Etching Mechanism of Ti_(3)C_(2)Cl_(2) MXene Phases by CuCl_(2)-Lewis Molten Salt Method

We described a method for obtaining fluorine-free Ti_(3)C_(2)Cl_(2)MXene phases by melting copper in CuCl_(2)instead of aluminum in Ti_(3)AlC_(2).XRD results show that when molten salt CuCl_(2)etches Ti_(3)AlC_(2),it forms an intermediate product Ti_(3)CuC_(2),and then reacts with Ti_(3)CuC_(2)to obtain Ti_(3)C_(2)Cl_(2).The reaction of Ti_(3)AlC_(2)and CuCl_(2)at a temperature of 800℃for 2 h to obtain Ti_(3)C_(2)Cl_(2)with an optimal lamellar structure is shown in SEM results.The pseudopotential plane-wave(PP-PW)method is used to calculate on the electronic structure.The etching mechanism is investigated by the total energies of each substance.The chemical reaction of Ti_(3)AlC_(2)and CuCl_(2)will first become Ti_(3)CuC_(2)and Cu,and then become Ti_(3)C_(2)Cl_(2)during the Lewis acid etching process,which are consistent with the experimental results.

Kinetics analysis of decomposition of vanadium slag by KOH sub-molten salt method

A novel process was developed for the decomposition of vanadium slag using KOH sub-molten salt under ambient pressure, and the effects of reaction temperature, alkali-to-ore mass ratios, particle size, and stirring speed on vanadium and chromium extraction were studied. The results suggest that the reaction temperature and KOH-to-ore mass ratio are more influential factors for the extraction of vanadium and chromium. Under the optimal reaction conditions （temperature 180 °C, initial KOH-to-ore mass ratio 4：1, stirring speed 700 r/min, gas flow 1 L/min, and reaction time 300 min）, vanadium and chromium extraction rates can reach up to 95% and 90%, respectively. Kinetics analysis results show that the decomposing process of vanadium slag in KOH sub-molten salt can be well interpreted by the shrinking core model under internal diffusion control. The apparent activation energies for vanadium and chromium are 40.54 and 50.27 kJ/mol, respectively.

Application of Fuzzy Comprehensive Evaluation Method Based on Entropy Weight Theory in Evaluation of Salt Tolerance of Cotton

[Objective] The aim was to propose a new entropy weight fuzzy compre- hensive evaluation method for assessing cotton salt tolerance, realizing the objective, accurate and comprehensive evaluation of salt tolerance of cotton. [Method] A sand culture experiment under salt stress of 150 mmol/L of NaCI was designed. The in- dicator weight was determined with the entropy weight fuzzy comprehensive evalu- ation method, based on the salt injury index of indicators. The salt tolerance of cotton was evaluated comprehensively. [Result] At the germination stage, the entropy and weight of salt injury index of germination energy, vigor index, hypocotyl length and fresh weight were highest, followed by germination rate and germination index, and of root length were lowest. At the seedling stage, the entropy and weight of salt injury index of plasma membrane permeability, root vigor and leaf expansion rate were highest, followed by plant height and net photosynthetic rate, and of shoot dry weight and root dry weight were lowest. The salt tolerance of cotton differed a- mong growth stages and cultivars. Among the 11 cultivars, CCRI-44 and CCRI-75 were steadily salt-tolerant at both germination and seedling stages; CCRI-17, Sumi- an 22, Sumian 15 and Dexiamianl had a stable moderate salt tolerance; while Sumian 12 and Simian 3 were steadily salt-sensitive. [Conclusion] The evaluated result was objective and exact, which indicated that this method could be used in comprehensive evaluation of salt tolerance of cotton.

