Characteristics of the SOL ion-to-electron temperature ratio on the J-TEXT tokamak with different plasma configurations

Accurate measurement of the average plasma parameters in the edge region,including the temperature and density of electrons and ions,is critical for understanding the characteristics of the scrape-off layer(SOL) and divertor plasma transport in magnetically confined fusion research.On the J-TEXT tokamak,a multi-channel retarding field analyzer(RFA) probe has been developed to study average plasma parameters in the edge region under various poloidal divertor and island divertor configurations.The edge radial profile of the ion-to-electron temperature ratio,τ_(i/e),has been determined,which gradually decreases as the SOL ion self-collisionality,v_(SOL)*,increases.This is broadly consistent with what has been observed previously from various tokamak experiments.However,the comparison of experimental results under different configurations shows that in the poloidal divertor configuration,even under the same v_(SOL)*,τ_(i/e) in the SOL region becomes smaller as the distance from the X-point to the target plate increases.In the island divertor configuration,τ_(i/e) near the O-point is higher than that near the X-point at the same v_(SOL)*,and both are higher than those in the limiter configuration.These results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.

Surface Patterning of Metal Zinc Electrode with an In‑Region Zincophilic Interface for High‑Rate and Long‑Cycle‑Life Zinc Metal Anode

The undesirable dendrite growth induced by non-planar zinc(Zn)deposition and low Coulombic efficiency resulting from severe side reactions have been long-standing challenges for metallic Zn anodes and substantially impede the practical application of rechargeable aqueous Zn metal batteries(ZMBs).Herein,we present a strategy for achieving a high-rate and long-cycle-life Zn metal anode by patterning Zn foil surfaces and endowing a Zn-Indium(Zn-In)interface in the microchannels.The accumulation of electrons in the microchannel and the zincophilicity of the Zn-In interface promote preferential heteroepitaxial Zn deposition in the microchannel region and enhance the tolerance of the electrode at high current densities.Meanwhile,electron aggregation accelerates the dissolution of non-(002)plane Zn atoms on the array surface,thereby directing the subsequent homoepitaxial Zn deposition on the array surface.Consequently,the planar dendrite-free Zn deposition and long-term cycling stability are achieved(5,050 h at 10.0 mA cm^(−2) and 27,000 cycles at 20.0 mA cm^(−2)).Furthermore,a Zn/I_(2) full cell assembled by pairing with such an anode can maintain good stability for 3,500 cycles at 5.0 C,demonstrating the application potential of the as-prepared ZnIn anode for high-performance aqueous ZMBs.

Production of the X(4014)as the Spin-2 Partner of X(3872)in e^(+)e^(-)Collisions

In 2021,the Belle collaboration reported the first observation of a new structure in theψ(2S)γfinal state produced in the two-photon fusion process.In the hadronic molecule picture,this new structure can be associatedwith the shallow isoscalar D*D* bound state and as such is an excellent candidate for the spin-2 partner of the X(3872)with the quantum numbers J^(PC)=2^(++)conventionally named X_(2).

Layered barium vanadate nanobelts for high-performance aqueous zinc-ion batteries

Aqueous zinc-ion batteries(ZIBs)are deemed as the idea option for large-scale energy storage systems owing to many alluring merits including low manufacture cost,environmental friendliness,and high operations safety.However,to develop high-performance cathode is still significant for practical application of ZIBs.Herein,Ba_(0.23)V_(2)O_(5)·1.1H_(2)O(BaVO)nanobelts were fabricated as cathode materials of ZIBs by a typical hydrothermal synthesis method.Benefiting from the increased interlayer distance of 1.31 nm by Ba2+ and H2O pre-intercalated,the obtained BaVO nanobelts showed an excellent initial discharge capacity of 378 mAh·g^(-1) at 0.1 A·g^(-1),a great rate performance(e.g.,172 mAh·g^(-1) at 5 A·g^(-1)),and a superior capacity retention(93% after 2000 cycles at 5 A·g^(-1)).

