Physical design and recent experimental results of the new ICRF antenna on EAST

Two new ICRF antennas operating in the ion cyclotron radio frequency(ICRF) range have been developed for EAST to overcome the low coupling problem of the original antennas.The original ICRF antennas were limited in their power capacity due to insufficient coupling.The new antenna design takes into account both wave coupling and absorption processes through comprehensive wave coupling and absorption codes,with the dominant parallel wave number k∥of 7.5 m-1at dipole phasing.Through the use of these new ICRF antennas,we are able to achieve 3.8 MW output power and 360 s operation,respectively.The initial experimental results demonstrate the reliability of the antenna design method.

Realization of T_(e0)>10 keV long pulse operation over 100 s on EAST

In 2021,EAST realized a steady-state long pulse with a duration over 100 s and a core electron temperature over 10 keV.This is an integrated operation that resolves several key issues,including active control of wall conditioning,long-lasting fully noninductive current and divertor heat/particle flux.The fully noninductive current is driven by pure radio frequency(RF)waves with a lower hybrid current drive power of 2.5 MW and electron cyclotron resonance heating of 1.4 MW.This is an excellent experimental platform on the timescale of hundreds of seconds for studying multiscale instabilities,electron-dominant transport and particle recycling(plasma-wall interactions)under weak collisionality.

Blob properties in I-mode and ELM-free H-mode compared to L-mode on EAST

The blob properties in I-mode and ELM-free H-mode plasmas compared to L-mode have been investigated on the EAST tokamak,including the blob detection rate Nb,sizeδb,lifetimeτb and radial velocity vr,b.The blob properties in L-mode and I-mode are similar,and those in ELM-free H-mode are different to them.The blob Nbis smaller whileτbis larger in H-mode.The experimental blob sizeδband velocity scalings vr,b-δb show a good agreement with the theoretical models.The variation in blob properties during the L-I and H-L transitions,and their relations to the scrape-off layer(SOL)density,edge and SOL turbulence,and SOL collisionality are discussed.The suppression of the edge(inside the last closed flux surface)turbulence is not reflected in the blob behavior,while the blob detection rate shows a correlation with the SOL density and its low-frequency(3–50 kH z)fluctuations.In addition,the blob detection rate is found to increase with the divertor collisionalityΛdiv,indicating a dependence of blob behavior onΛdiv.The differences in blob detection rates among the three operating regimes might be due to their different SOL densities and collisionalities.The investigation contributes to understanding the influences of edge and SOL plasma parameters on the blob behavior.

Experimental study of current loss of a single-hole post-hole convolute on the QG I generator

The post-hole convolute(PHC),which is used to transport and combine the pulse power flux,is a key component in huge pulsed power generators.Current loss at the PHC is a challenging problem for researchers.To explore a method of reducing the current loss,a single-hole PHC was designed for experiments on the current loss on the Qiang Guang I generator.The experimental results showed that the current loss at the single-hole PHC is related to the distance/between the vicinity of the cathode hole and the surface of the downstream side of the post.Meanwhile,a single-hole PHC with a blob cathode hole transmitted current more effectively than the PHC with a circle cathode hole.The relative current loss at the single-hole PHC with the cathode coaled w ith gold foil was about 30%-50% of that with the cathode coated with nickel and titanium foil.The gap closing speed was also obtained from the current waveforms in the experiments.The speed was 5.74-14.52 cmμs 1 which was different from the classical plasma expansion velocity of 3 cmμs 1.

Experimental study of density pump-out on EAST

In the experimental advanced superconducting tokamak,density pump-out phenomena were observed by using a multi-channel polarimeter-interferometer system under different heating schemes of ion cyclotron resonant heating,electron cyclotron resonance heating,and neutral beam injection.The density pump-out was also induced with application of resonant magnetic perturbation,accompanied with a degradation of particle confinement.For the comparison analysis in all heating schemes,the typical plasma parameters are plasma current 400 k A,toroidal field 2 T,and line average density 2×10^19m^-3.The experimental results show that the degree of pump-out is concerned with electron density and heating power.Low density deuterium low confinement（L-mode） plasmas（〈3.5×10^19m^-3） show strong pump-out effects.The density pump-out correlated with a significant drop of particle confinement.

