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The energy and water cycles under climate change

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National Science Review 2020年第3期7卷 553-557页

作者： Qingyun duan Anmin duan Hohai University the Institute of Atmospheric Physics Chinese Academy of Sciences

Energy and water cycles have been a hot research topic in the global scientific community. The global climate change observed over the last century is having a profound impact on global and regional energy and water cycles, leading to more frequent extreme climatic events and affecting water security, ecosystem and socioeconomic development around the world. The impact is especially obvious over the highland regions such as the Tibetan Plateau. Here we have an interview with one of world’s most renowned experts in hydroclimatology,Professor Soroosh Sorooshian from the University of California at Irvine, to share his insights on the subject of energy and water cycles.

关键词： cycle GEWEX The energy and water cycles under climate change

Review on engineering two-dimensional nanomaterials for promoting efficiency and stability of perovskite solar cells

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Journal of Energy Chemistry 2022年第5期31卷 154-175页

作者： Qingwei Zhou Jialong duan Yanyan duan Qunwei Tang Institute of New Energy Technology College of Information Science and TechnologyJinan UniversityGuangzhou 510632GuangdongChina State Centre for International Cooperation on Designer Low-Carbon and Environmental Material(SCICDLCEM) School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001HenanChina

Perovskite solar cell(PSC) has gradually shown its great superiority in photovoltaic filed to compete commercial solar cells owing to its great advantages, such as high efficiency and low fabrication cost. On the way towards commercialization, great efforts have been achieved by accelerating charge extraction and reducing carrier recombination. Recently, two-dimensional(2 D) layered materials have attracted increasing interests for application in PSCs due to their distinctive chemical and physical properties, such as high carrier mobility and tunable bandgap, which greatly determines the perovskite film growth kinetics, carrier transfer and stability of PSCs. Therefore, with the aim to better understand their recent development and application in PSC, in this review, the emerging 2D materials beyond graphene as charge transport layers, buffer layers and additives in perovskite film for enhancing the efficiency and stability of PSCs are summarized. However, there are still some crucial challenges to be addressed for commercialization. Finally, the challenges and prospects of these 2D nanomaterials for application in PSCs are further proposed for future development.

关键词： Perovskite solar cells 2D materials Interface engineering Charge transfer Stability

Influence of Fast Neutron Irradiation on Critical Current Densities of Bi-2223/Ag Tape

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Journal of Rare Earths 2004年第Z2期22卷 118-122页

作者： duan Zhenzhong Research Contor of Superconducting Materials General Research Institute for Non-Ferrous MatelsBeijing 100088China

Experimental results on the magnetic field behavior of the critical current in silver sheathed Bi-2223 tapes are presented. The experiments consist of transport and magnetic measurements in a wide temperature range and in external magnetic field up to 6 T. Significant enhancement of the intragrain critical current densities Jc are observed after irradiation with fast neutron. This is attributed to an improvement of flux pinning capability by the neutron induced defects, but the weak link structure is somewhat damaged as evidenced by the small degradation of transport critical current at low field. According to the measurement of remanent magnetic moment before and after irradiation with fast neutron, the connectivity in Bi-2223 tapes is reduced by 50% after irradiated to a fluence of 2 × 1021 m-2, which resulted in the critical currents degradated by a factor of 10%.

关键词： neutron irradiation critical current flux pinning weak link

Hot graphene sponge cleans viscous crude-oil spill

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Science China Materials 2017年第7期60卷 681-682页

作者： Xiangfeng duan Department of Chemistry and Biochemistry University of California

Ocean crude oil spill can cause instant and lasting damage to marine ecosystem,leading to disastrous environmental,economical and social consequences[1,2].The 2010 Gulf oil spill has cost British Petroleum over $60 bi... 详细信息

关键词：英语阅读理解材料科学

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降温过程中NaCl盐渍土相变的电化学特征

岩土工程学报 2025年第1期47卷 200-206页

作者：肖泽岸李康良段杰云王启航郭茂亮太原理工大学土木工程学院山西太原030024

氯盐渍土是中国西北寒旱区一种典型的盐渍土类型,其电化学特征是深入理解盐渍土腐蚀病害机理的关键。为探究盐渍土孔隙溶液相变与其电化学特征之间的联系,以NaCl盐渍粉质黏土为研究对象,测试了不同含盐量和温度条件下NaCl盐渍土的电化... 详细信息

氯盐渍土是中国西北寒旱区一种典型的盐渍土类型,其电化学特征是深入理解盐渍土腐蚀病害机理的关键。为探究盐渍土孔隙溶液相变与其电化学特征之间的联系,以NaCl盐渍粉质黏土为研究对象,测试了不同含盐量和温度条件下NaCl盐渍土的电化学阻抗谱。研究表明:NaCl盐渍土阻抗随着测试频率的增加而逐步降低,并在高频率时逐步达到稳定。NaCl盐渍土的阻抗模的对数值在冻结前随温度的降低线性增加,而在冻结后,冰晶和盐结晶的生成导致土体阻抗模值发生显著增加。NaCl盐渍土在冻结前表现为一段容抗弧,而在冻结后,由相变导致的土体水盐迁移使得土体在出现阻抗弧后又存在一段扩散阻抗。根据土体在冻结前后的导电路径,建立了土体在冻结前后的等效电路模型,并在此基础上分析了土体孔隙溶液相变与对应电路元件之间的联系。此研究对深入理解盐渍土电化学特征及孔隙溶液相变规律具有重要意义。

