Design and platform testing of the compact torus central fueling device for the EAST tokamak

Compact torus(CT)injection is a highly promising technique for the central fueling of future reactor-grade fusion devices since it features extremely high injection velocity and relatively high plasma mass.Recently,a CT injector for the EAST tokamak,EAST-CTI,was developed and platform-tested.In the first round of experiments conducted with low parameter settings,the maximum velocity and mass of the CT plasma were 150 km·s^(-1)and 90μg,respectively.However,the parameters obtained by EAST-CTI were still very low and were far from the requirements of a device such as EAST that has a strong magnetic field.In future,we plan to solve the spark problem that EAST-CTI currently encounters(that mainly hinders the further development of experiments)through engineering methods,and use greater power to obtain a more stable and suitable CT plasma for EAST.

MXene Lubricated Tribovoltaic Nanogenerator with High Current Output and Long Lifetime

Tribovoltaic nanogenerators(TVNGs)have the characteristics of high current density,low matched impedance and continuous output,which is expected to solve the problem of power supply for small electronic devices.However,wear occurrence in friction interface will seriously reduce the performance of TVNGs as well as lifetime.Here,we employ MXene solution as lubricate to improve output current density and lifetime of TVNG simultaneously,where a high value of 754 mA m^(-2)accompanied with a record durability of 90,000 cycles were achieved.By comparing multiple liquid lubricates with different polarity,we show that conductive polar liquid with MXene as additive plays a crucial role in enhancing the electrical output performance and durability of TVNG.Moreover,the universality of MXene solution is well demonstrated in various TVNGs with Cu and P-type Si,and Cu and N-GaAs as material pairs.This work may guide and accelerates the practical application of TVNG in future.

Association between the Lung Immune Prognostic Index and mortality in patients with idiopathic inflammatory myopathy-associated interstitial lung disease

Objective:To explore the association between the Lung Immune Prognostic Index(LIPI)and 1-year all-cause mortality in patients with idiopathic inflammatory myopathy related interstitial lung disease(IIM-ILD).Methods:Patients who were diagnosed with IIM-ILD at West China Hospital,Sichuan University from January 2008 to December 2021 were retrospectively included and categorized into three groups based on LIPI.Univariable and multivariable Cox proportional hazards models were conducted to explore potential association between the LIPI and patients'mortality.Results:A total of 1116 patients were screened,and 830 were included in this study.The multivariable Cox analysis showed that,compared with patients with poor LIPI,the hazard ratio(HR)for all-cause 1-year mortality was 0.22(95%CI 0.05-0.93,P=0.04)for patients in the good LIPI group(LDH<250 IU/L and dNLR<3).After excluding patients lost to follow-up within one year,a similar result was found for LIPI(HR 0.20,95%CI 0.05-0.86;P=0.03).Conclusions:Good LIPI was independently associated with decreased risk of all-cause 1-year mortality in patients with IIM-ILD.This easy-to-obtain index might be served as a potential marker for assessing the prognosis of IIM-ILD.

Effect of low-frequency electromagnetic field on the as-cast microstructure of a new super high strength aluminum alloy by horizontal continuous casting

The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-cast microstructure was studied. Results show that microstructure of the sample prepared by the LFEHC process was greatly refined. Microstructures at the border and the center of the ingots were fine, uniform and rosette-shaped. Electromagnetic frequency plays a key role in microstructure refining. Fine and uniform microstructures can be obtained with optimal electromagnetic frequency. In this experiment, under a frequency of 30 Hz the microstructure was the finest and the most uniform.

Investigation of the compact torus plasma motion in the KTX-CTI device based on circuit analyses

Compact torus(CT)injection is one of the most promising methods for the central fuelling of next-generation reactor-grade fusion devices due to its high density,high velocity,and selfcontained magnetised structure.A newly compact torus injector(CTI)device in Keda Torus e Xperiment(KTX),named KTX-CTI,was successfully developed and tested at the University of Science and Technology in China.In this study,first,we briefly introduce the basic principles and structure of KTX-CTI,and then,present an accurate circuit model that relies on nonlinear regression analysis(NRA)for studying the current waveform of the formation region.The current waveform,displacement,and velocity of CT plasma in the acceleration region are calculated using this NRA-based one-dimensional point model.The model results were in good agreement with the experiments.The next-step upgrading reference scheme of the KTX-CTI device is preliminarily investigated using this NRA-based point model.This research can provide insights for the development of experiments and future upgrades of the device.

