检索结果-南通市图书馆

Estimation of the J-resistance curve for Cr2Ni2MoV steel using the modified load separation parameter S_(pb) method

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第10期11卷 782-788页

作者： Chen BAO Li-xun cai School of Mechanics and Engineering Southwest Jiaotong University Chengdu 610031 China

Based on load separation theory, the load separation parameter Spb method is an effective approach for estimating the J-resistance curve from records of load versus displacement directly, using one sharp cracked specimen and an additional reference blunt cracked specimen. However, the effect of the reference blunt cracked specimen on J-resistance determination was not explicitly considered in past work. In this paper, a modified load separation parameter Spb method was developed to eliminate this effect, and then a unique estimation of instantaneous crack length for one sharp cracked specimen could be obtained. Furthermore, a forced blunting calibration method was also adopted to determine the instantaneous crack length in the load inseparable region, referring to a normalization method. Experiments on steam turbine rotator steel Cr2Ni2MoV were carried out to estimate J-resistance curves using an unloading compliance method. By removing unload and reload data from load-displacement records, the J-resistance curve for the same sharp cracked specimen was estimated using the modified separation parameter Spb method. The results indicate that the modified Spb method completely eliminates the effect of the reference blunt cracked specimen on the instantaneous crack length determination of the sharp cracked specimen. However, different J-resistance curves in a small range of crack extension are present when different blunting coefficients are used in the blunting line equation. The J-resistance curve obtained from the modified Spb method agrees well with that obtained from the compliance method.

关键词： Load separation J-resistance curve Separation parameter Spb Blunt cracked specimen Forced blunting calibration

Numerical Investigation on Effectiveness of Flow Separation Control in Two-dimensional High-load Compressor Cascade by Synthetic Jet

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2012年第5期21卷 441-446页

作者： Songtao Wang Le cai xun Zhou Shaopeng Lu Engine Aerodynamics Research Centre Harbin Institute of Technology Harbin 150001 China

The effectiveness of flow separation control in two-dimensional high load cascade by synthetic jet is investigated through numerical simulation of the effect of excitation frequency and amplitude together with the adaptability of synthetic jet to off-design conditions. Test results indicate that synthetic jet can be used to effectively control the large-scale two-dimensional flow separation in compressor cascade. Preferable results can be obtained when excitation frequency is close to or times of the characteristic frequency of original flow field. Excitation amplitude has a more important effect on the effectiveness of flow separation control, and the increase in excitation amplitude can bring about a dramatic decrease in the loss of total pressure. Synthetic jet has also a very good adaptability to off-design conditions. It can therefore be concluded that the incidence sensitivity of compressor cascade can be effectively reduced by synthetic jet.

关键词： synthetic jet excitation frequency excitation amplitude off-design conditions numerical simulation

Biodegradation of phenol and m-cresol by mutated Candida tropicalis

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第4期22卷 621-626页

作者： Yan Jiang xun cai Di Wu Nanqi Ren State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology Harbin 150090 China. Department of Chemical Engineering Daqing Oilfield Engineering Limited Company Daqing 163712 China School of Life Sciences and Chemistry Harbin University Harbin 150016 China

The phenol and m-cresol biodegradations were studied using the mutant strain CTM 2 obtained by the He-Ne laser irradiation on wild-type Candida tropicalis. The results showed that C. tropicalis exhibited the increased capacity of phenolic compounds degradation after laser irradiation. It could degrade 2600 mg/L phenol and 300 mg/L m-cresol by 5% inoculum concentration, respectively. In the dual-substrate biodegradation system, 0-500 mg/L phenol could accelerate m-cresol biodegradation, and 300 mg/L m-cresol could be completely utilized within 46 hr at the presence of 350 mg/L phenol. Besides, the maximum biodegradation of m-cresol could reach 350 mg/L with 80 mg/L phenol within 61 hr. Obviously, phenol, as a growth substrate, could promote CTM 2 to degrade m-cresol, and was always preferentially utilized as carbon source. Comparatively, low-concentration m-cresol could result in a great inhibition on phenol degradation. In addition, the kinetic behaviors of cell growth and substrate biodegradation were described by kinetic model proposed in our laboratory.

