期刊文献+
共找到24篇文章
< 1 2 >
每页显示 20 50 100
Validation of Veterans Specific Activity Questionnaire to assess exercise tolerance of Chinese elderly with coronary heart disease 被引量:4
1
作者 Yan WANG Jing-Jing SHI Bo-Zhong WANG 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2016年第12期973-977,共5页
Objective The Veterans Specific Activity Questionnaire (VSAQ) has been used to assess exercise tolerance. Nevertheless, there is no val- idated Chinese version. The aim of this study is to determine whether a questi... Objective The Veterans Specific Activity Questionnaire (VSAQ) has been used to assess exercise tolerance. Nevertheless, there is no val- idated Chinese version. The aim of this study is to determine whether a questionnaire-based method using the Chinese version of VSAQ (the modified VSAQ) is a practical tool to assess exercise tolerance of Chinese elderly with coronary heart disease. Methods One hundred thirty consecutive elderly patients who were diagnosed with coronary heart disease (CHD) (mean age 68.9 -4- 6.0 years) referred for treadmill exercise testing (TET) for clinical reasons were included in the study. They were asked to complete a questionnaire for clinical characteristics information on age, sex, history, exercise habits, medications, the original VSAQ and the modified VSAQ. We investigated the relationship between exer- cise tolerance in metabolic equivalents (METs) estimated by VSAQ and that obtained by TET. Results The METs by the original VSAQ and the modified VSAQ did not difference significantly (P = 0.528). The modified VSAQ scores were significantly correlated with the METs oh- mined by TET (r = 0.819, 95% CI: 0.7534).873, P 〈 0.01), and the scores of original VSAQ also correlated with the METs by TET (r = 0.804, 95% CI: 0.7454).854, P 〈 0.01). The Bland-Altman graph analysis showed few values outside the limits of agrcement, suggesting good precision between the METs estimated by questionnaire and the METs obtained by TET. Conclusions The Chinese version of the VSAQ confirmed its validity and equivalence to the original version, especially when evaluating individuals with coronary heart disease and older adults. The results showed that the VSAQ is a valuable tool to assess the exercise tolerance. 展开更多
关键词 Chinese Elderly Coronary heart disease Exercise tolerance Veterans specific activity Questionnaire
下载PDF
Inhibitory effect of ammonia nitrogen on specific methanogenic activity of anaerobic granular sludge 被引量:6
2
作者 周洪波 邱冠周 《Journal of Central South University of Technology》 EI 2006年第1期63-67,共5页
A series of batch experiments were conducted in 125 mL serum bottles to assess the toxicity of different concentrations of ammonia nitrogen to the specific methanogenic activity of anaerobic granular sludge from upflo... A series of batch experiments were conducted in 125 mL serum bottles to assess the toxicity of different concentrations of ammonia nitrogen to the specific methanogenic activity of anaerobic granular sludge from upflow anaerobic sludge bed(UASB) and expanded granular sludge bed(EGSB) reactors. The effects of pH value and temperature on toxicity of ammonia nitrogen to anaerobes were investigated. The results show that the specific methanogenic activity of anaerobic granular sludge suffers inhibition from ammonia nitrogen, the concentrations of ammonia nitrogen that produce 50 % inhibition of specific methanogenic activity for sludge from UASB and EGSB reactor are 2.35 and 2.75 g/L, respectively. Hydrogen utilizing methanogens suffers less inhibition from ammonia mtrogen than that of acetate utilizing methanogens. Hydrogen-producing acetogens that utilize propionate and butyrate as substrates suffer serious inhibition from ammonia nitrogen. The toxicity of ammonia nitrogen to anaerobic granular sludge enhances when pH value and temperature increase. Anaerobic granular sludge can bear higher concentrations of ammonia nitrogen after being acclimated by ammonia nitrogen for 7 d. 展开更多
