Graphitic Armor: A Natural Molecular Sieve for Robust Hydrogen Electroxidation.

Carbon coating layers have been found to improve the catalytic performance of transition metals, which is usually explained as an outcome of electronic synergistic effect. Herein we reveal that the defective graphitic carbon, with a unique interlayer gap of 0.342 nm, can be a highly selective natural molecular sieve. It allows efficient diffusion of hydrogen molecules or radicals both along the in-plane and out-of-plane direction, but sterically hinders the diffusion of molecules with larger kinetic diameter (e.g., CO and O2) along the in-plane direction. As a result, poisonous species lager than 0.342 nm are sieved out, even when their adsorption on the metal is thermodynamically strong; at the same time, the interaction between H2 and the metal is not affected. This natural molecular sieve provides a very chance for constructing robust metal catalysts for hydrogen-relevant processes, which are more tolerant to chemical or electrochemical oxidation or CO-relevant poisoning.

Performance Evaluation and Formation Mechanism of Viscoelastic Surfactant Fracturing Fluids with Moderate Interfacial Activity Enhanced by Janus-SiO2 Nanoparticles.

Nanoparticles (NPs) exhibit great potential to improve various properties of viscoelastic surfactant (VES) fracturing fluids in the development of low-permeability reservoirs. In the present study, the amphiphilic Janus NPs (JANPs) were fabricated via the Pickering emulsion method and employed to construct the novel JA12C (JANPs with dodecyl hydrophobic carbon chains)-assisted VES fracturing fluid (JAVES). The successful fabrication of JANPs was confirmed via Fourier transform infrared spectroscopy (FTIR) measurements and water contact angle tests. The rheology behavior of the VES fracturing fluid incorporating various SiO2 NPs including hydrophilic SiO2 NPs (HLNPs), JA8C (JANPs with octyl hydrophobic carbon chains), and JA12C was systematically investigated. It was revealed that the additional JA12C significantly improved the tolerance and proppant suspension properties. To explore the subsequent oil recovery performance of various gel breaking liquids, the formation wettability and the oil-water interfacial tension (IFT) were studied after the evaluation of breaking properties and formation damage properties of various fracturing fluids. The results suggested that the JAVES gel breaking liquid showed remarkable wettability alternation capability and moderate oil-water IFT reduction ability, which can partially reduce the impact on reservoir permeability. Moreover, the formation mechanism of the JAVES was proposed by molecular dynamics simulations at the molecular level, which was further visually verified via the cryo-TEM images. The improved viscoelasticity of developed the JAVES with moderate interfacial activity is advantageous to enhance subsequent oil recovery.

Enhanced Hydrogen Evolution Reaction over Co Nanoparticles Embedded N-Doped Carbon Nanotubes Electrocatalyst with Zn as an Accelerant.

The rational design for transition metals-based carbon nano-materials as efficient electrocatalysts still remains a crucial challenge for economical electrochemical hydrogen production. Carbon nanotubes (CNTs) as attractive electrocatalysts are typically activated by non-metal dopant to promote catalytic performance. Metals doping or metal/non-metal co-doping of CNTs, however, are rarely explored. Herein, this work rationally designs bimetal oxide templates of ZnCo2 O4 for heterogeneously doping Zn and N into Co nanoparticles embedded carbon nanotubes (Co@Zn-N-CNTs). During the formation of CNTs, Zn atoms volatilize from ZnCo2 O4 and in situ dope into the carbon skeleton. In particular, owing to the low electronegativity of Zn, the electrons aptly transfer from Zn to carbon atoms, which generate a high electron density for the carbon layers and offer more preponderant catalytic sites for hydrogen reduction. The Co@Zn-N-CNTs catalyst exhibits enhanced hydrogen evolution reaction activity in 0.5 m H2 SO4 electrolyte, with a low onset potential of -20 mV versus RHE at 1 mA cm-2 , an overpotential of 67 mV at 10 mA cm-2 , a small Tafel slope of 52.1 mV dec-1 , and persistent long-term stability. This study provides brand-new insights into the utilization of Zn as electronic regulator and activity promoter toward the design of high-efficiency electrocatalysts.

Insights into the Assembly of the Pseudogemini Surfactant at the Oil/Water Interface: A Molecular Simulation Study.

