基于非原始模型关联电解质水溶液的离子平均活度系数

本文采用非原始ＭＳＡ结果（等离子大小），结合粘性相互作用理论处理离子一离子间的缔合作用，统计缔合流体理论处理溶剂水分子的氢键缔合作用，进一步探讨对电解质水溶液的离子平均活度系数进行关联的可能性．对离子—偶极混合物，体系的直接相关函数由Ｏｒｎｓｔｅｉｎ...     

苯-甲醇-碘化钠体系汽液平衡盐效应参数的理论预测

运用Ｐｉｅｒｏｔｔｉ现代溶液理论预测了苯－甲醇－碘化钠体系的汽液平衡盐效应参数。硬球作用项采用ｍａｓｔｅｒｔｏｎ－Ｌｅｅ方程计算,软球作用项的计算采用简化的径向分布函数－第一配位圈为规则排列,圈外为随机混合－模拟溶液结构,分子间力在Ｌｅｎｎａｒｄ－Ｊｏｎｅｓ位能函数基础上计入偶极－偶极,偶极－诱导偶极,电荷－偶极,电荷－诱导偶极的贡献,针对溶剂性质在对溶液结构作出相应合理假设基础上,预测结果与文献     

硝酸钾电解质溶液的结构和热力学性质的计算机分子模拟

对硝酸钾电解质溶液进行了分子动力学计算机模拟研究。水分子采用简单点电荷（SPC）三节点模型，钾离子被看作带电硬球，硝酸根离子采用刚性四节点模型，同时考虑节点间的库仑长程作用和L-J相互作用，对库仑长程作用采用EWALD求和方法进行计算。研究结果表明，随着溶液浓度的增加，水-水相互作用的总势能绝对值升高；高浓度溶液中水水作用能的升高与水分子排列有序化程度的提高有关，即在浓溶液中水分子的偶极取向更加有序化，说明有更多的水分子参与水化。     

铀矿极谱测定

在各种支持电解质中,于不同 PH 值情况下进行铀的极谱测定,方法很多。其中抗坯血酸电解质,由于它的还原性和络合物的形成能力,可以用来在不经过预先分离的情况下进行铀的极谱测定。S(?)ic,Milenko,Propst,姚修仁等研究了在酸性溶液中,以抗坯血酸作底液,对铀的极谱测定法。可以避免大多数离子的干扰,但在大量铜、钒、钼等离子存在时,必须经过预先分离。S(?)ic 也研究了 PH 在7—9.5范围内在抗坯血酸支     

增强拉曼光谱和电势调节红外光谱对偶极-偶极相互作用的研究

本文讨论了最近用SERS、PDIR研究在电极溶液界面处吸附在电极表面的分子(或离子)之间的偶极-偶极相互作用。该法不仅能用于研究小分子(或离子).如CO、CN~-等,且已能用于苯、吡啶等较大的分子间的偶极-偶极耦合作用,并可探讨光谱与吸附方向间的关系。     

磁场在膜过滤电解质溶液体系中的应用

将磁场作用于陶瓷膜过滤电解质溶液体系,改变水溶液中离子的水合状态,磁场对膜通量没有影响,但可以提高过滤电解质溶液时的离子透过率;磁场作用方向和膜面流速的改变对离子透过率的影响不明显;增大磁感应强度、提高电解质溶液的浓度、减小膜孔径时,磁场对过滤过程的影响作用更明显。采用膜过滤的方法清洗颗粒表面的离子时,加入磁场的作用可以提高离子洗涤的速度,且颗粒浓度比较低时,清洗速度加快。     

磁场在膜过滤电解质溶液体系中的应用

将磁场作用于陶瓷膜过滤电解质溶液体系,改变水溶液中离子的水合状态。磁场对膜过滤通量没有影响,但可以提高过滤电解质溶液时的离子透过率。磁场作用方向和膜面流速的改变对离子透过率的影响不明显。增大磁场强度、提高电解质溶液的浓度,减小膜孔径时,磁场对过滤过程的影响作用更明显。采用膜过滤的方法清洗颗粒表面的离子时,加入磁场的作用可以提高离子洗涤的速率,且颗粒浓度比较低时,清洗速度更快。     

pH值对Q235碳钢与304L不锈钢在典型含硫环境中电偶腐蚀行为的影响

采用电化学法和浸泡法研究了Q235碳钢与304L不锈钢在典型含硫环境中的电偶腐蚀行为.采用SEM观察试样表面形貌.结果表明:在实验体系中304L的阴阳极过程均为电化学活化步骤控制;在pH为4和7的实验溶液中,Q235钢的阴阳极过程均受电化学活化控制;而在pH=13.3的实验溶液中,Q235阴极过程受电化学过程控制,阳极过程受离子扩散控制.在三种实验溶液中的电偶腐蚀效应随阴阳极面积比的增大而增大,但电偶电流随阴阳极面积比的变化并不呈现出对数正比规律.随着溶液pH值的升高,Q235钢的电偶腐蚀速率明显减小,但电偶腐蚀效应变化不明显.     

