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1,012 results on '"Sun, Jianbo"'

401. Effect of temperature and pressure on corrosion behavior of X65 carbon steel in water-saturated CO2 transport environments mixed with H2S.

Author

Sui, Pengfei, Sun, Jianbo, Hua, Yong, Liu, Huifeng, Zhou, Mingnan, Zhang, Yucan, Liu, Jiahang, and Wang, Yong

Subjects
CORROSION & anti-corrosives, TEMPERATURE, MORPHOLOGY, PRECIPITATION (Chemistry), THERMODYNAMICS
Abstract

The effect of temperature and pressure on corrosion behavior of X65 carbon steel in water-saturated supercritical CO 2 containing H 2 S was studied to determine the role of H 2 S on the corrosion product formation and corrosion mechanism. Weight loss measurements showed that the highest corrosion rate of 0.190 mm/year was recorded at 35 °C and 8 MPa. The presence of 1000 ppmv H 2 S resulted in the corrosion products comprised of a double-layer structure in both supercritical and non-supercritical conditions. The results indicated that the presence of 1000 ppmv H 2 S has significantly influenced on the corrosion mechanisms, corrosion product morphology and composition as well as promoted the precipitation of water based on thermodynamic model. [ABSTRACT FROM AUTHOR]

Published
2018
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403. Unsteady Flow Analysis of Pump Mode Small Discharge Condition for a Francis Pump-turbine

Author

Zhao Xiaoran, Yao Yangyang, Xu Wei, Sun Jianbo, Xiao Yexiang, XU Jincai, and Wang Zhengwei

Subjects
Engineering, business.industry, Turbulence, Flow (psychology), Mechanics, Computational fluid dynamics, Turbine, Vortex, Physics::Fluid Dynamics, Draft tube, Amplitude, business, Simulation, Backflow
Abstract

Unsteady flow phenomena, including vortex flow at runner inlet, helical backflow in the draft tube and numerous vortexes inside the guide vanes, can occur in pump-turbines under off design conditions at pump mode and can impact normal operation of pump-turbines. All of these phenomena cause serious pressure pulsation, which is quite different from cases in normal pump mode. There is also a difference of pressure pulsation frequency and amplitude in different place through the runner. This paper builds a whole flow passage of a model pump-turbine, simulates flow characteristics in runner by CFD technology, analyses pressure pulsation in the runner and explores the origin and mechanism of pressure pulsations. The SST-CC turbulence model is adopted to perform unsteady simulations of the pump-turbine under 0.46Q BEP small discharge condition at pump mode. Unsteady flow structures are proceeded combined with hydraulic loss and pressure amplitude spectra. The results indicates that there is complicated disordered flow inside the runner under 0.46Q BEP small discharge condition at pump mode, shows the amplitude and frequency characteristic of pressure pulsations through runner flow passage.

Published
2016

406. Super-resolution in thin section of lacustrine shale reservoirs and its application in mineral and pore segmentation

Author

Guo, Chao, Gao, Chao, Liu, Chao, Liu, Gang, Sun, Jianbo, Chen, Yiyi, and Gao, Chendong

Abstract

Lacustrine shale reservoirs present intricate attributes such as the prevalence of lamination, rapid sedimentary phase transitions, and pronounced heterogeneity. These factors introduce substantial challenges in analyzing and comprehending reservoir characteristics. Thin-section imaging offers a direct medium to observe these traits, yet the intrinsic compromise between image resolution and field of view impedes the concurrent capture of comprehensive details and contextual overview. This study delves into the application of super-resolution (SR) techniques to augment the segmentation of thin-section images from lacustrine shale, an unconventional reservoir. SR application furnishes high-resolution images, facilitating a robust analysis of morphology, texture, edge properties, and target classification. Utilizing data from the lacustrine shale reservoir of the Ordos Basin, we evaluate our methodology and assess the impact of SR enhancement on segmentation. Quantitative results indicate significant improvements, with the Jaccard index for shale increasing from 0.4790 (Low-Resolution) to 0.7803 (ESRGAN) in the Y channel of the YCrCb color space after level set segmentation, exemplifying the efficacy of SR in shale gas and oil reservoirs. This research underscores the necessity to consider lacustrine shale's unique features while formulating and implementing SR techniques for improved information extraction. Furthermore, it highlights SR's potential for propelling future research and industry-specific applications.

