铁路道岔结构优化与性能提升研究

提升铁路道岔质量,对于提升铁路线路的运行安全和使用寿命具有重要意义。针对铁路道岔的常见问题进行归类分析,形成四大类分类结果,包括几何尺寸问题、导曲部分问题、转辙部分问题和辙叉部分问题。在这一分类的基础上,进行总体适应度函数和分类适应度函数的设计。针对10组道岔展开实验研究,结果表明,经过该文优化设计的道岔,使用时间和过重总量获得明显增加,道岔质量得到明显提升。

Detection of Broad Bean Diseases by Fourier Transform Infrared Spectroscopy Combined with Curve Fitting

Fourier transform infrared （FTIR） spectroscopy was used to study diseased leaves in broad bean. Results showed that the infrared spectra of different broad bean diseased leaves were similar, which were mainly made up of the vibrational absorption bands of protein,lipid and polysaccharide.There were minor differences in-cluding the spectral peak position, peak shape and the absorption intensity in the range of 1 800-1 300 cm-1. There were obvious differences among their second derivative spectra in the range of 1 800-1 300 cm-1. After the procedure of the Fourier self-deconvolution and curve fitting of health bean leaves and broad bean diseased leaves in the range of 1 700-1 500 cm-1, three sub-peaks were obtained at 1 550 cm-1 （protein amide Ⅱ band）, 1 605 cm-1 （lignin） and 1 650 cm-1 （protein amide I band）.The ratios of relative areas of the bands of amide Ⅱ, lignin, and amide I were 38.86%, 28.68% and 32.47% in the spectra of healthy leaves, respec-tively. It was distinguished from the diseased leaves （chocolate spot leaf： 15.42%, 42.98% and 41.61%, ring spot leaf：32.39%, 35.63% and 31.98%, rust leaf： 13.97%, 46.40% and 39.65%, yel owing leaf curl disease leaf： 24.01%,36.55% and 39.44%）. For sub-peak area ratios （A1 563/A1 605, A1 650/A1 605 and A1 563/A1 654）, those of four kinds of diseased leaves were smal er than that of healthy leaves, and there were also differences among four kinds of diseased leaves. The results proved that FTIR combining with curve fitting might be a potential y useful tool for detecting different kinds of broad bean diseases.

Influence analysis of chevron alignment signs on drivers' speed choices at horizontal curves on highways

Using a driving simulator,the effects of Chinese chevrons on drivers’actual and perceived safe speeds at horizontal curves on two-lane rural highways are tested. Twelve horizontal curves with different roadway geometries are designed and used as the simulated scenarios.The results show that, regardless of the curve radius, chevrons at horizontal curves provide advance warning and speed control for vehicles on the nearside of chevrons.Besides,chevrons can be used as an addition to speed limit signs in preventing excessive speed at horizontal curves and, therefore, can contribute to a reduction in run-off-road crashes.Moreover, Chinese chevrons can also serve to provide an improved sense of safety while driving around sharp curves.These study results lay a foundation for setting Chinese chevrons more reasonably.

Rate decline analysis of multiple fractured horizontal well in shale reservoir with triple continuum

Multiple fractured horizontal well(MFHW) is widely applied in the development of shale gas. To investigate the gas flow characteristics in shale, based on a new dual mechanism triple continuum model, an analytical solution for MFHW surrounded by stimulated reservoir volume(SRV) was presented. Pressure and pressure derivative curves were used to identify the characteristics of flow regimes in shale. Blasingame type curves were established to evaluate the effects of sensitive parameters on rate decline curves, which indicates that the whole flow regimes could be divided into transient flow, feeding flow, and pseudo steady state flow. In feeding flow regime, the production of gas well is gradually fed by adsorbed gases in sub matrix, and free gases in matrix. The proportion of different gas sources to well production is determined by such parameters as storability ratios of triple continuum, transmissibility coefficients controlled by dual flow mechanism and fracture conductivity.

Dynamics of phase transformation of Cu-Ni-Si alloy with super-high strength and high conductivity during aging

The precipitation behaviors of the Cu-Ni-Si alloys during aging were studied by analyzing the variations of electric conductivity.The Avrami-equation of phase transformation kinetics and the Avrami-equation of electric conductivity during aging were established for Cu-Ni-Si alloys,on the basis of linear relationship between the electric conductivity and the volume fraction of precipitates,and the calculation results coincide well with the experiment ones.The transformation kinetics curves were established to characterize the aging process.The characteristics of precipitates in the supersaturated solid solution alloy aged at 723 K were established,and the results show that the precipitates areβ-Ni3Si andδ-Ni2Si phases.

