RESEARCH ON METHOD TO CALCULATE VELOCITIES OF SOLID PHASE AND LIQUID PHASE IN DEBRIS FLOW

Velocities of solid phase and liquid phase in debris flow are one key problem to research on impact and abrasion mechanism of banks and control structures under action of debris flow. Debris flow was simplified as two-phase liquid composed of solid phase with the same diameter particles and liquid phase with the same mechanical features. Assume debris flow was one-dimension two-phase liquid moving to one direction, then general equations of velocities of solid phase and liquid phase were founded in two-phase theory. Methods to calculate average pressures, volume forces and surface forces of debris flow control volume were established. Specially, surface forces were ascertained using Bingham＇s rheology equation of liquid phase and Bagnold＇s testing results about interaction between particles of solid phase. Proportional coefficient of velocities between liquid phase and solid phase was put forward, meanwhile, divergent coefficient between theoretical velocity and real velocity of solid phase was provided too. To state succinctly before, method to calculate velocities of solid phase and liquid phase was obtained through solution to general equations. The method is suitable for both viscous debris flow and thin debris flow. Additionally, velocities every phase can be identified through analyzing deposits in-situ after occurring of debris flow. It is obvious from engineering case the result in the method is consistent to that in real-time field observation.

Optical simulation of in-plane-switching blue phase liquid crystal display using the finite-difference time-domain method

The finite-difference time-domain method is used to simulate the optical characteristics of an in-plane switching blue phase liquid crystal display.Compared with the matrix optic methods and the refractive method,the finite-difference timedomain method,which is used to directly solve Maxwell＇s equations,can consider the lateral variation of the refractive index and obtain an accurate convergence effect.The simulation results show that e-rays and o-rays bend in different directions when the in-plane switching blue phase liquid crystal display is driven by the operating voltage.The finitedifference time-domain method should be used when the distribution of the liquid crystal in the liquid crystal display has a large lateral change.

Preparation of Microcapsules with Liquid Droplet Coalescence Method Followed by Phase Separation

Novel preparation method of microencapsules was developed on the basis of the liquid coalescence method followed by phase separation. Oil droplets of limonene dissolving expanded polystyrene as a shell material were forced to collide and coalesce with the Isopar oil droplets of core material in the continuous wates phase. When two kinds of oil droplets are collided and coalesced with each other, expanded polystyrene dissolved in the limonene oil may be phase-separated in the oil droplets newly formed to form the microcapsule shell, because the Isopar oil was a poor solvent for expanded polystyrene but a good solvent for the limonene oil. In the experiment, the diameter (or number) of limonene oil droplets dissolving expanded polystyrene was mainly changed, because the coalescence frequency between the droplets is strongly dependent on the number of droplets. Favorable core shell types of microcapsules with the shell thickness from 1.0 to 5.0 μm were able to be prepared under all the experimental conditions adopted here.

PEG-combined liquid phase synthesis and electrochemical properties of carbon-coated Li_3V_2(PO_4)_3

The carbon-coated monoclinic Li3V2(PO4)3(LVP) cathode materials were successfully synthesized by liquid phase method using PEG as reducing agent and carbon source. The effects of relative molecular mass of PEG on the properties of Li3V2(PO4)3/C were evaluated by X-ray diffraction(XRD), scanning electron microscope(SEM) and electrochemical performance tests. The SEM images show that smaller size particles are obtained by adding larger and smaller PEGs. The electrochemical cycling of Li3V2(PO4)3/C prepared by both PEG200 and PEG20 k has a high initial discharge capacity of 131.1 mA·h/g at 0.1C during 3.0-4.2 V, and delivers a reversible discharge capacity of 123.6 m A·h/g over 30 cycles, which is better than that of other samples. The improvement in electrochemical performance is caused by its improved lithium ion diffusion coefficient for the macroporous morphology, which is verified by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS).

