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Journal of Iron and Steel Research International 2020年第5期27卷 608-616页

作者： Jin-long Lu Guo-guang Cheng meng Wu Guo Yang Ju-long Che State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Research and Development Department Xining Special Steel Co.Ltd.Xining 810005QinghaiChina

An unqualifed six-cylinder heavy truck crankshaft has been studied to investigate the cause of magnetic particle testing defects on the rod ***-sized long-striped MnS inclusions are regarded as the major cause for the magnetic particle testing failure because they have been detected in situ under the magnetic particle *** the observation of macroscopic structures of the rod journals and corresponding counterweight blocks,it is found that for the 1#and 3#rod journals,the center metal of the original hot-rolled bar has been extruded to the inboard edge of the rod journals and large-sized long-striped MnS inclusions are exposed on the surface after fash removal,leading to the failure of magnetic particle *** for the 2#rod journal,the center metal of the original bar has not been extruded to the surface and MnS inclusions on the rod journal surface are small in size,few in number,resulting in passing the magnetic particle *** the quality of the hot-rolled bars fuctuates,it is more recommended to apply magnetic particle testing on samples at the center of bars before forging to evaluate the severity of defects caused by the long-striped MnS inclusions for fear of the scrap of the fnal crankshafts.

关键词： Crankshaft Magnetic particle testing MnS inclusion Microalloyed medium-carbon forging steel Defect

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基于弹道模型的磁测系统偏航干扰误差分析

导航定位与授时 2020年第2期7卷 78-82页

作者：朱孟龙高丽珍吕辰张莺莺张晓明刘俊中北大学电子测试技术国家重点实验室太原030051 中北大学仪器科学与动态测试教育部重点实验室太原030051

常规弹丸在使用地磁算法测量滚转角的过程中,常将偏航角设为0°解算弹丸滚转角。当弹丸在飞行过程中偏航角发生变化时,滚转角解算精度受到一定影响。针对偏航角变化带来的误差与多种因素有关,且规律不清楚。在建立偏航角误差系数的基础... 详细信息

常规弹丸在使用地磁算法测量滚转角的过程中,常将偏航角设为0°解算弹丸滚转角。当弹丸在飞行过程中偏航角发生变化时,滚转角解算精度受到一定影响。针对偏航角变化带来的误差与多种因素有关,且规律不清楚。在建立偏航角误差系数的基础上,使用Matlab软件建立了弹丸在不同偏航角、俯仰角、射向条件下的误差模型。首先建立了横风修正的质点弹道模型,通过蒙特卡罗方法仿真弹丸的轨迹分布,分析了弹载环境下磁测算法的滚转角误差,并验证了误差系数的准确性。通过仿真验证,误差系数可以较准确地表示滚转角误差与偏航角变化之间的关系,误差系数计算的误差与理论误差的差值小于10%,为后续实弹试验做好理论准备。

关键词：地磁算法弹丸滚转角弹道建模误差系数

On the fairness of the main galaxy sample of SDSS

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Research in Astronomy and Astrophysics 2011年第6期11卷 655-670页

作者： Ke-Lai meng Bin Ma Jun Pan long-long Feng Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008China National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China

Flux-limited and volume-limited galaxy samples are constructed from the Sloan Digital Sky Survey（SDSS）data releases DR4,DR6 and DR7 for statistical *** two-point correlation functionsξ（s）,monopole of three-point correlation functionsζ0,projected two-point correlation function wp and pairwise velocity dispersionσ12 are measured to test if galaxy samples are fair for these *** find that with the increment of sky coverage of subsequent data releases in SDSS, ξ（s）of the flux-limited sample is extremely robust and insensitive to local structures at low ***,for volume-limited samples fainter than L＊ at large scales s～10 h-1 Mpc,the deviation of ξ（s）from different SDSS data releases（DR7,DR6 and DR4）increases with the increment of absolute *** case of ζ0（s）is similar to that ofξ（s）.In the weakly nonlinear regime,there is no agreement between ζ0 of different data releases in all luminosity ***,wp of volume-limited samples of DR7 in luminosity bins fainter than -Mr,0.1=[18.5,19.5]are significantly larger and σ12 of the two faintest volume-limited samples of DR7 display a very different scale dependence than results from DR4 and *** findings call for caution in understanding clustering analysis results of SDSS faint galaxy samples and higher order statistics of SDSS volume-limited samples in the weakly nonlinear *** first zero-crossing points of ξ（s）from volume-limited samples are also investigated and discussed.

