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Effective and simultaneous organic micropollutant and insoluble oil removal from wastewater by using smart materials and feasible strategies is still a huge challenge. Herein, we design a novel two-dimensional (2D) metal–organic framework (MOF) {[Zn3(bcoba)2(H2O)2]·4DMA·2H2O}n (kgd-Zn) (H3bcoba = (3,5-bis((3′-carboxylbenzyl)oxy)benzoic acid)) with a kgd topology by using a reticular chemistry strategy for highly efficiently removing hazardous substances from wastewater. The excellent ciprofloxacin (CIP) adsorption of kgd-Zn may be attributed to the strong interaction forces between pollution molecules and the MOF. In addition, a macroporous melamine foam (MF) supported hybrid composite kgd-Zn@MF is prepared accordingly. The adsorption performance of CIP is significantly optimized due to the hierarchical microporous–macroporous kgd-Zn@MF system. Moreover, the synergetic hydrophobic/oleophilic properties endow the kgd-Zn@MF composite with an exceptional oil/water separation ability, including a high adsorption capacity (5077–13 786 wt%) towards various solvents and oils, easy collection and remarkable recyclability over 50 cycles. Meanwhile, the hybrid kgd-Zn@MF can simultaneously remove CIP molecules and soybean oil from simulated multi-component wastewater and the removal efficiencies reach above 99.0%, exhibiting a dual functional performance. This work presents a promising strategy of oriented design and topological construction of MOF materials and MOF-based composites acting as excellent candidates for purifying drinking water.

It is highly desirable to provide extra functionality for p-n junction to bypass the limits to Moore’s law. By combining magnetoelectric and photovoltaic effects of p-n junctions, we demonstrate a novel light-induced magnetoresistance (MR) effect, that the photovoltage in the conventional p-n junction can be significantly tuned by magnetic field. In contrast to the symmetric MR driven by external electric field, light-induced MR presents an asymmetric behavior at positive and negative magnetic induction. Theoretical fits using photovoltaic transport equations further reveal that the asymmetric MR induced by light directly reflects the asymmetric geometric of the space-charge region in p-n junction under the magnetic induction. The results not only further confirm our MR model of p-n junction, but also provide a new route by using magnetic control of energy flow in light harvest.

Underwater robots provide great possibilities for people to detect the marine environment. Robots need to keep moving stability, need to ensure the safety of the robot during the movement. A novel spherical underwater robot (SUR V) with hybrid propulsion devices that divided into two parts- vectored water-jet and propeller thrusters. A camera is added at robot to monitor the environments. To analyze the motion characteristics of the SUR V, the computational simulation is calculated in ADAMS and ANSYS CFX respectively. The simulation results verify the performance of the improved spherical underwater robot. Finally, the thrust experiments were conducted that evaluate the performance of the hybrid thruster. The thrust experiment proves that in the improved hybrid thruster proposed in this paper, the maximum thrust of the propeller thruster has increased by 4 times than before.

In this paper, the lifting platform structure of the father robot and the development of the insect-inspired biomimetic underwater microrobot are presented. The objective is to decrease the load of microrobot and realize more functions. In previous researchers, the platform of the father robot is fixed, which is not conducive to adopt and release the son robot. The structure of the lifting platform can effectively solve the problem in theory. The insect-inspired microrobot used wood which has high hydrophilism. It causes the body of microrobot increased weight and short-term works. The fillable structure with waterproof character which is made by a 3D printer. The new structure also can be changed weight for achieving different functions underwater efficiently. Then, two kinds of communication between the light source and microrobot like chasing rotation and fixed distance chasing are described in order to prove the feasibility of the software. In all these cases, experimental results show the performance of the microrobot.

