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41.
蔡静 《网络安全技术与应用》2014,(9):105-106
随着国际信息技术的发展,物联网已成为发展的主流;其中的智能家居系统,作为物联网发展的十大重点领域之一,也得到快速的发展.克服传统的智能家居系统内部有线组网的弊端,本文研究采用无线通信技术来组建家庭无线局域网的硬件系统,先对设计了总体的系统图,然后分别对硬件系统和软件系统分别进行设计,其中软件系统基于UC/OS-Ⅱ嵌入式操作系统的应用软件的开发,使用户操作起来更加方便,界面更加友好. 相似文献
42.
开发海洋潮流能对缓解能源危机具有重要意义,电力变换系统是潮流能发电系统的关键技术之一。提出了一种利用SOPC技术实现潮流能发电电力变换控制系统的设计方法,采用单片高性能FPGA芯片构建双NIOSⅡ软核系统,其中一个NIOSⅡ处理器负责系统任务调度和能量管理,一个NIOSⅡ处理器负责电力变换控制和异常诊断。针对电力变换系统的信息数据特点,提出了基于RAM、FIFO、GPIO的双NIOSⅡ处理器握手机制,并给出了系统的具体设计实现。该双NIOSⅡ处理器系统提高了系统的任务调度灵活性、控制算法处理速度和应急处理能力。 相似文献
43.
The dissolution rate coefficients of Cr‐substituted (0‐20 at.% Cr) iron oxides viz. hematite and magnetite were determined by using an inverse cubic rate (ICR) law applicable for spherical particles as well as by a general kinetic equation (GKE) applicable for polydispersed particles. An attempt is made to compare both the treatments for different kinds of dissolution profiles obtained by employing oxides with narrow particle size distribution in V(II)‐EDTA and citric acid‐EDTA‐ascorbic acid formulations at 353±5K. The dissolution profiles could be classified into three types based on the nature of oxide and formulations. It is observed that both ICR and GKE treat the dissolution course as a function of decrease in fraction of undissolved mass, m/m0. The dissolution rate coefficients determined by ICR and GKE have shown the similar trend of decrease with increasing Cr content of the oxides and was ascribed to lattice stabilization. 相似文献
44.
本研究提供了一种一步热解法制备纳米零价铁生物炭的方法。将海藻酸铁在高温缺氧条件下热解制备了球形零价铁生物炭复合材料(ZVIBC),考察了Cd(II)溶液pH、初始浓度、吸附时间、背景离子、空气中老化时间对ZVIBC吸附Cd(II)性能的影响,通过FTIR、XRD、XPS、EDS等方法对ZVIBC以及ZVIBC-Cd(II)进行了表征,研究了ZVIBC对Cd(II)的吸附机理。结果显示:pH对ZVIBC吸附Cd(II)有显著的影响,4为最佳吸附pH条件。ZVIBC吸附Cd(II)的过程符合Langmuir模型,拟合的饱和吸附量为240 mg/g。主要吸附机理为:活性官能团(O—H、C—O、C=C、C=O、COO)与Cd(II)形成配合物,以及Cd(II)与Fe2+生成Cd(OH)2沉淀。 相似文献
45.
Results are reported of experiments and modelling of cathodic Pb and anodic PbO2 electrodeposition, aimed at developing a process using both reactions simultaneously for treating aqueous effluents from lead–acid battery recycling plants. Pb(II) solubilities and equilibrium potentials were calculated as functions of pH and sulfate activities. Using kinetic parameters from the literature or determined experimentally, models were developed for current density–potential and current efficiency–potential relationships, together with the current density dependence of specific electrical energy consumptions for Pb(II) recovery. Experimental current density–potential and charge efficiency–potential relationships were in broad agreement with model predictions, with near unity current efficiencies for mass transport controlled PbO2 deposition from electrolytes containing 1 mol Pb(II) m–3 at pH 12. However, charge efficiencies for cathodic deposition of lead were typically 0.2 for 1 mol Pb(II) m–3 + 1 mol O2 (aq) m–3; removal of dissolved oxygen was predicted and determined to increase current efficiencies to near unity. Pb(II) concentrations were depleted to <60 ppb in a batch recycle reactor system with graphite felt anodes and graphite or titanium felt cathodes. Simultaneous cathodic Pb and anodic PbO2 electrodeposition resulted in more rapid Pb(II) depletion than for either reaction separately. 相似文献
46.
