Seismic Behavior of Diaphragm-Through Connections of Concrete-Filled Square Steel Tubular Columns and H-Shaped Steel Beams

Based on the introductions of a type of diaphragm-through connection between concrete-filled square steel tubular columns (CFSSTCs) and H-shaped steel beams,a finite element model of the connection is developed and used to investigate the seismic behavior of the connection.The results of the finite element model are validated by a set of cyclic loading tests.The cyclic loading tests and the finite element analyses indicate that the failure mode of the suggested connections is plastic hinge at the beam with inelastic rotation angle exceeding 0.04 rad.The suggested connections have sufficient strength,plastic deformation and energy dissipation capacity to be used in composite moment frames as beam-to-column rigid connections.

NUCLEATION AND CRYSTALLIZATION OF H-SHAPED(PS)_2PEG(PS)_2 BLOCK COPOLYMERS

A series of H-shaped （PS）2PEG（PS）2 block copolymers with different PS chain lengths were prepared. The influence of different confinements active on the crystallization and self-nucleation （SN） behavior of the PEG blocks was investigated by differential scanning calorimetry （DSC）. When the content of the crystalline block was high, a classical SN behavior was obtained. The block copolymer with PEG content of 49% （by weight） showed a classical SN behavior with a narrow self-nucleation domain and had bimodal crystallization exotherms. When the PEG dispersed as separated microdomains in the block copolymer, the self-nucleation domain disappeared and only annealing was observed.

Extrusion process of 304L H-shaped stainless steel used in passive residual heat removal heat exchanger

304L H-shaped stainless steel is used as the support frame of the passive residual heat removal heat exchanger(PRHR HX) in a nuclear fission reactor. The extrusion process is adopted to manufacture the 304L H-shaped stainless steel. Finite element method simulation is herein used to analyze metal flow characteristics, optimize the extrusion die, and predict the extrusion force at different temperatures and speeds. A Φ400-mm container and Φ388-mm forging billet are selected, and the 304L H-shaped stainless steel is successfully manufactured using a Germany SMS 60 MN horizontal extruder. The mechanical properties and microstructure of the manufactured 304L H-shaped stainless steel meet the requirements of the PRHR HX, and the surfaces of the product pass the dye penetration test. The H-shaped stainless steels are used in Haiyang nuclear power plant in Shandong Province.

Shake table experimental study of cable-stayed bridges with two different design strategies of H-shaped towers

As one of the main load-carrying components of cable-stayed bridges,bridge towers are typically required to remain elastic even when subjected to severe ground motions with a 2%-3%probability of exceedance in 50 years.To fulfill this special requirement imposed by current seismic design codes,reinforcement ratios in the bridge towers have to be kept significantly higher than if limited ductility behavior of the tower is allowed.In addition,since the foundation capacity is closely related to the moment and shear capacities of the bridge tower,a large increase in bridge construction cost for elastically designed cable-stayed bridge is inevitable.To further investigate the possibility of limited ductility bridge tower design strategies,a new 1/20-scale cable-stayed bridge model with H-shaped bridge towers designed according to strong strut-weak tower column design was tested.The shake table experimental results are compared with a previous strong tower column-weak strut designed full bridge model.A comparison of the results show that ductility design with plastic hinges located on tower columns,i.e.,strong strut-weak tower column design,is another effective seismic design strategy that results in only small residual displacement at the top of the tower column,even under very severe earthquake excitations.

Natural Convection in an H-Shaped Porous EnclosureFilled with a Nanofluid

This study simulates natural convection flow resulting from heat partitions in an H-shaped enclosure filled with a nanofluid using an incompressible smoothed particle hydrodynamics(ISPH)method.The right area of the H-shaped enclosure is saturated with non-Darcy porous media.The center variable partitions of the H-shaped enclosure walls are kept at a high-temperature Th.The left and right walls of the H-shaped enclosure are positioned at a low temperature Tc and the other walls are adiabatic.In ISPH method,the source term in pressure Poisson equation(PPE)is modified.The influences of the controlling parameters on the temperature distributions,the velocity field and average Nusselt number are discussed.The performed simulations proofed that the length of the heated partitions augments the velocity field and temperature distributions in an H-shaped enclosure.Rayleigh number rises the fluid velocity and heat transfer in an H-shaped enclosure.The porous layer on the right side of the H-shaped enclosure at a lower Darcy parameter causes a high resistance force for the fluid flow and heat transfer characteristic inside an H-shaped enclosure.Added nanoparticles reduces the velocity field and enhances the heat transfer inside an H-shaped enclosure.

Nonlinear optical properties of novel H-shaped chromophores

Novel and effective H-shaped chromophores were doped into polymethyl methacrylate （PMMA） to form guest-host polymer thin films. The measurement results of Maker fringe method show that the polymer thin films containing the H-shaped chromophores as a guest exhibit high second harmonic coefficients （d33） compared with other two-dimensional chromophores.

Constructal optimization for H-shaped multi-scale heat exchanger based on entransy theory

Analogizing with the definition of thermal efficiency of a heat exchanger,the entransy dissipation efficiency of a heat exchanger is defined as the ratio of dimensionless entransy dissipation rate to dimensionless pumping power of the heat exchanger.For the constraints of the total tube volume and total tube surface area of the heat exchanger,the constructal optimization of an H-shaped multi-scale heat exchanger is carried out by taking entransy dissipation efficiency maximization as optimization objective,and the optimal construct of the H-shaped multi-scale heat exchanger with maximum entransy dissipation efficiency is obtained.The results show that for the specified total tube volume of the heat exchanger,the optimal constructs of the first order T-shaped heat exchanger based on the maximizations of the thermal efficiency and entransy dissipation efficiency are obviously different with the lower mass flow rates of the cold and hot fluids.For the H-shaped multi-scale heat exchanger,the entransy dissipation efficiency decreases with the increase in mass flow rate when the heat exchanger order is fixed;for the specified dimensionless mass flow rate M(M<32.9),the entransy dissipation efficiency decreases with the increase in the heat exchanger order.The performance of the multi-scale heat exchanger is obviously improved compared with that of the single-scale heat exchanger.Moreover,the heat exchanger subjected to the total tube surface area constraint is also discussed in the paper.The optimization results obtained in this paper can provide a great compromise between the heat transfer and flow performances of the heat exchanger,provide some guidelines for the optimal designs of heat exchangers,and also enrich the connotation of entransy theory.

