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Two-stage aging treatment to accelerate aging kinetics without impairing strength in BC/7A04Al composite

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Science China Technological Sciences 2024年

作者： chen yuntao MA GuoNan ZHU ShiZe WANG Dong XIAO BoLü MA ZongYi Shi-Changxu Innovation Center for Advanced Materials Institute of Metal Research Chinese Academy of Sciences School of Materials Science and Engineering University of Science and Technology of China Centre of Excellence for Advanced Materials

Aging treatments are the key process to obtain satisfactory strength for 7xxxAl alloys and their composites. However, traditional single-stage （SS） aging is time-consuming to reach a peak strength condition. In this study, an efficient 120℃+160℃ two-stage（TS） aging treatment was proposed on a B4C/7A04Al composite fabricated via powder metallurgy （PM） technology, which could acquire similar peak-aging strength but only took about 15%of the time compared to traditional 120℃ SS aging. The evolution of precipitation during the TS aging was investigated, as well as those of the 7A04Al alloys for comparison. In the second stage aging process, the higher aging temperature accelerated the nucleation of η′phases inside the grains and thus increased the density of precipitates. Moreover, the short aging time limited the coarsening of precipitates and the broadening of precipitatefree zones. The above factors were beneficial for quickly obtaining satisfactory precipitation strengthening effects. The B4C/7A04Al composite exhibited slower aging kinetics than the 7A04Al alloy in the TS aging. Mg elements consumption by the chemical reaction between B impurities introduced by B4C particles and the Al matrix was considered to potentially retard the aging kinetics of the B4C/7A04Al composite. Nevertheless, the precipitation sequence was not affected.

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改进一维卷积神经网络的隧道围岩收敛变形分级预测

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应用基础与工程科学学报 2024年第1期32卷 145-159页

作者：吴浩陈运涛朱赵辉李秀文岳强中国水利水电科学研究院北京100048 中交天津港湾工程研究院有限公司天津300222 山东农业大学水利土木工程学院山东泰安271018

隧道围岩收敛变化是认识围岩和支护结构动态作用及其时空演变机理的前提,变形分级准确预测是对围岩稳定性和支护结构有效性评估的重要基础.本文提出了改进一维卷积和支持向量机融合深度网络的隧道收敛变形分级预报模型.根据围岩变形的... 详细信息

隧道围岩收敛变化是认识围岩和支护结构动态作用及其时空演变机理的前提,变形分级准确预测是对围岩稳定性和支护结构有效性评估的重要基础.本文提出了改进一维卷积和支持向量机融合深度网络的隧道收敛变形分级预报模型.根据围岩变形的主要影响因素和特征类型,选取强度应力比、隧道埋深、隧道等效直径、支护刚度和岩体质量指标,建立了变形等级的识别框架.收集了159组国内外经典的隧道收敛变形实例数据,采用全局均值池化层和支持向量机改进传统卷积神经网络中全连接层和Softmax层进行等级分类,利用改进的一维卷积神经网络自动提取隧道变形的隐含典型特征.运用衰减学习率和Dropout正则化深度学习训练技巧,防止模型出现过拟合.与其他方法的结果对比,证明了该方法有着更好的准确率和鲁棒性,模型完全利用数据驱动实现有限数据集的深层复杂且微妙关系学习.应用于多雄拉公路隧道的围岩收敛变形分级预测,预测结果与现场实际一致,进一步验证了方法的准确性和适用性.研究结果有利于提高隧道收敛变形预测的理论水平和可靠性,为类似工程提供参考.

关键词：隧道工程收敛变形预测深度学习改进一维卷积神经网络

Boring holes in Au nanoplates by active surface etching

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Nano Research 2024年第9期17卷 8610-8617页

作者： Haiyang Hu yuntao Wang Qian Wang Xudong Peng An Su Hong Wang Hongyu chen Institute of Advanced Synthesis(IAS)and School of Chemistry and Molecular Engineering Jiangsu National Synergetic Innovation Centre for Advanced MaterialsNanjing Tech UniversityNanjing 211816China Department of Environmental Science and Engineering University of Science and Technology of ChinaHefei 230026China Department of Chemistry School of Science and Key Laboratory for Quantum Materials of Zhejiang ProvinceResearch Center for Industries of the FutureWestlake UniversityHangzhou 310030China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310024China

In contrast to the conventional etching that makes nanoparticles rounder and our previous sharpening etching mode that causes serrated edges,here,we developed a new boring etching mode that targets the faces of Au nanoplates to make *** critical factors are the pre-incubation step with the ligand 2-mercapto-5-benzimidazolecarboxylic acid(MBIA)and the subsequent removal of excess ligands in the ***,etching is focused onto the few sites with initial loss of ligands,which cannot be quickly *** choice of ligand MBIA is also of importance,as it carries negative charge and repels each *** inability of forming a dense layer probably plays a critical role in the site-selectivity for faces,because ligands at the higher curvature edges and corners are expected to have less *** etching results from the comproportionation reaction between Au3+and Au0 in the nanoplates,where Br-coordination to Au and the extra stabilization from cetyltrimethylammonium bromide(CTAB)are *** believe that the ability of boring holes is an important tool for future synthetic designs.

