Remaining Useful Life for Heavy-Duty Railway Cast Steel Knuckles Based on Crack Growth Behavior with Hypothetical Distributions

The current research on the integrity of critical structures of rail vehicles mainly focuses on the design stage,which needs an effective method for assessing the service state.This paper proposes a framework for predicting the remaining useful life(RUL)of in-service structures with and without visible cracks.The hypothetical distribution and delay time models were used to apply the equivalent crack growth life data of heavy-duty railway cast steel knuckles,which revealed the evolution characteristics of the crack length and life scores of the knuckle under different fracture failure modes.The results indicate that the method effectively predicts the RUL of service knuckles in different failure modes based on the cumulative failure probability curves for different locations and surface crack lengths.This study proposes an RUL prediction framework that supports the dynamic overhaul and state maintenance of knuckle fatigue cracks.

Root growth and spatio-temporal distribution of three common annual halophytes in a saline desert, northern Xinjiang

Root growth and spatial and temporal distribution in the 0-100 cm soil profiles of three common annual halophytes Salsola subcrassa, Suaeda acuminate and Petrosimonia sibirica distributed in a saline desert in north- ern Xinjiang, China were studied in 2009 and 2010. The results showed that the root systems of the three halo- phytes were of the taproot type, vertically distributed in the 90-cm soil profile, and were deepest in late July. Their taproots reached maximum depth rapidly, early in the growth period, but with rare lateral roots. They were then dug out in an orderly way, from bottom to top, exhibiting vertical development first and then horizontal development. The distribution of specific root length, which reflects the characteristics of the feeder root, was gradually increased from top to bottom, whereas root weight displayed an opposite distribution pattern. The root length distribution of the three halophytes was concentrated （62% to 76%） in the middle soil profile （20-60 cm）, with less distribution in the surface （0-20 cm） and bottom （60-90 cm） soil profiles. The results indicated that the roots of the three annual halophytes grew rapidly into the deeper soil layer after germination, which ensured the plant survival and uptake of water and nutrition, and thus built up a strong tolerance to an arid, high-salt environment.

Grain size distribution and topology in 3D grain growth simulation with large-scale Monte Carlo method

Three-dimensional normal grain growth was appropriately simulated using a Potts model Monte Carlo algorithm. The quasi-stationary grain size distribution obtained from simulation agreed well with the experimental result of pure iron. The Weibull function with a parameter β=2.77 and the Yu-Liu function with a parameter v =2.71 fit the quasi-stationary grain size distribution well. The grain volume distribution is a function that decreased exponentially with increasing grain volume. The distribution of boundary area of grains has a peak at S/〈S〉=0.5, where S is the boundary area of a grain and 〈S〉 is the mean boundary area of all grains in the system. The lognormal function fits the face number distribution well and the peak of the face number distribution is f=10. The mean radius off-faced grains is not proportional to the face number, but appears to be related by a curve convex upward. In the 2D cross-section, both the perimeter law and the Aboav-Weaire law are observed to hold.

Effect of growth rate on microstructure and solute distribution of Al-Zn-Mg alloy

An Al-5.3%Zn-5.3%Mg alloy was unidirectionally solidified to determine morphological transition and solute distribution by a modification of the Bridgman technique for crystal growth with growth rates ranging from 4-500 μm/s and a temperature gradient of 25 K/cm. It was determined that growth rates from 6.5-9.5 μm/s generated a cell morphology, where the lower limit corresponds to the plane front to cellular transition and the upper limit indicates the cellular to columnar dendrite transition. The microstructures of the alloys solidified from 30 μm/s to growth rates less than 500 μm/s were mainly composed of columnar dendrites, while the microstructures solidified at growth rates greater than 500 μm/s were equiaxed. Regarding experimental results on solute distribution, a prediction of the model developed by Rappaz and Boettinger for dendrite solidification of multicomponent alloys was applied with excellent agreement. Results of solute distribution were employed to derive the precipitation fraction of τ-phase needed to increase the electrochemical properties of the alloy to be used as an Al-sacrificial anode.

