Recent advances in core-shell organic framework-based photocatalysts for energy conversion and environmental remediation

Direct conversion of solar energy into chemical energy in an environmentally friendly manner is one of the most promising strategies to deal with the environmental pollution and energy crisis.Among a variety of materials developed as photocatalysts,the core-shell metal/covalent-organic framework(MOF or COF)photocatalysts have garnered significant attention due to their highly porous structure and the adjustability in both structure and functionality.The existing reviews on core-shell organic framework photocatalytic materials have mainly focused on core-shell MOF materials.However,there is still a lack of indepth reviews specifically addressing the photocatalytic performance of core-shell COFs and MOFs@COFs.Simultaneously,there is an urgent need for a comprehensive review encompassing these three types of core-shell structures.Based on this,this review aims to provide a comprehensive understanding and useful guidelines for the exploration of suitable core-shell organic framework photocatalysts towards appropriate photocatalytic energy conversion and environmental governance.Firstly,the classification,synthesis,formation mechanisms,and reasonable regulation of core-shell organic framework were summarized.Then,the photocatalytic applications of these three kinds of core-shell structures in different areas,such as H_(2)evolution,CO_(2)reduction,and pollutants degradation are emphasized.Finally,the main challenges and development prospects of core-shell organic framework photocatalysts were introduced.This review aims to provide insights into the development of a novel generation of efficient and stable core-shell organic framework materials for energy conversion and environmental remediation.

Effects of processing technology on essential oil and pharmacological action of frankincense

Background:According to the traditional Chinese medicine theory,the common processing methods for Ruxiang(frankincense)include stir-frying processing and vinegar processing.Methods:With network pharmacology and thermal analysis methods,we selected and identified the main and irritating ingredients,established the pyrolysis characteristic parameters for identifying frankincense quality,quantified the starting and optimum temperature limits for processing frankincense,and analyzed the influences of processing adjuvants(vinegar)on combustion pyrolysis characteristics of frankincense.By applying Fourier transformation infrared spectrometry,high performance liquid chromatography,gas chromatography and UV-visible spectrometry,we evaluated the processing technology developed in our study of frankincense and its processed products.Results:Based on network pharmacology,we can find that the classical compounds of essential oil are the main pharmacodynamics components of frankincense possessing the anti-inflammatory,analgesia,anti-tumor,anti-ulcer and ant-inflammatory bowel disease effects.The pyrolysis combustion rate peaks of frankincense at 285.27±7.05℃and 476.99±13.46℃were the characteristic peaks used to identify frankincense quality.The specific temperature of slow-fire processing,including the vinegar processing and stir-frying processing,was 148.72±5.09℃.Heating for 5.67±0.98 min after reaching processing temperature was needed for processing frankincense with vinegar.The kinetics analysis showed that both frankincense and its vinegar mixture exhibited good linear relationships.The feasibility and practicability for our processing technology were verified through the determination of medicinal compounds by Fourier transformation infrared spectrometry,high performance liquid chromatography,gas chromatography and UV.Conclusion:Frankincense essential oils were the main active components of frankincense,which also can be taken as the internal chemical control indexes to judge the quality control and to optimize the processing technology of frankincense.The pyrolysis combustion rate peaks of frankincense at 285.27±7.05℃and 476.99±13.46℃were the characteristic peaks that can be used to identify frankincense quality.The optimum processing conditions of vinegar-processed frankincense with were as follows:with vinegar,20%;heating temperature,148.72±5.09℃;and heating time,5.67±0.98 min.Under these conditions,frankincense essential oil could cause a moderate effect on combustion pyrolysis characteristics to exert its corresponding pharmacological effects.

A Comparative Analysis of Sino-Thai College English Course Teaching——A Case of Comparison between Jiujiang University and Chiang Mai University