Design of improved compact decoupler based on adjustable capacitor for EAST-ICRF antenna

The Ion Cyclotron Radio Frequency(ICRF)heating antenna on EAST adopts a decoupling device to constrain power coupling among the radiation straps,which was discovered shortcomings such as long size,poor contact,and etc.In order to improve these weak points,a new type decoupler with terminal-loaded tunable capacitor is designed to replace the previous design.Besides the capability of the tunable admittance parameters of decoupler,the withstand voltage of the capacitor is the most significant consideration for working under high power.Therefore,the theoretical analysis carefully elaborates the capacitor withstand voltage,and the detailed analytical equations and criteria for design are given.After the comparative analysis of theoretical calculation and 3D simulation results,the decoupler design scheme is finalized.The capacitor-loaded decoupler has been successfully adopted for ICRF antenna at port N on EAST,and achieved the optimization of adjacent port isolation from-22 to-58 dB at 37 MHz without plasma to restrict mutual coupling.The new design of the decoupler has greatly improved its compactness and automatic adjustment performance,and could be good solution for the decoupling network of ICRF antennas.

Effects of H_2O_2 and NO on Flower Development and AP1 Gene Expression of Off-season Longan

[Objective] This study aimed to investigate the effects of H2O2 and NO on flower development and 4P1 gene expression of off-season longan. [Meth-od ]Nine-year-old off-season Chuliang longan was sprayed with enhancers and blockers of H2O2 and NO to analyze dynamic changes of flower development and API expression. [ Result] The expression level of API gene in off-season longan was improved during flower development. SNP and MV treatments up-regulated the expression level of API gene in leaves and terminal buds to varying degrees during lateral primordium formation. Especially, SNP treatment exhibited the most remark-able effect. DMTU treatment significantly inhibited the expression of AP1 gene in leaves and terminal buds during lateral primordium formation. L-NNA treatment slightly inhibited the expression of API gene in leaves and exerted no significant effect on expression of AP1 gene in terminal buds. [ Conclusion] It can be specu-lated that the enhancement of NO and H2O2 signals is conducive to flower development of off-season longan, while blocking H2O2 signals may inhibit flower develop-ment of off-season longan.

Nutritional Quality of Oat from Different Producing Areas in China

[Objectives]This study aimed to provide some theoretical support for breeders and processing enterprises in choosing suitable locations,in order to cultivate varieties of different functional types and complete the processing needs of different purposes.[Methods]The oat varieties that are currently being grown in large areas in different production areas were selected.In 11 provinces across China's main oat producing areas,15 pilot sites were deployed for unified planting management.After harvest,the contents of protein,crude fat,starch,β-glucan,avenanthramides(AVEs)and other components in oat kernels were determined.[Results]The protein content in oat kernels ranged from(10.68±1.35)%to(16.65±0.81)%,highest in Ningxia and lowest in Tibet;the fat content in oat kernels ranged from(5.15±1.06)%to(7.54±1.51)%,highest in Yunnan and lowest in Ningxia;the starch content in oat kernels was in the range of(60.70±1.62)%-(67.84±2.09)%,highest in Tibet and lowest in Jilin;theβ-glucan content in oat kernels ranged from(3.67±0.42)%to(4.48±0.33)%,highest in Xinjiang and lowest in Tibet;and the AVEs content in oat kernels was in the range of(58.67±20.25)%-(535.83±133.64)%.[Conclusions]The protein andβ-glucan contents in oat kernels were significantly positively correlated with latitude and longitude,and were significantly negatively correlated with altitude;the starch and fat contents in oat kernels were negatively correlated with latitude and longitude and were significantly positively correlated with altitude;theβ-glucan content in oat kernels and precipitation showed a negative correlation;and the AVEs content in oat kernels was negatively correlated with latitude and was positively correlated with longitude and precipitation.

Computing Approximation GCD of Several Polynomials by Structured Total Least Norm

The task of determining the greatest common divisors (GCD) for several polynomials which arises in image compression, computer algebra and speech encoding can be formulated as a low rank approximation problem with Sylvester matrix. This paper demonstrates a method based on structured total least norm (STLN) algorithm for matrices with Sylvester structure. We demonstrate the algorithm to compute an approximate GCD. Both the theoretical analysis and the computational results show that the method is feasible.

