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Chinese Chemical Letters 2022年第4期33卷 1659-1672页

作者： Pengli gao Zhigang xie Min Zheng School of Chemistry and Life Science Advanced Institute of Materials ScienceChangchun University of TechnologyChangchun 130022China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

As a new type of carbon-based fluorescent nanomaterials, carbon dots(CDs) are provided with the advantages of small size, excellent photoluminescence(PL) property, easy surface modification, robust stability,good water solubility and biocompatibility, which endow them with great potential in sensing. In this review, we first describe the preparation of CDs from different starting materials via various techniques, and pre-/post-modification strategies to modulate their PL properties. Second, we outline the optical properties of CDs, including UV-vis absorption and PL, especially the PL mechanisms of CDs are presented in detail from the size effect, molecular state, surface state and defect state. Third, we summarize the research progress of CDs in sensing environmental pollutants, bioactive substances, biological microenvironments,bacteria and viruses via different mechanisms. In addition, we envision the future development trends and prospects for CDs-based nanosensors. We believe that this type of small nanoparticles will bring about big prospect in the near future.

关键词： Carbon dots Synthesis Modification Mechanisms Sensing

STATISTICALLY FRACTAL STRENGTH THEORY FOR BRITTLE MATERIALS

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Acta Mechanica Solida Sinica 1996年第1期9卷 42-51页

作者： gao, F xie, HP CHINA UNIV MIN & TECHNOL DEPT MECH & MATHXUZHOU 221008PEOPLES R CHINA

Based on the hypothesis of the fractal distribution of crack sizes in brittle materials and the weakest link principle, the relationship between the fractal dimension of the size-frequency distribution of cracks and the Weibull Modulus is derived, which reveals the geometrical nature of the Weibull Modulus. The influences of the size distribution and the orientation distribution of cracks as well as the irregularity of the crack propagation on the strength are all taken into account. Finally, a general expression for the statistical strength of brittle materials in complex tensile stress state is obtained.

关键词： size-frequency distribution fractal dimension the weakest link principle statistical strength

Certificateless Sequential Aggregate Signature Scheme on NTRU Lattice

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Chinese Journal of Electronics 2019年第2期28卷 294-300页

作者： xie Jia HU Yupu gao Juntao JIANG Mingming School of Computer and Information Engineering Henan University of Economics and Law School of Telecommunications Engineering Xidian University School of Computer Science and Technology Huaibei Normal University

Having the advantages of certificateless signature and the aggregate signature at the same time,certificateless aggregate signature has been widely applied in e-business, e-government and software security since it was proposed in 2007. Although a number of certificateless aggregate signature schemes have been proposed, all of them are based on the classic number theory problem,which are no longer secure in the quantum era. In this paper, a certificateless sequential aggregate signature over number theory research unit lattice is proposed, which is proven to be secure in random oracle model. Moreover,we extend the new scheme into an efficient certificatebased sequential aggregate signature which is also secure in quantum era.

关键词： Certificateless Sequential Aggregate Signature Number theory research unit Secure Lattice

Enjoy the most beautiful scene now:a memetic algorithm to solve two-fold time-dependent arc orienteering problem

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Frontiers of Computer Science 2020年第2期14卷 364-377页

作者： Chao CHEN Liping gao Xuefeng xie Zhu WANG School of Computer Science Chongqing UniversityChongqing 400044China School of Computer Science Northwestern Polytechnical UniversityXi'an 710072China

Traditional route planners commonly focus on finding the shortest path between two points in terms of travel distance or time over road ***,in real cases,especially in the era of smart cities where many kinds of transportation-related data become easily available,recent years have witnessed an increasing demand of route planners that need to optimize for multiple criteria,e.g.,finding the route with the highest accumulated scenic score along(utility)while not exceeding the given travel time budget(cost).Such problem can be viewed as a variant of arc orienteering problem(AOP),which is well-known as an NP-hard *** this paper,targeting a more realistic AOP,we allow both scenic score(utility)and travel time(cost)values on each arc of the road network are time-dependent(2TD-AOP),and propose a memetic algorithm to solve *** be more specific,within the given travel time budget,in the phase of initiation,for each population,we iteratively add suitable arcs with high scenic score and build a path from the origin to the destination via a complicate procedure consisting of search region narrowing,chromosome encoding and *** the phase of the local search,each path is improved via chromosome selection,local-improvement-based mutation and crossover ***,we evaluate the proposed memetic algorithm in both synthetic and real-life datasets extensively,and the experimental results demonstrate that it outperforms the baselines.

