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Urchin-shaped Bi2S3/Cu2S/Cu3BiS3 nanocomposites were successfully prepared in this study through one-pot synthesis, which involved microwave-assisted simultaneous pyrolysis of two precursors. The as-prepared Bi2S3/Cu2S/Cu3BiS3 hybrids exhibit stronger absorption in the near-infrared regime than the individual components, i.e., Bi2S3, Cu2S, and Cu3BiS3. The photothermal conversion efficiency (η) of Bi2S3/Cu2S/Cu3BiS3 composites can even reach 43.8%, which is significantly higher than that seen with most of the transition metal chalcogenide materials. The excellent photothermal performance of Bi2S3/Cu2S/Cu3BiS3 hybrids is likely arising from its unique urchin-like structure, in which needle-like Bi2S3/Cu2S nanocomposites grow from the core of Cu3BiS3. The copresence of Bi2S3 and Cu2S also leads this newly synthesized composite to produce high contrast for X-ray computer tomography imaging, an important property required for a great potential application in theranostic cancer treatment.

A class of urchin-shaped nanocomposites composed of MoS 2 and Cd 0.8 Zn 0.2 S nanoparticles were fabricated in this study, yielding the highest hydrogen evolution rate of 1401 μmol/g/h when they are applied as the photocatalysts of water splitting reaction. The greatly enhanced photocatalytic activity could last over 24 h. Such great improvement in the photocatalytic activity, which is nearly 11 times higher than that of pure CdS and 9 times of Cd 0.7 Zn 0.3 S, and 1.7 times of MoS 2 –CdS, may be attributed to that the one-step synthetic procedure resulted in tighter interfacial contact of the urchin-like MoS 2 –Cd 0.8 Zn 0.2 S composites. Specifically, solvothermal reaction of molybdenum(V) dimethyldithiocarbamate, diethyldithiocarbamato cadmium(II) and zinc di(benzimidazol-2-yl) disulphide took place simultaneously in one-pot. Characterizations with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM) etc. illustrate that a class of novel urchin-shaped nanocomposite composed of MoS 2 and Cd 0.8 Zn 0.2 S nanoparticles were formed in this one-pot synthesis. This study therefore presents a simple and effective route to prepare chalcogenide-based photocatalysts for more efficient production of hydrogen from water.

Requirement change impact analysis has been acknowledged as one of the crucial steps in product design. In this paper, we propose a network-based method to analyze change impact. By defining interconnections among parts, we build a directed weighted complex product network model to represent the product structure under given requirements. Then, we discuss two requirement change cases and develop corresponding modification policies. To specify indirect impacts, we propose a change propagation searching model in light of Matthew Effect theory. To measure the degree of change impacts, we propose two criteria (network variation scale and extra network change cost), both of which can provide a systemic assessment of impacts. Finally, a case of clutch is presented to illustrate the proposed approach. The results can provide way of measuring overall change impacts on the product, which can support decision-makers to respond that the change request can be fulfilled or not.

Magnetic saturation problems and cogging torque normally result in a weak torque performance of conventional slotted limited-angle torque motors (LATMs). This paper presents a novel radial-flux slotted LATM with a tapered tooth-tip to improve the torque performance including average output torque and angular operation range. Firstly, the topology of tapered tooth-tip is analyzed and illustrated. Then, finite-element analysis is employed to compare the proposed LATM with the conventional slotted LATM. The comparisons of two topologies are concentrated in the air-gap flux density, cogging torque, back EMF, and output torque. Moreover, the influence of armature reaction on output torque is investigated. Finally, both conventional and proposed slotted LATMs are designed and prototyped. Torque characteristic experiments are carried out to confirm the torque capacity improvement of the proposed slotted LATM. Related experiment results are presented and discussed.

This paper proposes an improved analysis method in consideration of the relationship between temperature rise and electromagnetic performance. The heat sources of the motor can be investigated by electromagnetic analysis. And the calculation results of electric power losses are brought into the fluid-thermal field analysis as the heat sources. Using iterative computations, the relevant parameters of the motor are updated according to the results of thermal field calculation until the calculation errors of the torque and temperature rise meet the requirements. In order to investigate the accuracy of the proposed analysis method, a 16 poles-24 slots interior permanent magnet (IPM) motor with water cooling is analyzed by finite element method. The results indicate that the coupling method can evaluate and predict the performances of the motor accurately.

Permanent magnet motor composed of permanent magnets are used in various environments. In some special cases, such as temperature and pressure coupling environment, permanent magnets may be exposed to the risk of demagnetization and affect the performance of the entire motor. Therefore, when designing such a permanent magnet motor operating in extreme environments, the magnetic properties of the used permanent magnet should be determined firstly. The main research content of this paper is to analyze the influence of temperature and pressure coupling environment on the magnetic properties of permanent magnets. The finite element method is used firstly to determine the size of the measurement device, and then the effect of temperature and pressure coupling environment on the magnetic properties of permanent magnet materials is determined by experimental method. Permanent magnet of permanent magnet motor, according to magnetic circuit characteristic, work on the second demagnetization quadrant of the hysteresis loop between values of B r and H cB . Therefore, the behavior of the second demagnetization quadrant of hysteresis loop of permanent magnet under temperature and pressure coupling environment will be analyzed by the optimized device in detail.

