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基于射频单电子晶体管的超灵敏电荷计的数值分析 被引量:1
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作者 苏丽娜 李欣幸 +1 位作者 秦华 顾晓峰 《传感技术学报》 CAS CSCD 北大核心 2016年第4期484-488,共5页
集成单电子晶体管SET(Single Electron Transistor)与射频共振电路的射频单电子晶体管RF SET(Radio FrequencySingle Electron Transistor)是一种高速高灵敏的电荷计。通过建立RF SET的等效电路模型,对共振电路及其与射频传输线的集成... 集成单电子晶体管SET(Single Electron Transistor)与射频共振电路的射频单电子晶体管RF SET(Radio FrequencySingle Electron Transistor)是一种高速高灵敏的电荷计。通过建立RF SET的等效电路模型,对共振电路及其与射频传输线的集成进行模拟分析,得到了SET阻抗的最佳匹配,获得了所需的谐振频率、品质因子和对SET阻抗的灵敏度。结果表明,受电荷调制的SET阻抗直接影响着共振电路的品质因子、阻抗和射频透射/反射系数。射频信号随着SET的阻抗降低而减小,峰位基本不变。在SET阻抗小于200 kΩ时,共振信号幅度随阻抗的变化率较大。透射式与反射式两种结构相比,前者共振频率及品质因子更高,后者则具有更高的灵敏度优势。 展开更多
关键词 电荷计 射频单电子晶体管 等效电路 透射 反射
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单电子晶体管用于电荷检测的研究 被引量:3
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作者 苏丽娜 吕利 +2 位作者 李欣幸 秦华 顾晓峰 《微纳电子技术》 CAS 北大核心 2014年第10期617-622,共6页
单电子晶体管可用作超灵敏电荷计进行高灵敏电荷检测。首先建立了单电子晶体管电荷检测的电路模型,阐释了其电荷检测机制;然后利用COMSOL和MATLAB软件对检测过程进行了模拟研究,分析了不同电荷量和检测距离时单电子晶体管库仑岛的电势,... 单电子晶体管可用作超灵敏电荷计进行高灵敏电荷检测。首先建立了单电子晶体管电荷检测的电路模型,阐释了其电荷检测机制;然后利用COMSOL和MATLAB软件对检测过程进行了模拟研究,分析了不同电荷量和检测距离时单电子晶体管库仑岛的电势,并研究了电荷量、检测距离及电荷间静电耦合对单电子晶体管电导的影响。结果表明,单电子晶体管电荷检测时工作点和检测距离决定其电荷检测的量程,最佳检测距离应设置在电导-距离曲线的斜率最大处。 展开更多
关键词 单电子晶体管(SET) 库仑岛 电荷计 电荷检测 静电耦合
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一种用于质量和电荷传感的纳米谐振器分析和模拟 被引量:1
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作者 刘冰 刘泽文 +3 位作者 王程伟 方杰 余文革 刘理天 《纳米科技》 2005年第5期35-38,共4页
文章介绍了一种纳米双悬梁支撑微板谐振器。根据动力学微分方程模型,对器件的谐振特性进行模拟,结果表明,以Si3N4为功能材料,最小线宽175纳米的器件,其谐振频率18.1MHz。在常温真空环境下,采用静电驱动的双悬梁支撑结构,有效地... 文章介绍了一种纳米双悬梁支撑微板谐振器。根据动力学微分方程模型,对器件的谐振特性进行模拟,结果表明,以Si3N4为功能材料,最小线宽175纳米的器件,其谐振频率18.1MHz。在常温真空环境下,采用静电驱动的双悬梁支撑结构,有效地抑制了扭转模式谐振的干扰。用该结构作质量传感器,精度达到6.25×10^-19g/Hz,作电荷计,精度可以达到0.3e/Hz(e为电子电荷)。 展开更多
关键词 NEMS 微板谐振器 电荷计 微质量 静电驱动
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单电子晶体管探针的电荷检测机制(英文)
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作者 苏丽娜 李文佳 任舰 《微纳电子技术》 北大核心 2019年第6期429-434,共6页
单电子晶体管(SET)具有极高的电荷灵敏度,是一种超灵敏电荷计。在先前工作的基础上,首先建立了电荷检测的电路模型,该SET扫描探针系统将SET器件集成制备在探针针尖上。然后利用从已制备的SET探针系统中提取的器件参数,模拟研究了该探针... 单电子晶体管(SET)具有极高的电荷灵敏度,是一种超灵敏电荷计。在先前工作的基础上,首先建立了电荷检测的电路模型,该SET扫描探针系统将SET器件集成制备在探针针尖上。然后利用从已制备的SET探针系统中提取的器件参数,模拟研究了该探针系统对直流偏置的量子点(QD)进行电荷检测的过程,分析了探针系统的耦合系数、电压灵敏度及空间分辨率等性能参数。模拟结果表明,随着探测距离的增加,探针的电导响应减弱。该SET探针系统的电压灵敏度高达10^(-6) V/Hz^(1/2)、空间分辨率大于100 nm。通过模拟,最终获得了该探针系统的量子点的二维电势分布图。 展开更多
关键词 单电子晶体管(SET) 探针 电荷计 电荷检测 静电耦合
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Prospects of Shanghai City Network in 21~st Century 被引量:1
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作者 王之佩 《Electricity》 2000年第4期14-20,共7页
According to the population, area and economy development of Shanghai City, this paper introduces the load forecast of the city and points out that the development of urban power network should adapt the development o... According to the population, area and economy development of Shanghai City, this paper introduces the load forecast of the city and points out that the development of urban power network should adapt the development of its economy. In this paper, the developing targets of Shanghai power network are also presented. 展开更多
关键词 urban power network city power network load forecast planning
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Improved Z^(1/3) Law of Nuclear Charge Radius 被引量:1
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作者 LEI Yi-An ZHANG Zhen-Hua ZENG Jin-Yan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第1期123-125,共3页
An improved Z^1/3 law of nuclear charge radius is presented. The comparison between the calculated and experimental nuclear charge radii now available shows that this new formula is better than the other conventional ... An improved Z^1/3 law of nuclear charge radius is presented. The comparison between the calculated and experimental nuclear charge radii now available shows that this new formula is better than the other conventional formulae. 展开更多
