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Recent advances in “living”/controlled radical polymerization of phosphorus-containing monomers and their potential applications

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Science China Chemistry 2015年第11期58卷 1633-1640页

作者： Tianchi Xu lifen zhang Zhenping Cheng Xiulin Zhu Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application Department of Polymer Science and Engineering College of Chemistry Chemical Engineering and Materials ScienceSoochow University

Special research attention has been paid to phosphorus-containing materials and their corresponding applications. This mini review considers recent publications devoted to the "living"/controlled radical(co)polymerization of phosphorus-containing monomers. In addition, different properties of the polymers involved in the phosphonate group in various chemical environments are demonstrated, and their potential applications are briefly discussed.

关键词： living radical polymerization nitroxide-mediated polymerization (NMP) atom transfer radical polymerization (ATRP) reversible addition-fragmentation chain transfer (RAFT) phosphorus-containing monomer

Longitudinal residual circulation in the South Passage of Yangtze Estuary:Combined influences from runoff,tide and bathymetry

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Science China Earth Sciences 2021年第12期64卷 2129-2143页

作者： lifen zhang Zuosheng YANG Fan zhang Zhanhai LI Yaping WANG Shu GAO State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai200062China College of Marine Geosciences Ocean University of ChinaQingdao266100China School of Geographic and Oceanographic Sciences Nanjing UniversityNanjing210023China

Classical estuary circulation theory states that in the longitudinal direction of an estuary there exists a single circulation with landward,near-bottom,and seaward,near-surface flows;however,the situation becomes complicated with the presence of a river mouth *** we conducted tidal-cycle observations in the South Passage of the Yangtze Estuary during both the wet and dry seasons of 2018(July and December,respectively).The simultaneous current velocity,temperature,and salinity profile data were obtained from anchored boats and base tripods at three stations along the channel in the mouth bar *** results reveal two distinct longitudinal residual circulation patterns:a classic circulation which is formed on the seaward slope of the mouth bar during the wet season,and a double circulation system which is composed of two circulation cells over the landward and seaward slopes of the mouth bar during the dry *** Simpson number(Si),mixing parameter(M),and salinity data were used to quantify the mixing intensity,which shows that horizontal baroclinic pressure gradient is the dominant factor in the formation of the longitudinal residual ***,the double circulation pattern during the dry season is related to the mouth bar bathymetry,which affects saltwater *** double circulations can significantly influence the spatial and temporal evolution of the stagnation point in the estuarine channel,which in turn modifies the distribution patterns of suspended sediment concentration in the maximum turbidity ***,the changes in the mouth bar sandbar bathymetry in response to human activities and river basin hydrographic conditions indirectly affect the occurrence and scale of the double circulations.

关键词： Longitudinal residual circulation Tidal straining River mouth bar Double circulations Estuary turbidity maximum Yangtze River

A novel reversible-deactivation radical polymerization strategy via near-infrared light-controlled photothermal conversion dividing wall-type heat exchanger

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Science China Chemistry 2021年第7期64卷 1242-1250页

作者： Qun Gao Kai Tu Haihui Li lifen zhang Zhenping Cheng State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials Suzhou Key Laboratory of Macromolecular Design and Precision SynthesisCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China

As an effective means of utilizing light energy,photothermal conversion has excellent application in the field of ***,a dividing wall-type heat exchanger with the aid of photothermal conversion was designed to conduct polymerization under irradiation with near-infrared(NIR)light by utilizing the ketocyanine-type dye solution as the highly efficient activator(>83.2%photothermal conversion efficiency).Various types of reversible-deactivation radical polymerization(RDRP)methods,including reversible addition-fragmentation chain transfer,atom transfer radical polymerization,and bromine-iodine transformation RDRP,are suitable for this ***-defined polymers with excellent control over molar mass and molar mass dispersity(D<1.28)were thus synthesized within a few hours under NIR(λ_(max)=810 nm,850 nm)irradiation at room ***,in addition to conventional heating methods(such as electrical heating jackets),the designed dividing wall-type heat exchanger via NIR light activation has another unique advantage:it can enhance the polymerization by the synergistic effect of both heating and NIR light irradiation due to the deeper penetration of NIR light.

