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Numerical simulation of compaction parameters for sand-filled embankment using large thickness sand filling technique in Jianghan Plain district

Wentao WANG, Chongzhi TU, Rong LUO

《结构与土木工程前沿（英文）》 2018年 第12卷 第4期   页码 568-576 doi: 10.1007/s11709-017-0444-4

摘要： The study uses the finite element method to simulate a new technique of highway sand embankment filling in Jianghan Plain district, which can raise the thickness of sand-filled layer from 30 cm to 70 cm and can significantly shorten the construction period based on the guarantee of sand embankment construction quality. After simulating the three compacting proposals carried out on the field test, the study uses COMSOL software to research on the compacting effects of sand-filled layers in larger thicknesses by 22 ton vibratory roller alone, and then to investigate the steady compacting effect of 12 ton vibratory roller. The simulation results indicate that the sand-filled layer thickness of 70 cm is suitable for the new sand filling technique, and the sand-filled embankment project with tight construction period is suggested to choose the 12 ton vibration roller for steady compaction.

关键词： sand embankment     compaction in large thickness     numerical simulation     small size vibratory roller     steady compaction    

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Vibratory behaviors of Jeffcott system on cylindrical roller bearings

Hao WU, Jianwen WANG, Qi AN

《机械工程前沿（英文）》 2009年 第4卷 第3期   页码 305-309 doi: 10.1007/s11465-009-0036-7

摘要： A Jeffcott rotor system of cylindrical roller bearings is studied in detail. Its critical speed is calculated by a new calculation method with roller bearing stiffness and damping. The influences of bearing parameters, such as the roller length, rotor mass, distance between the bearings and the kinematics viscosity of oil on the system critical speed are numerically studied, and the influences of an oil film and damping on the critical speed are also studied. Regular curves of the relationship between the geometric parameters and the system critical speed are obtained. The results show that with increasing roller length and radial load, the critical speed increases; and with increasing rotor mass and the distance between the bearings and the kinematics viscosity, the critical speed decreases. This means that an oil film will decrease the critical rotational speed of the rotor system.

关键词： roller bearing     bearing-rotor system     design value     critical rotational speed    

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A better way to do small-for-size liver transplantation in rats

null

《医学前沿（英文）》 2011年 第5卷 第1期   页码 106-110 doi: 10.1007/s11684-011-0113-2

摘要：

Establishing a model for small-for-size liver transplantation is the basis for this study of partial and living donor graft liver transplantation. This study aims to explore a simpler and more effective way of establishing a 30% small-for-size liver transplantation in rats. Sprague-Dawley rats were selected as the donors and recipients. Small-for-size orthotopic liver transplantation was performed using Kamada’s two-cuff method. The donor’s liver was flushed via the abdominal aorta and hepatectomy was performed in situ. The animals were divided into three groups depending on the graft selected, with 40 pairs of rats in each group. In group I, the median lobe of the liver was used as graft; in group II, the right half of the median lobe and the right lobe were used as graft; and in group III, the median and right lobes were used as graft. In groups I and II, the bodyweights of donors were the same as those of recipients; however, in group III the bodyweights of donors were 100–120 g less than those of the recipients. The duration needed for transplantation, the 7-day survival rates, and the technical complication rates were compared among these three groups. The time required for hepatectomy was shorter in group III compared with groups I and II (8.8?±?0.7 min vs. 11.5?±?1.1 min and 10.1?±?1.0 min, P = 0.001). The cold ischemia time for the grafts, the anhepatic times, and the transplantation times for the recipients were not significantly different among the three groups. Compared with groups I and II, the incidence of bleeding, bile leakage, and inferior vena caval strictures were significantly decreased in group III (P<0.05). No significant differences between the three groups were found based on other complications after the operation (P>0.05). Group III had better 7-day survival rates and longer median survival times but the differences were not statistically significant. The method of small for donor bodyweight using the median and right lobes for grafting may be a more effective and simpler way of establishing a 30% small-for-size liver transplantation in rats, as shown by the shorter hepatectomy time and the occurrence of fewer complications after the operation.

