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Study on Component Synthesis Active Vibration Suppression Method Using Zero-placement Technique 被引量:4
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作者 张建英 刘暾 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2008年第4期304-312,共9页
The component synthesis active vibration suppression method (CSVS) can be applied to suppress the vibration of flexible systems. By this method, several same or similar time-varying components are arranged according... The component synthesis active vibration suppression method (CSVS) can be applied to suppress the vibration of flexible systems. By this method, several same or similar time-varying components are arranged according to certain rules along the time axis. The synthesized command can suppress the arbitrary unwanted vibration harmonic while achieving the desired rigid body motion. The number of the components increases rapidly when the number of harmonic vibration is growing. In this article, the CSVS based on zero-placement technique is used to construct the synthesized command to suppress the multi-harmonics simultaneously in the discrete domain. The nature of zero-placement method is to put enough zeros to cancel system poles at necessary points. The designed synthesized command has equal time intervals between each component and which is much easier to be implemented. Using this method, the number of components increases linearly with the increasing of the number of being suppressed harmonics. For the spacecraft with flexible appendages, CSVS based on zero-placement is used to design the time optimal large angle maneuver control strategy. Simulations have verified the validity and superiority of the proposed approach. 展开更多
关键词 flexible structure vibration suppression component synthesis active vibration suppression method zero-placement technique
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Extraction of Pumpkin Polysaccharide by Complex Enzyme Method and Its Antioxidant Research 被引量:20
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作者 孙婕 尹国友 +2 位作者 陈兰英 Guo-you Lan-ying 《Agricultural Science & Technology》 CAS 2010年第5期34-37,共4页
[Objective] This paper aims to study a new method of extracting pumpkin polysaccharide from pumpkin. Single factor experiments were conducted to examine the effects of extracting time,temperature,the solid-liquid rati... [Objective] This paper aims to study a new method of extracting pumpkin polysaccharide from pumpkin. Single factor experiments were conducted to examine the effects of extracting time,temperature,the solid-liquid ratio and pH value on the extraction yield of polysaccharide from pumpkin. [Method] The best enzyme ratio and extraction conditions for complex enzymes extraction were determined through orthogonal tests. Scavenging ·OH and O-2 activities of pumpkin polysaccharides were also investigated by salicylic acid and improved self-oxidation of o-pheno methods respectively. [Results] The results showed that the biggest extraction yield of polysaccharide from pumpkin can be got when adding 1% cellulose enzyme,1.5% pectinase,1.0% papain and Na2HPO4-citric acid buffer solution (pH was 4.6),and oscillating for 30 min under water at 40 ℃ with the solid-liquid ratio of 1:30. In addition,pumpkin polysaccharides had a strong activity of eliminating ·OH,but very weak activity to scavenge O-2. [Conclusion] This study provided basic data for research and application of Pumpkin polysaccharide. 展开更多
关键词 Complex enzymes method Pumpkin polysaccharide Extraction Antioxidant activity
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Limit analysis method for active earth pressure on laggings between stabilizing piles 被引量:2
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作者 WANG Ming-min WU Shu-guang WANG Gui-lin 《Journal of Mountain Science》 SCIE CSCD 2017年第1期196-204,共9页
Stabilizing pile is a kind of earth shoring structure frequently used in slope engineering. When the piles have cantilever segments above the ground,laggings are usually installed to avoid collapse of soil between pil... Stabilizing pile is a kind of earth shoring structure frequently used in slope engineering. When the piles have cantilever segments above the ground,laggings are usually installed to avoid collapse of soil between piles. Evaluating the earth pressure acting on laggings is of great importance in design process.Since laggings are usually less stiff than piles,the lateral pressure on lagging is much closer to active earth pressure. In order to estimate the lateral earth pressure on lagging more accurately,first,a model test of cantilever stabilizing pile and lagging