RESEARCH ON THE EVALUATION METHOD OF FRICTION AND LUBRICATION IN DEEP DRAWING

The deformation characteristic of bland in deep drawing is discussed. It is pointed out that the friction and lubrication conditions in for drawing are different from that in mechanical motion or machine work or other plastic process. The common test methods in laboratories are analyzed. It shows that though all those test methods can test the friction coefficient, the probe test method is most suitable for the research of friction and lubrication and the process in deep drawing, for this method is identical with the actual work condition either from the test principle or deformation status of the blank. Last the successful application in the deep drawing simulator newly developed the the probe method are intro- duced in detail.

A Probe Method of Gradient Projection Type

In this paper,a probe method for nonlinear programming wiht equality and inequality is given. Its iterative directions at an arbitrary point x can be obtained through solving a liear system. The terminate conditions and choices of the parameters are given. The global convergence of the method is proved. Further more,some well known gradient projection type algorithms [1-15] and new gradient projection type algorithms from the linear system are given in this paper.

Laboratory and field experiment on measurement of soil thermal conductivity by probe method

The authors presented a new measuring method of the soil thermal conductivity,the probe method,which is designed and made based on the theory of line heat source. This method is used to measure thermal conductivity of coarse sand,fine sand and silty clay in different water contents. The results that measured by the probe method are well consistent with those of QTM-D_2. The soil thermal conductivity increases in different levels with the increase of the water content. Compared the soil thermal conductivity measured by the probe method in laboratory with in-situ experiment,it shows that the measuring gap gradually increases with the increase of the depth. The reason is that the in-situ measuring thermal conductivity can reflect the actual situation of the soil mass.

An ultra low-input method for global RNA structure probing uncovers Regnase-1-mediated regulation in macrophages

To enable diverse functions and precise regulation,an RNA sequence often folds into complex yet distinct structures in different cellular states.Probing RNA in its native environment is essential to uncovering RNA structures of biological contexts.However,current methods generally require large amounts of input RNA and are challenging for physiologically relevant use.Here,we report smartSHAPE,a new RNA structure probing method that requires very low amounts of RNA input due to the largely reduced artefact of probing signals and increased efficiency of library construction.Using smartSHAPE,we showcased the profiling of the RNA structure landscape of mouse intestinal macrophages upon inflammation,and provided evidence that RNA conformational changes regulate immune responses.These results demonstrate that smartSHAPE can greatly expand the scope of RNA structure-based investigations in practical biological systems,and also provide a research paradigm for the study of post-transcriptional regulation.

The Impact of Electrode Configuration on Characteristics of Vacuum Discharge Plasma

Generation characteristics of vacuum discharge plasma are very important for the applied research of metal plasma. The vacuum discharge electrode configuration and the cathode material affect the generation characteristics of the metal plasma which consists of metal ions coming from cathode and generated by vacuum discharge. In this research, the generation characteristics of the metal plasma generated by vacuum discharge are discussed for four patterns of electrode configurations, i.e. cone-mesh electrode setup, cone-cross line electrode setup, cone-line electrode setup and cone-ring electrode setup. Characteristics of the metal plasma, such as elec- tron density, electron temperature, space potential, ion energy, are measured by the probe method for discussing the impacts of different electrode configurations on the density of generated metal plasma. Moreover, the diffusion velocities of the metal plasma are measured for cathode materials of Pb, Al, and Cu, respectively. The experimental results indicate that the plasma generated by the discharge of cone-ring electrode configuration possesses the maximum density and the metal plasma generated by the Al cathode possesses the fastest diffusion velocity and the highest kinetic energy.

