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High-Temperature Stability of Mg-1Al-12Y Alloy Containing LPSO Phase and Mechanism of Its Portevin-Le Chatelier(PLC)Effect

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 982-998页

作者： Qian-Long Ren Shuai Yuan Shi-Yu Luan Jin-Hui Wang xiao-wei li xiao-Yu liu Qinghai Provincial Key Laboratory of New light Alloys Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and FormingQinghai UniversityXining810016China School of Materials Science and Engineering Shenyang University of TechnologyShenyang110870China

In this study,the high-temperature stability and the generation mechanism of the Portevin-Le Chatelier(PLC)effect in solid-solution Mg-1Al-12Y alloy with different heat treatment processes were investigated by adjusting the content of long-period stacking ordered(LPSO)*** was found that the content of LPSO phases in the alloys differed the most after heat treatment at 530℃for 16 h and 24 h,with values of 13.56%and 3.93%***,high-temperature tensile experiments were conducted on these two alloys at temperatures of 150℃,200℃,250℃,and 300℃.The results showed that both alloys exhibited the PLC effect at temperatures ranging from 150 to 250℃.However,at a temperature 300℃,only the alloy with a greater concentration of LPSO phases exhibited the PLC effect,whereas the alloy with a lower proportion of LPSO phases did not exhibit this ***,both alloys exhibited remarkable high-temperature stability,with the alloy containing a greater percentage of LPSO phases also demonstrating superior *** underlying mechanism for this phenomenon lies in the exceptional high-temperature stability exhibited by the second phase within the ***,the LPSO phase effectively obstructs the movement of dislocations,and it also undergoing kinking to facilitate plastic deformation of the *** results indicate that the PLC effect can be suppressed by reducing dislocation pile-up at grain boundaries,which leads to a decrease in alloy plasticity but an increase in *** presence of the PLC effect in the WA121 alloy is attributed to the abundant dispersed second phase within the alloy,which initially hinders the movement of dislocations,leading to an increase in stress,and subsequently releases the dislocations,allowing them to continue their movement and thereby reducing in stress.

关键词： Magnesium alloy Long-period stacking ordered(LPSO)phase Portevin-Le Chatelier effect High temperature

Correlation and predictive value of pathological complete response and ultrasound characteristic parameters in neoadjuvant chemotherapy for breast

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World Journal of Clinical Cases 2024年第23期12卷 5320-5328页

作者： Lei Zheng li-Xian Yang Jing-Yi liu Zhe Jiang xiao-wei li Peng-Peng Pu Department of Breast Surgery Xingtai People's HospitalXingtai 054001Hebei ProvinceChina Department of Medical Imaging Xingtai People´s HospitalXingtai 054001Hebei ProvinceChina

BACKGROUND Breast cancer ranks as one of the most prevalent malignant tumors among women,significantly endangering their health and *** radical surgery has been a pivotal method for halting disease progression,it alone is insufficient for enhancing the quality of life for *** To investigate the correlation between ultrasound characteristic parameters of breast cancer lesions and clinical efficacy in patients undergoing neoadjuvant chemotherapy(NAC).METHODS Employing a case-control study design,this research involved 178 breast cancer patients treated with NAC at our hospital from July 2019 to June *** to the Miller-Payne grading system,the pathological response,***,of the NAC in the initial breast lesion after NAC was *** these,59 patients achieved a pathological complete response(PCR),while 119 did not(non-PCR group).Ultrasound characteristics prior to NAC were compared between these groups,and the association of various factors with NAC efficacy was analyzed using univariate and multivariate *** In the PCR group,the incidence of posterior echo attenuation,lesion diameter≥2.0 cm,and Alder blood flow grade≥II were significantly lower compared to the non-PCR group(Plimited predictiv

关键词： Breast cancer Ultrasound Neoadjuvant chemotherapy Efficacy Pathological complete response

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中国新型城镇化与绿色发展协调演进关系研究

自然资源学报 2024年第7期39卷 1682-1697页

作者：邓毛颖韦晓莉张国俊广州市规划和自然资源局广州510030 中山大学地理科学与规划学院广州510006 广东财经大学金融学院广州510320 广东财经大学乡村振兴研究院广州510320

