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Petroleum Science 2022年第3期19卷 1250-1261页

作者： Yun-tao Li Xiao-Ning He Jian shuai College of Safety and Ocean Engineering China University of PetroleumBeijingChina

Buried natural gas pipelines are vulnerable to external corrosion because they are encased in a soil environment for a long *** the causes of external corrosion and taking specific maintenance measures is *** this work,a risk analysis and maintenance decision-making model for natural gas pipelines with external corrosion is proposed based on a Bayesian network.A fault tree model is first employed to identify the causes of external *** Bayesian network for risk analysis is determined *** maintenance strategies are then inserted into the Bayesian network to show a reduction of the *** costs of maintenance strategies and the reduced risk after maintenance are combined in an optimization function to build a decision-making *** of the limitations of historical data,some of the parameters in the Bayesian network are obtained from a probabilistic estimation model,which combines expert experience and fuzzy set ***,a case study is carried out to verify the feasibility of the maintenance decision *** indicates that the method proposed in this work can be used to provide effective maintenance schemes for different pipeline external corrosion scenarios and to reduce the possible losses caused by external corrosion.

关键词： Natural gas pipelines External corrosion Risk analysis Maintenance decision making Bayesian network

Strain-controlled graphdiyne membrane for CO2/CH4 separation:First-principle and molecular dynamic simulation

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Chinese Journal of Chemical Engineering 2020年第7期28卷 1898-1903页

作者： xin Zheng shuai Ban Bei Liu Guangjin Chen State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China College of New Energy and Materials China University of PetroleumBeijing 102249China

Tensile strain of porous membrane materials can broaden their capacity in gas *** this work,using van der Waals corrected density functional theory(DFT)and molecular dynamics(MD)simulations,the performance and mechanism of CO2/CH4 separation through strain-oriented graphdiyne(GDY)monolayer were studied by applying lateral *** is demonstrated that the CO2 permeance peaks at 1.29×10^6 gas permeation units(GPU)accompanied with CO2/CH4 selectivity of 5.27×10^3 under ultimate strain,both of which are far beyond the Robeson’s ***,the GDY membrane exhibited a decreasing gas diffusion energy barrier and increasing permeance with the increase of applied tensile ***2 molecule tends to reoriented itself vertically to permeate the ***,the CO2 permeability decreases with the increase of the temperature from300 K to 500 K due to conserving of rotational freedom,suggesting an abnormal permeance of CO2 in relation to *** theoretical results suggest that the stretchable GDY monolayer holds great promise to be an excellent candidate for CO2/CH4 separation,owing to its extremely high selectivity and permeability of CO2.

关键词： Graphdiyne Strain CO2 separation Molecular dynamics Density functional theory

面向海上风电直流汇聚的四象限DC/DC变换器反向运行策略

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供用电 2025年第1期42卷 52-63页

作者：张帅王辉李欢王成张涛李庆民山东大学电气工程学院山东济南250061 南方电网科学研究院有限责任公司广东广州510663 华北电力大学电气与电子工程学院北京102206 国网山东省电力公司德州供电公司山东德州253000

直流汇聚与远距离传输并网的海上风电全直流系统与交流系统相比具有诸多优点,但目前尚有系统拓扑、运维及可靠性等诸多问题未解决。直流汇聚系统现有方案故障恢复与黑启动需要的能量多依赖于独立的反向拓扑,增大了运行成本。利用提出的... 详细信息

