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Density Functional Study on the Reaction Mechanism for the Reaction of Ni^+ with Ethane

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Chinese Journal of Chemistry 2002年第3期20卷 220-226页

作者：张冬菊刘成卜刘永军胡海泉 institute of Theoretical Chemistry Shandong University Jinan Shandong 250100 China

The mechanism of the reaction of Ni^+ (~2D) with ethane in the gas-phase wasstudied by using density functional theory. Both the B3LYP and BLYP functionals with standardall-electron basis sets are used to give the detailed information of the potential energy surface(PES) of [Ni, C_2, H_6]^+. The mechanisms forming the products CH_4 and H_2 in the reaction of Ni^+with ethane are proposed. The reductive eliminations of CH_4 and H_2 are typicaladdition-elimination reactions. Each of the two reactions consists of two elementary steps; C―C orC―H bond activations to form inserted species followed by isomerizations to form product-likeintermediate. The rate determining steps for the elimination reactions of forming CH_4 and H_2 arethe isomerizations of the inserted species rather than C―C or C―H bond activations. Theelimination reaction of forming H_2 was found to be thermodynamically favored compared to that ofCH_4.

关键词： Ni^+ C_2H_6 reaction mechanism density func- tional theory

Theoretical Studies of the Aminolysis for N-Methyl β-Sultam in Solution

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Chinese Journal of Chemistry 2005年第10期23卷 1319-1326页

作者：何茂霞冯大诚王焕杰蔡政亭 institute of Theoretical Chemistry Shandong University Jinan Shandong 250100 China

The aminolysis and the effect of water on the aminolysis processes of n-methyl β-sultam have been studied using density functional theory （DFF） method at the B3LYP/6-31G＊ level. The stationary structures and energies have been investigated for both reactions to find two different reaction channels. Specific and general solvent effects have been evaluated and the most favored pathway was found. The presence of solvent disfavors the reaction, whereas the participation of water in the aminolysis reaction plays a positive role and reduces the activation energy greatly. All transition states in the assisted aminolysis are 35-70 kJ/mol lower than those for the non-assisted reaction.

关键词： N-methyl β-sultam water-assisted aminolysis mechanism density functional theory (DFF)

Exploring seasonal acidification in the Yellow Sea

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维普期刊数据库

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Science China Earth Sciences 2018年第6期61卷 647-658页

作者： Weidong ZHAI institute of Marine Science and Technology Shandong University

The Yellow Sea on the western continental margin of the North Pacific Ocean is of major ecological and economic importance. Four field surveys were conducted during May and November 2012, August 2015, and January 2016, investigating seasonal variations in dissolved oxygen and carbonate system parameters of this marginal sea. Results showed that the Yellow Sea cold water mass accumulated respiration-induced CO_2 in subsurface and bottom waters in summer and autumn, leading to acidified seawaters with critical carbonate saturation states of aragonite(Ω_(arag)) of less than 1.5. These seriously acidified seawaters occupied one third of surveyed areas in summer and autumn, likely affecting local calcified organisms and benthic communities. In a future scenario for the 2050 s, in which the atmospheric CO_2 mole fraction increases by 100 μmol mol-1, half of the Yellow Sea benthos would be seasonally covered by acidified seawater having a critical Ω_(arag) of less than 1.5. The corresponding bottom-water p H_T would be around 7.85 in summer, and 7.80 in autumn. Of the China seas, the Yellow Sea cold water mass represents one of the ecosystems most vulnerable to ocean acidification.

关键词： CaCO_3saturation state Ocean acidification Yellow Sea pH Dissolved oxygen Benthic communities

Effects of the thermal environment on the thermal control system of AMS

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Science China(Technological Sciences) 2015年第3期58卷 526-533页

作者： CUI Zheng WANG NaiHua WANG Kun CHENG Lin institute of Thermal Science and Technology Shandong University

This paper presents an overview of the AMS thermal control system and its thermal environment on the *** give examples of analysis and correlation of space environmental impacting on the thermal control system of *** most critical factors that affect the thermal environment to AMS are beta angle,attitude of ISS,ISS solar array and ISS radiator *** design of a special sandwich structure with embedded heat pipes provides the radiator with higher heat transfer ability for electronics and power crates,and it provides a large heat retaining capacity to balance the frequent changes of the space environment temperatures as *** cold cases,the thermostatically controlled heaters are working actively to protect ***,sometimes,because of ISS special operations plus extreme beta angle condition,AMS needs to request NASA to adjust the ISS configuration for thermal *** AMS thermal control system is reliable and stable,which has been verified by its operation on the ISS for more than three *** the detectors operate normally,the electronics and crates work within their specific temperature limits.

