Ti与Nb微合金化汽车用钢二相粒子及织构研究

Ti与Nb微合金化汽车用钢中较大的二相析出粒子为方形的TiN,尺寸80~120 nm;较小的二相粒子主要为TiC、NbC及其复合析出物,尺寸12~25 nm;最小的析出粒子尺寸约3 nm,能谱分析为NbC。钢中析出的二相粒子均匀分布在基体中。试验钢的热轧织构主要由{001}110、{112}110、{111}110组分组成,同时也包含有γ和α组分,取向密度≥5。冷轧织构主要由高密度的γ织构和α织构组成,不稳定择优取向比热轧织构少。退火后组织中的α织构强度减弱,而γ织构呈管状分布且强度增加。从热轧到冷轧再从冷轧到退火,其织构具有遗传性。     

控轧14MnNbRE钢中微合金碳氮化物析出行为与沉淀强化

本文测定了14MnNbRE钢中微细析出相粒子化学成分，研究了析出相粒子直径及形状因子频数分布、终轧温度对析出相粒子直径和形状因子均值及标准差的影响和屈服强度增量与析出相粒子平均直弪的关系；探讨了(Nb．Ti)(C，N)与AlN微细析出相复合粒子的形成机制和析出相粒子的强化作用机制。     

Ti-IF钢第二相粒子在热轧过程中析出行为的热模拟研究

对Ti-IF钢进行再加热、热轧及卷取等过程的热模拟试验，用透电镜对样品中析出物的形貌进行了观察，系统研究了各析出物在热轧过程中变化的全过程。结果表明，TiN粒子在热轧和卷取过程中变化不大、比较稳定；TiS和Ti4C2S2粒子在热轧过程中断续析出、长大，并发生TiS与Ti4C2S2的转变；TiC粒子主要在热轧在卷取过程中析出、长大。     

热轧终轧温度对形变时效状态QBe2合金薄板性能的影响

通过对QBe2合金薄板的力学及物理性能进行测试,结合其不同热处理状态下的扫描电镜组织,研究了热轧终轧温度对形变时效状态QBe2合金薄板性能的影响.结果表明:热轧终轧温度在540~630℃范围内,较低终轧温度(540℃)的QBe2合金薄板经过形变时效热处理后显微组织中β相含量较高,并且析出物沿晶界局部脱溶的现象更为严重.热轧终轧温度从540℃升高到630℃,形变时效态下QBe2合金薄板的强度提高80~90 MPa,伸长率提高1.2%,弹性模量提高近10 GPa,导电率降低1.8%.造成不同热轧终轧温度的形变时效状态QBe2合金薄板性能不同的主要原因是显微组织中β相含量不同.     

Ti-IF钢热轧时第二相粒子析出行为研究的最新进展

介绍了有关Ｔｉ－ＩＦ钢热轧时第二相粒子析出行为的一些最新研究成果,内容包括：第二相粒子的种类;第二相粒子在热轧时的析出过程,化学成分和热轧工艺参数对第二相粒子析出行为的影响,今后应着重研究溶度积和析出动力学、尤其是各种析出物之间的相互作用,并寻找定量分析第二相粒子的方法。     

Ti,Nb复合添加IF钢热模拟过程中的析出行为

对Ｔｉ，Ｎｂ复合添加的ＩＦ钢进行再加热、热轧及卷取等过程的热模拟实验，用透射电镜和定量金相分别进行样品中Ｔｉ，Ｎｂ析出物的观察和粒度分析。结果表明，Ｔｉ的碳、氮化物先天Ｎｂ的碳、氮化物析出，析出过程主要在热轧时进行；在卷取及冷却过程中析出物长大，但在此过程中并不能清楚地看出有新的析出物产生。     

热轧含钒微合金钢在加速冷却条件下的强化因素

讨论了含钒微合金钢在热轧及加速冷却条件下终轧温度，终冷温度，冷却速度对钢的力学性能的影响，加速冷却含钒钢的显微组织为细小的无边形铁素体和粒状贝氏体组织，由此获得相变强化。钒引起的碳化物析出强化，在加速冷却条件下得到加强，这是由于生成了大量的弥散细小的析出物，并且析出强化效果在６００℃冷却条件下最大。     

热轧加热温度对3.0 %Si无取向硅钢组织及析出物的影响

研究了热轧加热温度对Si的质量分数3.0 %的无取向硅钢的热轧和常化组织及析出物的影响规律。结果表明：热轧组织沿厚度方向存在组织梯度、析出物呈球状和不规则形状分布在晶内;随着热轧加热温度的提高,中间层纤维状变形带宽度变窄;加热温度为1 150 ℃时,小于100 nm的AlN析出粒子数量增加。热轧板经900 ℃常化后,为完全再结晶铁素体组织,组织均匀性提高、析出物聚集和粗化;提高热轧板加热温度,常化组织的平均晶粒尺寸降低,大于100 nm的析出物和20~100 nm的 AlN、AlN+Ti复合析出相数目逐渐增多。     

正火对420MPa建筑用钢性能与Nb、V析出量的影响

研究了建筑结构用钢Q420GJC热轧及正火后的组织、性能及Nb、V析出物变化。采用电解法对热轧和正火后钢板进行Nb、V的析出物定量分析,在透射电子显微镜下进行析出物观察,结果表明,钢板正火后强度下降明显;热轧钢板厚度方向不同部位V的析出量差别不大,约为加入数量的30%,正火不能有效提高低氮钢中V的析出量,热轧态钢板中Nb的析出量从厚钢板表层到心部递增,空冷后钢板中Nb的析出量大于控冷后Nb的析出量;正火后Nb的析出量稍高于热轧。     

