资源类型

期刊论文 37

年份

2023 1

2022 2

2020 3

2019 4

2018 3

2017 4

2016 2

2015 1

2014 2

2010 1

2009 3

2008 3

2007 3

2006 3

2003 1

2000 1

展开 ︾

关键词

冲击波 4

Hugoniot 1

Mittag-Leffler稳定性；分数阶；四元数神经网络；脉冲 1

TNT装药爆炸 1

二维波达角估计；信道冲击响应估计；信号检测；均匀矩形阵列；大规模天线 1

全比尺模型试验 1

内爆炸 1

冲击强化 1

冲击损伤 1

到时 1

制冷系统 1

动态拉伸本构模型 1

化学焊炸 1

压力特性 1

发展趋势 1

含铝温压炸药 1

图像测量技术 1

多孔材料 1

岩石 1

展开 ︾

检索范围：

排序： 展示方式：

Centrifuge experiment and numerical analysis of an air-backed plate subjected to underwater shock loading

Zhijie HUANG, Xiaodan REN, Zuyu CHEN, Daosheng LING

《结构与土木工程前沿（英文）》 2019年 第13卷 第6期   页码 1350-1362 doi: 10.1007/s11709-019-0559-x

摘要： In this study, systematic centrifuge experiments and numerical studies are conducted to investigate the effect of shock loads due to an underwater explosion on the dynamic responses of an air-backed steel plate. Numerical simulations with three different models of pressure time history generated by underwater explosion were carried out. The first model of pressure time history was measured in test. The second model to predict the time history of shock wave pressure from an underwater explosion was created by Cole in 1948. Coefficients of Cole’s formulas are determined experimentally. The third model was developed by Zamyshlyaev and Yakovlev in 1973. All of them are implemented into the numerical model to calculate the shock responses of the plate. Simulated peak strains obtained from the three models are compared with the experimental results, yielding average relative differences of 21.39%, 45.73%, and 13.92%, respectively. The Russell error technique is used to quantitatively analyze the correlation between the numerical and experimental results. Quantitative analysis shows that the simulated strains for most measurement points on the steel plate are acceptable. By changing the scaled distances, different shock impulses were obtained and exerted on the steel plate. Systematic numerical studies are performed to investigate the effect of the accumulated shock impulse on the peak strains. The numerical and experimental results suggest that the peak strains are strongly dependent on the accumulated shock impulse.

关键词： underwater explosion     centrifuge experiment     shock load     dynamic response     accumulated shock impulse    

HTML PDF 收藏

Beneficial effect of arginine vasopressin on hemorrhagic shock through improving the vascular reactivity

LI Tao, YANG Guangming, XU Jing, LIU Jiancang, LIU Liangming

《医学前沿（英文）》 2008年 第2卷 第3期   页码 248-254 doi: 10.1007/s11684-008-0047-5

摘要： The vascular reactivity and calcium sensitivity were decreased following hemorrhagic shock. Arginine vasopressin (AVP) was beneficial to endotoxic, infectious/septic and hemorrhagic shock. Our previous studies found that Rho kinase played an important role in the occurrence of calcium desensitization following shock. It was reported that AVP was with stimulation effect of Rho kinase. So we hypothesized that AVP might have beneficial effect on shock via activation of Rho kinase to regulate the calcium sensitivity and vascular reactivity. Hemorrhagic shock (40 mmHg for 2 h) Wistar rats were adopted to observe the effects of small dose of AVP on hemodynamics, 24-h survival rate, the pressor effect of norepinephrine (NE) and the contractility of superior mesenteric artery (SMA). Isolated SMAs from hemorrhagic shock rats were adopted to observe the effects of AVP on vascular reactivity and calcium sensitivity and its relationship to Rho kinase with an isolated organ perfusion system. The results show that AVP at the concentration of 0.1 U/kg and 0.4 U/kg significantly improved the hemodynamic parameters and the 24-h survival rate of hemorrhagic shock rats. Meanwhile, these dosages of AVP significantly increased the pressor effect of NE and the contractile response of SMA to NE. Y-27632 (3 ?g/kg), a Rho kinase specific inhibitor, abolished the beneficial effects of AVP. , the calcium sensitivity and vascular reactivity of SMA to calcium and NE were significantly decreased following hemorrhagic shock. AVP at the concentration of 0.5 nmol/L and 5 nmol/L significantly increased the calcium sensitivity and vascular reactivity. These effects of AVP were abolished by Y-27632 (10 ?mol/L). Taken together, the results suggest that AVP at 0.1 U/kg and 0.4 U/kg is beneficial to hemorrhagic shock by improving the vascular reactivity, which involves activation of Rho kinase.
HTML PDF 收藏