关键词： liver transplantation     small-for-size     rats    

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Experimental measurement of double-K fracture parameters of concrete with small-size aggregates

ZHANG Xiufang, XU Shilang, ZHENG Shuang

《结构与土木工程前沿（英文）》 2007年 第1卷 第4期   页码 448-457 doi: 10.1007/s11709-007-0061-8

摘要： The double- fracture model can well describe the development of cracks undergoing during the entire fracture process in concrete. Therefore, it has been selected as the theoretical basis of the Norm for fracture test of

关键词： development     concrete     theoretical     double- fracture    

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Temperature control of transfer roller’s bearing based on finite element analysis

Peng ZHANG, Yourong LI, Han XIAO

《机械工程前沿（英文）》 2009年 第4卷 第2期   页码 215-218 doi: 10.1007/s11465-009-0026-9

摘要： After a heat preservation cover is installed on the main rolling line, the heat dissipation environment of the transfer roller working on the heat preservation cover is changed. To ensure the normal production, a reasonable working jet capacity of the roller neck is derived. First, a globe model of the transfer roller is built for finite element analysis. Second, the sub-model of the fixed end bearing is built and the boundary condition of the sub-model is supplied by the results of the globe model. The analysis result of the sub-model shows that the temperature of the transfer roller bearing exceeds 85°C a rolling periodicity later. With finite element analysis, the heat flux is obtained and the minimum working jet capacity is derived.

关键词： transfer roller bearing     finite element analysis     sub-model     temperature control    

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Finite element modeling of counter-roller spinning for large-sized aluminum alloy cylindrical parts

Dawei ZHANG, Fan LI, Shuaipeng LI, Shengdun ZHAO

《机械工程前沿（英文）》 2019年 第14卷 第3期   页码 351-357 doi: 10.1007/s11465-019-0528-z

摘要： Counter-roller spinning (CRS), where the mandrel is replaced by rollers, is an effective means of manufacturing large-sized, thin-walled, cylindrical parts with more than 2500 mm diameter. CRS is very complex because of multi-axis rotation, multi-local loading along the circumference, and radial-axial compound deformation. Analytical or experimental methods cannot fully understand CRS. Meanwhile, numerical simulation is an adequate approach to investigate CRS with comprehensive understanding and a low cost. Thus, a finite element (FE) model of CRS was developed with the FORGE code via meshing technology, material modeling, determining the friction condition, and so on. The local fine mesh moving with the roller is one of highlights of the model. The developed 3D-FE model was validated through a CRS experiment by using a tubular blank with a 720 mm outer diameter. The developed 3D-FE model of CRS can provide a basis for parameter optimization, process control, die design, and so on. The data on force and energy predicted by the 3D-FE model can offer reasonable suggestions for determining the main mechanical parameters of CRS machines and selecting the motors. With the predicted data, an all-electric servo-drive system/machine with distributed power was designed in this work for CRS with four pairs of rollers to manufacture a large-sized, thin-walled, cylindrical part with 6000 mm diameter.

关键词： large-sized cylindrical part     counter-roller spinning     aluminum alloy     finite element method     distributed power    

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圆锥滚子轴承振动的灰色模糊聚类分析

刘劲军,夏新涛,张立红

《中国工程科学》 2008年 第10卷 第7期   页码 112-117

摘要：

以30204型圆锥滚子轴承试验数据为基础，利用灰色模糊聚类分析方法对影响圆锥滚子轴承振动的 因素进行了综合分析，将圆锥滚子轴承各项参数按其对振动的影响分为三类：第一类对振动的影响最大，其 中包括滚子凸度、滚子直径偏差Dw 等参数；第二类对振动的影响较大，其中包括内滚道圆度，内滚道直线性 Li 等参数；第三类对振动的影响最小，其中包括内滚道波纹度，内滚道的角度偏差Δ２β 等参数。根据分类可 知，试验中圆锥滚子轴承的大部分参数都会对振动产生较大的影响。

关键词： 圆锥滚子轴承     振动     灰色模糊聚类分析    

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On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate

Hui Ching FAN, Hong Sen YAN

《机械工程前沿（英文）》 2012年 第7卷 第1期   页码 5-15 doi: 10.1007/s11465-012-0310-y

摘要：

Without modifying the cam contour, a cam mechanism with a variable input speed trajectory offers an alternative solution to flexibly achieve kinematic and dynamic characteristics, and then decrease the follower’s residual vibration. Firstly, the speed trajectory of cam is derived by employing Bezier curve, and motion continuity conditions are investigated. Then the motion characteristics between the plate cam and its roller follower are derived. To analyze the residual vibration, a single degree of freedom dynamic model of the elastic cam-follower system is introduced. Based on the motion equation derived from the dynamic model, the residual vibration of the follower is yielded. The design procedure to improve the kinematic and dynamic motion characteristics is presented and two design examples with discussions are provided. Finally, the simulations of the kinematic and dynamic models by ADAMS are carried out and verified that the design models as well as the performances of the mechanism are feasible.

