Experimental investigation of omnidirectional multiphysics bilayer invisibility cloak with anisotropic geometry

Thermal-electric bilayer invisibility cloak can prevent the heat flux and electric current from touching the object without distorting the external temperature and electric potential fields simultaneously.In this paper,we design an omnidirectional thermal-electric invisibility cloak with anisotropic geometry.Based on the theory of neutral inclusion,the anisotropic effective thermal and electric conductivities of confocal elliptical bilayer core-shell structure are derived,thus obtaining the anisotropic matrix material to eliminate the external disturbances omnidirectionally.The inner shell of the cloak is selected as an insulating material to shield the heat flux and electric current.Then,the omnidirectional thermal-electric cloaking effect is verified numerically and experimentally based on the theoretical anisotropic matrix and manufactured composite structure,respectively.Furthermore,we achieve the thermal-electric cloaking effect under a specific direction of heat flux and electric current using the isotropic natural materials to broaden the selection range of materials.The method proposed to eliminate anisotropy and achieve the omnidirectional effect could also be expanded to other different physical fields for the metadevices with different functions.

For more and purer hydrogen-the progress and challenges in water gas shift reaction

The water gas shift(WGS) reaction is a standard reaction that is widely used in industrial hydrogen production and removal of carbon monoxide. The improved catalytic performance of WGS reaction also contributes to ammonia synthesis and other reactions. Advanced catalysts have been developed for both high and low-temperature reactions and are widely used in industry. In recent years, supported metal nanoparticle catalysts have been researched due to their high metal utilization. Low-temperature catalysts have shown promising results, including high selectivity, high shift rates, and higher activity potential. Additionally, significant progress has been made in removing trace CO through the redox reaction in electrolytic cell. This paper reviews the development of WGS reaction catalysts, including the reaction mechanism, catalyst design, and innovative research methods. The catalyst plays a crucial role in the WGS reaction, and this paper provides an instant of catalyst design under different conditions. The progress of catalysts is closely related to the development of advanced characterization techniques.Furthermore, modifying the catalyst surface to enhance activity and significantly increase reaction kinetics is a current research direction. This review goals to stimulate a better understanding of catalyst design, performance optimization, and driving mechanisms, leading to further progress in this field.

Synergistic regulation of hydrophobicity and basicity for copper hydroxide-derived copper to promote the CO_(2)electroreduction reaction

A simple method was proposed to activate alkaline Cu(OH)_(2)with an acidic ionomer,Nafion,to regulate its surface microenvironment,including hydrophobicity and local basicity.In particular,the direct complete neutralization reaction between Cu(OH)_(2)and Nafion in aqueous solution induces the exposing of vast anions which can exclude the in-situ-formed hydroxides and raise the local basicity.Remarkably,the optimal Nafionactivated Cu(OH)_(2)-derived Cu can efficiently suppress the hydrogen evolution reaction(HER)and improve the selectivity for multi-carbon products in the CO_(2)electroreduction reaction(eCO_(2)RR).The H2 Faradaic efficiency(FE)decreased to 11%at a current density of 300 mA/cm2(−0.76 V vs.RHE)in a flow cell,while the bare one with H2 had an FE of 40%.The total eCO_(2)RR FE reaches as high as 83%,along with an evidently increased C2H4 FE of 44%as compared with the bare one(24%),and good stability(8000 s),surpassing that of most of the reported Cu(OH)_(2)-derived Cu.The experimental and theoretical results both show that the strong hydrophobicity and high local basicity jointly boosted the eCO_(2)RR as acquired by felicitously introducing ionomer on the Cu(OH)_(2)-derived Cu surface.

