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硅-锰系TRIP钢热处理工艺的研究 被引量:4
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作者 李壮 张平礼 +1 位作者 王佳夫 吴迪 《机械工程材料》 CAS CSCD 北大核心 2004年第12期42-45,共4页
硅 锰系TRIP钢仅含碳、硅、锰等合金元素,采用亚温等温淬火及完全淬火加亚温等温淬火热处理,获得铁素体、贝氏体和残余奥氏体三相组织,残余奥氏体分别呈块状和针状。该钢在Ms~Md温度之间拉伸试验表明其力学性能提高显著。完全淬火加亚... 硅 锰系TRIP钢仅含碳、硅、锰等合金元素,采用亚温等温淬火及完全淬火加亚温等温淬火热处理,获得铁素体、贝氏体和残余奥氏体三相组织,残余奥氏体分别呈块状和针状。该钢在Ms~Md温度之间拉伸试验表明其力学性能提高显著。完全淬火加亚温等温淬火试样在50℃拉伸时,伸长率最高值达41.5%。 展开更多
关键词 亚温等温淬火 相变诱发塑性 -锰系trip
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美国-智利FTA中TRIPS-plus条款对智利商标法的影响
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作者 李丹萍 《云南大学学报(法学版)》 2011年第1期115-120,共6页
经过两年14轮的谈判,2003年美国-智利自由贸易协定(FTA)正式签订,并于2004年1月1日开始执行。美国-智利FTA知识产权章节是文本第17章,其中不乏许多TRIPS-plus条款,对智利的知识产权保护标准提出了更高的保护要求,以更多的谋求美国的国... 经过两年14轮的谈判,2003年美国-智利自由贸易协定(FTA)正式签订,并于2004年1月1日开始执行。美国-智利FTA知识产权章节是文本第17章,其中不乏许多TRIPS-plus条款,对智利的知识产权保护标准提出了更高的保护要求,以更多的谋求美国的国家利益。作为美国与发展中国家签订的具有代表性、示范性的FTA,本文通过对美国-智利FTA涉及商标的TRIPS-plus条款进行分析,指出其对智利商标法带来的影响和冲击,以更深入的认识TRIPS-plus条款的实质,对我国自由贸易区战略的推行提供借鉴和参考。 展开更多
关键词 tripS—plus条款 美国-智利FTA 商标
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miR-324-5p通过靶向TRIP13基因调控宫颈癌细胞增殖、侵袭、迁移和凋亡 被引量:1
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作者 郭纪芬 刘艳菊 孟芳 《中国老年学杂志》 CAS 北大核心 2022年第3期676-681,共6页
目的探讨miR-324-5p对宫颈癌细胞增殖、侵袭、迁移和凋亡的影响及调控机制。方法培养正常宫颈细胞Ectl/E6E7和宫颈癌细胞系Hela、C-33A、CaSki、SiHa,实时定量聚合酶链式反应(qRT-PCR)检测细胞中miR-324-5p和甲状腺激素受体因子(TRIP)13... 目的探讨miR-324-5p对宫颈癌细胞增殖、侵袭、迁移和凋亡的影响及调控机制。方法培养正常宫颈细胞Ectl/E6E7和宫颈癌细胞系Hela、C-33A、CaSki、SiHa,实时定量聚合酶链式反应(qRT-PCR)检测细胞中miR-324-5p和甲状腺激素受体因子(TRIP)13 mRNA表达,Western印迹检测TRIP13蛋白表达。转染miR-324-5p模拟物或TRIP13小干扰RNA、或共转染miR-324-5p模拟物和TRIP13过表达载体至Hela细胞,噻唑蓝(MTT)检测细胞增殖,Transwell检测细胞迁移和侵袭,流式细胞仪检测细胞凋亡,Western印迹检测细胞Nanog、细胞周期蛋白(Cyclin)D1、基质金属蛋白酶(MMP)-2和含半胱氨酸的天冬氨酸蛋白水解酶(Caspase-3)蛋白表达。双荧光素酶报告基因实验验证miR-138-5p与TRIP13的调节关系。结果与Ectl/E6E7细胞比较,宫颈癌细胞系Hela、C-33A、CaSki、SiHa中miR-324-5p表达明显降低(P<0.05),TRIP13 mRNA和蛋白表达明显升高(P<0.05)。过表达miR-324-5p或沉默TRIP13均抑制了Hela细胞增殖、迁移和侵袭,诱导Hela细胞凋亡,并抑制Hela细胞中Nanog、CyclinD1和MMP-2蛋白表达,促进Caspase-3蛋白表达。miR-324-5p在Hela细胞中靶向负调控TRIP13。上调TRIP13部分逆转了过表达miR-324-5p对Hela细胞增殖、侵袭、迁移和凋亡的影响。结论miR-324-5p通过靶向抑制TRIP13阻碍宫颈癌细胞增殖、侵袭和迁移,并诱导细胞凋亡,其可能是宫颈癌治疗的分子靶点。 展开更多
关键词 宫颈癌 miR-324-5p trip13 细胞增殖 侵袭 迁移 凋亡
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Formation of epitaxial Tl_2Ba_2Ca_2Cu_3O_(10) superconducting films by dc-magnetron sputtering and triple post-annealing method 被引量:5
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作者 解伟 王培 +9 位作者 季鲁 葛德永 杜佳男 高晓昕 刘欣 宋凤斌 胡磊 张旭 何明 赵新杰 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第7期697-702,共6页
For obtaining pure phase T12Ba2Ca2Cu3O10 (T1-2223) films with good superconducting properties, the growth technique is improved by dc magnetron sputtering and a triple post-annealing process. The triple post-anneali... For obtaining pure phase T12Ba2Ca2Cu3O10 (T1-2223) films with good superconducting properties, the growth technique is improved by dc magnetron sputtering and a triple post-annealing process. The triple post-annealing process comprises annealing twice