关键词： AMS thermal control system thermal regularity thermal control

Numerical modeling and multi-objective optimization of a novel cross-flow heat exchanger with rotated aligned tube bank

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Science China(Technological Sciences) 2018年第7期61卷 982-993页

作者： WANG KunYu CHENG Lin institute of Thermal Science and Technology Shandong University

A novel cross-flow heat exchanger with a rotated aligned tube bank is designed and utilized in a cement plant. The heat exchanger is numerically modeled with various tube pitches in order to obtain correlations of the shell-side average Nusselt number and friction factor. Then, a multi-objective optimization approach is performed based on the genetic algorithm. The goal of this study is to maximize the heat transfer rate and minimize the pressure drop. Pareto optimal solutions are obtained, which indicate that the increase in the heat transfer rate leads to an increase in pressure drop, and vice versa. In addition, heat exchanger effectiveness, total cost, and the ratio of the heat transfer rate to the fan/pumping power demonstrate different variations with the two objective functions. Several selection criteria are discussed to determine the optimal design and to help designers select an appropriate solution based on actual requirements. Two multi-objective optimization design schemes are compared to the original design under the same heat transfer rate. Results show that pressure drop decreases by 67.9% and 69.7%, respectively,and total annual cost decreases by 2.4% and 16.3%, respectively.

关键词： tube bank numerical modeling multi-objective optimization genetic algorithm

Lunar absolute reflectance as observed by Chang'E-1 Imaging Interferometer

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Science China(Physics,Mechanics & Astronomy) 2015年第8期58卷 102-107页

作者： ZHANG Jiang LING ZongCheng LIU JianZhong WU ZhongChen LI Bo NI YuHeng School of Physics Shandong University institute of Space Sciences Shandong University shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space ScienceShandong University institute of Geochemistry Chinese Academy of Sciences

Lunar absolute reflectance, which describes the fraction of solar radiation reflected by the Moon, is fundamental for the Chang'E-1 Imaging Interferometer(IIM) to map lunar mineralogical and elemental distributions. Recent observations made by the Spectral Irradiance Monitor(SIM) onboard the Solar Radiation and Climate Experiment(SORCE) spacecraft indicate that temporal variation in the solar radiation might have non-negligible influence on reflectance calculation, and the SIM measurements are different from the two previously used solar irradiances, i.e., ATLAS3 and Newkur. To provide reliable science results, we examined solar irradiance variability with the SIM daily observations, derived lunar absolute reflectances from the IIM 2A radiance with the SIM, ATLAS3 and Newkur data, and compared them with the Chandrayaan-1 Moon Mineralogy Mapper(M3), the Robotic Lunar Observatory(ROLO) and the Kaguya Multispectral Imager(MI) results. The temporal variability of the SIM solar irradiance is 0.25%–1.1% in the IIM spectral range, and less than 0.2% during the IIM observations. Nevertheless, the differences between the SIM measurements and the ATLAS3 and Newkur data can respectively rise up to 8% and 5% at particular IIM bands, resulting in discrepancy between which might affect compositional mapping. The IIM absolute reflectance we derived for the Moon using the SIM data, except for the last two bands, is consistent with the ROLO and the MI observations, although it is lower.

