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Styrene epoxidation catalyzed by polyoxometalate/quaternary ammonium phase transfer catalysts: The effect of cation size and catalyst deactivation mechanism

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Chinese Journal of Chemical Engineering 2023年第3期55卷 192-201页

作者： Qiongna Xiao yuyan jiang Weiqiang Yuan Jingjing Chen Haohong Li Huidong Zheng College of Chemical Engineering Fuzhou UniversityFuzhou 350116China Qingyuan Innovation Laboratory Quanzhou 362801China Engineering Research Center of Advanced Manufacturing Technology for Fine Chemicals Fujian Province UniversityFuzhou UniversityFuzhou 350116China College of Chemistry Fuzhou UniversityFuzhou 350116China

Catalytic epoxidation of alkenes is an important type of organic reaction in chemical industry,and the deep insight into catalyst deactivation will help to develop new epoxidation *** this work,series of quaternary ammoniums bearing different cationic sizes,***+(methyltrioctylammonium,[(C_(8)H_(17))_(3)CH_(3)N]+),HTMA+(hexadecyltrimethylammonium,[(C_(16)H_(33))(CH_(3))_(3)N]+) and DMDOA+(dimethyldioctadecylammonium,[(C_(18)H_(37))_(2)(CH_(3))_(2)N]+) were incorporated with polyoxometalate (POM) anions to prepare phase transfer catalysts (PTCs),which were used in the styrene *** them,(MTOA)_(3)PW_(4)O_(24)exhibits the best catalytic performance judged from the highest styrene conversion rate(52%) and styrene oxide selectivity (93%),during which the styrene epoxidation conditions were ***,the deactivation mechanism of this kind of PTCs was proposed firstly,*** the case of low H_(2)O_(2) content,the oxidant can only be used in the styrene epoxidation,in which the catalyst can transform into stable Keggin-type *** when the content of H_(2)O_(2) is higher,the excess H_(2)O_(2) can reactivate the Keggin-type POM into active (PW_(4)O_(24))_(3)-anions,which can trigger the ring-opening polymerization of styrene ***,the catalyst is deactivated by adhered poly(styrene oxide)irreversibly,which was determined by NMR *** this situation,the active moiety{PO_(4)[WO(O_(2))_(2)]_(4)}_(3)-in phase-transfer catalytic system can break into some unidentified species with low W/P ratio with the presence of *** work will be beneficial for the design of new PTCs in alkene epoxidation in fine chemical industry.

关键词： Phosphotungstic acid phase-transfer catalyst Styrene epoxidation Catalyst deactivation mechanism Cation size effect

Cell cycle regulation through primary cilium:A long-forgotten story

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BIOCELL 2021年第4期45卷 823-833页

作者： LIN LIU ZHOUWEN XU yuyan jiang MD REZAUL KARIM XIAO HUANG Institute of Cell and Developmental Biology College of Life SciencesZhejiang UniversityHangzhou310058China

Protruded from cytomembrane,primary cilium is a widespread cell organelle that can be found in almost all cell types in *** of its comprehensive requirement in various cellular activities and various functions in different organs,primary cilium has been a valuable research area of human pathology research since the turn of the *** the potential application of the interaction between primary cilia and cell cycle regulation may be the most promising direction as many primary cilium-caused diseases are found to be caused by cell cycle dysregulation resulted from primary cilia ***,a deep understanding of the interaction between primary cilia and the cell cycle is in great *** in this review,we mainly described how the interaction between primary cilia and cell cycle proceeds and demonstrated three hypotheses raised from much different *** hypotheses include(1)Primary cilium as a cellular signaling hub to regulate the cell cycle,(2)Primary cilium as a reservoir of cell cycle regulation-related factors,and(3)Primary cilium as a cell cycle checkpoint or a ***,we also call for more attention on research of interaction between cell cycle and primary cilia and tried to point out some possible research directions for those who are interested.

关键词： Signaling pathway Cell cycle checkpoint Ciliopathy Cancer

Economic Policy Uncertainty,Heterogeneity of Executives and Enterprise Innovation

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Journal of Business Administration Research 2021年第3期4卷 36-50页

作者： Xun Han yuyan jiang Xianjing Huang Beijing International Studies University Beijing102601China Guangxi University of Finance and Economics NanningGuangxi530003China

This study analyzes how economic policy uncertainty affects corporate innovation,and the moderating effects of executive heterogeneity.A threephase dynamic investment and financing model is first built to analyze the *** analysis confirms that the increase in the degree of economic policy uncertainty promotes enterprise *** results show that this promotion effect is more significant in enterprises with male executives,low educational level,no financial experience and political ***,the positive impact is only found in enterprises with moderate executive ability,and the overconfidence of senior executives plays a positive regulating role in it.

