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Excitation functions of the natFe (p, x) 52,54Mn, 55Co, 51Cr, 52Fe, and 46Sc reactions were measured at the proton energy of 87, 94 and 100 MeV, using the stacked foil activation technique followed by the off-line γ-ray spectrometry. The experiment was carried out on the separated sector cyclotron at the Institute of Modern Physics, Chinese Academy of Sciences. The natNi (p, x)57Ni and natAl (p, x)22Na reactions with known cross sections was used to monitor the proton beam intensity. The results from this work were compared with the existing literature data available in EXFOR data library and were found to be in good agreement. TALYS-1.95 is able to reproduce, in most cases, the experimental trend. Our experimental results were also compared with evaluated nuclear data from the ENDF/B-VIII.0, JENDL-4.0/HE, and PADF-2007 libraries as a function of proton energy, which reproduced the trend of the excitation functions of the experimental natFe (p, x) reaction cross-sections. These data expand our knowledge on the related excitation functions to confirm the existing trends and to give additional experimental values on a wider energy range.

The experimental cross-sections of the n a t Mo(p,xn) 93 m + g , 94 g , 95 m , 95 g , 96 m + g Tc, 100Mo(p,x)99Mo and 100Mo(p,2n) 99 m Tc nuclear reactions were measured up to 18.3 MeV, by the stacked-foil activation technique at the superconducting linear accelerator of the Institute of Modern Physics, Chinese Academy of Sciences. And the proton beam current was monitored by the independent n a t Cu(p,x)65Zn and n a t Ti(p,x)48V reactions. The experimental results were compared with the literature data taken from EXFOR database, evaluation data of the charged-particle cross section database and theoretical values by using TALYS-1.95 code with six level density models. The obtained results for most of the radionuclides show good agreement with the available literature data. Besides, the theoretical calculations predicted by the TALYS-1.95 code demonstrate similar trends with experimental data. Although in some cases, cross-sections results are sensitive to the nuclear level densities. Evaluated nuclear values of the charged-particle cross section database correspond well with our measurements for 96 m + g , 99 m Tc and 99Mo.

Collapse of the edge flow shear as the line-averaged density approaches the Greenwald density limit has been observed as a precursor to the enhanced edge particle flux characteristic of proximity to the density limit regime. Here, we report the use of a biased electrode to sustain the edge shear layer in high density discharges, in which the shear layer would otherwise collapse. A stable increase in line-averaged density is observed along with a strong increase in edge density. These experiments were carried out on the J-TEXT tokamak. The Reynolds stress at the edge is enhanced, and the zonal flow sustained, while density perturbation levels, the flux of turbulence internal energy (i.e., turbulence spreading), and particle and heat flux all decrease significantly. Electron adiabaticity increases, and bias voltage modulation experiments show that an increase in the edge shear leads the increase in adiabaticity. These results suggest that external edge E × B flow shear drive may be of interest for sustaining edge plasma states at high density, and support the hypothesis that collapse of the edge shear layer triggers the onset of the strong transport and turbulence characteristic of the density limit regime.

This article develops an evolutionary bat algorithm (EBA) based fuzzy neural network (NN), which is applied to the adaptive controller in a plant, for the purpose of ensuring the asymptotic stability and heightening the stability of the vehicle. With a gray signal predictor, the Lyapunov theory as well as the backstepping method are adopted to ensure the non-linearity of the controlled system and derive the evolutionary control law of the signal tracking. The discrete gray model (DGM) (2,1) is used to predict the future motion of the nonlinear system, so that the fuzzy controller can ensure the Lyapunov stability and the feasibility of the parallel distributed compensation (PDC) scheme through the Lyapunov type lemma. The controller design is demonstrated in practical nonlinear systems, for a mechanical elastic wheel (MEW), as a feasible mathematical framework for the matching of this circular object revolving on an axle.

