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Frontiers of Materials Science 2019年第2期13卷 126-132页

作者： Chengzhi YANG Shikun CHEN Huilan SU Haoyue ZHANG Jianfei TANG Cuiping GUO Fang SONG Wang ZHANG Jiajun GU Qinglei LIU State Key Laboratory of Metal Matrix Composites School of Materials Science and Engineering Shanghai Jiaotong University Shanghai 200240 China

Biocompatible, small-sized but well-dispersed gold nanoparticles (Au nps) remain a major challenge for their synthesis. Here a convenient solution impregnation technique is developed to prepare such Au nps under the regulation of degummed silk fibroin fibers (SFFs) extracted from Bombyx mori cocoons. SFFs play multiple roles in the formation of Au nps such as reactive substrate to capture AuCl4^- ions by the chelation of -C = 0, reducing agent for Au(0) by the reduction of -OH , and modifiers to render biocompatible Au nps by some functional groups and biomolecules. The as-prepared Au nps with a size of 7-10 nm are embedded in the solid SFF substrate, and can disperse well in the liquid system by the disintegration of SFFs into silk fibroin (SF) in a certain CaCl2 solution. The biocompatible Au nps exhibit uniform small size and distribute stably in both solid and solution states, which have distinctive properties and functional advantages, and bring great convenience to their storage and transportation.

关键词： Au nps biocompatibility small size dispersivity silk fibroin fiber

Non-Point Pollution from Crop Production: Global, Regional and National Issues

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Pedosphere 2005年第4期15卷 499-508页

作者： D. NORSE Department of Geography University College London 4 Taviton Street London WC1H 0BT (UK)

China is now the world’s largest producer and user of industrial fertilizers and manures. Consequently China plays a substantial role in global N cycle dynamics and in man’s disruption of the nitrogen cycle though there are still significant uncertainties about the size and importance of emission and leaching rates. A major cause of China’s global role is the overuse of nitrogen fertilizers, which is most serious with intensive vegetable production where application rates can be up to 50% greater than crop needs, but is also a problem with wheat, rice and maize. China’s overuse of nitrogen fertiliser over the past 10-20 years has resulted in non-point source (nps) pollution from crop production becoming a major cause of water pollution, and the situation is projected to get worse. In contrast, water pollution from point sources such as intensive livestock production and urban or industrial development is being brought more under control. The consequences for air pollution are equally serious. Emissions of nitrous oxide from fertilizers and manures may be so large that China could be responsible for 25-30% of global emissions of this damaging greenhouse gas and of the global warming resulting from it. The main national and local issues relate particularly to low fertilizer use efficiency and the losses of ammonia and NOx that lead to acid precipitation, and leaching and run-off losses that result in high nitrate levels in groundwater and eutrophication of rivers and lakes. The reasons why farmers overuse nitrogen fertilizer are complex and not fully understood. They involve agro-climate differences between provinces and counties, farming systems and farm income structures. Although there is a wide range of institutional and technological improvements that can greatly reduce this overuse rapid progress in reducing nps is unlikely.

关键词：农作物中国肥料氮肥 nps 土壤肥力

Computer simulation studies on the interactions between nanoparticles and cell membrane

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Science China Chemistry 2014年第12期57卷 1662-1671页

作者： TIAN Fa Lin YUE Tong Tao LI Ye ZHANG Xian Ren State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical Technology State Key laboratory of Heavy Oil Processing Center for Bioengineering and BiotechnologyChina University of Petroleum (East China)

In recent times,nanoparticles(nps)have received intense attention not only due to their potential applications as a candidate for drug delivery,but also because of their undesirable effects on human health.Although extensive experimental studies have been carried out in literature in order to understand the interaction between nps and a plasma membrane,much less is known about the molecular details of the interaction mechanisms and pathways.As complimentary tools,coarse grained molecular dynamics(CGMD)and dissipative particle dynamics(DPD)simulations have been extensively used on the interaction mechanism and evolution pathway.In the present review we summarize computer simulation studies on the NP-membrane interaction,which developed over the last few years,and particularly evaluate the results from the DPD technique.Those studies undoubtedly deepen our understanding of the NP-membrane interaction mechanisms and provide a design guideline for new nps.

