高层转运站的抗侧力分析

混凝土高层转运站常用的结构体系有框架结构、框架-支撑结构、框架—抗震墙结构。本文以镇江某港口中的高层转运站为例,对以上三种不同结构体系的转运站进行了抗侧力分析。根据结构对比分析,得出了合理的结构体系,优化了结构设计。

Synthesis of spherical tremella-like Sb2O3 structures derived from metal-organic framworks and its lithium storage properties

A novel spherical tremella-like Sb2O3 was prepared by using metal-organic frameworks(MOFs)method under a mild liquid-phase reaction condition,and was further employed as an anode material for lithium-ion batteries(LIBs).The effect of reaction temperature and time on morphologies of Sb2O3 was studied.The results from SEM and TEM demonstrate that the tremella-like Sb2O3 architecture are composed of numerous nanosheets with high specific surface area.When the tremella-like Sb2O3 was used as LIBs anode,the discharge and charge capacities can achieve 724 and 446 mA·h/g in the first cycle,respectively.Moreover,the electrode retains an impressive high capacity of 275 mA·h/g even after 50 cycles at 20 mA/g,indicating that the material is extremely promising for application in LIBs.

Dimension-Controllable and Photo-Responsive Supramolecular Organic Framworks through Cucurbit[8]uril-based Self-Assembly

Dimension-controllable supramolecular organic frameworks(SOFs)with aggregation-enhanced fluorescence are hierarchically fabricated through the host-guest interactions of cucurbit[8]uril(CB[8])and coumarin-modified tetraphenylethylene derivatives(TPEC).The three-dimensional layered SOFs could be constructed from the further stacking of two-dimensional mono-layered structures via simply regulating the self-assembly conditions including the culturing time and concentration.Upon light irradiation under the wavelength of 365 nm,the photodimerization of coumarin moieties occurred,which resulted in the transformation of the resultant TPECn/CB[8]4n two-dimensional SOFs into robust covalently-connected 2D polymers with molecular thickness.Interestingly,the supramolecular system of TPEC/CB[8]exhibited intriguing multicolor fluorescence emission from yellow to blue in the time range of 0-24 h at 365 nm irradiation,possessing potential applicability for photochromic fluorescence ink.

Substituent Effects on the Photocatalytic Properties of a Symmetric Covalent Organic Framework

Symmetric covalent organic framework(COF)photocatalysts generally suffer from inefficient charge separation and short-lived photoexcited states.By performing density functional theory(DFT)and time-dependent density functional theory(TDDFT)calculations,we find that partial substitution with one or two substituents(N or NH_(2))in the linkage of the representative symmetric COF(N_(0)-COF)gives rise to the separation of charge carriers in the resulting COFs(i.e.,N_(1)-COF,N_(2)-COF,(NH_(2))1-N_(0)-COF,and(NH_(2))2-N_(0)-COF).Moreover,we also find that the energy levels of the highest occupied crystal orbital(HOCO)and the lowest unoccupied crystal orbital(LUCO)of the N_(0)-COF can shift away from or toward the vacuum level,depending on the electron-withdrawing or electron-donating characters of the substituent.Therefore,we propose that partial substitution with carefully chosen electron-withdrawing or electron-donating substituents in the linkages of symmetric COFs can lead to efficient charge separation as well as appropriate HOCO and LUCO positions of the generated COFs for specific photocatalytic reactions.The proposed rule can be utilized to further boost the photocatalytic performance of many symmetric COFs.

Nature of Gravitation.The Structural Intuition of Gravitation in the Framework of Early Modern Mechanical Philosophy