To study the biological function of activity of bcl complex (ABC1) proteins in Lepidium apetalum Willd., genes encoding ABC1 family proteins were identified from the seed transcriptome. The sequence most closely related to germination at a low temperature was selected and gene expressions in response to low temperature stress further studied. The results show that 21 ABC1 genes were expressed in seeds germinating at the low temperature: 4 genes were upregulated, 6 were downregulated, and 11 were not significantly different from controls. The results of fluorescence quantification of the low-temperature stress on the seedlings of 7-d-old L. apetalum showed that seven genes were up-regulated, six genes were down-regulated, and eight genes had no significant difference. Real-time quantitative PCR results show that under the low temperature stress, the expression of the LaAbc1-3 gene increased, but its expression decreased after some time. The expression of this gene increased again after removing the low temperature stress. The expression of LaAbc1-21 gene in L. apetalum seedlings showed a trend of decreasing first and then increasing. The LaAbc1-3 gene was insensitive to salt stress. Expression of the LaAbc1-21 gene was significantly up-regulated during the salt stress. Under osmotic stress, the expression of the LaAbc1-3 gene was down-regulated, and the expression was negatively correlated with polyethylene glycol (PEG-6000) concentration. Under the PEG-6000 treatment, the expression of the LaAbc1-21 gene was significantly up-regulated, and the expression was positively correlated with concentration. These results provide a basis for further analysis of the role of the ABC1 genes in the stress resistance of L. apetalum.

Phytase has long been used to decrease the inorganic phosphorus (Pi) input in poultry diet. The current study was conducted to investigate the effects of Pi supplementation on laying performance, egg quality and phosphate–calcium metabolism in Hy-Line Brown laying hens fed phytase. Layers (n = 504, 29 weeks old) were randomly assigned to seven treatments with six replicates of 12 birds. The corn–soybean meal-based diet contained 0.12% non-phytate phosphorus (nPP), 3.8% calcium, 2415 IU/kg vitamin D3 and 2000 FTU/kg phytase. Inorganic phosphorus (in the form of mono-dicalcium phosphate) was added into the basal diet to construct seven experimental diets; the final dietary nPP levels were 0.12%, 0.17%, 0.22%, 0.27%, 0.32%, 0.37% and 0.42%. The feeding trial lasted 12 weeks (hens from 29 to 40 weeks of age). Laying performance (housed laying rate, egg weight, egg mass, daily feed intake and feed conversion ratio) was weekly calculated. Egg quality (egg shape index, shell strength, shell thickness, albumen height, yolk colour and Haugh units), serum parameters (calcium, phosphorus, parathyroid hormone, calcitonin and 1,25-dihydroxyvitamin D), tibia quality (breaking strength, and calcium, phosphorus and ash contents), intestinal gene expression (type IIb sodium-dependent phosphate cotransporter, NaPi-IIb) and phosphorus excretion were determined at the end of the trial. No differences were observed on laying performance, egg quality, serum parameters and tibia quality. Hens fed 0.17% nPP had increased (P < 0.01) duodenum NaPi-IIb expression compared to all other treatments. Phosphorus excretion linearly increased with an increase in dietary nPP (phosphorus excretion = 1.7916 × nPP + 0.2157; R2 = 0.9609, P = 0.001). In conclusion, corn–soybean meal-based diets containing 0.12% nPP, 3.8% calcium, 2415 IU/kg vitamin D3 and 2000 FTU/kg phytase would meet the requirements for egg production in Hy-Line Brown laying hens (29 to 40 weeks of age).

Enhanced particle transport events are discovered and analyzed as the density limit of the J-TEXT tokamak is approached. Edge shear layer collapse is observed and the ratio of Reynolds power to turbulence production decreases. Simultaneously, the divergence of turbulence internal energy flux (i.e. turbulence spreading) increases, indicating that shear layer collapse triggers an outward spreading event. Studies of correlations show that the enhanced particle transport events are quasi-coherent, and manifested primarily in density fluctuations which exhibit positive skewness. Electron adiabaticity emerges as the critical parameter which signals transport event onset. For α < 0.35 as density approaches the Greenwald density, both turbulence spreading and density fluctuations rise rapidly. Taken together, these results elucidate the connections between edge shear layer, density fluctuations, particle transport events, turbulence spreading and plasma edge cooling as the density limit is approached.

A tangential hard x-ray (HXR) diagnostic on the newly constructed ENN XuanLong-50 (EXL-50) spherical tokamak for fast electron emission studies is presented. The HXR detection system consists of a symmetrical CdZnTe semiconductor detector array with a spectral sensitivity range of 20-300 keV. 25 channels have been designed on the 270° horizontal vacuum port with 12 sight lines to observe the forward emission, 12 sight lines to observe the backward emission of fast electrons, and 1 for viewing the central. Currently, ten channels have been in operation in the EXL-50 experiments. The systems are designed to measure the x-ray spectra for the estimation of fast electron temperature and electron velocity distribution in the EXL-50 experiment, which will be useful for understanding the dynamics of fast electrons generated by electron cyclotron resonance heating, for plasma instability and transport studies and for the analysis of plasma heating efficiency.

