Research the evaporating crystalization process of the magnesium sulfate subtypes brine at high temperature from Dalangtan salt lake in Qinghai province.It was revealed that the salt lake is a typical subtype magnesium
Crystallization in polymer systems actually is a process that transfers the entangled melts into a semi-crystalline layered structure. Whether or not a chain disentangles may result in different crystallization mechan...Crystallization in polymer systems actually is a process that transfers the entangled melts into a semi-crystalline layered structure. Whether or not a chain disentangles may result in different crystallization mechanism. When compared to the crystal thickness (d(c)), the volume occupied by the chain in the melts i.e., the radius of gyration (R-g), plays a very important role in polymer crystallization. When d(c) less than or equal to R-g, crystallization does not necessitate a chain disentangling. The entanglements are just shifted into the amorphous regions. However, as d(c)>R-g, i.e., as the crystal thickness gets larger than the radius of gyration of the chain in the melt, it becomes necessary for a chain to disentangle. Then a change of crystallization mechanism occurs. Such change has been experimentally observed in the crystallization of poly(I-butene). A change in the crystal morphologies from spherulite to quadrangle, is seen via PLM, as crystallization temperatures increase. Even more, such a change is molecular weight dependent, and shifts to lower temperature as molecular weight decreases. There exists a jump of crystal thickness and crystallinity associated with morphological change, as seen via SAXS. A change of crystallization kinetics and crystallinity is further evidenced via dilatometry. The unique feature of P1b crystallization has been discussed based on the radius of gyration of chain in the melt (R-g), and very good agreement is obtained.展开更多
To elucidate the deformation mechanisms ofγ-TiAl,the nanoindentation experiments and crystal plasticity finite element(CPFE)simulation were employed to investigate the effects of crystal orientations and GBs on the m...To elucidate the deformation mechanisms ofγ-TiAl,the nanoindentation experiments and crystal plasticity finite element(CPFE)simulation were employed to investigate the effects of crystal orientations and GBs on the mechanical properties ofγ-TiAl alloys.A crystal plasticity constitutive model was developed,and load-displacement curves,hardness,and Young's modulus were obtained for both single grains and GBs inγ-TiAl alloys.Based on the aforementioned model,this study investigated the distribution patterns of surface morphology around the indentation sites of individual grain and GBs.It also analyzed the cumulative shear strain distribution,slip system activation,and the interaction between GBs and dislocation slip for various crystal orientations.The results indicate that the mechanical response and pileup behavior exhibit significant anisotropy due to the interplay among the indenter geometry,material slip systems,and cumulative shear strain distribution.Moreover,the interaction between GBs and dislocation slip substantially alters dislocation distribution,thereby influencing material flow and playing a critical role in the mechanical response and plastic deformation of the material.展开更多
Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(...Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(PAm)]·2H_(2)O(2)were determined by single-crystal X-ray diffraction,IR spectroscopy,and powder X-ray diffraction.Hirshfeld surface analysis provided quantitative insights into the intermolecular interactions within the complexes,while molecular docking studies elucidated their binding modes and affinities toward urease.Furthermore,the biological activities of both complexes were systematically evaluated through a range of assays,including DNA binding,urease inhibition,antibacterial activity,and in vitro cytotoxicity against cancer cells.Both complexes exhibited binding affinity for DNA and displayed notable urease inhibitory activity.Under in vitro conditions,both complexes showed appreciable cytotoxicity toward HepG2 cells with efficacy comparable to clinically used platinumbased anticancer agents.CCDC:2479943,1;2479944,2.展开更多
Using multi-directional forging temperature as the independent variable and adopting the dual-mode phase field crystal model,the nucleation modes,reaction mechanisms,and interactions between grain boundaries and dislo...Using multi-directional forging temperature as the independent variable and adopting the dual-mode phase field crystal model,the nucleation modes,reaction mechanisms,and interactions between grain boundaries and dislocations at different temperatures were investigated.Results show that a mapping relationship between process parameters and grain refinement/coarsening is established,and the optimal processing temperature coefficient is 0.23.Compared with the cases with processing temperature coefficient of 0.19,0.20,0.21,0.25,and 0.27,the refinement effect increases by 256.0%,146.0%,113.0%,6.7%,and 52.4%,respectively.Excessively high temperatures lead to grain coarsening due to dislocation annihilation,and the application of strain can reduce the actual melting point of materials.Even if the processing temperature does not exceed the theoretical melting point,remelting and crystallization may still occur,resulting in an overburning phenomenon that reduces internal defects and increases overall grain size.This research is of great significance for the actual forging process design.展开更多
In this work,five kinds of crystals were successfully synthesized using the Czochralski method for the first time,namely Dy∶Ca_(3)Li_(0.275)Nb_(1.775)Ga_(2.95)O_(12)(CLNGG),Dy,Tb∶CLNGG,Dy,Eu∶CLNGG,Tb∶CLNGG,and Eu...In this work,five kinds of crystals were successfully synthesized using the Czochralski method for the first time,namely Dy∶Ca_(3)Li_(0.275)Nb_(1.775)Ga_(2.95)O_(12)(CLNGG),Dy,Tb∶CLNGG,Dy,Eu∶CLNGG,Tb∶CLNGG,and Eu∶CLNGG.A detailed investigation of spectral features and energy transfer mechanisms in such crystals was conducted by analyzing their optical absorption spectra,excitation and emission spectra,and fluorescence decay curves at ambient tem-perature.Calculations based on the Judd-Ofelt theory further elucidated these features.The results demonstrate that in the Dy^(3+)system,co-doping with Tb^(3+)and Eu^(3+)ions not only enhances the emission cross-sections in the yellow wavelength re-gion but also improves the fluorescence quantum efficiency.These improvements are particularly beneficial for achieving efficient yellow light output from Dy^(3+).Additionally,the studies confirm the occurrence of reciprocal energy transfer be-tween Dy^(3+)and Tb^(3+)ions in Dy,Tb∶CLNGG crystals,whereas unidirectional energy transfer from Dy^(3+)to Eu^(3+)occurs in Dy,Eu∶CLNGG crystals.Based on the obtained research results,Dy,Tb∶CLNGG and Dy,Eu∶CLNGG crystals could be utilized as compelling and potential laser media for diode-pumped all-solid-state yellow lasers.展开更多
Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'...Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'-bipyridine]were successfully synthesized by the volatilization of the solution at room temperature.The crystal structures of six complexes were determined by single-crystal X-ray diffraction technology.The results showed that the complexes all have a binuclear structure,and the structures contain free ethanol molecules.Moreover,the coordination number of the central metal of each structural unit is eight.Adjacent structural units interact with each other through hydrogen bonds and further expand to form 1D chain-like and 2D planar structures.After conducting a systematic study on the luminescence properties of complexes 1-4,their emission and excitation spectra were obtained.Experimental results indicated that the fluorescence lifetimes of complexes 2 and 3 were 0.807 and 0.845 ms,respectively.The emission spectral data of complexes 1-4 were imported into the CIE chromaticity coordinate system,and their corre sponding luminescent regions cover the yellow light,red light,green light,and orange-red light bands,respectively.Within the temperature range of 299.15-1300 K,the thermal decomposition processes of the six complexes were comprehensively analyzed by using TG-DSC/FTIR/MS technology.The hypothesis of the gradual loss of ligand groups during the decomposition process was verified by detecting the escaped gas,3D infrared spectroscopy,and ion fragment information detected by mass spectrometry.The specific decomposition path is as follows:firstly,free ethanol molecules and neutral ligands are removed,and finally,acidic ligands are released;the final product is the corresponding metal oxide.CCDC:2430420,1;2430422,2;2430419,3;2430424,4;2430421,5;2430423,6.展开更多
To address the challenges of complex metallic film coating processes and low integration in single-parameter detection for existing photonic crystal fiber surface plasmon resonance(PCF-SPR)sensors,a dual-parameter sen...To address the challenges of complex metallic film coating processes and low integration in single-parameter detection for existing photonic crystal fiber surface plasmon resonance(PCF-SPR)sensors,a dual-parameter sensor based on gold nanowire-integrated bias-core PCF-SPR is proposed.Unlike conventional in-hole coatings or metallic film structures,the gold nanowires are directly attached to the fiber cladding via chemical vapor deposition(CVD),eliminating uneven coating issues and significantly simplifying fabrica-tion.By optimizing the asymmetric bias-core fiber structure and leveraging the strong localized field en-hancement of gold nanowires,the sensor achieves high-sensitivity synchronous detection of temperature(25−60℃)and refractive index(1.31−1.40)in dual-polarization modes.The simulation results demonstrate that the x-polarization mode can achieve 1.31−1.40 refractive index detection with maximum wavelength sensitivity and amplitude sensitivity of 14800 nm/RIU and−1724.25 RIU^(−1),and maximum refractive index resolution of 6.75×10^(−6)RIU.The y-polarization mode achieves refractive index detection range of 1.34−1.40,and the maximum wavelength sensitivity and amplitude sensitivity are 28400 nm/RIU and−1298.93 RIU^(−1),and the maximum refractive index resolution is 3.52×10^(−6)RIU.For temperature sensing,the sensor exhibits a wavelength sensitivity of 7.8 nm/℃and a high resolution of 1.38×10^(−6)℃over the range of 25−60℃.This design synergizes gold nanowires and the bias-core architecture to simplify fabrication while enabling multi-parameter detection.The proposed sensor offers new insights for integrated applications in biochemical mon-itoring,environmental sensing,and related fields.展开更多
A metal-organic framework{[Zn(L)_(0.5)(1,2,4,5-tpb)_(0.5)]·DMF·3H_(2)O}_(n)(1)was synthesized by solvothermal reaction,where H4L=5,5'-(ethane-1,2-diyl)diisophthalic acid,and 1,2,4,5-tpb=1,2,4,5-tetra(pyr...A metal-organic framework{[Zn(L)_(0.5)(1,2,4,5-tpb)_(0.5)]·DMF·3H_(2)O}_(n)(1)was synthesized by solvothermal reaction,where H4L=5,5'-(ethane-1,2-diyl)diisophthalic acid,and 1,2,4,5-tpb=1,2,4,5-tetra(pyridin-4-yl)benzene.The analysis of the single crystal structure indicates that L^(4-)and 1,2,4,5-tpb are connected with Zn(Ⅱ)to form a 2D layered structure,and the layers are linked by 1,2,4,5-tpb to form a 3D structure.1 can be used as a highly selective fluorescent probe for the detection of 2,4-dinitrophenylhydrazine(DNP)and tetracycline(TET),and the detection limits were 0.013 and 0.31μmol·L^(-1),respectively.1 was applied successfully to the determination of TET content in the Yanhe River water sample.CCDC:2466221.展开更多
This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the correspo...This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the corresponding ester[Fe_(2)(CO)_(6)(μ‑tedt)](2),where tedt=SCH_(2)CH(CH_(2)OOC(5‑C_(3)HNSCH_(3)))S.Further reactions of complex 2 with tri(ptolyl)phosphine(tp)or tris(4‑fluorophenyl)phosphine(fp)gave the phosphine‑substituted derivatives[Fe_(2)(CO)_(5)(tp)(μ‑tedt)](3)and[Fe_(2)(CO)_(5)(fp)(μ‑tedt)](4).The structures of the newly prepared complexes were elucidated by elemental analysis,NMR,IR,and X‑ray photoelectron spectroscopy.Moreover,single‑crystal X‑ray diffraction analysis confirmed their molecular structures,showing that they contain a di‑iron core ligated by a bridged dithiolate bearing a thiazole moiety and terminal carbonyls.The electrochemical and electrocatalytic proton reduction were probed by cyclic voltammetry,revealing that three complexes can catalyze the reduction of protons to H_(2) under the electrochemical conditions.For comparison,complex 4 possessed the best efficiency with a turnover frequency of 23.5 s^(-1)at 10 mmol·L^(-1)HOAc concentration.In addition,the fungicidal activity of these complexes was also investigated in this study.CCDC:2477511,2;2477512,3;2477513,4.展开更多
To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the...To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the alloy across different planes were investigated.The anisotropy of SLM-fabricated Ti-6Al-4V alloys was analyzed,and the electron backscatter diffraction technique was used to investigate the influence of different grain types and orientations on the stress-strain distribution at various scales.Results reveal that in room-temperature compression tests at a strain rate of 10^(-3) s^(-1),both the compressive yield strength and microhardness vary along the deposition direction,indicating a certain degree of mechanical property anisotropy.The alloy exhibits a columnar microstructure;along the deposition direction,the grains appear equiaxed,and they have internal hexagonal close-packed(hcp)α/α'martensitic structure.α'phase has a preferential orientation approximately along the<0001>direction.Anisotropy arises from the high aspect ratio of columnar grains,along with the weak texture of the microstructure and low symmetry of the hcp crystal structure.展开更多
