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Circularly polarized lasing from chiral metal-organic frameworks

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Photonics Research 2024年第8期12卷 1654-1664页

作者： DEXIANG ZHU ZHOUYUANHANG WANG XIANGYU XU wenyu du WEI HUANG YAN KUAI BENLI YU JIANZHONG ZHENG ZHIJIA HU SIQI LI Information Materials and Intelligent Sensing Laboratory of Anhui Province Hefei 230601China School of Physics and Optoelectronic Engineering Anhui UniversityHefei 230601China Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of Education Hefei 230601China School of Environmental Science and Engineering Nanjing Tech UniversityNanjing 211816China

Circularly polarized lasers play a pivotal role in classical optics,nanophotonics,and quantum optical information processing,while their fabrication remains *** article begins with examining the interactions between stimulated emission and chiral matter,outlining a simple strategy for producing circularly polarized lasing from chiral metal-organic frameworks(MOFs),such as the zeolitic imidazolate framework(ZIF),embedded with achiral laser dyes(L∕D-ZIF?dyes).It is found that the stimulated emission threshold and intensity are influenced by the interplay between the chiral polarization of the pump light and the inherent chirality of the MOF *** further present the design of a chiral vertical-cavity surface-emitting laser(VCSEL),comprising an L∕D-ZIF?dyes solid-state film sandwiched between a high-reflectivity distributed Bragg reflector(DBR)mirror and a silver *** cavity-based lasing exhibits higher asymmetry between emitting left-handed and right-handed polarized light compared to chiral spontaneous emission(SE)and amplified spontaneous emission(ASE),with an asymmetry value glum of approximately±*** value is nearly four-fold greater than that of SE and twice that of *** findings reveal a new approach to amplify chiral signals,promoting the comprehension and application of chiral–matter interactions,and offering a simple yet effective strategy to fabricate chiral lasers.

关键词： chiral polarized lasing

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新质生产力助推能源结构低碳转型研究

中国矿业大学学报（社会科学版） 2024年第5期26卷 47-66页

作者：刘帅杜文宇辽宁工程技术大学工商管理学院

加快能源结构低碳转型是实现可持续发展的重要举措,新质生产力的形成正推动能源利用方式的革新,为能源结构低碳转型提供了新的动力。基于2012—2022年中国30个省份(含直辖市)的数据,构建评价指标体系测算新质生产力水平,实证分析新质生... 详细信息

加快能源结构低碳转型是实现可持续发展的重要举措,新质生产力的形成正推动能源利用方式的革新,为能源结构低碳转型提供了新的动力。基于2012—2022年中国30个省份(含直辖市)的数据,构建评价指标体系测算新质生产力水平,实证分析新质生产力对能源结构低碳化的影响程度及过程,并讨论产业结构升级和产业集聚在影响过程中的传导作用机制,同时检验环境规制发挥的调节作用。研究结果表明:新质生产力对能源结构低碳转型有较强的带动作用,且这种影响随时间变化逐渐增大;新质生产力可以通过推动产业结构升级和产业集聚的双重渠道促进能源结构低碳转型;环境规制对新质生产力和能源结构低碳转型之间的关系有显著的负向调节作用;新质生产力对能源结构低碳转型的影响存在地域差异,西部和可再生能源丰富的地区受新质生产力的促进作用更为显著。基于此,应大力发展新质生产力,加快产业结构升级步伐,发挥绿色产业集聚效应,并实施区域差异化策略。

关键词：新质生产力能源结构低碳化产业结构产业集聚环境规制

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基于语义边界增强的司法命名实体识别

清华大学学报（自然科学版） 2024年第5期64卷 749-759页

作者：张天宇孙媛媛杜文玉邢铁军林鸿飞杨亮大连理工大学计算机学院大连116024 最高人民检察院检察技术信息研究中心北京100726 东软集团股份有限公司大连116024

法律文书命名实体识别是智慧司法的关键任务。现有的序列标注模型仅关注字符信息,导致在法律文书命名实体识别任务中无法获得语义和词语的上下文信息,且无法对实体的边界进行限制。因此,该文提出了一个融合外部信息并对边界限制的司法... 详细信息

法律文书命名实体识别是智慧司法的关键任务。现有的序列标注模型仅关注字符信息,导致在法律文书命名实体识别任务中无法获得语义和词语的上下文信息,且无法对实体的边界进行限制。因此,该文提出了一个融合外部信息并对边界限制的司法命名实体识别模型(semantic and boundary enhance named entity recognition,SBENER)。该模型收集了40万条盗窃罪法律文书,首先,预训练模型,将获得的司法盗窃罪词向量作为输入模型的外部信息;其次,设计Adapter,将司法盗窃罪的信息融入字符序列以增强语义特征;最后,使用边界指针网络对实体边界进行限制,解决了序列标注模型丢失词语信息及缺少边界限制的问题。该模型在CAILIE 1.0数据集和LegalCorpus数据集上进行实验,结果表明,SBENER模型在2个数据集上的F_1值(F_1-score)分别达88.70%和87.67%,比其他基线模型取得了更好的效果。SBENER模型能够提升司法领域命名实体识别的效果。

