Phase Equilibrium of Quaternary System Cd^(2+)//Cl^-,SO_4^(2-),NO_3^--H_2O at 298 K

Solid-liquid equilibrium of quaternary system Cd2＋//Cl–, SO42–, NO3–-H2O at 298 K was studied by means of an isothermal solution saturation method. Experimental results indicate that there are three univariant curves BE, AE and CE, one invariant point E and three crystallization fields in the quaternary system. The quaternary system belongs to a simple type, and there are no double salts or solid solution existing. The crystallization zones of equilibrium solid phases are CdCl2·5/2H2O（AEB field）, 3CdSO4·8H2O（AEC field） and Cd（NO3）2·4H2O（BEC field）, respectively. The composition of the invariant point is CdCl2, Cd（NO3）2, CdSO4 and H2O and the contents of which are 17.02%, 45.50%, 4.52% and 32.96%, respectively. The physico-chemical properties of solution in the quaternary system show regular changes along with the increased cadmium concentration. The results indicate that Cd（NO3）2 possessed the highest solubility among those three salts, which means a strong transfer of Cd ion and a high pollution risk of soil environment. And the solubility of CdSO4 would be restrained as the salts existing together.

Solid-liquid Metastable Equilibria in Quaternary System Li_2SO_4+Li_2CO_3+Li_2B_4O_7+H_2O at 288 K

Metastable equilibrium solubilities and densities of quaternary system Li2SO4＋Li2CO3＋ Li2B4O7＋H2O at 288 K were determined by isothermal evaporation method. According to the experimental data, the metastable equilibrium phase diagram was plotted. The metastable phase diagram had one invariant point F, three double saturated liquid curves ElF, E2F and E3F, and three crystallization fields corresponding to Li2SO4·H2O, Li2CO3 and LiBO2·8H2O. It was found that lithium sulphate（Li2SO4） had the highest concentration and strong salting-out effects on the other salts. There were no solid solutions or double salts formed in the quaternary system at 288 K.

STRUCTURE AND PROPERTY OF PIEZOELECTRIC CERAMICS OF QUATERNARY SYSTEM

Composite perovskite piezoelectric ceramics of PMMN quaternary system were prepared by cold-pressing and solid-phase sintering. Piezoelectric modulus and density of the samples were measured after polarization. X-ray diffraction analysis and SEM were used to prove the result that the major phase of the piezoelectric ceramic spectimen based on PZT is PZT phase,which is tetragonal system and P-4mm space group.

Solid-liquid Metastable Equilibria in Quaternary System (NaCl+Na_2CO_3+Na_2SO_4+H_2O) at 273.15 K

The metastable phase equilibria of the quaternary system NaCl＋Na2CO3＋Na2SO4＋H2O were studied at 273.15 K. The salts＇ solubilities, densities and pH values of the equilibrated solution in this system were determined. According to the experimental data, the metastable equilibrium phase diagram, the diagram of density vs. composition and pH vs. composition diagram were plotted. The phase diagram consists of five univariant curves, four crystallization fields and two invariant points. The four crystallization fields correspond to sodium carbonate decahydrate （Na2CO3·10H2O）, sodium sulfate decahydrate（Na2SOn-10H2O）, sodium chloride（NaCl） and burkeite（2Na2SO4. Na2CO3）, respectively. The crystallization field of sodium sulfate decahydrate（Na2SO4.10H2O） is the largest, which indicates that sodium sulfate is easy to saturate and crystallize from solution at 273.15 K.

BUBBLE POINT PRESSURE MEASUREMENT FOR ISOTHERMAL QUATERNARY SYSTEM AND PREDICTION OF VAPOR-LIQUID EQUILIBRIUM

1 INTRODUCTIONVapor-liquid equilibrium(VLE)relations are required for practical use,such as in the designand operation of disitillation equipment.In the conventional experimental methods of vapor-liquid equilibria,some analytical instruments are applied.They are time-consuming and dif-ficult for multicomponent system because the proper method for the composition analysis isnot easy to be set up.

