科钻一井扩孔器的研制及应用

科钻一井在取心钻进中为了尽量避免大段划眼(扩孔),在钻具组合中岩心筒的上、下部位各装一套扩孔器,为此,采用无压浸渍焊接工艺研制出φ157．3 mm碳化钨胎体式表镶φ3mm×5 mm人造聚晶金刚石扩孔器。科钻一井99只扩孔器的现场应用证明,该扩孔器使用寿命较长,满足了全井取心钻进的需要,是一种较好的取心钻具配件,也有助于提高和完善我国硬岩深井大直径取心钻进技术。     

Shallow hydrogen-induced donor in monocrystalline silicon and quantum wires

Electrical and optical properties of bistable shallow donors in monocrystalline silicon, which are introduced by proton implantation followed by annealing at 450 °C, have been studied. The temperature dependences of equilibrium and non-equilibrium carrier concentration and relaxation kinetics were investigated. IR absorption lines of bistable shallow donor electronic excitations were detected. The obtained experimental data demonstrate that the bistable shallow donors can be identified as quantum wire defect nanoclusters.     

The complete sequence of a 10.8 kb segment distal of SUF2 on the right arm of chromosome III from Saccharomyces cerevisiae reveals seven open reading frames including the RVS161, ADP1 and PGK genes.

We have entirely sequenced a 10,835 bp segment of the right arm from chromosome III contained in the J11D and J11D-K3B GF clones. The segment contains seven open reading frames longer then 100 amino acids. Three of them, RVS161 (Urdaci et al., 1990; Crouzet et al., 1991), ADP1 (Purnelle et al., 1991) and PGK1 (Hitzeman et al., 1982) have been described previously. YCR10C encodes a putative membrane protein. YCR8W (encoding a putative protein kinase) and YCR14C extend inside the D10H (Skala et al., 1991) and 62B5-2D clones respectively. Four ARS elements previously reported by Palzkill et al. (1986) are located between RVS161 and YCR10C.     

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.     

Parameters affecting the frequencies of transformation and co-transformation with synthetic oligonucleotides in yeast.

Factors influencing the direct transformation of the yeast Saccharomyces cerevisiae with synthetic oligonucleotides were investigated by selecting for cyc1 transformants that contained at least partially functional iso-1-cytochrome c. Approximately 3 x 10(4) transformants, constituting 0.1% of the cells, were obtained by using 1 mg of oligonucleotide in the reaction mixture. Carrier, such as heterogeneous oligonucleotides, enhanced transformation frequencies. Transformation frequencies were dramatically reduced if the oligonucleotides had a large number of mismatches or had terminally located mismatches. Transformation with oligonucleotides, but not with linearized double-strand plasmid, was efficient in a rad52- strain, suggesting that the pathway for transformation with oligonucleotides is different from that with linearized double-strand plasmid. We describe a procedure of co-transformation with two oligonucleotides, one correcting the cyc1 defect of the target allele in the host strain, and the other producing a desired amino acid alteration elsewhere in the iso-1-cytochrome c molecule; approximately 20% of the transformants obtained by co-transformation contained these desired second alterations.     

LF6铝合金的超塑性／扩散连接组合工艺试验及理论研究EI

本文研究了ＬＦ６铝合金的超塑性／扩散连接组合工艺，用变形和再结晶的方法细化晶粒，成功地进行了ＳＰＦ／ＤＢ工艺试验，利用电子探针观察了扩散连接接头的界面微观区域，并从机理上分析了金属的超塑性／扩散连接两种工艺之间的内部联系及其金属学行为。     

包装发展需要环境友好包装材料

环境友好包装材料是一类具有环境意识特征的概念.环境友好包装材料依据“4R 1D“原则,注重包装材料与环境的协调性,指导包装材料的研发,一是有利于保护自然资源;二是对生态环境损害最少化.运用环境友好包装材料的概念,实现包装的可持续发展.     

常温冲孔性优良的CEM-1覆铜板的研制

本文介绍了一种CEM-1覆铜板的制作方法,采用这种方法制作的覆铜板具有优良的常温冲孔性和良好的性价 比。     

Homogenization of hardness distribution and distortion in high pressure gas quenching

Quenching with gases rather than oil or other liquid media has the advantages of reducing the risks concerning health and environment, while simultaneously homogenizing the quenching results and minimizing distortion due to a wide range of possible process parameter variations and the pure convective heat transfer. In this contribution, a coupled solution for increasing homogenization of quenching results within high pressure gas quenching will be presented. In the first stage, an experimental test facility was set up for flow investigations and in the second stage a numerical simulation model was generated. The numerical and experimental results of the flow through the chamber were compared for several boundary conditions. Finally, after complete verification of the simulation, the model may be used to assist in parameter variation for optimization of homogeneous high pressure gas quenching.     

Antioxidant activity of anacardic acids

Anacardic acids, 6-pentadec(en)ylsalicylic acids isolated from the cashew Anacardium occidentale L. (Anacardiaceae) nut and apple, were found to possess preventive antioxidant activity while salicylic acid did not show this activity. These anacardic acids prevent generation of superoxide radicals by inhibiting xanthine oxidase (EC 1.1.3.22, Grade IV) without radical-scavenging activity. Notably, the inhibition kinetics of anacardic acids do not follow hyperbolic dependence of enzyme inhibition on inhibitor contents (Michaelis–Menten equation) but follow the Hill equation instead. Anacardic acid (C_15:1) inhibited the soybean lipoxygenase-1 (EC 1.13.11.12, Type 1) catalyzed oxidation of linoleic acid with an IC₅₀ of 6.8 μM. The inhibition is a slow and reversible reaction without residual enzyme activity. The inhibition kinetics indicate that anacardic acid (C_15:1) is a competitive inhibitor and the inhibition constant, K_I, was 2.8 μM. Anacardic acids act as antioxidants in a variety ways, including inhibition of various prooxidant enzymes involved in the production of the reactive oxygen species and chelate divalent metal ions such as Fe²⁺ or Cu²⁺, but do not quench reactive oxygen species. The C₁₅-alkenyl side chain is largely associated with the activity.