13C-NMR研究LiClO4在PC+DMF混合溶剂中的优先溶剂化

锂盐 碳酸丙烯脂(PC) N, N -二甲基甲酰胺 (DMF) 混合物是锂电池电解液的重要模拟体系.在前期工作中[1～2],我们研究了该电解质溶液体系的某些宏观物理化学性质.根据所得到的实验结果,分析了Li 在PC DMF混合溶剂中的溶剂化行为.但是宏观的研究方法很难对离子与溶剂之间的相互作用给出确切的描述.     

高氯酸锂与γ-丁内酯相互作用的拉曼光谱研究

锂电池电解质溶液的性质对锂电池的性能具有决定性的作用，是锂电池开发的关键技术之一．目前，关于锂电池电解质溶液的研究多以宏观性质为主，从分子水平的层次来考察离子与溶剂间的相互作用者甚少．γ－丁内酯（ＢＬ）具有中等的介电常数和较宽的液程，在锂电池生产中被广泛使用．但运用光谱技术研究高氯酸锂与ＢＬ之间的相互作用尚未见文献报道．本文在广泛的浓度范围内，利用拉曼光谱技术详细研究了ＬｉＣｌＯ４／ＢＬ溶液中的离子溶剂化和离子缔合．高氯酸锂和ＢＬ均按标准方法提纯．拉曼光谱用法国Ｊｏｂｉｎ－ＹｖｏｎＵ１０００拉曼…     

Correlation between surface charge and hydration on mineral surfaces in aqueous solutions: A critical review

Surface charges and hydration are predominant properties of colloidal particles that govern colloidal stability in aqueous suspensions. These properties usually coexist and interact with each other. The correlation between the surface charge and hydration of minerals is summarized on the basis of innovative experimental, theoretical, and molecular dynamics simulation studies. The factors affecting the adsorption behavior of ions and water molecules, such as ion concentration, ion hydration radius and valence, and surface properties, are discussed.For example, the hydration and adsorption states completely differ between monovalent and divalent ions. For ions of the same valence, the effect of surface charge on the hydration force follows the Hofmeister adsorption series. Electrolyte concentration exerts a significant effect on the hydration force at high ion concentrations. Meanwhile, the ion correlations in high-concentration electrolyte systems become long range.The interfacial water structure largely depends on surface chemistry. The hydration layer between different surfaces shows large qualitative differences.     

Cyclotron frequency shifts arising from polarization forces

The cyclotron frequency of a charged particle in a uniform magnetic field B is related to its mass m and charge q by the relationship omega(c) = qB/m. This simple relationship forms the basis for sensitive mass comparisons using ion cyclotron resonance mass spectroscopy, with applications ranging from the identification of biomolecules and the study of chemical reaction rates to determinations of the fine structure constant of atomic spectra. Here we report the observation of a deviation from the cyclotron frequency relationship for polarizable particles: in high-accuracy measurements of a single CO+ ion, a dipole induced in the orbiting ion shifts the measured cyclotron frequency. We use this cyclotron frequency shift to measure non-destructively the quantum state of the CO+ ion. The effect also provides a means to determine to a few per cent the body-frame dipole moment of CO+, thus establishing a method for measuring dipole moments of molecular ions for which few comparably accurate measurements exist. The general perturbation that we describe here affects the most precise mass comparisons attainable today, with applications including direct tests of Einstein's mass-energy relationship and charge-parity-time reversal symmetry, and possibly the weighing of chemical bonds.     

束离子与离子声波准线性相互作用的研究

给出了束离子与离子声波准线性相互作用的数值解,由解出的波谱进一步给出湍动加速中的加速系数、脉动加速系数、粒子与湍动场间的等效碰撞频率,通过粒子与湍动场间的等效碰撞频率和粒子间有效碰撞频率的比较,说明在有较强湍动场的情形下采用无碰撞等离子体模型是很合适的。     

金属—苯重组能的计算

基于捕获力场潜能的模型的Ｂａｔｅｓ提出的绝热不变性理论,采用改进了平均偶极矩理论（ＩＡＤＯ理论）,我们计算了过渡金属离子－苯配合物之间的力常数及一系列内氛重组能,讨论了理论计算结果与实验结果之间差别的原因。结果表明该工作有效地改进了前人的工作,取得了与实验光谱标度数据一致的规律性,并与光发射实验结果吻合较好,它避免了因缺乏溶液中可信的振动光谱数据在内氛重组能计算上的困难,通过易得的离子和配体的物理     

