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LIAO Zheng-Pin 《国外塑料》2008,26(4):31-35
China's plastics industry has witnessed the leap-forward development with the stable and sound growth of national economy,having increased its economic and technical indicators stably and greatly for consecutive ten years. 相似文献
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In application, lithium-ion cells undergo expansion during cycling. The mechanical behavior and the impact of external stress on lithium-ion battery are important in vehicle application. In this work, 18 Ah high power commercial cell with Li Ni0.5Co0.2Mn0.3O2/graphite electrode were adopted. A commercial compress machine was applied to monitor the mechanical characteristics under different stage of charge(SOC), lifetime and initial external force. The ... 相似文献
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《Journal of the European Ceramic Society》2003,23(3):469-479
The crack paths, induced by Vickers indentation in alumina–zirconia composites, were analyzed using fractal geometry. The fractal dimension nS was calculated for each crack. This parameter refers to a corresponding three-dimensional fracture surface and indicates how its geometry varies by changing the magnification. An interesting correlation between KIC and nS was found: it suggests that the samples with high percentages of alumina and also the pure zirconia are characterized by an intergranular fracture mode, while the composites with high zirconia content present a transgranular fracture mode. This result is confirmed by analyzing the energies of fracture calculated using both the classical and fractal approaches. The results obtained in this research not only made it possible to understand the fracture behavior of the analyzed composites, but also confirmed the good potential of fractal analysis to explain complex mechanisms such as those involved in the fracture of brittle materials. 相似文献
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A systematic approach for the steady-state operation analysis of chemical processes is pro-posed.The method affords the possibility of taking operation resilience into consideration during thestage of process design.It may serve the designer as an efficient means for the initial screening ofalternative design schemes.An ideal heat integrated distillation column(HIDiC),without any reboileror condenser attached,is studied throughout this work.It has been found that among the various va-riables concerned with the ideal HIDiC,feed thermal condition appears to be the only factor exertingsignificant influences on the interaction between the top and the bottom control loops.Maximuminteraction is expected when the feed thermal condition approaches 0.5.Total number of stages andheat transfer rate are essential to the system ability of disturbance rejection.Therefore,more stagesand higher heat transfer rate ought to be preferred.But,too many stages and higher heat transfer ratemay increase the load of the compres 相似文献
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Cyril Aubry Muhammad Tariq Khan Ali Reza Behzad Dalaver H. Anjum Leo Gutierrez Jean-Philippe Croue 《Desalination》2014
The intact cross-section of two fouled reverse osmosis membranes was characterized using a scanning transmission electron microscope (STEM) equipped with an electron energy dispersive spectroscope (EDS). Focused ion beam (FIB) was used to prepare a thin lamella of each membrane. These lamellas were then attached to a TEM grid for further STEM/EDS analysis. The foulant in sample A was mainly inorganic in nature and predominantly composed of alumino-silicate particles. These particles were surrounded by carbon at high concentrations, indicating the presence of organic materials. Iron was diffusely present in the cake layer and this could have enhanced the fouling process. The cake layer of membrane B was mainly consisted of organic matter (C, O, and N representing 95% of the total elemental composition) and organized in thin parallel layers. Small concentrations of Si, F, Na, Mg, and Cl were detected inside the active layer and support layer of the membrane. 相似文献
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M. Olivares H. López-Valdivia G. Vázquez-Polo M. A. Mondragón R. Lima E. Martínez V. M. Castaño 《Polymer Bulletin》1996,37(2):221-228
Summary FT-Raman spectroscopy of commercial amorphous and crystalline nylon 6–12 filaments subjected to various -radiation doses are presented. The results show that a difference exists in the interaction of -radiation with these polyamides, depending on the crystallinity which can be evaluated by measuring the CH-stretching/CH-bending Raman band intensity ratio as a function of applied -dose. 相似文献
