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An Improved Preisach Distribution Function Identification Method Considering the Reversible Magnetization
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作者 Long Chen Lvsheng Cui +1 位作者 Tong Ben Libing Jing 《CES Transactions on Electrical Machines and Systems》 CSCD 2023年第4期351-357,共7页
This paper presents an identification method of the scalar Preisach model to consider the effect of reversible magnetization in the process of distribution function identification.By reconsidering the identification p... This paper presents an identification method of the scalar Preisach model to consider the effect of reversible magnetization in the process of distribution function identification.By reconsidering the identification process by stripping the influence of reversible components from the measurement data,the Preisach distribution function is identified by the pure irreversible components.In this way,the simulation accuracy of both limiting hysteresis loops and the inner internal symmetrical small hysteresis loop is ensured.Furthermore,through a discrete Preisach plane with a hybrid discretization method,the irreversible magnetic flux density components are computed more efficiently through the improved Preisach model.Finally,the proposed method results are compared with the traditional method and the traditional method considering reversible magnetization and validated by the laboratory test for the B30P105 electrical steel by Epstein frame. 展开更多
关键词 Magnetic material Preisach distribution function reversible magnetization Hybrid discretization method
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单层MoS_(2)表面Fe,Ir掺杂对NO吸附与直接解离反应性能提升的理论计算
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作者 肖香珍 胡林峰 《吉林大学学报(理学版)》 CAS 北大核心 2024年第1期165-173,共9页
用密度泛函理论中广义梯度近似下的PW91方法,结合周期性平板模型,研究NO分子在掺杂体系TM-MoS_(2)(TM=Fe,Ir)表面的吸附和解离行为.结果表明:与完整MoS_(2)表面的物理吸附(-0.05 eV)不同,Fe,Ir掺杂MoS_(2)表面NO吸附能分别为-3.30,-3.17... 用密度泛函理论中广义梯度近似下的PW91方法,结合周期性平板模型,研究NO分子在掺杂体系TM-MoS_(2)(TM=Fe,Ir)表面的吸附和解离行为.结果表明:与完整MoS_(2)表面的物理吸附(-0.05 eV)不同,Fe,Ir掺杂MoS_(2)表面NO吸附能分别为-3.30,-3.17 eV,说明掺杂表面对NO表现出优异的吸附性能;差分电荷密度分析表明,NO分子吸附后,N原子与掺杂原子Fe,Ir的中间出现电荷增加,形成共价键,掺杂原子周围电荷减少;态密度计算结果表明,NO在掺杂TM-MoS_(2)(TM=Fe,Ir)表面的吸附主要是N原子的2py,2px与掺杂原子Fe的3d_(xy),3d_(yz),3d_(xz)以及Ir的5d_(xy),5d_(yz),5d_(xz)轨道之间存在较强的相互作用;比较分析解离反应的活化能结果表明,相对贵金属Ir,掺杂廉价的Fe后,NO在Fe-MoS_(2)比在Ir-MoS_(2)表面解离的活化能小,且在Fe-MoS_(2)表面的吸附能与活化能非常接近,仅相差0.08 eV,表明在该体系中NO的吸附与解离存在相互竞争. 展开更多
关键词 FE ir掺杂 单层MoS_(2) 一氧化氮 吸附与解离 密度泛函理论
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Branched Polyamines Functionalized with Proposed Reaction Pathways Based on <sup>1</sup>H-NMR, Atomic Absorption and IR Spectroscopies
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作者 Vicente Cervantes-Mejía Elizabeth Baca-Solis +4 位作者 Judith Caballero-Jiménez Rosario Merino-García Jesús Cruz-Gatica Gabriela Moreno-Martínez Yasmi Reyes-Ortega 《American Journal of Analytical Chemistry》 2014年第16期1090-1101,共12页
