An attempt was made to improve the adsorption capability of the normal sand to be used as adsorbent for phenol and cadmium This has been done by producing a coated sand media. The coating process was done using emulsi...An attempt was made to improve the adsorption capability of the normal sand to be used as adsorbent for phenol and cadmium This has been done by producing a coated sand media. The coating process was done using emulsion asphalt to convert the normal sand to carbonated sand by using chemical treatment with sulfuric acid. The production process involves mixing of the sand with asphalt and an acid, then subjecting the mix to a heating process. Different mixing ratios, heating temperatures and times （activation times） were tried to obtain the optimum conditions at which the highest removal efficiency is obtained. Three types of acids were tried acetic acid, phosphoric acid and sulfuric acid. It was found that the sulfuric acid requires the lowest activation time, hence selected for the production. The removal efficiency of the produced media was significantly affected by the temperature, mixing ratio and activation heating time. The results show that, the optimum conditions for the production process are 350 , （1：2：3） （Asphalt/acid/sand） and 52 min for temperature, mixing ratio and activation heating time respectively. The final product was tested and found effective as an adsorbent media for phenol and cadmium. The removal efficiencies of these two pollutants in a batch adsorber were found 82.42% and 86.67%, respectively. The X-R diffraction and FTIR spectra tests had proved this media as an adsorbent.展开更多
An adenine nucleotide derivative 2-aminoadenosine 5＇-triphosphate was chemically synthesized through four steps and was characterized with 1H NMR, 31p NMR, 13C NMR, EA and FT-IR. Its ultraviolet and fluorescence prop...An adenine nucleotide derivative 2-aminoadenosine 5＇-triphosphate was chemically synthesized through four steps and was characterized with 1H NMR, 31p NMR, 13C NMR, EA and FT-IR. Its ultraviolet and fluorescence properties at various pH values were studied. Two pKa values for the compound were determined by the curves of UV absorption dependency on pH, Which were 0.68 and 4.83, respectively. The values were consistent with those calculated from ACD/Labs software. In addition, hydrolysis of the adenine nucleotide derivative in the catalysis of potato apyrase was studied. The competition of the ATP analogue with ATP for potato apyrase＇ active site was proved to be a sequential reaction mechanism.展开更多
Wastewater from paper mulberry （Broussonetia papyrifera） pulps production was subjected to biological activities evaluations and phenolics characterization. The EtOAc extract was found to be the best antioxidant （I...Wastewater from paper mulberry （Broussonetia papyrifera） pulps production was subjected to biological activities evaluations and phenolics characterization. The EtOAc extract was found to be the best antioxidant （IC50 = 0.4408 mg/mL） and tyrosinase inhibitor （IC50 = 1.6340 mg/mL） comparing to vitamin C （1C50 = 0.0011 mg/mL） and kojic acid （IC50 = 0.0244 mg/mL）, respectively, and the highest ferulic acid content （4.450 ±0.0077 ppm）. This fraction was further column chromatographed and antioxidant activity was archived （IC50 = 0.075 mg/mL） as well as tyrosinase inhibitory effect （IC50 = 0.042 mg/mL） in addition to ferulic acid （45.310 ± 0.0115 ppm）. Ferulic acid in paper mulberry was compared. Reflux with H2O gave the highest ferulic acid content （37.848 ± 1.2470 ppm） followed by a mixture of MeOH and H2O （2.002 ± 0.0370 ppm） and MeOH （1.185 ± 0.0320 ppm）, respectively. The reflux H2O was partitioned with EtOAc that extracted most of ferulic acid （256.678 ± 0.3760 ppm） and left less in the aqueous layer （9.408 ± 0.2820 ppm）.展开更多