An alternative elliptical and circle air-hole-assisted Al_(0.24)Ga_(0.76)As photonic crystal fiber(PCF)was proposed for generating broadband high-coherence mid-infrared supercontinuum,and the dispersion,effect-ive mod...An alternative elliptical and circle air-hole-assisted Al_(0.24)Ga_(0.76)As photonic crystal fiber(PCF)was proposed for generating broadband high-coherence mid-infrared supercontinuum,and the dispersion,effect-ive mode area and nonlinear coefficient were investigated by using finite element method(FEM),the evolu-tion of optical pulses propagating along the fiber was simulated,and the supercontinuum and the coherence were analyzed and evaluated under different pumping conditions.The results show that a supercontinuum spectrum with a spectral width of 4.852μm can be obtained in the proposed fiber with d_(1)/Λof 0.125,d_(2)/Λof 0.583 and the zero-dispersion wavelength of 3.228μm by pumping with a Gaussian pulse with a peak power of 800 W and a full width at half maximum(FWHM)of 20 fs at wavelength of 3.3μm.When the fiber is pumped by the pulse with the peak power of 2000 W,the FWHM of 80 fs at the wavelength of 4.0μm in the in the anomalous dispersion region,the modulation instability is obviously suppressed,and the high-coher-ence supercontinuum spectrum spanning from 1.1μm to 8.99μm is observed.A part of the pulse energy is transferred to the anomalous dispersion region when pumped at the wavelength of 2.8μm in the normal dis-persion region and a broadband high-coherence supercontinuum spectrum extending from 0.8μm to 9.8μm is generated in the 10 mm proposed fiber.This paper introduces elliptical air holes in the Al_(0.24)Ga_(0.76)As photonic crystal fiber,which enhances flexibility for tailoring the performance of supercontinuum,ultimately achieving the broadest supercontinuum spectrum with the shortest fiber length to date.展开更多
The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically in...The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.展开更多
5,5'-dithiobis(2-nitrobenzoic acid)(H_(2)DTNB)was employed as the second ligand to react with cucurbit[6]uril(Q[6])and Cd(NO_(3))_(2),and it was deprotonated or transformed into HDTNB^(-),TNB^(2-)and NSB^(2-)(H_(2...5,5'-dithiobis(2-nitrobenzoic acid)(H_(2)DTNB)was employed as the second ligand to react with cucurbit[6]uril(Q[6])and Cd(NO_(3))_(2),and it was deprotonated or transformed into HDTNB^(-),TNB^(2-)and NSB^(2-)(H_(2)TNB=5,5'-thiobis(2-nitrobenzoic acid),H_(2)NSB=2-nitro-5-sulfobenzoic acid)under different conditions to afford three novel supramolecular assemblies with the formulas of[Cd(H_(2)O)_(4)(Q[6])](HDTNB)_(2)·3H_(2)O(1),[Cd(H_(2)O)_(6)]_(2)(TNB)_(2)·Q[6]·4H_(2)O(2)and[Cd(H_(2)O)_(5)(NSB)]_(2)·Q[6](3).Singe-crystal diffraction(SC-XRD)analysis revealed that assembly 1 is constructed from 2D[Cd(H_(2)O)_(4)(Q[6])]2+supramolecular layers and HDTNB^(-)supra molecular layers,the structure of assembly 2 is comprised of the 2D{[Cd(H_(2)O)_(6)]_(2)·Q[6]}^(4+)supramolecular layers and 1D TNB^(2-)supramolecular chains,while assembly 3 is built from the 3D Q[6]frameworks with[Cd(H_(2)O)_(5)(NSB)]supramolecular chains filled in the pores.Meanwhile,the noncovalent interactions between the ligands HDTNB^(-)/TNB^(2-)/NSB^(2-)and the outer-surface of Q[6]molecules contributed greatly to the formation of the supramolecular architecture of assemblies 1-3.CCDC:2522253,1;2522254,2;2522255,3.展开更多
This study investigates the reduction in polarization measurement accuracy caused by varying in-cident angles in a liquid crystal variable retarder(LCVR).The phase delay characteristics of the LCVR were examined,with ...This study investigates the reduction in polarization measurement accuracy caused by varying in-cident angles in a liquid crystal variable retarder(LCVR).The phase delay characteristics of the LCVR were examined,with particular emphasis on the influence of different two-dimensional incident angles on phase delay behavior.Building upon the calibration of phase delay under normal incidence,a phase delay calibra-tion model was developed to account for variations in incident angle and driving voltage.A mathematical re-lationship was established between phase delay and the azimuth angle(α)and pitch angle(β).Experimental validation was conducted under three conditions:α=20°,β=0°;α=0°,β=20°;and an arbitrary angle whereα=5°,β=15°.The results demonstrated that the maximum average deviation between theoretical pre-dictions and experimental measurements did not exceed 0.059 rad.The proposed calibration method proved to be both accurate and practical.This approach offers robust support for LCVR parameter calibration and performance optimization in optical systems,particularly in polarization imaging applications.展开更多
The hydrated tricyclohexyltin theophylline-7-acetic acid(tpH)complex[Sn(C_(6)H_(11))_(3)(tp)(H_(2)O)]was synthesized via an ethanol solvothermal method using tricyclohexyltin hydroxide and tpH in a 1∶1 molar ratio.Th...The hydrated tricyclohexyltin theophylline-7-acetic acid(tpH)complex[Sn(C_(6)H_(11))_(3)(tp)(H_(2)O)]was synthesized via an ethanol solvothermal method using tricyclohexyltin hydroxide and tpH in a 1∶1 molar ratio.The complex was characterized by IR,^(1)H(^(13)C)NMR,elemental analysis,and powder X-ray diffraction,and the crystal structure was determined by single-crystal X-ray diffraction.The crystal belongs to the orthorhombic system with space group Iba2,and the central tin atom is in a five-coordinated trigonal bipyramidal configuration.Quantum chemistry ab initio calculations were performed to investigate the stability,molecular orbital energy,and frontier molecular orbital characteristics of the complex.Additionally,its thermal stability,electrochemical properties,and in vitro anticancer activity were evaluated.CCDC:2380308.展开更多
Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2...Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2)O(1)was synthesized as a 2D structure using Coas the metal source,methanol‑water(4∶6,V/V)as the solvent,and specific concentrations of 2,5‑furandicarboxylic acid(H_(2)FDCA)and 1,3,5‑triimidazole benzene(L).Adjusting to pure water and lowering the concentration of L yielded the 1D chain structure of[Co(HL)2(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(2).Using Cu(Ⅱ)as the metal source,methanol/water(9∶1,V/V)as the solvent,and specific concentrations of L and H2FDCA,the 1D chain structure of[Cu(L)(FDCA)(H_(2)O)]·2H_(2)O(3)was synthesized.Upon increasing the concentrations of L and H2FDCA,and switching the solvent to pure water,the 1D chain structure of[Cu(HL)_(2)(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(4)was obtained.This shows that changing the solvent and ligand concentrations can affect the structural changes of CPs.In addition,the solid‑state photoluminescence of CPs 1‑4 at room temperature was studied,and their morphological changes were observed via scanning electron microscopy.Density functional theory calculations revealed that the negative charge concentrates on the O and N atoms of the ligand,facilitating ligand‑metal ion coordination.CCDC:2403934,1;2403935,2;2403936,3;2403938,4.展开更多
Based on 4'-(1H-tetrazol-5-yl)-[1,1'-biphenyl]-2,4,6-tricarboxylic acid(H_(4)bta)ligand,zinc metal-organic framework(Zn-MOF):{[Zn_(2)(bta)(bpy)_(2)(H_(2)O)]·1.5H_(2)O}_(n)(bpy=2,2'-bipyridine)was desi...Based on 4'-(1H-tetrazol-5-yl)-[1,1'-biphenyl]-2,4,6-tricarboxylic acid(H_(4)bta)ligand,zinc metal-organic framework(Zn-MOF):{[Zn_(2)(bta)(bpy)_(2)(H_(2)O)]·1.5H_(2)O}_(n)(bpy=2,2'-bipyridine)was designed and synthesized by hydrothermal method.Its structure was characterized by elemental analysis,IR spectra,X-ray single crystal diffraction,etc.The asymmetric unit of Zn-MOF contains two crystallographically independent Zn^(2+)ions.Through the connection of Zn^(2+)ions via H_(4)bta,a 1D double-layer network structure is formed.Adjacent double-layer networks further form a 2D supramolecular network through hydrogen bonding.Notably,Zn-MOF exhibited excellent fluorescence properties and could efficiently and sensitively detect various water pollutants:4-nitrophenol(4-NP),Cu^(2+),and pyrimethanil(Pth).Additionally,the mechanism of fluorescence sensing was investigated.CCDC:2432230.展开更多
Energetic materials face critical challenges in balancing energy density and safety,driving the development of low-sensitivity high-energy materials.Though vital for modern defense and civilian applications,low-sensit...Energetic materials face critical challenges in balancing energy density and safety,driving the development of low-sensitivity high-energy materials.Though vital for modern defense and civilian applications,low-sensitivity high-energy materials remain scarce,with 1,3,5-trinitro-2,4,6-triaminobenzene as the only deployed example.Planar lamellar energetic crystals,which utilize weak interlamellarπ-πstacking for mechanical energy dissipation,have shown significant promise.However,their rational design is constrained by insufficient understanding of intermolecular interaction synergy.This review synthesizes the structural features of planar lamellar energetic crystals,emphasizing three core elements:the single-atomic-thickness planar stacking architecture,the"strong intralamellar and weak interlamellar interaction"paradigm(key to balancing energy density and safety for low-sensitivity high-energy materials,LSHEMs),and the role of molecular planarity in reducing shear slip barriers.It categorizes design strategies into two frameworks:H–bonding dominated(single-component:cross-shaped assembly,strong H–bonding in high symmetric molecules;multi-component methods:tenon-and-mortise,acceptor-donor separation)and other intermolecular interactions(e.g.,π-πstacking-drivenπ-π2max model,π-hole recognition).Case studies in single/multi-component crystals confirm that these strategies tune interaction synergy to achieve target packing motifs.The review highlights that interaction engineering is pivotal for PLEC design,offering a targeted theoretical framework for rational development of LSHEMs(to address the scarcity of practical LSHEMs)and guiding future crystal engineering for energy-safety balanced systems.展开更多
In 2024, the MOE Key Laboratory of Macromolecular Synthesis and Functionalization at Zhejiang University continued its impactful researches across five core areas. In controllable catalytic polymerization,organoboron ...In 2024, the MOE Key Laboratory of Macromolecular Synthesis and Functionalization at Zhejiang University continued its impactful researches across five core areas. In controllable catalytic polymerization,organoboron catalysts were developed for CO_(2) copolymerization and novel photoresist materials. Studies in microstructure and rheology elucidated universal deformation modes in graphene-based 2D membranes and improved graphene fiber properties through shear alignment engineering, defect control, and enhanced interlayer entanglement. For separating functional polymers, Janus membranes and channels were created for multiphase separation, liquid-phase molecular layer-by-layer deposition technique was developed to fabricate aromatic polyamide nanofilms, and the harmonic amide bond density was established as a valuable parameter for polyamide structural analysis. In biomedical functional polymers, a sustainable carboxyl-ester transesterification strategy was proposed for upcycling poly(ethylene terephthalate)(PET) waste into biodegradable plastics. Additionally, immunocompatible biomaterials were designed utilizing zwitterionic polypeptides and albumin-derived coatings, and Cu2+-phenolic nanoflower was designed to combat fungal infections by combining cuproptosis and cell wall digestion. Further,the researchers developed a gelatin-DOPA-knob/fibrinogen hydrogel to achieve rapid and robust hemostatic sealing, utilized a double-network polyelectrolyte-coated hydrogel for enhancing endothelialization of left atrial appendage(LAA) occluders, and the researchers also demonstrated that image-guided highintensity focused ultrasound enables manipulation of shape-memory polymers. Finally, in the realm of photo-electro-magnetic functional polymers, precise control of through-space conjugation was shown to enhance organic luminescence. Topologically structured hydrogels were revealed to exhibit autonomous actuation. Also, solar-driven photothermal ion pumps were developed for selective lithium extraction from seawater, and high-performance non-solvated C60single-crystal films were prepared via facile bar coating. Lastly, the researchers demonstrated outstanding dielectric properties of polyethylene(PE) lamellar single crystals. The relevant works are reviewed in this paper.展开更多
基金financially supported with General Project of Nat-ural Science Foundation of China (No. 21373252)
文摘Research the evaporating crystalization process of the magnesium sulfate subtypes brine at high temperature from Dalangtan salt lake in Qinghai province.It was revealed that the salt lake is a typical subtype magnesium
基金This work was supported by the Deutsche Forschungsgemeinschall and der Chemischen Industrierate, Alexander von Humboldt Stiffeng and the China National Distinguished Young Investigator Fund (No. 29925413).
