LEG STIFFNESS CHANGES IN DROP JUMPS WITH DIFFERENT STRETCH AMPLITUDE

The purpose of this study was to investigate the adjustment of leg stiffness and the relative electromyography (EMG) magnitude of different phases with shallow and deep drop jump (DJ) in order to understand the neuromuscular and contraction characteristics of different stretch amplitudes of SSC movement. There were 12 subjects tested in this experiment including jumpers and volleyball players whose ages are 20.5±1.93, heights are 181.01±6.23cm and weights are 71.95±4.93Kg. Kistler forceplatform, PEAK high speed video camera and EMG Biovision system were used to record the ground reaction force, kinematics data and the EMG signals of gastrocnemius and rectus femoris. The results of this study were that the leg stiffness between two different drops jump had the significant difference at the concentric and transmission phases in the progressive loads (

High Throughput Screening of 3D Printable Resins: Adjusting the Surface and Catalytic Properties of Multifunctional Architectures

Identification of 3D printable materials is crucial to expand the breadth of physical and chemical properties attainable by additive manufacturing. Stereolithography (SLA), a widespread 3D printing method based on resin photo-polymerization, is ideally suited for exploring a large variety of monomers to produce functional three-dimensional solids of diverse properties. However, for most of the commercially available SLA 3D printers, screening monomers and resin compositions requires large volumes (~150 mL) in each printing cycle, making the process costly and inefficient. Herein, a high throughput block (HTB) adaptor was developed to screen arrays of monomers and resin compositions, consuming lower volumes (\u3c 2 mL) and less time per print (\u3c 1/16 based on a 44 matrix) than using the original hardware. Using this approach, a library of materials with different surface hydrophobicities were 3D printed by including long chain acrylates in the resins. In addition, several metal salts were dissolved in an acrylic acid-based resin, 3D printed and screened as heterogeneous catalysts for the selective aerobic oxidation of benzyl alcohol to benzaldehyde. Cu(II)-based resins produced the most active structures. Combinations of Cu(II) and long chain acrylate monomers were then used to 3D print complex catalytic architectures with varying degrees of hydrophobicity. Linear relationships were observed between 3D printed surface area, surface hydrophobicity and catalyst performance. For a high surface Schwarz P topology ca. 60 % enhancement in the catalytic activity of Cu(II) was attained by replacing the parent resin with one containing hydrophobic isodecyl groups, indicating that the immediate environment of the catalytic site affected its performance. The HTB enables fast screening of resins for 3D printing multifunctional architectures with intrinsic catalytic activity, tunable surface properties, and minimal waste

The nature of CuA in cytochrome c oxidase

The isolation and purification of yeast cytochrome c oxidase is described. Characterization of the purified protein indicates that it is spectroscopically identical with cytochrome c oxidase isolated from beef heart. Preparations of isotopically substituted yeast cytochrome c oxidase are obtained incorporating [1,3-15N2]histidine or [beta,beta- 2H2]cysteine. Electron paramagnetic resonance and electron nuclear double resonance spectra of the isotopically substituted proteins identify unambiguously at least 1 cysteine and 1 histidine as ligands to CuA and suggest that substantial spin density is delocalized onto a cysteine sulfur in the oxidized protein to render the site Cu(I)-S

Using Technology-Supported Enrichment Activities to Extend Student Learning in a Chinese as a Foreign Language Classroom

The purpose of this study was to investigate whether exposing middle school students to content above their ability level produced significant differences in students’ confidence in their Chinese as a foreign language competence in each of the following four areas: reading, listening, speaking, and learning vocabulary. Participants (N = 30) were sixth and seventh graders. Results of paired t-test analyses indicated that there was no significant difference in student confidence in Chinese reading competence, t(30) = 0.78, p = 0.22; in Chinese speaking competence, t(30) = -0.50, p = 0.31; or to learn Chinese vocabulary, t(30) = -0.80, p = 0.21. However, there was a significant difference in student confidence in ability to learn Chinese listening, t(30) = -1.78, p \u3c 0.05. It is suggested that exposing students to content well above their ability level can increase their confidence in ability to learn Chinese listening

Pressure Effect on the Boson Peak in Deeply Cooled Confined Water: Evidence of a Liquid-Liquid Transition

The boson peak in deeply cooled water confined in nanopores is studied to examine the liquid-liquid transition (LLT). Below ∼180  K, the boson peaks at pressures P higher than ∼3.5  kbar are evidently distinct from those at low pressures by higher mean frequencies and lower heights. Moreover, the higher-P boson peaks can be rescaled to a master curve while the lower-P boson peaks can be rescaled to a different one. These phenomena agree with the existence of two liquid phases with different densities and local structures and the associated LLT in the measured (P, T) region. In addition, the P dependence of the librational band also agrees with the above conclusion.United States. Dept. of Energy (Grant DE-FG02-90ER45429

Magnetic Trapping of Atomic Nitrogen (14^{14}N) and Cotrapping of NH (XX3^{3}Σ\Sigma -)

We observe magnetic trapping of atomic nitrogen ($^{14}$N) and cotrapping of ground state imidogen ($^{14}$NH, $X$$^{3}$$\Sigma$ -). Both are loaded directly from a room temperature beam via buffer gas cooling. We trap approximately 1 x 10$^{11}$ $^{14}$N atoms at a peak density of 5 x 10$^{11}$ cm$^{-3}$ at 550 mK. The $12\pm{4} s 1/e$ lifetime of atomic nitrogen in the trap is limited by elastic collisions with the helium buffer gas. Cotrapping of $^{14}$N and $^{14}$NH is accomplished, with 10$^{8}$ NH trapped molecules at a peak density of 10$^{8}$ cm$^{-3}$.Physic