14 research outputs found

    Optical Phase Conjugation Conversion through a Nonlinear Bidirectional Semiconductor Optical Amplifier Configuration

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    The optical phase conjugation (OPC) process is thoughtfully investigated in a nonlinear bidirectional semiconductor optical amplifier subsystem (SOA), demonstrating the conjugation conversion through the two ports of the SOA, simultaneously. The spectral responses, the nonlinear power curves and the quality optimization of the conjugated are discussed through the simulation in nonlinear bidirectional configuration. The experimental investigation of the polarization-insensitive SOA further confirms the OPC behavior in the bidirectional operation, achieving the error-free conjugation conversion with an output optical signal-to-noise ratio (OSNR) of up to 16 dB. The nonlinear bidirectional SOA configuration tested in the system relaxes the requirement of the conventional four-wave mixing (FWM), enabling the OPC conversion with the signal regeneration in only one unit

    Adsorption of Phenol and <i>p</i>‑Nitrophenol from Aqueous Solutions on Metal–Organic Frameworks: Effect of Hydrogen Bonding

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    Three metal–organic frameworks (MOFs), MIL-100­(Fe, Cr) and NH<sub>2</sub>-MIL-101­(Al), were prepared, and their adsorption equilibria for phenol and <i>p</i>-nitrophenol (PNP) from water were investigated. All three MOFs show similar and limited adsorption capacities for phenol, but NH<sub>2</sub>-MIL-101­(Al) reveals exceptional adsorption capacity for PNP, greatly exceeding those of MIL-100­(Fe, Cr). MIL-100­(Fe, Cr) possess similar adsorption affinity for phenol and PNP, which suggests that the effect of metal ions and the coordinatively unsaturated sites in MOFs show negligible effect for phenol and PNP adsorption from water. NH<sub>2</sub>-MIL-101­(Al) exhibits superior adsorption capacity for PNP and uniquely higher adsorption selectivity for PNP over phenol than a benchmark activated carbon. The remarkable adsorption affinity is attributed to the hydrogen bonding between PNP and the amino groups in NH<sub>2</sub>-MIL-101­(Al). Phenol and PNP displayed a fast adsorption kinetics on NH<sub>2</sub>-MIL-101­(Al) and followed a pseudo-second-order kinetic model. This work highlights that introducing functional groups into MOFs through an organic linker is a promising way to tailor MOFs for aqueous adsorption and separation

    Comparative Mapping and Candidate Gene Analysis of SSIIa Associated with Grain Amylopectin Content in Barley (Hordeum vulgare L.)

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    Amylopectin concentration in barley endosperm has important effects on grain quality and end-use. In this study, quantitative trait locus (QTL) analysis together with genome-wide association studies (GWAS) were performed to identify markers linked to grain amylopectin content respectively using a doubled haploid (DH) population of 178 lines and a collection of 185 diverse barley germplasms both genotyped by genotyping-by-sequencing (GBS). A stable QTL on chromosome 7H and 11 associated single nucleotide polymorphisms (SNPs) were detected. In the co-localized region, the SSIIa (SSII-3) gene was predicted as the candidate gene. Then we isolated and characterized biparental SSIIa alleles of the DH population, investigated the expression pattern by quantitative real-time PCR (qRT-PCR), and revealed that a 33-bp deletion in exon 2 is responsible for reducing SSIIa transcript, thus resulting in a reduced amylopectin content. A sequence-based molecular marker was developed for the SSIIa allele and validated the effectivity, which would provide help for barley breeding

    Geological characteristics and models of fault-fold-fracture body in deep tight sandstone of the second member of Upper Triassic Xujiahe Formation in Xinchang structural belt of Sichuan Basin, SW China

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    In the second member of the Upper Triassic Xujiahe Formation (T3x2) in the Xinchang area, western Sichuan Basin, only a low percent of reserves has been recovered, and the geological model of gas reservoir sweet spot remains unclear. Based on a large number of core, field outcrop, test and logging-seismic data, the T3x2 gas reservoir in the Xinchang area is examined. The concept of fault-fold-fracture body (FFFB) is proposed, and its types are recognized. The main factors controlling fracture development are identified, and the geological models of FFFB are established. FFFB refers to faults, folds and associated fractures reservoirs. According to the characteristics and genesis, FFFBs can be divided into three types: fault-fracture body, fold-fracture body, and fault-fold body. In the hanging wall of the fault, the closer to the fault, the more developed the effective fractures; the greater the fold amplitude and the closer to the fold hinge plane, the more developed the effective fractures. Two types of geological models of FFFB are established: fault-fold fracture, and matrix storage and permeability. The former can be divided into two subtypes: network fracture, and single structural fracture, and the later can be divided into three subtypes: bedding fracture, low permeability pore, and extremely low permeability pore. The process for evaluating favorable FFFB zones was formed to define favorable development targets and support the well deployment for purpose of high production. The study results provide a reference for the exploration and development of deep tight sandstone oil and gas reservoirs in China

    Direct Benzothiophene Formation via Oxygen-Triggered Intermolecular Cyclization of Thiophenols and Alkynes Assisted by Manganese/PhCOOH

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    An intermolecular oxidative cyclization between thiophenols and alkynes for benzothiophene formation has been established. A variety of multifunctional benzothiophenes are synthesized. In addition, we demonstrated that the obtained benzothiophenes can be used for further transformation to give diverse benzothiophene derivatives efficiently and selectively
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