Theoretical Study on Structures and Electronic Spectra of Linear Chain Cluster BC_(2n)B (n=1～12)

应用密度泛函理论,在B3LYP/6-31G*水平上优化得到了线性簇合物BC2B(n=1～12,D∞h)的平衡几何构型,并n计算了它们的谐振动频率.在优化平衡几何构型下,通过TD-B3LYP/cc-pvDZ和TD-B3LYP/cc-pvTZ计算,分别得到了n=1～12和n=1～7的X1Σg→11Σ+u电子跃迁的垂直激发能和对应的振子强度.在B3LYP/6-311+G*水平上计算得到+了簇合物BC2B(n=1～12,D∞h)的电离能.基于计算结果,导出了BC2B体系X1Σg→11Σ+u电子跃迁能以及第一电离能+nn与体系大小n的解析表达式.Using density functional theory, the geometries and the vibrational frequencies of linear chain BC2 B (n=1～12, D∞h) have been investigated at the B3LYP/6-31G* level. Time-dependent density func- n tional theory (TD-DFT) has been used to calculate the vertical transition energies and oscillator strengths for X1Σg →11Σ+u transitions of BC2 B with the cc-pvTZ and cc-pvDZ basis sets. At the B3LYP/6-311+G* + n level, the single-point energies of the clusters have been calculated in order to determine the first ionization energies. On the basis of present calculations, the explicit expressions for the size dependence of the excita- tion energy, the first adiabatic ionization energies (AIE) and vertical ionization energies (VIE) in linear car- bon chains were suggested.厦门大学固体表面物理化学国家重点实验室开放课题基金;; 国家自然科学基金;; 河南省自然科学基金(Nos. 20173042; 20233020; 20021002;0311011200)资助项目

Structure and Electronic Spectrum of Linear Carbon Chains LiC_(2n)Li Studied with Density Functional Theory

应用密度泛函理论,在B3LYP/6 31G(d)水平上优化得到了线型簇合物LiC2nLi(n=1 ~10,D∞h)的基态平衡几何构型,并计算了它们的谐振动频率.利用含时密度泛函理论,计算了簇合物LiC2nLi的X1∑ +g→11∑ +u跃迁的垂直激发能,以及相应的振子强度.基于计算结果,建立了跃迁能和体系大小n的解析关系式. 同时也计算了体系的第一绝热电离能,讨论了体系的电离能与体系大小n的关系.The geometries and the vibrational frequencies of linear chains LiC_(2n)Li(n=1~10) were investigated by density functional theory at the B3LYP/631G(d) level. Time-dependent density functional theory was used to calculate the vertical transition energies and oscillator strengths of X~1∑~+_g→1~1∑~+_u transitions in LiC_(2n)Li. Based on the present calculations, the explicit analytic expression between the vertical transition energies and n was obtained. Meanwhile, the first adiabaticionization energies werecalculated, and the relationship between the adiabaticionization energiesand nhas also been discussed.固体表面物理化学国家重点实验室(厦门大学)开放课题基金 (200306);; 国家自然科学基金 (20173042);; 河南省自然科学基金 资助项目(0311011200)

Theoretical Study on the Electronic Spectra of cis-HOOOH and trans-HOOOH

用密度泛函方法(DFT)和全活化空间自洽场方法(CASSCF)以及耦合簇理论(CCSD)优化了反式和顺式HOOOH的平衡几何构型,用DFT计算了HOOOH顺反异构化反应的势能曲线和谐振动频率.用含时密度泛函理论(TD-DFT)和二阶全活化空间微扰理论(CASPT2)计算了反式和顺式HOOOH垂直激发能.计算结果表明:(1)反式异构体比顺式异构体稳定;(2)两种稳定构型的异构化反应有两种路径;(3)对于垂直跃迁能最低的单态和叁态,反式的垂直跃迁能比顺式的低;(4)在单激发态中,CASPT2方法预测的顺式HOOOH寿命最长的激发态为21A″,其跃迁能是167.43nm,寿命为1.44×10-5s;反式HOOOH寿命最长的激发态为21A,其跃迁能是165.52nm,寿命为2.07×10-5s.Equilibrium geometries of cis-HOOOH and trans-HOOOH have been investigated using the density functional theory (DFT), complete active space self-consistent-field (CASSCF), and coupled cluster with single and double replacement (CCSD) approaches. The harmonic vibrational frequencies on the optimized geometries were calculated using the DFT theory. The potential energy curve of the isomerization between the trans-HOOOH and cis-HOOOH was obtained by DFT calculations. Time-dependent density functional theory (TD-DFT) and complete active space perturbation theory of second order (CASPT2) calculations have been performed to obtain the vertical excitation energies of selected low-lying singlet and triplet excited states. Computed results show that: (1) trans-isomer is more stable than cis-isomer; (2) there are two pathways of the conversion between the trans-HOOOH and cis-HOOOH; (3) the vertical excitation energies of the lowest singlet and triplet excited states in trans-HOOOH are lower than those in cis-isomer; (4) in the singlet excited states, 21A state in trans-HOOOH and 21A″ state in cis-HOOOH have the longest lifetimes of 2.07×10-5 s and 1.44×10-5 s with the excitation energies of 165.52 and 167.43 nm, respectively.国家自然科学基金(20473062,20233020,20021002,20173042);; 厦门大学固体表面物理化学国家重点实验室开放课题基金(200306);; 河南省自然科学基金(0311011200,200510475012)资助项

Structure and Electronic Spectrum of Linear Carbon Chain PC_(2n)P Studied with DFT