A Stability Indicating Reverse Phase-HPLC Method Development and Validation for the Estimation of Rucaparib in Bulk and Pharmaceutical Dosage Form

The research was carried out for establishing a new reverse phase-HPLC stability indicating method for the quantification of Rucaparib. The experiment was determined on Waters HPLC instrument using 996 photo-diode array detector. The separation was done by using symmetry C-18 ODS (25 cm × 0.46 cm internal diameter) 5 μm analytical column containing mobile phase of Phosphate buffer (0.02 M) and methanol [65:35% v/v] adjusted pH to 4.8 by adding dilute ortho phosphoric acid. The method was run at 1 ml·min-1 at 286 nm detection. The drug was eluted at 5.484 min. After developing the method, it was assured for the intended use by validation which was done according to ICH Q2B guidelines. The analytical parameters checked were linearity, accuracy, repeatability, intermediate precision, limit of detection, limit of quantitation, ruggedness and robustness. It was observed that the response of the detector was linear in the range of 6 - 14 μg/ml with correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability indicating assay method was established by using the samples generated by forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative and photolytic degradation and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the analysis of quality of the rucaparib drug.

Treatment of discontinuous interface in liquid-solid forming with extended finite element method

Extended finite element method(XFEM) is proposed to simulate the discontinuous interface in the liquid-solid forming process.The discontinuous interface is an important phenomenon happening in the liquid-solid forming processes and it is difficult to be simulated accurately with conventional finite element method(CFEM) because it involves solid phase and liquid phase simultaneously.XFEM is becoming more and more popular with the need of solving the discontinuous problem happening in engineering field.The implementation method of XFEM is proposed on Abaqus code by using UEL(user element) with the flowchart.The key is to modify the element stiffness in the proposed method by using UEL on the platform of Abaqus code.In contrast to XFEM used in the simulation of solidification,the geometrical and physical properties of elements were modified at the same time in our method that is beneficial to getting smooth interface transition and precise analysis results.The analysis is simplified significantly with XFEM.

A Stability Indicating Reverse Phase-HPLC Method Development and Validation for the Estimation of Bimatoprost 0.3% &Timolol 0.5% Pharmaceutical Ophthalmic Dosage Form

The research was carried out to establish a new reverse phase-HPLC stability indicating method for quantifying Bimatoprost & Timolol in ophthalmic solution. The experiment of Bimatoprost & Timolol in ophthalmic solution method development was determined on Waters HPLC instrument using a UV Detector. The separation was done by using L11, Zorbex SB phenyl (4.6 mm × 250 mm internal diameter) 5 μm analytical column, containing mobile phase of Phosphate buffer (0.02 M), methanol, and acetonitrile [50:30:20 % v/v]. The method was run at 1 ml·min-1 at 210 nm for Bimatoprost and 295 nm for Timolol for detection. The drug was eluted at 10.81 min for Bimatoprost and 3.77 min for Timolol. After developing the method, it was assured for the intended use by validation, which was done according to ICH Q2B guidelines. The analytical parameters checked were Specificity/Selectivity, linearity, Range, accuracy, ruggedness, and robustness. It was observed that the response of the detector was linear in the range of 6 - 18 μg/ml with a correlation coefficient of 0.999. The results of all the parameters were found to be within the acceptance criteria. The stability-indicating assay method was established by using the samples generated by the forced degradation process. The forced degradation was carried out by subjecting the drug to acid, alkali, thermal, oxidative, and photolytic degradation, and the results showed that the degradation products were successfully separated from the drug. Hence, this can be applied perfectly later for the quantitative analysis of Bimatoprost 0.3% + Timolol 0.5% Ophthalmic Solution drugs for pharmaceutical use. Currently, there is no official method for Bimatoprost & Timolol combination products in USP or BP. Available research work related to single Bimatoprost or Timolol products was not suitable for testing Bimatoprost and Timolol combination drugs. Additionally, there is no stability-indicating method to test Bimatoprost & Timolol combination products which insist us to do research and develop a new reverse phase-HPLC indicating method which will be faster and more accurate.

