成形压力对氧化铝瓷球性能的影响

本文以不同的压力等静压成形瓷球，研究了成形压力对瓷球烧结温度、密度及耐磨性的影响。结果表明：在本研究系统内随着压力的增加瓷球的烧结温度下降，烧成温度范围拓宽。采用150MPa成形的瓷球密度最大且耐磨性最好。     

Relationship of threshold diameter and Darcean permeability in unconsolidated porous structures

Experiment was conducted on the threshold pressure for atmospheric air through unconsolidated narrow size distributed mini sphere and sand particles at low flow rates. The threshold diameter calculated from measured threshold pressure showed that it does not follow the traditional similarity theory. This is consistent with our experiment on accurate permeability measurement, and can be explained as a result of gas slip flow within such micro pore structure. Our current work tend to find the method to predict the permeability-threshold pressure relationship for unconsolidated porous structures.     

D级压力容器制造许可证鉴定评审中企业存在问题综述

阐述了在D级压力容器制造许可证取换证鉴定评审过程中,取换证制造企业存在的较为普遍的问题。     

我公司进行热电联产的可行性分析

大压差减温减压是能的严重贬值。根据公司供热现状，分析了热电联产的可行性，利用蒸汽余压发电后，再供生产系统各热用户，这样既节约了能源又缓解了集团公司用电紧张的局面，而且有相当可观的经济效益。     

Deformation and failure study of surrounding rocks of dynamic pressure roadways in deep mines

In order to understand the change rules of stress-displacement in surrounding rocks of dynamic pressure roadways in deep mines and to obtain a theoretical basis for analyses of roadway stability and designs of support,we established a coupling equation of adjacent rock strength,mining stress and supporting resistance on the basis of an elastic-plastic theory of mechanics.We obtained an analytical solution for stress and displacement distribution of elastic and plastic regions in surrounding rock of dynamic pressure roadway..Based on this theory,we have analyzed the changes in stress-displacement in elastic and plastic regions of surrounding rocks of dynamic pressure roadways in the Haizi Coal Mine.The results show that:1) radial and tangential stress change violently within the first 4 m from the inner surface of a roadway after excavation;radial stress increases while tangential stress decreases within a range of about 6 m from the inner surface of the roadway as a function of q3;2) radial and tangential stress increase with an increase in the mining pressure coefficient k;the increase in the rate of tangential stress is greater than that of radial stress;3) the radial displacement of the inner surface of roadways decreases with an increase in q3,provided that k remains unchanged.     

Optimizing storage performance in public cloud platforms

Cloud computing is an elastic computing model where users can lease computing and storage resources on demand from a remote infrastructure.It is gaining popularity due to its low cost,high reliability,...     

FEM analyses for influences of stress corrosion and pressure solution on THM coupling in dual-porosity rock mass

With the models of stress corrosion and pressure solution, by Yasuhara et al., two computation conditions were designed for a hypothetical nuclear waste repository in an unsaturated dual-porosity rock mass: (i) the fracture apertures are changed with the stress corrosion and pressure solution (the porosity of rock matrix is also a function of stress); (ii) the fracture apertures and the porosity of rock matrix are constants. Then the corresponding two-dimensional FEM analyses for the coupled thermohydro-mec...     

Calculation of single adsorption isotherms from gravimetrically measured binary gas mixture adsorption isotherms on activated carbon at high pressures

A method is developed for the calculation of single-component adsorption isotherms from gravimetrically measured binary gas mixture adsorption isotherms at high pressures, at two temperatures and for different mole fractions of the gas phase. The adsorption of nitrogen/methane on active carbon Norit R1 is taken as an experimental example.     

Probabilistic and interval reliability design of the composite pressure vessel

Considering the randomness or interval character of physical parameters and applied loads of composite pressure vessels (COPV), the COPV reliability-analyzing model is built. And then the computational expressions for the mean value, standard deviation and deviation of fiber stress are deduced by the random factor method. The probabilistic and interval reliability designs on COPV are implemented by utilizing the probabilistic method and interval method combined with the improved particle swarm optimization (PSO) algorithm, respectively. The influence of fluctuation of structure uncertain parameters on COPV design thickness is inspected. Finally, examples are given to demonstrate that both probabilistic and interval reliability methods can satisfy the safety requirement and both are of higher rationality than the traditional safety factor method. And probabilistic method has a lower relative error but a higher computational complexity contrasted with the interval method.     

Deformation transition of intact coal induced by gas injection

Gas migration in coal bed is a multiple-physical process, of which not only includes gas desorption/diffusion through coal matrix and gas Darcy flow through the cleat system, but also results in deform...