HYDROCHEMICAL COMPONENT AND ITS DYNAMIC TRENDS OF GROUNDWATER IN THE PLAIN OF SANTUN RIVER BASIN

该文依据水文地质条件将三屯河流域平原区划分为单一结构潜水子系统和多层结构潜水 -浅层承压水子系统及深层承压水子系统。通过地下水水质简分析数据 ,分析了各地下水子系统中主要离子 ,TDS和水化学类型的特征及其变化 ,并初步讨论了地下水系统的水循环特点In accordance with hydrogeological condition, three groundwater systems are presented in the paper, they are the phreatic water systems with single-layer structure, phreatic water together with shallow confined groundwater system and deep confined groundwater with multi-layer structures in the plain of Santun river basin The component and distribution of the major ions, TDS and hydrochemical types and their variations of the above-mentioned groundwater systems are analyzed, meanwhile, the circulatory characteristics of groundwater system are discussed preliminarily九五”国家重点科技攻关项目 (96 - 91 2 - 0 1 - 0 3S

Characterization and regulation of mechanical properties of fluid interfaces at micro- and nanoscales based on atomic force microscopy

随着新型储能技术、生物医学工程等前沿交叉领域的迅速发展，对微纳米尺 度下流体界面力学性质的表征与调控提出了新的需求。相较宏观流动，微纳尺度 下表面力效应凸显且涉及到多物理场耦合的问题，极大的增加了微纳尺度界面 力学性质研究的难度。另外，由于光学衍射极限的存在，传统的光学方法难以实 现对微纳尺度下界面流动及力学行为的表征。 因此，本文针对微纳尺度下流体界面力学性质的三个关键科学问题: 表征手 段、力学特性、调控机理开展了相关的工作。利用原子力显微镜在微纳尺度力学 测量及精确控制等优势，发展了导电型长针型悬臂探针技术对接触线动力学进 行研究，实现对接触线动力学与微观接触角动态行为的表征；结合胶体探针技术 对界面作用力进行表征。在此基础上，发现并阐明了电压调控下离子液体在金属 表面的接触角迟滞的转变；表征了离子液体限域环境下微纳尺度不同范围内的 界面力；实现了液-液相分离体系极低界面张力(10&minus;4 N/m 量级) 的定量表征。本 文的主要研究内容及研究成果如下： 首先，针对离子液体微纳尺度润湿动力学的表征与调控问题，本文发展了导 电型长针式原子力显微镜技术，具备对流体界面精确操控和亚纳牛尺度力学表 征的双重优势；发现并阐明了离子液体在金属表面的接触角迟滞在电压调控下 的明显转变；通过分子动力学模拟展现了带电界面上由离子液体形成的类固层 结构和能量的演化。综合实验和模拟结果给出了一种不同于传统电润湿原理的， 通过电压调控离子液体界面层结构的排列和能量的势垒，从而引起流体界面接 触角迟滞转变的新机制。 其次，针对离子液体固-液界面多尺度力学表征的问题，本文采用胶体探针 结合原子力显微镜技术，实现了离子液体限域环境下微纳尺度不同范围内的界 面力学的表征；通过测量远距离流体黏滞阻力，定量表征了离子液体的黏度；测 量了离子液体双电层静电排斥力，展示了离子液体与传统稀电解质间的明显区 别；测量了近壁面间类固层的作用力，获得了类固层的结构与力学信息。 最后，针对极低界面张力的力学表征与生物相分离液滴力学性质的表征与 调控问题，本文通过长针式原子力显微镜技术对多肽相分离液滴及ATXN2 蛋白 相分离液滴的界面力学性质进行研究，实现了对极低界面张力（10&minus;4 N/m 量级） 的定量表征，获得了生物相分离液滴的界面张力和黏度及其在盐浓度调控下的 改变，为后续研究生物相分离液滴的力学性质与生理功能间的联系提供基础。 以上工作发展的实验手段为研究微纳尺度流体界面力学行为提供了可行的 工具，为检验各类理论模型与数值模拟提供了可信数据，为探究界面上复杂现象 的物理本质提供参考。</p

探索微纳米世界的手——原子力显微镜

显微镜的发展让人类看到了真实的微纳米世界,原子力显微镜的出现则让我们进一步直接接触并感知其中的力学相互作用。借助这只微纳尺度的手,原子力显微镜技术越来越多地帮助我们探索和理解微纳米世界,甚至是生命世界。本文介绍了显微镜的发展,原子力显微镜的力学测量原理,以及在活细胞力学研究中的应用

Manipulation of Contact Angle Hysteresis at Electrified Ionic Liquid-Solid Interfaces

Room-temperature ionic liquids (RTILs) are intriguing fluids that have drawn much attention in applications ranging from tribology and catalysis to energy storage. With strong electrostatic interaction between ions, their interfacial behaviors can be modulated by controlling energetics of the electrified interface. In this work, we report atomic-force-microscope measurements of contact angle hysteresis (CAH) of a circular contact line formed on a micron-sized fiber, which is coated with a thin layer of conductive film and intersects an RTIL-air interface. The measured CAH shows a distinct change by increasing the voltage U applied on the fiber surface. Molecular dynamics simulations were performed to illustrate variations of the solidlike layer in the RTIL adsorbed at the electrified interface. The integrated experiments and computations demonstrate a new mechanism to manipulate the CAH by rearrangement of interfacial layers of RTILs induced by the surface energetics