蜂窝状离子印迹壳聚糖/ZSM-5复合泡沫对U(Ⅵ)的吸附特性

工业含铀废水排放导致的放射性污染严重危害环境安全和人体健康。文中制备了蜂窝状离子印迹壳聚糖/ZSM-5(ICZ)复合泡沫,用于选择性吸附U(Ⅵ)。结果表明,不同原料配比制备的ICZ泡沫中,ICZ-2对U(Ⅵ)吸附效果最佳,是由于其兼具发达的蜂窝状结构和丰富的功能基团。与非离子印迹吸附剂比较,离子印迹吸附剂ICZ-2能选择性识别目标离子,因此具有更高的吸附容量和选择性。吸附等温线符合Langmuir模型,表明为均相单分子层吸附,吸附容量达280.09 mg/g;吸附动力学符合拟二级模型,表明化学吸附是控速步骤。ICZ-2对U(Ⅵ)的吸附以功能基配位络合为主要机理。ICZ-2吸附容量高、吸附速率快、吸附选择性好,有望用于含铀废水处理。

Besshi-type mineral systems in the Palaeoproterozoic Bryah Rift-Basin, Capricorn Orogen, Western Australia： Implications for tectonic setting and geodynamic evolution

In this contribution we use VMS mineral systems in the Bryah rift-basin to constrain the tectonic setting of the widespread mafic and ultramafic magmatism that characterises the rift-basin in question.Two distinct,but temporally closely associated,lithostratigraphic sequences,Narracoota and Karalundi Formations,are discussed.The Karalundi Formation is the main host of VMS mineral systems in the region.The Karalundi Formation consists of turbiditic and immature clastic sediments,which are locally intercalated with basaltic hyaloclastites,dolerites and banded jaspilites.We propose that the basaltic hyaloclastites,dolerites and elastics and jaspilites rocks,form a distinct unit of the Karalundi Formation,named Noonyereena Member.The VMS mineral systems occur near the north-east trendingJenkin Fault and comprise the giant and world-class DeCrussa and the Red Bore deposits.The nature of these deposits and their intimate association with terrigenous clastic rocks and dominantly marine mafic volcanic and subvolcanic rocks,as well as the common development of peperitic margins,are considered indicative of a Besshi-type environment,similar to that of present-day Gulf of California.Our Re-Os age data from a primary pyrite yielded a mean model age of 2012 ± 48 Ma,which coincides（within error） with recent published Re-Os data（Hawke et al.,2015） and confirms the timing of the proposed geodynamic evolution.We propose a geodynamic model that attempts to explain the presence of the Narracoota and Karalundi Formations as the result of mantle plume activity,which began with early uplift of continental crust with intraplate volcanism,followed by early stages of rifting with the deposition of the Karalundi Formation（and Noonyereena Member）,which led to the formation of Besshi-type VMS deposits.With on-going mantle plume activity and early stages of continental separation,an oceanic plateau was formed and is now represented by mafic-ultramafic rocks of the Narracoota Formation.

Sulfur-linked carbonyl polymer as a robust organic cathode for rapid and durable aluminum batteries

Rechargeable aluminum batteries are believed as a promising next-generation energy-storage system due to abundant low-cost Al sources and high volumetric specific capacity.The Al-storage cathodes,however,are plagued by strong electrostatic interaction between host materials and carrier ions,leading to large overpotential and undesired cycling stability as well as sluggish ion diffusion kinetics.Herein,sulfur-linked carbonyl polymer based on perylene-3,4,9,10-tetracarboxylic dianhydride(PTCDA) as the cathode materials for ABs is proposed,which demonstrates a small voltage polarization(135 mV),a reversible capacity of 110 mAh g^(-1) at 100 mA g^(-1) even after 1200 cycles,and rapid Al-storage kinetics.Compared with PTCDA,the sulfide polymer possesses higher working voltage because of its lower LUMO energy level according to theoretical calculation.The ordered carbonyl active sites in sulfide polymer contribute to the maximized material utilization and rapid ion coordination and dissociation,resulting in superior rate capability.Besides,the bridged thioether bonds endow the polysulfide with robust and flexible structure,which inhibits the dissolution of active materials and improves cycling stability.This work implies the importance of ordered arrangement of redox active moieties for organic electrode,which provides the theoretical direction for the structural design of organic materials applied in multivalent-ion batteries.