Optogenetic activation of intracellular signaling based on light-inducible protein-protein homo-interactions

Dynamic protein-protein interactions are essential for proper cell functioning.Homointeraction events—physical interactions between the same type of proteins—represent a pivotal subset of protein-protein interactions that are widely exploited in activating intracellular signaling pathways.Capacities of modulating protein-protein interactions with spatial and temporal resolution are greatly desired to decipher the dynamic nature of signal transduction mechanisms.The emerging optogenetic technology,based on genetically encoded light-sensitive proteins,provides promising opportunities to dissect the highly complex signaling networks with unmatched specificity and spatiotemporal precision.Here we review recent achievements in the development of optogenetic tools enabling light-inducible protein-protein homo-interactions and their applications in optical activation of signaling pathways.

Effects of low-frequency magnetic field on grain boundary segregation in horizontal direct chill casting of 2024 aluminum alloy

Effects of low frequency electromagnetic field on grain boundary segregation in horizontal direct chill (HDC) casting process was investigated experimentally. The grain boundary segregation and microstructures of the ingots, which manufactured by conventional HDC casting and low frequency electromagnetic HDC casting were compared. Results show that low frequency electromagnetic field significantly refines the microstructures and reduces grain boundary segregation. Decreasing electromagnetic frequency or increasing electromagnetic intensity has great effects in reducing grain boundary segregation. Meanwhile, the governing mechanisms were discussed.

Temperature field in the hot-top during casting a new super-high strength Al-Zn-Mg-Cu alloy by low frequency electromagnetic process

The billets of a new super-high strength Al-Zn-Mg-Cu alloy in 200mm diameter were produced by the processesof low frequency electromagnetic casting (LFEC) and conventional direct chill (DC) casting, respectively. The effects of lowfrequency electromagnetic field on temperature field of the melt in the hot-top were investigated by temperaturemeasurement method. Temperature curves were measured from the surface to the center of the billets by locating type Kthermocouples into the casting during the processes. The results show that during LFEC process the temperature field inthe melt applying the hot-top is very uniform, which is helpful to reduce the difference of thermal gradients between thesurface and the center, and then to reduce the thermal stress and to eliminate casting crack.

Sc和Si微合金化提高Al-Cu-Li合金的耐热性

第三代铝锂合金(Al-Cu-Li合金)在航空航天领域应用广泛,但服役温度一般低于100℃.本研究中,我们提出了一种提高Al-Cu-Li合金在200-300℃下耐热性的新思路,即通过添加微量的Sc和Si元素,当T1相在热暴露过程中溶解后,促进θ′相的形核析出.在200-300℃的热暴露过程中,Sc和Si微合金化的Al-Cu-Li合金中有大量的纳米θ′相析出,并具有高的热稳定性,相反,无微合金化的Al-Cu-Li合金中的θ′相则迅速粗化.Sc和Si微合金化的Al-Cu-Li合金在300℃下的抗拉强度为155 MPa,延伸率为9.2%.因此,Sc和Si微合金化的Al-Cu-Li合金在200-300℃下的耐热性显著提高,与商用耐热铝合金2618和2219相比,具有更优异的高温强度和比强度.

Ultrahigh electrostrain with excellent fatigue resistance in textured Nb^(5+)-doped(Bi_(0.5)Na_(0.5))TiO3-based piezoceramics

(Bi_(0.5)Na_(0.5))TiO_(3)(BNT)-based lead-free piezoceramics exhibit excellent electric field-induced strain(electrostrain)properties,but often suffer from large hysteresis and poor fatigue resistance,which strongly limit their applications.Here,<00l>textured Nb5+-doped 0.8(Bi_(0.5)Na_(0.5))TiO_(3)–0.2(Bi_(0.5)K_(0.5))TiO_(3)(0.8BNT–0.2BKT)ceramics with a high degree of texturing(~80%)were prepared by the reactive template grain growth(RTGG)method using Bi4Ti3O12 as a template.By the combination of donor doping in the B-site and the RTGG method,the electrostrain performance achieves a significant enhancement.A high electrostrain of 0.65%and a piezoelectric coefficient(*33 d)of 1083 pm/V with reduced hysteresis at an electric field of 6 kV/mm are obtained.No electrostrain performance degradation is observed after unipolar electric field loading of 10^(5)cycles,showing excellent fatigue endurance.These results indicate that the texturing BNT-based lead-free piezoceramics by the RTGG method is a useful approach to developing eco-friendly actuators.