高氮不锈钢热轧开裂原因分析及工艺改进

采用显微电镜、扫描电镜对高氮不锈钢热轧后钢板开裂处的金相组织进行了观察,分析了钢板热轧开裂的原因,并对轧制工艺参数进行了优化。结果表明:钢中较多的σ析出相是钢板热轧开裂的主要原因,提高终轧温度后显著降低了钢板的轧制开裂倾向。     

风吹石墨在莱钢6m焦炉的应用

针对石墨在焦炉内的生成机理,对莱钢7号、8号焦炉炉墙上的石墨采用压缩空气进行吹扫,有效控制了石墨的生长速度,降低了劳动强度。     

Advances in Organolanthanide Chmistry in China

ＡｄｖａｎｃｅｓｉｎＯｒｇａｎｏｌａｎｔｈａｎｉｄｅＣｈｍｉｓｔｒｙｉｎＣｈｉｎａＳｈｅｎＱｉ（沈琪）（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＳｕｚｈｏｕＵｎｉｖｅｒｓｉｔｙ，Ｓｕｚｈｏｕ２１５００６，Ｃｈｉｎａ）Ｒｅｃｅｉｖｅｄ：Ａｐｒｉｌ２...     

浅谈博茨瓦纳某工程项目管理经验和总结

以博茨瓦纳某地方法院工程为例，简要介绍了在非洲承揽工程项目的管理经验和总结。     

武钢炼焦技术进步

介绍武钢焦化公司50年来炼焦技术进步,重点阐述炼焦配煤技术研究、焦炉热修补维护、140t／h干熄焦技术消化以及7．63m特大型焦炉的技术创新。     

Benzimidazole resistance in cyathostomes in horses in the Ukraine

The efficacy of treatment with cambendazole was tested in 1-year-old horses on a farm in Dubrovka, Ukraine. Thirty-five horses were treated. Their egg output was compared on the day of treatment and 14 days later with that of 33 untreated horses. Before treatment the mean number of eggs g-1 faeces was 614 in the controls and 766 in horses that had been treated. After 14 days the mean egg output in the controls was 580 and in the treated horses 369. This means a reduction of 54.5%. Only cyathostome larvae could be cultured from faeces collected after treatment. It can be concluded that benzimidazole resistance in cyathostomes is present in the Ukraine.     

重庆高校推进产学研合作的案例分析

以重庆大学、重庆邮电大学和重庆理工大学为例,剖析重庆高校推进产学研合作的基本模式,已经取得的突出成绩,分析总结其基本经验.从完善政策法规体系、强化经济调控、建立组织机构、加强中介建设及开展国际产学研合作等方面,提出了深入推进重庆高校产学研合作的对策建议.     

Trends in Temperature Extremes in Association with Weather-Intraseasonal Fluctuations in Eastern China

Trends in the frequencies of four temperature extremes (the occurrence of warm days, cold days, warm nights and cold nights) with respect to a modulated annual cycle (MAC), and those associated exclusively with weather-intraseasonal fluctuations (WIF) in eastern China were investigated based on an updated homogenized daily maximum and minimum temperature dataset for 1960-2008. The Ensemble Empirical Mode Decomposition (EEMD) method was used to isolate the WIF, MAC, and longer-term components from the temperature series. The annual, winter and summer occurrences of warm (cold) nights were found to have increased (decreased) significantly almost everywhere, while those of warm (cold) days have increased (decreased) in northern China (north of 40°N). However, the four temperature extremes associated exclusively with WIF for winter have decreased almost everywhere, while those for summer have decreased in the north but increased in the south. These characteristics agree with changes in the amplitude of WIF. In particular, winter WIF of maximum temperature tended to weaken almost everywhere, especially in eastern coastal areas (by 10%-20%); summer WIF tended to intensify in southern China by 10%-20%. It is notable that in northern China, the occurrence of warm days has increased, even where that associated with WIF has decreased significantly. This suggests that the recent increasing frequency of warm extremes is due to a considerable rise in the mean temperature level, which surpasses the effect of the weakening weather fluctuations in northern China.     

Apoptosis in experimental myocardial infarction in situ and in the perfused heart in vitro

We report the appearance of apoptotic cells in experimental myocardial infarction (rabbit heart) in in situ and in vitro preparations. Apoptosis was recognized by intravital staining with Hoechst 33342 (Ho342), by nick-end labeling (TUNEL) and by DNA laddering. A steady rise in the relative number of apoptotic cardiomyocytes (apoptotic index) was noted in in situ preparations. Apoptosis was first noted 6 h after the onset of ischemia with its highest value occurring after 72 h. Apoptotic nuclei were absent in remote areas of the left and right ventricles. Apoptotic nuclei within the infarcted area showed diminished intensity of Ho342 fluorescence. Three days after ischemia, a border zone adjacent to the infarcted area consisting of apoptotic macrophages was recognized. A novel finding was the appearance of apoptotic cardiomyocytes in the isolated perfused ischemic heart. Occurring as early as 50 min after the onset of ischemia, a high apoptotic index was present adjacent to the ligature placed around the coronary artery. This observation provides the opportunity to selectively examine factors leading to apoptosis in the ischemic heart under controlled experimental conditions.