关键词：法律文书外部法律信息实体边界命名实体识别

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镁合金板材弯曲回弹预测与控制研究进展

材料导报 2024年第15期38卷 70-76页

作者：计鸿鑫任伟杰蒋先贤杜文宇孙静娜黄华贵国家冷轧板带装备及工艺工程技术研究中心河北秦皇岛066004 燕山大学机械工程学院河北秦皇岛066004

镁合金是最轻的工程金属材料,在新能源汽车、航空航天等领域具有广阔的应用前景,而在这些领域中广泛存在弯曲变形。但镁合金弹性模量较低,室温弯曲成形回弹量大且不易控制,严重影响构件成形精度和后期服役性能,精确预测和控制镁合金回... 详细信息

镁合金是最轻的工程金属材料,在新能源汽车、航空航天等领域具有广阔的应用前景,而在这些领域中广泛存在弯曲变形。但镁合金弹性模量较低,室温弯曲成形回弹量大且不易控制,严重影响构件成形精度和后期服役性能,精确预测和控制镁合金回弹仍是目前亟待解决的重要问题。近年来,为了提高镁合金的成形精度,并扩大其工业化应用,各国学者针对镁合金板材弯曲回弹预测及控制方法进行了大量研究。本文综述了镁板弯曲回弹预测与控制的最新研究进展,介绍了常见的镁合金回弹预测手段,对比分析了镁合金回弹的影响因素与控制方法,最后对镁板弯曲回弹未来研究重点进行了展望。

关键词：镁合金弯曲回弹预测控制

Drimane-type sesquiterpenoids from fungi

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Chinese Journal of Natural Medicines 2022年第10期20卷 737-748页

作者： du wenyu YANG Qian XU Huimin DONG Liaobin State Key Laboratory of Natural Medicines School of Traditional Chinese PharmacyChina Pharmaceutical UniversityNanjing 211198China The Public Laboratory Platform China Pharmaceutical UniversityNanjing 211198China

Sesquiterpenoids are comprised of three Cs units and derived from farnesyl *** these Cis family of terpenoids,drimane-type sesquiterpenoids are unique as their chemical structure of decahydronaphthalene along with the methyl group decorations resemble the A/B rings of labdane derived diterpenoids and the eastern part of many *** the past decades,based on their chemical structural features and diverse bioactivities,great efforts have been made to perform chemical and biological research on this family of natural products,leading to the characterization of a large of new compounds and a few biosynthetic *** this review,we collected 164 new drimane-type sesquiterpenoids from fungi between January 2004 and October 2021 and classified them into three major subfamilies,so as to highlight their diverse chemical structures,biological activities,and biosynthetic pathways.

关键词： Drimane-type sesquiterpenoids Fungi Chemical structures Bioactivity Biosynthesis

Digital Entrepreneurship Ecosystem as a New Form of Organizing： The Case of Zhongguancun

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Frontiers of Business Research in China 2017年第1期11卷 69-100页

作者： Wenjie Li wenyu du Jiamin Yin Department of Management Science School of Business Renmin University of China Beijing100872 China School of EConomics and Management Beihang University Beijing 100083 China

Digital innovation is becoming increasingly important in today＇s economy. Many digital innovations are developed not within organizations, but in innovation-driven entrepreneurial ecosystems, where various entrepreneurship related stakeholders collaborate and cooperate. Despite its significance, studies on digital entrepreneurship ecosystems （DEEs） are limited and the concept is largely undertheorized. This study intends to fill that gap by studying how a DEE organizes. This organizing issue is challenging, because stakeholders of a DEE are self-organizing and are not governed by any formal authority. To answer that question, we adopt forms of organizing as a theoretical lens, which provides structure to examine organizing issues. Through an in-depth case study of Zhongguancun, the Silicon Valley of China, we unveil eight processes around the themes of division of labor and integration of efforts. We further show that the forms of organizing feature a balance of centralized design and de-centralized emergence. This balanced view extends the forms of organizing literature, which takes an either/or perspective. Ecosystem architects and policy makers who intend to build entrepreneurship ecosystems to promote local economies can derive practical implications from our findings.