关键词：氯盐渍土冻结过程电化学阻抗谱相变等效电路模型

A FAS approach for stabilization of generalized chained forms: part 1. Discontinuous control laws

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Science China(Information Sciences) 2024年第2期67卷 118-143页

作者： Guang-Ren duan Center for Control Science and Technology Southern University of Science and Technology Center for Control Theory and Guidance Technology Harbin Institute of Technology

In this paper, a type of general nonholonomic systems is proposed, which contains both the Brockett's two example systems, and their extended n-dimensional chained forms, as special cases. For the stabilization of such systems, a stabilizing controller is proposed based on the fully actuated system(FAS)approach, which is discontinuous at the origin but time-invariant when the open-loop system is time-invariant,and drives the feasible trajectories of the system to the origin exponentially. Furthermore, the proposed FAS approach is also extended to the sub-normal system case and the time-delay system case.

关键词： nonholonomic systems feedback stabilization exponential convergence sub-fully actuated systems time-delay systems

A FAS approach for stabilization of generalized chained forms: part 2. Continuous control laws

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Science China(Information Sciences) 2024年第3期67卷 114-135页

作者： Guang-Ren duan Shenzhen Key Laboratory of Control Theory and Intelligent Systems Southern University of Science and Technology Center for Control Theory and Guidance Technology Harbin Institute of Technology

In this paper, continuous time-varying stabilizing controllers for the type of general nonholonomic systems proposed and treated in part 1 are designed using the fully actuated system(FAS) approach. The key step is to differentiate the first scalar equation, and by control of the obtained second-order scalar system, a proportional plus integral feedback form for the first control variable is obtained. With the solution to this designed second-order scalar system, the rest equations in the nonholonomic system form an independent time-varying subsystem which is then handled by the FAS approach. The overall designed controller contains an almost arbitrarily chosen design parameter, and is proven to guarantee the uniformly and globally exponential stability of the closed-loop system. The proposed approach is simple and effective,and is demonstrated with a practical example of ship control.

关键词： nonholonomic systems feedback stabilization fully actuated systems Lyapunov stability continuous controllers

Distributed Optimal Control of Nonlinear Time-Delay System Subject to Delayed Measurements and Communication Disruptions

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Journal of Systems Science & Complexity 2021年第4期34卷 1426-1437页

作者： SU Baili duan Yuxing College of Engineering Qu/il Normal UniversityRizhao 276826China

This paper is focused on a distributed optimal control design for a class of nonlinear timedelay systems with delayed measurements and communication *** innovation lies in three *** distributed optimal control method which includes an optimal controller and a bounded controller is designed based on Lyapunov *** availability of data transmitted through the communication channel depends on a feasibility *** a sufficient condition to guarantee ultimate boundedness of the system is given based on appropriate *** significance of this paper is that this distributed optimal control method is applied to time-delay ***,a simulation example is given to verify the effectiveness of the proposed method.

关键词： Communication disruptions delayed measurements distributed optimal control nonlinear time-delay systems

A multi-strategy pigeon-inspired optimization approach to active disturbance rejection control parameters tuning for vertical take-off and landing fixed-wing UAV

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Chinese Journal of Aeronautics 2022年第1期35卷 19-30,I0001页

作者： Hangxuan HE Haibin duan State Key Laboratory of Virtual Reality Technology and Systems Beihang UniversityBeijing 100191China Peng Cheng Laboratory Shenzhen 518000China

In this *** Disturbance Rejection Control(ADRC)is utilized in the pitch control of a vertical take-off and landing fixed-wing Unmanned Aerial Vehicle(UAV)to address the problem of height fluctuation during the transition from hover to level *** the difficulty of parameter tuning of ADRC as well as the requirement of accuracy and rapidity of the controller,a Multi-Strategy Pigeon-Inspired Optimization(MSPIO)algorithm is *** Swarm Optimization(PSO),Genetic Algorithm(GA),the basic Pigeon-Inspired Optimization(PIO),and an improved PIO algorithm CMPIO are *** addition,the optimized ADRC control system is compared with the pure Proportional-Integral-Derivative(PID)control system and the non-optimized ADRC control *** effectiveness of the designed control strategy for forward transition is verified and the faster convergence speed and better exploitation ability of the proposed MSPIO algorithm are confirmed by simulation results.

关键词： Active Disturbance Rejection Control(ADRC) Pigeon-inspired optimization algorithm Transition mode Unmanned Aerial Vehicle(UAV) Vertical take-off and landing