A dipole wind curl pattern induced by Taiwan Island and its effect on upper stratification in the northeastern South China Sea

Using hydrographic data sampled during four successive late summer-early autumn cruises in 2004-2007, vertical stratification along transects in the lee of Taiwan Island was analyzed to investigate upper ocean responses to orographically induced dipole wind stress curl (WSC). Results indicate that mixed-layer depth (MLD) and its relationship with thermocline depth varied under different local wind forcings. Average MLD along the transects from the 2004 to 2007 cruises were 18.5,30.7,39.2 and 24.5m, respectively. The MLD along the transects deepened remarkably and resulted in thermocline ventilation in 2005 and 2006, whereas ventilation did not occur in 2004 and 2007. Estimates indicate that frictional wind speed was the major factor in MLD variations. To a large degree, the combined effects of frictional wind speed and Ekman pumping are responsible for the spatial pattern of MLD during the cruises.

Optical Conductivity of Impurity-Doped Parabolic Quantum Wells in an Applied Electric Field

The optical conductivity of impurity-doped parabolic quantum wells in anapplied electric field is investigated with the memory-function approach, and the analyticexpression for the optical conductivity is derived. With characteristic parameters pertaining toGaAs/Ga_(1-x)Al_xAs parabolic quantum wells, the numerical results are presented. It is shown that,the smaller the well width, the larger the peak intensity of the optical conductivity, and the moreasymmetric the shape of the optical conductivity; the optical conductivity is more sensitive to theelectric field, the electric Geld enhances the optical conductivity; when the dimension of thequantum well increases, the optical conductivity increases until it reaches a maximum value, andthen decreases.

Study and Design of Spiral Bent Waveguide Configuration

A new version of the scalar transverse electric(TE) wave equation in the bent waveguide is introduced. Then, TE polarized field in curved single-mode waveguides is analyzed by using the finite-difference beam propagation method(FD-BPM). The bending loss in bent waveguides is gotten for the optical fields obtained from BPM and comparisons are made among losses of the waveguides with various curvature radiuses, refractive index differences and cross sections. Based on the results, the design of spiral bent waveguide configuration is proposed as follows: refractive index difference being of 0.007, both width and thickness of waveguides being of 6 μm, the curvature radius in the spiral centre being of 4 mm, and the bending loss coefficient of the designed spiral bent waveguide being of 0.302 3 dB/cm.

Effect of Si content on microstructure and properties of Si/Al composites

Si/Al composites with different Si contents for electronic packaging were prepared by spark plasma sintering （SPS） technique. Properties of the composites were investigated, including density, thermal conductivity, coefficient of thermal expansion and flexural strength. The effects of the Si content on microstructure and thermal and mechanical properties of the composites were studied. The results show that the Si/Al composites consist of Si and Al components and Al uniformly distributes among Si grains. The relative density of the Si/Al composites gradually increases with the decrease of Si content and reaches 98.0% when the Si content is 50%. The thermal conductivity, the coefficient of thermal expansion and the flexural strength of the composite all decrease with the increase of the Si content, and an optimal matching of them is obtained when the Si content is 60%（volume fraction）.

The Development of Thermal Conductive Polymer Composites for Heat Sink

The thermal and mechanical properties of the polyamide 6/boron nitride and polyphenylene sulfide/graphite composites have been investigated as a function of composition and size of fillers. The addition of highly thermal conductive h-BN and graphite gives rise to large increase （about 2 times） of thermal conductivity of individual polymer. In PPS/graphite system, the higher conductivity value was obtained when smaller graphites were added. Meanwhile, the tensile and flexural strength are reduced upon increasing filler loading.

Theoretical Analysis and Experimental Evidence of Non-Fourier Heat Conduction Behavior

This paper consists of two parts. (1) For a hollow sphere with sudden temperature changes on its inner and outer surfaces, the hyperbolic heat conduction equation is employed to describe this extreme thermal case and an analytical expression of its temperature distribution is obtained. According to the expression, the non-Fourier heat conduction behavior that will appear in the hollow sphere is studied and some qualitative conditions that will result in distinct non-Fourier behavior in the medium is ultimately attained. (2) A novel experiment to observe non-Fourier heat conduction behavior in porous material (mainly ordinary duplicating paper) heated by a microsecond laser pulse is presented. The conditions for observing distinct non-Fourier heat conduction behavior in the experimental sample agree well with the theoretical results qualitatively.