Preparation of hydro-sodalite from fly ash using a hydrothermal method with a submolten salt system and study of the phase transition process

Hydro-sodalites are zeolitic materials with a wide variety of applications.Fly ash is an abundant industrial solid waste,rich in silicon and aluminum,from which hydro-sodalite can be synthesized.However,traditional hydrothermal synthesis methods are complex and cannot produce high-purity products.Therefore,there is a demand for processing routes to obtain high-purity hydro-sodalites.In the present study,high-purity hydro-sodalite(90.2 wt%)was prepared from fly ash by applying a hydrothermal method to a submolten salt system.Samples were characterized by powder X-ray diffraction(XRD),scanning electron microscopy(SEM),thermogravimetry and differential thermal analysis(TG–DTA),and Fourier transform infrared spectroscopy(FTIR)to confirm and quantify conversion of the raw material into the product phase.Purity of the samples prepared with an H2O/Na OH mass ratio of 1.5 and an H2O/fly ash mass ratio of 10 was calculated and the conversion process of the product phase was studied.Crystallinity of the product was influenced more by the Na OH concentration,less by the H2O/fly ash mass ratio.The main reaction process of the system is that the Si O ions produced by dissolution of the vitreous body in the fly ash and Na+ions in the solution reacted on the destroyed mullite skeleton to produce hydro-sodalite.This processing route could help mitigate processing difficulties,while producing high-purity hydro-sodalite from fly ash.

COMPUTERIZED SIMULATION OF MOLTEN SALT SOLUTION OF Li,KF,Cl SYSTEM BY MOLECULAR DYNAMIC METHOD

The structure and properties of molten salt solution o J Li,K|F,Cl system have been investiged by computerized simulation of molecular dynamic method.The partial RDF,the partial molar energy of mixing and the diffusion coeffients of Li^+,K^+,F^- and Cl^- have been calculated. The results are in agreement with the experimental values.The regularities of the distribution of ions and mieroscopic holes are discussed based on the results of computerized simulation.

Electrochemical performances of LiFePO_4/C composites prepared by molten salt method

LiFePO4/C composites were synthesized by a molten salt (MS) method using the mixture of LiCl,LiOH and NaCl.The prepared LiFePO4/C composites are characterized by X-ray diffractometry (XRD),field emission scanning electron microscopy (FESEM) and charge-discharge test.XRD patterns indicate that LiFePO4 prepared in the temperature range of 550-700 ℃ crystallizes well in an olivine-type structure.Through FESEM images,the sphere-like and homogeneous particles of 0.2 μm can be observed.The charge-discharge test shows that the materials prepared at 600 ℃ for 12 h have good electrochemical performance.At the rates of 0.2C (34 mA/g) and 0.5C,the discharge capacities are 144.6 and 122.3 mA·h/g,respectively,together with good cycle performances.

NEW IDEAS AND METHODS ON GEOMECHANICAL SAFETY ANALYSIS OF TOXIC AND RADIOACTIVE WASTE REPOSITORIES IN SALT MINE

In view of the need for geomechanical safety analysis of repositories in salt rock, failure criteria,creep rupture criteria,material models,pillar design methods and criteria for the assessment of barrier efficiency as well as investigations of the interaction between hydraulics and mechanics for the case of uncontrolled flooded repositories are necessary. The introduction of damage mechanics and of the Hou/Lux material model including damages into geomechanical safety analysis of repositories in salt rock can reduce some previous deficits in knowledge and modelling. This article will be as a part of geotechnical assessment to introduce the Hou/Lux material model,a new concept of hydro-mechanical coupling and a pillar design method as well as criteria for the assessment of efficiency of geological barriers.

Optimum mining method selection using fuzzy analytical hierarchy process–Qapiliq salt mine,Iran

Mining method selection is the first and the most critical problem in mine design and depends on some parameters such as geotechnical and geological features and economic and geographic factors. In this paper, the factors affecting mining method selection are determined. These factors include shape, thick- ness, depth, slope, RMR and RSS of the orebody, RMR and RSS of the hanging wall and footwall. Then, the priorities of these factors are calculated. In order to calculate the priorities of factors and select the best mining method for Qapiliq salt mine, Iran, based on these priorities, fuzzy analytical hierarchy process （AHP） technique is used. For this purpose, a questionnaire was prepared and was given to the associated experts. Finally, after a comparison carried out based on the effective factors, between the four mining methods including area mining, room and pillar, cut and fill and stope and pillar methods, the stope and nillar mining method was selected as the most suitable method to this mine.

