摘要：Some effective parameters on the copper extraction from Kiire chalcopyrite concentrate were optimized by using response surface methodology （RSM）. Experiments designed by RSM were carried out in the presence of ammonium persulfate （APS） and different types of impeller in an autoclave system. Ammonium persulfate concentration and leaching temperature were defined numerically and three types of impellers were defined categorically as independent variables using experimental design software. The optimum condition for copper extraction from the chalcopyrite concentrate is found to be ammonium persulfate concentration of 277.77 kg/m3, leaching temperature of 389.98 K and wheel type of impeller. The proposed model equation using RSM has shown good agreement with the experimental data, with correlation coefficients R2 and RaZaj for the model as 0.89 and 0.84, respectively.

摘要：Acellular porcine small intestinal submucosa(SIS)has been used for esophagoplasty with success in a canine ***,it did not lead to complete *** better reconstruction,a cellular component is ***,promotion of angiogenesis with copper has been widely recognized by basic research as well as clinical *** this study,we have evaluated the feasibility and effectiveness of combined Cu and SIS(SIS-Cu patch)for the esophageal repair using a canine *** male beagle dogs were subjected to surgical resection to produce cervical esophageal defects(5 cm in length,180°in range).SIS with Cu(5 or 25μmol L 1copper)or without Cu was patched on the esophageal *** esophagram and histology exam were carried out to evaluate the effectiveness of the *** shown,the SIS-Cu graft promoted re-epithelialization,re-vascularization and muscular ***-Cu patch is more effective than SIS alone for esophageal repair,and the SIS+25μmol L 1Cu group demonstrated additional advantages over the SIS+5μmol L 1Cu.

摘要：The leaching behavior of Tunceli malachite mineral was investigated in nitric acid solutions by two steps to evaluate the effect of various experimental *** the first step,the optimal conditions for the leaching process were determined,while in the second step,a kinetic evaluation for the process was *** the optimization experiments,the concentration of nitric acid,temperature,stirring speed,and solid-to-liquid ratio were selected as the independent variables,and the central composite design method(CCD)was applied to the experimental *** the end of the experiments,the optimal values for the concentration of nitric acid,temperature,solid-to-liquid ratio and stirring speed were determined to be 0.5 mol/L,50℃,0.004 g/m L and 500 r/min,*** the optimal conditions,the leaching rate was found to be 99%for 120 min of reaction *** the kinetic evaluation tests,the effects of the concentration of nitric acid,temperature,stirring speed,solid-to-liquid ratio and particle size on the leaching rate of copper from malachite were *** these tests,it was determined that the leaching rate increased with the increase in the temperature,acid concentration and stirring speed,and with the decrease in the particle size and solid-to-liquid *** consequence of the kinetic analysis,it was observed that the leaching kinetics followed the mixed kinetic model,and a mathematical model for the leaching process was *** activation energy for this process was calculated to be 36.23 k J/mol.

摘要：Components made by joining different materials are required in various engineering *** of suchcomponents is a challenging task due to the vast difference in mechanical,thermal and electrical properties of the materials *** stir welding(FSW)is capable of joining dissimilar materials such as aluminum(Al)and copper(Cu)and thereforeresearchers have used this novel process for dissimilar ***,several works pertaining to dissimilar joining,specifically Al?Cu,are available in the literature but they are scattered in different sources,which makes the task of gatheringinformation about dissimilar FSW of Al?Cu *** work has been written with an aim to provide all pertinentinformation related to dissimilar FSW of Al?Cu at one place to ease the problems of *** comprehensively covers andsummarizes the topics such as the effect of tool design and geometry,FSW process parameters,FSW strategies on mechanicalproperties,microstructure and formation of defects during dissimilar FSW of Al?*** addition,it also presents and discussesseveral variants of dissimilar FSW of Al?***,this work not only puts forth major findings of the previous researchers but alsosuggests future recommendations for dissimilar FSW of Al?Cu.

摘要：The wear behavior of multi-walled carbon nano-tubes(MWCNTs)reinforced copper metal matrix composites(MMCs)processed through powder metallurgy(PM)route was focused on and further investigated for varying MWCNT quantity viaexperimental,statistical and artificial neural network(ANN)*** increases with increment in *** loss against varying load and sliding distance was analyzed as per L16orthogonal array using a *** parameter optimization by Taguchi’s method revealed that wear loss was affected to a greater extent by theintroduction of MWCNT;this wear resistant property of newer composite was further analyzed and confirmed through analysis ofvariance(ANOVA).MWCNT content(76.48%)is the most influencing factor on wear loss followed by applied load(12.18%)andsliding distance(9.91%).ANN model simulations for varying hidden nodes were tried out and the model yielding lower MAE valuewith3-7-1network topology is identified to be *** model predictions with R value of99.5%which highly correlated withthe outcomes of ANOVA were successfully employed to investigate individual parameter’s effect on wear loss of Cu?MWCNTMMCs.

