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.

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。

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.

Tuning exsolution of nanoparticles in defect engineered layered perovskite oxides for efficient CO_(2) electrolysis

Solid oxide electrolysis cell(SOEC) could be a potential technology to afford chemical storage of renewable electricity by converting water and carbon dioxide.In this work,we present the Ni-doped layered perovskite oxides,(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2) with n=5,8,and 12(LSTNn) for application as catalysts of CO_(2) electrolysis with the exsolution of Ni nanoparticles through a simple in-situ growth method.It is found that the density,size,and distribution of exsolved Ni nanoparticles are determined by the number of n in LSTNn due to the different stack structures of TiO_6 octahedra along the c axis.The Ni doping in LSTNn significantly improved the electrochemical activity by increasing oxygen vacancies,and the Ni metallic nanoparticles afford much more active sites.The results show that LSTNn cathodes can successfully be manipulated the activity by controlling both the n number and Ni exsolution.Among these LSTNn(n=5,8,and 12),LSTN8 renders a higher activity for electrolysis of CO_(2) with a current density of 1.50A cm^(-2)@2.0 V at 800℃ It is clear from these results that the number of n in(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2)with Ni-doping is a key factor in controlling the electrochemical performance and catalytic activity in SOEC.

Effect of solvents on the morphology and structure of barium titanate synthesized by a one-step hydrothermal method

Tetragonal barium titanate was synthesized from barium hydroxide octahydrate and titanium tetrachloride through a simple one-step hydrothermal method.The effect of different solvents on the crystal structure and morphology of barium titanate nanoparticles during the hy-drothermal process was investigated.Except for ethylene glycol/water solvent,impurity-free barium titanate was synthesized in pure water,methanol/water,ethanol/water,and isopropyl alcohol/water mixed solvents.Compared with other alcohols,ethanol promotes the formation of a tetragonal structure.In addition,characterization studies confirm that particles synthesized in methanol/water,ethanol/water,and isopropyl al-cohol/water mixed solvents are smaller in size than those synthesized in pure water.In the case of alcohol-containing solvents,the particle size decreases in the order of isopropanol,ethanol,and methanol.Among all the media used in this study,ethanol/water is considered the optimum reaction media for barium titanate with high tetragonality(defined as the ratio of two lattice parameters c and a,c/a=1.0088)and small aver-age particle size(82 nm),which indicates its great application potential in multilayer ceramic capacitors.

Photocatalytic Degradation of Oxytetracycline Dihydrate from Aqueous Solution Using Nano ZnO and ZnO.xBaTiO3 (x = 3%, 18%, 33% and 48%)

Traditional wastewater mostly contains pharmaceutical ingredients. Therefore, the wastewater must be completely free from antibiotics before its release into the environment. In the present study, photocatalytic degradation was done to investigate the removal efficiency of Oxytetracycline Dihydrate (OTC) using ZnO, ZnO/3%BaTiO3 (3 BZ), ZnO/18%BaTiO3 (18 BZ), ZnO/ 33%BaTiO3 (33 BZ) and ZnO/48%BaTiO3 (48 BZ) under UV light. After the exposure time of 420 min, about 99.57% and 97.87% of OTC was degraded using ZnO and 3 BZ respectively. Further, increasing the amount of BaTiO3 in ZnO prolongs the degradation time. Therefore, faster efficiency was found using ZnO nanoparticles. The observed reaction rate constant using ZnO was 0.00933 min-1 which decreased to 0.00532 min-1 using 48 BZ, indicating the decrease of reaction rate for increasing the amount of BaTiO3. Hence, the use of ZnO photocatalyst is anticipated to be a promising technique for the photocatalytic degradation of contaminated wastewater with oxytetracycline antibiotics using UV light.

