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A STUDY OF PARTITIONING Q VECTOR ON BACKGROUND CONDITIONS OF A TORRENTIAL RAINFALL OVER SHANGHAI,CHINA ON 25 AUGUST 2008 被引量:4
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作者 岳彩军 鲁小琴 +1 位作者 李小凡 宗志平 《Journal of Tropical Meteorology》 SCIE 2011年第3期231-247,共17页
A rainfall that occurred during 0200–1400 Beijing Standard Time(BST)25 August 2008 shows the rapid development of a convective system,a short life span,and a record rate of 117.5 mm h-1for Xujiahui station since 1872... A rainfall that occurred during 0200–1400 Beijing Standard Time(BST)25 August 2008 shows the rapid development of a convective system,a short life span,and a record rate of 117.5 mm h-1for Xujiahui station since 1872.To study this torrential rainfall process,the partitioning method of Q vector is developed,in which a moist Q vector is first separated into a dry ageostrophic Q vector(DQ)and a diabatic-heating component.The dry ageostrophic Q vector is further partitioned along isothermal lines in the natural coordinate to identify different scale forcing in adiabatic atmosphere,and the large-scale and convective condensational heating in non-uniform saturated atmosphere,convective condensational heating, and Laplace of diabatic heating that includes radiative heating and other heating and cooling processes,are calculated to study the forcing from diabatic heating.The effects of the environmental conditions on the development of the rainfall processes are diagnosed by performing the partitioning of Q vector based on 6-hourly NCEP/NCAR Final Analysis(FNL)data with the horizontal resolution of 1°×1°.The results include the following:(1)a low-pressure inverted trough associated with the landfall of Typhoon Nuri (2008),a strong southwesterly jet along the western side of the subtropical high,and an eastward-propagating westerly low-pressure trough provide favorable synoptic conditions for the development of torrential rainfall;(2)the analysis of DQ vector showed that the upward motions forced by the convergence of DQ vector in the lower troposphere(1000–600 hPa)favor the development of torrential rainfall.When DQ vector converges in the upper troposphere(500–100 hPa),upward motions in the whole air column intensify significantly to accelerate the development of torrential rainfall;(3)the partitioning analysis of DQ vector reveals that large-scale forcing persistently favors the development of torrential rainfall whereas the mesoscale forcing speeds up the torrential rainfall;(4)the calculations of large-scale condensational heating in non-uniform saturated atmosphere,convective condensational heating, and Laplace of diabatic heating showed that the forcing related to diabatic heating has the positive feedback on the convective development,and such positive feedback decays and dissipates when the convective system propagates eastward and weakens. 展开更多
关键词 background conditions of torrential rainfall partitioning of q vector dry ageostrophic q vector diabatic heating
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Diagnosis of the Heavy Rain near a Meiyu Front Using the Wet Q Vector Partitioning Method 被引量:5
