1000MPa级微合金化冷轧双相钢退火工艺及强韧化机制

摘要：通过热处理试验结合物理化学相分析实验,对含铌与不含铌的2种试验钢在不同均热温度下的奥氏体晶粒长大情况及含铌钢中铌的固溶规律进行研究。结果表明,均热温度低于1200℃时,含铌钢奥氏体晶粒尺寸均小于无铌钢奥氏体晶粒尺寸;随着均热温度的升高,含铌钢奥氏体中固溶的Nb逐渐增多;均热温度升至1200℃时,含铌钢奥氏体晶粒较无铌钢无明显细化。通过相分析试验研究实际Nb的固溶量与均热温度的关系,发现实际测量得到Nb未溶量随均热温度的升高而减小,对比Nb在奥氏体中的实际固溶与理论固溶的关系,寻找适合的含铌试验钢的理论模型。     

均热温度对抗震钢筋奥氏体化及铌固溶的影响

摘要：通过热处理试验结合物理化学相分析实验,对含铌与不含铌的2种试验钢在不同均热温度下的奥氏体晶粒长大情况及含铌钢中铌的固溶规律进行研究。结果表明,均热温度低于1200℃时,含铌钢奥氏体晶粒尺寸均小于无铌钢奥氏体晶粒尺寸;随着均热温度的升高,含铌钢奥氏体中固溶的Nb逐渐增多;均热温度升至1200℃时,含铌钢奥氏体晶粒较无铌钢无明显细化。通过相分析试验研究实际Nb的固溶量与均热温度的关系,发现实际测量得到Nb未溶量随均热温度的升高而减小,对比Nb在奥氏体中的实际固溶与理论固溶的关系,寻找适合的含铌试验钢的理论模型。     

烟化炉磨煤机衬板损坏的研究分析及解决方法

通过理论分析和实践验证 ,论述了简式钢球磨煤机衬板损坏的主要原因 ,以及解决问题的措施和途径     

Stress and deformation analysis of plane-strain rolling process

A finite-element elastic-plastic deformation analysis is required in order to predict a complete stress and deformation in a material for metal forming. There have been a few attempts for rolling analysis using the elastic-plastic code, because the boundary conditions between roll and deforming material become complicated. In this study, an elastic-plastic plane-strain rolling analysis with friction has been attempted by the updated Lagrange code. Both slipping and sticking were taken into account for boundary conditions between roll and material. The stress and deformation analysis is performed using a nonsymmetric stiffness matrix solution (for curved and frictional boundaries). The elastic-plastic analysis, coupled with the proposed frictional boundary model, evidently provides a reliable stress and deformation solution in the metal rolling process.     

TiVFe基固溶体合金的储氢研究进展

综述了Ti-V-Fe基固溶体合金的储氢研究现状,结果表明合金成分的调整与合金储氢量和平台特性密切相关。同时,分析了VFe合金替代纯V的研究进展,这种替代会对合金的储氢性能产生极大的影响。指出了Ti-V-Fe基固溶体合金今后的研究方向,并提出将VFe合金中Al,Si,O等杂质元素对Ti-V固溶体储氢性能的影响作为研究重点。     

钛铁矿中钛和铁的联合测定

基于用碱熔法分解试样,试样溶液经酸化后无需分离作为母液备用。一份在适当的硫酸和盐酸溶液中,隔绝空气条件下,用铝将四价钛还原后,直接用硫酸铁铵滴定钛;另一份在适当酸度溶液中,用氯化亚锡将大量铁还原,再加三氯化钛将剩余少量铁还原后,用重铬酸钾标液滴定铁。本方法实现了钛铁矿中钛和铁的快速联测,简化了重复熔样,缩短了分析时间,测定全铁的相对标准偏差(n=6)小于0.30%,TiO2相对标准偏差(n=6)小于0.90%;测定标准样品,结果与认定值相符合,满足了生产分析要求。     

Carnitine supplementation improves myocardial function in hearts from ischemic diabetic and euglycemic rats