关键词 ammonia nitrogen TOXICITY anaerobic granular sludge specific methanogenic activity
下载PDF
STUDY ON MAXIMUM SPECIFIC SLUDGE ACTIVITY OF DIFFERENT ANAEROBIC GRANULAR SLUDGE BY BATCH TESTS
3
作者 杨虹 K.H.Rosenwinkel H.Meyer 《Journal of Shanghai Jiaotong university(Science)》 EI 2001年第1期67-71,共5页
The maximum specific sludge activity of granular sludge from large scale UASB, IC and Biobed anaerobic reactors were investigated by batch tests. The limitation factors related to maximum specific sludge activity (dif... The maximum specific sludge activity of granular sludge from large scale UASB, IC and Biobed anaerobic reactors were investigated by batch tests. The limitation factors related to maximum specific sludge activity (diffusion, substrate sort, substrate concentration and granular size) were studied. The general principle and procedure for the precise measurement of maximum specific sludge activity were suggested. The potential capacity of loading rate of the IC and Biobed anaerobic reactors were analyzed and compared by use of the batch tests results. 展开更多
关键词 maximum specific sludge activity anaerobic digestion batch test UASB IC Biobed
下载PDF
Effects of Exogenous Amylases and Metal Ions on the Amylase Specific Activities and Starch Degradation of the Upper Leaves of ‘KRK_(26)' during Flue-curing 被引量:1
4
作者 赵昶灵 崔国民 孟凡来 《Agricultural Science & Technology》 CAS 2014年第10期1676-1683,共8页
Objective] The aim of this study was to investigate the effects of exoge-nous amylases and Ca2+, Mn2+ and K+ on the amylase specific activities and starch degradation of the upper leaves of 'KRK26' planted in Yun... Objective] The aim of this study was to investigate the effects of exoge-nous amylases and Ca2+, Mn2+ and K+ on the amylase specific activities and starch degradation of the upper leaves of 'KRK26' planted in Yunnan Province during flue-curing. [Method] The amylase specific activities and starch degradation of the leaves were determined by using spectrophotometry. [Result] The 8 U/g exogenous α-amy-lase could improve the specific activity of the leaf α-amylase at yel owing and color-fixing stages, but could not at stem-drying stage, and similarly, the 80 U/g exoge-nous β-amylase could improved the specific activity of the leaf β-amylase at the yel owing stage and the early period of color-fixing stage. The leaf starch could be enhanced to degrade by the exogenous α- or β-amylases and the enhancing effect of the former was stronger than that of the later. 1.50 mg/ml Ca2+ improved the specific activity of the leaf (α+β)-amylase mainly due to its enhancing effect on the leaf α-amylase, and increased the starch degradation. 4 mmol/L Mn2+ inhibited the leaf α-amylase from yel owing to the early period of color-fixing and the β- and (α+β)-amylases from the yel owing to the later period of color-fixing, but enhanced the leafα-amylase from the later period of color-fixing to the later period of stem-drying and the β- and (α+β)-amylases at the later period of stem-drying. Meanwhile, Mn2+ ham-pered the starch degradation during yel owing, but promoted it from the early period of color-fixing to stem-drying. 1 mg/ml K+ enhanced the leaf α-, β- and (α+β)-amy-lases during the yel owing stage, but lowered them from the early period of color-fix-ing to the later period of stem-drying, and always inhibited the leaf starch degrada-tion. [Conclusion] The exogenous α-, β- amylases and Ca2+ of suitable concentra-tions could be used to treat the tobacco leaves before flue-curing to improve the leaf starch degradation during the curing. 展开更多
关键词 Exogenous amylases and metal ions Amylase specific activity Starchdegradation Upper leaves of flue-cured tobacco variety 'KRK26' Flue-curing
下载PDF
Storm Liquefaction Deposits:A Possibility of Time Reversal in Sedimentary Strata of an Estuarial Coastal Area
5
作者 XU Guohui REN Yupeng +3 位作者 HU Guanghai LIU Zhiqin SUN Yongfu LIN Lin 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第4期961-969,共9页