关键词： near-infrared light photothermal conversion ketocyanine dye reversible-deactivation radical polymerization dividing wall-type heat exchange

Persistent radical anion of perylene dianhydride:an emerging metal-free photocatalyst for near-infrared photocontrolled RAFT polymerization

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Science China Chemistry 2024年第2期67卷 677-686页

作者： Haitao Zhao Guoqing Bian Xiang Xu Weiwei He lifen zhang Zhenping Cheng State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials Jiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationSuzhou Key Laboratory of Macromolecular Design and Precision SynthesisCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou215123China

Developing a new type of photocatalyst(PC) and catalytic mechanism for near-infrared(NIR) photocontrolled reversibledeactivation radical polymerization(RDRP) system is charming but ***,a novel PC of the persistent radical anion(PRA)(possessing the properties of both radical and anion) was developed for NIR photocontrolled reversible additionfragmentation chain transfer(RAFT) polymerization,enabling successful polymerization while gaining a deep insight into the mechanism of photo-induced electron transfer RAFT(PET-RAFT) *** from the conventional and wellaccepted reductive quenching(RQ) pathway,in which the radical anion intermediates of PCs(PCs^(·-)) must be generated in an excited state(ES),here,the PRA(3,4,9,10-perylenetetracarboxylic dianhydride radical anion(PTCDA^(·-))) could generate conveniently in situ in the ground state(GS) and subsequently serve as highly efficient PC in the NIR region(740–850 nm).The successful implementation of this strategy elucidates the peculiar role played by light and the real way of electron transfer *** fact,the transfer of a single electron from PRA to chain transfer agent(CTA) and cleavage of the C–S bonds is a process from ES to GS,rather than always from GS(PCs^(·-)) to GS(CTA) in the RQ pathway as is well known to *** addition,the excellent spatial-temporal control and powerful penetration ability of the NIR light were also confirmed by this PRAcatalyzed polymerization system.

关键词： photocatalyst persistent radical anion(PRA) near-infrared(NIR)light reversible-deactivation radical polymerization(RDRP) photo-induced electron transfer RAFT(PET-RAFT)polymerization

Sensitive and environmental friendly sensor on porphyrin functionalized chitosan fiber membrane for Hg^(2+)

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Nano Research 2024年第11期17卷 9965-9970页

作者： Yafei Ma Xinman Liu Zhiping Fu lifen zhang Yuexin Guo Hui Wang Zhiqian Jia School of Pharmacy North China University of Science and Technology Tangshan 063210 China Tianjin TianShi College Tianjin 301700 China College of Chemistry Beijing Normal University Beijing 100875 China

Mercury is the most toxic and harmful heavy metal pollutant, and it is essential to detect and remove mercury from beverages. Inducing the porphyrin molecules into the chitosan structure, a novel membrane sensor tetrakis(4-carboxyphenyl)porphyrin-grafted chitosan fiber membrane (TCPP-CS) was prepared by electrospinning method and applied to recognize Hg^(2+) contaminant selectively. Compared with other common metal ions (Pb^(2+), Cu^(2+), Fe^(3+), Cr^(3+), Mg^(2+), and Zn^(2+)), the colorimetric sensor has specific color development and sensitivity to Hg^(2+) and the detection limit of the sensor reaches 1 × 10^(−5) mol·L^(−1). The response time of the membrane is 5 s, and it can be specifically colored in various pH environments convenient for practical application. Hg^(2+) resulted in a visual color change of the fiber membrane from brown to yellow-green, indicating a potential interaction between the porphyrin-functionalized chitosan fiber membrane and Hg^(2+) ions, and the wavelength shift of the UV–visible spectrum can be observed. It has the advantages of simplicity, rapidity, high selectivity, and high sensitivity, providing a new method for removing and detecting heavy metals in traditional Chinese medicine and drinks.

关键词： porphyrin functionalization selectivity Hg^(2+)removal electrospinning adsorption

Ultrasonic concentration measurement of citrus pectin aqueous solutions using PC and PLS regression

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International Journal of Agricultural and Biological Engineering 2012年第2期5卷 76-81页

作者： Meng Ruifeng Zhong Jianjun zhang lifen Ye Xingqian Liu Donghong School of Biosystems Engineering and Food Science Zhejiang UniversityHangzhou 310058China

This work demonstrated the use of multivariate statistical techniques called principal component(PC)and partial least squares(PLS)to extract the acoustic features of citrus pectin water *** concentration of citrus pectin water solution was predicted by PC and PLS regression method using the spectra of ultrasound pulse echoes travelling through *** values of root mean square error of validation(RMSEV)were 0.0675 g/100 g and 0.0662 g/100 g for PC and PLS regression model,*** the response variable was taken into account,PLS regression model was more accurate than PC regression ***,a method for temperature compensation was proposed to correct the impact of temperature variation on analyzed *** proposed methods for pectin concentration measurement are easily adaptable to similar applications using existing hardware.