Distribution Prediction of Suitable Growth Area for Eucommia ulmoides in China under Climatic Change Background

[ Objective] The research aimed to study distribution prediction of suitable growth area for Eucommia ulmoides in China under climatic change background. [ Method] By using the maximum entropy model and many kinds of climate change scenarios, we predicted current and future distribution pattems of suitable growth area for Eucommia ulmoides in China and its change process. [ Result ] At present, highly suitable growth area of E. ulmoides mainly distributed in Sichuan, Shaanxi and Chongqing, Under climate change background, total suitable growth areas in future three decades all drastically reduced when compared with that at present. It was noteworthy that moderately and highly suitable growth areas of wild E. ulmoides all disappeared, and junction between Shaanxi and Gansu and Taibai Mountain would be stable suitable growth area of wild E. ulmoides. [ Condusioa] The research could provide useful reference data for investigation, protection and sustainable development of the wild E. ulmoides resources.

Growth and Distribution of Amphioctopus fangsiao(d'Orbigny, 1839–1841) in Haizhou Bay, Yellow Sea

Octopus fisheries have prospered in many areas of the world ocean over the last six decades. Despite degradation and overexploitation of Chinese coastal ecosystems, octopus has become a stable Chinese domestic fishery species. Among the octopus species in the Bohai and Yellow, East and South China Seas, Amphioctopus fangsiao(d'Orbigny [in Férussac & d'Orbigny], 1839–1841) plays an increasingly important role both economically and ecologically. However, no systematic research has been conducted on its biology and population dynamics in the China Seas. In this study, we characterized the growth and distribution of A. fangsiao in Haizhou Bay, Yellow Sea based on four years of trawl survey data. As the results, A. fangsiao is characterized by allometric growth and an overall sex ratio of 0.97 with a slight male bias. Small octopus can be observed through a whole year, suggesting that A. fangsiao may have an extended or continuous spawning season. A. fangsiao may migrate short distances along with seasonal changes and coastal currents, considering they overwinter in the offshore water and spawn in the inshore water. In addition to fishing pressure, annual variations in the population structure and biomass appeared to be influenced by ambient water temperature. These results provide basic biological information for a better understanding of the population dynamics and the ecological importance of A. fangsiao.

Solute distribution in KNbO 3 melt-solution and its effect on dendrite growth during rapid solidification

This paper reports that the rapid solidification of mixed Li2B4O7 and KNbO3 melted in a Pt loop heater has been performed experimentally by the method of quenching, and various morphologies of KNbO3 crystals have been observed in different regions of the quenched melt-solution. Dendrites were formed in the central region where mass transfer is performed by diffusion, whereas polygonal crystals with smooth surface grew in the marginal region where convection dominates mass transport. Based on measurement of KNbO3 concentration along crystal interface by electronic probe analysis, it finds the variety of crystal morphologies, which is the result of different solute distributions： in the central region the inhomogeneity of solute concentration is much sharper and morphological instability is easier to take place; nevertheless in the marginal region the concentration homogeneity has been greatly enhanced by convection which prevents the occurrence of morphological instability. Additional solute distribution in the melt along the primary dendrite trunk axis as well as that in mushy zones has also been determined. Results show that the solute concentration in the liquid increases linearly with distance from the trunk tip and more solutes were found to be concentrated in mushy zones. The closer the mushy zone is to trunk tip, the lower the solute concentration will be there.

Distribution of platelet-derived growth factor-alpha receptor expressing oligodendrocyte precursor cells in the adult rat brain