systems was carried out. Then,basing the experimental results a three-dimensional sliding wedge model was established. Last,the calculation process of the total active force on lagging is presented based on the kinematic approach of limit analysis. A comparison is made between the total active force on lagging calculated by the formula presented in this study and the force on a same-size rigid retaining wall obtained from Rankine's theory. It is found that the proposed method fits well with the experimental results.Parametric studies show that the total active force on lagging increases with the growth of the lagging height and the lagging clear span; while decreases asthe soil internal friction angle and soil cohesion increase. 展开更多
关键词 Stabilizing pile Lagging Active earth pressure Limit analysis method Sliding surface
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Assessment of Patentability of Inventions Relating to "Rules and Methods for Mental Activities" 被引量:3
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作者 Cui Aiping Examiner of the Communication Department of the Patent Office of the State Intellectual Property Office 《中国专利与商标》 2006年第4期46-51,共6页
Examination of whether an invention is a patentable subject matter or not is one of the main parts of the patent examination. In the recently revised Guidelines for Examination a relatively major change has been made ... Examination of whether an invention is a patentable subject matter or not is one of the main parts of the patent examination. In the recently revised Guidelines for Examination a relatively major change has been made of the benchmark for the examination of inventions relating to "rules and methods for mental activities", for example, limiting the scope of application of Article 25.1 (2) of the Patent Law. As a result, the hitherto non-patentable subject matters are still excluded from patentability. That... 展开更多
关键词 Rules and methods for Mental Activities MODE
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Piezoelectric Actuator/Sensor Wave Propagation Based Nondestructive Active Monitoring Method of Concrete Structures 被引量:5
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作者 朱劲松 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第3期541-547,共7页
In order to monitor the basic mechanical properties and interior damage of concrete structures,the piezoelectric actuator/sensor based wave propagation method was investigated experimentally in the laboratory using a ... In order to monitor the basic mechanical properties and interior damage of concrete structures,the piezoelectric actuator/sensor based wave propagation method was investigated experimentally in the laboratory using a specifically designed test setup.The energy attenuation of stress waves was measured by the relative index between the output voltage of sensors and the excitation voltage at the actuator.Based on the experimental results of concrete cube and cylinder specimens,the effect of excitation frequencies,excitation amplitude,wave propagation paths and the curing age on the output signals of sensors are evaluated.The results show that the relative voltage attenuation coefficient RVAC is an effective indicator for measuring the attenuation of stress waves through the interior of concrete. 展开更多
关键词 piezoceramics actuator/sensor wave propagation method non-destructive evaluation (NDE) active monitoring concrete
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Simulation of oxygen transfer in liquid lead under influence of nanoparticles by using lattice Boltzmann method 被引量:1
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作者 Emad Pouryazdanpanah Kermani Yitung Chen 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2017年第1期22-29,共8页
Oxygen transfer presents a serious challenge in the application of liquid lead as a nuclear coolant in advanced reactors. To mitigate corrosion by liquid lead in contact with steel, carefully controlling the oxygen co... Oxygen transfer presents a serious challenge in the application of liquid lead as a nuclear coolant in advanced reactors. To mitigate corrosion by liquid lead in contact with steel, carefully controlling the oxygen concentration has been used as an effective way. Oxygen needs to mix in liquid lead uniformly and quickly. To enhance oxygen transport in liquid lead, nanoparticles are added to the liquid metal. In the current study, a lattice Boltzmann method is applied to investigate natural convection of copper/lead and aluminum oxide/lead in two-dimensional simplified container. Two thermal boundary cases are evaluated in order to check the effect of different natural convection flow patterns on oxygen transport. Some useful information are obtained such as improvement in natural convection and reduction in oxygen equilibrium time. 展开更多
