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Petroleum Science 2022年第5期19卷 2472-2482页

作者： Xue Xia Chuan-Xian Li guang-yu sun Ke-Ke Zhao Jie Zhang Bo Yao Fei Yang College of Pipeline and Civil Engineering China University of PetroleumQingdaoShandong266580PR China Shandong Provincial Key Laboratory of Oil&Gas Storage and Transportation Safety QingdaoShandong266580PR China China Petroleum Engineering&Construction Corp.Beijing Company PR China

Lauramine is widely considered to be an asphaltene flocculant,but its effect on the modification of crude oil by PPDs has been little studied.In this paper,the effect of LA dosage on the rheology improvement of EVA PPDs(100 ppm)on Qinghai waxy crude oil was investigated through rheological measurement,wax precipitating analysis,granularity test and resins/asphaltenes FTIR analysis.Compared with pure EVA,the compounding of LA and EVA obviously enhances the agglomeration degree and reduces the number of fine wax crystals,thus further enhancing the rheology of the oil samples,and the best performance is at the LA dosage of 200 ppm.At relatively small LA dosages,the LA facilitates the adsorption of EVA molecules on the asphaltene surfaces,which favors the becoming of EVA/asphaltenes composite particles;but at relatively high LA dosages,the LA makes the asphaltenes more aggregated and disturbs the EVA adsorption on the asphaltenes,which is adverse for the formation of EVA/asphaltenes compound particles.The compound particles can serve as wax precipitating templates and significantly influence its morphology,thus further improving the crude oil rheology.In consequence,the rheology improvement of EVA PPDs on Qinghai waxy crude oil first increases and then decreases with increasing the LA dosage.

关键词： Waxy crude oil EVA PPD Laurylamine Asphaltenes Synergistic effect

Pre-heating temperature induced flowability and wax deposition characteristics of crude oil adding wax inhibitors

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Petroleum Science 2023年第4期20卷 2468-2478页

作者： Bo Yao Hao-Ran Zhu Bao-Dong Yan Chuan-Xian Li Fei Yang guang-yu sun Hong-Bo Zeng College of Pipeline and Civil Engineering China University of PetroleumQingdaoShandong266580People's Republic of China Department of Chemical and Materials Engineering University of AlbertaEdmontonABT6G 1H9Canada School of Petroleum Engineering Changzhou UniversityChangzhouJiangsu213164People's Republic of China China Oil&Gas Pipeline Network Corporation Beijing100020China

This paper investigated the effects of pre-heating treatment temperatures(T_(pre))on the flowability and wax deposition characteristics of a typical waxy crude oil after adding wax inhibitors.It is found that there is little difference in wax precipitation exothermic characteristics of crude oils at different T_(pre),as well as the wax crystal solubility coefficient in the temperature range of 25-30℃.For the undoped crude oil,the flowability after wax precipitation gets much improved and the wax deposition is alleviated as T_(pre)increasing.At T_(pre)=50℃,the viscosity and wax deposition rate of crude oil adding wax inhibitors are higher than those of the undoped crude oil.When the T_(pre)increases to 60,70,and 80℃,the flowability of the doped crude oil are largely improved and the wax deposition is suppressed with the T_(pre)increase,but the wax content of wax deposit increases gradually.It is speculated that,on the one hand,the T_(pre)increase helps the dispersion of asphaltenes into smaller sizes,which facilitates the co-crystallization with paraffin waxes and generates more aggregated wax crystal flocs.This weakens the low-temperature gel structure and increases the solid concentration required for the crosslink to form the wax deposit.On the other hand,the decrease in viscosity increases the diffusion rate of wax molecules and accelerates the aging of wax deposits.The experimental results have important guiding significance for the pipeline transportation of doped crude oils.

