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Fritillaria, a traditional Chinese herbal medicine, is classified into many medicinal species and contains numerous complex components. It is thus difficult to simultaneously detect multiple pesticide residues in different Fritillaria species. An easy, reliable, and widely applicable analytical method based on a modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method coupled with LC-MS/MS was developed to solve these problems encountered during pesticide residue analysis in complex Fritillaria matrices. Ordered mesoporous carbon CMK-3 and a primary secondary amine (PSA) were used as efficient purification sorbents by optimization of the QuEChERS process. Systematic method validation was performed for four species of Fritillaria. The matrix effect of pesticides varied among different Fritillaria species, and matrix-matched standard solutions were thus employed for quantitative analysis. The mean recoveries of all pesticides ranged from 88.6% to 95.5%, with mean relative standard deviations (RSD) lower than 6% at spiked concentrations of 30, 120, and 240 μg kg−1. The limits of quantification (LOQ) for the developed method were in the range of 30–120 μg kg−1. This method was further used to analyze 47 Fritillaria samples from Zhejiang province, China, and seven pesticides were detected in 22 Fritillaria samples. These results demonstrate that the developed method is suitable for an accurate analysis of multiple pesticide residues in various Fritillaria.

An integrated QuEChERS strategy was developed by combining the extraction and purification processes into a single step. All of the pretreatment procedures could be performed in one tube within 5 min with the aid of magnetic nanoparticles and careful optimization of the key parameters, including the dosages of the sorbents (magnetic nanoparticles, C18, and graphitized carbon black), dehydrating and salting out reagents. The optimal method was validated and compared with the conventional QuEChERS method, demonstrating its clear superiority in terms of operating procedure, sample pretreatment time, and reagent dosages while affording equivalent pesticide recoveries and matrix effects. Further application of this method was performed to analyze 127 pesticide residues in solanaceous vegetables (tomato, pepper, and eggplant), leafy vegetables (brassica campestris and cabbage), legumes (green beans and cowpea), melon-type vegetables (cucumber and towel gourd), and a root vegetable (water bamboo), with the mean recoveries of the pesticides in the individual vegetable samples ranging from 70.6 to 92.8%. The method LOQs for these pesticides ranged from 10 to 50 μg/kg depending on the matrix. These results fully confirmed its wide applicability and versatility for achieving robust, rapid, and high-throughput multi-pesticide residues analysis in vegetable samples. More importantly, the developed strategy provides a greener and more “QuEChERS” design concept, which could be applied to the analysis of numerous types of pesticide residues in various matrices.

By rationally introducing multi-interactions sites, supramolecular polymer networks (SPN-TDPG) has been successfully designed and constructed. SPN-TDPG gel shows aggregation-induced emission, meanw...

A novel mushroom-like electrochemical immunoassay for the ultrasensitive detection of histone acetyltransferase activity (HAT p300) has been established on account of the new composite graphene oxide (GO) nanolayer. The immunoassay involves immobilization of substrate peptide onto Au electrode, acetylation in lysine of substrate peptide, and the interaction between acetyl group of lysine and acetyl-antibody (AbAc) of the GO nanolayer. The GO nanolayer comprises large amounts of methylene blue molecules (MB), giving rise to large signal amplification. Only in the presence of HAT p300, an obvious electrochemical signal appears and the peak linear current is proportion to the HAT p300 concentrations ranging from 0.01 to 150 nM with a detection limit of 0.0036 nM. The great enhancement on sensitivity of the proposed mushroom-like immunosensor derives from both the constructed Faraday cage and the extended outer Helmholtz plane (OHP). Further, the immunosensor with excellent sensitivity and selectivity can be applied for the HAT p300 activity detection in Hela cell lysates, serum and urine, hinting an improved and splendid analytical performance. Briefly, this stable, simple and ultrasensitive electrochemical immunoassay has considerable promise for further applications in the HATs-interrelated epigenetic studies and drug development.

It is noteworthy that highly selective molecular recognition endows host-guest gels, especially hydrogel, with valuable properties. Therefore, in pure water, a supramolecular hydrogel (SH-α-CD) was constructed by using benzimidazolium-based positive charged guest molecule (J2) assembled with cyclodextrin (α-CD) through host-guest interaction, and accompanied an aggregation-induced emission (AIE). The self-assemble process of the hydrogel-based AIEgen was investigated using 1H NMR titration, 2D NOESY, XRD and SEM. In particular, the hydrogel-based AIEgen was investigated as a good candidate for fluorescent quenching and gel state destruction dual-channel recognizing negative charged dye molecule methyl orange (MO). The competitive inclusion interaction triggered the dissolution of aggregate, which induced the gel to transform into sol, with disappearance of the AIE of SH-α-CD. However, the addition of the competitive dye molecules methylene blue (MB) and xylenol orange (XO) only made the fluorescence quenching of hydrogel-based AIEgen. Meanwhile, the hydrogel-based AIEgen also exhibited an excellent thermal responsiveness under temperature transition. Such a performance is highly beneficial for potential applications in probe material for organic dye molecules.

s High crystalline Na2Ni[Fe(CN)6] particles are synthesized by a new electrostatic spray assisted coprecipitation method. Their structures and electrochemical properties are analyzed by X-ray powder diffraction, scanning electron microscopy and galvanostatic cell cycling and so on. Given its highly stable structure, the optimized Na2Ni[Fe(CN)6] cathode shows impressive cycling performance with high retention capacity of 89% after 440 cycles at 1 C and excellent rate capability of 56 mAh g−1 at 25 C. In addition, the optimized Na2Ni[Fe(CN)6] cathode achieves superior low temperature performances with retains 87% capacity after 440 cycles at 0 °C and a stable capacity of 54 mAh g−1 can be delivered even at −25 °C after 440 cycles. Such a Na2Ni[Fe(CN)6] sample provides a promising cathode for sodium-ion batteries in large-scale storage systems.

Shape memory hydrogels with capacity of shape deformation after being triggered by physiological stimuli have potential to be used in biomedical fields. In this study, a body temperature and water-responsive shape memory hydrogel with excellent mechanical properties was prepared by crosslinking dopamine-terminated tetra-poly(ethylene glycol) (4-arm PEG) with an oxidation reaction. By adjusting the water content of hydrogels, the temperature/water responsivity and the mechanical properties could be well controlled. Under the synergistic effect of body temperature and water stimulation, the hydrogels can achieve fast shape recovery with a recovery time of 1 min 14 s, and a recovery ratio of 98.9%. Tensile tests reveal that the gel has good mechanical properties. The tensile fracture strength can reach the megapascal level ranging from 2.68 to 13.02 MPa, and the elongation at break can reach 2501%. The integration of body temperature and water-induced shape memory properties and mechanical properties will broaden the application of the 4-arm PEG hydrogel in the biomedical field.

