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Prediction and management of soil antibiotic contamination issues have gained popularity in recent years. In order to understand the effect of activated carbon on the migration of antibiotics in soil at different temperatures, the vertical migration mechanism of oxytetracycline hydrochloride in charcoal soil was studied. Based on soil column test and numerical simulation, the results indicated that adding low content of activated carbon into soil can obviously enhance the adsorption of antibiotics in soil and inhibit the migration of antibiotics in soil. Hydrus-1D software was used to run numerical simulations, with the adsorption partition coefficient having the most impact on the outcomes. The adsorption distribution coefficient is corrected by theoretical value and inversion value, the value of \({\phi }\) is 0.88.

The structure of polyolefin has an important influence on its performance and application. Ethylene/1-hexene copolymerization is one of the important ways to control the structure of the polyolefin. However, research on the ethylene/1-hexene copolymerization catalyzed by nickel complexes with different steric ligands remains to be refined. Here, three α-diimine nickel catalysts are used to study the ligand effect on catalytic performance in the ethylene/1-hexene copolymerization. Reaction activity, molecular weight, phase-transition temperature and branching density of the resultant copolymer are measured to evaluate the catalytic performance. The results indicate that the steric ligands could exert great effect on the copolymerization. As for the chemical valance of Ni species, detailed EPR demonstrate that the presence of excess co-catalyst can reduce Ni(II) to the lower valance and affect the catalytic performance.

In this article, glucose-responsive polymers were synthesized by introducing hydrophilic monomer N-vinyl-2-pyrrolidone and amino-containing monomer N,N-dimethylaminopropyl acrylamide to make phenylboronic acid-based polymers able to response in physiological temperature and physiological pH. The chemical structure of the polymer was confirmed by NMR spectroscopy. The aqueous solutions of polymer were characterized by lower critical solution temperature, which increased with rise of glucose concentration. Further, the glucose-sensitive microgels were prepared by reversed-phase microemulsion method. The results showed that the microgels could response at physiological environment and the particle size of microgels increased with increasing glucose concentration.

High molecular weight polyvinylpyrrolidone (PVP) and seeding conditions are considered to have important roles in the synthesis of AgNWs. In this work, we report a versatile synthesis of AgNWs in a salt-free environment and under Ar inert atmosphere using high molecular weight PVP and seeding step during the synthetic process. The high molecular weight PVP was found to efficiently promote the preparation of AgNWs via supporting the proper growth control of AgNWs on {111} facets and selective growth on {100} facets. The seeding step facilitates the formation of seeds such as multiple twinned nanoparticles (MTPs) and single crystal seeds, which promoted the feasible formation of AgNWs. The shape and size of the synthesized AgNWs were characterized by SEM and TEM. The crystalline nature of the synthesized AgNWs was characterized by HRTEM, SAED and XRD, and their LSPR peaks were confirmed by UV-Vis spectroscopy. The conductive properties of the synthesized AgNWs were determined by preparing their thin conductive film on a PET substrate. The prepared AgNWs thin films exhibited good sheet resistance.

Shape memory polymers (SMPs), as a class of intelligent materials, have shown great potential in biomedical and robotic fields. Although efforts have been made to design and fabricate SMPs in the p...

In this study, based on α-diimine-Ni(II) complex/MAO catalytic system, 1-octene was introduced into polyethylene chain to change the microstructure. The effects of reaction temperature, Al/Ni ratio and concentration of 1-octene on the catalytic effect were investigated. Furthermore, the differences between α-olefin homopolymerization and ethylene/α-olefin copolymerization were compared, and the differences between ethylene insertion and α-olefin insertion catalyzed by α-diimine-Ni(II) complex were studied. α-Diimine-Ni(II) complex tends to catalyze ethylene polymerization to form highly branched segments and catalyze α-olefin polymerization to form relatively linear segments due to the “chain walking” ability. The results of mechanical tests show that the synthesized ethylene/1-octene copolymers are polyolefin elastomers with excellent tensile properties. EPR was also employed to analyze the formation of Ni(I) species in the catalytic system and the catalytic mechanism.

With the continuous development of renewable energy sources, high-energy high-density lithium metal batteries (LMBs) are urgently needed to store the generated energy. However, the applications of current LMBs are severely limited by the formation of lithium dendrites and infinite volume expansion during cycling. Herein, we adopt a simple method to melt and mix a specified proportion of silicon, zinc oxide, and lithium to prepare a Li/Si/ZnO (LiSZ) composite anode. The mixture of Si and ZnO, acting as a lithium-philic nonconductive framework not only serve as a stable lithium “host” during the deposition/stripping process of lithium and reduce the expansion of lithium during cycling, but the Li-Si and Li-Zn alloy induce a uniform deposition of Li+, thereby inducing a uniform deposition of Li. The symmetrical LiSZ battery shows an exceedingly low hysteresis voltage and stable long-cycle performance (more than 900 h). In addition, the full LiSZ battery exhibits excellent rate performance. Thus, significant progress is has been made in developing stable lithium anodes for LMBs.