In the sedimentary strata dating of estuarial coastal areas,it is often found that there is phenomenon of time-reversal in strata.The seabed sediments could be liquefied under storm waves.A laboratory wave flume exper... In the sedimentary strata dating of estuarial coastal areas,it is often found that there is phenomenon of time-reversal in strata.The seabed sediments could be liquefied under storm waves.A laboratory wave flume experiment demonstrated that storm-induced liquefaction deposits are formed by the oscillations of liquefied sediments.In this paper,the particle size distribution and ^(210)Pb_(ex) specific activity of the sediment samples from the liquefaction disturbed zone and adjacent stable zone of the Yellow River Delta were tested.The stratigraphic divisions based on storm liquefaction deposit sequence can effectively explain the vertical changes in particle size and ^(210)Pb_(ex) specific activity.Due to the differentiation of particles during the storm induced liquefaction,coarse and fine particles regrouped,which could explain the phenomenon of time-reversal in dating data. 展开更多
关键词 ^(210)Pb_(ex)specific activity liquefaction deposition REVERSAL sediment
下载PDF
Effect of sulfate on the methanogenic activity of a bacterial culture from a brewery wastewater during glucose degradation 被引量:2
6
作者 Nusara Sinbuathong Sutha Khaodhiar +2 位作者 Winai Liengcharernsit Pramote Sirirote Daniel Watts 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第9期1025-1027,共3页
The maximum specific methanogenic activity (SMA) of a sludge originating from a brewery wastewater treatment plant on the degradation of glucose was investigated at various levels of sulfate on a specific loading ba... The maximum specific methanogenic activity (SMA) of a sludge originating from a brewery wastewater treatment plant on the degradation of glucose was investigated at various levels of sulfate on a specific loading basis. Batch experiments were conducted in serum bottles at pH 7 and 35℃. A comparison of the values indicates that the SMA of this mixed culture was increased and reached its highest level of 0.128 g CH4 gas COD/(g VSS.d) when biomass was in contact with sulfate at a ratio of 1:0.114 by weight. 展开更多
关键词 anaerobic biomass brewery wastewater sludge glucose degradation specific methane production specific methanogenic activity SULFATE
下载PDF
Fast estimation of Michaelis-Menten constant of arylesterase with a pair of medium concentrations of substrate 被引量:4
7
作者 廖飞 杨晓 +2 位作者 周岐新 曾昭淳 左渝萍 《Journal of Medical Colleges of PLA(China)》 CAS 2003年第5期312-316,共5页
Objective: To investigate the reliability for fast estimation of Michaelis-Menten constant (Km) with calibrated specific activity at only two medium concentrations of substrate by both simulation and experimentation w... Objective: To investigate the reliability for fast estimation of Michaelis-Menten constant (Km) with calibrated specific activity at only two medium concentrations of substrate by both simulation and experimentation with arylesterase (ArE)as model. Methods: Initial rates were simulated by randomly inserting uniform absolute error, and the experimental initial rates of ArE were determined by measuring the increaser of product absorbance. Calibrated specific activities at two substrate concentrations were obtained by regression analysis, and Km was calculated according to Michaelis-Menten equation. Results: By simulation with calibrated specific activities at two medium substrate concentrations, Km could be calculated according to Michaelis-Menten equation with reasonable precision and accuracy. By experimentation with substrates of 2-naphthyl acetate, phenyl acetate, and p-nitrophenyl acetate, there were no differences between the mean and SD of Km of ArE for either substrate by this linear kinetic method and the Lineweaver-Burk plot. Conclusion: This linear kinetic method was reliable for fast estimation of the Km of some specified enzyme on its substrate of lower solubility or lower sensitivity for quantification by common methods. 展开更多
