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Machine learning seismic reservoir prediction method based on virtual sample generation

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Petroleum Science 2021年第6期18卷 1662-1674页

作者： Kai-Heng Sang Xing-Yao Yin fan-chang Zhang School of Geosciences China University of Petroleum(East China)QingdaoShandong 266580China

Seismic reservoir prediction plays an important role in oil exploration and *** the progress of artificial intelligence,many achievements have been made in machine learning seismic reservoir ***,due to the factors such as economic cost,exploration maturity,and technical limitations,it is often difficult to obtain a large number of training samples for machine *** this case,the prediction accuracy cannot meet the *** overcome this shortcoming,we develop a new machine learning reservoir prediction method based on virtual sample *** this method,the virtual samples,which are generated in a high-dimensional hypersphere space,are more consistent with the original data ***,at the stage of model building after virtual sample generation,virtual samples screening and model iterative optimization are used to eliminate noise samples and ensure the rationality of virtual *** proposed method has been applied to standard function data and real seismic *** results show that this method can improve the prediction accuracy of machine learning significantly.

关键词： Virtual sample Machine learning Reservoir prediction Hypersphere characteristic equation

Determination of toluene diisocyanate in synthetic-rubber track by ion chromatography with ultraviolet detection after alkaline suppressor

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Chinese Chemical Letters 2009年第2期20卷 207-209页

作者： Mei Lan Chen Yun chang fan chang An Li Dong Fei Yan Zhu Biology and Environment College of Zhejiang Shuren University Hangzhou 310015 China Department of Chemistry Xixi Campus Zhejiang University Hangzhou 310028 China School of Economics and Management Zhejiang University of Science and Technology Hangzhou 310023 China Department of Material and Chemical Engineering Guilin University of Technology Guilin 541004 China

In the present work, a novel analytical method was proposed for the determination of toluene diisocyanate （TDI） in syntheticrubber track by ion chromatography （IC） coupled with an ultraviolet detector setting at 212 nm. TDI can be hydrolyzed to toluene diamine （TDA） which can be separated by cation-exchange IC easily. The optimum IC separation was performed on an IonPac CS12A column （150 mm ×4.0 mm） using 20 mmol L^-1 sodium sulfate, 10 mmol L^-1 sulfuric acid and 10% acetonitrile as eluent. It was found that a higher signal response of TDA could be obtained under alkaline condition. A suppressor was used to change the acidic eluent into alkaline one. 0.8 mol L^-1 potassium hydroxide was chosen as the optimum regeneration eluent. With the added suppressor and regenerant, signal response was magnified by about 16 times and lower limit of detection （LOD, 0.13 μg L^-1） was obtained. Within-day relative standard deviation （R.S.D.） was less than 3.6%. The recoveries of TDI spiked in synthetic-rubber track samoles were 96.4-110.6%.

关键词： Ion chromatography (IC) Ultraviolet detection Toluene diisocyanate (TDI)

Position-varying surface roughness prediction method considering compensated acceleration in milling of thin-walled workpiece

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Frontiers of Mechanical Engineering 2021年第4期16卷 855-867页

作者： Zequan YAO chang fan Zhao ZHANG Dinghua ZHANG Ming LUO Key Laboratory of High Performance Manufacturing for Aero Engine(Ministry of Industry and Information Technology) Northwestern Polytechnical UniversityXi'an 710072China Engineering Research Center of Advanced Manufacturing Technology for Aero Engine(Ministry of Education) Northwestern Polytechnical UniversityXi'an 710072China

Machined surface roughness will affect parts?service ***,predicting it in the machining is important to avoid *** roughness will be affected by system position dependent vibration even under constant parameter with certain toolpath processing in the *** at surface roughness prediction in the machining process,this paper proposes a position-varying surface roughness prediction method based on compensated acceleration by using regression *** reduce the stochastic error of measuring the machined surface profile height,the surface area is repeatedly measured three times,and Pauta criterion is adopted to eliminate abnormal *** actual vibration state at any processing position is obtained through the single-point monitoring acceleration compensation *** acceleration features are extracted,and valley,which has the highest/^-square proving the effectiveness of the filtering features,is selected as the input of the prediction model by mutual information ***,by comparing the measured and predicted surface roughness curves,they have the same trends,with the average error of 16.28%and the minimum error of 0.16%.Moreover,the prediction curve matches and agrees well with the actual surface state,which verifies the accuracy and reliability of the model.

