[en] This paper investigates a new formation motion problem of a class of first-order multi-agent systems with antagonistic interactions. A distributed formation control algorithm is proposed for each agent to realize the antagonistic formation motion. A sufficient condition is derived to ensure that all of the agents make an antagonistic formation motion in a distributed manner. It is shown that all of the agents can be spontaneously divided into several groups and that agents in the same group collaborate while agents in different groups compete. Finally, a numerical simulation is included to demonstrate our theoretical results. (paper)

[en] Geological disposal is thought as the best ultimate disposal way of High-Level-Radioactive -Wastes (HLW) to separate them from biosphere permanently with a multiple-barrier system. The man-made barriers are composed of bentonite and canisters, which play an important role in avoiding HLW leaking. However, once bentonite is soaked by underground water, corrosion of may happen causing the leakage of HLW. Therefore, it's necessary to learn about the corrosion behavior of carbon steel simulated geological disposal conditions. Former studies focus more on the corrosion behavior of carbon steel in underground water without bentonite. The states of the carbon steel surfaces are determined by corrosion potential and the corrosion rates could be calculated by electrochemical impedance spectroscopy. This passage compared the corrosion behavior of carbon steel with bentonite and without bentonite using in-situ electrochemical measurements. Experiments showed that carbon steel would rather passivate when in simulated underground water with high concentrations of HCO₃^- and without bentonite while it is more prone to activate with low concentrations of HCO₃^-. But carbon steel would activate with bentonite and the concentrations of HCO₃^- had little influence on the corrosion modes. What's more, the in-situ EIS results showed that corrosion rates of carbon steel were smaller in bentonite/underground-water than in according underground-water. (authors)

[en] A new-style cigarette works by a battery-powered device heating cut-tobacco to generate an aerosol. This product heats the tobacco at low temperature and produces less harmful and potentially harmful constituents (HPHCs). In this paper, a heat not burn tobacco product has been designed, and the heat transfer process in the cigarette has been studied based on a porous medium theory. Both of viscous resistance and inertia force effect on pressure gradient have been considered using Darcy-Forchheimer model. After numerical simulation the process of gas traversing the cut-tobacco medium, the temperature field distribution has been acquired in the new-style cigarette. The result shows the heating system of the heat not burn tobacco product satisfies the demand of temperature control. The aerosol of the new style cigarette can reduce the yield of tobacco combustion produces. (paper)

[en] Highlights: • Robust superhydrophobic surfaces were facilely constructed with a water-based formula. • Low free energy particles were incorporated into an aqueous system without surfactant. • The coatings can stand abrasion up to 1200 cycles even with a rough sand paper. • Good water resistance and promising oil/water separation function were achieved. • Content of low free energy particles were reduced to form superhydrophobic coatings. Resin based superhydrophobic coatings are effective to construct robust superhydrophobic surfaces on large scale without limitation of substrates. However, for most of the common resin based superhydrophobic coatings, it is inevitable to deteriorate environmental or health problems due to release of a large amount volatile solvents. In this work, a kind of water-based organic/inorganic hybrid consisted of acrylate copolymers and superhydrophobic silica nanoparticles were synthesized. The highly water-repellent silica nanoparticles were successfully involved into the aqueous dispersion of acrylate copolymers without additional surfactants. The as-synthesized hybrids simultaneously retain the excellent film-forming property of acrylate resins and amplify the contributions of low surface energy nanoparticles to the superhydrophobicity. Robust superhydrophobic coatings (CA > 160°, CA < 7°) with high adhesion strength, good scratch-resistance and excellent abrasion-resistance were constructed using the synthesized hybrids with significantly reduced content of low surface energy particles and organic solvent. The hybrid coating can stand abrasion up to 300 cycles with a fine sand paper and up to 1200 cycles under rough sand paper abrasion. Benefited from its good water-repellence property, the hybrid coating with a water-based formula not only showed improved water-resistance in comparison with commercial products; but also displayed attractive performances in self-cleaning and oil/water separation processes.

[en] The mechanical durability, especially wear-resistance seriously restricts the practical application of superhydrophobic surfaces. Lots of efforts have been put to improve the mechanical durability of superhydrophobic surfaces. However, due to the lack of a standard evaluation criterion, it is inaccurate to evaluate the mechanical durability of superhydrophobic surfaces by merely comparing the abrasion cycles or distance it can stand before losing superhydrophobicity. In this paper, the wear-resistance of superhydrophobic surfaces against sandpaper abrasion was evaluated based on a typical resin-hydrophobic filler formula. The mechanical strength, coefficient of friction and evolution of superhydrophobicity with growing abrasion cycles of as-prepared superhydrophobic surfaces were carefully studied by considering the hydrophobic filler sizes. In spite that superhydrophobic surfaces can all be achieved with hydrophobic fillers from nano-meter scale particles to micro-meter scale clusters at a certain content, the larger the filler size, the better the wear-resistance. For superhydrophobic coatings with a given surface roughness, its superhydrophobicity can be preserved when abraded against items which were rougher than coating itself. Furthermore, drag reduction performance of the developed superhydrophobic surfaces was evaluated against the polymer solution. This work will provide useful clues for establishing the standard to evaluate the wear-resistance of superhydrophobic coatings.