双碳目标下,新型城镇化与绿色发展的协调演进对于推动中国经济高质量发展意义重大。运用熵值法、耦合协调模型等研究方法,分析了2005-2020年中国30个省(自治区、直辖市)新型城镇化与绿色发展协调演进的时空格局特征与类型。结果表明:(1... 详细信息

双碳目标下,新型城镇化与绿色发展的协调演进对于推动中国经济高质量发展意义重大。运用熵值法、耦合协调模型等研究方法,分析了2005-2020年中国30个省(自治区、直辖市)新型城镇化与绿色发展协调演进的时空格局特征与类型。结果表明:(1)中国新型城镇化与绿色发展水平均呈现增长态势。(2)中国新型城镇化与绿色发展的协调度总体呈现上升趋势;协调等级空间分布总体呈现东、中部向西部、东北递减格局。(3)协调演进具有显著空间集聚特征,且以HH型、LL型、HL型为主。(4)协调演进重心呈现由东北向西南迁移的趋势。(5)协调发展类型分为“城镇化先行”“绿色发展先行”与“同步发展”三种,其中“城镇化先行”为最主要类型。针对不同协调发展类型的省(自治区、直辖市)提出相应的对策建议,持续助力新型城镇化与绿色发展协调演进。

关键词：新型城镇化绿色发展协调演进时空格局

Evaluating and Constraining Hardware Assertions with Absent Scenarios

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Journal of Computer Science & Technology 2020年第5期35卷 1198-1216页

作者： Hui-Na Chao Hua-wei li xiaoyu Song Tian-Cheng Wang xiao-wei li State Key Laboratory of Computer Architecture Institute of Computing TechnologyChinese Academy of Sciences Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China Peng Cheng Laboratory Shenzhen 518052China Department of Electrical and Computing Engineering Portland State UniversityPortlandOR 97207U.S.A.

Mining from simulation data of the golden model in hardware design verification is an effective solution to assertion *** the simulation data is inherently incomplete,it is necessary to evaluate the truth values of the mined *** paper presents an approach to evaluating and constraining hardware assertions with absent scenarios.A Belief-fail Rate metric is proposed to predict the truth/falseness of generated *** considering both the occurrences of free variable assignments and the conflicts of absent scenarios,we use the metric to sort true assertions in higher ranking and false assertions in lower *** Belief-failRate guided assertion constraining method leverages the quality of generated *** experimental results show that the Belief-failRate framework performs better than the existing *** addition,the assertion evaluating and constraining procedure can find more assertions that cover new design functionality in comparison with the previous methods.

关键词： hardware formal verification assertion generation data mining assertion evaluation assertion coverage

Efficient Syntheses of 2-Substituted Benzimidazoles and Benzoxazoles from β-Keto Esters

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Chemical Research in Chinese Universities 2011年第2期27卷 228-231页

作者： xiao li-wei ZHANG Min SUN Wen-hua Faculty of Chemistry and Material Science Langfang Teachers College Langfang 065000 P. R. China Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100190 P. R. China

An efficient synthetic method was developed to synthesize 2-substituted benzimidazoles and benzo- xazoles with β-keto esters as starting materials under mild reaction conditions, during which other functional groups ... 详细信息

关键词： Benzimidazole Benzoxazole β-Keto ester

Wide Operational Range Processor Power Delivery Design for Both Super-Threshold Voltage and Near-Threshold Voltage Computing

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Journal of Computer Science & Technology 2016年第2期31卷 253-266页

作者： Xin He Gui-Hai Yan Yin-He Han xiao-wei li State Key Laboratory of Computer Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

The load power range of modern processors is greatly enlarged because many advanced power management techniques are employed, such as dynamic voltage frequency scaling, Turbo Boosting, and near-threshold voltage （NTV） technologies. However, because the efficiency of power delivery varies greatly with different load conditions, conventional power delivery designs cannot maintain high efficiency over the entire voltage spectrum, and the gained power saving may be offset by power loss in power delivery. We propose SuperRange, a wide operational range power delivery unit. SuperRange complements the power delivery capability of on-chip voltage regulator and off-chip voltage regulator. On top of SuperRange, we analyze its power conversion characteristics and propose a voltage regulator （VR） aware power management algorithm. Moreover, as more and more cores have been integrated on a singe chip, multiple SuperRange units can serve as basic building blocks to build, in a highly scalable way, more powerful power delivery subsystem with larger power capacity. Experimental results show SuperRange unit offers lx and 1.3x higher power conversion efficiency （PCE） than other two conventional power delivery schemes at NTV region and exhibits an average 70% PCE over entire operational range. It also exhibits superior resilience to power-constrained systems.

