查找使用阿拉丁产品的科研文献

Synthesis, fluorescence property and cell imaging of a perylene diimide-based NIR fluorescent probe for hypochlorite with dual-emission fluorescence responses

Huan-ren Cheng,Botao Qu,Chen Qian,Meng Xu,Ruiping Zhang

In this study, for the first time, a novel near-infrared and ratiometric fluorescent probe was conveniently synthesized by reacting PDI-based salicylaldehyde with 2-(hydrazonomethyl)phenol. The probe was designed based on the intramolecular charge transfer (ICT) mechanism and the intramolecular electron transfer (IET) mechanism, which can be blocked by the hypochlorite and a larger conjugation is formed within the probe. Due to the turn-on fluorescence responses triggered by the PET and ICT processes after the ClO− addition, the probe produces simultaneous emission peaks at 600 nm and 820 nm. In addition, the probe shows a rapid fluorescence response towards the ClO− ions within 5 s, a low detection limit (0.8 × 10−7 M), intense color changes (from purple to light green), excellent selectivity, and reversibility. Importantly, cell imaging experiments show that the probe can identify endogenous ClO− successfully.

Effects of hydrogen sulfide (H2S) on respiration control of state 3/4 in mitochondria from bovine heart

Y Su,Y Cheng,D Wang,F Zhang,Y Su,Z Li

Synthesis and photopolymerization kinetics of 2-phenyl-benzodioxole

Wang Bowen,Yang Jinliang,Nie Jun,Zhu Xiaoqun

In this paper, a new photocoinitiator for free radical photopolymerization, belonging to the benzodioxole (BDO) derivatives, was synthesized and characterized, and the effect of phenyl at the 2-position of BDO was estimated. The structure of PhBDO was characterized by elemental analysis, 1 H NMR and 13 C NMR. Laser flash photolysis (LFP) and an electron spin resonance spin trapping technique (ESR-ST) were used to study the photochemical mechanisms. The rate of decomposition ( R d ) of PhBDO in acetonitrile was studied by UV-Vis spectroscopy and the photopolymerization kinetics were monitored by real time Fourier Transform near-IR (FT-IR). The FT-IR results showed that the concentration of PhBDO and BP functionalities of the acrylates and the light intensity affected the polymerization rate and the final conversion. The results showed that the BP/PhBDO system had the same hydrogen abstraction mechanism and reactivity as the BP/BDO system. Consequently, PhBDO could also be an effective coinitiator.

Characterization and properties of Zn/Co zeolitic imidazolate frameworks vs. ZIF-8 and ZIF-67

Kui Zhou,Bibimaryam Mousavi,Zhixiong Luo,Shophot Phatanasri,Somboon Chaemchuen,Francis Verpoort

A novel Zn/Co zeolitic imidazolate framework (ZIF) has been constructed by an easy and straightforward room temperature technique. Several characterization techniques such as SEM, TEM-EDX, single-crystal XRD and ICP have been applied to confirm that the structure formed is a sodalite (SOD) cage type structure. The Zn/Co-ZIF possesses a high nano-crystallinity and porosity with a large surface area. By tuning the amount of Co and Zn in the Zn/Co zeolitic imidazolate framework, the physical and chemical properties have been improved compared with those of the single metal frameworks (ZIF-8 and ZIF-67). Consequently, the Zn/Co-ZIF was investigated for two different applications; gas adsorption (CO2, CH4 and N2) and catalysis (CO2 conversion to cyclic carbonates) and the obtained results were compared with the performance of previously reported single metal frameworks (ZIF-8 and ZIF-67). Additionally, hydrolytic stability tests under ambient conditions and immersed in water at 75 °C were performed and pointed out that Zn/Co-ZIF exhibits a higher stability. Moreover, based on these results, the Zn/Co-ZIF demonstrates better properties compared with ZIF-8 and ZIF-67.

Shielding of Enzymes on the Surface of Graphene-Based Composite Cellular Foams Through Bioinspired Mineralization

Yiying Sun,Jingjing Zhao,Jiafu Shi,Shaohua Zhang,Zhongyi Jiang

Immobilization of enzyme on the surface of graphene-based composite cellular foams (GCCFs) is commonly prone to acquire stable and ultrahigh loading of enzymes and fast transport of substrates during the catalytic process. In this chapter, we reported a method of preparing GCCFs through combination of redox assembly and biomimetic mineralization with in situ enzyme immobilization . Briefly, GCCFs were first prepared through redox assembly of graphene oxide (GO) nanosheets enabled by polyethyleneimine (PEI). The cationic PEI in the resultant reduced GO/PEI (rGO/PEI) cellular foams acted as the mineralization-inducing agent could catalyze the condensation of silicate to form silica (biomimetic silicification) on the reduced graphene oxide (rGO) surface, where enzyme (with penicillin G acylase as model enzyme) is in situ entrapped and shielded within the silica network. Enzymes could be stably resided on the surface of GCCFs without any leaching against a broad range of pH values (3.5–10.0). GCCFs show a three-dimensional (3D) porous structure, which facilitates the fast transfer of substrate and, thereby, leads to desirable catalytic activity . Combined with the monolithic feature, GCCFs exhibit ease of recyclability and superior thermal/recycling stabilities during the catalytic synthesis of 6-aminopenicillanic acid (6-APA, an important pharmaceutical intermediate) compared to free enzyme and enzyme adsorbed on rGO/PEI cellular foams.

