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Chinese Physics B 2015年第3期24卷 412-417页

作者：张莹莹解廷献李泽瑞石英金明星 Institute of Atomic and Molecular Physics Jilin University Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy Jilin University Department of Physics Dalian Jiaotong University

A quasi-classical trajectory（QCT） calculation is used to investigate the vector and scalar properties of the D ＋ Br O → DBr ＋ O reaction based on an ab initio potential energy surface（X1A state） with collision energy ranging from 0.1 kcal/mol to 6 kcal/mol. The reaction probability, the cross section, and the rate constant are studied. The probability and the cross section show decreasing behaviors as the collision energy increases. The distribution of the rate constant indicates that the reaction favorably occurs in a relatively low-temperature region（T 〈 100 K）. Meanwhile, three product angular distributions P（θr）, P（φr）, and P（θr, φr） are presented, which reflect the positive effect on the rotational angular momentum j＇ polarization of the DBr product molecule. In addition, two of the polarization-dependent generalized differential cross sections（PDDCSs）, PDDCS00 and PDDCS20, are computed as well. Our results demonstrate that both vector and scalar properties have strong energy dependence.

关键词： quasi-classical trajectory cross section rate constant product angular distributions

Diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging parameters and serum tumor markers in rectal carcinoma prognosis

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 1796-1807页

作者： Ren-Qi Mu Jun-Wei Lv Cai-Yun Ma Xiao-Hui Ma Dong Xing Hou-Sheng Ma Department of Radiology Yantai Mountain HospitalYantai 264001Shandong ProvinceChina Department of Radiology Yantai Yuhuangding HospitalYantai 264000Shandong ProvinceChina Department of Gynaecology Yantai Yuhuangding HospitalYantai 264000Shandong ProvinceChina The First Clinical Medical College Xinjiang Medical UniversityUrumqi 830011Xinjiang Uygur Autonomous RegionChina

BACKGROUND Rectal carcinoma(RC),one of the most common malignancies globally,presents an increasing incidence and mortality year by year,especially among young people,which seriously affects the prognosis and quality of life of *** present,dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)parameters and serum carbohydrate antigen 19-9(CA19-9)and CA125 Levels have been used in clinical practice to evaluate the T stage and differentiation of ***,the accuracy of these evaluation modalities still needs further *** study explores the application and value of these methods in evaluating the T stage and differentiation degree of *** To analyze the diagnostic performance of DCE-MRI parameters combined with serum tumor markers(TMs)in assessing pathological processes and prognosis of RC *** A retrospective analysis was performed on 104 RC patients treated at Yantai Yuhuangding Hospital from May 2018 to January *** were categorized into stages T1,T2,T3,and T4,depending on their T stage and differentiation *** addition,they were assigned to low(L group)and moderate-high differentiation(M+H group)groups based on their differentiation *** levels of DCE-MRI parameters and serum CA19-9 and CA125 in different groups of patients were *** addition,the value of DCE-MRI parameters[volume transfer constant(Ktrans),rate constant(Kep),and extravascular extracellular volume fraction(Ve)in assessing the differentiation and T staging of RC patients was ***,the usefulness of DCE-MRI parameters combined with serum CA19-9 and CA125 Levels in the evaluation of RC differentiation and T staging was *** Ktrans,Ve,CA19-9 and CA125 were higher in the high-stage group and L group than in the low-stage group and M+H Group,respectively(P<0.05).The areas under the curve(AUCs)of the Ktran and Ve parameters were 0.638 and 0.694 in the diagnosis of high and low stages,respectively,and 0.672 and 0

关键词： Rectal carcinoma Volume transfer constant rate constant Extravascular extracellular volume fraction Serum carbohydrate antigen 19-9 Serum carbohydrate antigen 125

Consensus Hologram QSAR Model Studying on the Aqueous Hydroxyl Radical Oxidation Reaction rate constants of Organic Micropollutants

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Chinese Journal of Structural Chemistry 2021年第8期40卷 985-993,967页

作者： JIAO Long LEI Bin QU Le LI Rui YAN Chun-Hua LI Hong College of Chemistry and Chemical Engineering Xi’an Shiyou UniversityXi'an 710065China Shaanxi Cooperative Innovation Center of Unconventional Oil and Gas Exploration and Development Xi’an Shiyou UniversityXi'an 710065China College of Petroleum Engineering Xi’an Shiyou UniversityXi'an 710065China

The combination of hologram quantitative structure-activity relationship(HQSAR)and consensus modeling was employed to study the quantitative structure-property relationship(QSPR)model for calculating the aqueous hydroxyl radical oxidation reaction rate constants(kOH)of organic micropollutants(OMPs).Firstly,individual HQSAR model were established by using standard HQSAR *** optimal individual HQSAR model was obtained while setting the parameter of fragment distinction and fragment size to“B”and“3~6”***,consensus HQSAR model was established by building the regression model between the kOH and the hologram descriptors with consensus partial least-squares(cPLS)*** obtained individual and consensus HQSAR model were validated with a randomly selected external test *** result of external test set validation demonstrates that both individual and consensus HQSAR model are available for predicting the kOH of *** with the optimal individual HQSAR model,the established consensus HQSAR model shows higher prediction accuracy and *** is shown that the combination of HQSAR and consensus modeling is a practicable and promising method for studying and predicting the kOH of OMPs.

