952 results match your criteria: "China University of Petroleum Beijing[Affiliation]"

Experimental study on ultrasonic reduction of irreducible water saturation in low permeability reservoir.

Sci Rep

December 2024

Puyang Key Laboratory of Sound Field Assisted Oil and Gas Development, Puyang, 457000, China.

Irreducible water saturation is an important factor affecting the development effect of low permeability reservoir. Using the self-developed ultrasonic generator, kerosene was used as simulated oil, the natural low-permeability siltstone cores with different physical properties in Zhongyuan Oilfield were selected for indoor oil displacement experiment, and the effect of ultrasonic action on the saturation of irreducible water in low-permeability reservoirs was evaluated. It was found that ultrasound can further reduce the saturation of irreducible water on the basis of oil flooding.

View Article and Find Full Text PDF

Horizontal well hydraulic fracturing technology has significantly enhanced the productivity of shale reservoirs. However, our understanding of the expansion patterns within the complex fracture network and fluid seepage mechanisms under field conditions remains inadequate. Here, this work develops a dynamic geomechanical (DG) model to simulate the complete sequence of operations in hydraulic fracturing.

View Article and Find Full Text PDF

Phase boundary is highly recognized for its capability in engineering various physical properties of ferroelectrics. Here, field-induced polarization rotation is reported in a high-performance (K, Na)NbO-based ferroelectric system at the rhombohedral-tetragonal phase boundary. First, the lattice structure is examined from both macroscopic and local scales, implementing Rietveld refinement and pair distribution function analysis, respectively.

View Article and Find Full Text PDF

Switching CO-to-Acetate Electroreduction on Cu Atomic Ensembles.

J Am Chem Soc

December 2024

Beijing National Laboratory for Molecular Sciences, Key Laboratory of Colloid and Interface and Thermodynamics, Center for Carbon Neutral Chemistry Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.

The electrocatalytic reaction pathway is highly dependent on the intrinsic structure of the catalyst. CO/CO electroreduction has recently emerged as a potential approach for obtaining C products, but it is challenging to achieve high selectivity for a single C product. Herein, we develop a Cu atomic ensemble that satisfies the appropriate site distance and coordination environment required for electrocatalytic CO-to-acetate conversion, which shows outstanding overall performance with an acetate Faradaic efficiency of 70.

View Article and Find Full Text PDF

Preparation of Hot-Pressed Wheat Straw Board by Self-Adhesive Process: Effects of Raw Material Sizes and Acid/Alkali Pretreatment.

Materials (Basel)

November 2024

Guangdong Provincial Engineering & Technology Center for Corrosion and Safety in Petrochemical Industry, School of Chemical Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, China.

The development of wheat straw boards utilizing intrinsic bonding mechanisms not only facilitates the high-value utilization of agricultural solid waste but also diminishes the reliance on synthetic adhesives. In this study, using wheat straw as the primary substrate, we investigated the effects of mechanical smashing combined with pretreatment using inorganic acids or alkalis on the properties of hot-pressed boards, as well as the relationship between the properties of hot-pressed boards and the physical properties and chemical composition of wheat straw raw materials. These selective pretreatments effectively degraded lignin, hemicellulose, and other components, thereby promoting fiber reorientation and resulting in a denser microstructure with improved self-bonding capabilities.

View Article and Find Full Text PDF

Reservoir heterogeneity significantly affects reservoir flooding efficiency and the formation and distribution of residual oil. As an effective method for enhancing recovery, polymer-surfactant (SP) flooding has a complex mechanism of action in inhomogeneous reservoirs. In this study, the effect of reservoir heterogeneity on the SP drive was investigated by designing core parallel flooding experiments combined with NMR and CT scanning techniques, taking conglomerate reservoirs in a Xinjiang oilfield as the research object.

View Article and Find Full Text PDF

Self-Assembled Covalent Triazine Frameworks Derived N, S Co-Doped Carbon Nanoholes with Facilitating Ions Transportation Toward Remarkably Enhanced Oxygen Reduction Reaction and for Zinc-Air Batteries.

Small

December 2024

College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, Yichang, 443002, P. R. China.

3D assembled carbon materials, featuring unique hierarchical porosity and interconnected channels, are essential for the advancement of emerging zinc-air batteries (ZABs). In this study, nitrogen (N) and sulfur (S) co-doped 3D carbon nanoholes (N/S-CNHs) are synthesized through a straightforward procedure involving self-assembly followed by carbonization. This process utilizes a hybrid of self-assembled covalent triazine framework and sodium lignosulphonate (CTF@LS) as a multifunctional precursor.

