高职英语学习现状调查与分析     

甘萍  皮燕萍 《科教文汇》2014,(17):72-73

通过对高职学生英语学习现状展开问卷调查,并针对调查结果进行处理分析,为网络信息时代的高职英语教学教改提供卓有价值的参考与佐证信息。  相似文献   

Microfluidic electrical sorting of particles based on shape in a spiral microchannel     

John DuBose  Xinyu Lu  Saurin Patel  Shizhi Qian  Sang Woo Joo  Xiangchun Xuan 《Biomicrofluidics》2014,8(1)

Shape is an intrinsic marker of cell cycle, an important factor for identifying a bioparticle, and also a useful indicator of cell state for disease diagnostics. Therefore, shape can be a specific marker in label-free particle and cell separation for various chemical and biological applications. We demonstrate in this work a continuous-flow electrical sorting of spherical and peanut-shaped particles of similar volumes in an asymmetric double-spiral microchannel. It exploits curvature-induced dielectrophoresis to focus particles to a tight stream in the first spiral without any sheath flow and subsequently displace them to shape-dependent flow paths in the second spiral without any external force. We also develop a numerical model to simulate and understand this shape-based particle sorting in spiral microchannels. The predicted particle trajectories agree qualitatively with the experimental observation.  相似文献   

Microfluidic dielectrophoretic sorter using gel vertical electrodes     

Jason Luo  Edward L. Nelson  G. P. Li  Mark Bachman 《Biomicrofluidics》2014,8(3)

We report the development and results of a two-step method for sorting cells and small particles in a microfluidic device. This approach uses a single microfluidic channel that has (1) a microfabricated sieve which efficiently focuses particles into a thin stream, followed by (2) a dielectrophoresis (DEP) section consisting of electrodes along the channel walls for efficient continuous sorting based on dielectric properties of the particles. For our demonstration, the device was constructed of polydimethylsiloxane, bonded to a glass surface, and conductive agarose gel electrodes. Gold traces were used to make electrical connections to the conductive gel. The device had several novel features that aided performance of the sorting. These included a sieving structure that performed continuous displacement of particles into a single stream within the microfluidic channel (improving the performance of downstream DEP, and avoiding the need for additional focusing flow inlets), and DEP electrodes that were the full height of the microfluidic walls (“vertical electrodes”), allowing for improved formation and control of electric field gradients in the microfluidic device. The device was used to sort polymer particles and HeLa cells, demonstrating that this unique combination provides improved capability for continuous DEP sorting of particles in a microfluidic device.  相似文献   

Drama Festival Celebrated in Traditional Courtyard Alleys     

Gan Er 《中外文化交流(英文版)》2011,(7)

The 2011 Beijing Nanluoguxiang Drama Festival was recently opened in the experimental theatre of the Central Academy of Drama.  相似文献   

Historic Huanghuali Furniture Creates New Craze     

Gan Er 《中外文化交流(英文版)》2011,(10):15-17

<正>The Exhibition on Huanghuali Furniture, recently displayed at the Capital Museum in Beijing, created new craze among furniture collectors and ordinary viewer...  相似文献   

Examination of birthplace and birthdate in World Junior ice hockey players     

Bruner MW  Macdonald DJ  Pickett W  Côté J 《Journal of sports sciences》2011,29(12):1337-1344

The present study investigated birthdate (known as the Relative Age Effect; RAE) and birthplace as determinants of expertise in an international sample of elite ice hockey players. The sample included 566 World Junior (WJR) ice hockey players from four countries (Canada, n = 153; USA, n = 136; Sweden, n = 140; Finland, n = 137). Participants competed in the International Ice Hockey Federation World U20 Championship between 2001 and 2009. A series of Poisson regression models were conducted to examine the consistency of direct then interactive relationships between both birthdate and birthplace and WJR membership across the four countries (Canada, USA, Sweden, and Finland). Findings revealed a consistent RAE across the four countries for World Junior participation from 2000 to 2009. WJR players from the four countries were also less likely to be from major cities. In addition, there was no evidence in any of the four countries of an interaction between RAE and birthplace. Future research should explore the contextual and cultural factors that influence elite athlete development in smaller towns, cities and communities.  相似文献   

Movement and physiological match demands of elite rugby league using portable global positioning systems   总被引：1，自引：1，他引：0  