Three novel branched polyamines N,N,N’,N’-tetrakis-[3((pyridine-2-methyl)-amine) propyl]-1,4- butanediamine (1), N,N,N’,N’-tetrakis-[N-((2-methylpyridine)ethyl)propanamide]ethylenediamine (2) and N,N,N’,N’-tetra... Three novel branched polyamines N,N,N’,N’-tetrakis-[3((pyridine-2-methyl)-amine) propyl]-1,4- butanediamine (1), N,N,N’,N’-tetrakis-[N-((2-methylpyridine)ethyl)propanamide]ethylenediamine (2) and N,N,N’,N’-tetrakis-[3((2-hidroxibenziliden)-amine)propyl]-1,4-butanediamine (3), were synthesized starting from 2-pyridinecarboxaldeyde with DAB-Am-4 for 1, PAMAM G0 for 2 and from salicylaldehyde with DAB-Am-4 for 3. The pathway reactions have been proposed by 1H-NMR, IR and Atomic Absorption Spectroscopy. The optimal reaction time was set by IR spectroscopy following aldehyde? peak modification. 1 and 2 were obtained as both hydrochlorides and as free amines and 3 only as free imine. These polyamines were characterized by UV-Vis, IR, 1H-NMR and 13C-NMR and Mass Spectrometry. 展开更多
关键词 BRANCHED Polyamines functionalIZATION Reactions ir NMR Atomic Absorption Spectroscopy
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Transplantation of human telomerase reverse transcriptase gene-transfected Schwann cells for repairing spinal cord injury 被引量:3
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作者 Shu-quan Zhang Min-fei Wu +3 位作者 Jia-bei Liu Ye Li Qing-san Zhu Rui Gu 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第12期2040-2047,共8页
Transfection of the human telomerase reverse transcriptase(h TERT)gene has been shown to increase cell proliferation and enhance tissue repair.In the present study,h TERT was transfected into rat Schwann cells.A rat... Transfection of the human telomerase reverse transcriptase(h TERT)gene has been shown to increase cell proliferation and enhance tissue repair.In the present study,h TERT was transfected into rat Schwann cells.A rat model of acute spinal cord injury was established by the modified free-falling method.Retrovirus PLXSN was injected at the site of spinal cord injury as a vector to mediate h TERT gene-transfected Schwann cells(1×10^(10)/L;10μL)or Schwann cells(1×10^(10)/L;10μL)without h TERT gene transfection.Between 1 and 4 weeks after model establishment,motor function of the lower limb improved in the h TERT-transfected group compared with the group with non-transfected Schwann cells.Terminal deoxynucleotidyl transferase-mediated d UTP nick-end labeling and reverse transcription-polymerase chain reaction results revealed that the number of apoptotic cells,and gene expression of aquaporin 4/9 and matrix metalloproteinase 9/2decreased at the site of injury in both groups;however,the effect improved in the h TERT-transfected group compared with the Schwann cells without h TERT transfection group.Hematoxylin and eosin staining,PKH26 fluorescent labeling,and electrophysiological testing demonstrated that compared with the non-transfected group,spinal cord cavity and motor and sensory evoked potential latencies were reduced,while the number of PKH26-positive cells and the motor and sensory evoked potential amplitude increased at the site of injury in the h TERT-transfected group.These findings suggest that transplantation of h TERT gene-transfected Schwann cells repairs the structure and function of the injured spinal cord. 展开更多