关键词 nuclear charge radius improved Z^1/3 law isospin dependence
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First-Principles Study of Ca3Sc2Si3O12: Ce3+ Phosphors
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作者 丁文 闻军 +4 位作者 程军 宁利新 黄玉成 段昌奎 尹民 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2015年第2期150-154,I0001,共6页
Charge compensation plays a very important role in modifying the local atomic structure and moreover the spectroscopic property of an isolated luminescent center, and so has been widely adopted in phosphor designs. In... Charge compensation plays a very important role in modifying the local atomic structure and moreover the spectroscopic property of an isolated luminescent center, and so has been widely adopted in phosphor designs. In this work, we carry out first-principles calculations on various cases of Ce3+ centers in Ca3Sc2Si3O12 by considering the effects of the charge com- pensations related to N3-, Sc3+, Mn2+, Mg2+, and Na+. Firstly, the local structures around Ce3+ are optimized by using density functional theory calculations with supercell model. The 4f→5d transition energies of Ce3+ are then obtained from the CASSCF/CASPT2/RASSI-SO calculations performed on Ce3+-centered embedded clusters. The calculated energies support the previous assignments of the experimental spectra. Especially, a previously unclear peak is identified to be caused by Sc3+ substituting Si4+. The results show that the first-principles calculations can be used as an effective tool for predicting and interpreting spectroscopic properties of the phosphors. 展开更多
关键词 Ca3Sc2Si3O12:Ce3+ 4f→5d transition FIRST-PRINCIPLES Charge compensation Excitation spectra
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Non-contact and Automatic Measurement of 2D Size with CCD Matrix and Computer System 被引量:4
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作者 ZHANG Ye, WANG Wen-sheng, GUO Yang-xue, SONG Hui-ying (College of Photoelectr.Eng.,Changchun University of Science and Technology,Changchun 130022,CHN) 《Semiconductor Photonics and Technology》 CAS 2003年第3期189-192,共4页
A measurement system with the CCD matrix and computer system is designed to test the 2D size of any shape workpieces automatically. In addition, the system adopts the method of the relative measurement which increases... A measurement system with the CCD matrix and computer system is designed to test the 2D size of any shape workpieces automatically. In addition, the system adopts the method of the relative measurement which increases the precision and the velocity.More importantly,the precision cant be changed with the conditions of the temperature and air pressure.The experiments show that the relative precision of 0.002 9 and the absolute precision of 2.97 μm are obtained. The instrument may be used in the product line and make the testing on line possible. 展开更多
关键词 CCD matrix photographic objective COMPUTER
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Study on longitudinal wind load calculation method of cables for cable-stayed bridge 被引量:2
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作者 Pei Minshan Zhang Xigang Zhu Bin Hou Bin Liu Changpeng 《Engineering Sciences》 EI 2009年第1期18-22,58,共6页
Along with the expanding of span of cable-stayed bridge,wind load becomes a more and more important controlling factor for bridge the design.A very large proportion of the wind load acting on cables has exceeded that ... Along with the expanding of span of cable-stayed bridge,wind load becomes a more and more important controlling factor for bridge the design.A very large proportion of the wind load acting on cables has exceeded that acting on deck.There was not any detailed prescript in Chinese code for calculation of longitudinal wind load on cables due to lack of theoretical research and experiment,and conservative simplified calculation was adopted during design,which leads to conservative and uneconomical design of structures.To resolve this problem,cable force experiment was carried out during the design of Sutong Bridge.By comparing with international research results,the calculation formula of longitudinal wind drag coefficient for cables was advanced to fill the blank of bridge wind resistant code of China,and has already been adopted in the Highway Bridge Wind Resistant Design Code(JTG/T D60-01-2004)with great significance for bridge engineering. 展开更多