Three-dimensional (3D) porous carbon materials have received substantial attention owing to their unique structural features. However, the synthesis of 3D porous carbon, especially 3D porous carbon with hollow spheres structures at the connection points, still pose challenges. Herein, we first develop a metal-organic complexes@melamine foam (MOC@MF) template strategy, by using hot-pressing and carbonization method to synthesize 3D porous carbon with hollow spheres structures (denoted as NOPCs). The formation mechanism of NOPCs can be attributed to the difference in Laplace pressure and surface energy gradient between the carbonized MOC and carbonized MF. These rare 3D porous carbons exhibit high BET surface area (2453.8 m

Because fuel efficiency is significantly impacted by the timing of combustion in internal combustion engines, accurate control of combustion phasing is critical. In this paper, a nonlinear combustion phasing model is introduced and calibrated, and both a feedforward model-based control strategy and an adaptive model-based control strategy are investigated for combustion phasing control. The combustion phasing model combines a knock integral model, burn duration model and a Wiebe function to predict the combustion phasing of a diesel engine. This model is simplified to be more suitable for combustion phasing control and is calibrated and validated using simulations and experimental data that include conditions with high exhaust gas recirculation fractions and high boost levels. Based on this model, an adaptive nonlinear model-based controller is designed for closed-loop control, and a feedforward model-based controller is designed for open-loop control. These two control approaches were tested in simulations. The simulation results show that during transient changes the CA50 (the crank angle at which 50% of the mass of fuel has burned) can reach steady state in no more than 5 cycles and the steady state errors are less than +/-0.1 crank angle degree (CAD) for adaptive control, and less than +/-0.5 CAD for feedforward model-based control., Journal of Automobile Engineering, 2018

Dual fuel engines can achieve high efficiencies and low emissions but also can encounter high cylinder-to-cylinder variations on multi-cylinder engines. In order to avoid these variations, they require a more complex method for combustion phasing control such as model-based control. Since the combustion process in these engines is complex, typical models of this system are complex as well and there is a need for simpler, computationally efficient, control-oriented models of the dual fuel combustion process. In this paper, a mean-value combustion phasing model is designed. Combustion phasing is predicted using a knock integral model, burn duration model and a Wiebe function.

Amphibious spherical robot moving in a confined space or turbid water must have an effective motion control device and optimized algorithms. This paper proposed a control strategy for two amphibious robots in order to maintain a long time-parameterized path when the robot is moving underwater. Inspired by the biological phenomenon, this paper designs an artificial cooperative mode for two amphibious robots. The control method is based on underwater environment and we also take a detailed mechanical analysis of the thrust device, so the direction of the robot can be adjusted in real time according to the stability module, the purpose of cooperation between the two robots can be achieved. At the end of the paper, the underwater experiment is performed to analyze the cooperation and control system in order to give the best solution for cooperation and motion control methods of two robots.

Dual-fuel engines can achieve high efficiencies and low emissions but also can encounter high cylinder-to-cylinder variations on multicylinder engines. In order to avoid these variations, they require a more complex method for combustion phasing control such as model-based control. Since the combustion process in these engines is complex, typical models of the system are complex as well and there is a need for simpler, computationally efficient, control-oriented models of the dual-fuel combustion process. In this paper, a mean-value combustion phasing model is designed and calibrated, and two control strategies are proposed. Combustion phasing is predicted using a knock integral model (KIM), burn duration (BD) model, and a Wiebe function, and this model is used in both an adaptive closed loop controller and an open loop controller. These two control methodologies are tested and compared in simulations. Both control strategies are able to reach steady-state in five cycles after a transient and have steady-state errors in CA50 that are less than ±0.1 CA deg (CAD) with the adaptive control strategy and less than ±1.5 CAD with the model-based feedforward control method.

With the progress of science and technology, the growing demands for practical applications make low-dimensional multiferroics more appealing in areas such as chemical and bio-sensors, nanoelectronic, high-density data storage devices. One-dimensional BiFeO 3 nanotubes were successfully synthesized by sol–gel-based electrospinning process. The images of scanning electron microscopy and transmission electron microscopy collectively demonstrate that BiFeO 3 nanotubes with long slender structure and virtually uniform diameter of approximately 100 nm were observed at 500 °C annealing temperature. By compared with BiFeO 3 bulks observed at 800 °C annealing temperature, enhanced room temperature ferromagnetism was successfully realized in BiFeO 3 nanotubes at room temperature. The results of electron spin resonance measurement further confirm that ferromagnetic resonances were detected in BiFeO 3 nanotubes at different temperature. X-ray photoelectron spectroscopy study proves the existence of plentiful oxygen vacancies in BiFeO 3 nanotubes, which will play a key role in terms of enhanced ferromagnetism. The results will contribute to expand the applications of BiFeO 3 into the new field of spintronic devices and high-density data storage media.

