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表面活性剂在逆胶束酶反应系统中的作用机制 总被引:1,自引:0,他引:1
随着胶体界面科学与酶技术的发展,逆胶束酶反应系统作为酶等生物分子的高效分离或催化转化的介质体系,为分子生物技术的发展带来了新的机遇.表面活性剂分子特有的两亲性结构,能使微水相以纳米尺寸的水滴形式稳定在非极性有机溶剂中,为酶的活性保持提供了典型的类生物膜微环境.本文对逆胶束酶反应系统原理做简要介绍,并解析表面活性剂的浓度变化及其构型差异在逆胶束酶反应系统中的作用机制,综述近年来表面活性剂在逆胶束酶领域应用的最新成果,同时探讨了新型功能性表面活性剂在胶束酶学中的应用前景和研究趋势. 相似文献
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LI YingQiu HU YangLi & LIU QuanSheng College of Mathematics Computing Sciences Changsha University of Science Technology Changsha China College of Mathematics Computer Sciences Hunan Normal University Changsha LMAM University of Bretgne-Sud BP Vannes France 《中国科学 数学(英文版)》2011,(7)
Let W be the limit of the normalized population size of a supercritical branching process in a varying or random environment. By an elementary method, we find sufficient conditions under which W has finite weighted moments of the form EWpl(W), where p > 1, l 0 is a concave or slowly varying function. 相似文献
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A new process of magnetorheological figuring(MRF) based on the deliquescence theory is proposed to finish KDP crystals.A novel,non-aqueous,and abrasive-free magnetorheological(MR) fluid is explored,and polishing experiments are performed on a self-developed MRF machine.The removal mechanism is reckoned to be the result of a combination of dominant chemical etching and accessorial mechanical drag.The results indicate that the surface roughness of I plate KDP of 80 × 80(mm) polished by MRF is 1.2 nm(root mean square(RMS)),and the tool marks are completely removed.The surface accuracy by MRF is 0.035λ(RMS),and the low/middle-frequency errors are significantly corrected after MRF. 相似文献
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An optical delay line of coupled resonator optical waveguide(CROW) compensated by photonic crystal waveguide(PhCW) is proposed. In the structure,etching the periodic holes around the waveguide of the ring resonator waveguide does not increase the size of the CROW. Theoretical studies and numerical models indicate that through careful design,CROW and PhCW exhibit different group velocity dispersion(GVD) properties at a certain frequency range. Optical signal can not only be compensated in terms of GVD,but can also be delayed with longer time period. Due to the propagation mode mismatch of the two structures,optical loss becomes inevitable. 相似文献
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Coherent beam combination(CBC) of laser arrays is an efficient way to scale brightness.We demonstrate CBC of two slab laser amplifiers based on active phase locking.Instead of the complex phase detection system,intensity detection is used and the feedback control signal is calculated based on the stochastic parallel gradient descent(SPGD) algorithm.The experimental investigation on a 101.5-W CBC of two slab amplifiers shows that the entire system in a closed loop performs well for long-time observation.A combination efficiency of nearly 81% is realized.The slab amplifier laser arrays are the coherent beams efficiently combined by active phase locking based on the SPGD. 相似文献
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HE Lin YI ShiHe ZHAO YuXin TIAN LiFeng & CHEN Zhi College of Aerospace Material Engineering National University of Defense Technology Changsha China 《中国科学:物理学 力学 天文学(英文版)》2011,(9)
Particle image velocimetry was applied to the study of the statistical properties and the coherent structures of a flat plate turbulent boundary layer at Mach 3. The nanoparticles with a good flow-following capability in supersonic flows were adopted as the tracer particles in the present experiments. The results show that the Van Driest transformed mean velocity profile satisfies the incompressible scalings and reveals a log-law region that extends to y/ =0.4, which is further away from the wall than that ... 相似文献
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报道了以Nd∶LiYF(Nd∶LYF)为增益介质、用硅酸镓镧(La3Ga5SiO14,LGS)晶体进行电光调Q的非稳腔调Q激光器的脉冲特性。Nd∶LiYF的两端按σ偏振1.053μm光的布儒斯特角切割,不需另加起偏镜,实现了单一偏振光振荡。LGS晶体电光Q开关插入损耗小(2%),抗光伤阈值高(950MW/cm2),与DKDP相比,具有不潮解等优点。当抽运能量为120J、重复率3Hz时,单脉冲输出能量为275mJ,脉冲宽度为8ns,动静比为76%,输出能量不稳定度小于3%,偏振度大于99%,光束发散角为0.7mrad。文中还对本激光器偏振特性、非稳腔设计、LiYF导热性能和热透镜效应补偿进行了分析,对LGS电光调Q开关工作性能、工作方式以及存在的问题也进行了分析。 相似文献
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This paper discusses the solutions of the linear matrix equation B~T XB=D on some linear manifolds. Some necessary and sufficient conditions for the existence of the solution and the expression of the general solution are given. And also some optimal approximation solutions are discussed. 相似文献
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光子晶体中二能级原子的自发辐射 总被引:3,自引:0,他引:3
研究光子晶体中二能级原子的自发辐射。由于光的局域化以及缀饰态之间的量子相互作用 ,由局域场、传输场、弥散场组成的原子的辐射场发生变化 :随着激发态能级由禁带移往通带 ,发现局域场中的能量通过弥散场向传输场转移。当局域场和传输场共存时 ,激发态能级上的原子布居数的演化具有准振荡行为 ;当局域场和传输场不共存时 ,原子布居数的演化不具有准振荡行为。另外 ,激发态能级上的稳态原子布居数也发生改变。这些性质不仅依赖于原子的激发态能级ω1与光子频率能带边缘ωc 的相对位置δ,同时也依赖于光子晶体中带边缘的光子态密度 ρ(ωk) (或带边光滑参数ε)。 相似文献