English is one of the most common languages in the world,and it has become one of the most important subjects in various countries.The native languages of China and Thailand are not English,and both countries are located in Asia and have many similarities in geographical location and cultural background.The Ministries of Education of the two countries have successively put forward relevant policies to promote the development of English education in the country.The implementation of these policies has promoted the development of college English course teaching in the country.These factors determine that the two countries have similarities in college English course teaching for Non-English majors.However,there are differences in teaching mode and teaching staff in the two countries because of their different national conditions,which make many differences,exist in college English course teaching for non-English majors in the two countries.During the author’s career as an exchange student in Chiang Mai University,she experienced the difference of college English course teaching for non-English majors in Thai universities,so the author did some researches on the basis of the understanding of English course teaching in Thai universities.Therefore,this thesis takes Sino-Thai college English course teaching for non-English majors as the research object—takes Jiujiang University and Chiang Mai University as example,and analyses their present situation from the aspects of the development and evolution,the teaching mode,and teaching staff of college English course teaching for non-English majors.On this basis,the author makes a comparative analysis of the English course teaching for non-English majors in two selected universities,then find their respective advantages and disadvantages,and put forward some suggestions on the development of Sino-Thai college English course teaching.

THE EXACT MEROMORPHIC SOLUTIONS OF SOME NONLINEAR DIFFERENTIAL EQUATIONS

We find the exact forms of meromorphic solutions of the nonlinear differential equations■,n≥3,k≥1,where q,Q are nonzero polynomials,Q■Const.,and p_(1),p_(2),α_(1),α_(2)are nonzero constants withα_(1)≠α_(2).Compared with previous results on the equation p(z)f^(3)+q(z)f"=-sinα(z)with polynomial coefficients,our results show that the coefficient of the term f^((k))perturbed by multiplying an exponential function will affect the structure of its solutions.

Hydrothermal synthesis of Y(OH)_3,Y(OH)_3:Eu^(3+) nanotubes and the photoluminescence of Y(OH)_3:Eu^(3+),Y_2O_3:Eu^(3+)

The phase and morphology transformation during the hydrothermal treating process of Y2O3 was evaluated with X-ray difference (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), particle size and specific surface area determination. The results showed that the cubic Y2O3 did not transfer into hexagonal Y(OH)3 in pure water. Therefore, pure hexagonal Y(OH)3 with nanotube and microrod morphologies were obtained by hydrothermal treating Y2O3 at 150 oC for 12 h in 15 ml of 2 mol/L NaOH solution with and without PVA or PEG. It was suggested that the characteristic preferential growth of Y(OH)3 was attributed to the structure anisotropy of hexahedron Y(OH)3. The addition of PVA or PEG could promote the forming process of nanotubes by selective adsorption on different crystal planes, which altered the growth rate along different directions and resulted in the diffusion limit of constructing ions in the center top of rods. Finally, Y(OH)3:Eu and Y2O3:Eu nanotubes were also synthesized by using this method, and their photoluminescence properties were evaluated.

Effect of vibration frequency on primary phase and properties of grey cast iron fabricated by lost foam casting

The properties of gray cast iron(GCI)are affected by density of matrix,size of flake graphite and primary austenite.In this paper,the Y-type specimen of GCI was prepared by lost foam casting(LFC)with and without vibration,and the influence of vibration frequency on the density of matrix,size of primary phase,and properties of the GCI was studied.The results show that the length of the flake graphite and the size of the primary austenite in GCI firstly decrease and then increase with the increase of the vibration frequency.With a vibration frequency of 35 Hz,the length of the flake graphite is the shortest,the primary austenite is the finest and the density of the matrix is the highest.In addition,the tensile strength,elongation and hardness of the GCI firstly increase and then decrease with the increase of the vibration frequency,due to the refinement of the primary phase and the increase of the matrix density.In order to analyze the refinement mechanism of the primary phase of the GCI fabricated by the LFC with vibration,the solidification temperature fields of the GCI fabricated by the LFC with the vibration frequency of 0 and 35 Hz were measured.The results show that the vibration reduces the eutectic point of the GCI and increases the supercooling degree during the eutectic transformation.As a result,the length of the flake graphite and the size of the primary austenite in GCI fabricated by LFC with the vibration frequency of 35 Hz decrease.

Low-cost photoacoustic imaging systems based on laser diode and light-emitting diode excitation

Photoacoustic imaging,an emerging biomedical imaging modality,holds great promise for preclinical and clinical researches.It combines the high optical contrast and high ultrasound resolution by converting laser excitation into ultrasonic emission.In order to generate photoacoustic signal e±-ciently,bulky Q-switched solid-state laser systems are most commonly used as excitation sources and hence limit its commercialization.As an alternative,the miniaturized semiconductor laser system has the advantages of being inexpensive,compact,and robust,which makes a signi¯cant e®ect on production-forming design.It is also desirable to obtain a wavelength in a wide range from visible to nearinfrared spectrum for multispectral applications.Focussing on practical aspect,this paper reviews the state-of-the-art developments of low-cost photoacoustic system with laser diode and light-emitting diode excitation source and highlights a few representative installations in the past decade.