Overview of wall probes for erosion and deposition studies in the TEXTOR tokamak

An overview of diagnostic tools e test limiters and collector probes e used over the years for material migration studies in the TEXTOR tokamak is presented.Probe transfer systems are shown and their technical capabilities are described.This is accompanied by a brief pre-sentation of selected results and conclusions from the research on material erosion e deposition processes including tests of candidate materials(e.g.W,Mo,carbon-based composites)for plasma-facing components in controlled fusion devices.The use of tracer techniques and methods for analysis of materials retrieved from the tokamak are summarized.The impact of research on the reactor wall technology is addressed.

Study of Striated Heat Flux on EAST Divertor Plates Induced by LHW Using Infrared Camera

An upgraded infrared （IR） imaging system which provides a wide field of view （FOV） has been installed on the Experimental Advanced Superconducting Tokamak （EAST） to monitor the surface temperatures on plasma facing components. Modified magnetic topology induced by lower hybrid wave （LHW） can lead to the formation of striated heat flux （SHF} on divertor plates which can be clearly observed by IR camera. In this paper, LHW power modulation is applied to analyze the appearance of SHF. It is also demonstrated that deuterium （D） pellet injection and supersonic molecular beam injection （SMBI） can to some extent reduce the heat flux on the outer strike point （OSP）, but enhance the SHF on lower outer plates （LOP） of divertor. This may provide an optional approach to actively control the distribution of heat flux on diveror plates, which can protect materials from long duration high-heat flux.

Overview of the J-TEXT progress on RMP and disruption physics

The J-TEXT tokamak has been operated for ten years since its first plasma obtained at the end of 2007. The diagnostics development and main modulation systems, i.e. resonant magnetic perturbation （RMP） systems and massive gas injection （MGI） systems, will be introduced in this paper. Supported by these efforts, J-TEXT has contributed to research on several topics, especially on RMP physics and disruption mitigation. Both experimental and theoretical research show that RMP could lock, suppress or excite the tearing modes, depending on the RMP amplitude, frequency difference between RMP and rational surface rotation, and initial stabilities. The plasma rotation, particle transport and operation region are influenced by the RMP. Utilizing the MGI valves, disruptions have been mitigated with pure He, pure Ne, and a mixture of He and Ar （9：1）. A significant runaway current plateau could be generated with moderate amounts of Ar injection. The RMP has been shown to suppress the generation of runaway current during disruptions.

Challenges for plasma-facing components in nuclear fusion

The interaction processes between the burning plasma and the first wall in a fusion reactor are diverse:the first wall will be exposed to extreme thermal loads of up to several tens of megawatts per square meter during quasistationary operation,combined with repeated intense thermal shocks(with energy densities of up to several megajoules per square meter and pulse durations on a millisecond time scale).In addition to these thermal loads,the wall will be subjected to bombardment by plasma ions and neutral particles(D,T,and He)and by energetic neutrons with energies up to 14 MeV.Hopefully,ITER will not only demonstrate that thermonuclear fusion of deuterium and tritiumis feasible inmagnetic confinement regimes;it will also act as a first test device for plasma-facingmaterials(PFMs)and plasma-facing components(PFCs)under realistic synergistic loading scenarios that cover all the above-mentioned load types.In the absence of an integrated test device,material tests are being performed primarily in specialized facilities that concentrate only on the most essential material properties.New multipurpose test facilities are now available that can also focus on more complex loading scenarios and thus help to minimize the risk of an unexpected material or component failure.Thermonuclear fusion-both with magnetic and with inertial confinement-is making great progress,and the goal of scientific break-even will be reached soon.However,to achieve that end,significant technical problems,particularly in the field of high-temperature and radiation-resistant materials,must be solved.With ITER,the first nuclear reactor that burns a deuterium–tritium plasma with a fusion power gain Q≥10 will start operation in the next decade.To guarantee safe operation of this rather sophisticated fusion device,new PFMs and PFCs that are qualified to withstand the harsh environments in such a tokamak reactor have been developed and are now entering the manufacturing stage.