The interfacial assembly process and configuration of the pseudogemini surfactant fabricated by sodium dodecyl benzene sulfonate (SDBS) and 4,4'-oxydianilinium chloride (ODC) were studied using quantum mechanical calculations and molecular dynamics (MD) simulations. The MD simulation results revealed that SDBS and ODC showed the vertical and horizontal arrangements at the oil/water interface, respectively, and the interfacial assembled configuration presented an unexpected "H" shape rather than the traditional "U" shape. The radial distribution functions between the head groups and water molecules were employed to explore the effects of the surrounding water molecules on the SDBS/ODC interaction. Furthermore, the results of the nonbonded interaction calculations and the reduced density gradient method directly confirmed that the cation-π interaction should be responsible for the SDBS/ODC assembly mechanism and the final configuration at the oil/water interface.

Probing Active Sites on Pristine and Defective MnPX3 (X: S and Se) Monolayers for Electrocatalytic Water Splitting.

The state-of-the-art density functional theory approach was used to study the structural and electronic properties of pristine and defective MnPX3 monolayers as well as their activity toward water and hydrogen evolution reaction (HER) catalytic performance. The adsorption behavior of H2O on a pristine MnPX3 structure is of physisorption nature, whereas the adsorption energy is significantly increased for the defective structures. At the same time, the water dissociation process is more energetically favorable, and the reactivity of MnPX3 is determined by the vacancy configuration. Following Nørskov's approach, the HER catalytic performance is evaluated by calculating the hydrogen adsorption free energy on the respective MnPX3 surface. Our calculation results demonstrate that defective 2D MnPX3 with low coordinated P shows significantly higher HER performance compared to the pristine counterpart.

Study on the Nanopore Deformation Mechanisms in Shale Oil Reservoir: Insights from the Molecular Simulation.

The stress and adsorption motivation deformation during shale oil production directly affect its development dynamics. First, a mathematical simulation of pore deformation in shale oil under stress motivation is established. We analyzed the impact of factors including the reservoir pressure, Biot coefficient, bulk modulus, and tortuosity on the deformation characteristics of nanopores. Second, a pore deformation model under multifactor synergistic effect is derived by combining the molecular dynamics, which takes into account the influence of adsorption deformation on the total adsorption of shale oil reservoir. Finally, a shale oil pore deformation model under multifactor synergistic effect is obtained. The results show that the current pore diameter shows a trend of decreasing with the decrease of current formation pressure and the difference with original reservoir pressure increases. The pore shows a trend of less deformation with a decrease in the effective stress coefficient. When the Biot coefficient is 0.8, the pore diameter under 5 MPa is 4.01 nm. When the Biot coefficient decreases to 0.3, the pore diameter under 5 MPa becomes 9.12 nm, an increase of 127.43% compared to 4.01 nm. The bulk modulus affects the magnitude of pore deformation under the same pressure, which means that the pore diameter shows a tendency to deform more easily as the bulk modulus increases. Meanwhile, the pore diameter decreases with increasing tortuosity. In addition, the pore deformation is subject to both stress and adsorption motivation deformation synergistically. The stress motivation deformation leads to a decrease of pore diameter with pressure decrease, while, in contrast, the adsorption motivation leads to an increase of pore diameter. The pore diameter under synergy is influenced by the coupling effect, and the deformation under synergy tends to decrease as the pore diameter decreases. When the rock mechanical parameters are changed so that the pores are not easily deformed by stress, the adsorption motivation deformation plays a dominant role in synergy. The amount of synergistic deformation decreases with increasing temperature, while the change in the component ratio of multicomponent fluid mainly affects the corresponding adsorption and the amount of synergistic deformation. Interestingly, when the proportion of CO2 is the largest, the corresponding maximum deformation is higher than the other proportions (43.77%). It not only enhances the recovery rate of shale oil reservoirs by utilizing CO2 but also provides the possibility of geological CO2 burial.

Evaluating Histological Subtypes Classification of Primary Lung Cancers on Unenhanced Computed Tomography Based on Random Forest Model.

