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零回波时间MRA与TOF-MRA在颅内动脉瘤弹簧圈栓塞术后随访评估中的比较:初步的影像质量研究

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国际医学放射学杂志 2017年第6期 743-744页

作者： S.A.Shang j.Ye x.F.Luo j.x.qu Y.Zhen j.T.Wu 张毓婧 Department of Radiology Northern Jiangsu People ’s Hospital

摘要目的采用非增强零回波时间(z TE)MR血管成像(MRA)新方法,前瞻性评估颅内动脉瘤弹簧圈栓塞术后情况,并以数字减影血管造影(DSA)为参考标准,将其影像质

关键词：回波时间 MRA 动脉瘤弹簧圈栓塞术 TOF-MRA 随访评估影像质量

肾细胞癌肺转移抗血管生成靶向治疗的疗效评估:R2~*值作为预测标志物

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国际医学放射学杂志 2017年第6期 730-730页

作者： G.Y.Wu G.Q.Liu W.Kong j.x.qu S.T.Suo x.S.Liu 张毓婧 Department of Radiology Renji Hospital School of Medicine Shanghai Jiao Tong University

摘要目的探究R~*mapping用于评估肺转移性肾细胞癌(m RCC)抗血管生成靶向治疗(a ATT)的效能和最佳时间点。方法试验组和验证组分别有22例和16例病人。MR R~*

关键词：抗血管生成靶向治疗 R2 疗效评估

Strength reduction factors for seismic analyses of buildings exposed to near-fault ground motions

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Earthquake Engineering and Engineering Vibration 2011年第2期10卷 195-209页

作者： qu Honglue Zhang jianjing j.x. Zhao School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China Institute of Geological ＆ Nuclear Sciences PO Box 30-368 Lower Hutt New Zealand

To estimate the near-fault inelastic response spectra, the accuracy of six existing strength reduction factors （R） proposed by different investigators were evaluated by using a suite of near-fault earthquake records with directivity-induced pulses. In the evaluation, the force-deformation relationship is modelled by elastic-perfectly plastic, bilinear and stiffness degrading models, and two site conditions, rock and soil, are considered. The R-value ratio （ratio of the R value obtained from the existing R-expressions （or the R-p-T relationships） to that from inelastic analyses） is used as a measurement parameter. Results show that the R-expressions proposed by Ordaz ＆ Perez-Rocha are the most suitable for near-fault ground motions, followed by the Newmark ＆ Hall and the Berrill et al. relationships. Based on an analysis using the near-fault ground motion dataset, new expressions of R that consider the effects of site conditions are presented and verified.

关键词： strength reduction factors near-fault ground motion response spectra force-deformation relationship

Remarkably high fracture toughness of HfNbTaTiZr refractory high-entropy alloy

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journal of Materials Science & Technology 2022年第28期123卷 70-77页

作者： x.j.Fan R.T.qu Z.F.Zhang Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Nano Science and Technology Institute University of Science and Technology of ChinaSuzhou 215132China

High-entropy alloys(HEAs)with face-centered cubic(FCC)phase such as CoCrFeMnNi or CoCrNi generally exhibit ultra-high fracture toughness but relatively low *** contrast,body-centered cubic(BCC)HEAs often display higher strengths,but the few reports on fracture toughness measurement demonstrate low toughness *** we show that the BCC HfNbTaTiZr refractory HEA,which possesses a combination of high strength,good tensile ductility and excellent high-temperature properties,also exhibits a remarkably high fracture *** using the"single specimen"compliance method for j-integral measurement according to the ASTM E1820–17 standard,its fracture toughness K_(jIC)was experimentally determined to be 210 MPa m^(1/2),which renders this HEA among the toughest metallic *** excellent damage tolerance makes the HEA promising for applications as high-temperature structural materials such as in aerospace field.

关键词： High-entropy alloys BCC structure Fracture toughness j-integral

Multi-AUV SOM task allocation algorithm considering initial orientation and ocean current environment

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Frontiers of Information Technology & Electronic Engineering 2019年第3期20卷 330-341页

作者： Da-qi ZHU Yun qu Simon x.YANG Laboratory of Underwater Vehicles and Intelligent Systems Shanghai Maritime University Advanced Robotics and Intelligent Systems Laboratory University of Guelph

There is an ocean current in the actual underwater working environment. An improved self-organizing neural network task allocation model of multiple autonomous underwater vehicles(AUVs) is proposed for a three-dimensional underwater workspace in the ocean current. Each AUV in the model will be competed, and the shortest path under an ocean current and different azimuths will be selected for task assignment and path planning while guaranteeing the least total consumption. First, the initial position and orientation of each AUV are determined. The velocity and azimuths of the constant ocean current are determined. Then the AUV task assignment problem in the constant ocean current environment is considered. The AUV that has the shortest path is selected for task assignment and path planning. Finally, to prove the effectiveness of the proposed method, simulation results are given.