关键词： galaxies:distances and redshifts-galaxies:statistics-cosmology:observation-cosmology:large-scale structure

Direct and rapid detection of serum amino acid and monoamine neurotransmitters to assist the diagnosis of panic disorder

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Science China Chemistry 2025年第01期 377-384页

作者： Shiwen Liu Xuerui Wan meng Zhao Jiaqi Wang Weilan Wu Linlin You Yonggui Yuan Qian Xu Rong Gao Key Laboratory of Environmental Medicine Engineering Ministry of Education School of Public Health Southeast University Key Laboratory of Modern Toxicology of Ministry of Education Department of Hygienic Analysis and Detection School of Public HealthNanjing Medical University Department of Psychosomatics and Psychiatry Zhongda Hospital School of Medicine Southeast University

The measurement of amino acid and monoamine neurotransmitters（NTs） in serum plays a central role in the identification and monitoring of clinical panic disorder（PD）. However, the strong polarity and chemical heterogeneity of NTs make direct extraction and rapid detection extremely challenging. Herein, we developed a strategy that integrated solid phase extraction based on magnetic Fe3O4coated with polydopamine（Fe3O4@PDA） and direct analysis of mass spectrometry in real time（DART-MS） for quantification of 10 NTs. We systematically investigated the optimal conditions of this strategy to achieve good accuracy and precision. Compared with existing magnetic solid phase extraction methods for NTs detection in biological samples, this strategy could adsorb more targets while having similar adsorption efficiencies, and the total process time was reduced by an average of 69.42%. We rapidly determined the metabolic abnormality of 6 types of NTs in the serum of PD patients and demonstrated their diagnostic accuracy. In addition, an outstanding feature of PD in which tryptophan was more metabolized by the KYN pathway and the 5-hydroxytryptamine pathway was inhibited could be elucidated by this strategy. Our results highlighted the potential ability of Fe3O4@PDA coupled with DART-MS to assist in the clinical diagnosis of PD.

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High-performance, low-cost joint equalizer and trellis decoder for 1000BASE-T gigabit Ethernet transceiver

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The Journal of China Universities of Posts and Telecommunications 2007年第2期14卷 106-111页

作者： zhu Yue RONG meng-tian Department of Electronic Engineering School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University Shanghai 200240 China

This article presents an M-algorithm （MA） decoder with 4 survival paths （MA4） for Institute of Electrical and Electronics Engineers （IEEE） 802.3ab 1000BASE-T gigabit Ethernet （GbE） transceiver. To fulfill the entire requirements, various methods were introduced to accelerate the MA4 decoder while retaining the desired high performance and low complexity. Optimized look-ahead architecture was employed to solve the critical path problem with minimal gate consumption. Symbol compression methods saved registers during pipeline stages. A sorting network accelerated the kernel sorting operation at low hardware cost by utilizing the special characteristics of MA4. Simulations and synthesis results show that the proposed decoder achieves 125 MHz clock frequency and l Gb/s throughput in 1.8 V 0.18μm standard cell complementary metal-oxide-semiconductor （CMOS） process. It achieves additional 0.4 dB coding gain over 14tap parallel decision feedback decoder （PDFD） with 39% area reduction.

关键词： 1000BASE-T GbE M-algorithm PDFD look-ahead technology

Gridless Variational Bayesian Inference of Line Spectral from Quantized Samples

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China Communications 2021年第10期18卷 77-95页

作者： Jiang zhu Qi Zhang Xiangming meng The Engineering Research Center of Oceanic Sensing Technology and Equipment Ministry of EducationZhoushan 316021China Ocean College Zhejiang UniversityZhoushan 316021China Institute for Physics of Intelligence Graduate School of ScienceThe University of Tokyo7-3-1HongoTokyo 113-0033Japan