关键词 nerve regeneration spinal cord injury Schwann cells TRANSPLANTATION motor function TELOMERASE reverse transcriptase PROLIFERATION MODIFICATION cells neural regeneration
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JNK3 involvement in nerve cell apoptosis and neurofunctional recovery after traumatic brain injury 被引量:4
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作者 Jiang Long Li Cai +3 位作者 Jintao Li Lei Zhang Haiyang Yang Tinghua Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第16期1491-1499,共9页
Increasing evidence has revealed that the activation of the JNK pathway participates In apoptosis o1 nerve cells and neurological function recovery after traumatic brain injury. However, which genes inI the JNK family... Increasing evidence has revealed that the activation of the JNK pathway participates In apoptosis o1 nerve cells and neurological function recovery after traumatic brain injury. However, which genes inI the JNK family are activated and their role in traumatic brain injury remain unclear. Therefore, in this study, in situ end labeling, reverse transcription-PCR and neurological function assessment were adopted to investigate the alteration of JNK1, JNK2 and JNK3 gene expression in cerebral injured rats, and their role in celt apoptosis and neurological function restoration. Results showed that JNK3 expression significantly decreased at 1 and 6 hours and 1 and 7 days post injury, but that JNK1 and JNK2 expression remained unchanged. In addition, the number of apoptotic nerve cells surrounding the injured cerebral cortex gradually reduced over time post injury. The Neurological Severity Scores gradually decreased over 1,3, 5, 14 and 28 days post injury. These findings suggested that JNK3 expression was downregulated at early stages of brain injury, which may be associated with apoptosis of nerve cells. Downregulation of JNK3 expression may promote the recovery of neurological function following traumatic brain injury. 展开更多
关键词 neural regeneration JNK1 JNK2 JNK3 traumatic brain injury TdT-mediated dUTP nick endlabeling reverse transcription-PCR cell apoptosis neurological function recovery NEUROREGENERATION
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Density Functional Theoretical Study of 5 ,5 '-Azotetrazolate Nonmetallic Salts
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作者 LAI Weipeng GE Zhongxue +4 位作者 LIAN Peng YU Tao CHEN Xiaofang QIU Shaojun WANG Bozhou 《Defence Technology(防务技术)》 SCIE EI CAS 2013年第2期133-138,共6页