文摘Crystallization in polymer systems actually is a process that transfers the entangled melts into a semi-crystalline layered structure. Whether or not a chain disentangles may result in different crystallization mechanism. When compared to the crystal thickness (d(c)), the volume occupied by the chain in the melts i.e., the radius of gyration (R-g), plays a very important role in polymer crystallization. When d(c) less than or equal to R-g, crystallization does not necessitate a chain disentangling. The entanglements are just shifted into the amorphous regions. However, as d(c)>R-g, i.e., as the crystal thickness gets larger than the radius of gyration of the chain in the melt, it becomes necessary for a chain to disentangle. Then a change of crystallization mechanism occurs. Such change has been experimentally observed in the crystallization of poly(I-butene). A change in the crystal morphologies from spherulite to quadrangle, is seen via PLM, as crystallization temperatures increase. Even more, such a change is molecular weight dependent, and shifts to lower temperature as molecular weight decreases. There exists a jump of crystal thickness and crystallinity associated with morphological change, as seen via SAXS. A change of crystallization kinetics and crystallinity is further evidenced via dilatometry. The unique feature of P1b crystallization has been discussed based on the radius of gyration of chain in the melt (R-g), and very good agreement is obtained.
基金National Natural Science Foundation of China(52065036,52365018)Natural Science Foundation of Gansu(23JRRA760,24JRRA175,25JRRA060)+1 种基金Hongliu Outstanding Youth Foundation of Lanzhou University of TechnologyLeading Innovative Talents Project of Changzhou(CQ20210111)。
文摘To elucidate the deformation mechanisms ofγ-TiAl,the nanoindentation experiments and crystal plasticity finite element(CPFE)simulation were employed to investigate the effects of crystal orientations and GBs on the mechanical properties ofγ-TiAl alloys.A crystal plasticity constitutive model was developed,and load-displacement curves,hardness,and Young's modulus were obtained for both single grains and GBs inγ-TiAl alloys.Based on the aforementioned model,this study investigated the distribution patterns of surface morphology around the indentation sites of individual grain and GBs.It also analyzed the cumulative shear strain distribution,slip system activation,and the interaction between GBs and dislocation slip for various crystal orientations.The results indicate that the mechanical response and pileup behavior exhibit significant anisotropy due to the interplay among the indenter geometry,material slip systems,and cumulative shear strain distribution.Moreover,the interaction between GBs and dislocation slip substantially alters dislocation distribution,thereby influencing material flow and playing a critical role in the mechanical response and plastic deformation of the material.
文摘Two Co(Ⅱ)and Ni(Ⅱ)complexes were synthesized by synergistic coordination of 3,3-diphenylpropionic acid(HDPA)and 2,2′-bipyridylamine(PAm).The structures of complexes[Co(DPA)_(2)(PAm)]·2H_(2)O(1)and[Ni(DPA)_(2)(PAm)]·2H_(2)O(2)were determined by single-crystal X-ray diffraction,IR spectroscopy,and powder X-ray diffraction.Hirshfeld surface analysis provided quantitative insights into the intermolecular interactions within the complexes,while molecular docking studies elucidated their binding modes and affinities toward urease.Furthermore,the biological activities of both complexes were systematically evaluated through a range of assays,including DNA binding,urease inhibition,antibacterial activity,and in vitro cytotoxicity against cancer cells.Both complexes exhibited binding affinity for DNA and displayed notable urease inhibitory activity.Under in vitro conditions,both complexes showed appreciable cytotoxicity toward HepG2 cells with efficacy comparable to clinically used platinumbased anticancer agents.CCDC:2479943,1;2479944,2.
基金National Natural Science Foundation of China(52375394,52275390,U23A20628,52305429)Major Project of Science and Technology in Shanxi(202301050201004)Natural Science Foundation of Shanxi Province(202403021222132)。
文摘Using multi-directional forging temperature as the independent variable and adopting the dual-mode phase field crystal model,the nucleation modes,reaction mechanisms,and interactions between grain boundaries and dislocations at different temperatures were investigated.Results show that a mapping relationship between process parameters and grain refinement/coarsening is established,and the optimal processing temperature coefficient is 0.23.Compared with the cases with processing temperature coefficient of 0.19,0.20,0.21,0.25,and 0.27,the refinement effect increases by 256.0%,146.0%,113.0%,6.7%,and 52.4%,respectively.Excessively high temperatures lead to grain coarsening due to dislocation annihilation,and the application of strain can reduce the actual melting point of materials.Even if the processing temperature does not exceed the theoretical melting point,remelting and crystallization may still occur,resulting in an overburning phenomenon that reduces internal defects and increases overall grain size.This research is of great significance for the actual forging process design.
