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冲压叶片厚度对液力变矩器性能的影响

北京理工大学学报 2020年第5期40卷 471-476页

作者：闫清东李新毅魏巍陈修齐北京理工大学机械与车辆学院北京100081 北京市电动车协同创新中心北京100081

以某型冲焊型液力变矩器为基础,对叶片厚度设计了全因素试验,结合流场数值模拟分析不同叶片厚度对变矩器外特性的主效应影响和交互效应影响.结果表明主效应影响随着叶片厚度的增加而使变矩器能容下降,而叶片厚度的交互效应影响并不明显... 详细信息

以某型冲焊型液力变矩器为基础,对叶片厚度设计了全因素试验,结合流场数值模拟分析不同叶片厚度对变矩器外特性的主效应影响和交互效应影响.结果表明主效应影响随着叶片厚度的增加而使变矩器能容下降,而叶片厚度的交互效应影响并不明显.进一步分析叶片厚度对于性能影响的数值变化,结果表明叶片厚度的增加导致了液力变矩器传递转矩的下降,并且这种下降程度是由慢到快的.根据性能的影响研究对冲压叶片厚度进行优化,结合实际工程板材厚度确定叶片厚度并进行试验验证.与泵轮转矩随叶片厚度的变化规律类似,涡轮转矩随叶片厚度的增加而下降,尤其是在变矩器低速比区域下降幅度较大.叶片厚度在3 mm之内时,每增大0.5 mm厚度,涡轮转矩值下降幅度在0.5%;当叶片厚度超过3 mm时,涡轮转矩变化加快,每增加0.5 mm,泵轮转矩最大变化约为3.8%.

关键词：液力变矩器冲压叶片厚度外特性

COMPLEX SYSTEM ANALYSIS OF MARKET RETURN PERCOLATION MODEL ON SIERPINSKI CARPET LATTICE FRACTAL

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Journal of Systems Science & Complexity 2014年第4期27卷 743-759页

作者： dong Yanfang WANG Jun Department of Mathematics College of ScienceBeijing Jiaotong University

This paper investigates the statistical behaviors of fluctuations of price changes in a stock *** Sierpinski carpet lattice fractal and the percolation system are applied to develop a new random stock price for the financial *** Sierpinski carpet is an infinitely ramified fractal and the percolation theory is usually used to describe the behavior of connected clusters in a random *** authors investigate and analyze the statistical behaviors of returns of the price model by some analysis methods,including multifractal analysis,autocorrelation analysis,scaled return interval ***,the authors consider the daily returns of Shanghai Stock Exchange Composite Index,and the comparisons of return behaviors between the actual data and the simulation data are exhibited.

关键词： Percolation return Sierpinski carpet lattice fractal statistical analysis stock market.

Research Progress on the Risk Factors and Outcomes of Human Carotid Atherosclerotic Plaques

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Chinese Medical Journal 2017年第6期130卷 722-729页

作者： Xiang-dong Xiong wei-dong Xiong Shang-Shen Xiong Gui-Hai Chen Department of Neurology The First Affiliated Hospital of Anhui Medical University Hefei Anhui 230022 China Department of Neurology Lu'an Affiliated Hospital of Anhui Medical University (People's Hospital of Lu'an City) Lu'an Anhui 237005 China High and New Technology Group Office Hefei National Level High and New Technology Development Zone Hefei Anhui 230088 China Department of Neurology The Affiliated Chaohu Hospital of Anhui Medical University Chaohu Anhui 238000 China

Objective： Atherosclerosis is an inflamrnatory process that results in complex lesions or plaques that protrude into the arterial lumen. Carotid atherosclerotic plaque rupture, with distal atheromatous debris embolization, causes cerebrovascular events. This review aimed to explore research progress on the risk factors and outcomes of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention. Data Sources： We searched the PubMed database for recently published research articles up to June 2016, with the key words of＂risk factors＂, ＂outcomes＂, ＂＇blood components＂, ＂molecular mechanisms＂, ＂cellular mechanisms＂, and ＂human carotid atherosclerotic plaques＂. Study Selection： The articles, regarding the latest developments related to the risk factors and outcomes, atherosclerotic plaque composition, blood components, and consequences of human carotid atherosclerotic plaques, and the molecular and cellular mechanisms of human carotid atherosclerotic plaque vulnerability for therapeutic intervention, were selected. Results： This review described the latest researches regarding the interactive effects of both traditional and novel risk factors for human carotid atherosclerotic plaques, novel insights into human carotid atherosclerotic plaque composition and blood components, and consequences of human carotid atherosclerotic plaque. Conclusion： Carotid plaque biology and serologic biomarkers of vulnerability can be used to predict the risk ofcerebrovascular events. Furthermore, plaque composition, rather than lesion burden, seems to most predict rupture and subsequent thrombosis.

关键词： Human Carotid Atherosclerosis Outcomes Plaques Progress Risk Factors

Development of a Novel Parallel-spool Pilot Operated High-pressure Solenoid Valve with High Flow Rate and High Speed

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Chinese Journal of Mechanical Engineering 2015年第2期28卷 369-378页

作者： dong Dai LI Xiaoning School of Mechanical Engineering Nanjing University of Science and Technology

High-pressure solenoid valve with high flow rate and high speed is a key component in an underwater driving ***,traditional single spool pilot operated valve cannot meet the demands of both high flow rate and high speed simultaneously.A new structure for a high pressure solenoid valve is needed to meet the demand of the underwater driving system.A novel parallel-spool pilot operated high-pressure solenoid valve is proposed to overcome the drawback of the current single spool *** models of the opening process and flow rate of the valve are *** response time of the valve is subdivided into 4 parts to analyze the properties of the opening *** formulas to solve 4 parts of the response time are *** factors that influence the opening response time are *** to the mathematical model of the valve,a simulation of the opening process is carried out by *** are chosen based on theoretical analysis to design the test prototype of the new type of *** response time of the designed valve is tested by verifying response of the current in the coil and displacement of the main valve *** experimental results are in agreement with the simulated results,therefore the validity of the theoretical analysis is *** opening response time of the valve is 48.3 ms at working pressure of 10 *** flow capacity test shows that the largest effective area is 126 mm2 and the largest air flow rate is 2320 L/*** to the result of the load driving test,the valve can meet the demands of the driving *** proposed valve with parallel spools provides a new method for the design of a high-pressure valve with fast response and large flow rate.