关键词 cable-stayed bridge stayed cable longitudinal wind load
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Effects of Sintering Atmosphere on the Microstructure and Surface Properties of Symmetric TiO2 Membranes 被引量:3
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作者 周守勇 仲兆祥 +2 位作者 范益群 徐南平 贺跃辉 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第5期739-745,共7页
The effects of sintering atmosphere on the properties of symmetric TiO2 membranes are studied with regard to sintering behavior, porosity, mean pore size, surface comPosition. and surface charge properties. The exerim... The effects of sintering atmosphere on the properties of symmetric TiO2 membranes are studied with regard to sintering behavior, porosity, mean pore size, surface comPosition. and surface charge properties. The exerimental results show that the symmetric TiO2 membranes display better sintering activity in the air than in argon, and the mean pore diameters and porosities of the membrane sintered in argon are higher than those of the membrane sintered in the air at the same temperature. The surface compositions of the symmetric TiO2 membrane sintered in the air and in argon at different temperatures, as studied by X-ray photoelectron spectroscopy, are discussed in terms of their chemical composition, with particular emphasis on the valence state of the titanium ions. The correlation between the valence state of the titanium ions at the surface and the surface charge properties is examined.It is found that the presence of Ti^3+, introduced at the surface of the symmetric TiO2 membranes by sintering in a lower partial pressure of oxygen, is related to a significant decrease in the isoelectric point. TiO2 with Ti^4+ at the interface has an isoelectric point of 5.1, but the non-stoichiometric TiO2-x with Ti^3+ at the interface has a lower isoelectric point of 3.6. 展开更多
关键词 TiO2 membrane sintering atmosphere sintering behavior SURFACE MICROSTRUCTURE
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The Generation of Electric Load Profiles in the UK Domestic Buildings through Statistical Predictions 被引量:1
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作者 Abdelbaset Ihbal HS Rajamani Read A. Abd-Alhameed Mohamed Jalboub 《Journal of Energy and Power Engineering》 2012年第2期250-258,共9页
Various forecasting tools exist for planners of national networks that are based on historical data. These are used to make decisions at the national level to meet a countries commitment to CO2 emission targets. Howev... Various forecasting tools exist for planners of national networks that are based on historical data. These are used to make decisions at the national level to meet a countries commitment to CO2 emission targets. However, at a local community level, the guidance is not easily understood by planners. This work presents for the first time a methodology for the generation of realistic domestic electricity load profiles for different types of UK households for small communities. The work is based on a limited set of data, and has been compared with measurement. Daily load profiles from individual dwelling to community can be predicted using this method. Results have been presented, and discussed. 展开更多
关键词 Electricity load profile demand side management energy consumption electrical appliances.
