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AZ91镁铝合金中HCP/BCC相界面结构 被引量:26
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作者 肖晓玲 罗承萍 +3 位作者 刘江文 吴东晓 聂建峰 Barry C Muddle 《中国有色金属学报》 EI CAS CSCD 北大核心 2003年第1期15-20,共6页
采用常规和高分辨电镜研究了时效AZ91镁铝合金中 2种形态γ Mg17Al12 析出相的HCP/BCC相界面结构。发现第一类析出相的惯习面 (0 0 0 2 ) α∥ { 330 } γ 以及与其对接的另外 2组主要晶面的面间错配度都很小 (4%和2 % ) ,因此界面能较... 采用常规和高分辨电镜研究了时效AZ91镁铝合金中 2种形态γ Mg17Al12 析出相的HCP/BCC相界面结构。发现第一类析出相的惯习面 (0 0 0 2 ) α∥ { 330 } γ 以及与其对接的另外 2组主要晶面的面间错配度都很小 (4%和2 % ) ,因此界面能较小 ;而第 2类析出相的惯习面 (0 110 ) α∥ (330 ) γ 以及与其对接的另一组主要晶面的面间错配度都较大 (11%和 15 % ) ,因此界面能较大。从界面能和相变应变两方面讨论了各类析出相析出密度差别的原因 ,提出了改变析出密度。 展开更多
关键词 AZ91镁铝合金 析出相 HCP/BCC相界面 透射电镜分析
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AZ91 Mg-Al合金中β-(Mg_(17)Al_(12))析出相的形态及其晶体学特征 被引量:60
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作者 肖晓玲 罗承萍 +1 位作者 聂建峰 B.C.Muddle 《金属学报》 SCIE EI CAS CSCD 北大核心 2001年第1期1-7,共7页
应用透射电镜研究了时效AZ91 Mg-Al合金连续析出相的显微组织形态及晶体学特征。发现四种不同形态和晶体学特征的β-(Mg17Al12)析出相,其中占绝大多数的是板条状析出相沿基面(0001)α析出的板条析出相与基... 应用透射电镜研究了时效AZ91 Mg-Al合金连续析出相的显微组织形态及晶体学特征。发现四种不同形态和晶体学特征的β-(Mg17Al12)析出相,其中占绝大多数的是板条状析出相沿基面(0001)α析出的板条析出相与基体保持Burgers位向关系,生长方向为[7, 2,9,0];其晶体学特征与由不变线应变原理预测的完全一致。第二类析出相是以其轴线与基面垂直的六棱柱体,六个棱柱面都是{1100}α//{110}β,与基体保持对称性好的Crawley位向关系。另有少量短棒状析出相与基体保持Porter位向关系。实验中还观察到一种未见报道过的位向关系。讨论了形成不同形态和晶体学特征的机制。 展开更多
关键词 AZ91MG-AL合金 β-(MG17AL12)析出相 透射电镜分析 晶体学特征 镁合金
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论商品的不开箱检验 被引量:1
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作者 张明辉 孙勇 熊彪 《包装工程》 CAS CSCD 北大核心 1998年第5期16-18,共3页
探讨和研究了综合运用振动分析技术。
关键词 商品检验 不开箱 振动分析 故障诊断 模糊逻辑
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恒星中子源^(13)C(α,n)^(16)O反应的研究
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作者 郭冰 李志宏 +24 位作者 M.Lugaro J.Buntain 庞丹阳 李云居 苏俊 颜胜权 吴志丹 白希祥 陈永寿 杜先超 樊启文 甘林 金孙均 A.I.Karakas 李二涛 李志常 连钢 刘建成 刘鑫 施建荣 舒能川 王宝祥 王友宝 曾晟 柳卫平 《原子能科学技术》 EI CAS CSCD 北大核心 2014年第2期193-200,共8页
13 C(α,n)16 O是渐进巨星支(AGB)星中慢速中子俘获(s)过程的主中子源反应,而17 O 6.356 MeV1/2+阈下共振对13 C(α,n)16 O反应影响很大。本文使用HI-13串列加速器和Q3D磁谱仪,首次测量了13C(11B,7Li)17 O转移反应角分布,确定了影响13C(... 13 C(α,n)16 O是渐进巨星支(AGB)星中慢速中子俘获(s)过程的主中子源反应,而17 O 6.356 MeV1/2+阈下共振对13 C(α,n)16 O反应影响很大。本文使用HI-13串列加速器和Q3D磁谱仪,首次测量了13C(11B,7Li)17 O转移反应角分布,确定了影响13C(α,n)16 O反应最关键、最不确定的17 O(Ex=6.356MeV)阈下共振态的α宽度,从而得出天体物理能区13 C(α,n)16 O反应的天体物理S因子和反应率,澄清了国际上已有S因子数据间高达25倍的巨大分歧。AGB星s过程核合成网络计算表明:新反应率数据导致恒星中铅的丰度增加了25%。 展开更多
关键词 转移反应角分布 阈下共振 天体物理 S因子 AGB星 s过程
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Ets1 as a marker of malignant potential in gastric carcinoma 被引量:8
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作者 YongYu Yi-ChuZhang +4 位作者 Wen-ZhuZhang Li-SongShen PaulHertzog TrevorJWilson Da-KangXu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2003年第10期2154-2159,共6页
AIM: Ets1 proto-oncogene is a transcription factor involved in the activation of several genes of tumor invasion and metastasis. We aimed to determine the relationship between the extent and intensity of Ets1 expressi... AIM: Ets1 proto-oncogene is a transcription factor involved in the activation of several genes of tumor invasion and metastasis. We aimed to determine the relationship between the extent and intensity of Ets1 expression and patients'' clinicopathological factors in gastric carcinoma. METHODS: Immunohistochemical analysis was performed for gastric tumor paraffin-embedded sections, followed by