From Quaternary Science to Earth System Science

This article details how AN Zhisheng and his colleagues,through decades of dedicated research,began with the study of loess in China and integrated it with climatic and environmental researches.AN and his team developed a novel research approach to identifying the dynamics of changes of natural environments,including loess environment in East Asia.Their work has not only highlighted the global significance of Chinese loess as a record for global climate change,but also led to the formulation of the monsoon control theory regarding environmental changes in East Asia,as well as insights into Asian and global monsoon dynamics.The paradigm shift from a singular discipline of Quaternary science into a comprehensive Earth system science has happened.Their contributions have been instrumental in promoting sustainable development of the society in the Chinese Loess Plateau and western China.

Efficient fixation of CO_(2) to cyclic carbonates and oxazolidinones with multi-hydroxyl bis-(quaternary ammonium) ionic liquids as catalysts under mild conditions

A series of multi-hydroxyl bis-(quaternary ammonium)ionic liquids(Ils1‒7)was prepared as bifunctional catalysts for the chemical fixation of CO_(2).All these ionic liquid compounds were efficient for the catalytic synthesis of cyclic carbonates and oxazolidinones via the cycloaddition reactions between CO_(2) and epoxides or aziridines with excellent yield and high selectivity in the absence of co-catalyst,metal and solvent.Due to the synergistic effects of hydroxyl groups and halogen anion,the cycloaddition reactions proceeded smoothly either at atmospheric pressure or room temperature.The selectivity for substituted oxazolidinones at 5-and 4-positions can be tuned via changing the reaction conditions.Finally,possible mechanisms including the activation of both CO_(2) and epoxide or aziridines were proposed based on the literatures and experimental results.

Thermodynamic descriptions of quaternary Mg-Al-Zn-Bi system supported by experiments and their application in descriptions of solidification behavior in Bi-additional AZ casting alloys

16 Mg-Al-Zn-Bi quaternary alloys were utilized to measure the phase equilibria and transformation temperatures in the Mg-rich Mg-Al-Zn-Bi quaternary system by means of the X-ray diffraction,electron probe micro-analysis and differential scanning calorimetry techniques.The isothermal section at 400℃and three vertical sections along Mg-8 wt%Al-0.75 wt%Zn-vBi,Mg-3.4 wt%Al-0.5 wt%Zn-ABi and Mg-6.9 wt%Al-2.3 wt%Zn-xBi in the Mg-Al-Zn-Bi quaternary system were constructed.Based on the literature data,the ternary Mg-Al-Bi and Mg-Bi-Zn systems were re-assessed using the CALculaiton of PHAse Diagram(CALPHAD)approach.The calculated phase equilibria agree well with the measured data.By directly extrapolating the constituent sub-ternary systems,the thermodynamic database for the Mg-Al-Zn-Bi quaternary system was developed.The remarkable consistency between the predicted phase equilibria and the presently measured data in Mg-Al-Zn-Bi quaternary system further demonstrated the accuracy and reliability of the established thermodynamic database.After that,by using the newly developed thermodynamic database,the growth restrict factors and the solidification curves in Bi-containing AZ series magnesium alloys were calculated and analyzed.It was confirmed that the grain size of AZ alloys can be refined with the addition of Bi,and the comp on ent Al had larger grain refinement effect than Bi.Besides,the amount of Bi had also no ticeable effect on the solidification sequence of the AZ alloys.

