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We have developed a new global eigenvalue code, Multiscale Analysis for plasma Stabilities (MAS), for studying plasma problems with wave toroidal mode number n and frequency omega in a broad range of interest in general tokamak geometry, based on a five-field Landau-fluid description of thermal plasmas. Beyond keeping the necessary plasma fluid response, we further retain the important kinetic effects including diamagnetic drift, ion finite Larmor radius, finite parallel electric field, ion and electron Landau resonances in a self-consistent and non-perturbative manner without sacrificing the attractive efficiency in computation. The physical capabilities of the code are evaluated and examined in the aspects of both theory and simulation. In theory, the comprehensive Landau-fluid model implemented in MAS can be reduced to the well-known ideal MHD model, electrostatic ion-fluid model, and drift-kinetic model in various limits, which clearly delineates the physics validity regime. In simulation, MAS has been well benchmarked with theory and other gyrokinetic and kinetic-MHD hybrid codes in a manner of adopting the unified physical and numerical framework, which covers the kinetic Alfven wave, ion sound wave, low-n kink, high-n ion temperature gradient mode and kinetic ballooning mode. Moreover, MAS is successfully applied to model the Alfven eigenmode (AE) activities in DIII-D discharge #159243, which faithfully captures the frequency sweeping of RSAE, the tunneling damping of TAE, as well as the polarization characteristics of KBAE and BAAE being consistent with former gyrokinetic theory and simulation. With respect to the key progress contributed to the community, MAS has the advantage of combining rich physics ingredients, realistic global geometry and high computation efficiency together for plasma stability analysis in linear regime., Comment: 40 pages, 21 figures

Collision process is crucial to the transport in magnetized plasmas. This article reviews the three typical approaches, i.e. the Fokker-Planck (FP) approach, the Bogoliubov-Born-Green-Kirwood-Yvon (BBGKY) approach, and the quasilinear (QL) approach, to deriving the kinetic equation for weakly coupled uniformly magnetized plasmas. The collision terms derived based on these three approaches are shown to be identical and satisfy the conservation laws and H theorem. Relatively speaking, the BBGKY and QL approaches are more systematic and readily to be generalized from weakly magnetized plasmas to strongly magnetized plasmas. The FP approach is pretty simple for weakly magnetized plasmas and has the advantage that the collision term derived based on it can be naturally separated into two parts, one part arising from the polarization and the other from the correlation of the fluctuating electrostatic field. However, the usual form of the FP equation is not suitable for strongly magnetized plasmas. To derive the magnetized collision term based on the FP approach, a general form of the FP equation for magnetized plasmas has to be found first.

With the increasingly serious global climate problem, the low-carbon design of products has gradually become an important direction of sustainable manufacturing. The optimization design of product structure is one of the important means to realize the low-carbon operation of product structure. Therefore, how to carry out the low-carbon optimization design of the product is the focus of this paper. In this paper, a new framework of low-carbon manufacturing is constructed, the load on the crane of the offshore wind power installation platform is analyzed, and the dynamic load generated by the crane during lifting, rotating, and luffing is analyzed in detail. The simulation results are compared with the empirical formula provided by the crane design specification and the dynamic analysis results of the crane, which proves the rationality of the simulation results and the dynamic theoretical analysis. And the wind load on the crane is calculated, which provides support for the rigid-flexible coupling dynamic analysis of other parts of the solution. Based on the dynamic simulation and load analysis of the offshore platform crane, the low-carbon optimization design of the offshore platform pile leg is carried out, the carbon emission of the whole life cycle is optimized, and the feasibility of the scheme is verified.

