华菱衡钢成功开发特殊低温用钢

华菱衡钢近日传出喜讯,该公司在低温用管开发方面取得飞跃,已成功批量冶炼A333Gr8低温管道用管连铸圆坯,并轧制了超低温用管,钢管的拉伸、冲击功、硬度、压扁等各项数据均满足美国材料与试验协会(简称ASTM)A333的要求。A333Gr8低温用管是美国ASTM标准中的牌号,主要应用于液化天然气的存储和运输,是民用钢材产品中技术水平最高、难度最大、附加值最高的产品之一。能否成功生产该类产品,代表了一个企业的整体技术水平。为确保该类钢管材质要     

低温用ASTM A333/A333M-2011Gr.6低合金钢无缝管的开发及应用

摘要：ASTMA333／A333M-2011中的Gr．6借助微合金化技术提高了其低温性能,使其由碳钢提升为低合金钢。从化学成分、低温冲击性能、生产应用等方面介绍宝钢产低温用Gr．6低合金钢无缝管。评估表明,宝钢产Gr．6低合金钢无缝管在-80％时的低温冲击功仍高于-45％时的标准要求,具备替代2Ni低温合金钢Gr．7和Gr．9的潜质,不仅成功替代进口,还实现出口。建议在充分论证低合金钢Gr．6低温性能的基础上,适当降低其使用温度。     

活性炭和多效唑对垂花百合试管鳞茎膨大的影响

[目的]探索活性炭(AC)及多效唑(PP333)的适宜浓度,以提高垂花百合试管苗移栽成活率.[方法]以垂花百合试管苗为外植体,研究不同浓度AC(0.3、0.5、1.0、2.0 g/L)及PP333(5、10、20、40 mg/L)处理对垂花百合试管鳞茎膨大的影响.[结果]一定浓度范围的AC及PP333对试管鳞茎的膨大有显著作用,随着AC及即PP333浓度的升高,试管鳞茎直径及鲜重均呈现先增加后减少趋势,说明AC及PP333的浓度既不宜过高也不宜过低.[结论]AC浓度为0.5 mg/L时,试管鳞茎增大效果最显著,鲜茎直径达10.01 mm,鳞茎鲜重达403.9 mg;PP333浓度为10 mg/L时,试管鳞茎增大效果最显著,鳞茎增大2.47倍,鳞茎鲜重达到最大值333.3 mg.     

西藏班怒带有望形成超大型铜多金属资源基地

近日从西藏地勘局了解到，经过十多年的地质勘查工作，西藏班怒带地质找矿成果显著，特别是多龙地区初步探明铜金属资源700多万吨，伴生金150多吨，有望形成超大型铜多金属资源基地。项目重点对多不杂铜矿、波龙铜矿和尕尔勤铜金矿等进行普查评价，初步估算多不杂铜矿（333＋3341）铜资源总量321万吨，伴生金资源总量7017吨；波龙铜矿（333＋3341）铜资源量383．7万吨，金资源量98．1吨，为特大型斑岩型铜矿。其中333铜资源量268．9万吨，     

微波场中ChCl/CrCl_3·6H_2O离子液体的吸波特性研究

研究了不同温度(298K,313K,333K,353K,和373K)下Ch Cl/Cr Cl3·6H2O离子液体微波波谱图,结果显示333K以下介电常数(εˊ)和介电损耗(ε〞)均随温度的增加而增加。这是由于不同离子赋存形态的极化现象影响了介电损耗。介电品质因数随着Cr Cl3·6H2O摩尔分数的增加而减小,这是由于电导率的增加而造成的。     

江西发现超大型锡矿

1993年被原地质矿产部列为部控重点项目—江西省会昌锡坑迳地区锡矿普查 ,属原国家计委一类项目 ,要求提交锡金属量 15万t。江西赣南地质调查大队开展地质勘查工作 ,现已提交 (333+334)锡金属量 2 1 36万t,其中 (333)为6 2 3万t,矿床远景规模达到超大型 ,在锡坑迳周边地区新发现矿产地 2处 ,值得进一步工作的矿化异常区 3处 ,区域找矿取得重大突破。江西发现超大型锡矿     