image analysis. RESULTS: Ets1 was not expressed in the normal gastric epithelium and its surrounding cells. The percentage of Ets1 expressing cells detected increased significantly in both epithelial tumor and stromal cells from high T classification, lymph node metastasis positive, clinical advanced-stage groups (P<0.05). The level of Etsl staining in epithelial tumor cells also reflected the degree of cell differentiation. The percentage of epithelial and stromal cells expressing Ets1 was significantly correlated with the presence of lymph node metastasis (P=0.014 and P=0.O01 respectively). Ets1 expression was not observed in tissue samples from patients with benign gastric ulcers.CONCLUSION: Ets1 protein expression in epithelial tumor cells reflects the degree of differentiation, and the percentage of Etsl positive tumor and stromal cells correlates with lymph node metastasis. Thus Etsl is a valuable marker of malignant potential in terms of invasiveness and metastasis of gastric carcinoma. It is also possible that inhibition of Etsl is a potential avenue for therapy in gastric cancer. 展开更多
关键词 胃癌 致癌基因 肿瘤侵袭 肿瘤转移 免疫组织化学 ETS1 基质细胞
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Microstructure and Mechanical Properties of Molybdenum Sheet after Cross Rolling Processing 被引量:2
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作者 ChengfanGu JunliangZhang 《材料热处理学报》 EI CAS CSCD 北大核心 2004年第5期61-65,共5页
A substantial body of work exists here that describe the relationship between the microstructure, ingot processing and fabrication and mechanical properties of molybdenum sheet after cross rolling process. The objecti... A substantial body of work exists here that describe the relationship between the microstructure, ingot processing and fabrication and mechanical properties of molybdenum sheet after cross rolling process. The objective of this study is to clarify how much the crossing rolling process procedure affects the microstructure, texture and mechanical property of this type of materials. This experiment begins from the power metallurgy to the final molybdenum strip (0.15mmxlOOmmx2000mm) through the cross rolling processing procedure. As a result, good mechanical property, improved elongation, enhanced ductility for further process, such as deep drawing and punching, and the reduced difference of the strength and plasticity between the parallel to rolling direction and perpendicular to rolling direction are achieved by the cross rolling processing procedure. According to discussing all the details about this experiment, it is confirmed that cross rolling molybdenum sheet can provide a concise and comprehensive explanation of processes and can guarantee the optical mechanical property and suitable for large production. 展开更多
关键词 钼板 等断面轧制 横轧 显微结构 机械性质
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Effect of Partial Recrystallization on Microstructure and Mechanical Properties for Cross-rolled Molybdenum Sheet
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作者 ChengfanGu JunliangZhang 《材料热处理学报》 EI CAS CSCD 北大核心 2004年第5期244-247,共4页
