液压传动与液压-机械分流传动的特性和在船舶上的应用

本文从目前船舶应用液压传动的现状出发,分析研究液压传动和液压机械分流传动的特性,以及运用液压机械分流传动对船舶节能产生的效果和价值。

基于机械分流的等离子体点火调节技术仿真研究

等离子体燃烧器在点火过程中存在一个合适的风速及煤粉浓度最有利于点火,但是,随着运行工况的改变,一次风速及煤粉浓度均会发生改变,从而偏离最佳工况,导致点火变差。为了解决这个问题,文章提出了基于机械分流的等离子体点火调节技术,并且对某电厂330 MW机组进行了数值仿真研究,结果表明此技术可以很好地调整等离子体燃烧器各级筒的煤粉浓度,解决等离子体燃烧器点火调节性差的问题。

机械分流泵防治门脉高压食管静脉曲张破裂出血的动物实验研究

目的通过实验犬门脉高压模型验证机械泵门体分流对防治门脉高压食管静脉曲张破裂出血的有效性和安全性。方法 24条实验成年犬行腹部手术采用门脉主干捆绑气囊导管引出体外注水的方式制成门脉高压动物模型,同时行门脉插管,出现食管静脉曲张破裂出血后随机分为机械泵持续门体分流A组和保守治疗B组治疗时间1周,分别对门脉压改变、止血率、血液主要有形成份及病死率进行检测记录。结果 24条模型犬均出现门脉高压食管静脉曲张破裂出血,A、B两组发生出血的时间和门脉压升高程度以及血红蛋白降低程度无明显差异。治疗后A组门脉压降低程度、止血率明显高于B组。病死率则明显低于B组(P<0.01)。A组使用机械分流泵未见血液成份明显机械损伤。结论使用机械分流泵在大型动物中行门体分流可以快速、可控降低门静脉压,从而即时、高效、确切中止门脉压食管静脉破裂出血。中长时段的机械分流对血液成份无明显损伤。

液力－机械外分流变矩器结构参数的选择

利用已有液力变矩器机型，在不改变原基本结构参数的前提下通过增加一组行星传动机构可以设计出具有较大能容量的液力-机械外分流变矩器。探讨了液力-机械外分流变矩器中行星传动机构参数选择的有关问题。研究表明，在组合变矩器结构设计中，为充分提高它的能容量、传动效率和穿透系数，应尽可能选取较小的齿数比。

一种液力－机械外分流变矩器的特性分析与计算

依据引进技术的结构方案和有关技术数据对一种液力－机械外分流式变矩器进行了动力特性的理论分析和计算。

基于支持向量机的农田水利灌溉分流机械运行异常检测

农田水利灌溉分流机械运行中未对运行数据进行处理,导致其存在检测性能差和检测率低等问题。为此,提出基于支持向量机的农田水利灌溉分流机械运行异常检测方法。采用组织映射算法聚类处理灌溉分流机械的运行数据,通过尺度不变特征变换SIFT方法获取运行数据特征,把免疫算法引入支持向量机中,将获取的运行数据特征输入支持向量机中,完成农田水利灌溉分流机械运行的异常检测。实验结果表明,该方法提升了农田水利灌溉分流机械检测的有效性。

Increasing the toughness while reducing the viscosity of carbon nanotube/ polyether imide/polyether ether ketone nanocomposites

Polyether ether ketone(PEEK)has good mechanical properties.However,its high viscosity when molten limits its use because it is hard to process.PEEK nanocomposites containing both carbon nanotubes(CNTs)and polyether imide(PEI)were pre-pared by a direct wet powder blending method using a vertical injection molding machine.The addition of an optimum amount of PEI lowered the viscosity of the molten PEEK by approximately 50%while producing an increase in the toughness of the nanocom-posites,whose strain to failure increased by 129%,and fracture energy increased by 97%.The uniformly dispersed CNT/PEI powder reduced the processing difficulty of PEEK nanocomposites without affecting the thermal resistance.This improvement of the strength and viscosity of PEEK facilitate its use in the preparation of thermoplastic composites.

HST在拖拉机上的匹配和使用

目前,小型拖拉机开始采用静液压传动元件,简化传动系的结构,提高整机负载适应能力。从静液压传动和传统机械传动的对比、HST元件和发动机的匹配、控制方式及刹车能力几方面阐述了HST在拖拉机上的应用。

HYBRID INTERNET TRAFFIC CLASSIFICATION TECHNIQUE

Accurate and real-time classification of network traffic is significant to network operation and management such as QoS differentiation, traffic shaping and security surveillance. However, with many newly emerged P2P applications using dynamic port numbers, masquerading techniques, and payload encryption to avoid detection, traditional classification approaches turn to be ineffective. In this paper, we present a layered hybrid system to classify current Internet traffic, motivated by variety of network activities and their requirements of traffic classification. The proposed method could achieve fast and accurate traffic classification with low overheads and robustness to accommodate both known and unknown/encrypted applications. Furthermore, it is feasible to be used in the context of real-time traffic classification. Our experimental results show the distinct advantages of the proposed classifi- cation system, compared with the one-step Machine Learning (ML) approach.

Feasibility of monitoring a mine fan by using interaction of vibrator system

The impeller of turbo machinery is a typical nonlinear multi-oscillator system.The vibration of each module is coupling, including fluid-solid coupling of the blade.The subject of our investigation was a KDF-5 mine fan for which we analyzed air vibration signals and axial vibration signals by using correlation dimension analysis under five variable working conditions.The results indicate that their correlation dimension curves show a uniform trend.That is to say, the characteristics of the variation signals of the integral structure are correlated and mutually embodied.It proves that it is possible to monitor the working state of a mine fan by coupling the vibration signals and air vibration signals for these are more sensitive in representing the status of the impeller system.