关键词： Partial Least Square Regression Principal Component Regression concentration measurement acoustic velocity

Power ultrasound for the preservation of postharvest fruits and vegetables

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International Journal of Agricultural and Biological Engineering 2013年第2期6卷 116-125页

作者： Xu Yuting zhang lifen Zhong Jianjun Shu Jie Ye Xingqian Liu Donghong School of Biosystems Engineering and Food Science Zhejiang UniversityHangzhou 310058China College of Food Science and Technology Henan University of TechnologyZhengzhou 450001China Fuli Institute of Food Science Zhejiang UniversityHangzhou 310058China

Increasing public demands for improved safety and quality of fruits and vegetables in the fresh market,awaken a growing interest for novel technologies for the preservation of postharvest fruits and vegetables before *** technology provides one of the methods that with better treating time,enhanced products quality,reduced chemical hazards,low consumption of energy,and is environmentally *** review provides an up-to-date summary of published findings on the application of ultrasound in the preservation of fresh fruits and *** ultrasound devices commonly utilized,effects of power ultrasound treatment as a factor that affects decay incidence,safety and quality of fresh fruits and vegetables are *** challenges and research trends in the future are also *** is concluded that much progress has been achieved in this field during recent *** achievements paved the way for the industrial-scale application of ultrasound in the preservation of postharvest fruits and vegetables.

关键词： power ultrasound postharvest fruits and vegetables decontamination quality

Groundwater level prediction of landslide based on classification and regression tree

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Geodesy and Geodynamics 2016年第5期7卷 348-355页

作者： Yannan Zhao Yuan Li lifen zhang Qiuliang Wang Key Laboratory of Earthquake Geodesy Institute of Seismology China Earthquake Administration Wuhan Base of Institute of Crustal Dynamics China Earthquake Administration

According to groundwater level monitoring data of Shuping landslide in the Three Gorges Reservoir area, based on the response relationship between influential factors such as rainfall and reservoir level and the change of groundwater level, the influential factors of groundwater level were selected. Then the classification and regression tree（CART） model was constructed by the subset and used to predict the groundwater level. Through the verification, the predictive results of the test sample were consistent with the actually measured values, and the mean absolute error and relative error is 0.28 m and 1.15%respectively. To compare the support vector machine（SVM） model constructed using the same set of factors, the mean absolute error and relative error of predicted results is 1.53 m and 6.11% respectively. It is indicated that CART model has not only better fitting and generalization ability, but also strong advantages in the analysis of landslide groundwater dynamic characteristics and the screening of important variables. It is an effective method for prediction of ground water level in landslides.

关键词： Landslide Groundwater level Prediction Classification and regression tree Three Gorges Reservoir area

Source parameters determination for earthquakes in Kushiro,Japan considering source time function

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Earthquake Science 2012年第2期25卷 137-142页

作者： lifen zhang Wulin Liao Guichun Wei Jinggang Li Qiuliang Wang Institute of Seismology China Earthquake AdministrationWuhan 430071China Institute of Geophysics China Earthquake AdministrationBeijing 100081China

This paper applies a new formulation to do moment tensor inversion for earthquakes in the Kushiro area of Japan. Comparing with conventional moment tensor inversion method, the new one takes the effect of source time function into consideration. For the inversion, best solution is obtained by minimizing the difference between the observed seismograms and the synthetic ones. And the best-fitting focal depth is determined from the variance reduction. The results indicate that half duration of source time function is proportional to the magnitude of earthquakes. Large earthquakes have long half duration, whereas that of moderate-small earthquakes is comparatively shorter. The focal mechanisms of all three earthquakes are of thrust fault type, which is mainly ascribed to the collision of the North American plate with the Eurasia plate in the late Cretaceous or Paleogene.

关键词： moment tensor inversion half duration source time function Kushiro