BACKGROUND: Nonischemic myocardial dysfunction in patients with diabetes mellitus appears to be attenuated with long-term L-carnitine therapy. The effect of acute L-carnitine supplementation on rat hearts from euglycemic and diabetic animals subjected to ischemia and reperfusion is investigated in this study. METHODS: Study rats had diabetes mellitus induced by streptozocin (65 mg/kg intraperitoneally), and control rats had injection of saline solution (n = 12 per group). About 1 month later, the hearts were suspended on a Langendorff apparatus and perfused with either standard buffered Krebs-Henseleit solution or this standard solution supplemented with L-carnitine (5 mmol/L). After stabilization, normothermic, zero-flow ischemia was instituted for 20 minutes followed by 60 minutes of reperfusion. There were four study groups (n = 6 per group): hearts that were from euglycemic rats and that were perfused with standard buffered Krebs-Henseleit solution (E-STD); hearts that were from diabetic animals and that were perfused with the same standard buffered solution (DM-STD); hearts taken from diabetic animals and perfused with L-carnitine-enriched solution (DM-CAR); and hearts taken from euglycemic rats and perfused with the enriched solution (E-CAR). RESULTS: At 60 minutes of reperfusion, left ventricular developed pressure was significantly better in hearts from both groups (diabetic and euglycemic) with carnitine supplementation (DM-CAR versus DM-STD and E-CAR versus E-STD, p < 0.01 for both, by analysis of variance). Left ventricular end-diastolic pressure was significantly lower in the DM-CAR group compared with all other groups (p < 0.01 by analysis of variance). CONCLUSIONS: These findings suggest that acute L-carnitine supplementation significantly improves the recovery of the ischemic myocardium in diabetic and euglycemic rats.     

Synthesis and Characterization of Lanthanum Complexes with Amino Acid Schiff Base

Ｉｎｔｈｅｌｉｖｉｎｇｂｅｉｎｇｓ ,ｃａｌｃｉｕｍｉｏｎｐｏｓｓｅｓｓ ｅｓｍａｎｙｋｉｎｄｓｏｆｉｍｐｏｒｔａｎｔｂｉｏｌｏｇｉｃａｌｆｕｎｃｔｉｏｎ .Ｔｈｅｒａｄｉｕｓａｎｄｔｈｅｃｏｏｒｄｉｎａｔｅａｃｔｉｏｎｏｆｌａｎ ｔｈａｎｕｍｉｏｎａｒｅｓｉｍｉｌａｒｔｏｔｈａｔｏｆｃａｌｃｉｕｍｉｏｎ .Ｃｏｎｓｅｑｕｅｎｔｌｙ ,ｌａｎｔｈａｎｕｍｉｏｎ ,ｗｈｉｃｈｅｎｔｅｒｓｔｈｅｂｏｄｙ ,ｗｉｌｌｒｅｐｌａｃｅｃａｌｃｉｕｍｉｏｎａｎｄｓｈｏｗａｓｅｒｉｅｓｏｆｂｉｏｌｏｇｉｃａｌｅｆｆｅｃｔｓ…     

金的光度法分析研究进展

文中收集了近10年来金的光度法分析测定研究文献,重点概述了碱性染料、含硫和含氮三类重要显色剂在测定岩石矿物、氰化法浸出液、氯化法浸出液、硫代硫酸盐浸出液及含金废水等物料中金的应用,并加以评论.     

云南澜沧县银锰矿中银的化学物相分析探讨

银的化学物相分析主要是分析银在各载体矿物中的含量。以往银的化学物相分析研究主要集中在铅锌矿,银锰矿中银的化学物相分析报道很少。实验通过对云南澜沧县银锰矿中锰的化学物相分析后,确定了该矿中银主要分为碳酸锰中银、与锰结合银、自然银、硫化银、铁氧化物中银和硅酸盐中银6相。选取醋酸溶液浸取碳酸锰中银,亚硫酸溶液浸取与锰结合银,硝酸铁溶液浸取金属银,硫脲-硫酸溶液浸取硫化银,硝酸浸取硫化物中的银,最后残渣测定硅酸盐中的银。通过对该矿进行6次分析,得到其各相态中银的含量,分析结果稳定,各相态银的相对标准偏差(RSD)均小于10%,满足物相分析的误差要求,且各相态银加和等于总银,说明分相正确。     