Effect of Friction on the Drawing Process of Hot-Galvanized Sheet Steel

A probe test method was employed to detect the friction condition of the interfaces between tools and blank. At the same time a self-developed measurement apparatus to realize the probe test method was also presented. Based on the analysis of force, a correlative friction model was also given. With the self-developed measurement apparatus,the effects of three kinds of lubricating oils which were in common use during the process of sheet steel drawing were studied. By probing the friction coefficient values of different lubricating oils during the drawing process of the hot-galvanized sheet steel （steel brand： ST07Zn）, we can see that the friction caused by PK oil was the lowest, so the effect of PK oil was the best. Then PK oil was used as the base lubricating oil and some solid additive powers was added into it to make a new type lubrication （named as L oil）.The result of test proved that the new lubricating oil had remarkable effect on the drawing process of hot-galvanized sheet steel.

Comparison between Conventional and Improved Gas Engine-Driven VRF under Same Climate Conditions

This paper reports the on-site performance evaluation of conventional and improved gas engine-driven VRF （variable refrigerant flow） units and （abbreviated as GHP） units. The study aims to elucidate two actual GHP units by using the probe insertion method. There is a tendency to decrease energy efficiency compared to a high loading factor. GHP operation was almost all part load operation. This on-site evaluation indicates a clear difference between conventional and improved GHP.

Study of Defect and Large Thermal Strain Nature in Organic Crystal of Rubidium Hydrogen Phthalate

Imperfections in the(001) plate of rubidium hydrogen phthalate(RAP, RbC8H5O4) crystals have been studied by means of X-ray topography. The main defects are the grown-in dislocations, inclusions, growth layers and the thermal strain lobes caused by heat. The large thermal strain nature was determined by an Inclusion Probed Method (IPM), which is due to the gradient of the interplanar spacing formed by atomic displacement to <110> directions.

NUMERICAL IMPLEMENTATION FOR A 2-D THERMAL INHOMOGENEITY THROUGH THE DYNAMICAL PROBE METHOD

In this paper, we present the theory and numerical implementation for a 2-D thermal inhomogeneity through the dynamical probe method. The main idea of the dynamical probe method is to construct an indicator function associated with some probe such that when the probe touch the boundary of the inclusion the indicator function will blow up. From this property, we can get the shape of the inclusion. We will give the numerical reconstruction algorithm to identify the inclusion from the simulated Neumann-to-Dirichlet map.

Onset of slugging fluidization in supercritical water fluidized bed

The supercritical-water fluidized bed(SCWFB)is a reactor for coal and biomass gasification without pollutant emission.We carried out a series of experiments in a SCWFB,and a dual-capacitance probe measurement system was applied to measure the hydrodynamics of slugs,such as the slug frequency,chord length,and rising velocity.Four groups of Geldart-B particles with different mean diameters were fluidized by supercritical water with a system pressure of 20-27MPa and at 410-570℃.The minimum slugging Reynolds number increases logarithmically with Archimedes number and a predicting correlation of the minimum slugging fluidization velocity in the SCWFB is presented:Rems=32908.84 ln(Ar^0.55+260376.65)-410361.90.The relative error of the above correlation was within ±15% and the averaged relative error was 7.5%.The effect of operating conditions on the minimum slugging fluidization velocity is discussed.This research provides useful guidance for scaling-up design and for determining the optimum range of operating conditions in the SCWFB.

Synthesis,Crystal Structural and Electrical Conductivity Properties of Fe-Doped Zinc Oxide Powders at High Temperatures

The synthesis,crystal structure and electrical conductivity properties of Fe-doped ZnO powders（in the range of 0.25-15 mol%） were reported in this paper.I-phase samples,which were indexed as single phase with a hexagonal（wurtzite） structure in the Fe-doped ZnO binary system,were determined by X-ray diffraction（XRD）.The solubility limit of Fe in the ZnO lattice is 3 mol% at 950℃.The above mixed phase was observed.And the impurity phase was determined as the cubic-ZnFe 2 O 4 phase when compared with standard XRD data using the PDF program.This study focused on single I-phase ZnO samples which were synthesized at 950℃ because the limit of the solubility range is the widest at this temperature.The lattice parameters a and c of the I-phase decreased with Fe-doping concentration.The morphology of the I-phase samples was analyzed with a scanning electron microscope.The grain size of the I-phase samples increased with heat treatment and doping concentration.The electrical conductivity of the pure ZnO and single I-phase samples was investigated using the four-probe dc method at 100-950℃ in air atmosphere.The electrical conductivity values of pure ZnO,0.25 and 3 mol% Fe-doped ZnO samples at 100℃ were 2×10-6,1.7×10-3 and 6.3×10-4 S.cm-1,and at 950℃ they were 3.4,8.5 and 4 S.cm-1,respectively.

