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Na-Mn共掺对磷酸铁锂正极材料结构与性能的影响

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稀有金属与硬质合金 2024年第1期52卷 90-98页

作者：刘庆生符亲武喻修远江西理工大学材料冶金化学学部江西赣州341000

利用碳热还原法成功制备了Li_(0.97)Na_(0.03)Fe_(7/8)Mn_(1/8)PO_(4)正极材料,运用XRD、SEM、EDS和电化学测试等手段对其晶体结构、形貌、元素分布和电化学性能进行研究,并结合第一性原理计算分析材料性能提升的机理。结果表明,Na-Mn... 详细信息

利用碳热还原法成功制备了Li_(0.97)Na_(0.03)Fe_(7/8)Mn_(1/8)PO_(4)正极材料,运用XRD、SEM、EDS和电化学测试等手段对其晶体结构、形貌、元素分布和电化学性能进行研究,并结合第一性原理计算分析材料性能提升的机理。结果表明,Na-Mn掺杂一方面导致LiFePO_(4)晶格畸变,晶格体积增大,扩大了锂离子迁移通道,为锂离子嵌入/脱出提供更大的空间;另一方面使材料在电化学性能上表现出优异的高倍率性能和循环稳定性。Na-Mn掺杂有利于提高材料的锂离子扩散系数和电导率,从而提高其电化学性能。基于第一性原理计算结果表明,Na-Mn共掺杂使LiFePO_(4)晶格膨胀,晶格体积增大,并促使带隙宽度减小,增强了费米能级附近的电子态密度,提高了材料的电子电导率和锂离子迁移率。

关键词： Na-Mn共掺 LiFePO_(4) 正极材料晶体结构电化学性能能带第一性原理计算

计算化学和计算材料学项目式实验设计:锂离子电池有机电解液分子动力学模拟

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化学教育（中英文） 2024年第6期45卷 91-98页

作者：许真铭郑明波刘振辉刘庆生南京航空航天大学材料科学与技术学院江苏南京210016 江西理工大学材料冶金化学学部江西赣州341000

分子动力学模拟已在化学、材料等科研领域得到广泛应用,但在本科化学、材料学实验中鲜有涉及。为培养学生化学、材料计算设计思维,同时帮助学生充分掌握分子动力学模拟方法,基于锂离子电池有机电解液研究案例设计了一个分子动力学模拟... 详细信息

分子动力学模拟已在化学、材料等科研领域得到广泛应用,但在本科化学、材料学实验中鲜有涉及。为培养学生化学、材料计算设计思维,同时帮助学生充分掌握分子动力学模拟方法,基于锂离子电池有机电解液研究案例设计了一个分子动力学模拟综合实验。本实验设计包括分子和溶液结构建模、结构优化、模拟退火、热浴平衡、后处理性质计算等操作步骤,帮助学生初步掌握分子动力学模拟的基本原理、流程和分析方法,实现理论方法水平和软件操作技能的双重提升。

关键词：计算化学计算材料学理论计算分子模拟化学实验

Monitoring of winter wheat distribution and phenological phases based on MODIS time-series： A case study in the Yellow River Delta, China

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Journal of Integrative Agriculture 2016年第10期15卷 2403-2416页

作者： CHU Lin liu qing-sheng HUANG Chong liu Gao-huan State Key Laboratory of Resources and Environmental Information System/Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 P.R.China University of Chinese Academy of Sciences Beijing 100049 P.R. China

Accurate winter wheat identification and phenology extraction are essential for field management and agricultural policy making. Here, we present mechanisms of winter wheat discrimination and phenological detection in the Yellow River Delta（YRD） region using moderate resolution imaging spectroradiometer（MODIS） time-series data. The normalized difference vegetation index（NDVI） was obtained by calculating the surface reflectance in red and infrared. We used the Savitzky-Golay filter to smooth time series NDVI curves. We adopted a two-step classification to identify winter wheat. The first step was designed to mask out non-vegetation classes, and the second step aimed to identify winter wheat from other vegetation based on its phenological features. We used the double Gaussian model and the maximum curvature method to extract phenology. Due to the characteristics of the time-series profiles for winter wheat, a double Gaussian function method was selected to fit the temporal profile. A maximum curvature method was performed to extract phenological phases. Phenological phases such as the green-up, heading and harvesting phases were detected when the NDVI curvature exhibited local maximum values. The extracted phenological dates then were validated with records of the ground observations. The spatial patterns of phenological phases were investigated. This study concluded that, for winter wheat, the accuracy of classification is 87.07%, and the accuracy of planting acreage is 90.09%. The phenological result was comparable to the ground observation at the municipal level. The average green-up date for the whole region occurred on March 5, the average heading date occurred on May 9, and the average harvesting date occurred on June 5. The spatial distribution of the phenology for winter wheat showed a significant gradual delay from the southwest to the northeast. This study demonstrates the effectiveness of our proposed method for winter wheat classification and phenology det

