V-Ti-Fe master alloys were prepared by metaUothermic reduction method, and the influences of the mass ratio of V205 to TiO2, Al and Al-Mg alloy addition amounts on the metal recovery rates and alloy compositions were ...V-Ti-Fe master alloys were prepared by metaUothermic reduction method, and the influences of the mass ratio of V205 to TiO2, Al and Al-Mg alloy addition amounts on the metal recovery rates and alloy compositions were investigated. The results show that appropriate technological parameters are： the mass ratio of V205 to TiO2 is 0.5：1, Al addition represents 95% of the theoretical value, and the Al-Mg alloy addition amount is one third that of the Al addition. The results from energy spectrum analysis show that V and Fe distribute uniformly in the prepared alloy, while the segregation for Ti, i.e. Ti-rich phase is detected. A spray refming process was carried out to reduce the impurity contents of Al and O in the prepared alloys. The Al content drops from 4.27% to 1.86%, and the O content drops from 2.10% to 0.91% after the refining process.展开更多
In this research work, extraction and purification of germanium from zinc leach residues(ZLR) were investigated. The results of ICP, XRF, and atomic adsorption spectroscopy(AAS) tests show that contents of germanium, ...In this research work, extraction and purification of germanium from zinc leach residues(ZLR) were investigated. The results of ICP, XRF, and atomic adsorption spectroscopy(AAS) tests show that contents of germanium, iron, lead, and zinc within the leaching residue were 105×10^(-6), 3.53%, 10.35%, and 8.8%, respectively. XRD results indicate that the main minerals were in different forms of sulfates(CaSO_4·2H_2O, PbSO_4 and ZnSO_4·6H__2O), silicate(SiO_2), and oxide(Fe_2O_3). Dissolution of leaching filter cake was carried out using 5 parameters and each in 4 levels(acid concentration, temperature, time, liquid-to-solid ratio, and stirring speed) by Taguchi method(L_(16)), and then optimization of the effective parameters by response surface method. Under optimum conditions, zinc and germanium dissolution efficiencies were 88.71% and 8%, respectively. Leaching tests with sulfuric acid(added di-ammonium oxalate monohydrate) and hydrochloric acid(HCl) on the residues obtained from previous-stage sulfuric acid dissolution, yielded germanium and iron recoveries of 83%, 88%, 40%, and 90%, respectively. Thus, leaching experiment with sulfuric acid(added di-ammonium oxalate monohydrate) was superior to that with hydrochloric acid due to high and low extraction amounts of germanium and iron, respectively. Precipitation experiments revealed that germanium purification with tannic acid presented a better result compared to sodium hydroxide and ammonia. Under optimum conditions, contents of germanium and iron in the solution after precipitation were 0.1505% and 14.7% with precipitation yields of 91% and 52%, respectively.展开更多
Under the condition of the designated collection ratio and the interfused ratio of mullock, to ensure the least energy consumption, the parameters of collecting head （the feed speed, the axes height of collecting hea...Under the condition of the designated collection ratio and the interfused ratio of mullock, to ensure the least energy consumption, the parameters of collecting head （the feed speed, the axes height of collecting head, and the rotate speed） are chosen as the optimized parameters. According to the force on the cutting pick, the collecting size of the cobalt crust and bedrock and the optimized energy consumption of the collecting head, the optimized design model of collecting head is built. Taking two hundred groups seabed microtopography for grand in the range of depth displacement from 4.5 to 5.5 era, then making use of the improved simulated annealing genetic algorithm （SAGA）, the corresponding optimized result can be obtained. At the same time, in order to speed up the controlling of collecting head, the optimization results are analyzed using the regression analysis method, and the conclusion of the second parameter of the seabed microtopography is drawn.展开更多