关键词 Lattice Boltzmann method Oxygen transfer Active oxygen control technique Nanoparticles Natural convection
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Comparative Study of the Geomagnetic Activity Effect on foF2 Variation as Defined by the Two Classification Methods at Dakar Station over Solar Cycle Phases
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作者 Sibri Alphonse Sandwidi Doua Allain Gnabahou Frédéric Ouattara 《International Journal of Geosciences》 2020年第8期501-517,共17页
This paper aims to establish a comparison between both geomagnetic activity classification methods on foF2 diurnal variation over solar cycle phases. It concerns first a comparison of geomagnetic activity occurrences ... This paper aims to establish a comparison between both geomagnetic activity classification methods on foF2 diurnal variation over solar cycle phases. It concerns first a comparison of geomagnetic activity occurrences according to both classification methods;and second the geomagnetic effect on foF2 diurnal variation profiles as defined for the equatorial latitudes. The occurrences of the different disturbed geomagnetic activities (recurrent activity (RA), shock activity (SA) and fluctuant activity (FA)) according to both classifications (ancient classification (AC) and new classification (NC)) have been studied at Dakar ionosonde station (Lat: 14.8°N;Long: 342.6°E). Regarding both classifications, the RA occurs more during the decreasing phase. And it’s observed that the RA occurs the most during the increasing phase for the AC and during the minimum phase for the NC. The maximum gap of occurrence (<img src="Edit_e4627ea9-9a9a-4473-9017-202d04a16377.bmp" alt="" /><span><span style="font-family:Verdana;">) between both classifications is <span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&#45</span></span></span><span style="font-family:;" "=""><span style="font-family:Verdana;">11.1%</span><span style="font-family:Verdana;"> (for the negative value which is observed during the increasing phase) and </span><span style="font-family:Verdana;">+16.74%</span><span style="font-family:Verdana;"> (for the positive one which is observed during the decreasing phase). The occurrence of the SA in relation with both classifications is the lowest during the minimum phase and the maximum occurrence is observed during the maximum and decreasing phases, for the AC, with a value close to </span><span style="font-family:Verdana;">37%</span><span style="font-family:Verdana;"> and for the NC at the maximum phase with a percentage of </span><span style="font-family:Verdana;">54.47%</span><span><span style="font-family:Verdana;">. The maximum gap of occurrence (</span><img src="Edit_20fa141b-ecee-4e06-8024-144ba0969395.bmp" alt="" /></span></span><span style="font-family:Verdana;">) between both classifications is <span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&#45</span></span></span><span style="font-family:;" "=""><span style="font-family:Verdana;">17.85%</span><span style="font-family:Verdana;"> (for the negative value which is observed at maximum phase) and </span><span style="font-family:Verdana;">+13.53%</span><span style="font-family:Verdana;"> (for the positive one which is observed during the decreasing phase). For both classifications, the FA occurs the least during the minimum phase and the most during the maximum phase for the AC and at maximum and decreasing phases with percentage values of occurrence of roughly </span><span style="font-family:Verdana;">37%</span><span><span style="font-family:Verdana;"> for the NC. The maximum gap of occurrence (</span><img src="Edit_eecb8939-783e-4d43-b92c-80c528c1890b.bmp" alt="" /><span style="font-family:Verdana;"></span></span></span><span style="font-family:Verdana;">) between both classifications is <span style="font-size:10.0pt;font-family:;" "=""><span style="font-family:Verdana, Helvetica, Arial;white-space:normal;background-color:#FFFFFF;">&#45</span></span>10% (for the negative value which is observed during the decreasing phase) and </span><span style="font-family:;" "=""><span style="font-family:Verdana;">+20.11%</span><span style="font-family:Verdana;"> (for the positive one which is observed during the maximum phase). foF2 diurnal profiles throughout solar cycle phases concerning the AC and the NC have been compared. The FA diurnal profiles don’t present a difference. The RA and the SA present a difference during minimum and increasing phases and the least at maximum and decreasing phases.</span></span></span> 展开更多