Effect of Doping and High-Temperature Annealing on the Structural and Electrical Properties of Zn_(1-X)Ni_XO(0≤X≤0.15) Powders

This paper reported the synthesis, crystal structure and electrical conductivity properties of Ni-doped ZnO powders （i.e. Zn1-xNixO binary system, X=0, 0.0025, 0.005, 0.0075 and in the range 0.01≤X〈0.15）. I- phase samples, which were indexed as single phase with a hexagonal （wurtzite） structure in the Zn1-xNixO binary system, were determined by X-ray diffraction （XRD）. The widest range of the I-phase was determined as 0≤X≤0.03 at 1200℃; above this range the mixed phase was observed. The impurity phase was determined as NiO when compared with standard XRD data, using the PDF program. We focused on single f-phase ZnO samples which were synthesized at 1200℃ because of the widest range of solubility limit at this temperature. It was observed that the lattice parameters a and c of the I-phase decreased with Ni doping concentration. The morphology of the I-phase samples was analyzed with a scanning electron microscope. The electrical conductivity of the pure ZnO and single I-phase samples were studied by using the four-probe dc method at temperatures between 100 and 950℃ in air atmosphere. The electrical conductivity values of pure ZnO and 3 mol% Ni-doped ZnO samples at 100℃C were 2×10^-6 and 4.8×10^-6 Ω-1.cm^-1, and at 950℃ they were 1.8 and 3.6 Ω-1cm-1, respectively. In other words, electrical conductivity increased with Ni doping concentration.

I_(c) measurement of twisted multifilamentary MgB_(2) wires with non-magnetic sheath over a wide range of temperatures and fields

All‐superconducting rotating machines have the potential for meeting the high power density and high efficiency required for electrical aircraft applications.However,very high AC loss encountered in superconducting armature windings could hinder their development.Multifilamentary MgB_(2) wires are one of the promising candidates for the stator windings,due to their potentially low AC loss properties with small filament size and twist pitches.As the first step,the dependence of critical current and n‐value on magnetic fields and temperatures I_(c)(B,T)and n(B,T),which are basic input parameters for AC loss simulation,needs to be measured.In this work,we present transport I_(c)measurements in three non‐magnetic multifilamentary MgB_(2) wires(MgB_(2)/Nb/CuNi/CuZn):one large wire with a 0.70 mm diameter and 25 mm twist pitch,and two small wires with a 0.48 mm diameter each and a 10 mm and 30 mm twist pitch respectively.A four‐probe direct current method is used to measure I_(c) of the MgB_(2) wires with variations in temperature(15-35 K)and magnetic field(0-5.5 T).Full I_(c) data for the small wire with 10 mm twist pitch was obtained,and the n‐values were mostly less than 20.While the I_(c) data for the large wire at low fields was more limited due to heating,the n‐values were higher and could be up to around 100.The difference is attributed to the different filament sizes.Experiments also found that there is no significant hysteresis in the transport critical current measured by decreasing or increasing magnetic fields due to the non‐magnetic sheaths.This non‐hysteretic characteristic is critical for lowering AC loss because the additional losses from magnetic sheaths can be eliminated.From the magnetic‐field dependence of critical current density,an empirical expression has been developed that provides suitable extrapolations to lower fields for the large wire.