检索结果-南通市图书馆

Polarization engineering in porous organic polymers for charge separation efficiency and its applications in photocatalytic aerobic oxidations

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第3期67卷 1000-1007页

作者： Kun Wu Pei-Wen Cheng xin-yi liu Ji Zheng Xiao-Wei Zhu Mo Xie Puxin Weng Weigang Lu Dan Li College of Chemistry and Materials Science Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and ApplicationsJinan UniversityGuangzhou 510632China Guangdong Rare Earth Photofunctional Materials Engineering Technology Research Center School of Chemistry and EnvironmentJiaying UniversityMeizhou 514015China

Photocatalytic aerobic oxidation reactions are largely governed by the efficiency of charge separation and subsequent reactive oxygen species(ROS) generation. Herein, we report a polarization engineering strategy to promote the charge separation and ROS generation efficiency by substituting the benzene unit with furan/thiophene in porous organic polymers(POPs). Benefiting from the extent of local polarization, the thiophene-containing POP(JNU-218) exhibits the best photocatalytic performance in aerobic oxidation reactions, with a yield much higher than those for the furan-containing POP(JNU-217) and the benzenecontaining POP(JNU-216). Experimental studies and theoretical calculations reveal that the increase of local polarization can indeed reduce the exciton binding energy, and therefore facilitate the separation of electron-hole pairs. This work demonstrates a viable strategy to tune charge separation and ROS generation efficiency by modulating the dipole moments of the building blocks in porous polymeric organic semiconductors.

关键词： porous organic polymer local polarization photocatalytic aerobic oxidation charge separation reactive oxygen species exciton binding energy

Structures and Surface States of Polymer Brushes in Good Solvents:Effects of Surface Interactions

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2018年第9期36卷 1047-1054页

作者： yi-xin liu Hong-Dong Zhang State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science Fudan University

The influence of the surface interaction on the mesoscopic structure of grafted polymers in good solvents has been examined. At high surface coverage, tethered polymers are in the brush state and the parabolic segment density profile is confirmed by self-consistent field theory （SCFT） calculations. It is found that this is a universal behavior for a whole range of surface interactions from complete repulsion to strong attraction. More interestingly, finite surface repulsion may lead to the maximum in the proximal layer of its segment density profile, which is significantly different from both the depletion layer of pure repulsion and the adsorbing layer of attraction. In addition to the brush state on both repulsive and attractive surfaces, three additional surface states were identified by analyzing the scaling behavior of the layer thickness of polymer brushes： the mushroom state on repulsive substrates, the dilute and the semidilute surface states on attractive substrates.

关键词： Self-consistent field theory Scaling theory Polymer thin film Polymer brush

Astrocyte polarization in glaucoma: a new opportunity

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2022年第12期17卷 2582-2588页

作者： yi-xin liu Hao Sun Wen-yi Guo Department of Ophthalmology Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineShanghaiChina Shanghai Key Laboratory of Orbital Diseases and Ocular Oncology ShanghaiChina

Astrocyte polarization is a new concept which is similar to microglia polarization and in which astrocytes are classified as A1(neurotoxic)and A2(neuroprotective).Several studies on astrocyte polarization have focused mainly on neurodegenerative diseases,trauma,and ***,the role of astrocyte polarization in glaucoma,a neurodegenerative disease,has not been fully *** this review,we first describe the characteristics of astrocyte astrogliosis in glaucoma,including morphological,molecular,proliferative and functional *** then summarize understanding of astrocyte polarization in other diseases,and show that A1 astrocytes are involved in the death of retinal ganglion cells in glaucoma,and that their neurotoxins kill only damaged retinal ganglion *** on this,we propose new interesting conjecture on astrocyte polarization in glaucoma:(1)That the neurotoxin from A1 astrocytes is a product of the complement system(membrane-attacking complex),since this system is known to mediate synaptic elimination and the C3 expression is clearly increased in A1 astrocytes;(2)that reactive scar-forming astrocytes in the optic nerve head may be classified as A2 astrocytes since their ablation leads to a worse prognosis in ***,current therapeutic research progress on astrocyte polarization in other diseases is also *** of astrocyte polarization can be achieved by extracellular microglia-related and intracellular *** A1 or increased A2 astrocytes can rescue the *** example,glucagon-like peptide-1 receptor agonist rescues retinal ganglion cells by reducing A1 astrocytes via the extracellular microglia-related pathway in an ocular hypertension model,suggesting that regulation of astrocyte polarization as a therapeutic target in glaucoma is feasible.