Three hundred, one-day-old Japanese quail （Coturnixjaponica） divided into four groups, with three subgroups each, were fed a basal diet that served as control, or a basal diet containing 6 g calcium formate （CF）/k...Three hundred, one-day-old Japanese quail （Coturnixjaponica） divided into four groups, with three subgroups each, were fed a basal diet that served as control, or a basal diet containing 6 g calcium formate （CF）/kg or 2 g mannan oligosaccharides （MOS）/kg or both 6 g CF/kg plus 2 g MOS/kg. On 21st and 42nd days the pH of the quail crop, proventriculus, gizzard, duodenum, jejunum, ileum, large intestine and ceca were measured in situ and the total aerobic bacteria, lactic acid bacteria, Enterobacteriaceae and coliforms counts of the cecal content were recorded. Results showed that MOS decreased the cecal pH on the 42nd day and the total aerobic bacteria counts on 21st day. Moreover, CF decreased the cecal pH on the 42nd day and the lactic acid bacteria counts on 21st day. Interaction between MOS and CF was noticed on the cecal pH on the 42nd day, as the combined dietary addition of MOS and CF resulted in lower pH, compared to each separate addition. Also, interaction was noticed on the cecal bacterial counts on the 21st day, as the combined dietary addition of MOS and CF resulted in lower total aerobic bacteria, Enterobacteriacea and coliform counts, compared to each separate addition.展开更多
89 Au geochemical anomalies are delineated by using 1/200000 regional geochemical exploration data. By researching regional geochemical characteristics and the relationship with the geological background, the author p...89 Au geochemical anomalies are delineated by using 1/200000 regional geochemical exploration data. By researching regional geochemical characteristics and the relationship with the geological background, the author points out that： the main factors causing high background of Au geochemical anomalies are Gaixian and Dashiqiao formation of Liaohe group, intrusions of Mesozoic intermediate-acid intrusive rocks. The elements combination types of typical anomalies are determined by using factorial analysis,cluster analysis and other mathematical methods with the combination of elements association in typical anomalies：the composite anomaly of Baiyun gold deposits is Au-As-Sb, Maoling gold deposit is Au-As- Bi-Mo, Wulong gold deposits is Au-As-Bi-W, Xiaotongjiapuzi gold deposit is Au-As-Bi-Mo-Sb. By using multivariate statistical analysis method,62 ore-caused anomaly are preferred in 89 Au geochemical anomalies delineated. On this basis, the 62 anomalies are divided into 4 kinds of anomaly types reference to elements combination types of typical anomalies,the classification results of ore-caused anomalies are： 4 geochemical anomalies of Baiyun type,36 geochemical anomalies of Maoling type,11 geochemical anomalies of Wulong type, 11 geochemical anomalies of Xiaotongjapuzi type. According to the results, the prospecting direction is provided for the futme of gold exploration.展开更多
Poly （methyl methacrylate） is widely used as denture base material. During fabrication of a denture, the physical and mechanical properties are influenced by cure condition. Each cure cycle or fabrication technique ...Poly （methyl methacrylate） is widely used as denture base material. During fabrication of a denture, the physical and mechanical properties are influenced by cure condition. Each cure cycle or fabrication technique is attempts to optimize the properties for a given application. The aim of this study was to compare two types of commercially available denture base materials （heat-cure and self-cure） in their mechanical properties. The samples were prepared according to the daily routine work for sample preparation in dental laboratories. After reaching dough stage the mix packed into dumbbell shaped of stainless steel mould and pressed in a hydraulic bench press for 25 mins at room temperature. For heat cure the polymerization cycle was carried out using water bath, while self cure was done at room temperature. The impact strength was evaluated using Charpy impact test. The hardness test was conducted using a calibrated Vickers hardness tester machine. The lowest impact strength was observed in self-cure denture base material （self cure material 6.2 kJ/m^2 while heat cure 12.69 kJ/m^2. It appears that the tendency of heat cure to fracture was lower than self-cure denture base materials. Heat cure denture base material has significantly higher hardness test values than self-cure denture base material. The observed VHN value of the heat-cure was 20.09 g/mm^2 while the self-cure value was 12.7 g/mm^2. This is may be due to the plasticizer effect of residual monomer which was higher in self curing material as reported in previous work. Generally, the heat cure material showed better properties compared to self cure material.展开更多