Formation of disinfection byproducts from accumulated soluble products of oleaginous microalga after

Yu Liu, Qiao Zhang, Yu Hong

《环境科学与工程前沿（英文）》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0938-2

摘要： When microalgae are simultaneously applied for wastewater treatment and lipid production, soluble algal products (SAP) should be paid much attention, as they are important precursors for formation of disinfection byproducts (DBPs), which have potential risks for human health. sp. HQ is an oleaginous microalga that can generate SAP during growth, especially in the exponential phase. This study investigated the contribution of SAP from sp. HQ to DBP formation after chlorination. The predominant DBP precursors from SAP were identified with the 3D excitation-emission matrix fluorescence. After chlorination, a significant reduction was observed in the fluorescence intensity of five specific fluorescence regions, particularly aromatic proteins and soluble microbial by-product-like regions, accompanied with slight shifting of the peak. The produced DBPs were demonstrated to include trihalomethanes and haloacetic acids. As the algal cultivation time was extended in wastewater, the accumulated SAP strengthened the formation of DBPs. The trend for DBP formation was as follows: chloroform>dichloroacetic acid>trichloroacetic acid.

关键词： Chlorella sp. HQ     Chlorination     Disinfection byproducts     Fluorescence spectroscopy     Soluble algal products    

HTML PDF 收藏

Accumulated damage process of thermal sprayed coating under rolling contact by acoustic emission technique

Jia XU,Zhen-yu ZHOU,Zhong-yu PIAO

《机械工程前沿（英文）》 2016年 第11卷 第3期   页码 227-232 doi: 10.1007/s11465-016-0395-9

摘要：

The accumulated damage process of rolling contact fatigue (RCF) of plasma-sprayed coatings was investigated. The influences of surface roughness, loading condition, and stress cycle frequency on the accumulated damage status of the coatings were discussed. A ball-on-disc machine was employed to conduct RCF experiments. Acoustic emission (AE) technique was introduced to monitor the RCF process of the coatings. AE signal characteristics were investigated to reveal the accumulated damage process. Result showed that the polished coating would resist the asperity contact and remit accumulated damage. The RCF lifetime would then extend. Heavy load would aggravate the accumulated damage status and induce surface fracture. Wear became the main failure mode that reduced the RCF lifetime. Frequent stress cycle would aggravate the accumulated damage status and induce interface fracture. Fatigue then became the main failure mode that also reduced the RCF lifetime.

关键词： accumulated damage     spray coating     rolling contact fatigue     acoustic emission    

HTML PDF 收藏

Expression of heat shock protein gp96 in osteosarcoma and its clinical significance

