Analysis of the MSS51 region on chromosome XII of Saccharomyces cerevisiae.

We have localized gene MSS51 on chromosome XII of Saccharomyces cerevisiae between the RDN1 and CDC42 loci. 'Head to head' with MSS51 is another gene, QRI5, the function of which is unknown. However, the proximity of these genes, the structure of the intergenic region and the presence of an ABF1 binding site right in the middle of this region suggest that the MSS51 and QRI5 expressions are submitted to a common regulatory process.     

Liquid–liquid extraction of a recombinant protein with reverse micelles

Recombinant cytochrome b₅ was extracted into the reversed micelle phase of an anionic surfactant (AOT) in octane and back-extracted to a final aqueous phase. The extraction of the protein was controlled by an electrostatic mechanism, since it was dependent on the global charge of the protein. This was directly demonstrated by experiments with native and mutant cytochromes obtained by site directed mutagenesis. The back-extraction of cytochrome b₅ to a fresh aqueous phase was decreased by factors that reduced the size of the water pool of the organic phase, such as high salt concentrations (1–2 mol dm^?3 NaCl) and low temperatures (4°C), probably because of an increase in a favourable interaction of this protein with the surfactant at closer distances.     

用分步沉积法去除Nb(OH)5/Ta(OH)5中Ti,Sb等金属杂质的工艺研究

从理论和实践应用方面，研究了在不同活性金属离子存在的条件下控制pH值，应用分步沉积的方法去除Nb(OH)5/Ta(OH)5中某些金属杂质。在一定温度下，可在不影响Nb(OH)5/Ta(OH)5沉积的条件下，达到有效去除Ti，Sb，Sn，Al，Fe等杂质元素的目的。     

Synthesis of ZSM-5 zeolite membranes without organic templates using a varying-concentration technique

Template-free nanosized ZSM-5 seeds with an average size of 15 nm were prepared from a synthesis solution with the composition 12Na2O:100SiO2:2Al2O3:2500H2O. By the use of these seeds, thin ZSM-5 zeolite membranes were prepared on the outer surface of a porous α-alumina tube with a pore size of 2 μm in a gel system by varying-concentration synthesis with organic-free template. The first composition synthesis sol-gel was the same as seeds of molar composition and the second one was 12Na2O:100SiO2:2Al2O3:5000H2O at 180 ℃ for 10 h, respectively. XRD shows that the film consists of well-crystallized ZSM-5 zeolite. SEM investigation indicats that the zeolite films on the supports are defect free and the film thickness is approximately 8 μm. The permeances for H2, N2, CH4 and CO2 are 8.94×10-7 , 3.27×10-7 , 3.9×10-7 , 3.14×10-7 and 0.874×10-7 mol·m2·s-1·Pa-1 , respectively. The ideal selectivity of membrane at room temperature for H2/CO2, H2/N2, H2/CH4 are 2.84, 2.73 and 2.29, respectively.     

P油田长4+52小层孔隙度三维模型的建立

为了更准确的评价P油田主要产层长4 52小层的储集能力，以随机模拟建模方法对该层的孔隙度进行研究，建立孔隙度分布三维模型。研究表明，长4 52小层属于低孔储层，平均孔隙度为11．85％。根据P油田储层物性分类原则，该储层在本区分布较为广泛，是今后挖潜的重点。     

Yeast mutants with increased bacterial transposon Tn5 excision

Five complementing recessive mutations that exhibit increased bacterial transposon Tn5 precise excision in yeast Saccharomyces cerevisiae were obtained by ethylmethanesulfonate treatment. One of these mutations (tex1) was submitted to extensive genetic analysis. tex1 is a recessive temperature-sensitive mutation resulting in a 20-100-fold increase in Tn5 excision. It also has increased frequencies of ochre mutation reversion, of forward mutation to canavanine resistance, and loss of chromosome III or its right arm. The possible mechanism of tex1 effects is discussed.     

锆(Ⅳ)-3,5-diBr-PADAP-安替比林三元配合物的分光光度研究与应用

本文提出在安替比林存在下,以3,5-diBr-PADAP为显色剂,分光光度测定微量锆的新方法。在pH1～2的HCl介质中,锆(W)与试剂和安替比林形成配合比为1:1:1的红色三元配合物,最大吸收值在615nm波长处,摩尔吸光系数ε=1.35×10~5。锆(Ⅳ)量在0～25μg/25ml范围内,遵守比尔定律。方法简单、快速、准确。若采用钽试剂—苯萃取法分离共存离子,可适用于钽铌矿和合金中痕量锆的测定。     

Li-intercalation behaviour of vanadium oxide thin film prepared by thermal oxidation of vanadium metal

In order to produce thin films of crystalline V₂O₅, vanadium metal was thermally oxidised at 500 °C under oxygen pressures between 250 and 1000 mbar for 1-5 min. The oxide films were characterised by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). The lithium intercalation performance of the oxide films was investigated by cyclic voltammetry (CV), chronopotentiometry and electrochemical impedance spectroscopy (EIS). It was shown that the composition, the crystallinity and the related lithium intercalation properties of the thin oxide films were critically dependent on the oxidation conditions. The formation of crystalline V₂O₅ films was stimulated by higher oxygen pressure and longer oxidation time. Exposure for 5 min at 750 mbar O₂ at 500 °C resulted in a surface oxide film composed of V₂O_5, and consisting of crystallites up to 200 nm in lateral size. The thickness of the layer was about 100 nm. This V₂O₅ oxide film was found to have good cycling performance in a potential window between 3.8 and 2.8 V, with a stable capacity of 117 ± 10 mAh/g at an applied current density of 3.4 μA/cm². The diffusion coefficients corresponding to the two plateaus at 3.4 and 3.2 V were determined from the impedance measurements to (5.2 and 3.0) × 10⁻¹³ cm² s⁻¹, respectively. Beneath the V₂O₅ layer, lower oxides (mainly VO₂) were found close to the metal. At lower oxygen pressure and shorter exposure times, the oxide films were less crystalline and the amount of V⁴⁺ increased in the surface oxide film, as revealed by XPS. At intermediate oxygen pressures and exposure times a mixture of crystalline V₂O₅ and V₆O₁₃ was found in the oxide film.     

5-(4''-甲基联苯-2-基)-1H-四唑的合成研究进展

5-(4-甲基联苯-2-基)-1H-四唑是血管紧张素Ⅱ受体拮抗剂的关键原料,综述其合成方法的研究进展.     

4-氨基-3-肼基-5-巯基-1,2,4-三唑的合成及其对醛的检验

以硫脲和水合肼合成了可用于检验醛的试剂——4-氨基-3-肼基-5-巯基-1，2，4-三唑(别名：紫醛)，其结构通过红外光谱、核磁进行了确定。试验表明，紫醛对醛的检验敏感、专一、快速、操作简单。