The structures, infrared spectra and cation stability of seven 5,5′-azotetrazolate nonmetallic salts are investigated by using B3LYP method with 6-311+G (d) basis set. The salts are guanidinium (GZT), aminoguanidiniu... The structures, infrared spectra and cation stability of seven 5,5′-azotetrazolate nonmetallic salts are investigated by using B3LYP method with 6-311+G (d) basis set. The salts are guanidinium (GZT), aminoguanidinium (AGZT), diaminoguanidinium (DAGZT), triaminoguanidinium (TAGZT), azidoformamidinium (AFZT), ammonium (AZT), and hydrazinium (HZT), respectively. The calculated results indicate that the carbon and nitrogen atoms of the cations in seven nonmetallic salts are characterized to be sp2 hybrid atoms, and the ranges of characteristic absorption peaks in IR spectra of the seven nonmetallic salts are approximative consistent. All their cations are stable and their stabilities decrease with the increase in their nitrogen contents. 展开更多
关键词 physical chemistry 5 5′-azotetrazolate nonmetallic salt density functional theory STRUCTURE ir spectrum STABILITY
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Functional Perspective in Drama Translation: A Case Study of Translating Courting Passages in a Canonical Chinese Play
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作者 Ann-Marie Hsiung 《Journal of Literature and Art Studies》 2019年第3期329-337,共9页
This study explores some complex issues of drama translation-whether it should be treated as literary translation or not-by investigating two English translations of the same canonic Chinese drama, Xixiang ji. One tra... This study explores some complex issues of drama translation-whether it should be treated as literary translation or not-by investigating two English translations of the same canonic Chinese drama, Xixiang ji. One translation claims to be literature piece while the other, stage-script. In comparing the two of different function and discussing their specific divergent expressions, this paper intends to shed some light on drama translation. It examines the translators’ purpose that closely links to their translation strategy and the function of their translation, followed by sample translations of courting passages. It illuminates the relative strength and weakness of drama translation as literature and as stage-script. 展开更多
关键词 functional theories text type skopos INTERCULTURAL communication GENDER reversAL
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Direct and Reverse Carleson Conditions on Generalized Weighted Bergman-Orlicz Spaces
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作者 Waleed Al-Rawashdeh 《Analysis in Theory and Applications》 CSCD 2017年第3期287-300,共14页