关键词 Michaelis-Menten constant linear kinetic method calibrated specific activity simulation ARYLESTERASE
下载PDF
Decomposition of Plant Materials in Upland and Submerged Soils Under Different Climatic Conditions 被引量:3
8
作者 LIZHONG LINXIN-XIONG 《Pedosphere》 SCIE CAS CSCD 1993年第1期89-92,共4页
The decomposition of plant materials in soil, along with the factors affecting it, has been frequently studied, and much information has been accumulated. Most reports indicated that the decomposition of organic mater... The decomposition of plant materials in soil, along with the factors affecting it, has been frequently studied, and much information has been accumulated. Most reports indicated that the decomposition of organic materials proceeded more slowly in paddy soil than in upland soil because of the insufficient 02 supply, the lower soil temperature and the weaker activity of aquatic invertebrates in the former as compared with those in 展开更多
关键词 14C specific activity decomposition rate plant residue
下载PDF
Nondestructive high-sensitivity measurement method for activation estimation in accelerator room concrete
9
作者 Hiroshi Matsumura Go Yoshida +9 位作者 Akihiro Toyoda Kazuyoshi Masumoto Hajime Nakamura Taichi Miura Koichi Nishikawa Kotaro Bessho Kimikazu Sasa Tetsuaki Moriguchi Fumiyoshi Nobuhara Yoko Nagashima 《辐射防护》 CAS CSCD 北大核心 2020年第6期677-682,共6页
This study established a method for easily and quickly estimating the specific activity produced in the concrete walls and floors of accelerator rooms during long-term operation of accelerator,for advanced zoning of a... This study established a method for easily and quickly estimating the specific activity produced in the concrete walls and floors of accelerator rooms during long-term operation of accelerator,for advanced zoning of activated/nonactivated areas in planning the decommissioning of an accelerator.We propose a new,highly sensitive method for nondestructively estimating the specific activity in concrete that can be applied to activation zoning.In this method,instead of direct determination of the specific activities of important long-half-life radionuclides for decommissioning,such as 152 Eu and 60 Co,we determine the specific activities of short-half-life radionuclides,24 Na and 56 Mn,in situ to obtain neutron flux.The obtained neutron flux and accelerator operation history yield the specific activities of 152 Eu and 60 Co for the advance zoning of activated/non-activated concrete.This method is a powerful long-term prediction tool for concrete activation. 展开更多
关键词 ACCELERATOR ACTIVATION CONCRETE specific activity DECOMMISSIONING
下载PDF
Studies on Properties of Lipase Produced from Aspergillus sp. Isolated from Compost Soil
10
作者 Chijioke O. Ezenwelu Oladejo A. Afeez +3 位作者 Obiano U. Anthony Okoro A. Promise Ude-Ezika C. Mmesoma Oparaji E. Henry 《Advances in Enzyme Research》 CAS 2022年第2期49-60,共12页
Lipase producing Aspergillus was isolated from soil collected from a refuse dump site located at Awka, Anambra State, Nigeria using standard microbiology and biochemical techniques. Crude extract of lipase was produce... Lipase producing Aspergillus was isolated from soil collected from a refuse dump site located at Awka, Anambra State, Nigeria using standard microbiology and biochemical techniques. Crude extract of lipase was produced after a successful screening of the isolates using mineral broth containing p-NPP through submerged fermentation system with optimized physiologic conditions. Three steps of purification were carried out: Ammonium sulphate, dialysis and gel filtration (sephadex G-150). Crude extract was precipitated by using 70% saturation of ammonium sulphate at pH 6.0 which gave the optimum precipitation of the protein with specific activity of 260.56 U/mg. Precipitation using ammonium sulphate carried out at pH 6.5 and 8.0 gave specific activity of 217 U/mg of the protein. The precipitates were further desalted through dialysis for twelve hours and specific activity