Поверхностное соединение при адсорбции Be на W(100): определение абсолютной концентрации и свойства

Be adsorption and T = 900 - 1100 K results in formation of a stable adsorption state; it drops the activation energy of atomic Be dissolution in the substrate bulk, and all newly deposited Be dissolves in the substrate. The absolute concentration of atomic Be has been measured by Auger electron spectroscopy using specially designed ultra high vacuum getter Be source. The concentration is (1 ± 0.1)•1015 сm-2 , and corresponds to WBe stoichiometry relative to W surface concentration. The layer is destroyed at T > 1100 K, the atomic Be dissolves in the bulk with the activation energy ~ 3,5 eV.

Microscopic Residual Oil Distribution Characteristics and Quantitative Characterization of Producing Degree Based on Core Fluorescence Analysis Technology

In this study, to address the insufficiency of research on the distribution characteristics and quantitative characterization of oil, water, and rock in a reservoir, laser confocal and core fluorescence analysis techniques are combined with core flooding experiments to investigate oil–water distribution characteristics in the core and the microscopic origin of residual oil. The results obtained show that the three-dimensional (3D) distribution characteristics of oil, water, and rock can be depicted using a laser confocal technique. Free and bound states are dominated by water flooding, and their total proportion is 93.65%, while the semibound state only accounts for 6.35% of the total. Polymer flooding has clear effects such as production of cluster-like residual oil, interparticle adsorption state residual oil, pore surface oil film, and corner residual oil. After alkali-surfactant-polymer (ASP) flooding, the residual oil produced at the lowest degree corresponds to particle adsorption oil, pore surface oil films, and interparticle adsorption state residual oil. The emulsion transition process in porous media, i.e., Winsor I→Winsor III→Winsor II, is studied. Moreover, the fluorescence analysis technology is used to clarify the causes for residual oil production, namely, pore structure, crude oil viscosity, the Jia Min effect, particle migration, and adsorption capacity. The combination of laser confocal and fluorescence analysis technology can help realize the three-dimensional reconstruction of the fluid in the core, and it can quantitatively characterize the microscopic residual oil. According to the analysis results, it can also guide the formulation and adjustment of oilfield development plans.

Applying surface strain and coupling with pure or N/B-doped graphene to successfully achieve high HER catalytic activity in 2D layered SnP3-based nanomaterials: a first-principles investigation

Applying external strain and coupling with pure or N/B-doped graphene can be viewed as effective strategies to further improve the HER activity of 2D layered SnP3 nanomaterials by optimizing the adsorption state of H* and electronic properties.

Surface phenomena related to applications regarding optimum dosages of casein superplasticizer in self-leveling underlayment cements

We experimentally investigated the optimum dosage of casein superplasticizer (SP) in self-leveling underlayments (SLUs). The undersaturated adsorption state of casein in cement pore solution was characterized by zeta potential measurements. Different amounts of casein were dosed in SLU pastes and their dispersion performance was investigated by a mini slump test. Flow values of the SLU pastes were found to increase with casein dosage, but an obvious segregation of the pastes was observed at high dose levels of SP. At an SP dosage of 0.12 wt.% bwob (by weight of binder), a homogeneous SLU paste with a spread flow of >15 cm over a time span of 30 min was obtained, which was identified as the optimum casein dosage for SLUs. Casein was found to adsorb significantly onto the surface of cement, thus producing strong dispersive power at low dose levels.