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1.
The Synthesis of Sulfated Titanium Oxide Nanotubes   总被引:1,自引:0,他引:1  
TiO2 nanotubes can be prepared in gram quantities by treating anatase TiO2 powder with concentrated NaOH solution. These TiO2 nanotubes acquired strong acidity after being impregnated with sulfuric acid solution and calcined at 300 °C. The anatase TiO2 powder used to prepare the nanotube did not catalyze the esterification between cyclohexanol and acetic acid, while sulfated TiO2 nanotubes were very reactive toward the esterification reaction.  相似文献   
2.
The corrective reaction time (tcr) is an essential motor property when modelling hand control movements. Many studies designed experiments to estimate tcr, but reported only group means with inconsistent definitions. This study proposes an alternative methodology using Drury's (1994) intermittent illumination model. A total of 24 participants performed circular tracking movements under five levels of visual information delay using a modified monitor in a darkened room. Measured movement speeds and the manipulated delays were used with the model to estimate tcr of individuals and test effects of gender and path width. The results showed excellent model fits and demonstrated individual differences of tcr, which was 273 ms on average and ranged from 87 to 441 ms. The wide range of tcr values was due to significant effects of gender and path width. Male participants required shorter tcr compared to female participants, especially for narrow path widths.  相似文献   
3.
Microsystem Technologies - A new digital scanning approach is proposed and its feasibility is demonstrated. The Cascaded Mirror Array applies an array of reflectors, with each reflector movable...  相似文献   
4.
In this study, batch experiments were performed to investigate a novel process for high concentration arsenate removal in the presence of air and/or CO(2) bubbling. The pretreatment step, CO(2) bubbling at 300 mL/min for 5 min, was taken to adjust the solution pH to an acidic environment, followed by air bubbling at 300 mL/min for 10 min to increase dissolved oxygen in the solution. In the treatment period, the nano-scale zero-valent iron was applied to remove aqueous arsenate of 3000 μg/L, while the treatment system was continuously bubbled by 300 mL/min of air. Such a process resulted in outstanding performance in arsenate removal. Furthermore, in the field groundwater application, the arsenate removal rate for the proposed process was 5 times faster than the rate measured when the system was pretreated by acidic chemical species only.  相似文献   
5.
Amyloid-β (Aβ) peptides play a key role in Alzheimer’s disease (AD), the most common type of dementia. In this study, a polysaccharide from Bletilla striata (BSP), with strong antioxidant and anti-inflammatory properties, was extracted using a low-temperature method and tested for its efficacy against AD, in vitro using N2a and BV-2 cells, and in vivo using an AD rat model. The characterization of the extracted BSP for its molecular structure and functional groups demonstrated the effectiveness of the modified method for retaining its bioactivity. In vitro, BSP reduced by 20% reactive oxygen species (ROS) levels in N2a cells (p = 0.0082) and the expression levels of inflammation-related genes by 3-fold TNF-α (p = 0.0048), 4-fold IL-6 (p = 0.0019), and 2.5-fold IL-10 (p = 0.0212) in BV-2 cells treated with Aβ fibrils. In vivo, BSP recovered learning memory, ameliorated morphological damage in the hippocampus and cortex, and reduced the expression of the β-secretase protein in AlCl3-induced AD rats. Collectively, these findings demonstrated the efficacy of BSP for preventing and alleviating the effects of AD.  相似文献   
6.
The present study investigates the effect of the addition of nanoparticles into epoxy resins as the matrix on the impact absorbed energy of CFRP (carbon fiber reinforced polymer). Impact absorbed energy is one of the main properties to evaluate the CFRP's performance for transportation and aerospace structures. Two types of nanoparticle, namely nanofibers and nano-silica beads, were added into the epoxy resin to improve the impact absorption capacity of the CFRP. Two modified additives and conventional epoxy resins were quantitatively compared. The impact test results showed that impact absorbed energy for nanofibers was higher than nano-silica beads, and nanofibers as the additive promoted about 11% of impact absorbed energy compared with neat epoxy resin.  相似文献   
7.
Carbon fiber composites have high strength, high stiffness and light weight characteristics to apply to many fields, such as leisure, energy and transportation industries. The CFRP (carbon fiber reinforced polymers/plastics) composites made of carbon fibers as reinforcement and epoxy resins as matrix were prepared by drum winding process. Various parameters such as molding temperature, molding pressure and pressing time were selected as the pre-pregs were laminated to be the CFRP. The effects of fabricating parameters which affected the mechanical properties of CFRPs were analyzed by Taguchi method in this study. The results showed that molding temperature was the main factor to influence the mechanical properties of composites.  相似文献   
8.
9.
The axial discharge continuous mixer combines the features of a continuous mixer and a twin screw extruder, expanding the flexibility of this compounding machine. In this work we analyzed the influence of rotor design on the dispersive mixing performance of a LCMAX 40 unit. Specifically we looked at various arrangements for the pushing and counter pushing units in the design of the LCMAX 40. A fluid dynamics analysis package—FIDAP, based on the finite element method, was used to model the flow behavior of a power law model fluid under different pressurization conditions. Dispersive mixing efficiency was quantified in terms of shear stresses and elongational flow components generated in the flow field. We found that the counter-pushing unit generally contributes more in building up high shear stresses. However, the generation of elongational flow components, which is beneficial for dispersive mixing, is not solely dependent upon the pushing–counter pushing configuration but rather on the overall rotor geometry. We found that the maximum number of counter-pushing units in the rotor design of the LCMAX 40 should not exceed two in order to provide adequate material pumping. Rotor designs with alternating arrangements of pushing and counter-pushing units provide overall better dispersive mixing conditions.  相似文献   
10.
Hand-Off Evolution with Multiple Interfaces   总被引:1,自引:0,他引:1  
Under the upcoming 4G network, mobile devices will have to handle multiple interfaces. Each network mechanism has its merits, such as WiFi's high speed and the long transmission range of High Speed Download Packet Access (HSDPA), but managing a combination of different interfaces during a hand-off procedure presents new challenges for next-generation networks because the network environment will continue to become more complex. A hand-off mechanism called hand-around allows users to manage multiple interfaces, but can cause bandwidth exhaustion and signal integrity problems. Interface scheduling could offer routing optimization, connection QoS, power savings, and bandwidth utilization. New issues, such as simultaneous location, will also arise under the upcoming 4G network, making multiple-interface integration an urgent topic.  相似文献   
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