Metastable Phase Equilibrium in the Reciprocal Quaternary System LiCl＋MgCl2＋Li2SO4＋MgSO4＋H2O at 348.15 K and 0.1 MPa

The metastable solubilities and the physicochemical properties including density and pH of the reciprocal quaternary system（LiCl＋MgCl2＋Li2SO4＋MgSO4＋H2O） at 348.15 K and 0.1 MPa were determined using the isother- mal evaporation method. The dry-salt diagram and water-phase diagram were plotted based on the experimental data. There are five invariant points, eleven tmivariant curves, and seven crystallization zones corresponding to hexahy- drite, tetrahydrite, kieserite, bischofite, lithium sulfate monohydrate, lithium chloride monohydrate and lithium car- nallite. Comparison between the stable and metastable diagrams at 348.15 K indicates that the metastable phenome- non of magnesium sulfate is obvious, and the crystallization regions of hexahydrite and tetrahydrite disappear in the stable phase diagram. A comparison of the metastable dry-salt phase diagrams at 308.15, 323.15 and 348.15 K shows that with the increasing of temperatttre the epsomite crystallization zone disappears from the dry-salt phase diagranl of 303.15 K, and a new kieserite crystallization zone is presented at 348.15 K. The density and pH in the metastable equilibrium solution present regular change with the increasing of Janecke index J（2Li＋）, and the calculated densities using the empirical equation agree well with the experimental values.

Direct synthesis of propylene carbonate from propylene and carbon dioxide catalyzed by quaternary ammonium heteropolyphosphatotungstate–TBAB system

In this paper,we have developed a highly efficient method for the direct preparation of propylene carbonate from propylene and carbon dioxide（CO2） using quaternary ammonium heteropolyphosphatotungstate–quaternary ammonium halide catalytic system with anhydrous hydrogen peroxide as an oxidant through one-pot two-step process.The effects of the amount of tetrabutylammonium bromide（TBAB）,the concentration of hydrogen peroxide and other reaction conditions were investigated.The catalyst system gave an optimum propylene oxide yield（91%） at75°C in oxidation step and the highest propylene carbonate yield（99%） at 140°C and 3.0 MPa in cycloaddition step.Based on the results,a reaction mechanism has been proposed.

Studies on Systems of Lithium and Potassium Halides from Salt Lake and Bittern Resources（V）──The Quaternary Reciprocal System Li￣＋■Br￣－，I￣－－H＿2O and Boundary Ternary System NH＿4Br－NH＿4I－H＿2O at 25℃

he solubilities , refractive indexes of saturated solutions of the quaternary re-ciprocal system Li￣+ , Br￣(-) ,I￣(-)H_(2)O and its boundary ternary system NH_(4)Br-NH_(4)I-H_(2)O at 25℃ have been investigated using isothermal method. In the titleternary system which belongs to Roozeboom Ⅳ type, there are two limited solid so-lutions. Entering into the quaternary system, the region of the solid solutions re-duces and disappears with the increase of Li￣+ , and finally, the quaternary systembecomes a simple system.

IR and Raman Spectra Properties of Bi₂O₃-ZnO-B₂O₃-BaO Quaternary Glass System

Among new low-melting-point glasses, bismuth ate glass is deemed to have the most potential as an environmentally friendly replacement for polluting Pb-containing glasses. Current studies of boro-bismuthate glasses focus on the structural influence of the additional oxide in the context of low-melting-point electronic sealing applications. In this study, the structure of quaternary Bi2O3- ZnO-B2O3-BaO glasses was investigated spectroscopic ally, with Fourier-transform-infrared (FT-IR) and Raman spectra recorded for glasses with different main oxide contents. Signals in the FT-IR are mainly observed around 500 cm﹣1, 720 cm﹣1, 840 cm﹣1, 980 - 1080 cm﹣1, and 1200 - 1500 cm﹣1, while the Raman scattering peaks are located at 130 cm﹣1, 390 cm﹣1, 575 cm﹣1, 920 cm﹣1, and 1250 cm﹣1. The glasses are mainly structured around [BO3] units and the numbers of [BiO6] and [BiO3] units increase with the Bi2O3 content increasing. Concurrently, the FT-IR absorption peaks associated with [BO4] units shift to lower wave numbers, indicating a loosening of the glass structure. However, as the B2O3 content is increased, the numbers of [BO3] and [BO4] units increase, while those of [BiO3] and [BiO6] units decrease, highlighting a densification of the glass structure. ZnO acts as a network modifier in these glasses.

