改性阳离子交换树脂的制备、表征及催化合成双酚F

用浸渍法制备了改性阳离子交换树脂,通过红外光谱、热重分析和扫描电镜等对其进行了分析,探讨了不同改性树脂对以苯酚和甲醛为原料催化合成双酚F收率的影响。当等摩尔比Al Cl3和Ti Cl4加入总量为树脂质量的8%,反应温度为80℃,改性时间为10h,Al Cl3-Ti Cl4改性阳离子交换树脂催化合成双酚F,其收率高达90.02%,比未改性或Al Cl3单独改性树脂的催化效果都好,其重复利用率也优于后两者。结果说明,Al Cl3-Ti Cl4改性阳离子交换树脂催化性能好,是一种环境友好高效合成双酚F的催化剂。     

新型咔唑类卟啉的合成与性能

以咔唑、对氟苯甲醛和吡咯为原料制得meso-四（4-咔唑）苯基卟啉（TCPP）。以对硝基苯甲醛与吡咯为原料制得meso-四(4-硝基)苯基卟啉（TNPP）； TNPP经还原反应制得meso-四（4-氨基苯基）卟啉（TAPP）; TAPP与咔唑苯甲醛经缩合反应制得新型meso-四[对-（P-N-咔唑基亚苄基亚氨基）]苯基卟啉(TCIPP)，其结构和性能经UV-Vis, ¹H NMR, ¹³C NMR, IR,元素分析和循环伏安法（CV）表征。结果表明：TCPP在270~300 nm处有新吸收峰；TCIPP的Q带和B带相比于TCPP有明显红移。TCPP和TCIPP的E_LUMO和E_HOMO分别为-3.18 eV, -5.17 eV和-3.49 eV, -5.08 eV，两者的能级结构与纳米TiO₂的导带能级相匹配。     

Mott-Insulator-Superfluid Phase Transition with Coupled-Cavity Frequency Conversion System

An array of coupled cavities, each of which contains a triangle-down-level atom, is investigated. An effective Hamiltonian can be achieved under the strong classical driving. We can control the transition between Mott-insulator and superfluid states by the classical driving. The frequency conversion in one site has the same effects of nonlinear in BH hamiltonian which can induce insulator-superfluid states.     

Co3+-Rich Na1.95CoP2O7 Phosphates as Efficient Bifunctional Catalysts for Oxygen Evolution and Reduction Reactions in Alkaline Solution

Implementing sustainable energy conversion and storage technologies is highly reliant on crucial oxygen electrocatalysis, such as the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). However, the pursuit of low cost, energetic efficient and robust bifunctional catalysts for OER and ORR remains a great challenge. Herein, the novel Na-ion-deficient Na_2−xCoP₂O₇ catalysts are proposed to efficiently electrocatalyze OER and ORR in alkaline solution. The engineering of Na-ion deficiency can tune the electronic structure of Co, and thus tailor the intrinsically electrocatalytic performance. Among the sodium cobalt phosphate catalysts, the Na_1.95CoP₂O₇ (NCPO5) catalyst exhibits the lowest ΔE (E_J10,OER−E_J−1,ORR) of only 0.86 V, which favorably outperforms most of the reported non-noble metal catalysts. Moreover, the Na-ion deficiency can stabilize the phase structure and morphology of NCPO5 during the OER and ORR processes. This study highlights the Na-ion deficient Na_2−xCoP₂O₇ as a promising class of low-cost, highly active and robust bifunctional catalysts for OER and ORR.     

Paraplantaricin L-ZB1, a Novel Bacteriocin and Its Application as a Biopreservative Agent on Quality and Shelf Life of Rainbow Trout Fillets Stored at 4 °C

Paraplantaricin L-ZB1 was produced by Lactobacillus paraplantarum L-ZB1, which was isolated from the traditional China fermented sausage. In this work, paraplantaricin L-ZB1 was used to maintain quality of rainbow trout fillets at 4 °C. Rainbow trout fillets were left untreated (CK) or treated with 200 activity units (AU)/ml paraplantaricin L-ZB1 (P1), 400 AU/ml paraplantaricin L-ZB1 (P2) or 200 AU/ml Nisin (N). The treated samples were stored at 4 °C for up to 10 days, and the quality changes were determined by microbiological (total viable count [TVC], Enterobacteriaceae, Pseudomonas, spore-forming bacteria), sensory, chemical (pH, total volatile basic nitrogen [TVB-N]) and biochemical (biogenic amines, K value) methods. Results show that paraplantaricin L-ZB1 could inhibit the growth of microflora, especially Enterobacteriaceae, Pseudomonas and spore-forming bacteria during sample storage. Meanwhile, the increases of pH, TVB-N, K value and biogenic amine levels were significantly delayed in paraplantaricin L-ZB1-treated samples compared to the control group. Paraplantaricin L-ZB1 of 400 AU/ml extended the rainbow trout fillets’ shelf life to 4–6 days, and the sample showed good sensory characteristics. Therefore, paraplantaricin L-ZB1 could be used as a suitable biological preservative for chilled rainbow trout fillets.     

An efficient label-free immunosensor based on ce-MoS2/AgNR composites and screen-printed electrodes for PSA detection

Journal of Solid State Electrochemistry - Label-free electrochemical immunosensors (EIs) are simple and sensitive in cancer diagnosis. Electrode materials which can offer a large specific area and...