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Homogeneous catalytic wet air oxidation for the treatment of textile wastewaters

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Journal of Environmental Sciences 2000年第4期12卷 410-415页

作者： lei, L. Sun, y. Dept. of Envtl. Science and Engrg. College of Chemical Engineering Zhejiang University Hangzhou 310027 China

An extensive series of experiments was carried out in order to identify suitable catalysts to boost the reaction rate of wet air oxidation of real textile wastewaters at relatively mild temperature and pressure. Experimental results indicated that all catalysts tested in this investigation had shown an impressive increase in the initial COD and TOC removal rate as well as the COD and TOC removal levels in two hours reaction. Among all the catalysts tested, copper salts were more effective than the rest. Anions of the salt solutions also played a role in the catalytic process with nitrate ions having better effect than sulfate ions. Hence copper nitrates were more effective than copper sulfates. It was also found that a mixture of salts with different metals performed better than either of the component single salt alone.

关键词： Catalysis Chemical oxygen demand Copper compounds Low temperature effects Negative ions Nitrates Oxidation Pressure effects Rate constants Salts

Ab Initio Study on the Thermal Isomerization from 1,2-Butadiene to1,3-Butadiene

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Chinese Chemical Letters 1997年第1期8卷 71-72页

作者： Feng, WL lei, M Wang, y Qian, y BEIJIng NORMAL UNIV DEPT CHEMBEIJING 100875PEOPLES R CHINA BEIJIng IND UNIV DEPT ENVIRONM & ENGNBEIJINGPEOPLES R CHINA

Ab initio UHF/6-31G** method has been employed to study the mechanism of the thermal isomerization from 1,2-butadiene to 1,3-butadiene. The energies were corrected at MP2//6-31G**+ZPE(zero-point energy) level. The results indicate that it is a stepwise reaction via a radical intermediate. The calculated activation barriers are 65.01 and 64.16 kcal./mol., respectively.

关键词： Ab Initio Study on the Thermal Isomerization from 1,2-Butadiene to1,3-Butadiene

Nanotexturing and Wettability Ageing of Polypropylene Surfaces Modified by Oxygen Capacitively Coupled Radio Frequency Plasma

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Journal of Materials Science & Technology 2014年第10期30卷 965-972页

作者： y.P.Li M.K.lei Surface Engineering Laboratory School of Materials Science and EngineeringDalian University of Technology

Polypropylene （PP） was treated by an oxygen capacitively coupled radio frequency plasma （CCP） under a radio frequency （RF） power of 200 W for exposure time of 1, 5, and 10 rain. The ageing process of the plasma- treated PP was studied at an ageing temperature of 90 ~C during an ageing time up to 25 h. The formation of the nanotextures with different geometry and aspect ratio and the grafting of large number of oxygen- containing groups were achieved on as-treated PP surfaces under the oxygen CCP treatment for the increased exposure time. The hydrophilicity on the as-treated PP surfaces with the stable nanotextures was rapidly depressed during the ageing process at 90 ℃ due to the restructuring of chemical composition. The surface restructuring rate was dependent on the aspect ratio and the oxygen-containing groups on the nanotextured PP with increasing exposure time. The hydrophobic over-recovery to high hydrophobicity and superhydrophobicity were observed on the post-aged surfaces with the stable nanofibrils from as-treated hydrophilic surfaces. The superhydrophobicity with the low water adhesion was achieved on the post-aged surfaces preserving the nanofibrils with high aspect ratio and large distance due to the decrease of the oxygen-containing groups after the surface restructuring.

关键词： Polypropylene Plasma nanotexturing Ageing Surface restructuring Superhydrophobicity

Dielectric Behavior of Middle Phase Microemulsion

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Chinese Chemical Letters 2000年第8期11卷 739-742页

作者： lei, JP Li, y Zhao, KS S China Normal Univ Dept Chem Guangzhou 510631 Peoples R China

Dielectric measurements were performed on middle phase microemulsions composed of sodium dodecylsulfate(SDS), cetyltrimethylammonium bromide(CTAB), n-butanol, n-heptane and brine. Distinct and unique dielectric behavior, with characteristic frequency dependence regularity on the salinity of the microemulsions, was observed in the low-frequency range from 10-10(3)Hz. It can be considered to be an interfacial polarization mechanism.