Waldron M  Twist C  Highton J  Worsfold P  Daniels M 《Journal of sports sciences》2011,29(11):1223-1230

Twelve elite players from an English Super League club consented to participate in the present study using portable global positioning system (GPS) devices to assess position-specific demands. Distances covered at low-intensity running, moderate-intensity running, high-intensity running, very high-intensity running, and total distance were significantly (P < 0.05) lower in forwards compared with outside backs and adjustables. Metres per minute was higher in adjustables and forwards, owing to higher values for relative distance in medium-intensity running and a rise in high-intensity running from previous absolute values. Sprint distance, sprint frequency, and peak speed were higher in outside backs than both adjustables and forwards. A moderate, significant correlation (r = 0.62, P = 0.001) was apparent between session ratings of perceived exertion and summated heart rate. Results support the requirement for position-specific conditioning and provide preliminary evidence for the use of session ratings of perceived exertion as a measure of match load.  相似文献   

Capillary flow in sacrificially etched nanochannels     

Hamblin MN  Hawkins AR  Murray D  Maynes D  Lee ML  Woolley AT  Tolley HD 《Biomicrofluidics》2011,5(2):21103

Planar nanochannels are fabricated using sacrificial etching technology with sacrificial cores consisting of aluminum, chromium, and germanium, with heights ranging from 18 to 98 nm. Transient filling via capillary action is compared against the Washburn equation [E. W. Washburn, Phys. Rev. 17, 273 (1921)], showing experimental filling speeds significantly lower than classical continuum theory predicts. Departure from theory is expressed in terms of a varying dynamic contact angle, reaching values as high as 83° in channels with heights of 18 nm. The dynamic contact angle varies significantly from the macroscopic contact angle and increases with decreasing channel dimensions.  相似文献   

A cell electrofusion microfluidic device integrated with 3D thin-film microelectrode arrays     

Hu N  Yang J  Qian S  Joo SW  Zheng X 《Biomicrofluidics》2011,5(3):34121-3412112

A microfluidic device integrated with 3D thin film microelectrode arrays wrapped around serpentine-shaped microchannel walls has been designed, fabricated and tested for cell electrofusion. Each microelectrode array has 1015 discrete microelectrodes patterned on each side wall, and the adjacent microelectrodes are separated by coplanar dielectric channel wall. The device was tested to electrofuse K562 cells under a relatively low voltage. Under an AC electric field applied between the pair of the microelectrode arrays, cells are paired at the edge of each discrete microelectrode due to the induced positive dielectrophoresis. Subsequently, electric pulse signals are sequentially applied between the microelectrode arrays to induce electroporation and electrofusion. Compared to the design with thin film microelectrode arrays deposited at the bottom of the side walls, the 3D thin film microelectrode array could induce electroporation and electrofusion under a lower voltage. The staggered electrode arrays on opposing side walls induce inhomogeneous electric field distribution, which could avoid multi-cell fusion. The alignment and pairing efficiencies of K562 cells in this device were 99% and 70.7%, respectively. The electric pulse of low voltage (～9 V) could induce electrofusion of these cells, and the fusion efficiency was about 43.1% of total cells loaded into the device, which is much higher than that of the convectional and most existing microfluidics-based electrofusion devices.  相似文献   

The application of transformational leadership theory to parenting: questionnaire development and implications for adolescent self-regulatory efficacy and life satisfaction     

Morton KL  Barling J  Rhodes RE  Mâsse LC  Zumbo BD  Beauchamp MR 《运动与训练心理学杂志》2011,33(5):688-709

We draw upon transformational leadership theory to develop an instrument to measure transformational parenting for use with adolescents. First, potential items were generated that were developmentally appropriate and evidence for content validity was provided through the use of focus groups with parents and adolescents. We subsequently provide evidence for several aspects of construct validity of measures derived from the Transformational Parenting Questionnaire (TPQ). Data were collected from 857 adolescents (M(age) = 14.70 years), who rated the behaviors of their mothers and fathers. The results provided support for a second-order measurement model of transformational parenting. In addition, positive relationships between mothers' and fathers' transformational parenting behaviors, adolescents' self-regulatory efficacy for physical activity and healthy eating, and life satisfaction were found. The results of this research support the application of transformational leadership theory to parenting behaviors, as well as the construct validity of measures derived from the TPQ.  相似文献