添加Mn和Cr对Cu-9Ni-6Sn合金组织与性能的影响

对中频真空熔铸含Mn量为0．76wt％～1．05wt％和Cr量为0．19wt％～0．2lwt％的Cu-9Ni-6Sn合金的铸锭组织、时效和形变时效特征及其组织变化作了研究。实验证明：(1)0．76wt％～1．05wt％Mn、0．19wt％～0．2lwt％Cr能完全固溶于Cu-9Ni-6Sn合金中；(2)含少量的Mn、Cr的合金的铸锭组织、时效硬化、形变时效和组织变化等基本特征与不含Mn、Cr的合金相类似，但少量Mn、Cr促进合金时效、形变时效过程，提高最佳时效温度，增加硬化效果和盐酸、硫酸水溶液中的耐蚀性。     

形变热处理对Cu-0.1Fe-0.03P合金组织与性能的影响

成分为Cu-0．1％Fe-0．03％P（TFe0．1）的引线框架铜合金连续铸坯经热轧成厚15mm宽60mm的带坯，之后进行固溶-冷轧变形-时效处理和在线固溶-冷轧变形-时效处理，冷轧变形量为85％，90％和95％，在此基础上测试了合金的拉伸力学性能和电导率，用金相和透射电子显微分析研究了不同处理态合金的微观组织结构及其变化。结果表明，合金热轧后在线固溶-95％冷轧变形．500℃／2h时效处理是TFe0．1合金比较好的形变热处理工艺，在此条件下，合金的抗拉强度、屈服强度、延伸率和电导率分别为258，192MPa，22．5％和86．0％IACS，合金的显微组织结构为固溶体基体和弥散分布的第二相颗粒，析出强化和亚结构强化是TFe0．1合金强化的主要原因。     

导热性能高的铝硅合金的制造方法

本专利提供一种铝硅铸造合金，它既有一般铝硅合金较高的力学性能，又具有较好的铸造性能。铝合金中含有6．0％～8．0％硅，除了铝和硅以外，其它单个金属元素含量均在0．6％以下。硅在铝中的固溶量为0．5％～1．1％，同时通过加热到400-510℃且保温1小时，可以使金属显微组织内的晶体物析出量达到5％～8％。     

碳,镍,钼对铸造Fe—Cr—Ni合金高温抗拉强度的影响

当碳含量为０．１０％￣０．７０％时，随碳量增加，Ｆｅ－Ｃｒ－Ｎｉ合金１２５０℃高温抗拉强度显著提高，在碳量大约为０．４０％，时达到峰值，而后急剧下降，同样，镍为１０％和钼为０．３％，合金１２５０℃高温强度最大。     

预变形对含钪Al-Cu-Li合金组织与性能的影响

采用显微组织观察和室温拉伸试验等手段，研究了形变时效中预变形对含钪Al-3.5Cu-1.5Li-0.12Zr合金微观组织与拉伸性能的影响。结果表明：时效前的预变形能促进T1（Al2CuLi）相弥散细小析出，显著提高合金强度，使时效峰值提前。合金强度随预变形量和时效时间增加而增加，到峰值后，随预变形量增加和时效时间的延长，T1相长大粗化，合金强度和塑性降低。在本试验条件下该合金合宜的预变形量为3．5％～5．6％。     

整体干电池锌筒新型材料的研究

采用单因素试验化选法，研究了以铈为主的轻混合稀土的含量变化（含量变化范围的质量分数为0％～0．5％）对Zn－0．5％Pb合金性能的影响，并与XD2合金的性能进行了比较．试验结果表明：当混合稀土的添加量为0．07％～0．2％时，Zn－0．5％Ph－RE合金的抗拉强度与XD2合金的基本相同，冲压性能略低，但耐均匀腐蚀性能比XD2合金优越，延伸率高7％，代替XD2合金作干电池的负极材料，能延长干电池的使用寿命．     

混合稀土变质对Al—4.5%Cu合金热裂的影响

用对比的方法，研究了混合稀土变质处理对Ａｌ－４．５％Ｃｕ合金热裂倾向的影响。试验结果表明：混合稀土变质处理缩小Ａｌ－４．５％Ｃｕ合金有效结晶区间，减小合金的线收缩、净化合金、提高合金的导热率，从而有效地降低Ａｌ－４．５％Ｃｕ合金的热裂倾向，混合稀土加入量为０．２％时，裂纹的最大宽度和裂纹的总长度都出现最小值，合金的热裂倾向最小。     