Purpose Gastrointestinal neuroectodermal tumors (GNETs) are uncommon malignant tumors derived from ectodermal primitive neural cells. Patients and Methods We retrospectively analyzed 2 GNET cases at our hospital and the remaining 94 cases in the literature to determine clinicopathological prognostic factors. Results The patients had a mean age of 36 years and a median tumor size of 4.5 cm. A total of 67.0% of the tumors were located in the small intestine, and 76.4% of the patients presented recurrence or metastasis. There was a significant difference in sex and presence of osteoclast-like cells (P

Background The current epidemiology shows that the incidence of breast cancer is increasing year by year and tends to be younger. Triple-negative breast cancer is the most malignant of breast cancer subtypes. The application of bioinformatics in tumor research is becoming more and more extensive. This study provided research ideas and basis for exploring the potential targets of gene therapy for triple-negative breast cancer (TNBC). Methods We analyzed three gene expression profiles (GSE64790、GSE62931、GSE38959) selected from the Gene Expression Omnibus (GEO) database. The GEO2R online analysis tool was used to screen for differentially expressed genes (DEGs) between TNBC and normal tissues. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were applied to identify the pathways and functional annotation of DEGs. Protein–protein interaction network of these DEGs were visualized by the Metascape gene-list analysis tool so that we could find the protein complex containing the core genes. Subsequently, we investigated the transcriptional data of the core genes in patients with breast cancer from the Oncomine database. Moreover, the online Kaplan–Meier plotter survival analysis tool was used to evaluate the prognostic value of core genes expression in TNBC patients. Finally, immunohistochemistry (IHC) was used to evaluated the expression level and subcellular localization of CCNB2 on TNBC tissues. Results A total of 66 DEGs were identified, including 33 up-regulated genes and 33 down-regulated genes. Among them, a potential protein complex containing five core genes was screened out. The high expression of these core genes was correlated to the poor prognosis of patients suffering breast cancer, especially the overexpression of CCNB2. CCNB2 protein positively expressed in the cytoplasm, and its expression in triple-negative breast cancer tissues was significantly higher than that in adjacent tissues. Conclusions CCNB2 may play a crucial role in the development of TNBC and has the potential as a prognostic biomarker of TNBC.

A hybrid novel structure of monolayer WS 2 with Ag nanograting and distributed Bragg reflector (DBR) on Si substrate has been proposed to obtain broad-band absorption response for two-dimensional (2D) materials. It is effective to reduce light loss and reflect the incident light efficiently for monolayer WS 2 absorption with DBR dielectric layers. Moreover, by combining Ag nanograting with DBR structure, the average absorption achieves as high as 52.9% within broad wavelength ranging from 420 to 700 nm, which is attributed to the plasmonic resonant effect of metal nanostripes. The absorption would be influenced by the period and height of the Ag nanograting, and shows incident angle dependent characteristics, while an average absorption higher than 50% has been obtained at the incident angle around 40°. These results indicate that 2D WS 2 in combination with DBR and metal nanograting have a promising potential applications for optical nano-devices.

A novel structure with bilayer hybrid graphene/metal (G/M) gratings to realize tunable double Fano resonances has been proposed. Different band gaps can be obtained by applying voltages on the bilayer graphenes. Due to the tunability of the hybrid structure, two different resonances are separately tuned under various parametric conditions. The Fano resonances are produced by the interaction between the metal and graphene gratings, the related mechanism is investigated by the electric field distribution and transmission phase. The superior characteristics of the separately tunable double Fano resonances indicate a promising application in THz optical devices.

A hybrid novel structure of monolayer MoS 2 with Ag nanograting and DBR on Si substrate has been proposed to obtain broad-band absorption response for two-dimensional (2D) materials. It is effective to reduce light loss and reflect the incident light efficiently for monolayer MoS 2 absorption with DBR dielectric layers. Moreover, by combining Ag nanograting with DBR structure, the average absorption achieves as high as 59% within broad wavelength ranging from 420 to 700 nm, which is attributed to the plasmonic resonant effect of metal nanostripes. The absorption would be affected by the duty ratio and period of the Ag nanograting, and shows incident angle dependent characteristics, while an average absorption higher than 60% has been obtained at the incident angle around 40°. These results indicate that 2D MoS 2 in combination with DBR and metal nanograting have a promising potential applications for optical nano-devices.