直流汇聚与远距离传输并网的海上风电全直流系统与交流系统相比具有诸多优点,但目前尚有系统拓扑、运维及可靠性等诸多问题未解决。直流汇聚系统现有方案故障恢复与黑启动需要的能量多依赖于独立的反向拓扑,增大了运行成本。利用提出的新型四象限隔离型DC/DC变换器拓扑的自身特性,提出和设计实现了拓扑反向重构与能量传输,为风场故障恢复与黑启动提供了低成本辅助方案。该拓扑利用反并联晶闸管构成串联谐振DC/DC变换器二次侧电路,可实现DC/DC变换器的四象限运行。首先,重点分析了拓扑反向运行模式工作原理及参数关系,并设计了反向电压闭环控制策略。其次,利用分段状态空间方程得到变换器在电感电流连续模式(continuous current mode,CCM)以及2种电感电流断续模式(discontinuous current mode,DCM)下的谐振变量时域表达式,并利用其获得反向运行时的谐振电流应力。通过时域分析法和功率守恒推导了电压增益与品质因数、开关频率之间的数学关系,划分了反向运行时的5种工况,并设计了控制策略。最后,通过MATLAB/Simulink仿真以及样机实验验证了反向运行策略的有效性。

关键词： DC/DC变换器黑启动反并联晶闸管四象限运行时域分析法

Spatial and Temporal Changes in Vapor Pressure Deficit and Their Impacts on Crop Yields in China during 1980–2008

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Journal of Meteorological Research 2017年第4期31卷 800-808页

作者： shuai ZHANG Fulu tao Zhao ZHANG Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University

Vapor pressure deficit（VPD） is a widely used measure of atmospheric water demand. It is closely related to crop evapotranspiration and consequently has major impacts on crop growth and yields. Most previous studies have focused on the impacts of temperature, precipitation, and solar radiation on crop yields, but the impact of VPD is poorly understood. Here, we investigated the spatial and temporal changes in VPD and their impacts on yields of major crops in China from 1980 to 2008. The results showed that VPD during the growing period of rice, maize, and soybean increased by more than 0.10kPa（10 yr）^–1 in northeastern and southeastern China, although it increased the least during the wheat growing period. Increases in VPD had different impacts on yields for different crops and in different regions. Crop yields generally decreased due to increased VPD, except for wheat in southeastern China. Maize yield was sensitive to VPD in more counties than other crops. Soybean was the most sensitive and rice was the least sensitive to VPD among the major crops. In the past three decades, due to the rising trend in VPD, wheat, maize, and soybean yields declined by more than 10.0% in parts of northeastern China and the North China Plain, while rice yields were little affected. For China as a whole, the trend in VPD during 1980–2008 increased rice yields by 1.32%,but reduced wheat, maize, and soybean yields by 6.02%, 3.19%, and 7.07%, respectively. Maize and soybean in the arid and semi-arid regions in northern China were more sensitive to the increase in VPD. These findings highlight that climate change can affect crop growth and yield through increasing VPD, and water-saving technologies and agronomic management need to be strongly encouraged to adapt to ongoing climate change.

关键词： agriculture climate change vapor pressure deficit evapotranspiration water stress

Modeling the rice phenology and production in China with SIMRIW： sensitivity analysis and parameter estimation

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Frontiers of Earth Science 2014年第4期8卷 505-511页

作者： shuai ZHANG Fulu tao Runhe SHI Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Key Laboratory of Geographic Information Science East China Normal University Shanghai 200062 China

Crop models are robust tools for simulating the impact of climate change on rice development and production, but are usually designed for specific stations and varieties. This study focuses on a more adaptable model called Simulation Model for Rice-Weather Relations （SIMRIW）. The model was calibrated and validated in major rice production regions over China, and the parameters that most affect the model＇s output were determined in sensitivity analyses. These sensitive parameters were estimated in different ecological zones. The simulated results of single and double rice cropping systems in different ecological zones were then compared. The accuracy of SIMRIW was found to depend on a few crucial parameters. Using optimized parameters, SIMRIW properly simulated the rice phenology and yield in single and double cropping systems in different ecological zones. Some of the parameters were largely dependent on ecological zone and rice type, and may reflect the different climate conditions and rice varieties among ecological zones.