Recently, electrical switching of interface states in nonferromagnet/ferromagnet (FM)/antiferromagnet (AFM) heterostructure using spin–orbit torque (SOT) is promising due to its high efficiency, zero magnetic field, and multilevel memory state. However, the reversal mechanism of the AFM interface state is still unclear. In this work, we explained the bipolar current switching of the AFM interface state at zero magnetic field by spin–orbit torque (SOT) in a perpendicularly magnetized Pt/Co/IrMn multilayer. By considering symmetry, we reveal that the mechanism behind the AFM interface bipolar current switching is consistent with FM layers perpendicularly switching induced by SOT. The distinct AFM bipolar current switching by SOT is contributed to the symmetry broken by adjacent FM interface coupling. Under such broken symmetry, the antiparallel interface configuration (AP) between FM and AFM could be switched to parallel configuration (P) for both positive and negative currents; however, P is only allowed to be switched to the AFM multiple domain configuration (M), instead of AP. Our result will be helpful for the formulation of a comprehensive understanding of AFM switching induced by SOT and for the development of the interface AFM spintronic devices.

Accurate control of combustion phasing is indispensable for diesel engines due to the strong impact of combustion timing on efficiency. In this work, a non-linear combustion phasing model is developed and integrated with a cylinder-specific model of intake gas. The combustion phasing model uses a knock integral model, a burn duration model and a Wiebe function to predict CA50 (the crank angle at which 50% of the mass of fuel has burned). Meanwhile, the intake gas property model predicts the EGR fraction and the in-cylinder pressure and temperature at intake valve closing (IVC) for different cylinders. As such, cylinder-to-cylinder variation of the pressure and temperature at intake valves closing is also considered in this model. This combined model is simplified for controller design and validated. Based on these models, two combustion phasing control strategies are explored. The first is an adaptive controller that is designed for closed-loop control and the second is a feedforward model-based control strategy for open-loop control. These two control approaches were tested in simulations for all six cylinders and the results demonstrate that the CA50 can reach steady state conditions within 10 cycles. In addition, the steady state errors are less than +/-0.1 crank angle degree (CAD) with the adaptive control approach, and less than +/-1.3 CAD with feedforward model-based control. The impact of errors on the control algorithms is also discussed in the paper., Comment: nternational Journal of Engine Research, 2018

An optimal combustion phasing leads to a high combustion efficiency and low carbon emissions in diesel engines. With the increasing complexity of diesel engines, model-based control of combustion phasing is becoming indispensable, but precise prediction of combustion phasing is required for such strategies. Since cylinder-to-cylinder variations in combustion can be more significant with advanced combustion techniques, this work focuses on developing a control-oriented combustion phasing model that can be leveraged to provide cylinder-specific estimates. The pressure and temperature of the intake gas reaching each cylinder are predicted by a semi-empirical model and the coefficients of this intake pressure and temperature model are varied from cylinder-to-cylinder. A knock integral model is leveraged to estimate the SOC (start of combustion) and the burn duration is predicted as a function of EGR fraction, equivalence ratio of fuel and residual gas fraction in a burn duration model. After that, a Wiebe function is utilized to estimate CA50 (crank angle at 50% mass of fuel has burned). This cylinder-specific combustion phasing prediction model is calibrated and validated across a variety of operating conditions. A large range of EGR fraction and fuel equivalence ratio were tested in these simulations including EGR levels from 0 to 50%, and equivalence ratios from 0.5 to 0.9. The results show that the combustion phasing prediction model can estimate CA50 with an uncertainty of ±0.5 crank angle degree in all six cylinders. The impact of measurement errors on the accuracy of the prediction model is also discussed in this paper.