关键词： middle phase microemulsions dielectric spectroscopy relaxation time

Activatable chemiluminescence probe based on four-arm PEGconjugated-pyropheophorbide-a for in vivo autofluorescence-free imaging of peroxynitrite

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Science China Chemistry 2025年

作者： Jianmei Ke lei Ding Ronggui Lian Cheng Zheng Wenjun Li Aixian Zheng yupeng Sun Ming Wu y.ngyi Zeng Xiaolong Liu Maochun Hong Xiaolong Zhang The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province Mengchao Hepatobiliary Hospital of Fujian Medical University Ganjiang Innovation Academy Chinese Academy of Sciences School of Rare Earths University of Science and Technology of China College of Chemistry Fuzhou University State Key Laboratory of Structure Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

Peroxynitrite（ONOO-） is a highly reactive nitrogen species that plays pivotal roles in cell signal transduction and physiological or pathological progresses. However, commonly used ONOO-optical imaging probes are still hampered by high background/autofluorescence（fluorescence probe）, short emission wavelength, or poor selectivity in the case of chemiluminescence. Herein,we report a facile method to prepare an activatable chemiluminescence probe（PPA-PEG） with good biocompatibility and functionality for in vivo autofluorescence-free imaging of ONOO-. The PPA-PEG consists of pyropheophorbide-a（PPA）, a typical deep red photosensitizer that acts as both the recognition and signaling element, and 4-arm poly（ethylene glycol）(4-arm PEG), which improves the biosafety and water solubility of probe. These components can self-assemble into nanoparticles（namely PPA-PEG nanoprobe） in aqueous solution. The PPA-PEG nanoprobe showed an ultra-low chemiluminescence signal before interacting with ONOO-, but exhibited good selectivity, high sensitivity and a fast response toward ONOO-. The PPAPEG was successfully applied to image cellular ONOO-changes, as well as the endogenous ONOO-changes in inflammation models and subcutaneous or orthotopic hepatocellular carcinoma（HCC） tumors models in living mice. In vitro and in vivo studies verified the good detection and imaging capabilities of PPA-PEG for peroxynitrite, demonstrating suitable tissue penetration and a high signal-to-background ratio（SBR）. Thus, our nanoprobe can serve as a valuable activatable chemiluminescence imaging tool for study.ng important peroxynitrite-related chemical and biological applications.

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Nucleon-pair approximation with uncoupled representation

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Chinese Physics C 2021年第5期45卷 129-140页

作者： y.lei y.Lu y.M.Zhao School of National Defense Science and Technology Southwest University of Science and TechnologyMianyang 621010China College of Physics and Engineering Qufu Normal UniversityQufu 273165China Shanghai Key Laboratory of Particle Physics and Cosmology School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IFSA(CICIFSA) Shanghai Jiao Tong UniversityShanghai 200240China

In this paper,we propose an approach to nucleon-pair approximation(NPA)with m-scheme bases,in which the collective nucleon pairs are represented in terms of antisymmetric matrices,and commutations between nucleon pairs are given using a matrix multiplication that avoids angular-momentum couplings and *** the present approach significantly simplifies the NPA ***,it is formulated on the same footing with and without isospin.