Herein, a novel way to design and construct multi-functional spongy supramolecular polymer gels through an easy to make tripodal guest (TA) and a naphthalimide functionalized-pillar[5]arene host (AP5) has been developed. According to this approach, a novel pillar[5]arene-based supramolecular polymer gel (SHG) was constructed via multi-non-covalent interactions such as host-guest inclusion, C-Hπ, ππ and hydrogen bonds and so on. Interestingly, the SHG exhibits a spongy structure and strong aggregation induced emission (AIE). Furthermore, the SHG also exhibited multi-responsiveness toward outer stimuli such as heating-cooling, pH, competitive agents and mechanical. More importantly, the SHG xerogel shows separation properties for Fe3+, methyl orange, methylene blue and sudan I dyes. The separation rates of SHG xerogel for Fe3+ ions and organic dyes can reach up to 99.8%. Simultaneously, the SHG could ultrasensitively detect Fe3+ (LOD is 0.9 nM). In addition, a thin film based on SHG was also prepared, which was confirmed to be a convenient test kit for detecting Fe3+.

Efficient detection of explosives (e.g. picric acid) and toxic compounds (e.g. cyanide) is an important task. Herein, we report a simple and efficient method for the selective and sensitive detection of picric acid (PA) and CN−via a novel guest competitive controlled aggregation-induced emission (AIE) method. First, a tripodal host compound (TG) based on a tris-naphthalimide derivative was designed and synthesized. The TG can self-assemble to a supramolecular system and show blue AIE. Then, we employed the TG-based supramolecular system as a novel supramolecular sensor (S-TG). Interestingly, S-TG could selectively detect PA through a competitive binding interaction, and the detection limit (LOD) of S-TG for PA is 1.19 × 10−8 M. In this process, the self-assembly of S-TG was destroyed and a TG and PA complex (TG–PA) was produced, meanwhile, the AIE of S-TG was quenched. More interestingly, TG–PA could act as a novel supramolecular sensor for the AIE fluorescent ‘turn-on’ detection of CN−, and the LOD of TG–PA for CN− is 7.45 × 10−7 M. Moreover, PA and CN− test kits were prepared by loading S-TG or TG–PA on silica gel plates. These test kits could conveniently and efficiently detect PA or CN− with high selectivity and sensitivity.

A novel supramolecular aggregation induced emission (AIE) π-gel (ONT) was constructed by using a functionalized trimesic amide (TCP) molecule assembled with a bis-pyridine functionalized naphthalene diimide (ND) molecule using a non-covalent interaction. The ONT showed strong AIE at 468 nm. Furthermore, the ONT could detect and adsorb ferric (Fe3+) or cupric (Cu2+) ions from water. Meanwhile, a thin film based on supramolecular AIE π-gel ONT was prepared, which could be used as a fluorescent security display material for detecting Fe3+ or Cu2+. Thus, the AIE π-gel ONT shows potential for practical applications in efficient multi-analyte detection and separation and as a fluorescent display material.

Prussian blue analogues are considered as the promising cathodes for sodium-ion batteries. Since the electrochemical properties are closely related to the morphology, the monodisperse copper hexacyanoferrate nanoflakes with highly crystalline are synthesized by a glycol-assisted coprecipitation method and a tentative synthetic mechanism is proposed to explain the formation of nanostructures. The structure and electrochemical properties are characterized by X-ray photoelectron spectroscopy, FTIR spectra and galvanostatic cycle tests, respectively. Due to the novel architecture of copper hexacyanoferrate, a high electrochemical activity is obtained, resulting a high initial coulombic efficiency of 93%, a capacity retention of 73% at 1 C after 300 cycles and 51 mAh g −1 is maintained at high rate of 15 C at 25 °C.

Herein, we report two novel approaches for highly sensitive detection and efficient adsorption of formaldehyde and 3-fluorobenzaldehyde by forming a water-soluble supramolecular polymer and an aggregation-induced emission enhancement (AIEE) hydrogel, respectively. The host compound DTA could highly selectively and sensitively detect formaldehyde by forming a water-soluble supramolecular polymer in pure water. The LOD of DTA for formaldehyde was 1.79 × 10−8 M. More importantly, DTA could also efficiently adsorb formaldehyde from its water solution, and the adsorption percentage was 98.41%. In addition, DTA could also selectively detect 3-fluorobenzaldehyde from its isomers by forming a supramolecular AIEE hydrogel. The LOD of DTA for 3-fluorobenzaldehyde was 8.87 × 10−9 M; this result reached an ultrasensitive level. These methods are novel and useful approaches for highly sensitive detection and adsorption of aldehydes, as well as new ways for the construction of water-soluble supramolecular polymer materials and hydrogels.

An efficient, highly sensitive and selective electrochemical sensor was developed for determination of fenitrothion in tap water, cropland water and canal water samples. The synthesized reduced graphene oxide (RGO) and molybdenum sulfide (MoS2)-Au were introduced using their synergetic enhancement effect to improve the sensor sensitivity. Zirconia (ZrO2) nanoparticles were electro-deposited onto modified gold electrode to selectively adsorb fenitrothion, which can be further captured by cyclic voltammetry or square wave voltammetry on the basis of its redox behavior of nitrobenzene group. The immobilization process was characterized by electrochemical impedance spectroscopy, illustrating the enhancement of RGO/MoS2-Au composite and the successful electro-deposition of ZrO2. Systematical method validation was performed including linearity, sensitivity, selectivity, reproducibility, regeneration and stability. The current is linearly correlated with the fenitrothion concentration from 5.0 to 600 ng mL−1 with the limit of detection of 2.2 ng mL−1. The developed electrochemical sensor displayed satisfactory performance in real water samples analysis.