Application of Gravitational Methods to Prospecting Salt(Potash) Rocks in the Kuqa Depression

The Kuqa depression deposited thick rock salt,which has a lower density than surrounding rocks.When salt bodies form a certain scale,obvious negative gravity anomalies can be detected in the surface.Therefore,gravitational method can quickly obtain the shape,plane distribution of deep-seated salt bodies and overall tectonic morphology of the basin.

Structural and Piezoelectric Properties of Sr_(0.6)Ba_(0.4)Nb_2O_6 Micro-rods Synthesized by Molten-Salt Method

Sr0.6 Ba0.4 Nb2 O6 micro-rods are prepared by the molten-salt method with K2 SO4,KCl-K2 SO4,and KCl as fluxes.It reveals that the Sr0.6 Ba0.4 Nb2 O6 synthesized with KCl as a flux exhibits a single phase with tetragonal tungsten bronze structure.The measurement of X-ray diffraction indicates that the Sr0.6 Ba0.4 Nb2 O6 micro-rods synthesized at 1 300℃are anisotropic.The morphology of the powers is examined by transmission electron microscope.It reveals that the length-diameter ratio of Sr0.6 Ba0.4 Nb2 O6 micro-rods increases with increasing annealing temperature from 900℃to 1 300℃.At 1 300℃,the rod possesses a large length-diameter ratio of 8∶1.Moreover,the analysis of the piezoelectric properties of single micro-rods using apiezo-response force microscope indicates that the domains of the material are arranged along its radial direction.

The Study on the determination method of Aluminum and its salts

This paper reviews the standard methods for the determination of the Aluminum and its salts, and makes comparative analyses from the operation conditions and its characteristics. The current national standard and the industry standard methods include： the inductively coupled plasma atomic emission spectrometry, the inductively coupled plasma mass spectrometry, the atomic absorption spectrometry, the spectrophotometric method, the potential analysis and the titration analysis.

Effect of inorganic salt on the thermal degradation of nitrocellulose and reaction mechanism of its mixture

In this study,to better understand the reaction mechanism between inorganic salts and nitrocellulose,CaCO_(3) and Li_(2)CO_(3) were evaluated with respect to their effects on the thermal degradation of NC in nitrogen atmosphere using TG/DSC at three different heating rates(2,5,10 K/min).The numerical relationship between activation energy(E)and conversion rate was obtained by FWO and KAS method,and it was discovered that CaCO_(3) could improve the thermal stability of NC.Activation energy values were calculated by Kissinger method,and it was found that NC that contain Li2CO3had the highest activation energy while NC containing CaCO3had the lowest E value.By combining the thermal analysis data with Malek method,the most probable mechanism model of thermal degradation is obtained as Sesták-Berggren model,which expression is f(α)=α^(m)(1-α)^(n).As a result of this study,there are certain guiding principles that can be applied to the pyrolysis reaction model and to the actual production process of nitrocellulose.

盐碱胁迫对植物的影响及抗性机制研究进展

盐碱胁迫是仅次于干旱胁迫抑制植物生长发育的主要非生物胁迫之一,不仅影响植物的生长发育,而且对农业生产和生态环境造成严重威胁。研究植物的耐盐碱机制,对耐盐碱作物选育及盐碱地的开发利用具有重要的现实意义。结合近年来国内外的相关研究总结性阐述了盐碱胁迫对植物代谢的伤害(包括离子伤害、膜系统伤害、诱导渗透伤害等)机制,并从膜系统保护以及诱导基因表达方面综述了植物对盐碱胁迫的缓解机制,进而提出外源物质的导入、生物技术手段、耐盐碱品种培育是解决植物抗盐碱的主要手段。最后就植物适应盐碱胁迫方面的研究进行了展望,指出了当前研究者需要解决的问题和突破口,旨在为提高植物耐盐碱能力、增加作物产量提供一定的理论依据。

