检索结果-南通市图书馆

Theoretical Studies on the Ground State and Excited State of 2,7′- （Ethylene）-bis-8-hydroxyquinoline

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2008年第3期21卷 263-269页

作者： Hui-xue Li Su-juan pan xiao-feng Wang Tai xiao Biochemical College of Tianshui Normal University Tianshui 741000 China College of Chemical Engineering Northwest Normal University Lanzhou 730070 China

2,7′-（Ethylene）-bis-8-hydroxyquinoline was optimized with DFT/B3LYP and ab initio HF methods, so ion- ization potential and electron affinity could be determined. Absorption spectrum was calculated by ZINDO and TD-DFT. CIS method was used to calculate the S1 excited states of the compound and afterwards the emission spectrum was computed. When the solvent effect was taken into account, the computed results show encouraging agreement with known experimental data. The results of analyzing the relationship between the energies and absorption spectra indicate that the ability to transporting electrons is strengthened compared with 8-hydroxyquinoline and that absorption and emission spectra are red-shifted. The intramoleeular reor- ganization energy of tris（2,7′-（ethylene）-bis-8-hydroxyquinoline）-aluminum implies its electron transporting property is worse than tris（8-hydroxyquinoline）-aluminum. The predicted maximum emission wavelength is red-shifted compared with tris（8-hydroxyquinoline）-aluminum.

关键词： 2,7′(Ethylene)-bis-8-hydroxyquinoline Absorption spectrum Emission spectrum Densityfunctional theory

Assessment of bacterial biomass in the highly contaminated urban Nanming River,Guiyang,SW China

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geochimica 2017年第4期36卷 638-644页

作者： Hao xiao Hua-Yun xiao pan Wu Resource and Environmental Engineering College Guizhou University State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of Sciences

High anthropogenic N loads and abundant bacteria are characteristic of highly contaminated urban *** better understand the dispersal and accumulation of bacteria, we determined contents and isotopic compositions of suspended particulate organic matter(SPOM) and bacteria in a highly contaminated urban river(the Nanming)and effluents in winter and summer of 2013. Relative to SPOM, bacterial biomass in the river was depleted in ^(13)C and ^(15)N and its C/N ratio was lower(δ^(13)C:-33.2% ± 3.1%; δ^(15)N:-1.5% ± 1.2%; C/N:4.8 ± 0.6), while effluents showed higher ^(13)C and ^(15)N contents and C/N ratios(δ^(13)C:-25% ± 2.1%; δ ^(15)N:-8.5% ± 1.1%; C/N: 8.1 ± 1.2). Source recognition of SPOM was based on carbon isotopes because they are conservative and distinct between end-members(effluent detritus and bacterial biomass). Using a mixing model,bacterial biomass in the river was calculated to account for <20% and <56% of bulk suspended particulate organic nitrogen in winter and summer, respectively. An N budget showed that bacterial N was a small proportion of total nitrogen(<7.4%) in the riverwater.

关键词： δ^13C δ^15C Bacterial biomass N budget Nanming River

Degradation behaviors of Nabumetone and its metabolite during UV/monochloramine process:Experimental and theoretical study

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第8期142卷 103-114页

作者： Xiang Tu Yunsong Bai Qing Fu Sheng chang Kunfeng Zhang Yang pan Ruiyang xiao Yifu Fu Qi Zhang State Key Laboratory of Environmental Criteria and Risk Assessment State Environmental Protection Key Laboratory of Drinking Water Source ProtectionResearch Centre of Lake EnvironmentNational Engineering Laboratory for Lake Pollution Control and Ecological RestorationChinese Research Academy of Environmental SciencesBeijing 100012China School of Environmental Science and Engineering Suzhou University of Science and TechnologySuzhou 215009China Institute of Environmental Engineering School of Metallurgy and EnvironmentCentral South UniversityChangsha 410083China School of Forestry Northeast Forestry UniversityHarbin 150040China