GUO Weichun, CHEN Anmin

《医学前沿（英文）》 2008年 第2卷 第2期   页码 200-203 doi: 10.1007/s11684-008-0038-6

摘要： This study aims to detect the expression of heat shock protein gp96 (HSPgp96) in osteosarcoma and explore its role in anti-tumor immunity. Expression of HSPgp96 in 45 cases of osteosarcoma, including 24 cases of the osteoblast type, 21 cases of chondroblast type and 5 cases of normal bone tissue were detected by immunohistochemistry (IHC). The expression rate of HSPgp96 was 100% (45/45) in osteosarcoma, compared with 20% (1/5) in normal bone tissue. The average positive cell rates were 97.23% and 0.48% in osteosarcoma and normal bone tissue, respectively, and the difference between them was significant ( < 0.01). The positive cell rates in osteoblast type and chondroblast type were 97.78% and 96.56%, respectively, and the difference had no statistical significance ( > 0.05). The expression degree of HSPgp96 in osteosarcoma had a clear correlation with the pathologic degree ( < 0.05), while it had no relationship with the clinical stage ( > 0.05). The expression of HSPgp96 is high in osteosarcoma and it may be a significant index for judgment of malignancy degree and an important target site of anti-tumor immunity.
HTML PDF 收藏

Influence evaluation of loading conditions during pressurized thermal shock transients based on thermal-hydraulics

Jinya KATSUYAMA, Shumpei UNO, Tadashi WATANABE, Yinsheng LI

《机械工程前沿（英文）》 2018年 第13卷 第4期   页码 563-570 doi: 10.1007/s11465-018-0487-9

摘要：

The thermal hydraulic (TH) behavior of coo-lant water is a key factor in the structural integrity assessments on reactor pressure vessels (RPVs) of pressurized water reactors (PWRs) under pressurized thermal shock (PTS) events, because the TH behavior may affect the loading conditions in the assessment. From the viewpoint of TH behavior, configuration of plant equipment and their dimensions, and operator action time considerably influence various parameters, such as the temperature and flow rate of coolant water and inner pressure. In this study, to investigate the influence of the operator action time on TH behavior during a PTS event, we developed an analysis model for a typical Japanese PWR plant, including the RPV and the main components of both primary and secondary systems, and performed TH analyses by using a system analysis code called RELAP5. We applied two different operator action times based on the Japanese and the United States (US) rules: Operators may act after 10 min (Japanese rules) and 30 min (the US rules) after the occurrence of PTS events. Based on the results of TH analysis with different operator action times, we also performed structural analyses for evaluating thermal-stress distributions in the RPV during PTS events as loading conditions in the structural integrity assessment. From the analysis results, it was clarified that differences in operator action times significantly affect TH behavior and loading conditions, as the Japanese rule may lead to lower stresses than that under the US rule because an earlier operator action caused lower pressure in the RPV.

关键词： structural integrity     reactor pressure vessel     pressurized thermal shock     thermal hydraulic analysis     pressurized water reactor     weld residual stress    

HTML PDF 收藏

认知无线电网络中利用信道冲击响应的主用户仿真攻击检测技术 Article

Qiao-mu JIANG, Hui-fang CHEN, Lei XIE, Kuang WANG

《信息与电子工程前沿（英文）》 2017年 第18卷 第10期   页码 1665-1676 doi: 10.1631/FITEE.1700203

摘要： 认知无线电通过将空闲频谱动态地分配给未授权用户,可以有效地解决频谱资源稀缺的问题。然而，在认知无线电网络中，存在着一种严重的拒绝服务攻击，称为“主用户仿真攻击”，该攻击会导致认知无线电网络系统性能的下降。在本文中，我们提出了一种在认知无线电网络中利用无线信道信息进行主用户仿真攻击检测的方法。在该方法中，我们利用信号源与从用户之间信道冲激响应的独特性，判断从用户接收到的信号来源是主用户还是仿真主用户。我们进一步推导了所提出检测方法的虚警概率和检测概率的闭合表达式。另外，为使所提出的检测方法在从用户没有主用户信号结构和内容先验信息的场景下也能顺利工作，我们提出了一种改进的基于子空间的盲信道估计方法。仿真结果表明，即使主用户与仿真主用户到从用户之间信道冲激响应的差别较小，所提出的主用户仿真攻击检测方法也能取得较好的检测性能。