关键词： Au nanoplates active surface etching boring etching mode cetyltrimethylammonium bromide(CTAB)passivation holes

Interaction Between Ustilaginoidea virens and Rice and Its Sustainable Control

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Rice science 2024年第3期31卷 269-284页

作者： ZHANG Fengmin CAO Zhenzhen ZHENG Xin HE yuntao chen Mingxue LIN Xiaoyan Rice Product Quality Inspection&Supervision Testing Center of Ministry of Agriculture and Rural Affairs China National Rice Research InstituteHangzhou 310006China

Ustilaginoidea virens is a common rice pathogen that can easily lead to a decline in rice quality and the production of toxins pose potential risks to human *** this review,we present a comprehensive literature review of research since the discovery of rice false *** provide a comprehensive and,at times,critical overview of the main results and findings from related research,and propose future research ***,we delve into the interaction between *** and rice,including the regulation of transcription factors,the process of *** infecting rice panicles,and the plant immune response caused by rice *** that,we discuss the identification and characterization of mycotoxins produced by the pathogenic fungus,as well as strategies for disease *** emphasize the importance of comprehensive agricultural prevention and control methods for the sustainable management of *** knowledge will update our understanding of the interaction between *** and rice plants,offering a valuable perspective for those interested in ***.

关键词： rice false smut flower-specific infection mycotoxin food safety plant disease

有机-无机复合固化剂合成及重金属污染底泥固化研究

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环境工程 2024年第3期42卷 82-91页

作者：陈运涛肖瑶王健男高忠帅崔美黄仁亮中交天津港湾工程研究院有限公司天津300222 港口岩土工程技术交通运输行业重点实验室天津300222 天津市港口岩土工程技术重点实验室天津300222 中交第一航务工程局有限公司天津300222 天津大学海洋科学与技术学院天津300072

疏浚重金属污染底泥由于具有含水率高、强度低等特性,无法直接作为工程材料应用,并且会对环境造成污染。设计合成了一种丙烯酸-苯乙烯磺酸共聚物(AA-SSS),并与水泥和纳米水化硅酸钙(早强剂)混合,开发了一种有机-无机复合固化剂。探究了... 详细信息

疏浚重金属污染底泥由于具有含水率高、强度低等特性,无法直接作为工程材料应用,并且会对环境造成污染。设计合成了一种丙烯酸-苯乙烯磺酸共聚物(AA-SSS),并与水泥和纳米水化硅酸钙(早强剂)混合,开发了一种有机-无机复合固化剂。探究了有机-无机复合固化剂对底泥固化抗压强度和重金属离子稳定化的影响,并分析了其机理。结果表明:有机-无机复合固化剂对底泥固化强度增强效果显著,在10%水泥、1%AA-SSS、2%早强剂添加量下,底泥固化1 d的抗压强度为0.85 MPa,相比未加固化剂,提高了467%。在该条件下,底泥中的Pb^(2+)、Ni^(2+)、Cd^(2+)、Cr^(3+)的浸出浓度分别从7.05,8.32,4.40,7.12 mg/L降至2.68,2.61,0.68,2.05 mg/L,经固化稳定化后底泥酸浸出液中重金属浓度均低于危险废物鉴别标准值。水泥水化产物加强了淤泥颗粒之间的胶结,并包裹固定金属离子,同时AA-SSS和纳米水化硅酸钙可以分散和促进水泥水化,并通过静电作用和吸附作用固定金属离子。研究表明有机-无机复合固化剂在提高底泥抗压强度和重金属离子稳定化具有良好的应用前景。

关键词：重金属污染底泥固化剂无侧限抗压强度稳定化

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Quantitative method for calculating spatial release region for laser-guided bomb

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Journal of Systems Engineering and Electronics 2024年第4期35卷 1053-1062页

作者： YANG Ping XIAO Bing chen Xin HAO yuntao Air Force Early Warning Academy Wuhan 430019China Unit 93175 of the PLA Changchun 136000China

The laser-guided bomb(LGB)is an air-to-ground pre-cision-guided weapon that offers high hit rates,great power,and ease of *** are guided by semi-active laser ground-seek-ing technology,which means that atmospheric conditions can affect their *** spatial release region(SRR)of LGBs is difficult to calculate precisely,especially when there is a poor field of *** can result in a lower real hit *** increase the hit probability of LGBs in tough atmospheric situa-tions,a novel method for calculating the SRR has been *** method is based on the transmittance model of the 1.06μm laser in atmospheric species and the laser diffuse reflection model of the target surface to determine the capture target time of the laser ***,it calculates the boundary ballistic space starting position by ballistic model and gets the spatial scope of the spatial release *** method can determine the release region of LGBs based on flight test data such as instantaneous velocity,altitude,off-axis angle,and atmospheric *** more effectively employing aircraft release conditions,atmospheric visibility and other factors,the SRR calculation method can improve LGB hit probabi-lity by 9.2%.