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New Active Digital Pixel Circuit for CMOS Image Sensor
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作者 WUSun-tao ParrGerard 《Semiconductor Photonics and Technology》 CAS 2001年第2期65-69,75,共6页
A new active digital pixel circuit for CMOS image sensor is designed consisting of four components: a photo-transducer, a preamplifier, a sample & hold (S & H) circuit and an A/D converter with an inverter. It... A new active digital pixel circuit for CMOS image sensor is designed consisting of four components: a photo-transducer, a preamplifier, a sample & hold (S & H) circuit and an A/D converter with an inverter. It is optimized by simulation and adjustment based on 2 μm standard CMOS process. Each circuit of the components is designed with specific parameters. The simulation results of the whole pixel circuits show that the circuit has such advantages as low distortion, low power consumption, and improvement of the output performances by using an inverter. 展开更多
关键词 CMOS image sensor Active pixel circuit Circuit design
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Molecular Dipole Moment Computed with Ab Initio MKS Charges
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作者 FAN Jian-Fen WANG Qu-Xia +2 位作者 XIA Qi-Ying XIAO He-Ming B.van de Graaf 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2002年第2期139-141,共3页
Molecular dipole moments computed at the levels of HF/STO-3G, HF/6-31G(d, p), HF/6-311+G(2d, 2p), MP2/6-31G(d, p) and MP2/6-311+G(2d, 2p) have been investigated. HF/6-311+G(2d, 2p) was found to be the relatively good ... Molecular dipole moments computed at the levels of HF/STO-3G, HF/6-31G(d, p), HF/6-311+G(2d, 2p), MP2/6-31G(d, p) and MP2/6-311+G(2d, 2p) have been investigated. HF/6-311+G(2d, 2p) was found to be the relatively good choice to compute MKS charges for reproducing the experimental values of molecular dipole moments. Root mean square deviation of computed dipole moments for 21 small polar molecules is about 0.1969 D. 展开更多
关键词 molecular dipole moment MKS charge HF/6-311+G(2d 2p)
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Substituent Effects on the Photocatalytic Properties of a Symmetric Covalent Organic Framework
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作者 Ting-Ting Liu Xin-Ping Wu Xue-Qing Gong 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2022年第4期647-654,I0062-I0085,I0150,共33页
Symmetric covalent organic framework(COF)photocatalysts generally suffer from inefficient charge separation and short-lived photoexcited states.By performing density functional theory(DFT)and time-dependent density fu... Symmetric covalent organic framework(COF)photocatalysts generally suffer from inefficient charge separation and short-lived photoexcited states.By performing density functional theory(DFT)and time-dependent density functional theory(TDDFT)calculations,we find that partial substitution with one or two substituents(N or NH_(2))in the linkage of the representative symmetric COF(N_(0)-COF)gives rise to the separation of charge carriers in the resulting COFs(i.e.,N_(1)-COF,N_(2)-COF,(NH_(2))1-N_(0)-COF,and(NH_(2))2-N_(0)-COF).Moreover,we also find that the energy levels of the highest occupied crystal orbital(HOCO)and the lowest unoccupied crystal orbital(LUCO)of the N_(0)-COF can shift away from or toward the vacuum level,depending on the electron-withdrawing or electron-donating characters of the substituent.Therefore,we propose that partial substitution with carefully chosen electron-withdrawing or electron-donating substituents in the linkages of symmetric COFs can lead to efficient charge separation as well as appropriate HOCO and LUCO positions of the generated COFs for specific photocatalytic reactions.The proposed rule can be utilized to further boost the photocatalytic performance of many symmetric COFs. 展开更多
关键词 Covalent organic framework PHOTOCATALYSIS Electronic structure Charge separation Density functional theory calculation
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Research on HJ-1A/B satellite data automatic geometric precision correction design