低碳脂肪胺的治理技术研究进展

低碳脂肪胺(LCFAs)的末端处理技术主要分为物理法、化学法和生物法等3类,物理方法主要包括液相吸收法、吸附法、空气吹脱法、膜分离法;化学法主要包括低温等离子体法、高温催化氧化、光催化氧化、微波辐射法和液相高级氧化法。重点介绍各种方法的原理、处理效率和优缺点等。研究表明,LCFAs的去除方法虽然多样,但每种方法在不同程度上都存在一定局限性。鉴于LCFAs出色的水溶性,提出将液相吸收法与高级氧化法/生物法联合使用将是一种十分具有前景的LCFAs治理技术。最后对LCFAs未来的治理方向提出了展望。

低温液相法从脱硫废渣中制备不溶性硫磺

HPF脱硫废渣是煤气脱硫工序的副产物,含有焦油、铵盐、酚、萘等多种杂质,是煤化工企业难以处理的固体废弃物。通过萃取-结晶技术,得到了纯度高于99.97%的高纯度硫磺。在较低的温度条件下,用提纯的硫磺制备了不溶性硫磺,通过三因素三水平正交试验,得到了低温液相法的最佳工艺条件。采用化学分析、差热、热重分析和X射线衍射分析技术,对产品的结构和性质进行了分析定性。试验结果表明,不溶性硫磺晶体结构和普通硫磺存在显著差异,具有较好的热稳定性。

Preparation and Characterization of Titania Microspheres and Their Application in a Liquid Chromatography Stationary Phase

Titania microspheres were synthesized using hydrothermal methods to exploit a new liquid chromatography stationary phase. The prepared titania microspheres were approximately 7 μm in diameter, and the particle size distribution was relatively narrow and uniform. Furthermore, the average specific surface area was 276.0 m2·g·1, the average pore volume was approximately 0.25 mL·g·1, and the pore diameter was approximately 35.9 nm for sintering titania microspheres. These parameters indicate that the titania microspheres prepared for this study have excellent surface properties for chromatography. Additionally, columns filled with the titania microspheres were able to separate basic compounds, including benzene, nitrobenzene and o-nitroanisole. It could be proposed that the titania microspheres prepared for this study would be a promising stationary phase for liquid chromatography.

转轮及导叶流域固液两相流研究

为了研究灯泡贯流式机组内流状态和磨损规律基于欧拉-欧拉法中的Particle非均匀相模型,对不同固相直径、浓度、导叶开度下水轮机固液两相流工况进行计算。结果表明,固相高浓度区集中在转轮域和尾水管进口处,且随着固相直径和浓度的增加而增加。随着固相直径和浓度的增加,导叶域表面压力、固相速度、固相浓度分布均增加,导叶背面更易发生磨损。在转轮域,固相高浓度区分布在叶片正面轮毂处和进水边,叶片背面整体固相浓度分布较高,且表面固相速度、浓度分布与固相直径和入口浓度呈正相关。

井下巷道喷浆过程产尘的运移及分布特性

煤矿井下全气动喷浆技术的喷射过程涉及浆体基料、喷雾作用与周围空气等,是典型的气、液、固三相流。基于CFD-DPM方法,采用欧拉双流体模型模拟气相和水相,采用拉格朗日模型追踪喷浆过程产生的粉尘,研究了多种工况喷雾作用下粉尘的扩散过程,分析了粉尘运移及分布特性,获得了喷雾角度与流量对粉尘分布的影响规律。喷射角度的变化对粉尘扩散的影响主要集中在中下部区域,控制喷雾流量可有效降低区域粉尘,为合理降尘、提高喷射效率提供了理论支持。