A simple, accurate, and high-throughput analytical method was developed to detect 123 pesticide residues in Chinese medicinal herb Paeoniae Radix Alba (PRA) by introducing nano-MgO as a highly efficient purification material based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) design concept. Various PRA samples were extracted using 8 mL 0.5% acetic acid-acetonitrile solution and purified by a dispersive solid-phase extraction method with 30 mg nano-MgO, 40 mg primary secondary amine (PSA), and 40 mg octadecylsilane (C18) as the cleanup adsorbents, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). 70.7% of pesticides showed a weak matrix effect after the purification process, indicating that this method can give the precise quantitative analysis of trace pesticides residue. The method was systematically validated under optimal conditions in five different kinds of PRA samples; good linearity was observed in the concentration range of 0.5–250 μg/L or 1–250 μg/L. Pesticide recovery in each sample spiked at concentrations of 20, 50, and 200 μg/kg ranged from 98.0% to 111% and the mean relative standard deviation ranged from 2.72% to 5.70%. Furthermore, the method comparison with the traditional QuEChERS method suggested the feasibility, advantages, and potential application prospect of the present method for the multi-pesticide residue analysis in various PRA samples.

With global climate change, plants are frequently being exposed to various stresses, such as pathogen attack, drought, and extreme temperatures. Transcription factors (TFs) play crucial roles in numerous plant biological processes; however, the functions of many tomato (Solanum lycopersicum L.) TFs that regulate plant responses to multiple stresses are largely unknown. Here, using an RNA-seq approach, we identified SlNAP1, a NAC TF-encoding gene, which was strongly induced by various stresses. By generating SlNAP1 transgenic lines and evaluating their responses to biotic and abiotic stresses in tomato, we found that SlNAP1-overexpressing plants showed significantly enhanced defense against two widespread bacterial diseases, leaf speck disease, caused by Pseudomonas syringae pv. tomato (Pst) DC3000, and root-borne bacterial wilt disease, caused by Ralstonia solanacearum. In addition, SlNAP1 overexpression dramatically improved drought tolerance in tomato. Although the SlNAP1-overexpressing plants were shorter than the wild-type plants during the early vegetative stage, eventually, their fruit yield increased by 10.7%. Analysis of different hormone contents revealed a reduced level of physiologically active gibberellins (GAs) and an increased level of salicylic acid (SA) and abscisic acid (ABA) in the SlNAP1-overexpressing plants. Moreover, EMSAs and ChIP-qPCR assays showed that SlNAP1 directly activated the transcription of multiple genes involved in GA deactivation and both SA and ABA biosynthesis. Our findings reveal that SlNAP1 is a positive regulator of the tomato defense response against multiple stresses and thus may be a potential breeding target for improving crop yield and stress resistance.

Implanting a stent in the body through a minimally invasive operation and tracking its location in real-time is still a challenge. Herein, a near-infrared (NIR) light-triggered shape-memory polymer possessing a long-time fluorescence imaging function has been developed by cross-linking 6-arm poly(ethylene glycol)–poly(e-caprolactone) using a croconate dye YHD798 as the chemical crosslinker and NIR-absorption perssad. Due to the extraordinary photothermal conversion property of YHD798, the temperature of the material raised from 20 °C to 120 °C under 808 nm near-infrared irradiation at 0.4 W cm−2, leading to shape recovery in 50 s in a programmed shape-transition process. YHD798 also exerted an aggregation-induced emission effect, endowing the polymer with a clear NIR fluorescence imaging function even when covered by a 2 mm pork slab and could be used for the real-time visualization of the implanted device fabricated from this polymer in deep tissues of the body. When a tubular stent that was fabricated from this polymer, was implanted into the carotid artery of a Sprague-Dawley rat, it could recover to its permanent shape under 808 nm laser irradiation in 60 s owing to the shape-memory function and facilitated NIR-I fluorescence imaging after implantation for a week owing to the croconate dye. This work provides a new strategy for designing and developing smart polymers with NIR-light-triggered shape-memory effect and long-term fluorescence imaging function for biomedical applications.

A probe-immobilized molecularly imprinted electrochemical sensor was constructed for selective determination of tebuconazole in vegetable and fruit samples. Thiol graphene was introduced onto a glassy carbon electrode modified with gold nanoparticles to increase its specific surface area. Prussian blue was co-deposited with gold nanoparticles on the modified electrode and served as the immobilized probe, followed by electro-polymerization of the molecularly imprinted polymer film as the recognition element. Systematic validation and characterization were performed to verify the successful preparation and mechanisms of the Prussian blue and molecularly imprinted polymers in the electrode. Several important parameters, including monomer concentration, scan cycles and pH, were systematically varied to elucidate their influence on the performance of the sensor. Meanwhile, the surface features of the modified electrode were characterized using scanning electron microscopy, atomic force microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The optimized sensor demonstrated a wide linear range from 5.0 × 10−8 mol L−1 to 4.0 × 10−4 mol L−1 with a detection limit of 1.25 × 10−8 mol L−1. The proposed sensor exhibited specific recognition of tebuconazole in selectivity experiments and contrast tests. Furthermore, the sensor can be used for detection of tebuconazole in real samples with satisfactory recoveries.

Abnormal formaldehyde (FA) is known to induce a variety of diseases. Herein, we report a novel and efficient method for ultrasensitive detection of formaldehyde in gas and solutions by a catalyst preplaced sensor based on the pillar[5]arene derivative (DP5J). By the catalyzation of (CF3SO3)2Bi, DP5J could selectively and sensitively sense formaldehyde through an aggregation-induced emission (AIE) “turn-on” response within 7.5 s, and the detection limits for formaldehyde is 3.27 × 10–9 M. Moreover, a FA test kit was prepared by loading the catalyst (CF3SO3)2Bi preplaced DP5J sensor (DP5J-Bi) on a silica gel plate. The test kit could conveniently and efficiently detect formaldehyde in gas or solution with ultrasensitivity. The catalysts preplaced method and FA reaction-induced AIE fluorescence “turn-on” mechanism is a novel approach to achieve ultrasensitive detection of FA. Importantly, it is also a novel approach for the efficient detection of other volatile organic compounds.

Phytosulfokine (PSK) is a disulfated pentapeptide that is an important signaling molecule. Although it has recently been implicated in plant defenses to pathogen infection, the mechanisms involved remain poorly understood. Using surface plasmon resonance and gene silencing approaches, we showed that the tomato (Solanum lycopersicum) PSK receptor PSKR1, rather than PSKR2, functioned as the major PSK receptor in immune responses. Silencing of PSK signaling genes rendered tomato more susceptible to infection by the economically important necrotrophic pathogen Botrytis cinerea Analysis of tomato mutants defective in either defense hormone biosynthesis or signaling demonstrated that PSK-induced immunity required auxin biosynthesis and associated defense pathways. Here, using aequorin-expressing tomato plants, we provide evidence that PSK perception by tomato PSKR1 elevated cytosolic [Ca2+], leading to auxin-dependent immune responses via enhanced binding activity between calmodulins and the auxin biosynthetic YUCs. Thus, our data demonstrate that PSK acts as a damage-associated molecular pattern and is perceived mainly by PSKR1, which increases cytosolic [Ca2+] and activates auxin-mediated pathways that enhance immunity of tomato plants to B. cinerea.