关键词： uncoupled representation nucleon-pair approximation formalism computational efficiency

Role of equal-strain assumption in unit-cell theory for consolidation with vertical drains

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Journal of Central South University 2017年第12期24卷 2914-2923页

作者： lei Guo-hui XU Li-dan ZHEng Qiang ng Charles Wang Wai Key Laboratory of Geomechanics and Embankment Engineering of the Ministry of Education Geotechnical Research Institute Hohai University Department of Civil and Environmental Engineering The Hong Kong University of Science and Technology

In the development of unit-cell theory for the analytical analysis of consolidation with vertical drains, the equal-strain assumption is often made with the intention of modelling consolidation under uniform settlement conditions. In contrast, the free-strain assumption for modelling consolidation under uniform load conditions is seldom employed, mainly because of the complexities involved in the analysis. This study derives a rigorous analytical solution to the generalised governing equations of free-strain consolidation with a vertical drain subjected to an instantaneous load. Calculated results from the newly proposed solution are compared with those from three available solutions derived based on the equal-strain assumption. Surprisingly good agreement is obtained in terms of excess pore-water pressure, degree of consolidation, and settlement. Horizontal profiles of settlement were not uniform before the end of consolidation. This indicates that the uniform settlement condition is not actually reproduced by the analytical solutions derived based on the equal-strain assumption. The equal-strain assumption is a sufficient but not necessary condition for deriving an analytical solution to unit-cell consolidation theory. The assumption plays no role in modelling consolidation under uniform settlement conditions but simplifies the analytical analysis of free-strain consolidation and results in an approximate solution of high accuracy for consolidation under uniform load conditions. Moreover, drain resistance and smear effects not only retard the consolidation rate, but also importantly shape the vertical and horizontal profiles of excess pore-water pressure, respectively.

关键词： consolidation ground improvement pore pressures settlement vertical drain

Fluctuating hydrodynamic methods for fluid-structure interactions in confined channel geometries

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Applied Mathematics and Mechanics(English Edition) 2018年第1期39卷 125-152页

作者： y. WAng H. lei P.J. ATZBERGER Department of Mathematics University of California Santa Barbara Santa Barbara CA 93106 U. S. A. Pacific Northwestern National Laboratories Richland WA 99354 U. S. A.

We develop computational teractions subject to thermal fluctuations geometry. The methods take into account methods for the study of fluid-structure in- when confined within channels with slit-like the hydrodynamic coupling and diffusivity of microstructures when influenced by their proximity to no-slip walls. We develop stochas- tic numerical methods subject to no-slip boundary conditions using a staggered finite volume discretization. We introduce techniques for discretizing stochastic systems in a manner that ensures results consistent with statistical mechanics. We show how an exact fluctuation-dissipation condition can be used for this purpose to discretize the stochastic driving fields and combined with an exact projection method to enforce incompressibil- ity. We demonstrate our computational methods by investigating how the proximity of ellipsoidal colloids to the channel wall affects their active hydrodynamic responses and passive diffusivity. We also study for a large number of interacting particles collective drift-diffusion dynamics and associated correlation h/actions. We expect the introduced stochastic computational methods to be broadly applicable to applications in which con- finement effects play an important role in the dynamics of microstructures subject to hydrodynamic coupling and thermal fluctuations.

关键词： fluctuating Eulerian-Lagrangian method hydrodynamics immersed (SELM) ellipsoidal colloid boundary method stochastic mobility nanochannel

Effect of Inorganic Filler on Thermally Stimulated Current in Low-density Polyethylene

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Journal of Materials Science & Technology 1997年第3期13卷 223-226页

作者： lei, QQ Fan, y Wang, X Lin, JQ Xiong, yL Dept. of Electrical Materials Engineering Harbin University of Science and Technology Harbin 150040 China

By measuring the thermally stimulated current (TSC) spectra at various fields in low-density polyethylene with inorganic filler (f-LDPE) and comparing with those in LDPE, we found that their TSC spectra show significant distinction. In virtue of analysing change of peak current, peak temperature and activation energy with poling field, it can be depicted that the TSC in f-LDPE specimen comes from dipole relaxation of residual silanol groups on surface of filler, but the injected electrons in very high fields, no doubt, are captured in deeper traps, and they can not be released even near 100 degrees C. The filler (kaolin) plays a key role in changing the TSC spectra through deep and interfacial traps existing between the filler and the polymer matrix. Whereas, the TSC spectra of LDPE specimen possess marked characteristics of electron release from traps in amorphous-crystalline or crystalline region.

关键词： Low density polyethylenes