PHASE EQUILIBRIUM AND PROPERTIES OF THE SATURATED SOLUTION IN THE QUATERNARY SYSTEM Li_2B_4O_7-Li_2SO_4-LiCl-H_2O AT 25℃

Seawater is a natural solution which contains many elements. In general, Na+, K+, Mg++, Ca++, Cl-, SO4--, and H2O are considered as its main constituents. This is the famous 'seawater system'. As indicated in the previous paper, most of the salt lakes on the Qinghai-Xizang Pla-

Temperature-responsive self-separation ionic liquid system of zwitterionic-type quaternary ammonium-KI for CO_2 fixation

A series of zwitterionic‐type quaternary ammoniums(ZTQAs)with varying lengths of alkyl chains combined with KI were synthesized and considered as catalysts for the coupling reaction of CO2 and various terminal epoxides.The prolonged alkyl chain of ZTQAs exhibited temperature‐responsive self‐separation in propylene carbonate(PC).The interaction between ZTQAs and KI was confirmed by X‐ray photoelectron spectroscopy and quantum chemical calculations.This interaction strengthened the nucleophilicity of the I?ion,favoring the catalytic reaction.The 3‐(dimethyltetradecylammonium)propane sulfonate(DTPS)/KI showed an excellent yield of PC(95.1%)at 125°C,1.5 MPa,and 1 mol%loading of catalyst.The precipitate formed spontaneously from the catalytic system,providing high catalytic activity of the homogeneous catalyst,as well as easy recovery of the heterogeneous catalyst.

Deformation Patterns and Shortening Rates in the East Part of the Kalpin Thrust System in the Southwest Tianshan Mountains During the Late Quaternary

Deformation patterns, shortening amounts and rates in the late Quaternary across the Kalpin thrust system have received tittle attention in the past. This paper attempts to discuss them, mainly in the eastern part of the thrust system by doing field investigation along the faults and folds, measuring geomorphic deformation, excavating trenches in several important sites where young alluvial fans were obviously displaced and dating young deposits of alluvial terraces. There are two types of deformation in the surface and near surface for the Kalpin thrust system in the late Quaternary. They are movement of thrust faults on lower angles and bending of young folds. Both kinds of deformation are shown by shortening and uplifting of young geomorphic surfaces. The surface ages of 3 stages are calculated by dating 20 examples using the TL method in the study area and comparing the results of our predecessors on the deposition and incision times of alluvial terraces in the Tianshan mountain which are 100ka B. P., 33 - 18ka B.P. and 6.6 - 8.2ka B.P. respectively for the large-scale deformed alluvial surfaces： T3, T2 and T1 in the Kalpin region. Then, 19 sets of shortening amounts and rates are obtained in 13 sites along 4 rows of anticlines in front of the Kalpin thrust system and Piqiang fold. The shortening amounts and rates show that there are two sections where deformation is stronger than others. The two sections consist of two arcs that are towards the south. The shortening rates near the top of arcs are 1.32mm/a in the west and 1.39mm/a in the east across the thrust system, respectively. In addition, deformation is stronger in the front rows than the rear ones for bifurcate folds.