关键词：相互作用机制计算机模拟纳米粒子细胞膜耗散粒子动力学分子动力学 nps 人体健康

Poly(Dimethylbenzimidazolium) Iodide Assisted Dispersion of Multiwalled Carbon Nanotubes and Their Palladium Nanoparticle Hybrid

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Journal of Shanghai Jiaotong university(Science) 2018年第S1期23卷 132-136页

作者：张燕黎宇平潘丽静薛敏钊王巍胡祖明 School of Chemistry and Chemical Engineering Shanghai Jiao Tong University College of Materials Science and Engineering Donghua University

The multi walled carbon nanotubes(MWNTs) have always been as the catalyst supporting materials,but for high-performance composite catalysts, the dispersion and functionalization of MWNTs are important challenging problems. In this paper, Electrocatalytically active palladium nanoparticles(Pd nps) on MWNTs with the high-performance and excellent solubility polymer, poly(dimethylbenzimidazolium) iodide(P(DMBI)-I-)as modifier and glue was first discussed. The results of transmission electron microscopy(TEM) demonstrate a better dispersion of MWNTs with the assist of P(DMBI)-I-. The Raman spectra indicate a strong π-π interaction between MWNTs and P(DMBI)-I-. Taking advantages of the coordination effect of imidazole groups and the electrostatic attraction to Pd nps, the prepared Pd/MWNTs-P(DMBI)-I-(Pd/MPDI-) hybrid is of well electrocatalytic activity to the ethanol fuel cells by electrochemical measurements. So it is believed that P(DMBI)-Ican be further applied in the dispersion of different carbon-based materials and metal nanoparticles for fabricating more novel composites for catalyst and electrode material.

关键词： MWNTs P(DMBI)-I- Pd nps electro-catalytic activity ethanol

Characterization,occurrence,environmental behaviors,and risks of nanoplastics in the aquatic environment:Current status and future perspectives

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Fundamental Research 2021年第3期1卷 317-328页

作者： Junyu Wang Xiaoli Zhao Fengchang Wu Lin Niu Zhi Tang Weigang Liang Tianhui Zhao Mengyuan Fang Hongzhan Wang Xiaolei Wang State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China College of Water Sciences Beijing Normal UniversityBeijing 100875China

Microplastics(MPs)are emerging contaminants that have attracted worldwide attention in recent years.Compared with MPs,nanoplastics(nps)may exhibit greater toxicity and higher potential risks because of their unique physiochemical nanoscale properties.However,the environmental fate,ecosystem toxicity,and potential risks associated with nps have been less explored.This study summarizes the current research status of nps through a comprehensive bibliometric analysis.The research hotspots and future trends of nps were identified.We comprehensively searched the Web of Science Core Collection scientific database from its inception(2004)to November 26,2020.The results showed that the number of papers on nps has increased significantly since 2014.The keywords used in NP research were divided into three clusters.Cluster 1 related to the physical,chemical,and biological behaviors of nps in aquatic environments.Cluster 2 represented a relatively new and hot research field concerning the exposure,accumulation,and toxicity of nps in organisms.Cluster 3 corresponded to the identification and quantification of nps in marine environments and sediments.Moreover,we systematically elaborated the main areas of NP research,such as the characterization,occurrence,environmental behavior,ecological toxicity,and human health risks of nps.The results showed that the quantification of nps at environmentally relevant concentrations remains a challenge.Most studies have investigated polystyrene nps,spherical nps,and nps in marine environments,while few studies have examined the aggregation,deposition,and ecological toxicity of nps under environmentally relevant conditions.In addition,much less is known about the human health risks associated with nps because little research has been conducted on estimating the overall human exposure to nps and its effect.Finally,the current challenges and future perspectives of NP research are discussed.

关键词： nps Bibliometric analysis Characterization Environmental behavior Ecological toxicity Human health

A公司在线学习APP客户满意度提升策略研究

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A公司在线学习APP客户满意度提升策略研究

作者：李俊广西师范大学

学位级别：硕士

2020年底国家“十四五”规划提出要充分利用在线教育的优势,推动学习型社会的建设。在疫情期间,中国有将近两亿的中小学生面临不得不停课在家学习,各家在线教育机构纷纷推出形式多样的免费直播课,使得沉寂了十多年的互联网在线教育迎来... 详细信息