摘要：The inhibition of copper corrosion by acid extract of Gnetum africana was studied using weight loss method of monitoring corrosion rate. The inhibition of Gnetum africana on copper corrosion was optimized by application of 23 factorial design. While the interactive effects of temperature, inhibition concentration and reaction time were investigated, the input factors and output response were also optimized. Optimum conditions for inhibition of Gnetum africana on copper corrosion were recorded at temperature of 303 K, reaction time of 24 h and inhibition concentration of 0.003 g/L. It could be concluded that factorial design was adequately applicable in the optimization of process variables and that Gnetuma africana sufficiently inhibited the corrosion of copper at the conditions of the experiment.

摘要：Electrocatalytic CO_(2) reduction has attracted growing attention as a promising route to realize artificial carbon *** transfer plays an essential role in CO_(2) reduction and dramatically impacts product ***,the precise control of proton transfer during CO_(2) reduction remains *** this study,we present a well-controlled proton transfer through the modification of several purines with similar molecular structures,and reveal a direct correlation between surface proton transfer capability and CO_(2) reduction selectivity over Cu *** a moderate proton transfer capability,the guanine modification can remarkably boost CH_(4) production and suppress C2 products ***-situ ATR-SEIRAS suggests a weakened^(*)CO intermediate adsorption and a relatively low local pH environment after the guanine modification,which facilitates the^(*)CO protonation and detachment for CH_(4) generation.

摘要：Abstract： An optimization study on electrodeposition of copper film from sulfuric acid bath in presence of supercritical carbon dioxide fluid was explored for electronic application. Factors that influence roughness of copper deposit were also discussed. A material property of copper deposition has been considered as a response variable and statistical experimental methods have been used to optimize the process parameters and the response. Effects of various current density, pressure and temperature were investigated to select the optimal operation factors. Scanning electron microscopy and atomic force microscopy were applied to determine average particle sizes and to confirm the characteristic of the metallic film obtained. Box-Behnken design and RSM （response surface methodology） were applied to find the optimal conditions of supercritical electroplating process. Regression model was built by fitting the experimental results with a second-order polynomial and was proved to be statistically significant since the coefficient of determination coefficient （R^2） was 0.9844. The optimal film of deposited can be obtained at current density 0.17 A/dm^2, pressure 186 bar and temperature 31.5 ℃.

摘要：copper oxides and its salts are now widely used as pesticides to control fungal and bacterial diseases of field crops. copper toxicity is often a major contributor of human health problems caused through accumulation of excess copper ions in various organs via drinking water, fruits and vegetables. So, detection and estimation of cupric ions in biological organs, drinking water, fruits and vegetables are extremely important. Recently, a fluorescence based sensor using coumarin dye (high quantum yield) has been proposed to detect micromolar Cu++ ion in biological organs. But major problem with coumarin dye is that it is insoluble in water and undergoes dye-dye aggregation in organic solvents. We proposed here a synthetic scheme of preparation of graphene oxide conjugated coumarin dye derivative which would be water dispersible and expected to be an ideal candidate for Cu2+ ion estimation in biological organs and drinking water.

摘要：A factorial experimental design method was used to examine the “Cu2+” removal from acid mine drainage wastewater by ion exchange technique. Ion Exchange technique is preferred because of reduced sludge generation compared to conventional treatment techniques and better decontamination efficiency from highly diluted solutions. Factorial design of experiments is employed to study the effect of four factors pH (3, 5, and 6), flow rate (5, 10, 15 L/hr), resin bed height (20, 40 and 60 cm) and initial concentration of the metal (100, 150 and 200 mgl-1) at three levels. The efficiency of metal removal was determined after 100 min of treatment. Main effects and interaction effects of the four factors were analyzed using statistical techniques. A regression model was recommended and it was found to fit the experimental data very well. The results were analyzed statistically using the Student’s t-test, analysis of variance, F-test and lack of fit to define most important process variables affecting the percentage “Cu2+” removal. In this study , pH was thus found to be the most important variable.