An easy-to-make supramolecular polymer was successfully constructed by self-assembly of tripodal tri-(pyridine-4-yl)-functionalized trimesic amide (DTB) in DMSO–H2O binary solutions. The supramolecular polymer DTB showed strong white aggregation-induced emission (AIE) in the solid state as well as in water suspensions. DTB could also form a stable supramolecular polymer hydrogel (DTB-G) in pure water. Interestingly, DTB showed excellent coordination ability for rare earth metal ions (Tb3+, Eu3+, La3+, Th4+ and Ce3+) and formed the corresponding complexes (DTB-Ms). Interestingly, by introducing the above-mentioned rare earth metal ions, the fluorescence colour of the obtained DTB-Ms showed corresponding variations. By inseting UV-LED lamps (λ = 365 nm) into different rare earth metal ion-coordinated xerogel DTB-Ms in small test tubes, a series of LED devices with multicolour lights were obtained. Therefore, DTB and DTB-Ms can act as fluorescence colour-tunable photoluminescence materials.

A novel organic gelator (WJ) based on benzimidazole and acylhydrazone naphthol moities has been designed and synthesized. The organic gelator (WJ) could form a stable organogel (WJG) with strong aggregation-induced emission (AIE). Interestingly, the WJG shows multi-stimuli-response for many analytes such as CN−, Al3+ and Fe3+ and L-Cys. Therefore, a multi-analyte sensor array based on WJG has been successfully developed. The WJG presents selective fluorescent and colorimetric response for CN−. Meanwhile, the WJG could selectively identify Fe3+ and Al3+ in the gel state. With the addition of Fe3+ the yellow-green AIE of WJG was quenched. In addition, the AIE of WJG could be selectively recovered by adding L-Cys. So the AIE presents an “on–off–on” type by alternatively adding Fe3+ and L-Cys. Moreover, upon the addition of Al3+, the yellow-green AIE of WJG shows a blue shift and changes to blue. The detection limits of the sensor array for CN−, Al3+ and Fe3+ are 3.02 × 10−6 M, 5.78 × 10−8 M, and 3.81 × 10−9 M, respectively. The WJG could act as a multi-analyte detection and fluorescent display material.

Herein, using black talc as a carrier, a ternary black talc-TiO2/ZnO composite photocatalyst was prepared by the sol-gel method, and the effect of the black talc on the hetero-structure properties of the TiO2 and ZnO was systematically studied. The prepared composite photocatalyst showed an excellent degradation performance of the pollutant, where black talc plays an important role in promoting the interface interaction by enhancing the contact area between the TiO2 and ZnO. Moreover, the free carbon element doping in black talc favors the formation of more oxygen vacancies, thereby improving the response as a photocatalyst in visible light. In addition, the carbon in the black talc can also adsorb organic pollutants and enrich the surroundings of the photocatalyst with pollutants, so it further improves the catalytic efficiency of the photocatalyst. Under UV irradiation, the degradation rate of Rhodamine B on black talc-TiO2/ZnO was found 3.3 times higher than that of black talc-TiO2 with good stability.

In this paper, a TiO2/black talc composite photocatalyst was prepared by the sol-gel method using TBOT as titanium source and black talc as carrier. Rhodamine B was used as the targeted pollutant to study the adsorption role of carbon in black talc. The results showed that with the adsorption-degradation cycles, the illumination time can be reduced by 40%. The adsorption rate and degradation rate of the composite photocatalyst was also increased. The degradation rate of Rhodamine B reached more than 95%, which fully shows the synergistic effect between TiO2 nanoparticles and black talc. In this way, the adsorption-degradation coupling of the photocatalyst could be realized.

Chitin and its derivatives contain biologically fixed nitrogen elements, which can provide nitrogen sources for N-containing chemicals. Herein, a series of pyridinium-based ionic liquids were synthesized to directly catalyze the conversion of N-acetyl-D-glucosamine (NAG, the monomer of chitin) to 3-acetamido-5-acetylfuran (3A5AF). The yield of 3A5AF in 1-carboxymethyl pyridinium chloride ionic liquid reached 37.49%, without any additives. Using B2O3 and CaCl2 as additives, the optimum yield increased to 67.37% at 180 °C in 20 min. In addition, HPLC-MS analysis has been utilized to elucidate the reaction mechanism. This research on turning “waste” into “wealth” opens up new ways for the utilization of biomass waste, which not only reduces environmental pollution but also has potential economic value.

PrBa0.92CoCuO6-delta (PB0.92CoCu), a layered perovskite oxide with Ba2+-deficiency at A-site and Cu2+ doping at B-site was synthesized and characterized as cathode material of intermediate-temperature solid oxide fuel cell (IT-SOFC) in comparison with performance of the parent oxide of PrBaCo2O6-delta (PBCoO). PB0.92CoCu had the same phase structure as that of PBCoO but showed a slight lattice expansion. Results of iodometric titration and thermogravimetry (TG) measurements demonstrated that PB0.92CoCu had a higher concentration of oxygen vacancy than PBCoO did. Electrical conductivities of PB0.92CoCu ranged from 255 S cm(-1) at 400 degrees C to 134 S cm(-1) at 800 degrees C in air, meeting the requirement for the cathode of SOFCs. Thermal expansion coefficient (TEC) of PB0.92CoCu was about one quarter decreased compared with TEC of PBCoO. PB0.92CoCu showed improved electrochemical performance than PBCoO characterized by low area specific resistances (ASRs) ranging from 0.12 Omega cm(2) at 600 degrees C to 0.017 Omega cm(2) at 750 degrees C. High peak power densities, 1541 mW cm(-2) at 800 degrees C, 1228 mW cm(-2) at 750 degrees C and 930 mW cm(-2) at 700 degrees C were achieved in a single cell using the PB0.92CoCu cathode. This single cell also showed an operational stability using hydrogen fuel at 650 degrees C without any decay for 100 h. These results have demonstrated that PB0.92CoCu is a promising cathode material of IT-SOFCs. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