关键词 Geomagnetic Activity Classification method Solar Cycle Phases foF2 Diurnal Profile
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Study on extracting alumina from fly ash by compound additive activation method
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作者 WANG Yongwang 《Global Geology》 2014年第3期182-188,共7页
According to the chemical and mineral composition characteristics of the fly ash,alumina can be extracted from fly ash through the calcining method by using sodium carbonate and calcium carbonate additives.The effects... According to the chemical and mineral composition characteristics of the fly ash,alumina can be extracted from fly ash through the calcining method by using sodium carbonate and calcium carbonate additives.The effects on leaching rate of alumina have been investigated. The results showed that the fly ash can be activated effectively and the leaching rate of alumina can be improved to more than 92% through this method. The best process parameters were the ratio of raw materials,i. e. the material weight ratio of fly ash,calcium carbonate and sodium carbonate was 1. 0∶1. 2∶0. 9. The activating temperature was 850℃-900℃,activating time was 3 h. This process has a potential application prospect and improves the value of comprehensive utilization of fly ash. 展开更多
关键词 fly ash compound additive activation method EXTRACT ALUMINA
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Preparation and Performance of Si^4+ -doping Rod-shaped TiO2 Powder by Nonhydrolytic Sol-gel Method
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作者 杨金萍 QIAO Ning +1 位作者 WEI Hengyong CHEN Yang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第3期575-578,共4页
Titania(TiO2) nanorod powder was prepared by nonhydrolytic sol-gel method using titanic chloride(TiCl4) as titanium source, methylene dichloride(CH2Cl2) as solvent, absolute ethyl alcohol(CH(-3)CH2OH) as oxy... Titania(TiO2) nanorod powder was prepared by nonhydrolytic sol-gel method using titanic chloride(TiCl4) as titanium source, methylene dichloride(CH2Cl2) as solvent, absolute ethyl alcohol(CH(-3)CH2OH) as oxygen donor. The effects of Si^(4+) doping on the TiO2 nanocrystalline phase transformation temperature were systematically researched. The results showed that when the molar ratio of Ti^(4+) to Si^(4+) is 1 to1.3, TiO2 prepared by calcination at 1 100 ℃ for 1 hour exhibits rod shape and has good photocatalytic activity. Doping of Si^(4+) makes glass phase core-shell structure forming on the surface of anatase crystal particles, which can inhibit crystal phase transformation and raise the transformation temperature, making TiO2 stable in anatase phase at 1 200 ℃. 展开更多
关键词 nonhydrolytic sol-gel method anatase doping nanorod photocatalytic activity
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The K Method for Estimating Earthquake Activity Parameters and Effect of the Boundary Uncertainty of the Source Region:Discussion on the Seismic Zoning Method
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作者 Huang Yurui and Zhang TianzhongInstitute of Geophysics,SSB,Beijing 100081,China 《Earthquake Research in China》 1997年第3期75-81,共7页
Two aspects of a new method,which can be used for seismic zoning,are introduced in this paper.On the one hand,the approach to estimate b value and annual activity rate proposed by Kijko and Sellevoll needs to use the ... Two aspects of a new method,which can be used for seismic zoning,are introduced in this paper.On the one hand,the approach to estimate b value and annual activity rate proposed by Kijko and Sellevoll needs to use the earthquake catalogue.The existing earthquake catalogue contains both historical and recent instrumental data sets and it is inadequate to use only one part.Combining the large number of historical events with recent complete records and taking the magnitude uncertainty into account,Kijko’s method gives the maximum likelihood estimation of b value and annual activity rate,which might be more realistic.On the other hand,this method considers the source zone boundary uncertainty in seismic hazard analysis,which means the earthquake activity rate across a boundary of a source zone changes smoothly instead of abruptly and avoids too large a gradient in the calculated results. 展开更多
关键词 The K method for Estimating Earthquake Activity Parameters and Effect of the Boundary Uncertainty of the Source Region Source Activity
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THE ACTIVATION METHOD FOR DISCRETIZED CONSERVATIVE NONLINEAR STABILITY PROBLEMS WITH MULTIPLE PARAMETER AND STATE VARIABLES