文摘In this work,five kinds of crystals were successfully synthesized using the Czochralski method for the first time,namely Dy∶Ca_(3)Li_(0.275)Nb_(1.775)Ga_(2.95)O_(12)(CLNGG),Dy,Tb∶CLNGG,Dy,Eu∶CLNGG,Tb∶CLNGG,and Eu∶CLNGG.A detailed investigation of spectral features and energy transfer mechanisms in such crystals was conducted by analyzing their optical absorption spectra,excitation and emission spectra,and fluorescence decay curves at ambient tem-perature.Calculations based on the Judd-Ofelt theory further elucidated these features.The results demonstrate that in the Dy^(3+)system,co-doping with Tb^(3+)and Eu^(3+)ions not only enhances the emission cross-sections in the yellow wavelength re-gion but also improves the fluorescence quantum efficiency.These improvements are particularly beneficial for achieving efficient yellow light output from Dy^(3+).Additionally,the studies confirm the occurrence of reciprocal energy transfer be-tween Dy^(3+)and Tb^(3+)ions in Dy,Tb∶CLNGG crystals,whereas unidirectional energy transfer from Dy^(3+)to Eu^(3+)occurs in Dy,Eu∶CLNGG crystals.Based on the obtained research results,Dy,Tb∶CLNGG and Dy,Eu∶CLNGG crystals could be utilized as compelling and potential laser media for diode-pumped all-solid-state yellow lasers.
文摘Six new lanthanide complexes:[Ln(3,4-DEOBA)3(4,4'-DM-2,2'-bipy)]2·2C_(2)H_(5)OH,[Ln=Dy(1),Eu(2),Tb(3),Sm(4),Ho(5),Gd(6);3,4-DEOBA-=3,4-diethoxybenzoate,4,4'-DM-2,2'-bipy=4,4'-dimethyl-2,2'-bipyridine]were successfully synthesized by the volatilization of the solution at room temperature.The crystal structures of six complexes were determined by single-crystal X-ray diffraction technology.The results showed that the complexes all have a binuclear structure,and the structures contain free ethanol molecules.Moreover,the coordination number of the central metal of each structural unit is eight.Adjacent structural units interact with each other through hydrogen bonds and further expand to form 1D chain-like and 2D planar structures.After conducting a systematic study on the luminescence properties of complexes 1-4,their emission and excitation spectra were obtained.Experimental results indicated that the fluorescence lifetimes of complexes 2 and 3 were 0.807 and 0.845 ms,respectively.The emission spectral data of complexes 1-4 were imported into the CIE chromaticity coordinate system,and their corre sponding luminescent regions cover the yellow light,red light,green light,and orange-red light bands,respectively.Within the temperature range of 299.15-1300 K,the thermal decomposition processes of the six complexes were comprehensively analyzed by using TG-DSC/FTIR/MS technology.The hypothesis of the gradual loss of ligand groups during the decomposition process was verified by detecting the escaped gas,3D infrared spectroscopy,and ion fragment information detected by mass spectrometry.The specific decomposition path is as follows:firstly,free ethanol molecules and neutral ligands are removed,and finally,acidic ligands are released;the final product is the corresponding metal oxide.CCDC:2430420,1;2430422,2;2430419,3;2430424,4;2430421,5;2430423,6.
文摘To address the challenges of complex metallic film coating processes and low integration in single-parameter detection for existing photonic crystal fiber surface plasmon resonance(PCF-SPR)sensors,a dual-parameter sensor based on gold nanowire-integrated bias-core PCF-SPR is proposed.Unlike conventional in-hole coatings or metallic film structures,the gold nanowires are directly attached to the fiber cladding via chemical vapor deposition(CVD),eliminating uneven coating issues and significantly simplifying fabrica-tion.By optimizing the asymmetric bias-core fiber structure and leveraging the strong localized field en-hancement of gold nanowires,the sensor achieves high-sensitivity synchronous detection of temperature(25−60℃)and refractive index(1.31−1.40)in dual-polarization modes.The simulation results demonstrate that the x-polarization mode can achieve 1.31−1.40 refractive index detection with maximum wavelength sensitivity and amplitude sensitivity of 14800 nm/RIU and−1724.25 RIU^(−1),and maximum refractive index resolution of 6.75×10^(−6)RIU.The y-polarization mode achieves refractive index detection range of 1.34−1.40,and the maximum wavelength sensitivity and amplitude sensitivity are 28400 nm/RIU and−1298.93 RIU^(−1),and the maximum refractive index resolution is 3.52×10^(−6)RIU.For temperature sensing,the sensor exhibits a wavelength sensitivity of 7.8 nm/℃and a high resolution of 1.38×10^(−6)℃over the range of 25−60℃.This design synergizes gold nanowires and the bias-core architecture to simplify fabrication while enabling multi-parameter detection.The proposed sensor offers new insights for integrated applications in biochemical mon-itoring,environmental sensing,and related fields.
文摘A metal-organic framework{[Zn(L)_(0.5)(1,2,4,5-tpb)_(0.5)]·DMF·3H_(2)O}_(n)(1)was synthesized by solvothermal reaction,where H4L=5,5'-(ethane-1,2-diyl)diisophthalic acid,and 1,2,4,5-tpb=1,2,4,5-tetra(pyridin-4-yl)benzene.The analysis of the single crystal structure indicates that L^(4-)and 1,2,4,5-tpb are connected with Zn(Ⅱ)to form a 2D layered structure,and the layers are linked by 1,2,4,5-tpb to form a 3D structure.1 can be used as a highly selective fluorescent probe for the detection of 2,4-dinitrophenylhydrazine(DNP)and tetracycline(TET),and the detection limits were 0.013 and 0.31μmol·L^(-1),respectively.1 was applied successfully to the determination of TET content in the Yanhe River water sample.CCDC:2466221.
文摘This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the corresponding ester[Fe_(2)(CO)_(6)(μ‑tedt)](2),where tedt=SCH_(2)CH(CH_(2)OOC(5‑C_(3)HNSCH_(3)))S.Further reactions of complex 2 with tri(ptolyl)phosphine(tp)or tris(4‑fluorophenyl)phosphine(fp)gave the phosphine‑substituted derivatives[Fe_(2)(CO)_(5)(tp)(μ‑tedt)](3)and[Fe_(2)(CO)_(5)(fp)(μ‑tedt)](4).The structures of the newly prepared complexes were elucidated by elemental analysis,NMR,IR,and X‑ray photoelectron spectroscopy.Moreover,single‑crystal X‑ray diffraction analysis confirmed their molecular structures,showing that they contain a di‑iron core ligated by a bridged dithiolate bearing a thiazole moiety and terminal carbonyls.The electrochemical and electrocatalytic proton reduction were probed by cyclic voltammetry,revealing that three complexes can catalyze the reduction of protons to H_(2) under the electrochemical conditions.For comparison,complex 4 possessed the best efficiency with a turnover frequency of 23.5 s^(-1)at 10 mmol·L^(-1)HOAc concentration.In addition,the fungicidal activity of these complexes was also investigated in this study.CCDC:2477511,2;2477512,3;2477513,4.
