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Endowing inorganic mineral pigments with superhydrophobicity greatly improves their stability for applications in architectural coatings and artworks. However, it remains challenging in the preparation of superhydrophobic pigments, such as complicated processes, high-cost, use of organic solvents, and fluorine-containing materials. Here, we report superhydrophobic colorful inorganic pigments with color gradient that were synthesized under atmospheric pressure and water-based conditions through a one-pot method, which is simple, fluorine-free, low-cost, and mild. The as-prepared pigments were assembled with nanostructures (nano spikes or nanoparticles), which exhibit the micro-/nanoscale hierarchical structures desired for superhydrophobicity. By precisely adjusting the ratio of Ni2+ and Fe3+, the in situ color matching and hydrophobic modification by dodecylbenzene sulfonic acid of micro–nano pigments were simultaneously realized. The superhydrophobic pigments retained their functions in a variety of harsh environments (e.g., corrosive solution, ultraviolet irradiation, high temperature, and so on) and were available in various coating techniques to construct superhydrophobic coatings, superhydrophobic paintings, and superhydrophobic tapes with colorfulness. Additionally, the waste liquid generated in the preparation process could be completely recycled and reused for pigment preparation, which is highly environmental-friendly for saving raw materials and avoiding pollution discharge. These superhydrophobic pigments would have great potential for eco-friendly industrial production and application in architecture coating, artworks, and building decoration. [ABSTRACT FROM AUTHOR]

A facile covalent assembly strategy is proposed for the preparation of superhydrophobic COF-stabilized MXene separation membranes. Ultra-high separation fluxes of up to 54 280 L m−2 h−1 and 643 200 L m−2 h−1 bar−1 are obtained for emulsified water-in-oil mixtures by adopting gravity and external pressure, respectively. Moreover, the challenges of easy swelling and oxidation properties of MXene have been effectively overcome via the COF-stabilized mechanism. [ABSTRACT FROM AUTHOR]

Selective hydrogenation of alkynes to obtain alkenes is a key reaction in petrochemical and fine chemical industries. However, the development of stable and highly selective catalysts with uniformly dispersed active sites is still immensely challenging for the semi-hydrogenation of alkynes. In this study, N-doped porous carbon nanospheres (NPCNs) were synthesized by the nanoemulsion self-assembly and subsequently carbonization method. Ultrafine PdCu bimetallic nanoparticles (NPs) were uniformly dispersed and immobilized on NPCNs. The obtained PdCu/NPCNs catalyst exhibited an open framework and abundant active sites originating from ultrafine PdCu NPs. In the semi-hydrogenation of alkynes, the PdCu/NPCNs catalyst exhibited a remarkable performance and stability, outperforming most of the classical catalysts. The excellent performance was related to the introduction of a secondary metal Cu, which can regulate the electronic state of Pd active sites to further enhance the hydrogenation activity and selectivity. Hence, the facile approach reported herein may be useful for constructing highly dispersed bimetallic NP-based catalysts for selective hydrogenation of alkynes in the petrochemical industry. [ABSTRACT FROM AUTHOR]

Considering the serious environmental pollution and economic losses caused by increasing oil spills and chemical leaks, effective and eco-friendly methods of oil/water separation should be urgently developed. Herein, a facile strategy (about 20 min) was developed for integrating covalent organic framework (COF) particles with melamine sponges (MS) by covalent bonding, and then a superhydrophobic COF/MS composite (denoted OA-CP@MS) could be further obtained by following modification with a 1-octadecylamine/water dispersion. Specifically, the synthesis process was developed under a mild condition that avoid the need for sealing and high-temperature treatments. It was proven that the fabricated OA-CP@MS presented a prominent absorption capacity for various organic reagents, in which adsorption capacity of chloroform could be up to 173 g/g. Owing to its excellent chemical robustness in strong alkaline and saline environments and in various organic solvents, the prepared OA-CP@MS showed a great potential to perform oil/water separation in complex practical conditions. Its rapid preparation process, fluorine-free treatment, and water-based modification would extend the application of COF materials in oil/water separation. [ABSTRACT FROM AUTHOR]