纳米氧化锌液相法制备技术进展

纳米氧化锌是一种新型无机功能材料,广泛用于橡胶、涂料、催化等领域。其液相法制备技术具有产物粒径及形貌易控制、经济成本低、易于实现工业化的优点。重点综述了包括微乳液法、溶胶-凝胶法、水热/溶剂热法和化学沉淀法在内的纳米氧化锌液相法制备技术,阐释了各方法的基本原理、关键影响因素,强调了过程强化技术在制备过程中的重要作用。进一步介绍了“气泡液膜法”的新思路,其特征在于通过表面活性剂与反应液、空气的快速混合,形成具有高堆密度微气泡的纳米反应环境,成核晶体在气泡间10~100 nm的液膜内限域生长,通过控制气泡间液膜厚度调控纳米粒子大小,所得产物粒径均一、不易团聚,有望实现低成本纳米氧化锌的连续规模化生产。

分步液相还原法制备六方片状纳米银粉工艺研究

为探究分步液相还原法制备六方片状纳米银粉工艺条件对纳米银粉形貌及粒径的影响,以硝酸银为银源,过氧化氢为氧化刻蚀剂,硼氢化钠、抗坏血酸为还原剂,柠檬酸钠为形貌诱导剂,通过分步液相还原法制备出了六方片状纳米银粉。考察了制备工艺中晶种阶段过氧化氢用量、硼氢化钠用量、生长阶段柠檬酸钠用量、反应溶液pH值等工艺条件对纳米银粉形貌及粒径的影响规律,并分析了其影响机理。结果表明,当晶种阶段过氧化氢与硝酸银摩尔比为50∶1、硼氢化钠与硝酸银摩尔比为2∶1、生长阶段柠檬酸钠与硝酸银摩尔比为2∶1,反应溶液pH=8时,可制备出粒度分布均匀的六方片状纳米银粉,其六边形平均边长为40~60nm。晶种阶段过氧化氢用量是影响纳米银粉形貌的关键因素,随过氧化氢用量增大,纳米银粉形貌发生由类球状到片状的转化,过氧化氢过量可使片状纳米银粉边缘发生刻蚀作用;生长阶段反应溶液酸碱度是影响纳米银粉粒径的关键因素,随反应溶液pH值增大,纳米银粉平均粒径逐渐减小;柠檬酸钠可在纳米银粉表面发生选择性吸附,诱导纳米银粉发生各向异性生长,生成片状结构。

多元醇液相还原法制备银纳米线的研究

银纳米线(AgNWs)因具有高导电性、高透光性及良好的耐弯曲柔性,已成为传统氧化铟锡(ITO)透明导电材料的替代品。采用液相多元醇还原法制备了不同规格的银纳米线,并通过SEM、UV-Vis、XRD等测试手段对制备的银纳米线进行了表征。结果表明,不同的制备参数可以获得颗粒状、短棒状、线状等不同形态的银产物。反应温度160℃,反应体系中聚乙烯吡咯烷(PVP)与AgNO_(3)的摩尔比为2∶1,FeCl_(3)的浓度保持在0.1~0.2mmol/L之间时,可以制备得到长度约30μm、直径约50nm的高纯度银纳米线。

Ni-Pt/MgAl_(2)O_(4)双金属催化剂构筑及其对不同构型烃类蒸汽重整制氢性能的影响

航空煤油成分复杂,由上百种不同构型的烃类组成,然而正构烷烃、异构烷烃、环烷烃和芳香烃这几类主要组分的构型和性质差异甚大,导致其蒸汽重整反应特性存在较大差异。本论文在前期研发Ni/MgAl_(2)O_(4)基础上,引入Pt构建Ni-Pt双金属催化剂,系统考察了该催化剂对不同构型组分重整反应性能的差异,并对不同构型组分在该催化剂上的重整反应路径进行了阐述。结果表明:液相还原法引人Pt能够使双金属催化剂具有合适的酸性和良好的金属Ni分散性,Ni-Pt两种金属协同效应,不仅能够提高单Ni催化剂活性,同时能够减少Ni烧结,优化催化剂稳定性;另外,不同构型组分在双金属催化剂上的重整性能具有显著差异,其中正癸烷重整的产气率以及H,选择性较为优异。不同构型烃类燃料的反应活性为:甲基环已烷>正癸烷>乙苯。由于甲基环已烷在反应过程中C-C键键能弱,易开环形成链状自由基与水发生重整反应,乙苯具有芳香烃结构且不易开环,重整反应所需能量较高。

