垂直绿化综合效应研究     

Tang Van Tai  Tran Ngoc Binh  Nguyen Nhu Anh  Phan Hong Nhung 《黑龙江生态工程职业学院学报》2017,30(4)

除了美观上的效果,垂直绿化缓解热岛效应,减少水土流失,防尘减噪,节能环保,延长建筑寿命等作用也被越来越多的人意识到,有关垂直绿化各方面定性的研究也不断得到开展.以南京的三种墙面绿化形式—攀援式墙面绿化、铺贴式墙面绿化和组合移动式墙面绿化作为研究对象,通过测定垂直绿化的降温、减噪和心理效应探讨垂直绿化对建筑环境的综合影响.  相似文献   

Passive optical separation and enrichment of cells by size difference     

Hoi SK  Kim VH  Huy NM  Sow CH  Ow YS  Bettiol AA 《Biomicrofluidics》2010,4(4):44111

A size-selective cell sorting microfluidic device that utilizes optical force is developed. The device consists of a three-dimensional polydimethylsiloxane microstructure comprised of two crossed microchannels in a three-dimensional configuration. A line shaped focused laser beam is used for automatic size-selective cell sorting in a continuous flow environment. As yeast cells in an aqueous medium are fed continuously into a lower channel, the line shaped focused laser beam is applied (perpendicular to the direction of flow) at the junction of the two crossed channels. The scattering force of the laser beam was employed to push cells matching specific criteria upward from one channel to another. The force depends on the size of the cells, the laser power, and the fluid flow speed. The variation in size of yeast cells causes them to follow different routes at the intersection. For flow speeds below 30 μm∕s, all yeast cells larger than 3 μm were removed from the main stream. As a result, a high purity sample of small cells can be collected at the outlet of bottom channel.  相似文献   

Oxygen plasma treatment for reducing hydrophobicity of a sealed polydimethylsiloxane microchannel     

Tan SH  Nguyen NT  Chua YC  Kang TG 《Biomicrofluidics》2010,4(3):32204

Rapid prototyping of polydimethylsiloxane (PDMS) is often used to build microfluidic devices. However, the inherent hydrophobic nature of the material limits the use of PDMS in many applications. While different methods have been developed to transform the hydrophobic PDMS surface to a hydrophilic surface, the actual implementation proved to be time consuming due to differences in equipment and the need for characterization. This paper reports a simple and easy protocol combining a second extended oxygen plasma treatments and proper storage to produce usable hydrophilic PDMS devices. The results show that at a plasma power of 70 W, an extended treatment of over 5 min would allow the PDMS surface to remain hydrophilic for more than 6 h. Storing the treated PDMS devices in de-ionized water would allow them to maintain their hydrophilicity for weeks. Atomic force microscopy analysis shows that a longer oxygen plasma time produces a smoother surface.  相似文献   

Changing views of teachers and teaching in Vietnam     

Huong Nguyen Thi Mai  Christine Hall 《Teaching Education》2017,28(3):244-256

In order for Vietnam to seek better international integration into an increasingly globalised world, the Vietnamese Government has launched educational reforms requiring teachers to adopt ‘Western’ constructivist pedagogies. This paper reports on an action research study in a Vietnamese teacher training institution which found that Vietnamese student teachers were willing to accommodate and accept change and were often very enthusiastic about the ‘Western ideas’ of teaching and learning, but that their unquestioning respect for the authority of their tutors remained firmly fixed. The data also showed that the students’ tutors had a relatively limited exposure to the ‘Western theories’ and their implications and therefore did not model or demonstrate the theories effectively. The paper draws on these findings to argue that the focus for transforming Vietnamese teachers’ practice should be on promoting the responsibility of teacher educators to introduce student teachers to new ideas about the processes of teaching and learning. This strategy is likely to be more supportive of student teachers’ development as it allows them to separate the processes of teaching from culturally dominant beliefs about roles which are part of their established identities.  相似文献   

Effect of Ethanol Stress on Fermentation Performance of Saccharomyces cerevisiae Cells Immobilized on Nypa fruticans Leaf Sheath Pieces     

Hoang Phong Nguyen  Hoang Du Le  Van Viet Man Le 《Food Technology and Biotechnology》2015,53(1):96-101

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Temperature-induced droplet coalescence in microchannels     

Xu B  Nguyen NT  Wong TN 《Biomicrofluidics》2012,6(1):12811-128118

This paper reports a technique for temperature-induced merging of droplets in a microchannel. The multiphase system consists of water droplet and oil as the dispersed phase and the carrying continuous phase. A resistive heater provides heating in a rectangular merging chamber. The temperature of the chamber is controlled by the voltage applied to the heater. The merging process of two neighboring droplets was investigated with different applied voltage, flow rate ratio between water and oil and total flowrate. Merging is found to be effective at high flow rate ratio, high temperature, and low total flowrate. The presented technique could be used for merging and mixing in droplet-based lab-on-a-chip platforms.  相似文献   

The effects of a family fitness program on the physical activity and nutrition behaviors of third-grade children     

