On the Second Boundary Value Problem for a Class of Fully Nonlinear Equations

We proved the existence of convex solution to a class of fully nonlinear elliptic equations with second boundary condition on uniformly convex domains in \(\mathbb {R}^{n}\), and then applied it to solve a boundary value problem for minimal Lagrangian graphs in the pseudo-Euclidean space \(\mathbb {R}^{2n}_n\).     

A highly sensitive DNA-AIEgen-based “turn-on” fluorescence chemosensor for amplification analysis of Hg<Superscript>2+</Superscript> ions in real samples and living cells

Functional nucleic acids (FNAs)-based biosensors have shown great potential in heavy metal ions detection due to their low-cost and easy to operate merits. However, in most FNAs based fluorescence probes, the ingenious designs of double-labeled (fluorophore and quencher group) DNA sequence, not only bring the annoyance of organic synthesis, but also restrict its use as a robust biosensor in practical duties. In this paper, we design a simple AIEgens functional nucleic acids (AFNAs) probe which consists of only fluorogen but no quencher group. With the help of duplex-specific nuclease (DSN) enzyme based target recycling, high fluorescence signal and superior sensitivity towards Hg²⁺ are achieved. This robust assay allows for sensitive and selective detection of Hg²⁺ in real water samples and mapping of intracellular Hg²⁺, without double-labeling of oligonucleotide with a dye-quencher pair, nor the multiple assay steps.     

通过自分类构筑以两种分立金属有机大环为交联点的超分子聚合物凝胶

通过合理分子设计,合成了分别含有柱芳烃主体基元和氰基客体基元且具有不同尺寸的吡啶给体D1和D2,同时选择120?双铂金属盐A作为受体,从三组分出发,通过"一锅法"配位键导向自组装,自分类得到分别含有3个柱[5]芳烃单元的金属有机大环H和含有3个氰基中性客体的金属有机大环G.随着体系浓度增大,通过柱芳烃共价大环与中性氰基客体之间主客相互作用,逐级自组装形成以2种分立金属有机大环为交联点的新型超分子聚合物.所得到的超分子聚合物通过变浓度核磁氢谱(1H-NMR)、动态光散射(DLS)、二维核磁扩散序谱(DOSY)、扫描电镜(SEM)等进行了表征.有趣的是,进一步增加浓度(9.9 wt%),超分子聚合物转化成超分子聚合物凝胶,并且在温度、中性有机小分子及卤素离子等多重刺激下实现凝胶-溶液的可逆转化.     

Mononuclear piano-stool iron 2-ethynylbenzo[b]thiophene complex: crystal structure and reversible oxidation studied by spectro-electrochemical and DFT methods

A mononuclear iron complex with 2-ethynylbenzo[b]thiophene C-coordinated to the (η⁵-Cp*)(η²-dppe)Fe (Cp* = pentamethylcyclopentadienyl, dppe = 1,2-diphenylphosphinoethane) framework (1) was prepared and characterized by ¹H NMR, elemental analysis, and single crystal X-ray diffraction. The redox behavior of 1 was investigated by voltammetric methods and anodic spectroelectrochemistry in the UV–vis-NIR-IR region and compared with reference complexes including 2-ferrocenylbenzo[b]thiophene (2) and the 2-ethynylpyridine derivative of 1. The spin density distribution along the linear molecular backbone in 1⁺ was analyzed by DFT (BLYP35) and TDDFT calculations of a truncated model complex. The combined experimental and theoretical results revealed an important role of the ethynylene linker in determining the redox properties of this family of complexes and participation of the 2-ethynylbenzo[b]thiophene framework in the largely iron-based anodic electron transfer.     

Photo-responsive polymer materials for biological applications

In this review, we briefly summarized the remarkable progress of photo-responsive polymer materials from zero-dimensional micelles, twodimensional surfaces to three-dimensional hydrogels with irreversible or reversible moieties. Based on the photo-responsiveness, polymer have been designed, synthesized and applied for various biological fields including drug delivery and cell manipulation.     

Recent development of perylene diimide-based small molecular non-fullerene acceptors in organic solar cells

This review summarizes the recent progress of perylene diimide (PDI) derivatives used as the acceptor materials in non-fullerene organic solar cells. The resulting structure-property correlations and design strategies of this type of acceptors are discussed and commented, which will help to constructing high-performance PDI-based acceptor materials in the future. The problems at present and the effort direction are also pointed out in this review.     