关键词： cam mechanism     variable input speed     kinematic design     dynamic design     optimal design    

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Nonlinear dynamic behaviour of a cam mechanism with oscillating roller follower in presence of profile

Walha LASSAAD, Tounsi MOHAMED, Driss YASSINE, Chaari FAKHER, Fakhfakh TAHER, Haddar MOHAMED

《机械工程前沿（英文）》 2013年 第8卷 第2期   页码 127-136 doi: 10.1007/s11465-013-0254-x

摘要：

In this paper we investigate the nonlinear dynamic behaviour of a cam mechanism with oscillating roller follower in presence of defects. The nonlinear developed lumped-mass model includes eight degrees of freedom with two nonlinear hertzian contacts. The first one is located between cam and first roller while the second is between second roller and the sliding rod. The nonlinear dynamic behaviour is described by second order differential equations which are resolved by using the implicit Newmark algorithm combined with the Newton-Raphson iterative scheme. The influence of the cam profile error on the dynamic behaviour is also investigated.

关键词： cam     nonlinear behaviour     oscillating roller follower     profile error    

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基于Wasserstein GAN的新一代人工智能小样本数据增强方法——以生物领域癌症分期数据为例 Article

刘宇飞, 周源, 刘欣, 董放, 王畅, 王子鸿

《工程（英文）》 2019年 第5卷 第1期   页码 156-163 doi: 10.1016/j.eng.2018.11.018

摘要：

以大数据为基础的深度学习算法在推动新一代人工智能快速发展中意义重大。然而深度学习的有效利用对标注样本数量的高度依赖，使得深度学习在小样本数据环境下的应用受到制约。本研究提出了一种基于生成对抗网络（generative adversarial network，GAN）和深度神经网络（deep neural network，DNN）分类器的方法。首先，将原始样本划分为训练集样本和测试集样本，采用训练集样本训练GAN 后生成模拟样本数据，扩增训练集样本规模；然后，使用模拟样本训练DNN 分类器；最后，使用测试集样本测试分类器，并通过指标验证该方法在小样本多分类问题下的有效性。作为实证案例，将该方法应用于生物领域癌症分期识别，结果表明该方法比传统方法获得更高的识别准确率。同时，该方法是一次将基于原始样本的经典统计机器学习分类方法转变为基于数据增强的深度学习分类方法的尝试。本研究有助于探索以深度学习为代表的新一代人工智能技术在应用范围与应用效果方面的潜力。这将对各领域全面推进新一代人工智能的发展具有重要意义。

关键词： 人工智能     生成式对抗网络     深度神经网络     小样本     癌症    

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The size distribution of airborne bacteria and human pathogenic bacteria in a commercial composting plant

《环境科学与工程前沿（英文）》 2021年 第15卷 第3期 doi: 10.1007/s11783-020-1356-4

摘要：

•Bacterial concentrations from eight stages were 104–105copies/m3.

关键词： Size distribution     Airborne bacteria     Biological diversity     Human pathogenic bacteria     Composting plants    

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A ruptured recurrent small bowel gastrointestinal stromal tumour causing hemoperitoneum

null

《医学前沿（英文）》 2015年 第9卷 第1期   页码 108-111 doi: 10.1007/s11684-014-0344-0

摘要：

Hemoperitoneum is a rare and potentially life-threatening complication of GIST. We reported a 54-year-old man who developed disseminated intra-abdominal recurrence from a previously resected gastrointestinal stromal tumour (GIST) of the small bowel, and the patient presented with hemoperitoneum. Emergent debulking surgery was performed. A high dose imatinib was prescribed. Despite the presence of residual disease, the patient was well clinically 8 months after the operation. Even though, there is no evidence to support the routine use of debulking surgery in the management of GIST. In our patient, disease progression after second line targeted therapy and the absence of alternative treatment options for spontaneous rupture and hemoperitoneum prompted us to treat the patient aggressively. Resection of the ruptured GIST was carried out for control of bleeding and to prevent recurrent bleeding in this patient with good surgical risks. During the treatment decision-making, the patient’s general condition, the risk of surgery and the extent of dissemination were taken into consideration. In this patient who presented with spontaneous rupture of a small intestinal GIST, the novel use of targeted therapy and aggressive surgical treatment produced reasonably good survival outcome.

