5,062 research outputs found
CASCADE MULTIPLE MOSFET IN CURRENT-MODE LOGIC BUFFER TO REDUCE COMMON MODE NOISE OF SERDES
Addressing the common-mode (CM) noise issue in a Serializer/Deserializer (SerDes) raises a variety of challenges. To address those types of challenges, techniques are presented herein that support cascading multiple metal–oxide–semiconductor field-effect transistors (MOSFETs) in a current-mode logic (CML) output buffer to reduce the CM noise in a SerDes with nearly no impact on, among other things, cost, thermal performance, chip real estate, and power consumption
μ-4,4′-Bipyridine-bis[aqua(4-hydroxypyridine-2,6-dicarboxylato)copper(II)]
The title compound, [Cu2(C7H3NO5)2(C10H8N2)(H2O)2], exhibits a centrosymmetric binuclear molecule. Each completely deprotonated 4-hydroxypyridine-2,6-dicarboxylic acid molecule assumes a tridentate chelating coordination mode. The square-pyramidal coordination geometry around the CuII ion is completed by the bridging bipyridine ligand and an apical water molecule. Adjacent complexes are connected via O—H⋯O and C—H⋯O hydrogen bonds to generate a three-dimensional supramolecular structure
catena-Poly[[tris[silver(I)-μ-4,4′-bipyridine-κ2 N:N′]] tris(perchlorate) dihydrate]
In the title compound, {[Ag3(C10H8N2)3](ClO4)3·2H2O}n, one of the AgI ions, one of the 4,4′-bipyridine (bipy) ligands and one of the perchlorate anions are each situated on a twofold rotation axis. Each AgI ion is coordinated by two N atoms from two bridging bipy ligands, forming chains along [101]. π–π interactions between the pyridine rings [centroid–centroid distances = 3.638 (8) and 3.688 (8) Å] connect the chains. Intermolecular O—H⋯O hydrogen bonds link the uncoordinated water molecules and the perchlorate anions
EFFECT OF STIFFNESS OF KNEE AND ANKLE ALIGNMENT ON THE IMPACT LOADS DURING LANDING IN GYMNASTIC FLOOR EXERCISE
This work was to investigate the effect of stiffness of the knee and ankle alignment on impact loads in lower extremity during gymnastic floor exercise. A movement of a floor exercise landing was captured��with its kinematic data were obtained using digitization software. A multi-body model with 14 segments of the gymnast and a model of the mat were separately developed. Computer simulation of landing with different stiffness of the knee and ankle alignment was performed. The peak vertical and horizontal GRFs were 11.8 BW and 2.5 BW during the actual landing. Peak knee extensor moment was increased by 11.6%, but peak knee flexor was decreased by 5.2%, when the stiffness increased by 40%. This work suggests that increase in stiffness of knee and ankle alignment would increase the peak moment of knee extensor and decrease the peak moment of knee abduction
Frequency, severity, and risk factors related to sexual dysfunction in Chinese women with T2D
Background: The aim of the present study was to assess the frequency and severity of female sexual dysfunction (FSD) in those with T2D (T2D) compared with non-diabetic controls. In addition, risk factors for FSD were analyzed. Methods: Sexual dysfunction, measured using the Female Sexual Function Index (FSFI), was evaluated using a questionnaire in 184 women with T2D and 146 non-diabetic controls at three study sites in China. In the T2D group, FSD was examined by education level, correlations between FSD and other variables were analyzed, and risk factors were studied. Results: The frequency of FSD in the T2D group was 75.0%, much higher than in the control group (56.2%; P = 0.001). The severity of FSD in the T2D group was 17.84 ± 8.47 (mean ± SD), significantly lower than in the control group (21.14 ± 8.08; P = 0.001). In patients with T2D, being older (P = 0.001), taking oral antidiabetic medications (P = 0.013), and having diabetic neuropathy (P = 0.036) were risk factors for FSD. Conclusions: The rate of FSD is high in China and, as seen in the literature, more severe in diabetics than non-diabetics. Being older, taking oral antidiabetic medications, and diabetic neuropathy are risk factors for FSD
Long-rod penetration: the transition zone between rigid and hydrodynamic penetration modes
AbstractLong-rod penetration in a wide range of velocity means that the initial impact velocity varies in a range from tens of meters per second to several kilometers per second. The long rods maintain rigid state when the impact velocity is low, the nose of rod deforms and even is blunted when the velocity gets higher, and the nose erodes and fails to lead to the consumption of long projectile when the velocity is very high due to instantaneous high pressure. That is, from low velocity to high velocity, the projectile undergoes rigid rods, deforming non-erosive rods, and erosive rods. Because of the complicated changes of the projectile, no well-established theoretical model and numerical simulation have been used to study the transition zone. Based on the analysis of penetration behavior in the transition zone, a phenomenological model to describe target resistance and a formula to calculate penetration depth in transition zone are proposed, and a method to obtain the boundary velocity of transition zone is determined. A combined theoretical analysis model for three response regions is built by analyzing the characteristics in these regions. The penetration depth predicted by this combined model is in good agreement with experimental result
Immobilization of Acetobacter sp. CCTCC M209061 for efficient asymmetric reduction of ketones and biocatalyst recycling
BACKGROUND: The bacterium Acetobacter sp. CCTCC M209061 is a promising whole-cell biocatalyst with exclusive anti-Prelog stereoselectivity for the reduction of prochiral ketones that can be used to make valuable chiral alcohols such as (R)-4-(trimethylsilyl)-3-butyn-2-ol. Although it has promising catalytic properties, its stability and reusability are relatively poor compared to other biocatalysts. Hence, we explored various materials for immobilizing the active cells, in order to improve the operational stability of biocatalyst. RESULTS: It was found that Ca-alginate give the best immobilized biocatalyst, which was then coated with chitosan to further improve its mechanical strength and swelling-resistance properties. Conditions were optimized for formation of reusable immobilized beads which can be used for repeated batch asymmetric reduction of 4′-chloroacetophenone. The optimized immobilized biocatalyst was very promising, with a specific activity of 85% that of the free-cell biocatalyst (34.66 μmol/min/g dw of cells for immobilized catalyst vs 40.54 μmol/min/g for free cells in the asymmetric reduction of 4′-chloroacetophenone). The immobilized cells showed better thermal stability, pH stability, solvent tolerance and storability compared with free cells. After 25 cycles reaction, the immobilized beads still retained >50% catalytic activity, which was 3.5 times higher than degree of retention of activity by free cells reused in a similar way. The cells could be recultured in the beads to regain full activity and perform a further 25 cycles of the reduction reaction. The external mass transfer resistances were negligible as deduced from Damkohler modulus Da < <1, and internal mass transfer restriction affected the reduction action but was not the principal rate-controlling step according to effectiveness factors η < 1 and Thiele modulus 0.3<∅ <1. CONCLUSIONS: Ca-alginate coated with chitosan is a highly effective material for immobilization of Acetobacter sp. CCTCC M209061 cells for repeated use in the asymmetric reduction of ketones. Only a small cost in terms of the slightly lower catalytic activity compared to free cells could give highly practicable immobilized biocatalyst
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