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Based on the interfacial ligand exchange model and the law of conservation of mass, the multi-stage enantioselective liquid–liquid extraction model has been established to analyze and discuss on multi-stage centrifugal fractional extraction process of 4-nitrobenzene glycine (PGL) enantiomers. The influence of phase ratio, extractant concentra-tion, and PF6?concentration on the concentrations of enantiomers in the extract and raffinate was investigated by experiment and simulation. A good agreement between model and experiment was obtained. On this basis, the influence of many parameters such as location of stage, concentration levels, extractant excess, and number of stages on the symmetric separation performance was simulated. The optimal location of feed stage is the middle of fractional extraction equipment. The feed flow must satisfy a restricted relationship on flow ratios and the liquid throughout of centrifugal device. For desired purity specification, the required flow ratios decrease with extractant concentration and increase with PF6?concentration. When the number of stages is 18 stages at extractant excess of 1.0 or 14 stages at extractant excess of 2.0, the eeeq (equal enantiomeric excess) can reach to 99%. 相似文献
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Accidents in chemical production usually result in fatal injury,economic loss and negative social impact.Chemical accident reports which record past accident information,contain a large amount of expert knowledge.However,manually finding out the key factors causing accidents needs reading and analyzing of numerous accident reports,which is time-consuming and labor intensive.Herein,in this paper,a semiautomatic method based on natural language process(NLP) technology is developed to construct a k... 相似文献
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A bifurcation analysis approach is developed based on the process simulator gPROMS platform, which can automatically trace a solution path, detect and pass the bifurcation points and check the stability of solutions. The arclength continuation algorithm is incorporated as a process entity in gPROMS to overcome the limit of turning points and get multiple solutions with respect to a user-defined parameter. The bifurcation points are detected through a bifurcation test function τ which is written in C ++ routine as a foreign object connected with gPROMS through Foreign Process Interface. The stability analysis is realized by evaluating eigenvalues of the Jacobian matrix of each steady state solution. Two reference cases of an adiabatic CSTR and a homogenous azeotropic distillation from literature are studied, which successfully validate the reliability of the proposed approach. Besides the multiple steady states and Hopf bifurcation points, a more complex homoclinic bifurcation behavior is found for the distillation case compared to literature. 相似文献
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《Journal of the European Ceramic Society》2000,20(4):403-412
A microstructural study of mullite obtained by the reaction sintering of kaolinite–α–alumina mixtures in the range 1150–1700°C has been performed by using X-ray line profile analyses together with scanning and transmission electron microscopy equipped with microanalysis by energy dispersion (SEM-EDS, TEM-AEM). Two kinds of morphology corresponding to primary (elongated grains) and secondary (equiaxed grains) mullite have been observed. A bimodal crystallite size distribution has been detected through XRD microstructural analysis from 1300°C. The results obtained by this method are compared with SEM/TEM data. 相似文献
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Abnormal melting point depression of metal nanoparticles often occurs in heterogeneous catalytic reactions,which leads to a reduction in the stability of reactive nanoclusters.To study this abnormal phenomenon,the original and surface-energy modified Gibbs-Thomson equations were analyzed in this work and further modified by considering the effect of the substrate.The results revealed that the original Gibbs-Thomson equation was not suitable for the particles with radii smaller than 10 nm.Moreover,the performance of the surface-energy modified Gibbs-Thomson equation was improved,and the deviation was reduced to(-350-100) K,although further modification of the equation by considering the interfacial effect was necessary for the small particles(r 5 nm).The new model with the interfacial effect improved the model performance with a deviation of approximately-50 to 20 K,where the interfacial effect can be predicted quantitatively from the thermodynamic properties of the metal and substrate.Additionally,the micro-wetting parameter α_W can be used to qualitatively study the overall impact of the substrate on the melting point depression. 相似文献
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Exergy analysis of humidification–dehumidification desalination systems using driving forces concept