Quantitative HRTEM and its application in the study of oxide materials

On the basis of a state-of-the-art aberration-corrected transmission electron microscope, the spherical aberration coefficient CSof the objective lens can be tuned to either a positive or a negative value. The use of a negative value of CS combined with an overfocus setting of the objective lens leads to the development of the negative CSimaging（NCSI） technique. Images obtained using the NCSI technique show superior contrast and signal intensity at atomic column positions than the corresponding positive CSimages, especially for weakly scattering oxygen columns that are in close proximity to strongly scattering cation columns in oxides. Based on the images obtained under the NCSI condition, quantification of the image contrast allows measurements of the atom positions with a precision of a few picometers and the local chemistry on atomic scale. In the present review, we discuss firstly the benefits of the NCSI technique in studies of oxide materials,and then show a procedure for quantitative analysis of the image based on the absolute value of contrast. In the last part,examples are given for the application of the quantitative high-resolution transmission electron microscopy（HRTEM） to the study of electric dipoles of oxide ferroelectrics and atomic-scale chemistry of interfaces.

热障涂层用高熔点多元钙钛矿的大气等离子喷涂

高熔点材料作为热障涂层材料,已成为备受关注的发展趋势。在高熔点材料中,人们开发了由Ba(Mg1/3Ta2/3)O3和La(Al1/4Mg1/2T1/4)O3组成的多元钙钛矿合成物,并采用大气等离子喷涂方法将其沉积在热障涂层体系中。本文对喷涂参数进行了优化,并记录了飞行粒子温度。对涂层的相组成、稳定性、形貌和孔隙率进行了检测,同时对热障涂层体系在高温的热循环寿命进行了研究。研究表明,起始物料的性能在大气等离子体喷涂中具有决定性的作用,并最终影响热障涂层的寿命。由粒子分析而得到的过程图表明了适宜的喷涂条件,这一喷涂条件可在钙钛矿的等离子喷涂过程中尽可能避免第二相的产生。

Probe manipulators for Wendelstein 7-X and their interaction with the magnetic topology

Probe manipulators are a versatile addition to typical plasma edge diagnostics.Equipped with material samples they allow for detailed investigation of plasma–wall interaction processes,such as material erosion,deposition or impurity transport pathways.When combined with electrical probes,a study of scrape-off layer and plasma edge density,temperature and flow profiles as well as magnetic topologies is possible.A mid-plane manipulator is already in operation on Wendelstein 7-X.A system in the divertor region is currently under development.In the present paper we discuss the critical issue of heat and power loads,power redistribution and experimental access to the complex magnetic topology of Wendelstein 7-X.All the aforementioned aspects are of relevance for the design and operation of a probe manipulator in a device like Wendelstein？7-X.A focus is put on the topological region that is accessible for the different coil current configurations at Wendelstein 7-X and the power load on the manipulator with respect to the resulting different magnetic configurations.Qualitative analysis of power loads on plasma-facing components is performed using a numerical tracer particle diffusion tool provided via the Wendelstein 7-X Webservices.

Equivalent Trap Energy Level Extraction for SiGe Using Gate-Induced-Drain-Leakage Current Analysis

MOSFET 的 gate-induced-drain-leakage 被分析更好理解 SiGe 隧道地效果晶体管和他们的 band-to-band 通道机制的次于最低限度的秋千降级。分析的数字模型被详细描述。相等的陷井精力层次为 Si 被提取并且拉紧 SiGe。在 SiGe 的相等的陷井精力水平在 Si 是比那浅的，这被发现。

Physical properties and magnetic structure of a layered antiferromagnet PrPd0.82Bi2

We report the physical properties, crystalline and magnetic structures of singe crystals of a new layered antiferromagnetic(AFM) material PrPd0.82Bi2. The measurements of magnetic properties and heat capacity indicate an AFM phase transition at TN^7K. A large Sommerfeld coefficient of 329.23 m J·mol-1·K-2 is estimated based on the heat capacity data, implying a possible heavy-fermion behavior. The magnetic structure of this compound is investigated by a combined study of neutron powder and single-crystal diffraction. It is found that an A-type AFM structure with magnetic propagation wavevector k =(0 0 0) is formed below TN. The Pr3+ magnetic moment is aligned along the crystallographic c-axis with an ordered moment of 1.694(3) μBat 4K, which is smaller than the effective moment of the free Pr3+ ion of 3.58 μB.PrPd0.82Bi2 can be grown as large as 1 mm×1 cm in area with a layered shape, and is very easy to be cleaved, providing a unique opportunity to study the interplay between magnetism, possible heavy fermions, and superconductivity.

