the key factors for device performance and stability. In this work, the effect of interfacial diffusion of a classic interfacial material PFN on device performance of polymer solar cells was studied quantitatively by doping PFN into active layer based on P3HT：PC61BM blend. The PCEs of devices with 550 ppm PFN de- crease to half compared to those of the control devices without PFN, which are mainly attributed to the decrease of short-circuit current （Jsc） and fill factor （FF）. Advanced analyses of equivalent circuit, absorption spectra, and atomic force mi- croscopy indicates that the presence of PFN in the active layer increases the leakage current, decreases the aggregation of P3HT, and reduces the phase separation. This research reveals the physical mechanism of interfacial diffusion in device per- forrnance and provides a basis for further improving the performance and stability of PSCs.

关键词： bulk-heterojunction solar cells interfacial diffusion PFN stability degradation