Simultaneous Enhancement of Electrical Conductivity and Seebeck Coefficient of Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate)Films Treated with Urea

The thermoelectric performance of free-standing poly(3,4-ethylenedioythiophene):poly(styrenesulfonate)(PEDOT:PSS)thin films deposited from aqueous dispersion treated by different concentrations of urea are investigated in detail.The electrical conductivity,Seebeck coefficient and power factor of PEDOT:PSS films versus temperature are determined,respectively.It is found that both the electrical conductivity and Seebeck coefficient of PEDOT:PSS films are enhanced after treatment with urea.Conductivity could be enhanced from 8.16 to 63.13S-cm^(-1),the Seebeck coefficient is increased from 14.47 to 20.7μV.K^(-1)and the power factor is rises to 2.7μW.m^(-1)K^(-2)at 300K.

ELECTROCHEMICAL COPOLYMERIZATION OF 3-(4-FLUOROPHENYL)THIOPHENE AND 3-METHYLTHIOPHENE IN BORON TRIFLUORIDE DIETHYL ETHERATE

The copolymer poly（3-（4-fluorophenyl）thiophene-co-3-methylthiophene） was successfully prepared from mixtures of 3-（4-fluorophenyl）thiophene （FPT） and 3-methylthiophene （MET） via electrochemical oxidation in boron trifluoride diethyl etherate （BFEE） and its mixed electrolytes with acetonitrile （ACN）. The influence of monomer concentration ratios on the copolymerization was investigated by using linear sweep voltammetry and cyclic voltammetry. The structure and morphology of these copolymer films were elucidated by UV-Vis, infrared spectroscopy, elemental analysis, thermal analysis and scanning electron microscopy （SEM）, respectively. The results showed that the molar ratio of FPT and MeT units, when copolymer was electrodeposited from feed ratio of FPT：MeT = 1：2, was about 1.08：1. In addition, the introduction of ACN into BFEE has little effect on the properties of as-formed copolymers.

H_∞ couple-group consensus of stochastic multi-agent systems with fixed and Markovian switching communication topologies

The paper addresses the issue of H_∞ couple-group consensus for a class of discrete-time stochastic multi-agent systems via output-feedback control. Both fixed and Markovian switching communication topologies are considered. By employing linear transformations, the closed-loop systems are converted into reduced-order systems and the H_∞ couplegroup consensus issue under consideration is changed into a stochastic H_∞ control problem. New conditions for the mean-square asymptotic stability and H_∞ performance of the reduced-order systems are proposed. On the basis of these conditions, constructive approaches for the design of the output-feedback control protocols are developed for the fixed communication topology and the Markovian switching communication topologies, respectively. Finally, two numerical examples are given to illustrate the applicability of the present design approaches.

Effect of annealing processing on microstructure and properties of Ti-6Al-4V alloy by powder injection molding

Ti6A14V alloy parts were prepared by metal injection molding. Brown parts were densified at 1 200-1 260℃for 2-4 h in vacuum atmosphere. The as-sintered specimens were treated through Hot-Isostatic Pressure(HIP) at 960℃and 140 MPa. Ti6A14V alloy compacts were annealed at 720-760℃for 1 h. The results show that binder in the parts can be removed by solvent debinding and thermal debinding process. Ti6A14V alloy has an uniform duplex microstructure with many equiaxedαgrains and a littleβgrains. When the annealing temperature is higher than 800℃, T16A14V alloy has lower mechanical properties.After solution treatment and aging, a typical martensite microstructure can be achieved.

Deposition of photocatalytic TiO_2 and N-doped TiO_2 films by arc ion plating

TiO2 and N-doped TiO2 films were deposited on the glass substrates by arc ion plating method. The results show that the deposition rate does not change with the increasing deposition time. The increase of mass flow rate of N2 gives rise to the increase of deposition rate. All as-deposited TiO2 and N-doped TiO2 films are amorphous. The anatase TiO2 phase with preferred orientation(101) is acquired by post-annealing at 400 ℃ for 2 h. The incorporation of N into the TiO2 films and the heat treatment extensively shift the band edge to the visible light region.