of 343.20 U/mg was recorded from the dialysate afterwards. Further purification was done by using sephadex G-150 and specific activity of 490.55 U/mg was recorded from the active pooled fractions. The purification table showed a 2.32 purification folds of lipase was gotten after gel filtration (sephadex G-150) with a lipase percentage yield of 2.00%. The specific activity of lipase increased from 211.81 to 490.55 U/mg. Characterization of β-galactosidase gave optima pH and temperature of the enzyme at 6.0 and 60°C respectively. Kinetic constants: K<sub>m</sub> and V<sub>max</sub> values were obtained at various concentrations of p-NPP where 0.32 mM and V<sub>max</sub> of 200.00 μmol/min respectively. Ca<sup>2+</sup> and Co<sup>2+</sup> showed greater effect on lipase activity in a concentration-dependent manner (0.03 - 0.05 M) when compared to Mn<sup>2+</sup> and Fe<sup>2+</sup>. The results from this study have shown that lipase produced from filamentous Aspergillus has a wide range of activity over physiologic conditions in regards to industrial and clinical standard operational procedures. 展开更多
关键词 LIPASE PURIFICATION specific activity Precipitation Purification Folds
下载PDF
Radioactive Element Distribution Characteristics of Red Mud based Field Road Cement before and after Hydration
11
作者 王晓 MA Juntao +1 位作者 ZHANG Lei 杨久俊 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第2期452-458,共7页
Red mud was firstly used as a raw material in sintering field road cement. Then, the radioactive element distribution characteristics of red mud based field road cement(RFC) before and after hydration were comparati... Red mud was firstly used as a raw material in sintering field road cement. Then, the radioactive element distribution characteristics of red mud based field road cement(RFC) before and after hydration were comparatively investigated. The experimental results indicated that the specific activity of ^(226)Ra and ^(232)Th increased after sintering process from raw material to clinker, as a result of concentrating effect on ^(226)Ra and ^(232)Th during sintering process, but the specific activity of ^(40)K decreased after sintering process as a result of volatilization effect. Radionuclide ^(226)Ra mainly distributed in RFC silicate phases(C_xS), ^(232)Th distributed more in RFC interstitial phases than RFC silicate phases(C_xS), ^(40)K mainly distributed in RFC interstitial phases. With increasing hydration ages of RFC pastes, the specific activity of ^(226)Ra kept increasing, ^(232)Th remained consistency all the same and ^(40)K declined. The radioactivity of RFC was in the recommended safe limit of Chinese National Standards GB6566-2010 during its preparation and application process. 展开更多
关键词 red mud distribution radioactivity specific activity cement hydration
下载PDF
Production of Rhenium by Transmuting Tungsten Metal in Fast Reactors with Moderator
12
作者 Tsugio Yokoyama Yuki Tanoue +1 位作者 Atsunori Terashima Masaki Ozawa 《Journal of Energy and Power Engineering》 2016年第3期159-165,共7页
The feasibility of rhenium (Re) production by irradiating tungsten (W) metal in a medium size fast reactor was evaluated by using a Monte Carlo code. The fast reactor can produce about 50 kilograms of Re per every... The feasibility of rhenium (Re) production by irradiating tungsten (W) metal in a medium size fast reactor was evaluated by using a Monte Carlo code. The fast reactor can produce about 50 kilograms of Re per every 3 years, which corresponds 10% of Japanese domestic production. The specific activity of Re can be reduced below the exemption level or even the natural Re level if W and osmium is separated after the irradiation. The use of ZrD1.7 moderator reduces the specific activity by half compared to that of ZrH1.7 case, and even the no moderator case is permissible to produce the production of Re which has lower specific reactivity than that of natural Re. 展开更多
关键词 RHENIUM TUNGSTEN fast reactor TRANSMUTATION MVP ORIGEN2 specific activity.