关键词： 认知无线电网络；主用户仿真攻击；基于子空间的盲信道估计；信道冲击响应    

HTML PDF 收藏

Alteration of heat shock protein 20 expression in preeclamptic patients and its effect in vascular and

Fanfan Li, Mengzhou He, Meitao Yang, Yao Fan, Yun Chen, Xi Xia, Yin Xie, Dongrui Deng

《医学前沿（英文）》 2018年 第12卷 第5期   页码 542-549 doi: 10.1007/s11684-017-0576-x

摘要：

Preeclampsia (PE) is a pregnancy-specific, multi-system disorder and the leading cause of maternal and perinatal morbidity and mortality in obstetrics worldwide. Excessive vasoconstriction and dysregulated coagulation function are closely associated with PE. Heat shock protein 20 (HSP20) is ubiquitously expressed under normal physiological conditions and has important roles in vascular dilatation and suppression of platelet aggregation. However, the role of HSP20 in the pathogenesis of PE remains unclear. In this study, we collected chorionic plate resistance arteries (CPAs) and serum from 118 healthy pregnant women and 80 women with PE and detected the levels of HSP20 and its phosphorylated form. Both HSP20 and phosphorylated HSP20 were downregulated in CPAs from women with PE. Comparison of the vasodilative ability of CPAs from the two groups showed impaired relaxation responses to acetyl choline in preeclamptic vessels. In addition to the reduced HSP20 in serum from women with PE, the platelet distribution width and mean platelet volume were also decreased, and the activated partial thromboplastin time and thromboplastin time were elevated. With regard to the vital roles of HSP20 in mediating vasorelaxation and coagulation function, the decreased HSP20 might contribute to the pathogenesis of PE.

关键词： preeclampsia     heat shock protein 20     vascular relaxation     coagulation-fibrinolytic system    

HTML PDF 收藏

Anefficient quadrature demodulator for medical ultrasound imaging

Hao ZHOU,Yin-fei ZHENG

《信息与电子工程前沿（英文）》 2015年 第16卷 第4期   页码 301-310 doi: 10.1631/FITEE.1400205

摘要： Quadrature demodulation is used in medical ultrasound imaging to derive the envelope and instantaneous phase of the received radio-frequency (RF) signal. In quadrature demodulation, RF signal is multiplied with the sine and cosine wave reference signal and then low-pass filtered to produce the base-band complex signal, which has high computational complexity. In this paper, we propose an efficient quadrature demodulation method for B-mode and color flow imaging, in which the RF signal is demodulated by a pair of finite impulse response filters without mixing with the reference signal, to reduce the computational complexity. The proposed method was evaluated with simulation and in vivo experiments. From the simulation results, the proposed quadrature demodulation method produced similar normalized residual sum of squares (NRSS) and velocity profile compared with the conventional quadrature demodulation method. In the in vivo color flow imaging experiments, the time of the demodulation process was 5.66 ms and 3.36 ms, for the conventional method and the proposed method, respectively. These results indicated that the proposed method can maintain the performance of quadrature demodulation while reducing computational complexity.

关键词： B-mode ultrasound imaging     Color flow imaging     Quadrature demodulation     Finite impulse response filter    

HTML PDF 收藏

岩石冲击损伤演化规律数值流形方法模拟

刘红岩,吕淑然,秦四清

《中国工程科学》 2007年 第9卷 第3期   页码 92-96

摘要：

采用应力波衰减损伤模型对仅适用于模拟基于线性本构关系和恒定载荷作用下物体变形规律的数值 流形程序进行了扩展；利用扩展后的程序对岩石长杆在冲击载荷作用下的损伤演化规律进行了模拟，得出了不 同位置点处的损伤演化曲线和材料总体的损伤演化曲线。模拟结果表明，损伤的增加主要集中在冲击载荷作用的初始阶段，随着时间的推移，应力波强度衰减，损伤将不再明显增加。

关键词： 岩石     数值流形方法     冲击损伤     演化规律    

HTML PDF 收藏

Effects on mechanical properties in electron beam welding of TC4 alloy by laser shock processing