关键词： laser-guided bombs(LGBs) hit probability atmo-spheric transmittance spatial release region(SRR)boundary ballistic

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绿色建筑设计理念在建筑方案中的应用研究

城市建筑 2022年第16期19卷 106-109页

作者：陈云涛深圳和华国际工程与设计有限公司

进入21世纪以来,建筑业不断发展,同时其能耗也不断增加,对生态环境造成污染和破坏,人们开始将目光转向绿色建筑施工。本文立足于绿色建筑设计理念,以大连市某办公大楼设计为例,从土地利用、室外环境设计等方面深入剖析,结合施工要求,通... 详细信息

进入21世纪以来,建筑业不断发展,同时其能耗也不断增加,对生态环境造成污染和破坏,人们开始将目光转向绿色建筑施工。本文立足于绿色建筑设计理念,以大连市某办公大楼设计为例,从土地利用、室外环境设计等方面深入剖析,结合施工要求,通过施工用材、围护结构、窗墙比及照明系统的设计选用,实践绿色设计理念,达到节能环保、减少能源浪费和环境污染的目的。以期为绿色建筑设计的应用提供参考。

关键词：大连绿色建筑设计应用绿色施工

基于偏移-份额分析法的我国区域创新质量及其影响因素研究

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科技管理研究 2022年第22期42卷 86-95页

作者：张林陈云涛李培祥广西大学经济学院广西南宁530004 广州理工学院工商管理学院广东广州510540

鉴于目前创新质量动态分析不足,在中观区域视角下,基于2007—2019年我国3类专利申请数据,利用偏移-份额分析法,综合考虑区域发明专利占国家总体和本地区比例情况,分别计算出我国31个省份创新的国家平均份额、结构份额和竞争力份额,考察... 详细信息

鉴于目前创新质量动态分析不足,在中观区域视角下,基于2007—2019年我国3类专利申请数据,利用偏移-份额分析法,综合考虑区域发明专利占国家总体和本地区比例情况,分别计算出我国31个省份创新的国家平均份额、结构份额和竞争力份额,考察各地实施“专利倍增计划”对创新质量的影响,同时基于一般生产过程理论分析创新质量的影响因素。结果发现:对于区域创新质量,以结构份额来衡量更加合理;R&D经费投入、R&D机构课题数的增长具有促进作用,其作用效果均在“专利倍增计划”实施前更加显著;R&D人员投入的影响呈正“U”型趋势;高新技术企业产值占地区生产总值的比例越高反而影响越不利;不同发展阶段的技术市场的影响不尽相同。根据研究结论,提出加强实施高质量创新战略、加大R&D内部经费投入、优化R&D人员投入和建立高质量技术市场等促进区域创新质量提升的对策建议。

关键词：创新质量结构份额区域创新发明专利偏移-份额分析法

Meridional deflection of global eddy propagation derived from tandem altimetry: Mechanism and implication

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Science China Earth Sciences 2024年第3期67卷 811-825页

作者： Ge chen Xiaoyan chen Frontiers Science Center for Deep Ocean Multispheres and Earth System School of Marine TechnologyOcean University of ChinaQindao 266100China Laboratory for Regional Oceanography and Numerical Modeling Laoshan LaboratoryQindao 266237China

A common view on meridional deflection of eddy propagation is poleward for cyclones and equatorward for anticyclones. This widely accepted polarity-sensitive pattern has been increasingly undermined given that it is systematically violated on both zonal and regional scales as recently reported. Here, we approach the problem by exploring these violations in terms of eddy effects of spatiotemporal geostrophy, thermal fading, and flow dragging, yielding the following main conclusions.(1) The polarity-dependent deflection discrepancy is a pseudo feature resulting from a biased fit to the normalized eddy tracks which are spatially asymmetric(though azimuthally symmetric) between the two signs;Instead, the primary pattern of eddy deflection appears to be geographically correlated and polarity independent.(2) Geostrophic adjustment plays a critical role in defining the meridional movement of an eddy. Specifically, a consistent poleward(equatorward) trajectory bending of spatially(temporally) ageostrophic eddies is observed irrespective of their polarity.(3) The mechanism of eddy deflection is also determined by its zonal propagation direction. Westward propagating eddies are substantially affected by thermal fading, while opposite ones by flow dragging. A realistic and comprehensive understanding of eddy deflection mechanisms serves as a significant contribution to the prediction of eddy trajectory, and the protection of ocean environment.

关键词： Mesoscale eddies Eddy propagation Eddy meridional deflection Satellite observation Geostrophic adjustment

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