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Application of Feedforward and Feedback Control Strategy for Wire Rod Hot Rolling Line

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Journal of Iron and Steel Research International 2005年第5期12卷 21-23页

作者： ZHU Hong-xiang HAO Xiao-hong WEN Zhia HU ze-qiang ZHANG Yao-gen chen Hu-qiu University of Science and Technology Beijing Beijing 100083 China Baoshan Iron and Steel Co Ltd Shanghai 201900 China

The feedforward and feedback control strategy of water flowrate based on the analysis of thermal process in water cooling box was proposed, and the control strategy was applied to wire rod hot rolling at Baosteel Co. The operation has proved that the strategy can control water flowrate in the cooling water box reasonably to ensure the temperature requirement of the wire discharged from the cooling water box.

关键词： wire feedforward feedback controlled cooling

Twelve-year outcomes after revascularization for ostial/shaft lesions in unprotected left main coronary artery

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Journal of Geriatric Cardiology 2020年第6期17卷 338-343页

作者： Xian-Peng YU Yu LI Ji-qiang HE ze-Ning JIN Department of Cardiology Beijing Anzhen HospitalCapital Medical UniversityBeijingChina Department of Cardiology and Macrovascular Disease Beijing Tiantan HospitalCapital Medical UniversityBeijingChina

Objective To evaluate a very long-term clinical outcomes of patients treated with coronary artery bypass grafting(CABG) and percutaneous coronary intervention(PCI) with drug-eluting stents(DES) for ostial/shaft lesions in unprotected left main coronary artery(ULMCA). Methods & Results A total of 472 patients with isolated ostial/shaft lesions in ULMCA were enrolled, who received DES implantation or underwent CABG between January 2003 and July 2009 in Beijing Anzhen Hospital. The major endpoints of this study were death, repeat revascularization, non-procedural myocardial infarction(MI) and stroke. The median follow-up was twelve years(interquartile range: 9.4–14.0 years) in the overall patients. There were no significant differences of incidence of death(23.3% vs. 25.6%, P = 0.227), repeat revascularization(27.3% vs. 28.4%, P = 0.423), non-procedural MI(20.0% vs. 14.5%, P = 0.561), and stroke(6.1% vs. 9.3%, P = 0.255) between PCI and CABG groups before multivariate adjusting. After adjusting covariates with multivariate Cox hazard regression model, there were still no significant differences between PCI and CABG groups. Conclusions During the median follow-up of twelve years, we found that PCI with DES was as effective and safe as CABG in patients with left main ostial/shaft lesion in this observational study.

关键词： Coronary artery bypass grafting Left main ostial/shaft lesions Percutaneous coronary intervention Prognosis

Diffusion of helium in FCT zircon

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Science China Earth Sciences 2019年第4期62卷 719-732页

作者： Shun YU Wen chen Jingbo SUN ze SHEN Laboratory of Isotope Thermochronology Institute of Geology Chinese Academy of Geological Sciences Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources Institute of GeologyChinese Academy of Geological Sciences

To gain a better quantitative understanding of zircon(U-Th)/He ages and evaluate the applicability of zircon(U-Th)/He dating, the diffusion characteristics, He diffusion kinetics, helium partial retention zone(HePRZ), closure temperature, and(U-Th)/He ages were investigated using high-precision laboratory step heating experiments based on the thermally activated diffusion process. The ln(D/a^2) in Fish Canyon Tuff(FCT) zircons determined from laboratory step heating experiments was negatively correlated with reciprocal temperature, as expected for thermally activated volume diffusion. The zircon activation energies ranged from 144 to 184 kJ mol^(-1) with a mean of 169±12 kJ mol^(-1). The closure temperatures ranged from 144 to 216°C(a cooling rate of 10°C Ma^(-1) and an effective grain radius of 38–60 μm) with an average of 176±18°C. The calculated closure temperature increased with increasing cooling rate, yielding an average zircon He closure temperature of ～136°C at a slow cooling rate of 0.1°C Ma^(-1), whereas the closure value was ～199°C at a cooling rate of 100°C Ma^(-1). The closure temperature increased with the equivalent spherical radius assuming a constant cooling rate. The He ages from FCT zircons were negligibly affected by grain size because of the rapid cooling. He preserved in the zircon was sensitive to temperature and holding time, and the temperature range for zircon HePRZ gradually decreased with increasing holding time. The(U-Th)/He ages from 26 FCT zircons yielded an algorithmic mean of 28.3±0.3 Ma(S.E.) and a geometric mean of 28.4±0.3 Ma(S.E.), consistent with the ages of 28.4±1.9 Ma reported by other laboratories. The FCT zircons were characterized by rapid cooling, young(U-Th)/He ages with good reproducibility, and low alpha doses. Weak correlations between the He ages and effective uranium(eU) concentrations from the FCT zircons indicated radiation damage did not significantly affect He diffusivity.