关键词： Economic policy uncertainty Executive heterogeneity R&D Political association

Epidemiological Evaluation of Bacillus cereus-Induced Foodborne Outbreaks — China, 2010–2020

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China CDC weekly 2023年第33期5卷 737-741页

作者： Shenggang Duan Yue Yu Yunchang Guo Donglei Lu Ning Li Zhitao Liu Jinjun Liang yuyan jiang Santao Wang Ping Fu Jikai Liu Hong Liu Shanghai Municipal Center for Disease Control and Prevention ShanghaiChina NHC Key Laboratory of Food Safety Risk Assessment Food Safety Research Unit(2019RU014)of Chinese Academy of Medical Science China National Center for Food Safety Risk AssessmentBeijingChina Yunnan Provincial Center for Disease Control and Prevention Kunming CityYunnan ProvinceChina Hunan Provincial Center for Disease Control and Prevention Changsha CityHunan ProvinceChina Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention Nanning CityGuangxi Zhuang Autonomous RegionChina Shanxi Provincial Center for Disease Control and Prevention Taiyuan CityShanxi ProvinceChina.

Introduction:Bacillus cereus(***)is a common gram-positive bacterium that contaminates starch-rich food and can cause outbreaks of foodborne *** study describes characteristics of outbreaks caused by *** in China during 2010–2020 and explore the possible reasons for changes in the number of outbreaks over *** of this analysis can efficiently help guide and allocate public resources to prevent *** caused foodborne ***:Descriptive statistical methods were used to analysis the data on *** outbreaks in China during this *** data were identified,reported at all levels in China through National Foodborne Disease Outbreak Surveillance ***:From 2010 to 2020,a total of 419 foodborne outbreaks prompted by *** were reported in China,leading to 7,892 cases,2,786 hospital admissions,and 5 *** bulk of the outbreaks were recorded in the summer,primarily between May and *** most recurrent food vehicle was linked with rice or flour-based products,notably those made with rice or fried *** canteens bore the brunt of the *** *** multifactor outbreaks,food contamination was identified as the most common culprit;while in instances where only one factor contributed,improper storage was most frequently ***:The prevalence of *** outbreaks remained relatively consistent throughout the studied *** the types of foods,causative factors,and contributing elements leading to *** outbreaks can help inform prevention strategies for foodborne *** majority of outbreaks were associated with rice-or flour-based foods in school canteens,suggesting contamination and improper storage during food ***,it is essential to prioritize continuous education for canteen staff on food safety,efficacious management,and proper *** implementation of comprehensive guidelines,encompassing multiple critical aspects,can po

关键词： prevention prompt instance

pH-sensitive and biodegradable charge-transfer nanocomplex for second near-infrared photoacoustic tumor imaging

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Nano Research 2019年第1期12卷 49-55页

作者： Zhimin Wang Paul Kumar Upputuri Xu Zhen Ruochong Zhang yuyan jiang Xiangzhao Ai Zhijun Zhang Ming Hu Zhenyu Meng Yunpeng Lu Yuanjing Zheng Kanyi Pu Manojit Pramanik Bengang Xing Division of Chemistry and Biological Chemistry School of Physical&Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore School of Chemical and Biomedical Engineering Nanyang Technological University70 Nanyang DriveSingapore 637459Singapore School of Electrical and Electronic Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798Singapore

The emerging technique of photoacoustic imaging,especially in the near infra-red(NIR)window,permits high resolution,deep-penetration,clinically reliable ***,few contrast agents are available that can specifically respond to intricate biological environments,and which are biodegradable and ***,we in troduce a new class of pH-sensitive orga nic photoacoustic con trast age nt that operates in the second NIR window(NIR-II,960-1,700 nm),which is derived from the self-assembled charge-transfer nanocomplex(CTN)by 3,3',5,5'-tetramethylbenzidine(TMB)and its dication structure(TMB++).The unique NIR-ll-responsive CTN can specifically respond to pH change in the physiological range and allows noninvasive and sensitive visualization of the tumor acidic microenvironment(*** pH5)in mice with higher signal-to-noise *** CTN is biodegradable under physiological conditions(*** 7.4),which alleviates the biosafety concern of nan oparticle accumulati on in *** results clearly show the pote ntial of the TMB/TMB++-based CTN as a promisi ng pH-activated and biodegradable molecular probe for specific tumor photoacoustic imaging in the NIR-II region.