Effect of partial pressure of reactive gas on chromium nitride and chromium oxide deposited by arc ion plating

The effects of reactive gas partial pressure on droplet formation, deposition rate and change of preferred orientation of CrN and Cr2O3 coatings were studied. For CrN coatings, as nitrogen partial pressure increases, the number and size of droplets increases, the deposition rate initially increases obviously and then slowly, and the preferred orientation of CrN changes from high-index plane to low-index one. For Cr2O3 coatings, with the increase of oxygen partial pressure, the number and size of droplets decreases, the deposition rate decreases and the (300) becomes the preferred orientation. These differences are ascribed to the formation of CrN (with a lower melting point) and Cr2O3 (with a higher melting point) on the surface of Cr target during the deposition of CrN and Cr2O3. Complete coatings CrN or Cr2O3 film can be formed when reactive gas partial pressure gets up to 0.1 Pa. The optimized N2 partial pressure for CrN deposition is about 0.1?0.2 Pa in order to suppress the formation of droplets and the suitable O2 partial pressure for Cr2O3 deposition is approximately 0.1 Pa for the attempt to prevent the peel of the coating.

Thermoelectric Performances of Free-Standing Polythiophene and Poly（3-Methylthiophene） Nanofilms

Thermoelectric performances of free-standing polythiophene （PT） and poly（3-methylthiophene） （PMeT） nanofilms with high tensile strength electrosynthesized from boron trifluoride diethyl etherate （BFEE） are systematically investigated. They display decent electric conductivity （47 and 73S.cm^-1）, high Seebeck coefficient （130 and 76μV.K^-1） and low thermal conductivity （0.17 and 0.15 W.m^-1.K^-1） at room temperature. Their figure of merit can reach 3.0 × 10^-2 at 250K, higher than that of many other conducting polymers. The decrease of charge carrier concentration resulting from volatile and water-sensitive dopants from BFEE leads to the decrease of electrical conductivity but a substantial increase of the Seebeck coet^cient, making their figure-of-merit values maintained at more than 10-2 even after prolonged storage （two months）. Moreover, free-standing PT and PMeT exhibit much better thermoelectric performances than those in pressed pellets due to the good arrangement of the polymer chains and preferably oriented structure in films. It therefore provides a way to improve the thermo- electric performances of conducting polymers by controlling regularity of the extended conjugated chain structure and/or the chain packing to achieve high charge mobility.

Syntheses, Structures and Fluorescent Properties of Two 1D Chain Organic Amines and Metal Iodine Organic-inorganic Hybrid Compounds

Two bifunctional amines, 4-(2-aminoethyl)morpholine and histamine, were heated with PbI_2 and BiI_3 in concentrated HI aqueous solution to give one-dimensional(1D) organicinorganic hybrid compounds [(C_6H_(16)N_2O)PbI4]n(1) and [(C_(16)H_(20)N_(20))Bi_2I_(10)](2), respectively. In 1, the [PbI6] octahedra formed double chain anions through sharing-corner and-edge, and the protonated(C_6H_(16)N_2O)^(2+) cations were located at the vicinity of the double chains by hydrogen bonds. In 2, the [BiI_6] octahedra firstly formed dimeric [Bi_2I_(10)]^(4-) anion through sharing edge, and subsequently, the protonated histamine cations worked as bridge to link alternately with [Bi_2I_(10)]^(4-) anion by hydrogen bonds to form organic-inorganic hybrid 1D chains. In addition, compound 1 emitted a green light at the excitation wavelength of 400 nm and the maximum emission wavelength is at 503 nm.

ELECTROCHEMICAL POLYMERIZATION OF 5-CYANOINDOLE IN MIXED ELECTROLYTES OF BORON TRIFLUORIDE DIETHYL ETHERATE AND DIETHYL ETHER

High quality poly（5-cyanoindole） （P5CI） films were electrosynthesized by direct anodic oxidation of 5-cyanoindole on stainless steel sheet in the mixed electrolytes of boron trifluoride diethyl etherate （BFEE） and diethyl ether （EE） （by volume 1：1） ＋ 0,05 mol L^-1 Bu4NBF4. The film formed can be peeled off the electrode into freestanding films, The addition of EE into BFEE can improve the solubility of monomer. P5CI films obtained from this medium showed excellent electrochemical behavior with conductivity of 10^-2 S cm^-1, Structural studies showed that the polymerization of 5-cyanoindole occurred at the 2,3 position. As-formed P5CI films were thoroughly soluble in strong polar organic solvent dimethyl sulfoxide （DMSO） while partly soluble in tetrahydrofuran （THF） or acetone. Fluorescence spectral studies indicated that P5CI was a good blue-ight emitter.