Efficient estimation of line spectral from quantized samples is of significant importance in information theory and signal processing,e.g.,channel estimation in energy efficient massive MIMO systems and direction of arrival *** goal of this paper is to recover the line spectral as well as its corresponding parameters including the model order,frequencies and amplitudes from heavily quantized *** this end,we propose an efficient gridless Bayesian algorithm named VALSE-EP,which is a combination of the high resolution and low complexity gridless variational line spectral estimation(VALSE)and expectation propagation(EP).The basic idea of VALSE-EP is to iteratively approximate the challenging quantized model of line spectral estimation as a sequence of simple pseudo unquantized models,where VALSE is ***,to obtain a benchmark of the performance of the proposed algorithm,the Cram′er Rao bound(CRB)is ***,numerical experiments on both synthetic and real data are performed,demonstrating the near CRB performance of the proposed VALSE-EP for line spectral estimation from quantized samples.

关键词： variational Bayesian inference expectation propagation quantization line spectral estimation mmse gridless

A multiscale adaptive framework based on convolutional neural network:Application to fluid catalytic cracking product yield prediction

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Petroleum Science 2024年第4期21卷 2849-2869页

作者： Nan Liu Chun-meng zhu meng-Xuan Zhang Xing-Ying Lan College of Artificial Intelligence China University of Petroleum(Beijing)Beijing102249China State Key Laboratory of Heavy Oil Processing China University of Petroleum(Beijing)Beijing102249China

Since chemical processes are highly non-linear and multiscale,it is vital to deeply mine the multiscale coupling relationships embedded in the massive process data for the prediction and anomaly tracing of crucial process parameters and production *** the integrated method of adaptive signal decomposition combined with time series models could effectively predict process variables,it does have limitations in capturing the high-frequency detail of the operation state when applied to complex chemical *** light of this,a novel Multiscale Multi-radius Multi-step Convolutional Neural Network(Msrt Net)is proposed for mining spatiotemporal multiscale ***,the industrial data from the Fluid Catalytic Cracking(FCC)process decomposition using Complete Ensemble Empirical Mode Decomposition with Adaptive Noise(CEEMDAN)extract the multi-energy scale information of the feature ***,convolution kernels with varying stride and padding structures are established to decouple the long-period operation process information encapsulated within the multi-energy scale ***,a reconciliation network is trained to reconstruct the multiscale prediction results and obtain the final *** Net is initially assessed for its capability to untangle the spatiotemporal multiscale relationships among variables in the Tennessee Eastman Process(TEP).Subsequently,the performance of Msrt Net is evaluated in predicting product yield for a 2.80×10^(6) t/a FCC unit,taking diesel and gasoline yield as *** conclusion,Msrt Net can decouple and effectively extract spatiotemporal multiscale information from chemical process data and achieve a approximately reduction of 30%in prediction error compared to other time-series ***,its robustness and transferability underscore its promising potential for broader applications.

关键词： Fluid catalytic cracking Product yield Data-driven modeling Multiscale prediction Data decomposition Convolution neural network

Asymptotic analysis of a nonlinear stochastic eco-epidemiological system with feedback control

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Applied Mathematics(A Journal of Chinese Universities) 2022年第3期37卷 317-339页

作者： ZHANG Sheng-qiang meng Xin-zhu College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China Business School University of Shanghai for Science and TechnologyShanghai 200093China

This paper proposes a new stochastic eco-epidemiological model with nonlinear incidence rate and feedback ***,we prove that the stochastic system has a unique global positive ***,by constructing a series of appropriate stochastic Lyapunov functions,the asymptotic behaviors around the equilibria of deterministic model are obtained,and we demonstrate that the stochastic system exists a stationary Markov ***,the conditions for persistence in the mean and extinction of the stochastic system are ***,we carry out some numerical simulations with respect to different stochastic parameters to verify our analytical *** obtained results indicate that the stochastic perturbations and feedback controls have crucial effects on the survivability of system.