甘肃省岷县寨上金矿发现30条储量巨大矿脉

日前,由中国地质调查局和甘肃省国土资源厅共同主办,西安地质调查中心、武警黄金指挥部承办的甘肃西秦岭地区金矿整装勘查交流研讨会在兰州召开。会议透露,甘肃省岷县寨上金矿发现矿脉30条,估算金资源量108 t（333＋334）。     

武钢投资50亿美元在巴西建钢厂 年产钢500万吨

据海关最新统计，3月份我国出口钢材333万吨，较2月份增加84万吨，与去年同期相比增长99．4％。1～3月累计出口871万吨，同比增长69．5％。     

Mn含量对La0.65Mg0.35Ni3.1-xMnx(x=0.0～0.4)贮氢合金高温电化学性能的影响

研究了Mn含量对La0.65Mg0.35Ni3.1-xMnx(x=0.0,0.1,0.2,0.3,0.4)贮氢电极合金高温(333K)放电性能的影响.随Mn含量的增加,该系列合金电极在70 mA·g-1放电电流密度下的高温容量保持率从93.9%(x=0.0)增加到119.4%(x=0.4),而且,x＞0.1合金的高温容量保持率几乎相同.333K的电化学P-C-T曲线测试结果表明,Mn对Ni的部分代替明显降低了合金的放氢平台压,x＞0.1合金的吸/放氢平台滞后相对较小,说明x＞0.1合金的高温特性有所改善.腐蚀曲线测量结果表明,由于合金中Mn的存在,合金电极的腐蚀电流Icorr减小,腐蚀电位Ecorr正移,表明合金的耐腐蚀性能增强.     

山东省烟台市牟平区某金矿床特征及找矿前景分析

"山东省烟台市牟平区某金矿普查"勘查目的是大致查明区内地层、构造、岩浆岩特征,大致查明矿化带、矿体的分布规律、形态、规模、产状、矿石质量、矿床类型及成矿远景,估算(333)金资源量,并对该区做出综合评价。     

Comparison of continuous versus pulsed CO2 and Nd:YAG laser-induced pulmonary parenchymal lung injury in a rabbit model

Two studies investigated the effects of delayed visual feedback on manual tracking. In Experiment 1, individuals practiced with visual feedback provided either immediately (0 delay) or with a 333-ms delay. During acquisition, the 0 delay group performed with less error than the 333-ms delay group. A retention test with 0 delay feedback was performed with the least error by the 0 delay group. A transfer test using a different 0 delay tracking pattern, was performed with the least error by the 333-ms delay group. In Experiment 2, individuals practiced at six different delays. Error increased as training feedback delay increased. For retention there were no differences between the delay groups during the 0 delay retention. At a 417-ms retention, test error decreased as training feedback delay increased. Results indicate that error during acquisition does not necessarily impair learning and that feedback delays can be beneficial for learning.     

Population study in West Austria using DNA single locus probes

Allele frequency distribution of the single-locus system YNH 24 (n = 302), G3 (n = 251), MS 43A (n = 333), and MS 31 (n = 333) was determined in Western Austria. After digestion with Hinf I, electrophoresis and Southern blotting, the genomic DNA was hybridised with the probes YNH 24, G3, MS 43A, and MS 31. Blood samples were taken from 333 unrelated caucasians living in the area of Innsbruck, Tyrol, Austria. The fragment distribution was calculated for each of the 4 single-locus systems. A single fragment pattern, indicating homozygosity, was shown in 9.93% with YNH 24, 12.45% with G3, 9.61% with MS 43A, and 7.21% with MS 31; the corresponding heterozygosity rates were 90.07%, 87.55%, 90.39%, and 92.79%, respectively. Our data are compared with those from England [18], Germany [3], Greenland [7], and Denmark [14]. Discrimination indices (Table 2) were calculated and statistical parameters (Table 3) presented.     

