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In order to understand the loading path and further anticipate the bearing capacity of the staggered perforated RC flanged shear walls, this paper proposed an improved strut-and-tie model and perforated reduction coefficient based on the theoretical and numerical analysis. The finite element model has been validated experimentally. The parametric study was conducted numerically to investigate the influence of shear-span ratio, axial compression load ratio, flange, dimension of perforation, and the additional rebar on the seismic performance of shear walls. When the ratio of perforation area to the wall is ranged from 10% to 26%, the proposed strut-and-tie model can effectively predict the loading path and the lateral ultimate bearing capacity with the different combinations of shear-span ratio and axial compression load ratio; however, if the ratio of the perforation area is either lower than 10% or higher than 26%, the proposed strut-and-tie model is not applicable. While the perforated reduction coefficient can be used to calculate the lateral ultimate bearing capacity of the perforated shear wall.

Scalable synthesis of multicompartment polyion complex (PIC) systems has been achieved via visible light-initiated RAFT polymerization of cationic monomer in the presence of anionic diblock copolymer micelles in water at 25 °C. This polymerization-induced hierarchical electrostatic self-assembly (hierarchical PIESA) implements structural hierarchy via programmable self-assembly to form multicompartment PIC micelles and their monolayer colloidal nanosheets and nanocages. The anionic micelles play decisive roles in such a hierarchical PIESA to access biologically relevant yet otherwise inaccessible multicompartment PIC systems.

Electrostatic manipulation of triblock terpolymer nanofilm compartmentalization has been achieved via visible light-initiated reversible addition–fragmentation chain transfer aqueous dispersion pol...

Polymerization-induced self-assembly (PISA) is a powerful method for the synthesis of polymeric kinetically frozen core nanoparticles. However, the PISA synthesis of biologically important polymeric fluidic materials is unexplored. Herein we present a liquid-liquid phase separation mode PISA. The proof of concept is established by means of complex coacervation in visible light-initiated RAFT dispersion polymerization of anionic monomer in the presence of a protonated polyethylenimine in water at 25 °C. We demonstrate a stage-by-stage nano to micron droplet growth mechanism via an increase in growing chain DP or electrical neutralization. Liquid coacervate droplets and their glassy nanowires or vesicles can be interconverted upon changing the ethanol/water solvent. As such, tunable construction of coacervate droplets and nanowires or vesicles can be achieved using this smart PISA method.

Block copolymer nanoparticles have been widely used for advanced materials. However, the stabilization is challenging. Herein, we present a method for convenient yet reliable synthesis of stabilized polyion complex (PIC) nanometer-sized spheres and micrometer-sized ultrathin lamellae and vesicles by taking advantage of the wavelength orthogonality of UV-induced disulfide exchange and visible light-initiated polymerization-induced electrostatic self-assembly (PIESA). Disulfide-containing PIC vesicles are synthesized at scale using this PIESA, undergoing a small sphere-to-larger sphere-to-lamella-to-vesicle transition. As such, surface-neutralized and surface-charged micrometer-sized vesicles can be achieved. UV irradiation of the vesicles (5.0 mg/mL in water) in ambient air induces very fast exchange reaction of locally confined/enriched disulfide motifs, leading to cross-linking, shape transition, and cystamine salt release in 4 min. As such, cross-linked PIC spheres, lamellae, and vesicles can be achieve...

We herein present sequence-controlled polymerization-induced self-assembly (PISA) via photoswitchable reversible addition-fragmentation chain transfer (RAFT) copolymerization of oppositely-charged monomers using polyethylene glycol chain transfer agent in water at 25 °C. Thorough block copolymerization leads to a polymerization-induced electrostatic self-assembly named ABC-mode polymerization-induced electrostatic self-assembly (PIESA), by which PEGylated (PEG, polyethylene glycol) polyion complex (PIC) spheres, lamellae, and vesicles are achieved. We demonstrate the inherent spontaneous zwitterionic alternating copolymerization nature, which leads to the charge-dictated alternating or gradient zwitterionic sequence. As such, we developed sequence-controlled synthesis of nanostructured block-gradient zwitterionic terpolymer PICs via complete zwitterionic copolymerization starting from photoswitched incomplete first polymerization, i.e., AB(BC)-mode PIESA. This sequence-controlled PISA method provides the unprecedented control of the low-dimensional polyelectrolyte complex nanostructure involving not only shape but also size and thickness of micrometer-sized ultrathin PIC vesicles and lamellae, without necessarily changing the whole chemical composition and degree of polymerization.

The noncovalent structural locking of thermoresponsive polyion complex micelles, nanowires, and vesicles can be implemented via hydrogen bonding assisted polyion complexation through polymerization-induced electrostatic self-assembly (PIESA) using an arginine-like cationic monomer.

Summary Reinforced concrete (RC) shear walls have been extensively used as lateral load resisting structural members in tall buildings. However, in the past, strong earthquake events RC structural walls in some buildings suffered severe damage, which concentrated at the bottom and was very difficult to be repaired. The installation of the replaceable corner components (RCCs) at the bottom of the structural wall is a new method to form an earthquake resilient structural wall whose function can be quickly restored by replacing the RCCs after the strong earthquake because of the damage concentrating on RCCs. In this study, a new kind of replaceable energy-dissipation component installed at the bottom corner of RC structural walls was proposed. To study the seismic performance of the new structural wall with RCCs, the cyclic loading tests on three new structural wall specimens and one conventional RC structural wall specimen were conducted. One of the new structural wall specimens experienced replacement and reloading process to verify the feasibility of replacement. The results show that the structural behavior of all specimens was flexure dominating. The damage in the new shear specimens mainly concentrated on RCCs. The replacement of RCCs can be implemented conveniently after the residual deformation occurred in the structure. Compared with the conventional structural wall specimen, the seismic performance of new structural wall specimens was improved significantly. Copyright © 2017 John Wiley & Sons, Ltd.

The problem of controlling the start-up of heating system is considered and the need for a self-tuning start control scheme is explained. The internal temperature change process of building is analyzed under the influence of heating source and external environment, and the change principle is found out. From the point of thermodynamics, the mathematical model of the process of intermittent heating is established on the basis of similitude principle. The self-tuning control strategy is introduced to finish the simulation and experiment of intermittent heating start, the results show that the self-tuning controller behaves well and has superior performance characteristics compared to two traditional methods.

Das beschriebene Auswuchten elastischer Rotoren mit Hilfe umschaltbarer Lagersteifigkeiten kommt ohne Testgewichtssetungen aus. Ahnlich wie bei den klassischen Verfahren wird zwischen Einfluszahlen-Methode und modaler Methode unterschieden. Die modale Methode setzt wie ublich die Kenntnis der auszuwuchtenden Eigenformen voraus. Die Messung der Wellenschwingung in den Ausgleichsebenen ist beim modalen Verfahren dafur nicht erforderlich, fur das Einfluszahlenverfahren dagegen ist es notwendig. Wie in der Arbeit gezeigt wird, setzt die Einfluszahlenmethode beim Auswuchten mit umschaltbaren Lagersteifigkeiten symmetrische Systemmatrizen voraus, eine Einschrankung, die bei dem Verfahren mit Testgewichtssetzungen nicht notwendig ist. Die vorgestellten ersten experimentellen Ergebnisse zeigen deutliche Auswuchterfolge, die aber schlechter sind als die Ergebnisse aus Vergleichsversuchen mit Testgewichtssetzungen. Allerdings wurde bei den bisherigen Versuchen mit relativ geringeren Resonanzverschiebungen zwischen 2% bis 5% gearbeitet.