关键词： Pre-heating treatment Wax inhibitor Flowability Wax deposition Waxy crude oil

Co-adsorption behavior of aggregated asphaltenes and silica nanoparticles at oil/water interface and its effect on emulsion stability

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Petroleum Science 2022年第4期19卷 1793-1802页

作者： guang-yu sun Hao Zhang Dai-Wei Liu Chuan-Xian Li Fei Yang Bo Yao Ze Duan Xin-Ya Chen Fu-Jun Sheng College of Pipeline and Civil Engineering China University of Petroleum(East China)Qingdao266580ShandongPeople's Republic of China Shandong Key Laboratory of Oil&Gas Storage and Transportation Safety Qingdao266580ShandongPeople's Republic of China

In petroleum industry, crude oil emulsions are commonly formed in oilfields. The asphaltenes and fine particles in crude oil may affect the stability of the emulsions by adsorbing at the water/oil interface. In this research, the effect of silica nanoparticles and asphaltenes on emulsion stability is explored first. The asphaltenes are proved to benefit emulsion stability. Unlike the asphaltenes, however, the modified silica nanoparticles may have positive or negative effect on emulsion stability, depending on the asphaltene concentration and aggregation degree in the emulsions. Further, it is confirmed by conducting interfacial experiment that the asphaltenes and particles can adsorb at the interface simultaneously and determine the properties of the interfacial layer. More in-depth experiments concerning contact angle and asphaltene adsorption amount on the particles indicate that the asphaltenes can modify the wettability of the particles. Higher concentration and lower aggregation degree of the asphaltenes can increase their adsorption amount on the surface of particles and then improve the modification effectiveness of the particles. Resultantly, the particles with good modification effectiveness can enhance the emulsion stability while the particles with poor modification effectiveness will weaken the emulsion stability.

关键词： Asphaltene Silica nanoparticle Co-adsorption behavior Modification effectiveness Emulsion stability

Area Efficient Pattern Representation of Binary Neural Networks on RRAM

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Journal of Computer Science & Technology 2021年第5期36卷 1155-1166页

作者： Feng Wang Guo-Jie Luo guang-yu sun yu-Hao Wang Di-Min Niu Hong-Zhong Zheng Center for Energy-Efficient Computing and Applications Peking UniversityBeijing 100871China Pingtouge Alibaba GroupHangzhou 310052China

Resistive random access memory(RRAM)has been demonstrated to implement multiply-and-accumulate(MAC)operations using a highly parallel analog fashion,which dramatically accelerates the convolutional neural networks(CNNs).Since CNNs require considerable converters between analog crossbars and digital peripheral circuits,recent studies map the binary neural networks(BNNs)onto RRAM and binarize the weights to{+1,-1}.However,two mainstream representations for BNN weights introduce patterns of redundant 0s and 1s when dealing with negative weights.In this work,we reduce the area of redundant 0s and 1s by proposing a BNN weight representation framework based on the novel pattern representation and a corresponding architecture.First,we spilt the weight matrix into several small matrices by clustering adjacent columns together.Second,we extract 1s'patterns,i.e.,the submatrices only containing 1s,from the small weight matrix,such that each final output can be represented by the sum of several patterns.Third,we map these patterns onto RRAM crossbars,including pattern computation crossbars(PCCs)and pattern accumulation crossbars(PACs).Finally,we compare the pattern representation with two mainstream representations and adopt the more area efficient one.The evaluation results demonstrate that our framework can save over 20%of crossbar area effectively,compared with two mainstream representations.

关键词： binary neural network(BNN) pattern resistive random access memory(RRAM)

Modelling vacuum flashover mitigation with complex surface microstructure:mechanism and application

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High Voltage 2020年第2期5卷 110-121页

作者： Shu Zhang guang-yu sun Hai-Bao Mu Bai-Peng Song Jianyi Xue Guan-Jun Zhang Research Center for Advanced High Voltage and Plasma Technology State Key Laboratory of Electrical Insulation and Power EquipmentSchool of Electrical EngineeringXi'an Jiaotong University710049 Xi'anShaanxiPeople's Republic of China