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作者 Xiong Wencheng Shen Wenming +3 位作者 Wang Qiao Shi Yuanli Xiao Rulin Fu Zhuo 《Engineering Sciences》 EI 2014年第5期90-96,共7页
Developed independently by China,HJ-1A/B satellites have operated well on-orbit for five years and acquired a large number of high-quality observation data.The realization of the observation data geometric precision c... Developed independently by China,HJ-1A/B satellites have operated well on-orbit for five years and acquired a large number of high-quality observation data.The realization of the observation data geometric precision correction is of great significance for macro and dynamic ecological environment monitoring.The paper analyzed the parameter characteristics of HJ-1 satellite and geometric features of HJ-1 satellite level 2 data(systematic geo- corrected data).Based on this,the overall HJ- 1 multi- sensor geometric correction flow and charge-coupled device(CCD) automatic geometric precision correction method were designed.Actual operating data showed that the method could achieve good result for automatic geometric precision correction of HJ-1 satellite data,automatic HJ-1 CCD image geometric precision correction accuracy could be achieved within two pixels and automatic matching accuracy between the images of same satellite could be obtained less than one pixel. 展开更多
关键词 HJ-1 satellite AUTOMATIC geometric precision correction CCD
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Thermo-mechanical analysis of an SI engine piston using different boundary condition treatments
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作者 Amir-Hasan Kakaee Javad Gharloghi +1 位作者 Aliasghar Foroughifar Abdoreza Khanlari 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第10期3817-3829,共13页
Heat transfer of an SI engine's piston is calculated by employing three different methods based on resistor-capacitor model with the help of MATLAB code, and then the piston is thermo-mechanically analyzed using c... Heat transfer of an SI engine's piston is calculated by employing three different methods based on resistor-capacitor model with the help of MATLAB code, and then the piston is thermo-mechanically analyzed using commercial ANSYS code. The results of three methods are compared to study their effects on the piston thermal behavior. It is shown that resistor-capacitor model with less number of equations and consequently less solution time, is an appropriate method for solving problems of engine piston heat transfer. In the second part, the thermal stresses due to non-uniform temperature distribution, and mechanical stresses due to mechanical loads are calculated. Finally, the temperature distributions as a thermal load along with mechanical loads are applied to the piston to determine the total stress distribution and critical fracture zones. It is found that the amount of thermal stresses is considerable. 展开更多
关键词 PISTON TEMPERATURE boundary condition STRESS thermo-mechanical analysis
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Estimation of the Maximum Annual Loads Modeling for Kingdom of Bahrain 被引量:2
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作者 Isa Salman Qamber 《Journal of Energy and Power Engineering》 2013年第10期2006-2011,共6页
The present paper proposes the impact of the air temperature on electricity demand as expected. It is clear that the annual maximum load is recorded versus the years starting by the year 2009 up to 2012. At present, t... The present paper proposes the impact of the air temperature on electricity demand as expected. It is clear that the annual maximum load is recorded versus the years starting by the year 2009 up to 2012. At present, the graph fitting technique is applied with some mathematical and computational tools based on the actual values of the years 2009 up to 2012 considering the lower values, the higher values and the average values of the annual maximum loads for Kingdom of Bahrain. For the three scenarios, the models are obtained by curve fitting technique. As well, the model of actual loads is obtained finally which has mostly the closest values obtained. 展开更多
关键词 Annual maximum load curve fitting load scenarios.