pMH2, a small plasmid bearing the nif gene cluster of Enterobacter agglomerans 333 as an excisable cassette

A small plasmid containing the entire nif gene cluster of Enterobacter agglomerans 333 as an excisable cassette has been constructed, using pACYC177 as a vector. Two cosmid clones taken from a gene library of E. agglomerans plasmid pEA3 were used as a source of nif genes. A SmaI fragment of peaMS2-2, containing the H,D,K,Y,E,N,X,U,S,V,W,Z,M,L,A and B genes and an ApaI fragment of peaMS2-16 containing nif A,B,Q,F and J were selected to construct pMH2. The resulting plasmid of 33 kb carries the complete nif gene cluster as a nif cassette on a single XbaI fragment. The nif construct pMH2 in Escherichia coli strains has significant nitrogenase activity compared to wild-type E. agglomerans 333. The nif gene cluster construct was found to be very stable.     

Steady state and time-resolved fluorescence study of residual structures in an unfolded form of yeast phosphoglycerate kinase

A previous study performed using steady state fluorescence has revealed the existence of residual structures surrounding the two tryptophan residues in an unfolded form of yeast phosphoglycerate kinase [Garcia, P., et al. (1995) Biochemistry 34, 397-404]. In this paper, we present a more detailed characterization of these residual structures, through the study of two single tryptophan-containing mutants of yPGK, W333F and W308Y. Denaturation experiments have first been performed at low temperatures to assess the nature of the interactions stabilizing these residual structures. On the other hand, the compactness and dynamics of the protein matrix were probed using tryptophan fluorescence quenching by acrylamide at various denaturant concentrations. Taking into consideration the changes in sample viscosity induced by addition of guanidinium chloride made feasible the use of this technique during the denaturation process. These different approaches have shown that the residual structures around tryptophan 308 are mainly stabilized by hydrophobic interactions and are more compact and less fluctuant than the ones surrounding tryptophan 333. Native and denatured yPGK have also been studied by time-resolved fluorescence spectroscopy. In the native protein, tryptophan buried in the core, W333, is mainly associated with a lifetime close to 0.1 ns, whereas tryptophan that is partially accessible to the solvent, W308, has a lifetime close to 0. 5 ns. The time-resolved tryptophan fluorescence emission of wild-type yPGK can be accounted for quantitatively by the summed emissions of its two single tryptophan mutants. The significance of minor long lifetime components is discussed for the two tryptophan residues. This new assignment of fluorescent decay times has allowed for the detection of a folding intermediate in which the environment of tryptophan 333 is modified for denaturant concentrations lower than those for tryptophan 308.     

Enzymatic activity of 2'-5'-oligoadenylate synthetase is impaired by specific mutations that affect oligomerization of the protein

Previous studies from our laboratory have shown that deletion of residues 321 to 344 of the 9-2 isozyme of 2'-5'-oligoadenylate (2-5(A)) synthetase causes a loss of its enzyme activity (Ghosh, S. K., Kusari, J., Bandyopadhyay, S. K., Samanta, H., Kumar, R., and Sen, G. C. (1991) J. Biol. Chem. 266, 15293-15299). Sequence comparison of this region among the different isozymes of 2-5(A) synthetases revealed that the residues at positions 330 to 333 are highly conserved. Alanine-scanning mutagenesis of these residues demonstrated that the residues present at 331, 332, and 333 are important for activity but the proline at position 330 was dispensable. The triple mutant containing Ala residues at 331, 332, and 333 was completely inactive. Different double mutants were slightly active, and the three single mutants were partially active. The triple mutant was further characterized for delineating the nature of its defect. The mutant protein was enzymatically inactive irrespective of whether it was synthesized in rabbit reticulocyte lysate, Escherichia coli or Trichoplusia ni insect cells. It could bind double-stranded RNA and ATP as efficiently as the wild type protein. It was, however, defective in oligomerization. Gel filtration and sedimentation velocity analyses of in vitro synthesized proteins revealed that the wild type protein, but not the triple mutant, formed tetramers. The tetrameric fraction, but not the monomeric fraction of the wild type protein was enzymatically active. The failure of the triple mutant to participate in homomeric protein-protein interaction was confirmed by in vivo assays in insect cells. These results indicate that tetramerization of the protein is required for the enzymatic activity of the small 2-5(A) synthetases.     