Let D be the open unit disk in the complex plane C. For a〉 -1, let dAa(z)=(1 +a) (1 -|z}^2) ^a da(z)be the weighted Lebesgue measure on ]D. For a positive function ω ∈ L^1(D,dAa), the generalized weight... Let D be the open unit disk in the complex plane C. For a〉 -1, let dAa(z)=(1 +a) (1 -|z}^2) ^a da(z)be the weighted Lebesgue measure on ]D. For a positive function ω ∈ L^1(D,dAa), the generalized weighted Bergman-Orlicz spaceA^ψω(D,dAa)is||f||ω^ψ=∫Dψ|F(z)|ω(z)dA^(z) 〈 ∞,where q; is a strictly convex Orlicz function that satisfies other technical hypotheses. Let G be a measurable subset of D, we say G satisfies the reverse Carleson condition for A^ψω (D, dAa) if there exists a positive constant C such that ∫Gψ(f(z))ω(z)dAa(z)≥C∫Dψ(|f(z)dAa(z).for all f ∈ .A^ψω (D,dAa). Let μ be a positive Borel measure, we say μ satisfies the direct Carleson condition if there exists a positive constant M such that for all f∈Aψ^ω (D,dAa),∫Dψ(|f(z)|)dμ(z)≤M∫Dψ(|f(z)|)ω(z)dAa(a).In this paper, we study the direct and reverse Carleson condition on the generalized weighted Bergman-Orlicz space Aω^ψ(D,dAa).We present conditions on the set G such that'the reverse Carleson condition'holds. "Moreover, we give a sufficient condition for the finite positive Borel measure μ to satisfy the direct carleson condition on the generalized weighted Bergman-Orlicz spaces. 展开更多
关键词 Orlicz function global ?2-condition reverse Carleson condition Direct Carleson condition closed range Pseudohyperbolic disks Orlicz spaces weighted Bergman spaces generalized weighted Bergman-Orlicz spaces
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Preparation and Characterization of Functionalized Polypropylene with Acrylamide and Itaconic Acid
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作者 A. R. Oromiehie H. Ebadi-Dehaghani +3 位作者 K. Ansari K. Karimi Z. Rahmani S. Mirbagheri 《Journal of Materials Science and Chemical Engineering》 2014年第10期43-51,共9页
Functionalized polypropylene with acryl amide (AAm) and itaconic acid (IA) were prepared in the molten state in the presence of dicumyl peroxide. The effects of the concentration of both mono- mers on the degree of fu... Functionalized polypropylene with acryl amide (AAm) and itaconic acid (IA) were prepared in the molten state in the presence of dicumyl peroxide. The effects of the concentration of both mono- mers on the degree of functionalization and properties of the products were investigated by FT-IR, contact angle measurement and DSC analysis. It was found that the degree of functionalization depends on the initial concentration of both monomers that used in the reaction. The influence of the AAm and IA content on the melting and crystallization temperature of PP was investigated by DSC. The contact angle of water on film surfaces of the functionalized PP (PP-g-AAm and PP-g-IA) decreased with increasing modified polymer content. From FT-IR spectra of functionalized PP a calculation was made of carbonyl index on the films surfaces. It was found that the higher intensity of the carbonyl index, the lower contact angle value and the lower crystallinity confirmed the ex- istence of functionalized AAm and/or IA in PP. It was concluded from the different characteriza- tion methods that the polarity and percentage of functionalized PP were increased up to 3 phr for both monomers, and then it was decreased by increasing the amount of monomers and had a threshold value, due to nucleating agents of monomers in PP. 展开更多