Syntheses, Crystal Structure and Magnetism of a Hexanuclear Copper(II) Cluster with the Unique Two-parallel Three-site Strings Configuration

Treatment of a heptadentate ligand 2,2＇-（（（pyridine-2,6-diyl-bis（methylene））- bis（（pyridin-2-ylmethyl）azanediyl））bis（methylene））diphenol （H2L） possessing pyridinyl- and phenolate groups, with three equivalents of Cu（C104）2·6H2O in methanol under base conditions, gave rise to a hexanuclear cluster complex [Cu6L2（OH）4]（C104）4·4MeCN·0.5MeOH （1）. Complex 1 crystallizes in triclinic, space group Pi with a = 12.068（12）, b = 12.567（12）, c = 16.279（16） A, α = 105.694（12）, β = 93.631（13）, γ = 112.017（11）°, V= 2166（4） A3, Z = 1,μ= 1.651 mm^-1, Dc = 1.599 Mg/m^3, T = 296（2） K, C74.5H795N14O24.5Cl4Cu6, Mr = 2086.12, F（000） = 1062.5, S = 1.061, R = 0.0521 and wR = 0.1270. In the cation of complex 1, the six copper cores are arranged into a two-parallel three-site strings configuration with each metal exhibits a slightly distorted square-pyramidal geometry, resulting from the connection of donor pyridinyi nitrogen and phenolate oxygen atoms in ligand H2L, and/or the oxygen donors in hydroxyl groups. In addition, magnetic susceptibility measurements revealed complex 1 displayed antiferromagnetic coupling.

A Dinuclear Zinc(Ⅱ) Complex Derived from a ‘Click' Ligand Containing Phenol,Pyridine and Triazole Donors

A novel 1,2,3-triazolyl-containing ligand （H2L） with long donor arms extending from the central pyridyl linker was synthesized by click cycloaddition of 2,6-bis（azidomethyl）pyri- line and 2-（（prop-2-yn-1-yl（pyridin-2-ylmethyl）amino）methyl）phenol. Further treatment of the igand H2L with zinc（II） perchlorate in the presence of triethylaminc, followed by anion exchange vith Na[BPh4], provided a dinuclear zinc（II） complex [Zn2L][BPh4]E-2DMF （1）. Complex 1 crystallizes in monoclinic, space group P21 with a = 10.4873（4）, b = 14.9078（5）, c = 25.8620（9） A, = 94.566（2）°, V = 4030.5（2） A3, Z = 2,μ= 0.657 mm-1, Dc = 1.324 Mg/m3, T = 296（2） K, C93H91N13B2O4Zn2, Mr = 1607.19, F（000） = 1684, S = 0.958, R = 0.0271 and wR = 0.0607. In the tructurc of cation, the phenolate oxygen atoms of ligand act as the bridging nodes to form a hombic Zn2（OAr）2 core.

Energy relaxation in disordered lattice φ4 system:The combined effects of disorder and nonlinearity

We address the issue of how disorder together with nonlinearity affect energy relaxation in the latticeφ~4 system.The absence of nonlinearity leads such a model to only supporting fully localized Anderson modes whose energies will not relax.However,through exploring the time decay behavior of each Anderson mode’s energy–energy correlation,we find that adding nonlinearity,three distinct relaxation details can occur.(i)A small amount of nonlinearity causes a rapid exponential decay of the correlation for all modes.(ii)In the intermediate value of nonlinearity,this exponential decay will turn to power-law with a large scaling exponent close to-1.(iii)Finally,all Anderson modes’energies decay in a power-law manner but with a quite small exponent,indicating a slow long-time tail decay.Obviously,the last two relaxation details support a new localization mechanism.As an application,we show that these are relevant to the nonmonotonous nonlinearity dependence of thermal conductivity.Our results thus provide new information for understanding the combined effects of disorder and nonlinearity on energy relaxation.