As is generally known, Newton＇s notion of universal gravitation surpassed various theories of particular gravities in the early modem age, as represented mainly by Kepler and Hooke. In his seminal work Hooke and the Law of Universal Gravitation： A Reappraisal of a Reappraisal Richard S. Westfall argues that Hooke could not reach beyond the concept of spatially bounded particular gravities, as he deployed the method of analogy between the material principle of congruity and incongruity and the extension of gravitational spheres and their action at a distance. However, the doctrine of universal gravitation does not exclude the nature of particular gravities; it is predicated on the notion of an infinite expansion of individual-gravitational spheres and their uniform nature, namely the mutual and centripetal attraction. In my treatise 1 attempt to reinvestigate the nature and structure of gravitation, as established historically in the framework of Newtonian Classical Mechanics, by a method of structural intuition. It examines how the structural intuition, as represented in the celestial-mechanical intuitions of Hooke and Kepler, could unfold into an innovative process within the context of early modem mechanical philosophy, attaining thus a historical siglaificance and legitimacy as against the prevailing Newtonian method of geometric-mathematical axiomatization of mechanical principles. It also explores the actual demonstrative features of the tidal phenomenon with regard to its lunar- and solar-gravitational causation, which has been considered to date to be an important piece of empirical evidence for the theory of universal gravitation.

Dynamic Performance Test and Estimation of Reinforcement Effect on a Workshop after Column-Cut Supported by Joist

The reinforcement effect of a reconstruction scheme for a steel factory building was investigated using finite element method and dynamic performance test. The workshop concerned is a portal frame structure with four spans and two slope roofs, of which ten columns need cutting for expanding span. The design and reconstruction project of column-cut supported by joist were introduced, which includes column reinforcement, connection rebuilding between brackets and crane beams, and the changing of rigid joint into hinge joint. The construction scheme was put forward in the light of the characteristics of the reinforcement and reconstruction. Spot test of dynamic performance on the workshop and comparison with theoretical analysis results show that the column-cut supported by joist design is effective and the reconstruction project is successful.

Single crystal metal-organic framework constructed by vertically self-pillared nanosheets and its derivative for oriented lithium plating

This vertically self‐pillared(VSP)structure extends the application range of traditional porous materials with facile mass/ion transport and enhanced reaction kinetics.Here,we prepare a single crystal metal‐organic framework(MOF),employing the ZIF‐67 structure as a proof of concept,which is constructed by vertically self‐pillared nanosheets(VSP‐MOF).We further converted VSP‐MOF into VSP‐cobalt sulfide(VSP‐CoS2)through a sulfidation process.Catalysis plays an important role in almost all battery technologies;for metallic batteries,lithium anodes exhibit a high theoretical specific capacity,low density,and low redox potential.However,during the half‐cell reaction(Li++e=Li),uncontrolled dendritic Li penetrates the separator and solid electrolyte interphase layer.When employed as a composite scaffold for lithium metal deposition,there are many advantage to using this framework:1)the VSP‐CoS2 substrate provides a high specific surface area to dissipate the ion flux and mass transfer and acts as a pre‐catalyst,2)the catalytic Co center favors the charge transfer process and preferentially binds the Li+with the enhanced electrical fields,and 3)the VSP structure guides the metallic propagation along the nanosheet 2D orientation without the protrusive dendrites.All these features enable the VSP structure in metallic batteries with encouraging performances.

Optimum design of lander structure based on finite element method

Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander with four-legged truss structure is proposed. In the premise of ensuring that the main and assistant structures of landing legs are not changed, six possible lander body structures of the new lander are put forward. Taking the section size of each component of lander as design variables, and taking the total mass of the structure as the objective function, the six structures are analyzed by using the software Altair. OptiStruct and the results show that the mass of the basic structure is the lightest, and it is selected as the final design scheme of lander due to its simple structure and convenient manufacture. The optimization on the selected lander structure is conducted, and the detailed results are presented.

Construction of three high-nuclearity heterometallic cluster organic frameworks by introducing a bifunctional tripodal alcohol ligand