以NiSO4、ZnSO4和Nd(NO3)3为原料,采用共沉淀快速冷冻法制备出了复合掺杂稀土Nd(III)和Zn(II)的非晶态氢氧化镍粉体材料。测试发现:样品材料微结构无序性强,结晶水含量较高。将样品材料制备成镍电极并组装成MH—Ni电池,在80mA/g恒电流充电5.5h、40mA/g恒电流放电、终止电压为1.0V的充放电制度下,复合掺杂6%Nd(III)和6%Zn(II)样品材料电池的放电平台为1.2624V,放电比容量为343.12mAh/g,远高于目前应用的B-Ni(OH)2电极活性材料的放电比容量。 相似文献
47.
Ali Bayri Mustafa Sulu 《Journal of Inorganic and Organometallic Polymers and Materials》2006,16(2):185-188
This study reports the magnetic structures of newly reported trinuclear vanadium(II)–diamine complexes. Using the isotropic
Heisenberg exchange Hamiltonian, it is suggested that there are strong intramolecular antiferromagnetic interactions among
the vanadium(II) ions. It is also suggested that these complexes are good candidates to the geometrically frustrated systems.
For part 1 see A. Bayri, J. Inorg. Organomet. Polym. Mater., (in press)
An erratum to this article can be found at 相似文献
48.
This study reports the magnetic properties of newly reported nickel(II) complex of the antiprine Schiff base of 3-formylsalicylic
acid. Using the isotropic magnetic interaction model it is suggested that there is a strong antiferromagnetic interactions
between metal centers in dimeric units. It is also suggested that the system become demagnetized below a certain temperature.
An erratum to this article can be found at 相似文献
49.
In this paper, a new liquid membrane technique, hollow fiber renewal liquid membrane (HFRLM), is presented, which is based on the surface renewal theory, and integrates the advantages of fiber membrane extraction, liquid film permeation and other liquid membrane processes. The results from the system of CuSO4+D2EHPA in kerosene+HCl show that the HFRLM process is very stable. The liquid membrane is renewed constantly during the process, the direct contact of organic droplets and aqueous phase provides large mass transfer area. These effects can significantly reduce the mass transfer resistance in the lumen side. Then the mixture of feed phase and organic phase flowing through the lumen side gives a higher mass transfer rate than that of stripping phase and organic phase, because the aqueous layer diffusion of feed phase is the rate-controlling step. The overall mass transfer coefficient increases with increasing flow rates and D2EHPA concentration in the organic phase, and with decreasing initial copper concentration in the feed phase. The overall mass transfer coefficient also increases with increasing pH in the feed phase, and reaches a maximum value at pH of 4.44, then decreases. Also, there is a favorable w/o volume ratio of 20:1 to 30:1 for this process. Compared with hollow fiber supported liquid membrane and hollow fiber membrane extraction processes, HFRLM process has a high mass transfer rate. Mathematical model for the HFRLM process based on the surface renewal theory is developed. The calculated results are in good agreement with experimental results under the conditions studied. 相似文献
50.
Su‐Hsia Lin Hsiang‐Chien Kao Shih‐Hung Huang Ruey‐Shin Juang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2002,77(2):168-174
The equilibrium and kinetics of solvent extraction of Cu2+ from aqueous solutions containing equimolar EDTA with Aliquat 336 in n‐decanol and kerosene at 298 K were investigated. The concentrations of Cu2+ (8–50 mol m?3), Cl? (5–60 mol m?3), and Aliquat 336 (20–100 mol m?3) were varied. A semi‐empirical model with three parameters was proposed to describe the equilibrium behavior, in which the non‐idealities in both aqueous and organic phases were considered. Over the ranges studied, the model agreed reasonably well with the experimental data (standard deviation, 15%). The forward and backward reaction rate constants were determined as (5.31 ± 0.16)×10?6 m9/4 mol?3/4 s?1 and (2.62 ± 0.09)×10?7 s?1, respectively, at 298 K. An interfacial reaction mechanism was proposed, which revealed that the reaction between the chelated anions and trimeric amine molecules at the interface was rate limiting. The derived rate laws were consistent with the experimental results. © 2002 Society of Chemical Industry 相似文献