In this study, several methods were compared for the efficiency to concentrate venom from the tentacles of jellyfish Rhopilema esculentum Kishinouye. The results show that the methods using either freezing-dry or gel ...In this study, several methods were compared for the efficiency to concentrate venom from the tentacles of jellyfish Rhopilema esculentum Kishinouye. The results show that the methods using either freezing-dry or gel absorption to remove water to concentrate venom are not applicable due to the low concentration of the compounds dissolved. Although the recovery efficiency and the total venom obtained using the dialysis dehydration method are high, some proteins can be lost during the concentrating process. Comparing to the lyophilization method, ultrafiltration is a simple way to concentrate the compounds at high percentage but the hemolytic activities of the proteins obtained by ultrafiltration appear to be lower. Our results suggest that overall lyophilization is the best and recommended method to concentrate venom from the tentacles of jellyfish. It shows not only the high recovery efficiency for the venoms but high hemolytic activities as well.展开更多
[ Objective] The aim was to establish a method for the determination of Rhodamine B in food by HPLC-UV. [ Metkod] Rhodamine B was extracted with acetone/hexane from food samples. After concentrated and purified by alu...[ Objective] The aim was to establish a method for the determination of Rhodamine B in food by HPLC-UV. [ Metkod] Rhodamine B was extracted with acetone/hexane from food samples. After concentrated and purified by alumina cartridge, the Rhodamine B content in the food was determined by using high performance liquid chromatography with ultraviolet visible detector. [ Result] Within tile concentration range of 0.005 - 2.000 mg/kg, the peak area of Rhodamine B presented good linear relation with the concentration, and the related coefficient was 0.999 98. With high average recovery rate, the detection limit of the method was 0.005 mg/kg[ Concision] It is a fast and accurate method with high sensitivity to detect Rhodamine B in food.展开更多
Here we propose a method for determination of Avermectin residual content in milk and beef content. After extracting and processing the sample, use high performance liquid chromatography （HPLC） for determination. Mo...Here we propose a method for determination of Avermectin residual content in milk and beef content. After extracting and processing the sample, use high performance liquid chromatography （HPLC） for determination. Mobile phase is： V（Methanol）： V（Water）=90： 10; determination wavelength is 245 nm; flow rate is 0.8 mL/min. Avermectin is completely separated in 17min, linear range is 5 - 0.3 g/L, correlation coefficient is 0.9997, average recovery rates of Avermectin in milk and beef are respectively 91.20 %- 100.32 % and 89.93 %-99.15 %, the relative standard deviations are respectively less than 7% and 4%. This method is simple, sensitive and accurate, so is suitable for determination of Avermectin residues in milk and beef, and it can meet domestic and foreign testing requirements.展开更多
Twenty two fresh water fish samples namely Puntius sarana （Shawrputi）, Cyprinus carpio （Karp）, Oreochromis niloticos （Telapia）, Channa punctatus （Taki）, Wallogonia attu （Boal）, Eutropiichthys vacha （Bacha）...Twenty two fresh water fish samples namely Puntius sarana （Shawrputi）, Cyprinus carpio （Karp）, Oreochromis niloticos （Telapia）, Channa punctatus （Taki）, Wallogonia attu （Boal）, Eutropiichthys vacha （Bacha）, Macrognathus aculiatus （Baim）, Ailia coila （Kajoli）, Mystus cavasisus（Gulsa）, Ompok pabda （Pabdha）, Corica soborna （Kachki）, Mystus vittatus （Tengra）, Glossogobius giuris （Baila）, Macrobrachium malcolmsli （Chingri）, Amblypharyngodon microlepis （Mola）, Anabas testudineus （Koi）, Macrognathus aculiatus （Baim）, Channa striatus （Shole）, Heteropnueste fossilis （Shing）, Puntius sophore （Small Puti） and Pseudambassis ranga （Telapia） were collected from two rivers and one cultured fish pond. The samples were extracted by QuEChERS method, cleaned up with conc. H2SO4 treatment and cleaned extracts were analyzed by GC-ECD. Small size cultured rui fish sample which did show detectable amount of DDT and its metabohtes was used for the recovery experiments. Percent recovery was found to be in the range of 70%-113%. Amount of total DDTs were found to be 54.34, 48.81, 62.09, 54.72,78.81, 60.07, 47.0, 42.7, 26.31, 10.36, 25.32, 12.96, 20.10, 12.78, 17.65, and 4.71, 8.58, 11.3 and 19.01 ng/g in gulsa, pabhda, baila, bacha, baim, small purl, tengra, chanda, kachki, boal, taki, chingri, mola, shole, shing, koi, swarpurl, karp and telapia fish samples, respectively. However, the residual amounts of DDTs in all the fish samples were below maximum residue limit （MRL of DDTs in fish 5.0 mg/kg） according to Codex Alimentarius Commission. The ratios of 4,4＇-DDT/DDTs were in the range of 0.03-0.44 which indicated that exposure to DDT is not due to recent use.展开更多