Lung cancer is the leading cause of cancer-related death in many countries, and an accurate histopathological diagnosis is of great importance in subsequent treatment. The aim of this study was to establish the random forest (RF) model based on radiomic features to automatically classify and predict lung adenocarcinoma (ADC), lung squamous cell carcinoma (SCC), and small cell lung cancer (SCLC) on unenhanced computed tomography (CT) images. Eight hundred and fifty-two patients (mean age: 61.4, range: 29-87, male/female: 536/316) with preoperative unenhanced CT and postoperative histopathologically confirmed primary lung cancers, including 525 patients with ADC, 161 patients with SCC, and 166 patients with SCLC, were included in this retrospective study. Radiomic features were extracted, selected, and then used to establish the RF classification model to analyse and classify primary lung cancers into three subtypes, including ADC, SCC, and SCLC according to histopathological results. The training (446 ADC, 137 SCC, and 141 SCLC) and testing cohorts (79 ADC, 24 SCC, and 25 SCLC) accounted for 85% and 15% of the whole datasets, respectively. The prediction performance of the RF classification model was evaluated by F1 scores and the receiver operating characteristic (ROC) curve. On the testing cohort, the areas under the ROC curve (AUC) of the RF model in classifying ADC, SCC, and SCLC were 0.74, 0.77, and 0.88, respectively. The F1 scores achieved 0.80, 0.40, and 0.73 in ADC, SCC, and SCLC, respectively, and the weighted average F1 score was 0.71. In addition, for the RF classification model, the precisions were 0.72, 0.64, and 0.70; the recalls were 0.86, 0.29, and 0.76; and the specificities were 0.55, 0.96, and 0.92 in ADC, SCC, and SCLC. The primary lung cancers were feasibly and effectively classified into ADC, SCC, and SCLC based on the combination of RF classification model and radiomic features, which has the potential for noninvasive predicting histological subtypes of primary lung cancers.

Durable super-hydrophobic PDMS@SiO2@WS2 sponge for efficient oil/water separation in complex marine environment.

The robust and eco-friendly super-hydrophobic sponge with remarkable performances has been potential adsorption material for the treatment of offshore oil spills. In this work, the durable PDMS@SiO2@WS2 sponge was fabricated via a green and facile one-step dipping method. The mixed tungsten disulfide (WS2) microparticles and hydrophobic SiO2 nanoparticles were immobilized on the sponge by non-toxic polydimethylsiloxane (PDMS) glue tier, which featured the hierarchical structure and extreme water repellency with the water contact angle of 158.8 ± 1.4°. The obtained PDMS@SiO2@WS2 sponge exhibits high oil adsorption capacity with 12-112 times of its own weight, and oil/water selectivity with separation efficiency over 99.85%. Notably, when subjected to the complex marine environment including high temperature, corrosive condition, insolation, and strong wind and waves, the modified sponge can maintain sable super-hydrophobicity with water contact angle over 150°. Moreover, it possesses superior mechanical stability for sustainable reusability and oil recovery. The sponge fabricated by non-toxic modifiers along with its sable super-hydrophobicity in complex marine environment makes it a potential material for practical applications.

[Cognitive quality of professional divers].

OBJECTIVE: To explore and analyze the cognitive quality of professional divers. METHODS: 165 professional divers were tested with Raven's Standard Progressive Matrices (SPM), 80.8 Neural Type Measuring Form, etc. with 230 common people, 49 sailors and 66 trainee divers as control. RESULTS: There were significant difference among professional divers of different ages in the type of nerve activity, cognitive style, action stability, memory span, time reaction, the perception of space, act of attention and dark adaptation (P < 0.05); Over all, the cognitive quality of professional divers did not differ significantly in education level or working years (P < 0.05); Professional divers were superior to the common people in depth perception, cognitive style, act of attention, action stability, the perception of space and dark adaptation, but inferior to them in intelligence, memory span and time reaction (P < 0.05); There were significant difference in such cognitive indicators as the type of nerve activity, depth perception, kinesthetic memory, cognitive style, the perception of space and dark adaptation (P < 0.05); Compared with the trainee divers, professional divers were significantly better in the type of nerve activity, cognitive style, act of attention, action stability and the perception of space (P < 0.05). CONCLUSION: As a specified profession, diving needs some particular cognitive quality, while the profession itself would affect professional divers' cognitive ability to a certain extent.

Willingness to engage in and current status of social participation among Chinese merchant sailors.

China has the largest population of sailors in the world, but little is known of their social participation. This study examined Chinese merchant sailors' social participation using a nationwide survey. Across 12 Chinese provinces, 7,296 merchant sailors completed the questionnaire on sailor' willingness to engage in and status of social participation. The results showed that most Chinese merchant sailors were willing to participate in social affairs, but few of them reported having joined relevant social organizations, over half of sailors reported never having participated in public affairs, and half of them chose to ignore when they faced with an obvious mistake in shipping-related information in the media. Most of sailors reported unknowing the role of the labor union related to Chinese seafarers and NGO related to navigation well, and their evaluation of these organizations were mostly negative. Chinese merchant sailors reported higher expectations of services in terms of protection of rights, providing information and technology, and providing employment opportunity. We conclude that Chinese merchant sailors have willingness to social participation although the reality is not positive and discuss implications for improving the social participation of Chinese merchant sailors.