The WRF-lake, as a one-dimensional (1D) lake model popularly used for coupling with the Weather Research and Forecasting (WRF) system and modeling lake–atmosphere interactions, does not consider the heat exchange caused by inflow–outflow, which is an important characteristic of large reservoirs and can affect the energy budget and reservoir–atmosphere interactions. We evaluated the WRF-lake model by applying it at a large dimictic reservoir, Miyun Reservoir, in northern China. The results show that the WRF-lake model, though ignoring inflow–outflow, yields good surface water temperature simulation through reasonable parameterization. The Minlake model, as a better physically based model in reservoirs, was used to test the effect of inflow–outflow, including heat carried by inflow–outflow water exchange and water level change on the 1D model's performance. The effect of heat carried by inflow–outflow is mainly in summer, negatively correlated with hydraulic residence time and positively correlated with temperature difference between inflow and outflow. For a reservoir with hydraulic residence time of 3 years and temperature difference between inflow and outflow about 10°C in summer, the heat carried by inflow–outflow is far less than the heat exchange through the surface (<2%) and therefore has little influence on total energy balance. The effect of water level change is mainly on latent heat and sensible heat in unit area, rather than outgoing longwave radiation. Though influencing the temperature in deep layers, the water level change does not have a significant impact on the surface temperature. Significance Statement: The purpose of this study is to evaluate the applicability of WRF-lake, an important submodule of the Weather Research and Forecasting (WRF) system, in the large dimictic reservoir. This is important because WRF-lake does not consider the effect of inflow–outflow and water level change, which are important characteristics of large reservoirs and can affect the heat budget and reservoir–atmosphere interactions. The applicability of WRF-lake in large reservoirs with frequent inflow–outflow and water level change is widely concerned but has never been discussed in previous studies. Our research explored the applicability of WRF-lake in the large dimictic reservoir and discussed the effect of inflow–outflow and water level change quantitively. [ABSTRACT FROM AUTHOR]

Atmospheric pressure plasma jet (APPJ) is a promising technique for the sterilization of pathogenic microorganisms in an ambient environment. In this work, a helium-APPJ was generated by double dielectric barrier discharge and applied to the sterilization of model microorganism in air and water. Discharge characteristics (including waveform and frequency of applied voltage), jet properties (such as feed gas flow rate, jet length, thermal effect, and optic emission spectra), and sterilization performance (in terms of clear/sterilized area, size of plaques, and sterilization efficiency) were investigated. Homogeneous helium plasma jet was generated in an energy-efficient way (18 kHz, 6 kV, 0.08 W) with a 19 mm jet and limited heating. The He-APPJ achieved good sterilization performances within very short treatment time (as short as 30 s). For surface sterilization, the area of clear zone and size of the plaque were 1809 mm2 and 48 mm, respectively, within 5 min treatment. For water sterilization, 99.8% sterilization efficiency was achieved within 5 min treatment. The optic emission spectra suggest that active species such as excited molecules, ions, and radicals were produced in the He-APPJ. The as-produced active species played important roles in the sterilization process. [ABSTRACT FROM AUTHOR]

Based on the dynamic design of the large deformation of weak surrounding rock in Muzhailing Tunnel, the article introduced the special geological environment of the tunnel, analyzed the causes of the primary support intruding into tunnel structure gauge and the secondary lining cracking during construction, and studied the special measures to solve the problem of the large deformation in weak surrounding rock with extreme crystal stress, such as the multiple support system, enlargement of the advance heading for stress release, the reinforcement of long system anchor bolt (anchor cable), the reinforcement of invert steel truss and the setting of cushion structure. The engineering practice suggested, the technical countermeasures adopted were safe, reliable and effective, and the problems to be solved in construction were discussed, which could be used for reference in similar projects. [ABSTRACT FROM AUTHOR]

Large lakes and reservoirs play important roles in modulating regional hydrological cycles and climate; however, their representations in coupled models remain uncertain. The existing lake module in the Weather Research and Forecasting (WRF) system (hereafter WRF-Lake), although widely used, did not accurately predict temperature profiles in deep lakes mainly due to its poor lake surface property parameterizations and underestimation of heat transfer between lake layers. We therefore revised WRF-Lake by improving its (1) numerical discretization scheme; (2) surface property parameterization; (3) diffusivity parameterization for deep lakes; and (4) convection scheme, the outcome of which became WRF-rLake (i.e., revised lake model). We evaluated the off-line WRF-rLake by comparing simulated and measured water temperature at the Nuozhadu Reservoir, a deep reservoir in southwestern China. WRF-rLake performs better than its predecessor by reducing the root-mean-square error (RMSE) against observed lake surface temperatures (LSTs) from 1.4 to 1.1 ∘ C and consistently improving simulated vertical temperature profiles. We also evaluated the sensitivity of simulated water temperature and surface energy fluxes to various modeled lake processes. We found (1) large changes in surface energy balance fluxes (up to 60 W m -2) associated with the improved surface property parameterization and (2) that the simulated lake thermal structure depends strongly on the light extinction coefficient and vertical diffusivity. Although currently only evaluated at the Nuozhadu Reservoir, we expect that these model parameterization and structural improvements could be general and therefore recommend further testing at other deep lakes and reservoirs. [ABSTRACT FROM AUTHOR]

In this work, an effective and versatile modification approach of palladium (Pd)/nitrogen doped carbon by iron series element for the semihydrogenation of phenylacetylene is presented. Pd and iron series element M (M=Fe, Co or Ni) particles were co‐reduced and supported on nitrogen‐doped activated carbon (Pd−M/NC). Experimental results showed that the Pd−M/NC exhibited relatively good catalytic performance when the Pd/M content mass ratio was approximately 1 : 1. The selectivity of styrene could be maintained at relatively good levels even with the prolongation of reaction time. The good catalytic effect of the Pd−M/NC may be attributed to the incorporation of iron series element species. The catalysts had been characterized in detail and contrastive study was made to validate the modification effect. The catalyst could maintain its catalytic activity and selectivity in the recycle process. This work may show industrial application potentiality and developing directions in selective hydrogenation process. Pd does it again! The modification of palladium/nitrogen‐doped carbon with iron series elements M (M=Fe, Co or Ni) species promoted the selectivity for the semihydrogenation of phenylacetylene to styrene. [ABSTRACT FROM AUTHOR]