关键词： surface roughness prediction compensated acceleration milling thin-walled workpiece

Improvement of Electronic Line-shafting Control in Multi-axis Systems

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International Journal of Automation and computing 2018年第4期15卷 474-481页

作者： chang-fan Zhang Yuan-Yuan Xiao Jing He Min Yan College of Electrical and Information Engineering Hunan University of Technology College of Mechatronic Engineering and Automation National University of Defense Technology

Electronic line-shafting （ELS） is the most popular control strategy for printing machines with shaftless drives. A sliding-mode controller for tracking control is designed in this study as the first step towards an improved ELS control scheme. This controller can eliminate the negative effects on synchronization precision resulting from the friction at low speed present in the pre-registration step of a shaftless driven printing machine. Moreover, it can eliminate the synchronization error of the printing process resulting from nonlinearities and load disturbances. Based on observer techniques, the unknown components of load torque and system parameter variations are estimated. On this basis, a novel ELS control method using equivalent load-torque observers is proposed. Experimental results demonstrate the effectiveness of the proposed control system for four-axis position control.

关键词： Shaftless drive sliding-mode controller nonlinearity observer synchronization position control multi-axis system

A compensation circuit for the gain temperature drift of silicon photomultiplier tube

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Radiation Detection Technology and Methods 2023年第4期7卷 571-577页

作者： chang-ge Zi Jin-fan chang Ming-jie Yang Feng-fan Yang Yu-Sheng Wang Institute of High Energy Physics Chinese Academy of SciencesBeijing100049China University of Chinese Academy of Sciences Beijing100049China State Key Laboratory of Particle Detection and Electronics of China Beijing100049China Key Laboratory of Particle Astrophysics&Experimental Physics Division&Computing Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing100049China TIANFU Cosmic Ray Research Center Chengdu610213SichuanChina

Background Silicon photomultiplier tube(SiPM)has been widely applied in high energy physics *** wide field of view Cherenkov telescope array of Large High Altitude Air Shower Observatory(LHAASO)consists of 12 arrays of *** of the array includes 32*32 *** Array of imaging atmospheric Cherenkov Telescopes(LACT),the next generation of particle astrophysics experiment,will also adopt SiPM *** LACT will located at a high altitude,leading to a significant operating temperature variation of the *** the gain of SiPM is temperature-sensitive,in order to keep it stable,compensation for the gain is necessary by adjusting the bias voltage of *** The compensation circuit provides the bias voltage of SiPM by using a high-voltage output Digital-to-Analog Converter and several high-voltage output *** reduce the temperature drift of the gain,the compensation circuit adjust the bias voltage of SiPM according to the operating *** The compensation circuit supplies SiPM with an adjustable bias voltage from 0 to 80 V,and the adjustment step is 1.22 *** the output voltage of the compensation circuit is 64 V,the voltage ripple is 2.59 mV,and the temperature drift is 0.17 mV/℃.In the temperature range from−20 to 30℃,the compensation circuit reduces the gain temperature drift of SiPM to within 2%.

关键词： SiPM Gain Compensation LACT

Simultaneous denoising and resolution enhancement of seismic data based on elastic convolution dictionary learning

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Petroleum Science 2023年第4期20卷 2127-2140页

作者： Nan-Ying Lan fan-chang Zhang Kai-Heng Sang Xing-Yao Yin School of Geosciences China University of Petroleum(East China)QingdaoShandong266580China

Enhancing seismic resolution is a key component in seismic data processing, which plays a valuable role in raising the prospecting accuracy of oil reservoirs. However, in noisy situations, existing resolution enhancement methods are difficult to yield satisfactory processing outcomes for reservoir characterization. To solve this problem, we develop a new approach for simultaneous denoising and resolution enhancement of seismic data based on convolution dictionary learning. First, an elastic convolution dictionary learning algorithm is presented to efficiently learn a convolution dictionary with stronger representation capability from the noisy data to be processed. Specifically, the algorithm introduces the elastic L1/2 norm as a sparsity constraint and employs a steepest gradient descent strategy to efficiently solve the frequency-domain linear system with substantial computational cost in a half-quadratic splitting framework. Then, based on the learned convolution dictionary, a weighted convolutional sparse representation paradigm is designed to encode the noisy data to acquire an optimal sparse approximation of the effective signal. Subsequently, a high-resolution dictionary with a broadband spectrum is constructed by the proposed parameter scaling strategy and matched filtering technique on the basis of atomic spectrum modeling. Finally, the optimal sparse approximation of the effective signal and the constructed high-resolution dictionary are used for data reconstruction to obtain the seismic signal with high resolution and high signal-to-noise ratio. Synthetic and field dataset examples are executed to check the effectiveness and reliability of the developed method. The results indicate that this method has a more competitive performance in seismic applications compared with the conventional deconvolution and spectral whitening methods.

