Computer-Assisted Recombination (CompassR) Teaches us How to Recombine Beneficial Substitutions from Directed Evolution Campaigns

A main remaining challenge in protein engineering is how to recombine beneficial substitutions. Systematic recombination studies show that poorly performing variants are usually obtained after recombination of 3 to 4 beneficial substitutions. This limits researchers in exploiting nature's potential in generating better enzymes. The Computer-assisted Recombination (CompassR) strategy provides a selection guide for beneficial substitutions that can be recombined to gradually improve enzyme performance by analysis of the relative free energy of folding (ΔΔG_fold). The performance of CompassR was evaluated by analysis of 84 recombinants located on 13 positions of Bacillus subtilis lipase A. The finally obtained variant F17S/V54K/D64N/D91E had a 2.7-fold improved specific activity in 18.3 % (v/v) 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]). In essence, the deducted CompassR rule allows recombination of beneficial substitutions in an iterative manner and empowers researchers to generate better enzymes in a time-efficient manner.     

高离化金离子态-态双电子复合速率系数

研究了类铍Au⁷⁵⁺离子三类态-态双电子复合过程，基于多组态准相对论自洽场 方法和 扭曲波方法，计算了该离子在电子温度0.6—10.0keV范围内的态-态双电子复合速率系数， 并讨论了它们随电子温度、复合类型和上下能态的变化. 关键词： 75+离子')" href="#">Au⁷⁵⁺离子 态-态双电子复合     

等离子体波导中的复合X射线激光

短脉冲强激光和气体靶相互作用可产生等离子体波导。利用自相似模型，得到了等离子体波导中等离子体参数的时空演化。利用自编制的程序，以类Ｈｅ氮为例，研究了在这种等离子体波导中，产生复合机制Ｘ射线激光的过程。研究表明，在等离子体波导中有可能产生复合机制Ｘ射线激光，从而有可能利用等离子波导获得大ＧＬ值的复合机制Ｘ射线激光     

An extremely low offset voltage AlInAs/GaInAs heterostructure-emitter bipolar transistor

A new Al_0.48In_0.52As/ Ga_0.47In_0.53As heterostructure-emitter bipolar transistor (HEBT) with a very low offset voltage of 40 mV has been fabricated by molecular beam epitaxy. From the theoretical analysis and experimental results, it is found that a 500-Å thick emitter used in the studied device can effectively eliminate the potential spike at the N–AlInAs/n–GaInAs heterointerface. However, a degenerate current gain of about 25 is obtained, attributed to the increase of recombination current at the neutral-emitter regime. This is caused by the short hole diffusion length of GaInAs, which reduces the emitter injection efficiency. Due to the small surface recombination velocity, the emitter edge-thinning design is not essential to improve the device performance of our proposed AlInAs/GaInAs HEBT.     

Deposition features of Ni on self-assembled microtubule template from biolipid by electroless method

The self-assembly of lipid molecules is in close relationship with the structure and function of a cell membrane. A cell membrane has a variety of lipid molecules. Lipid molecules have their amphiphile na-tures, and their self-assembly can form a variety of thermodynamically stable microstructures, such as single-bilayer or multi-bilayer spherical and ellipsoidal liposome, microcylindrical and microtubular struc-tures[1]. These microstructures exhibit different bio-logical functions in living …     

Variation of Satellite Intensity Factors with n in the 1s~2s∈lc→1s~23dnl→1s~2pnl Dielectronic Recombination of Lithiumlike Ions

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类钠铜离子软X射线激光三体复合泵浦机制的研究

 详细研究了类钠铜离子激光等离子体中的各种复合过程，并从理论上描述了类钠铜离子软X射线激光的低温三体复合泵浦机制。     

Atomic size effects on recombination processes during thermoluminescence in doped crystals

Atomic size effects on recombination processes during thermoluminescence (TL) in KCl: Harshaw (nominally pure samples), KCl: Ag (14 ppm), KCl: Na(>250 ppm) and KCl: Li (1 ppm) following room temperature (RT) γ-irradiation (20Mrad) has been examined. Results show that the stability of defects increases with decreasing dopant atomic size. (Peak temperatures are 210°C, 255°C and 277, 5°C in Ag-doped Na-doped and Li-doped samples respectively.) The trap-depth also increases as atomic size of dopants decreases. Emission spectrum indicates that only a perturbation of the well known band peak at 440 nm is caused by impurities. Additional band peaks occur in Ag-doped samples.     

Effect of Cathodic Polarization on the Hydrogen Diffusion through a Steel Membrane from Ethylene Glycol Solutions of HCl Containing As(V)

The connection of the hydrogen diffusion flux through a steel membrane and the fraction of adsorbed hydrogen removed due to the absorption in the metal with the cathodic polarization of the working membrane side and the hydrogen evolution rate in ethylene glycol solutions of HCl (0.05–0.99 M) with a constant ionic force containing 0.5–10 mM of As(V) in the form of H₃AsO₄ is studied.     

Excitation Intensity Dependence of Free-exciton Transitions in GaN Grown by Low-pressure Metalorganic Chemical Vapor Deposition

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