BACKGROUND： Studies have demonstrated that NG2-positive glial cells in the adult rats are predominantly located in the gray and white matter of the cerebral cortex and hippocampus. Platelet-derived growth factor-a receptor （PDGF-αR） cells are a subset of oligodendrocytes, which are not as mature as NG2-positive cells. Distribution and migration of PDGF-αR-positive cells in the rat brain remain poorly understood. OBJECTIVE： Using immunohistochemical methods, the distribution of oligodendrocyte precursor cells （PDGF-αR-positive） was analyzed in the adult rat brain. DESIGN, TIME AND SETTING： Immunohistochemical study was performed at the Department of Histology and Embryology of the Third Military Medical University from September 2007 to September 2008. MATERIALS： Rabbit anti-PDGF-αR polyclonal antibody was purchased from Santa Cruz Biotechnology, USA. Streptomycin-avidin-biotin complex immunohistochemistry kit was purchased from Zhongshan Goldenbridge Biotechnology, China. METHODS： Whole brains from 5 healthy, adult, Wistar rats were collected for immunohistochemistry, and the mean value of PDGF-αR-expressing cells was quantified. The absolute values were translated to ranked data of high, moderate, and low grades （high grade： 10 positive cells; moderate grade： 5-9 cells; low grade： 〈 5 cells in a 400 × visual field）. Based on the number of cell processes and branches, as well as the number of PDGF-αR-positive cells, in different regions, the cells were classified into three categories, i.e., type Ⅰ-Ⅲ. From type I to type Ill, the number of processes gradually increased. MAIN OUTCOME MEARSURES： The number and distribution of PDGF-αR-positive cells in different brain regions of adult rats. RESULTS： PDGF-αR-positive cells were located in the forebrain and midbrain, but not in the cerebellum or brainstem. In the olfactory bulb and hippocampus, a total of 60% PDGF-αR-positive cells were type Ⅰ and these cells were not mature as others. In the cerebral cortex, olfactory system, hippocampus, and optic chiasma, where neuronal bodies aggregated, approximately 40% of the PDGF-αR-positive cells were type Ⅱ, with few type Ⅲ cells. In the white matter, corpus callosum, basal nucleus, and thalamus, PDGF-αR-positive cell density was moderate. In the olfactory bulb and hippocampus, PDGF-αR-positive cell density was high. PDGF-αR-positive cells were not observed in the cerebellum or brainstem CONCLUSION： PDGF-αR-positive cells were aggregated in the olfactory bulb and hippocampus in the adult, rat brain, but few cells were detected in the cerebellum and brainstem.

Population Distribution Evolution Characteristics and Shift Growth Analysis in Shiyang River Basin

In recent years, the population size and scale of the Shiyang River Basin unceasingly expanding lead to a series of ecological environment: surface water reducing, land desertification and Ground water levels fall, etc. Research evolution characteristics of population distribution and migration growth of Shiyang River Basin contribute to river water resources and the industrial development of the comprehensive management. The article using the distribution of population structure index, population distribution center of gravity model and the population migration growth analysis model analyzes the distribution of the population evolution characteristics and population migration growth characteristics of Shiyang River Basin in 2000 to 2010. The results show that: 1) Considering Shiyang River Basin, population density is generally low, population distribution difference is bigger and concentration distribution in the middle corridor plain and three big population distribution center of Minqin oasis area, presenting a “point-areas-ribbon” structure characteristics. 2) The population distribution trend of Shiyang River Basin is constantly concentration, but the change is slow;the population distribution of Minqin is in the highest concentration degree, but the trend has been declining. 3) The focus of population density in river basin locates in Liangzhou district of Daliu country;in ten years, it migrates about 1209 m to southwest Wuwei City direction, but migration along the direction things is bigger than the north and south direction. The focus of population density and the basin geometry center is far away. 4) For ten years, at the township for basic statistics unit, each level population migration change within the overall is not significant: township level > prefecture-level cities level > counties level. 5) For ten years, there are significant changes in population migration between watershed township units, Wuwei City and Gulang Town are the two main concentrations of population centers.

Effects of Salt Stress on Growth and Ion Distribution in Seedlings of Asparagus officinalis L.

An Asparagus officinalis L. cultivar NJ978 was used to study the growing rate, salt ion content and mineral ion uptake and distribution in plants under salt stress. The results showed that salt stress significantly inhibited seedling growth and there was a negative relationship between seedling growth and salt concentration. The seedlings growth showed no significant decrease under low salt stress （NaCl≤50 mmol/L）, while high concentrations of NaCl led to detrimental effects on the growth of A. officinalis L.. With the increase of NaCl concentration, the Na ＋ content increased gradually in A. officinalis L. roots, stems and leaves while the K^＋ and Ca^2＋ contents had slow decreases. Under low salt stress, the seedlings of A. officinalis L. could prevent Na ＋ from transporting to aerial part by withholding Na ＋ in root, which could keep the balance of ions in aerial part, but under high salt stress （NaCl 〉 100 mmol/L）, the aerial part of seedlings accumulated superabundance of Na ＋, which limited the uptake of K^＋ and Ca^2＋ , so seedlings were damaged heavily, which manifested as the gradual decrease of K^＋/Na ＋ and Ca^2＋ /Na ＋ in the roots and aerial part of the seedlings. The selective absorption of K^＋, Ca^2＋ and Na ＋ （AS K,Na and AS Ca,Na ） was significantly increased with increased salinity, while the selective transportation （TS K,Na and TS Ca,Na ） increased at first and then decreased with the increased salinity. Therefore, the strong ability of salt exclusion and the regionalized distribution of ions in roots, stems and leaves could be one of the salt tolerance mechanisms of A. officinalis L.