in argon and once in oxygen at different temperatures. In the first low-temperature annealing phase in argon, T12Ba2CaCu2O8 (T1-2212) is obtained to effectively minimize evaporation in the next step. With the increase of temperature in the second annealing stage in argon, the previously prepared T1-2212 inter-phase is converted into T1-2223 phase. An additional annealing in oxygen is also adopted to improve the properties of T1-2223 films, each containing an optimal oxygen content value. The results of X-ray diffraction (XRD) θ-2θ scans, 09 scans and rotational φ scans show that each of the T1-2223 films has a high phase purity and an epitaxial structure. Smooth films are observed by scanning electron microscopy (SEM). The critical temperatures Tc of the films are measured to be about 120 K and the critical current densities Jc can reach 4.0 MA/cm2 at 77 K at self field. 展开更多
关键词 T1-2223 superconducting films POST-ANNEALING critical temperature critical current density
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Fe-0.4C-10Mn-4Al系TRIP钢的显微组织与拉伸性能分析 被引量:1
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作者 樊伟 冯运莉 +1 位作者 王宇辰 刘帅 《热加工工艺》 北大核心 2022年第18期63-67,共5页
利用OM、XRD、EBSD,对Fe-C-10Mn-4AlTRIP钢的铸态、热轧态以及双相区退火态的微观组织进行观察,并对其不同状态下的拉伸性能进行测试。结果表明:铸态下该实验钢的主要组织为铁素体与奥氏体,且δ-铁素体保留到室温;经过热轧与双相区退火... 利用OM、XRD、EBSD,对Fe-C-10Mn-4AlTRIP钢的铸态、热轧态以及双相区退火态的微观组织进行观察,并对其不同状态下的拉伸性能进行测试。结果表明:铸态下该实验钢的主要组织为铁素体与奥氏体,且δ-铁素体保留到室温;经过热轧与双相区退火处理,钢中奥氏体的体积分数达到89.3%。在拉伸过程中奥氏体发生马氏体转变(相变诱发塑性,TRIP效应),双相区退火处理后的试样抗拉强度达757.3 MPa,伸长率为44.9%,强塑积达到了33.8GPa·%,实验钢的强韧性大幅提高。 展开更多
关键词 Δ-铁素体 trip效应 组织 拉伸性能
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Effects of WIN 55,212-2 on I_K Current in Cultured Trigeminal Ganglion Neurons of Rat
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作者 明章银 谭艳 +5 位作者 付晖 曹雪红 潘建萍 胡本容 刘烈炬 向继洲 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2005年第2期124-126,共3页
Summary: To investigate the effects of WIN 55,212-2 on I K in cultured rat trigeminal ganglion (TG) neurons, whole-cell patch clamp techniques were used to record the I K before and after WIN 55,212-2 perfusion at d... Summary: To investigate the effects of WIN 55,212-2 on I K in cultured rat trigeminal ganglion (TG) neurons, whole-cell patch clamp techniques were used to record the I K before and after WIN 55,212-2 perfusion at different concentrations. 30 μmol/L WIN 55,212-2 markedly (35 7 %± 7 3 %, P<0.01, n=8) inhibited I K currents, and the currents were partially recovered after washing. 30 μmol/L WIN 55,212-2 also induced a significant depolarizing shift in conductance-voltage parameters (control: V 0 5=10 43 ± 4.25 mV, k=16 27±3 86; WIN 55,212-2: V 0.5=24.71±3.91 mV, k =16.69±2.75; n = 8, P<0.01 for V 0.5). 0.01 μmol/L WIN 55,212-2 slightly (27.0 %± 7.9 %, P<0.05, n=7) increased I K currents, but had no significant change in conductance–voltage parameters (control: V 0.5=10.74±5.27 mV, k=17.33±2.96; WIN 55,212-2: V 0.5=11.06±2.05 mV, k=19.69±6.60; n=7, P>0.05 for V 0.5 and k). These results suggested that WIN 55,212-2 has dual action, which might be through different receptors. 展开更多