基金National Natural Science Foundation of China(51504138,51674118,52271177)Hunan Provincial Natural Science Foundation of China(2023JJ50181)Supported by State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology(P2024-022)。
文摘To explore the formation mechanism of anisotropy in Ti-6Al-4V alloy fabricated by selective laser melting(SLM),the compressive mechanical properties,microhardness,microstructure,and crystallographic orientation of the alloy across different planes were investigated.The anisotropy of SLM-fabricated Ti-6Al-4V alloys was analyzed,and the electron backscatter diffraction technique was used to investigate the influence of different grain types and orientations on the stress-strain distribution at various scales.Results reveal that in room-temperature compression tests at a strain rate of 10^(-3) s^(-1),both the compressive yield strength and microhardness vary along the deposition direction,indicating a certain degree of mechanical property anisotropy.The alloy exhibits a columnar microstructure;along the deposition direction,the grains appear equiaxed,and they have internal hexagonal close-packed(hcp)α/α'martensitic structure.α'phase has a preferential orientation approximately along the<0001>direction.Anisotropy arises from the high aspect ratio of columnar grains,along with the weak texture of the microstructure and low symmetry of the hcp crystal structure.
文摘An alternative elliptical and circle air-hole-assisted Al_(0.24)Ga_(0.76)As photonic crystal fiber(PCF)was proposed for generating broadband high-coherence mid-infrared supercontinuum,and the dispersion,effect-ive mode area and nonlinear coefficient were investigated by using finite element method(FEM),the evolu-tion of optical pulses propagating along the fiber was simulated,and the supercontinuum and the coherence were analyzed and evaluated under different pumping conditions.The results show that a supercontinuum spectrum with a spectral width of 4.852μm can be obtained in the proposed fiber with d_(1)/Λof 0.125,d_(2)/Λof 0.583 and the zero-dispersion wavelength of 3.228μm by pumping with a Gaussian pulse with a peak power of 800 W and a full width at half maximum(FWHM)of 20 fs at wavelength of 3.3μm.When the fiber is pumped by the pulse with the peak power of 2000 W,the FWHM of 80 fs at the wavelength of 4.0μm in the in the anomalous dispersion region,the modulation instability is obviously suppressed,and the high-coher-ence supercontinuum spectrum spanning from 1.1μm to 8.99μm is observed.A part of the pulse energy is transferred to the anomalous dispersion region when pumped at the wavelength of 2.8μm in the normal dis-persion region and a broadband high-coherence supercontinuum spectrum extending from 0.8μm to 9.8μm is generated in the 10 mm proposed fiber.This paper introduces elliptical air holes in the Al_(0.24)Ga_(0.76)As photonic crystal fiber,which enhances flexibility for tailoring the performance of supercontinuum,ultimately achieving the broadest supercontinuum spectrum with the shortest fiber length to date.
文摘The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.
文摘5,5'-dithiobis(2-nitrobenzoic acid)(H_(2)DTNB)was employed as the second ligand to react with cucurbit[6]uril(Q[6])and Cd(NO_(3))_(2),and it was deprotonated or transformed into HDTNB^(-),TNB^(2-)and NSB^(2-)(H_(2)TNB=5,5'-thiobis(2-nitrobenzoic acid),H_(2)NSB=2-nitro-5-sulfobenzoic acid)under different conditions to afford three novel supramolecular assemblies with the formulas of[Cd(H_(2)O)_(4)(Q[6])](HDTNB)_(2)·3H_(2)O(1),[Cd(H_(2)O)_(6)]_(2)(TNB)_(2)·Q[6]·4H_(2)O(2)and[Cd(H_(2)O)_(5)(NSB)]_(2)·Q[6](3).Singe-crystal diffraction(SC-XRD)analysis revealed that assembly 1 is constructed from 2D[Cd(H_(2)O)_(4)(Q[6])]2+supramolecular layers and HDTNB^(-)supra molecular layers,the structure of assembly 2 is comprised of the 2D{[Cd(H_(2)O)_(6)]_(2)·Q[6]}^(4+)supramolecular layers and 1D TNB^(2-)supramolecular chains,while assembly 3 is built from the 3D Q[6]frameworks with[Cd(H_(2)O)_(5)(NSB)]supramolecular chains filled in the pores.Meanwhile,the noncovalent interactions between the ligands HDTNB^(-)/TNB^(2-)/NSB^(2-)and the outer-surface of Q[6]molecules contributed greatly to the formation of the supramolecular architecture of assemblies 1-3.CCDC:2522253,1;2522254,2;2522255,3.
文摘This study investigates the reduction in polarization measurement accuracy caused by varying in-cident angles in a liquid crystal variable retarder(LCVR).The phase delay characteristics of the LCVR were examined,with particular emphasis on the influence of different two-dimensional incident angles on phase delay behavior.Building upon the calibration of phase delay under normal incidence,a phase delay calibra-tion model was developed to account for variations in incident angle and driving voltage.A mathematical re-lationship was established between phase delay and the azimuth angle(α)and pitch angle(β).Experimental validation was conducted under three conditions:α=20°,β=0°;α=0°,β=20°;and an arbitrary angle whereα=5°,β=15°.The results demonstrated that the maximum average deviation between theoretical pre-dictions and experimental measurements did not exceed 0.059 rad.The proposed calibration method proved to be both accurate and practical.This approach offers robust support for LCVR parameter calibration and performance optimization in optical systems,particularly in polarization imaging applications.
文摘The hydrated tricyclohexyltin theophylline-7-acetic acid(tpH)complex[Sn(C_(6)H_(11))_(3)(tp)(H_(2)O)]was synthesized via an ethanol solvothermal method using tricyclohexyltin hydroxide and tpH in a 1∶1 molar ratio.The complex was characterized by IR,^(1)H(^(13)C)NMR,elemental analysis,and powder X-ray diffraction,and the crystal structure was determined by single-crystal X-ray diffraction.The crystal belongs to the orthorhombic system with space group Iba2,and the central tin atom is in a five-coordinated trigonal bipyramidal configuration.Quantum chemistry ab initio calculations were performed to investigate the stability,molecular orbital energy,and frontier molecular orbital characteristics of the complex.Additionally,its thermal stability,electrochemical properties,and in vitro anticancer activity were evaluated.CCDC:2380308.