For the purpose of enhancing automobile safety and the effectiveness of recalls,increasing manufacturers' quality control capabilities,and reducing defects,we investigated thestatus of recalls over the last five y...For the purpose of enhancing automobile safety and the effectiveness of recalls,increasing manufacturers' quality control capabilities,and reducing defects,we investigated thestatus of recalls over the last five years.We have examined patterns and trends in motor vehiclesafety recalls using databases from China,Europe and the United States.A recall rate parameterwas developed to evaluate the level of recall enforcement based on analyzing the reasonsfor recalls and manufactures' characteristics.Moreover,there were substantial differencesin the recall rates of China compared with those in other countries,indicating that Chinese manufacturersneed to take more active action in recall.展开更多
基金Project (2006AA068128) supported by the High-tech Research and Development Program of China
文摘V-Ti-Fe master alloys were prepared by metaUothermic reduction method, and the influences of the mass ratio of V205 to TiO2, Al and Al-Mg alloy addition amounts on the metal recovery rates and alloy compositions were investigated. The results show that appropriate technological parameters are： the mass ratio of V205 to TiO2 is 0.5：1, Al addition represents 95% of the theoretical value, and the Al-Mg alloy addition amount is one third that of the Al addition. The results from energy spectrum analysis show that V and Fe distribute uniformly in the prepared alloy, while the segregation for Ti, i.e. Ti-rich phase is detected. A spray refming process was carried out to reduce the impurity contents of Al and O in the prepared alloys. The Al content drops from 4.27% to 1.86%, and the O content drops from 2.10% to 0.91% after the refining process.
文摘In this research work, extraction and purification of germanium from zinc leach residues(ZLR) were investigated. The results of ICP, XRF, and atomic adsorption spectroscopy(AAS) tests show that contents of germanium, iron, lead, and zinc within the leaching residue were 105×10^(-6), 3.53%, 10.35%, and 8.8%, respectively. XRD results indicate that the main minerals were in different forms of sulfates(CaSO_4·2H_2O, PbSO_4 and ZnSO_4·6H__2O), silicate(SiO_2), and oxide(Fe_2O_3). Dissolution of leaching filter cake was carried out using 5 parameters and each in 4 levels(acid concentration, temperature, time, liquid-to-solid ratio, and stirring speed) by Taguchi method(L_(16)), and then optimization of the effective parameters by response surface method. Under optimum conditions, zinc and germanium dissolution efficiencies were 88.71% and 8%, respectively. Leaching tests with sulfuric acid(added di-ammonium oxalate monohydrate) and hydrochloric acid(HCl) on the residues obtained from previous-stage sulfuric acid dissolution, yielded germanium and iron recoveries of 83%, 88%, 40%, and 90%, respectively. Thus, leaching experiment with sulfuric acid(added di-ammonium oxalate monohydrate) was superior to that with hydrochloric acid due to high and low extraction amounts of germanium and iron, respectively. Precipitation experiments revealed that germanium purification with tannic acid presented a better result compared to sodium hydroxide and ammonia. Under optimum conditions, contents of germanium and iron in the solution after precipitation were 0.1505% and 14.7% with precipitation yields of 91% and 52%, respectively.
基金Project(50875265) supported by the National Natural Science Foundation of ChinaProject(20080440992) supported by the Postdoctoral Science Foundation of ChinaProject(2009SK3159) supported by the Technology Support Plan of Hunan Province,China
文摘Under the condition of the designated collection ratio and the interfused ratio of mullock, to ensure the least energy consumption, the parameters of collecting head （the feed speed, the axes height of collecting head, and the rotate speed） are chosen as the optimized parameters. According to the force on the cutting pick, the collecting size of the cobalt crust and bedrock and the optimized energy consumption of the collecting head, the optimized design model of collecting head is built. Taking two hundred groups seabed microtopography for grand in the range of depth displacement from 4.5 to 5.5 era, then making use of the improved simulated annealing genetic algorithm （SAGA）, the corresponding optimized result can be obtained. At the same time, in order to speed up the controlling of collecting head, the optimization results are analyzed using the regression analysis method, and the conclusion of the second parameter of the seabed microtopography is drawn.