整体干电池锌筒新型材料的研究

采用单因素试验优选法，研究了以铈为主的轻混合稀土的含量变化（含量垢重百分比为０．０．５％）对Ｚｎ－０．５％Ｐｂ合金性能的影响，并与ＸＤ２合金的性能进行了比较。试验结果表明，当混合稀土的添加量为０．０７－０．２％时，Ｚｎ－０．５％Ｐｂ－ＲＥ合金的抗拉强度与ＸＤ２合金的基本相同，冲压性能略低，但耐均匀腐蚀性能比ＸＤ２合金优越，延伸率７％，代替ＸＤ２合金作干电池的负极材料，能处长干电池的使用寿命。     

磁导率μ=60的铁镍钼合金软磁材料及其制造方法

本发明涉及磁性物体的制造方法，尤其涉及种磁导率μ=60的铁镍钼合金软磁材料及其制造方法。磁导率μ=60的铁镍钼合金软磁材料，该铁镍钼合金软磁材料由以下的组分压制成型：铁镍钼粉末，其中镍的含量为75％-85％，钼的含量为1％～4％，余量为Fe；对铁镍铝粉末表面处理的磷酸，为铁镍钼合金粉末重量的1．2％-1．8％；酚醛树脂，为铁镍钼合金粉末重量的0．2％-0．6％。本发明具有以下优点：（1）制作工艺简单，使用设备简单；（2）采用价低的铁镍钼粉末，生产成本大大降低；（3）采用此种方法制作的产品，具有良好的电感量，较高的品质因数，较低的功率损耗值；（4）在较高的温度条件下，铁镍钼合金仍能保持优异的软磁性能。     

Sr含量对4004铝合金铸锭变质效果的研究

研究了Sr加入量分别为0．01％、0．015％、0．02％,变质保温时间分别为60min、80min、100min,对4004铝合金变质效果的影响。结果表明：Sr加入量低于0．015％、变质保温时间小于80min时,合金组织和力学性能均没有达到完全变质状态;Sr加入量0．015％、变质保温时间80min时,4004铝合金变质效果最好,合金组织中的初晶硅转变为细小的圆状或短棒状,共晶硅也由片状或针状转变为纤维状,合金的抗拉强度和伸长率达到最大值193MPa和4．2％;Sr加入量超过0．015％、变质保温时间超过80min时,随着加入量的增加,合金组织开始变得粗大,抗拉强度随着下降。     

Phosphorylation of sic1, a cyclin-dependent kinase (Cdk) inhibitor, by Cdk including Pho85 kinase is required for its prompt degradation

In the yeast Saccharomyces cerevisiae, Sic1, an inhibitor of Clb-Cdc28 kinases, must be phosphorylated and degraded in G1 for cells to initiate DNA replication, and Cln-Cdc28 kinase appears to be primarily responsible for phosphorylation of Sic1. The Pho85 kinase is a yeast cyclin-dependent kinase (Cdk), which is not essential for cell growth unless both CLN1 and CLN2 are absent. We demonstrate that Pho85, when complexed with Pcl1, a G1 cyclin homologue, can phosphorylate Sic1 in vitro, and that Sic1 appears to be more stable in pho85Delta cells. Three consensus Cdk phosphorylation sites present in Sic1 are phosphorylated in vivo, and two of them are required for prompt degradation of the inhibitor. Pho85 and other G1 Cdks appear to phosphorylate Sic1 at different sites in vivo. Thus at least two distinct Cdks can participate in phosphorylation of Sic1 and may therefore regulate progression through G1.     

Availability of PSC833, a substrate and inhibitor of P-glycoproteins, in various concentrations of serum

BACKGROUND: P-glycoproteins are membrane-associated transporters that can render cells resistant to a variety of chemotherapeutic drugs. Reversal agents are (preferably nontoxic) drugs that can inhibit these P-glycoproteins and thereby overcome multidrug resistance. PSC833, a cyclosporin A analog, is a reversal agent that has shown potential in in vitro experiments and in clinical trials. We tested PSC833 to determine whether it is a transported substrate of human and murine P-glycoproteins associated with multidrug resistance (encoded by the human MDR1 gene and its murine homolog, mdr1a) and whether it can completely inhibit these P-glycoproteins under simulated in vivo conditions. METHODS: Monolayers of polarized LLC-PK1 pig kidney cells transfected with complementary DNA containing either MDR1 or mdr1a sequences were used to measure the directional transport of P-glycoprotein substrates under various serum conditions. RESULTS: In contrast to two previous studies, we found that PSC833 is transported by both the MDR1 and the mdr1a P-glycoproteins, albeit at a low rate. PSC833 has a very high affinity for the MDR1 P-glycoprotein, and its Michaelis constant (Km) for transport is 50 nM, fourfold lower than for cyclosporin A. Inhibition of drug transport by PSC833 is approximately eightfold less effective in 100% fetal bovine serum than in tissue culture medium containing 10% serum. The concentration of PSC833 necessary to fully inhibit transport of digoxin and paclitaxel (Taxol) under complete (i.e., 100%) serum conditions is higher than the plasma concentrations achieved in clinical trials. CONCLUSIONS: Although PSC833 binds efficiently to the MDR1 P-glycoprotein and is released only sluggishly, the high concentrations of PSC833 necessary to inhibit this P-glycoprotein under complete serum conditions in our in vitro system suggest that it may be difficult for PSC833 alone to produce total inhibition of P-glycoprotein activity in patients.     