云南澜沧县银锰矿中银的化学物相分析探讨

银的化学物相分析主要是分析银在各载体矿物中的含量。以往银的化学物相分析研究主要集中在铅锌矿,银锰矿中银的化学物相分析报道很少。实验通过对云南澜沧县银锰矿中锰的化学物相分析后,确定了该矿中银主要分为碳酸锰中银、与锰结合银、自然银、硫化银、铁氧化物中银和硅酸盐中银6相。选取醋酸溶液浸取碳酸锰中银,亚硫酸溶液浸取与锰结合银,硝酸铁溶液浸取金属银,硫脲-硫酸溶液浸取硫化银,硝酸浸取硫化物中的银,最后残渣测定硅酸盐中的银。通过对该矿进行6次分析,得到其各相态中银的含量,分析结果稳定,各相态银的相对标准偏差(RSD)均小于10%,满足物相分析的误差要求,且各相态银加和等于总银,说明分相正确。     

TZM合金的组织及强化机理分析

采用粉末冶金法制备TZM合金,通过SEM和EDS检测手段观察其显微组织,并在此基础上分析TZM合金的三种强化,即固溶强化、第二相强化和形变强化的强化机理.     

Cs(ATZ)化合物的合成及表征

A new compound of Cs (ATZ) was synthesized by reaction of CsOH aqueous solution with 5-aminotetrezole. This compound was identified by C, H and N elemental analysis and quantitative analysis of Cs atom. The molecular formula is Cs (ATZ). The physicochemical properties were characterized by FTIR, Raman spectroscopy and X-ray power diffraction and the peaks of FT-IR were also assigned.     

烧结矿中CaO，MgO，Al2O3的湿法滴定分析

采用混合熔剂快速熔融试样,盐酸低温溶解熔球,1．5ml硝酸充分溶解,制备母液．分别移取3份母液,以钙指示剂为指示剂,加入少量Mg^2＋,EDAT标准溶液滴定CaO;以铬黑T为指示剂,EDAT标准溶液滴定MgO;以PAN指示剂,用硫酸铜标准溶液滴定Al2O3,滴定终点均突变明显．本法具备快速、准确、设备简单、分析成本低的特点,效果良好,特别适用于小型工厂实验室的日常分析．并在生产中已得到了应用．     

罗丹明B与铁(Ⅲ)的荧光猝灭反应及其应用

在pH 10.0的NH_3-NH_4Cl缓冲溶液中,微量Fe(Ⅲ)对罗丹明B的荧光强度具有明显的猝灭作用。实验研究了该猝灭反应并讨论了将其应用于铁(Ⅲ)分析的最佳条件。实验表明,于25mL比色管中,分别依次加入3.00mL罗丹明B溶液、一定量的Fe(Ⅲ)标准溶液、2.00mL pH 10.0的NH_3-NH_4Cl缓冲溶液,用水稀释至刻度,摇匀,用1cm四面透光的石英比色皿进行测定,体系的最大发射波长λem=580nm,最大激发波长λex=550nm。Fe(Ⅲ)的质量浓度在0.004~0.028μg/mL范围内与其对应的荧光猝灭值ΔF呈良好的线性关系,相关系数为0.987 9,方法的检出限为0.003 8μg/mL。将实验体系应用于不同环境水样(矿泉水、山泉水、自来水)中Fe(Ⅲ)的测定,测得结果与原子吸收光谱法(国家水质标准方法GB 11911—1989)基本一致,相对标准偏差(RSD,n=6)为3.5%~7.5%,回收率在99%~106%之间。     

铸铁轧辊中Si、P、Mn、Cr、Mo、Ni、Mg的联合测定

用硝硫混合酸统一处理方法制备试液,用同一母液分别以光度法分析Si、P、Mn、Cr、Mo、Ni、Mg元素的含量。通过控制分析的酸度,各元素线性良好,分析误差完全在国标误差范围内。该方法可缩短分析周期,精密度、准确度高,镍、锰、铬、钼、硅、磷、镁的相对标准偏差分别≤2.76%、2.11%、3.25%、3.21%、1.88%、7.22%、4.13%,方法可行。     