In this paper, a new method for exergy analysis of humidification–dehumidification (HD) desalination systems is presented. It is based on the principle that there are exergy losses wherever the driving forces exist. A methodology was developed for investigating various parametric effects on exergy losses. The method involved developing a sink and source model as well as basic relations in the system. Results showed that the mass transfer phenomenon does not have any effect on the total exergy losses of the HD systems. Heater was the largest irreversibility resource. Flow rate of the Un-heated fluid and the maximum temperature of the system had key roles in the total exergy losses. An optimum point for the water-heated HD desalination system is also introduced. Finally, some comparisons are proposed between the water-heated and the air-heated HD desalination systems. 相似文献
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T.M. Souza M.A.L. Braulio A.P. Luz P. Bonadia V.C. Pandolfelli 《Ceramics International》2012,38(5):3969-3976
The use of magnesia sources with high specific surface area and small particle size in the Al2O3–MgO system can induce faster in situ spinel (MgAl2O4) formation in castable compositions, improving the slag corrosion resistance. However, the higher reactivity of these raw materials lead to an intensive brucite formation (followed by volumetric expansion), spoiling the castable's properties during the curing and drying steps. Considering these aspects, a systemic analysis of three magnesia sources (dead-burnt and caustic ones) was carried out in order to evaluate: (1) their hydration impact on the refractory castables properties, and (2) their bonding ability in cement-free compositions. Mechanical strength, thermogravimetric and Young's modulus tests were conducted during the castables’ curing and drying steps. According to the results, the elastic modulus measurement is an efficient tool to evaluate the magnesia hydration. The addition of proper amounts of calcium aluminate cement and/or silica fume to the castables can inhibit the crack formation and provide suitable mechanical properties. The results also show that under certain conditions, MgO can be used as a binder, replacing calcium aluminate cement and leading to a significant reduction in the castables costs with no drawbacks to their refractoriness. 相似文献
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M. C. Rufino P. Tittonell P. Reidsma S. López-Ridaura H. Hengsdijk K. E. Giller A. Verhagen 《Nutrient Cycling in Agroecosystems》2009,85(2):169-186
Smallholder farming systems in sub-Saharan Africa are often nutrient-limited, and therefore imports must be increased to compensate
exports and losses. To explore whether the properties of nutrient cycling networks relate to the systems’ capability to sustain
rural families, we investigated N flows within contrasting crop-livestock systems in Ethiopia, Kenya and Zimbabwe applying
concepts from ecological network analysis. Farm households were conceptualised as networks, the compartments were the household
and their farming activities which were connected by the N flows. Indicators assessing network size, activity and cycling,
and the organisation and diversity of the N flows were compared with system productivity and food self-sufficiency. Results
showed that organisation and diversity of N flows to, from and within the farm households differed more between farms of different
resource endowments than across sites. The amount of N cycled per household was small and comparable across sites: less than
25 kg N year−1, and for the poor households less than 5 kg N year−1. Poor households with soil N stocks that were 50–60% smaller than wealthier households depended more on external inputs (e.g.
a dependence of 65% vs. 45% in Zimbabwe). Productivity was positively related to network size, its organisation and N cycling,
but utilisation efficiencies were different across sites in relation to soil N stock and the importance of livestock for N
flows. Greater size of the N flow network and its organisation led to increased productivity and food self-sufficiency, reducing
dependence, which may increase the adaptability and reliability of smallholder crop-livestock systems. 相似文献
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Xueguang Li Mengyan Yu Changfa Zhang Xiangtong Li Guangqing Liu Jianjun Dai Chunbao Zhou Yang Liu Jie Fu Yingwen Zhang Bang Yao 《中国化学工程学报》2023,53(1):25-36
Soybean soapstock(SS) is one of the main solid wastes produced in the refinery of edible oil processing. In this study, the co-pyrolysis of SS with iron slag(IS) and aluminum scrap(AS) was carried out in a tubular furnace. The gas, liquid and solid products were characterized and the char yield decreased with increasing IS/AS ratio. IS and AS can improve the gas yield, and when the ratio of SS/IS was 1:0.25, the total pyrolysis gas and hydrogen contents were significantly increased. The content ... 相似文献