关键词 WIN 55 212-2 trigeminal ganglion neuron I K current RAT
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A, ■-Ω METHOD FOR 3-D EDDY CURRENT ANALYSIS
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作者 施展伟 赵兴华 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1998年第11期0-0,0-0+0-0+0,共7页
After the field equations and the snonumuoo conditions between the interfaces for 3D eddy current problems Under various gauges were discussed, it was pointed cut in this paper that using the magnetic vector potentia... After the field equations and the snonumuoo conditions between the interfaces for 3D eddy current problems Under various gauges were discussed, it was pointed cut in this paper that using the magnetic vector potential A. the electric scalar potential and Coulomb gauge △ .A = 0 in eddy current regions and using the magntetic scalar potential Ω in the non-conducting regions are more suitable. All field equations, the boundary conditions, the interface continuity conditions and the corresponding variational principle of this method are also given 展开更多
关键词 3-D eddy current field A -Ω method interface continuous conditions
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EFFECTS OF THE HOE 694 ON TRANSIENT INWARD CURRENT AND NA^+- CA^(2+) EXCHANGE IN GUINEA PIG CARDIOMYOCYTES
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作者 刘华军 陈灏珠 +1 位作者 杨学义 程介士 《Chinese Medical Sciences Journal》 CAS CSCD 2001年第1期5-9,共5页
To determine the effects of HOE 694, a new and potent Na+- H+ exchanger blocker, on transient inward current (Iti) and Na+- Ca2+ exchange during hypoxia- reoxygenation in guinea pig cardiomyocytes. Methods. Cardio... To determine the effects of HOE 694, a new and potent Na+- H+ exchanger blocker, on transient inward current (Iti) and Na+- Ca2+ exchange during hypoxia- reoxygenation in guinea pig cardiomyocytes. Methods. Cardiomyocytes were isolated from adult guinea pig ventricle. Experiment was performed in an experimental chamber that allowed the cells to be exposed to a sufficiently low O2 pressure. The cells were subjected to hypoxia and reoxygenation. The ionic currents were studied with patch clamp technique. Results. In the absence of HOE 694, hypoxia- reoxygenation induced Iti in 12 of 15 experiments; but in cardiomyocytes pretreated with HOE 694 (10~ 50μ mol/L), the incidence of Iti observed during reoxygenation was reduced to 5 of 11 experiments and 3 of 10 experiments, P Conclusions. Blockade of the Na+- H+ exchange by HOE 694 could reduce Ca2+ overload upon hypoxia- reoxygenation, and inhibition of Na+- H+ exchange may also indirectly decrease Na+- Ca2+ exchange activity during hypoxia. 展开更多
关键词 HOE 694 transient inward current Na+- Ca2+ exchange
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Exact Traveling Wave Solutions of Nano-Ionic Solitons and Nano-Ionic Current of MTs Using the exp(-φ (ξ ))-Expansion Method
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作者 Emad H. M. Zahran 《Advances in Nanoparticles》 2015年第2期25-36,共12页