Requirements analysis and understanding play a key role in the successful development of Product-Service System (PSS). Some PSS requirements may interact with others and even with the environment due to different stakeholder's preference and PSS heterogeneity. Thus, it is necessary to understand the dependencies and correlations between the underlying PSS requirements. However, there are few researches on requirement interaction evaluation and analysis in the early planning phase of PSS development. Besides, PSS requirement interaction evaluation often involves much vagueness due to the subjective judgments. To solve these problems, a systematic method for assessing and analyzing PSS requirement dependencies under vagueness is proposed. The proposed method integrates strength of group DEMATEL (Decision-Making and Trial Evaluation Laboratory) in assessing interaction relationship and merit of rough set theory in manipulating subjective judgments. To demonstrate the potential of the approach, an application in an air compressors system is also illustrated.

The increasing complexity of product and radical changing environment lead companies towards innovation network (IN) collaboration. Although recent researches highlight the importance and benefits of innovation network (IN) to new product development (NPD), this subject is still developing and it has the potential to expand into new dimensions. However, there is a significant lack in the literature regarding holistic, systematic and integrated framework when it comes to manipulating the challenge of true NPD projects. The current researches mainly focus on the strategy level which provides less application guidance for NPD. Thus, in this work, the authors propose an integrative framework of innovation network for NPD based on the literature review. In addition, a case study of new refrigerator development reveals the feasibility and potentials of the overall framework to its broad usage in industry.

As concerning the present gap in the dynamic information association and integration between engineering design and engineering analysis, this paper is devoted to a parametric skeleton model-based dynamic information association and integration between design model and analysis model. After the description of the gap between engineering design and analysis was analysed, the modeling method of the product skeleton model was proposed. Then the integrated design and analysis method based on the skeleton model was proposed based on the parameterized design method for analysis. The parametric skeleton model-based design modeling method could be used to resolve the integrating design and analysis problem in product design. The integrated design and analysis of an offshore crane were given as an example with about 25 % time reduction in design cycle, which demonstrates that the methodology is helpful to the associativity of design-analysis models.

The energetic-particle-induced geodesic acoustic mode (EGAM) is studied using gyrokinetic particle simulations in tokamak plasmas. In our simulations, exponentially growing EGAMs are excited by energetic particles with a slowing-down distribution. The frequencies of EGAMs are always below the frequencies of GAMs, which is due to the non-perturbative contribution of energetic particles (EPs). The mode structures of EGAMs are similar to the corresponding mode structures of GAMs. Our gyrokinetic simulations show that a high EP density can enhance the EGAM growth rate, due to high EP free energy, and that EPs' temperature and the pitch angle of the distribution modify the EGAM frequency/growth rate by means of the resonance condition. Kinetic effects of the thermal electrons barely change the EGAM frequency, and have a weak damping effect on the EGAM. Benchmarks between the gyrokinetic particle simulations and a local EGAM dispersion relation exhibit good agreement in terms of EGAM frequency and growth rate.

The influences of the temperature gradient and toroidal effects on drift-tearing modes have been studied using the Gyrokinetic Toroidal code. After the thermal force term is introduced into the parallel electron force balance equation, the equilibrium temperature gradient can cause a significant increase in the growth rate of the drift-tearing mode and a broadening of the mode structure. The simulation results show that the toroidal effects increase the growth rate of the drift-tearing mode, and the contours of the perturbation field “squeeze” toward the stronger field side in the poloidal section. Finally, the hybrid model for fluid electrons and kinetic ions has been studied briefly, and the dispersion relation of the drift-tearing mode under the influence of ion finite Larmor radius effects is obtained. Compared with the dispersion relation under the fluid model, a stabilizing effect of the ion finite Larmor radius is observed.

Synthetic aperture radar (SAR) is widely used in remote sensing and surveillance area, including observing internal waves (IWs). In this paper, the basic form of IW is studied in order to find out the affection of radar parameters, which can help improve the precision of IW parameter estimation by SAR sensor. A new method is proposed to analyze the influence of internal waves. Simulations and experiments are drawn, and the result proved the proposed analyzing method efficient for understanding the internal waves and the influence of radar parameters.

