Search results

Introduction Railway freight turnover is an important indicator in railway transportation, it is equal to multiply the number of transportation freight by the distance of transportation, and the freight turnover indicator not only concludes the number of transportation object, but also concludes the factor of transportation distance, so it can reflect the output of transportation production entirely.
As the railway freight turnover are influenced by many factors, such as gross domestic product, raw coal output, grain output, railway operating mileage, and the mechanism of these influence factors always cannot precisely describe by accurate mathematical linguistics.
The network is trained to learn this mapping using a number of training examples.
Railway freight turnover is influenced by many factors, This paper set the gross domestic product, coal output, grain output, steel output and railway operating mileage as input variables.
Table 1 Input and output data of BP neural network Year The gross domestic product [billion Yuan] Coal output [billion tons] Grain output [ten thousand tons] Steel output [ten thousand tons] Railway operating mileage [ten thousand Kilometer] Railway freight turnover [billion tons Kilometer] 1998 84402.3 12.50 51229.5 10894.2 6.64 12560.1 1999 89677.1 10.45 50838.6 11559.0 6.74 12910.3 2000 99214.6 9.98 46217.5 12426.0 6.87 13770.5 2001 109655.2 11.10 45263.7 12850.0 7.01 14694.1 2002 120332.7 13.80 45705.8 15163.4 7.19 15658.4 2003 135822.8 16.67 43069.5 18236.6 7.30 17246.7 2004 159878.3 19.56 46946.9 28291.1 7.44 19288.8 2005 184937.4 21.90 48402.2 35324.0 7.54 20726.0 2006 216314.4 23.80 49804.2 41914.9 7.71 21954.4 2007 265810.3 25.36 50160.3 48928.8 7.80 23797.0 2008 314045.4 27.93 52870.9 50091.5 7.97 25106.3 2009 340902.8 30.50 53082.1 57218.2 8.55 25239.2 2010 401512.8 32.40 54647.7 62665.4 9.12 27644.1 2011 472881.6 35.20 57120.8 69550.0 9.32 29465.8 2012 516282.0 36.50

Applied stress raises the amount of defection as dislocation and grain boundary defects, thus elevate Ms.
Table 2 The stress applied programs of samples Samples number Loading temperature (oC) Loading stress (MPa) S1 700 100 S2 700 200 S3 600 100 S4 600 200 S5 500 100 S6 500 200 S7 -- 0 Results and Discussion Fig. 1 illustrates the relationship between martensitic transformation start temperature (Ms) and applied stress.
Compressive strain would increase the free energy of the austenite, decrease its stability and introduce defects (such as grain boundary, shear band and dislocation) in the metastable austenite.
The grain boundary energies and defects caused by deformation provide more nucleation sites and then promote the martensitic transformation.
Applied stress also results in the broken of δ-ferritic grain, and refinement of martensitic lath.

A decrease in abrasive grain size during USM leads to better surface finish.
However, for a particular concentration, as the size of the abrasive particles increases, there is a reduction of the real number of effective particles.
Any further increase in grit number decreases the grain size considerably, resulting into several layers of abrasive particles, which make the machining less effective [10].
The MRR increases with the increase in effective number of particles upto second level.
Grains may have been disintegrating instead of cutting, reducing the average grain size and consequently increasing the drilling time.

., Ltd, No.8 Wenchang Avenue, Beijing Economic-Technological Development Area, China E-mail: aboyu.dong@naura.com Keywords: SiC powder, Grain size, Synthesis, PVT system Abstract: By using a NAURA Advanced Physical Vapor Transport (PVT) System, the character of the synthesized SiC powder were studied.
As the temperature increased further, the nucleation rate would cause an excessive nucleation number to prevent grain growth and increase small size particles.
As the reaction continually occurred, SiC grains were growing up.