Currently, the main maize production areas in northeastern China are facing soil fertility loss, which severely affects root growth and limits photosynthesis. It is widely acknowledged that physiological conditions of the root system are closely related to the photosynthetic capacity; therefore, we evaluated whether there are certain differences in root bleeding sap characteristics and photosynthetic capacity between the hybrids and their parents. The results showed that heterosis of the photosynthetic capacity occurred at the milk-ripe stage; however, heterosis of bleeding-sap mass (BSM) and organic biomass occurred during the whole growth period. Photosynthetic rate correlated positively with BSM and the bleeding components; a similar trend was also observed between BSM and bleeding components. These data suggested that appropriate water and fertilizer supply can improve the photosynthesis-related parameters and yield of maize.

A novel film adhesive was proposed to bond carbon fiber reinforced polymer (CFRP) laminas to steel substrates to improve comprehensive bonding performances in terms of bond strength, toughness and high-temperature behavior. This film adhesive was shown to possess excellent high-temperature resistance via dynamic mechanical analysis (DMA). CFRP-steel double-lap joints (DLJs) were experimentally studied at room and elevated temperatures, focusing on the failure modes, effective bond length, bond-slip relationship, and bond strength. The results show that the film-adhesive bonded joints failed with CFRP delamination. The bonding interface has an effective bond length of approximately 65 mm, beyond which no increase of ultimate load can be achieved with the increase of bond length. The bond-slip relationship of the film-adhesive bonding interface exhibits a trapezoidal (ductile) shape at room temperature (25℃), which transfers to bilinear or bilinear-like shapes at elevated temperatures. It is also found that the joint bond strength can retain 96% at 70℃ compared with that at 25℃. In all, bonding interfaces with superior strength, ductility, and high-temperature resistance in CFRP-steel composites are achieved by using the new film adhesive.

A hard X-ray (HXR) spectrometer has been developed to study the runaway electrons during the sawtooth activities and during the runaway current plateau phase on the J-TEXT tokamak. The spectrometer system contains four NaI scintillator detectors and a multi-channel analyzer (MCA) with 0.5 ms time resolution. The dedicated peak detection circuit embedded in the MCA provides a pulse height analysis at count rate up to 1.2 million counts per second (Mcps), which is the key to reach the high time resolution. The accuracy and reliability of the system have been verified by comparing with the hardware integrator of HXR flux. The temporal evolution of HXR flux in different energy ranges can be obtained with high time resolution by this dedicated HXR spectrometer. The response of runaway electron transport with different energy during the sawtooth activities can be studied. The energy evolution of runaway electrons during the plateau phase of runaway current can be obtained.

A waterless cleaning method of Cu foil for chemical vapor deposition (CVD) graphene growth is proposed in this work. In our method, the Cu foil is first annealed in high temperature air and then cooled rapidly, contaminated Cu surface layer was oxided in annealing and separated in the following cooling process, so as to get a clean Cu surface, the whole process does not require the participation of water and other reagents. Due to the influence of oxygen, the density of graphene domains on the waterless cleaning substrate is even lower than that on the polished substrate. Waterless cleaning provides a simple, economical and environment friendly.

Recent J-TEXT research has highlighted the significance of the role that non-axisymmetric magnetic perturbations, so called three-dimensional (3D) magnetic perturbation (MP) fields, play in a fundamentally 2D concept, i.e. tokamaks. This paper presents the J-TEXT results achieved over the last two years, especially on the impacts of 3D MP fields on magnetohydrodynamic instabilities, plasma disruptions and plasma turbulence transport. On J-TEXT, the resonant MP (RMP) system, capable of providing either a static or a high frequency (up to 8 kHz) rotating RMP field, has been upgraded by adding a new set of 12 in-vessel saddle coils. The shattered pellet injection system was built in J-TEXT in the spring of 2018. The new capabilities advance J-TEXT to be at the forefront of international magnetic fusion facilities, allowing flexible study of 3D effects and disruption mitigation in a tokamak. The fast rotating RMP field has been successfully applied for avoidance of mode locking and the prevention of plasma disruption. A new control strategy, which applies pulsed RMP to the tearing mode only during the accelerating phase region, was proved by nonlinear numerical modelling to be efficient in accelerating mode rotation and even completely suppresses the mode. Remarkably, the rotating tearing mode was completely suppressed by the electrode biasing. The impacts of 3D magnetic topology on the turbulence has been investigated on J-TEXT. It is found that the fluctuations of electron density, electron temperature and plasma potential can be significantly modulated by the island structure, and a larger fluctuation level appears at the X-point of islands. The suppression of runaway electrons during disruptions is essential to the operation of ITER, and it has been reached by utilizing the 3D magnetic perturbations on J-TEXT. This may provide an alternative mechanism of runaway suppression for large-scale tokamaks and ITER.