盐湖卤水中硼酸盐化学形态及Raman光谱定量分析

我国青藏盐湖以富含硼锂而著称,卤水中硼化学赋存状态随湖水化学类型的不同而发生变化,其中以硫酸盐型盐湖卤水中硼酸盐的存在形式变化最为复杂,卤水蒸发过程一般不以固体盐形式结晶析出,而是以多硼物种形式富集于氯化镁饱和老卤中,表现出严重的过饱和性,对后续锂盐和镁盐的分离提取影响较大。开展盐湖卤水体系中硼酸盐化学形态、分布规律及离子间作用机制等溶液化学研究对盐湖资源高效开发具有重要的意义。相比常规拉曼光谱技术,拉曼积分球基于拉曼散射原理可极大地提高激发光的使用效率和拉曼散射信号,对硼酸盐溶液结构检测具有拉曼响应信号强、检出限低、信噪比高等优点,为盐卤复杂体系硼酸盐化学形态的定量分析奠定了基础。利用拉曼积分球开展了盐湖卤水硼酸盐化学形态研究,阐述了卤水蒸发过程多硼酸根离子的变化规律;同时借助响应曲面法进行实验设计与优化,建立了共存盐类干扰回归模型用于盐湖卤水中单硼物种B(OH)_(3)的准确测定。结果表明,盐湖卤水浓缩过程中硼不断聚合生成多聚度硼酸根离子如B_(3)O_(3)(OH)_(4)^(-)和B_(6)O_(7)(OH)_(7)^(2-)等,硼的化学形态变化规律与碱土金属如MgCl_(2)-MgO-2B_(2)O_(3)-H_(2)O体系中硼物种变化一致,但与碱金属溶液体系物种变化差别较大。回归模型对卤水中正硼酸B(OH)_(3)定量分析的相对误差小于5%,准确度较高;阐明了蒸发浓缩过程中B(OH)_(3)物种分布的变化规律,从定量视角初步阐述了卤水富集过程硼酸根离子间的聚合作用关系,可为后续开展盐卤体系多硼物种分布及作用机制研究提供新思路、新方法。

库车坳陷西部阿瓦特—博孜地区构造变形差异及数值模拟分析

库车坳陷西部的阿瓦特-博孜地区位于构造挤压转换区,沿走向构造变形差异显著。本文基于最新的三维地震资料和离散元数值模拟方法,对该区域进行了精细的地质建模,模拟了其形成演化过程,讨论了差异变形的控制因素。阿瓦特地区盐下沿克深断裂远距离逆冲推覆,形成上下叠置的两套沿侏罗系煤层滑脱的逆冲体系;盐上发育厚度较小的阿瓦特凹陷;盐构造以不整合型为主。博孜地区盐下在克深断裂以北为高角度基底卷入变形,以南为沿煤层的滑脱,整体为楔形叠瓦冲断构造;盐上发育厚度巨大的拜城凹陷;盐构造以整合型为主。模拟结果表明,温宿古隆起限制了中生界至古近系的沉积范围,阻碍了变形的向前传递,是造成阿瓦特-博孜地区变形差异性的最主要原因。先存盐底辟构造和南天山的差异挤压作用对该区域的差异变形也具有一定的控制作用。综合地震剖面解释和数值模拟结果的演化过程表明,该区域构造活动具有由弱到强的变化趋势,构造变形开始于早中新世吉迪克组沉积时期,在上新世早期康村组沉积之后发生显著的构造加速事件。

NdF_(3)在LiF熔盐中的溶解及离子结构

LiF-NdF_(3)熔盐体系中离子的构成形式对解析电解钕工艺的电解过程至关重要,本文采用冰点降低法分析LiF-NdF_(3)熔盐体系的离子结构。通过Temkin和Flood模型及热力学计算分析熔盐体系内可能存在的离子团簇,结果表明,NdF_(3)在LiF中的溶解模型符合TemkinⅠ、TemkinⅡ、TemkinⅥ、TemkinⅦ和FloodⅡ、FloodⅥ、FloodⅦ,在LiF-NdF_(3)熔盐体系中主要形成含有1~2个Nd^(3+)的分子团簇,NdF_(3)在LiF内溶解主要形成游离的Nd^(3+)、F-、Li^(+)以及Li^(+)·[NdF_(4)]^(-)、Li^(+)·[Nd2F7]-、2Li^(+)·[Nd_(2)F_(8)]^(2-)分子团簇。

