复混肥冷却工艺参数及设备尺寸的确定

90 kt/ a复肥厂 ,冷却系统一直采用流化床 ,冷却效果不好 ,包装温度偏高 ,产品结块时有发生 ,后改为转筒冷却。详细介绍冷却转筒、引风机 ,圆布袋除尘器工艺参数及设备尺寸的确定。改造后 ,包装温度降低近 2 0℃ ,生产能力由原班产 10 0吨提高到 130吨 ,粉尘收率由 96 %提高到 98.5 %。     

X-射线荧光光谱法测定催化剂中硫含量

采用X－射线荧光光谱中的基本参数法测定催化剂中硫元素含量，测量结果与化学分析法一致，此方法相对标准偏差小于7％，平均回收率为96％，检出限为0．01％，本方法简单，测定快速，测量结构准确。     

工艺参数对TiO2碳热还原合成Ti（C,N）粉末的影响

本文探讨了ＴｉＯ２碳热还原法合成Ｔｉ（Ｃ，Ｎ）粉末过程中合成温度，保温时间，Ｎ２气流量，Ｃ／Ｔｉ比值等工艺参数的变化对粉末性状的影响，实验表明，Ｎ比Ｃ更易于Ｔｉ结合，改变工艺对数可调整Ｔｉ（Ｃ１－ｘＮｘ）的ｘ值。在１４００～１７００℃间可获得ｘ值的０．６～０．８５的Ｔｉ（Ｃ１－ｘＮｘ）粉末。     

Impact of Modal Parameters on Milling Process Chatter Stability Lobes

1 Introduction Nowadays, millingis widely usedinfabricating of components of autos ,aircrafts , moulds and dies . Withthe rapid development of numerical control techniques ,the production efficiency and product quality are in theli melight . However ,as millingis anintermittent process ,a periodic forceinteracts betweenthe cuttingtool andworkpiece which makes the chatter vibration developed at specific conditions . This phenomenon may result in areduced productivity,increased cost andinconsist…     

抗滑桩设计参数的敏感性分析

利用自编程序ASP1.0,对滑坡的物理力学参数、桩截面型式及截面尺寸等对桩的锚深、内力、配筋量的影响进行了定量计算分析,结果表明:滑床土的内摩擦角φ对桩锚深、内力和配筋量的影响较大,桩锚深、内力和配筋量对φ变化很敏感;桩锚深、内力和配筋量对滑床土粘聚力c的变化相对不敏感;桩锚深对地基系数m的变化相对不敏感,而内力及配筋量则受m影响较大;滑坡的推力对桩的锚深、内力及配筋量影响显著,近似成线性关系,当过大的锚深导致施工困难时,单靠增大桩宽的方法来减小锚深是不经济的,而应通过调整桩距、削坡、改变桩截面等综合措施予以实现;同一滑坡条件下,空心抗滑桩一般是最经济的桩型.     

翻驳领纸样的参数化设计

分析翻驳领纸样设计中的翻折基点和翻领松量等关键影响因素，实现了基于服装CAD的翻驳领纸样参数化设计．这种方法能充分发挥服装CAD软件的优势，有利于提高纸样设计的质量和效率．     

Recommended NDT Practice and its Model-based Investigation for Eddy Current Inspection of Aerospace Structures

This paper describes a model-based investigation of inspection standards being developed as a recommended practice for eddy current (EC) NDT of aerospace structures for surface cracks. Compared to experimental investigations that can be laborious and expensive, model-based approach provides cost-effective and quantitative verifications of the recommended practice that covers wide ranges of materials, probes, instruments, frequencies, and test conditions. Probe signals for a number of specified standard notches are predicted and the expected amplitudes and phase-angle ranges are determined for various test conditions, in order to examine the influence of material electrical conductivity, frequency, and probe types. For a few selected situations, the model predictions are validated against experimental data. This study verifies the adequacies of the recommended specifications, especially of the reference notch selections and their response amplitudes for various test conditions, as well as confirming the suitability of using vertical amplitude alone for all the test situations. The influence of probe cable and the issue of three-point calibration are also discussed specifically in this investigation.     

Thermal Diffusivity Measurements on Insulation Materials with the Laser Flash Method

An iterative approach is adopted to determine the thermal diffusivity of the xonotlite-type calcium silicate insulation material with very low thermal conductivity. The measurements were performed with a conventional laser flash apparatus by rear-face detection of the temperature response of the three-layered sample, where the insulating material is sandwiched between two iron slices. In the evaluation of the thermal conductivity, the theoretical curve is fitted to the complete temperature–time curve, instead of just using the t _1/2 point. The theoretical model is based on the thermal quadrupole method. The nonlinear parameter estimation technique is used to estimate simultaneously the thermal diffusivity, heat transfer coefficient, and absorbed energy. Based on experimental results, the optimal thickness range of the insulation material in the sample is indicated as 1.6 to 1.9 mm. The effects of the uncertainties of the thicknesses, contact resistance, and thermophysical properties of the three layers on the measurement uncertainty are estimated, giving an overall uncertainty in the thermal conductivity of approximately 7.5%.Paper presented at the Seventh Asian Thermophysical Properties Conference, August 23–28, 2004, Hefei and Huangshan, Anhui, P. R. China.     

The results of the participation of the VNIIFTRI in the first international key comparisons of standards in the field of hydroacoustic measurements

The results of comparisons of the state special standard of the unit of sonic pressure in an aqueous medium, kept at the VNIIFTRI, are analyzed. These results were presented to the COOMET at the first international key comparisons in the field of the calibration of hydrophones in a free field, carried out in the period from 2002 to 2004 under the aegis of the Consultative Committee on Acoustics, Ultrasonics, and Vibrations. __________ Translated from Izmeritel’naya Tekhnika, No. 3, pp. 65–70, March, 2006.     

Inverse Analyses in Fracture Mechanics

The present purpose is a survey of some engineering-oriented research results which may be representative of the main issues in the title subject. Some recent or current developments are pointed out in the growing area of fracture mechanics centered on the calibration of cohesive fracture models for quasi-brittle materials, by approaches which combine experimentation, experiment simulation and minimisation of the discrepancy between measured and computed quantities. Specifically, reference is made herein to the following topics in calibration of fracture constitutive models: (a) deterministic characterisation of concrete-like materials by traditional three-point-bending tests (TPBTs), supplemented by optical measurements; (b) wedge-splitting tests (WST) and extended Kalman filter (EKF) for the stochastic estimation of fracture parameters; (c) in situ parameter identification for the local diagnosis of possibly deteriorated concrete dams on the basis of flat-jack tests; (d) fracture properties of ceramic materials and coating-substrate interfaces identified through indentation tests, imprint mapping and inverse analysis in micro-technologies.