Using machine learning (ML) techniques to develop disruption predictors is an effective way to avoid or mitigate the disruption in a large-scale tokamak. The recent ML-based disruption predictors have made great progress regarding accuracy, but most of them have not achieved acceptable cross-machine performance. Before we develop a cross-machine predictor, it is very important to investigate the method of developing a cross-tokamak ML-based disruption prediction model. To ascertain the elements which impact the model’s performance and achieve a deep understanding of the predictor, multiple models are trained using data from two different tokamaks, J-TEXT and HL-2A, based on an implementation of the gradient-boosted decision trees algorithm called LightGBM, which can provide detailed information about the model and input features. The predictor models are not only built and tested for performance, but also analyzed from a feature importance perspective as well as for model performance variation. The relative feature importance ranking of two tokamaks is caused by differences in disruption types between different tokamaks. The result of two models with seven inputs showed that common diagnostics is very important in building a cross-machine predictor. This provided a strategy for selecting diagnostics and shots data for developing cross-machine predictors.

A tangential X-ray imaging crystal spectrometer (XICS) has been upgraded in the J-TEXT tokamak. The XICS system has been used to measure ion and electron temperature, plasma rotation velocities, selected impurity densities, and can be used for impurity transport. The XICS on J-TEXT was designed to receive Ar XVII emissions from the -0.5a to +0.5a region with a spatial resolution of 1.8 cm in the vertical direction, a is the minor radius. The temporal evolution of argon impurity density profiles after an argon gas puffed were observed with a time resolution of up to 2 ms. The behaviour of argon was investigated under different discharge conditions. The experimental results show that, as the density increased, the impurity confinement time obviously increased. Simulation results obtained by STRAHL showed that the convection velocity changed from negative to positive as the electron density increased. This indicated that impurities moved more favourably toward the plasma boundary.

This study investigated the influence of the copper substrate surface fluctuations on the transfer of graphene fabricated via chemical vapor deposition. Typical fluctuations, such as reconstructed stripes, grain boundaries, and mechanical creases on Cu surface were explored. The upper graphene which have consistent morphology with the fluctuations were not incompletely copied into the target but by rearrangement after the transfer process. Moreover, some fluctuations may induce damage or glue residual formation in the transfer process.

This work demonstrates the feasibility of nitric oxide removal by using the synergy of nitrifying and aerobic denitrifying microorganisms in a thermophilic membrane biofilm reactor (TMBfR) at 60 °C. In 200 days of operation, the TMBfR system achieved a NO removal efficiency of 96.4%, and the maximum elimination capacity was 207.8 g-NO·m − 3 ·h − 1 , respectively, which was higher than that of mesophilic membrane biofilm reactor (MBfR). Sulfur dioxide and gaseous elemental mercury (Hg 0 ) inhibited NO biological process, while TMBfR with nitrifying and denitrifying bacteria were able to remove 85.5% of mercury vapor. NO removal efficiency in the TMBfR at 60 °C was higher up from 8.5 to 10.8% than that in the mesophilic MBfR. No nitrite accumulation was observed. Bacterial communities in the TMBfR played the dominant role in the biological processes of metabolism, nitrification, and denitrification. TMBfR had more denitrification than mesophilic MBfR. Alcaligenes sp. and Nitrospira sp. turn NO into NO 3 − thought nitrification, and then Pseudomonas sp. reduced NO 3 − to N 2 thought denitrification. Lysobacter sp. and Alcaligenes sp. contributed to the biological nitrogen fixation process. These results show that the thermophilic membrane biofilm reactor is achievable and open new possibilities for applying the TMBfR to flue gas denitration.