关键词： remote sensing monitoring time-series winter wheat discrimination Yellow River Delta phenology detection

On models for landscape connectivity: a case study of the new-born wetland of the Yellow River Delta

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Journal of Geographical Sciences 2002年第2期12卷 63-72页

作者： Yue Tian-xiang Ye qing-hua liu qing-sheng Gong Zheng-hui Institute of Geographic Sciences and Natural Resources Research CAS Beijing China Gudao Monitoring Station of shengli Oil Field Administration Dongying China

The models for landscape connectivity are distinguished into models for line connectivity, vertex connectivity, network connectivity and patch connectivity separately. Because the models for line connectivity, for vertex connectivity, and for network connectivity have long been studied and have become ripe, the model for patch connectivity is paid special attention in this paper. The patch connectivity is defined as the average movement efficiency (minimizing movement distance) of animal migrants or plant propagules in patches of a region under consideration. According to this definition, a model for landscape connectivity is mathematically deduced to apply to GIS data. The application of model for patch connectivity in the new-born wetland of the Yellow River Delta shows patch connectivity has a negative interrelation with human impact intensity and landscape diversity.

关键词： landscape connectivity mathematical model human impact landscape diversity

CD8＋ Tc-lymphocytes immunodeviation in peripheral blood and airway from patients of chronic obstructive pulmonary disease and changes after short-term smoking cessation

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Chinese Medical Journal 2013年第19期 3608-3615页

作者： YU Mu-qing liu Xian-sheng WANG Jian-miao XU Yong-jian Department of Respiratory and Critical Care Medicine TongjiHospital of Yongji Medical College Huazhong University of Scienceand Technology Wuhan Hubei 430030 China

Background Cigarette smoke induces an acute but persisting inflammation in peripheral blood and airway in chronic obstructive pulmonary disease （COPD）,and CD8＋ Tc-lymphocytes are considered as a key role in this *** aimed to investigate the Tc-lymphocytes immunodeviation in system and local airway of COPD patients and changes of the immunodeviation after short-term smoking *** Peripheral blood （PB） and bronchoalveolar lavage fluid （BALF） were collected from 42 patients （14 COPD patients,16 smokers with normal lung function and 12 nonsmokers）,while PB and induced sputum （IS） were obtained from other 19 patients （10 quitting smokers and 9 continuing smokers） at baseline and follow-up respectively of 4-week smoking *** of CD8＋ Tc-lymphocytes （%CD3＋） and Tc1/Tc2 ratios were measured by flow *** Percentages of CD8＋ Tc-lymphocytes were higher in COPD patients than those in smokers and nonsmokers in both PB and ***1/Tc2 ratio in PB and in BALF from COPD patients was greater than that from smokers and nonsmokers and negatively correlated with FEV1%*** comparing the ratios between PB and BALF,significantly positive correlation was found in COPD ***,after 4-week smoking cessation,percentages of CD8＋ Tc-lymphocytes in PB and IS in quitting smokers were decreased compared to that in baseline and continuing smokers,whereas Tc1/Tc2 ratios were not *** CD8＋ Tc1-trend immunodeviation profiles occurred in both system and local airway of COPD *** exceptional immunodeviation could not be relieved by short-term smoking cessation.

关键词： pulmonary disease, chronic obstructive smoke CD8-positive T-lymphocytes smoking cessation

Design parameter optimization method for a prestressed steel structure driven by multi-factor coupling

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Frontiers of Structural and Civil Engineering 2024年第7期18卷 1066-1083页

作者： Guo-Liang SHI Zhan-sheng liu De-Chun LU qing-Wen ZHANG Majid DEZHKAM Ze-Qiang WANG Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing 100124China The Key Laboratory of Urban Security and Disaster Engineering of the Ministry of Education Beijing University of TechnologyBeijing 100124China Beijing Building Construction Research Institute Co. Ltd.Beijing 100039China

To achieve efficient structural design,it is crucial to reduce the cost of materials while ensuring structural *** study proposes an optimization method for design parameters(DPs)in a prestressed steel structure driven by multi-factor *** accomplish this,a numerical proxy model of prestressed steel structures is established with integration of DPs and mechanical parameters(MPs).A data association-parameter analysis-optimization selection system is established.A correlation between DPs and MPs is established using a back propagation(BP)neural *** correlation provides samples for parameter analysis and optimization *** are used to characterize the safety of the *** on the safety grade analysis,the key DPs that affect the mechanical properties of the structure are obtained.A mapping function is created to match the MPs and the key *** optimal structural DPs are obtained by setting structural materials as the optimization objective and safety energy as the constraint *** theoretical model is applied to an 80-m-span gymnasium and verified with a scale test physical *** MPs obtained using the proposed method are in good agreement with the experimental *** with the traditional design method,the design cycle can be shortened by more than 90%.Driven by the optimal selection method,a saving of more than 20% can be achieved through reduction of structural material ***,the cross-sectional dimensions of radial cables have a substantial influence on vertical *** initial tension and cross-sectional size of the upper radial cable exhibit the most pronounced impact on the stress distribution in that *** initial tension and cross-sectional size of the lower radial cable hold the greatest sway over the stress distribution in that cable.