关键词： biodegradation the mutant strain CTM 2 phenol m-cresol kinetic

在线全文

学校读者我要写书评

暂无评论

间接型光谱成像仪相对光谱响应函数标定方法

物理学报 2024年第12期73卷 108-117页

作者：李潇潇李娟柏财勋畅晨光郝雄波文镇清王鹏冲冯玉涛中国科学院西安光学精密机械研究所光谱成像技术重点实验室西安710119 中国科学院大学北京100049 山东理工大学物理与光电工程学院淄博255000

间接型光谱成像仪通常采用面阵探测器作为光电转换器件,探测器像元间光谱响应的不一致性会导致采集到的目标光谱失真,所以标定和修正像元间光谱响应的不一致性是提升间接型光谱成像仪光谱辐射测量精度的重要手段.本文以干涉光谱成像仪为... 详细信息

间接型光谱成像仪通常采用面阵探测器作为光电转换器件,探测器像元间光谱响应的不一致性会导致采集到的目标光谱失真,所以标定和修正像元间光谱响应的不一致性是提升间接型光谱成像仪光谱辐射测量精度的重要手段.本文以干涉光谱成像仪为例,分析了系统像元间相对光谱响应不一致对目标光谱辐射测量准确性的影响,提出了基于傅里叶变换调制定标源的间接型光谱成像仪全系统相对光谱响应函数测量方法,并建立了相对光谱响应函数标定的数理模型.仿真分析结果表明,理想无噪声时,像元间1%的相对光谱响应不一致性会对复原光谱造成1.02%的相对误差,经过相对光谱响应校正后,不同行复原光谱的相对误差降至0.08%.最后,仿真分析了相对光谱响应不一致性在不同光谱信噪比下的校正效果.该方法可提高间接型光谱成像仪光谱测量的准确性和一致性.

关键词：间接型光谱成像仪傅里叶变换光谱仪相对光谱响应定标

Feature-based adaptive texture visualization for vector field

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2013年第9期56卷 168-181页

作者： XU Huaxun LI SiKun ZENG Liang cai xun School of Computer National University of Defense Technology

An adaptive sparse texture rendering method is proposed to solve for occlusion effects when visualizing 3D flows, building on an extensible fuzzy feature extraction approach. First, the flow feature is described by fuzzy theory and rules for some typical features are obtained. The significance value for each voxel is then calculated by a clustering method under the minimum square-sum rule. An adaptive Gaussian noise field is obtained from the significance field by a noise generation process, and is used as the input for the LIC convolution process. We also present two cool/warm-illumination-based approaches to overcome the shortcomings of texture-based visualization methods, which are usually unable to represent the flow direction. The experiments show that our method can effectively extract the typical flow feature region and can be extended to other flow features easily, and the adaptive technique used lessens the occlusion effects significantly. Furthermore, the main disadvantage of the texture-based method, that is, the direction representation problem, can also be solved by the proposed cool/warm illumination methods.

关键词： vector field feature visualization adaptive processing fuzzy theory feature structure

Effect of Cyclic Loading on Cracking Behaviour of X-70 PipelineSteel in Near-Neutral pH Solutions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2005年第4期21卷 459-464页

作者： Hao GUO Guangfu LI xun cai Ruipeng YANG Wu YANG College of Materials Science and Engineering Shanghai Jiao Tong University Shanghai 200030 China Shanghai Research Institute of Materials Shanghai 200437 China

The cracking behaviour of X-70 pipeline steel in near-neutral pH solutions was studied under different modes of cyclic loading. The crack propagation process of X-70 pipeline steel under low frequency cyclic loading condition was controlled mainly by stress corrosion cracking （SCC） mechanism. Under mixed-mode cyclic loading, both higher tensile stress and shear stress made cracks easier to propagate. Applied cathodic potentials and high content of carbon dioxide in solutions also promoted the propagation of cracks. The propagation directions of cracks were different under different cyclic loading conditions. Under mode I （pure tensile stress） cyclic loading condition, cracks were straight and perpendicular to the tensile stress axis, while under mixed-mode 1/111 （tensile/shear stress） cyclic loading,cracks were sinuous and did not propagate in the direction perpendicular to the main tensile stress axis. Under the mixed-mode cyclic loading, cracks were much easier to propagate, suggesting that shear stress intensified the role of tensile stress. In addition, shear stress promoted the interaction between cracks, resulting in easier coalescence of cracks.