Author(s): Zhao, KJ; Chen, ZP; Shi, Y; Diamond, PH; Dong, JQ; Chen, ZY; Ding, YH; Zhuang, G; Liu, YB; Zhang, HQ; Chen, YQ; Liu, H; Cheng, J; Nie, L; Rao, B; Cheng, ZF; Gao, L; Zhang, XQ; Yang, ZJ; Wang, NC; Wang, L; Li, JQ; Jin, W; Xu, JQ; Yan, LW; Liang, YF; Xie, YY; Liu, B | Abstract: Enhancements of residual Reynolds stresses and symmetry breaking with resonant magnetic perturbations (RMPs) are presented. These experiments were performed using a Langmuir probe array in the edge plasmas of the J-TEXT tokamak. This study aims to explain the mechanisms for generating residual stresses and intrinsic rotations. It is observed that with RMPs, peaked residual stresses, steeper pressure gradients and stronger shear layers all appear around the resonant surface. The toroidal rotation is accelerated in the direction of the plasma current and shows a correlation with turbulence and the measured residual stresses near the resonant surfaces of RMPs. Symmetry breaking induced by magnetic islands is proposed as a new mechanism, which qualitatively explains the enhanced residual stresses and the acceleration of the toroidal rotation. The changes to the residual stresses and symmetry breaking with RMPs near the last closed surface are also discussed.

A fast frame camera diagnostics has been developed to study the penetration of impurities gas jet on J-TEXT. The fast frame camera has 22 k frame rate with 640 × 480 pixel resolutions. The penetration processes of gas jet have been studied by the fast frame camera with optical filters. It is found that the gas jet propagated from the bottom to the high field side along the magnetic surface before the disruption. The cold front induced by the gas jet propagated into the plasma interior in the order of 200 m/s. The cold front was stopped at the location near the q = 2 surface.

The integrated microwave with Mn/γ-Al2O3 and ozone was employed to oxidize elemental mercury (Hg0) in simulated flue gas. Hg0 oxidation efficiency in the integrated system attained 92.2%. Mn/γ-Al2O3 catalyst was characterized by XRD, XPS, FT-IR, SEM. XPS spectra indicate the formation of a stable mercuric oxide species (HgO) from mercury oxidation. Ozone molecules in air could enhance free radical formation. Hg0 was oxidized to HgO in the presence of ozone and free radical. The coupling role between ozone and radical on mercury oxidation was formed. Microwave catalytic oxidation of elemental mercury reaction with the Mn/γ-Al2O3 catalyst follows Langmuir–Hinshelwood kinetics.

A high spectra resolution X-ray imaging crystal spectrometer has been implemented on J-TEXT Tokamak for the measurements of Kα spectra of helium-like argon and its satellite lines. The wavelength range of Kα spectra of helium-like argon is from 3.9494 A to 3.9944 A that includes the resonance line w, intercombination lines x and y, forbidden line z and numerous satellite lines, referenced using standard Gabriel notation. In low-density discharge, the intensity of q, r satellite lines and z lines can be significantly enhanced by non-thermal electrons. Non-thermal electrons are produced due to the low plasma density. The high hard X-ray flux from NaI detector and significant downshift electron cyclotron emissions from energetic runaway electrons also indicated that there is a large population of runaway electrons in the low-density discharge. The non-thermal part of electrons can affect the excitation/transition equilibrium or ionization/recombination equilibrium. The q line is mainly produced by inner-shell excitation of lithium-like argon, and the r line is partially produced by inner-shell excitation of lithium-like argon and dielectronic recombination of helium-like argon.

Chloroplatinic acid (H 2 PtCl 6 ·6H 2 O) was used to modify the grain boundaries of graphene films grown by chemical vapor deposition. Modification occurred only on the edge of the graphene layer in contact with Cu substrate. The grain boundaries of the continuous graphene films were directly observed after modification by optical microscopy and scanning electron microscopy. Energy-dispersive spectroscopy was also used to prove that only Pt nano-particles were modified on the grain boundaries. After chloroplatinic acid modification, the electrical properties of the graphene continuous films were optimized by Hall testing.

We present here a detailed study of the oxidation resistance of chemical vapor deposition (CVD) graphene. The results reveal that CVD graphene shows an excellent performance as a passivation layer below 200 °C, but the protection ability degenerates rapidly with increasing the air temperature. Our work demonstrates for the first time that the most adverse effect on the degeneration of oxidation resistance in high temperature air comes from wrinkles but not others, such as Cu grain boundaries, periodic surface depressions due to Cu surface reconstruction induced by the graphene overlay, graphene domain boundaries, which are always believed the primary factor for inferior quality of the CVD graphene at present. In addition, we found that the distribution of the wrinkles in CVD graphene depended on the Cu crystal structure, and the results of the Electron-backscatter diffraction indicate that the folded wrinkles always appear on Cu (0 0 1) facets, while the standing collapsed wrinkles appear more easily on the Cu (1 1 1) facets.