Engineered two-dimensional Ising interactions in a trapped-ion quantum simulator with hundreds of spins

The presence of long-range quantum spin correlations underlies a variety of physical phenomena in condensed-matter systems, potentially including high-temperature superconductivity. However, many properties of exotic, strongly correlated spin systems, such as spin liquids, have proved difficult to study, in part because calculations involving N-body entanglement become intractable for as few as N?≈?30 particles. Feynman predicted that a quantum simulator--a special-purpose 'analogue' processor built using quantum bits (qubits)--would be inherently suited to solving such problems. In the context of quantum magnetism, a number of experiments have demonstrated the feasibility of this approach, but simulations allowing controlled, tunable interactions between spins localized on two- or three-dimensional lattices of more than a few tens of qubits have yet to be demonstrated, in part because of the technical challenge of realizing large-scale qubit arrays. Here we demonstrate a variable-range Ising-type spin-spin interaction, J(i,j), on a naturally occurring, two-dimensional triangular crystal lattice of hundreds of spin-half particles (beryllium ions stored in a Penning trap). This is a computationally relevant scale more than an order of magnitude larger than previous experiments. We show that a spin-dependent optical dipole force can produce an antiferromagnetic interaction J(i,j) proportional variant d(-a)(i,j), where 0?≤?a?≤?3 and d(i,j) is the distance between spin pairs. These power laws correspond physically to infinite-range (a = 0), Coulomb-like (a = 1), monopole-dipole (a = 2) and dipole-dipole (a = 3) couplings. Experimentally, we demonstrate excellent agreement with a theory for 0.05???a???1.4. This demonstration, coupled with the high spin count, excellent quantum control and low technical complexity of the Penning trap, brings within reach the simulation of otherwise computationally intractable problems in quantum magnetism.     

冰晶石溶液结构的计算机模拟

用蒙特卡洛法计算机模拟研究了 2.7NaF·AlF_3系熔液结构。计算结果表明:熔液中 Al~(3+)离子的第一配位数平均为4个F~-离子,熔液中的主要质点因此是 AlF_4~-离子。此外在未分解的 AIF_6~(3-)离子中存在比较稳定的 AlF_3 由于质点间的交互作用还形成 Al_2F_7~-离子。     

铯溅射负离子源负离子发射过程的理论分析

本文采用改进的偶极层模型和量子理论,研究了铯溅射负离子源中负离子形成机理,给出了吸附铯原子层的金属表面功函数变化及电子转移几率公式,并用量子隧道模型导出负离子形成几率,计算了负离子产额和引出束流强.其结果与实验值基本相符.与测量值相比,比 Alton 的计算结果要好,且计算过程简单.它为溅射型负离子源机理研究提供了一种理论模式.     

An open-system quantum simulator with trapped ions

The control of quantum systems is of fundamental scientific interest and promises powerful applications and technologies. Impressive progress has been achieved in isolating quantum systems from the environment and coherently controlling their dynamics, as demonstrated by the creation and manipulation of entanglement in various physical systems. However, for open quantum systems, engineering the dynamics of many particles by a controlled coupling to an environment remains largely unexplored. Here we realize an experimental toolbox for simulating an open quantum system with up to five quantum bits (qubits). Using a quantum computing architecture with trapped ions, we combine multi-qubit gates with optical pumping to implement coherent operations and dissipative processes. We illustrate our ability to engineer the open-system dynamics through the dissipative preparation of entangled states, the simulation of coherent many-body spin interactions, and the quantum non-demolition measurement of multi-qubit observables. By adding controlled dissipation to coherent operations, this work offers novel prospects for open-system quantum simulation and computation.     

用阴极沉淀法制备超细金属氧化物粉体

针对超细氧化物粉体制备条件苛刻、体系复杂等问题,对阴极沉淀制备氧化物方法进行研究。采用自制的以阴离子渗透膜为隔膜的两室电解装置,在阴极电流密度为50~150 A/m2时,对热解Ti3+、Mg2+及两复合离子的阴极沉淀物进行对比分析实验,探讨分散剂、电流密度、溶液pH值等因素对氧化物形貌和粒度的影响。结果表明:三种沉淀均能得到粒度较均匀的超细氧化物,易于水解沉淀得到的TiO2粒度随电流密度增加变化不明显,经过热解氢氧化镁得到的MgO,其粒度随电流密度增加呈增大的趋势,而复合离子氧化物的粒度更接近同条件下得到的MgO粒度。添加分散剂前后制备的氧化物颗粒形貌未见明显变化。该方法具有一定的通用性,通过金属离子沉淀、热解可以得到粒度较均匀的超细氧化物。