关键词 functionalIZED POLYPROPYLENE ACRYL AMIDE Itaconic Acid FT-ir Contact Angle
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Information System Construction and Function Module Design Based on Reverse Logistics
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作者 赵佳妮 石丽娜 《Journal of Donghua University(English Edition)》 EI CAS 2015年第2期328-331,共4页
Reverse logistics are playing more and more important role with the development of competition and the social responsibility of enterprises.It could be divided into commission acceptance,recycling and returned goods h... Reverse logistics are playing more and more important role with the development of competition and the social responsibility of enterprises.It could be divided into commission acceptance,recycling and returned goods handling.Reverse logistics information system consists of the database establishment,network structure and logic structure design.The collection,storage,processing,transmission and output functions of the reverse logistics information system were discussed in the thesis.Eventually,it established seven modules for the reverse logistics information system including the system management module,oriented module,returning goods processing module,reverse transportation management module,information sharing module,statistical analysis module and cost control module. 展开更多
关键词 logistics responsibility goods commission competition acceptance recycling Module collection customers
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可逆交联聚丁二烯网络的技术进展
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作者 郝鹏 陈艳君 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2024年第6期152-162,共11页
简介了聚丁二烯的种类、优异性能及重要性,简述了聚丁二烯使用过程中硫化交联制备的含有不可逆交联网络带来的难以回收和资源浪费的问题,设计合成基于可逆交联键的聚丁二烯网络对于发展高弹性、高强度、可回收和其它功能的先进材料具有... 简介了聚丁二烯的种类、优异性能及重要性,简述了聚丁二烯使用过程中硫化交联制备的含有不可逆交联网络带来的难以回收和资源浪费的问题,设计合成基于可逆交联键的聚丁二烯网络对于发展高弹性、高强度、可回收和其它功能的先进材料具有重要意义。构筑可逆交联聚丁二烯的关键是在聚丁二烯分子链上引入官能基团,再通过官能基团之间的反应或相互作用构筑可逆交联聚丁二烯网络。根据官能基团在聚丁二烯分子链的位置不同,介绍了基于链端官能化聚丁二烯的可逆交联网络、基于链中官能化聚丁二烯的可逆交联网络和基于链端和链中双重官能化聚丁二烯的可逆交联网络这3种聚丁二烯网络的制备方法和性能。最后提出,引入更多的可逆交联键以及功能基团,拓宽其应用领域是未来的重点研发方向。 展开更多
关键词 聚丁二烯 官能化 可逆交联 回收
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改进贝叶斯网络在变压器故障诊断中的应用 被引量:2
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作者 仝兆景 兰孟月 荆利菲 《电子科技》 2024年第5期47-53,70,共8页
针对变压器故障诊断精度低的问题,文中提出一种基于改进黏菌优化算法(Improved Slime Mould Algorithm,ISMA)优化贝叶斯网络(Bayesian Network,BN)的变压器故障诊断方法。通过爬山算法对定向最大支撑树搜索得到贝叶斯网络初始结构即初... 针对变压器故障诊断精度低的问题,文中提出一种基于改进黏菌优化算法(Improved Slime Mould Algorithm,ISMA)优化贝叶斯网络(Bayesian Network,BN)的变压器故障诊断方法。通过爬山算法对定向最大支撑树搜索得到贝叶斯网络初始结构即初始种群,在改进黏菌优化算法中引入反向学习策略,增加种群多样性。添加正弦-余弦算法(Sine Cosine Algorithm,SCA),更新解的位置以避免种群陷入局部最优。根据改良的无编码比值法选取变压器故障状态的特征,利用改进黏菌优化算法优化贝叶斯网络结构,提高基于贝叶斯网络的变压器故障诊断的准确率,并利用不同种类的测试函数验证了改进黏菌优化算法具有收敛速度快、收敛精度高的优良性能。仿真结果表明,ISMA-BN诊断模型的训练集和测试集准确率分别为98.2%和97.14%,具有一定的研究价值。 展开更多