关键词： stochastic eco-epidemiological model stationary markov process feedback controls asymptotic behavior persistence in the mean

Period Investigation on Two W UMa Binaries HH UMa and V1175 Her

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Research in Astronomy and Astrophysics 2023年第4期23卷 184-193页

作者： Linfeng Chang Liying zhu Fangbin meng Yunnan Observatories Chinese Academy of Sciences(CAS)Kunming 650216China University of Chinese Academy of Sciences Beijing 101408China Key Laboratory of the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China

HH UMa and V1175 Her are two W UMa contact binary systems whose periods were reported as undergoing secular *** this paper,we improved their period analyses with a more extensive database of eclipse timings,finding that both periods show cyclic *** cyclic variation could be attributed to a Light Travel Time Effect induced by a third *** circular orbit and eccentric orbit cases were *** HH UMa,the cyclic variation with a period of around 20 yr has been detected,which may be caused by a third body with the mass larger than 0.23 M_(⊙).However,no parabolic variation was detected in its O−C curve,implying the balance of the mass transfer between the two components and the angular momentum loss from the binary *** to V1175 Her,a long-term period increase superposed on a periodic oscillation was *** period increase with a rate of about dP/dt=2×10^(-7)day yr^(−1)indicates the mass transfer from the less massive component to its *** cyclic variation of about 7.5 yr could be caused by a hierarchical third body with a minimal mass exceeding 0.46M_(⊙)orbiting around the central *** mass is larger than that of the less massive component of the binary,which means that the secondary component was not replaced by the third body during early stellar interactions,implying that it keeps original dynamical *** removing angular momentum from the central binary system,the tertiary component has played a significant role in the formation of contact binaries.

关键词： (stars:)binaries eclipsing-(stars:)binaries(including multiple) close-stars late-type

Serum microRNA-221 as a biomarker for diabetic retinopathy in patients associated with type 2 diabetes

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International Journal of Ophthalmology(English edition) 2018年第12期11卷 1889-1894页

作者： He-Nan Liu Xun Li Na Wu meng-meng Tong Shuo Chen Shan-Shan zhu Wei Qian Xiao-long Chen Department of Ophthalmology Shengjing Hospital China Medical University Department of Endocrinology Shengjing Hospital China Medical University Sino-Dutch Biomedical and Information Engineering School Northeastern University Department of Electrical and Computer Engineering College of Engineering University of Texas at El Paso

AIM: To investigate the candidate microRNA(miRNA), miR-221 as a novel biomarker for diabetic retinopathy(DR) in patients associated with type 2 diabetes(T2D).METHODS: The subjects involved were divided into four groups: healthy control(HC), no diabetic retinopathy(NDR), non-proliferative diabetic retinopathy(NPDR) and proliferative diabetic retinopathy(PDR) group. Serum miR-221 was validated by real-time quantitative reversetranscription polymerase chain reaction(qRT-PCR). Also, serum angiotensin II(Ang II) and vascular endothelial growth factor(VEGF) were examined by enzyme-linked immunosorbent assay. In addition, receiver operating characteristic(ROC) curve was performed to explore the diagnostic accuracy of miR-221, Ang Ⅱ and VEGF for DR in patients with T2D. Spearman’s rank correlation coefficient was executed to estimate the correlations of serum miR-221 with metabolic parameters and serum markers in patients with ***: Primarily, serum miR-221, Ang Ⅱ and VEGF were increased significantly in T2D patients compared to HC participant respectively, and progressive up-regulated in NDR, NPDR and PDR groups(P<0.001). Additionally, miR-221 in serum was remarkably positively correlatedwith metabolic parameters such as glycated hemoglobin(r=0.310, P=0.002) and homeostasis model assessment for insulin resistance(r=0.413, P<0.001), as well as serum markers for instance Ang Ⅱ(r=0.667, P<0.001) and VEGF(r=0.499, P<0.001). Furthermore, serum miR-221(AUC, 0.894; 95%CI, 0.833-0.955; P<0.001), Ang Ⅱ(AUC, 0.888; 95%CI, 0.828-0.949; P<0.001) and VEGF(AUC, 0.785; 95%CI, 0.695-0.875; P<0.001) had evidently diagnostic efficiency in DR, and miR-221 is the most effective among ***: Serum miR-221 as a potential biomarker could be related to not only occurrence but also progression for DR in patients with T2D. However, a prospective clinical trial is warranted.

关键词： microRNA-221 biomarker diabetic retinopathy type 2 diabetes