关键词： rice phenology parameter optimization,SIMRIW simulation

Improved thermal resistance network model of motorized spindle system considering temperature variation of cooling system

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Advances in Manufacturing 2018年第4期6卷 384-400页

作者： Yang Liu Ya-xin Ma Qing-Yu Meng Xi-Cheng xin shuai-shuai Ming School of Mechanical Engineering and Automation. Northeastern University Shenyang 110819 Liaoning People's Republic of China

In the motorized spindle system of a computer numerical control (CNC) machine tool, internal heat sources are formed during high-speed rotation;these cause thermal errors and affect the machining accuracy. To address this problem, in this study, a thermal resistance network model of the motorized spindle system is established based on the heat transfer theory. The heat balance equations of the critical thermal nodes are established according to this model with Kirchhoffs law. Then, they are solved using the Newmark-β method to obtain the temperature of each main component, and steady thermal analysis and transient thermal analysis of the motorized spindle system are performed. In order to obtain accurate thermal characteristics of the spindle system, the thermal conduction resistance of each component and the thermalconvection resistance between the cooling system and the components of the spindle system are accurately obtained considering the effect of the heat exchanger on the temperature of the coolant in the cooling system. Simultaneously, high-precision magnetic temperature sensors are used to detect the temperature variation of the spindle in the CNC machining center at different rotational speeds. The experimental results demonstrate that the thermal resistance network model can predict the temperature field distribution in the spindle system with reasonable accuracy. In addition, the influences of the rotational speed and cooling conditions on the temperature increase of the main components of the spindle system are analyzed. Finally, a few recommendations are provided to improve the thermal performance of the spindle system under different operational conditions.

关键词： Motorized spindle system Thermal resistance network model Temperature field Cooling system

Chaotic block iterating method for pseudo-random sequence generator

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The Journal of China Universities of Posts and Telecommunications 2007年第1期14卷 45-48页

作者： CHEN shuai ZHONG Xian-xin Physics Department Huainan Normal University Huainan 232001 China Key Laboratory of Optoelectronic Technology and System of State Ministry ofEducation Chongqing University Chongqing 400030 China

A pseudo-random sequence generator is a basic tool for cryptography. To realize a pseudo-random sequence generator, a new block iterating method using shifter, multiplier, and adder operations has been introduced. By increasing the iteration of the counter and by performing calculations based on the initial value, an approximate pseudo-random sequence was obtained after exchanging bits. The algorithm and the complexity of the generator were introduced. The result obtained from the calculation shows that the self-correlation of the ＂m＂ block sequence is two-valued; the block field value is [0, 2^m - 1 ], and the block period is 2^m＋8 - 1.

关键词： pseudo-random sequence generator algorithm,calculation

Two Feasible Schemes for Preparing Cluster States with Ion-Trap Setup

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Communications in Theoretical Physics 2008年第5期49卷 1217-1220页

作者： WANG xin-Wen CAO shuai XIA Li-xin Department of Physics Hunan University of Science and Engineering Yongzhou 425100 China College of Science South China Agricultural University Guangzhou 510642 China Department of Physics Tsinghua University Beijing 100084 China

We present two schemes for preparing cluster states with atomic qubits in an ion-trap system. In the first scheme an auxiliary atomic level is needed. While in the second scheme an additional classical driven field is used, and the multi-ion cluster states can be generated by one step. Both the schemes are insensitive to thermal motion of the ions, all the facilities used in them are well within state of the art.