关键词： Chang'E-1 Imaging Interferometer (IIM) absolute reflectance solar irradiance

Modeling of Rectangular Microchannel Heat Sink with Non-Uniform Channels and Multi-Objective Optimization

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Journal of Thermal Science 2024年第5期33卷 1701-1711页

作者： SHANG Xueshuo WANG Yixin LI Qingwen WANG Rui CUI Zheng SHAO Wei institute of Advanced Technology Shandong UniversityJi'nan 250014China institute of Thermal Science and Technology Shandong UniversityJi'nan 250014China shandong institute of Advanced Technology Ji'nan 250100China

Rectangular microchannel heat sinks(MCHS)are widely used to cool high-heat-flux electronic ***,previous studies focused mainly on MCHS with uniform channels(UCs).This study considers a microchannel heat sink with non-uniform channels(NUCs).A mathematical model is developed based on energy equations and the Darcy flow *** expressions for total thermal resistance and coolant pressure drop are derived using the thermoelectric *** and numerical simulations are performed to verify the mathematical *** non-uniformity increases,total coolant pressure drop decreases but at the cost of higher thermal *** overall performance of NUCs is better than that of UCs because of their lower ratio of pumping power to cooling *** transfer performance of NUCs changes little for more than 120 channels and depends mainly on channel arrangement.A multi-objective optimization is conducted to minimize the thermal resistance and pumping power of an *** optimal NUC saves 64%pumping power compared with a conventional UC for the total thermal resistance of 0.1℃/W,indicating that the use of non-uniform channels could be very helpful to reduce the flow resistance of MCHS.

关键词： microchannel heat sink non-uniform channel mathematical model multi-objective optimization

Adsorption and Desorption of Mercury(Ⅱ) in Three Forest Soils in shandong Province,China

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Pedosphere 2013年第2期23卷 265-272页

作者： XUE Tong WANG Ren-Qing ZHANG Meng-Meng DAI Jiu-Lan Environment Research institute Shandong University institute of Ecology and Biodiversity School of Life SciencesShandong University shandong Provincial Engineering and Technology Research Center for Vegetation Ecology Shandong University

As one of the most toxic heavy metals with persistence, bioaccumulation, and toxicity in environment, mercury and its envi- ronmental problems have caused a global concern. To fully understand the behavior and fate of mercury （Hg）（II） in forest soils, a series of batch experiments were conducted to determine the adsorption and desorption characteristics of Hg（II） by three dark brown forest soils from Mount Taishan, Laoshan Mountain, and Fanggan Village in shandong Province, China. The adsorption solution was prepared using 0.1 mol L-1 NaNO3 as background electrolyte, with Hg（II） at rising concentration gradients of 0.0, 2.0, 4.0, 6.0, 8.0, and 10.0 mg L-1. Fourier transform infrared （FTIR） spectroscopy was adopted to characterize the soil samples and soil-Hg complexes. It was found that Hg（II） adsorption isotherms could be well fitted with both Langmuir and Freundlich equations. The soil from Mount Taishan had the largest potential Hg（II） adsorption capacity, though with less adsorptive intensity. The percentages of Hg（II） desorbed from all soil samples were less than 0.6~, which suggested that all the soils studied had a high binding strength for Hg（II）. The soil from Mount Taishan had a higher Hg（II） desorption capacity than the other soils, which indicated that the Hg（II） deposited on the topsoil of Mount Taishan from atmosphere may easily discharge to surface water through runoff. Results of the FTIR spectroscopy showed that the three soils contained the same functional groups. The relative absorbencies of soil-Hg complexes changed significantly compared with those of the soil samples and the adsorption of Hg（II） mainly acted on the O-H, C-O, and C=O groups of the soils.

关键词： atmosphere deposition binding strength FTIR spectroscopy functional groups soil^Hg complex

Scheduling Jobs with Release and Delivery Times Subject to Nested Eligibility Constraints

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Journal of the Operations Research Society of China 2021年第1期9卷 63-77页

作者： Yu-Zhong Zhang Shu-Guang Li institute of Operations Research Qufu Normal UniversityRizhao 276826ShandongChina Key Laboratory of Intelligent Information Processing in Universities of shandong(shandong institute of Business and Technology) Yantai 264005ShandongChina College of Computer Science and Technology Shandong Institute of Business and TechnologyYantai 264005ShandongChina

The problem of scheduling jobs with release and delivery time subject to machine eligibility constraints is *** eligible sets of the jobs are nested,and pre-emptions are not *** goal is to minimize the maximum delivery completion time,i.e.,the time by which all jobs are *** the special case of equal release time,a 2-approximation algorithm is presented whose running time depends linearly on the number of *** the general case of unequal release time,a polynomial time approximation scheme is derived.

关键词： Scheduling Nested eligibilityconstraints Release time Deliverytime Polynomial timeapproximationscheme