In this work, the exp(-φ (ξ )) -expansion method is used for the first time to investigate the exact traveling wave solutions involving parameters of nonlinear evolution equations. When these parameters are taken to... In this work, the exp(-φ (ξ )) -expansion method is used for the first time to investigate the exact traveling wave solutions involving parameters of nonlinear evolution equations. When these parameters are taken to be special values, the solitary wave solutions are derived from the exact traveling wave solutions. The validity and reliability of the method are tested by its applications to Nano-ionic solitons wave’s propagation along microtubules in living cells and Nano-ionic currents of MTs which play an important role in biology. 展开更多
关键词 The exp(-φ )) -Expansion Method Nano-Solitons of IONIC Wave’s Propagation along Microtubules in Living Cells Nano-Ionic currents of MTS Traveling WAVE SOLUTIONS KINK and Anti KINK WAVE SOLUTIONS
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Effects of Angiotensin Ⅱ and ACE Inhibitor,Captopril on L-type Calcium Current and Sodium Current of Single Guinea Myocytes
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作者 徐延敏 黄体钢 陈元禄 《South China Journal of Cardiology》 CAS 2002年第2期95-98,共4页
Objectives To investigate effect of Angll, captopril on single guinea myocytes on L - type calcium current and sodium current. Methods Membrane patch clamp whole cell recording technique was used to investigate effect... Objectives To investigate effect of Angll, captopril on single guinea myocytes on L - type calcium current and sodium current. Methods Membrane patch clamp whole cell recording technique was used to investigate effect of angll, captopril on L - Ca maximum current density and sodium maximum current density. Resutls Angll increased the maximum current density compared with control after perfused 5 min, 357. 7 ±219. 7 Vs 279. 5± 240. 5 PA/PF, increase rate is 27. 9 %, the shape of current - voltage relationship curve was unchanged, peaked at + 10 mv, indicated that angll increased L - Ca current density in voltage - dependent. After perfused with captopril, captopril + angll 3, 5 min, L - Ca current was recorded, results suggest L - Ca maximum current density decreased significantly compared with control, in captopril group, 128. 4 ± 92. 6Vs286. 2 ± 89. 7, 66. 7±68. 3Vs 286. 2 ± 89. 7, respectively, rate of inhibition is 55. 1 %, 76. 6 %, respectively. L - Ca current further decreased in captopril perfused 5 min compared with 3 min, 66. 7 ± 68. 3 Vs 128. 4 ± 92. 6, in captopril + angll group, L - Ca current decreased greatly in 3, 5 min than control, 143. 4±117. 6Vs 267. 7±141. 4, 96. 4±82. 5 Vs 267. 7±141. 4, respectively, rate of inhibition is 46. 4 % , 63. 9 % respectively. We also investigated effect of captopril on Na current, which decreased significantly in 1 min and 3 min compared with control, 939. 1 ±319. 1 Vs 1398. 0±144. 6 PA/PF, 469. 95 ± 314. 9 Vs 1398. 0 ±144. 6 PA/PF, respectively, rate of inhibition is 32. 8 % , 66. 