This study investigated degradation behaviors of a nonsteroidal anti-inflammatory drug Nabumetone(NMT)and its major metabolite 6-methoxy-2-naphthylacetic acid(MNA)in the coupling process of ultraviolet and monochloramine(UV/NH2Cl).The second-order rate constants of the contaminants reacting with reactive radicals(HO·,Cl·,Cl_(2)·-,and CO_(3)·^(-))were determined by laser flash photolysis ***·and Cl·contributed predominantly with 52.3%and 21.7%for NMT degradation and 60.8%and 22.3%for MNA *** presence of chlorides retarded the degradation of NMT,while promoted the destruction of MNA,which was ascribed to the photosensitization effects of MNA under UV *** functional theory(DFT)calculations revealed that radical adduct formation(RAF)was dominant pathway for both HO·and Cl·reacting with the contaminants,and hydrogen atom transfer(HAT)preferred to occur on side chains of NMT and *** reacted with NO_(2)·through single electron transfer(SET)with the second-order rate constant calculated to be 5.35×10^(7)(mol/L)^(-1)sec^(-1),and the contribution of NO_(2)·was predicted to be 13.0%of the total rate constant of NMT in pure water,which indicated that NO_(2)·played a nonnegligible role in the degradation of *** acute toxicity and developmental toxicity of NMT were enhanced after UV/NH_(2)Cl treatment,while those of MNA were *** transformation products of both NMT and MNA exhibited higher mutagenicity than their parent *** study provides a deep understanding of the mechanism of radical degradation of NMT and MNA in the treatment of UV/NH2Cl.

关键词： UV/NH_(2)Cl Reactive species Degradation kinetics Reaction mechanism Degradation products

Dynamic model of multi-agent social evolutionary algorithm and its convergence

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2013年第6期20卷 122-128页

作者： pan xiao-ying CHEN Hao School of Computer Science & Technology Xi'an University of Posts & Telecommunications

With a typical and simple 2-bit problem, a dynamic model of multi-agent social evolutionary algorithm （MASEA） is constructed by dynamic method. Then, the global dynamic shape of MASEA is comprehensively analyzed and the common evolution operators are also formally described. Furthermore, the effect that every evolutionary operator has on the dynamic shape is discovered by attraction analysis of the fixed points in the models. The global convergence of MASEA is also proved.

关键词： multi-agent social evolutionary algorithm fixed point attractive point attractiveness

Optimal synthesis of multi-plant heat exchanger networks considering both direct and indirect methods

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2020年第2期28卷 456-465页

作者： Chenglin chang YufeiWang xiao Feng State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China School of Chemical Engineering Xi'an Jiaotong UniversityXi'an 710049China

Heat exchanger networks(HENs)in separated plants can be simultaneously synthesized through process streams directly or intermediate fluids ***,the direct and indirect methods are studied separately in most existing *** the result,conventional designs are probably suboptimal,because optimal solutions may call for hybrid approach wherein direct and indirect integration methods are used *** circumvent this drawback aforementioned,we propose in this research a novel methodology to synthesize multi-plant HENs considering both direct and indirect *** methodology employs a novel superstructure covering most potential topologies for both interplant and intra-plant heat *** also take into account multiple kinds of intermediate fluids for indirect integration and this has not been fully addressed in previous research.A mixed-integer nonlinear programming(MINLP)is formulated to optimize multi-plant HENs involving indirect and direct *** example from existing literature and one industrial problem are solved to demonstrate the methodology’s capability.

关键词： HENs Multi-plant Heat integration Superstructure MINLP

Improved Electrical Insulation of Rare Earth Permanent Magnetic Materials With High Magnetic Properties

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2009年第2期16卷 84-88页

作者： chang Ying WANG Da-peng LI Wei pan Wei YU xiao-jun QI Min School of Automotive Engineering Dalian University of Technology Dalian 116024 Liaoning China School of Material Science and Technology Dalian University of Technology Dalian 116024 Liaoning China Functional Materials Research Institute China Iron and Steel Research Institute Group Beijing 100081 China