关键词： voltage regulator power delivery near-threshold computing multicore processor

Microstructure evolution and thixoforming behavior of 7075 aluminum alloy in the semi-solid state prepared by RAP method

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International Journal of Minerals,Metallurgy and Materials 2016年第12期23卷 1404-1415页

作者： Jin-long Fu Kai-kun Wang xiao-wei li Hai-kuan Zhang School of Materials Science and Engineering University of Science and Technology Beijing Tianjin Zhonglian Precision Casting Co. Ltd.

The effects of isothermal treatments on the microstructural evolution and coarsening rate of semi-solid 7075 aluminum alloy produced via the recrystallization and partial remelting （RAP） process were investigated. Samples of 7075 aluminum alloy were subjected to cold extrusion, and semi-solid treatment was carried out for 5-30 min at temperatures ranging from 580 to 605℃. A backward-extrusion experiment was conducted to investigate liquid segregation during the thixoforming process. The results revealed that obvious grain coarsening and spheroidization occurred during prolonged isothermal treatments. In addition, higher soaking temperatures promoted the spheroidization and coarsening process because of the increased liquid fraction and the melting of second phases. Segregation of the liquid phase caused by the difference in fluidity between the liquid and the solid phases was observed in different regions of the thixoformed specimens.

关键词： aluminum alloys microstructural evolution thixoforming grain coarsening segregation

Trace formula of the integro-differential operator on a quantum graph

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 311-318页

作者： wei li-xiao YANG Chuan-fu School of Mathematics and Statistics Nanjing University of Science and TechnologyNanjing 210094China.

In this paper we study the eigenvalue problem for integro-differential operators on a lasso *** trace formula of the operator is established by applying the residual technique in complex analysis.

关键词： integro-differential operators eigenvalue trace formula

Maternal and Fetal Exposure to Four Carcinogenic Environmental Metals

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Biomedical and Environmental Sciences 2010年第6期23卷 458-465页

作者： HUAI GUAN FENG-YUAN PIAO xiao-wei li QIU-JUAN li LEI XU KAZUHITO YOKOYAMA Department of Occupational and Environmental Health Dalian Medical University Dalian 116044 Liaoning China Department of Obstetrics and Gynecology No. 210 Hospital of PLA Dalian 116021 Liaoning China Department of Public School of Medicine Mie University Tsu Mie-Prefecture Japan

Objective To examine maternal and fetal exposure levels to four carcinogenic metals, arsenic （As）, cadmium （Cd）, nickel （Ni）, and beryllium （Be）, and to investigate their environmental influences. Methods Metal concentrations in maternal and umbilical cord blood were measured by inductively coupled plasma-mass spectrometry （ICP-MS）. Environmental factors that might play a role in exposure were analyzed using Mann Whitney nonparametric U-tests and multiple linear regression. Results The concentrations of As, Cd, and Ni in umbilical cord blood （5.41, 0.87, and 139.54 gg/L） were significantly lower than those in maternal blood （6.91, 1.93, and 165.93 p.g/L）. There were significant positive correlations between the maternal and cord concentrations of each carcinogen. Our results showed that：（i） exposures to potentially harmful occupational factors during pregnancy were associated with high levels of maternal As, Cd, and Ni; （ii） living close to major transportation routes （〈500 m） or exposure to second-hand smoke during pregnancy increased the maternal Cd levels and （iii） living close to industrial chimneys induced high maternal Ni levels. Multiple linear regression analysis showed that these environmental factors remained significant in models of the influences of these four carcinogens. Conclusion Both mothers and fetuses had been exposed to As, Cd, Ni, and Be. The increased levels of these carcinogens in pregnant women were associated with some detrimental environmental factors, such as occupational exposure, contact with second-hand smoke and living close to major transportation routes or industrial chimneys.

关键词： Carcinogenic metals Exposure in utero Maternal blood Cord blood Environment