LU Jinzhong, ZHANG Yongkang, KONG Dejun, REN Xudong, GE Tao, ZOU Shikun

《机械工程前沿（英文）》 2007年 第2卷 第4期   页码 478-482 doi: 10.1007/s11465-007-0083-x

摘要： The surface of TC4 titanium alloy welding line by electron beam welding (EBW) was processed by high power Q-switched and repetition-rate Nd: glass laser. Effects of laser power and spot diameter on residual stress and micro-hardness of the TC4 alloy welding line by laser shock processing (LSP) have been analyzed. Results show that residual stresses almost do not change as laser power is 45.9 J, spot diameter is φ9 mm; While laser power is 45.9 J, spot diameter less than φ3 mm, the distribution of residual stress in welding line occurs obvious variation, which residual stress increase obviously with spot diameter decrease. When power density is bigger than 1.8×10 W/cm, residual stresses of electron beam welding line occur change by LSP, which improve obviously residual stress distribution; while laser power is bigger than 1.2×10 W/cm, the surface micro-hardness of electron beam welding line occurs change by LSP, which improve obviously micro-hardness distribution. Mechanical properties of TC4 titanium alloy welding line will be improved by LSP, which provides experimental foundation for further controlling the distributions of residual stress and micro-hardness during laser shock processing.
HTML PDF 收藏

水下钻孔爆破的爆炸冲击波测试与分析

柯松林,李琳娜,司剑峰,钟冬望

《中国工程科学》 2014年 第16卷 第11期   页码 103-106

摘要：

以厦门港古雷航道水下炸礁为例，分析了水下钻孔爆破的水击波形成特征，并通过爆破区的水中冲击波压力监测，实测了不同距离处的水击波压力大小和变化规律，研究了水中冲击波压力幅值、正压作用时间等作用特性，得到了水击波传播衰减公式。研究成果对指导工程设计施工和环境安全评估具有参考意义。

关键词： 水下钻孔爆破     水中冲击波     压力特性    

HTML PDF 收藏

化爆冲击波在90°拐角通道内的到时规律

沈俊,李永池,庞伟宾,

《中国工程科学》 2006年 第8卷 第3期   页码 53-57

摘要：

对空气冲击波在90°拐角坑道内传播的到时规律及其影响因素进行了实验研究，在无量纲分析基础上建立了简化的工程模型。通过对实验数据拟合建立了可以对高能炸药在90°拐角坑道内爆炸产生的空气冲击波到达时间进行预计的公式，利用该公式可以进一步求得空气冲击波在90°拐角坑道内的传播速度。

关键词： 内爆炸     冲击波     到时    

HTML PDF 收藏

Acoustic characteristics of bi-directional turbines for thermoacoustic generators

Dongdong LIU, Yanyan CHEN, Wei DAI, Ercang LUO

《能源前沿（英文）》 2022年 第16卷 第6期   页码 1027-1036 doi: 10.1007/s11708-020-0702-3

摘要： Bi-directional turbines combined with rotary motors may be a feasible option for developing high power thermoacoustic generators with low cost. A general expression for the acoustic characteristics of the bi-directional turbine was proposed based on theoretical derivation, which was validated by computational fluid dynamics modeling of an impulse turbine with fixed guide vanes. The structure of the turbine was optimized primarily using steady flow with an efficiency of near 70% (the shaft power divided by the total energy consumed by the turbine). The turbine in the oscillating flow was treated in a lumped-parameter model to extract the acoustic impedance characteristics from the simulation results. The key acoustic impedance characteristic of the turbine was the resistance and inertance due to complex flow condition in the turbine, whereas the capacitance was treated as an adiabatic case because of the large-scale flow channel relative to the heat penetration depth. Correlations for the impedance were obtained from both theoretical predictions and numerical fittings. The good fit of the correlations shows that these characteristics are valid for describing the bi-directional turbine, providing the basis for optimization of the coupling between the thermoacoustic engine and the turbine using quasi-one-dimensional theory in the frequency domain.

