搜索结果: 46-60 共查到“工学 STEP”相关记录75条 . 查询时间(0.078 秒)
阶梯隔舌对离心泵压力脉动和径向力影响的数值模拟（Numerical Simulation on Pressure Fluctuations and Radial Hydraulic Forces in Centrifugal Pump with Step-tongue）
离心泵 阶梯隔舌 动静干涉 径向力
2010/12/29
通过改变隔舌形状，采用SST模型分别对常规隔舌和阶梯隔舌蜗壳的离心泵进行全流道非稳态数值模拟。通过模拟分别获得了常规隔舌和阶梯隔舌蜗壳的离心泵压力脉动特性、作用在蜗壳和叶轮上的径向力特性，并对其进行比较分析。结果表明：采用常规隔舌和阶梯隔舌时，离心泵进出口压力、作用在蜗壳和叶轮上的径向力均随时间呈周期波动，脉动频率均以叶片通过频率为主；采用阶梯隔舌蜗壳后，进出口压力大小值和脉动幅值均明显减弱，高频...
The analysis of a semiconductor single asymmetric and symmetric step-index laser for even and odd fields by alpha method
Normalized frequency normalized propagation constant wave number confinement factor field probability ratio
2010/10/12
In this work, semiconductor step-index single waveguide has been analyzed by Alpha Method. A requested quantity of wave guide can be obtained in terms of normalized propagation constant, which is repr...
First Demonstration of Bidirectional Gigabit Transmission over a Single Step-Index Plastic Optical Fibre
Fiber optics communications Optical Communications
2015/6/9
We demonstrated a Gigabit Ethernet bidirectional transmission over a single POF. The solution is attractive for very low cost consumer electronic short-distance cabling at high data rate requiring ext...
Fast Implementation of the Split-Step Fourier Method using a Graphics Processing Unit
Optical communications Fiber optics communications
2015/6/9
We describe how simulations based on the Split-Step Fourier Method can be significantly accelerated by using commodity graphics hardware. Results for a benchmark scenario are provided to highlight per...
Channel Capacity of Step-Index Polymer Optical Fibers: Experiments and Simulation with Realistic Parameters
Fiber optics communications Modulation
2015/6/4
Step-index Polymer Optical Fibers (SI-POF) are candidates for broadband in-house networks. For the first time, we give a comprehensive overview over the real channel capacity of POF links up to 100 m,...
数控G代码转换为STEP文件方法的研究
G代码STEP复合元转换
2010/8/31
为了解决ISO10303和ISO14649标准的数控代码兼容性问题，基于可拓理论中的基元理论，建立了表达ISO6983标准中数控G代码知识的信息模型——复合元RG-function。根据STEP标准的要求，给出了G代码信息模型的EXPRESS语言描述模型，并在此基础上实现对G代码描述模型的实例化，从而生成STEP文件。构建了数控G代码向STEP文件转换的系统模型，介绍了其主要组成模块，并重点讨论了...
Understanding road users’expectations: an essential step for ADAS development
road users’expectations essential step ADAS development
2009/9/29
This article indicates the need for understanding road users’ expectations when developing Advanced Driver Assistance Systems (ADAS). Nowadays, technology allows more and more opportunities to provide...
在分析焦油形成机理和裂解条件的基础上提出了一种高效的低焦油生物质气化技术。该技术将生物质低温热解和高温气化两个过程分开进行，且要求热解发生于350～500℃之间，气化温度控制在1000℃左右，气化剂当量比大约为0.3。分步气化保证了焦油强化裂解的高温条件，使其充分裂解为小分子不凝性可燃气体，从而降低了可燃气体中基础焦油质量浓度，提高了燃气品质。该工艺可使燃气中基础焦油质量浓度降低到20mg/m3以...
两阶段聚类分析在烤烟外观质量评价中的应用（Application of Two-step Cluster Analysis for Appearance Quality Evaluation of Flue-cured Tobacco）
烤烟 外观质量 两阶段聚类分析
2009/8/11
应用两阶段聚类法对云南省大理州14个主栽烤烟品种C3F和C3L 2个等级的中部烟叶外观质量进行聚类分析，并应用多元方差分析对聚类效果进行了检验。结果表明，产地和品种对烤烟外观质量的影响较小，并将100 个烤烟样品外观质量分为3 个类型；明确了各类型烟叶外观质量的重要性状、变异特点和类型间的分类特性；其聚类分析结果与烤烟外观质量的实际表现相吻合，因而两阶段聚类分类结果客观、合理、准确、可靠。
基于STEP的协同设计版本存储控制策略
完整存储 差值存储 存储阈值
2009/8/10
计算机支持的协同设计的版本管理应保存整个设计过程中产生的所有版本，以便查询和检索。在对版本信息的存储方式中，完整版本存储的存取速度快，但占用存储空间大、冗余信息多，差值存储需要的存储空间少，但存取速度慢、安全性低。该文基于STEP数据交换标准，提出2个差值存储模型，通过构造版本存储阈值函数，将差值存储与完整存储相结合，有效实现了空间效率和时间效率的平衡。
A Novel Theoretical Procedure to Determine Absorption and Gain Coefficients in a Symmetric Single Step-Index Quantum Well Laser
Novel Theoretical Procedure Determine Absorption Gain Coefficients Symmetric Single Step-Index Quantum Well Laser
2009/7/28
If the indices nII, nI,III of the regions, the thickness 2a of the active region (AR) and the wavelength l for a single symmetric step-index quantum well laser (SSSIQWL) are given, the normalized prop...
The design and characterization of monolithically integrated optical transceiver PIC in InP is reported.The PIC is fabricated in one growth step and comprises a DFB laser / monitor in 1310nm, a PIN ph...
Real-time Gigabit Ethernet Transmission over up to 25 m Step-Index Polymer Optical Fibre using LEDs and FPGA-Based Signal Processing
Gigabit Ethernet Transmission Step-Index Polymer Optical Fibre LED FPGA-Based Signal Processing
2015/7/15
Real-time Gigabit Ethernet transmission over up to 25 m Step-Index Polymer Optical Fibre is demonstrated using a commercial LED. This is enabled by use of PAM-4 modulation and receiver equalisation in...
A precooling step is necessary to convert heated soymilk to freeze-gel. In order to estimate the significance of precooling, soymilk was precooled at various temperatures and then frozen. Based on the...
阶梯螺旋孔口式孔板消能降压装置性能（Performance on the Orifice Energy Dissipation and Decompression Equipment of the Step and Spiral-orifice Style）
阶梯螺旋孔口 消能降压 装置
2009/5/22
提出一种管道孔板消能装置，利用孔板扭转形成阶梯螺旋孔口使水流强制扭转，因水流在短距离内瞬间作较大角度的扭转而形成强度较大的螺旋流，其消能降压比率较高，并可在较大范围内进行调节，是一种农业节水灌溉管道系统消能降压装置，可用于农业节水灌溉供水系统和其他类似需要消能降压的管道系统。