关键词： Zircon Helium diffusion (U-Th)/He Closure temperature Thermochronometry

Synthesis of magnetic carrier sub-microparticles with high stability through carbon reduction and solation coating methods

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Rare Metals 2016年第11期35卷 870-873页

作者： qiang Zhang Li-Bo Gao Jun-Yang Li ze-Bin Guo Zhen-Yin Hai Yan-Ting Xing chen-Yang Xue National Key Laboratory for Electronic Measurement Technology North University of China Science and Technology on Electronic Test & Measurement Laboratory North University of China

This paper presents a novel approach in synthesizing SiO_2-Fe_3O_4magnetic carrier with high *** Fe_3O_4 magnetic powders were synthesized via onestep method named carbon reduction method. The advantages of the methods are of simple process, none lead-in pollution agent, low cost and adaptation to large-lot production. The stability of the magnetic powders is improved through modifying the Fe_3O_4 with SiO_2 in solation *** results of the characterizations show that the superparamagnetic SiO_2-Fe_3O_4sub-microparticles（~600 nm）with saturation intensity of 36.4 m A·m^2·g^（-1）are obtained successfully. Moreover, the quantitating, repeatability and high stability of the carbon reduction method are demonstrated as well.

关键词： Carbon reduction method Superparamagnetic Fe304-SiO2

Subspace-based identification of discrete time-delay system

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Frontiers of Information Technology & Electronic Engineering 2016年第6期17卷 566-575页

作者： qiang LIU Jia-chen MA School of Astronautics Harbin Institute of Technology School of Information and Electrical Engineering Harbin Institute of Technology

We investigate the identification problems of a class of linear stochastic time-delay systems with unknown delayed states in this study. A time-delay system is expressed as a delay differential equation with a single delay in the state vector. We first derive an equivalent linear time-invariant(LTI) system for the time-delay system using a state augmentation technique. Then a conventional subspace identification method is used to estimate augmented system matrices and Kalman state sequences up to a similarity transformation. To obtain a state-space model for the time-delay system, an alternate convex search(ACS) algorithm is presented to find a similarity transformation that takes the identified augmented system back to a form so that the time-delay system can be recovered. Finally, we reconstruct the Kalman state sequences based on the similarity transformation. The time-delay system matrices under the same state-space basis can be recovered from the Kalman state sequences and input-output data by solving two least squares problems. Numerical examples are to show the effectiveness of the proposed method.

关键词： Identification problems Time-delay systems Subspace identification method Alternate convex search Least squares

Relationship between Coordination Structure and Biological Activity of Copper(II) Nicotinate

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Chinese Journal of Structural Chemistry 2006年第9期25卷 1141-1147页

作者： chen qiang LI Qing-Lu Institute of Animal Science and Technology Agricultural and Forestry University Fuzhou 350002 China Institute of Life Science Key Laboratory of Biological Pesticide and Chemicobiology of Education Ministry Agricultural and Forestry University Fuzhou 350002 China

The copper（Ⅱ） complexes of pyridine-3-carboxylic acid （nicotinic acid） and pyridine-2-carboxylic acid （isonicotinic acid） were synthesized, and their structures were characterized by elemental analysis, infrared spectrum, powder X-ray diffraction and so on. The results show that under experimental conditions, the ligands of synthesized copper nicotinate and copper isonicotinate are coordinated simultaneity with copper（Ⅱ） via the nitrogen of pyridine group and an oxygen of carboxylic acid group to form bidentate chelates. The crystal of copper nicotinate with two six-membered chelate rings belongs to monoclinic system, while that of copper isonicotinate having two five-membered chelate rings is of triclinic system. The tests show that the biological activities, such as the improvement of feed utilization, growth, anti-oxidation ability of organism and disease-resistant power, are different when copper nicotinate, copper inicotinate, copper-lysine chelate, copper-methionine chelate and copper sulphate are added in pig＇s feed, respectively. Due to its higher biological activity, less pollution and lower toxicity, copper nicotinate has wide potential applications as a feed additive.