Free-Energy and Emittance Growth Caused by Bunched Beam with Nonuniform Distributions in Both Longitudinal and Transverse Directions in Linac

The nonlinear space charge effect of bunched beam in linac is one of theimportant factors that induces the emittance growth due to the conversion of thefield energy to kinetic energy. Using a cylinder model of space charge in a linac,we derive the internal energy for a bunched beam with some nonuniform spacecharge distributions, such as Gaussian, waterbag and parabolic distributions inboth the longitudinal and transverse directions. And the emittance growth causedby these nonuniformities is worked out.

Emittance Growth Caused by the Transverse Nonuniform Space Charge Distributions of Bunched Beam in Linac

The nonlinear space charge effect of bunched beam in linac is one of the im-portant factors that induces the emittance growth due to the conversion of the field en-ergy to kinetic energy.In this paper,the internal field energies associated with sometransverse nonuniform space charge distributions of a bunched beam,such as Gaussiandistribution,waterbag distribution and parabolic distribution,are worked out.And theemittance growth caused by these nonuniformities are obtained.

Free Energy and Emittance Growth Caused by Bunched Beam With Gaussian Distribution in Longitudinal Direction in Linac

The nonlinear space charge effect of bunched beam in linac is one of the important factors thatinduces the emittance growth due to the conversion of the field energy to kinetic energy.In this paper,us-ing a cylinder model of space charge in linac,we derived the internal energy for a bunched beam withsome nonuniform space charge distributions,such as longitudinal Gaussian distribution combined withKapchinskij-Vladimirski1,waterbag,parabolic or Gaussian transverse distribution.And the emittancegrowth caused by the above distributions is worked out.

FIBER ORIENTATION DISTRIBUTION OF PAPER SURFACE CALCULATED BY IMAGE ANALYSIS

Anisotropy of paper is an important parameter of paper structure. Image analysis technique was improved for accurate fiber orientation in paper surfaces. Image analysis using Fast Fourier Transform was demonstrated to be an effective means to determine fiber orientation angle and its intensity. Binarization process of micrograph images of paper surface and precise calculation for average Fourier coefficients as an angular distribution by interpolation developed were found to improve the accuracy. This analysis method was applied to digital optical micrographs and scanning electron micrographs of paper. A laboratory handsheet showed a large deviation in the average value of fiber orientation angle, but some kinds of machine-made paper showed about 90 degrees in the orientation angle with very small deviations as expected. Korea and Japanese paper made in the traditional ways showed its own characteristic depending on its hand making processes.

Environment, Health and Economic Growth： Study on Optimal Energy Tax Revenue Distribution

Under the dual pressures of economic growth and environmental protection,how to curb pollution and raise public welfare without harming the economy or with minimal economic output losses has become a major question facing China in its efforts to transform growth pattern and accomplish economic transition. On the basis of an overlapping generation(OLG) model, this paper introduces the health effects of environmental pollution to systematically discuss the optimal distribution ratio of energy tax revenues in subsidizing household income and emission abatement under given tax rates to reduce the risks of "environment-health-poverty" trap. Our research shows that an optimal distribution ratio for maximizing per capita output or an optimal distribution ratio for maximizing public welfare exists. Based on China's actual parameters, however, this study has found that China's energy tax revenue distribution policy hardly meets the two optimal targets at the same time. Specific distribution ratio is subject to government decision-making preference, and needs to be adjusted according to actual differences.