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作者 岳彩军 寿绍文 +1 位作者 林开平 姚秀萍 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2003年第1期37-44,共8页
A heavy rain process of the Changjiang-Huaihe Meiyu front (MYF) is diagnosed by the agency of the traditional Q vector partitioning (QVP) method to decompose the wet Q vector (Q) in a natural coordinate system that fo... A heavy rain process of the Changjiang-Huaihe Meiyu front (MYF) is diagnosed by the agency of the traditional Q vector partitioning (QVP) method to decompose the wet Q vector (Q) in a natural coordinate system that follows the isoentropes and by using the numerical simulation results of the revised MM4 meso-scale model. The technique shows that the partitioned wet Q vectors can lead to a significant scale separation of vertical motion related to the torrential rain. The results not only verify the existing conclusion that different scales interact throughout the rainstorm but also indicate the largely different roles of these scales during differing phases of the heavy ramfall on a quantitative basis. Specifically, during the developing stage, the large-scale plays a predominant role in forcing vertical motion, while frontal-scale forcing is secondary; during the intense stage, the frontal-scale evolves into the primary factor of forcing vertical motion, whereas the large-scale forcing is minor and plays a diminishing role and can even be ignored; and during the decaying stage, the large-scale once again serves as the main forcing of vertical motion in such a way that the forcing of the frontal-scale decays quickly and is of secondary importance. Furthermore, the partitioned wet Q vectors are suggested to be more suitable than the total wet Q vector for evaluating the potential physical mechanism of rainstorm genesis. The first step is that the forcing of large-scale $2?bla cdot {? Q}_s^*$ gives rise to the genesis of meso-scale $2?bla cdot {? Q}_n^*$ forcing; and then, accordingly as $2?bla cdot {? Q}_n^*$ forcing increases, whereby the secondary circulation is reinforced, the intensity of the rainfall is strengthened; and at last, the secondary circulation caused by $2?bla cdot {? Q}_n^*$ forcing is directly responsible for generation of the MYF heavy rainfall. 展开更多
关键词 wet q vector partitioning wet q vector Meiyu front heavy rainfall interaction of different scales dIAGNOSIS
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A Modified Moist Ageostrophic Q Vector 被引量:2
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作者 岳彩军 寿绍文 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2008年第6期1053-1061,共9页