关键词： pyridine-3-carboxylic acid (copper nicotinate) copper pyridine-2-carboxylic acid (copper isonicotinate) copper coordination structure toxicity growth-promoting enzyme activity

Deciphering fungal metabolon coupling tandem inverse-electrondemand Diels-Alder reaction and semipinacol rearrangement for the biosynthesis of spiro polycyclic alkaloids

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Science China Chemistry 2025年第01期 288-296页

作者： Shuai Liu Wen-qiang Xu Ying-Tong Di Man-cheng Tang Ding-Kang chen Ming-Ming Cao Yao-Wen Chang Hong-Yu Tang Chun-Mao Yuan Jun-Bo Yang Zhi-Li Zuo Han Guo Zi-Fei Xu Ying zeng Yun-Dong Wu Xiao-Jiang Hao Key Laboratory of Phytochemistry and Natural Medicines (Chinese Academy of Sciences) Kunming Institute of Botany Chinese Academy of Sciences University of Chinese Academy of Sciences Lab of Computational Chemistry and Drug Design State Key Laboratory of Chemical Oncogenomics Peking University Shenzhen Graduate School Shenzhen Bay Laboratory State Key Laboratory of Microbial Metabolism School of Life Sciences & Biotechnology Shanghai Jiao Tong University State Key Laboratory of Functions and Applications of Medicinal Plants Guizhou Medical University Molecular Biology Experimental Center Germplasm Bank of Wild Species in Southwest China Kunming Institute of Botany Chinese Academy of Sciences Yunnan Key Laboratory for Wild Plant Resources Kunming Institute of Botany Chinese Academy of Sciences Research Unit of Chemical Biology of Natural Anti-Virus Products Chinese Academy of Medical Sciences

In the intricate process of natural product biosynthesis, a metabolon can enhance metabolic flux by associating sequential enzymes. A fungal metabolon, comprising of flavin-dependent monooxygenase Spe F and P450 monooxygenase Spe G, is identified in the biosynthesis of spiro polycyclic alkaloids(+)-notoamide B and its diastereomer(+)-versicolamide B. Using notoamide E as a substance, Spe F/Spe G metabolon can control the stereoselectivity of its 2,3-epoxidation, followed by hydrogen atom ion at C-17 to generate reactive epoxide tau-m A with dienyl iminium unit. Subsequently,(+)-notoamide B and(+)-versicolamide B are produced via tandem nonenzymatic inverse-electron-demand Diels-Alder reaction and semipinacol rearrangement. This provides the first example of metabolon in the biosynthesis of spiro-prenylated indole alkaloids.

关键词：

同方期刊数据库

A methodology for laser tool setters calibration and its precise mathematical model

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Chinese Journal of Aeronautics 2024年第7期37卷 564-581页

作者： Tao FANG Zixi FANG ze Zhong chen Zhiyong CHANG School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an 710072China Gina Cody School of Engineering and Computer Science Concordia UniversityMontrealQuebec H3G 1M8Canada Changsha Optimum CNC Corporation Changsha 410221China Institute for Aero-engine Smart Assembly of Shaanxi Province Xi’an 710072China

On-machine tool setting is a pivotal approach in achieving intelligent manufacturing,and laser tool setters have become a crucial component of smart machine *** tool setters play a crucial role in precisely measuring the dimensions of cutting tools during the part machining process,focusing on tool length and *** a measuring instrument,the positions of the laser axis of the laser tool setter need to be accurately calibrated before ***,in actual calibration scenarios,traditional calibration methods face challenges due to installation errors in the tool setter and geometric errors in the measuring *** address this issue,this study proposes a novel calibration ***,the calibration mechanism of the laser beam axis is *** on the accurate mathematical model of the laser beam and the measuring rod,and using the polygon clipping algorithm,the mathematical mechanism of the laser tool setter’s work is ***,a novel method is introduced to calculate the compensation distance between the laser beam reference point and the rod bottom center point at each moment during ***,by utilizing the kinematic chain of the tool setter calibration system,a new calibration method is developed to accurately calibrate the position of the laser beam axis in the machine tool coordinate ***,the accuracy of the calibration method is verified through simulation experiments and calibration *** method improves the calibration accuracy of the tool setter,and the mathematical model of the laser tool setter can be extended to the measurement of tools,thereby improving the precision of tool *** research significantly improves the efficient production performance of smart machine tools.

关键词： On-machine tool setting Smart machine tools Mathematical model Calibration method Laser tool sette

Stability analysis for a size-structured model of species in a space-limited habitat

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International Journal of Biomathematics 2016年第6期9卷 241-262页

作者： ze-Rong He qiang-Jun Xie Hai-Tao Wang Institute of Operational Research and Cybernetics Hangzhou Dianzi University Hangzhou 310018 P. R. China

We investigate the stability of steady states of a size- and stage-structured population model, which is a hybrid system of ordinary and partial differential equations with global integral feedbacks. After the formulation of a criterion by spectrum method, we derive conditions for global stability of the trivial state and local stability of the positive equilibrium via the basic reproduction rate. Furthermore, some examples and simulations ure .presented to illustrate the obtained results.

关键词： Space-limitation size-dependence spectrum reproduction number stability.