Published
2023
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407. Research on damping control system of optimized coordination of AGC and AVC

Author

Hu Wei, Li Miao, Li Xiaoping, Xu Fei, Yao Haowei, and Sun Jianbo

Subjects
Coupling, Engineering, Automatic Generation Control, Control theory, Iterative method, business.industry, Numerical analysis, Control system, Automatic gain control, Control engineering, AC power, Low-frequency oscillation, business
Abstract

Based on generation rescheduling, we can damp low-frequency oscillation effectively. In this paper, the authors calculate the three kinds of sensitivities used later in this paper with both analytic method and numerical method. Then the authors give a brief introduction on static HAGVC system as well as static damping HAGVC system, and draw a control diagram of the system. Static damping HAGVC system can not only eliminate some weak damping modes, but also overcome the negative interaction between traditional AGC and AVC control, as the coupling between active and reactive power become much stronger, to coordinate AGC and AVC control systems effectively. As to the top level of the static damping HAGVC system, a diagram about control flow as well as the function of each control module based on cross iteration optimization algorithm is given in this paper. Finally, the simulations of the IEEE 5-machine 14-bus system in five situations indicate the validity of the proposed theory.

Published
2011

408. Bacterial Magnetosome: A Novel Biogenetic Magnetic Targeted Drug Carrier with Potential Multifunctions

Author

Sun, Jianbo, Li, Ying, Liang, Xing-Jie, and Wang, Paul C.

Subjects
stomatognathic diseases, Article Subject, education, digestive, oral, and skin physiology
Abstract

Bacterial magnetosomes (BMs) synthesized by magnetotactic bacteria have recently drawn great interest due to their unique features. BMs are used experimentally as carriers for antibodies, enzymes, ligands, nucleic acids, and chemotherapeutic drugs. In addition to the common attractive properties of magnetic carriers, BMs also show superiority as targeting nanoscale drug carriers, which is hardly matched by artificial magnetic particles. We are presenting the potential applications of BMs as drug carriers by introducing the drug-loading methods and strategies and the recent research progress of BMs which has contributed to the application of BMs as drug carriers.

Published
2011
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415. RNA Exosome-Regulated Long Non-Coding RNA Transcription Controls Super-Enhancer Activity

Author

Pefanis, Evangelos, primary, Wang, Jiguang, additional, Rothschild, Gerson, additional, Lim, Junghyun, additional, Kazadi, David, additional, Sun, Jianbo, additional, Federation, Alexander, additional, Chao, Jaime, additional, Elliott, Oliver, additional, Liu, Zhi-Ping, additional, Economides, Aris N., additional, Bradner, James E., additional, Rabadan, Raul, additional, and Basu, Uttiya, additional

Published
2015
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425. PC-Based Modeling and Simulation of Large Marine Propulsion Plant

Author

Guo Chen and Sun Jianbo

Subjects
Dynamic simulation, Modeling and simulation, Matching (statistics), Computer science, Marine propulsion, Water cooling, ComputerApplications_COMPUTERSINOTHERSYSTEMS, Transient (computer programming), Fuel injection, Diesel engine, Automotive engineering
Abstract

At present, most of marine engine room simulators (MERS) in the world are based on networking technology. But such MERS needs much money and large space to install and use. So it can not meet the demand of the training individually in spare time for the crew. So a simulation system of a PC-Based marine propulsion plant has been developed for training. In this paper, a transient simulation model for large marine propulsion system was proposed. At the same time, the marine propulsion plant control, fuel system, cooling water and etc are also developed in the simulation system. The model is a modularized structure and the modules describing system’s components can be added to it easily. And related subsystems of marine propulsion plant are also established in this simulation system. The simulation experiments demonstrate the steady and dynamic results matching properly the voyage trial ones. The model can be used for marine propulsion plant performance analyzing and prediction.

Published
2009

426. Research on the modeling and simulation of the Four-stroke engine and it’s control system

Author

Zhang Yuanyuan, Chen Guo, and Sun Jianbo

Subjects
Computer science, business.industry, MathematicsofComputing_NUMERICALANALYSIS, PID controller, ComputerApplications_COMPUTERSINOTHERSYSTEMS, Solid modeling, Four-stroke engine, Diesel engine, Automation, Modeling and simulation, Model predictive control, Control theory, Control system, Hardware_CONTROLSTRUCTURESANDMICROPROGRAMMING, business
Abstract

The simulation of the engine model and the control system were researched on in this paper. The model of the main parts of the four-stroke engine were built, the PID controller, integral separation PID controller and anti-saturated PID controller were designed for the velocity. Visual C++ is used for the model simulation and the controllerspsila design. The velocity control results of different controllers were given and by analyze the simulation atlases, the efficiency of the PID controllers were visual represented, at the same time the advantage and disadvantage of the PID controllers were obtained, and the ascendancy of the new style PID controller was visible.

