In debris flow modelling,the viscosity and yield stress of fine-grained sediments should be determined in order to better characterize sediment flow.In particular,it is important to understand the effect of grain size...In debris flow modelling,the viscosity and yield stress of fine-grained sediments should be determined in order to better characterize sediment flow.In particular,it is important to understand the effect of grain size on the rheology of fine-grained sediments associated with yielding.When looking at the relationship between shear stress and shear rate before yielding,a high-viscosity zone(called pseudoNewtonian viscosity) towards the apparent yield stress exists.After yielding,plastic viscosity(called Bingham viscosity) governs the flow.To examine the effect of grain size on the rheological characteristics of fine-grained sediments,clay-rich materials(from the Adriatic Sea,Italy; Cambridge Fjord,Canada; and the Mediterranean Sea,Spain),silt-rich debris flow materials(from La Valette,France) and silt-rich materials(iron tailings from Canada) were compared.Rheological characteristics were examined using a modified Bingham model.The materials examined,including the Canadian inorganic and sensitive clays,exhibit typical shear thinning behavior and strong thixotropy.In the relationships between the liquidity index and rheological values(viscosity and apparent yield stress),the effect of grain size on viscosity and yield stress is significant at a given liquidity index.The viscosity and yield stress of debris flow materials are higher than those of low-activity clays at the same liquid state.However the viscosity and yield stress of the tailings,which are mainly composed of silt-sized particles,are slightly lower than those of low-activity clays.展开更多
Among the different methods used for reducing viscosity of bitumen,acoustic cavitation during sonication is well recognised.Several chemical methods were used to detect the production of reactive species such as hydro...Among the different methods used for reducing viscosity of bitumen,acoustic cavitation during sonication is well recognised.Several chemical methods were used to detect the production of reactive species such as hydroxyl radicals and hydrogen peroxide during acoustic cavitation processes.However,quantification of cavitation yield in sonochemical systems is generally limited to low frequencies and has not been applied to bitumen processing.An empirical determination of the cavitation yield in midto high-frequency range（378,574,850,992,and1173 k Hz）was carried out by measuring the amount of iodine liberated from the oxidation of potassium iodide（KI）.Further,cavitation yield and the effects of different sonic operating conditions such as power input（16.67%–83.33%）and solute concentration on cavitation yield were carried out in KI solution and sodium carboxymethyl cellulose–water mixture to obtain benchmark changes in rheology and chemistry using these two model fluids.The findings were then applied to bitumen upgrading through sonication.Through this study,it was found that the chemical cavitation yield peaked with a sonication frequency of 574 k Hz.It was also found that cavitation yield and viscosity change were correlated directly in bitumen and a 38%lower bitumen viscosity could be obtained by acoustic cavitation.展开更多
Currently the project'Development and commercia application of FCC catalyst for boosting gasoline yield'jointly undertaken by the SINOPEC Research Institute of Petroleum Processing(RIPP),the SINOPEC Yanshan Br...Currently the project'Development and commercia application of FCC catalyst for boosting gasoline yield'jointly undertaken by the SINOPEC Research Institute of Petroleum Processing(RIPP),the SINOPEC Yanshan Branch Co.and the Branch of SINOPEC Catalyst Company has passed the appraisal.The catalyst aimed at boosting展开更多
