Sodium Titanates Formation by Roasting of Pellets or Powder Mixture of Soda Ash and Rossetta Region Ilmenite Ore Concentrate in Air

Alkaline metals and hydrogen titanates are of great interest for possible applications. The qualities of soda ash and Rosetta ilmenite ore concentrate pellets were investigated. The kinetic formation of sodium titanate via roasting of soda ash and ilmenite pellets and powder was studied in the temperature range of 800。C to 900。C.

Selected aspects of dielectric behavior of plasma sprayed titanates

XRD measurements were carried out on plasma sprayed titanates BaTiO_(3),CaTiO_(3),MgTiO_(3)and a mixture of the last two.Samples were tested as dielectrics and volume resistivities of the materials were also summarized.Microwave microscopy was used for mapping of the dielectric response of selected samples.The results show differences in the crystal structure between plasma sprayed coatings and feedstock powders in the case of BaTiO_(3)and MgTiO_(3)whereas CaTiO_(3)is crystalograffically identical with its feedstock.The reason can be found in larger sensitivity of BaTiO_(3)and MgTiO_(3)to the reductive conditions at plasma spraying whereas CaTiO_(3)seems to be rather inert from this viewpoint.However CaTiO_(3)exhibits anomalous dielectric losses because of intrinsic conductivity.

Layered alkali titanates(A_(2)Ti_(n)O_(2n+1)):possible uses for energy/environment issues

Uses of layered alkali titanates(A_(2)Ti_(n)O_(2n+1);Na_(2)Ti_(3)O_(7),K_(2)Ti_(4)O_(9),and Cs_(2)Ti_(5)O_(11))for energy and environmental issues are summarized.Layered alkali titanates of various structural types and compositions are regarded as a class of nanostructured materials based on titanium oxide frameworks.If compared with commonly known titanium dioxides(anatase and rutile),materials design based on layered alkali titanates is quite versatile due to the unique structure(nanosheet)and morphological characters(anisotropic particle shape).Recent development of various synthetic methods(solid-state reaction,flux method,and hydrothermal reaction)for controlling the particle shape and size of layered alkali titanates are discussed.The ion exchange ability of layered alkali titanate is used for the collection of metal ions from water as well as a way of their functionalization.These possible materials design made layered alkali titanates promising for energy(including catalysis,photocatalysts,and battery)and environmental(metal ion concentration from aqueous environments)applications.

From titanates to TiO_2 nanostructures: Controllable synthesis, growth mechanism, and applications

The design and fabrication of nanostmctures based on titanium dioxide （TiO2） have attracted much attention because of their low cost, non-toxicity, stability, and potential applications in industry and technology. Recently, one-dimensional （1 D） struc- tured titanates have been used as titanium source to prepare TiO2 nanostructures with various crystalline phases, shapes, sizes, exposed facets, and hierarchical structures. Among the synthetic strategies, hydrothermal method is a facile route to controlla- ble preparation of well-crystalline TiO2 in one step. Herein, we review our recent progress in transferring 1D titanates into TiO2 nanostructures through hydrothermal method, including the transformation mechanism and applications.

Adsorption and photo-catalytic properties of layered lepidocrocite-like quasi-amorphous compounds based on modified potassium polytitanates

TiO2 compounds possess relatively high adsorption abilities and exhibit high photocatalytic activities that exhibit potential for the destruction of organic pollutants in natural and waste waters.Nanostructured potassium polytitanates modified using transition metals and their oxides/hydroxides generate new nanomaterials that operate in the visible spectral range.This study presents the synthesis and investigation of the structure,composition and photocatalytic activity of powdered nanoscale quasi-amorphous potassium polytitanates particles modified with iron,zinc,copper,cobalt and nickel sulfate in aqueous solutions.All of the powders investigated in this work exhibit a high adsorption capacity for methylene blue dye（15-20mg/g） related to the welldeveloped surface of the layered potassium polytitanate particles.Introducing transition metals and their oxides/hydroxides influences the electronic structure of the obtained systems.A high photocatalytic activity was observed for systems containing iron,zinc,nickel and their oxides/hydroxides in the ultraviolet and visible ranges.

The chance of sodium titanate anode for the practical sodium-ion batteries

Supporting sustainable green energy systems,there is a big demand gap for grid energy storage.Sodiumion storage,especially sodium-ion batteries(SIBs),have advanced significantly and are now emerging as a feasible alternative to the lithium-ion batteries equivalent in large-scale energy storage due to their natural abundance and prospective inexpensive cost.Among various anode materials of SIBs,beneficial properties,such as outstanding stability,great abundance,and environmental friendliness,make sodium titanates(NTOs),one of the most promising anode materials for the rechargeable SIBs.Nevertheless,there are still enormous challenges in application of NTO,owing to its low intrinsic electronic conductivity and collapse of structure.The research on NTOs is still in its infancy;there are few conclusive reviews about the specific function of various modification methods.Herein,we summarize the typical strategies of optimization and analysis the fine structures and fabrication methods of NTO anodes combined with the application of in situ characterization techniques.Our work provides effective guidance for promoting the continuous development,equipping NTOs in safety-critical systems,and lays a foundation for the development of NTO-anode materials in SIBs.

