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Highly green fluorescent Nb2C MXene quantum dots for Cu2+ion sensing and cell imaging

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Chinese Chemical Letters 2020年第12期31卷 3173-3177页

作者： Xiang Yan junfei ma Kaixuan Yu Jiapeng Li Lei Yang Jjiaqi Liu Juncheng Wang Lulu Cai School of materials Science and Engineering.Baise University.Baise 533000 China State Key Laboratory of Heavy Oilt Processing China University of Petroleum-BeijingBeijing 102249China Personalized Drug Therapy Key Laboratory of Sichuan Province Department of PharmacySichuan Provincial Peoples Hospital School MedicineUniversity of Electronic Science and Technology of China.Chengdu 610072China Stomatology Department of the General Haspital of Chinese PLA Beijing 100853China

Niobium carbide MXene quantum dots(Nb2 C MQDs)derived from 2 D Nb2 CTx(MXene)are the rising-star material ***,a sulfur and nitrogen co-doped Nb2 C MQDs(S,N-MQDs)were synthesized through a hydrothermal *** obtained Nb2 C MQDs have excellent green fluorescence with a quantum yield(QY)of 17.25%.In addition,they exhibited excitatio n-dependent photoluminescence,antiphotobleaching and dispersion *** emit light at 520 nm when excited at 390 *** Nb2 C MQDs could be successfully applied to copper ion detection with detection limit of 2μmol/L and Caco-2 cells imaging.

关键词： 2D-QDs Nb2C-Mxene Cell imaging Ion sensing Sulfur-nitrogen co-doping

Highly fluorescence Ta_(4)C_(3) MXene quantum dots as fluorescent nanoprobe for heavy ion detection and stress monitoring of fluorescent hydrogels

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Chinese Chemical Letters 2022年第4期33卷 1850-1854页

作者： Shouzhen Li junfei ma Xuelin Zhao Peide Zhu Meng Xu Yingchun Niu Dixian Luo Quan Xu State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development National Energy Shale Oil Research and Development CenterChina University of Petroleum(Beijing)Beijing 102249China Department of Musculoskeletal Tumor Senior Department of Orthopedicsthe Fourth Medical Center of PLA General HospitalBeijing 100142China Department of Laboratory Medicine Huazhong University of Science and Technology Union Shenzhen Hospital(Nanshan Hospital)Shenzhen 518000China

Compared with other transition metal Mxene derived quantum dots(MQD_(S)),Ta-based Mxene quantum dots have good functionality,but Ta-based Mxene quantum dots and their applications have not been studied so *** this paper,we report for the first time the synthesis of high fluorescence quantum yield(QY) N-doped Ta_(4)C_(3) quantum dots(N-MQDs) using Ta_(4)C_(3) quantum dots in acid reflux damaged Ta_(4)C_(3) nanosheets as precursors and ethylenediamine as nitrogen *** prepared N-MQDs have excellent blue photoluminescence(PL) properties,particle size is only 2.60 nm,QY is up to 23.4%,and good *** addition,it has been reported that N-MQDs can be used as fluorescent probe for detection of Fe;and remote force sensing analysis In liquid ion sensing,N-MQDS shows a unique selective quenching of Fe;with a detection limit as low as 2 μmol/L,and has great potential as a fast and super-sensitive fluorescent probe for the detection of heavy *** importantly,in solid mechanics sensing,the introduction of N-MQDs into self-healing hydrogels can be developed into a fluorescent hydrogel that can be used for accurate remote force measurement and applied in the field of mechanical sensing ***,Ta-based N-MQDs show excellent potential in the field of fluorescence sensing,which provides a door for multi-dimensional sensing of new materials in the future.