Nanobubbles produced by hydraulic air compression technique

The anoxia of coastal water has already been a serious problem all over the word.Nanobubbles are proved to have great applications in water remediation because they could effectively increase the oxygen content and degrade organic matters in water.But the existing methods to produce nanobubbles are complicated and high cost to operate,especially in deep sea.In this paper,we presented a low-cost method,hydraulic air compression(HAC),to produce a large number of nanobubbles and proved that nanoscale gas bubbles could be produced by HAC for the first time.Nanoparticle tracking analysis was used to measure the size and concentration of produced nanobubbles.It indicated that the concentration of nanobubbles would increase as the downpipe height increases.Degassed measurements proved that produced“nanoparticles”are gas nanobubbles indeed.More dissolved oxygen in water would provide the source for larger number of nanobubble formation.Those results are expected to be very helpful for water remediation in ocean in the future.

Seasonal and spatial variations of dimethylsulfoxide(DMSO) in the East China Sea and the Yellow Sea

Seasonal and spatial distributions of dissolved and particulate dimethylsulfoxide(DMSOd,DMSOp)were measured in the East China Sea and the Yellow Sea during March–April 2011 and October–November 2011.The concentrations of DMSOd and DMSOp in the surface water were 20.6(5.13–73.8)and 8.90(3.75–29.6)nmol/L in spring,and 13.4(4.17–42.7)and 8.18(3.44–22.6)nmol/L in autumn,respectively.Both DMSOd and DMSOp concentrations revealed similar seasonal changes with higher values occurring in spring,mainly because of the higher phytoplankton biomass observed in spring.Moreover,the ratios of DMSOp/chlorophyll a also exhibited an apparent seasonal change with higher values in autumn(35.7 mmol/g)and lower values in spring(23.4 mmol/g),thereby corresponding with the seasonal variation in the proportion of DMSO producers in the phytoplankton community between spring and autumn.In addition,DMSOd and DMSOp concentrations in the surface seawater revealed obvious diurnal variations with the maxima appearing in the afternoon.

Long noncoding RNA CCDC183-AS1 depletion represses breast cancer cell proliferation, colony formation, and motility by sponging microRNA-3918

Many studies have illustrated the significance of long noncoding RNAs in oncogenesis and promotion of breast cancer(BC).However,the biological roles of CCDC183 antisense RNA 1(CCDC183-AS1)in BC have rarely been characterized.Thus,we explored whether CCDC183-AS1 is involved in the malignancy of BC and elucidated the possible underlying mechanisms.Our data confirmed elevated CCDC183-AS1 expression in BC,which was associated with poor clinical outcomes.Functionally,knocking down CCDC183-AS1 hampered cell proliferation,colony formation,migration,and invasion in BC.Additionally,the absence of CCDC183-AS1 restrained tumor growth in vivo.Mechanistically,CCDC183-AS1 executed as a competitive endogenous RNA in BC cells by decoying microRNA-3918(miR-3918)and consequently overexpressing fibroblast growth factor receptor 1(FGFR1).Furthermore,functional rescue experiments confirmed that inactivation of the miR-3918/FGFR1 regulatory axis by inhibiting miR-3918 or increasing FGFR1 expression could abrogate the CCDC183-AS1 ablation-mediated repressive effects in BC cells.In summary,CCDC183-AS1 deteriorates the malignancy of BC cells by controlling miR-3918/FGFR1 regulatory axis.We believe that our study can deepen our understanding of BC etiology and contribute to an improvement in treatment choices.

Long noncoding RNA PPP1R14B-AS1 imitates microRNA-134-3p to facilitate breast cancer progression by upregulating LIM and SH3 protein 1

