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Precipitation kinetics of complex precipitate in multicomponent systems

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Journal of Iron and Steel Research International 2018年第10期25卷 1086-1093页

作者： Yong Yang tian-rui li Tao Jia Zhao-dong Wang State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110819 Liaoning China

A kinetic model based on the classical nucleation and growth theory has been proposed to predict the precipitation behavior of complex precipitate. The method for calculating absolute solution temperature, which is an important guidance for determining solution treatment temperature, is also proposed based on thermodynamic model. In the model, nucleation of the second phase is assumed to be controlled by the effective diffusion, which involves the bulk diffusion and dislocation pipe diffusion, and growth is controlled by the bulk diffusion of forming elements. The interfacial energy of complex precipitate is calculated by the linear interpolation method, and the effects of alloying elements on precipitation behavior are manifested using weighted means of their diffusivities and concentration. The predictions were compared with the experimental measurements, and a good agreement was obtained.

关键词： Complex precipitate Carbide Kinetic model Nucleation and growth theory Absolute solution temperature

Hot Deformation Behavior and Microstructural Characteristics of Ti–46Al–8Nb Alloy

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Acta Metallurgica Sinica(English Letters) 2018年第9期31卷 933-944页

作者： tian-rui li Guo-Huai liu Mang Xu tian-liang Fu Yong tian Ra-Ja Devesh Kumar Misra Zhao-DongWang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China Laboratory for Excellence in Advanced Steel Research Department of MetallurgicalMaterials and BiomedicalEngineeringUniversity of Texas at E1 PasoE1 PasoTX 79968-0521USA

Hot deformation behavior, microstructural evolution and flow softening mechanism were investigated in Ti-46A1-8Nb alloy via isothermal compression approach. The true stress-strain curves exhibited typical work hardening and flow softening, in which the dependence of the peak stress on temperature and strain rate was obtained by hyperbolic sine equation with Zener-Hollomon （Z） parameter, and the activation energy was calculated to be 446.9 kJ/mol. The microstructural analysis shows that the alternate dark and light deformed ribbons of Al-rich and Nb-rich regions appeared and were associated with local flow involving solute segregation. The Al segregation promoted flow softening mainly arising from the recrystaUization of V phase with low stacking fault energy. The coarse recrystallized 7 and several massive phase were observed at grain boundaries. While in the case of Nb segregation, t/B2 phase harmonized bending of lamellae, combined with the growth of recrystallized γ grains and α ＋ β ＋ γ→α＋ γ transition under conditions of temperature and stress, leading to the breakdown of α2/γ lamellar colony. During the hot compression process, gliding and dissociation of dislocations occurred in γ phase that acted as the main softening mechanism, leading to extensive γ twins and cross twins in α/γ lamellae and at grain boundaries. In general, homogeneous microstructure during the hot defor- mation process can be obtained in TiAl alloy with high Nb addition and low Al segregation. The deformation substructures intrinsically promote the formability of Ti--46Al-8Nb alloy.

关键词： Titanium aluminides Deformation behavior Activation energy Dynamic recrystallization Local flow softening

Extraction, purification and antioxidant activity of polysaccharides from bamboo leaves

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Journal of Forestry Research 2012年第1期23卷 139-143页

作者： GAO Ya-ni · tian Cheng-rui · ZHAO li-li College of Food Engineering and Nutritional Science Shaanxi NormalUniversity Shaanxi Province Xi'an 710062 China

Ultrasonic extraction （UE） was employed for the extraction of bamboo leaf polysaccharides （BLP）. The influential parameters of UE procedure including extraction time, ultrasonic power and solid/liquid ratio were optimized by orthogonal experiments. DEAE-cellulose col- umn chromatography was applied to purify BLP and then the radical scavenging activity of BLP was also evaluated. Optimal extraction con- ditions were： extraction time .of 15 min, ultrasonic power of 300 W, and solid/liquid ratio of 1：15. Four kinds of polysaccharides were obtained by DEAE-cellulose colunm chromatography; the maximum superoxide radical scavenging rate （20.4%） of BLP was inferior to that of vitamin C （Vc, the control） and the hydroxyl radical scavenging rate （50%） was equivalent to that of Vc.