General application of ＂greener methods＂ to the synthesis of monodisperse colloidal nanocrystals introduces impurities, including metal carboxylate precursors, non-volatile solvents, free ligands, and non-nanocrysta...General application of ＂greener methods＂ to the synthesis of monodisperse colloidal nanocrystals introduces impurities, including metal carboxylate precursors, non-volatile solvents, free ligands, and non-nanocrystalline side products. These impurities seriously diminish the solution processability and potential applications of colloidal nanocrystals. A protocol was established for evaluating purification schemes. The results revealed that commonly applied purification schemes and their variants do not exhibit a high level of performance and may degrade the ligand surface coverage. A new scheme involving chloroformacetonitrile precipitation quantitatively removed all impurities from colloidal solutions of CdSe and CdS nanocrystals coated with a variety of carboxylate ligands. The new scheme was benign to the surface structure of nanocrystaMigands complexes and resulted in each nanocrystal bearing a close-packed monolayer of carboxylate ligands.展开更多
文摘An attempt was made to improve the adsorption capability of the normal sand to be used as adsorbent for phenol and cadmium This has been done by producing a coated sand media. The coating process was done using emulsion asphalt to convert the normal sand to carbonated sand by using chemical treatment with sulfuric acid. The production process involves mixing of the sand with asphalt and an acid, then subjecting the mix to a heating process. Different mixing ratios, heating temperatures and times （activation times） were tried to obtain the optimum conditions at which the highest removal efficiency is obtained. Three types of acids were tried acetic acid, phosphoric acid and sulfuric acid. It was found that the sulfuric acid requires the lowest activation time, hence selected for the production. The removal efficiency of the produced media was significantly affected by the temperature, mixing ratio and activation heating time. The results show that, the optimum conditions for the production process are 350 , （1：2：3） （Asphalt/acid/sand） and 52 min for temperature, mixing ratio and activation heating time respectively. The final product was tested and found effective as an adsorbent media for phenol and cadmium. The removal efficiencies of these two pollutants in a batch adsorber were found 82.42% and 86.67%, respectively. The X-R diffraction and FTIR spectra tests had proved this media as an adsorbent.
文摘An adenine nucleotide derivative 2-aminoadenosine 5＇-triphosphate was chemically synthesized through four steps and was characterized with 1H NMR, 31p NMR, 13C NMR, EA and FT-IR. Its ultraviolet and fluorescence properties at various pH values were studied. Two pKa values for the compound were determined by the curves of UV absorption dependency on pH, Which were 0.68 and 4.83, respectively. The values were consistent with those calculated from ACD/Labs software. In addition, hydrolysis of the adenine nucleotide derivative in the catalysis of potato apyrase was studied. The competition of the ATP analogue with ATP for potato apyrase＇ active site was proved to be a sequential reaction mechanism.
文摘Wastewater from paper mulberry （Broussonetia papyrifera） pulps production was subjected to biological activities evaluations and phenolics characterization. The EtOAc extract was found to be the best antioxidant （IC50 = 0.4408 mg/mL） and tyrosinase inhibitor （IC50 = 1.6340 mg/mL） comparing to vitamin C （1C50 = 0.0011 mg/mL） and kojic acid （IC50 = 0.0244 mg/mL）, respectively, and the highest ferulic acid content （4.450 ±0.0077 ppm）. This fraction was further column chromatographed and antioxidant activity was archived （IC50 = 0.075 mg/mL） as well as tyrosinase inhibitory effect （IC50 = 0.042 mg/mL） in addition to ferulic acid （45.310 ± 0.0115 ppm）. Ferulic acid in paper mulberry was compared. Reflux with H2O gave the highest ferulic acid content （37.848 ± 1.2470 ppm） followed by a mixture of MeOH and H2O （2.002 ± 0.0370 ppm） and MeOH （1.185 ± 0.0320 ppm）, respectively. The reflux H2O was partitioned with EtOAc that extracted most of ferulic acid （256.678 ± 0.3760 ppm） and left less in the aqueous layer （9.408 ± 0.2820 ppm）.