Long noncoding RNA PPP1R14B antisense RNA 1(PPP1R14B-AS1)has emerged as a critical modulator of liver cancer and lung adenocarcinoma progression.However,the functional importance and biological relevance of PPP1R14B-AS1 in breast cancer remain unclear.Therefore,this study was designed to detect PPP1R14B-AS1 levels in breast cancer cells using qRT–PCR and elucidate the influence of PPP1R14B-AS1 on aggressive phenotypes.Furthermore,molecular events mediating the action of PPP1R14B-AS1 were characterized in detail.Functional experiments addressed the impacts of PPP1R14B-AS1 knockdown on breast cancer cells.In this study,PPP1R14B-AS1 was found to be overexpressed in breast cancer,exhibiting a close correlation with poor patient prognosis.Results also showed that breast cancer cell proliferation and motility were suppressed when PPP1R14B-AS1 was silenced.Mechanistically,PPP1R14B-AS1 acted as a competing endogenous RNA for microRNA-134-3p(miR-134-3p)in breast cancer cells.PPP1R14B-AS1 also increased LIM and SH3 protein 1(LASP1)levels by imitating miR-134-3p in breast cancer cells.Rescue experiments further corroborated that the knockdown of miR-134-3p or an increase in LASP1 restored the aggressive malignant characteristics of breast cancer cells that were weakened by PPP1R14B-AS1 depletion.In summary,PPP1R14B-AS1 facilitated the oncogenicity of breast cancer cells by controlling the miR-134-3p/LASP1 axis.We believe that ourfindings may contribute to the development of precision therapy techniques in thefield of breast cancer treatment.

Long noncoding RNA LINC02568 sequesters microRNA-874-3p to facilitate malignancy in breast cancer cells via cyclin E1 overexpression

Increasing numbers of long noncoding RNAs(lncRNAs)are implicated in breast cancer oncogenicity.However,the contribution of LINC02568 toward breast cancer progression remains unclear and requires further investigation.Herein,we evaluated LINC02568 expression in breast cancer and clarified its effect on disease malignancy.We also investigated the mechanisms underlying the pro-oncogenic role of LINC02568.Consequently,LINC02568 was upregulated in breast cancer samples,with a notable association with worse overall survival.Functionally,depleted LINC02568 suppressed cell proliferation,colony formation,and metastasis,whereas LINC02568 overexpression exerted the opposite effects.Our mechanistic investigations suggested that LINC02568 was physically bound to and sequestered microRNA-874-3p(miR-874-3p).Furthermore,miR-874-3p mediated suppressive effects in breast cancer cells by targeting cyclin E1(CCNE1).LINC02568 positively controlled CCNE1 expression by sequestering miR-874-3p.Rescue experiments revealed that increased miR-874-3p or decreased CCNE1 expression recovered cell growth and motility functions induced by LINC02568 in breast cancer cells.In conclusion,the tumor-promoting functions of LINC02568 in breast cancer cells were enhanced by sequestering miR-874-3p and consequently over-expressing CCNE1.Our data may facilitate the identification of novel therapeutic targets in clinical settings.

Structure and Electrical Properties of Oxide Doped Rhombohedral Pb(Ni1/3Nb2/3)O3-PbTiO3 Ferroelectric Ceramics

0.7Pb(Ni1/3Nb2/3)O3-0.3PbTiO3 (0.7PNN-0.3PT) and 1 mol% La2O3-, Y2O3-, ZnO-, MnO2- and Nb2O5-doped 0.7PNN- 0.3PT ferroelectric ceramics were prepared by the conventional solid-state reaction method via the columbite precursor route. The ceramics sintered at 1180℃ exhibit pure rhombohedral perovskite structure except the Y2O3-doped 0.7PNN-0.3PT ceramics. The oxide-doped 0.7PNN-0.3PT ceramics exhibit rather homogeneous microstructure and improved densification, especially for the MnO2-and La2O3-doped 0.7PNN-0.3PT (defect) ceramics whose relative density is larger than 96%. All the above dopants decrease the dielectric loss of the 0.7PNN-0.3PT ceramics, whereas the values of the dielectric maximum (?m) and the temperature of ?m (Tm), and the character of dielectric response vary differently. ZnO and Nb2O5 doping increase remanent polarization Pr, and La2O3, ZnO, MnO2 and Nb2O5 doping decrease coercive field Ec of the 0.7PNN-0.3PT ceramics. Piezoelectric property is greatly improved by Y2O3, MnO2, Nb2O5 and ZnO doping, where the MnO2-doped 0.7PNN-0.3PT ceramics exhibit the largest value of piezoelectric constant d33, which reaches 191 pC/N.