关键词： gastrointestinal stromal tumour     hemoperitoneum     small bowel GIST     small bowel neoplasm     imatinib    

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基于混沌振动力学的压路机工程

龙运佳,杨勇,王聪玲

《中国工程科学》 2000年 第2卷 第9期   页码 76-79

摘要：

为将混沌振动力学的理论研究转化为压路机工程的新技术成果，研制了三种混沌振动压路机（0.75t,10t,14t)，并进行了振动测试、数值仿真与压实试验，证明混沌振动压路机比普通振动压路机提高工效12.2%。其中，14t重型混沌振动压路机已用于我国西部高速公路开发。

关键词： 混沌     振动     压路机工程    

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高碾压混凝土坝智能碾压理论研究

刘东海,李丙扬,崔博

《中国工程科学》 2011年 第13卷 第12期   页码 74-79

摘要：

给出了高碾压混凝土坝智能碾压的概念及实现过程，提出了大坝实时监控和智能反馈控制的原理；在实时分析压实指标的基础上，建立了大坝压实质量多元回归模型，进而提出了碾压混凝土坝压实度全仓面实时评价方法；实现了施工过程中碾压机工作性态的自适应调整，确保碾压机速度、激振力、碾压遍数和压实厚度等全过程达标，可有效保证碾压质量，提高施工效率，为碾压混凝土坝建设质量控制提供了一条新的途径。

关键词： 碾压混凝土坝     质量控制     智能碾压     实时监控     质量实时评估    

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Particle size distribution and shape control of Au nanoparticles used for particle gun

S. Kida, M. Ichiji, J. Watanabe, I. Hirasawa

《化学科学与工程前沿（英文）》 2013年 第7卷 第1期   页码 60-64 doi: 10.1007/s11705-013-1313-x

摘要： Au nanoparticles are expected for the media to transfer genes into plants. However, the control of particle size distribution (PSD) and shape of Au nanoparticles is too difficult to design and prepare particles with suitable quality for the gene supporting media. Reduction crystallization experiments were performed in aqueous solution in order to clarify the effect of feeding conditions such as feeding profile, feeding rate, and feeding amount on PSD and shape of Au nanoparticles. Ascorbic acid (AsA) was selected as a reducing agent because it is safe for plants. Au particles of 50 nm, 50–200 nm, and 150–400 nm were obtained in batch operation, single-jet, and double-jet, respectively. Moreover, in single-jet and double-jet, the mean size of the obtained Au particles increases with the decrease of feeding rate or the increase of feeding amount. It is concluded that PSD of Au nanoparticles can be controlled in the range of 50–400 nm by changing feeding conditions of AsA and HAuCl aqueous solution.

关键词： reduction crystallization     particle size distribution     gene transferring media    

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标题 作者 时间 类型 操作

Numerical simulation of compaction parameters for sand-filled embankment using large thickness sand filling technique in Jianghan Plain district

Wentao WANG, Chongzhi TU, Rong LUO

期刊论文

Vibratory behaviors of Jeffcott system on cylindrical roller bearings

Hao WU, Jianwen WANG, Qi AN

期刊论文

A better way to do small-for-size liver transplantation in rats

null

期刊论文

Experimental measurement of double-K fracture parameters of concrete with small-size aggregates

ZHANG Xiufang, XU Shilang, ZHENG Shuang

期刊论文

Temperature control of transfer roller’s bearing based on finite element analysis

Peng ZHANG, Yourong LI, Han XIAO

期刊论文

Finite element modeling of counter-roller spinning for large-sized aluminum alloy cylindrical parts

Dawei ZHANG, Fan LI, Shuaipeng LI, Shengdun ZHAO

期刊论文

圆锥滚子轴承振动的灰色模糊聚类分析

刘劲军,夏新涛,张立红

期刊论文

On the improvement design of dynamic characteristics for the roller follower of a variable-speed plate

Hui Ching FAN, Hong Sen YAN

期刊论文

Nonlinear dynamic behaviour of a cam mechanism with oscillating roller follower in presence of profile

Walha LASSAAD, Tounsi MOHAMED, Driss YASSINE, Chaari FAKHER, Fakhfakh TAHER, Haddar MOHAMED

期刊论文

基于Wasserstein GAN的新一代人工智能小样本数据增强方法——以生物领域癌症分期数据为例

刘宇飞, 周源, 刘欣, 董放, 王畅, 王子鸿

期刊论文

The size distribution of airborne bacteria and human pathogenic bacteria in a commercial composting plant

期刊论文

A ruptured recurrent small bowel gastrointestinal stromal tumour causing hemoperitoneum

null

期刊论文

基于混沌振动力学的压路机工程

龙运佳,杨勇,王聪玲

期刊论文

高碾压混凝土坝智能碾压理论研究

刘东海,李丙扬,崔博

期刊论文

Particle size distribution and shape control of Au nanoparticles used for particle gun

S. Kida, M. Ichiji, J. Watanabe, I. Hirasawa

期刊论文