关键词： arc orienteering problem two-fold timedependent scenic score travel time memetic algorithm

Improved Fractional-order Damping Method for Voltage-controlled DFIG System Under Weak Grid

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Journal of Modern Power Systems and Clean Energy 2022年第6期10卷 1531-1541页

作者： Zhen xie Xiang gao Shuying Yang Xing Zhang School of Electrical Engineering and Automation Hefei University of TechnologyHefeiChina

When a doubly-fed induction generator(DFIG)is connected to a weak grid,the coupling between the grid and the DFIG itself will increase,which will cause stability *** is difficult to maintain the tracking accuracy and robustness of the phase-locked loop(PLL)in the weak grid,and the risk of instability of the current-controlled DFIG(CC-DFIG)system will *** this paper,a new type of voltage-controlled DFIG(VC-DFIG)mode is adopted,which is a grid-forming structure that can independently support the voltage and frequency with a certain adaptability in the weak grid.A small-signal impedance model of the VC-DFIG system is also *** impedance of DFIG inevitably generates coupling with the grid impedance in the weak grid,especially in parallel compensation grids,and results in *** the basis of the VC-DFIG,impedance stability analysis is performed to study the influences of the control structure and short-circuit ***,a feedforward damping method is proposed to modify the impedance of the VC-DFIG system at resonance *** proposed fractional order damping is utilized,which can enhance the robustness and rapidity of resonance suppression under parameter ***,the experimental results are presented to validate the effectiveness of the proposed control strategy.

关键词： Weak grid voltage-controlled doubly-fed induction generator(DFIG) resonance feedforward damping fractional-order damping

direct capture efficiency of range hoods in the confined kitchen space

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Building Simulation 2022年第10期15卷 1799-1813页

作者： Changsheng Cao Wuhao xie Yunfei Xia Jun gao School of Mechanical Engineering Tongji UniversityShanghai 200092China

Range hood is a local ventilation device applied widely in residential kitchen for maintaining healthy environment. This study firstly defines the direct capture efficiency (DCE) based on the two-zone model in a confined kitchen space. A mass flux ratio of the secondary captured pollutant to the entrained pollutant from the room zone is proposed for the determination of DCE, where the distribution coefficient is firstly solved, and then its sensitivity analysis on the DCE is carried out. To validate the mass flux ratio and concisely identify the DCE, a virtual purification method that artificially sets the escaped pollutant to zero, is further applied. Compared with the newly developed DCE, the existing indexes, such as contaminant removal efficiency (CRE), total capture efficiency (TCE), fail to differentiate the direct capture from the total capture. Finally, the effects of such factors as makeup airflow pattern, exhaust flow rate, cooking source temperature and the individual occupied/unoccupied on the DCE are fully studied. It is confirmed that different makeup airflow pattern results in distinguished airflow distribution, which makes a significant difference of more than 30% in DCE. Over 50% increase of DCE can be achieved when the exhaust flow rate is increased from 300 to 600 m3/h. About 30% decrease of DCE is observed with the increased cooking source temperature from 100 to 300 °C, and 10% increase of DCE is appeared in the individual occupied case. This reasonable definition and determination of DCE would help to improve the real capture performance of range hoods.

关键词： kitchen ventilation capture efficiency air distribution local exhaust makeup airflow

direct measurement and theoretical prediction model of interparticle adhesion force between irregular planetary regolith particles

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International Journal of Mining Science and Technology 2023年第11期33卷 1425-1436页

作者： Heping xie Qi Wu Yifei Liu Yachen xie Mingzhong gao Cunbao Li State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering Shenzhen UniversityShenzhen 518060China Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Shenzhen UniversityShenzhen 518060China Department of Civil&Mineral Engineering University of TorontoToronto M5S 1A1Canada

Interparticle adhesion force has a controlling effect on the physical and mechanical properties of planetary regolith and *** current research on the adhesion force of planetary regolith and rock particles has been primarily based on the assumption of smooth spherical particles to calculate the intergranular adhesion force;this approach lacks consideration for the adhesion force between irregular shaped *** our study,an innovative approach was established to directly measure the adhesion force between the arbitrary irregular shaped particles;the probe was modified using simulated lunar soil particles that were a typical representation of planetary *** experimental results showed that for irregular shaped mineral particles,the particle size and mineral composition had no significant influence on the interparticle adhesion force;however,the complex morphology of the contact surface predominantly controlled the adhesion *** the contact surface roughness increased,the adhesion force gradually decreased,and the rate of decrease gradually slowed;these results were consistent with the change trend predicted via the theoretical models of quantum ***,a theoretical model to predict the adhesion force between the irregular shaped particles was constructed based on Rabinovich’s theory,and the prediction results were correlated with the experimental measurements.

