Co3O4 catalysts prepared with different precipitants（NH3·H2O,KOH,NH4HCO3,K2CO3 and KHCO3）were investigated for the oxidation of formaldehyde（HCHO）.Among these,KHCO3-precipitated Co3O4（KHCO3-Co） was the most...Co3O4 catalysts prepared with different precipitants（NH3·H2O,KOH,NH4HCO3,K2CO3 and KHCO3）were investigated for the oxidation of formaldehyde（HCHO）.Among these,KHCO3-precipitated Co3O4（KHCO3-Co） was the most active low-temperature catalyst,and was able to completely oxidize HCHO at the 100-ppm level to CO2 at 90℃.In situ diffuse reflectance infrared spectroscopy demonstrated that hydroxyl groups on the catalyst surface were regenerated by K~＋ and CO3^（2-）,thus promoting the oxidation of HCHO.Moreover,H2-temperature programmed reduction and X-ray photoelectron spectroscopy showed that employing KHCO3 as the precipitant increased the Co^3＋/Co^2＋molar ratio on the surface of the Co3O4 catalyst,thus further promoting oxidation.Structural characterization revealed that catalysts precipitated with carbonate or bicarbonate reagents exhibited greater specific surface areas and pore volumes.Overall,these data suggest that the high activity observed during the Co3O4 catalyzed oxidation of HCHO can be primarily attributed to the presence of K~＋ and CO3^（2-） on the Co3O4 surface and the favorable Co^3＋/Co^2＋ ratio.展开更多
AIM: To compare a lansoprazole-based triple versus quadruple therapy for Helicobacter pylori (H pylori) eradication with emphasis on side effect prof ile,patient compliance and eradication rate at a rural district gen...AIM: To compare a lansoprazole-based triple versus quadruple therapy for Helicobacter pylori (H pylori) eradication with emphasis on side effect prof ile,patient compliance and eradication rate at a rural district general hospital in Wales,United Kingdom. METHODS: One hundred one patients with H pylori infection were included in the study. Patients were randomised to receive triple therapy comprising of lansoprazole 30 mg,amoxycillin 1 g,clarithromycin 500 mg,all b.d. (LAC),or quadruple therapy comprising of lansoprazole 30 mg b.d.,metronidazole 500 mg t.d.s.,bismuth subcitrate 240 mg b.d.,and tetracycline chloride 500 mg q.d.s. (LMBT). Cure was defi ned as a negative 13C urea breath test 2 mo after treatment. RESULTS: Seven patients were withdrawn after randomisation. Fifty patients were assigned to LAC group and 44 to LMBT group. The intention-to-treat cure rates were 92% and 91%,whereas the per-protocol cure rates were 92% and 97%,respectively. Side effects were common,with 56% experiencingmoderate to severe symptoms in the LAC group and 59% in the LMBT group. Symptoms of vomiting,diarrhoea and black stools were significantly more common in the LMBT group. Patient compliance was 100% for triple therapy and 86% for quadruple therapy (P < 0.01). One-third of patients in both groups were still taking acid-reducing medications at six-month follow-up. CONCLUSION: One-week triple and quadruple therapies have similar intention-to-treat eradication rates. Certain side effects are more common with quadruple therapy,which can compromise patient compliance. Patient education or modifi cations to the regimen are alternative options to improve compliance of the quadruple regimen.展开更多
Microsized single-crystalline Co3O4 has been synthesized by high-temperature hydrolysis of CoCD2H20 at 600℃. The samples were characterized by powder X-ray diffraction （XRD）, scanning electron microscopy （SEM） an...Microsized single-crystalline Co3O4 has been synthesized by high-temperature hydrolysis of CoCD2H20 at 600℃. The samples were characterized by powder X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results reveal that the as-prepared powders are microsized single-crystalline CO3O4 with cubic spinel structure. An increase in the high-temperature hydrolysis time results in the evolution of particle shapes from cube to quasi-sphere, and then to octahedron. The effect of NaCl additive on the surface morphologies of Co3O4 particles was experimentally investigated. The results indicate that the NaCl additive acts as an inert disperse phase in the high-temperature hydrolysis, and prevents the aggregation of Co3O4 particles effectively.展开更多