关键词： QSPR hologram QSAR consensus modeling organic micropollutants hydroxyl radical rate constant

Predicting rate constants for Nucleophilic Reactions of Amines with Diarylcarbenium Ions Using an ONIOM Method

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Chinese Journal of Chemical Physics 2010年第6期23卷 669-674,745页

作者：张志平王晨傅尧郭庆祥中国科学技术大学化学系合肥230026

The rate constants of the nucleophilic reactions between amines and benzhydrylium ions were calculated using first-principles theoretical methods. Solvation models including PCM, CPCM, and COSMORS, as well as different types of atomic radii including UA0, UAKS, UAHF, Bondi, and UFF, and several single-point energy calculation methods （B3LYP, B3P86, B3PW91, BHANDH, PBEPBE, BMK, M06, MP2, and ONIOM method） were examined. By comparing the correlation between experimental rate constants and the calculated values, the ONIOM（CCSD（T）/6-311＋＋G（2df,2p）：B3LYP/6-311＋＋G（2df,2p））//B3LYP/6- 31G（d）/PCM/UFF） method was found to perform the best. This method was then employed to calculate the rate constants of the reactions between diverse amines and diarylcarbenium ions. The calculated rate constants for 65 reactions of amines with diarylcarbenium ions are in agreement with the experimental values, indicating that it is feasible to predict the rate constant of a reaction between an amine and a diarylcarbenium ion through ab initio calculation.

关键词： Amine Diarylcarbenium ion Nucleophilic reaction rate constant N-layered integrated molecule orbit and molecule mechanics

Dependence of Reaction rate constants on Density in Supercritical Fluids

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Chinese Journal of Chemical Engineering 2002年第4期10卷 480-482页

作者：王涛沈忠耀 Department of Chemical Engineering Tsinghua University 北京 100084

A new method,which correlates rate constants of chemical reactions and density or pressure in supercritical fluids,was *** on the transition state theory and thermodynamic principles, the rate constant can be reasonably correlated with the density of the supercritical fluid,and a correlation equation was obtained. Coupled with the equation of state (EOS) of a supercritical solvent,the effect of pressure on reaction rate constant could be *** typical systems were used to test this *** result indicates that this method is suitable for dilute supercritical fluid solutions.

关键词： supercritical reaction rate constant density

Theoretical Study on Mechanism of Reaction of OH with HO2NO2

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Chinese Journal of Chemical Physics 2008年第1期21卷 32-38页

作者： Yan Tian Tian-jing He Li He Fan-chen Liu Dong-ming Chen Department of Chemical Physics University of Science and Technology of China Hefei 230026 China Department of Electronic Science and Technology University of Science and Technology of ChinaHefei 230025 China School of Science Anhui Agricultural University Hefei 230036 China

The reaction of HO2NO2 （peroxynitric acid, PNA） with OH was studied by the hybrid density functional B3LYP and CBS-QB3 methods. Based on the calculated potential energy surface, five reaction channels, H20＋NO2＋O2, HOOH＋NO3, NO2＋HO3H, HO2＋HONO2 and HO2＋HOONO, were examined in detail. The major reaction channel is PNA＋OH→M1→TS1→H2O＋NO2＋O2. Taking a pre-equilibrium approximation and using the CBS-QB3 energies, the theoretical rate constant of this channel was calculated as 1.13×10-12 cm^3/（molecule s） at 300 K, in agreement with the experimental result. Comparison between reactions of HOONO2＋OH and HONO2＋OH was carried out. For HOR＋OH reactions, the total rate constants increase from R=NO2 to R=ONO2, which is consistent with experimental measurements.

关键词： Reaction Peroxynitric acid ab initio calculation rate constant

Theoretical Study on the Reaction Mechanism of SiCl_4 with H in the Gas Phase

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Chinese Journal of Structural Chemistry 2006年第4期25卷 491-496页

作者：孙仁安李钠艾纯芝张宏 Department of Chemistry Liaoning Normal University Dalian 116029 China Department of Chemistry Liaoning Normal University Dalian 116029 China Beijing No.161 High School Beijing 100031 China

The reaction mechanism of SiCl4 with H2 has been studied theoretically using Gaussian 98 program at B3LYP/6-311G^＊ level. Three different reaction paths （a, b, c） in the gas phase were obtained. The geometries, vibrational frequencies and energies of every stagnation point in the reaction channel were calculated and the mechanisms have been confirmed. The results show that path a has an activation energy of 79.12 kcal/mol, which was considered as the main reaction path. Comparably, paths b and c have the energy barriers of 125.07 and 136.25 kcal/mol, respectively. The reaction rate constant was calculated by TST method over a wide temperature range of 900～1600 K, which further confirmed that path a was the main reaction channel

