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91.
用TiO2粉末、NaOH和蒸馏水为原料合成金红石型TiO2纳米棒。XRD和FESEM分析表明,制备的样品为单晶且无杂质,其平均粒径约为40 nm。当样品于600°C退火2 h后,FESEM观察发现生成了TiO2纳米棒。XRD分析表明纳米棒为单晶。纳米棒表面光滑,其长约为1μm,直径约为80 nm。紫外和拉曼光谱研究表明,所制备样品的能带间隙为3.40 eV。 相似文献
92.
Jeff Niederdeppe Hye Kyung Kim Helen Lundell Faheem Fazili Bonnie Frazier 《The Journal of communication》2012,62(5):758-777
This study attempts to advance theorizing about narrative persuasion by explicating types of thoughts, beyond counterarguing, generated in response to a short narrative with persuasive intent. We examine responses to four types of narratives (focus: individual vs. community; by sidedness: one‐ vs. two‐sided) about causes and solutions for obesity in an attempt to increase support for policies to address the issue. Using a randomized experiment (n = 245), we show that narrative focus and sidedness interact to produce different patterns of thoughts, attributions, and policy support. Simple elaboration, counterelaboration, and counterarguing predicted causal attributions and policy support, but only simple elaboration mediated message effects on intended persuasive outcomes. We conclude by discussing the study's contributions to communication theory and practice. 相似文献
93.
The aim of this research is to investigate the antibacterial activity of Kapok fibers modified with AgCl/TiO2 and Chitosan colloid. A very simple, single-step (pad-dry-cure) method was used for the application of AgCl/TiO2 and Chitosan colloid on kapok fibers, the chemicals used are easily available. Different blend ratios of chitosan and AgCl/TiO2 colloid were applied to the bleached kapok fibers and antibacterial properties were assayed against gram positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The treated kapok fibers were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). It was observed that the bacterial growth was significantly reduced in the samples which had a higher concentration of chitosan and AgCl/TiO2 colloid. However, a significant reduction in bacterial growth with the use of this colloid was observed. 相似文献
94.
Mohamed Mamdouh Ahmed Faheem Doaa Khalil Mohammed Mohammed 《Electric Power Systems Research》2008,78(11):1865-1872
This paper proposes a differential protection scheme for transmission lines using the energy conservation law. The real power signals at both ends (sending and receiving) of the line are compared with a pre-specified value, if the resultant is more than this value, an internal fault is indicated in the transmission line zone.The proposed technique is evaluated using PSCAD/EMTDC program configurated to model the effect of faults on typical 500 kV transmission line. Extensive simulation studies show that this protection scheme has the ability to discriminate internal faults fast and accurately, and is more reliable than conventional biased differential protection scheme, and suitable for all types of lines. Details of the proposed relay design are given in the paper; also results of some performance studies are given. 相似文献
95.
Muzafar A. Kanjwal Nasser A. M. Barakat Faheem A. Sheikh Hak Yong Kim 《Journal of Materials Science》2010,45(5):1272-1279
Titanium dioxide-cadmium oxide (TiO2/CdO) nanofibers were prepared by the electrospinning technique followed by a single-step calcination from a solution of titanium
isopropoxide and cadmium acetate dihydrate. Scanning electron microscopy, transmission electron microscopy, and the Brunauer–Emmett–Teller
technique were employed to characterize the as-spun nanofibers as well as the calcined product. The specific surface area
of the calcined product was calculated to be 65.3067 m2 g−1. X-ray powder diffractometry analysis was conducted on the samples to study their chemical composition as well as their crystallographic
structure. The results obtained indicated that the prepared nanostructure product can eliminate all of the methyl orange dye
within about 75 min, whereas the pristine titanium dioxide nanofibers could not eliminate more than 50% even after 180 min. 相似文献
96.
This article describes a framework for intrusion detection using agent-based technology. Agents are ideally qualified due to their reactivity, interactivity, autonomy and intelligence. The system discussed is implemented in a TCP/IP LAN (local area network) environment. It represents a step towards a complete multi-agent based system for networking security. 相似文献
97.