To start the tracking of targets in the environment with heavy clutters is always a problem in radar data procedure. In this paper, a Hough Transform method based on Morphology is proposed to solve the problem of starting track in radar system. This method first uses morphological method to reduce clutter and noise in imagery domain, then use the Hough transform to detect the starting tracks. Simulation results show that the method well detected the short straight lines of target starting track.

In order to improve the dynamic response and anti-interference ability of the system, a sliding mode control method for a fixed frequency bidirectional DCDC converter is proposed in this paper. The sliding mode of Buck mode and Boost mode is established in Simulink with voltage and current as control volume respectively, and the simulation results of PI control are compared. The effectiveness of the sliding mode algorithm is verified. It is proved that the sliding mode system has good robustness and fast dynamic response.

AlGaN solar-blind avalanche photodiodes (APDs) with AlInN/AlGaN distributed Bragg reflectors (DBRs) operated at lower avalanche breakdown voltage are numerically demonstrated. The p-type AlGaN layer and the multiplicative layer with low Al composition are introduced to construct the polarization-induced electric field, which can significantly reduce the avalanche breakdown voltage of the APDs. Calculated results exhibit that the avalanche breakdown voltage of the designed APDs decrease by 13% compared with the conventional device structure. Simultaneously, an improved solar-blind spectral responsivity is achieved due to the inserted AlInN/AlGaN DBRs.

We give theoretical analyses of the Magneto-Rayleigh-Taylor instability driven by a rotating magnetic field. Both slab and liner configurations with finite thicknesses are dealt with in the WKB and the non-WKB approximations. Results show that instabilities for all modes (combinations of wave vectors) are alleviated. We further discuss the potential application of the alternant/nested configurations of a theta and a Z pinch to the Theta-Z Liner Inertia Fusion (Theta-Z-LIF) concept., in Chinese

Nonlinear self-interaction of finite amplitude energetic particle induced geodesic acoustic mode (EGAM) is investigated using nonlinear gyrokinetic theory. It is found that both zero frequency zonal flow(ZFZF) and second harmonic can be driven by finite amplitude EGAM, with energetic particles (EPs) playing a dominant role in the nonlinear couplings through finite orbit width effects. For ZFZF, the effects of EPs on EGAM nonlinear self-coupling dominate that of the thermal plasmas which are also present; while the second harmonic generation is only possible via finite amplitude coupling though EPs. Our findings may improve the understanding of stabilizing zonal modes, and consequently, drift wave turbulence.

Dynamics is concerned with the study of forces and torques and their effect on motion. As formulating the suitable dynamics models for an offshore crane is very crucial for analyzing the behavior and lightweight design, many researches have been focused on it in recent decades with a result of many valuable contributions. However, current researches always focus on rigid crane, while the crane is always a rigid-flexible coupling multibody system, which can affect the accuracy of dynamic analysis. This paper proposed a model of dynamics analysis of an offshore crane based on rigid-flexible coupling virtual prototyping. After the structure and performance parameters of the 800-ton offshore crane were introduced, rigid-flexible coupling virtual prototyping-based dynamics analysis and numerical simulation were then put forward. The dynamics experiment is carried out based on offshore crane physical prototyping, and experimental results indicate successful lifting load with predetermined boom angle, which demonstrates that the accuracy of the dynamics analysis is based on rigid-flexible coupling virtual prototyping. The design of an offshore crane is given as an example which demonstrates that the methodology is obviously helpful to offshore crane design.