关键词： bamboo leaves polysaccharide scavenging radical separa-tion and purification ultrasonic extraction

Forest fire danger ratings in the 2040s for northeastern China

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Forestry Studies in China 2011年第2期13卷 85-96页

作者： tian Xiao-rui SHU li-fu WANG Ming-yu ZHAO Feng-jun Key Open Laboratory of Forest Protection of the State Forestry Administration Research Institute of Forest Ecology Environment and Protection Chinese Academy of Forestry Beijing 100091 E R. China

The average temperature of northeastern China is expected to increase 2.22 and 2.55℃ under two scenarios selected from the Intergovemmental Panel on Climate Change （IPCC）, i.e., A2 and B2, during the 2040s （2041-2050）, which will have an impact on fire activities in those areas. We calculated the output of regional climate models, using the Canadian Forest Fire Weather Index （FWI） on a scale of 50 km × 50 km. Meteorological data and fire weather index were interpolated to a scale of 1 km × 1 km by using ANUSPliN software. The results show that the model of Providing Regional Climate for Impacts Studies （PRECIS） had the ability to provide good temperature and precipitation estimates of the study area in the baseline period, by simulation. In the 2040s the mean FWI values of the study area will increase during most of the fire seasons under both selected scenarios, compared with the baseline period. Under scenario B2 the peak fire season will appear in advance. The changes of FWI ratio （2×CO2/l ×CO2） show that the potential burned areas will increase 20% under scenario B2 and lightly increase under scenario A2 in 2040s. The days of high, very high and extreme fire danger classes will add 5 and 18 d under scenarios A2 and B2, respectively. It suggests adapting the climate change through improving fuel management and enhancing the fighting abilities.

关键词： climate change forest fire danger fire season FWI northeastern China

Microstructure characteristics of Ti-43Al alloy during twin-roll strip casting and heat treatment

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Transactions of Nonferrous Metals Society of China 2019年第5期29卷 1017-1025页

作者： Mang XU Guo-huai liU tian-rui li Bing-xing WANG Zhao-dong WANG State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

To shorten the fabrication process of difficult-to-form TiAl sheets, twin-roll strip casting and microstructural control were investigated in Ti-43Al alloy. A crack-free sheet with dimensions of 1000 mm × 110 mm × 2 mm was obtained. The microstructure of stip casting sheets and heat treatments was systematically studied. The macrostructure consisted of columnar crystals extending inward and centrally located equiaxed crystals with severe Al segregation were observed along the thickness direction, due to the symmetrical solidification process and decreasing cooling rates. The strip casting alloy was characterized by fine duplex microstructure with a grain spacing of 20-30 μm and a lamellar spacing of 10-20 nm. Furthermore, multiple microstructures of near gamma, nearly lamellar and fully lamellar were obtained through heat treatment process with significantly improved homogeneity of the microstructure.

关键词： strip casting TiAl alloy sheet fabrication microstructure characterization heat treatment

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蒙脱石纳米颗粒聚集中的离子特异性效应

土壤学报 2018年第3期55卷 673-682页

作者：刘汉燚刘新敏田锐李航李睿土壤多尺度界面过程与调控重庆市重点实验室西南大学资源环境学院重庆400715

原子力显微镜(AFM)是一种研究颗粒聚集与黏附力比较直观的显微工具。运用原子力显微镜观察测定了几种碱金属氯化盐溶液处理的蒙脱石颗粒在风干条件下的形貌图和黏附力。结果发现,蒙脱石颗粒聚集存在明显的离子特异性效应。在50 mmol L^(... 详细信息

原子力显微镜(AFM)是一种研究颗粒聚集与黏附力比较直观的显微工具。运用原子力显微镜观察测定了几种碱金属氯化盐溶液处理的蒙脱石颗粒在风干条件下的形貌图和黏附力。结果发现,蒙脱石颗粒聚集存在明显的离子特异性效应。在50 mmol L^(-1)的高浓度条件下,CsCl体系中蒙脱石颗粒聚集的高度、直径以及针尖与颗粒的黏附力均存在离子特异性效应,其序列满足liCl

关键词：原子力显微镜(AFM) 蒙脱石聚集离子特异性效应黏附力

Construction of a lentiviral vector for RNA interference of human VIM gene and its silencing effect in pancreatic cancer cells

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The Chinese-German Journal of Clinical Oncology 2009年第3期8卷 145-149页

作者： Jianxin Jiang Ming Shen Renyi Qin rui tian Jing li Min Wang Department of Biliary-Pancreatic Surgery Tongji Hospital Tongji Medical College Huazhong University of Scienceand Technology Wuhan 430030 China