Li metal battery (LMB) is a commonly used chemical battery with excellent application potential in high-energy storage devices. However, several limitations impede the practical application of LMB, such as the uneven deposition of Li+, uncontrolled growth of dendrites and severe side reactions. Herein, we report a lithiophilic Li22Ge5 alloy framework which is fabricated by reacting Li with GeO2 particles. Li22Ge5 alloy framework can serve as a stable Li “host”, provide a fast transport channel for Li+ and reduce volume change. Furthermore, it guides Li+ to deposit at the bottom to prevent a loose structure below the deposited Li layer and suppress the growth of Li dendrites with repeated cycling. Based on the galvanostatic measurements, the symmetric cells with the 3D GeO2-Li electrode exhibit long cycling life at a current density of 1 mA cm−2 with fixed capacity of 1 mA h cm−2 over 1100 h. When GeO2-Li electrode used in the full cells, the coulombic efficiency (CE) of GeO2-Li/ LiFePO4 is 98.53% at 1 C after 200 cycles. Moreover, this work demonstrates that Li22Ge5 acting as a lithiophilic material is an effective method to guide the uniform deposition of Li+ and reduce volume change for Li metal battery.

In this paper, we propose a low complexity hybrid ordered statistics decoding (OSD) successive cancellation (SC) decoding algorithm for the polar codes. By replacing smaller size SC decoder with OSD decoder, we can improve the error correcting performance of the SC algorithm. The size of the OSD decoder can be changed to control the trade-off between the decoding complexity and the error correcting performance of the proposed algorithm. We also provide a method to further simplify the proposed algorithm. Simulation results show that the proposed algorithm offers about 0.3 dB gain comparing to the SC at target bit error rate (BER) 10$^{-5}$ with code length N = 1024, 512,256 and code rate R = 1 /3. The impact of the OSD size is also simulated and analyzed.

In this paper, we propose a low-complexity ordered statistics decoding (OSD) algorithm called threshold-based OSD (TH-OSD) that uses a threshold on the discrepancy of the candidate codewords to speed up the decoding of short polar codes. To determine the threshold, we use the probability distribution of the discrepancy value of the maximal likelihood codeword with a predefined parameter controlling the trade-off between the error correction performance and the decoding complexity. We also derive an upper-bound of the word error rate (WER) for the proposed algorithm. The complexity analysis shows that our algorithm is faster than the conventional successive cancellation (SC) decoding algorithm in mid-to-high signal-to-noise ratio (SNR) situations and much faster than the SC list (SCL) decoding algorithm. Our addition of a list approach to our proposed algorithm further narrows the error correction performance gap between our TH-OSD and OSD. Our simulation results show that, with appropriate thresholds, our proposed algorithm achieves performance close to OSD&rsquo, s while testing significantly fewer codewords than OSD, especially with low SNR values. Even a small list is sufficient for TH-OSD to match OSD&rsquo, s error rate in short-code scenarios. The algorithm can be easily extended to longer code lengths.

Lithium–sulfur (Li–S) batteries have attracted significant attention due to their high theoretical specific capacity (1675 mAh g−1) and energy density (2600 Wh kg−1) as well as abundant natural reserves. However, polysulfide shuttling, low conductivity of sulfur species and low cell energy densities hinder the practical applications of these batteries. Herein, carbon nanofiber (CNF) is subjected to excimer ultraviolet (EUV) irradiation in ZnCl2 solution affording ZnO grains attached to the CNF (denoted as EUV-ZnO/CNF) as an interlayer for Li–S batteries. EUV-ZnO/CNF shows strong chemical anchoring and physical block effects on the polysulfides as CNF provide a conductive network allowing the fast transmission of electrons, and ZnO particles provide active sites to adsorb the polysulfide intermediate. The electrode with the EUV-ZnO/CNF interlayer exhibits a high initial discharge capacity of 1388.3 mAh g−1, and a capacity of 780.4 mAh g−1 is retained after 200 cycles with S loading of 1.55 mg cm−2. Our work demonstrates an effective and environmentally friendly method to prepare EUV-ZnO/CNF as an interlayer for high performance Li–S batteries.

Silicon anodes are one of the most promising candidate materials for next-generation lithium-ion batteries because of their high theoretical capacity and natural abundance. Unfortunately, the poor conductivity of silicon and large volume expansion (>400%) during the cycle restrict its commercialization. Herein, we combine Si with stable TiO2 and electrically conductive Ti2O3 to significantly increase the capacity and cycle stability of the Si-based anodes. The preparation of a Si/TiO2/Ti2O3-Carbon Nanofiber (denoted as STTC) composite via mechanical blending, electrospinning and subsequent carbonization of Si, TiO2, and polyacrylonitrile (PAN). This material exhibits a reversible specific capacity of 924 mAh g−1 after 500 cycles of 1 A g−1 current density. Moreover, it also exhibits excellent rate performance even at current densities of 6 A g−1. The outstanding electrochemical performance can be ascribed to Ti2O3 generates in the carbonization process has high ion diffusivity and electrical conductivity. Furthermore, the disordered frame of TiO2/Ti2O3 forms voids, which can alleviate the volume expansion of silicon, maintain the electrode integrity during charge and discharge, and form a thin and stable solid electrolyte interphase (SEI). Additionally, the conductive frame of carbon nanofibers also significantly improves the ion and electron conductivity of the complete electrode.

The reported new U-Pb age by sensitive high-resolution ion microprobe (SHRIMP II) on zircon was obtained from a tuff sample at the basal Doushantuo Formation in the Jiuqunao section, which situated at the western limb of the Huangling anticline in the Yangtze Gorges in Zigui, Hubei, South China. Eighteen spots of zircons were analyzed and they form two clusters: one includes three spots, with an inherited age of 784±15 Ma (MSWD=0.05); the other consists of 15 spots and gives a weighted mean 206Pb/238U age of 628.3±5.8 Ma (MSWD=0.86). It is the first SHRIMP U-Pb zircon age obtained nearly the base of the Doushantuo Formation of Ediacaran and represents a maximum age of the Doushantuo Formation It also forms an age constraint on the upper limit age of the Nantuo (Marinoantype) glaciation.