A novel rcgularization-based approach is presented for super-resolution reconstruction in order to achieve good tradeoff between noise removal and edge preservation. The method is developed by using L1 norm as data fi...A novel rcgularization-based approach is presented for super-resolution reconstruction in order to achieve good tradeoff between noise removal and edge preservation. The method is developed by using L1 norm as data fidelity term and anisotropic fourth-order diffusion model as a regularization item to constrain the smoothness of the reconstructed images. To evaluate and prove the performance of the proposed method, series of experiments and comparisons with some existing methods including bi-cubic interpolation method and bilateral total variation method are carried out. Numerical results on synthetic data show that the PSNR improvement of the proposed method is approximately 1.0906 dB on average compared to bilateral total variation method, and the results on real videos indicate that the proposed algorithm is also effective in terms of removing visual artifacts and preserving edges in restored images.展开更多
A simple ultrasound-assisted co-precipitation method was developed to prepare ferroferric oxide/graphene oxide magnetic nanoparticles(Fe_3O_4/CO MNPs).The hysteresis loop of Fe_3O_4/GO MNPs demonstrated that the sampl...A simple ultrasound-assisted co-precipitation method was developed to prepare ferroferric oxide/graphene oxide magnetic nanoparticles(Fe_3O_4/CO MNPs).The hysteresis loop of Fe_3O_4/GO MNPs demonstrated that the sample was typical of superparamagnetic material.The samples were characterized by transmission electron microscope,and it is found that the particles are of small size.The Fe_3O_4/GO MNPs were further used as an adsorbent to remove Rhodamine B.The effects of initial pH of the solution,the dosage of adsorbent,temperature,contact time and the presence of interfering dyes on adsorption performance were investigated as well.The adsorption equilibrium and kinetics data were fitted well with the Freundlich isotherm and the pseudosecond-order kinetic model respectively.The adsorption process followed intra-particle diffusion model with more than one process affecting the adsorption of Rhodamine B.And the adsorption process was endothermic in nature.Furthermore,the magnetic composite with a high adsorption capacity of Rhodamine B could be effectively and simply separated using an external magnetic field.And the used particles could be regenerated and recycled easily.The magnetic composite could find potential applications for the removal of dye pollutants.展开更多
基金supported by the National Natural Science Foundation of China(21577088)~~
文摘Co3O4 catalysts prepared with different precipitants（NH3·H2O,KOH,NH4HCO3,K2CO3 and KHCO3）were investigated for the oxidation of formaldehyde（HCHO）.Among these,KHCO3-precipitated Co3O4（KHCO3-Co） was the most active low-temperature catalyst,and was able to completely oxidize HCHO at the 100-ppm level to CO2 at 90℃.In situ diffuse reflectance infrared spectroscopy demonstrated that hydroxyl groups on the catalyst surface were regenerated by K~＋ and CO3^（2-）,thus promoting the oxidation of HCHO.Moreover,H2-temperature programmed reduction and X-ray photoelectron spectroscopy showed that employing KHCO3 as the precipitant increased the Co^3＋/Co^2＋molar ratio on the surface of the Co3O4 catalyst,thus further promoting oxidation.Structural characterization revealed that catalysts precipitated with carbonate or bicarbonate reagents exhibited greater specific surface areas and pore volumes.Overall,these data suggest that the high activity observed during the Co3O4 catalyzed oxidation of HCHO can be primarily attributed to the presence of K~＋ and CO3^（2-） on the Co3O4 surface and the favorable Co^3＋/Co^2＋ ratio.