Design of High-Speed PM Synchronous Motor Thermal and Mechanical Analyzes Study for Aerospace Retraction Wheel Motor Application

A 3-D modeling of FEA （finite element analysis） design provides for high-speed synchronous with PMs （permanent magnets） applied in aerospace application will be examined under design considerations ofn = 12,000 rpm, short-duty operation, and etc. for an ARWM （aerospace retraction wheel motor）. First, lumped-elements will be fine-tuned following numerical method results is reported steady-state and transient solutions. Besides, the equations of thermal modeling such as Re, N,,, G,. and Pr numbers in order to calculate heat-transfer coefficient of convection on the rotor and stator surfaces in the air-gap have calculated. This section illustrates the temperature distribution of each point in a clear view. By CFD （fluid dynamic analysis） analysis, the fluid dynamics were modeled, pressure and velocity streamlines of cooling-flow have analyzed. An optimization algorithm was derived in order to have optimized number of water-channels as well. Second, calculation of nodal and tangential forces which deal with mechanical stresses of the ARWM have represented. The paper discusses an accurate magnetic-field analysis that addresses equivalent stress distribution in the magnetic core through using the transient FEA to estimate motor characteristics. The whole model shear and normal mechanical stresses and total deformation oftbe ARWM has been investigated by transient FEA. The end-winding effects were included by the authors.

Mechanical Analysis for Progressive Failure of Debris Landslide

It is of significance to research failure mechanism of debris landslides that are widespread in the Three Gorges Reservoir Area. Based on the statistical analysis of the developmental law and failure mode of debris landslides in the Three Gorges Reservoir, the mode of progressive failure is found. The mechanical model for progressive failure of debris landslides with two slip bands is also established by applying slice method. According to the results of the downslide force between adjacent slices, if the downslide force of lower slice is larger than zero, the slice fails along the major sliding surface, otherwise it is stable. In result, the failure range is obtained. The stress function can be determined through dimensional analysis of failure slice. According to static boundary conditions of the slice, stress state of any point in the slice can be obtained. Then stress state of any point in the secondary slip band can also be established. The failure of the secondary slip band is judged on the basis of Mohr-Coulomb failure criterion. Therefore, a mechanical method is proposed to analyze the progressive failure of debris landslide with two slip bands.

Thermodynamic compatibility and mechanical analogue of the generalized Jeffreys and generalized Oldroyd-B fluids with fractional derivatives

The study of generalized Jeffreys and generalized Oldroyd-B fluids with fractional derivatives has made rapid progress as an example of applications of fractional calculus in theology. However, their thermodynamic compatibility and mechanical ana- logue have not yet been properly considered. In the present study, by discussing both these issues, we find that the two orders of fractional derivatives in the constitutive equation of the generalized Jeffreys fluid must be the same in order to ensure that the equation is physically correct. Based on this generalized Jeffreys fluid, a thermodynamically compatible generalized Oldryd-B fluid is also proposed by the convected coordinates approach.

A new classification for epidemiological study of me- chanical eye injuries

Objective： Considering the difficulty in classifying some cases with eye trauma by Birmingham Eye Trauma Terminology （BETT） in our epidemiological study, we introduce a new classification for epidemiological study of mechanical eye injuries based on BETT. Methods： A retrospective investigation was carried out in 31 hospitals from January 2005 to December 2010. All medical records of inpatients with eye injuries were reviewed. A total of l0 718 patients （11 227 eyes） were diagnosed as mechanical eye injuries. All mechanical eye injuries were tried to be classified using BETT. While some eye injuries were difficult to categorize. We recorded the injury type and case number. A new classification based on BETT was also used for the same project. Results： Of 10 718 patients （11 227 eyes） with me- chanical eye injuries, the following cases cannot be classi- fied by BETT： 1 488 patients （1 559 eyes） with merely orbitalor ocular adnexa injury, 1 961 （2 054） globe injuries associ- ated with orbital or ocular adnexa injury, 271 （284） ocular surface foreign body （OSFB） or ocular wall foreign body （OWFB）, 77 （89） contusion, 9 （11） lamellar laceration asso- ciated with OSFB or OWFB, 29 （30） rupture associated with OSFB, OWFB or intraocular foreign body and 60 （62） lace- ration associated with OSFB or OWFB. While according to our new classification, all eye injuries can be categorized without any difficulty. Conclusion： Difficulty in classifying some eye injuries in epidemiological study by BETT brings some trouble to our study, which can be solved by our new eye injury clas- sification to some extent. It is hoped that other ophthal- mologists present better ones to make the classification more perfect.

Mechanical properties of nanocrystalline nanoporous gold complicated by variation of grain and ligament: A molecular dynamics simulation

A series of large-scale molecular dynamics(MD) simulations has been performed to study the effects of grain size and ligament diameter on the mechanical properties of nanocrystalline nanoporous gold. Such simulations indicate that the principal deformation mechanism is a combination of grain boundary sliding, grain rotation and dislocation movement. The results of uniaxial tensile tests reveal the presence of a reverse Hall-Petch relation between strength and nominal grain size, rather than the conventional Hall-Petch relationship in the present range of nominal grain size(7.9–52.7 nm). An increase of flow stress may possibly attribute to the lower total proportion of grain boundary sliding and grain rotation in the deformation of samples with larger grain size. The Young's modulus shows a linear relation with the reciprocal of nominal grain size, which depends largely on the volume fraction of grain boundaries and thus decreasing grain size leads to relatively lower Young's modulus. MD simulations on samples with ligament diameter ranging from 4.07 to 8.10 nm are also carried out and results show that the increasing ligament diameter resulted in decreased flow stress and increased Young's modulus.