Optimal Scheduling Algorithms of System Chip Power Density Based on Network on Chip

Russian Physics Journal - The improvement of chip integration leads to the increase of power density of system chips, which leads to the overheating of system chips. When dispatching the power...     

The Molecular Basis of Catalysis by SDR Family Members Ketoacyl-ACP Reductase FabG and Enoyl-ACP Reductase FabI in Type-II Fatty Acid Biosynthesis

The short-chain dehydrogenase/reductase (SDR) superfamily members acyl-ACP reductases FabG and FabI are indispensable core enzymatic modules and catalytic orientation controllers in type-II fatty acid biosynthesis. Herein, we report their distinct substrate allosteric recognition and enantioselective reduction mechanisms. FabG achieves allosteric regulation of ACP and NADPH through ACP binding across two adjacent FabG monomers, while FabI follows an irreversible compulsory order of substrate binding in that NADH binding must precede that of ACP on a discrete FabI monomer. Moreover, FabG and FabI utilize a backdoor residue Phe187 or a “rheostat” α8 helix for acyl chain length selection, and their corresponding triad residues Ser142 or Tyr145 recognize the keto- or enoyl-acyl substrates, respectively, facilitating initiation of nucleophilic attack by NAD(P)H. The other two triad residues (Tyr and Lys) mediate subsequent proton transfer and (R)-3-hydroxyacyl- or saturated acyl-ACP production.     

水平地震时斜面水坝受到的非线性动水压力的全过程的解析解

本文给出在非线性Ｒａｙｌｅｉｇｈ阻尼作用下，由水平地震激发的水库内动水压力变化全过程的解析解：在激发初期其幅值较小，可用小参数法使控制方程线性化，从而求得各阶渐近控制方程的解析解；当动水压力的幅值增大到小参数展开不适用时，用ｖａｎ ｄｅｒｐｏｌ法求得非线性控制方程的渐近解，从而显示了动水压力的幅值从有序变化到发生突然跳跃的多值性的非线性本质。     

Chaotic Oscillation of Saddle Form Cable-Suspended Roofs under Vertical Excitation Action

The purpose of this paper is to investigate the dynamic behaviour of saddle form cable-suspended roofs under vertical excitation action. The governing equations of this problem are system of nonlinear partial differential and integral equations. We first establish a spectral equation, and then consider a model with one coefficient, i.e., a perturbed Duffing equation. The analytical solution is derived for the Duffing equation. Successive approximation solutions can be obtained in likely way for each time to only one new unknown function of time. Numerical results are given for our analytical solution. By using the Melnikov method, it is shown that the spectral system has chaotic solutions and subharmonic solutions under determined parametric conditions.     

Preparation and biodegradation of electrospun PLLA/keratin nonwoven fibrous membrane

As a kind of natural protein, wool keratin was used to improve the cell affinity of poly(l-lactic acid) (PLLA). After small keratin particles were prepared from keratin solution by spray-drying process, they were blended with PLLA solution. PLLA/keratin nonwoven fibrous membrane was produced by electrospinning the blend solutions. The release rate of keratin from the composite membrane was detected by Fourier transform infrared (FTIR) after PLLA/keratin membranes were degraded in PBS up to 4 weeks. The chemical compositions of the PLLA/keratin surface were examined by X-ray photoelectron spectroscope. Although more than half of the keratin was removed from PLLA/keratin membrane during the first few hours of degradation, some keratin particles were still embedded in the PLLA fibers. Osteoblast cells were used to evaluate the cellular behaviors of the composite membrane. After 7 days culturing, more cells were observed on PLLA/keratin membranes than on pure PLLA membranes. MTT assay and alkaline phosphatase (ALP) activity results suggested that keratin could improve the interactions between osteoblast cells and the polymeric membranes.     

几种常见光源特性的研究

本通过大学物理实验中常用光源特性的分析，说明了实验中光源使用的合理性。     

Charge storage mechanisms of cathode materials in rechargeable aluminum batteries

Science China Chemistry - Rechargeable aluminum batteries (RABs) have attracted great interest as one of the most promising candidates for large-scale energy storage because of their high...     

ANALYTICAL SOLUTION FOR MODE Ⅲ DYNAMIC RUPTURE OF STANDARD LINEAR VISCOELASTIC SOLID WITH NONLINEAR DAMPING

Ｎｏｍｅｎｃｌａｔｕｒｅ ｘ , ｙ　ｄｉｍｅｎｓｉｏｎａｌａｂｓｃｉｓｓａａｎｄｏｒｄｉｎａｔｅｒｅｓｐｅｃ ｔｉｖｅｌｙ (ｍ)ｌ　ｈａｌｆｌｅｎｇｔｈｏｆｔｈｅｃｒａｃｋ (ｍ)δ　ｈａｌｆｗｉｄｔｈｏｆｔｈｅｃｒａｃｋ (ｍ) ｔ　ｄｉｍｅｎｓｉｏｎａｌｔｉｍｅｖａｒｉａｂｌｅ (ｓ) ｗ　ｄｉｍｅｎｓｉｏｎａｌｖｅｒｔｉｃａｌｄｉｓｐｌａｃｅｍｅｎｔ (ｍ) Ａ/ ρ　ｏｎｅｏｆｔｈｅｄｉｍｅｎｓｉｏｎａｌｐａｒａｍｅｔｅｒｉｎＲａｙｌｅｉｇｈｄａｍｐｉｎｇｆｏｒｍｕｌａ (ｓ- 1 ) Ｂ/ ρ　ｔｈｅｏｔｈｅｒｄｉ…     

多相聚合物体系熔体动态过程中相形成与发展——PS/PcBR非相容体系的扫描电子显微镜图样分析

以连续共混过程间歇出料法研究了PS/PcBR非相容体系共混过程中的扫描电子显微镜图样演化过程 ,从平均粒径、特征长度Λ和平均特征长度Λm 多个方面讨论了非相容体系的共混过程 ,并以标度函数P(Λ/Λm)证明非相容体系共混过程在一定时间和空间范围内具有自相似性 ,且分形维数D可以作为一个参数描述熔体动态过程     

ANALYTICAL SOLUTION FOR MODE Ⅲ DYNAMIC RUPTURE OF STANDARD LINEAR VISCOELASTIC SOLID WITH NONLINEAR DAMPING

Introducing the nonlinear Rayleigh damping into the governing equation of the Mode Ⅲ dynamic rupture for standard viscoelastic solid, this equation is a partial differential and integral equation. First, eliminating the integral term, a PDE of third-order is obtained. Then, applying the small parameter expansion method, linearized asymptotic governing equation for each order of the small parameter is obtained. Dividing the third-order PDE into an elastic part with known solution, the rest part pertains to viscous effect which is neither a Mathieu equation nor a Hill one. The WKBJ method is still adopted to solve it analytically.