Fabrication of heterogeneous catalysts with excellent activity, selectivity and stability is significant for various catalytic applications. Here, we prepared a hypercrosslinked polymer (HCP) via a facile and cost‐effective strategy using ferrocenecarboxaldehyde and melamine as building blocks. Then, the HCP was modified with highly dispersed ultrafine Pd nanoparticles (Pd/HCP). The obtained Pd/HCP shows excellent catalytic activity in the catalytic reduction of nitroarenes under mild reaction conditions. It′s worth mentioning that the N atoms in the HCP can efficiently coordinate Pd ions to form small Pd nanoparticles (NPs) and subsequently prevent the aggregation and leaching of Pd NPs during the reaction, so the Pd/HCP catalyst is highly stable and can be reused at least eight cycles without loss of catalytic activity. Therefore, this work may provide possibilities for using HCPs as ideal supporting materials for fabricating highly stable and efficient heterogeneous catalysts. Aminal kingdom! A highly active Pd/HCP catalyst was prepared via a facile and low‐cost strategy. Ultrafine Pd NPs were stably anchored on the HCP surface with high dispersity. The Pd/HCP catalyst shows excellent catalytic performance for catalytic reduction of nitroarenes. [ABSTRACT FROM AUTHOR]

The internal structure design of membrane module is very important for gas removal performance using membrane contactor via physical absorption. In this study, a novel membrane contactor developed by weaving polytetrafluoroethylene (PTFE) hollow fibers was applied to remove CO2 from 60% N2 + 40% CO2 mixture (with CO2 concentration similar to that of biogas) at elevated pressure (0.8 MPa) using water as absorbent. Compared with the conventional module with randomly packed straight fibers, the module with woven PTFE fibers exhibited much better CO2 absorption performance. The weaving configuration facilitated the meandering flow or Dean vortices and renewing speed of water around hollow fibers. Meanwhile, the undesired influences such as channeling and bypassing were also eliminated. Consequently, the mass transfer of liquid phase was greatly improved and the CO2 removal efficiency was significantly enhanced. The effects of operation pressure, module arrangement, feed gas, and water flow rate on CO2 removal were systematically investigated as well. The overall mass‐transfer coefficient (KOV) varied from 1.96 × 10−5 to 4.39 × 10−5 m/s (the volumetric mass‐transfer coefficient KLa = 0.034–0.075 s−1) under the experimental conditions. The CO2 removal performance of novel woven fiber membrane contactor matched well with the simulation results. © 2017 American Institute of Chemical Engineers AIChE J, 64: 2135–2145, 2018 [ABSTRACT FROM AUTHOR]

In this work, a slippery lubricant-infused surface (LIS) was prepared by simple one-step mixing of polydimethylsiloxane (PDMS) resin and dimethyl silicone oil (PMX-200) directly. Silicone oil showed good compatibility with PDMS resin, and the added amount of silicone oil had no significant effect on the surface morphology of LIS. According to the results of surface observations, once the silicone oil film anchored on the LIS was removed, the silicone oil inside the PDMS polymer automatically diffused to the surface and formed a new silicone oil film again in a short time. Furthermore, with the increase of silicone oil content, the oil self-replenishment speed and amount of the LIS were enhanced, which also promoted a decrease of the surface water sliding angle and the improvement of the lubrication ability of the LIS. In the icing/deicing cycle tests, the slippery LIS still maintained very low ice adhesion strength after 24 cycles, showing excellent anti-icing performance. [ABSTRACT FROM AUTHOR]

Reservoirs change downstream thermal regimes by releasing water of different temperatures to that under natural conditions, which may then alter downstream biodiversity and ecological processes. The hydropower exploitation in the mainstream Lancang-Mekong River has triggered concern for its potential effects on downstream countries, especially the impact of the released cold water on local fishery production. However, it was observed recently that the annual water temperature downstream of the Jinghong Reservoir (near the Chinese border) has increased by 3.0 °C compared to its historical average (1997–2004). In this study, a three-dimensional (3D) model of the Jinghong Reservoir was established to simulate its hydro- and thermodynamics. Results show that: (1) the impoundment of the Jinghong Reservoir contributed about 1.3 °C to the increment of the water temperature; (2) the solar radiation played a much more important role in comparison with atmosphere-water heat exchange in changing water temperatures; and (3) the outflow rate also imposed a significant influence on the water temperature by regulating the residence time. After impoundment, the residence time increased from 3 days to 11 days, which means that the duration that the water body can absorb solar radiation has been prolonged. The results explain the heating mechanism of the Jinghong Reservoir brought to downstream water temperatures. [ABSTRACT FROM AUTHOR]