Calcium titanate corrosion inhibitor enabling carbon as inert anode for oxygen evolution in molten chlorides

The corrosion inhibition efficacy of titanate(CaTiO_(3))for carbon anodes in molten salts was investigated through various analytical techniques,including linear sweep voltammetry,X-ray diffraction,scanning electron microscopy,and energy dispersion spectroscopy.The results demonstrate that the addition of CaTiO_(3)corrosion inhibitor efficiently passivates the carbon anode and leads to the formation of a dense CaTiO_(3)layer during the electrolysis process in molten CaCl_(2)-CaO.Subsequently,the passivated carbon anode effectively undergoes the oxygen evolution reaction,with an optimal current density for passivation identified at 400 m A/cm^(2).Comprehensive investigations,including CaTiO_(3)solubility tests in molten CaCl_(2)-CaO and numerical modeling of the stability of complex ionic structures,provide compelling evidence supporting“complexation-precipitation”passivation mechanism.This mechanism involves the initial formation of a complex containing TiO_(2)·nCaO by CaTiO_(3)and CaO,which subsequently decomposes to yield CaTiO_(3),firmly coating the surface of the carbon anode.In practical applications,the integration of CaTiO_(3)corrosion inhibitor with the carbon anode leads to the successful preparation of the FeCoNiCrMn high-entropy alloy without carbon contamination in the molten CaCl_(2)-CaO.

Mussel-inspired PTW@PDA composites for developing high-energy gun propellants with reduced erosion and enhanced mechanical strength

The severe erosion and inadequate mechanical strength are prominent challenges for high-energy gun propellants.To address it,novel PTW@PDA composites was prepared by polydopamine(PDA)-modifying onto potassium titanate whisker(PTW,K_(2)Ti_(6)O_(13)),and after was incorporated into gun propellant as erosion-reducing and mechanical-reinforcing fillers.The interfacial characterizations results indicated that as-prepared PTW@PDA composites exhibits an enhanced surface compatible with propellant matrix,thereby facilitating their dispersion into propellants more effectively than raw PTW materials.Compared to original propellants,PTW@PDA-modified propellants exhibited significant less erosion,with a Ti-Kbased protective coating being detected on the eroded steel.And 0.5 wt%and 1.0 wt%addition of PTW@PDA significantly improved impact,compressive and tensile strength of propellants.Despite the inevitably reduction in relative force,PTW@PDA slightly increase propellant burning rate while exerting little adverse impact on propellant dynamic activity.This strategy can provide a promising alternative to develop high-energy gun propellant with less erosion and more mechanical strength.

冬小麦不同指标的干旱响应阈值及干旱程度定量分级研究

为评估冬小麦水分亏缺程度,需要采用合理的评价标准表征植株受旱程度,这对规避气候变化新常态下可能的干旱风险具有重要意义。以冬小麦为研究对象,设置雨养(T1)、漫灌(T2)、滴灌W1(40%~50%FC)、滴灌W2(60%~70%FC)和滴灌W3(80%~100%FC)5个水分处理,测定了形态指标、光合指标、叶绿素荧光参数和土壤水分含量,采用阈值指标分类法(thresholdindicatortaxaanalysis,简称TITAN)分析上述各农学参数与干旱程度(drought degree,简称D)的定量响应关系,并确定其对干旱程度发生明显改变的临界点,从而对冬小麦受旱程度进行定量分级。结果表明,相较于周麦27,洛麦22的受旱程度较高,各农学参数对干旱胁迫适应性强。基于TITAN法确定了不同冬小麦品种各农学参数的干旱响应临界点,并将2个冬小麦品种划分为4个受旱等级:轻旱D1、中旱D2、中旱D3和重旱D4,其中,洛麦22为0.00<D1≤0.277、0.277<D2≤0.504、0.504<D3≤0.714和0.714<D4≤1.00;周麦27为0.00<D1≤0.112、0.112<D2≤0.390、0.390<D3≤0.690、0.690<D4≤1.00。在冬小麦受到轻旱(D1)时,各农学参数降幅为4.39%~14.35%,其中以净光合速率和气孔导度降幅最为敏感,分别为11.20%~14.35%和10.64%~13.60%,其次是茎生物量(11.76%~12.82%);在冬小麦受到中旱(D2)时,各农学参数降幅均比较严重,降幅为21.73%~4429%;在D3干旱等级时,冬小麦干旱胁迫加剧,其中以周麦27的叶干重降幅最高。本研究结果将为科学评估作物干旱受灾程度提供依据,也为农业防旱抗旱和稳定国家粮食生产提供重要保障。