Grain yield security is a basic national policy of China,and changes in grain yield are influenced by a variety of factors,which often have a complex,non-linear relationship with each other.Therefore,this paper propos...Grain yield security is a basic national policy of China,and changes in grain yield are influenced by a variety of factors,which often have a complex,non-linear relationship with each other.Therefore,this paper proposes a Grey Relational Analysis-Adaptive Boosting-Support Vector Regression(GRA-AdaBoost-SVR)model,which can ensure the prediction accuracy of the model under small sample,improve the generalization ability,and enhance the prediction accuracy.SVR allows mapping to high-dimensional spaces using kernel functions,good for solving nonlinear problems.Grain yield datasets generally have small sample sizes and many features,making SVR a promising application for grain yield datasets.However,the SVR algorithm’s own problems with the selection of parameters and kernel functions make the model less generalizable.Therefore,the Adaptive Boosting(AdaBoost)algorithm can be used.Using the SVR algorithm as a training method for base learners in the AdaBoost algorithm.Effectively address the generalization capability problem in SVR algorithms.In addition,to address the problem of sensitivity to anomalous samples in the AdaBoost algorithm,the GRA method is used to extract influence factors with higher correlation and reduce the number of anomalous samples.Finally,applying the GRA-AdaBoost-SVR model to grain yield forecasting in China.Experiments were conducted to verify the correctness of the model and to compare the effectiveness of several traditional models applied to the grain yield data.The results show that the GRA-AdaBoost-SVR algorithm improves the prediction accuracy,the model is smoother,and confirms that the model possesses better prediction performance and better generalization ability.展开更多
[Objectives] Rice-Tartary buckwheat is a special type of Tartary buckwheat with easy hulling thin shell.This study was conducted to characterize the carbohydrate metabolism,quality and yield and provide a basis for fo...[Objectives] Rice-Tartary buckwheat is a special type of Tartary buckwheat with easy hulling thin shell.This study was conducted to characterize the carbohydrate metabolism,quality and yield and provide a basis for food processing and breeding of rice-Tartary buckwheat.[Methods]The local rice-Tartary buckwheat‘cv.Xiaomiqiao’(XMQ) was used to explore the characteristics of photosynthesis,starch synthesis enzyme activities,traits of yield and quality,as compared to Tartary buckwheat‘cv.Jinqiao 2’(JQ2).[Results]XMQ showed significantly lower values of net photosynthetic rate,ADPGase activity and starch synthase activity at one or more periods during grain filling than JQ2.The effective branch number and grain number per plant of XMQ were similar to that of JQ2 regardless of different years,but the 1 000-grain weight was significantly lighter that resulted in the significantly lower yield.XMQ accumulated similar contents of starch(amylose,amylopectin) and protein(glutelin,albumin,prolamin,globulin) to those of JQ2,but exhibited significantly lower flavonoid content.The values of peak viscosity and hot paste viscosity in XMQ were similar to those of JQ2,but the values of cool paste viscosity,breakdown and setback were significantly lower.In conclusion,XMQ showed low yield due to the insufficient of photosynthesis and starch synthesis.XMQ exhibited high nutritional quality as well as normal Tartary buckwheat and stored 18.88 mg/g of flavonoid,that might be consumed as daily diet.[Conclusions]The present results will provide a basis for utilization and improvement of rice-Tartary buckwheat.展开更多
Radiation induced grafting of various polymers with different monomers proved to be an attractive means to modify the physical or chemical properties of polymeric materials or textile fabrics. In the present work, rad...Radiation induced grafting of various polymers with different monomers proved to be an attractive means to modify the physical or chemical properties of polymeric materials or textile fabrics. In the present work, radiation induced grafting of viscose rayon fabrics, consisting mainly of cellulose fibers, with acrylic acid monomer has been carried out. The grafting yields have been thoroughly studied as a function of different applied