Electric cars foreshadow the future direction of the automotive industry owing to its great potential for environment protection. Electric car rental may be an effective mode to popularise the electric car, before the cost of the electric car can be reduced substantially. To provide the electric car rental service well, the company must understand how consumers value renting an electric car and what they consider to be value-added, which is the main objective of the research. First, the concepts of customer participation (CP), service quality (SERVQUAL) and customer value (CV) are identified. Then, the value-added path structural equation is constructed by exploratory factor analysis and confirmatory factor analysis. Use path coefficient and standard factor loading to identify the value-added paths and key factors in the electric car rental. The results show that CP will improve customer satisfaction and the post-purchase intentions, through the improvements of SERVQUAL and CV and thus realising the added...

The workspace denotes the work area of a robot, which is an important foundation of designing a robot. As formulating the suitable workspace models for a robot wrist is very crucial for analyzing its behavior, many researches have been focused on it in recent decades with a result of many valuable contributions. However, current researches always focus on rigid and full actuated robot wrist, while the robot wrist is always a multibody system, which can affect the accuracy of workspace analysis and simulation. This paper proposed a model of workspace analysis of a novel underactuated robot wrist based on virtual prototyping. After the conceptual design of a novel underactuated mechanism was introduced, the degree of freedom of the underactuated robot wrist was calculated. Then the detailed design of underactuated robot wrist was done. The whole workspace model of the robot system was then established. It was indicated that the working points in the workspace of the robot were distributed compactly and uniformly, which can meet design requirements with high efficiency. The workspace analysis of underactuated robot wrist and the accuracy analysis of underactuated robot wrist were also put forward. The result was testified by the simulation on Matlab, which demonstrated that the methodology is obviously helpful for robot design.

A novel configuration of a monolayer MoS2 covered on a silicon photonic crystal slab with cross-shaped groove of air resonator, supported by a gold back reflector, has been proposed to achieve perfect absorption in monolayer MoS2 both theoretically and numerically. The perfect absorption of monolayer MoS2 is explored by the critical coupling with guided resonance. Simulated results demonstrate that the absorption wavelengths of monolayer MoS2 depend on the geometrical parameters of the structure, exhibiting advantageous tunability of operating wavelength in monolayer MoS2. These results indicate that the designed optical structure might open promising technologies for improving the light–matter interaction in two-dimensional transition-metal dichalcogenides (TMDCs) and has potential applications in wavelength-sensitive optoelectronic devices.

The dynamics of magnetic islands including toroidal rotation in tokamaks is studied. It is found that the contribution of toroidal rotation to the dynamics of magnetic islands is mainly through the coupling of magnetic curvature with pressure and density. In the presence of toroidal rotation, pressure and density are poloidal asymmetric. Then, their coupling with magnetic curvature provides a perpendicular current, and a corresponding return parallel current is induced to affect the dynamics of magnetic islands. It is found that the effect of toroidal rotation depends on its magnitude, rather than the shear. It also depends on the relative magnitude of the island propagation frequency to sound frequency. When the Mach number is large enough, the effect of toroidal rotation is stabilizing and dramatic, and overcomes the contribution of polarization current, namely the onset threshold of NTMs increases. Further, it is also suggested that the toroidal rotation plays an important role in the stability of small scale magnetic islands.

Toroidal rotation has always existed in tokamak plasmas, and its Mach number can reach unity during neutral beam injection. Toroidal rotation can affect plasma equilibrium and magnetohydrodynamic instabilities significantly. Based on linearized equations including the toroidal rotation effect, the toroidal model derived by Glasser et al. [Phys. Fluids 18, 875 (1975)] is extended to include this effect, and a set of resistive equations including the toroidal rotation effect in the axi-symmetry toroidal geometry is derived. Based on these derived equations, the effect of toroidal rotation on tearing modes is considered, and the growth rate of tearing modes is obtained analytically. It is shown that the effect of toroidal rotation on tearing modes depends on both the direction of toroidal rotation flow and the sign of toroidal rotation flow shear. When they have the same sign, they play a role in stabilizing tearing modes, while when they have opposite signs, they have a destabilizing effect on tearing modes.