High-performance p-type transparent conducting materials (TCMs) must exhibit a rare combination of properties including high mobility, transparency, and p-type dopability. The development of high-mobility/conductivity p-type TCMs is necessary for many applications such as solar cells or transparent electronic devices. Oxides have been traditionally considered as the most promising chemical space to dig out novel p-type TCMs. However, nonoxides might perform better than traditional p-type TCMs (oxides) in terms of mobility. We report on a high-throughput computational search for nonoxide p-type TCMs from a large data set of more than 30 000 compounds which identified CaTe and Li3Sb as very good candidates for high-mobility p-type TCMs. From our calculations, both compounds are expected to be p-type dopable: intrinsically for Li3Sb while CaTe would require extrinsic doping. Using electron-phonon computations, we estimate hole mobilities at room temperature to be about 20 and 70 cm2/V s for CaTe and Li3Sb, respectively. These are “upper bound” values as only scattering with phonons is taken into account. The computed hole mobility for Li3Sb is quite exceptional and comparable with the electron mobility in the best n-type TCMs.

In the application of the soft magnetic materials in electrical machines, it can be noticed that there is a large area of rotational flux on the T -joint region of three-phase transformers or on the stator core of three-phase motors and generators. Therefore, it is very necessary to investigate the magnetic properties of soft magnetic materials under various rotational magnetizations. For this reason, this paper proposes a novel rotational single sheet tester that the rotor structure of an induction motor is utilized to measure and model the magnetic properties of soft magnetic materials under two-dimensional vector magnetization. In order to maximize the area of the homogenous magnetic field and the value of the magnetic field in the sample, the novel single sheet tester is simulated by the finite element method (FEM) to find the best structural parameters. In addition, the effects of excitation mode and excitation current on the magnetic field in the sample are also analyzed in detail.

This paper focuses on the study of torque model for permanent magnet synchronous machines (PMSMs). An improved torque model is derived strictly according to the assumption of ideal machines. In order to investigate the accuracy of the model, the previous and improved models are studied on a fractional slot concentrated winding (FSCW) 20-pole/24-slot and a distributed winding (DW) 20-pole/60-slot inset-SPM machines by finite element method (FEM). The two kinds of machines are analyzed on stator MMFs and inductances to study the differences between them. Furthermore the linear, nonlinear and zero-consequence problems are investigated. It can be concluded that the torque model is more suit for the DW PMSMs with more slots operating without zero-consequence current.

This paper presents a novel limited-angle torque motor (LATM) with a moving coil for oscillating mirror system. The proposed LATM has a constant torque coefficient over its operation range, rapid dynamic response, and easy mounting oscillating mirror owing to a special structure of the stator and the rotor. In design process, some design equations are derived to analyze toque coefficient, moment of inertia, and other parameters of the LATM. A novel optimization approach is carried out to obtain the maximum torque/moment of inertia ratio in consideration of the stator outer diameter and volume limitations. Coil parameters have also been optimized by this method so that a less time constant can be obtained. In addition, 3-D finite-element analysis is performed for verifying the proposed optimization method. Finally, a prototype machine is accomplished and its experimental results are presented and discussed. Meanwhile, a conventional position closed loop system of the LATM is established to validate the dynamic performance of the LATM.

This paper presents an analytical method for estimating the maximum angular operation range (MAOR) in a permanent-magnet slotted limited-angle torque motor (LATM). The operating principle of three topologies is analyzed and discussed, including a toroidal LATM, a slotted LATM with common pole/slot combination, and a slotted LATM with special pole/slot combination. The analysis indicates that no effective methods have been proposed to estimate the MAOR for a slotted LATM with special pole/slot combination. Hence, this paper is focused on solving this problem. The results obtained from the analytical method are validated by a finite-element (FE) method. The average time of the proposed method takes far less than that of an FE method, so that the design cycle of LATMs can be shortened. Finally, two prototype machines are manufactured, and their experimental results are presented and discussed. The FE and experimental results validate the accuracy of an analytical method.

Inevitable perturbations have a significant impact on collaborative production (CP) cause that the complexity are greatly increased. In order to assess the impact accurately enterprises to make precise decisions, it is prerequisite to master the dynamic behaviour of CP when changes occur. Accordingly, in this paper, an evolution model for simulating CP task state to perturbations is proposed. Regard CP tasks as a directed weighted complex network (DWCPTN) firstly, and statistical properties of DWCPTN are analysed. Two perturbation cases and two modifications policies are defined followed. Based on above mentioned, evolution model based on cellular automaton (CA) and SIS (Susceptible-Infected-Susceptible) is presented to reveal the varying process by three indices (friction of resolved nodes, convergence time and economic behaviour). Finally, analytic results from a case of a chemical product CP network (CPNCP) are used to illustrate the model and method proposed in this paper. Simulation results shows that unplanned perturbations promote a negative role to CP but the improvements of self-healing can decrease the negative effects efficiently. With the analysis, it can provide insight into ways of improving the strategic and operational decision making for enterprises.