Diesel engines can operate with high efficiencies, but this efficient operation is contingent on proper combustion phasing control. As engine complexity increases, model-based control of combustion phasing is becoming more essential. Such a control method requires an efficient model that can predict combustion metrics based on factors such as engine speed, injection timings and fuel equivalence ratio. A mean-value control-oriented model of diesel engine combustion phasing is presented in this paper. This model combines a knock integral model, burn duration prediction model and a Wiebe function to estimate the combustion phasing of a diesel engine. The model is validated with over 500 simulations as well as experimental results and is shown to accurately predict the control phasing of diesel engine.

The anomalous Hall effect in ferromagnetic materials has attracted much attention for more than a century due to its physical complexity and important applications. Depending on its origin, this effect has been explained by three typical mechanisms: intrinsic contribution [1], skew scattering [2], and side jump [3], which cause exponential dependences with different power indexes between the extraordinary Hall conductivity σ xy and the longitudinal conductivity σ xx in experiments [4]. The power law has been extensively studied experimentally in a large series of ferromagnetic materials, by changing the temperature, disorder scattering, and the density of states at the Fermi surface [1].

The Active Disturbance Rejection Control (ADRC) prefers the cascaded integral system for a convenient design or better control effect and takes it as a typical form. However, the state variables of practical system do not necessarily have a cascaded integral relationship. Therefore, this paper proposes an algebraic substitution method and its structure, which can convert a noncascaded integral system of PID control into a cascaded integral form. The adjusting parameters of the ADRC controller are also demonstrated. Meanwhile, a numerical example and the oscillation control of a flexible arm are demonstrated to show the conversion, controller design, and control effect. The converted system is proved to be more suitable for a direct ADRC control. In addition, for the numerical example, its control effect for the converted system is compared with a PID controller under different disturbances. The result shows that the converted system can achieve a better control effect under the ADRC than that of a PID. The theory is a guide before practice. This converting method not only solves the ADRC control problem of some noncascaded integral systems in theory and simulation but also expands the application scope of the ADRC method.

Because of its high NOx reduction efficiency, selective catalyst reduction (SCR) has become an indispensable part of diesel vehicle aftertreatment. This paper presents a control strategy for SCR systems that is based on an on-line radial basis function neural network (RBFNN) and an on-line backpropagation neural network (BPNN). In this control structure, the radial basis function neural network is employed as an estimator to provide Jacobian information for the controller; and the backpropagation neural network is utilized as a controller, which dictates the appropriate urea-solution to be injected into the SCR system. This design is tested by simulations based in Gamma Technologies software (GT-ISE) as well as MATLAB Simulink. The results show that the RBF-BPNN control technique achieves a 1–5 % higher NOx reduction efficiency than a PID controller.

In contrast to traditional concepts that eliminate magnetic impurities to achieve larger thermoelectric efficiencies, we report an enhanced thermoelectric efficiency for Cu through doping with the magnetic impurity Co. With doping concentrations from 15% to 30%, the amplitude of the Seebeck coefficient increases from 1.90 μV/K up to 16.3 μV/K, which greatly enhances the thermoelectric efficiency (i.e., power factor). Measuring the magnetoresistance and magnetothermoelectric powers at different temperatures indicates that the enhancement of thermoelectric efficiency is a result of spin-dependent scattering from Co nanoparticles, which are less sensitive to the superparamagnetic transitions. Our finding illustrates a path for the use of nanomagnets to develop potential thermoelectric materials.

Using the rotational magnetization curve approach, we investigated the magnetization rotational process of the exchange-biased bilayers system with the theoretical calculation and the experimental measurement. For all of EB bilayers, the in-plane rotation of magnetization can undergo non-reversed, discontinuous reversal and continuous reversal magnetization rotational process with increasing external magnetic fields. The magnetization rotational process of EB bilayers was determined by the magnitude of the external field. Moreover, the uniaxial anisotropic field and the unidirectional anisotropic field and the ratio between them in the sample and their ratio affected the critical switching external fields, which divided the magnetization rotational process into three different cases. The theoretical calculation showed these different magnetization rotational processes, which were proved by experiment results.