ISOTOPE COMPONENT CHARACTERISTICS OF GROUNDWATER IN TIANSHAN NORTH PIEDMONT PLAIN AND ITS SIGNIFICANCE ──TAKING SANTUN RIVER BASIN PLAIN AS AN EXAMPLE

该文依据水文地质条件将三屯河流域平原区划分为单一结构潜水子系统、多层结构潜水—浅层承压水子系统和深层承压水子系统。通过氢氧稳定同位素、氚同位素和碳 - 14的测试数据 ,分析了各地下水子系统的环境同位素组成 ,并初步讨论了地下水系统的水循环特点。 【英文摘要】 In the paper, In accordance with hydrogeological conditions,groundwater of Santun River basin plain is divided into phreatic water subsystem with single-layer structure,phreatic water both of shallow confined groundwater subsystem and deep confined groundwater subsystem with multi-layer structures.By means of the tested data of Hydrogen-Oxygen stable isotope,and isotopes of tritium and Carbon-14,the environmental isotope components of various groundwater subsystems being analyzed,meanwhile,the circulatory c...“九五”国家重点科技攻关项目 (96 -912 - 0 1- 0 3S

探索微纳尺度润湿动力学:长针式原子力显微镜的应用与进展

“如何在微观层面测量界面现象”是微纳尺度实验流体力学的关键科学问题,被列入世界前沿125个科学问题名单(Sanders S, Science, 2021).由于光学衍射极限的限制,传统光学手段很难直接测量微纳尺度下的流动与界面现象.利用原子力显微镜的精准操控和小尺度力学测量等优势,结合长针式探针组装成的微流变计可以直接测量气-液-固三相接触线上的毛细力,并监测探针在垂直方向运动中力的动态变化.通过该技术手段,可以实现对流体界面的动力学行为以及各类材料在液体环境中力学性质在微纳尺度的精确表征.文章将系统介绍长针式原子力显微镜技术的实验原理和方法,及其在微纳尺度非理想界面润湿动力学中的最新研究进展,包括低能垒表面毛细力的速度依赖性与非对称性、无序粗糙表面接触线黏滑运动的统计学规律、柔性表面接触线动力学的状态与速度定律、以及离子液体-金属界面处电场对接触角迟滞的调控等,最后展望了该技术在新兴领域中的应用.该实验手段为检验各类理论模型与数值模拟提供了可信数据,为探究界面上复杂现象的物理本质提供参考

Study on the mechanism of infiltration and evaporation of phreatic groundwater in the planting conditions

在天山北麓昌吉地下水均衡试验场 ,选择具有代表性的作物玉米进行不同埋深条件下的模拟种植试验 ,分析研究种植条件下不同潜水埋深水平的潜水入渗补给量、潜水蒸发损耗量、土壤水储存量和作物耗水量的变化规律。研究成果对于地下水资源和土壤水资源评价以及地下水和土壤水资源的有效调控利用具有重要实用意义In the text station of the groundwater balance, located in the northern slope of Tianshan Mountain, the corn, local typical crop, is chosen to plant for the text under the conditions of the different groundwater level depth. Through the text, the infiltration and evaporation of the phreatic groundwater, the storage of the soil moisture, and the water requirement of crop are observed and analyzed. The experimentation achievements are significant for the groundwater resource evaluation, the soil moisture resources evaluation, as well as controlling and utilizing effectively the groundwater and soil moisture.“九五”国家重点科技攻关项目的部分研究成果 ( 96 912 0 1 0 3S

Sub-Nanogram Resolution Measurement of Inertial Mass and Density Using Magnetic-Field-Guided Bubble Microthruster

Artificial micro/nanomotors using active particles hold vast potential in applications such as drug delivery and microfabrication. However, upgrading them to micro/nanorobots capable of performing precise tasks with sophisticated functions remains challenging. Bubble microthruster (BMT) is introduced, a variation of the bubble-driven microrobot, which focuses the energy from a collapsing microbubble to create an inertial impact on nearby target microparticles. Utilizing ultra-high-speed imaging, the microparticle mass and density is determined with sub-nanogram resolution based on the relaxation time characterizing the microparticle's transient response. Master curves of the BMT method are shown to be dependent on the viscosity of the solution. The BMT, controlled by a gamepad with magnetic-field guidance, precisely manipulates target microparticles, including bioparticles. Validation involves measuring the polystyrene microparticle mass and hollow glass microsphere density, and assessing the mouse embryo mass densities. The BMT technique presents a promising chip-free, real-time, highly maneuverable strategy that integrates bubble microrobot-based manipulation with precise bioparticle mass and density detection, which can facilitate microscale bioparticle characterizations such as embryo growth monitoring. This work demonstrates a substantial progress of using swimming microrobots to perform precise tasks with sophisticated functions. This magnetic-field-guided bubble microthruster technique presents a promising chip-free, real-time, highly maneuverable strategy that integrates bubble microrobot-based manipulation with precise bioparticle mass and density detection with sub-nanogram resolution. This technique can facilitate microscale bioparticle characterizations such as embryo growth monitoring. imag