The Fokker-Planck approach is employed to derive the kinetic equation for spatially uniform magnetized plasmas. By using the fluctuating electrostatic field for quiescent plasmas, the magnetized Fokker-Planck coefficients are calculated explicitly based on the wave theory which takes into account the collective effects in a proper manner. Manipulating the magnetized Fokker-Planck collision term into the Landau form, the magnetized Balescu-Lenard-Guernsey collision term is obtained, which is identical to the results derived by using the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy of equations and the quasilinear method. The H theorem is proved in the end.

A toroidal particle-in-cell (PIC) code, suitable for investigating nonlinear phenomena in radio frequency (RF) heating and current drive, is developed and verified thereafter through a series of fidelity tests for field solvers and single particle motions in toroidal geometry, where simulation results show good coincidence with analytical prediction. The RF capability is then demonstrated through the integrated benchmarks with linear lower hybrid wave and ion Bernstein wave theory in cylindrical geometry, where the analytic result is easily available. The frequency and mode structure in the simulations agree well with the theoretical prediction.

Pushforward transformation is one of the two important transformations in modern nonlinear gyrokinetic theory. In this work, a gyrokinetic system under electromagnetic fluctuations has been derived using a purely pushforward transformation, where the finite Larmor radius (FLR) effect is fully retained. From the perspective of polarization and magnetization, clear physical pictures of macroscopic equilibrium flow are presented, and the generation of macroscopic perturbed flow is discussed with the incorporation of the full FLR effect using the systematical analysis of the gyrocenter gyroradius and the decoupling of particle velocity.

Current-driven resistive tearing instability is verified using the newly developed global first-principles particle-in-cell code called VirtEx, which was coded from scratch in conformity with the C++'11 specifications. The tearing instability is first verified in the fluid limit in a cylinder geometry by ignoring the gyrokinetic effect of ions, and the numerical results agree well with the analytical predictions of the resistive tearing theory. Then, the effect of toroidicity on resistive tearing instability is investigated.

Using the quantum hydrodynamic (QHD) equations with magnetic field on the Wigner–Maxwell system, the general dielectric tensor and dispersion equation for quantum plasmas were derived. Dispersion relations of one-, two-stream and beam-plasma instabilities in uniform quantum magnetized plasmas are investigated through the new dielectric tensor. The magnetic field which is parallel to the fluid velocity does not work on stream instabilities. The quantum and thermal effects have remarkable impact on two-stream instability. The critical wave number for beam-plasma instability with quantum effects correction is given too.

Geodesic acoustic mode (GAM) is analyzed by using modified gyro-kinetic (MGK) equation applicable to low-frequency microinstabilities in a rotating axisymmetric plasma. Dispersion relation of GAM in the presence of arbitrary Mach number is analytically derived. Toroidal rotation plays the same effects on the GAM regardless of the orientation of equilibrium flow. It is shown that the toroidal Mach number $M$ increases the GAM frequency and dramatically decreases the Landau damping rate. The valid of classical gyro-kinetic (CGK) equation is also examined. For zero electron temperature, CGK is identical with MGK. For non-zero electron temperature, CGK gives the same real frequency of GAM as MGK but induces an instability with a growth rate proportional to $M^3/q$, where $q$ is the safety factor.

A new mechanism for geodesic acoustic mode (GAM) excitation by a not fully slowed down energetic particle (EP) beam is analyzed to explain experimental observations in Large Helical Device. It is shown that the positive velocity space gradient near the lower-energy end of the EP distribution function can strongly drive the GAM unstable. The new features of this EP-induced GAM (EGAM) are: (1) no instability threshold in the pitch angle; (2) the EGAM frequency can be higher than the local GAM frequency; and (3) the instability growth rate is much larger than that driven by a fully slowed down EP beam. © 2015 AIP Publishing LLC.

By solving the coupled Schrodinger and Poisson's equations self-consistently, we have theoretically investigated the in-plane magnetic-field-induced negative effective mass (NEM) in n-doped wide quantum wells. The NEM originates from the interaction of Hartree potential and magnetic-field-introduced potential. Without n-type doping, no NEM section arises at any magnetic field densities. The value of NEM and the width of NEM section can be effectively adjusted by magnetic field, electrical field, and doping concentration, which make it possible to utilize the above system to realize the tunable terahertz source.