关键词： MXene quantum dots Fluorescent probe Fluorescent hydrogel Hydrothermal method Quantum yield

Clustering stream profiles to understand the geomorphological features and evolution of the Yangtze River by using DEMs

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Journal of Geographical Sciences 2021年第11期31卷 1555-1574页

作者： ZHAO Fei XIONG Liyang WANG Chun WEI Hong ma junfei TANG Guoan Key Laboratory of Virtual Geographic Environment Ministry of EducationNanjing Normal UniversityNanjing 210023China School of Geography Nanjing Normal UniversityNanjing 210023China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing 210023China School of Remote Sensing&Geomatics Engineering Nanjing University of Information Science&TechnologyNanjing 210044China

Stream morphology is an important indicator for revealing the geomorphological features and evolution of the Yangtze *** studies on the morphology of the Yangtze River focus on planar ***,the vertical features are also *** features mainly control the flow ability and erosion ***,traditional studies often focus on a few stream profiles in the Yangtze ***,stream profiles are linked together by runoff nodes,thus affecting the geomorphological evolution of the Yangtze River *** this study,a clustering method of stream profiles in the Yangtze River is proposed by plotting all profiles ***,a stream evolution index is used to investigate the geomorphological features of the stream profile clusters to reveal the evolution of the Yangtze *** on the stream profile clusters,the erosion base of the Yangtze River generally changes from steep to gentle from the upper reaches to the lower reaches,and the evolution degree of the stream changes from low to *** asymmetric distribution of knickpoints in the Hanshui River Basin supports the view that the boundary of the eastward growth of the Tibetan Plateau has reached the vicinity of the Daba Mountains.

关键词： stream profile clusters Yangtze River geomorphological feature stream evolution digital elevation model

mass production of highly fluorescent full color carbon dots from the petroleum coke

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Chinese Chemical Letters 2021年第4期32卷 1532-1536页

作者： junfei ma Linzhou Zhang Xiu Chen Rigu Su Quan Shi Suoqi Zhao Quan Xu Chunming Xu State Key Laboratory of Heavy Oil Processing China University of Petroleum-BeijingBeijing 102249China Engineering Technology Research Institute o/PetroChina Xinjiang Oilfield Company Karamay 834000China

Heavy oil is treated as an undesirable raw material in traditional refining markets because of its low ***,its rich natural aromatic structure and heteroatomic compounds make it possible to be a precursor to large-scale production of carbon *** heavy oil and three SDA products as precursors,we synthesized highly fluorescent multi-color carbon dots(CDs)by hydrothermal method,which can precisely control the photoluminescence wavelength in the range of 350-650 *** synthesized carbon dots have the advantages of good long-term stability and stability under extreme pH conditions and low ***,the carbon dots synthesized with asphalt as the precursor have the highest fluorescence quantum yield.X-ray photoelectron spectroscopy(XPS)is used to elucidate the effects of different precursor on emission color change and photoluminescence quantum yield(PLQY),thus providing a controlled tuning of the system for the functionalization of *** we further used the CDs in macrophage *** pathway gives a reliable and repeatable industry possibility and may boost the applications of CDs into reality.

关键词： Full color Carbon dots Petroleum coke macrophage labeling SDA

Impacts of Sloping Land Conversion Program on the vegetation in loess hilly and gully area of northern Shaanxi

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Ecological Economy 2009年第2期5卷 160-167页

作者： ma junfei Lu Changhe Yu Bohua Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 P. R China Graduate University Chinese Academy of Sciences Beijing 100049 P. R. China

Aiming at alleviating the serious soil erosion, the Chinese government initiated the Sloping Land Conversion Program （SLCP） in 1999. Now; after 8 years of project implementation, the ecological recovery effects of the SLCP have become the hot issue of academic circle. This paper; raking the loess hill and gully area of northern Shaanxi as an example, presents a methodology for assessing the vegetation restoration effect of SLCP with normalized difference vegetation index （NDVI）. The key components include calculation of the Growing Season NDVI （GSNDVI）, and estimation of the NVDI change induced by climate and SLCP, respectively. Based on the method, the NDVI change between 2000 and 2006 was obtained using the GSNDVI that excluded the noise from snow and ice. After the part of total NDVI change caused to： climate variation was estimated using empiric formulae, we obtained the part induced by human factors, i.e. the SLCP The human induced part of ND VI change was considered as an approximation indicating the effect of the SLCP on the vegetation. Finally, we analyzed the ND VI change characters of the whole study area, different slope lands and different land use types by spatial statistics method. Results show that the vegetation condition is significantly improved by the SLCP, particularly land types that directly involved in the SLCP, such as steeply slope farmlands, degraded grasslands, etc.