Interaction between the core and the edge for ion cyclotron resonance heating based on artificial absorption plasma model

In numerical simulations of the ion cyclotron range of frequencies(ICRF)wave heating scheme,core solvers usually focus on wave propagation and absorption mechanisms within the core plasma region.However,the realistic scrape-off layer(SOL)plasma is usually simplified,making it difficult to have deeper understanding of wave propagation and absorption within the SOL.In this work,we employ a cold plasma assumption and an artificial absorption mechanism based on the approach of reference(Zhang et al 2022 Nucl.Fusion 62076032),to study wave propagation and absorption in the realistic SOL plasma of the EAST.During the exponential decay of the total coupled power with respect to the toroidal mode numbers,several fluctuations are observed in the case of low collisional frequencies.The fluctuations may be caused by the cavity modes associated with specific toroidal mode numbers.Due to the presence of cut-off densities,the edge power losses and the total coupled power exhibit different behaviors before and after the cut-off layer is“open”.Furthermore,the simulation results obtained from the kinetic model in reference(Zhang et al 2022 Nucl.Fusion 62076032)is discussed.This suggests that both the core-edge combined model and the artificial mechanism are capable of simulating wave propagation and absorption.

tRNA-derived small RNAs:Mechanisms and potential roles in cancers

Transfer RNAs(tRNAs)are essential for protein synthesis.Mature or pre-tRNAs may be cleaved to produce tRNA-derived small RNAs(tsRNAs).tsRNAs,divided into tRNA-derived stress-induced RNA(tiRNAs)and tRNA-derived fragments(tRFs),play versatile roles in a number of fundamental biological processes.tsRNAs not only play regulatory roles in gene silencing,RNA stability,reverse transcription,and translation,but are also closely related to cell proliferation,migration,cell cycle,and apoptosis.Their abnormal expression is associated with the occurrence and development of various human diseases,especially cancer.This paper reviews the classification,biogenesis,and mechanism of action of tsRNAs,and the research progress to date on tsRNAs in cancers.These findings provide new opportunities for diagnostic biomarkers and treatment targets of several types of cancers including gastric cancer,colorectal cancer,hepatocellular carcinomas,pancreatic cancer,breast cancer,prostate cancer,renal cell carcinoma,ovarian cancer,lung cancer,bladder cancer,thyroid cancer,oral cancer,and leukemia.

财务数字化赋能管理会计研究—海通证券数字财务实践

以“大、智、移、云、物、区”为代表的新一代财务数字化技术正在深度影响着管理会计的走向。基于管理会计展开的企业流程重组、决策支持、组织架构重塑已成为企业财务数字化转型的重要组成部分。近年来,海通证券紧紧围绕国家“十四五”发展规划和公司集团化、国际化、信息化的发展战略,以“风险管控+业财融合+精细化管理”为目标,以“科技+数据+场景”为驱动,依靠内生动力进行系统整合,通过全面深化财务数字化技术赋能管理会计,切实推进业财融合,防范财务风险,支持经营决策,服务战略发展,促进财务转型和职能转变,全面提升管理能级。

Edge localized modes suppression via edge E × B velocity shear induced by RF sheath of ion cyclotron resonance heating in EAST

The control of large edge localized modes(ELMs) is a critical issue for the successful operation of future burning plasma devices,such as the international thermonuclear experimental reactor(ITER) and China fusion engineering test reactor(CFETR). In this paper, we present a new active and effective means of ELM suppression using ion cyclotron resonant heating(ICRH) on the experimental advanced superconducting tokamak(EAST). We obtained the key role of the external E × B velocity shear near the pedestal top and the scrape-off-layer(SOL) induced by the RF sheath potential of ICRH in ELM suppression. The experimental results showed a positive correlation between the RF sheath and the E × B shear rate in SOL. BOUT++ simulations indicate that increased E × B velocity shear rates in the pedestal and SOL regions promote ELM suppression;thereby, supporting the experimental observations on EAST. These findings suggest a new simple approach to access the ELM suppressed regimes in plasma with low torque input as ITER baseline discharges.

Aestheticization of Illness in A Dream of The Red Mansions

疾病叙事构成了《红楼梦》重要的部分,兼具审美意义和叙事功能。本文从身份、社会、情节三个方面讨论了疾病对于林黛玉和薛宝钗的不同意义。对林黛玉而言,疾病是认识社会的工具,是避风港和内心情感的宣泄。对薛宝钗而言,疾病和药是彰显社会地位的符号、一种社会资本。小说对二人疾病的刻画,反映了审美理想与伦理理想之间的张力,是儒家知识分子两难境地的写照。