Influence of the X-point location on edge plasma transport in the J-TEXT tokamak with a high-field-side single-null divertor

High-density experiments in the high-field-side mid-plane single-null divertor configuration have been performed for the first time on J-TEXT.The experiments show an increase in the highest central channel line-averaged density from 2.73×10^(19)m^(-3) to 6.49×10^(19)m^(-3),while the X-point moves away from the target by increasing the divertor coil current.The corresponding Greenwald fraction rises from 0.50 to 0.79.For the impurity transport,the density normalized radiation intensity(absolute extreme ultraviolet and soft x-ray)of the central channel density decreased significantly(>50%)with an increase in the plasma density.To better understand the underlying physics mechanisms,the 3 D edge Monte Carlo code coupled with EIRENE(EMC3-EIRENE)has been implemented for the first time on J-TEXT.The simulation results show good agreement with the experimental findings.As the X-point moves away from the target,the divertor power decay length drops and the scrape-off layer impurity screening effect is enhanced.

Effect of edge magnetic island on carbon screening in the J-TEXT tokamak

The effect of externally applied resonant magnetic perturbation(RMP)on carbon impurity behavior is investigated in the J-TEXT tokamak.It is found that the m/n=3/1 islands have an impurity screening effect,which becomes obvious while the edge magnetic island is generated via RMP field penetration.The impurity screening effect shows a dependence on the RMP phase with the field penetration,which is strongest if the O point of the magnetic island is near the low-field-side(LFS)limiter plate.By combining a methane injection experimental study and STRAHL impurity transport analysis,we found that the variation of the impurity transport dominates the impurity screening effect.The impurity diffusion at the inner plasma region(r/a<0.8)is enhanced with a significant increase in outward convection velocity at the edge region in the case of the magnetic island’s O point near the LFS limiter plate.The impurity transport coefficient varies by a much lower level for the case with the magnetic island’s X point near the LFS limiter plate.The interaction of the magnetic island and the LFS limiter plate is thought to contribute to the impurity transport variation with the dependence on the RMP phase.A possible reason is the interaction between the magnetic island and the LFS limiter.

Experimental I-V and C-V Analysis of Schottky-Barrier Metal-Oxide-Semiconductor Field Effect Transistors with Epitaxial NiSi2 Contacts and Dopant Segregation

We present an experimental analysis of Schottky-barrier metal-oxide-semiconductor field effect transistors （SB- MOSFETs） fabricated on ultrathin body silicon-on-insulator substrates with a steep junction by the dopant implantation into the silicide process. The subthreshold swing of such SB-MOSFETs reaches 69mV/dec. Em- phasis is placed on the capacitance-voltage analysis of p-type SB-MOSFETs. According to the measurements of gate-to-source capacitance Cgs with respect to Vgs at various Vds, we find that a maximum occurs at the accumulation regime due to the most imbalanced charge distribution along the channel. At each Cgs peak, the difference between Vgs and Vds is equal to the Schottky barrier height （SBH） for NiSi2 on highly doped silicon, which indicates that the critical condition of channel pinching off is related with SBH for source/drain on chan- nel. The SBH for NiSi2 on highly doped silicon can affect the pinch-off voltage and the saturation current of SB-MOSFETs.

Mobility Enhancement and Gate-Induced-Drain-Leakage Analysis of Strained-SiGe Channel p-MOSFETs with Higher-k LaLuO3 Gate Dielectric

A strained-SiGe p-channel metal-oxide-semiconductor-field-effect transistors （p-MOSFETS） with higher-k LaLu03 gate dielectric was fabricated and electrically characterized. The novel higher-k （k-30） gate dielectric, LaLuO3, was deposited by molecular-beam deposition and shows good quality for integration into the transistor. The transistor features good output and transfer characteristics. The hole mobility was extracted by the splitting C-V method and a value of 2OOcm2/V.s was obtained for strong inversion conditions, which indicates that the hole mobility is well enhanced by SiGe channel and that the LaLuO3 layer does not induce additional significant carrier scattering. Gate induced drain leakage is measured and analyzed by using an analytical model. Band-to- band tunneling et^ciencies under high and low fields are found to be different, and the tunneling mechanism is discussed.