A facile strategy was developed for the fabrication of a magnetic covalent organic framework (COF) via grafting of the monomers, 2,5-dihydroxyterephthalaldehyde (Dt) and 1,3,5-tris(4-aminophenyl) benzene (Tb) onto surface-modified Fe3O4 nanoparticles. The magnetic COF, named as magnetic COF-DtTb, was readily fabricated without high temperature or harsh reaction conditions. The synthesized magnetic COF-DtTb nanoparticles were fully characterized, presenting a regular core-shell spherical structure, large specific surface area, superparamagnetism, and good thermal stability. Their potential as an enrichment adsorbent was investigated to establish an efficient magnetic solid-phase extraction method for the determination of organophosphorus pesticide residues in fruits. Systematic method validation revealed good linearity in the concentration range of 1–200 μg L−1 (correlation coefficient >0.9957). The method limits of detection were in the range of 0.002–0.063 μg kg−1, the method limit of quantification was 1.00 μg kg−1 and recoveries ranged from 72.8% to 111% with RSDs lower than 12.3%. The results indicated that magnetic COF-DtTb possesses superior trace enrichment properties for organophosphorus pesticides in fruits.

Herein, an aggregation-induced emission (AIE) supramolecular organic framework gel (SOF-TPN-G) was successfully constructed from novel supramolecular polymer networks based on tripodal pillar[5]are...

A novel approach for the ultrasensitive detection and separation of F− has been successfully developed. F− could induce a tripodal naphthalene imide sensor (TNA) to result in supramolecular polymerization, leading to strong AIEE. The TNA could act as an excellent recyclable material for F− detection and separation.

As an important “food and drug dual-use” product, chrysanthemums are widely used in both botanical medicine and food applications. However, the misuse of pesticides during chrysanthemum cultivation makes pesticide residue monitoring crucial. The aim of the present work was to address this practical demand for the simultaneous determination of multiple pesticide residues in various species of chrysanthemums. Both the sample pre-treatment and instrumental methods were systematically investigated. Seven chrysanthemum samples were extracted using acetonitrile and purified by dispersive solid-phase extraction with amino-modified multi-walled carbon nanotubes (MWCNTs-NH2) and C18 as the cleanup co-adsorbents. After optimizing the amounts of MWCNTs-NH2 and C18, matrix effects could not be avoided during LC-MS/MS analysis of 112 pesticides, although satisfactory recoveries were obtained. The use of SFC-MS/MS was evaluated, which demonstrated the significant positive role of SFC-MS/MS in reducing the matrix effects during pesticide residue analysis. In addition, the use of SFC-MS/MS permitted a shorter run time and afforded greater analytical efficiency. Method validation was further performed to evaluate the linearity, sensitivity, recovery, and precision of the developed method. Good linearity was observed for 92% of the analytes in the concentration range of 2–250 μg L−1 for all seven of the chrysanthemum samples. The LODs of the 112 pesticides ranged from 0.01 to 31.41 μg L−1, depending on the sample, while the mean recoveries of all of the spiked pesticides ranged from 81.8% to 102% for concentrations of 20, 50, and 200 μg kg−1. These results clearly demonstrate the applicability of the developed method for the simultaneous determination of multi-pesticides in various chrysanthemum samples.

Poly(aspartic acid-lysine) copolymers (PAL), as an alternative product to traditional water treatment agents, was developed based on poly(aspartic acid) through microwave-assisted synthesis of aspartic acid and lysine. Its biocompatibility and performance in inhibiting scale and corrosion are determining factors in its application. In this paper, biodegradability of PAL was investigated by carbon dioxide evolution tests. The degradation ratio of PAL on day 10 and day 28 respectively reached 35.01% and 80.00%, which indicated that PAL was a degradable water treatment agent. PAL is superior to polyacrylic acid and phosphonic carboxylic acid in biodegradability. With the increase in the addition ratio of lysine in copolymerization process and the decrease in the molecular weight of copolymer, the biodegradability of PAL was significantly enhanced. In addition, the incubation period before the biodegradation was shortened. The result showed that Cu 2+ could decrease the degradation rate through inhibiting enzymatic activities.

In this study, coenzyme A (CoA)-based coordination polymers (CPs) have been generated in situ by exploiting the reaction of thiols with metal ion (Au(III) or Ag(I)), which are dependent on both thiol-metal and aurophilic metal∙metal interaction. It is interesting to note that CPs-related biosensing capabilities toward some biomolecules including ascorbic acid (AA), cysteine (Cys) and glutathione (GSH) are also investigated via SYBR Green II (SGII)-derived fluorescence switchable mechanisms. The synthesized CPs display especial RNA-like structure and are capable of initiating the fluorescence of SGII. Conversely, AA, Cys or GSH can give rise to the structural destruction of RNA-like CPs, thus inhibiting the fluorescence signal, and quantitative detection of these biomolecules are achieved favorably with a detection limit of 7.2, 0.55 and 0.48 nM, respectively. Meanwhile, the fascinating fluorescence on-off property and simple synthetic process are employed to build a series of basic logic gates (YES, NOT, OR, AND, INHIBIT and NOR) and multiple configurable logic gates (OR-AND and OR-OR-INHIBIT) along with different logic inputs. In view of these, developing CoA-based CPs as a new material to execute logic operations provides a valuable platform to establish the next generation of advanced molecular devices for clinic diagnostic and biomedical research.

A simple and efficient magnetic solid-phase extraction (MSPE) method was established with magnetic covalent organic framework (COF) as adsorbent to enrich organophosphorus pesticides from fatty milk samples, followed by the sensitive determination via LC-MS/MS. The key parameters influencing the MSPE efficiency were comprehensively investigated to afford an optimized procedure. All the target analytes could be captured directly by magnetic COF from milk without protein precipitation, making the pretreatment rapid and convenient. Systematic method validation demonstrated its satisfactory linearity, recoveries (80.0-105 %), and precision (RSDs

To achieve multi-pesticides residue analysis in seawater, hydrophilic-lipophilic-balanced magnetic particles were designed and fabricated by swelling polymerization of divinyl benzene (DVB) and N-vinyl pyrrolidone (NVP) on the surface of Fe3O4@SiO2 magnetic particles. The ratio of DVB to NVP was adjusted to achieve a proper balance in hydrophilicity and lipophilicity. The obtained magnetic particles were systematically characterized by TEM, SEM, FT-IR and vibrating sample magnetization. Based on the optimized magnetic nanoparticles, a sensitive magnetic solid-phase extraction method was developed for the simultaneous pre-concentration and determination of 96-pesticide residues from large-volume seawater samples prior to being detected by liquid chromatography-tandem mass spectrometry. Recoveries of pesticides in spiked seawater samples (0.001, 0.01, 0.1, 1.0 μg L−1) ranged from 62% to 112% with RSDs less than 21%. The method limits of detection of 96 pesticides ranged from 0.13 to 0.42 ng L−1, the method limits of quantification of 96 pesticides ranged from 1.0 to 10 ng L−1. The method was successfully applied to pesticide residue analysis in water samples from Jiulong River Estuary of China, demonstrating the prospects of this technique as a potential method for the rapid determination of trace levels of multi-pesticide residues in seawater.