The developments of Kirkendall's idea for sub-surface (SS) and grain boundary (GB) interdiffusion have been considered and applied for the advanced structural materials, such as thin films and nano-composites.
Kozma: Handbook of Grain and Interface Boundary Diffusion Data (Zeigler, Stuttgart, 1989)
Gusak: Did you measure the change of grain size during GB Kirkendall effect.
Paritskaya: We didn`t measure the change of grain size during GB Kirkendall effect.
The necessary condition of Kirkendall effect is a change of the number of regular positions, which resulted from the interaction of vacancies with dislocations and subsequent elimination/building up of atomic planes.

This growth method is applicable to continuous synthesis a large number of single-crystalline GaN nanorods with a high purity at a low cost.
The center is the grain-aggregates with many defects and no grains attach to the surface of the nanorods.
In the aggregating process from small grains to lager ones, many defects occur in the aggregates which become the favorite growth site of the nanorods.
Due to the low surface energy, these defects become the potential nucleation sites for the GaN grains.
The subsequent deposition of the GaN results in growth of nuclei into grain-aggregates.

The last stage (E) showed more voids and microcracks in the grain boundary, indicating extensive degradation.
Creep crack initiation generally occurs via formation of cavities at grain boundaries, which then coalesce to form a crack [7].
After 2000 h of testing, the carbides were distributed throughout the grain boundaries and the finer carbides within the grains.
The grain boundary carbides possess a largely coarse M7C3 composition; the intragranular carbides are spheroidised as M6C.
The accuracy of the life fraction intervals depends on various factors, such as sample preparation, carbide identification, the analytical techniques used and the number of interruptions during the accelerated creep test.

Table 1 Structure of System Rule Base Name of table Primary key Filed name Description Data type Whether it can be null RULE TRUE RULE-NO Rule number int NOT NULL FALSE If rule antecedent varchar NOT NULL FALSE Then rule consequent varchar NOT NULL Every rule in the rule base is formed in this form.
Rule number Antecedent fact Consequent action The specific meanings are as follows: (l) Rule number: It is the number generated when establishing the rule sheet and it is used to confirm one unique rule in the table.
At the same time it undertakes the task of rule ordering, that is to say, the rule is in the sequence of natural ordering with the number
(3) Consequent action: It describes the processing parameters of lapping and processing and includes the following properties: abrasive grain, eccentricity, grinding pressure, speed of main spindle and other primary parameters.
Rule 2: IF the material of work piece is hard alloy; AND production process is fine lapping; AND expected value of Ra <3.3nm; THEN the abrasive grain is selected as W3.5 The meaning of this rule is that when the material of work piece is hard alloy, and production process is fine lapping, and expected value of Ra <3.3nm, select abrasive grain of W3.5.

Fig.1 and Fig.2 present the cyclic stress amplitude, 2/σ∆ , with the number of cycles corresponding to two alloys respectively.
There is a common rule in both the hardening in the earlier stage of cyclic deformation and different softening after several cyclic numbers.
The former is assumed as a short-range stress resulting from the pinning effect of interstitial atoms atmosphere on dislocations, and the latter as a long-range stress resulting from the interaction of dislocations with the other ones, second particles and grain boundaries and so on [3,4].
In fatigue failure dislocations interaction and high concentrated stress stimulate micro crack to nucleate in grains and propagate, and so decrease fatigue life.
A number of fatigue cracks and micro cracks shown in Fig.5c, Fig.5d are the principal feature in the stage of crack propagation for alloy 2#.

It is proposed that LFMR is due to spin-polarized tunnelling through energy barriers at grain boundaries between grains with different spin orientation [13], [14].
The grey grains are LSCMO, while the purple distributions are TiO2.
The SEM image also shows that the LSCMO grains and TiO2 in LT5 are bigger than LT10 and TiO2 distributed in the grain boundary of LSCMO.
In the study of electron transport, the grain size value has a more dominant factor than the size of the crystallites, as well as the role of TiO2 that is between the boundaries of LSCMO grains.
According to Maxwell-Boltzmann statistics, at an absolute temperature T, the number of magnetic dipoles having energy U is proportional to exp-UkBT, where kB is the Botzmann’s constant.