摘要：A series of novel 4,5-disubstituted-3-S-（β-D-acetylglycosyl）-l,2,4-triazole derivatives was designed and synthesized via the strategy of introducing S-β-D-acetylglycosyl fragments into 1,2,4-triazole ring. The structures of 17 target compounds were characterized by means of lH NMR, 13C NMR and high-resolution mass spectrometer （HRMS）. The results of insecticidal activity indicated that compound 5a displayed 60% lethality rate at 100 mg/L concentration. More importantly, the introduction of the carbohydrate fragment to the 1,2,4-triazole core could im- prove the insecticidal activities since the insecticidal activities of compounds 5 were better than those of compounds 4 and this result was also supported by calcium imaging technique. The antifungal activity of the target compounds showed that some novel compounds displayed moderate to good inhibition rate against Sclerotinia sclerotiorum and Botrytis cinerea, in which compound 5p exhibited 78.8% inhibition rate against Sclerotinia sclerotiorum and 68.6% inhibition rate against Botrytis cinerea. The herbicidal activities of compounds 5 against Brassica campestris indi- cated that most of the target compounds showed moderate to good activities, especially compound 5g which showed 52.9% herbicidal activity at the concentration of 200 mg/L.

摘要：Hierarchical Pt-alloys enriched with active sites are highly desirable for efficient catalysis,but their syntheses generally need time-consuming and elaborate annealing treatment at high *** herein report a surface active-site engineering strategy for constructing the hierarchical PtNi nanocatalysts with an atomic Pt-skin layer(PtNi@Pt-SL)towards efficient triiodide reduction reaction(TRR)via an acid-dealloying *** facile acid-dealloying process promotes the formation of surface Pt active sites on the hierarchical Pt-alloys,and thus results in good catalytic performance towards *** calculation reveals that the enhanced catalytic property stems from the moderate energy barriers for iodide atoms on the surface Pt *** surface active-site engineering strategy paves a new way for the design of active and durable electrocatalysts.

摘要：Cu-based catalysts are commonly used in industry for methanol *** this study,supported catalysts of 5 wt%Cu/Al_(2)O_(3)and 5 wt%Cu/ZnO were prepared,and their surface characteristics during H_(2) reduction and CO_(2)hydrogenation were investigated using in situ Fourier transform infrared spectroscopy(FTIR),ex situ X-ray photoelectron spectroscopy,and high sensitivity low energy ion scattering *** the H2 reduction and CO_(2)hydrogenation processes,it was found that Al_(2)O_(3)can stabilize Cu^(+).In situ FTIR spectra indicated that the 5 wt%Cu/Al_(2)O_(3)can adsorb large amounts of bicarbonate and carbonate species,which then convert into formate during CO_(2)*** the 5 wt%Cu/ZnO,it was found that Cu nanoparticles were gradually covered by a highly defective ZnOx overlayer during H2 reduction,which can effectively dissociate *** CO_(2)hydrogenation,the adsorbed bicarbonate or carbonate species can convert into formate and then into a methoxy *** these surface sensitive methods,a more in-depth understanding of the synergistic effect among the Cu,Al_(2)O_(3),and ZnO components of Cu-based catalysts was achieved.

摘要：A successful qualitative and quantitative analysis of polycyclic aromatic hydrocarbons (PAHs) in air-borne particulates in Hong Kong City has been carried out by the heuristic evolving latent projection (HELP) method recently developed in chemometrics. The resolution result showed that 47 compounds were involved in this sample. Eighteen of them were interesting PAHs and/or their derivatives. The result agreed very well with the one obtained by capillary column GGMS. The resolved UV-visible spectra match well with the standards. With the help of HELP method, accurate quantitative results were also obtained for all the overlapping peaks. The separation ability of chromatography is greatly enhanced by chemometric methods. The HELP method provides a completely new way for quick and accurate analysis of the two-dimensional data produced by hyphenated chromatographic instruments.

摘要：Gas sensors have received extensive attention because of the gas pollution caused by rapid construction of urbanization and *** sensors based on semiconductor metal oxide(SMO)have the advantages of high response,excellent repeatability,stability,and cost-effectiveness,and have become extremely important components in the gas sensor *** with regular structures and controllable morphology exhibit more consistent and repeatable ***,during the process of material synthesis,because of the uncontrollability of the microcosm,nanomaterials often show irregularities,unevenness,and other ***,the synthesis of gas sensors with well-aligned one-dimensional(1D)structures,two-dimensional(2D)layered structures,and three-dimensional(3D)hierarchical structures has received extensive *** obtain regular structured nanomaterials with desired morphologies and dimensions,a template-assisted synthesis method with low cost and controllable process seems a very efficient *** this review,we introduce the morphology and performance of SMO sensors with 1D,2D,and 3D structures,discuss the impact of a variety of morphologies on gas sensor performance(response and stability),and shed new light on the synthesis of gas sensing materials with stable structure and excellent performance.

