Oriented assembly of metal-organic frameworks and deficient TiO_(2) nanowires directed by lattice matching for efficient photoreversible color switching

The photoreversible color switching system(PCSS)is attracting increasing attention for use in alleviating energy crisis and environmental problems.We report a robust PCSS in which lattice matching enables bottom-up oriented assembly between metal-organic frameworks(MOFs)and inorganic nanocrystals(INCs),two distinct entities that differ drastically in structure and function.Specifically,cubic-phase Prussian blue(PB)of a framework backbone is spontaneously attached to rutile TiO_(2)nanowires in a defined orientation triggered by the lattice matching between the(001)plane of TiO_(2)and the(222)plane of PB.Ultraviolet light irradiation accelerates the photoelectron transport within the oriented TiO_(2)/PB system and enables fast photo switching.The derived TiO_(2)/PB paper can be ranked as one of the best light-printing papers in literature because of its high resolution(∼µm)and capability to be repeatedly written for>100 times without significant loss of contrast.The ultrathin TiO_(2)nanowires are rich in oxygen and Ti vacancies,which allow visible-and sunlight-light printing.Density functional theory calculations suggest that the[Fe(CN)_(6)]^(4−) ligand from the PB attaches preferentially to the(110)surface of TiO_(2)to give the ordered TiO_(2)/PB assembly.The findings demonstrate the strong versatility of particles-mediated assembly in advanced materials design.

Structure-dependent re-dispersibility of graphene oxide powders prepared by fast spray drying

The graphene oxide powder(GOP)obtained from the spray drying process often exhibits poor redispersibility which is considered due to the partial reduction of GO sheets.The reduction of drying temperature can effectively increase the redispersibility of GOP,but result in a decreased drying efficiency.Herein,we found that the redispersibility of GOP is strongly affected by its microstructure,which is determined by the feed concentration.With the increase of feed concentration,the GO nanosheet assembly varies from the disordered stacking to relatively oriented assembly,making the morphology of the GOP transform from balllike(the most crumpled one)to flakelike(the least crumpled one),and the 0.8 mgml 1 is the threshold concentration for the morphology,structure,and redispersibility change.Once the feed concentration reaches 0.8 mg ml 1,the appearance of the nematic phase in droplet ensures the relatively oriented assembly of GO sheets to form the layered structure with a low crumpling degree,which greatly improves the polar parts surface tension of the solid GOP,making the GOP easier to form hydrogen bonding with water during the redispersion process,thus stabilizing dispersion.This work provides useful information for understanding the relationships between the morphology,microstructure,and final redispersibility of GOPs.

Surface-Oriented Assembly of Cyclodextrin Metal-Organic Framework Film for Enhanced Peptide-Enantiomers Sensing

Oriented metal-organic framework(MOF)films are attracting great attention due to their fascinating physicochemical properties and unique functionalities.Here,we report an[110]-oriented biomolecularγ-cyclodextrin(γCD)MOF film with arrayed CD channels running perpendicular to the substrate surface.This sophisticated architecturewas realized by combining liquid phase epitaxial layer-by-layer(lbl)methods with aγCD-based thiol self-assembled monolayer(SAM)functionalized surface.This first demonstration of the lbl method for MOF growth from aqueous conditions yielded oriented,highly homogeneous,and chiralγCD-SURMOFs(surfacecoordinated MOFs)with tunable thickness.Using a quartz crystal microbalance(QCM)to monitor adsorption of biomolecules,we demonstrated thatγCD-SURMOF provides highly-efficient recognition of tripeptide enantiomers(Tyr-(L-Ala)-Phe vs Tyr-(D-Ala)-Phe),clearly outperformingγCD(SH)_(8) SAMs as well as polycrystalline,mixed-orientationsγCDMOF film.The presence of well-alignedγCD-channels enables highly efficient transport channels with large adsorption capacity and fast loading,along with high enantioselectivity.In addition,the fast and highly specific loading rates allow for the realization of highly specific sensors for biomolecules with short response times.

Highly [010]-oriented self-assembled LiCoPO4/C nanoflakes as high-performance cathode for lithium ion batteries

In this artide, highly [010]-oriented self-assembled LiCoPO4/C nanoflakes were prepared through simple and facile solution-phase strategies at low temperature and ambient pressure. The formation of 5-hydroxylmethylfurfural and levoglucosan via the dehydration of glucose during the reaction played a key role in mediating the morphology and structure of the resulting products. LiCoPO4 highly oriented along the （010）-facets exposed Li^＋ ion transport channels, facilitating ultrafast lithium ion transportation. In turn, the unique assembled mesoporous structure and the flake-like morphology of the prepared products benefit lithium ion batteries constructed using two-dimensional （2D） LiCoPO4/C nanoflakes self- assembles as cathodes and commercial Li4Ti5O12 as anodes. The tested batteries provide high capacities of 154.6 mA·h·g^-1 at 0.1 C （based on the LiCoPO4 weight of 1 C = 167 mA·h·g^-1） and stable cycling with 93.1% capacity retention after 100 cycles, which is outstanding compared to other recently developed LiCoPO4 cathodes.

Research on uncertainty in measurement assisted alignment in aircraft assembly

Operations in assembling and joining large size aircraft components are changed to novel digital and flexible ways by digital measurement assisted alignment.Positions and orientations（P＆O）of aligned components are critical characters which assure geometrical positions and relationships of those components.Therefore,evaluating the P＆O of a component is considered necessary and critical for ensuring accuracy in aircraft assembly.Uncertainty of position and orientation（U-P＆O）,as a part of the evaluating result of P＆O,needs to be given for ensuring the integrity and credibility of the result;furthermore,U-P＆O is necessary for error tracing and quality evaluating of measurement assisted aircraft assembly.However,current research mainly focuses on the process integration of measurement with assembly,and usually ignores the uncertainty of measured result and its influence on quality evaluation.This paper focuses on the expression,analysis,and application of U-P＆O in measurement assisted alignment.The geometrical and algebraical connotations of U-P＆O are presented.Then,an analytical algorithm for evaluating the multi-dimensional U-P＆O is given,and the effect factors and characteristics of U-P＆O are discussed.Finally,U-P＆O is used to evaluate alignment in aircraft assembly for quality evaluating and improving.Cases are introduced with the methodology.

Synthesis and orientational assemblies of MgO nanosheets with exposed(111) facets

MgO nanosheets with exposed（111） facets were obtained through the preparation of Mg（OH）2 precursor by a hydrothermal method in the presence of oleylamine and subsequent calcination in air. The different preferred orientational assemblies of Mg O nanosheets, achieved by adjusting the polarity of dispersing solvents（ethanol and cyclohexane） during the sample preparation, show different structural and spectral features.

Factors Influencing Bonding Strength of Laminated Bamboo Strips Lumber

Factors influencing bonding strength of laminated bamboo strips lumber (LBSL) were investigated in this paper. In order to find an optimized technology, this paper investigated how the thickness of bamboo strips, the assembly orientation of bamboo curtain, the type of adhesives, as well as coupling agent treatment of bamboo curtain affected the bonding strength. The following conclusions were drawn: 1)The thinner the thickness of the bamboo strips, the bigger the bonding strength of LBSL; 2) The assembly orientation of the bamboo curtain benefited the bonding strength, MOR and MOE; 3) The bonding strength increased with the use of phenol-resorcinol-formaldehyde (PRF) resin; and 4) Treatment of coupling agent could increase the bonding strength but decrease both MOR and MOE.