关键词： density functional theory transition state reaction mechanism rate constant

Theoretical Study on Dissociation Mechanisms of Di-ethyl Berylliums and Di-t-butyl Berylliums

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Chinese Journal of Chemical Physics 2014年第2期27卷 168-174,I0003页

作者：孟令彪赵妍张吉强张继成莫卫东汪卓中国工程物理研究院激光聚变研究中心绵阳621900 西南科技大学材料科学与工程学院非金属复合与功能材料重点实验室绵阳621010

The potential energy surfaces （PES） of unimolecular dissociation reactions for di-ethyl beryl- lium and di-t-butyl beryllium are investigated by B3LYP, CCSD（T）, and G3B3 approaches. Possible reaction pathways through either the radical or transition state （TS） of the molecules are considered. The geometries, vibrational frequencies and relative energies for various sta- tionary points are determined. From the study of energetics, the TS pathways arising from concerted molecular eliminations are indicated to be the main dissociation pathways for both molecules. The PES differences of the dissociation reactions are investigated. The activation energies and rate constants will be helpful for investigating the predictive ability of the reaction in further theoretical and experimental research.

关键词： Di-t-butyl beryllium Dissociation reaction Transition state rate constant G3B3 theory

Effect of relative humidity and the presence of aerosol particles on the α-pinene ozonolysis

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Journal of Environmental Sciences 2018年第9期30卷 99-107页

作者： Guoqiang Zhang Hongbo Fu Jianmin Chen Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention(LAP^(3)) Department of Environmental Science and EngineeringInstitute of Atmospheric SciencesFudan UniversityShanghai 200433China

The α-pinene ozonolysis under the different environmental conditions were observed in a smog chamber. The second-order rate constant （k） was determined to be （7.25 ± 0.06） x 10^-17 cm^3/（***） under 20% of relative humidity （RH） and room temperature. RH showed a marked influence on the α-pinene ozonolysis. The value of k increased with KH increase, which was 1.6 times faster at RH = 80% than that at RH = 20%. Additionally, the value of k apparently changed in the presence of the aerosol particles. The diesel soot increased the k value. The fly ash prohibited the reaction, however, H2SO4-treated fly ash promoted the reaction. The information of products gained using FT-IR and SPAMS showed that pinonic acid, 10-hydroxy-pinonic acid and pinic acid could be generated during the α- pinene ozonolysis. Water molecules could take part in the formation of the products, and play a vital role in the degradation of α-pinene. The atmospheric residence time calculation showed that the ozonolysis in the atmosphere is an important way of the α-pinene consumption as compared to that reacted with OH during daytime. The results suggested that the degradation of α-pinene via the ozonization in the atmosphere may be affected greatly by RH, as well as the presence of aerosol particles. The ozonolysis reaction may be an important way of the a-pinene consumption during daytime.

关键词： α-Pinene Ozonolysis RH% Seed aerosol rate constant

Kinetic study of the gas-phase reaction of O3 with three unsaturated alcohols

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Journal of Environmental Sciences 2018年第9期30卷 292-299页

作者： Weiran Li Yi Chen Shengrui Tong Yucong Guo Yunhong Zhang Maofa Ge The Institute of Chemical Physics School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 China State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of SciencesBeijing 100190 China State Key Laboratory for Structural Chemistry of Unstable and Stable Species Peking University Beijing 100871 China University of Chinese Academy of Sciences Beijing 100049 China CAS Research/Education Center for Excellence in Molecular Sciences Beijing 100190 China

rate constants for the reactions of ozone with 1-octen-3-ol, 1-nonen-3-ol and 1-nonen-4-ol have been determined at 298 ±1 K and atmospheric pressure for the first time. The experiments were performed in a 100-L FEP Teflon film bag using absolute rate method; the rate constants were （1.91 ± 0.19） ×10^-17, （1.89 ± 0.20） × 10^-17, and （0.83 ± 0.08） × 10^-17 cm^3/（***） for 1-octen-3-ol, 1-nonen-3-ol, and 1-nonen-4-ol, respectively. The rate constants have been compared with those of unsaturated alcohols structural homologs, and used to estimate the reaction reactivity. The electronegativity of carbon-carbon double bond was calculated by atomic charges analysis. The calculated results show that the electronic effect of the lone pair electrons of hydroxyl oxygen is the main cause of the difference in rate coefficient. According to the obtained rate constants, the atmospheric lifetimes of studied unsaturated alcohols were also estimated, which indicates that the reaction with ozone is an important loss pathway in the atmosphere, especially in polluted areas.

关键词： rate constant Ozone Unsaturated alcohols Atmospheric lifetime