“含腐植酸水溶肥料”在朝天椒上的肥效试验

利用含腐植酸水溶肥料在我院新选育出的朝天椒新品种“安蔬三樱10号”进行试验,试验表明:“含腐植酸水溶肥料”在三樱椒生产上有着明显的提高座果率、提高产量效果。

Radio-frequency system of the high energy photon source

Purpose High energy photon source is a 6 GeV diffraction-limited storage ring light source currently under construction in Beijing.A low-frequency fundamental radio-frequency(rf)system of 166.6 MHz was proposed to accommodate the accelerator physics design.Superconducting rf(srf)technologies were chosen for the storage ring rf accompanied by solid-state power amplifiers and digital low-level rf controls.The design of the rf system was completed,and the parameters are frozen.Elucidation of the rf design with key parameters is desired.Methods The requirements from the accelerator physics design will be presented followed by the detailed rf design.The logic behind the choice of key rf parameters is elaborated.The configuration of the entire rf system is presented.Results and conclusions The fundamental srf cavity of 166.6 MHz was designed to accelerate the ultrarelativistic electron beam.Heavy damping of higher-order modes in these cavities is required to avoid the coupled bunch instabilities.An active third harmonic srf of 499.8 MHz was adopted to realize the required rf gymnastics.Normal-conducting 5-cell cavities will be used for the booster rf.Solid-state amplifiers of 2.4 MW in total will be installed at HEPS to drive these cavities in the booster and the storage ring.A digital low-level rf system will be used to regulate rf field inside each cavity with high stabilities.The rf configuration during the commissioning and the operation scenarios are also presented.

Equilibrium electron beam parameters of the High Energy Photon Source

Purpose The physics design of the High Energy Photon Source(HEPS)was finished after many times of iteration.Hereby,the typical equilibrium electron beam parameters corresponding to the proposed two baseline operation modes in the baseline design of HEPS are presented.Methods To compute the equilibrium parameters of the electron beam,the lattice parameters,RF parameters,and the parameters of the insertion devices(IDs)were determined first.Furthermore,it is more precise to use the full-current electron beam parameters in the estimations of the performance of the synchrotron light.Therefore,not only the single-particle dynamics but also the current-dependent collective effects need to be considered in the computations of the full-current,equilibrium parameters of the electron beam.Both analytic computations and multi-particle tracking simulations were carried out.Results The full-current,equilibrium parameters of the electron beams in the HEPS storage ring are presented in this paper.Moreover,the main beam parameters in the injector(the booster and the LINAC),corresponding to the two baseline operation modes of the storage ring,are also presented.Conclusion The typical electron beam parameters corresponding to the two baseline operation modes are given in detail in this paper.

Design of the HEPS booster lattice

Purpose The high energy photon source(HEPS)is a diffraction-limited storage ring light source being built in China.Along with the deeper studies of booster and the evolution of the lattice design and injection scheme of the storage ring,four versions of the booster lattices have been proposed from the project proposal stage.Methods Unlike the design of the storage ring,in the booster design,more effort was made to realize stable and reliable operation rather than advanced performance.A FODO structure lattice and the"high-energy accumulation"scheme was adopted in the HEPS booster design.To find the ultimate performance of the lattice,a multi-objective genetic algorithm(MOGA)and particle swarm optimization(PSO)were used to optimize the emittance and the dynamic aperture.Results In the latest booster lattice design,the emittance was reduced to 16.3 nm rad.At the same time,the single-bunch charge limit was increased by minimizing the average vertical beta function and reducing the chromaticity.Conclusions Through multi iterations with the hardware system,the current lattice was basically frozen and can be used as a basis for related physics studies,hardware and engineering design of the booster.In the future,more detailed physical studies will be performed based on this lattice.

Effects of heating rate on the alloy element partitioning and mechanical properties in equiaxedα+βTi-6Al-4V alloy

The effects of heating rate on the alloy element partitioning and mechanical properties during the phase transformation ofα→βin Ti-6Al-4 V alloy under solution treatment have been investigated by the experiments and phase field simulations,which reveal the evolutions of microstructure and compositions at the non-equilibrium state and well verify the experimental results.The specific results indicate that the compositions measured through electron probe micro-analysis(EPMA)under a lower heating rate are close to the equilibrium ones corresponding to the solution temperature.Heating up to the target solution temperature,as the heating rate increases,the Al content decreases and V increases in the primaryα(α_(p))grain with a larger size,the volume fraction ofα_(p)increases and the composition gradient betweenα_(p)andβphases gets steeper.The interrelated relationship among the diffusion,compositions,solution temperature and free energy of the system has been discussed in detail.Moreover,increasing the heating rate(~20.0 K/min)may help to improve the mechanical properties of the alloy by mainly adjusting theα_(p)/β;volume fractions,α_(p)particle size and secondaryα(α_(p))size during the process of heating up to the solution temperature.These results may shed some light on the optimization of the knowledge-based heat treatment route.

Phase field simulation of the stress-inducedαmicrostructure in Ti–6Al–4 V alloy and its CPFEM properties evaluation

Variant selection under specific applied stresses during precipitation of a plates from prior-βmatrix in Ti-6 Al-4 V was investigated by 3 D phase field simulations.The model incorporates the Burgers transformation path fromβto a phase,with consideration of interfacial energy anisotropy,externally applied stresses and elastic interactions among a variants andβmatrix.The Gibbs free energy and atomic mobility data are taken from available thermodynamic and kinetic databases.It was found that external stresses have a profound influence on variant selection,and the selection has a sensitive dependence,as evidenced by both interaction energy calculations and phase field simulations.Compared with normal stresses,shear stresses applied in certain directions were found more effective in accelerating the transformation,with a stronger preference to fewer variants.The volume fractions of various a variants and the final microstructure were determined by both the external stress and the elastic interaction among different variants.The a clusters formed by variants with Type2 misorientation([11-20]/60°)relation were found more favored than those with Type4([-1055-3]/63.26°)under certain applied tensile stress such as along<111>β.The mechanical properties of different microstructures from our phase field simulation under different conditions were calculated for different loading conditions,utilizing crystal plastic finite element simulation.The mechanical behavior of the various microstructures from phase field simulation can be evaluated well before the alloys are fabricated,and therefore it is possible to select microstructure for optimizing the mechanical properties of the alloy through thermomechanical processing based on the two types of simulations.

A phase-field model for simulating the growth ofαsideplates with branching in titanium alloys

In recent years,titanium and titanium alloys are widely used in the fields of aerospace,oceans,etc.due to their high strength to weight ratio,good toughness and excellent corrosion resistance[1].Various microstructures and mechanical properties can be ob-tained simply by varying the thermomechanical processing or heat treatment.As an example,the Widmanstätten structure may pos-sess good tensile strength,fracture toughness,fatigue properties and high resistance to crack growth[2].It is formed when tita-nium alloys are cooled from theβphase region.During the cooling process,αGB(grain boundaryα)may first nucleates at the priorβgrain boundary,and then theαW(Widmanstättenα)grows fromαGB and forms intragranularαsideplates colony[3].The compli-cated evolution process is difficult to characterize experimentally,since the microstructures observed experimentally are mostly ul-timate results,but not a dynamic evolution process.