Three new metal organic frameworks,[Mn^(Ⅲ)_(4)Mn^(Ⅱ)_(8)O_(2)(4-thmpy)_(4)(O_(2)CPh)_(10)(OMe)_(2)(H_(2)O)_(2)]·3CH_(3)OH·4H_(2)O(1),[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)O(4-thmpy)_(4)(O_(2)CPh)_(6)(H_(2)O)_(4)]·CH_(3)OH·3H_(2)O(2),and[Mn^(Ⅱ)_(4)Ni^(Ⅱ)_(6)O(4-thmpy)_(4)(O_(2)CPh)_(6)(H_(2)O)_(4)]·2CH_(3)OH·2H_(2)O(3),have been successfully synthesized by using 4-[tri-(hydroxymethyl)methyl]pyridine(4-thmpyH_(3))as ligand.Crystal structure analyses show that compound 1 is a disk-like twelve nuclear[Mn^(Ⅲ)_(4)Mn^(Ⅱ)_(8)]0D cluster.Compounds 2 and 3 are isomorphic,and the decanuclear heteronuclear cluster[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)]node in compound 2 can be seen as a hyper-tetrahedron of four coboundary cubic alkanes[Mn^(Ⅱ)Co^(Ⅱ)_(3)O_(4)],then each ten-nuclear heteronuclear cluster[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)]is connected by six 4-thmpy^(3-)with six adjacent decanuclear clusters[Mn^(Ⅱ)_(4)Co^(Ⅱ)_(6)],forming the NaCl-type 3D topological structure.Magnetic studies showed that there exist antiferromagnetic interactions between metal ions in 1-3.

Highly efficient and broad electromagnetic wave absorbers tuned via topology-controllable metal-organic frameworks

Advanced electromagnetic(EM)wave absorbing materials with strong absorption and broad bandwidth are important for military stealth and elimination of microwave pollution in consumers’electronics.Metal organic framework(MOF)-derived metal/carbon hybrids with ordered structure are significantly urgent in this field.In this contribution,we presented a design strategy of hollow cage-like or solid box-like magnetic/dielectric Fe/Co/C and dielectric Fe/Mn/C EM wave absorbing nanomaterials via pyrolyzing Prussian blue’s analogs with controllable topology and phase composition.The solid box-like Fe/Co/C and hollow cage-like Fe/Mn/C showed favorable absorption property with a broad effective absorption bandwidth(EAB)and a low reflection loss(RL).Especially,the EAB of 8.8 GHz at a thickness of 2.5 mm for solid box-like Fe/Co/C nanocomplex prepared at 900℃is a new record for this type of materials.The design and tuning strategy for EM wave absorbers derived from topology-controllable MOF is important for EM functional materials possessing great potential in military stealth and consumers’electronics.

Mass transport through metal organic framework membranes

Metal-organic frameworks(MOFs), which are composed of metal nodes and organic ligands, possess crystal phase, ordered well-defined porous structure and large surface area. Since first reported in 1990, MOFs have attracted extensive attention and the fabrication of MOF membranes has expanded their applications and endowed them with a bright future in various fields. The mass transportation process through MOF membranes is vital during their diverse applications. In this review, the strategies of preparing continuous and well-intergrown MOF membranes are presented firstly.The selective transportation processes of gas molecules, liquid molecules and ions through MOF membranes are discussed in detail, respectively. The effects of pore entrance size, interaction, functional groups decorating on the ligands and guest components on mass transportation have been summarized in this review as well. In addition, MOF membranes with selective transportation performance demonstrate potential in separation, catalysis, energy transformation and storage devices,and so on.

Three alkaline earth metal-organic frameworks based on fluorene-containing carboxylates:syntheses,structures and properties

Three metal-organic frameworks,{[Mg_2(MFDA)_2(DMF)_3]·0.5H_2O}_n(1),{[Ca(MFDA)(DMF)(H_2O)]·0.5DMF}_n(2)and[Ca(MFDA)(DMF)_2]_n(3)(DMF=N,N-dimethylformamide)have been synthesized by the solvothermal reactions between the ligand 9,9-dimethylfluorene-2,7-dicarboxylic acid(H_2MFDA)and the corresponding metal salts,respectively.The single crystal X-ray structural analyses reveal that compounds 1-3 display three-dimensional structures based on the M(Ⅱ)-O-C chains.It is interesting that the MFDA ligands in 1-3 have different dihedral angles between the two carboxylate groups ranging from 9.9(1)°to 41.8(2)°.All of compounds exhibit strong ligand-centered blue emissions under UV lights.Their thermal properties have also been studied.