应用密度泛函理论,在B3LYP/6-31G**和B3LYP/6-311G**水平上优化得到了线型簇合物PC2nP(n=1-10)的基态平衡几何构型,计算了它们的谐振动频率.在基态平衡构型下,利用含时密度泛函理论,计算得到了簇合物PC2nP(n=1-10)的垂直激发能和相应的振子强度,导出了激发能与体系大小n的解析关系式.The geometries and the vibrational frequencies of linear carbon chain PC_ 2nP (n=1-10) were investigated by density functional theory(DFT) at the B3LYP/6-31G ** and B3LYP/6-311G ** levels. Time-dependent density functional theory (TD-DFT) was employed to calculate the vertical transition energies and oscillator strengths. On the basis of present calculations, the explicit expressions for the size dependence of the excitation energy in linear carbon chain was suggested.ThisresearchwassupportedbyStateKeyLaboratoryforPhysicalChemistryofSolidSurfaces(XiamenUniversity)(200306),andNaturalScienceFoundationofChina(20173042,20233020)

动脉粥样硬化性肾动脉狭窄的早期发现

探讨冠状动脉造影同时行肾动脉造影的必要性及动脉粥样硬化性肾动脉狭窄的相关危险因素分析。共 4 91例临床疑似冠心病患者行冠状动脉造影同时行非选择性或选择性肾动脉造影 ,并对相关的临床因素进行评价 ,筛选出动脉粥样硬化性肾动脉狭窄的独立危险因素。冠心病组患者中动脉粥样硬化性肾动脉狭窄的发病率为2 0 % ,显著高于非冠心病组 (2 .6 % )。冠心病、外周血管疾病是动脉粥样硬化性肾动脉狭窄的独立危险因素 (多元Logistic回归分析示 ,P <0 .0 0 1、P =0 .0 0 3) ,是其早期发现的指标。对怀疑有冠心病的患者 ,在冠状动脉造影同时行肾动脉造影有助于动脉粥样硬化性肾动脉狭窄的早期发现

Research on the Mechanisms by Which Thermophilic Fungi Promote the Hyphal Growth of Agaricus bisporus

嗜热真菌是蘑菇堆肥二次发酵后培养阶段的主要微生物类群。它们在堆肥中的数量及活性与蘑菇的产量有很大的相关性。本文综述了近年来，国外以嗜热色串孢（SCyTAlIdIuMTHErMOPHIluM）为典型种，研究其对蘑菇菌丝促生作用的生物机制的主要成果，国外主要研究了嗜热色串孢在堆肥中的分布、数量，生长动力学特性以及呼吸机制等，同时发现嗜热色串孢的呼吸作用形成适宜的CO2浓度可使得蘑菇菌丝尽早占料，获取生态优势，本文还介绍了国内有关嗜热真菌的研究及应用。Thermophilic Fungi are the dominant species among all kinds of microorganisms in mush-room compost during the temperature-controlled process of phase Ⅱ.The amount and activity of the Fun-gal mycelium have been observed to be positively correlated with mushroom yield.This article summaries the recent research on the mechanisms by which thermophilic Fungi promote thehyphal growth of Agaricus bisporus.In order to study the growth-promoting eFFect by these Fungi, Scytal-idium thermophilum was used as a model organism to investigate its distribution and amount in compost,growth characteristics,respiration pathway.The results showed that the concentration of CO2 was an im-portant parameter that inFluenced the hyphal extension rates of Agaricus bisporus.The research in China was also presented

温度对油页岩快速热解特性的影响

采用喷动载流床快速热解装置,研究桦甸大城子4层油页岩的低温快速热解特性.采用改变气速的方法使不同热解温度下气体的停留时间一致,探讨不同热解温度对油页岩热解的气、液、固三相产物的产率、组成以及三者之间相互关系的影响,确定了在以获得液体燃料为主要目的时,530℃为桦甸大城子4层油页岩低温快速热解的最适宜温度

烟煤固体热载体低温快速热解实验研究

以连续式热解装置为实验平台,藁城和府谷煤为原料,石英砂为热载体,考察了460～520℃范围内热解所得气、液产物收率、组成和性质的变化规律.结果表明,在考察的温度范围内,提高热解温度,热解气、液产物收率增加,液体产物收率最高可达12%左右.热解温度对热解产物中不凝气组成影响显著,热解煤气热值高达25MJ/Nm3以上.焦油组分中酚衍生物含量最高,稠环烃、芳香烃、链烃组分的含量也较高,酚含量随热解温度增高有所降低,而芳烃含量则显著提高.根据实验结果提出了酚-芳烃转化的可能路径

煤与生物油的成浆性能研究

利用不同煤种的煤和生物油制备了不同浓度的生物油煤浆,考察了生物油煤浆的成浆浓度、表观黏度、流变特性和稳定性。结果表明,生物油煤浆是具有一定屈服应力的非牛顿流体,其流变特性可用宾汉姆方程来描述;生物油煤浆的屈服应力和表观黏度都随着固体浓度的增加而增大;随着剪切速率的增加,生物油煤浆的表观黏度减小;四种煤中,无烟煤的成浆浓度最高,可达42%,其含碳量高达49%,相当于同种煤制成的74%的水煤浆含量。烟煤次之,褐煤最低;生物油与煤粉之间能够形成絮凝性的大分子网络结构,使得生物油煤浆存在屈服应力并能够保持良好的静态稳定性,4.0～5.0 d天没有软沉淀产生,数月没有硬沉淀产生