Objective： To construct a lentiviral expression vector for RNA interference （RNAi） of human VIM gene; and assess its gene silencing effect in pancreatic cancer cell line Panc-1. Methods： Three pairs of human VIM gene short hairpin RNA（shRNA） sequences were designed using a software available on-line and one pair came from document. After synthesis and annealing, four double-stranded oligonucleotides （dsOligo） were cloned into the pGCL-GFP/U6 plasmid, which were subsequently confirmed by polymerase chain reaction （PCR） and DNA sequencing analysis. Real-time PCR and Westemblotting were used to screen the effective pGCL-GFP-shRNA plasmid in 293T cells, then the most effective one was packed into the recombinant lentivirus Lv-VIM-shRNA with lentiviral packing materials pHelper 1.0 and pHelper 2.0 in 293T cells. The titer of lentivirus was determined by hole-by-dilution titer assay. The silencing effect of Lv-VIM-shRNA in Panc-1 calls were validated by real-time PCR and Western-blotting. Results： An effective Lv-VIM-shRNA was successfully constructed. The titer of lentivirus was determined on 2× 10^9TU/mL. The expressions of VIM mRNA and vimentin were down-regluated in the Panc-1 cells infected with Lv-VIM-shRNA. Conclusion： An effective Lv-VIM-shRNA could inhibit the expression of VIM gene in Panc-1 cells in vitro, which provides a tool for investigating the role of VIM gene in the signaling pathway involved in tumorigenesis and progression of pancreatic cancer and searching new therapeutic targets.

关键词： vimentin RNA interference lentivirus pancreatic carcinoma

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尿液分析仪在尿液潜血检验中的价值比较

中国医疗器械信息 2020年第22期26卷 95-96,117页

作者：田瑞丽天津市宝坻区人民医院医学检验科天津301800

目的:分析在实施尿液潜血检验的过程中尿液分析仪的临床应用价值。方法:本次研究对象的纳入时间在2019年1月~2020年1月,包括尿潜血检验的患者140例,所有患者均给予尿液分析仪检验和显微镜红细胞计数检验,对比两种检验方法的准确性。结果... 详细信息

目的:分析在实施尿液潜血检验的过程中尿液分析仪的临床应用价值。方法:本次研究对象的纳入时间在2019年1月~2020年1月,包括尿潜血检验的患者140例,所有患者均给予尿液分析仪检验和显微镜红细胞计数检验,对比两种检验方法的准确性。结果:对两种检验方法检验敏感度、特异性、误诊率、漏诊率进行统计学分析可知,显微镜红细胞计数与尿液分析仪无明显差异,不具有统计学意义(P>0.05)。结论:在实施尿液潜血检验时尿液分析仪和显微镜红细胞计数均为较为常用的检验方法,这两种方法各自具有自己的优势和不足,在实际的临床应用过程中可以针对性的进行选择,同时为了达到互补的效果,提高检验的准确率也可以联合运用两种检验方法,为临床提供更加准确的检验结果。

关键词：尿液分析仪显微镜红细胞计数尿液潜血检验敏感度特异性

全自动血细胞分析仪联合血涂片细胞形态学在血常规检验中的应用效果

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中国医疗器械信息 2020年第18期26卷 90-91页

作者：田瑞丽天津市宝坻区人民医院医学检验科天津301800

目的:分析全自动血红细胞分析仪联合血涂片细胞形态学在血常规检验过程中的应用效果。方法:本次实验研究对象的纳入时间在2019年2月~2020年2月,共包括在本院接受血常规检查的患者85例,分别为患者提供全自动血细胞分析仪与血涂片细胞形... 详细信息

目的:分析全自动血红细胞分析仪联合血涂片细胞形态学在血常规检验过程中的应用效果。方法:本次实验研究对象的纳入时间在2019年2月~2020年2月,共包括在本院接受血常规检查的患者85例,分别为患者提供全自动血细胞分析仪与血涂片细胞形态学检验,其中联合两种检验方法的样本作为实验组,接受全自动血细胞分析仪检验的样本作为对比组A,接受血涂片细胞形态学检验的样本作为对比组B。结果:实验组血红蛋白、红细胞、白细胞等血细胞阳性检出率以及淋巴细胞、单核细胞、中性粒细胞和嗜酸性细胞、嗜碱性细胞等相关细胞检出率均明显高于对比组A和对比组B,差异具有统计学意义(P<0.05)。结论:全自动血细胞分析仪联合血涂片细胞形态学的运用提高了血红细胞阳性率与相关细胞检出率,临床检验价值显著。

关键词：全自动血细胞分析仪血涂片细胞形态学血常规检验血红蛋白中性粒细胞