2020年底国家“十四五”规划提出要充分利用在线教育的优势,推动学习型社会的建设。在疫情期间,中国有将近两亿的中小学生面临不得不停课在家学习,各家在线教育机构纷纷推出形式多样的免费直播课,使得沉寂了十多年的互联网在线教育迎来了井喷式爆发。但好景不长,2021年第三季度,国家正式落地了关于减轻义务教育学龄学生校内和校外学业负担的“双减”政策,让疯狂“烧钱”发展的互联网在线教育正式进入了调整期,各互联网教育公司不得不一边配合政策对相关业务进行整改,一边寻找新的转型出路。对于互联网在线教育产品客户满意度,一直是困扰各教育机构市场营销的重要致命因素,客户满意度也最终影响到互联网在线教育公司,如何在激烈的竞争中持续发展经营下去。本论文以A公司的在线学习APP产品为例,研究双减背景下初中生客户对该产品的满意度的提升策略。通过使用定性与定量相结合的分析方法,对A公司整个APP端内产品满意度情况进行分析与论证,旨在准确地获得初中学生客户对A公司在线学习产品和服务的态度及成因,有针对性地为初中学生客户提供各种差异化、个性化的服务,提高初中学生客户的满意度,让A公司原本就有的注册客户可以在端内活跃使用,让通过各流量渠道引流来的新客户能够快速转化成为忠诚的活跃客户,在流量如此昂贵的今天,让A公司得以在激烈的竞争中胜出。本研究在当前教育“双减”政策的背景下,调查了A公司在线学习APP的发展现状,发现该APP正在面临着用户观望情绪较大,延迟购买且数量下降的问题。针对该问题,本文研究如何提高当前客户的满意度以期达到保留客户的目的。本文在现有客户满意度研究理论和模型的基础上,结合该在线学习APP产品的特点,设计了针对该在线学习APP产品客户满意度的评价指标,采用问卷调查的方式,收集了230份初中生客户的样本数据,利用SPSS 26.0软件、Spsspro在线统计分析软件进行分析和处理,采用主成分因子分析法获得影响客户满意度的三个主要因子,针对这三个因子分析该在线学习APP在客户满意度这方面存在的问题并分析了问题的成因。在问题和成因的基础上,本文分别针对这三个因子,从客户体验维度提出增加学习互动感、提高学习趣味性的提升策略,从功能维度提出优化界面丰富功能的提升策略,从课程维度提出结合教材更新和优化课程的提升策略,以期进一步改善该在线学习APP的客户满意度,从而达到保留客户的目的。

关键词：在线学习客户满意度影响因素 nps

亲水性FePt纳米颗粒协同催化有机污染物的降解

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高等学校化学学报 2020年第4期41卷 697-705页

作者：刘丛远刘佳杜佩瑶张振卢小泉天津市分子光电科学重点实验室天津大学理学院化学系天津300072

以半胱氨酸为配体,采用一锅法简便合成了亲水性的FePt纳米颗粒(nps).超小的FePt nps对水中常见有机污染物表现出良好的催化降解性能,以NaBH 4为还原剂时可实现对染料罗丹明B(RhB)和有害物质4-硝基苯酚(4-NP)的有效还原;以H 2O 2为氧化... 详细信息

以半胱氨酸为配体,采用一锅法简便合成了亲水性的FePt纳米颗粒(nps).超小的FePt nps对水中常见有机污染物表现出良好的催化降解性能,以NaBH 4为还原剂时可实现对染料罗丹明B(RhB)和有害物质4-硝基苯酚(4-NP)的有效还原;以H 2O 2为氧化剂时可实现亚甲基蓝(MB)的高效降解.实验结果表明,FePt nps对3种有机污染物的降解率均高于90%.对FePt原子对之间的协同催化机理进行了探讨,揭示了不同反应体系中微观反应历程和催化机理的区别.磁性测试结果表明,FePt催化剂可以通过外加磁场进行收集并重复利用,解决了催化剂二次污染问题.该研究为设计合成绿色环保催化剂提供了思路.

关键词：亲水性FePt nps 协同催化有机污染物降解可回收

Z证券公司财富管理业务客户关系管理优化研究

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Z证券公司财富管理业务客户关系管理优化研究

作者：杨鑫上海外国语大学

学位级别：硕士

伴随中国经济的发展,我国居民财富持续增长,2020年中国已成为全球第二大财富管理市场。然而,作为居民财富管理重要参与者的券商行业,却面临着传统的炒股佣金费率持续下行、竞争加剧、客户不断流失等困境。尤其自2015年由“一人多户”政... 详细信息

伴随中国经济的发展,我国居民财富持续增长,2020年中国已成为全球第二大财富管理市场。然而,作为居民财富管理重要参与者的券商行业,却面临着传统的炒股佣金费率持续下行、竞争加剧、客户不断流失等困境。尤其自2015年由“一人多户”政策开启的券商互联网扩展浪潮更是彻底打破了券商以往依靠信息不透明维持的费率优势,同时也强化了券商对同行存量客户的争夺,促使券商加快财富管理转型及对自身存量客户深度经营的重视与投入。在目前的竞争格局中,券商想要在财富管理领域战胜竞争对手,提升客户粘性,就必须要全面提升自身的客户关系管理水平。作为传统金融机构,证券公司由于自身的牌照优势等历史原因,在客户关系管理方面一贯缺乏重视,另外一方面,券商作为销售渠道,其所代理的金融产品具有天然的风险属性,同时产品的信息对于非专业投资者来说具有不对称性,其未来收益具有不确定性,因此客户对券商的专业服务期望较高,不同客群之间对服务的要求也有很大差异,此外,随着互联网的发展,客户与券商的交互遍布线下线上,数据分散问题严重,券商难以全量捕捉、统筹数据。这些都给券商的客户关系管理带来极高的难度,也因此行业里各类学说不绝于耳。本文结合国内外权威的客户关系管理理论——从Z证券现有的客户体验监控净推荐值nps(Net Promoter Score)结果入手,通过系统技术与自动化工具(如自动化调研问卷精准投放等方式),第一时间内捕捉客户反馈,高效、准确、全面地完成数据的采集与整合,同时运用大数据文本挖掘方式提炼影响Z证券客户体验的关键词,并结合内外部访谈的方法,全方位剖析Z券商客户关系管理中存在的问题。与传统的静态客户分群服务不同,本文提出了动态客户画像配合智能产品服务库,结合服务缺口模型,提出利用MOT(Moment Of Truth)实现服务缺口快速弥补全面提升Z证券客户关系管理水平的改进策略。同时,也用国内外的研究实践和Z证券自身数据阐述了nps与客户交易意愿的关联,为Z证券公司进行实时客户满意度监控找到了最佳工具。最后,本文在提出改进策略的基础上,对容易被忽略的实施策略及保障进行了详细的设计及描述,进一步阐述了执行环节对预期结果的重要性。同时,本文也在结尾对可能存在的不足进行了表述。