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作者 邓长根 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1993年第10期919-929,共11页
For nonlinear stability problems of discretized conservative systems with multiple parameter variables and multiple state variables, the activation method is put forward, by which activated potential functions and act... For nonlinear stability problems of discretized conservative systems with multiple parameter variables and multiple state variables, the activation method is put forward, by which activated potential functions and activated equilibrium equations are derived. The activation method is the improvement and enhancement of Liapunov-Schmidt method in elastic stability theory. It is more generalized and more normalized than conventional perturbation methods. The activated potential functions may be transformed into normalized catastrophe potential functions. The activated equilibrium equations may be treated as bifurcation equations. The researches in this paper will motivate the combination of elastic stability theory with catastrophe theory and bifurcation theory 展开更多
关键词 multiple parameter variables multiple state variables discretized conservative nonlinear stability activation method asymptotic analyses
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Supplementing Qi and activating blood circulation method to treat vertebrobasilar dolichoectasia with posterior circulatory watershed infarction:a case report of two patients 被引量:1
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作者 LI He SU Wenquan +7 位作者 LI Shanshan JI Hanrui CHENG Jiangyan CUI Fangyuan TANG Lu ZHOU Li GAO Ying DONG Xinglu 《Journal of Traditional Chinese Medicine》 SCIE CSCD 2023年第4期824-828,共5页
Vertebrobasilar dolichoectasia(VBD),a rare posterior circulation vascular variant disease,is an important risk factor for many acute cerebrovascular diseases.An insufficient understanding of VBD often leads to misdiag... Vertebrobasilar dolichoectasia(VBD),a rare posterior circulation vascular variant disease,is an important risk factor for many acute cerebrovascular diseases.An insufficient understanding of VBD often leads to misdiagnose.Two cases of VBD that were initially diagnosed as posterior circulation watershed infarction are reported here.Absence of common causes of stroke including hypoperfusion,blood system diseases,carotid and aortic dissection,and eosinophil elevation,the symptoms of the 2 patients met the diagnostic criteria of VBD.Both patients displayed symptoms that were in line with the Traditional Chinese Medicine(TCM)syndrome pattern of"Qi deficiency and blood stasis".Accordingly,they were comprehensively treated with Supplementing Qi and activating blood circulation method.The clinical manifestations of the 2 patients were remarkably improved and no recurrence of watershed infarction was found in a 1-year follow-up.A detailed medical history and laboratory examination are capable of improving diagnostic accuracy of VBD.TCM treatment based on syndrome identification might be a promising candidate for VBD management. 展开更多
关键词 vertebrobasilar insufficiency STROKE MEDICINE Supplementing Qi and activating blood circulation method integrative medicine case reports
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Low-temperature Denitration Mechanism of NH_(3)-SCR over Fe/AC Catalyst
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作者 杨征宇 黄帮福 +3 位作者 ZHANG Guifang DAI Meng WEN Zhenjing LI Wanjun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第3期475-484,共10页
To study the modification mechanism of activated carbon(AC)by Fe and the low-temperature NH_(3)-selective catalytic reduction(SCR)denitration mechanism of Fe/AC catalysts,Fe/AC catalysts were prepared using coconut sh... To study the modification mechanism of activated carbon(AC)by Fe and the low-temperature NH_(3)-selective catalytic reduction(SCR)denitration mechanism of Fe/AC catalysts,Fe/AC catalysts were prepared using coconut shell AC activated by nitric acid as the support and iron oxide as the active component.The crystal structure,surface morphology,pore structure,functional groups and valence states of the active components of Fe/AC catalysts were characterised by X-ray diffraction,scanning electron microscopy,nitrogen adsorption and desorption,Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy,respectively.The effect of Fe loading and calcination temperature on the low-temperature denitration of NH_(3)-SCR over Fe/AC catalysts was studied using NH_(3)as the reducing gas at low temperature(150℃).The results show that the iron oxide on the Fe/AC catalyst is spherical and uniformly dispersed on the surface of AC,thereby