laser cladding of Ni-Al bronze on Al alloy AA333

The present study investigates the effects of laser-processing parameters, such as laser power, traverse speed, powder-feed rate, and flow rate and species of assisting gas, and material prop-erties, such as substrate surface condition, on laser cladding of Ni-Al bronze on Al alloy AA333. The proper processing parameters were determined experimentally and are discussed in terms of their effects on laser-clad quality and microstructure as observed using optical and scanning electron microscopes. Despite a large difference in melting points between the cladding material, Ni-AI bronze (MP = 1063 °C), and the substrate, Al-alloy AA333 (MP = 577 °C), clads of thickness from 1.2 to 2.5 mm that are crack-free and had good fusion were achieved. The substrate surface condition and the flow rate and species of assisting gas were found to be important for clad formation. A sandpaper-polished substrate absorbs less energy at the molten pool front and facilities reducing dilution. A large flow rate of assisting gas, such as helium, also has an effect on reducing dilution. A laser-generated molten-pool model was developed to explain the preceding experimental results. Y. LIU formerly Research Associate, Center for Laser Aided Materials Processing, Department of Mechanical and Industrial Engineering, University of Illinois at Urbana-Champaign.     

Proliferation in the rat olfactory epithelium: age-dependent changes

Vertebrate olfactory sensory neurons are replaced continuously throughout life. We studied the effect of age on proliferation in olfactory epithelium in postnatal rats ranging in age from birth (P1) until P333. Using BrdU to label dividing cells, we determined the proliferation density of basal cells, i.e., the number of labeled nuclei/unit length (240 microm) of olfactory epithelium in coronal sections from six different anterior-posterior levels from each animal. A total length of >1 m of olfactory epithelium was counted in each age group. We observed a dramatic decrease of proliferation density from P1 through P333. At P1, proliferation density is 151 cells/mm; it decreases to approximately half at P21 (70 cells/mm), and half again at P40 (37 cells/mm). At P333 the proliferation density was only 8/mm, approximately 5% of that seen at P1. The changes were clearly related to age and not to body weight, because the values were essentially identical for males and females of the same age but of different body weight. Proliferating cells appear in patches that, after P40, become more separated from one another and contain fewer cells. In 6- and 11-month-old rats, 30 and 45% of all units contained no labeled cells. We confirmed the data of others that the olfactory surface area continuously increases with age; we showed that there is a reciprocal relationship between proliferation density and surface area. The proliferating cells provide neurons to sustain growth as well as to replace dying cells.     

Leaching of zinc sulfide concentrate from the ganesh-himal deposit of nepal

The leaching of zinc concentrate obtained from the zinc ore located in the Ganesh-Himal region of Nepal has been carried out in the presence of ammonium persulfate (APS) as an oxidant. Leaching variables such as time, temperature, acid, and oxidant concentration, E _h , and particle size of sphalerite concentrate were studied to optimize the condition and to understand the mechanism of the reaction. The zinc extraction increased up to a temperature of 333 K and a further rise in the temperature to 343 K resulted in lowering of metal extraction. A decrease in particle size and increase in oxidant concentration enhanced the dissolution rate of zinc. The leaching data best fitted to the mixed controlled kinetic model. An activation energy of 43 kJ/mol was obtained for the dissolution of zinc in the temperature range 303 to 333 K with APS. The leaching mechanism was further established by characterizing the original concentrate and the leach residue by X-ray diffraction (XRD) phase identification and scanning electron microscopy (SEM) studies.