The vacuum discharge along the dielectric surface,also called surface flashover,brings significant damages to the vacuum-solid insulation system.Here the authors implement shape-flexible,complex surface groove microstructures on the dielectric to mitigate the initiation of vacuum flashover.A particle-in-cell simulation is employed to reveal the real-time discharge development considering the blockage of the multipactor propagation as well as the space field distortion in the presence of specific surface microstructures.Electron trajectories within barriers are theoretically analysed to present how the barrier shape affects the discharge process,showing consistent results with the simulation.By analysing three parameters,namely the anode current,the surface average charge density and the flashover threshold,it is found that the effect of suppressing surface flashover remarkably augments when the groove number and depth rise up,while such effect gradually saturates when the groove depth reaches a critical value.Theoretical analyses are also provided for the decay factor as well as the optimal shape and trapezoid grooves are proved as the optimal shape distribution of microstructures.Furthermore,different secondary emission yield(SEY)distributions are considered with two kinds of structures,including the material with low-SEY inside and on the top surface of grooves.

关键词： flash vacuum surface

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Preface

Journal of Computer Science & Technology 2020年第2期35卷 379-381页

作者： Wen-guang Chen Ying-Wei Luo guang-yu sun Department of Computer Science and Technology Tsinghua UniversityBeijing School of Electronics Engineering and Computer Science Peking UniversityBeijing Energy-Efficient Computing and Applications Peking UniversityBeijing

ACM SIGOPS ChinaSys conference is organized twice a year by ChinaSys, which is an active community forresearchers and practitioners on computer systems in China. Since August 2015, ChinaSys has become an ACMSIGOPS chapter. The first ChinaSys conference happened in November 2011 in Shenzhen. Now it has become anew leading international forum for academia, industry, and government to present novel research results in theprinciple and practice of computer systems. All topic areas related to design and implementation of computersystems are of interest and in scope.

关键词： China. computer happen

Three-dimensional stability calculation method for high and large composite slopes formed by mining stope and inner dump in adjacent open pits

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International Journal of Mining Science and Technology 2024年第4期34卷 507-520页

作者： Zuchao Liang Dong Wang guanghe Li guangyu sun Mingyu yu Dong Xia Chunjian Ding College of Mining Engineering Liaoning Technical UniversityFuxin 123000China Inner Mongolia Pingxi Baiyinhua Coal Industry Co. Ltd.Xilingol League 026000China Guoneng Baorixile Energy Co. Ltd.Hulunbuir 021008China

The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope engineering.Using the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding mass.By integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is proposed.Subsequently,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is examined.The analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear failure.The spatial form equation of the sliding mass comprises an ellipsoid and weak plane equation.The analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite slopes.Furthermore,the3D stability coefficient of the composite slope exhibits an exponential correlation with the coordinated development dista

关键词： Composite slope Destabilization mechanism 3D mechanical effect Three-dimensional stability Coordinated development distance

Bigflow: A General Optimization Layer for Distributed Computing Frameworks

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Journal of Computer Science & Technology 2020年第2期35卷 453-467页

作者： yun-Cong Zhang Xiao-Yang Wang Cong Wang Yao Xu Jian-Wei Zhang Xiao-Dong Lin guang-yu sun Gong-Lin Zheng Shan-Hui Yin Xian-Jin Ye Li Li Zhan Song Dong-Dong Miao Baidu Inc. Beijing 100193China Center for Energy-Efficient Computing and Applications Peking UniversityBeijing 100871China

As data volumes grow rapidly, distributed computations are widely employed in data-centers to provide cheap and efficient methods to process large-scale parallel datasets. Various computation models have been proposed to improve the abstraction of distributed datasets and hide the details of parallelism. However, most of them follow the single-layer partitioning method, which limits developers to express a multi-level partitioning operation succinctly. To overcome the problem, we present the NDD (Nested Distributed Dataset) data model. It is a more compact and expressive extension of Spark RDD (Resilient Distributed Dataset), in order to remove the burden on developers to manually write the logic for multi-level partitioning cases. Base on the NDD model, we develop an open-source framework called Bigflow, which serves as an optimization layer over computation engines from most widely used processing frameworks. With the help of Bigflow, some advanced optimization techniques, which may only be applied by experienced programmers manually, are enabled automatically in a distributed data processing job. Currently, Bigflow is processing about 3 PB data volumes daily in the data-centers of Baidu. According to customer experience, it can significantly save code length and improve performance over the intuitive programming style.