基于“种子-生长”的液相法制备的CoFe_(2)O_(4)纳米颗粒及磁性能

依据不同的应用需求,实现纳米材料颗粒尺寸和形状的可控制备一直是材料制备领域研究的重点。为了研究CoFe_(2)O_(4)纳米颗粒尺寸和形状对于磁性能的影响,本文分别通过传统的液相法和基于“种子-生长”的液相法制备出了不同颗粒尺寸和形状的CoFe_(2)O_(4)纳米颗粒并研究其磁性能。结果表明:CoFe_(2)O_(4)颗粒的尺寸和形状变化会影响纳米颗粒的分散性和矫顽力。其中,通过“种子-生长”的液相法制备的六边形CoFe_(2)O_(4)纳米颗粒的矫顽力在室温下可达383Oe,80K时高达13105Oe。

重掺杂p型SiC晶片Ni/Al欧姆接触特性

系统研究了Al和Ni/Al两种金属体系在重掺杂p型SiC晶片上的欧姆接触特性和电学性质。利用X射线衍射、扫描电子显微镜和综合物性测量系统对这两种电极表面的微观结构和样品的电学性质进行了表征。结果表明:在真空环境下经过800℃退火后Al电极可呈现出欧姆接触行为,其比接触电阻率为1.98×10^(-3)Ω·cm^(2),退火处理后Al电极与SiC在接触界面形成化合物Al_(4)C_(3),有助于提高接触界面稳定性。在Ni/Al复合体系中,当Ni金属层厚度为50 nm时,其比接触电阻率显著降低至4.013×10^(-4)Ω·cm^(2)。退火后Ni与SiC在接触界面生成的Ni_(2)Si有利于欧姆接触的形成和降低比接触电阻率。研究结果可为开发液相法生长的p型SiC晶片电子器件提供参考。

Al组分含量对CuZnAl催化剂CO加氢制乙醇和高级醇性能影响

随着原油储量的减少和环境问题的加剧,迫切需要寻找生产燃料和化学品的新技术。Cu基催化剂是合成气直接制乙醇和高级醇(C_(2+)醇)的重要催化剂之一,但存在目标产物选择性低的问题。采用完全液相法制备了一系列不同Al组分含量(n(Al)/n(Zn)计)的CuZnAl催化剂(Cat-Alx),结合X射线衍射、N_(2)吸/脱附和H_(2)-程序升温还原等对催化剂的物相组成、织构性质和还原性能等进行了表征。在模拟浆态床反应器中研究了Cat-Alx对CO加氢制乙醇和C_(2+)醇反应的催化性能。结果表明,Cat-Al0.8表面具有最丰富的Cu^(+)物种以及较多的氧空位,表现出相对最优的催化性能。在280℃、4 MPa和V(H_(2))/V(CO)=2/1的条件下反应24 h,Cat-Al0.8的CO转化率为18.45%,总醇选择性为30.34%,乙醇在总醇中的占比为30.19%,C_(2+)醇在总醇中的占比为48.08%。

液相法制备超细铂及其复合粉的研究进展

铂及其复合粉因具有独特的性能,广泛应用于电子信息、能源、汽车等高端制造领域。随着我国高端装备制造业的高质量、快速发展,对铂及其复合粉性能提出了更高的要求,需求也日益增大。综述了目前制备铂及其复合粉应用最广泛的液相法的研究现状,重点总结了溶胶-凝胶法、水热法、微乳液法、液相化学还原法的研究进展,以及各制备方法的优势及面临的问题,并对铂等贵金属超细粉体的高效制备发展方向进行了展望。