关键词： SLCP MODIS ND VI Loess hilly and gully area Land use

The SLCP-driven land use changes and farmers' responses in the loess hilly and gully region:a case study for Ansai County

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Ecological Economy 2009年第4期5卷 375-381页

作者： Wang Qian Lu Changhe Yu Bohua ma junfei Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 P. R. China Graduate University Chinese Academy of Sciences Beijing 100049 P. R. China

Taking Ansai County located in loess hilly and gully area as a case, this study analyzes the land use changes driven by the SLCP （Slope Land Conversion Program） and the farmers＇ responses by household survey and participatory rapid appraisal （PRA）. It is found that the SLCP aroused various changes in land use, agricultural production, rural incomes, etc. In the period of 1999-2005, the farmland and grasslands were reduced by 26,809 ha and 17,571 ha respectively, while forestland increased by 38,203 ha; greenhouse vegetable and orchard got a quick development, with the area enlarged by about 7 times and nearly doubled respectively. The SLCP reduced the area of crops particularly those that normally grown on slope lands, e.g. the sowing area of winter wheat ped from 19.39% of the total cropping area in 1999 to 0.98% in 2005. Draught animals, pigs and sheep have a decline in the number because the remained land and the ban on grazing on natural grasslands can not provide sufficient feed forage. Thanks to the financial subsidy, farmers increased land inputs and thus outputs. To achieve long-term sustainable development and improve rural income, the government should continuously support farmers to improve the land management, to adopt alternative land use systems, and to increase inputs on soil conservation. Vegetable and fruit production are two promise land use systems, and should be further developed.

关键词： SLCP Household survey Land use changes Agricultural production

Accuracy of triage strategies for human papillomavirus DNA-positive women in low-resource settings:A cross-sectional study in China

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Chinese Journal of Cancer Research 2017年第6期29卷 496-509页

作者： margaret Wang Shangying Hu Shuang Zha o Wenhua Zhang Qinjing Pan Xun Zhang FengChen Jinxiu Han junfei ma Jennifer S.Smith Youlin Qiao Caihong Zhou Fanghui Zhao Department of Cancer Epidemiology National Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Pritzker School of Medicine University of ChicagoChicagoIL 60637-5415USA UJMT Fogarty Consortium NIH Fogarty International CenterBethesdaMD 20892-2220USA Department of Gynecological Oncology National Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Department of Cytology National Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Department of Pathology National Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Wuxiang maternal and Child Health Care and Family Planning Service Center Changzhi 046300China Xiangyuan maternal and Child Health Care and Family Planning Service Center Changzhi 046200China Department of Epidemiology University of North CarolinaChapel HillNC 27599-7435USA Department of Education National Cancer Center/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China

Objective： CareHPV is a human papillomavirus （HPV） DNA test for low-resource settings （LRS）. This study assesses optimum triage strategies for careHPV-positive women in LRS. Methods： A total of 2,530 Chinese women were concurrently screened for cervical cancer with visual inspection with acetic acid （VIA）, liquid-based cytology and HPV testing by physician- and self-collected careHPV, and physician-collected Hybrid Capture 2 （HC2）. Screen-positive women were referred to colposcopy with biopsy and endocervical curettage as necessary. HPV-positivity was defined as _〉1.0 relative light units/cutoff （RLU/CO） for both careHPV and HC2. Primary physician-HC2, physician-careHPV and self-careHPV and in sequential screening with cytology, VIA, or increased HPV test-positivity performance, stratified by age, were assessed for cervical intraepithelial neoplasia （CIN） grade 2/3 or worse （CIN2/3＋） detection. Results： The sensitivities and specificities of primary HPV testing for CIN2＋ were： 83.8%, 88.1% for physician- careHPV; 72. 1%, 88.2% for self-careHPV; and 97.1%, 86.0% for HC2. Physician-careHPV test-positive women with VIA triage had a sensitivity of 30.9% for CIN2＋ versus 80.9% with cytology triage. Self-careHPV test- positive women with VIA triage was 26.5% versus 66.2 % with cytology triage. The sensitivity of HC2 test-positive women with VIA triage was 38.2 % versus 92.6% with cytology triage. The sensitivity of physician-careHPV testing for CIN2＋ decreased from 83.8% at _〉1.0 RLU/CO to 72.1% at _〉10.00 RLU/CO, while the sensitivity of self- careHPV testing decreased from 72.1% at _〉1.0 RLU/CO to 32.4% at _〉10.00 RLU/CO; similar trends were seen with age-stratification. Conclusions： VIA and cytology triage improved specificity for CIN2/3 than no triage. Sensitivity with VIA triage was unsuitable for a mass-screening program. VIA provider training might improve this strategy. Cytology triage could be feasible where a high-quality cytology program exists. Triage of HPV t