下载PDF
Comparison between controlled landfill reactor and conditioned landfill bioreactor 被引量:2
13
作者 LUOFeng CHENWan-zhi +2 位作者 SONGFu-zhong LIXiao-peng ZHANGGuo-qing 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第5期874-880,共7页
Bioreactor landfills allow a more active landfill management that recognizes the biological, chemical and physical processes involved in a landfill environment. The laboratory-scale simulators of landfill reactors tre... Bioreactor landfills allow a more active landfill management that recognizes the biological, chemical and physical processes involved in a landfill environment. The laboratory-scale simulators of landfill reactors treating municipal solid wastes were studied, the effect of solid waste size, leachate recirculation, nutrient balance, pH value, moisture content and temperature on the rate of municipal solid waste(MSW) biodegradation were determined, and it indicated the optimum pH value, moisture content and temperature decomposing MSW. The results of waste biodegradation were compared with that of the leachate-recirculated landfill simulator and conservative sanitary landfill simulator. In the control experiment the antitheses of a decreasing trend of the organic load, measured as biological oxygen demand and chemical oxygen demand, was shown. An obvious enhancement of effective disposal from conservative sanitary landfill(CSL) simulator, to the leachate-recirculated landfill(LRL) simulator and to the conditioned bioreactor landfill(CBL) simulator would be noted, through displaying the compared results of solid waste settlement, heavy metal concentration in leachate, methane production rate, biogas composition, BOD and COD as well as their ratio. 展开更多
关键词 landfill bioreactor METHANOGENESIS methane production municipal solid waste leachate recirculation biodegradation of solid waste specific methanogenic activity(SMA)
下载PDF
CELLULAR IMMUNITY EFFECT OF LEUKEMIA VACCINE ON TUMOR BURDEN RAT
14
作者 赵万红 张王刚 +4 位作者 何爱丽 王一理 耿宜萍 田玮 宋长锁 《Journal of Pharmaceutical Analysis》 SCIE CAS 2003年第1期51-54,共4页
Objective To evaluate the effect of the active specific immunotherapy with leukemia vaccine in the malignant hematopoietic diseases. Methods We established the animal models by inoculating C 57 BL/6 rats with FB... Objective To evaluate the effect of the active specific immunotherapy with leukemia vaccine in the malignant hematopoietic diseases. Methods We established the animal models by inoculating C 57 BL/6 rats with FBL 3 erythroleukemia cells and prepared three types of tumor vaccine, which were administered on the rats respectively. The MTT colorimetric assay was adopted 2 and 4 weeks later to test the cytotoxicity of macrophage( M Φ ) and that of cytotoxic T lymphocyte(CTL) derived from the rats injected with tumor vaccines, and compared the results with the control group. Results With the growth of erythroleulemia cells in the rats, the cellular immunity was seriously depressed, and the inhibition of specific cellular immunity was later than that of non specific cellular immunity. The tumor vaccine made from inactivated tumor cells, IFA and cytokines (rGM CSF, rIL 2 and rIL 6), promote the cellular immunity of tumor burden rats, especially the specific cellular immunity more efficiently than that of tumor vaccine made from inactivated tumor cells and IFA, but the third vaccine made from inactivated tumor cells alone has no effect. Conclusion The tumor vaccine made from inactivated tumor cells with addition of IFA and cytokines (rGM CSF, rIL 2 and rIL 6) provides a promising future in the active specific immunotherapy against hematopoietic tumor. 展开更多
关键词 active specific immunotherapy LEUKEMIA tumor vaccine MACROPHAGE cytotoxicity T lymphocyte
下载PDF
Microbiological Characteristics of Anaerobic Granular Sludge in Hybrid Anaerobic Baffled Reactor
15
作者 刘荣荣 石光辉 +3 位作者 田晴 杨波 管荣辉 陈季华 《Journal of Donghua University(English Edition)》 EI CAS 2010年第5期700-704,共5页
Anaerobic granular sludge is of key importance for highly effective operation of hybrid anaerobic baffled reactor(HABR).An observation and analysis on the composition of anaerobic granular sludge in each separation co... Anaerobic granular sludge is of key importance for highly effective operation of hybrid anaerobic baffled reactor(HABR).An observation and analysis on the composition of anaerobic granular sludge in each separation compartment of HABR was conducted by using scanning electron microscope(SEM)and molecular biotechnology,and specific methanogenic activity(SMA)and coenzyme F420 content were determined.It was indicated that the disparity of microbial composition was significant among these separation compartments of HABR,and the HABR encouraged phase separation.The results show the understanding of microbiological characteristics of anaerobic granular sludge in HABR is helpful for cultivating granular sludge,which ensures the effective operation of the reactor. 展开更多
