Nonlocal Optical Response of Particle Plasmons in Single Gold Nanorods

Particle plasmons in metal nanoparticles have primarily been investigated through the use of local optical response approximations. However, as nanoparticle size approaches the average distance of electrons to the metal surface, mesoscopic effects such as size-dependent plasmon linewidth broadening and resonance energy blue shifts are expected to become observable. In this work, we compared the experimental spectral characteristics with simulated values obtained using a generalized nonlocal optical response theory-based local analogue model. Our results show that the nonlocal plasmon damping effects in single nanoparticles are less significant compared to those observed in plasmon-coupled systems. Moreover, our study demonstrates that single-particle dark-field spectroscopy is an effective tool for investigating the nonlocal optical response of particle plasmons in single nanoparticles. These results have important implications for the rational design of novel nanophotonic devices

Conformational dynamics of a single protein monitored for 24 hours at video rate

We use plasmon rulers to follow the conformational dynamics of a single protein for up to 24 h at a video rate. The plasmon ruler consists of two gold nanospheres connected by a single protein linker. In our experiment, we follow the dynamics of the molecular chaperone heat shock protein 90, which is known to show open and closed conformations. Our measurements confirm the previously known conformational dynamics with transition times in the second to minute time scale and reveals new dynamics on the time scale of minutes to hours. Plasmon rulers thus extend the observation bandwidth 3/4 orders of magnitude with respect to single-molecule fluorescence resonance energy transfer and enable the study of molecular dynamics with unprecedented precision

Local Resistance in Early Medieval Chinese Historiography and the Problem of Religious Overinterpretation

Official Chinese historiography is a treasure trove of information on local resistance to the centralised empire in early medieval China (third to sixth century). Sinologists specialised in the study of Chinese religions commonly reconstruct the religious history of the era by interpreting some of these data. In the process, however, the primary purpose of the historiography of local resistance is often overlooked, and historical interpretation easily becomes ‘overinterpretation’—that is, ‘fabricating false intensity’ and ‘seeing intensity everywhere’, as French historian Paul Veyne proposed to define the term. Focusing on a cluster of historical anecdotes collected in the standard histories of the four centuries under consideration, this study discusses the supposedly ‘religious’ nature of some of the data they contain

Sliding mode control for longitudinal motion of underground mining electric vehicles

Nowadays, zero-emission electric vehicles (EVs) become more and more attractive personnel transport vehicles for mining industry. However, underground mining electric vehicles (UMEVs) require more stable, reliable and robust vehicle system compared with traditional EVs due to their special working conditions and the complex road conditions. Thus, a proper controller needs to be designed. This paper first presents the modeling of an UMEV for both acceleration and braking. Then, the controller based on the sliding mode control (SMC) is designed to track the longitudinal velocity and keep the longitudinal slip ratio in a desired stable region in the presence of the bounded system uncertainties. The comparison of the simulation results for both the proposed SMC controller and a traditional PID controller shows that the proposed SMC controller has a better performance for the long-distance up/down slopes with varying rolling resistance coefficients

Fuzzy Sliding Mode Control for logitudinal motion of underground mining electric vehicles

Cost and safety are always the most important factors for personnel transport and mining vehicles in mining industry. That is why the development of underground mining electrical vehicles (UMEVs) becomes more and more attractive in undergrounds mines. However, a stable, reliable and robust controller for the UMEV is also a critical condition due to the safety requirements. Sliding Mode Control (SMC) is able to deal with system uncertainties and external disturbances, but it cannot achieve smooth performance during the transition between different subspaces in the state space. This paper first presents the modeling of an UMEV for acceleration, braking and speed maintenance, and a global fuzzy model will be developed based on that. Then, a Fuzzy Sliding Mode Controller (FSMC) of the UMEV will be proposed. The comparison of the simulation results for both the proposed FSMC controller and an SMC controller shows that the proposed FSMC controller has a better performance when the system switches in different subspaces in the state space