improving the crystallisation performance and increasing the number of active sites and specific surface area on AC in contact with the reaction gas.Hence,a rapid NH_(3)-SCR reaction was realised.When the roasting temperature remains constant,the iron oxide crystals formed by increasing the amount of loading can enter the AC pore structure and accumulate to form more micropores.When the roasting temperature is raised from 400 to 500℃,the iron oxide is mainly transformed fromα-Fe_(2)O_(3)toγ-Fe_(2)O_(3),which improves the iron oxide dispersion and increases its denitration active site,allowing gas adsorption.When the Fe loading amount is 10%,and the roasting temperature is 500℃,the NO removal rate of the Fe/AC catalyst can reach 95%.According to the study,the low-temperature NH_(3)-SCR mechanism of Fe/AC catalyst is proposed,in which the redox reaction between Fe~(2+)and Fe~(3+)will facilitate the formation of reactive oxygen vacancies,which increases the amount of oxygen adsorption on the surface,especially the increase in surface acid sites,and promotes and adsorbs more reaction gases(NH_(3),O_(2),NO).The transformation from the standard SCR reaction to the fast SCR reaction is accelerated. 展开更多
关键词 nitric acid activation method coconut shell activated carbon Fe/AC catalyst NH_(3)-SCR low-temperature denitrification mechanism
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Expediting carbon dots synthesis by the active adaptive method with machine learning and applications in dental diagnosis and treatment
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作者 Yaoyao Tang Quan Xu +3 位作者 Xinyao Zhang Rongye Zhu Nuo Zhao Juncheng Wang 《Nano Research》 SCIE EI CSCD 2024年第11期10109-10118,共10页
Synthesis of functional nanostructures with the least number of tests is paramount towards the propelling materials development. However, the synthesis method containing multivariable leads to high uncertainty, exhaus... Synthesis of functional nanostructures with the least number of tests is paramount towards the propelling materials development. However, the synthesis method containing multivariable leads to high uncertainty, exhaustive attempts, and exorbitant manpower costs. Machine learning (ML) burgeons and provokes an interest in rationally designing and synthesizing materials. Here, we collect the dataset of nano-functional materials carbon dots (CDs) on synthetic parameters and optical properties. ML is applied to assist the synthesis process to enhance photoluminescence quantum yield (QY) by building the methodology named active adaptive method (AAM), including the model selection, max points screen, and experimental verification. An interactive iteration strategy is the first time considered in AAM with the constant acquisition of the furnished data by itself to perfect the model. CDs exhibit a strong red emission with QY up to 23.3% and enhancement of around 200% compared with the pristine value obtained through the AAM guidance. Furthermore, the guided CDs are applied as metal ions probes for Co^(2+) and Fe^(3+), with a concentration range of 0–120 and 0–150 µM, and their detection limits are 1.17 and 0.06 µM. Moreover, we also apply CDs for dental diagnosis and treatment using excellent optical ability. It can effectively detect early caries and treat mineralization combined with gel. The study shows that the error of experiment verification gradually decreases and QY improves double with the effective feedback loops by AAM, suggesting the great potential of utilizing ML to guide the synthesis of novel materials. Finally, the code is open-source and provided to be referenced for further investigation on the novel inorganic material prediction. 展开更多
关键词 machine learning simulated annealing active adaptive method carbon dots Ions detection dental diagnosis and treatment
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Preparation, Characterization and Photocatalytic Activity of Fe, La Co-doped Nanometer Titanium Dioxide Photocatalysts 被引量:2
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作者 石中亮 郭满 +1 位作者 王林军 姚淑华 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2016年第2期199-204,I0001,共7页