The quasi-geostrophic Q vector is an important rainfall associated with large-scale weather systems diagnostic tool for studying development of surface and is calculated using data at single vertical level. When ageos... The quasi-geostrophic Q vector is an important rainfall associated with large-scale weather systems diagnostic tool for studying development of surface and is calculated using data at single vertical level. When ageostrophic Q vector was introduced, it required data at two vertical levels. In this study, moist ageostrophic Q vector is modified so that it can be calculated using data at a single vertical level. The comparison study between the original and modified moist ageostrophic Q vectors is conducted using the data from 5 to 6 July 1991 during the torrential rainfall event associated with the Changjiang-Huaihe mei-yu front in China. The results reveal that divergences of original and modified moist ageostrophic Q vectors have similar horizontal distributions and their centers are almost located in the precipitation centers. This indicates that modified moist ageostrophic Q vector can be used to diagnose convective development with reasonable accuracy. 展开更多
关键词 moist ageostrophic q vector MOdIFICATION latent heating torrential rainfall associated with mei-yu front
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The Curl of Q Vector: A New Diagnostic Parameter Associated with Heavy Rainfall 被引量:3
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作者 YANG Shuai WANG Dong-Hai 《Atmospheric and Oceanic Science Letters》 2008年第1期36-39,共4页
As a powerful tool to diagnose vertical motion, frontogenesis, and secondary circulation, the Q vector and its divergence are widely used. However, little attention has been given to the curl of Q vector. In this pape... As a powerful tool to diagnose vertical motion, frontogenesis, and secondary circulation, the Q vector and its divergence are widely used. However, little attention has been given to the curl of Q vector. In this paper, a new set of analyses combining the divergence of the Q vector (DQ) with the vertical component of the curl of the Q vector (VQ) is applied to a Northeastern cold vortex rainfall case. From the derivation, it was found that the expressions of the Q vectors and their divergences in saturated moist flow (DQm) differ from those of dry and unsaturated moist atmosphere (DQ), while the VQs of various background flows are exactly the same, which largely simplified the analyses. This case study showed that, compared with the DQ, not only can the DQm diagnose precipitation more effectively, but the VQ may also be indicative of precipitation (especially for heavy rainfall and strong convection) because of its direct, close relationship with ageostrophic motion. Thus, the VQ may be computed and analyzed with ease, and may serve as a useful tool for analyses of precipitation and strong convective svstems. 展开更多
关键词 the divergence of q vector the curl of qvector Northeastern rainfall
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Analysis of Non-geomorphic Wet Q Vector during a Rainstorm Process in Ulanqab
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作者 Haidan YAN 《Meteorological and Environmental Research》 CAS 2022年第1期1-4,8,共5页