关键词： distributed computing programming model optimization technique

Multifaceted role of microRNAs in gastric cancer stem cells: Mechanisms and potential biomarkers

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World Journal of Gastrointestinal Oncology 2024年第2期16卷 300-313页

作者： Qian-Hui sun Zi-yu Kuang guang-Hui Zhu Bao-Yi Ni Jie Li Department of Oncology Guang'anmen HospitalChina Academy of Chinese Medical SciencesBeijing 100053China Graduate College Beijing University of Traditional Chinese MedicineBeijing 100029China Department of Oncology Heilongjiang University of Chinese MedicineHarbin 150040Heilongjiang ProvinceChina

MicroRNAs(miRNAs)have received much attention in the past decade as potential key epigenomic regulators of tumors and cancer stem cells(CSCs).The abnormal expression of miRNAs is responsible for different phenotypes of gastric cancer stem cells(GCSCs).Some specific miRNAs could be used as promising biomarkers and therapeutic targets for the identification of GCSCs.This review summarizes the coding process and biological functions of miRNAs and demon-strates their role and efficacy in gastric cancer(GC)metastasis,drug resistance,and apoptosis,especially in the regulatory mechanism of GCSCs.It shows that the overexpression of onco-miRNAs and silencing of tumor-suppressor miRNAs can play a role in promoting or inhibiting tumor metastasis,apart from the initial formation of GC.It also discusses the epigenetic regulation and potential clinical applications of miRNAs as well as the role of CSCs in the pathogenesis of GC.We believe that this review may help in designing novel therapeutic approaches for GC.

关键词： Gastric cancer,Cancer stem cells MicroRNAs Epigenetics Therapeutic target

Interaction between adolescent sleep rhythms and gender in an obese population

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World Journal of Clinical Cases 2024年第1期12卷 86-94页

作者： Nan-Nan Wu Guo-Li Yan Hong-yu Zhang Ling sun Min Hou guang-Ming Xu Department of Laboratory Medicine Tianjin Chest HospitalTianjin 300222China Mental Health Center of Tianjin Medical University Tianjin Anding HospitalTianjin 300222China Department of Child and Adolescent Psychology Mental Health Center of Tianjin Medical UniversityTianjin 300222China

BACKGROUND The obesity rate of adolescents is gradually increasing,which seriously affects their mental health,and sleep plays an important role in adolescent obesity.AIM To investigate the relationship between sleep rhythm and obesity among adolescents and further explores the interactive effect of sleep rhythm and gender on adolescent obesity,providing a theoretical basis for developing interventions for adolescent obesity.METHODS Research data source Tianjin Mental Health Promotion Program for Students.From April to June 2022,this study selected 14201 students from 13 middle schools in a certain district of Tianjin as the research subject using the convenient cluster sampling method.Among these students,13374 accepted and completed the survey,with an effective rate of 94.2%.The demographic data and basic information of adolescents,such as height and weight,were collected through a general situation questionnaire.The sleep rhythm of adolescents was evaluated using the reduced version of the morningness-eveningness questionnaire.RESULTS A total of 13374 participants(6629 females,accounting for 49.56%;the average age is 15.21±1.433 years)were analyzed.Among them,the survey showed that 2942 adolescent were obesity,accounting for 22%and 2104 adolescent were overweight,accounting for 15.7%.Among them,1692 male adolescents are obese,with an obesity rate of 25.1%,higher than 18.9%of female adolescents.There is a statistically significant difference between the three groups(χ2=231.522,P<0.000).The obesity group has the smallest age(14.94±1.442 years),and there is a statistical difference in age among the three groups(F=69.996,P<0.000).Obesity rates are higher among individuals who are not-only-child,have residential experience within six months,have family economic poverty,and have evening-type sleep(P<0.05).Logistic regression analysis shows a correlation between sleep rhythm and adolescent obesity.Evening-type sleep rhythm can increase the risk of obesity in male adolescents[1.250(1.067-1.468)],but the effect on fema

关键词： Adolescent Obesity Sleep rhythm Gender Interaction