关键词： Autonomous underwater vehicles Self-organizing neural networks Azimuths Ocean current

INFLUENCE OF HOT DEFORMATION ON CONTINUOUSCOOLING BAINITIC TRANSFORMATION IN A LOWCARBON STEEL

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Acta Metallurgica Sinica(English Letters) 1998年第2期11卷 121-127页

作者： Z.D.Wang j.B.qu x.H.Liu G.D.Wang Northeastern Univ Shenyang China

The influence of hot deformation conditions on continuous cooling bainitic transformation has been investigated for a low carbon microalloyed steel. The CCT diagrams show that deformation in unrecrpstallized austcnite ation can accelerate transformation process. Bainitic transformation in intermediate transformation temperature region is prominent, and the proeutectoid polygonal ferrite transformation at evelated high temperature is suppressed. According to optical and TEM analyses, low carbon bainitic ferrite is characterized by granular and lathlike ferrite, based on the cooling rate and deformation conditions. For nondeformation, groaps of coarse parallel ferrite lath form from the prior austenite grain boundaries with the same crystallographic orientation. For heavy deformaton, cell structure within the austenite grains due to the high dislocation density formed, which provides more nucleation sites for bainite ferrite. So deformation can discontinue the growth of ferrite laths and decrease the length of ferrite laths.

关键词： bainite continuous cooling transformation low carbon steel deformation

Resolution of 3,3'-Dioxo-1,1'(3H,3(H)spirobi[isobenzofuran] -5,6,5'6'-tetracarboxylic acid and Optically active Polyimides thereof

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Chinese Chemical Letters 2000年第12期11卷 1077-1080页

作者： Han, FS qu, jQ Zhang, x Ding, Mx Gao, Lx Chinese Acad Sci Changchun Inst Appl Chem PCLCC State Key Lab Polymer Phys & Chem Changchun 130022 Peoples R China

3,3`-Dioxo-1,1'(3H,3'H)spirobi[isobenzofuran]-5,6,5',6'-tetracarboxylic acid 1 was resolved successfully and the corresponding optically active polyimides PI were synthesized. The properties of the optically active PI and the racemic one were investigated. The results showed that the specific rotation of (-)-PI was about two times to that of the (+)-PI, and the regularity of the optically active PI was higher than that of the racemic one.

关键词： Resolution spirodilactone tetracarboxylic acid optically active polyimide.

MODELLING FOR PREDICTION OF CONTINUOUS COOLING TRANSFORMATION KINETICS OF HOT-DEFORMED AUSTENITE STEEL

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Acta Metallurgica Sinica(English Letters) 1998年第3期11卷 225-229页

作者： j.B.qu Z.D.Wang x.H.Liu G.D.Wang Northeastern Univ Shenyang China

On the thermodynamics basis of regular solution sub-lattice model and soperelement model, kinetics basis of Cahn's transformation kinetics theory, and according to Scheil's additivity rule and eoperimental results obtained by thermal dilation method,a prediction model of transformations from hot-deformed austenite to ferrite, pearlite and bainite in low alloy steels, which could be applied to continuoas cooling process, is developed. The calculated transformed junctions of each phase based on laboratory controlled rolling and controlled cooling conditions in a low alloy steel are in reasonable agreement with the measured ones.

关键词： transformation kinetics thermodynamics continuous cooling,hot-deformed austenite

SYNTHESIS AND SOLID STATE SINTERING OF W-Ni-Fe NANO-COMPOSITE POWDERS

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Acta Metallurgica Sinica(English Letters) 2000年第3期13卷 917-920页

作者： qu, x.H. Fan, j.L. Li, Y.M. Huang, B.Y. Central South Univ of Technology Changsha China

The mixture of 90 wt%W, 7 wt%Ni and 3 wt%Fe elemental powders was milled in a planetary high-energy ball mill. The evolution of the structure during milling and the sintering behavior of the milled powders were tested. The results showed that by mechanical alloying W(Ni, Fe) supersaturated solid solution with nano-meter size formed, which can enhance the sintering process. Fully dense alloy from the milled powders was obtained through solid state sintering. The tensile strength of the obtained alloy is over 900 MPa which is comparable to that of the alloy sintered by traditional liquid-phase sintering from un-milled powders of the same composition.

关键词： Tungsten alloys Nickel alloys Iron alloys Mechanical alloying Powder metals Sintering Morphology Tensile strength