土壤中总砷的测定方法优化探讨

土壤中总砷的前处理是影响氢化物发生原子荧光法测定的主要因素,土壤需经过消解后上机测试。本文分析了国家标准方法、王水沸水浴加热以及1＋1王水沸水浴加热三种不同的消解方法消解土壤,结果表明王水沸水浴消解土壤样品能够达到与国家标准方法相近的回收率且比稀释一倍的王水消解的效果好,与国家标准方法相比,王水消解具有操作性强的优点,可以成批次的消解样品。     

The CR1 and CR3 domains of the adenovirus type 5 E1A proteins can independently mediate activation of ATF-2

The adenovirus 12S E1A protein can stimulate the activity of the c-jun promoter through a conserved region 1 (CR1)-dependent mechanism. The effect is mediated by two AP-1/ATF-like elements, jun1 and jun2, that preferentially bind c-Jun-ATF-2 heterodimers. In this study, we show that the ATF-2 component of the c-Jun-ATF-2 heterodimer is the primary target for 12S E1A: 12S E1A can enhance the transactivating activity of the N terminus of ATF-2 when fused to a heterologous DNA-binding domain, whereas the transactivating activity of the c-Jun N terminus is not significantly affected. Activation of the ATF-2 N terminus by 12S E1A is dependent on CR1. In the context of the 13S E1A protein, CR1 and CR3 can both contribute to activation of ATF-2, and their relative contributions are dependent on the cell type. In contrast to activation of ATF-2 by stress-inducing agents, CR1-dependent activation of ATF-2 was found not to depend strictly on the presence of threonines 69 and 71 in the N terminus of ATF-2, which are targets for phosphorylation by stress-activated protein kinases (SAPKs). In agreement with this observation, we did not observe phosphorylation of threonines 69 and 71 or constitutively enhanced SAPK activity in E1A- plus E1B-transformed cell lines. These data suggest that CR1-dependent activation of ATF-2 by 12S E1A does not require phosphorylation of threonines 69 and 71 by SAPK.     

The formation of intramolecular disulfide bridges is required for induction of the Sindbis virus mutant ts23 phenotype

The Sindbis virus envelope protein spike is a hetero-oligomeric complex composed of a trimer of glycoprotein E1-E2 heterodimers. Spike assembly is a multistep process which occurs in the endoplasmic reticulum (ER) and is required for the export of E1 from the ER. PE2 (precursor to E2), however, can transit through the secretory pathway and be expressed at the cell surface in the absence of E1. Although oligomer formation does not appear to be required for the export of PE2, there is evidence that defects in E1 folding can affect PE2 transit from the ER. Temperature-sensitive mutant ts23 of Sindbis virus contains two amino acid substitutions in E1, while PE2 and capsid protein have the wild-type sequence; however, at the nonpermissive temperature, both E1 and PE2 are retained within the ER and can be isolated in protein aggregates with the molecular chaperone GRP78-BiP. We previously demonstrated that the temperature sensitivity for ts23 was lost as oligomer formation took place at the permissive temperature, suggesting that temperature sensitivity is initiated early in the process of viral spike assembly (M. Carleton and D. T. Brown, J. Virol. 70:952-959, 1996). Experiments described herein investigated the defects in envelope protein maturation that occur in ts23-infected cells and which result in retention of both envelope proteins in the ER. The data demonstrate that in ts23-infected cells incubated at the nonpermissive temperature, E1 folding is disrupted early after synthesis, resulting in the rapid incorporation of both E1 and PE2 into disulfide-stabilized aggregates. Furthermore, the aberrant E1 conformation which is responsible for induction of the ts phenotype requires the formation of intramolecular disulfide bridges formed prior to E1 association with PE2 and the completion of E1 folding.