Photoelectric Conversion Performance of Composite Perovskite Solar Cell Device and Its Application in Photovoltaic Building

Yuan Min,Wang Zheng,Zhang Guangjun

A new generation of photosensitive materials, namely perovskite inorganic or organic hybrid halides, is regarded as photoelectric conversion materials. Many researchers focus on the related research. Improving the photovoltaic performance of perovskite materials and optoelectronic devices based on this material has become an important research topic. Firstly, polyoxometalate (PW12) and perovskite (CH3NH3PbI3) were combined to form polyoxometalate modified perovskite precursor solution by solution chemistry. Photoconductivity test showed that the photocurrent intensity of the composite perovskite material was three times higher than that of the pure perovskite material. Monochromatic light detection results showed that the addition of polyoxometalates increased the sensitivity of the perovskite material at 365 nm, from 0.637 A/W to 1.168 A/W, and at 420 nm, from 0.238 A/W to 0.625 A/W. Based on the above test results, the analysis of the separation and recombination process of photogenerated carriers in the polyoxometalate modified perovskite composites showed that the introduction of polyoxometalate promoted the separation of carriers and accelerated their migration, thereby weakening the recombination ability of photogenerated electrons and holes. HOOC(CH2)4NH3I was combined with CH3NH3PbI3, and polyacid was introduced to prepare perovskite solar cells. The photovoltaic cells with the composite perovskite materials were used in photovoltaic buildings. The cells’ photoelectric conversion efficiency (PCE) changed from 9.26% to 11.37%, and the efficiency was increased by 23%. Compared with the open circuit voltage of perovskite solar cells before and after adding polyoxometalates, polyoxometalates doping significantly increased the short circuit current of building solar cells (from 17.88 mA/cm2 to 22.28 mA/cm2).

Unexpected Rheological Behavior of a Hydrophobic Associative Shellac-Based Oligomeric Food Thickener

Jianan Gao,Kun Li,Juan Xu,Wenwen Zhang,Jinju Ma,Lanxiang Liu,Yanlin Sun,Hong Zhang,Kai Li

Sodium shellac constituted of a “surfactant” monomer, which is sensitive to shear stress, exhibits shear-thickening behavior at a low concentration (5 wt %), and reacts with H+ to retain transient high viscosity under shear, is introduced in this study. The steady shear flow test proved that, under a high shear rate, sodium shellac suspension could change from Newtonian fluid to continuous shear-thickening non-Newtonian fluid. The dynamic oscillation test suggested that the sodium shellac solution at low concentrations (0.1 and 1 wt %) under a low shear rate behaved as the viscous fluid (G″ > G′), and the solution at high concentrations (5, 10, and 15 wt %) behaved as the elastic fluid (G″ < G′). Moreover, a high shear rate caused a cross-linking point between the G″ and G′ curve. At a low concentration, it could be the sol–gel point. At a high concentration, it could be the gel–sol point. All of these transforming points were related to the interaction between the sodium clusters. This interaction should be the hydrophobic association between the particles. To prove the assumption, hydrophilic polymer poly(ethylene oxide) (PEO) was employed as the disrupting factor to the hydrophobic association. As expected, the shear-thickening behavior vanished after mixing with PEO, which verified our assumption. On the other hand, the high viscosity of the suspension under shear could be retained by reaction with H+ to solidify the transient hydroclusters under shear. Meanwhile, sodium shellac had great potential as the functional shear thickener, which could modify the rheological property of the polymer with carboxyl groups, e.g., pectin, alginate, or poly(acrylic acid). Thus, this natural and green thicker has great potential in food, medical gel, green adhesive, or cosmetic products.

The Korean Socio-Political Context of the 1970s in Robot Taekwon V (1976)

Hyunseok Lee

As one of the masterpieces of early South Korean animation, the film Robot Taekwon V has instilled hopes and dreams in a younger generation of Koreans since the late 1970s when it was released, while critics have cited Robot Taekwon V as being influenced by American pop culture, particularly the Disney animation style, and have accused it of plagiarizing the designs of the popular Japanese animation Mazinger Z. In the 1970s, the Korean government actively promoted economic development for the ‘modernization of the country’ under the military regime’s inculcation of anti-communism. Robot Taekwon V was produced with the intent of being an anti-communist tool and, further, it sought the nationalism of postwar South Korea and promoted the country’s confidence in the future that eventually resulted in rapid economic development. This socio-political context is portrayed both in the form of a ‘gigantic robot’ and in the use of non-Korean appearances for Korean characters. Considering these aspects, the author examines how Robot Taekwon V navigates the intricacies of the postwar ideological framework, manages foreign cultural influences and suggests transnationalism through its character design and narrative.

