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1,220 results on '"ZHANG Lizhen"'

1. Progress and prospect of experimental technologies for continental shale oil development

Author

SUN Zhigang, YU Chunlei, CHEN Hui, ZHANG Min, SUN Qiang, JIA Lihua, SUN Chao, CHEN Ting, ZHANG Hongxin, FAN Fei, and ZHANG Lizhen

Subjects
continental facies, shale oil, experimental development technologies, porosity, permeability, oil-water saturation, wettability, relative permeability, imbibition, Chemical technology, TP1-1185, Petroleum refining. Petroleum products, TP690-692.5, Geology, QE1-996.5
Abstract

As shale oil exploration and development intensifies， the experimental technologies for shale oil development have been continuously improved while inheriting the experimental technologies and methods of conventional reservoirs and shale gas reservoirs， and a set of experimental technology systems of reservoir physics and flow mechanisms has been initially formed， which provides strong technical support for geological evaluation of shale reservoirs， reservoir engineering optimization design， and enhanced oil recovery. The development status of six experimental technologies in China and abroad， including porosity， permeability， oil-water saturation， wettability， relative permeability， and imbibition， was systematically summarized. In view of the characteristics of continental shale oil， such as low maturity， strong heterogeneity， and well-developed lamina and micro-fractures， the measurement methods and principles， key influencing factors， control conditions of experiments， advantages and disadvantages and technical applicability of experiment methods were analyzed. The main problems， development trends， and research direction of these experimental technologies were put forward. The results show that ① unifying the cleaning agent and cleaning time of rock samples is the key to improving the comparability of different measurement methods of porosity， and nuclear magnetic resonance measurement of porosity is the technological development direction to meet the needs of rapid analysis in mining fields； ② the irregular and multi-directional permeability measurement technology capable of simulating formation pressure changes is the future technological development direction； ③ the alcohol soaking method and two-dimensional nuclear magnetic resonance （T1-T2） method are the technological development direction of the determination of shale oil-water saturation， but they still face the problem of the influence of clay bound water and adsorbed oil on the determination accuracy； ④ the droplet morphology method is one of the future development directions of measurement technology of shale reservoir wettability， which requires further research and unified standards in experimental methods and comprehensive evaluation methods for surface wetting and spontaneous imbibition processes； ⑤ the combination of experimental measurement and numerical method is an effective way to obtain the relative permeability of shale reservoirs， and the micro-oil and water metering， end-effect correction， as well as technologies and methods considering the time-varying pressure are the key directions； ⑥ pressure imbibition measurement method should be used to evaluate imbibition effect and optimize well kill time in elastic development after fracturing. Pressure imbibition measurement methods based on nuclear magnetic resonance T2 spectrum， stratification T2 spectrum， and T1-T2 spectrum will be one of the essential technological development directions.

Published
2024
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2. SELF-STABILIZING STRUCTURAL DESIGN OF SEMI-SUBMERSIBLE UNMANNED BOAT

Author

LI Wei, LU XingYi, WU Di, HU QingSong, and ZHANG LiZhen

Subjects
Semi-submersible unmanned boat, Stability, Overall structure, Modular, Mechanical engineering and machinery, TJ1-1570, Materials of engineering and construction. Mechanics of materials, TA401-492
Abstract

The design of the self-stabilizing structure is the key to the design and research of semi-submersible unmanned boat,which directly affects the self-stabilization state of the boat in the water. By calculating and adjusting the center of gravity and buoyancy of the structure of the boat,it can sail stably in large wind waves and water currents. The structure of the boat adopts the modular idea design method. By changing the weight and volume of the module,the center of gravity and the floating center of the whole structure are more easily adjusted; based on the theoretical calculation of the center of gravity and the floating center,the arrangement and installation between the hull modules can be adjusted. In addition,the initial stability of the boat was analyzed and a Matlab program was calculated. The verification of the calculation results shows that the design of the selfstabilizing structure of the boat meets the requirements. The lake test and the sea test prove that the boat can effectively resist the wind and water flow interference,and verify that the overall self-stable structure design of the boat is reasonable and effective. At the same time,the research results can also provide some reference for the design of the semi-submersible unmanned boat.

Published
2021
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4. Stationary solution to Stochastically Forced Euler-Poisson Equations in Bounded Domain: Part 2. 1-D Ohmic Contact Boundary

Author

Li, Yachun, Mei, Ming, and Zhang, Lizhen

Subjects
Mathematics - Analysis of PDEs, Mathematics - Probability, 34D05, 34D20, 35B35, 35K51, 60H15, 82D37
Abstract

In this paper, we establish the asymptotic stability of the steady-state for a 1-D stochastic Euler-Poisson equations with Ohmic contact boundary conditions forced by the Wiener process. We utilize Banach's fixed point theorem and the a priori energy estimates uniformly in time to ensure the global existence of solutions around the steady state. In contrast to the deterministic case, the presence of stochastic forces lead to the lack of temporal derivatives of momentum, posing challenges for energy estimates. Furthermore, Ohmic contact boundary conditions pose greater challenges for energy estimates compared to systems with insulating boundary conditions. To address this issue, we establish asymptotic stability concerning the spatial derivatives through weighted energy estimates for the estimates of stochastic integrals, employing a technique distinct from that of the deterministic case. Furthermore, we demonstrate the existence of an invariant measure based on the a priori energy estimates. This invariant measure precisely corresponds to the Dirac measure generated by the steady state, due to the exponential decay of perturbed solutions around the steady state.