TITAN系统的移植开发及个例应用

TITAN(thunderstorm identification tracking analysis and nowcasting)是美国国家大气研究中心(NCAR)基于雷达体系开发的风暴识别、跟踪、分析和预报系统。首先深入分析TITAN的结构、基本算法、主要功能、物理量产品及其模块设计和数据接口,其次结合我国各类气象数据的特点,开发实现了雷达、卫星、闪电、探空、飞行作业航迹及中尺度模式产品等数据的接入和融合,自主完成对TITAN的移植和多类数据的融合开发。利用移植的TITAN系统,通过一次典型降水个例的分析,展示了TITAN对风暴单体初生、发展演变、分裂合并、风暴体积、持续时间等的追踪分析功能,显示了其强大的雷达数据分析、追踪识别、统计分析及对云降水的内部结构、物理属性变化分析和外推预报的能力。完整移植开发的TITAN系统,将在短时临近预报、中小尺度天气研究、人工影响天气播云条件追踪分析以及催化作业效果检验等方面有着广阔的应用前景。

Effect of additives on properties of aluminium titanate ceramics

The influence of some additives on bulk density,phase composition,mechanical strength and thermal shock resistance of aluminium titanate （AT） ceramics was investigated.AT ceramics with different additives of MgO,SiO2 and Fe2O3 were prepared by reaction sintering.Properties of AT ceramics were tested by using Archimedes,three-point bending and thermal cycling tests.It was found that additives of MgO,SiO2 and Fe2O3 or their compound additives are favorable to reduce the porosities of AT,enhance mechanical strength and thermal shock resistance.The role of additives can be rationalized in terms of promotion of sintering process,formation of new phases and influence on lattice constant c of AT ceramics.

矿业GIS空间数据在TITAN中的组织应用

矿业 Ｇ Ｉ Ｓ作为行业 Ｇ Ｉ Ｓ具有行业特色，在对空间数据进行组织时更加注重空间分析的实现和图形与属性的相互查询。文中结合优秀的 Ｇ Ｉ Ｓ软件开发平台 Ｔ Ｉ Ｔ Ａ Ｎ，对矿业 Ｇ Ｉ Ｓ中的空间数据进行了组织，其中重点讨论了工作区 工程 主题 地物类 地物的总体矿山空间数据组织模式、地物类型在 Ｔ Ｉ Ｔ Ａ Ｎ 中的归纳、地物类的面向对象抽象以及主题的初步定义。

环北京地区八月风暴云的气候分布特征

基于2006—2008年8月北京新一代天气多普勒雷达资料,在TITAN（Thunderstorm Identifi-cation Tracking Analysis and Nowcasting）三维风暴识别、跟踪、分析算法的基础上,客观分析了北京地区8月的风暴气候特征。结果表明：（1）风暴初生的日变化特征表现为典型的双峰型,峰值分别在凌晨06~08时和傍晚18~20时;西南—东北走向的山脉附近风暴云初生频次明显高于其它地区,且迎风坡大于背风坡,表明地形对风暴触发的重要作用,同时地形对风暴移速、降水的分布等产生重要影响;（2）环北京地区8月50%的对流风暴云持续时间〈30 min,绝大部分风暴云体积〈400 km3,平均风暴云顶高度为6.9 km;（3）反射率因子阈值为35 dBz的风暴体积、面积、高度的频率近似呈对数正态分布;（4）通过尺度分析发现8月主要为D尺度风暴云,其平均组合面积较低纬度偏大,平均回波顶高比低纬偏高。

基于面向对象的高分影像地表覆盖典型要素快速提取对比研究

全国第一次地理国情普查工作正在开展,涉及大量影像解译工作,高分辨率遥感影像是当前解译工作中应用最广泛、最基础的影像产品。然而,由于高分辨率遥感影像地物颜色多样、纹理结构复杂,传统的基于像元的解译方法对高分辨率遥感影像进行地物要素自动提取的效果不能满足日益工程化项目要素提取效率与分类精度要求。因此,针对基于像元的影像解译方法存在的不足,本文采用面向对象的解译方法,对几种常见影像处理软件进行对比试验,并对精度进行验证。结果表明:基于eCognition(易康)软件的遥感影像自动分割分类解译精度较ENVI EX、Titan Image软件解译精度高。