摘要：Climate change caused by the increasing emission of CO_(2)to the atmosphere has become a global *** ameliorate this issue,converting CO_(2)into valuable chemicals is highly desirable,enabling a sustainable low-carbon *** this end,developing efficient catalytic systems for CO_(2)conversion has sparked intense interests from both academia and *** advantage of their highly porous structures and unique properties,metal−organic frameworks(MOFs)have shown great potential as heterogeneous catalysts for CO_(2)*** transformations involving CO_(2)have been accomplished over MOFs-based *** we provide a comprehensive and up-to-date review on recent advances of heterogeneous CO_(2)thermocatalysis using MOFs,highlighting relationships between structures and *** attention is given to the design strategies for improving the catalytic performance of *** available to enrich the catalytic active sites in MOF structures are stressed and their respective impacts on CO_(2)conversion efficiency are *** synergistic effects between each active site within the structure of MOFs and derivatives are *** the end,future perspectives and challenges in CO_(2)conversion by heterogeneous catalysis with MOFs are described.

摘要：Dextran-hyaluronate （Dex-HA） based supermacroporous cryogel scaffolds for soft tissue engineering were prepared by free radical cryo-copolymerization of aqueous solutions containing the dextran methacrylate （Dex-MA） and hyaluronate methacrylate （HA-MA） at various macromonomer concentrations under the freezing condition. It was observed that the suitable total concen- tration of macromonomers for the preparation of Dex-HA cryogel scaffold with satisfied properties was 5% （w/w） at the HA-MA concentration of 1% （w/v）, which was then used to produce the test scaffold. The obtained cryogel scaffold with 5% （w/w） macromonomer solution had high water permeability （5.1 × 10 ^-2m2） and high porosity （92.4%）. The pore diameter examined by scanning electron microscopy （SEM） was in a broad range of 50-135 um with the mean pore diameter of 91 um. Furthermore, the cryogel scaffold also had good elastic nature with the elastic modulus of 17.47±1.44 kPa. The culture of 3T3-L1 preadipocyte within the scaffold was investigated and observed by SEM. Cells clustered on the pore walls and grew inside the scaffold indicating the Dex-HA cryogel scaffold could be a promising porous biomaterial for applications in tissue engineering.

摘要：The electrolysis of water powered by renewable energy sources offers a promising method of"green hydrogen"production,which is considered to be at the heart of future carbon-neutral energy *** the past decades,researchers have reported a number of hydrogen evolution reaction(HER)electrocatalysts with activity comparable to that of commercial Pt/C,but most of them are tested within a small current density range,typically no more than 500 mA cm^(-2).To realize the industrial application of hydrogen production from water electrolysis,it is essential to develop high-efficiency HER electrocatalysts at high current density(HCD≥500 mA cm^(-2)).Nevertheless,it remains challenging and significant to rational design HCD electrocatalysts for *** this paper,the design strategy of HCD electrocatalysts is discussed,and some HCD electrocatalysts for HER are reviewed in seven categories(alloy,metal oxide,metal hydroxide,metal sulfide/selenide,metal nitride,metal phosphide and other derived electrocatalysts).At the end of this article,we also pro-pose some viewpoints and prospects for the future development and research directions of HCD electrocatalysts for HER.

摘要：铂(Pt)是质子交换膜燃料电池(PEMFCs)阳极氢氧化反应(HOR)中最先进的电催化剂.然而,Pt催化剂对CO(工业低成本氢燃料中的杂质)极度敏感从而中毒,这会引起器件性能的急剧衰退,导致器件运行成本高.因此,提高Pt催化剂的CO耐受性对PEMFCs的商业化推广至关重要.在此,我们设计合成了一种独特的PtNiW@WO_(x)核壳纳米线来提高Pt基催化剂对CO的耐受能力.机理研究表明,表面无定形的WO_(x)壳层可以作为分子围栏,在动力学上阻碍CO扩散到达Pt位点.在热力学上,Ni和W元素合金化产生的电子效应可以使Pt的d带中心降低,减弱CO在Pt位点上的化学吸附.此外,亲氧W元素可以加速水的解离,提供更多OH活性物种,促进CO的氧化脱附.因此,在1000ppm CO/H_(2)条件下,所设计的PtNiW@WO_(x)核壳纳米线催化剂表现出优异的HOR抗CO中毒性能,在4000 s后仍能保持超过90%的HOR电流密度,超过了原始的PtNi纳米线和目前报道的绝大多数Pt基催化剂.

摘要：The one-pot assembly reaction of a trilacunary,lone-pair-containing[B-α-SbW9O33]*** with Co2+ions in an aqueous medium led to the isolation of a novel{SbO3(H2O)3}bridging,dicobalt-substituted,sandwich-type tungstoantimonate{Co2Sb2(H2O)10[B-β-SbW9O33]2}^4–(1a).This compound was structurally characterized in the solid state by single-crystal X-ray diffraction,elemental analyses,thermogravimetric analysis,and IR *** most remarkable feature was that 1a comprises two trilacunary[B-β-SbW9O33]9^-fragments trapping a novel,centrally symmetric,rhomb-like{Co2Sb2}belt with 10 terminal water *** combined with the photosensitizer[Ru(bpy)3]^2+and the sacrificial electron acceptor S2O82.,1a exhibited efficient catalytic activity for water oxidation with a remarkable turnover number(TON)of 193,initial turnover frequency(TOFinitial)of 5.3 s^-1,O2 yield of 30.8%,and quantum yield(ФQY)of 36.2%under light-driven conditions.