3 % , respectively. Na current density decreased significantly in 3 min compared with 1 min, 469. 9±314. 9 Vs 939. 1±319. 1PA/PF, rate of inhibition is 49. 9 % . Conclusions Angiotensin Ⅱexerts increased maximum current density of L - Ca in voltage dependent, captopril decreased maximum current density of L - Ca in voltage dependent, decreased sodium maximum current density, which is the prominently antiarrhythmia mechanisms through inhibition of angiotensin Ⅱ evoked calcium dependent transient inward current and calcium overload. 展开更多
关键词 Membrane patch clamp IL - Ca current Na - current Angiotensin Captopril
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淬火-碳分配-回火钢的低温组织和性能 被引量:8
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作者 周澍 张柯 +1 位作者 顾剑锋 戎咏华 《材料热处理学报》 EI CAS CSCD 北大核心 2012年第6期30-34,共5页
Fe-0.25C-1.5Mn-1.2Si-1.5Ni-0.05Nb(质量分数,%)钢通过淬火-碳分配-回火(Q-P-T)工艺抗拉强度可达1250 MPa以上兼具良好塑性(大于17%),显微组织为位错型板条马氏体、微合金碳化物和薄片状残留奥氏体。通过低温拉伸试验分析了Q-P-T钢在-8... Fe-0.25C-1.5Mn-1.2Si-1.5Ni-0.05Nb(质量分数,%)钢通过淬火-碳分配-回火(Q-P-T)工艺抗拉强度可达1250 MPa以上兼具良好塑性(大于17%),显微组织为位错型板条马氏体、微合金碳化物和薄片状残留奥氏体。通过低温拉伸试验分析了Q-P-T钢在-85~25℃下的力学性能并采用透射电镜观察了试样在25℃和-85℃时拉伸前后的显微组织。结果表明,Q-P-T钢在-70~25℃时显示了良好的低温力学性能,仅当拉伸温度低于-70℃时试样塑性开始出现大幅下降;残留奥氏体在未变形前具有良好的低温稳定性,但在变形过程中会发生马氏体相变,产生相变诱发塑性(TRIP)效应,这是Q-P-T钢具有高强度和良好塑性的主要原因。 展开更多
关键词 淬火-碳分配-回火(Q-P-T)工艺 残留奥氏体 trip效应 碳化物 马氏体
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冲击温度对Fe-25Mn-3Al-3Si钢冲击性能及其微观组织的影响 被引量:8
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作者 陈亚 谢盼 +2 位作者 伍翠兰 尹炎祺 田松栗 《电子显微学报》 CAS CSCD 2015年第4期304-312,共9页
在不同实验温度下对Fe-Mn-Al-Si钢进行了V型缺口的夏比冲击实验。利用金相显微镜、扫描电子显微镜(SEM)、电子背散射衍射仪(EBSD)和透射电子显微镜(TEM)对冲击试样的微观组织结构进行表征。结果表明:在-190℃-200℃的冲击温度范... 在不同实验温度下对Fe-Mn-Al-Si钢进行了V型缺口的夏比冲击实验。利用金相显微镜、扫描电子显微镜(SEM)、电子背散射衍射仪(EBSD)和透射电子显微镜(TEM)对冲击试样的微观组织结构进行表征。结果表明:在-190℃-200℃的冲击温度范围内,该TRIP/TWIP钢均为韧性断裂,没有出现韧脆转变现象。冲击温度影响冲击变形机制,高温冲击变形以位错滑移为主,室温下以形变孪晶诱导塑性(TWIP效应)为主,低温下逐渐以相变诱导塑性(TRIP效应)为主。该TRIP/TWIP钢在低温冲击过程中发生的TWIP、TRIP效应赋予其优异的低温冲击韧性。 展开更多
关键词 TWIP效应 trip效应 冲击韧性 形变孪晶 ε-马氏体
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度量空间中Current的某些特征
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作者 赵培标 杨孝平 《数学物理学报(A辑)》 CSCD 北大核心 2006年第1期104-112,共9页
作者从代数观念出发研究了Current的表示定理.对于完备不变Current,利用构建的极小三元组技巧,给出了一个类似的Radon-Nikodym定理.
关键词 current 表示定理 C^*-代数 不变current HILBERT空间 张量积
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TRIP800钢板Q&P处理后的疲劳性能研究
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作者 陈立伟 颜景润 +2 位作者 倪笑宇 王烁 李欣 《热加工工艺》 CSCD 北大核心 2017年第12期205-207,211,共4页
采用最小应力/最大应力σ_(min)/σ_(max)≈0的拉-拉循环加载,测定了TRIP钢经Q&P处理后的疲劳应力-循环次数(S-N)曲线。并对所得的试验数据进行了拟合处理。结果表明:TRIP钢经Q&P处理后在加载频率8Hz、应力比R≈0时的S-N曲线的... 采用最小应力/最大应力σ_(min)/σ_(max)≈0的拉-拉循环加载,测定了TRIP钢经Q&P处理后的疲劳应力-循环次数(S-N)曲线。并对所得的试验数据进行了拟合处理。结果表明:TRIP钢经Q&P处理后在加载频率8Hz、应力比R≈0时的S-N曲线的拟合公式为:lgN=42.062-15.026lgσ(N为循环周次;σ为最大循环应力σ_(max));TRIP800钢板经过Q&P处理后疲劳源在表面下的第二相处,裂纹的扩展区为微孔聚集型断裂,而瞬断区为典型的脆性断裂。 展开更多
关键词 trip钢板 应力-循环次数(S-N)曲线 疲劳断裂 断口扫描
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临界区退火温度对0.02C-7Mn钢拉伸过程中的多相组织演变和力学性能的影响
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作者 梁小凯 刘岗 +2 位作者 孙新军 杨跃标 王贺 《材料科学与工程学报》 CAS CSCD 北大核心 2022年第4期557-566,共10页