关键词 hybrid anaerobic baffled reactor(HABR) anaerobic granular sludge microbiological characteristic specific methanogenic activity(SMA) coenzyme F420
下载PDF
Influence of Pore-expansion Agent on the Structure and Performance of Activated Alumina Synthesized from Waste Aluminum Sludge
16
作者 吴任平 阮玉忠 于岩 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第9期1096-1100,共5页
The chemical compositions of the sludge after treatment are tested by fully chemical analysis techniques. Its crystalline phase structure changes of the sludge calcined at different temperature are characterized by XR... The chemical compositions of the sludge after treatment are tested by fully chemical analysis techniques. Its crystalline phase structure changes of the sludge calcined at different temperature are characterized by XRD method. Nitrogen gas isothermal adsorption method (77 K) is applied to measure the influences of ammonium bicarbonate on specific surface area and pore structure of activated alumina synthesized from waste aluminum sludge. The result shows that the amount of Al2O3 in the sludge accounts for more than 94%, and Na2Owt% in a 0.1-0.2% range. By calcining raw sludge at 600℃, monophase γ-Al2O3 is obtained. And this can satisfy the performance requirements of activated alumina adsorbent. The specific surface area of the specimen with NH4HCO3 added has expanded from 179 to 249 m^2/g and the pore volume from 0.25 to 1.11 cm^3/g as well as the average pore diameter from 5.6 to 17.8 nm. All these show that NH4HCO3 is an effective pore-expansion agent to remarkably improve the structure and performance of activated alumina synthesized from waste aluminum sludge. 展开更多
关键词 sludge synthesized from waste aluminum sludge activated alumina specific surface area pore structure
下载PDF
Mechanism of Suppressing ASR Using Ground Reactive Sandstone Powders instead of Cement
17
作者 李洋 何真 HU Shuguang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第2期344-351,共8页
In order to understand the effect of powders ground from reactive sandstone replacing cement on reducing or suppressing alkali-silica reaction(ASR), and to identify the mechanism of suppressing ASR by this powders, ... In order to understand the effect of powders ground from reactive sandstone replacing cement on reducing or suppressing alkali-silica reaction(ASR), and to identify the mechanism of suppressing ASR by this powders, mortar and paste containing reactive sandstone powders of four replacement levels ranging from 10wt% to 40wt% and four specific surfaces areas ranging from 210 m^2/kg to 860 m^2/kg were studied. The experimental results showed that incorporation of 40wt% reactive sandstone powders could suppress ASR effectively except for mortar containing reactive sandstone powders with specific surface area of 610 m^2/kg, which disagreed with the most results reported that the higher reactive powder specific surface area, the smaller ASR expansion. By means of fl ame photometry, Fourier transform infrared spectroscopy(FT-IR) and thermo gravimetric analysis(TG), the mechanism of reactive sandstone powders on reducing or suppressing ASR was soluble alkalis type of reactive sandstone powders and the competition of liberating and bonding alkali of cement paste containing reactive sandstone powders,when the ability of alkali bonding was greater than the ability of alkali liberation, ASR caused by reactive sandstone was supressed effectively. 展开更多
关键词 sandstone powder specific surface area replacement level activity effect alkali-silica reaction alkali liberation
下载PDF
Effect of 2-butenal manufacture wastewater to methanogenic activity and microbial community 被引量:1
18
作者 Guangqing Song Hongbo Xi +2 位作者 Xiumei Sun Yudong Song Yuexi Zhou 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2018年第5期75-85,共11页