关键词： astrocytes glaucoma heterogeneity microglia neurodegenerative disease neuroinflammation neuroprotection optic nerve retina therapy

An Efficient Algorithm for Self-consistent Field Theory Calculations of Complex Self-assembled Structures of Block Copolymer Melts

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2018年第4期36卷 488-496页

作者： Jun-Qing Song yi-xin liu Hong-Dong Zhang State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science Fudan University

Self-consistent field theory（SCFT）, as a state-of-the-art technique for studying the self-assembly of block copolymers, is attracting continuous efforts to improve its accuracy and efficiency. Here we present a fourth-order exponential time differencing Runge-Kutta algorithm（ETDRK4） to solve the modified diffusion equation（MDE） which is the most time-consuming part of a SCFT calculation. By making a careful comparison with currently most efficient and popular algorithms, we demonstrate that the ETDRK4 algorithm significantly reduces the number of chain contour steps in solving the MDE, resulting in a boost of the overall computation efficiency, while it shares the same spatial accuracy with other algorithms. In addition, to demonstrate the power of our ETDRK4 algorithm, we apply it to compute the phase boundaries of the bicontinuous gyroid phase in the strong segregation regime and to verify the existence of the triple point of the O70 phase, the lamellar phase and the cylindrical phase.

关键词： Block copolymer Self-consistent field theory Algorithm Pseudo-spectral Phase structure

Capillary Electrophoretic Determination of Jinggangmycin A in Formulations Using Direct UV Detection

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2005年第11期16卷 1511-1514页

作者： Jin HE xin liu yi Shi liu Zi Niu YU National Key Laboratory of Agricultural Microbiology Huazhong Agricultural University Wuhan 430070

A simple, fast and reliable method was developed for the analysis of jinggangmycin A （validamycin A） in commercial formulations. The running buffer used was acetate buffer （100 mmol/L, pH 4.7） with 15 kV as the applied voltage. The detection was achieved by using direct UV mode at 200 nm and the detection limit was 0.2 μg/mL. Linearity in the concentration range of 5-500 μg/mL was excellent （RE 〉 0.999）. The run-to-run repeatability （n = 3）, as expressed by the relative standard deviation （RSD） for migration times and peak areas were less than 0.5% and 3.0% respectively. The mean recovery ranged from 97.2% to 101.4%.

关键词： Jinggangmycin A validamycin A capillary zone electrophoresis direct UV detection.

Effect of chemical reactivity on the detonation initiation in shock accelerated flow in a confined space

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2013年第1期29卷 54-61页

作者： Yue-Jin Zhu Gang Dong yi-xin liu Bao-Chun Fan Hua Jiang State Key Laboratory of Transient Physics Nanjing University of Science and Technology State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology

The interactions of a spherical flame with an incident shock wave and its reflected shock wave in a confined space were investigated using the three-dimensional reactive Navier-Stokes equations, with emphasis placed on the effect of chemical reactivity of mixture on the flame distortion and detonation initiation after the passage of the reflected shock wave. It is shown that the spatio-temporal characteristics of detonation initiation depend highly on the chemi- cal reactivity of the mixture. When the chemical reactivity enhances, the flame can be severely distorted to form a reactive shock bifurcation structure with detonations initiating at different three-dimensional spatial locations. Moreover, the detonation initiation would occur earlier in a mixture of more enhanced reactivity. The results reveal that the detona- tions arise from hot spots in the unburned region which are initiated by the shock-detonation-transition mechanism.