关键词： digital entrepreneurship ecosystem new forms of organizing case study

Functional characterization of a cycloartenol synthase and four glycosyltransferases in the biosynthesis of cycloastragenol-type astragalosides from Astragalus membranaceus

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Acta Pharmaceutica Sinica B 2023年第1期13卷 271-283页

作者： Yangyang duan wenyu du Zhijun Song Ridao Chen Kebo Xie Jimei Liu Dawei Chen Jungui Dai State Key Laboratory of Bioactive Substance and Function of Natural Medicines CAMS Key Laboratory of Enzyme and Biocatalysis of Natural DrugsNHC Key Laboratory of Biosynthesis of Natural ProductsInstitute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China

Astragalosides are the main active constituents of traditional Chinese medicine Huang-Qi,of which cycloastragenol-type glycosides are the most typical and major bioactive *** kind of compounds exhibit various biological functions including cardiovascular protective,neuroprotective,*** to the limitations of natural sources and the difficulties encountered in chemical synthesis,re-engineering of biosynthetic machinery will offer an alternative and promising approach to producing ***,the biosynthetic pathway for astragalosides remains elusive due to their complex structures and numerous reaction types and ***,guided by transcriptome and phylogenetic analyses,a cycloartenol synthase and four glycosyltransferases catalyzing the committed steps in the biosynthesis of such bioactive astragalosides were functionally characterized from Astragalus ***1,the first reported cycloartenol synthase from Astragalus genus,is capable of catalyzing the formation of cycloartenol;AmUGT15,AmUGT14,AmUGT13,and AmUGT7 are four glycosyltransferases biochemically characterized to catalyze 3-O-xylosylation,3-O-glucosylation,25-O-glucosylation/O-xylosylation and 2’-O-glucosylation of cycloastragenol glycosides,*** findings not only clarified the crucial enzymes for the biosynthesis and the molecular basis for the structural diversity of astragalosides in Astragalus plants,also paved the way for further completely deciphering the biosynthetic pathway and constructing an artificial pathway for their efficient production.

关键词： Cycloastragenol-type astragalosides Cycloartenol synthase Glycosyltransferase Biosynthesis Astragalus membranaceus

Picosecond gain-switched polymer fiber random lasers

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Chinese Optics Letters 2024年第4期22卷 20-25页

作者：杜文彧高森张小娟李思祺蒯雁王治强曹志刚徐峰刘宇徐林张俊喜谢康俞本立胡志家 Information Materials and Intelligent Sensing Laboratory of Anhui Province Key Laboratory of Opto-Electronic Information Acquisition and Manipulation of Ministry of EducationSchool of Physics and Opto-electronics EngineeringAnhui UniversityHefei 230601China School of Instrument Science and Opto-electronics Engineering Laboratory of Optical Fibers and Micro-nano PhotonicsHefei University of TechnologyHefei 230009China School of Opto-electronic Engineering Zaozhuang UniversityZaozhuang 277160China

Random lasers are a type of lasers that lack typical resonator structures,offering benefits such as easy integration,low cost,and low spatial *** features make them popular for speckle-free imaging and random number ***,due to their high threshold and phase instability,the production of picosecond random lasers has still been a *** this work,we have developed three dyes incorporating polymer optical fibers doped with various scattering nanoparticles to produce short-pulsed random fiber ***,stable picosecond random laser emission lasting600 ps is observed at a low pump energy of 50μJ,indicating the gain-switching *** inversion and gain undergo an abrupt surge as the intensity of the continuously pumped light nears the threshold *** the intensity of the continuously pumped light reaches a specific value,the number of inversion populations in the“scattering cavity”surpasses the threshold *** results based on a model that considers power-dependent gain saturation confirmed the above *** research helps expand the understanding of the dynamics behind random medium-stimulated emission in random lasers and opens up possibilities for mode locking in these systems.

关键词： random laser polymer optical fiber gain-switched laser picosecond pulse

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哈密瓜农药残留检测及风险评估

中国果菜 2024年第10期44卷 7-12页

作者：闫新焕许敏刘雪梅杜文瑜范艺璇黄勇平中华全国供销合作总社济南果品研究所山东济南250220 海南省食品检验检测中心海南海口570314

为明确哈密瓜样品中的农药残留现状并评估其慢性膳食摄入风险,本研究采用QuEChERS样品前处理方法,结合超高效液相色谱-串联质谱(UPLC-MS/MS)、气相色谱串联质谱(GC-MS/MS),对哈密瓜样品中可能存在的156种农药含量进行测定,并采用慢性膳... 详细信息

为明确哈密瓜样品中的农药残留现状并评估其慢性膳食摄入风险,本研究采用QuEChERS样品前处理方法,结合超高效液相色谱-串联质谱(UPLC-MS/MS)、气相色谱串联质谱(GC-MS/MS),对哈密瓜样品中可能存在的156种农药含量进行测定,并采用慢性膳食摄入风险评估模型进行慢性膳食摄入风险评估。结果表明,哈密瓜样品的农残阳性检出率为81.8%,共检出22种农药。其中,腐霉利和多菌灵的检出率较高,分别为68.2%和45.5%。4~6岁儿童、孕妇及一般人群食用哈密瓜摄入农药的膳食风险均远低于100%。综上,哈密瓜中普遍存在农药残留,但残留水平不高,膳食摄入风险均在可接受范围内,正常食用不会对人体健康造成危害,从而为哈密瓜的质量安全监管提供科学依据,也可为消费者提供参考。

关键词：哈密瓜 QuEChERS 超高效液相色谱-串联质谱气相色谱串联质谱农药残留