ELECTROCHEMICAL STUDY OF CHOLINE DERIVATIVES TRANSFER ACROSS THE LIQUID LIQUID INTERFACE

Transfer behaviors across the water/nitrobenzene interface were studied for five choline derivatives by chronopotentiometry with linear current scanning, cyclic voltammetry and differential pulse voltammetry. The irreversible hydrolysis reactions coupled to the phase transfer of ions across the water/nitrobenzene interface were observed. The Gibbs energies of the transfer of choline derivatives show the effects of an additive constitution on hydrophobic property of the medicine.

THERMODYNAMICS OF COMPLEXATION OF RARE EARTHS BY L-METHIONINE

The protonation constant of the ligand and stability constants of it complexes with rare earths have been determined by potentiometric titration at 25 degrees C and ionic strength mu=0.15 mol - L-1. The results indicate that rare earth elements can form 1:1 complexes with L methionine. There is an apparent "tetrad effect" in this system. Shift of the yttrium position to the vicinity of Gd can he explained by the different polarisation between the Ln(3+) and the ligand. The enthalpy changed (Lambda H-101) of the coordination reaction as represented by the reaction (M + L (sic) ML) here been measured by calorimetric titration, where M and L. denote are eartus and L-Mer respectively. The Lambda G(101) and Delta S-101 of these reaction have been calculated by using Gibbs' equation, Furthermore, the stability of rare earth complexes with L-Met has been compared with that of Ca3+ Zn3+, Fe2+, Fe3+ complexes with L-Met.

ELECTROCHEMICAL INVESTIGATION OF LIQUID/LIQUID SYSTEMS USING VARIOUS ORGANIC SOLVENTS

The potential windows of the system water/pure solvent (W/P) and water/solvent mixtures(W/S) have been investigated by cyclic voltammetry with solvents whose dielectric constants lie between 5.87 and 34.82. In the presence of LiCI in the aqueous phase and tetrabutytammoniumtetraphenylborate(TBATPB) in the organic phase, the systems water/allyl iso-thiocyanate (W/AIT) and water/nitrobensene (W/NB) show a same wide epotential window. thermodynamic parameters of ion transfer W/AIT interface were determined. In systems of W/P and V/S the influence solvent effect on the standard gibbs energies of transfer of was discussed.

液/液界面新溶剂体系的电化学研究

用循环伏安法测定了离子在水-异硫氰酸烯丙脂(AIT)体系中的标准转移Gibbs能△_o~w G_(tr,i)~0。对含有AIT的混合溶剂的研究,发现了一系列电位窗比较宽的水/有机溶剂体系,讨论了溶剂效应对△_o~w G_(tr,i)~0的影响。

胆碱类药物的液液界面电化学研究

用循环线性电流扫描计时电位法(CLC)、循环伏安法(CV)和微分脉冲伏安法(DPV)研究了五种胆碱类药物在水/硝基苯界面(W/NB)上的转移行为.在水相溶液呈碱性时,观察到了伴有不可逆水解反应的相转移过程.讨论了药物结构中的取代基效应,并依据离子转移的标准 Gibbs 能△_o~wG_(tr)~o 度量了取代基的疏水性效应及药物的脂溶性.