Published
2024

5. Stationary solution to Stochastically Forced Euler-Poisson Equations in Bounded Domain: Part 1. 3-D Insulating Boundary

Author

Li, Yachun, Mei, Ming, and Zhang, Lizhen

Subjects
Mathematics - Analysis of PDEs, Mathematics - Probability, 34D05, 34D20, 35B35, 35K51, 60H15, 82D37
Abstract

In this paper, we establish the asymptotic stability of steady-state for $3$-D stochastic Euler-Poisson equations with insulating boundary conditions forced by the Wiener process. We use Banach's fixed point theorem and the a priori energy estimates uniformly in time to get the global existence of solutions around the steady state. Compared with the deterministic case, due to the stochastic forces, the momentum does not have the temporal derivative, which causes troubles to the energy estimates. We establish the asymptotic stability about the spatial derivatives by the weighted energy estimates for the estimates of stochastic integrals, employing a technique distinct from the deterministic case. The existence of invariant measure generated by the solutions to the evolving semiconductor equations is shown from the a priori energy estimates. Furthermore, the invariant measure is exactly the Dirac measure generated by the steady state, in which the exponential decay of perturbed solutions around the steady state plays an essential role., Comment: arXiv admin note: substantial text overlap with arXiv:2407.20104

Published
2024

7. Effects of subsoiling on maize yield and water-use efficiency in a semiarid area

Author

Jiao Yinzhu, Yi Yanli, Feng Liangshan, Sun Zhanxiang, Yang Ning, Yu Jialin, Zheng Muzi, Zhang Lizhen, and Zheng Jiaming

Subjects
rain-fed farmland, soil water-holding capacity, water-use efficiency, zone subsoiling, Biology (General), QH301-705.5
Abstract

A 3-year field research was conducted to investigate the effect of four subsoiling methods on maize yield and water use efficiency. These four subsoiling methods included bulk subsoiling in autumn (BS), annual ridge subsoiling in autumn, annual furrow subsoiling in early summer, and interannual alternate zone subsoiling (AS), which were compared with rotary tillage in spring. The results suggested that the bulk density of the soil was alternately changed by AS, but AS had limited effect on the average water storage in the soil. Overall, soil tilled by BS and AS maintained a high water-holding capacity, which could stabilize the yield of maize under varying rainfall across different years. Maize under the AS subsoiling method maintained a relatively higher production capacity and water-use efficiency compared with those under the other three types of subsoiling methods.

Published
2017
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18. The Global Existence of Martingale Solutions to Stochastic Compressible Navier-Stokes Equations with Density-dependent Viscosity

Author

Li, Yachun and Zhang, Lizhen

Subjects
Mathematics - Analysis of PDEs, Mathematics - Probability
Abstract

The global existence of martingale solutions to the compressible Navier-Stokes equations driven by stochastic external forces, with density-dependent viscosity and vacuum, is established in this paper. This work can be regarded as a stochastic version of the deterministic Navier-Stokes equations \cite{Vasseur-Yu2016} (Vasseur-Yu, Invent. Math., 206:935--974, 2016.), in which the global existence of weak solutions was established for adiabatic exponent $\gamma > 1$. For the stochastic case, the regularity of density and velocity is even worse for passing the limit in nonlinear terms. We design a regularized system to approximate the original system. To make up for the lack of regularity of velocity, we need to add an artificial Rayleigh damping term besides the artificial viscosity and damping forces in \cite{Vasseur-Yu-q2016,Vasseur-Yu2016}. Moreover, we have to send the artificial terms to $0$ in a different order.

Published
2022

38. Fatty acids metabolism affects the therapeutic effect of anti-PD-1/PD-L1 in tumor immune microenvironment in clear cell renal cell carcinoma

Author

Lin, Hansen, Fu, Liangmin, Li, Pengju, Zhu, Jiangquan, Xu, Quanhui, Wang, Yinghan, Mumin, Mukhtar Adan, Zhou, Xinwei, Chen, Yuhang, Shu, Guannan, Yao, Gaosheng, Chen, Minyu, Lu, Jun, Zhang, Lizhen, Liu, YuJun, Zhao, Yiqi, Bao, Jiahao, Chen, Wei, Luo, Junhang, Li, Xiaofei, Chen, Zhenhua, and Cao, Jiazheng

Published
2023
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