Temporal and spatial distribution of phytoplankton functional groups and role of environment factors in a deep subtropical reservoir

Phytoplankton and environment factors were investigated in 2015 and phytoplankton functional groups were used to understand their temporal and spatial distribution and their driving factors in Wanfeng Reservoir. Seventeen functional groups(B, D, E, F, G, J, Lo, MP, P, S1, T, W1, W2, X1, X2, Xph, Y) were identified based on 34 species. The dominant groups were: J/B/P/D in dry season, X1/J/Xph/G/T in normal season and J in flood season. Phytoplankton abundance ranged from 5.33×10~4 cells/L to 3.65×10~7 cells/L, with the highest value occurring in flood season and lowest in dry season. The vertical profi le of dominant groups showed little differentiation except for P, which dominated surface layers over 20 m as a result of mixing water masses and higher transparency during dry season. However, the surface waters presented higher values of phytoplankton abundance than other layers, possibly because of greater irradiance. The significant explaining variables and their ability to describe the spatial distribution of the phytoplankton community in RDA diff ered seasonally as follows: dry season, NH4-N, NO_3-N, NO_2-N, TN:TP ratio and transparency(SD); normal season, temperature(WT), water depth, TN, NH4-N and NO_3-N; flood season, WT, water depth, NO_3-N and NO_2-N. Furthermore, nitrogen, water temperature, SD and water depth were significant variables explaining the variance of phytoplankton communities when datasets included all samples. The results indicated that water physical conditions and hydrology were important in phytoplankton community dynamics, and nitrogen was more important than phosphorus in modifying phytoplankton communities. Seasonal differences in the relationship between the environment and phytoplankton community should be considered in water quality management.

Population distribution, urban construction and urban management in the process of China urbanization

Along with China＇s urbanization, a series of problems came, such as the rapidly expanding urban population, large-scale urban construction and investment, the financing gap of government＇s investment in construction, and urban management, etc. This article first describes the growth of urban population, the scale and the input of urban construction, and then analyzes the financial revenue and expenditure, and at last argues for the necessity of urban management, and puts forward the research content of urban management.

Disadvantage Pressure Changes on the Decline of Water Quality in Water Distribution Systems

Systems that have big transmission line may have problem on changes of pressure in the distribution system. Because pressure rate changes have been too much between water treatment plant and dead ends in distribution system. This study is to analyze the effects pressure changes on the water quality in water distribution systems. It is located in south west of Ahwaz in IRAN. Ahwaz has five water treatment plants. In Ahwaz, two methods will be utilized. In the first method, samples will be taken from different locations in other to examine the quality of water in the distribution systems and the other method involves the use of simulation of models EPANET. Based on the EPANET model analysis of the water distribution system of Ahwaz as shown in result above the systems has large transmission line and exten- sive networks. So, the distance travelled and residence times have been causing to increase bacterial growth (HPC), chlorine consumption and hydraulic change (pressure) in water distribution system in Ahwaz. Pressure has a reversed relationship with bacterial growth (HPC) and Pressure has a direct relationship with residual chlorine. Pressure change has been causing to increase chlorine consumption more. So, Kw hasn’t any relationship with pressure and bacterial growth (HPC). The result of pressure changes among others can decrease in chlorine content and hydraulic factors, because the systems may be extensive and thus possess complex networks and hangs in quantity cause pressure of flow. Hence hydraulic changes (pressure) could affect of water quality in the water distribution system.

Real-Time Characterization of Crystal Shape and Size Distribution Based on Moving Window and 3D Imaging in a Stirred Tank

Crystal shape distribution, i.e. the multidimensional size distribution of crystals, is of great importance to their down-stream processing such as in filtration as well as to the end-use properties including the dissolution rate and bioavailability for crystalline pharmaceuticals. Engineering crystal shape and shape distribution requires knowledge about the growth behavior of different crystal facets under varied operational conditions e.g. supersaturations. Measurement of the facet growth rates and growth kinetics of static crystals in a crystallizer without stirring has been reported previously. Here attention is given to study on real-time characterization of the 3D facet growth behavior of crystals in a stirred tank where crystals are constantly moving and rotating. The measurement technique is stereo imaging and the crystal shape reconstruction is based on a stereo imaging camera model. By reference to a case study on potash alum crystallization, it is demonstrated that the crystal size and shape distributions (CSSD) of moving and rotating potash alum crystals in the solution can be reconstructed. The moving window approach was used to correlate 3D face growth kinetics with supersaturation (in the range 0.04 - 0.12) given by an ATR FTIR probe. It revealed that {100} is the fastest growing face, leading to a rapid reduction of its area, while the {111} face has the slowest growth rate, reflected in its area continuously getting larger.