Based on NCEP/NCAR 1°×1°reanalysis data,according to the non-geostrophic wet Q vector,a rainstorm weather process in Ulanqab from July 24 to 25,2016 was diagnosed and analyzed.The results show that the ... Based on NCEP/NCAR 1°×1°reanalysis data,according to the non-geostrophic wet Q vector,a rainstorm weather process in Ulanqab from July 24 to 25,2016 was diagnosed and analyzed.The results show that the rainstorm area in Ulanqab City had a good corresponding relationship with the convergence area of non-geostrophic wet Q vector and the rising motion area.The rainstorm occurred in the convergence area of non-geostrophic wet Q vector divergence,and the secondary circulation excited by the non-geostrophic wet Q vector was conducive to the maintenance and development of rainstorm.The falling area of rainstorm was located on the side of the ascending branch of the secondary circulation.The non-geostrophic wet Q vector provides a new idea for the forecast of rainstorm and its falling area in Ulanqab. 展开更多
关键词 RAINSTORM Non-geostrophic wet q vector Secondary circulation Ulanqab
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La-Ce稀土对Q345D钢夹杂物和冲击性能的影响 被引量:2
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作者 罗钢 隋亚飞 +2 位作者 刘彭 梁亮 徐李军 《特殊钢》 2024年第3期33-39,共7页
通过现场试验,分析了La-Ce稀土处理对Q345D结构钢夹杂物、连铸可浇性和钢种性能的影响。结果表明,RE在Q345D结构钢中的合金收得率为21.5%;与未添加RE的炉次相比,脱硫率提高了37.5%,单位夹杂物密度从80.16个/mm^(2),降低至60.78个/mm^(2)... 通过现场试验,分析了La-Ce稀土处理对Q345D结构钢夹杂物、连铸可浇性和钢种性能的影响。结果表明,RE在Q345D结构钢中的合金收得率为21.5%;与未添加RE的炉次相比,脱硫率提高了37.5%,单位夹杂物密度从80.16个/mm^(2),降低至60.78个/mm^(2);La-Ce稀土处理前钢液中夹杂物主要是MgO-Al_(2)O_(3)-CaO复合夹杂,La-Ce稀土处理对小尺寸(D≤5μm)夹杂物的改性作用较为明显,小尺寸夹杂物改性为(La-Ce-S)和(La-Ce-Al-S-O)稀土类夹杂物;La-Ce稀土处理可以明显降低钢中MnS类夹杂物的纵横比,使MnS类夹杂物在轧制后的形貌更接近椭圆形,而没有长线形,这是Q345D结构钢横向冲击功提高20%的主要原因。 展开更多
关键词 La-Ce稀土处理 q345d结构钢 横向冲击功 夹杂物改性 精炼 洁净度
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基于D3QN的火力方案优选方法
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作者 佘维 岳瀚 +1 位作者 田钊 孔德锋 《火力与指挥控制》 CSCD 北大核心 2024年第8期166-174,共9页
针对在多类弹药协同攻击地面工事类目标任务中火力方案优选效率低的问题,提出一种基于双层决斗DQN(dueling double deep Q network,D3QN)的火力方案优选方法。该方法将打击过程建模为马尔科夫决策过程(Markov decision processes,MDP),... 针对在多类弹药协同攻击地面工事类目标任务中火力方案优选效率低的问题,提出一种基于双层决斗DQN(dueling double deep Q network,D3QN)的火力方案优选方法。该方法将打击过程建模为马尔科夫决策过程(Markov decision processes,MDP),设计其状态空间和动作空间,设计综合奖励函数激励火力方案生成策略优化,使智能体通过强化学习框架对策略进行自主训练。仿真实验结果表明,该方法对地面工事类目标的火力方案进行决策,相较于传统启发式智能算法能够获得较优的火力方案,其计算效率和结果的稳定性相较于传统深度强化学习算法具有更明显的优势。 展开更多
关键词 深度强化学习 深度q网络 d3qN 组合优化 火力方案优选
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Mathematical Wave Functions and 3D Finite Element Modelling of the Electron and Positron
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作者 Declan Traill 《Journal of Applied Mathematics and Physics》 2024年第4期1134-1162,共29页
The wave/particle duality of particles in Physics is well known. Particles have properties that uniquely characterize them from one another, such as mass, charge and spin. Charged particles have associated Electric an... The wave/particle duality of particles in Physics is well known. Particles have properties that uniquely characterize them from one another, such as mass, charge and spin. Charged particles have associated Electric and Magnetic fields. Also, every moving particle has a De Broglie wavelength determined by its mass and velocity. This paper shows that all of these properties of a particle can be derived from a single wave function equation for