Control system of space scanning mirror has high requirement of scanning accuracy. The use of optimal tracking controller, instead of traditional PID controller, can effectively improve the scanning accuracy of space scanning mirror control system. State space model of the control system is established; the control system based on optimal tracking controller is designed; simulation experiment of the control system based on optimal tracking controller is carried out. The simulation result, in comparison with the system based on a PID controller, shows that the scanning mirror control system using optimal tracking controller instead of PID controller has higher scanning accuracy and faster response.

[NiFe/FeMn] n exchange-coupled multilayer films have been fabricated on the silicon substrate by magnetron sputtering deposition. The static and dynamic magnetic properties of multilayer films have been investigated with varying numbers of layers. The results show that the linewidth and permeability of imaginary resonance peak are increased with increasing numbers of layers. For the NiFe/FeMn/NiFe sample, the resonance frequency shows a different shift with applying external magnetic field along the direction of easy and hard magnetization axis of the sample, respectively, indicating a different magnetic reversal process in two ferromagnetic layers. It proved that the increase of linewidth was originated from the different interface exchange coupling.

Effective anisotropy of the ferromagnetic pinned layer of ferro(FM)-antiferromagnetic (AF)-coupled NiFe(FM)/FeMn(AF) exchange-biased system was investigated in a broad frequency range (100 MHz–5 GHz) using a complex permeability spectrum. The exchange bias and effective uniaxial anisotropy fields of the thin film have been computed theoretically using the Landau–Lifs c hitz–Gilbert (LLG) equation. From the measurements, uniaxial anisotropy of the pinned FM layer has been extracted to understand the nature of the exchange bias in the system. It is found that the uniaxial anisotropy field of NiFe layer when exchange biased with the AF layer increases from 5 to 15 Oe at different external magnetic fields.

CoFe 2 O 4 nanowire arrays were fabricated by electrodeposition of Fe 2+ and Co 2+ into anodic aluminum oxide (AAO) templates and further oxidization. The phase structure of the nanowires is cubic spinel-type, and the XRD result exhibits perfect preferred crystallite orientation along the nanowire axes. Compared with CoFe 2 O 4 nanowire arrays synthesized by other methods, the magnetic hysteresis loops demonstrate that the arrays of nanowires exhibit uniaxial magnetic anisotropy with easy magnetization direction along the nanowire axes owing to the large shape anisotropy. This approach provides a facile technology to fabricate oxide nanowires with uniaxial magnetic anisotropy.

We report a large but asymmetric magnetoresistance in silicon p-n junctions, which contrasts with the fact of magnetoresistance being symmetric in magnetic metals and semiconductors. With temperature decreasing from 293 K to 100 K, the magnetoresistance sharply increases from 50% to 150% under a magnetic field of 2 T. At the same time, an asymmetric magnetoresistance, which manifests itself as a magnetoresistance voltage offset with respect to the sign of magnetic field, occurs and linearly increases with magnetoresistance. More interestingly, in contrast with other materials, the lineshape of anisotropic magnetoresistance in silicon p-n junctions significantly depends on temperature. As temperature decreases from 293 K to 100 K, the width of peak shrinks from 90° to 70°. We ascribe these novel magnetoresistance to the asymmetric geometry of the space charge region in p-n junction induced by the magnetic field. In the vicinity of the space charge region the current paths are deflected, contributing the Hall field to the asymmetric magnetoresistance. Therefore, the observed temperature-dependent asymmetry of magnetoresistance is proved to be a direct consequence of the spatial configuration evolution of space charge region with temperature.

The FeCoZr/Cu multilayers were prepared by radio frequency sputtering. The static and microwave properties of these films were investigated by measuring the hysteresis loops and microwave permeability spectra. According to the static magnetic results, the multilayers were well in-plane uniaxial anisotropic samples with high saturation magnetization 1.7 T. The anisotropic field of these multilayer thin films can be adjusted from 18 Oe to 64 Oe by changing the thickness of Cu interlayer from 8.7 nm to 1.8 nm. As a consequence, the microwave permeability and resonance frequency can also be adjusted from 1.70 GHz to 2.88 GHz. This work might facilitate search for new materials with high permeability at high frequency.