关键词：券商财富管理客户关系管理 nps MOT

静电纺丝基碳纤维载纳米钯催化剂的制备及应用

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无机材料学报 2014年第8期29卷 814-820页

作者：郭丽萍白杰梁海欧李春萍孙炜岩孟庆润内蒙古工业大学化工学院呼和浩特010051

采用静电纺丝、化学还原及高温碳化方法制备了碳纳米纤维螯合钯纳米粒子复合催化剂。实验详细考察了三种还原剂(硼氢化钠、水合肼、氢气)在催化剂制备过程中对钯纳米粒子及碳纤维形貌的影响。通过固体紫外、X射线粉末衍射、红外、扫描... 详细信息

采用静电纺丝、化学还原及高温碳化方法制备了碳纳米纤维螯合钯纳米粒子复合催化剂。实验详细考察了三种还原剂(硼氢化钠、水合肼、氢气)在催化剂制备过程中对钯纳米粒子及碳纤维形貌的影响。通过固体紫外、X射线粉末衍射、红外、扫描电镜、场发射透射电镜等测试方法对已制备的一系列催化剂进行表征。结果表明选择氢气为还原剂时,碳纤维上获得了7 nm左右、粒子分布均匀的钯纳米粒子,催化剂相对柔韧,继而将此催化剂应用于Heck偶联反应测试其催化及循环利用特性。催化结果证实此方法制备的催化剂具有优异的稳定性、底物耐受性、可回收性。

关键词：静电纺丝钯纳米粒子 Pd nps CNFs Heck反应

STUDIES ON DERIVATIVES OF 2,3-DIHYDRO-4H-1,3,2-BENZOXAZAPHOSPHORINE——SYNTHESIS AND STRUCTURE ANALYSIS OF 2,3-DISUBSTITUTED-2, 3-DIHYDRO-4H-1,3,2-BENZOXAZAPHOSPHORIN-4-ONE-(THIONE)-2-SULFIDE(OXIDE)

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Science in China,Ser.B 1984年第11期27卷 1131-1141页

作者：杨石先陈其杰王明德吴伸董贻诚 Institute of Element-organic Chemistry Nankai University Tianjin Institute of Biophysics Academia Sinica Beijing

A series of novel organocyclophosphorus compounds including twenty-three 2, 3-disubsti-tuted-2,3-dihydro-4H-1,3,2-benzoxazaphosphorin-4-one-2-sulfide （compounds Ⅰ） and three 2, 3-disubstituted-2,3,-dihydro-4H-1,3,2-benzoxazaphosphorin-4-thione-2-oxide （compounds Ⅱ） havebeen synthesized. Their structures were determined by IR, UV, HNMR, X-ray diffractionand elemental analysis. Each of compounds Ⅰ showed a strong absorption between 1290-1319em-1 in the IR spectrum. Comprehensive studies of the spectral data and experimental re-sults indicated that this strong characteristic absorption is different from that of the P = Olinkage and thus could be considered as a result of the stretching vibration of （unsaturatedC）-N single bond. In the course of synthesis of the compounds, an abnormal productisomers could be made predominantly in yield and be readily isolated from the other byrecrystallizing for several times from appropriate solvent. Data for the melting point, IR,UV and HNMR spectra of three pairs o

关键词： nps OC SULFIDE SYNTHESIS AND STRUCTURE ANALYSIS OF 2,3-DISUBSTITUTED-2,3-DIHYDRO-4H-1,3,2-BENZOXAZAPHOSPHORIN-4-ONE THIONE OXIDE STUDIES ON DERIVATIVES OF 2,3-DIHYDRO-4H-1,3,2-BENZOXAZAPHOSPHORINE