关键词： Simultaneous denoising and resolution enhancement Elastic convolution dictionary learning Weighted convolutional sparse representation Matched filtering

Carbon and oxygen isotopic constraints on paleoclimate and paleoelevation of the southwestern Qaidam basin, northern Tibetan Plateau

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Geoscience Frontiers 2017年第5期8卷 1175-1186页

作者： Lin-Lin Li Chao-Dong Wu chang-Fu fan Ji-Jun Li chang-Hao Zhang Key Laboratory of Crustal Dynamics Institute of Crustal DynamicsChina Earthquake AdministrationBeijing 100085China Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of EducationSchool of Earth and Space SciencesPeking UniversityBeijing 100871China Institute of Oil&Gas Peking UniversityBeijing 100871China MLR Key Laboratory of Metallogeny and Mineral Resource Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China No.1 Oil Producing Plant of PetroChina Qinghai Oilfield Company Dunhuang 736202China Exploration Department PetroChina Qinghai Oilfield CompanyDunhuang 736202China

We investigate the growth of the northern Tibetan Plateau and associated climate change by applying oxygen and carbon isotopic compositions in Cenozoic strata in the southwestern Qaidam basin. The X-ray diffraction and isotopic studies reveal that the carbonate minerals are mainly authigenic and they do not preserve any evidence for detrital carbonate and diagenesis. The isotope data show large fluctuations in the δ^(18)O and δ^(13)C values in the middle-late Eocene, indicating relatively warm and seasonal dry *** positive correlation of the δ^(18)O and δ^(13)C values in the Oligocene and the positive shift of the δ^(13)C values from the Eocene to Oligocene suggest that the climate changed to arid in the Oligocene. However,the δ^(18) values show negative shift, which is closely related to the global cooling event. During the Miocene, the δ^(13)C values vary between-2‰ and-4‰, whereas the δ^(18)O values show continuous negative shift. The mean δ^(18) values decrease from-8.5‰, in the early Miocene to-10.0‰, in the late Miocene. The stable isotope-based paleoaltimetry results suggest that the elevation of the southwestern Qaidam basin was approximately 1500 m in the middle-late Eocene and Oligocene. Subsequently, during Miocene the crustal uplift process started and the elevation reached approximately 2000 m in the early Miocene and 2500 m in the late Miocene, which suggests large-scale growth of the northern Tibet Plateau during the Miocene.

关键词： Carbon and oxygen isotopes Northern Tibetan Plateau Qaidam basin Paleoelevation

The catassembled generation of naphthalene diimide coordination networks with lone pair-π interactions

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Science China Chemistry 2016年第11期59卷 1492-1497页

作者： Yong Chen Jian-Jun Liu chang-Rong fan Jun-Qian Li Mei-Jin Lin College of Chemistry Fuzhou University State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences

Catassembly is a new concept in molecular assembly that is analogous to catalysis in chemical synthesis. However, for most molecular-assembled processes, the catassembler contributions are rather inconspicuous due to the low activation barriers. As a result, few systems dealing with the catassembly are available until now. In this paper, we report that naphthalene diimide coordination networks are formed under the catassembly of lone-pair-bearing catassemblers(e.g., N,N-dimethylacetamide, N-methylpyrrolidin-2-one). During such molecular assembly, a stable transition state between the electron-deficient naphthalene diimide tectons and catassemblers via the less common lone pair-π interactions was observed, which is supposed to play the key role in the enhancement of coordination abilities of organic tectons and thus formation of the final coordination networks.

关键词： catassembly coordination network naphthalene diimide lone pair-π interaction

Determination of inorganic anions in ethyl acetate by in-line hollow fiber membrane extraction with ion chromatography

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Chinese Chemical Letters 2009年第12期20卷 1498-1501页

作者： Zhen Zhen Hu Ying Ying Zhong Yun chang fan Yan Zhu Department of Chemistry Xixi Campus Zhejiang University Hangzhou 310028 China

In this work, a novel hollow fiber membrane extractor was set up to extract inorganic anions from ethyl acetate using deionized water. Inorganic anions in slightly soluble organic solvents can be determined by the in-line hollow fiber membrane extractor coupled with ion chromatography at first time. Different aspects of the extraction procedure such as magnetic stirring speed, extraction flow rate and extraction time were optimized to achieve high extraction efficiency and good separation results. Satisfactory linear range, limits of detection and good repeatability were obtained. The procedure was applied to analyze inorganic anions in two commercial ethyl acetate samples.

关键词： Inorganic anions Ethyl acetate In-line hollow fiber membrane extraction Ion chromatography