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In this paper, we develop a simple and fast online algorithm for solving a class of binary integer linear programs (LPs) arisen in general resource allocation problem. The algorithm requires only one single pass through the input data and is free of matrix inversion. It can be viewed as both an approximate algorithm for solving binary integer LPs and a fast algorithm for solving online LP problems. The algorithm is inspired by an equivalent form of the dual problem of the relaxed LP and it essentially performs (one-pass) projected stochastic subgradient descent in the dual space. We analyze the algorithm in two different models, stochastic input and random permutation, with minimal technical assumptions on the input data. The algorithm achieves O m n expected regret under the stochastic input model and O (m + log n) n expected regret under the random permutation model, and it achieves O (m n) expected constraint violation under both models, where n is the number of decision variables and m is the number of constraints. The algorithm enjoys the same performance guarantee when generalized to a multi-dimensional LP setting which covers a wider range of applications. In addition, we employ the notion of the permutational Rademacher complexity and derive regret bounds for two earlier online LP algorithms for comparison. Both algorithms improve the regret bound by a factor of m by paying more computational cost. Furthermore, we demonstrate how to convert the possibly infeasible solution to a feasible one through a randomized procedure. Numerical experiments illustrate the general applicability and effectiveness of the algorithms. [ABSTRACT FROM AUTHOR]

In the current investigation, X70 pipeline steel plate was welded using submerged-arc welding. Thereafter, a (Fe0.5Ni0.2)61Cr9Co6Si1.5B17.5Nb5 amorphous alloy coating with a thickness of 400 ± 30 μm was successfully deposited on the surface of welded X70 pipeline steel by high velocity oxy-fuel (HVOF). The corrosion resistance of the substrate and coating in acidic environments was discussed, and the corrosion mechanisms were analyzed. The results show that the coating is completely amorphous with a dense microstructure, showing a typical thermal spray laminar flow-like structure. The corrosion potential (Ecorr) and self-corrosion current density (Icorr) are − 396 mV and 2.061 × 10−6 A/cm2, respectively. The Ecorr of all coatings is better than that of substrate. The coating A, where the BM zone is located, has the largest capacitance resistance arc radius and the smallest Icorr (1.427 × 10−7 A/cm2), which provides the best corrosion resistance. The maximum Icorr of the coating (Icorr = 2.320 × 10−7 A/cm2) is one order of magnitude lower than the minimum Icorr of the substrate (Icorr = 2.061 × 10−6 A/cm2), which indicates that the coating has better corrosion resistance than the substrate. The corrosion mechanism of the coating in H2SO4 solution is active dissolution of metal elements in the coating (initial stage) and passivation film protection coating (later stage). This work provides a very valuable idea to solve the problem of corrosion failure of X70 pipeline steel. [ABSTRACT FROM AUTHOR]

Porous silicon (PSi) has become one of the current hotspots in lithium-ion anode materials research. However, due to their large volume change in the charge and discharge processes, which results in poor electrochemical performance, the material's practical value is significantly impacted. In this study, PSi@poly(3,4-ethylenedioxythiophene) (PSi@PEDOT) composites were prepared by coating porous micron Si etched from the commercial Al–Si alloy with a conductive polymer synthesized via the in situ polymerization of 3,4-ethylenedioxythiophene (EDOT). The PEDOT shell not only ensures the conductive network in the composite material but also inhibits Si volume expansion. In addition, the pores inside the PSi material's core layer provide space gaps to buffer Si volume expansion, which can effectively improve its cycling stability and rate performance. Electrochemical test results show that the PSi@PEDOT-2 composite with mass ratio of 1.5:1 exhibits the best cycling stability. The initial discharge capacity is 1338.62 mAh g−1 at a current density of 0.5 A g−1, and the postcapacity retention rate is 70.3% after 200 cycles. Further, the preparation method may be used as an approach for preparing high-performance Si-based anode materials. [ABSTRACT FROM AUTHOR]

A novel layered metal sulfide (K1.87Zn0.13Sn6.4S12.67, KZTS) with high adsorption capacity was synthesized by hydrothermal method for selective removal of Pb2+ ions from wastewater. Scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, thermogravimetric analysis and BET were used to characterize the synthesized materials. The removal efficiency of KZTS for Pb2+ and effects of various factors including the solution pH, adsorption time and initial concentration on the adsorption behavior were evaluated. Under an optimal condition, the maximum adsorption capacity is as high as 431.26 mg·g−1. Moreover, the KZTS exhibited excellent adsorption selectivity against competitive ions such as Ca2+, Cd2+, Co2+, Al3+ and Mn2+. The adsorption kinetics and isotherms were also studied. The adsorption process is in good agreement with the Langmuir adsorption isotherm and conforms to the pseudo-second-order model, indicating that the adsorption of Pb2+ by KZTS is a monolayer chemisorption process. Namely, the adsorption of Pb2+ is mainly caused by the chemical bonding interaction between S2− and Pb2+, accompanying the exchange of K+ ion with Pb2+ ion. The excellent properties of KZTS enable it to be a promising adsorbent for the removal of Pb2+ from heavy metal wastewater. [ABSTRACT FROM AUTHOR]

The characterization of 61 Streptococcus suis strains isolated from Chinese slaughter pigs was investigated. S. suis serotypes 1, 2, 3, 4, 7, 9, 10, 11, 12, 13, 14, 15, 16, 22, 23, 25, 26, 28, 29, and 1/2 were found in the isolates by serum agglutination. Of all the prevalent serotypes, S. suis serotype 7 is the most predominant circulating in Chinese slaughter pigs. The virulence-associated genes profile and multilocus sequence typing scheme of the isolates were analyzed. The mrp-/ epf-/ sly- virulence-associated genes type is the most prevalent in the isolates from slaughter pigs. It is the first time to find S. suis serotypes 7 and 9 isolates with epf. The serotypes 7 and 9 isolates with mrp and/or epf genes did not express MRP and/or EF in the present research. Thirteen new ST types were identified for the first time. ST1 complex and ST27 complex of S. suis are prevalent in China. This paper supplied information to understand the characteristics, such as capsular serotypes, virulence factors, and gene backgrounds of S. suis carried by slaughter pigs. [ABSTRACT FROM AUTHOR]

The voltage-gated chloride channel (CLC) superfamily is one of the most important anion channels that is widely distributed in bacteria and plants. CLC is involved in transporting various anions such as chloride (Cl-) and fluoride (F-) in and out of cells. Although Camellia sinensis is a hyper-accumulated F plant, there is no studies on the CLC gene superfamily in the tea plant. Here, 8 CLC genes were identified from C. sinensis and they were named CsCLC1-8. The structure of CsCLC genes and the proteins were not conserved; the number of exons varied from 3 to 24, and the number of transmembrane domains contained 2 to 10. Furthermore, phylogenetic analysis revealed that CsCLC4-8 in subclass I contained the typical conserved domains GxGIPE (I), GKxGPxxH (II) and PxxGxLF (III), and CsCLC1-3 in subclass II did not contain any of the three conserved residues. We measured the expression levels of CsCLCs in roots, stems and leaves to assess the responses to different concentrations of Cl- and F-. The result indicated that CsCLCs participated in subfunctionalization in response to Cl- and F-, and CsCLC1-3 was more sensitive to F- treatments than CsCLC4-8, CsCLC6 and CsCLC7 may participate in absorption and long-distance transport of Cl-. [ABSTRACT FROM AUTHOR]