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Electronic and Magnetic Properties of Double Perovskite Ca_2CrSbO_6
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作者 赵元 倪广鑫 +1 位作者 刘会平 易林 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第1期180-184,共5页
First-principles calculations have been performed for the study of the electronic band structure and ferromagnetic properties of double perovskite Ca2CrSbO6. The density of states, total energy, spin magnetic moment, ... First-principles calculations have been performed for the study of the electronic band structure and ferromagnetic properties of double perovskite Ca2CrSbO6. The density of states, total energy, spin magnetic moment, and charge density were calculated and analyzed in details. It is found that Ca2CrSbO6 has a stable ferromagnetic ground state and the spin magnetic moment per molecule is about 2.99#B. The chromium contributes the most in the total magnetic moments. The results indicate that Ca2CrSbO6 is half-metallic. 展开更多
关键词 first-principles calculations electronic structure ferromagnetic properties
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Culture of Scenedesmus acuminatus in Corn Steep Liquor
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作者 Cristiane Tomas Kubo] Rafael Luan Sehn Canevest +2 位作者 Edson Antonio da Silva , Nyamien Yahaut Sebastien Tatiana Rodrigues da Silva Baumgartner 《Journal of Agricultural Science and Technology(B)》 2017年第5期346-350,共5页
Microalgae have been evaluated as a source of lipids for biodiesel production. They can be grown on effluent and produce biomass while removing organic and mineral components from the medium. The use of agro-industria... Microalgae have been evaluated as a source of lipids for biodiesel production. They can be grown on effluent and produce biomass while removing organic and mineral components from the medium. The use of agro-industrial wastes for the production of microalgae is an alternative to reduce the costs related to the composition of the culture medium, thus reducing operational costs considerably. This work was conceived as a research about the cultivation of microalgae Scenedesmus acuminatus on the substrate composed by corn steep liquor. A central composite design (CCD) was carried to study the influence of the effluent and inoculum concentration on the chemical oxygen demand (COD) of the culture. Statistical analysis indicated that the percentage of inoculum and effluent had an influence on the COD. The cultivation, together with the coagulation procedure, was efficient for the removal of organic matter, verified through the COD reduction and changing of pH value. These two parameters reached the appropriate level according to the standard required by current legislation. 展开更多
关键词 SCENEDESMUS com steep liquor chemical oxygen demand BIOMASS microalgae.
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Development of Vibrating Monitoring for Hydro Power Turbines under Operating Condition
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作者 Skvorcov Oleg 《Journal of Mechanics Engineering and Automation》 2014年第11期878-886,共9页
Units and components of the powerful power equipment are exposed to the big static and dynamic load. An example of such equipments is turbines hydraulic power plant and, especially, hydroelectric pumped storage power ... Units and components of the powerful power equipment are exposed to the big static and dynamic load. An example of such equipments is turbines hydraulic power plant and, especially, hydroelectric pumped storage power plant. Existing techniques of control of a vibrating condition do not consider: very wide frequency range of vibrating processes, difficult character of such processes in the form of the sum multiharmonic, random and close to shock processes. Such techniques usually do not consider intervals of start-up and stop, and also work on transitive modes when loadings on a construction are maximum. Available techniques of an estimation of admissible level of vibrating influence and tests for vibration durability are not harmonized enough among themselves. Various known interpretations of communication of vibrating characteristics and durability estimations on mechanical pressure at broadband vibrating influence yield ambiguous result. On the basis of the analysis of the published information, we attempt to formulate the requirement to system of vibrating monitoring of the hydraulic turbine and power motor pumps. System should provide data acquisition and the analysis of the data on a vibrating condition taking into account accumulation of vibrating influences and long term of operation on the basis of estimation methods as low-cycle, and high-cycle (gigacycle) fatigue is made. 展开更多
关键词 Vibrating durability shock random transitive modes water-wheel ACCELERATION velocity DISPLACEMENT pumped-storage
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