Biomimetic Au/CeO2 Catalysts Decorated with Hemin or Ferrous Phthalocyanine for Improved CO Oxidation via Local Synergistic Effects.

Biomimetic catalysts have drawn broad research interest owing to both high specificity and excellent catalytic activity. Herein, we report a series of biomimetic catalysts by the integration of biomolecules (hemin or ferrous phthalocyanine) onto well-defined Au/CeO2, which leads to the high-performance CO oxidation catalysts. Strong electronic interactions among the biomolecule, Au, and CeO2 were confirmed, and the CO uptake over hemin-Au/CeO2 was roughly about 8 times greater than Au/CeO2. Based on the Au/CeO2(111) and hemin-Au/CeO2(111) models, the density functional theory calculations reveal the mechanisms of the biomolecules-assisted catalysis process. The theoretical prediction suggests that CO and O2 molecules preferentially bind to the surface of noncontacting Au atoms (low-coordinated sites) rather than the biomolecule sites, and the accelerating oxidation of Au-bound CO occurs via either the Langmuir-Hinshelwood mechanism or the Mars-van Krevelen mechanism. Accordingly, the findings provide useful insights into developing biomimetic catalysts with low cost and high activity.

Biogenic Pt/CaCO3 Nanocomposite as a Robust Catalyst toward Benzene Oxidation.

Fabricating the highly dispersive and stable Pt nanoparticles (NPs) on an economical and environmentally friendly support is of great concern in the field of catalysis. Herein, a waste eggshell was used as the support to prepare supported Pt catalysts through a plant-mediated biosynthesis method, in which the Pt precursor was reduced to Pt NPs by employing Cacumen platycladi (CP) leaf extract. The temperature and atmosphere for thermal treatment of such eggshell-supported Pt catalysts were assessed to understand their effects on catalytic performance toward the oxidation of benzene. The optimal Pt/eggshell-Ar (calcined at 400 °C in Ar) demonstrated that the temperature required for 90% benzene conversion (T90%) was as low as 178 °C (80 000 mL g-1 h-1) and could operate steadily for at least 300 h of onstream reaction. The structure of the catalyst after reaction is much the same as that of the unreacted one. Transmission electron microscopy (TEM), thermogravimetry (TG), and X-ray photoelectron spectroscopy (XPS) results showed that Pt NPs were evenly distributed on the eggshell supports, and the calcination conditions had important influences on the residual CP leaf extract, the average Pt NPs size, and the ratio of Pt0/Pt2+ over the catalysts. Density functional theory (DFT) calculations indicated that the interactions between Pt NPs and porous CaCO3 could promote benzene activation adsorbed onto the Pt NPs. In addition, biogenic Pt catalysts were proved to overtake the chemically reduced counterparts in the field of catalytic performance; furthermore, both biogenic and chemically reduced Pt NPs supported on the eggshell demonstrated preferable catalytic activity than that of commercial 5Pt/C (com-Pt/C) catalysts. Collectively, immobilizing biogenic noble metal active components on the eggshell-based support could be a promising approach for the preparation of supported noble metal catalysts with excellent catalytic performance toward catalytic oxidation of volatile organic compounds (VOCs).

Assessing Chinese coach drivers' fitness to drive: The development of a toolkit based on cognition measurements.

Road traffic accidents resulting in group deaths and injuries are often related to coach drivers' inappropriate operations and behaviors. Thus, the evaluation of coach drivers' fitness to drive is an important measure for improving the safety of public transportation. Previous related research focused on drivers' age and health condition. Comprehensive studies about commercial drivers' cognitive capacities are limited. This study developed a toolkit consisting of nine cognition measurements across driver perception/sensation, attention, and reaction. A total of 1413 licensed coach drivers in Jiangsu Province, China were investigated and tested. Results indicated that drivers with accident history within three years performed overwhelmingly worse (p<0.001) on dark adaptation, dynamic visual acuity, depth perception, attention concentration, attention span, and significantly worse (p<0.05) on reaction to complex tasks compared with drivers with clear accident records. These findings supported that in the assessment of fitness to drive, cognitive capacities are sensitive to the detection of drivers with accident proneness. We first developed a simple evaluation model based on the percentile distribution of all single measurements, which defined the normal range of "fit-to-drive" by eliminating a 5% tail of each measurement. A comprehensive evaluation model was later constructed based on the kernel principal component analysis, in which the eliminated 5% tail was calculated from on integrated index. Methods to categorizing qualified, good, and excellent coach drivers and criteria for evaluating and training Chinese coach drivers' fitness to drive were also proposed.