Location layout design of aircraft parts assembly based on MSVR

Location layout of aircraft assembly is an important factor affecting product quality.Most of the existing re-searches use the combination of finite element analysis and intelligent algorithm to optimize the location layout,which are limited by numerical simulation accuracy and the selection and improvement of intelligent algorithms.At present,the analysis and decision-making technology based on field data is gradually applied in aircraft manufacturing.Based on the perception data of intelligent assembly unit of aircraft parts,a regression model of multi-input and multioutput support vector machine with Gauss kernel function as radial basis function is established,and the hyperparameters of the model are optimized by hybrid particle swarm optimization genetic algorithm(PSO-GA).GA-MSVR,PSO-MSVR and PSOGA-MSVR model are constructed respectively,and their results show that PSOGA-MSVR model has the best performance.Finally,the design of the aircraft wing location layout is taken as an example to verify the effectiveness of the method.

Hot-top direct chill casting assisted by a twin-cooling field:Improving the ingot quality of a large-size 2024 Al alloy

Microstructure inhomogeneity and negative segregation have long been challenges for large-size alloy ingots,directly affecting the downstream processing and final performance of products.Here,we used2024 aluminum alloy as a model alloy to propose a technique,named double-cooling field casting,i.e.,one 2024 Al alloy rod(Φ20 mm)at room temperature was introduced into the melt along the central axis of the hot-top with the protection of a thermal-insulation tube during the direct chill(DC)casting process of aΦ300 mm 2024 Al alloy ingot.The results show that the introduction of the same alloy solid insert has a remarkable influence on refining grains in the center region of the ingot,reducing negative centerline segregation and decreasing the depth of the center part of the sump.With the application of the 2024 Al insert,the mean size of equiaxed grains at the center part of the ingot decreased from1204±132μm to 721±69μm.The relative deviation of the Cu and Mg main solutes reduced from-0.062 and-0.054 to-0.03 and-0.024,respectively,and the sump depth decreased from 280 mm to242 mm.Moreover,the shape of the solidification front was changed from‘V’-shaped to‘W’-shaped.The ingot quality was thus improved,mainly arising from the dissolution of the cold 2024 Al insert at a proper position of the hot-top counteracting some latent heat of solidification of the ingot,dissipating the heat of the central part of the hot-top by conducting the 2024 Al insert to the outside,and providing extra-nuclei from the unmoltenα-Al particles of the insert.

Microstructure and mechanical properties of low frequency electromagnetic casting 7075 aluminum alloy

This work explores the microstructure of low frequency electromagnetic casting （LFEC） 7075 aluminum alloys and investigates the effect of heat treatment process on its mechanical properties via the mechanical properties test, X-ray diffraction and transmission electron microscopy. It was found that the grains of LFEC ingot were finer and more evenly distributed than that of the conventional direct chill cast （DC） ingots. The microstructure of LFEC ingot extruded kept their original as-cast struc- ture with small and fine grains. With the same extrusion ratio, the average grain diameters of LFEC and conventional DC extruded were about 10 and 20 #m, re- spectively. LFEC extruded also had a better aging property, since the regime of T6 treatment peak value aging was at 120 ~C for 24 h, the tensile strength and hardness （HV） of the LFEC extruded were 673.50 MPa and 194.62, respectively, which were all higher than those of the conventional DC extruded, indicating that the process regime can be applied in the industrial production.

On the low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing

The low cycle fatigue behaviour of an Al-Zn-Mg-Cu alloy processed via non-isothermal ageing(NIA)was examined at different strain amplitudes.We showed that NIA improved the low cycle fatigue life(more than 7000 cycles)by optimising the precipitate configuration within 5.5 h while maintaining comparable mechanical properties(570 MPa for tensile strength)and conductivity(nearly 39%IACS)to conventional isothermal ageing,simultaneously.Experimental observation combined with molecular dynamic simula-tion revealed that precipitation configuration manipulated by NIA had a crucial effect on fatigue resis-tance.A great number of repeatedly sheared and locally destructed GP zones enhanced co-planar slip and slip localisation in the under-aged alloy during the early stage of NIA,responsible for the dramatic displacement steps on the surface and resultant poor fatigue performance.As the NIA further proceeded,moderately coarsened precipitates with an average dimension of 6.0 nm and elevated number density ef-fectively impeded the dislocation movement and weaken the slip localisation to a great extent,improving the fatigue performance within a few hours.