壳聚糖涂层亲和层析在超氧化物歧化酶纯化中的应用

1前言亲和层析是蛋白质纯化中分离效率最高的技术之一。亲和配基有多种形式如单机、底物、活性染料、金属离子等。固定化金属离子亲和层析（Immobilizedmetalionaffinitychromatog’“PhyIMAC）是Porath在1975年首先研究的一种高效分离技术［‘3。IMAC和普通的亲和层析相比,具有一些优点,如亲和配基Cu’”、Zn’“价廉;可在高盐浓度下操作;稳定,容易再生。Sulkowke曾用IMAC技术分离纯化干扰素,一步可纯化产品几十倍【“,收率达90％。目前IMAC介质制备是先在软基质SePharose或SePhadex上用化学交联法弓卜螫合剂IDA（Imino…     

新型结构有机硼表面活性剂的特征及应用

从硼系表面活性剂的结构出发,对它的性能,应用作了全面阐述。     

氧气分压对甲苯液相氧化的影响

在直径为48 mm的鼓泡塔反应器中,模拟工业条件研究了氧气分压对甲苯液相催化氧化生成苯甲酸反应的影响.结果表明,甲苯液相催化氧化反应在低氧气分压下对氧气是1级反应,随氧气分压增加,氧气的影响逐渐减弱,在高氧气分压区过渡为对氧气是0级反应.根据甲苯氧化的自由基链式反应机理,推导出了覆盖整个氧气浓度区的动力学方程,不仅可以很好地解释在不同氧气分压区氧气级数变化的现象,而且对反应过程的描述具有很高的计算精度,在145℃和155℃反应温度下的计算误差小于4%.     

Green Synthesis,Characterization, and Properties of Acyl Lysine,Serine, Threonine,and Methionine Derived from Three Types of Natural Oils

The development of environmentally benign products has been the subject of growing interest in the field of surfactant chemistry. Acyl amino acid surfactants bearing lysine, serine, threonine, and methionine residues were synthesized using natural oils extracted from coconut, palm kernel, and soybean as acyl donors. The chemical structures were confirmed by high-performance liquid chromatography (HPLC/MS) and infrared (IR) spectra. Their surface activities, ion-specific effects, detergency, and foam properties were studied systematically. The critical micelle concentration (CMC) values depend significantly on amino acid and oil types and follow the orders: (i) Lys > Thr ≈ Ser > Met and (ii) Coconut ≈ Palm kernel > Soybean oil. Interestingly, the ion-specific effects showing that the γ_CMC value decreases with increasing counterion size and hydrophobicity were observed, and the results were consistent with the famous Hofmeister series. The detergency ability of acyl amino acid surfactants is better than multiple traditional surfactants in distilled water. Although the detergency ability of our products for oil-soiled swatches decreased significantly in hard water, this problem was solved by the C-Lys-Na/AES mixed system showing excellent synergistic effects. Excellent foamability and foam stability were achieved for acyl threonine and serine bearing hydroxyl groups on their headgroups, suggesting that the packing of these surfactants at the air–water interface was assisted by hydrogen bonding.     

Preparation of an ionic‐liquid antistatic/photostabilization additive and its effects on polypropylene

An ionic liquid (IL) was synthesized and incorporated into polypropylene (PP) via melt blending. The structure of the IL was confirmed by infrared spectroscopy and NMR spectroscopy. The volume resistance of neat PP and PP/IL blends indicated that the IL had excellent antistatic properties. The tensile strength and impact strength of the PP and PP/IL blends showed that the IL also had good light stability. Thermogravimetric analysis (TGA) was performed in both nitrogen and air, and the effect of the heating rate in dynamic measurements (5°–30°C/min) on kinetic parameters such as activation energy was also investigated. The Flynn–Wall–Ozawa method was used to determine the apparent activation energy for the degradation of neat PP and the PP/IL blended composites. The TGA results showed that the addition of the IL improved the thermal stability of PP, and the kinetic results showed that the apparent activation energy for the degradation of PP/IL was much higher than that for neat PP. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers     

Profile Prediction and Fabrication of Wet-Etched Gold Nanostructures for Localized Surface Plasmon Resonance

Dispersed nanosphere lithography can be employed to fabricate gold nanostructures for localized surface plasmon resonance, in which the gold film evaporated on the nanospheres is anisotropically dry etched to obtain gold nanostructures. This paper reports that by wet etching of the gold film, various kinds of gold nanostructures can be fabricated in a cost-effective way. The shape of the nanostructures is predicted by profile simulation, and the localized surface plasmon resonance spectrum is observed to be shifting its extinction peak with the etching time.     

Symbolic derivation of potential based constitutive equations

Structural alloys used in high temperature applications exhibit complex thermomechanical behavior that is inherently time dependent and hereditary, as the current behavior depends not only on current conditions but on the thermomechanical history. Derivation of mathematical expressions (constitutive equations) which describe this high temperature material behavior can be quite time consuming, involved, and error-prone, thus intelligent application of symbolic systems to facilitate this tedious processes can be of significant benefit. Here a computerized package, running under MACSYMA, capable of efficiently deriving potential based constitutive models, in analytical form (involving tensors, partial differentiation, invariants, and the like) is presented. Special purpose utility algorithms are designed and implemented to perform partial differentiation (chain rule), tensor manipulation, case distinction and simplification. Four constitutive theories reported in the literature are utilized to verify implementation accuracy. It is expected that this symbolic package can and will provide a significant incentive to the development of new constitutive theories.     

用纵波首波幅度识别砂岩气层的方法

从纯砂岩、泥质砂岩(人工岩样)与其含气情况下的纵波首波幅度比与含气饱和度的实验发现,当砂岩内含气饱和度大于20%时,纵波首波幅度的衰减可达到最大值。而且,纵波首波幅度对砂岩内的天然气响应比纵波首波频率和速度敏感。基于这一实验结果,本文提出了用纵波首波幅度识别砂岩气层的方法。目的层岩石的纵波首波幅度可由声波波形分析图求取,而该目的层岩石的纵波首波幅度背景值,可用邻近含水层或含油层(轻质油层除外)岩石的纵波首波幅度代替。这样,当目的层岩石的纵波首波幅度小于该层的幅度背景值30%±10%时,则指示此目的层岩石泥浆侵入带内存在天然气。据此,可识别此处目的层是气层。另外,文中还给出了描述含气层岩石和含水层岩石纵波首波幅度的数学模型及应用纵波首波幅度识别砂岩气层的两个实例。