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A model zwitterionic polysulfobetaine, poly(3-(acrylamidopropyl-dimethyl-ammonium) propyl-1-sulfonate) (pAPAPS), phase separates upon cooling and exhibits an upper critical solution temperature (UCST) behavior with no added salt in deuterium oxide solutions. Dynamic light scattering measurements indicate the presence of distinct fast and slow diffusive modes, where the fast mode is interpreted as a collective diffusion coefficient and the slow mode is attributed to the diffusion of multi-chain dynamic clusters. The relative population of fast and slow modes varies systematically with temperature and concentration. A clustering temperature (T*) was assigned when the slow mode first appeared upon cooling. The slow mode then increases in relative scattering amplitude as the phase boundary is approached. The fast mode exhibits a concentration dependence above T* consistent with the virial expansion in the collective diffusion. The sign of the virial coefficient (kd) is negative, even in the good solvent region above the expected Flory temperature (Θ ≈ 39 °C), a behavior distinct from synthetic neutral polymers in organic solvents. The onset of multi-chain clustering at T < T* coincides with the poor solvent regime (T < Θ). Attractive dipolar interactions due to the zwitterionic sulfobetaine groups in pAPAPS are suggested as the origin of the multi-chain clusters with no salt. Upon the addition of 100 mM NaCl, the slow mode is suppressed, and the hydrodynamic radius is consistent with polyzwitterion chain dimensions in a dilute solution. We find that concentration dependent diffusion is highly linked to the theta temperature and the emergence of dynamic clusters as the polymer goes from good to poor solvent on approach to the UCST. The slow mode in the semidilute regime is reported along with preliminary small-angle neutron scattering data that show salt reduces clustering and leads to predominantly chain scattering. [ABSTRACT FROM AUTHOR]

Responsive polyzwitterionic materials have become important for a range of applications such as environmental remediation and targeted drug delivery. Much is known about the macroscopic phase-behaviors of such materials, but how the smaller scale single-chain structures of polyzwitterions respond to external stimuli is not well understood, especially at temperatures close to their phase boundaries. Such chain conformation responses are important in directing larger-scale associative properties. Here, we study the temperature dependent single-chain structure of a model polysulfobetaine, poly[3-(acrylamidopropyl-dimethyl-ammonium) propyl-1-sulfonate], using small angle neutron scattering. In the absence of salt, we find that temperature has a large effect on solvent quality with a decreasing trend from good solvent conditions at 50 °C to poor solvent at 10 °C (a temperature just above the cloud point of 7.6 °C) and an estimated theta temperature of 39 °C. When 100 mM NaCl is present, the solvent quality is good with weak temperature dependence. Without salt present, the polymer chain appears to have a nearly Gaussian coil conformation and the backbone becomes slightly more rigid as the temperature is lowered to the cloud point as determined by the Debye-local rod model on a Kratky plot. The addition of salt has a notable effect on the intra-chain correlations where an increase in chain dimensions to a swollen coil conformation and an increase in chain rigidity is observed at 100 mM NaCl in D2O, however, with a negligible temperature dependence. [ABSTRACT FROM AUTHOR]

Labeling the fault data is a time-consuming and expensive operation. Therefore, the monitoring data obtained from wind farms are rarely accurately labeled. The method of deep adversarial transfer neural network for diagnosis of gearbox in wind turbine was put forward, which used the auxiliary data set and solved the problem of large data distribution differences with the help of domain adversarial method to transfer the features learned by auxiliary data set to the data from wind turbines. The fault diagnosis model under the condition of unsupervised was established, which, to a certain extent, reduced the dependence of the deep learning model to the labeled data obtained from wind turbine. The effectiveness of proposed method was verified by using vibration data from bearing failure test at Case Western Reserve University and measured vibration data from the gearbox in wind turbine. The results showed that this method was effective in realizing the cross-domain transfer mission of the fault diagnosis model between similar domains and provided a new direction for constructing the data-driven fault diagnosis model. [ABSTRACT FROM AUTHOR]

The design and fabrication of dual‐channel charge transmission mode are crucial to developing highly effective photocatalysts. However, constructing double charge transfer paths by loading dual cocatalysts in a nanocomposite is still a great challenge. Here, hollow Co9S8 nanocages are utilized to design a hierarchical Co9S8/CdIn2S4/Pt heterostructure with dual‐channel for charge transfer, in which Co9S8 nanocages and Pt particles act as cocatalysts. Moreover, Co9S8 and CdIn2S4 form an atomic interfacial contact by intermediate sulfur atoms. Due to double‐channel charge transfer and atomic interfacial bonding, the Co9S8/CdIn2S4/Pt nanocages accelerate the photo‐induced carriers transfer and suppress the combination of electron–hole pairs. As a result, the Co9S8/CdIn2S4/Pt nanocages exhibit increased photocurrent density of 62.8 µA cm−2, far exceeding that of pristine Co9S8 (6.87 µA cm−2). The optimized Co9S8/CdIn2S4/Pt nanocages display excellent photocatalytic H2 in production rate of 13 426 µmol g−1 h−1 and high cyclic stability for water splitting. [ABSTRACT FROM AUTHOR]

Hybrid simulation has been regarded as an innovative and feasible solution of conducting anti-seismic test of structures. In hybrid simulations, the test duration mainly depends on numerical calculation duration, data communication duration, and loading duration. The differences in integration methods selection and numerical modelling may lead to a large variation of test durations, which may even affect the accuracy of the test results. OpenFresco is an environmental independent software framework for implementing hybrid tests. However, the research on the test duration of hybrid simulation based on OpenFresco has not been sufficiently studied. A single-storey and single-span frame was analysed in this paper. Specifically, the steel column was selected as the experimental substructure whilst the rest of the model was taken as the numerical substructure. The test results helped to reveal the factors which might influence the duration of hybrid simulation. It could be concluded that integration method, model complexity, and ramp time were the main factors affecting the durations of hybrid simulations. Moreover, the relation between the test duration and test accuracy was also discussed. The results showed that the explicit integration method and the Newmark integration method with fixed steps were recommended in the hybrid simulation based on OpenFresco. Besides, the numerical model should be simplified to improve the test accuracy. [ABSTRACT FROM AUTHOR]

Associating soft matter such as surfactants, polymers, proteins, and liposomes, may form structures with dimensions not readily accessible by optical methods. Scattering methods can provide detailed information about the mechanism of associative phase separation including nucleation density, size, and shape. Ultra-small angle neutron scattering, a reciprocal space method, provides sensitivity to submicron to micron-scale structures in a non-invasive manner and described in the context of nucleation and growth of dilute droplets formed by a temperature jump into the meta-stable region of polyelectrolyte complex coacervates., (2021 Published by Elsevier Inc.)