The paper presented here reports an appropriate static heat treatment and analyses the microstructure with different partially recrystallized annealing temperatures of cross-rolled molybdenum sheet in order to improve... The paper presented here reports an appropriate static heat treatment and analyses the microstructure with different partially recrystallized annealing temperatures of cross-rolled molybdenum sheet in order to improve mechanical property of this type of materials and reduce anisotropy at the same time for perspective application. Five different temperature ranges are chosen in this experiment. The samples of a cross-rolled molybdenum sheet are obtained through powder metallurgy, forged ingots and hot or cold rolled sheet. A period of first-stage annealing at 800°C for one hour is not qualified for the further processing because of bad plasticity, working hardening and crack on the surface. The appropriate second-stage annealing temperature at 950°C for one hour is chosen for improving the elongation and reduces yield strength. The results show that this appropriate partially recrystallized annealing treatment has achieved the ideal grain size and mechanical properties when it is compared with the other four different temperatures with the same second-stage annealing conditions. 展开更多
关键词 显微结构 钼板 静态热处理 机械特性
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THE EFFECT OF THE MULTIGLYCOSIDES OF TRIPTERYGIUM WILFORDII ON THE HYPOTHALAMOPITUITARY-TESTIS AXIS OF MALE RATS
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作者 TONGJian-Sun QINJin-Xi +2 位作者 LIUXi-Guang SUNYun-Tian D.M.deKretser 《Journal of Reproduction and Contraception》 CAS 1989年第1期138-138,共1页
The multiglycosides of Tripterygium wilfordii Hook. f. (GTW) is a Chinese herb medicine used traditionally for the treatment of rheumatoid arthritis, chronic nephritis and some skin diseases. It has been recently show... The multiglycosides of Tripterygium wilfordii Hook. f. (GTW) is a Chinese herb medicine used traditionally for the treatment of rheumatoid arthritis, chronic nephritis and some skin diseases. It has been recently shown to cause infertility in men, male rats 展开更多
关键词 雷公藤 下丘脑 垂体 睾丸系统 不育症
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从雷曼兄弟破产浅谈风险管理
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作者 洪琨 《经济视野》 2014年第21期90-91,共2页
本文通过分析雷曼兄弟(Lehman brothers)破产原因,讨论金融衍生品的作用并为管理风险提供意见,它包括以下几点(1)简介雷曼兄弟的破产和全球金融危机的背景;(2)分析风险管理系统;(3)风险管理建议.
关键词 雷曼兄弟 金融危机 金融衍生品 风险管理
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Role of the Protease—activated Receptor—1 in Crescentic Glomerulonephritis
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作者 XinChen PeterG.Tipping +1 位作者 ShaunR.Coughlin EricRondeau 《临床医药杂志》 2003年第1期1-7,共7页
Objective Fibrin deposition combined with glomerular epithelial cell proliferation and monocyte/macrophage infiltration is involved in the pathogenesis of crescentic glomerulonephritis and results from local thrombin ... Objective Fibrin deposition combined with glomerular epithelial cell proliferation and monocyte/macrophage infiltration is involved in the pathogenesis of crescentic glomerulonephritis and results from local thrombin generation.In addition to its effect on procoagulation and fibrinolysis,thrombin exerts many cellular effects through a functional thrombin receptor,protease-activated receptor-1(PAR-1).The paper is To determine the role of PAR-1 in the pathogenesis of crescentic glomerulonephritis.Methods wild type and PAR-1 knockout mice in an accelerated model of anti-glomerular basement menbrane antibody nephritis were studied.Results The wild type mice exhibited severe glomerular injury 10 days after injection of sheep anti-mouse glomerular besement membrane antibody,such as thrombus formation,extracapillary proiferation as well as renal failure.APR-1 knockout mice showed significant protection from crescentic glomerulonephritis.Conclusion PAR-1 plays a critical role in the pathogenesis of crescentic glomerulonephritis and may be a new target for therapeutic intervention. 展开更多