that particle. Wave functions for the Electron and the Positron are presented and principles are provided that can be used to calculate the wave functions of all the fundamental particles in Physics. Fundamental particles such as electrons and positrons are considered to be point particles in the Standard Model of Physics and are not considered to have a structure. This paper demonstrates that they do indeed have structure and that this structure extends into the space around the particle’s center (in fact, they have infinite extent), but with rapidly diminishing energy density with the distance from that center. The particles are formed from Electromagnetic standing waves, which are stable solutions to the Schrödinger and Classical wave equations. This stable structure therefore accounts for both the wave and particle nature of these particles. In fact, all of their properties such as mass, spin and electric charge, can be accounted for from this structure. These particle properties appear to originate from a single point at the center of the wave function structure, in the same sort of way that the Shell theorem of gravity causes the gravity of a body to appear to all originate from a central point. This paper represents the first two fully characterized fundamental particles, with a complete description of their structure and properties, built up from the underlying Electromagnetic waves that comprise these and all fundamental particles. 展开更多
关键词 ELECTRON POSITRON Wave Function Solution Electromagnetic Spin Mass Charge Proof Fundamental Particle Properties quantum Mechanics Classical Physics Computer 3d Model Schrödinger Equation RMS KLEIN GORdON Electric Magnetic Lorentz Invariant Hertzian vector Point Potential Field density Phase Flow Attraction REPULSION Shell Theorem Ehrenfest VIRIAL Normalization Harmonic Oscillator
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基于d-q变换及WOA-LSTM的异步电机定子匝间短路故障诊断方法
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作者 王喜莲 秦嘉翼 耿民 《电机与控制学报》 EI CSCD 北大核心 2024年第6期56-65,共10页
为了实现对异步电机定子绕组匝间短路故障的可靠在线诊断,提出一种基于d-q变换及鲸鱼优化算法(WOA)优化的长短期记忆网络(LSTM)的故障诊断方法。通过理论推导可知,d-q变换可有效提取定子电流中的特征频谱数据。采用鲸鱼优化算法对长短... 为了实现对异步电机定子绕组匝间短路故障的可靠在线诊断,提出一种基于d-q变换及鲸鱼优化算法(WOA)优化的长短期记忆网络(LSTM)的故障诊断方法。通过理论推导可知,d-q变换可有效提取定子电流中的特征频谱数据。采用鲸鱼优化算法对长短期记忆网络中的3个关键参数进行优化,建立WOA-LSTM故障分类模型。为了验证基于d-q变换和WOA-LSTM故障诊断方法的有效性,分别以小波变换、快速傅里叶变换及d-q变换提取电流频谱数据作为输入数据集,以一台YE2-100L1-4型异步电机为实验对象进行实验验证。研究结果表明:相比于小波变换及快速傅里叶变换,采用d-q变换能更准确的提取出定子电流中的故障特征,更精确地反映电机故障状态,有助于提高故障分类准确率;相比于传统的LSTM算法,经WOA优化后的LSTM算法分类准确率可达98.3%,能可靠地实现不同程度匝间短路故障的诊断。 展开更多
关键词 异步电机 故障诊断 定子绕组匝间短路 d-q变换理论 鲸鱼优化算法 长短期记忆神经网络
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Q690D多道次GMAW接头的组织和力学性能 被引量:1
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作者 刘五兵 王世清 李方坡 《热加工工艺》 北大核心 2024年第3期53-56,61,共5页
在无预热和焊后热处理的条件下,采用熔化极气体保护焊(GMAW)和CHW-80C1实芯焊丝对20 mm厚Q690D热机械轧制钢板进行多道次焊接试验,分析该钢焊接接头的组织转变特征和冲击性能。结果表明,采用CHW-80C1焊丝可获得成型优良的焊接接头;Q690... 在无预热和焊后热处理的条件下,采用熔化极气体保护焊(GMAW)和CHW-80C1实芯焊丝对20 mm厚Q690D热机械轧制钢板进行多道次焊接试验,分析该钢焊接接头的组织转变特征和冲击性能。结果表明,采用CHW-80C1焊丝可获得成型优良的焊接接头;Q690D各道次的焊缝组织相似,均由粒状贝氏体和少量的针状铁素体、先共析铁素体组成;热影响区由粒状贝氏体、针状铁素体、先共析铁素体及M-A组元组成。焊缝与细晶热影响区的冲击吸收功相对于母材的有一定幅度的下降,焊缝与细晶热影响区的断裂类型均为韧性断裂。 展开更多