EDTA滴定法测定镍镁合金中镍和镁

建立了EDTA络合滴定法测定镍镁合金中镍和镁含量的分析方法。试样以硝酸、滴加盐酸溶解,分取一定体积的试液,加柠檬酸掩蔽铁离子,以丁二酮肟沉淀镍,用硝酸和高氯酸破坏沉淀剂,以紫脲酸铵作指示剂,用EDTA标准溶液滴定镍含量;同时,另取部分试液,以铜试剂预先分离镍基体,并以盐酸羟胺、氰化钾、三乙醇胺等掩蔽剩余干扰离子,以铬黑T为指示剂,用EDTA标准溶液滴定镁含量。对沉淀剂进行探讨,结果表明,测定镍时,加沉淀剂丁二酮肟与其络合沉淀,选择性好;而测定镁时,选择铜试剂络合沉淀基体镍和其他干扰离子,滤液可直接用于镁离子的测定,干扰少。对镍镁合金样品中镍、镁含量进行多次平行测定,相对标准偏差(RSD,n=6)分别为0.23%~0.57%和0.76%~0.90%。并模拟镍镁合金的主要成分及含量合成试样溶液进行测定,结果与理论值一致。将方法应用于镍镁合金实际样品分析,结果与参照方法结果一致。     

喷雾热分解法合成BaTiO_3超细粉末及其形貌控制

以钛酸四异丙酯(TTIP)及醋酸钡为前驱体,采用超声喷雾热分解法制备了钛酸钡超细粉体。在分析了BaTiO3粉体喷雾合成机理的基础上,考察了反应温度、前驱体溶液浓度、溶液流量和载气流量等工艺参数对粉体粒度和形貌的影响。结果表明:反应温度、前驱体溶液浓度、溶液流量及载气流量与产物颗粒的粒度及分布、球形度、纯度以及结晶度等密切相关;当反应温度为900℃、前驱体溶液浓度为0.1mol/L、溶液流量为2ml/min、载气流量为2 L/min时,得到的BaTiO3粉体平均粒径为2.4μm,粒度分布较均匀、结晶度高、球形度好、空心破壳少。     

某砂铀矿地浸单元酸浸初期溶质运移与溶液渗流关系

采用水文化学分析及数值模拟方法,对新疆某砂岩铀矿地浸单元酸法地浸初期SO_4~(2-)、H~+、Ca~(2+)等主要溶质离子的运移与溶液渗流之间的关系进行了探讨。SO_4~(2-)前锋用时8d运移至抽孔,40d后抽、注液SO_4~(2-)浓度开始同幅变化,表明大部分溶液已渗流至抽孔,根据渗流模拟计算,在流向抽液孔的溶液中,最快的可在5~6d抵达,40d时83%的溶液抵达;H~+在水岩作用过程中被部分消耗,其前锋21d运移抽液孔,而由H~+溶蚀出来的Ca~(2+)、Mg~(2+)则与SO_4~(2-)同步运移;66d地浸流场达到H~+的补给与消耗平衡,表明绝大部分溶液已经达到抽液孔,而根据计算,这一比例已经达到94%。水文化学分析与水动力计算结果吻合。     

Comparison between Coupled and Uncoupled Consolidation Analysis of a Rigid Sphere in a Porous Elastic Infinite Space

Linear consolidation analyses are usually treated either by means of Terzaghi-Rendulic uncoupled theory or Biot’s consolidation theory. In this note, the problem of consolidation displacements around an axially loaded sphere was considered. It is demonstrated that both the uncoupled analysis and the coupled analysis give the same governing equation for pore fluid pressure dissipation with time. A simplified procedure for deriving transient strain components is illustrated. A general solution for time-dependent displacements is obtained using uncoupled consolidation analysis. Close agreement is evident between the new approximate uncoupled analysis solution and the existing coupled analysis solution with a maximum error of less than 0.5%.