本实验研究了临界区退火温度对0.02C-7Mn钢拉伸过程中的多相组织演变及力学性能的影响。研究结果表明,随退火温度升高,实验钢的屈服强度和抗拉强度先降后升,而延伸率则先升后降。实验钢在600℃退火后,室温组织由残余奥氏体和退火马氏体... 本实验研究了临界区退火温度对0.02C-7Mn钢拉伸过程中的多相组织演变及力学性能的影响。研究结果表明,随退火温度升高,实验钢的屈服强度和抗拉强度先降后升,而延伸率则先升后降。实验钢在600℃退火后,室温组织由残余奥氏体和退火马氏体双相组成;在620~700℃退火后,室温组织由残余奥氏体、α'-马氏体和ε-马氏体组成。随退火温度升高,实验钢在拉伸过程中分别出现了γ→α'、γ→ε和ε→α'相变。其中,γ→ε相变对延伸性能的影响最为显著,而ε→α'相变对加工硬化性能的影响最为显著。在620℃退火后,实验钢在拉伸过程中共发生了γ→α'、γ→ε和ε→α'三种相变,抗拉强度为776.5MPa,屈服强度为675.0MPa,延伸率为29.5%。 展开更多
关键词 临界区退火温度 超低碳中锰钢 trip效应 机械稳定性 ε-马氏体
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Ionic Conduction and Fuel Cell Performance of Ba0.98Ce0.8Tm0.2O3-α Ceramic
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作者 仇立干 王茂元 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2010年第6期707-712,746,共7页
The perovskite-type oxide solid solution Ba0.98Ce0.8Tm0.2O3-α was prepared by high temperature solid-state reaction and its single phase character was confirmed by X-ray diffraction. The conduction property of the sa... The perovskite-type oxide solid solution Ba0.98Ce0.8Tm0.2O3-α was prepared by high temperature solid-state reaction and its single phase character was confirmed by X-ray diffraction. The conduction property of the sample was investigated by alternating current impedance spectroscopy and gas concentration cell methods under different gases atmospheres in the temperature range of 500-900 ℃. The performance of the hydrogen-air fuel cell using the sample as solid electrolyte was measured. In wet hydrogen, the sample is a pure protonic conductor with the protonic transport number of 1 in the range of 500-600 ℃, a mixed conductor of proton and electron with the protonic transport number of 0.945-0.933 above 600 ℃. In wet air, the sample is a mixed conductor of proton, oxide ion, and electronic hole. The protonic transport numbers are 0.010-0.021, and the oxide ionic transport numbers are 0.471-0.382. In hydrogen-air fuel cell, the sample is a mixed conductor of proton, oxide ion and electron, the ionic transport numbers are 0.942 0.885. The fuel cell using Ba0.98Ce0.8Tm0.2O3-α as solid electrolyte can work stably. At 900 ℃, the maximum power output density is 110,2 mW/cm2, which is higher than that of our previous cell using Ba0.98Ce0.8Tm0.2O3-α (x〈≤1, RE=Y, Eu, Ho) as solid electrolyte. 展开更多
关键词 Ba0.98Ce0.8Tm0.2O3-α Ionic conduction Gas concentration cell Alternating current impedance Fuel cell
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侯月线沁水-嘉峰牵引供电运行方式优化分析 被引量:1
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作者 李卫民 《电气化铁道》 2022年第5期20-25,31,共7页
侯月线沁水—嘉峰下行方向因供电臂长、车流量大、电压损耗大,多次发生阻抗保护动作,且末端分区所电压最低为16 kV左右,严重影响运输生产。本文对该区段牵引供电运行方式进行优化研究,以提高供电质量。
关键词 牵引变电所 提高牵引网末端电压 上下行电流 减少跳闸次数 继电保护
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第二脉冲电流对TRIP 980钢板电阻点焊接头显微组织和力学性能的影响 被引量:5
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作者 王涛 张梅 +3 位作者 刘仁东 卢林 张亮 吴文恒 《上海金属》 CAS 北大核心 2019年第5期19-25,31,共8页