Chitin is the most widely distributed oceanic biomass resources. Its monomer unit, N-acetyl-D-glucosamine (NAG), contains precious atomic nitrogen and represents a potential feedstock for the manufacture of regenerative organic nitrogen chemicals. Herein, the conversion of NAG to the platform chemical, 3-acetamido-5-acetylfuran (3A5AF), catalyzed by amino acid ionic liquids, was investigated. The reaction, catalyzed by a very small amount of glycine chloride ionic liquid without any additives, could yield 43.22% 3A5AF in 10 min. By adding CaCl2, a higher yield up to 52.61% was obtained. This work demonstrated the conversion of chitin biomass to 3A5AF in higher yield without using a boron-based catalyst for the first time. Moreover, the ionic liquid catalyst exhibited excellent recyclability, and afforded 43.22–36.59% yield over during eight cycles. This research provides new and green procedures to convert shellfish fishery waste into value-added platform chemicals.

Thermoelectric (TE) material is a kind of energy conversion material, which can be used for power generation and refrigeration. Until now, traditional inorganic TE materials have shown high dimensionless thermoelectric figure of merit (ZT) values. But their expensive raw material and high processing cost, heavy metal pollution and poor processability limit their broad applications. Poly(3,4-ethylenedioxythiophene) (PEDOT) conducting polymers possess some excellent features, such as high electrical conductivity, low thermal conductivity, flexibility, low cost, abundance, and light weight. More and more attention has recently been paid to the TE properties of PEDOT polymers and PEDOT polymer based nanocomposites. Ascorbic acid (VC) is used as a reducing agent to tune the PEDOT-Tos-PPP film. The PEDOT-Tos-PPP films via VPP technique are treated with VC solutions with different concentrations. The TE properties of the films before and after being treated with VC at different concentrations are measured. The effect of concentration of VC aqueous solution on the thermoelectric properties and stabilities of the film are studied. The results indicate that the power factor of the film after being treated with 20% VC is 55.6 μW·m–1·K–2, which is 1.7 times as high as that of the pristine PEDOT-Tos-PPP film (34.4 μW·m–1·K–2). The maximum ZT value at room temperature is 0.032. After the VC treatment, the conductivity and Seebeck coefficient of the PEDOT film show unstable characteristics in the air, which is mainly due to the further oxidation of the neutral state on the PEDOT film surface in the air.

With the rapid development of the electronics industry, the dielectric materials with high energy storage density, fast charge and discharge speed, easy-to-process and easy-to-mold, and stable performance are urgently needed to meet the requirements for lightweight and miniaturization of electronic component equipment. Dielectric ceramics has a high dielectric constant, but low breakdown field strength. Polyvinylidene fluoride (PVDF) has the advantages of good flexibility, high breakdown field strength, and light weight, but its dielectric constant is low. Achieving the ability to tailor the interface between dielectric ceramics filler and PVDF polymer matrix is a key issue for realizing the desirable dielectric properties and high energy density in the nanocomposites. As a result, much effort has been made to prepare the polymer composites through the surface modification of the nanoparticles with high dielectric constant fillers dispersed in a matrix, with the hope of preparing composites containing the high dielectric constant of the ceramic fillers and the high breakdown strength of polymers. In this work, in order to obtain the high dielectric-constant and high-energy-storage-density dielectric ceramics, the electrospinning method is used to prepare the SrTiO3 one-dimensional nanofibers as the inorganic fillers and the casting method is adopted to prepare PVDF as the polymer matrix. To improve the interface between inorganic nanofiber fillers and PVDF matrix, the SrTiO3 nanofibers are modified by surface hydroxylation. The effects of suface hydroxylated SrTiO3 nanofibers on the dielectric properties and energy storage properties of PVDF composites are studied. The correlation between interface modification and energy storage performance of composites is investigated to reveal the mechanism of enhanced energy storage performance of SrTiO3 nanofibers/PVDF composites. The results show that the dispersion of surface-hydroxylating SrTiO3 nanofibers in PVDF polymer can be improved. The composites exhibit improved dielectric properties and enhanced breakdown strength. When the filling quantity of the surface-hydroxylating SrTiO3 nanofiber fillers is 2.5 vol%, the energy storage density of the composite reaches 7.96 J/cm3. Suface-hydroxylating SrTiO3 nanofibers exhibit excellent dispersion in the PVDF polymer matrix and strong interfacial adhesion with the matrix, leading the composites to possess excellent dielectric constant and energy storage performance. The surface hydroxylation of ceramic fillers can improve the energy storage performance of the composites.

With the development of power electronic device equipment towards miniaturization and high performance, the dielectric materials with high energy storage density, high charge and discharge efficiency, easy processing and molding, and stable performance are urgently needed. At present, Barium titanate-based dielectric ceramics have a high dielectric constant, but low breakdown field strength and poor flexibility. Polymer-based dielectric materials have ultra-high functional density, ultra-fast charge and discharge response time, good flexibility, high breakdown field strength, light weight and other advantages, but low dielectric constant and low polarization strength. Their energy storage density is low, which limits the power capacitor component size and application scope. In order to obtain material with high energy storage performance, it was proposed to add high dielectric constant inorganic ceramic fillers to the polymer through a composite method to improve the energy storage performance of the material. The interface plays a vital role in the performance of the composite material. In this article, we review the latest research advance in the interface design and control of barium titanate/polyvinylidene fluoride composite dielectric materials. The effects of interface modification methods such as organic surface modification, inorganic functionalization and organic-inorganic synergistic modification on the polarization and energy storage performance of composite materials are summarized. The existing interface models and theoretical research methods are discussed, and the existing challenges and practical limitations, and the future research directions are prospected.