关键词： charge-transfer nanocomplex second near-infrared window photoacoustic imaging pH-sensitive biodegradable tumor acidic microenvironment

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环境规制影响企业绿色创新的异质性分析

工程管理科技前沿 2024年第4期43卷 83-89页

作者：姜玉砚山西财经大学管理科学与工程学院山西太原030006

本文将环境规制与企业绿色创新纳入统一的分析框架,考察环境规制对企业绿色创新的影响机制,并重点关注绿色专利类型维度、企业所有制维度以及行业属性维度的异质性特征。研究发现:整体而言,环境规制对企业绿色创新具有U型非线性影响,当... 详细信息

本文将环境规制与企业绿色创新纳入统一的分析框架,考察环境规制对企业绿色创新的影响机制,并重点关注绿色专利类型维度、企业所有制维度以及行业属性维度的异质性特征。研究发现:整体而言,环境规制对企业绿色创新具有U型非线性影响,当环境规制强度超过一定临界值后,其对企业绿色创新的影响将由抑制效应转变为促进效应;相较于绿色实用新型专利,环境规制对绿色发明专利的影响更加突出;环境规制对非制造业企业绿色创新表现为单调的促进效应,对制造业企业绿色创新的影响则为U型;同时,环境规制对不同所有制企业绿色创新的影响均为U型,但非国有企业所面临的临界值明显更小。据此提出,环境规制策略的制定不能“一刀切”,而应积极设计差异化的环境规制策略。

关键词：环境规制绿色创新异质性 U型

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经济转型和城镇化背景下的区域产业布局优化研究——基于山西的实证

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城市发展研究 2012年第12期19卷 166-169页

作者：姜玉砚山西财经大学管理科学与工程学院

产业布局的优化和资源型城市经济转型及城镇化是互促互进的良性互动关系。在对山西产业布局和城镇化的现状及问题的研究基础上,认为应该通过以"一核一圈三群"的"人"字形城镇化格局为依托,选择具有区位优势的主导产业优先发展;优化三次... 详细信息

产业布局的优化和资源型城市经济转型及城镇化是互促互进的良性互动关系。在对山西产业布局和城镇化的现状及问题的研究基础上,认为应该通过以"一核一圈三群"的"人"字形城镇化格局为依托,选择具有区位优势的主导产业优先发展;优化三次产业布局,升级调整三次产业之间和各产业内部结构;以产业链延伸为导向进行多元化发展,加快资源型经济平稳转型;强化开发区和产业集聚区建设,增强城镇化产业布局的合理推动力等路径优化山西产业布局。

关键词：经济转型城镇化产业布局山西

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阿根廷“国宝”马黛茶的种植史演变

农业考古 2023年第2期 202-208页

作者：姜玉妍南开大学历史学院拉丁美洲研究中心

马黛茶被誉为阿根廷的“国宝”,出口远销至欧洲、中东、东亚等地。马黛茶的原始种植最早始于殖民前期的巴拉圭地区,西班牙殖民者的到来使马黛茶消费在殖民地区开始蔓延,但最初被殖民当局视作恶习而禁止饮用。17至18世纪,耶稣会通过人工... 详细信息

马黛茶被誉为阿根廷的“国宝”,出口远销至欧洲、中东、东亚等地。马黛茶的原始种植最早始于殖民前期的巴拉圭地区,西班牙殖民者的到来使马黛茶消费在殖民地区开始蔓延,但最初被殖民当局视作恶习而禁止饮用。17至18世纪,耶稣会通过人工培育形成大型马黛茶种植园,使马黛茶在拉普拉塔河流域迅速实现商业化运行与发展。拉美独立运动后,巴西曾一度成为马黛茶生产大国,但1870年三国同盟战争后,阿根廷的米西奥内斯政府通过移民和农业扩张使得当地重新成为马黛茶的主要种植和消费区,塑造了当地小农户与大庄园并存的双元制农业结构。20世纪30年代,米西奥内斯的马黛茶种植达到顶峰,但此后却陷入了生产性扩张和危机轮替的经济周期。新自由主义改革后,随着马黛茶进入现代化生产和大规模分销模式,消费与出口不断增加,成为阿根廷及南美各国的民族象征。

关键词：马黛茶阿根廷种植史

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方管两相流中微液膜的测量与分析

工程热物理学报 2022年第7期43卷 1911-1915页

作者：张鹏姜玉雁王涛中国科学院工程热物理研究所北京100190 中国科学院大学北京100049

在微通道流动沸腾换热中,微液膜的蒸发对其起到了至关重要的作用,本文探究了0.6 mm方管在气液两相流条件下的液膜厚度变化,实验通过激光共聚焦位移计测量液膜厚度和高速相机采集图像,实现了同步测量。实验发现,当气泡速度小于1.27 m/s时... 详细信息

在微通道流动沸腾换热中,微液膜的蒸发对其起到了至关重要的作用,本文探究了0.6 mm方管在气液两相流条件下的液膜厚度变化,实验通过激光共聚焦位移计测量液膜厚度和高速相机采集图像,实现了同步测量。实验发现,当气泡速度小于1.27 m/s时,液体会集中在方管的四角,不会形成液膜;当气泡速度为1.21~2.71 m/s时,会在管壁形成液膜,液膜的变化呈阶梯式,并且随着气泡速度增大而增大;当气泡速度大于3.21 m/s时,流型会转变为环状流,液膜厚度会开始出现振荡。

关键词：气液两相流微方管液膜厚度同步测量