关键词 血管球性肾炎 凝血酶 肾小球囊损伤 纤维蛋白
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建筑工程施工管理问题及应对措施
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作者 唐潮 唐美蓉 《地产》 2022年第24期110-112,共3页
近几年以来,随着我国国民经济的不断发展,人们的生 活水平不断提升,且建筑企业也在一定程度上取得很大成就, 同时还对建筑工程的建设要求不断提升,其建设规模也不断扩 大,因此,这就需要建筑工程的施工单位认真对待这份工作。 现阶段我... 近几年以来,随着我国国民经济的不断发展,人们的生 活水平不断提升,且建筑企业也在一定程度上取得很大成就, 同时还对建筑工程的建设要求不断提升,其建设规模也不断扩 大,因此,这就需要建筑工程的施工单位认真对待这份工作。 现阶段我国政府非常重视生态管理和建筑企业的可持续发展, 但是要对建筑工程施工期间所使用的建筑材料、资金、人力进 行有效节约,建筑企业就必须极力推广施工管理,其这对建筑 行业内的先进技术和工作人员的经验都是一种考验,及时组织 相关人员主动学习,这样才能全面推动建筑行业的发展,有效提 升建筑工程整体施工质量。本文将建筑工程施工管理情况作为切 入点进行重点分析,并针对其存在的不足提出相应的解决策略。 展开更多
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南京市2005-2007年机动车驾乘人员安全带佩戴情况调查 被引量:5
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作者 覃玉 武鸣 +8 位作者 杨婕 周金意 向全永 陶然 韩仁强 潘晓群 林萍 Virginia Routley Joan Ozanne-Smith 《中华流行病学杂志》 CAS CSCD 北大核心 2009年第5期459-461,共3页
目的调查道路安全法或条例出台3年后南京市机动车驾乘人员安全佩戴情况。方法在市区内选取4个观察点,在不同时间段对出租车、小轿车(8座以内)、厢式小货车和“皮卡”4种车型的司机和前排乘车人安全带的佩戴情况进行观察。结果2005-2... 目的调查道路安全法或条例出台3年后南京市机动车驾乘人员安全佩戴情况。方法在市区内选取4个观察点,在不同时间段对出租车、小轿车(8座以内)、厢式小货车和“皮卡”4种车型的司机和前排乘车人安全带的佩戴情况进行观察。结果2005-2007年共观察35256辆车辆和司机,以及15772名前排乘车人。其中司机安全带佩戴率为49.9%,不佩戴率和假戴率分别为44.1%和4.6%;乘车人安全带佩戴率为9.1%,不佩戴率90.9%。在调整了性别、车型等因素后,3年来无论是司机还是前排乘车人安全带佩戴率均呈现下降趋势(P〈0.01),司机不佩戴安全带会增加前排乘车人不佩戴的风险(OR=8.10,P〈0.01)。结论现有法律或条例在司机和乘车人佩戴安全带方面并无具体的规定,妨碍了法律或条例的有效执行。 展开更多
关键词 道路交通伤害 机动车 安全带
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植物雌激素对血压的影响 被引量:2
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作者 梁雨露 HelenaTeede +1 位作者 FabienDalais BarryPMcGrath 《中华心血管病杂志》 CAS CSCD 北大核心 2006年第8期726-729,共4页
目的研究大豆饮食中所含的植物雌激素对健康人血压、血脂谱的影响。方法213名健康受试者(男性108人,绝经后女性105人),年龄50-75岁,随机、双盲接受特定大豆蛋白饮食(试验组)或酪蛋白安慰剂(安慰剂组)干预,为期3个月。建立多变量模型以... 目的研究大豆饮食中所含的植物雌激素对健康人血压、血脂谱的影响。方法213名健康受试者(男性108人,绝经后女性105人),年龄50-75岁,随机、双盲接受特定大豆蛋白饮食(试验组)或酪蛋白安慰剂(安慰剂组)干预,为期3个月。建立多变量模型以评价治疗效果。结果饮食干预后,仅在试验组受试者尿液中植物雌激素含量增高。试验组血压较安慰剂组下降明显[收缩压(-7.5±1.2)mm Hg比(-3.6±1.1)mm Hg,P<0.01;舒张压(-4.3±0.8)mm Hg比(-1.9±0.7)mm Hg,P<0.05;平均压(-5.5±1.0)mm Hg比(-0.9±1.0)mm Hg,P<0.008]。试验组血脂水平较安慰剂组有显著改变(P<0.001),其中试验组低密度脂蛋白胆固醇/高密度脂蛋白胆固醇比值显著下降[(-0.33±0.10) mmol/L比(0.04±0.10) mmol/L,P<0.05],甘油三酯水平也有显著下降[(-0.20±0.05)mmol/L比(-0.01±0.05)mmol/L,P<0.05],而脂蛋白(a)水平升高(±95%可信区间)[42(17-67)mg/L比4(-22-31)mg/L,P<0.05]。两组中总胆固醇和低密度脂蛋白胆固醇水平均下降,高密度脂蛋白胆固醇水平升高。副作用的发生率两组相似,并且都没有观察到男性激素水平发生改变。结论在正常血压男性和绝经后女性人群中,大豆饮食对血压和血脂水平有改善作用。 展开更多
关键词 黄豆 植物雌激素 血压 脂类
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矢量集诱导度量意义下转子最大残余振动极小化
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作者 朱向阳 钟秉林 JosephMATHEW 《科学通报》 EI CAS CSCD 北大核心 1999年第2期152-155,共4页
引入R2 上的矢量集诱导度量 ,并研究该度量意义下挠性转子的最大残余振动幅值极小化问题 ,在此基础上提出一种转子平衡质量计算方法 .该方法可应用于具有上界约束的平衡质量计算 ,并可得到近似最优的平衡质量 .
关键词 转子 矢量集诱导度量 平衡 最大残余振动 极小化
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TESTING FOR OUTLIERS IN TIME SERIES USING WAVELETS 被引量:1