文摘Three hundred, one-day-old Japanese quail （Coturnixjaponica） divided into four groups, with three subgroups each, were fed a basal diet that served as control, or a basal diet containing 6 g calcium formate （CF）/kg or 2 g mannan oligosaccharides （MOS）/kg or both 6 g CF/kg plus 2 g MOS/kg. On 21st and 42nd days the pH of the quail crop, proventriculus, gizzard, duodenum, jejunum, ileum, large intestine and ceca were measured in situ and the total aerobic bacteria, lactic acid bacteria, Enterobacteriaceae and coliforms counts of the cecal content were recorded. Results showed that MOS decreased the cecal pH on the 42nd day and the total aerobic bacteria counts on 21st day. Moreover, CF decreased the cecal pH on the 42nd day and the lactic acid bacteria counts on 21st day. Interaction between MOS and CF was noticed on the cecal pH on the 42nd day, as the combined dietary addition of MOS and CF resulted in lower pH, compared to each separate addition. Also, interaction was noticed on the cecal bacterial counts on the 21st day, as the combined dietary addition of MOS and CF resulted in lower total aerobic bacteria, Enterobacteriacea and coliform counts, compared to each separate addition.
文摘89 Au geochemical anomalies are delineated by using 1/200000 regional geochemical exploration data. By researching regional geochemical characteristics and the relationship with the geological background, the author points out that： the main factors causing high background of Au geochemical anomalies are Gaixian and Dashiqiao formation of Liaohe group, intrusions of Mesozoic intermediate-acid intrusive rocks. The elements combination types of typical anomalies are determined by using factorial analysis,cluster analysis and other mathematical methods with the combination of elements association in typical anomalies：the composite anomaly of Baiyun gold deposits is Au-As-Sb, Maoling gold deposit is Au-As- Bi-Mo, Wulong gold deposits is Au-As-Bi-W, Xiaotongjiapuzi gold deposit is Au-As-Bi-Mo-Sb. By using multivariate statistical analysis method,62 ore-caused anomaly are preferred in 89 Au geochemical anomalies delineated. On this basis, the 62 anomalies are divided into 4 kinds of anomaly types reference to elements combination types of typical anomalies,the classification results of ore-caused anomalies are： 4 geochemical anomalies of Baiyun type,36 geochemical anomalies of Maoling type,11 geochemical anomalies of Wulong type, 11 geochemical anomalies of Xiaotongjapuzi type. According to the results, the prospecting direction is provided for the futme of gold exploration.
文摘Poly （methyl methacrylate） is widely used as denture base material. During fabrication of a denture, the physical and mechanical properties are influenced by cure condition. Each cure cycle or fabrication technique is attempts to optimize the properties for a given application. The aim of this study was to compare two types of commercially available denture base materials （heat-cure and self-cure） in their mechanical properties. The samples were prepared according to the daily routine work for sample preparation in dental laboratories. After reaching dough stage the mix packed into dumbbell shaped of stainless steel mould and pressed in a hydraulic bench press for 25 mins at room temperature. For heat cure the polymerization cycle was carried out using water bath, while self cure was done at room temperature. The impact strength was evaluated using Charpy impact test. The hardness test was conducted using a calibrated Vickers hardness tester machine. The lowest impact strength was observed in self-cure denture base material （self cure material 6.2 kJ/m^2 while heat cure 12.69 kJ/m^2. It appears that the tendency of heat cure to fracture was lower than self-cure denture base materials. Heat cure denture base material has significantly higher hardness test values than self-cure denture base material. The observed VHN value of the heat-cure was 20.09 g/mm^2 while the self-cure value was 12.7 g/mm^2. This is may be due to the plasticizer effect of residual monomer which was higher in self curing material as reported in previous work. Generally, the heat cure material showed better properties compared to self cure material.
基金This work was supported by the National Natural Science Foundation of China （Nos. 21233005 and 91433204） and Fundamental Research Funds for the Central Universities （No. 2014FZA3006）.
文摘General application of ＂greener methods＂ to the synthesis of monodisperse colloidal nanocrystals introduces impurities, including metal carboxylate precursors, non-volatile solvents, free ligands, and non-nanocrystalline side products. These impurities seriously diminish the solution processability and potential applications of colloidal nanocrystals. A protocol was established for evaluating purification schemes. The results revealed that commonly applied purification schemes and their variants do not exhibit a high level of performance and may degrade the ligand surface coverage. A new scheme involving chloroformacetonitrile precipitation quantitatively removed all impurities from colloidal solutions of CdSe and CdS nanocrystals coated with a variety of carboxylate ligands. The new scheme was benign to the surface structure of nanocrystaMigands complexes and resulted in each nanocrystal bearing a close-packed monolayer of carboxylate ligands.