Study on Inhibitionof Growth of ACHN Cells via shRNA Expression Vector-Mediated Cycline1 Gene Silencing

OBJECTIVE To explore the inhibition of ACHN cells via shRNAexpression vector mediated cyclinE1 gene silencing.METHODS The shRNA targeting at cyclinE1 gene was designedand synthesized. By ligation, the fragment was inserted intopGenesil-1-U6 to construct the recombinant plasmid pGenesil-1-U6-cyclinE1. The identified recombinant plasmid was introducedinto ACHN cells with lipofectamine 2000. The inhibition ofcyclinE1 mRNA and protein expression were analyzed by RT-PCRand western-blotting. MTT method was used for observing cellproliferation and drawing growth curve. The cell cycle and ratiosof apoptotic cell were assessed by flow cytometric detection. Theability of invasion and speed of cell migration were detected bytranswell chamber invasive models and cell scratch method.RESULTS The inhibition of expression of cyclinE1 in ACHN cellsmediated by recombinant vector (0.0933 ± 0.05) was significantlylower than that in the group of transfected with empty vector(0.8827 ± 0.04) and the control group (0.9021 ± 0.03) (P < 0.05).Flow cytometry showed that recombinant cells were blocked inthe G_1 phase and the apoptotic ratio was increased significantly(11.15 ± 4.00)% (P < 0.05). The curves of cell growth indicated thatthe proliferation of cell transfected with recombinant plasmid wasinhibited significantly compared with that in control group (P <0.05). The results of transwell and cell scratch suggested that theabilities of invasion and migration of the cells transfected withrecombinant plasmid were decreased conspicuously (P < 0.05).CONCLUSION The expression of cyclinE1 could be inhibitedsuccessfully by RNA interference induced by shRNA expressionvector. This consequently inhibits the cell growth and inducesapoptosis. Our study provided a preliminary result in searching ofRNA interference (RNAi) therapy for renal cell carcinoma.

Study of WDM polymer planar curved waveguide couplers

A wavelength division multiplexer based on curved polymer planar waveguide is proposed. According to the coupled modetheory and the waveguide structure, the performance of the curved waveguide coupler (CWC) is analyzed. The results showthat CWC can accommodate wider multiplexing bandwidth than parallel straight waveguide coupler (SWC) due to thecompensation effect of the effective coupling length. The two variables, curvature radius and minimum spacing, increasethe design flexibility of the waveguide device. A 4-channel wavelength division multiplexing (WDM) system based onCWC is designed. The deviation of the center wavelength, due to the errors of curvature radius and minimum spacingduring fabrication process, is investigated. The smaller the curvature radius and the minimum spacing are, the larger thecentral wavelength deviation caused by the error of the curvature radius and the minimum spacing is, which provides someuseful theoretical basis for the design and the fabrication of polymer waveguide devices.

Interaction of Methane with Single-Walled Carbon Nanotubes: Role of Defects,Curvature and Nanotubes Type

We investigate the interaction of single-walled carbon nanotubes （SWCNTs） and methane molecule from the first principles. Adsorption energies are calculated, and methane affinities for the typical semiconducting and metallic nanotubes are compared. We also discuss role of the structural defects and nanotube curvature on the adsorption capability of the SWCNTs. We could observe larger adsorption energies for the metallic CNTs in comparison with the semiconducting CNTs. The obtained results for the zig zag nanotubes with various diameters reveal that the adsorption energy is higher for nanotubes with larger diameters. For defected tubes the adsorption energies are calculated for various configurations such as methane molecule approaching to the defect sites pentagon, hexagon, and heptagon in the tube surface. The results show that the introduce defects have an important contribution to the adsorption mechanism of the methane on SWNTs.

Pulmonary embolism after transcatheter arterial chemoembolization for hepatocellular carcinoma:a retrospective analysis on 10 years' experience

To study the clinical characteristics and treatment of pulmonary embolism （PE） after transcatheter arterial chemoembolization （TACE） for hepatocellular carcinoma （HCC）. Methods： The clinical records of 13 512 patients diagnosed with HCC and received TACE from January 2000 to December 2009 were reviewed. Among these patients, 5 031 were allocated into group A who had one or more disorders like diabetes, hypertension, coronary heart disease, obesity or varicose vein of lower limb, while the other 8 481 patients who did not have such disorders were in group B. Results： A total of 39 185 TACE procedures were performed for the 13 512 patients. Five （0.01%） patients in group A developed PE after TACE, of whom two recovered 4 and 5 d later with early anticoagulant therapy while the hypertension, coronary heart disease, obesity or varicose vein of lower limb are possibly more likely to develop PE other 3 died of respiratory failure within 5 h. The mortality of PE was 60% （3/5）. Conelusion： HCC patients with diabetes, after TACE than those without such disorders. Patients who have such disorders should be more carefully observed after TACE and early treatment with heparin should be applied once PE develops.

Defects detection in typical positions of bend pipes using low-frequency ultrasonic guided wave

In order to analyze the possibility of detecting defects in bend pipe using low-frequency ultrasonic guided wave, the propagation of T(0,1) mode and L(0,2) mode through straight-curved-straight pipe sections was studied. FE(finite element) models of bend pipe without defects and those with defects were introduced to analyze energy distribution, mode transition and defect detection of ultrasonic guided wave. FE simulation results were validated by experiments of four different bend pipes with circumferential defects in different positions. It is shown that most energy of T(0,1) mode or L(0,2) mode focuses on extrados of bend but little passes through intrados of bend, and T(0,1) mode or L(0,2) mode is converted to other possible non-axisymmetric modes when propagating through the bend and the defect after bend respectively. Furthermore, L(0,2) mode is more sensitive to circumferential notch than T(0,1) mode. The results of this work are beneficial for practical testing of pipes.