A series of photocatalysts of un-doped, single-doped and co-doped nanometer titanium diox- ide (TiO2) have been successfully prepared by template method using Fe(NO3)3.9H2O, La(NO3)3.6H2O, and tetrabutyl titanat... A series of photocatalysts of un-doped, single-doped and co-doped nanometer titanium diox- ide (TiO2) have been successfully prepared by template method using Fe(NO3)3.9H2O, La(NO3)3.6H2O, and tetrabutyl titanate as precursors and glucan as template. Scanning electron microscopy, X-ray diffraction, and N2 adsorption-desorption measurement were employed to characterize the morphology, crystal structure and surface structure of the samples. The photo-absorbance of the obtained catalysts was measured by UV-Vis absorption spectroscopy, and the photocatalytic activities of the prepared samples under UV and visible light were estimated by measuring the degradation rate of methyl orange in an aqueous solution. The characterizations indicated that the prepared photocatalysts consisted of anatase phase and possessed high surface area of ca. 163-176 m2/g. It was shown that the Fe and La co-doped nano-TiO2 could be activated by visible light and could thus be used as an effective catalyst in photo-oxidation reactions. The synergistic effect of Fe and La co-doping played an important role in improving the photocatalytic activity. In addition, the possibility of cyclic usage of co-doped nano-TiO2 was also confirmed, the photocatalytic activity of codoped nano-TiO2 remained above 89.6% of the fresh sample after being used four times. 展开更多
关键词 Nanometer titanium dioxide Fe and La co-doping Photocatalytic activity Template method Methyl orange
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Development in vitro in Reconstitution of Embryo from Porcine Somatic Cell Nuclear Transfer 被引量:3
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作者 张德福 王英 +3 位作者 陈茵 王凯 Karl Schellander LIN Cai-lu 《Developmental and Reproductive Biology》 2002年第1期13-22,共10页
In present paper,a study on reconstitution of porcine oocytes by using nuclear transfer with cumulus cells(CC) and fibroblast cells(FC) was carried out.Reconstituted oocytes which were the fusion with CC and showed a ... In present paper,a study on reconstitution of porcine oocytes by using nuclear transfer with cumulus cells(CC) and fibroblast cells(FC) was carried out.Reconstituted oocytes which were the fusion with CC and showed a cleavage rate of 56.7%,developed into morula (11.7%) and blastocysts (6.7%) phases which were higher than those derived from the fusion with FC( P <0.05).The results of this study also involved the effects of oocyte collection method,activation protocol and maturational age of recipient oocytes during the in vitro develpoment of nuclear transfer embryos which were reconstituted with cultured cumulus cells.The cumulus cells synchronized in G 0/G 1 phases through serum starvation culture,were transferred into enuclated oocytes which were collected by aspiration or dissection method and cultured for 33 or 44 h.Reconstituted embryos were activated with a combination of calcium ionophore A23187 or electric pulsation and 6 DMAP,and cultured for 6 days.As for the oocyte collection methods,activation treatment in the presence of cytochalasin B and activation protocols did not affect the developmental rate of embryos reconstituted with 44 h mature recipients.However,the development rate of reconstituted embryos with 33 h mature recipients were significantly higher( P <0.05) by activation with the combination of electric pulsation and 6 DMAP.These results suggest that the reconstituted porcine embryos derived from cultured cumulus cells can develop into the blastocyst stage and that the development of the former could be improved for the reconstitution with young oocyte cytoplast after the activation with the combination of electric pulsation and 6 DMAP. 展开更多
关键词 PIG nuclear transfer (NT) activation method oocyte age
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Function Projective Synchronization of Two Identical New Hyperchaotic Systems 被引量:7
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作者 LI Xin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第5X期864-870,共7页
A function projective synchronization of two identical hyperchaotic systems is defined and the theorem of sufficient condition is given. Based on the active control method and symbolic computation Maple, the scheme of... A function projective synchronization of two identical hyperchaotic systems is defined and the theorem of sufficient condition is given. Based on the active control method and symbolic computation Maple, the scheme of function projective synchronization is developed to synchronize the two identical new hyperchaotic systems constructed by Yan up to a scaling function matrix with different initial values. Numerical simulations are used to verify the effectiveness of the scheme. 展开更多
关键词 function projective synchronization active control method hyperchaotic Chen system
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Optical quasi-periodic oscillation and color behavior of blazar PKS 2155–304 被引量:5