关键词： Planetary regolith Adhesion force Particle morphology Prediction model

Gas leakage recognition for CO2 geological sequestration based on the time series neural network

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Chinese Journal of Chemical Engineering 2020年第9期28卷 2343-2357页

作者： Denglong Ma Jianmin gao Zhiyong gao Hongquan Jiang Zaoxiao Zhang Juntai xie School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an 710049China School of Chemical Engineering and Technology Xi'an Jiaotong UniversityXi'an 710049China

The leakage of stored and transported CO2 is a risk for geological sequestration technology. One of the most challenging problems is to recognize and determine CO2 leakage signal in the complex atmosphere background. In this work, a time series model was proposed to forecast the atmospheric CO2 variation and the approximation error of the model was utilized to recognize the leakage. First, the fitting neural network trained with recently past CO2 data was applied to predict the daily atmospheric CO2. Further, the recurrent nonlinear autoregressive with exogenous input(NARX) model was adopted to get more accurate prediction. Compared with fitting neural network, the approximation errors of NARX have a clearer baseline, and the abnormal leakage signal can be seized more easily even in small release cases. Hence, the fitting approximation of time series prediction model is a potential excellent method to capture atmospheric abnormal signal for CO2 storage and transportation technologies.

关键词： Leakage identification Process safety Gas leakage Monitoring carbon sequestration CO2 storage

TMAHS:a truthful multi-unit double auction framework for heterogeneous spectrum in secondary market

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The Journal of China Universities of Posts and Telecommunications 2019年第1期26卷 82-94页

作者： Li Xin xie Gang gao Jinchun School of Electrical Engineering Beijing University of Posts and Telecommunications Beijing Key Laboratory of Work Safety Intelligent Monitoring Beijing University of Posts and Telecommunications School of information and Communication Engineering Beijing University of Posts and Telecommunications

Auction was widely used to tackle spectrum allocation and sharing in the secondary market under the condition of spectrum scarcity. In real communication system, such as broadband communication, the utilization of spectrum resource is various because of different requirements and complex application scenarios. So, these schemes cannot be directly applied to the above wireless communication system. To solve this problem, a new model where sellers/buyers can sell/buy multi-unit for heterogeneous spectrum was proposed and a truthful multi-unit double auction framework was designed for heterogeneous spectrum trading. A valuation function is first applied to represent the buyer's true valuation of the sub-band and reflect the buyer's satisfaction degree and a novel concept termed ‘virtual player' was introduced. Then the buyer group was constructed based on the conflict graph to reuse the same spectrum among interference-free buyers in both spatial and temporal domains. The winner determination strategy and algorithm of clearing price were designed elaborately. According to the theoretical analysis, the scheme can satisfy three critical economic properties: truthfulness, individual rationality, and budget balance. Finally, simulation results show that the proposed scheme can achieve better user satisfaction, auction efficiency and spectrum reuse rate for the real communication system. The proposed auction framework is practical and effective.

关键词： spectrum auction double auction spectrum reuse heterogeneous spectrum multi-unit valuation function

Fully Bio-Based Composites of Poly(Lactic Acid)Reinforced with Cellulose-Graft-Poly-(ε-Caprolactone)Copolymers

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Journal of Renewable Materials 2023年第3期11卷 1137-1152页

作者： Chengtao gao Yang Wu Haibo xie College of Materials and Metallurgy Guizhou UniversityGuiyangChina National Engineering Research Center for Compounding and Modification of Polymer Materials(Guizhou Material Industrial Technology Institute) GuiyangChina College of Materials Science&Engineering University of NanchangNanchangChina

Due to the increasing demand for modified polylactide(PLA)meeting“double green”criteria,the research on sustainable plasticizers for PLA has attracted broad *** study reported an open-ring polymerization method to fabricate cellulose(MCC)-g-PCL(poly(ε-caprolactone))copolymers with a fully sustainable and biodegradable ***-g-PCL copolymers were synthesized,characterized,and used as green plasticizers for the PLA *** results indicated that the MCC-g-PCL derivatives play an important role in the compatibility,crystallization,and toughening of the PLA/MCC-g-PCL *** mechanical properties of the fully bio-based PLA/MCC-g-PCL composites were optimized by adding 15 wt%MCC-g-PCL,that is,the elongation at break was 22.6%(~376%higher than that of neat PLA),the tensile strength was 47.3 MPa(comparable to that of neat PLA),and the impact strength was 26 J/m(~130%higher than that of neat PLA).DSC results indicated that MCC-g-PCL reduced the Tg of the PLA *** the addition amount was 15 wt%,the Tg of the blend was 58.4°*** with MCC,MCC-g-PCL polyester plasticizer has better thermal stability,T5%(°C)can still be maintained above 300°*** rheological results showed that MCC-g-PCL acted as a plasticizer,the introduction of PCL flexible chain increased the mobility of PLA molecular chain,and decreased the complex viscosity,storage modulus and loss modulus of PLA *** MCC-g-PCL derivatives,as a new green plastic additive,have shown an interesting prospect to prepare fully bio-based composites.

关键词： Green plasticizers PLA cellulose(MCC)-g-PCL fully bio-based composites