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作者 ZHANGTong ZHANGXibin ZHANGShiying 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2003年第4期453-465,共13页
One remarkable feature of wavelet decomposition is that the waveletcoefficients are localized, and any singularity in the input signals can only affect the waveletcoefficients at the point near the singularity. The lo... One remarkable feature of wavelet decomposition is that the waveletcoefficients are localized, and any singularity in the input signals can only affect the waveletcoefficients at the point near the singularity. The localized property of the wavelet coefficientsallows us to identify the singularities in the input signals by studying the wavelet coefficients atdifferent resolution levels. This paper considers wavelet-based approaches for the detection ofoutliers in time series. Outliers are high-frequency phenomena which are associated with the waveletcoefficients with large absolute values at different resolution levels. On the basis of thefirst-level wavelet coefficients, this paper presents a diagnostic to identify outliers in a timeseries. Under the null hypothesis that there is no outlier, the proposed diagnostic is distributedas a χ_1~2. Empirical examples are presented to demonstrate the application of the proposeddiagnostic. 展开更多
关键词 OUTLIER wavelet decomposition wavelet coefficients
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Properties of Semijoin Sequences
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作者 BengC.Ooi B.Srinivasan 《Journal of Computer Science & Technology》 SCIE EI CSCD 1989年第2期106-115,共10页
The problem of finding optimum semijoin sequ4ence of an arbitrary query under linear cost function for the transmission cost is NP.hard.Hence heuristic algorithms with desirable properties are explored.In this paper f... The problem of finding optimum semijoin sequ4ence of an arbitrary query under linear cost function for the transmission cost is NP.hard.Hence heuristic algorithms with desirable properties are explored.In this paper four properties of semijoin programs for distributed query processing are identified,The use of these properties in constructing semijoin sequence is justified.An existing algorithm is modified incorporating these properties.Empirical comparison with existing algorithms shows the superiority of the proposed algorithm. 展开更多
关键词 分布式数据库系统 数据处理 数据查询
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Competition Based Neural Networks for Assignment Problems
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作者 李涛 LuyuanFang 《Journal of Computer Science & Technology》 SCIE EI CSCD 1991年第4期305-315,共11页
Competition based neural networks have been used to solve the generalized assignment problem andthe quadratic assignment problem.Both problems are very difficult and are ε approximation complete.Theneural network app... Competition based neural networks have been used to solve the generalized assignment problem andthe quadratic assignment problem.Both problems are very difficult and are ε approximation complete.Theneural network approach has yielded highly competitive performance and good performance for thequadratic assignment problem.These neural networks are guaranteed to produce feasible solutions. 展开更多
关键词 PRO Competition Based Neural Networks for Assignment Problems
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