关键词： structure design association relationship performance analysis optimum selection experimental verification

Improving mathematical model of burden distribution and correcting chute angle to cope with fluctuation of stock line

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Journal of Iron and Steel Research International 2024年第2期31卷 342-356页

作者： Jian-sheng Chen Wen-guo liu Hao Guo Wang Ding qing-guo Xue Jing-song Wang Hai-bin Zuo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China MCC Capital Engineering&Research Incorporation Limited Beijing100176China Hunan Valin Xiangtan Iron and Steel Co. Ltd.Xiangtan411101HunanChina

Accurate evaluations of the burden distribution are of critical importance to stabilize the operation of blast *** mathematical model and discrete element method(DEM)are two attractive methods for predicting burden *** on DEM,the initial velocities of the pellet,sinter,and coke were calculated,and the velocity attenuations of the above three particles between the burden and the chute were *** initial velocity and velocity attenuation were applied to a mathematical model for improving the ***,based on the improved model,a scheme for rectifying the chute angles was proposed to address the fluctuation of the stock line and maintain a stable burden *** validity of the scheme was confirmed via a stable burden distribution under different stock *** mathematical model has been successfully applied to evaluate the online burden distribution and cope with the fluctuation of the stock line.

关键词： Burden distribution Mathematical model Discrete element method Velocity attenuation Stock line fluctuation

Association between DPP6 polymorphism and the risk of sporadic amyotrophic lateral sclerosis in Chinese patients

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Chinese Medical Journal 2009年第24期122卷 2989-2992页

作者： LI Xiao-guang ZHANG Jiang-hu XIE Man-qing liu Ming-sheng LI Ben-hong ZHAO Yan-huan REN Hai-tao CUI Li-ying Department of Neurology Peking Union Medical College Hospital Chinese Academy of Medical Science and Peking Union Medical College Beijing 100730 China

Background Amyotrophic lateral sclerosis （ALS） is a progressive degenerative disease characterized by the loss of motor neurons in the spinal cord, brainstem, and cerebral cortex, which results in muscle weakness, atrophy. Sporadic ALS （SALS） accounts for about 90% of ALS cases, but the etiology is largely unknown. Most of the researchers consider it to be a complex disease. There have been several genome-wide association （GWA） studies reporting several single nucleotide polymorphisms （SNPs） which are susceptible to ALS, but no data of Asians （including Chinese） yet. We investigate whether the polymorphism of rs10260404 in DPP6 gene is associated with SALS in Chinese Han origin to compare the ethnic differences between Chinese Han origin and other populations. Methods The genomic DNA was extracted from the leukocytes of whole blood samples in 58 Chinese Han patients with SALS and 52 healthy controls. The asymmetric PCR was processed in the presence of an unlabeled probe that contained the rs10260404 locus. The product was genotyped on a light scanner using high resolution melting method and some were confirmed with sequencing. Results The rs10260404 polymorphism was in Hardy-Weinberg equilibrium in patients and controls. The CC genotype and the C allele were similar in patients compared with healthy subjects and not associated with an increased risk of Chinese SALS patients （X^2=0.29, OR=1.26, 95% CI 0.55-2.87, P 〉0.05）. Conclusions The rs10260404 is not associated with ALS susceptibility in Chinese people with Han origin which may be due to ethnic differences. More study with large number of cases in Chinese population is really necessary.

关键词： amyotrophic lateral sclerosis, sporadic polymorphism, single nucleotide Chinese high-resolution melting

Day-ahead P2P Energy Sharing Strategy Among Energy Hubs Considering Flexibility of Energy Storage and Loads

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1105-1118页

作者： Penghua Li Wanxing sheng qing Duan Jun Liang Cunhao Zhu China Electric Power Research Institute Beijing 100192China School of Engineering Cardiff UniversityUK IEEE

Multi-energy systems are one of the key technologies to tackle energy crisis and environmental *** energy hub(EH)is a minimum multi-energy *** of multiple EHs through energy routers(ERs)can realize mutual energy *** paper proposes a peer-to-peer(P2P)energy sharing strategy between EHs including ERs in an interconnected system,which is divided into two *** the lower level,a method of determining the charging/discharging constraints of energy storage devices is *** on the Lyapunov optimization method,virtual queues are used to model the energy storage devices and flexible loads in the *** objective is to minimize the overall operating cost of the interconnected *** the upper level,a non-cooperative game model is introduced to minimize the cost of purchasing power from other EHs for each EH.A best response-based method is adapted to find the Nash *** simulation outcomes demonstrate that application of the proposed strategy can reduce operating costs of an interconnected system and each *** basis of a real-world dataset of interconnected EHs,both analytical and numerical results show the effectiveness of the proposed strategy.

关键词： Energy hub energy router Lyapunov optimization non-cooperative game peer to peer virtual queue