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作者 Bing-Kai Zhang Xiao-Yun Zhao +1 位作者 Chun-Xiao Wang Ben-Zhong Dai 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2014年第8期933-941,共9页
PKS 2155-304 is a well studied BL Lac object in the southern sky. The historical optical data during different periods have been collected and compiled. Light curves spanning 35 yr have been constructed. The R-band li... PKS 2155-304 is a well studied BL Lac object in the southern sky. The historical optical data during different periods have been collected and compiled. Light curves spanning 35 yr have been constructed. The R-band light curve has been ana- lyzed by means of three methods: the epoch folding method, the Jurkevich method and the discrete correlation function method. It is derived that there is an evident periodic component of 317 d (i.e. 0.87 yr) superposed on a long-term trend with large- amplitude variation in the light curve. The variability of this source is accompanied by a slight color variation, and the brightness and color index are correlated with each other. On a long-term time scale, PKS 2155-304 exhibits a tendency of bluer-when- brighter, which means the spectrum becomes flatter when the source brightens. 展开更多
关键词 BL Lacertae objects general -- BL Lacertae objects individual (PKS 2155-304) -- galaxies active -- method statistical
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Preparation and Photocatalytic Activity of Ce, H3PW12O40 co-doped TiO2 Hollow Fibers 被引量:3
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作者 Shu-hua Yao Shuang Chen Zhong-liang Shi 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第3期343-349,共7页
A series of Ce, H3PW12O40 co-doped TiO2 hollow fibers photocatalysts have been prepared by sol-gel method using ammonium ceric nitrate, H3PW12O40 and tetrabutyltitanate as precursors and cotton fibers as template, fol... A series of Ce, H3PW12O40 co-doped TiO2 hollow fibers photocatalysts have been prepared by sol-gel method using ammonium ceric nitrate, H3PW12O40 and tetrabutyltitanate as precursors and cotton fibers as template, followed by calcination at 500 ℃ in N2 atmosphere for 2 h. Scanning electron microscopy, X-ray diffraction, nitrogen adsorption-desorption mea- surements, and UV-Vis spectroscopy are employed to characterize the morphology, crystal structure, surface structure, and optical absorption properties of the samples. The photo- catalytic performance of the samples has been studied by photodegradation phenol in water under UV and visible light irradiation. The results show that the TiO2 fiber materials have hollow structures, and the co-doped TiO2 hollow fibers exhibit higher photocatalytic activities for the degradation of phenol than un-doped, single-doped TiO2 hollow fibers under UV and visible light. In addition, the recyclability of co-doped TiO2 fibers is also confirmed that the TiO2 fiber retains ca. 90% of its activity after being used four times. It is shown that the co-doped TiO2 fibers can be activated by visible light and may be potentially applied to the treatment of water contaminated by organic pollutants. The synergistic effect of Ce and H3PW12O40 co-doping plays an important role in improving the photocatalytic activity. 展开更多
关键词 TiO2 hollow fibers Ce and H3PW12O40 co-doping Photocatalytic activity Template method PHENOL
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Wavelet Analysis of Several Important Periodic Properties in the Relative Sunspot Numbers 被引量:16
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作者 Gui-MingLe Jia-LongWang 《Chinese Journal of Astronomy and Astrophysics》 CSCD 北大核心 2003年第5期391-394,共4页
We investigate the wavelet transform of yearly mean relative sunspot number series from 1700 to 2002. The curve of the global wavelet power spectrum peaks at 11-yr, 53-yr and 101-yr periods. The evolution of the ampli... We investigate the wavelet transform of yearly mean relative sunspot number series from 1700 to 2002. The curve of the global wavelet power spectrum peaks at 11-yr, 53-yr and 101-yr periods. The evolution of the amplitudes of the three periods is studied. The results show that around 1750 and 1800, the amplitude of the 53-yr period was much higher than that of the the 11-yr period, that the ca. 53-yr period was apparent only for the interval from 1725 to 1850, and was very low after 1850, that around 1750, 1800 and 1900, the amplitude of the 101-yr period was higher than that of the 11-yr period and that, from 1940 to 2000, the 11-yr period greatly dominates over the other two periods. 展开更多
关键词 Sun: sunspots - Sun: activity - methods: data analysis
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