一种无缆自动返回式采水器的设计与研究

海洋环境污染监测、海水化学与地质调查和生物采样，大多数情况下需要现场采集水样。有时需要在不同深度依次采样，获取梯度剖面的现场水体信息，以保证分析结果的统一性、规范性和类比性。近几十年来，水体取样和保存技术迅速发展，各式各样的采水器纷纷问世并获得成功应用。常规CTD葵花式采水器（CTD rosette sampler）（配备尼斯金采样瓶（Niskin bottle）或郭福洛采样瓶（Go-Flo bottle））和船用吸泵均为目前广泛使用的梯度水样采集装置。但其应用各有一定缺陷。因此，设计一种既适用于大型科考船又适用于小型船只、采样深度可精确控制、采水操作简便、无沾污的采水器在海洋科学研究中有较大实用意义。 本课题所设计的无缆自动返回式采水器（a New Auto-Returned Column Water Sampling Device-‘ARWAD’）是一种新型垂直剖面采水器，该采水器外挂四个1.5L卡盖式结构的HOUSKIN采水瓶。为采水器加载适当重量的配置体，使其在水中受到负浮力下潜。采水是在释放配置体后，采水器受到正浮力上升的过程中依次完成的。 本文的主要内容为：（1） 本课题详述了该无缆自动返回式采水器的机械机构与密封方案。采水器的主壳体为硬铝合金圆柱状防水耐压设计，外挂四个卡盖式结构的采水瓶，其机械机构主要包括①配置体的悬挂与释放机构；②采水瓶关闭采水机构；（2） 详述该采水器的控制系统，包括硬件设计方案和软件设计，并对控制系统进行了调试。控制系统装置于主体的防水耐压仓内，以单片机为核心，装载压力传感器获知水深。下位机程序控制在到达指定深度时释放配置体和关闭各采样瓶，上位机程序实现在甲板上的自检、设定配置体的释放深度和各采水瓶的关闭采样深度；（3） 用解析法和经验公式对该采水器承压零件尺寸进行设计，同时用数值计算方法对其强度校核；（4） 为保证采水器的采水精度和确保其工作安全，对采水器进行水动力学计算，确定阻力及阻力系数等参数，使采水器在上升采水过程中最大速度小于2.0m/s，以为外形设计提供参考；（5） 采水器采样性能验证。现场采集水样后，在实验室测定悬浮颗粒物的质量浓度和体积浓度分布。在采集水样的同时，应用激光粒度仪获取现场悬浮物粒径分布信息。通过与激光粒度仪现场测定结果对比，证明该自动返回式采水器采水深度准确，质量较好。 该采水器使用时无需钢丝绳，而是装载压力传感器获知水深，由此避免了使用绞车和由钢丝绳计量深度带来的深度误差；采样时也无须连接电缆，节省电力；自由下潜和上升，无需配备绞车深度补偿设施，避免出现深度逆变现象。主要应用于驾驶小规模船只在较浅水域（湖泊或河口）采水，亦可用于大型科考船，其结构轻便、造价低廉以及操作方便等性能使其成为CTD葵花式采水器和泵采系统的有益补充。

机器人化月表采样器的研制

首先介绍了月表采样的新特点与存在的困难;根据月表环境、月表样品的特点以及嫦娥三期工程中对月表采样的要求,合理地选择了采样方式,研制出了一台六自由度机器人化月表采样器,并且对采样器的采样原理,机械系统和运动原理做了详细的分析;最后在石灰粉上做了采样实验,验证了多功能的机器人化月表采样器的基本功能与可行性。

机器人化月表采样器控制系统研究

在未来的深空探测任务中迫切需要采样任务的机器人化。为突破这一关键的技术,我们研制了一台六自由度的机器人化月表采样器原理样机,为其选择合理的控制方式并搭建了一套基于CAN总线的分布式控制系统。本文将详细介绍该机器人化月表采样器的工作原理及其控制系统的基本结构,并将阐述在操作采样器执行采样任务时采用的控制方式。最后搭建试验平台进行采样试验,验证采样器和控制系统的基本功能及其有效性。

机器人化月表采样器的研究

月球是离地球最近的行星，了解开发月球是人类认识太空的第一步。月壤是月球的重要组成部分，也是人类认识月球的基本切入点，现在许多国家都在开展无人探月活动，因此设计一种无人操作的能够适应月表环境的机器人化月表采样器将是我们认识月球地质状况的关键。应用于月表探测的机器人化月表采样器在作业时往往面对极为复杂的苛刻的月表环境。传统的采样器受其自身的机械结构限制，一般不能够适应这么苛刻的月表环境，或者是不能达到预定的采样目标。具有多种采样形式的月表采样器的出现，解决了这一问题。国外自50年代开始研究机器人化行星采样器，并且已经研制出了许多样机。目前已有的行星采样器存在着只具有单种采样形式，或者受着陆舱体积的限制不能够进行深层采样等不足，因此都不能满足探月活动中要求越来越高的月表样品采集活动。本文叙述了行星采样器的研究和发展现状，并设计了一种用于月表探测时进行月壤采集的多功能机器人化月表采样器。该采样器具有三种针对不同月表样品的采样形式：夹取、铲取和钻取，根据采样的对象的不同能够自动改变采样方式，整个机械系统由仿生蚌式铲和转塔式钻机两大部分组成，仿生蚌式铲具有多种采样形式，转塔式钻机解决了空间受限的情况下采集深层样品的问题，整个系统具有六个运动副。机器人化月表采样器采用了基于CAN总线的集中式控制系统。本文在详细介绍机器人化月表采样器机械系统设计的基础上，对机器人化月表采样器对月壤的采样过程进行了数学建模，以便于将来对采样器的可靠性进行改进，并且减少设计费用和提高了终端产品的性能。通过采样实验验证了机器人化月表采样器机械结构确实满足预期采样目的。最后，本文对机器人化月表采样器的发展和后续研究工作进行了展望。