A fully-kinetic ion and gyrokinetic electron Vlasov-Maxwell particle simulation model is derived through Lie transform perturbation theory for Hamiltonian system in terms of four ordering parameters $\epsilon_B$, $\epsilon_\omega$, $\epsilon_{\shortparallel}$ and $\epsilon_\delta$. The combination of field equations is Poisson's equation together with Amp\`ere's law in the model. This scheme preserves the phase-space volume and retains the ion cyclotron motion while fine scale electron motion is ignored, so that the frequency falls in range $\Omega_i \leq \omega l \Omega_e$. Using perturbative method ($\delta f$) and ignoring the high order terms, this model is then formulated in magnetic flux coordinate system with equilibrium Maxwellian distribution for particles. Thus, this model is especially suitable for the global particle simulation of high-frequency physical processes such as lower hybrid wave and ion cyclotron range of frequencies waves.

The nonlinear co-existence of β–induced Alfven eigenmode (BAE) and β–induced Alfven-acoustic eigenmode (BAAE) is found in simulations using the gyrokinetic toroidal code, which provides a new mechanism responsible for BAAE excitation in tokamaks. Here, the normalized pressure β is the ratio between plasma thermal pressure and magnetic pressure. The nonlinear simulation results show that the BAAE branch emerges after the BAE branch is saturated. The mode structure's evolution shows that existence of BAAE will change the original BAE mode structure. The perturbed distribution functions in the velocity phase space show that a new resonance region manifesting the wave-particle resonance in the BAAE branch appears during the nonlinear co-existence stage.

Separate absorption and multiplication AlGaN solar-blind avalanche photodiodes with dual-periodic III–nitride distributed Bragg reflectors (DBRs) are numerically demonstrated. The designed devices exhibit an improved solar-blind characteristic with a maximum spectral responsivity of 0.184 A/W at λ = 284 nm owing to the optimized optical properties of the dual-periodic III–nitride DBRs. Compared with their conventional counterparts, an increased multiplication gain and a reduced breakdown voltage are achieved by using p-type Al0.15Ga0.85N layers with a lower Al content and multiplication layers. These improvements are attributed to the high p-doping efficiency and large hole ionization coefficient.

The fast-electron driven beta-induced Alfven eigenmode (e-BAE) in toroidal plasmas is investigated for the first time using global gyrokinetic particle simulations, where the fast electron is described by the drift kinetic equation. The simulation shows that the e-BAE propagates in the fast electron diamagnetic direction and its polarization is close to an ideal MHD mode. The phase space structure shows that only the fast electron processional resonance is responsible for the e-BAE excitations while fast-ion driven BAE can be excited through all the channels, including transit, bounce, and processional resonance.

The onset threshold of neoclassical tearing modes with finite ion orbit width is studied. The evolution of neoclassical tearing modes including the effect of ion orbit is derived analytically. When ion orbit width is comparable to island width, the effect of ion orbit is significant. It would increase the island width needed to flatten pressure in the island, and reduce the amplitude of ion perturbed bootstrap current. It is found that ion orbit effect tends to increase the onset threshold βθonset for a given seed island. It also would increase the lowest threshold βθ,min and the corresponding marginal island width. It has important implications for the onset of neoclassical tearing modes with comparable ion orbit width and island width in International Thermonuclear Experimental Reactor.

In contrast with the stability effects of trapped energetic ions on tearing modes, the effects of circulating energetic ions (CEI) on tearing modes depend on the toroidal circulating direction, and are closely related to the momentum of energetic ions. CEI provide an additional source or sink of momentum to affect tearing modes. For co-CEI, tearing modes can be stabilized if the momentum of energetic ions is large enough. On the other hand, the growth of tearing modes can be enhanced by counter-CEI. Further, a possibility to suppress the island growth of neoclassical tearing modes by co-CEI is pointed out.