Synthesis and electrochemical properties of highly dispersed Li_(4)Ti_(5)O_(12)nanocrystalline for lithium secondary batteries

A sol-gel method using lauric acid as surfactant was used to synthesize Li4Ti5O12 nanocrystals with an ultra-fine particle size distribution between 120 and 250 nm.In order to obtain the electrode materials with the best electrochemical performance,the content of lauric acid during Li4Ti5O12 synthesis was systematically studied.The physical and electrochemical properties of the synthesized samples were characterized by X-ray diffraction（XRD）,field emission scanning electron microscopy（FESEM）,transmission electron microscopy（TEM）,laser particle size analysis,alternating current impedance（AC） and galvanostatic charge-discharge experiments.The highly dispersed Li4Ti5O12 nanocrystals obtained at 800 ℃ for 10 h can deliver a specific capacity of 163.3 mA-h/g at 1C rate without obvious capacity fade up to 50 cycles.The results suggest that well dispersed Li4Ti5O12 nanocrystals shorten the Li-ion diffusion length and enhance the electrochemical kinetics of the samples,which are very crucial to high rate capability.

弱天气系统强迫下黄土高原强对流云的初生及演变

基于NCAR的风暴识别追踪系统(Thunderstorm Identification Tracking Analysis and Nowcasting,TITAN)及其对流云识别算法,在个例分析的基础上,归纳总结弱天气系统强迫下陕北黄土高原对流云的初生、演变机制。结果表明:(1)夏季弱天气系统强迫下,对流云的触发可分为地形、干线、冷池、暖堆、辐合线等5种机制,其中地形强迫作用最为显著,其次为干线、辐合线、暖堆、冷池;(2)合适的湿度场是触发对流云的关键条件,如果有干线存在,即使动力或热力条件较弱,也会触发较多对流云生成,但当抬升作用较弱时,对流云通常不会进一步发展;(3)地形、暖堆、边界层辐合线的作用在于加速对流云触发并促使其强度加强,但这些因子在不同时段所起的作用是不同的,清晨至正午地形抬升占主导作用,正午前后地面暖堆作用加强,午后地面辐合线的作用更为显著。

Preparation and electrostriction of BaTiO_3/polyurethane nanocomposite elastomers

BaTiO3/polyurethane （BaTiO3/PU） nanocomposite elastomers were prepared from barium titanate nanoparticles, polyester polyol, 2, 4-toluene diisocyanate, 1,4-butanediol and 1, 1, 1-trimethanol propane by the one-step method. The density, hardness and dielectric constant of BaTiO3/PU nanocomposite elastomers increased with the increase of the content of BaTiO3 nanoparticles in nanocomposites. The electrostrictive properties of BaTiO3/PU nanocomposite elastomers were investigated by the digital speckle correlation method （DSCM）. It was found that through the on-and-off of the electric field, the electrostrictive strains of BaTiO3/PU nanocomposite elastomers revealed corresponding shrinkage and recovery. The electrostrictive coefficient of BaTiO3/PU nanocomposite elastomers was greater than that of the corresponding polyurethane elastomers, and the electrostrictive coefficient of composites decreased with the increase of the content of barium titanate nanoparticles.

Preparation and electrochemical performance of tantalum-doped lithium titanate as anode material for lithium-ion battery

The electrochemical performance of Ta-doped Li4Ti5O12 in the form of Li4Ti4.95Ta0.05O12 was characterized.X-ray diffraction（XRD） and scanning electron microscopy（SEM） were employed to characterize the structure and morphology of Li4Ti4.95Ta0.05O12.Ta-doping does not change the phase composition and particle morphology,while improves remarkably its cycling stability at high charge/discharge rate.Li4Ti4.95Ta0.05O12 exhibits an excellent rate capability with a reversible capacity of 116.1 mA·h/g at 10C and even 91.0 mA·h/g at 30C.The substitution of Ta for Ti site can enhance the electronic conductivity of Li4Ti5O12 via the generation of mixing Ti4＋/Ti3＋,which indicates that Li4Ti4.95Ta0.05O12 is a promising candidate material for anodes in lithium-ion battery application.

基于三维雷达图像数据的风暴体追踪算法研究

TITAN算法是目前临近天气预报的主要方法之一,主要用于对强对流天气的识别、跟踪和预报。在原算法中速度约束是固定的、预报方法只适用于结构较稳定的风暴,它们会对算法的总体性能有较大的影响。针对这些不足,通过使用动态速度约束和光流法对算法进行了改进。通过实验证明,这些改进对风暴结构变化较大的情况有较好的效果,可以使算法的总体性能平均提高6%左右。