关键词： thermoacoustic power generator     acoustic characteristics     bi-directional impulse turbine     energy conversion    

HTML PDF 收藏

冲击作用下多孔材料热力学特征的模拟与分析

许爱国,张广财,蔚喜军,潘小飞,朱建士

《中国工程科学》 2009年 第11卷 第9期   页码 13-19

摘要：

强冲击波的作用可在多孔材料中诱发复杂的时空耗散过程，在这期间系统整体处于远离平衡的状态，对这一过程的稳定模拟和结果分析均具有较强的挑战性。使用近期针对超高速碰撞而发展起来的物质点方法对这一过程进行模拟，引入积分几何和数值图像处理中的形态学描述来处理和分析系统热力学特征量例如温度的Turing斑图， 揭示出3个Minkowski泛函(白色区域相对面积、边界总长度、欧拉特征量)与系统中“高温区”所占份额、“热点”在空间的分布方式之间的对应，揭示出Minkowski泛函演化特征与冲击波及多孔材料相互作用过程之间的对应。研究了孔隙度和冲击波强度对物质状态参量的影响。

关键词： 冲击波     多孔材料     物质点法     形态学量度    

HTML PDF 收藏

标题 作者 时间 类型 操作

Centrifuge experiment and numerical analysis of an air-backed plate subjected to underwater shock loading

Zhijie HUANG, Xiaodan REN, Zuyu CHEN, Daosheng LING

期刊论文

Beneficial effect of arginine vasopressin on hemorrhagic shock through improving the vascular reactivity

LI Tao, YANG Guangming, XU Jing, LIU Jiancang, LIU Liangming

期刊论文

Formation of disinfection byproducts from accumulated soluble products of oleaginous microalga after

Yu Liu, Qiao Zhang, Yu Hong

期刊论文

Accumulated damage process of thermal sprayed coating under rolling contact by acoustic emission technique

Jia XU,Zhen-yu ZHOU,Zhong-yu PIAO

期刊论文

Expression of heat shock protein gp96 in osteosarcoma and its clinical significance

GUO Weichun, CHEN Anmin

期刊论文

Influence evaluation of loading conditions during pressurized thermal shock transients based on thermal-hydraulics

Jinya KATSUYAMA, Shumpei UNO, Tadashi WATANABE, Yinsheng LI

期刊论文

认知无线电网络中利用信道冲击响应的主用户仿真攻击检测技术

Qiao-mu JIANG, Hui-fang CHEN, Lei XIE, Kuang WANG

期刊论文

Alteration of heat shock protein 20 expression in preeclamptic patients and its effect in vascular and

Fanfan Li, Mengzhou He, Meitao Yang, Yao Fan, Yun Chen, Xi Xia, Yin Xie, Dongrui Deng

期刊论文

Anefficient quadrature demodulator for medical ultrasound imaging

Hao ZHOU,Yin-fei ZHENG

期刊论文

岩石冲击损伤演化规律数值流形方法模拟

刘红岩,吕淑然,秦四清

期刊论文

Effects on mechanical properties in electron beam welding of TC4 alloy by laser shock processing

LU Jinzhong, ZHANG Yongkang, KONG Dejun, REN Xudong, GE Tao, ZOU Shikun

期刊论文

水下钻孔爆破的爆炸冲击波测试与分析

柯松林,李琳娜,司剑峰,钟冬望

期刊论文

化爆冲击波在90°拐角通道内的到时规律

沈俊,李永池,庞伟宾,

期刊论文

Acoustic characteristics of bi-directional turbines for thermoacoustic generators

Dongdong LIU, Yanyan CHEN, Wei DAI, Ercang LUO

期刊论文

冲击作用下多孔材料热力学特征的模拟与分析

许爱国,张广财,蔚喜军,潘小飞,朱建士

期刊论文