关键词 故障诊断 改进黏菌优化算法 贝叶斯网络 结构学习 变压器 反向学习策略 正弦-余弦算法 测试函数
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基于电磁时间反演的VSC-HVDC系统架空线-电缆混合线路故障定位方法
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作者 张艳霞 李婷 《电力自动化设备》 EI CSCD 北大核心 2024年第3期180-186,224,共8页
针对传统故障定位方法无法应用于架空线-电缆混合直流线路的问题,提出了一种架空线-电缆混合直流线路的故障定位方法,该方法采用先确定故障点所在区段、后在区段中定位的原理。利用故障附加网络的直流分量定义了故障区段判别函数,通过... 针对传统故障定位方法无法应用于架空线-电缆混合直流线路的问题,提出了一种架空线-电缆混合直流线路的故障定位方法,该方法采用先确定故障点所在区段、后在区段中定位的原理。利用故障附加网络的直流分量定义了故障区段判别函数,通过该判别函数在不同区段发生故障时数值不同实现故障区段的判定。然后,分析了电磁时间反演理论在故障定位中的可行性,分析确定了故障特征谐波。利用线路两端特征谐波的电流行进波作为时间反演电路的电流源,设置与原线路拓扑结构镜像的线路,利用时间反演电流源与镜像线路构建时间反演电路。在此基础上,根据时间反演的能量聚焦特性列写故障区段内的故障定位方程并实现区段内故障定位。利用PSCAD/EMTDC搭建的电压源型换流器高压直流输电(VSC-HVDC)系统仿真证明了所提方法能实现线缆混合直流输电线路的故障定位。 展开更多
关键词 架空线-电缆混合直流线路 故障定位 故障区段判别函数 时间反演 能量聚焦
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基于Tene-cor自动聚焦成像算子的弹性波微地震逆时定位
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作者 唐杰 唐正威 +1 位作者 韩盛元 王海成 《石油物探》 CSCD 北大核心 2024年第5期968-980,共13页
微地震震源定位是微地震研究中的关键技术,微地震震源位置可以通过微地震信号的逆时反传来确定。在弹性介质逆时定位过程中,微地震信号中的P波、S波会耦合在一起,在震源聚焦结果中产生假象,影响震源方位的拾取。提出了基于Tene-cor聚焦... 微地震震源定位是微地震研究中的关键技术,微地震震源位置可以通过微地震信号的逆时反传来确定。在弹性介质逆时定位过程中,微地震信号中的P波、S波会耦合在一起,在震源聚焦结果中产生假象,影响震源方位的拾取。提出了基于Tene-cor聚焦成像算子的弹性波微地震逆时定位算法,首先,通过纵横波解耦的弹性波方程得到P波和S波的逆时波场,然后,施加Tene-cor成像算子对解耦的逆时波场记录进行互相关成像得到震源位置。分别利用合成数据和野外实际数据测试了该算法的定位效果。数值算例表明,该定位算法除了能够压制成像结果中因波场耦合导致的串扰噪声外,还可以聚焦因干涉成像产生的辐射状假象,在不同检波器采集条件、频带缺失和速度模型不精确的条件下,该算法相较于传统定位成像算法能够有效提高震源定位分辨率。 展开更多
关键词 微地震 逆时定位 聚焦函数 弹性波解耦 成像算子
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稀缺主焦煤高效重介分选工艺在吕家坨矿选煤厂的应用
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作者 郑庆学 石伟 +2 位作者 丁卫清 李小刚 赵永喜 《煤炭加工与综合利用》 CAS 2024年第4期5-9,共5页
针对吕家坨矿选煤厂原生产工艺存在的问题,分析了入选原煤煤质特性,采用超宽粒级原煤三产品重介质旋流器选煤工艺、新型煤泥重介质旋流器选煤技术-反分流分选工艺、粗精煤泥两段弧形筛组合脱泥回收技术进行技术改造。改造后工艺系统指... 针对吕家坨矿选煤厂原生产工艺存在的问题,分析了入选原煤煤质特性,采用超宽粒级原煤三产品重介质旋流器选煤工艺、新型煤泥重介质旋流器选煤技术-反分流分选工艺、粗精煤泥两段弧形筛组合脱泥回收技术进行技术改造。改造后工艺系统指标检测结果表明,改造可提高综合精煤产率1.78%,增加税前利润10573.2万元。 展开更多
关键词 选煤厂 分选工艺 超宽粒级 重介质旋流器 反分流 两段弧形筛
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印度测图卫星IRS-P5定位精度初步研究 被引量:29
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作者 赵利平 刘凤德 +1 位作者 李健 王薇 《遥感信息》 CSCD 2007年第2期28-32,I0001,共6页
简要回顾了印度遥感卫星系列的发展历程;给出了IRS-P5卫星及传感器的有关性能参数,并与IKONOS、SPOT5 HRS做了初步比较;详细论述了IRS-P5使用有理函数模型的定位方法。最后,使用中国北京地区的立体像对数据进行了有关试验研究,结果表明... 简要回顾了印度遥感卫星系列的发展历程;给出了IRS-P5卫星及传感器的有关性能参数,并与IKONOS、SPOT5 HRS做了初步比较;详细论述了IRS-P5使用有理函数模型的定位方法。最后,使用中国北京地区的立体像对数据进行了有关试验研究,结果表明,在良好的地面控制点的支持下,平面和高程精度均可达到5m,满足国家1∶50000基本比例尺地形图测图规范要求。 展开更多
关键词 测图卫星 irS-P5 有理函数模型 RFM 定位精度
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东胜长焰煤热解含氧官能团结构演化的^(13)C-NMR和FT-IR分析 被引量:23
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作者 宋昱 朱炎铭 李伍 《燃料化学学报》 EI CAS CSCD 北大核心 2015年第5期519-529,共11页