关键词： ion-trap cluster states one-step implementation controlled phase gates

Facile synthesis of accordion-like porous carbon from waste PET bottles-based MIL-53(Al)and its application for high-performance Zn-ion capacitor

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Green Energy & Environment 2024年第7期9卷 1138-1150页

作者： Jiaxin Li shuai Zhang Yumeng Hua Yichao Lin xin Wen Ewa Mijowska tao Tang Xuecheng Chen Rodney S.Ruoff Faculty of Chemical Technology and Engineering West Pomeranian University of TechnologyPiastow Ave.4271-065SzczecinPoland Key State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of Safety Engineering China University of Mining and TechnologyXuzhou221116China Institute of Advanced Electrical Materials Qingdao University of Science and TechnologyQingdao266042China Institute for Basic Science Center for Multiple Dimensional Carbon Materials Ulsan44919Republic of Korea Department of Chemistry Ulsan National Institute of Science and Technology(UNIST)Ulsan44919Republic of Korea Department of Materials Science and Engineering Ulsan National Institute of Science and Technology(UNIST)Ulsan44919Republic of Korea School of Energy and Chemical Engineering Ulsan National Institute of Science and Technology(UNIST)Ulsan44919Republic of Korea

It is of great scientific and economic value to recycle waste poly(ethylene terephthalate)(PET)into high-value PET-based metal organic frameworks(MOFs)and further convert it into porous carbon for green energy storage *** the present study,a facile and costeffective hydrothermal process was developed to direct recycle waste PET bottles into MIL-53(Al)with a 100% conversation,then the MOFderived porous carbon was assembled into electrodes for high-performance *** results indicated that the as-synthesized carbon exhibited high SSA of 1712 m^(2)g^(-1)and unique accordion-like structure with hierarchical *** to these advantageous characters,the assembled three-electrode supercapacitor displayed high specific capacitances of 391 F g^(-1)at the current density of 0.5 A g^(-1)and good rate capability of 73.6% capacitance retention at 20 A g^(-1)in 6 mol L^(-1)KOH ***,the assembled zinc ion capacitor still revealed outstanding capacitance of 335 F g^(-1)at 0.1 A g^(-1),excellent cycling stability of 92.2% capacitance retention after 10000 cycles and ultra-high energy density of 150.3 Wh kg^(-1)at power density of 90 W kg^(-1)in 3 mol L^(-1)ZnSO_(4)*** is believed that the current work provides a facile and effective strategy to recycle PET waste into high-valuable MOF,and further expands the applications of MOF-derived carbons for high-performance energy storage devices,so it is conducive to both pollution alleviation and sustainable economic development.

关键词： PET Recycling Porous carbon Supercapacitor Energy storage

Upcycling of Poly(butylene adipate-co-terephthalate)into Dual Covalent Adaptable Networks through Chain Breaking-Crosslinking Strategy

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Chinese Journal of Polymer Science 2024年第10期42卷 1505-1513,I0011页

作者： Bin-Bo Wang Rong Huang xin Wang tao Jiang Yi Wang shuai Du Fa-Lin Li Jin Zhu Song-Qi Ma Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi214122China Key Laboratory of Bio-based Polymeric Materials Technology and Application of Zhejiang Province Divisions of Polymers and CompositesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China University of Chinese Academy of Sciences Beijing100049China

Poly(butylene adipate-co-terephthalate)(PBAT),a widely studied biodegradable material,has not effectively addressed the problem of plastic *** into consideration the cost-effectiveness,upcycling PBAT should take precedence over direct composting *** present work adopts a chain breaking-crosslinking strategy,upcycling PBAT into dual covalent adaptable networks(CANs).During the chainbreaking stage,the ammonolysis between PBAT and polyethyleneimine(PEI)established the primary crosslinked ***,styrene maleic anhydride copolymer(SMA)reacted with the hydroxyl group,culminating in the formation of dual covalent adaptable *** contrast to PBAT,the PBAT-dual-CANs exhibited a notable Young's modulus of 239 MPa,alongside an inherent resistance to creep and *** to catalysis from neighboring carboxyl group and excess hydroxyl groups,the PBAT-dual-CANs exhibited fast stress ***,they could be recycled through extrusion and hot-press reprocessing,while retaining their *** straightforward strategy offers a solution for dealing with plastic waste.

关键词： Poly(butylene adipate-co-terephthalate) Dynamic crosslinked networks Chain breaking-crosslinking strategy Upcycle Recycle