The synthesis of 2-butenal,which is a vital raw material for the production of sorbic acid as a food preservative,generates some toxic by-products,so it is urgent to seek better detoxification strategies for the treat... The synthesis of 2-butenal,which is a vital raw material for the production of sorbic acid as a food preservative,generates some toxic by-products,so it is urgent to seek better detoxification strategies for the treatment of 2-butenal manufacture wastewater.In this study,batch experiments were carried out to investigate the inhibition effect of wastewater on the methanogenic activity.To understand the wastewater toxicity to anaerobic granular sludge,variations of the specific methanogenic activity(SMA)and extracellular polymeric substance(EPS)constituents at various wastewater CODs were investigated.Ultraviolet-visible(UV-vis)spectra and Fourier transform infrared(FT-IR)spectra were employed to analyze the structure of the EPS.The results showed that the inhibitory ratio of 2-butenal manufacture wastewater was less than 8.4%on the anaerobic granular sludge when the CODs were less than 959 mg/L.However,the inhibitory ratio increased from 36.4%to 93.6% when CODs increased from 2396 mg/L to 9585 mg/L,with the SMA decreasing from 39.1 mL CH4/(gVSS·d)to 3.2 mL CH4/(gVSS·d).The diversity of the microbial community under various CODs was researched by Illumina 16S rRNA Miseq sequencing and the results demonstrated that Proteiniphilum、Petrimonas and Syntrophobacter were the dominant bacteria genera in all sample.Regarding archaea,Methanobacterium was the most dominated archaea genera,followed by the Methanosaeta group in all samples.Moreover,the bacterial communities had changed obviously with increasing CODs,which indicated high CODs played a negative impact on the richness and diversity of bacterial community in the sludge samples. 展开更多
关键词 2-butenal manufacture wastewater Methanogenic activity specific methanogenic activity(SMA) Extracellular polymeric substance(EPS) Microbial community
原文传递
An ultra-highly active nanozyme of Fe,N co-doped ultrathin hollow carbon framework for antibacterial application 被引量:3
19
作者 Jinyu Hao Cui Zhang +6 位作者 Chenxi Feng Qian Wang Zhong-Yi Liu Yan Li Jianshuai Mu En-Cui Yang Yan Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第3期388-391,共4页
In recent years, nanozymes have received more and more attention, but the low activity limits the development of nanozymes. Therefore, the design and development of efficient nanozymes is still a major challenge for r... In recent years, nanozymes have received more and more attention, but the low activity limits the development of nanozymes. Therefore, the design and development of efficient nanozymes is still a major challenge for researchers. Herein, the Fe,N co-doped ultrathin hollow carbon framework(Fe,N-UHCF) exhibit ultra-high peroxidase-like activity. The specific activity of Fe,N-UHCF nanozyme is as high as 36.6 U/mg,which is much higher than almost all of other reported nanozymes. In practical applications, the Fe,N-UHCF show good antibacterial effects. 展开更多
关键词 Peroxidase-like Nanozyme Ultra-highly active specific activity ANTIBACTERIAL
原文传递
Enhanced performance for propane dehydrogenation through Pt clusters alloying with copper in zeolite 被引量:2
20
作者 Jie Zhou Ying Zhang +5 位作者 Hao Liu Chao Xiong Peng Hu Hao Wang Shenwei Chen Hongbing Ji 《Nano Research》 SCIE EI CSCD 2023年第5期6537-6543,共7页
Metal alloys have been widely applied for heterogeneous catalysis,especially alkane dehydrogenation.However,the catalysts always suffer from sintering and coke deposition due to the rigorous reaction conditions.Herein... Metal alloys have been widely applied for heterogeneous catalysis,especially alkane dehydrogenation.However,the catalysts always suffer from sintering and coke deposition due to the rigorous reaction conditions.Herein,we described an original approach to prepare a catalyst where highly dispersed Pt clusters alloying with copper were encapsulated in silicalite-1(S-1)zeolite for propane dehydrogenation(PDH).The introduction of Cu species significantly enhances the catalytic activity and prolongs the lifetime of the catalyst.0.1Pt0.4CuK@S-1 exhibits a propane conversion of 24.8%with 98.2%selectivity of propene,and the specific activity of propylene formation is up to 32 mol·gPt^(−1)·h^(−1)at 500℃.No obvious deactivation is observed even after 73 h on stream,affording an extremely low deactivation constant of 0.00032 h^(−1).The excellent activity and stability are ascribed to the confinement of zeolites and the stabilization of Cu species for Pt clusters. 展开更多
关键词 Highly dispersed Pt clusters silicalite-1(S-1)zeolite propane dehydrogenation specific activity low deactivation constant
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部