熔盐辅助合成硼化铪工艺研究

这是一篇冶金工程领域的论文。以氧化铪和碳化硼为原料,采用氯化钠为熔盐介质,通过硼/碳热还原法合成了纯度较高的硼化铪粉体。研究了反应温度、保温时间等合成工艺参数以及原料配比对材料晶相组成和显微结构的影响。结果表明,以氯化钠为熔盐介质时,氧化铪在1300℃的合成温度下开始转化为硼化铪,其温度远低于传统的硼化铪合成所需温度。在硼过量20%,反应温度和保温时间分别为1400℃和2 h所制备的硼化铪粉体纯度较高,X射线衍射中可以明显观察到硼化铪结晶峰,且在扫描电镜中可以观察到紧密团聚形貌的硼化铪。

盐益智仁-盐小茴香药对止泻活性部位筛选及“谱效”关系研究

目的筛选盐益智仁-盐小茴香药对(YZYH)止泻活性部位,并通过“谱效”关系研究推测其药效物质基础和质量标志物。方法制备大鼠脾肾阳虚泄泻模型,测定盐益智仁-盐小茴香药对石油醚(YZYH⁃L)、乙酸乙酯(YZYH⁃M)、水(YZYH⁃H)3部位药效指标,包括体重、肛温、腹泻潜伏期(diarrhea incubation period,DIP)、腹泻指数(diarrheal index,DI)等行为学指标及一氧化氮合成酶(nitric oxide synthetase,NOS)、环磷酸鸟苷(cyclic guanosine monophosphate,cGMP)、磷酸肌酸激酶(creatine phosphate kinase,CPK)等生化指标;建立不同部位高效液相色谱(high performance liquid chromatography,HPLC)图谱,采用灰色关联法分析各部位化学成分与止泻药效指标间的“谱效”关系。结果与空白对照组大鼠相比,15 d后,模型组大鼠出现泄泻证主症关键病理指标—水样便,同时,伴随食后腹胀、食欲不振和弓背等脾阳和肾阳虚泄泻的次症典型特征;给与治疗药物后,泄泻主症和次症均有不同程度的改善,其中阳性药、YZYH⁃M部位第28天后泄泻模型大鼠关键指标DIP极显著延长(P<0.01)、DI极显著降低(P<0.01),以及脾、肾阳虚泄泻的次症典型特征代表性指标体重、24 h摄食、饮水量、肛温和血清生化指标NOS、cGMP、CPK等活性的调节作用均较其它给药组好;“谱效”关系研究表明茴香醛、4号色谱峰等成分与DIP、DI、NOS、cGMP、CPK 5个药效指标的关联度重要。结论YZYH⁃M部位为药对止泻活性部位,其作用机制与抑制胃肠功能亢进和调节机体能量代谢与免疫相关;茴香醛及4号峰作为药对的质量标志物。

蓄盐沥青混合料与冰层粘结程度评价方法探究

为了能更精确地评价蓄盐沥青混合料与冰层的粘结程度,通过对拉拔头、冰层冻结方式、拉拔方式等方面进行改进,采用粘结强度和残冰率作为蓄盐沥青混合料与冰层粘结程度的评价指标,开发出一种基于马歇尔试件全断面的试验方法。试验结果表明,试件与冰层之间的粘结强度及残冰率随温度降低而增加,蓄盐沥青混合料在-10℃以内能降低试件与冰层的粘结强度30%以上,-7℃的粘结强度相比于普通沥青混合料减小约50%,-9℃以内残冰率减小比例均大于50%。冰层与试件粘结强度的测量准确度随残冰率的增大而降低,建议在-10℃内采用本试验方法。开发的评价试件与冰层粘结程度的试验方法区分度较高,试验的变异系数在10%以内,稳定性较好。