关键词 q690d 熔化极气体保护焊(GMAW) 显微组织 冲击韧性 断口
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Chaos game representation(CGR)-walk model for DNA sequences 被引量:4
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作者 高洁 徐振源 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第1期370-376,共7页
Chaos game representation (CGR) is an iterative mapping technique that processes sequences of units, such as nucleotides in a DNA sequence or amino acids in a protein, in order to determine the coordinates of their ... Chaos game representation (CGR) is an iterative mapping technique that processes sequences of units, such as nucleotides in a DNA sequence or amino acids in a protein, in order to determine the coordinates of their positions in a continuous space. This distribution of positions has two features: one is unique, and the other is source sequence that can be recovered from the coordinates so that the distance between positions may serve as a measure of similarity between the corresponding sequences. A CGR-walk model is proposed based on CGR coordinates for the DNA sequences. The CGR coordinates are converted into a time series, and a long-memory ARFIMA (p, d, q) model, where ARFIMA stands for autoregressive fractionally integrated moving average, is introduced into the DNA sequence analysis. This model is applied to simulating real CGR-walk sequence data of ten genomic sequences. Remarkably long-range correlations are uncovered in the data, and the results from these models are reasonably fitted with those from the ARFIMA (p, d, q) model. 展开更多
关键词 CGR-walk model dNA sequence LONG-MEMORY ARFIMA(p d q model
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基于d-q理论的双馈异步电机定子匝间短路故障诊断方法
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作者 秦嘉翼 周锦晗 +3 位作者 王喜莲 耿民 李志国 张川宝 《北京交通大学学报》 CAS CSCD 北大核心 2024年第2期185-192,共8页
为实现双馈异步电机定子绕组匝间短路的早期故障诊断,提出一种基于转子电流特征频率分量的故障诊断方法 .首先,通过分析故障后电机的电磁特性,得到故障后转子电流中会产生特征频率分量的结论 .然后,通过对转子单相电流进行特殊的相移构... 为实现双馈异步电机定子绕组匝间短路的早期故障诊断,提出一种基于转子电流特征频率分量的故障诊断方法 .首先,通过分析故障后电机的电磁特性,得到故障后转子电流中会产生特征频率分量的结论 .然后,通过对转子单相电流进行特殊的相移构造出三相电流,并对该组电流进行d-q变换,利用理论推导证明d-q变换后的直流分量幅值能够反映特征谐波的大小,将直流分量作为故障特征量进行双馈异步电机匝间短路故障的诊断.最后,依据有限元法建立故障前后电机的仿真模型,对不同工况下故障特征量的变化进行研究.结果表明:基于d-q理论提取的故障特征量与定子绕组的短路匝数呈正相关,且在转速变化和电压不平衡时也可有效诊断出匝间短路故障;通过设置合理的故障阈值可实现对双馈异步电机定子绕组匝间短路故障的精确辨识.研究结果可以为电机绕组匝间短路故障诊断提供参考. 展开更多
关键词 双馈异步电机 定子绕组匝间短路 故障诊断 d-q变换理论
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Q355D特厚核电模块用同质复合钢板生产技术分析
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作者 周全 魏茹 《冶金与材料》 2024年第11期41-43,共3页
核电领域生产发展期间,对特厚钢板的需求量不断提升,但板材均匀性、探伤检测、Z向性能等方面存在较高的技术生产难度。为促进核电领域稳步发展,文章以Q355D特厚钢板为研究对象,围绕Q355D特厚核电模块用同质复合钢板生产技术展开深入探究... 核电领域生产发展期间,对特厚钢板的需求量不断提升,但板材均匀性、探伤检测、Z向性能等方面存在较高的技术生产难度。为促进核电领域稳步发展,文章以Q355D特厚钢板为研究对象,围绕Q355D特厚核电模块用同质复合钢板生产技术展开深入探究,指出核心生产技术要点。研究结果表明,通过运用连铸坯真空复合轧制生产技术,可得到高品质的Q355D特厚钢板,符合核电模块用钢要求,有助于创造更大的生产效益、核电效益。 展开更多
关键词 q355d钢材 特厚 核电模块 生产技术
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QSAR of Estrogen of Bisphenol A with 3D Vector of Atomic Property Correlation 被引量:2