Rare earth permanent magnetic materials are typical electrical conductor, and their magnetic properties will decrease because of the eddy current effect, so it is difficult to keep them stable for a long enough time under a high frequency AC field. In the present study, as far as rare earth permanent magnets are concerned, for the first time, rare earth permanent magnets with strong electrical insulation and high magnetic performance have been obtained through experiments, and their properties are as follows：（i） Sm1 TM17 ： Br=0. 62 T, jHc=803.7 kA/m, （BH）m= 58.97 kJ/m^3, p=7 Ω· m; （2） NdFeB： Br=0.485 T, jHc=766.33 kA/m, （BH）m=37.96 kJ/m^3, ρ=Ω · m. The magnetic properties of Sm2TM17 and NdFeB are obviously higher than those of ferrite permanent magnet, and the electric insulating characteristics of Sm2TM17 and NdFeB applied have in fact been approximately the same as those of ferrite. Therefore, Sm2TM17 and NdFeB will possess the ability to take the place of ferrite under a certain high frequency AC electric field.

关键词： Sm2 TM17 NdFeB electrical insulation eddy current

Influence of baryons on the spatial distribution of matter:higher order correlation functions

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2012年第12期12卷 1603-1612页

作者： xiao-Jun Zhu Jun pan Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China National Astronomical Observatories Chinese Academy of Sciences B eijing 100012 China

Physical processes involving baryons could leave a non-negligible imprint on the distribution of cosmic matter.A series of simulated data sets at high resolution with identical initial conditions are employed for count-in-cell analysis,including one N-body pure dark matter run,one with only adiabatic gas and one with dissipative *** and higher order cumulants Sn of dark matter and gas are *** is found that physical processes with baryons mainly affect distributions of dark matter at scales less than 1 h-1 *** comparison with the pure dark matter run,adiabatic processes alone strengthen the variance of dark matter by～10%at a scale of 0.1 h-1 Mpc,while the Sn parameters of dark matter only mildly deviate by a few *** dissipative gas run does not differ much from the adiabatic run in terms of variance for dark matter,but renders significantly different Sn parameters describing the dark matter,bringing about a more than 10%enhancement to S3 at 0.1 h-1 Mpc and z=0 and being even larger at a higher *** patterns of gas in two hydrodynamical simulations are quite *** of gas at z=0 decreases by～30%in the adiabatic simulation but by～60%in the nonadiabatic simulation at 0.1 h-1 *** attenuation is weaker at larger scales but is still obvious at～10 h-1 *** parameters of gas are biased upward at scales 〈～4 h-1 Mpc,and dissipative processes show an～84%promotion at z=0 to S3 at 0.1 h-1 Mpc in contrast with the～7%change in the adiabatic *** segregation in clustering between gas and dark matter could have dramatic implications on modeling distributions of galaxies and relevant cosmological applications demanding fine details of matter distribution in a strongly nonlinear regime.

关键词： cosmology:dark matter-large-scale structure of universe-methods: statistical

Thermally Stable Guest-Host Polyetherketone Poled Polymer for Electro-Optical Applications

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2002年第8期19卷 1125-1127页

作者： pan Qi-Wei, Fang chang-Shui State Key Laboratory of Crystal Materials Shandong University Ji\'nan 250100 State Key Laboratory on Integrated Optoelectronics of Semiconductor Chinese Academy of Sciences Beijing 100083

The high glass transition temperature polymer polyetherketone doped with disperse red 13 (DR13/PEK-c) has been prepared by the spin-coating method. Through in situ second-harmonic generation, the corona poling temperature was optimized by measuring the temperature dependence of the in situ second-harmonic generation signal intensity under the poling electric field. The linear electro-optic coefficients of the poled polymer films have been determined at 632.8 nm by using a simple interferometric technique. The polymer system was measured after 13 000 h, and found that it remained at 80% of its initial value.

关键词： Harmonic generation

Distance Estimates for Simple Choreographic Solutions of the Three-body Problem

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2022年第10期38卷 1823-1830页

作者： Kuo chang CHEN Bo Yu pan Department of Mathematics “National Tsing Hua University”HsinchuTaiwanChina Department of Applied Mathematics “National Chung Hsing University”TaichungTaiwanChina

In this article we estimate mutual distances of simple choreographic solutions for the Newtonian three-body *** formulas will be proved and our applications include the famous figure-8 orbit.

关键词： n-body problem variational method mutual distance