关键词： high-pressure pneumatic solenoid valve parallel-spool high flow rate high speed opening response time

Effects of Gap Width and Groove on the Mechanical Properties of Butt Joint Between Aluminum Alloy and Stainless Steel

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Acta Metallurgica Sinica(English Letters) 2013年第2期26卷 143-148页

作者： Honggang dong Chuanqing LIAO School of Materials Science and Engineering Dalian University of Technology Shanghai Aerospace Equipments manufacturer

Butt joining of 5A02 aluminum alloy to 304 stainless steel sheets was conducted using gas tungsten arc welding process with Al-12%Si （wt.%, the same below） and Zn-15%Al flux-cored filler wires. The effects of gap width and groove in steel side on the microstructure and tensile strength of the resultant joints were investigated. For the joint made with 0 mm-wide gap and without groove in steel side, severe incomplete brazing zone occurred along the steel side and bottom surfaces, and consequently seriously deteriorated the joint strength. However, presetting 1.5 mm-wide gap or with groove in steel side could promote the wetting of molten filler metal on the laying surfaces, and then significantly enhance the resultant joint strength. Moreover, post-weld heat treatment could further improve the tensile strength of the joints. During tensile testing, the specimens from the joints made with AI-12%Si flux-cored filler wire fractured through the weld or interracial layer, but those from the heat-treated joints made with Zn-15%AI flux-cored filler wire fractured in the aluminum base metal.

关键词： Aluminum Stainless steel Arc-brazing Gap width Groove Mechanical property

Quantum key-recovery attack on Feistel structures

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Science China(Information Sciences) 2018年第10期61卷 240-246页

作者： Xiaoyang dong Xiaoyun WANG Institute for Advanced Study Tsinghua University Key Laboratory of Cryptologic Technology and Information Security Ministry of EducationShandong University

Post-quantum cryptography has drawn considerable attention from cryptologists on a global scale. At Asiacrypt 2017, Leander and May combined Grover’s and Simon’s quantum algorithms to break the FX-based block ciphers, which were introduced by Kilian and Rogaway to strengthen DES. In this study,we investigate the Feistel constructions using Grover’s and Simon’s algorithms to generate new quantum key-recovery attacks on different rounds of Feistel constructions. Our attacks require 2quantum queries to break an r-round Feistel construction. The time complexity of our attacks is less than that observed for quantum brute-force search by a factor of 2. When compared with the best classical attacks, i.e.,Dinur et al.’s attacks at CRYPTO 2015, the time complexity is reduced by a factor of 2without incurring any memory cost.

关键词： quantum cryptanalysis quantum key-recovery Feistel structure Simon Grover

Metal-halide perovskites for high-efficiency radiation shielding applications

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Light(Science & Applications) 2023年第1期12卷 8-9页

作者： Qingfeng dong Yanjun Fang State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China State Key Laboratory of Silicon Materials and School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China

The ionizing radiation possesses extremely strong penetration capability,which poses serious risk on the health of the human body and jeopardize *** the authors demonstrate that MAPbl3/epoxy composites prepared by a s... 详细信息

关键词： composites perovskite halide

On a New Hybrid Estimator for the Central Mean Space

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Journal of Systems Science & Complexity 2017年第1期30卷 111-121页

作者： XIA Qi dong Yuexiao Department of Statistical Science Temple University USA.

Existing estimators of the central mean space are known to have uneven performances across different types of link functions. By combining the strength of the ordinary least squares and the principal Hessian directions, the authors propose a new hybrid estimator that successfully recovers the central mean space for a wide range of link functions. Based on the new hybrid estimator, the authors further study the order determination procedure and the marginal coordinate test. The superior performance of the hybrid estimator over existing methods is demonstrated in extensive simulation studies.

关键词： Marginal coordinate test order determination ordinary least squares principal Hessiandirections sufficient dimension reduction.

The Onset of the Monsoon over the Bay of Bengal:The Observed Common Features for 2008-2011

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Atmospheric and Oceanic Science Letters 2012年第4期5卷 314-318页

作者： YU wei-dong SHI Jian-wei LIU Lin LI Kui-Ping LIU Yan-Liang WANG Hui-Wu Center for Ocean and Climate Research First Institute of OceanographyState Oceanic AdministrationQingdao 266061China

In situ buoy observation data spanning four years(2008-2011) were collected and used to perform a composite analysis of the monsoon onset process in the Bay of Bengal(BoB).The sea surface temperature(SST) in the central BoB increases dramatically during the monsoon transition period and reaches its annual maximum just before the onset of the *** process is illustrated by the northward-propagating deep convection phase of the intraseasonal oscillation and the establishment of a steady southwest *** is argued that the SST peak plays a potential role in triggering the onset of the monsoon in the BoB and its *** general picture of the BoB monsoon onset summarized here reveals the possibility of regional land-ocean-atmosphere *** possibility deserves further examination.

关键词： monsoon onset Indian Ocean SST intra- seasonal oscillation