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作者 CHEN Zhi-Tao ZHOU Peng +1 位作者 HE Liu LI Zhi-Liang 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第8期988-994,共7页
Considering atomic property vector and atomic correlative function, the 3-dimensional structural vector of atomic property correlation (3D-VAPC), a novel descriptor,is defined to characterize a 3-dimensional molecul... Considering atomic property vector and atomic correlative function, the 3-dimensional structural vector of atomic property correlation (3D-VAPC), a novel descriptor,is defined to characterize a 3-dimensional molecular structure by introducing self-adaptability regulation mechanism and the idea of orientating to customers. Characterizing the structures of 25 bisphenol A compounds by this vector, the QSAR models of three kinds of estrogen activities (ER affinities, gene induction and cell proliferation) have high multiple correlation coefficient (Rcum^2=0.933, 0.813, 0.959) and cross verification coefficient (Qcum^2=0.847, 0.953, 0.798) by support vector machine (SVM), which suits for nonlinear circumstances. The above results show that the models successfully express the correlation between structure and three kinds of estrogen activities. Therefore, 3D-VAPC exactly reflects the molecular structural information and SVM method correctly describes the correlation between information and property of the compounds. 展开更多
关键词 3d vector of atomic property correlation (3d-VAPC) support vector machine (SVM) quantitative structure-activity relationship qSAR) bisphenol A ESTROGEN
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Q690D高强度钢的动态连续冷却转变曲线
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作者 鹿超超 孙雪娇 方金林 《理化检验(物理分册)》 CAS 2024年第4期12-16,共5页
在热模拟试验机上对Q690D高强度钢进行不同冷却速率的热模拟试验,绘制动态连续冷却转变曲线,用光学显微镜观察该钢的显微组织,用维氏硬度计测试其维氏硬度。结果表明:当冷却速率小于0.1℃/s时,Q690D高强度钢的组织基本为珠光体、铁素体... 在热模拟试验机上对Q690D高强度钢进行不同冷却速率的热模拟试验,绘制动态连续冷却转变曲线,用光学显微镜观察该钢的显微组织,用维氏硬度计测试其维氏硬度。结果表明:当冷却速率小于0.1℃/s时,Q690D高强度钢的组织基本为珠光体、铁素体和少量贝氏体;当冷却速率为0.5℃/s时,珠光体消失,组织全部为贝氏体;当冷却速率为3℃/s时,组织中出现马氏体;当冷却速率增大至8℃/s时,贝氏体几乎全部消失,基体组织基本为马氏体;当冷却速率大于10℃/s时,组织全部为马氏体,得到马氏体临界转变冷却速率为10℃/s。 展开更多
关键词 q690d高强度钢 连续冷却转变曲线 热模拟 显微组织
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探针D13S319和D13S25检测慢性淋巴细胞白血病13q14缺失 被引量:8
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作者 李丽 徐卫 +3 位作者 仇海荣 程月新 张苏江 李建勇 《中国实验血液学杂志》 CAS CSCD 2007年第2期229-232,共4页
为了探讨慢性淋巴细胞白血病(CLL)中13q14的缺失情况,采用SpectrumOrangeTM直接标记的位于13q14的序列特异性DNA探针D13S319、D13S25和应用间期荧光原位杂交(I-FISH)技术检测24例CLL患者13q14缺失[del(13q14)]情况。结果显示:24例CLL中... 为了探讨慢性淋巴细胞白血病(CLL)中13q14的缺失情况,采用SpectrumOrangeTM直接标记的位于13q14的序列特异性DNA探针D13S319、D13S25和应用间期荧光原位杂交(I-FISH)技术检测24例CLL患者13q14缺失[del(13q14)]情况。结果显示:24例CLL中用D13S319探针检测,del(13q14)异常10例(41.7%);用D13S25探针检测,del(13q14)异常11例(45.8%),两个位点同时存在del(13q14)异常者9例(37.5%)。del(13q14)在不同的Binet分期中分别为A期4/7(57.1%),B期3/7(42.9%),C期5/10(50%),在各组间无显著性差异(P>0.05)。结论:CLL患者13q14缺失区域可能位于D13S319和D13S25之间,FISH是一种检测del(13q14)异常快速而准确的方法。 展开更多
关键词 慢性淋巴细胞白血病 d13S319~ d13525探针 13q14缺失 间期荧光原位杂交
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基于d-q坐标的谐波与无功电流检测方法及仿真分析 被引量:9
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作者 李增国 丁祖军 梅军 《电力自动化设备》 EI CSCD 北大核心 2009年第11期71-73,86,共4页