Design and Fabrication of a Geometrically Ordered Hydrophobic Interlayer to Prepare High-Quality QD/SiO2 for Cell Imaging

Luo Dan,Han Rongcheng,Chen Ying,Zheng Qiang,Wang Lijun,Hong Yuankai,Sha Yinlin

The use of silica coatings has been a popular approach for the fabrication of water-soluble and biocompatible surfaces of quantum dots (QDs). However, most methods presently used cause a significant decrease in QD photoluminescence (PL), hampering further applications in biological and clinical research. We report a convenient method for the preparation of silica-shelled CdSeS/ZnS QDs (QD/SiO2) with a single semiconductor core and a high PL quantum yield (QY) in water (∼0.94, more than twice that of uncoated QDs in chloroform (∼0.44)). In our approach, a hydrophobic interlayer surrounding the CdSeS/ZnS nanocrystal core was fabricated prior to silanization. This allowed for optimization of intermolecular assembly between surfactants, and the geometric optimization of silane precursors and their initial coordinating ligands, by modulating their alkyl chain lengths. The resulting, geometrically well-matched interlayer exhibited higher hydrophobicity and lower molecular motility, both of which have been shown to enhance QY. QD/SiO2 surfaces, functionalized with triphenylphosphine, yielded targeted, high-quality fluorescent images of mitochondria in live cells.

Facilely Prepared Cl-Doped Graphene as an Efficient Anode for the Electrochemical Catalytic Degradation of Acetaminophen

Zhang Qian,Wang Bingxin,Hong Jun-Ming

The application of electrochemical catalytic oxidation in wastewater treatment with powerful Cldoped graphene as an anode has been discussed as a novel approach to degrade acetaminophen effectively. The characteristics of Cl-doped graphene that were related to Cl loading content and microscopic morphology were analyzed by using several instruments, and the defects created by Cl doping were identified. Quenching experiments and electron paramagnetic resonance detection were proposed to clarify the mechanism underlying the production of active free radicals by Cldopedgraphene. The degradation results indicated that efficiency increased with the percentage of Cl atoms doped into the graphene. The best degradation efficiency of acetaminophen could reach 98% when Cl-GN-12 was used. In the process of electrocatalytic oxidation, O•− 2, and active chlorine, as the main active species, persistently attacked acetaminophen into open-ring intermediates, such as 4-chlororesorcinol, and finally into CO2 and H2O.

Impact of synthesis methods on nanosized silver modified titania photocatalysts

Zhang Dongfang

This work reports the synthesis and studies on photocatalytic activity of a material based on titanium oxide doped with silver. Two kinds of Ag-deposited TiO 2 were synthesized via soft chemical reduction (SCR) and photodeposition (PD) methods. The structure, composition and chemical properties of the obtained products were investigated by X-ray diffraction, UV-vis diffuse reflectance spectroscopy, photoluminescence spectra and Fourier transformation infrared spectroscopy techniques. The photocatalytic oxidation activity in a course of removal and destruction of organic compounds such as methyl orange dye using Ag/TiO 2 hybrid material was studied. The results suggest that SCR synthesized Ag/TiO 2 exhibited better photocatalytic performance that that obtained by PD method. The relationship between the synthesis method and photocatalytic activity of synthesized Ag/TiO 2 was analyzed with a focus on the plasmonic photocatalysis of silver. When compared to PD method, the SCR produced more homogeneous and smaller silver particles with a better dispersion than photodeposition that results in a relative increase of material activity in the photocatalytic degradation of dye pollutant.

Cosmopolitan Bias: Salman Rushdie Reads Richard Burton

Paulo Lemos Horta

Taking as its point of departure Rushdie’s use of Burton’s Nights and South Asian travelogues in Shame and The Satanic Verses, this paper reads Burton and Rushdie against their cultural moments and their variant understandings of cosmopolitanism. Contra Appiah’s deployment of Burton in his seminal study of cosmopolitanism, it suggests that Burton’s prejudices were not as Appiah ventures “counter-cosmopolitan” but (because they were often acquired abroad) integral to his cosmopolitanism. In his fiction Rushdie repeatedly deploys the image of a boy’s discovery of Burton’s Nights in a patriarch’s library as emblematic of a neglected cosmopolitanism. Yet he may also be invoking Burton to critique the prejudices of Burton’s cosmopolitan personae in commenting on South Asia and the Nights. In engaging the legacy of Burton’s Nights, Rushdie’s narrators appear most certain of the dangers of neglecting the inheritance of a cosmopolitan tradition than of the virtues of embracing it.