A novel polymeric monolith prepared with multi-acrylate crosslinker for retention-independent efficient separation of small molecules in capillary liquid chromatography

Low column efficiency for small molecules in reversed-phase chromatography is a major problem commonly encountered in polymer-based monoliths. Herein, a novel highly crosslinked porous polymeric monolith was in situ prepared by using a multi-acrylate monomer, dipentaerythritol penta-/hexa-acrylate (DPEPA), as crosslinker, which copolymerized with lauryl methacrylate (LMA) as functional monomer in a UV-transparent fused-silica capillary via photo-initiated free-radical polymerization within 5 min. The mechanical stability and permeability of the resulting poly(LMA-co-DPEPA) monolith were characterized in detail. One series of highly crosslinked poly(LMA-co-DPEPA) columns were prepared with relatively higher content of crosslinker (63.3%) in the precursor. Although they exhibited lower permeability, high column efficiency for alkylbenzenes was acquired in cLC, and the minimum plate height (column B) was in the range of 6.04–9.00 μm, corresponding to 111,000–165,000 N m⁻¹. Meanwhile, another series of poly(LMA-co-DPEPA) columns prepared with relatively lower content of crosslinker (52.7%) in the precursor exhibited higher permeability, but the minimum plate height (column E) was relatively low in the range of 10.75–20.04 μm for alkylbenzenes, corresponding to 50,000–93,000 N m⁻¹. Compared with common poly(LMA-co-EDMA) columns previously reported, the highly crosslinked poly(LMA-co-DPEPA) columns using a multi-acrylate monomer as crosslinker possessed remarkably high column efficiency for small molecules in cLC. By plotting of plate height (H) of alkylbenzenes versus the linear velocity (u) of mobile phase, the results revealed a retention-independent efficient performance of small molecules in the isocratic elution, indicating that the use of multi-functional crosslinker possibly prevents the generation of gel-like micropores in the poly(LMA-co-DPEPA) monolith, reducing the mass transfer resistance (C-term).     

New Pentacyclic Triterpenoids from Centella asiatica

Three new pentacyclic triterpenoids, named centellasaponins G, H, and F ( 1 – 3 , resp.), together with four known compounds, 4 – 7 , were isolated from the whole plants of Centella asiatica. Their structures were elucidated on the basis of chemical and spectral analysis, including 1D‐ and 2D‐NMR and HR‐MS experiments, and by comparison with literature data.     

TiO2修饰La0.6Sr0.4Co0.2Fe0.8O3-δ用于中温固体氧化物燃料电池的阴极

纳米TiO2修饰的La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)阴极被直接应用于YSZ电解质电池上. TiO2可阻止LSCF和YSZ间的化学反应,抑制SrZrO3的形成. LSCF-0.25 wt% TiO2阴极电池在0.7 V和600°C下的电流密度是LSCF阴极电池的1.6倍.电化学阻抗谱结果表明, TiO2修饰显著加快了氧离子注入电解质的过程,这可能与TiO2抑制了阴极/电解质界面处高电阻SrZrO3层的形成有关.本文为在ZrO2基电解质上使用高性能的(La,Sr)(Co,Fe)O3阴极材料提供了一种简单有效的方法.     

Poly(thiophene-3-acetic acid)-palladium nanoparticle composite modified electrodes for supersensitive determination of hydrazine

 A promising electrochemical sensor was fabricated by electrodeposition of Pd nanoparticles (PdNPs) on poly(thiophene-3-acetic acid) (PTAA)-modified glassy carbon electrode (GCE), forming a PdNPs/PTAA composites-modified GCE (PdNPs/PTAA/GCE). Scanning electron microscope (SEM) and electrochemical techniques were used for the characterization of these composites. It was found that the PdNPs/PTAA layer was very uniform. Electrochemical experiments showed that this proposed PdNPs/PTAA composites-modified electrode exhibited excellent electrocatalytic activity towards the oxidation of hydrazine. Under the optimum conditions, the proposed sensor can be applied to the quantification of hydrazine with a wide linear range from 8.0?10^-9 mol/L to 1.0?10^-5 mol/L with a low detection limit of 2.67?10^-9 mol/L. The experiment results also showed that the sensor exhibited good reproducibility and long-term stability, as well as high selectivity with no interference from other potential competing species.