基于广义正交多项式迭积微分算子的地震波场数值模拟研究

Seismic Numerical Modeling is one of bases of the Exploratory Seismology and Academic Seismology, also is a research field in great demand. Essence of seismic numerical modeling is to assume that structure and parameters of the underground media model are known, simulate the wave-field and calculate the numerical seismic record that should be observed. Seismic numerical modeling is not only a means to know the seismic wave-field in complex inhomogeneous media, but also a test to the application effect by all kinds of methods. There are many seismic numerical modeling methods, each method has its own merits and drawbacks. During the forward modeling, the computation precision and the efficiency are two pivotal questions to evaluate the validity and superiority of the method. The target of my dissertation is to find a new method to possibly improve the computation precision and efficiency, and apply the new forward method to modeling the wave-field in the complex inhomogeneous media. Convolutional Forsyte polynomial differentiator (CFPD) approach developed in this dissertation is robust and efficient, it shares some of the advantages of the high precision of generalized orthogonal polynomial and the high speed of the short operator finite-difference. By adjusting the operator length and optimizing the operator coefficient, the method can involve whole and local information of the wave-field. One of main tasks of the dissertation is to develop a creative, generalized and high precision method. The author introduce convolutional Forsyte polynomial differentiator to calculate the spatial derivative of seismic wave equation, and apply the time staggered grid finite-difference which can better meet the high precision of the convolutional differentiator to substitute the conventional finite-difference to calculate the time derivative of seismic wave equation, then creating a new forward method to modeling the wave-field in complex inhomogeneous media. Comparing with Fourier pseudo-spectral method, Chebyshev pseudo-spectral method, staggered- grid finite difference method and finite element method, convolutional Forsyte polynomial differentiator (CFPD) method has many advantages: 1. Comparing with Fourier pseudo-spectral method. Fourier pseudo-spectral method (FPS) is a local operator, its results have Gibbs effects when the media parameters change, then arose great errors. Therefore, Fourier pseudo-spectral method can not deal with special complex and random heterogeneous media. But convolutional Forsyte polynomial differentiator method can cover global and local information. So for complex inhomogeneous media, CFPD is more efficient. 2. Comparing with staggered-grid high-order finite-difference method, CFPD takes less dots than FD at single wave length, and the number does not increase with the widening of the studying area. 3. Comparing with Chebyshev pseudo-spectral method (CPS). The calculation region of Chebyshev pseudo-spectral method is fixed in , under the condition of unchangeable precision, the augmentation of calculation is unacceptable. Thus Chebyshev pseudo-spectral method is inapplicable to large area. CFPD method is more applicable to large area. 4. Comparing with finite element method (FE), CFPD can use lager grids. The other task of this dissertation is to study 2.5 dimension (2.5D) seismic wave-field. The author reviews the development and present situation of 2.5D problem, expatiates the essentiality of studying the 2.5D problem, apply CFPD method to simulate the seismic wave-field in 2.5D inhomogeneous media. The results indicate that 2.5D numerical modeling is efficient to simulate one of the sections of 3D media, 2.5D calculation is much less time-consuming than 3D calculation, and the wave dispersion of 2.5D modeling is obviously less than that of 3D modeling. Question on applying time staggered-grid convolutional differentiator based on CFPD to modeling 2.5D complex inhomogeneous media was not studied by any geophysicists before, it is a fire-new creation absolutely. The theory and practices prove that the new method can efficiently model the seismic wave-field in complex media. Proposing and developing this new method can provide more choices to study the seismic wave-field modeling, seismic wave migration, seismic inversion, and seismic wave imaging.

通过第一性原理计算研究内地核的结构与成分

The determination of the composition and structure of the Earth’s inner core has long been the major subject in the study of the Earth’s deep interior. It’s widely believed that the Earth’s core is formed by iron with a fraction of nickel. However, light elements must exist in the inner core because the earth core is less dense than pure iron-nickel alloy (~2-3% in the solid inner core and ~6-7% in the liquid outer core). The questions are what and how much light element is there in the iron-nickel alloy. Besides the composition, the crystal structure of the iron with or without light element is also not well known. According to the seismological observations, the sound waves propagate 3-4% faster along the spin axis than in the equatorial plane. That means the inner core is anisotropic. The densest structure of iron-nickel alloy should be h.c.p structure under the very high pressures. However, the h,c,p structure does not propagate waves anisotropic ally. Then what is the structure of the iron-nickel alloy or the iron-nickle-light element alloy. In this study, we tried to predict the composition and the structure of the inner core through ab initio calculation of the Gibbs free energy, which is a function of internal energy, density and entropy. We conclude that the h.c.p structure is more stable than the b.c.c structure under high pressure and 0 K, but with the increase of temperature, the free energy of the b.c.c structure is decreasing much faster than the h.c.p structure caused by the vibration of the atomics, so the b.c.c structure is more stable at high temperatures. With the addition of light elements (S or Si or both), the free energy of b.c.c. decreases even faster, about 3at% of Si not only explains why the inner core is about 2-3 % lighter than the iron-nickle alloy, but also reasons why the inner core is anisotropic, since the b.c.c. structure becomes more stable than the h.c.p structure at 5500-6000K and b.c.c. is anisotropic in propagating seismic waves. Therefore, we infer that the inner core of the earth is formed by b.c.c iron and a fraction of nickel plus ~3at.% Si, with a temperature higher than 5500K, which is consistent with the studies from other approaches.