experimental parameters. The impact of the graft yield on the physical properties of the fabrics such as tensile strength, elongation, swelling, moisture absorption, crease recovery angle and also the dyeing properties of the fabrics has been studied. The effect of increasing the contact time of the fabric and monomer solution, at room temperature, after stopping irradiation has been studied in detail as well as the effect of temperature on the irradiated samples also after stopping irradiation. The best grafting yield was obtained on irradiating viscose rayon fabric in methanol-water solvent containing acrylic acid monomer, at a dose 20 kGys, then heating for 7 hours at 80℃ and finally keeping the samples at room temperature for about 20 hours. That treatment significantly increased the final graft yield.展开更多
基金funded by the Natural Sciences and Engineering Research Council,Canada,via the COSTA(Continental Slope Stability)-Canada projectsupported by the Public Welfare & Safety Research Program through the National Research Foundation of Korea(NRF)+1 种基金funded by the Ministry of Science,ICT&Future Planning(Grant No.2012M3A2A1050983)the Research Project (11-7622,13-3212)of the Korea Institute of Geoscience and Mineral Resources(KIGAM)
文摘In debris flow modelling,the viscosity and yield stress of fine-grained sediments should be determined in order to better characterize sediment flow.In particular,it is important to understand the effect of grain size on the rheology of fine-grained sediments associated with yielding.When looking at the relationship between shear stress and shear rate before yielding,a high-viscosity zone(called pseudoNewtonian viscosity) towards the apparent yield stress exists.After yielding,plastic viscosity(called Bingham viscosity) governs the flow.To examine the effect of grain size on the rheological characteristics of fine-grained sediments,clay-rich materials(from the Adriatic Sea,Italy; Cambridge Fjord,Canada; and the Mediterranean Sea,Spain),silt-rich debris flow materials(from La Valette,France) and silt-rich materials(iron tailings from Canada) were compared.Rheological characteristics were examined using a modified Bingham model.The materials examined,including the Canadian inorganic and sensitive clays,exhibit typical shear thinning behavior and strong thixotropy.In the relationships between the liquidity index and rheological values(viscosity and apparent yield stress),the effect of grain size on viscosity and yield stress is significant at a given liquidity index.The viscosity and yield stress of debris flow materials are higher than those of low-activity clays at the same liquid state.However the viscosity and yield stress of the tailings,which are mainly composed of silt-sized particles,are slightly lower than those of low-activity clays.
文摘Among the different methods used for reducing viscosity of bitumen,acoustic cavitation during sonication is well recognised.Several chemical methods were used to detect the production of reactive species such as hydroxyl radicals and hydrogen peroxide during acoustic cavitation processes.However,quantification of cavitation yield in sonochemical systems is generally limited to low frequencies and has not been applied to bitumen processing.An empirical determination of the cavitation yield in midto high-frequency range（378,574,850,992,and1173 k Hz）was carried out by measuring the amount of iodine liberated from the oxidation of potassium iodide（KI）.Further,cavitation yield and the effects of different sonic operating conditions such as power input（16.67%–83.33%）and solute concentration on cavitation yield were carried out in KI solution and sodium carboxymethyl cellulose–water mixture to obtain benchmark changes in rheology and chemistry using these two model fluids.The findings were then applied to bitumen upgrading through sonication.Through this study,it was found that the chemical cavitation yield peaked with a sonication frequency of 574 k Hz.It was also found that cavitation yield and viscosity change were correlated directly in bitumen and a 38%lower bitumen viscosity could be obtained by acoustic cavitation.