View Article and Find Full Text PDF

The interaction of microwave radiation with carbon-based materials induces rapid, instantaneous heating. When combined with the plasma excitation capabilities of microwaves, this property presents novel avenues for synthesizing carbon-based materials that require high temperatures and catalytic activity. This review investigates the response of carbon-based materials to microwave radiation, analyzes the dielectric loss mechanism responsible for heat generation, and details the microwave plasma excitation mechanisms employed in the synthesis and processing of carbon-based materials.

View Article and Find Full Text PDF

Buildings, especially installed windows, account for a large proportion of global energy consumption. The research trend of smart windows leans towards multi-functional integration, concurrently achieving solar modulation and thermal management. However, sometimes a one-time performance switch cannot meet demands, making the design of multi-gradient adjustable smart windows particularly important.

View Article and Find Full Text PDF

Boston ivy has received much attention from researchers owing to its exceptional climbing abilities. However, many aspects of their adhesion behavior remain unresolved. Our research has discovered a phenomenon of oxidation and discoloration in Boston ivy pads, which leads to a significant decrease in adhesion force.

View Article and Find Full Text PDF

As a typical kind of persistent organic pollutants, polychlorinated biphenyls (PCBs) may cause great harm to human health. Recently, MXene has gained considerable attention due to its specific properties for the removal of pollutants by various principles. Present work reported a new functionalized MXene material, NHMIL-88 modified magnetic NbCT, for developing a facile and efficient magnetic solid phase extraction method for enrichment and sensitive detection of PCBs in environmental water samples.

View Article and Find Full Text PDF

Hydrogels, with their high water content and flexible nature, are a promising class of medical dressings for combating bacterial wound infections. However, their development has been hindered by low sterilization efficiency. Here, this issue is addressed by designing a peptide hydrogel that assembles ordered metal-organic framework (MOF) nanoparticles with photocatalytic bactericidal activity.

View Article and Find Full Text PDF

With the widespread application of the Internet, network security issues have become increasingly prominent. As an important infrastructure of the Internet, the domain name server has been attacked in various forms. Traditional methods for detecting malicious domain servers are usually based on rules or feature engineering, requiring a large amount of manual participation and rule library updates.

View Article and Find Full Text PDF

Nanoconfined electrostatic interaction for efficient anion sieving in graphene oxide membranes.

Water Res

November 2024

MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China; Center for Healthcare Materials, Shaoxing Institute, Zhejiang University, Shaoxing 312000, China. Electronic address:

Controllable ion transport and precise ion sieving are crucial for sustainable water treatment and resource recovery. 2D materials, including graphene oxide (GO) with tunable nanochannels, are emerging as ideal material platforms to develop ion sieving membranes. However, accurate ion sieving remains challenging due to the swollen and enlarged interlayer spacing of GO membranes in aqueous solution, resulting in the non-selective of small ions.

View Article and Find Full Text PDF

Theoretical and experimental research on the impacts of the Joukowsky hydrofoils on the bubble collapse dynamics within a confined space.

Ultrason Sonochem

November 2024

College of Mechanical and Transportation Engineering, China University of Petroleum-Beijing, Beijing 102249, China; Beijing Key Laboratory of Process Fluid Filtration and Separation, China University of Petroleum-Beijing, Beijing 102249, China.

The present paper investigates the bubble collapse dynamics near hydrofoils within a confined space. Experiments involving high-speed photography reveal in detail the typical bubble morphological evolution near different hydrofoils between two glass plates (namely the confined space), and the partitioning of the thickness-related and camber-related parameters is analyzed quantitatively. Based on conformal transformation, the liquid velocity field and Kelvin impulse are used to analyze the bubble collapse characteristics qualitatively and quantitatively, including the bubble interface motion, cross-sectional roundness, and collapse jet.

View Article and Find Full Text PDF

This study presents an innovative approach to utilize coal gasification coarse slag (CGCS) for efficient and low-cost gallium extraction. Using a one-step acid leaching process, mesoporous silica with a surface area of 258 m/g and a pore volume of 0.15 cm/g was synthesized.

View Article and Find Full Text PDF

This study selected 27 soil samples from four representative horizontally distributed onshore oilfields in China to explore the diversity of soil microbial communities and their carbon fixation capacity, with a focus on the potential interaction between pollution and carbon fixation under oil pollution stress. The analysis of the soil physicochemical properties and microbial community structures from these oilfield samples confirmed a clear biogeographic isolation effect, indicating spatial heterogeneity in the microbial communities. Additionally, the key factors influencing microbial community composition differed across regions.