通过对abc三相坐标进行d-q坐标变换的方法,提出了一种新型的基于d-q坐标变换的谐波与无功电流的检测方法。该方法通过对三相电压与电流进行d-q变换后对相应的分量进行分离的方法实现对谐波与无功电流的检测。详细地说明了基于d-q坐标变... 通过对abc三相坐标进行d-q坐标变换的方法,提出了一种新型的基于d-q坐标变换的谐波与无功电流的检测方法。该方法通过对三相电压与电流进行d-q变换后对相应的分量进行分离的方法实现对谐波与无功电流的检测。详细地说明了基于d-q坐标变换的谐波与无功电流检测算法的流程,给出了具体的框图并其特点进行了总结;同时利用PSCAD/EMTDC软件对基于d-q坐标变换的谐波与无功电流检测方法进行仿真分析。仿真结果表明,所提方法可以准确及时地实现电网中谐波与无功电流的检测。 展开更多
关键词 有源电力滤波器 d-q变换 无功电流检测 谐波电流检测 PSCAd仿真
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不同卷取温度对Q550D组织性能的影响
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作者 邢天庆 《河北冶金》 2024年第3期19-22,共4页
通过对不同卷取温度工艺参数下生产的6.0 mm规格Q550D热卷进行热轧组织性能对比,分析了卷取温度对Q550D热轧组织性能的影响。结果表明,在相同的化学成分、加热制度、层流冷却模式下,采用较高的卷取温度620℃时,可获得铁素体+珠光体的组... 通过对不同卷取温度工艺参数下生产的6.0 mm规格Q550D热卷进行热轧组织性能对比,分析了卷取温度对Q550D热轧组织性能的影响。结果表明,在相同的化学成分、加热制度、层流冷却模式下,采用较高的卷取温度620℃时,可获得铁素体+珠光体的组织,平均粒径4.98μm,晶粒度12级,钢的抗拉强度为683 MPa,冲击功为62.7 J,均为最低值,但延伸率为24%,塑性最高;随着卷取温度的降低,组织中开始产生细小弥散的贝氏体,使得钢具有更好的抗拉强度、低温冲击韧性,但塑性有所下降;当卷取温度降到300℃时,组织为铁素体、贝氏体和少量的M/A岛,平均粒径约5.58μm,晶粒度12级,钢的抗拉强度为731 MPa,冲击功为106.4 J,塑性明显降低,断后延伸率低于国标下限。实际生产Q550D的过程中,应在保持钢板较高晶粒度的前提下,控制珠光体或贝氏体组织的析出,以满足Q550D综合性能的要求,过低的卷取温度不利于钢板综合性能的控制。 展开更多
关键词 卷取温度 q550d 贝氏体 层流冷却 冲击功
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1700 MPa级超高强钢和Q550D高强钢异种接头组织性能研究
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作者 刘春柏 周明文 +2 位作者 刘敏 赵醍 吕绪腾 《机械制造文摘(焊接分册)》 2024年第2期13-18,共6页
通过采用MAG熔焊方法并选择合适的高强钢焊丝,进行1700 MPa级超高强钢和Q550D高强钢板的异种焊接,得出了最佳焊接工艺参数,并对焊接机头进行了组织及力学性能试验。结果表明,异种焊缝组织主要由羽毛状的下贝氏体组成,在焊态焊缝组织中... 通过采用MAG熔焊方法并选择合适的高强钢焊丝,进行1700 MPa级超高强钢和Q550D高强钢板的异种焊接,得出了最佳焊接工艺参数,并对焊接机头进行了组织及力学性能试验。结果表明,异种焊缝组织主要由羽毛状的下贝氏体组成,在焊态焊缝组织中没有发现马氏体组织;而在1700 MPa级超高强钢的熔合线附近一侧,发现大量沿熔合线垂直生长的板条马氏体组织;力学性能测试表明,焊接接头性能满足生产使用要求,为超高强钢的应用提供了试验依据。 展开更多
关键词 1700 MPa级超高强钢 q550d高强钢 MAG焊 组织性能
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Chaos game representation walk model for the protein sequences 被引量:3
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作者 高洁 蒋丽丽 徐振源 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第10期4571-4579,共9页
A new chaos game representation of protein sequences based on the detailed hydrophobic-hydrophilic (HP) model has been proposed by Yu et al (Physica A 337(2004) 171). A CGR-walk model is proposed based on the ne... A new chaos game representation of protein sequences based on the detailed hydrophobic-hydrophilic (HP) model has been proposed by Yu et al (Physica A 337(2004) 171). A CGR-walk model is proposed based on the new CGR coordinates for the protein sequences from complete genomes in the present paper. The new CCR coordinates based on the detailed HP model are converted into a time series, and a long-memory ARFIMA(p, d, q) model is introduced into the protein sequence analysis. This model is applied to simulating real CCR-walk sequence data of twelve protein sequences. Remarkably long-range correlations are uncovered in the data and the results obtained from these models are reasonably consistent with those available from the ARFIMA(p, d, q) model. 展开更多
关键词 chaos game representation CGR-walk model protein sequence long-memory ARFIMA(p d q model autocorrelation function
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