儿童阻塞性睡眠呼吸暂停综合征对认知和脑功能影响的研究进展

阻塞性睡眠呼吸暂停综合征(obstructive sleep apnea syndrome, OSAS)作为儿童睡眠障碍中最为常见的疾病之一,其特点是睡眠期间反复出现上气道阻塞,导致间歇性缺氧和睡眠碎片化。患儿如果得不到及时诊断和有效干预会影响脑发育,进而导致认知功能障碍。近年来,磁共振成像、脑电图等技术被广泛应用于探讨OSAS患儿脑结构和功能的异常。总结已有研究发现,OSAS患儿大脑灰质和白质皮层均出现广泛性的受损,额叶和海马等主要脑区功能存在异常,同时一般认知功能和执行功能等显著降低。然而目前对于OSAS影响儿童脑结构和功能的研究仍局限于对大脑局部区域特性的考察,缺乏对整体脑网络机制的关注。此外,OSAS患儿大脑结构和功能的损伤与其认知功能障碍的对应关系尚不清楚。基于此,未来的研究一方面可以借助多模态神经成像技术深入揭示儿童OSAS的脑网络整体变化情况;另一方面可探究脑网络特征与认知功能障碍的关联,从而阐明儿童OSAS的脑网络核心表征指标。这些工作将为儿童OSAS的脑发育监测、临床筛查提供神经影像学依据,有望发展基于脑网络的干预和诊疗措施。

Low soil C:N ratio results in accumulation and leaching of nitrite and nitrate in agricultural soils under heavy rainfall

Nitrate (NO-3) and nitrite (NO2-) leaching threatens groundwater quality.Soil C:N ratio,i.e.,the ratio of soil organic carbon to total nitrogen,affects mineralization,nitrification,and denitrification;however,its mechanism for driving soil NO-3and NO-2accumulation and leaching remains unclear.Here,a field investigation in a fluvo-aquic soil and a soil column experiment were performed to explore the relationships between soil C:N ratio and soil NO-3and NO-2leaching in three soil layers (0–20,20–40,and 40–60 cm) under heavy rainfall (rainfall rate>25 mm d-1).The field investigation results showed that both soil NO-3-N and NO-2-N contents decreased exponentially (P<0.001) with increasing soil C:N ratio in each soil layer.Furthermore,negative exponential relationships (P<0.001) were found between soil C:N ratio and both NO-3-N and NO-2-N concentrations in soil solution in each soil layer under heavy rainfall.The soil column divided into three layers was leached with simulated heavy rainfall;the results confirmed negative exponential relationships (P<0.05) between soil C:N ratio and both NO-3-N and NO-2-N concentrations in the leachate from each soil layer.A total of 18 soil samples obtained from three depths at six field sites during the rainy season were used to elucidate the microbial mechanisms induced by soil C:N ratio using high-throughput sequencing and real-time polymerase chain reaction.High abundances of ammonifying bacteria (Flavobacterium,Bacillu,and Pseudomonas),ammonia-oxidizing bacteria (Nitrosospira),and nirS/K gene were observed when soil C:N was low,concomitant with low abundances of NO-2-oxidizing bacteria (Nitrospira) and narG gene.Partial least squares path modeling showed that the high NO-3and NO-2levels at low soil C:N ratio might be attributed to the inhibition of NO-3reduction (i.e.,low narG gene) and NO-2oxidation (i.e.,low Nitrospira) and thus the accumulation of soil NO-3and NO-2,respectively.Therefore,the leaching of NO-2and NO-3in low C:N soils requires more attention during the rainy season.

Lattice Boltzmann Simulations of Two Linear Microswimmers Using the Immersed Boundary Method

The performance of a single or the collection of microswimmers strongly depends on the hydrodynamic coupling among their constituents and themselves.We present a numerical study for a single and a pair of microswimmers based on lattice Boltzmann method(LBM)simulations.Our numerical algorithm consists of two separable parts.Lagrange polynomials provide a discretization of the microswimmers and the lattice Boltzmann method captures the dynamics of the surrounding fluid.The two components couple via an immersed boundary method.We present data for a single swimmer system and our data also show the onset of collective effects and,in particular,an overall velocity increment of clusters of swimmers.