文摘Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2)O(1)was synthesized as a 2D structure using Coas the metal source,methanol‑water(4∶6,V/V)as the solvent,and specific concentrations of 2,5‑furandicarboxylic acid(H_(2)FDCA)and 1,3,5‑triimidazole benzene(L).Adjusting to pure water and lowering the concentration of L yielded the 1D chain structure of[Co(HL)2(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(2).Using Cu(Ⅱ)as the metal source,methanol/water(9∶1,V/V)as the solvent,and specific concentrations of L and H2FDCA,the 1D chain structure of[Cu(L)(FDCA)(H_(2)O)]·2H_(2)O(3)was synthesized.Upon increasing the concentrations of L and H2FDCA,and switching the solvent to pure water,the 1D chain structure of[Cu(HL)_(2)(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(4)was obtained.This shows that changing the solvent and ligand concentrations can affect the structural changes of CPs.In addition,the solid‑state photoluminescence of CPs 1‑4 at room temperature was studied,and their morphological changes were observed via scanning electron microscopy.Density functional theory calculations revealed that the negative charge concentrates on the O and N atoms of the ligand,facilitating ligand‑metal ion coordination.CCDC:2403934,1;2403935,2;2403936,3;2403938,4.
文摘Based on 4'-(1H-tetrazol-5-yl)-[1,1'-biphenyl]-2,4,6-tricarboxylic acid(H_(4)bta)ligand,zinc metal-organic framework(Zn-MOF):{[Zn_(2)(bta)(bpy)_(2)(H_(2)O)]·1.5H_(2)O}_(n)(bpy=2,2'-bipyridine)was designed and synthesized by hydrothermal method.Its structure was characterized by elemental analysis,IR spectra,X-ray single crystal diffraction,etc.The asymmetric unit of Zn-MOF contains two crystallographically independent Zn^(2+)ions.Through the connection of Zn^(2+)ions via H_(4)bta,a 1D double-layer network structure is formed.Adjacent double-layer networks further form a 2D supramolecular network through hydrogen bonding.Notably,Zn-MOF exhibited excellent fluorescence properties and could efficiently and sensitively detect various water pollutants:4-nitrophenol(4-NP),Cu^(2+),and pyrimethanil(Pth).Additionally,the mechanism of fluorescence sensing was investigated.CCDC:2432230.
基金supported by the National Natural Science Foundation of China under Grant No.22505100.
文摘Energetic materials face critical challenges in balancing energy density and safety,driving the development of low-sensitivity high-energy materials.Though vital for modern defense and civilian applications,low-sensitivity high-energy materials remain scarce,with 1,3,5-trinitro-2,4,6-triaminobenzene as the only deployed example.Planar lamellar energetic crystals,which utilize weak interlamellarπ-πstacking for mechanical energy dissipation,have shown significant promise.However,their rational design is constrained by insufficient understanding of intermolecular interaction synergy.This review synthesizes the structural features of planar lamellar energetic crystals,emphasizing three core elements:the single-atomic-thickness planar stacking architecture,the"strong intralamellar and weak interlamellar interaction"paradigm(key to balancing energy density and safety for low-sensitivity high-energy materials,LSHEMs),and the role of molecular planarity in reducing shear slip barriers.It categorizes design strategies into two frameworks:H–bonding dominated(single-component:cross-shaped assembly,strong H–bonding in high symmetric molecules;multi-component methods:tenon-and-mortise,acceptor-donor separation)and other intermolecular interactions(e.g.,π-πstacking-drivenπ-π2max model,π-hole recognition).Case studies in single/multi-component crystals confirm that these strategies tune interaction synergy to achieve target packing motifs.The review highlights that interaction engineering is pivotal for PLEC design,offering a targeted theoretical framework for rational development of LSHEMs(to address the scarcity of practical LSHEMs)and guiding future crystal engineering for energy-safety balanced systems.
基金supported by the Fundamental Research Funds for the Central Universities(No.226-2025-00031).
文摘In 2024, the MOE Key Laboratory of Macromolecular Synthesis and Functionalization at Zhejiang University continued its impactful researches across five core areas. In controllable catalytic polymerization,organoboron catalysts were developed for CO_(2) copolymerization and novel photoresist materials. Studies in microstructure and rheology elucidated universal deformation modes in graphene-based 2D membranes and improved graphene fiber properties through shear alignment engineering, defect control, and enhanced interlayer entanglement. For separating functional polymers, Janus membranes and channels were created for multiphase separation, liquid-phase molecular layer-by-layer deposition technique was developed to fabricate aromatic polyamide nanofilms, and the harmonic amide bond density was established as a valuable parameter for polyamide structural analysis. In biomedical functional polymers, a sustainable carboxyl-ester transesterification strategy was proposed for upcycling poly(ethylene terephthalate)(PET) waste into biodegradable plastics. Additionally, immunocompatible biomaterials were designed utilizing zwitterionic polypeptides and albumin-derived coatings, and Cu2+-phenolic nanoflower was designed to combat fungal infections by combining cuproptosis and cell wall digestion. Further,the researchers developed a gelatin-DOPA-knob/fibrinogen hydrogel to achieve rapid and robust hemostatic sealing, utilized a double-network polyelectrolyte-coated hydrogel for enhancing endothelialization of left atrial appendage(LAA) occluders, and the researchers also demonstrated that image-guided highintensity focused ultrasound enables manipulation of shape-memory polymers. Finally, in the realm of photo-electro-magnetic functional polymers, precise control of through-space conjugation was shown to enhance organic luminescence. Topologically structured hydrogels were revealed to exhibit autonomous actuation. Also, solar-driven photothermal ion pumps were developed for selective lithium extraction from seawater, and high-performance non-solvated C60single-crystal films were prepared via facile bar coating. Lastly, the researchers demonstrated outstanding dielectric properties of polyethylene(PE) lamellar single crystals. The relevant works are reviewed in this paper.