基金Supported by the Award Foundation of Scientific Research for Excellent Young and Middle-age Scientist of Shandong Province (No. 2006BS07003)the Knowledge Innovation Project of Chinese Academy of Sciences (KZCX2-YW-R-104)
文摘In this study, several methods were compared for the efficiency to concentrate venom from the tentacles of jellyfish Rhopilema esculentum Kishinouye. The results show that the methods using either freezing-dry or gel absorption to remove water to concentrate venom are not applicable due to the low concentration of the compounds dissolved. Although the recovery efficiency and the total venom obtained using the dialysis dehydration method are high, some proteins can be lost during the concentrating process. Comparing to the lyophilization method, ultrafiltration is a simple way to concentrate the compounds at high percentage but the hemolytic activities of the proteins obtained by ultrafiltration appear to be lower. Our results suggest that overall lyophilization is the best and recommended method to concentrate venom from the tentacles of jellyfish. It shows not only the high recovery efficiency for the venoms but high hemolytic activities as well.
文摘[ Objective] The aim was to establish a method for the determination of Rhodamine B in food by HPLC-UV. [ Metkod] Rhodamine B was extracted with acetone/hexane from food samples. After concentrated and purified by alumina cartridge, the Rhodamine B content in the food was determined by using high performance liquid chromatography with ultraviolet visible detector. [ Result] Within tile concentration range of 0.005 - 2.000 mg/kg, the peak area of Rhodamine B presented good linear relation with the concentration, and the related coefficient was 0.999 98. With high average recovery rate, the detection limit of the method was 0.005 mg/kg[ Concision] It is a fast and accurate method with high sensitivity to detect Rhodamine B in food.
文摘Here we propose a method for determination of Avermectin residual content in milk and beef content. After extracting and processing the sample, use high performance liquid chromatography （HPLC） for determination. Mobile phase is： V（Methanol）： V（Water）=90： 10; determination wavelength is 245 nm; flow rate is 0.8 mL/min. Avermectin is completely separated in 17min, linear range is 5 - 0.3 g/L, correlation coefficient is 0.9997, average recovery rates of Avermectin in milk and beef are respectively 91.20 %- 100.32 % and 89.93 %-99.15 %, the relative standard deviations are respectively less than 7% and 4%. This method is simple, sensitive and accurate, so is suitable for determination of Avermectin residues in milk and beef, and it can meet domestic and foreign testing requirements.
文摘Twenty two fresh water fish samples namely Puntius sarana （Shawrputi）, Cyprinus carpio （Karp）, Oreochromis niloticos （Telapia）, Channa punctatus （Taki）, Wallogonia attu （Boal）, Eutropiichthys vacha （Bacha）, Macrognathus aculiatus （Baim）, Ailia coila （Kajoli）, Mystus cavasisus（Gulsa）, Ompok pabda （Pabdha）, Corica soborna （Kachki）, Mystus vittatus （Tengra）, Glossogobius giuris （Baila）, Macrobrachium malcolmsli （Chingri）, Amblypharyngodon microlepis （Mola）, Anabas testudineus （Koi）, Macrognathus aculiatus （Baim）, Channa striatus （Shole）, Heteropnueste fossilis （Shing）, Puntius sophore （Small Puti） and Pseudambassis ranga （Telapia） were collected from two rivers and one cultured fish pond. The samples were extracted by QuEChERS method, cleaned up with conc. H2SO4 treatment and cleaned extracts were analyzed by GC-ECD. Small size cultured rui fish sample which did show detectable amount of DDT and its metabohtes was used for the recovery experiments. Percent recovery was found to be in the range of 70%-113%. Amount of total DDTs were found to be 54.34, 48.81, 62.09, 54.72,78.81, 60.07, 47.0, 42.7, 26.31, 10.36, 25.32, 12.96, 20.10, 12.78, 17.65, and 4.71, 8.58, 11.3 and 19.01 ng/g in gulsa, pabhda, baila, bacha, baim, small purl, tengra, chanda, kachki, boal, taki, chingri, mola, shole, shing, koi, swarpurl, karp and telapia fish samples, respectively. However, the residual amounts of DDTs in all the fish samples were below maximum residue limit （MRL of DDTs in fish 5.0 mg/kg） according to Codex Alimentarius Commission. The ratios of 4,4＇-DDT/DDTs were in the range of 0.03-0.44 which indicated that exposure to DDT is not due to recent use.
文摘For the purpose of enhancing automobile safety and the effectiveness of recalls,increasing manufacturers' quality control capabilities,and reducing defects,we investigated thestatus of recalls over the last five years.We have examined patterns and trends in motor vehiclesafety recalls using databases from China,Europe and the United States.A recall rate parameterwas developed to evaluate the level of recall enforcement based on analyzing the reasonsfor recalls and manufactures' characteristics.Moreover,there were substantial differencesin the recall rates of China compared with those in other countries,indicating that Chinese manufacturersneed to take more active action in recall.