Across two phylogeographic breaks: Quaternary evolutionary history of a mountain aspen (Populus rotundifolia) in the Hengduan Mountains

Biogeographical barriers to gene flow are central to plant phylogeography.In East Asia,plant distribution is greatly influenced by two phylogeographic breaks,the Mekong-Salween Divide and Tanaka-Kaiyong Line,however,few studies have investigated how these barriers affect the genetic diversity of species that are distributed across both.Here we used 14 microsatellite loci and four chloroplast DNA fragments to examine genetic diversity and distribution patterns of 49 populations of Populus rotundifolia,a species that spans both the Mekong-Salween Divide and the Tanaka-Kaiyong Line in southwestern China.Demographic and migration hypotheses were tested using coalescent-based approaches.Limited historical gene flow was observed between the western and eastern groups of P.rotundifolia,but substantial flow occurred across both the Mekong-Salween Divide and Tanaka-Kaiyong Line,manifesting in clear admixture and high genetic diversity in the central group.Wind-borne pollen and seeds may have facilitated the dispersal of P.rotundifolia following prevalent northwest winds in the spring.We also found that the Hengduan Mountains,where multiple genetic barriers were detected,acted on the whole as a barrier between the western and eastern groups of P.rotundifolia.Ecological niche modeling suggested that P.rotundifolia has undergone range expansion since the last glacial maximum,and demographic reconstruction indicated an earlier population expansion around 600 Ka.The phylogeographic pattern of P.rotundifolia reflects the interplay of biological traits,wind patterns,barriers,niche differentiation,and Quaternary climate history.This study emphasizes the need for multiple lines of evidence in understanding the Quaternary evolution of plants in topographically complex areas.

基于Quaternary编码的球面三角格网邻近搜索算法

分析了球面Quaternary编码的特点,给出了三角格网方向判断的规则,并对该算法与Bartholdi邻近搜索算法的时间复杂度进行了对比。结果表明,分解算法的平均时间耗时量约是Bartholdi邻近搜索算法的23.66%。

Studies on Solvent System of Cesium Chloride and Lanthanum Chloride and Synthesization of Four Types of New Compounds

This article describes the solubility data of the quaternary systems of CsCl LaCl 3 HCl H 2O(25 ℃, HCl 13% or 23%(wt)) and CsCl LaCl 3 HAc H 2O(30 ℃, HAc 42%(wt)), and the corresponding solubility equilibrium diagrams. Three new compounds, CsCl·LaCl 3·4H 2O, 2CsCl·LaCl 3·2H 2O and 3CsCl·LaCl 3·3H 2O have been found. From analysis of the systems by the X ray powder diffraction, TG DTG and DTA, the properties of the compounds are presented. The interpretation of the mechanism of Meyer′s reactions is discussed further and the synthesis method of four type new compounds is offered.

Global patterns of taxonomic and phylogenetic endemism in liverwort assemblages

Exploring the worldwide patterns of endemism and the processes that lead to the formation of highendemism centers is crucial in biogeography.This study examines the geographic distribution and ecological influences on the endemism of liverworts across 390 regions worldwide.We assess phylogenetic endemism and relative phylogenetic endemism in relation to eleven environmental factors,which represent current and Quaternary climate variations,as well as topographic and environmental heterogeneity.Areas with higher endemism in liverworts tend to have higher temperatures,precipitation,and environmental heterogeneity,but lower temperature seasonality and lesser impacts from Quaternary climate changes.Regions exhibiting notably high endemism are predominantly found in tropical Asia,Madagascar,eastern Australia,and the Andes,while those with notably low endemism are generally in temperate Eurasia and North America,parts of Africa,and eastern South America.Centers of neo-endemism are mainly in southern Africa,whereas centers of paleo-endemism are in southern South America,tropical Asia,and New Zealand.Environment variability is a more significant predictor of phylogenetic endemism than current climate conditions,which are themselves more predictive than variables related to Quaternary climate changes.Nevertheless,these three types of explanatory variables combined explain only about one-third of the variance in phylogenetic endemism.

Palaeoclihlatic Indicators of China's Quaternary Saline Lake Sediments and Hydrochemistry

In this paper the authors classify saline lake sediments into the cold, warm and eurythermal phases, reveal the consistency between the zoning of hydrochemical types of modern saline lake water and climatic zoning and give climatic parameters under the conditions of typical cold phase (mirabilite and natron), warm phase (thenar-dite) and slightly warm phase (bloedite) saline lake deposition.