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。

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。

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。

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。

Titan听力测试平台在新生儿听力筛查及听力诊断中的应用

目的应用Titan对初筛未通过的听力高危新生儿进行复筛,评价Titan在新生儿听力筛查及听力诊断中的作用。方法对223例(446耳)初筛未通过的听力高危新生儿在出生后第40天左右(前后不超过3 d)应用Titan分别行自动听性脑干反应(automated auditory brainstem response,AABR)、耳声发射(otoacoustic emission,OAE)、声导抗检测;AABR、OAE系统自动判断是否通过,声导抗检测采用1 KHz探测音,鼓室压低于-50 dapa、声顺<0.3 ml认定为异常;统计数据,并分析其结果。结果 AABR复筛通过436耳,复筛通过率为97.76%(436/446),OAE复筛通过348耳,通过率为78.03%(348/446),二者差异有显著性(χ~2=81.59,P<0.05);声导抗检测异常者共81耳,异常率为18.16%(81/446),其中在AABR复筛未通过10耳中存在声导抗检测异常者共1耳,异常率为10%(1/10),OAE复筛未通过98耳中存在声导抗检测异常者共57耳,异常率为58.16%(57/98),二者差异有显著性(χ~2=6.64,P<0.05)。结论 Titan是一款集AABR、OAE、声导抗检测于一体的新型听力检测仪器,应用于新生儿听力筛查可有效降低假阳性率,并能及早评价患儿的中耳功能,鼓室负压、咽鼓管功能不良是新生儿听力筛查假阳性率高的一个重要因素。

基于TitanImage软件的QuickBird影像融合

基于北京东方泰坦科技股份有限公司研发具有完全自主知识产权的Titan Image7.0遥感图像处理软件平台,对QuickBird标准组合(全色0.61 m+多光谱2.44 m)影像进行像素级融合,探讨Titan Image7.0遥感图像处理平台在影像融合及评价方面的应用。结果表明:该软件以友好的全中文界面,在同一平台上以简单的操作过程即可完成影像的融合过程与质量评价指标的求算,不仅有效的避免了跨平台、语言差异等因素带来的操作不便与信息损失,而且丰富的融合算法和质量评价指标,可以完成多种影像数据的融合和质量评价;从QuickBird影像融合与质量评价结果来看,参与融合的4种算法中以Pansharp融合算法最好,其次为小波变换算法,IHS算法、PCA算法融合效果最差,这与前人的研究结果基本一致。因此,可以认为Titan Image7.0软件是一种非常好的遥感影像融合平台。

近红外光Titan治疗面颈部皮肤松弛临床观察

目的:评价近红外光Titan治疗面颈部皮肤松弛的临床疗效和安全性。方法:选取27例临床面、颈部皮肤轻度松弛患者。采用美国Cutera公司生产的Titan治疗仪进行治疗,共治疗3次,每次间隔4周。由两位医生和患者根据治疗前后照片共同对治疗前后改善情况进行评价。结果:所有患者均完成治疗,在治疗结束3个月后进行评估,显示结果:10%的患者没有改善,25%的患者轻微改善,27%的患者中度改善,38%的患者良好改善。在治疗6个月后评估显示:12%的患者轻微改善,34%的患者中度改善,54%的患者显著改善。75%的患者表示满意和非常满意。仅治疗后出现轻微红斑,无1例出现严重副反应。结论:近红外光1100～1800nm能有效改善面颈部皮肤松弛,是一种安全、有效,副作用小的非剥脱性面颈部紧肤治疗的新方法。

NH^++H_2→NH_2^++H反应机理的量子力学研究

运用耦合簇理论CCSD方法对文献[1]提出的Titan大气中可能生成NH3的链式反应中第三个反应:NH++H2→NH2++H进行了热化学计算和分析.发现:①反应(3)在Titan环境中具有良好的反应自发性,在低温下自发反应可能性更大.反应(3)的转变温度为11881.7 K,高于这个温度反应才不可能自发正向进行.运用量子化学MP2方法在6-311g(d)基组下计算研究了反应的机理,发现:②此反应分为两步反应,第一步为放热反应,无能垒.第二步反应的过渡态为平面构型.正反应能垒仅为38.991 Kcal.mol-1,完全可以由第一步反应放出能量来补偿.结果均经过振动分析和IRC计算验证.在不同温度下,尤其是低温下第一步反应平衡常数很大.③由于此反应有较高的反应自发性,可以认为该反应在这六个在Titan大气的低温环境中自然合成NH3的链式反应中起着积极的作用.④耦合簇理论方法和MP2理论两种方法的计算结果是一致的,互相印证了结论的可靠性.

基于地闪定位资料的雷暴识别

TITAN算法常用于对雷达体扫资料进行雷暴识别与追踪;但使用的雷达体扫资料成本较高,相比之下地闪定位资料成本较低且易于获得。因此,将TITAN算法运用到地闪定位资料中,探索TITAN算法对地闪定位资料的适用性以及在TITAN算法中地闪定位资料能否取代雷达资料。利用山西省一次雷暴活动过程地闪定位资料,使用TITAN算法对雷暴能够进行了很好地识别;且得出算法阈值选取的大小会影响雷暴的识别。