关键词： Pipeline steel Stress corrosion cracking Near-neutral pH Cyclic loading Shear stress Propagation

在线全文

学校读者我要写书评

暂无评论

趋化因子及其受体在肝癌中的功能及预后价值

肝脏 2024年第3期29卷 293-299页

作者：冯洁蔡勋全潘勤聪上海市第五人民医院消化内科 200240

目的通过分析TCGA数据库中的肝癌样本联合GTEx数据库中的正常样本,探讨趋化因子受体(CCRs)在肝癌中的重要性。方法收集66个CCRs,筛选差异表达的CCRs,并进行GO功能注释和KEGG通路富集分析,以探索其潜在的生物学功能。使用单因素及多因素... 详细信息

目的通过分析TCGA数据库中的肝癌样本联合GTEx数据库中的正常样本,探讨趋化因子受体(CCRs)在肝癌中的重要性。方法收集66个CCRs,筛选差异表达的CCRs,并进行GO功能注释和KEGG通路富集分析,以探索其潜在的生物学功能。使用单因素及多因素Cox回归分析并联合Lasso回归分析,构建了基于四个CCRs(CCR9、CCR7、CCR3和ACKR2)特征的预测评分模型,构建列线图来评估HCC患者的预后并进行免疫分析。结果我们发现风险评分是HCC的独立预后因素。免疫分析提示风险评分与免疫细胞浸润有相关性,表明模型中CCRs可能在HCC免疫微环境中发挥关键作用。结论我们构建了一个预测模型,该模型可用于指导HCC患者的个性化治疗和预后的预测。

关键词：趋化因子趋化因子受体肝癌预后免疫浸润

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

框架结构对薄膜体声波谐振器性能提升的研究

电子学报 2024年第2期52卷 407-413页

作者：吴永乐吴昊鹏赖志国蔡洵唐滨杨清华杨雨豪王卫民北京邮电大学集成电路学院北京100876 北京邮电大学电子工程学院北京100876 苏州汉天下电子有限公司江苏苏州215000

本文研究了框架结构(Frame)对薄膜体声波谐振器(Film Bulk Acoustic Resonator,FBAR)提升性能的作用,从两种Frame结构对体声波能量的反射匹配基础理论出发,针对其功能特点,以实验的方式确定了低频和高频多组框架微结构的组合,对多组FBA... 详细信息

本文研究了框架结构(Frame)对薄膜体声波谐振器(Film Bulk Acoustic Resonator,FBAR)提升性能的作用,从两种Frame结构对体声波能量的反射匹配基础理论出发,针对其功能特点,以实验的方式确定了低频和高频多组框架微结构的组合,对多组FBAR进行了版图绘制以及光刻流片,最终通过片上测试得到了所有分组的谐振器性能.对测试得到的性能进行了分组统计筛选,从测试结果来看,经过优选之后的Frame结构分组无论是对低频还是高频FBAR谐振器都具有提升性能的作用.对低频(1.7 GHz附近)FBAR来说,并联谐振品质因数可以提升1000以上.对高频(5.5 GHz附近)FBAR来说,并联谐振品质因数可以提升300以上.对横向寄生模式较强的高频FBAR,优选的Frame结构可以提升谐振器的横向寄生模式抑制,使串联谐振频率之下的阻抗相位波动减少5°以上.

关键词：薄膜体声波谐振器框架结构流片实验阻抗相位波动

Coherently Controlled Periodic Entanglement of Two Moving Atoms in a Cavity

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第4期49卷 1017-1021页

作者： cai xun-Ming GE Guo-Qin YIN Miao HE Qing Department of Physics Huazhong University of Science and Technology Wuhan 430074 China College of Physics and Electronic Information Guizhou University for Nationalities Guiyang 550025 China

We analyze the entanglement of two atoms in a cavity. The evolvement of entanglement of two atoms is disorderly when two atoms in the cavity are fixed at initial time. However, the evolvement of entanglement of two atoms becomes well-regulated orderly under the coherent cavity field when atoms are in motion at beginning. We find that it is possible to control this periodic entanglement by properly choosing the velocity of atoms, and the initial state of the field.

关键词： periodic entanglement atomic evolvement concurrence