采用单脉冲、多脉冲电阻点焊工艺对主要成分为0.28%C、2.0%Mn、0.97%Si和0.93%Al(质量分数)、1.5 mm厚的相变诱发塑性TRIP 980钢板进行了焊接。研究了第二脉冲电流对点焊接头显微组织、硬度和拉剪强度的影响。结果表明:采用两种工艺点... 采用单脉冲、多脉冲电阻点焊工艺对主要成分为0.28%C、2.0%Mn、0.97%Si和0.93%Al(质量分数)、1.5 mm厚的相变诱发塑性TRIP 980钢板进行了焊接。研究了第二脉冲电流对点焊接头显微组织、硬度和拉剪强度的影响。结果表明:采用两种工艺点焊的接头熔核的显微组织主要为下贝氏体和板条马氏体;施加5和6 kA第二脉冲电流可以消除接头熔核的中心缩孔,而施加6和7 kA第二脉冲电流可使熔核局部重熔,并使先前形成的熔核回火,导致熔核平均硬度降低14~25 HV0.3;施加较大的第二脉冲电流(7 kA)还使点焊接头热影响区的宽度增加,并提高点焊接头的拉剪强度。 展开更多
关键词 电阻点焊 第二脉冲电流 trip 显微组织 拉剪强度
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双极MMC-HVDC系统站内接地故障特性及保护策略 被引量:19
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作者 李振动 安海清 +3 位作者 樊小伟 杨大伟 杨敏祥 张建坡 《电力系统自动化》 EI CSCD 北大核心 2020年第5期77-83,共7页
针对双极柔性直流输电系统模块化多电平换流器(MMC)交直流出口接地故障,研究了换流器闭锁后的电压电流暂态特性,并推导了故障分量的数学解析式。研究结果表明,交流出口发生单相接地故障时,换流器闭锁后非故障相上、下桥臂分别出现了过... 针对双极柔性直流输电系统模块化多电平换流器(MMC)交直流出口接地故障,研究了换流器闭锁后的电压电流暂态特性,并推导了故障分量的数学解析式。研究结果表明,交流出口发生单相接地故障时,换流器闭锁后非故障相上、下桥臂分别出现了过电压和过电流现象,并且交流侧电流出现直流偏置导致故障相短路电流不存在过零点。直流出口发生单极接地故障,换流器闭锁后桥臂短路电流主要由交流系统注入的稳态电流和上下桥臂电抗间衰减的环流构成。针对交流出口发生单相接地故障这一特殊的故障特性,提出了一种选相跳闸保护策略,解决了故障电流不存在过零点时交流断路器无法正常断开的难题。最后搭建了张北四端环网结构柔性直流电网仿真模型,仿真结果验证了换流器出口故障特性分析的准确性以及所提选相跳闸保护策略的有效性和可行性。 展开更多
关键词 双极柔性直流 模块化多电平换流器 接地故障 故障特性 选相跳闸保护策略
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Effects of alternating current interference on corrosion of X60 pipeline steel 被引量:9
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作者 Yan-Bao Guo Cheng Liu +1 位作者 De-Guo Wang Shu-Hai Liu 《Petroleum Science》 SCIE CAS CSCD 2015年第2期316-324,共9页
With rapid economic development in China, demand for energy and transportation is growing. Due to the limitations of factors such as terrain and traffic, a large number of buried oil and gas pipelines are parallel to ... With rapid economic development in China, demand for energy and transportation is growing. Due to the limitations of factors such as terrain and traffic, a large number of buried oil and gas pipelines are parallel to high- voltage transmission lines and electrified railways over long distances. Alternating pipelines is very serious in laboratory experiments were current (AC) corrosion of such cases. In this work, carried out with an electrochemical method in a simulated soil solution at various AC current densities from 0 to 200 A]m2 and AC frequencies from 10 to 200 Hz. Experimental results indicated that with an increase in the AC current density, the corrosion po- tential of an X60 steel electrode shifted negatively, the anodic current density increased significantly, and the corrosion rate increased. Moreover, with an increase in the AC frequency, the corrosion potential of the X60 electrode shifted positively and the anodic current density decreased, which led to a decrease in the corrosion rate. Furthermore, the morphology of X60 electrodes indicated that uniform corrosion occurred at a low AC current density; while corrosion pits were found on the X60 electrode surface at a high AC current density, and deep corrosion pits seriously damaged the pipelines and might lead to leakage. 展开更多
关键词 Alternating current interference - X60pipeline steel CORROSION AC current density - ACfrequency
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