关键词： Chemical reactivity Reactive shock bifurcation structure ~ Detonation initiation Hot spot Shock wave

Metal-organic frameworks as photocatalysts for aerobic oxidation reactions

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2023年第6期66卷 1634-1653页

作者： Kun Wu xin-yi liu Pei-Wen Cheng Mo Xie Weigang Lu Dan Li College of Chemistry and Materials Science Guangdong Provincial Key Laboratory of Functional Supramolecular Coordination Materials and ApplicationsJinan UniversityGuangzhou 510632China

Metal-organic frameworks(MOFs)are emerging as one of the most intriguing classes of heterogeneous photocatalysts owing to their abundant structures,tunable porosity,and versatile *** advantages of bottom-up design and reticular synthesis render MOF materials with desired photocatalytic properties for targeted *** this review,we discussed the design and synthesis of MOF-based photocatalysts as well as strategies for enhancing photocatalytic *** progress on MOFs as platforms for photocatalytic aerobic oxidation reactions was summarized and categorized according to the types of bond *** hope this review will give an in-depth insight into MOF-based photocatalytic systems for not only aerobic oxidation reactions but also other organic transformations.A brief outlook on the challenges and opportunities of MOFs as heterogeneous photocatalysts is provided at the end of the review.

关键词： metal-organic frameworks heterogeneous photocatalyst reactive oxygen species aerobic oxidation organic synthesis

Evaluation of water management on arsenic methylation and volatilization in arsenic-contaminated soils strengthened by bioaugmentation and biostimulation

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第3期137卷 515-526页

作者： Peng Chen yi liu Guo-xin Sun State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074China University of Chinese Academy of Sciences Beijing 100049China

Arsenic(As) fate in paddy fields has been one of the most significant current issues due to the strong As accumulation potential of rice plants under fooded conditions. However,no attempt was done to explore As methylation and volatilization under non-fooded conditions. Herein, we investigated the effects of water management on As methylation and volatilization in three arsenic-contaminated soils enhanced by biostimulation with strawderived organic matter and bioaugmentation with genetic engineered Pseudomonas putida KT2440(GE P. putida). Under fooded conditions, the application of biochar(BC), rice straw(RS)and their combination(BC+RS) increased total As in porewater. However, these effects were greatly attenuated under non-fooded conditions. Compared with RS amendment alone, the combination of GE P. putida and RS further promoted the As methylation and volatilization,and the promotion percentage under non-fooded conditions were significantly higher than that under fooded conditions. The combined GE P. putida and RS showed the highest efficiency in As methylation(88 μg/L) and volatilization(415.4 μg/(kg·year)) in the non-fooded soil with moderate As contamination. Finally, stepwise multiple linear regression analysis presented that methylated As, DOC and p H in porewater were the most important factors contributing to As volatilization. Overall, our findings suggest that combination of bioaugmentation with GE P. putida and biostimulation with RS/BC+RS is a potential strategy for bioremediation of arsenic-contaminated soils by enhancing As methylation and volatilization under non-fooded conditions.

关键词： Arsenic methylation Arsenic volatilization Water management Straw incorporation Bioaugmentation

Simulation of gamma minitype reference radiation for calibration of personal dosimeter

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2020年第1期31卷 112-122页

作者： yi-xin liu yi-Kun Qian Zhi-Qiang Chen Biao Wei Peng Feng Ben-Jiang Mao Department of Engineering Physics Tsinghua UniversityBeijing 100084China Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621999China Key Laboratory of Optoelectronics Technology and System Ministry of EducationChongqing UniversityChongqing 400044China

An investigation using Monte Carlo simulation on a minitype reference radiation(MRR) for the calibration of gamma personal dosimeters is reported. The distributions of dose rate and scattering gamma spectrum are the main simulation objects with the variable physical structures of MRR and the dosimeters as parameters that are to be calibrated. Further, the influences on the reference radiation caused by these parameters are analyzed in *** work provides a theoretical basis for better understanding of MRR used for calibration of gamma personal dosimeters. This analysis can help in the development of a calibration technology for such tools based on MRR.

关键词： Gamma personal dosimeter Minitype reference radiation Monte Carlo simulation Calibration