Treatment of primary hepatic carcinoma by transcatheter arterial perfusion of batroxobin combined with TACE:a preliminary clinical study

Objective:The aim of the study was to explore the therapeutic efficacy and safety of batroxobin in patients with primary hepatic carcinoma(PHC) and the advantages of transcatheter arterial perfusion of batroxobin combined with transcatheter arterial chemoembolization(TACE).Methods:Forty patients with PHC were randomized into experimental group(transcatheter arterial perfusion of batroxobin combined with TACE treatment,20 patients) and control group(TACE alone group,20 patients).The patients were followed up and the data were recorded,compared and analyzed.Results:(1) Compared with the control group,the FIB level in the experimental group was significantly decreased at the first month after treatment(P < 0.05).(2) The baseline of the tumor was shortened in both groups after the treatment.There was a significant difference between the two groups at different time intervals(P < 0.05).(3) After the treatment,there was a significant difference of progression-free survival(PFS) levels between the two groups(t =2.877,P < 0.05).(4) The incidence of metastasis were 5.0%(1/20) in both groups at 6 months after treatment,and that after one year was 10.0%(2/20) in the experimental group and 25.0%(5/20) in the control group.However,the difference was not significant(χ2 = 0.693,P > 0.05).Conclusion:Batroxobin can rapidly and effectively decrease the FIB level of the PHC cases.Therefore it may be used as an effective and safe adjuvant drug for the treatment of primary hepatic carcinomas.Transcatheter arterial perfusion of batroxobin combined with TACE therapy has advantages in comparison with TACE alone therapy.It could be taken as a new therapeutic regimen in the PHC treatment.

Braneworld Inflation with Induced Gravity and Curvature Effect

We construct a general braneworld inflation scenario where the inflaton field evolves on the DGP brahe and curvature effects are taken into account via incorporation of the Gauss-Bonnet term in the bulk action. While induced gravity on the DGP brane modifies the IR limit of general relativity, the Gauss-Bonnet term in the bulk action modifies the UV sector of the theory. In this setup, the dynamics of perturbations on the brane are studied with details and some confrontation with recent observations are discussed. While the Einstein-Gauss-Bonnet inflation scenario favors only a red spectrum of the scalar perturbation, pure DGP and GBIG inflation models have the capacity to realize the blue spectrum too. In addition, the GBIG inflation scenario in the large field limit requires a smaller number of e-folds than other proposed scenarios in the same situation. For the tensor-to-scalar ratio, the GBIG inflation scenario g/yes a better fit with observationally supported value of R≈ 0.24.

The diagnosis of hyperkalemia induced by potassium chloride in experimental rabbits

Objective： To observe the electrocardiogram （ECG） and heart rate in a rabbit model ofhyperkalemia induced by potassium chloride, and provide theoretical and experimental reference for timely diagnosis of hyperkalemia clinically. Methods： Forty rabbits were randomly assigned into four groups. 0.9% isotonic saline solution was perfused in the group I , while 1.0%, 4.0% and 10.0% potassium chloride solutions were perfused in the other groups, respectively, to induce hyperkalemia. Results： The changes of serum potassium, ECG and heart rate before perfusion were significantly （P〈 0.05） different from those after perfusion in the other groups compared with group I . The effect of ECG variability rates was well consistent （Kappa = 0.724, P〈0.01） with that of serum potassium on diagnostic tests in the other groups. The area under ROC curve in diagnosis effect of ECG variability rates and sermn potassium on hyperkalaemia was much significantly larger （P〈0.01 and P〈0.05） compared with 0.5. There was asignificantly positive correlation between ECG variability rates and serum potassium （r= 0.865, P〈0.05 for bilateral Pearson test）. There was certain positive correlation between heart rate and serum potassium, but the correlation was poor （r= 0.526, R2=0.277）. Conclusion： A combination of serum potassium, ECG variability rates and heart rate should be considered and analyzed by synthesis to establish an accurate and timely diagnosis for hyperkalemia.

Study on detonation characteristic of low energy detonating fuse in bending conditions

Detonation of low energy detonating fuse was studied in numerical simulation and experiments in bending conditions using LS_DYNA3D. The results show that pressure of the explosion and detonation velocity decrease in the same section areas after bending. In bending conditions, detonation wave was similar to small angle comer diffraction. So the detonation velocity was lower than normal velocity.