关键词： Cervical cancer human papillomavirus careHPV testing screening triage

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基于改进灰狼算法的舰载机弹药保障调度优化

系统工程与电子技术 2024年第4期46卷 1264-1272页

作者：刘哲马俊飞陈佳峰马嵩华山东大学机械工程学院山东济南250061 高效洁净机械制造教育部重点实验室山东济南250061 山东大学机械工程国家级实验教学示范中心山东济南250061 湖南云箭集团有限公司湖南长沙419503

针对航空母舰飞行甲板上舰载机弹药保障面临的调度效率不高的问题,提出了一种改进灰狼优化(grey wolf optimizer, GWO)算法。根据甲板上多升降机多运输车的场景特点,建立了由多车场出发、向多目标转运的问题模型。融合遗传算法算子交叉... 详细信息

针对航空母舰飞行甲板上舰载机弹药保障面临的调度效率不高的问题,提出了一种改进灰狼优化(grey wolf optimizer, GWO)算法。根据甲板上多升降机多运输车的场景特点,建立了由多车场出发、向多目标转运的问题模型。融合遗传算法算子交叉思想实现了对灰狼种群初始解的初步优化,并通过直线转运路径中间点定义、整数编码、负整数标志分组等方法实现了对GWO算法求解过程的改进。同时,增加了灰狼个体自由狩猎流程,有效克服了结果陷入局部最优和早熟的问题。最终,通过对场景实例的优化求解,验证了所提方法的有效性和可行性。

关键词：灰狼优化算法多车场多目标整数编码标志分组

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低低温电除尘器飞灰理化特性规律研究

中国电机工程学报 2021年第10期41卷 3454-3465页

作者：马俊飞王建峰徐克涛华电电力科学研究院有限公司浙江省杭州市310030

通过采集低低温电除尘器烟气沿程各位置的飞灰样品,应用激光粒度仪测定飞灰粒度分布,使用扫描电镜(scanningelectronmicroscope,SEM)、X射线衍射仪(X-raydiffractometer,XRD)和X射线荧光光谱仪(X-ray fluorescence spectrometer,XRF)研究烟气沿程飞灰的微观形貌、物相构成和化学成分变化,同时应用X光能谱仪(energy dispersivespectrometerEDS)对沿程各形貌颗粒元素构成进行分析。结果表明:烟气将过低温省煤器后,烟气温度降低,颗粒间团聚现象明显,细小颗粒在烟气中相互碰撞黏附团聚在一起形成较大颗粒,或被吸附在较大颗粒的表面,增大了颗粒的粒径,降低了烟气中细小颗粒的浓度;烟气沿程方向飞灰样品颜色逐渐由灰黑色向淡黄色转变,微观态颗粒物的规则程度增加,末电场飞灰基本呈圆形或圆球形颗粒;烟气温度降低到酸露点后烟气中的SO_(3)以硫酸雾的形式被细小颗粒吸附,在内部扩散的作用下,细小颗粒凝并成团形成较大颗粒;沿程方向飞灰颗粒物中Si含量逐渐降低,Na、Mg、Al、S、Ca、Fe、P的含量逐渐升高,分析沿程同形貌颗粒的元素组分变化,随颗粒粒度的减少,除Ti的含量相对稳定外,Si、Al的含量逐渐降低,C、K、Na、Ca的含量有升高的趋势。

关键词：燃煤电厂低低温电除尘器飞灰 SO3 粒度分布化学成分