文摘Currently the project'Development and commercia application of FCC catalyst for boosting gasoline yield'jointly undertaken by the SINOPEC Research Institute of Petroleum Processing(RIPP),the SINOPEC Yanshan Branch Co.and the Branch of SINOPEC Catalyst Company has passed the appraisal.The catalyst aimed at boosting
基金This work was support in part by Research on Key Technologies of Intelligent Decision-Making for Food Big Data under Grant 2018A01038in part by the National Science Fund for Youth of Hubei Province of China under Grant 2018CFB408+2 种基金in part by the Natural Science Foundation of Hubei Province of China under Grant 2015CFA061in part by the National Nature Science Foundation of China under Grant 61272278in part by the Major Technical Innovation Projects of Hubei Province under Grant 2018ABA099。
文摘Grain yield security is a basic national policy of China,and changes in grain yield are influenced by a variety of factors,which often have a complex,non-linear relationship with each other.Therefore,this paper proposes a Grey Relational Analysis-Adaptive Boosting-Support Vector Regression(GRA-AdaBoost-SVR)model,which can ensure the prediction accuracy of the model under small sample,improve the generalization ability,and enhance the prediction accuracy.SVR allows mapping to high-dimensional spaces using kernel functions,good for solving nonlinear problems.Grain yield datasets generally have small sample sizes and many features,making SVR a promising application for grain yield datasets.However,the SVR algorithm’s own problems with the selection of parameters and kernel functions make the model less generalizable.Therefore,the Adaptive Boosting(AdaBoost)algorithm can be used.Using the SVR algorithm as a training method for base learners in the AdaBoost algorithm.Effectively address the generalization capability problem in SVR algorithms.In addition,to address the problem of sensitivity to anomalous samples in the AdaBoost algorithm,the GRA method is used to extract influence factors with higher correlation and reduce the number of anomalous samples.Finally,applying the GRA-AdaBoost-SVR model to grain yield forecasting in China.Experiments were conducted to verify the correctness of the model and to compare the effectiveness of several traditional models applied to the grain yield data.The results show that the GRA-AdaBoost-SVR algorithm improves the prediction accuracy,the model is smoother,and confirms that the model possesses better prediction performance and better generalization ability.
基金Supported by National Natural Science Foundation of China(31660366)Natural Science Foundation of Guizhou Province(QKH CG[2019]4336,QKH ZC[2019]2298,QKH LH[2017]7359,QKH PT[2017]5726)。
文摘[Objectives] Rice-Tartary buckwheat is a special type of Tartary buckwheat with easy hulling thin shell.This study was conducted to characterize the carbohydrate metabolism,quality and yield and provide a basis for food processing and breeding of rice-Tartary buckwheat.[Methods]The local rice-Tartary buckwheat‘cv.Xiaomiqiao’(XMQ) was used to explore the characteristics of photosynthesis,starch synthesis enzyme activities,traits of yield and quality,as compared to Tartary buckwheat‘cv.Jinqiao 2’(JQ2).[Results]XMQ showed significantly lower values of net photosynthetic rate,ADPGase activity and starch synthase activity at one or more periods during grain filling than JQ2.The effective branch number and grain number per plant of XMQ were similar to that of JQ2 regardless of different years,but the 1 000-grain weight was significantly lighter that resulted in the significantly lower yield.XMQ accumulated similar contents of starch(amylose,amylopectin) and protein(glutelin,albumin,prolamin,globulin) to those of JQ2,but exhibited significantly lower flavonoid content.The values of peak viscosity and hot paste viscosity in XMQ were similar to those of JQ2,but the values of cool paste viscosity,breakdown and setback were significantly lower.In conclusion,XMQ showed low yield due to the insufficient of photosynthesis and starch synthesis.XMQ exhibited high nutritional quality as well as normal Tartary buckwheat and stored 18.88 mg/g of flavonoid,that might be consumed as daily diet.[Conclusions]The present results will provide a basis for utilization and improvement of rice-Tartary buckwheat.
文摘Radiation induced grafting of various polymers with different monomers proved to be an attractive means to modify the physical or chemical properties of polymeric materials or textile fabrics. In the present work, radiation induced grafting of viscose rayon fabrics, consisting mainly of cellulose fibers, with acrylic acid monomer has been carried out. The grafting yields have been thoroughly studied as a function of different applied experimental parameters. The impact of the graft yield on the physical properties of the fabrics such as tensile strength, elongation, swelling, moisture absorption, crease recovery angle and also the dyeing properties of the fabrics has been studied. The effect of increasing the contact time of the fabric and monomer solution, at room temperature, after stopping irradiation has been studied in detail as well as the effect of temperature on the irradiated samples also after stopping irradiation. The best grafting yield was obtained on irradiating viscose rayon fabric in methanol-water solvent containing acrylic acid monomer, at a dose 20 kGys, then heating for 7 hours at 80℃ and finally keeping the samples at room temperature for about 20 hours. That treatment significantly increased the final graft yield.