View Article and Find Full Text PDF
Article Synopsis
  • - Circular RNAs (circRNAs) have unique structures that make them valuable in gene regulation and potential targets for therapies, especially in cardiovascular diseases (CVDs).
  • - This review examines how circRNAs are created, their functions in diseases, and recent therapeutic developments, such as small-molecule drugs and delivery systems targeting circRNAs.
  • - It also acknowledges existing challenges in circRNA therapies, like stability and delivery, while stressing the importance of ongoing research to exploit their full therapeutic potential in heart-related conditions.
View Article and Find Full Text PDF

The supply of shale oil is of significant importance to the sustainability of energy resources. However, due to the diversity of shale lithofacies, the occurrence characteristics and enrichment patterns of free oil and adsorbed oil remain unclear. Based on this, taking the shale oil reservoir of the Fengcheng Formation in the Mahu Sag as the research object, a series of experiments were conducted, including X-ray diffraction analysis (XRD), total organic carbon (TOC) content analysis, high-pressure mercury injection (HPMI), and field emission scanning electron microscopy (FE-SEM).

View Article and Find Full Text PDF

Rational design of defect engineering and interfacial built-in electric fields of photocatalysts is imperative for renewable energy conversion. Herein, a multi-strategy involving the introduction of Ni vacancies, the adjustment of the Se/S ratio, and the construction of dual junctions are employed to simultaneously realize NiSSe/phase junction CdS (HCC) an excellent photocatalytic activity and broad light absorption. With the help of V and the regulation of S/Se, the local electrons are redistributed to occupy more antibonding orbitals and adjust the p-band center, thus optimizing the H adsorption energy of the catalyst to accelerate the photocatalytic reaction kinetics.

View Article and Find Full Text PDF

Research on the dynamic characteristics of the cavitation bubble collapsing between multiple particles.

Ultrason Sonochem

November 2024

College of Mechanical and Transportation Engineering, China University of Petroleum-Beijing, Beijing 102249, China; Beijing Key Laboratory of Process Fluid Filtration and Separation, China University of Petroleum-Beijing, Beijing 102249, China.

The combined action of multiple particles and cavitation bubbles can severely damage hydraulic machinery. Combining the Kelvin impulse theory and the results of high-speed photography experiments, this paper researches the dynamic behaviors of a single bubble located between three equal-sized spherical particles. Non-spherical morphological evolution characteristics in the collapse stage of the bubble are described.

View Article and Find Full Text PDF

Experimental and numerical research on jet dynamics of cavitation bubble near dual particles.

Ultrason Sonochem

November 2024

School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China. Electronic address:

The current paper delves into the jet dynamics arising from a cavitation bubble in proximity to a dual-particle system, employing both experimental methodology and numerical simulation. The morphological development of a laser-induced bubble as well as the production of jets are captured by utilizing high-speed photography. The principles of bubble morphology evolution and jet formation are revealed by a OpenFOAM solver, which takes into account the effects of two-phase fluid compressibility, phase changes, heat transfer, and surface tension.

View Article and Find Full Text PDF
Article Synopsis
  • College students in Western China experience unique challenges that contribute to emotional distress, with limited research focused on this issue.
  • The study examines how a sense of belonging at school affects the link between students’ expectations about school and their emotional well-being, finding that feelings of exclusion significantly mediate this relationship.
  • Physical exercise is found to play a role in moderating the negative impacts of school exclusion, suggesting that it could be an effective intervention for improving emotional health in this population.
View Article and Find Full Text PDF

N-doped anatase/rutile TiO (AR-N/TiO) photocatalysts were prepared by combining the strategy of N-doping and in situ heterophase junction generation, which significantly enhanced the photocatalytic H generation (1.68 mmol· h·g). Under monochromatic light at 400 nm, the light exhibits an apparent quantum efficiency of 8.

View Article and Find Full Text PDF
Article Synopsis
  • This study uses computer simulations to explore how different interparticle potentials affect the interactions of probes moving freely in a 2D colloidal crystal.
  • Attractive potentials between background particles and probes greatly change how these probes interact with each other, while long-range repulsive forces have little effect.
  • The research also finds that the temperature influences the effective force differently for soft versus stiff repulsions among background particles, highlighting the role of interparticle potentials in shaping effective forces in colloidal systems.
View Article and Find Full Text PDF