An imprinted electrochemical sensor was constructed for the detection of carbofuran with high sensitivity and selectivity. AuNPs were used as the electron wire for signal amplification, and molecularly imprinted polymer was used as the recognition element. The preparation process of the modified electrode was optimized, and the electrode was characterized using scanning electron microscopy, cyclic voltammetry and differential pulse voltammetry. The results proved that the prepared sensor can selectively detect carbofuran and the AuNPs can increase its sensitivity. The method validation included the systematic evaluation of the linearity, sensitivity, selectivity, reproducibility and stability. The optimized sensor showed a wide linear response to carbofuran in the range from 5.0 × 10−8 to 4.0 × 10−4 mol L−1 with a low detection limit of 2.4 × 10−8 mol L−1. The sensor also exhibited a high selectivity to carbofuran. The real sample analysis for vegetable samples suggested its potential application in the analysis of vegetable samples.

A highly sensitive electrochemical biosensor based on the synthetized L -Cysteine-Ag(I) coordination polymer ( L -Cys-Ag(I) CP), which looks like a protein-mimicking nanowire, was constructed to detect acetylcholinesterase (AChE) activity and screen its inhibitors. This sensing strategy involves the reaction of acetylcholine chloride (ACh) with acetylcholinesterase (AChE) to form choline that is in turn catalytically oxidized by choline oxidase (ChOx) to produce hydrogen peroxide (H2O2), thus L -Cys-Ag(I) CP possesses the electro-catalytic property to H2O2 reduction. Herein, the protein-mimicking nanowire-based platform was capable of investigating successive of H2O2 effectively by amperometric i-t (current-time) response, and was further applied for the turn-on electrochemical detection of AChE activity. The proposed sensor is highly sensitive (limit of detection is 0.0006 U/L) and is feasible for screening inhibitors of AChE. The model for AChE inhibition was further established and two traditional AChE inhibitors (donepezil and tacrine) were employed to verify the feasibility of the system. The IC50 of donepezil and tacrine were estimated to be 1.4 nM and 3.5 nM, respectively. The developed protocol provides a new and promising platform for probing AChE activity and screening its inhibitors with low cost, high sensitivity and selectivity.

A novel composite of LiFePO4 with phosphorus-doped carbon layers has been prepared via a simple hydrothermal method using glucose as the carbon source to generate a carbon coating and triphenylphosphine as the phosphorus source. The effects of phosphorus doping on the phase purity, morphology and electrochemical performance of the materials are studied by the characterizations using X-ray diffraction, Raman spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy and electrochemical techniques. It is indicated that phosphorus doping into the carbon layers is beneficial for the graphitization of the carbon. Phosphorus in the carbon layers exists in the form of P–C bonds and its concentration depends on the second calcination temperature. Moreover, the phosphorus-doped carbon layers on the particle surface make the charge transfer resistance decrease remarkably from 156.5 Ω to 49.1 Ω, which can be ascribed to the free carriers donated by phosphorus. The as-prepared LiFePO4 with phosphorus-doped carbon layers calcined at 600 °C shows the best electrochemical performance with a discharge capacity of 124.0 mA h g−1 at a high rate of 20 C and an excellent retention rate of 91.4% after 50 cycles. The LiFePO4 with phosphorus-doped carbon layers exhibits excellent electrochemical performances, especially at high current rates; thus, it is a promising cathode material for high-performance lithium ion batteries.

Electrochemical methods allow fast and inexpensive analysis of enzymatic activity. Here, a simple and yet efficient "signal-on" electrochemical assay for sensitive, label-free detection of DNA-related enzyme activity was established on the basis of terminal deoxynucleotidyl transferase (TdT)-mediated extension strategy. TdT, which is a template-independent DNA polymerase, can catalyze the sequential addition of deoxythymidine triphosphate (dTTP) at the 3'-OH terminus of single-stranded DNA (ssDNA); then, the TdT-yield T-rich DNA nanowires can be employed as the synthetic template of copper nanoclusters (CuNCs). Grown DNA nanowires-templated CuNCs (noted as DNA-CuNCs) were attached onto graphene oxide (GO) surface and exhibited unique electrocatalytic activity to H2O2 reduction. Under optimal conditions, the proposed biosensor was utilized for quantitatively monitoring TdT activity, with the observed LOD of 0.1 U/mL. It also displayed high selectivity to TdT with excellent stability, and offered a facile, convenient electrochemical method for TdT-relevant inhibitors screening. Moreover, the proposed sensor was successfully used for BamHI activity detection, in which a new 3'-OH terminal was exposed by the digestion of a phosphate group. Ultimately, it has good prospects in DNA-related enzyme-based biochemical studies, disease diagnosis, and drug discovery. Graphical Abstract Extraordinary TdT-generated DNA-CuNCs are synthesized and act as a novel electrochemical sensing platform for sensitive detection of TdT and BamHI activity in biological environments.

A water-soluble cationic pillar[5]arene (CWP5) without lager conjugated construction was first reported as a novel pillar[5]arene-based aggregation-induced emission luminogen (AIEgen), which showed a remarkable aggregation-induced emission (AIE) with the concentration increasing. The AIE effect of CWP5 has affected by different solvent, it had the lowest critical aggregation concentration (CAC) value and highest fluoresence emission intensity in DMSO solution. Simultaneously, CWP5 can serve as a chemosensor for the successively fluorescent detection of Fe3+ and F-/H2PO4- with high sensitivity and selectivity. A rewritable portable test kit made from CWP5 provides a possibility to on-site detection and manufacture of encryption and decryption materials.

While the effects of potassium ion (K + ) on the settlement and metamorphosis of mollusc larvae have been studied in some species, little of this research has focused on the Pacific oyster ( Crassostrea gigas ). It is still unclear which of the potassium channels, the voltage-gated channel or the inward rectifier channel, plays the more important role in the settlement and metamorphosis of mollusc larvae. In this study, the effects of K + and K + channel inhibitors on the settlement and metamorphosis of Pacific oyster larvae were examined. After 24, 48, or 72 h, the highest oyster larval settlement rate was observed at 19 mM K + . The relative metamorphosis rate (number of larvae at metamorphosis ∕ number of larvae at settlement) decreased with increasing K + concentration, however, the highest total metamorphosis rate (number of larvae at metamorphosis ∕ total number of larvae) was observed at 19 mM K + as a result of the very high settlement rate at this concentration. Treatment with tetraethyl-ammonium, the voltage-gated potassium channel inhibitor, resulted in a more obvious suppression of K + -induced oyster larval settlement than Glyburide (Glib), an inhibitor of the inward rectifier potassium channel. These results suggest that the voltage-gated potassium channel may play a more important role than the inward rectifier potassium channel in the settlement of oyster larvae.

