仲壬基苯氧基乙酸基本常数的测定

利用两相滴定法在(25±0 5)℃下测定了仲壬基苯氧基乙酸(CA-100)在水中的溶解度S,离解常数Ka,以及庚烷中的二聚常数K2和水-庚烷两相间的分配常数Kd.实验测得S=1 30×10-4mol/L,Ka=2 94×10-4,K2=3 29×102,Kd=4 15×102.     

2-乙基已基膦酸单2-乙基已基酯(P_(507))在水—癸醇体系中两相电离常数的测定

本文用VPO 法证实P_(507)在癸醇中以单体形式存在的基础上,用电导滴定法测定了水相中萃取剂总浓度S,并用pH 两相滴定法测定了P_(507)在水一癸醇体系中的电离常数K_α、两相分配常数Kd 和两相电离常数K_(αE).测定值:S=5.30×10~(-5)M; pKα=3.88;1gKd=3.18; pK_(αE)=7.06.     

Fenton降解活性黑5的褪色动力学研究

利用在线分光光度法对Fenton试剂降解活性黑5模拟废水进行褪色行为研究,考察了FeSO4初始浓度、H2O2初始浓度、pH值、反应温度等因素对活性黑5褪色过程的影响规律.结果表明,Fenton氧化过程分为两个拟一级动力学过程,反应前期褪色速率常数(k1)和反应后期褪色速率常数(k2)相差约5倍.增大Fe2+的初始浓度和体系温度能够增加k1和去除率,且k1与Fe2+初始浓度线性相关,反应活化能为3.451 kJ/mol;H2O2初始浓度和pH值存在最佳值,分别为2.118 mmol/L和3.     

安徽省自然科学基金结题项目简介(14)

1.主要研究结果和创新之处 (1)利用牛肾上腺皮质束、网状带细胞(BAC细胞)培养,放射性同位素受体结合标记,首次证明本地黄牛BAC细胞表面分布有机能性碱性成纤维细胞生长因子(FGF2)的高、低亲和力受体。它们高亲和力受体(具有酪氨酸激酶活性)的数目为4500个/细胞,低亲和力受体(硫酸乙酰肝素蛋白多糖HSPG)数目为28000个/细胞。两种受体的平衡解离常数(Kd)分别为23.5和381.9pm;转化生长因子β1(TGFβ1)和促肾上腺皮质激素(ACTH)刺激均可增加BAC细胞表面的FGF2受体数目。前者增加的高、低亲和力受体数目分别为6500个/细胞和140000个/细胞(Kd分别为3.151×10~(-11)mol/l     

中蜂(Apis cerana Smith)和意蜂(Apismellifera Linnaeus)乙酰胆碱酯酶(AChE)性质比较研究

试验结果表明,中蜂(Apis cerana Smith)和意蜂(Apis mellifera Linnaeus)的乙酰胆碱酯酶(AchE)对底物乙酰硫代胆碱的反应性质具有明显的不同。中蜂的AchE的反应初速度和反应进程曲线的线性相关时间范围分别是0.027(OD_(412)值/min,0.8头)和0—10分钟,而意蜂则分别为0.012和0—15分钟。米氏常数值和最大反应速度值,中蜂分别为6.25mmol/L和0.105(OD_(412)值/min,0.4头),意蜂分别为0.862和0.015(仅为中蜂的13.8％和14.3％)。中蜂和意蜂AchE对残杀威的双分子速率常数值(K_i),氨基甲酰化常数(K_2)、解离常数(K_d)以及I_(50)值没有明显的差异。但是,对敌百虫的反应确明显不同,K_i、K_2、K_d和I_(50)值分别相差2.70、1.39、1.94和5.64倍。说明中蜂和意蜂AchE对氨基甲酸酯类化合物和有机磷类化合物的反应是不同的。     