Published
2008

427. Effect of impurity interaction on the corrosion film characteristics and corrosion morphology evolution of X65 steel in water-saturated supercritical CO2 system.

Author

Sun, Chong, Sun, Jianbo, Wang, Yong, Sui, Pengfei, Lin, Xueqiang, Liu, Huifeng, Cheng, Xiangkun, and Zhou, Mingnan

Subjects
SUPERCRITICAL carbon dioxide, IMPURITY-dislocation interactions, CORROSION & anti-corrosives testing, WATER-saturated sites (Archaeology), STEEL pipe
Abstract

The corrosion behavior of X65 steel in water-saturated supercritical CO 2 system containing NO 2 with or without O 2 , H 2 S and SO 2 impurities was investigated using weight loss measurement and surface analysis techniques. The interactions between NO 2 and O 2 , SO 2 or H 2 S promoted the formation of extra corrosive species and subsequently changed the corrosion film characteristics. In water-saturated supercritical CO 2 -NO 2 -O 2 -SO 2 -H 2 S system, FeSO 4 and S preferentially formed in the early corrosion stage due to the impurity interactions. As the corrosion time prolonged, (NH 4 )Fe 3 (SO 4 ) 2 (OH) 6 and FeOOH formed due to the subsequent reactions of the impurity interaction products, and S disappeared in the corrosion scale via participating in the subsequent corrosion reactions during long-term corrosion. Localized corrosion was initiated by the inhomogeneous precipitation of acid-rich water in the presence of NO 2 . However, the propagation rate of the corrosion pit in depth direction greatly reduced with time, and the corrosion morphology of X65 steel shifted from localized corrosion towards general corrosion during long-term corrosion. [ABSTRACT FROM AUTHOR]

Published
2017
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441. E3-ubiquitin Ligase Nedd4 Determines the Fate of AID-associated RNA Polymerase II in B cells

Author

Sun, Jianbo, Keim, Celia D., Wang, Jiguang, Kazadi, David, Oliver, Paula M., Rabadan, Raul, Basu, Uttiya, Sun, Jianbo, Keim, Celia D., Wang, Jiguang, Kazadi, David, Oliver, Paula M., Rabadan, Raul, and Basu, Uttiya

Abstract

Programmed mutagenesis of the immunoglobulin locus of B lymphocytes during class switch recombination (CSR) and somatic hypermutation requires RNA polymerase II (polII) transcription complex-dependent targeting of the DNA mutator activation-induced cytidine deaminase (AID). AID deaminates cytidine residues on substrate sequences in the immunoglobulin (Ig) locus via a transcription-dependent mechanism, and this activity is stimulated by the RNA polII stalling cofactor Spt5 and the 11-subunit cellular noncoding RNA 39-59 exonucleolytic processing complex RNA exosome. The mechanism by which the RNA exosome recognizes immunoglobulin locus RNA substrates to stimulate AID DNA deamination activity on its in vivo substrate sequences is an important question. Here we report that E3-ubiquitin ligase Nedd4 destabilizes AID-associated RNA polII by a ubiquitination event, leading to generation of 39' end free RNA exosome RNA substrates at the Ig locus and other AID target sequences genome-wide. We found that lack of Nedd4 activity in B cells leads to accumulation of RNA exosome substrates at AID target genes and defective CSR. Taken together, our study links noncoding RNA processing following RNA polII pausing with regulation of the mutator AID protein. Our study also identifies Nedd4 as a regulator of noncoding RNAs that are generated by stalled RNA polII genome-wide. © 2013, Published by Cold Spring Harbor Laboratory Press.

Published
2013

443. Correction to: Niche differentiation and higher uptake of available nitrogen maintained the productivity of alpine meadow at early degradation.

Author

Lai, Chimin, Peng, Fei, Sun, Jianbo, Zhou, Jun, Li, Chengyang, Xu, Xingliang, Chen, Xiaojie, You, Quangang, Sun, Hongyang, Sun, Jian, Xue, Xian, and Lambers, Hans

Subjects
MOUNTAIN meadows, SOIL moisture
Abstract

Different lowercase letters indicate significant differences in soil water content, exchangeable HT NH4+ ht , HT NO3- ht , dissolved organic C (DOC) and DON, and the ratio of exchangeable HT NH4+ ht to HT NO3- ht among degradation stages at I p i < 0.05. Different uppercase letters indicate significant differences between exchangeable HT NH4+ ht and HT NO3- ht at I p i < 0.05 at the same degradation stage. [Extracted from the article]

Published
2023
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