The geometries, polarizabilities (αs), and first hyperpolarizabilities (βtot) of a series of green fluorescent protein chromophore coupled diradicals and their corresponding optical isomers were investigated using density functional theory (DFT). The results show that the introductions of the electron donor/acceptor significantly enhance the polarizabilities and have a different influence on the first hyperpolarizabilities. For trans isomers, the βtot values of the studied compounds increase with increasing strength of the electron-withdrawing ability of the substituent, whereas the βtot values decrease significantly with increasing strength of the electron-donating ability of the substituent. For cis isomers, the trends in the changes in the βtot values are the opposite of those for trans isomers on introduction of a donor/acceptor. Significantly, photoisomerization can lead to the different βtot values. The βtot values of cis isomers are smaller than those of trans isomers when electron acceptors are introduced. For example, the βtot value of the cis isomer with the strongest electron acceptor, i.e.,―NO2, is about 1/6 that of the corresponding trans isomer. However, the βtot values of trans isomers are smaller than those of cis isomers when electron donors are introduced. For example, the βtot value of the trans isomer with the strongest electron donor, i.e., ―NH2, is about six times smaller than that of the corresponding cis isomer. As a result, photoisomerization can modulate the molecular nonlinear optical (NLO) responses effectively. 2543 Acta Phys. -Chim. Sin. 2013 Vol.29 1 引 言 近几十年,人们对新型有机非线性光学(NLO) 分子材料进行了大量研究. 这些材料具有较高的 NLO响应和良好的光电特性,引起了理论和实验 工作者的重视.研究发现,共轭链长度、电荷价态、 给受体基团的改变等都可以影响分子的 NLO特 性. 最初人们研究的有机NLO分子为闭壳层体 系, 近年来人们开始关注开壳层体系, 对有机自由 基分子的NLO性质进行理论与实验探讨,以期成为 一种新的NLO材料.在诸多开壳层体系中,氮氧自 由基以其良好的热稳定性、简易的制备方法、灵活 的配位能力以及协同磁效应而倍受关注.最近, NLO分子开关材料引起了人们的重视.将开关效应 引入到NLO材料拓宽了其应用领域,并且对分子光 电器件的发展产生深远影响. NLO开关是指分子 的NLO响应在“开”和“关”两种状态下能够被可逆 地调整.这种转换包括顺反异构、开闭环、氧化 还原 及分子内质子转移 等,这些结构转换导 致分子NLO性质的改变. Lamere等 对金属羰基配 合物进行了实验与理论研究,发现分子内旋转可以 显著衰减此类配合物的 NLO响应. 目前大多数 NLO分子开关主要基于有机金属配合物分子,自由 基体系的NLO开关效应研究相对较少. 1998年, Tsien合成了光照引起结构可逆变化 的荧光蛋白发色团. Voliani等 进一步研究了系列 荧光蛋白发色团的热稳定性,发现荧光蛋白发色团 表现出相当大的二次谐波响应. Meulenaere等 对 荧光蛋白发色团的NLO性质进行了理论和实验研 究.最近, Bhattacharya等 以绿色荧光蛋白(GFP)发 色团为基础, 引入亚胺基氮氧自由基, 研究了系列 含氮氧双自由基衍生物的磁性耦合规律,此类GFP 发色团结构转换引起NLO性质研究未见报道.基于 以上研究,我们对系列含双自由基的GFP发色团结 构改变引起的NLO转换效应进行讨论,为有机自由 基NLO材料的设计提供理论依据. 2 计算模型与方法 GFP发色团分子模型如图 1所示,每个分子有 两个单电子,磁性研究表明,反式结构分子为反铁 磁性耦合,顺式结构分子为铁磁性耦合,所以 a系列 双自由基分子为单重态, b系列双自由基分子为三 重态. 为了获得准确的结构, 溶剂化效应在优化中 被考虑.采用DFT-UB3LYP方法 和6-31G*基组,分 别在气相和极化连续模型(PCM)基础上,以甲醇为 溶剂,优化分子单、三重态的几何构型.计算时分子 的坐标原点选在C1位置, z轴通过桥连键并指向苯 环, xz平面为咪唑啉酮环所在平面. 长程校正杂化交换相关函数CAM-B3LYP方法 降低了被B3LYP方法过高估计的体系第一超极化 率值,并接近耦合簇(CC)方法的计算结果,因此本 文采用UCAM-B3LYP方法计算分子的第一超极化 率.同时采用UBHandHLYP方法对第一超极化率值 进行可靠性分析, Li等 研究表明, UBHandHLYP方 法可将第一超极化率计算机时和有效性进行良好 折中. 在均匀静电场中,分子的能量可按Taylor级数 展开: E = E -∑ i μ i Fi 1 2∑ij αij Fi Fj 1 3∑ijk βijk Fi Fj Fk 4∑ijkl γijkl Fi Fj Fk Fl ... (1) E为无外场时分子的能量, μi 为分子的永久偶极 矩, Fi为外电场在方向 i的分量, αij为线性极化率张 量, βijk和γijkl分别为分子第一、第二超极化率分量.计 算分子极化率和第一超极化率可以采用解析导数 法或数值导数法.文献 报道,解析导数方法较数值 导数法更高效,因此采用解析导数方法计算分子的 静态第一超极化率βtot.计算公式如下: β tot = (β 2 x + β 2 y + β 2 z ) 1 2 (2)

A new halogenation method to construct halogen-substituted quinoline moieties is described. The Cu-catalyzed intramolecular aza-Diels–Alder reaction and halogenation reaction proceeded smoothly under mild conditions to produce the corresponding 7-chloro-6H-chromeno[4,3-b]quinolines and 7-chloro-6H-thiochromeno[4,3-b]quinolines in satisfactory yields.

A new halogenation method to construct halogen-substituted quinoline moieties is described. The Cu-catalyzed intramolecular aza-Diels–Alder reaction and halogenation reaction proceeded smoothly under mild conditions to produce the corresponding 7-chloro-6H-chromeno[4,3-b]quinolines and 7-chloro-6H-thiochromeno[4,3-b]quinolines in satisfactory yields.