Faten Faheem Mahmoud Nicholas J. Salamon Walter R. Marks 《International journal for numerical methods in engineering》1982,18(2):245-257
The solution of elastostatic bodies in frictionless contact is obtained by an automated direct method which exploits the theory of linear elasticity and circumvents the need for the inclusion of artificial interface elements, mathematical programming techniques or computation of contact pressure. The method is simple and economical to use and can be easily appended to existing numerical schemes such as the finite element method. The formulation and numerical algorithm are presented for body combinations which are independent of relative tangential displacements along the contact surface. The method is illustrated through an elementary example amenable to hand calculation. Numerical results for more realistic problems are given and compared to known solutions. It is concluded that the method provides a powerful means for both the analysis and design of contacting bodies when used in conjunction with a finite element computer program. 相似文献
98.
Faheem A. Sheikh Nasser A. M. Barakat Muzafar A. Kanjwal Santosh Aryal Myung Seob Khil Hak-Yong Kim 《Journal of materials science. Materials in medicine》2009,20(3):821-831
In the present study, we have aimed to produce nanoparticles (NPs) possessing the capability of carrying both of the hydrophobic
and hydrophilic drugs and reveal significant release for both drug types. Poly(ε-caprolactone) (PCL) grafted poly(vinyl alcohol)
(PVA) copolymer (PCL-g-PVA) has been prepared and shaped in nano-particulate form to be adequate for carrying the drugs. Stannous
octoate (Sn(II)Oct2) was used to catalyze PVA and ε-caprolactone monomer to chemically bond. Moreover, this catalyst enhanced side chain polymerization
reaction for the utilized ε-caprolactone monomer to form poly(ε-caprolactone) (PCL). The formed PCL was attached as branches
with PVA backbone. 1H NMR has confirmed formation of PCL and grafting of PVA by this new polymer. Moreover, the vibration modes in the functional
groups of PCL-g-PVA have been detected by FT-IR. The thermal alteration in the grafted polymer was checked by TGA analysis.
The successfully synthesized grafted copolymer was able to self-aggregate into NPs by direct dialysis method. The size, morphology
and charges associated with the obtained NPs were analyzed by DLS, TEM and ELS, respectively. PCL-g-PVA NPs were investigated
as drug carrier models for hydrophobic and hydrophilic anti cancer drugs; paclitaxel and doxorubicin. In vitro drug release experiments were conducted; the loaded NPs reveal continuous and sustained release form for both drugs,
up to 20 and 15 days for paclitaxel and doxorubicin, respectively. However, in a case of using pure drugs only, both drugs completely released within 1–2 h. The overall obtained
results strongly recommend the use these novel NPs in future drug delivery systems. 相似文献
99.
Jahanzeb Bhatti Abdul Faheem Khan A. R. Bushroa 《Journal of Adhesion Science and Technology》2016,30(20):2224-2235
Electrodeposition and magnetron sputtering techniques have been employed for the deposition of Ni and bilayer NiCrN coatings, respectively, on mild steel substrate. Ni electrodeposition was performed using sulfate Watt’s bath, while magnetron sputtering was performed on electrodeposited Ni using DC power 350 W and base pressure of 3 × 10?5 Torr in order to prepare bilayer NiCrN coatings. Structural and mechanical properties of Ni and bilayer NiCrN coatings have been investigated using various characterization techniques such as SEM-EDX, XRD, hardness, adhesion testing, etc. SEM analysis reflects the formation of spherical/nodular particles of varying sizes in NiCrN coating whereas Ni coating shows irregular, agglomerated, and non-uniform distribution of particles. Formation of hard CrN phase in NiCrN coating has been confirmed by XRD and EDX. NiCrN coating exhibits better hardness in comparison with Ni coating due to the formation of nitride phase. Micro scratch testing of bilayer NiCrN coating shows better interlayer adhesion and adhesion with mild steel substrate. The combination of electrodeposition and magnetron sputtering can produce inexpensive NiCrN coating containing hard CrN phase with better mechanical properties for automotive applications. 相似文献