以东胜煤田色拉一号井田2号煤层长焰煤为研究对象,利用浮沉离心法富集其镜质组。基于工业分析、元素分析、13C-NMR、FT-IR、谱图分峰拟合技术和化学分析测试,求取镜煤及一系列热解煤含氧官能团结构与含量参数,从不同角度研究了含氧官能... 以东胜煤田色拉一号井田2号煤层长焰煤为研究对象,利用浮沉离心法富集其镜质组。基于工业分析、元素分析、13C-NMR、FT-IR、谱图分峰拟合技术和化学分析测试,求取镜煤及一系列热解煤含氧官能团结构与含量参数,从不同角度研究了含氧官能团的分布规律与演化特点。镜煤中羧基、羰基含量分别为8.91~10.90 mol/kg、1.61~1.79 mol/kg,随热解温度升高羧基显著减少。热解作用促使以端基形式连接在脂肪链或脂肪环结构氧上的甲基和亚甲基首先脱去,且在温度高于350℃后基本稳定。氧在热解过程赋存状态的变化是芳香体系与脂肪体系相互竞争的结果,510℃热解煤中芳香类氧和脂肪类氧的含量分别为7.49、3.45 mol/kg。羟基的演化过程与热解过程中氧的赋存状态密切相关。随着热解过程的进行,在热解温度低于440℃时,各种羟基含量均减少,热解过程对于大分子网络的破坏干扰了各种氢键作用,而羟基π作用则暂时增强,至510℃时各种氢键含量均降为最低。东胜长焰煤中含氧官能团化学活性顺序为:[COOH]>[R-O]>[Ar-O-Ar,Ar-O-C,C-O-C]>[C=O]。镜煤非活性醚键含量为0.68 mol/kg,活性醚键为0.48 mol/kg,主要为非活性醚键。 展开更多
关键词 东胜长焰煤 热解 含氧官能团 结构演化 13C-NMR FT-ir
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M_6^(0,±)(M=Os,Ir,Pt)团簇结构与性质的密度泛函理论研究 被引量:11
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作者 张秀荣 崔彦娜 +1 位作者 洪伶俐 张伟 《分子科学学报》 CAS CSCD 北大核心 2009年第2期109-115,共7页
采用密度泛函理论(DFT)中的杂化密度泛函(B3LYP)方法,在LANL2DZ基组水平上对M06,±(M=Os,Ir,Pt)团簇的各种可能构型进行了几何结构优化,得出各团簇的最稳定构型,并对其能量、振动频率、热力学性质、核独立化学位移(NICS)和极化率进... 采用密度泛函理论(DFT)中的杂化密度泛函(B3LYP)方法,在LANL2DZ基组水平上对M06,±(M=Os,Ir,Pt)团簇的各种可能构型进行了几何结构优化,得出各团簇的最稳定构型,并对其能量、振动频率、热力学性质、核独立化学位移(NICS)和极化率进行了理论研究.结果表明,M06,±(M=Os,Ir)团簇的基态都是三棱柱结构,Pt-6团簇的基态是平面三角形结构;M06,±(M=Os,Ir,Pt)团簇生成焓都为负值,热力学上是稳定的;NICS值都为负值,表明M06,±(M=Os,Ir,Pt)团簇都具有芳香性,其中Os-6团簇的芳香性最强;从光谱分析来看,Os6的IR和Raman谱的较强吸收峰的个数最多,Ir6的IR和Raman谱的最强吸收峰都只有一个,IR最强吸收峰在137.0和143.5 cm-1之间,Raman谱最强的吸收峰位于169.5 cm-1处;Pt6的IR和Raman谱的最强吸收峰分别位于50.2和194.7 cm-1处. 展开更多
关键词 M06 ±(M=Os ir Pt)团簇 结构与性质 密度泛函理论
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In-Au(111)和Ir-Au(111)合金表面的性质及其对巴豆醛的吸附比较 被引量:3
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作者 蒋军辉 钱梦丹 +3 位作者 薛继龙 夏盛杰 倪哲明 邵蒙蒙 《物理化学学报》 SCIE CAS CSCD 北大核心 2016年第12期2932-2940,共9页
采用密度泛函理论研究了M(M=In,Ir)原子修饰的M-Au(111)合金表面的稳定性,并选其最优模型探讨了合金表面的活性及其对巴豆醛的吸附。合金的几何构型、形成能和结合能等性质表明,In-Au(111)面的稳定性随In原子的间距增大而提高,Ir-Au(111... 采用密度泛函理论研究了M(M=In,Ir)原子修饰的M-Au(111)合金表面的稳定性,并选其最优模型探讨了合金表面的活性及其对巴豆醛的吸附。合金的几何构型、形成能和结合能等性质表明,In-Au(111)面的稳定性随In原子的间距增大而提高,Ir-Au(111)面的稳定性随Ir原子的间距增大而降低。对于巴豆醛在MAu(111)面上的吸附,当其通过C=O吸附于合金表面的TopM位时,吸附能最大,吸附构型最稳定。从巴豆醛的结构变化、态密度、差分电荷密度以及Mulliken电荷布居等分析可以看出,稳定吸附构型的巴豆醛分子形变较大,电荷转移明显。其中,位于-7.04 e V至费米能级处的p、d轨道杂化,对体系的吸附具有重要贡献。分析比较In-Au(111)面与Ir-Au(111)面,发现后者的配体效应更佳,不仅具有更高的稳定性和活性,而且对于巴豆醛具有更强的吸附力。此外,相比于改性前的Au(111)面,M原子的修饰明显提升了金属表面的稳定性及吸附能力。 展开更多
关键词 In-Au(111)面 ir-Au(111)面 修饰 巴豆醛 吸附 密度泛函理论
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基于壳聚糖/银离子的可逆温敏水凝胶的制备与性能
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作者 徐世宽 张弘妹 +2 位作者 戚鹏飞 曹张军 邢彦军 《精细化工》 EI CAS CSCD 北大核心 2024年第5期1036-1042,共7页
以壳聚糖(CS)和AgNO_(3)为主要原料,通过CS与Ag^(+)的超分子络合作用制备了一系列可逆温敏CS-Ag水凝胶,采用FTIR、XRD、XPS、SEM和EDS对CS-Ag水凝胶的结构和化学状态进行了表征。结果表明,通过同时调节AgNO_(3)用量和体系pH可制备具有... 以壳聚糖(CS)和AgNO_(3)为主要原料,通过CS与Ag^(+)的超分子络合作用制备了一系列可逆温敏CS-Ag水凝胶,采用FTIR、XRD、XPS、SEM和EDS对CS-Ag水凝胶的结构和化学状态进行了表征。结果表明,通过同时调节AgNO_(3)用量和体系pH可制备具有相同凝胶温度的CS-Ag水凝胶。当CS用量为0.60 g、AgNO_(3)用量为0.19 g、体系总体积为21 mL、保持水凝胶pH=4.24时,制备的CS-Ag-19水凝胶凝胶温度为50℃,具有最佳的热可逆性能,至少可循环相变5次,具有室温避光保存5个月的稳定性,并表现出对大肠杆菌良好的抗菌性能。CS-Ag-19的溶胶-凝胶转换是由CS的氨基在不同温度下的超分子相互作用控制,H^(+)和Ag^(+)在温度、浓度变化的驱动下,对游离氨基的竞争反应(质子化和络合作用)之间的平衡关系使水凝胶具有温敏可逆性。CS-Ag-19水凝胶的可注射和温敏凝胶性能使其具有作为水凝胶抗菌敷料的应用潜力。 展开更多
关键词 可逆温敏水凝胶 壳聚糖 银离子 抗菌性 可注射性 功能材料
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