Controlled Self-assembly of Thermo-responsive Amphiphilic H-shaped Polymer for Adjustable Drug Release

Despite the fact that some progress has been made in the self-assembly of H-shaped polymers, the corresponding self-assemblies that respond to external stimulus and are further utilized to adjust the release of drugs are still deficient. The stimuli-responsive segments with amphiphilic H-shaped structure are generally expected to enhance the controllability of self-assembly process. The synthesis and self-assembly behavior of thermo-responsive amphiphilic H-shaped polymers with poly（ethylene glycol） （PEG）, polytetrahydrofuran （PTHF） and poly（N-isopropyl acrylamide） （PNIPAM） as building blocks are reported in this paper. The inner architecture structure and size of complex micelles formed by H-shaped self-assemblies were effectively adjusted when the solution temperature was increased above the lower critical solution temperature of PNIPAM segments. Furthermore, it was found that the architecture of self-assemblies underwent a transition from the complex micelles based on primary micelles with hybrid PEG/PNIPAM shells to large complex micelles based on primary micelles with hybrid PTHF/PNIPAM cores and PEG shells during the thermal-induced self-assembly process. The adjustable release rate ofdoxorubicin （DOX） from the DOX-loaded complex micelles and basic cell experiments further proved the feasibility of these self-assemblies as the thermal-responsive drug delivery system.

Load-carrying capacity and practical calculation method for hollow cylinder joints connected with H-shaped beams

A type of hollow cylinder joints connected with H-shaped beams is proposed for spatial structures. Based on von Mises yield criterion and perfect elasto-plasticity model, a series of finite element models of the joints is established, in which the effect of geometric nonlinearity is taken into account. Then mechanical behavior and load-carrying capacity of the joints were investigated, which were subjected to axial load, in- and out-plane bending moments, and their combinations. The results show that the ultimate loads of the joints are determined by the maximum displacement. Furthermore, the case of one joint connected with multiple beams was discussed. Experiments on a set of typical full-scale joints were conducted to understand the structural behavior and the failure mechanism of joint, and also to validate the finite element models. Finally, the practical calculation method was established through finite elements analysis (FEA) results and numerical fitting. The results show that the joints are more ductile and materially economical than welded hollow spherical joints, and the practical calculation method can provide a reference for direct design and the revision of relevant design codes.

A Comparison Study of Physicochemical Properties and Stabilities of H-Shaped Molecule and the Corresponding Polymer

Rare attention has been paid to the comparison between a monomer and its corresponding polymer in terms of the optoelectronic characteristics. In this article, a model H-shaped molecule and its corresponding polymer, both of which exhibited similar properties including blue emission and solution processing, were designed and synthesized. Optoelectronic properties and various kinds of stability features, including the thermostabilities, spectral stabilities and amplified spontaneous emission characteristic of the monomer and polymer were investigated. In general, the corresponding polymer PH exhibited similar optoelectronic properties but deteriorated stabilities compared with its H-shaped monomer H-1 probably owing to the similar chemical structure but the wider molecular weight distribution and metal catalyst residue. Importantly, monomer H-1 displayed a comparable ASE threshold value with its polymer PH,suggesting that H-shaped fluorene-based small molecules may be more promising optical gain media in solid state amplifers and lasers.

Double U-Shaped Slots Loaded Stacked Patch Antenna for Multiband Operation

The design of a seven-band stacked patch antenna for the C, X and Ku band is presented. The antenna consists of an H-slot loaded fed patch, stacked with dual U-slot loaded rectangular patch to generate the seven frequency bands. The total size of the antenna is 39.25 × 29.25 mm2. The multiband stacked patch antenna is studied and designed using IE3D simulator. For verification of simulation results, the antenna is analyzed by circuit theory concept. The simulated return loss, radiation pattern and gain are presented. Simulated results show that the antenna can be designed to cover the frequency bands from (4.24 GHz to 4.50 GHz, 5.02 GHz to 5.25 GHz) in C-band application, (7.84 GHz to 8.23 GHz) in X-band and (12.16 GHz to 12.35 GHz, 14.25 GHz to 14.76 GHz, 15.25 GHz to 15.51 GHz, 17.52 GHz to 17.86 GHz) in Ku band applications. The bandwidths of each band of the proposed antenna are 5.9%, 4.5%, 4.83%, 2.36%, 3.53%, 1.68% and 1.91%. Similarly the gains of the proposed band are 2.80 dBi, 4.39 dBi, 4.54 dBi, 10.26 dBi, 8.36 dBi and 9.91 dBi, respectively.

On the Spectral Characterization of <i>H</i>-Shape Trees

A graph G is said to be determined by its spectrum if any graph having the same spectrum as G is isomorphic to G. An H-shape is a tree with exactly two of its vertices having maximal degree 3. In this paper, a formula of counting the number of closed 6-walks is given on a graph, and some necessary conditions of a graph Γ cospectral to an H-shape are given.