超参数控制下的波阻抗约束反演

The seismic survey is the most effective geophysical method during exploration and development of oil/gas. As a main means in processing and interpreting seismic data, impedance inversion takes up a special position in seismic survey. This is because the impedance parameter is a ligament which connects seismic data with well-logging and geological information, while it is also essential in predicting reservoir properties and sand-body. In fact, the result of traditional impedance inversion is not ideal. This is because the mathematical inverse problem of impedance is poor-pose so that the inverse result has instability and multi-result, so it is necessary to introduce regularization. Most simple regularizations are presented in existent literature, there is a premise that the image(or model) is globally smooth. In fact, as an actual geological model, it not only has made of smooth region but also be separated by the obvious edge, the edge is very important attribute of geological model. It's difficult to preserve these characteristics of the model and to avoid an edge too smooth to clear. Thereby, in this paper, we propose a impedance inverse method controlled by hyperparameters with edge-preserving regularization, the inverse convergence speed and result would be improved. In order to preserve the edge, the potential function of regularization should satisfy nine conditions such as basic assumptions edge preservation and convergence assumptions etc. Eventually, a model with clear background and edge-abnormity can be acquired. The several potential functions and the corresponding weight functions are presented in this paper. The potential functionφLφHL andφGM can meet the need of inverse precision by calculating the models. For the local constant planar and quadric models, we respectively present the neighborhood system of Markov random field corresponding to the regularization term. We linearity nonlinear regularization by using half-quadratic regularization, it not only preserve the edge, and but also simplify the inversion, and can use some linear methods. We introduced two regularization parameters (or hyperparameters) λ2 and δ in the regularization term. λ2 is used to balance the influence between the data term and the transcendental term; δ is a calibrating parameter used to adjust the gradient value at the discontinuous position(or formation interface). Meanwhile, in the inverse procedure, it is important to select the initial value of hyperparameters and to change hyperparameters, these will then have influence on convergence speed and inverse effect. In this paper, we roughly give the initial value of hyperparameters by using a trend- curve of φ-(λ2, δ) and by a method of calculating the upper limit value of hyperparameters. At one time, we change hyperparameters by using a certain coefficient or Maximum Likelihood method, this can be simultaneously fulfilled with the inverse procedure. Actually, we used the Fast Simulated Annealing algorithm in the inverse procedure. This method overcame restrictions from the local extremum without depending on the initial value, and got a global optimal result. Meanwhile, we expound in detail the convergence condition of FSA, the metropolis receiving probability form Metropolis-Hasting, the thermal procession based on the Gibbs sample and other methods integrated with FSA. These content can help us to understand and improve FSA. Through calculating in the theoretic model and applying it to the field data, it is proved that the impedance inverse method in this paper has the advantage of high precision practicability and obvious effect.

Heat capacity enhancement and thermodynamic properties of nanostructured amorphous SiO2

The heat capacity of nanostructured amorphous SiO2 (na-SiO2) has been measured by adiabatic calorimetric method over the temperature range 9-354 K. TG and differential scanning calorimeter (DSC) were also employed to determine the thermal stability. Glass transition temperature (T-g) for the two same grain sizes with different specific surface of naSiO(2) samples and one coarse-grained amorphous SiO2 (ca-SiO2) sample were determined to be 1377, 1397 and 1320 K, respectively. The low temperature experimental results show that there are significant heat capacity (C-P) enhancements among na-SiO2 samples and ca-SiO2. Entropy, enthalpy, Gibbs free energy and Debye temperature (theta (D)) were obtained based on the low temperature heat capacity measurement of na-SiO2. The Cp enhancements of na-SiO2 were discussed in terms of configurational and vibrational entropy. (C) 2001 Elsevier Science B.V. All rights reserved.

Beneficios da integracao entre lavoura e pecuaria.

2001

Examining the Aesthetic Dimensions of the Constitutional Treaty

Gibbs, Nathan, Examining the Aesthetic Dimensions of the Constitutional Treaty. European Law Journal, Vol. 11, No. 3, pp. 326-342, May 2005 RAE2008