两种分子形式尿激酶直接水解苄氧羰-L-酪氨酸P-硝基酚酯(CTN)的化学动力学

(1) 以纤维蛋白溶酶原(PG)为底物,H—uk的Km值为L—uk的一半。但以CTN为底物时,H—uk和L—uk的Km值很接近,分别为5×10~(-4)M和4×10~(-4)M。 (2) 在PH7.5—9.0范围内,改变氢离子浓度只影响两种尿激酶水解CTN的最大反应速度V,而Km保持不变。由此断定k_(-1)>>k_2。Km是平衡常数的倒数。以pH对logV作图,求得H—uk和L—uk活性中心可解离基团的PK很接近,分别为7.65和7.85。 (3) ∈—氨基已酸(E-ACA)对两种尿激酶都呈现典型的竞争性抑制作用。EACA对H—uk的Ki为0.8×10~(-2)M,对L—uk的Ki为1.5×10~(-1)M。来源不同的天然胰蛋白酶抑制剂对两种尿激酶都不抑制。 (4) 观察了温度对K_m和k_2的影响,计算了平衡反应和活化过程的各种热力学常数。 (5) 从所得动力学和热力学结果推测,两种分子形式尿激酶的活性中心性质相同,但二者的构象却很不相同,H—uk的结构更有利于进行反应,由此推测H—uk是尿激酶的天然形式,L—uk是前者的降解产物。     

电导法测定298.15K时硫酸氧钒离子对解离常数

为优化钒电池电解液配比和设置合理的充放电制度,需弄清自由钒离子活度和离子对的解离常数及其热力学性质.研究了电导法测定在298.15 K时水溶液中VOSO4.3.53H2O(s)的电导率,利用Origin数据拟合求出极限摩尔电导;采用改进的Ostwald稀释定律和改进的Davies方程求解活度系数,进而求得溶液的真实离子强度;采用Fuoss方法求解硫酸氧钒离子对的解离常数.经过数据处理得到298.15 K时硫酸氧钒极限摩尔电导率Λ0为203.2520325 S.dm2.mol-1,硫酸氧钒离子对的解离常数Kd为0.001 961 62,为电池性能有关的热力学性质提供了基础数据.     

叔丁基氯NMR水解动力学机理的研究

运用NMR技术对叔丁基氯在60％丙酮水溶液中的水解动力学机理进行了研究。该水解反应为准一级反应,其速率常数k=(1.34±0.2)×10~(-4)/s,反应的半衰期为τ_(1/2)=k_1~(-1) In2=5284s。     

HO2 + ClO气相反应机理及主通道速率常数的理论研究

本文采用CCSD(T)/aug-cc-pVTZ//B3LYP/6-311+G(2df,2p)方法构建了HO_2+ClO反应体系的单、三重态反应势能剖面,并对该反应主通道的速率常数进行了计算研究.结果表明,HO_2+ClO反应中存在4条抽氢通道R1(HOCl+~1O_2)、R2(HOCl+~3O_2)、R3(HCl+~1O_3)和R4(HCl+~3O_3)以及2条抽氧通道R5(OOCl+HO)和R6(OClO+HO),其中抽氢通道R2(HOCl+~3O_2)和R3(HCl+1O3)的能垒比其它四个通道的能垒降低了9.08~42.90kcal·mol-1,是标题反应的优势通道.采用传统过渡态理论并结合Wigner校正对优势通道R2(HOCl+~3O_2)和R3(HCl+~1O_3)在240~425K范围内的速率常数进行了计算.计算结果表明,通道R2(HOCl+3 O2)的速率常数比R3(HCl+~1O_3)的对应值大了3~5个数量级,表明标题反应的速率主要取决于通道R2(HOCl+~3O_2).此外在298 K时,通道R2(HOCl+3O2)的速率常数为2.76×10-15 cm3·molecule-1·s-1,与实验值较为吻合.     

Zn(Ⅱ)/Zn交换反应速度常数的交流阻抗法测定

本文应用交流胆抗法测定Zn(Ⅱ)/Zn体系在微酸性硫酸盐溶液中的交换反应速度常数.根据电荷转移电阻(R_(ct))计算得交换反应速度常数(k)为(3.1±0.5)×10~(-5)ms~(-1).k值与转速无关,表明Zn~(2+)离子从本体溶液向电极表面的扩散不参与界面上的交换速度过程.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the