[en] An adsorption resin CX-6 was synthesized and used for acid soluble lignin (ASL) removal from sugarcane bagasse hydrolysate (SCBH). The adsorption conditions of pH value, amount of adsorbent, initial ASL concentration, and temperature on ASL adsorption were discussed. The results showed the adsorption capacity of ASL was negatively affected by increasing temperature, solution pH, and adsorbent dose, and was positively affected by increasing initial concentration. The maximum adsorption capacity of ASL was 135.3 mg/g at initial ASL concentration 6.46 g/L, adsorption temperature 298 K, and pH 1. Thermodynamic study demonstrated that the adsorption process was spontaneous and exothermic. Equilibrium and kinetics experiments were proved to fit the Freundlich isotherm model and pseudo-second-order model well, respectively. Fermentation experiment showed that the SCBH after combined overliming with resin adsorption as fermentation substrate for microbial lipid production by Trichosporon cutaneum and Trichosporon coremiiforme was as better as that of SCBH by combined overliming with active charcoal adsorption, and more efficient than that of SCBH only by overliming. Moreover, the regeneration experiment indicated that the CX-6 resin is easy to regenerate and its recirculated performance is stable. In conclusion, our results provide a promising adsorbent to detoxify lignocellulose hydrolysate for further fermentation.

[en] Paraelectric state ferroelectric material is proposed as a novel substitution for the conventional high-k dielectric used in AlGaN/GaN metal-insulator-semiconductor (MIS) field-effect transistors. Its superior potential for improving device transconductance is due to its unique switchable polar nature. By self-consistent calculation involving the switchable polarization of the paraelectric, the 2DEG properties and C—V characteristics are investigated and compared for the novel AlGaN/GaN metal-paraelectric-semiconductor (MPS) structure and an equivalent conventional MIS structure. It is shown that owing to the paraelectric polarization, the gate control of the 2DEG density is remarkably enhanced in the MPS structure and the gate capacitance is significantly improved with a smaller threshold voltage. The self-consistent polarization of the paraelectric in the MPS structure is non-linearly dependent on the saturated polarization, which implies an optimum saturated polarization of 5–10 μC/cm² for the paraelectric. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

[en] We systematically investigate the polarization gradient cooling (PGC) process in an optical molasses of ultracold cesium atoms. The SR mode for changing the cooling laser, which means that the cooling laser frequency is stepped to the setting value while its intensity is ramped, is found to be the best for the PGC, compared with other modes studied. We verify that the heating effect of the cold atoms, which appears when the cooling laser intensity is lower than the saturation intensity, arises from insufficient polarization gradient cooling. Finally, an exponential decay function with a statistical explanation is introduced to explain the dependence of the cold atom temperature on the PGC interaction time. (atomic and molecular physics)

[en] The transient radial shearing interferometry technique based on fast Fourier transform (FFT) provides a means for the measurement of the wavefront phase of transient light field. However, which factors affect the spatial bandwidth of the wavefront phase measurement of this technology and how to achieve high-precision measurement of the broad-band transient wavefront phase are problems that need to be studied further. To this end, a theoretical model of phase-retrieved bandwidth of radial shearing interferometry is established in this paper. The influence of the spatial carrier frequency and the calculation window on phase-retrieved bandwidth is analyzed, and the optimal carrier frequency and calculation window are obtained. On this basis, a broad-band transient radial shearing interference phase-retrieval method based on chirp Z transform (CZT) is proposed, and the corresponding algorithm is given. Through theoretical simulation, a known phase is used to generate the interferogram and it is retrieved by the traditional method and the proposed method respectively. The residual wavefront RMS of the traditional method is 0.146λ, and it is 0.037λ for the proposed method, which manifests an improvement of accuracy by an order of magnitude. At the same time, different levels of signal-to-noise ratios (SNRs) from 50 dB to 10 dB of the interferogram are simulated, and the RMS of the residual wavefront is from 0.040λ to 0.066λ. In terms of experiments, an experimental verification device based on a phase-only spatial light modulator is built, and the known phase on the modulator is retrieved from the actual interferogram. The RMS of the residual wavefront retrieved through FFT is 0.112λ, and it decreases to 0.035λ through CZT. The experimental results verify the effectiveness of the method proposed in this paper. Furthermore, the method can be used in other types of spatial carrier frequency interference, such as lateral shearing interference, rotational shearing interference, flipping shearing interference, and four-wave shearing interference. (paper)

[en] Ultracold polar RbCs molecules are produced via photoassociation in a laser-cooled mixture of ⁸⁵Rb and ¹³³Cs atoms. The a³Σ⁺ state molecules which decay from electronically excited (2)0⁻ state RbCs molecules are detected by resonance-enhanced two-photon ionization. The new rovibrational levels (v = 189, 190) in the (2)0⁻ state are also observed, which exist in theory and have not been observed in experiments yet. The corresponding rotational constants are measured by photoassociation spectroscopy, which are consistent with theoretical calculations using a nonrigid rotor model. (atomic and molecular physics)