To understand the distribution of the in-plane magnetic anisotropy under a dc electric field, FeCo films deposited onto Pb(Mg1/3Nb2/3)O3-PbTiO3 (011)-orientated substrates by RF-magnetron sputtering were investigated. Vibrating sample magnetometer was performed and the occurrence of switching was demonstrated of the magnetization easy axis in FeCo films upon applying solely a dc electric field. A theoretical calculation was performed to provide a simplified account of the magnetoelastic contribution to the magnetic anisotropy. Quantification of the angular distribution of the magnetic anisotropy field under various electric fields was obtained, which can contribute to realizing low-loss electric-field-turning devices.

Rotational magnetization curves of the exchange-bias bilayers were investigated based on the Stoner-Wohlfarth model, which can be grouped into three cases according to the magnetization reversal process. The unidirectional anisotropic field HE = 41.4 Oe, the uniaxial anisotropic field Hk = 4.2 Oe and the accurate direction of the easy axis of our FeNi/FeMn exchange-bias bilayers were obtained by fitting their experimental rotational magnetization curves. During the rotational process the magnetization reversal of the bilayers is a coherent rotation with a critical magnetization reversal field H1 = 41.372 Oe.

The effect of thermal annealing on structural and magnetic properties has been investigated for Zn ferrite films deposited on Si (111) substrates using radio frequency magnetron sputtering. The saturation magnetization at room temperature was enhanced upto 303 emu/cm3 by annealing at relatively low temperature of 200 °C and decreased at higher temperatures. The complex permeability μ=μ′-iμ″ values of the ferrite films as-deposited and annealed at 200 and 400 °C were measured at frequency upto 5 GHz. These films exhibited better high-frequency properties, especially, the film annealed at 200 °C had a large μ′ of 19.5 and high resonance frequency fr of 1.61 GHz. And the reason was investigated preliminarily based on the bianisotropy model.

In this work, the static and high frequency magnetic properties of (Co90Nb10/Ta)(n) multilayers have been investigated. The results show that the in-plane uniaxial magnetic anisotropy fields can be adjusted from 12 to 520 Oe only by decreasing the thickness of Ta interlayers from 8.0 to 1.8 nm. As a consequence, the resonance frequencies of the multilayers continuously increased from 1.4 to 6.5 GHz. It was found that the changes in the in-plane uniaxial anisotropy field are ascribed to the interlayer interactions among the magnetic layers by investigating the delta M(H) curves.

A series of (Co0.65Fe0.35)1?x(Ni0.5Zn0.5Fe2O4)x bi-magnetic composite granular films with different ferrite atom fraction x are fabricated by magnetron sputtering. Scanning electron micrographs and x-ray diffraction results show that the films consist of bcc Co0.65Fe0.35 particles, uniformly with particle size around a few nanometres. These results reveal that the Ni0.5Zn0.5Fe2O4 in the composite films is electrically insulate for Ni0.5Zn0.5Fe2O4, thus exhibiting promising magnetic properties for suitable proportions of Co0.65Fe0.35. They also reveal that the films show in-plane isotropy, in-plane uniaxial anisotropy and super paramagnetic magnetic properties while x changes from 0 to 0.16. In particular, for the samples with x = 0.085 and x = 0.116, the saturation magnetizations are 1.41?T and 1.19?T, the resistivities reach 677????cm and 1371????cm, the real part of the complex permeability is more than 100 and 150 below 2.0?GHz and the ferromagnetic resonance frequencies reach 3.61?GHz and 2.84?GHz, respectively.

Room temperature ferromagnetism (RTF) is observed in pure copper oxide (CuO) nanoparticles which were prepared by precipitation method with the post-annealing in air without any ferromagnetic dopant. X-ray photoelectron spectroscopy (XPS) result indicates that the mixture valence states of Cu1+ and Cu2+ ions exist at the surface of the particles. Vacuum annealing enhances the ferromagnetism (FM) of CuO nanoparticles, while oxygen atmosphere annealing reduces it. The origin of FM is suggested to the oxygen vacancies at the surface/or interface of the particles. Such a ferromagnet without the presence of any transition metal could be a very good option for a class of spintronics.