Hopper CA  Munoz KD  Gruber MB  Nguyen KP 《Research quarterly for exercise and sport》2005,76(2):130-139

This study examined the efficacy of a school-based exercise and nutrition program with a parent component. Third-grade children (N = 238) from six elementary schools participated in the study, with three schools randomly assigned to a program group and the other three schools to a control group. The program group received a health-related fitness school-based program and a home program that required parents and children to complete activities and earn points for nutrition and exercise activities. The control group received their traditional physical education and nutrition education program. Univariate analysis of variance on pre- and posttest scores were completed on the following variables: height, weight, body mass index, skinfold, blood cholesterol, mile run, exercise and nutrition knowledge, calories, protein, carbohydrates, total fat, saturated fat, dietary cholesterol, fiber, sodium, percentage of calories from carbohydrates, and percentage of calories from fat. At pretest, the treatment and control groups did not significantly differ on the measures using schools as the unit of analysis. Girls scored significantly higher than boys on skinfold and pretest knowledge. At posttest, the treatment group scored significantly higher than the control group on exercise and nutrition knowledge and significantly lower than the control group on total fat intake, using schools as the unit of analysis. There was no improvement in physiological measures, including blood cholesterol. The study demonstrated that schools can adjust curriculum to meet some health needs of students and achieve modest changes in exercise and nutrition knowledge and diet. The family component of the program provided a practical approach to improving physical activity and nutrition behaviors for elementary school teachers who teach many participants in a crowded curriculum.  相似文献   

Hormonal responses to exercise after partial sleep deprivation and after a hypnotic drug-induced sleep     

Mougin F  Bourdin H  Simon-Rigaud ML  Nguyen NU  Kantelip JP  Davenne D 《Journal of sports sciences》2001,19(2):89-97

The aim of this study was to determine the hormonal responses, which are dependent on the sleep wake cycle, to strenuous physical exercise. Exercise was performed after different nocturnal regimens: (i) a baseline night preceded by a habituation night; (ii) two nights of partial sleep deprivation caused by a delayed bedtime or by an early awakening; and (iii) two nights of sleep after administration of either a hypnotic compound (10 mg zolpidem) or a placebo. Eight well-trained male endurance athletes with a maximal oxygen uptake of 63.5 +/- 3.8 ml x kg(-1) x min(-1) (mean value +/- s(x)) were selected on the basis of their sleeping habits and their physical training. Polygraphic recordings of EEG showed that both nights with partial sleep loss led to a decrease (P< 0.01) in stage 2 and rapid eye movement sleep. A delayed bedtime also led to a decrease (P < 0.05) in stage 1 sleep. Zolpidem had no effect on the different stages of sleep. During the afternoon after an experimental night, exercise was performed on a cycle ergometer. After a 10-min warm-up, the participants performed 30 min steady-state cycling at 75% VO(2-max) followed by a progressively increased workload until exhaustion. The recovery period lasted 30 min. Plasma growth hormone, prolactin, cortisol, catecholamine and lactate concentrations were measured at rest, during exercise and after recovery. The concentration of plasma growth hormone and catecholamine were not affected by partial sleep deprivation, whereas that of plasma prolactin was higher (P < 0.05) during the trial after an early awakening. Plasma cortisol was lower (P < 0.05) during recovery after both sleep deprivation conditions. Blood lactate was higher (P < 0.05) during submaximal exercise performed after both a delayed bedtime and an early awakening. Zolpidem-induced sleep did not affect the hormonal and metabolic responses to subsequent exercise. Our results demonstrate only minor alterations in the hormonal responses to exercise after partial sleep deprivation.  相似文献   

Improvement of rectification effects in diffuser/nozzle structures with viscoelastic fluids     

Nam-Trung Nguyen  Yee-Cheong Lam  Soon-Seng Ho    Cassandra Lee-Ngo Low 《Biomicrofluidics》2008,2(3)

This paper reports the improvement of rectification effects in diffuser∕nozzle structures with viscoelastic fluids. Since rectification in a diffuser∕nozzle structure with Newtonian fluids is caused by inertial effects, micropumps based on this concept require a relatively high Reynolds numbers and high pumping frequencies. In applications with relatively low Reynolds numbers, anisotropic behavior can be achieved with viscoelastic effects. In our investigations, a solution of dilute polyethylene oxide was used as the viscoelastic fluid. A microfluidic device was fabricated in silicon using deep reactive ion etching. The microfluidic device consists of access ports for pressure measurement, and a series of ten diffuser∕nozzle structures. Measurements were carried out for diffuser∕nozzle structures with opening angles ranging from 15° to 60°. Flow visualization, pressure drop and diodicity of de-ionized water and the viscoelastic fluid were compared and discussed. The improvement of diodicity promises a simple pumping concept at low Reynolds numbers for lab-on-a-chip applications.  相似文献   

Basic Serials Cataloging Workshop     

Les Hawkins  Hien Nguyen  Stephen Kharfen 《期刊图书馆员》2015,68(1-4):5-16

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