基金Wyeth,United Kingdom and North West Wales NHS Trust
文摘AIM: To compare a lansoprazole-based triple versus quadruple therapy for Helicobacter pylori (H pylori) eradication with emphasis on side effect prof ile,patient compliance and eradication rate at a rural district general hospital in Wales,United Kingdom. METHODS: One hundred one patients with H pylori infection were included in the study. Patients were randomised to receive triple therapy comprising of lansoprazole 30 mg,amoxycillin 1 g,clarithromycin 500 mg,all b.d. (LAC),or quadruple therapy comprising of lansoprazole 30 mg b.d.,metronidazole 500 mg t.d.s.,bismuth subcitrate 240 mg b.d.,and tetracycline chloride 500 mg q.d.s. (LMBT). Cure was defi ned as a negative 13C urea breath test 2 mo after treatment. RESULTS: Seven patients were withdrawn after randomisation. Fifty patients were assigned to LAC group and 44 to LMBT group. The intention-to-treat cure rates were 92% and 91%,whereas the per-protocol cure rates were 92% and 97%,respectively. Side effects were common,with 56% experiencingmoderate to severe symptoms in the LAC group and 59% in the LMBT group. Symptoms of vomiting,diarrhoea and black stools were significantly more common in the LMBT group. Patient compliance was 100% for triple therapy and 86% for quadruple therapy (P < 0.01). One-third of patients in both groups were still taking acid-reducing medications at six-month follow-up. CONCLUSION: One-week triple and quadruple therapies have similar intention-to-treat eradication rates. Certain side effects are more common with quadruple therapy,which can compromise patient compliance. Patient education or modifi cations to the regimen are alternative options to improve compliance of the quadruple regimen.
基金Project(50704038) supported by the National Natural Science Foundation of ChinaProject(108170) supported by the Key Foundation of Ministry of Education,China
文摘Microsized single-crystalline Co3O4 has been synthesized by high-temperature hydrolysis of CoCD2H20 at 600℃. The samples were characterized by powder X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The results reveal that the as-prepared powders are microsized single-crystalline CO3O4 with cubic spinel structure. An increase in the high-temperature hydrolysis time results in the evolution of particle shapes from cube to quasi-sphere, and then to octahedron. The effect of NaCl additive on the surface morphologies of Co3O4 particles was experimentally investigated. The results indicate that the NaCl additive acts as an inert disperse phase in the high-temperature hydrolysis, and prevents the aggregation of Co3O4 particles effectively.
基金Projects(60963012,61262034)supported by the National Natural Science Foundation of ChinaProject(211087)supported by the Key Project of Ministry of Education of ChinaProjects(2010GZS0052,20114BAB211020)supported by the Natural Science Foundation of Jiangxi Province,China
文摘A novel rcgularization-based approach is presented for super-resolution reconstruction in order to achieve good tradeoff between noise removal and edge preservation. The method is developed by using L1 norm as data fidelity term and anisotropic fourth-order diffusion model as a regularization item to constrain the smoothness of the reconstructed images. To evaluate and prove the performance of the proposed method, series of experiments and comparisons with some existing methods including bi-cubic interpolation method and bilateral total variation method are carried out. Numerical results on synthetic data show that the PSNR improvement of the proposed method is approximately 1.0906 dB on average compared to bilateral total variation method, and the results on real videos indicate that the proposed algorithm is also effective in terms of removing visual artifacts and preserving edges in restored images.
基金Supported by the National Natural Science Foundation of China(21107143,21207033)the Fundamental Research Funds for the Central Universities,South-Central University for Nationalities(CZY15003)
文摘A simple ultrasound-assisted co-precipitation method was developed to prepare ferroferric oxide/graphene oxide magnetic nanoparticles(Fe_3O_4/CO MNPs).The hysteresis loop of Fe_3O_4/GO MNPs demonstrated that the sample was typical of superparamagnetic material.The samples were characterized by transmission electron microscope,and it is found that the particles are of small size.The Fe_3O_4/GO MNPs were further used as an adsorbent to remove Rhodamine B.The effects of initial pH of the solution,the dosage of adsorbent,temperature,contact time and the presence of interfering dyes on adsorption performance were investigated as well.The adsorption equilibrium and kinetics data were fitted well with the Freundlich isotherm and the pseudosecond-order kinetic model respectively.The adsorption process followed intra-particle diffusion model with more than one process affecting the adsorption of Rhodamine B.And the adsorption process was endothermic in nature.Furthermore,the magnetic composite with a high adsorption capacity of Rhodamine B could be effectively and simply separated using an external magnetic field.And the used particles could be regenerated and recycled easily.The magnetic composite could find potential applications for the removal of dye pollutants.