H_(3)PO_(4) activated biochars derived from different agricultural biomasses for the removal of ciprofloxacin from aqueous solution

Biochars were prepared by the pyrolysis of various H_(3)PO_(4) activated agricultural biomasses at 600℃and subsequently used as adsorbents for the removal of ciprofloxacin(CIP)from aqueous solution.Peanut shell-based biochar(PSBC),corncob-based biochar(CCBC)and cotton-based biochar(CTBC)had high surface areas(571.0-1006.3 m^(2)/g),well-developed pore structures(mesopores with large pore volumes)and available adsorption functional groups(C=C,C-N and C-O-C).The CIP adsorption onto the biochars was investigated by batch experiments(kinetics,isotherms,thermodynamics,pH,etc.).Thermodynamics calculations showed the spontaneous(ΔG^(θ)<0)and endothermic(ΔH^(θ)>0)nature of the mechanism.In particular,CCBC exhibited high adsorption capacity(120.6 mg/g)of CIP in real lake water and it also had significant removal efficiency of other common pharmaceutical contaminants from real lake environ-ment,and even in a coexisting quintuple system.Finally,multiple interaction mechanisms of CIP adsorption onto aromatized biochar were explored combining characterization analysis and theoretical calculations.Elucidation of the mechanism of CIP adsorption onto biochar provides new insights into the assessment of the removal of pharmaceuticals from the aqueous environment.

Broadly neutralizing antibodies derived from the earliest COVID-19 convalescents protect mice from SARS-CoV-2 variants challenge

Coronavirus disease 2019(COviD-19)was first reported three years ago,when a group of individuals were infected with the original SARS-CoV-2 strain,based on which vaccines were developed.Here,we develop six human monoclonal antibodies(mAbs)from two elite convalescents in Wuhan and show that these mAbs recognize diverse epitopes on the receptor binding domain(RBD)and can inhibit the infection of SARS-CoV-2 original strain and variants of concern(VOCs)to varying degrees,including Omicron strains XBB and XBB.

中国斑岩铜矿床中的主要关键矿产

斑岩铜矿床是Re、Se及Te等关键矿产的最主要来源.中国目前有70余个斑岩铜矿床,包括11个超大型及16个大型矿床,但其内的关键矿产禀赋及规律尚不清楚.本文在简要综述斑岩铜矿中主要关键矿产及中国斑岩铜矿床的基础上,详细分析了中国斑岩铜矿床中关键矿产,特别是Re的吨位品位、赋存状态及成矿规律等.中国斑岩铜矿床中Re品位主要介于0.03~0.5 g/t之间,资源量变化于3~313 t之间,主要形成于侏罗纪和第三纪;有10个矿床的资源量超过50 t,其中, Re资源量超过200 t的3个矿床(玉龙、甲玛、驱龙)均形成于后碰撞环境;矿床中的Re主要赋存于辉钼矿中,与钾硅酸盐化和/或绢英岩化蚀变有关,辉钼矿中的Re平均含量主要介于30~1000μg/g之间,且与矿床的Mo品位呈明显的负相关.中国斑岩铜矿中Se、Te及PGE品位数据相对有限,已有的数据显示多个矿床的硫化物(如斑铜矿和黄铜矿)中的Se及Te含量在300μg/g之上,特别是冈底斯厅宫-岗讲矿集区蚀变斑岩中的Te含量高达0.1~0.7μg/g;而矿石中的PGE含量变化范围较大, Pd+Pt含量介于0.2~450 ng/g之间.总之,中国斑岩铜矿具有与世界其他地区斑岩铜矿类似的Re、Se、Te及PGE品位,显示出较好的成矿及利用潜力.不过,针对中国斑岩铜矿中关键矿产的研究尚处于起步阶段,亟须开展矿化特征、成矿规律及控矿要素的典型解剖和区域对比研究,优化分析测试技术,早日查明可利用资源量,并实现勘查增储及综合回收利用.

中国共产党领导下的戒毒机构发展演变——基于1927—1953年的研究

戒毒机构在禁毒工作中占有重要地位。从戒毒机构的设置与管理体制、组织机构与人员配置、经费保障、收治对象、戒治措施、成效六个方面系统梳理土地革命战争时期至中华人民共和国成立初期中国共产党领导下的戒毒机构的发展情况发现,川陕省戒烟局是党首次在省级政府中设置的戒毒专管机构;陕甘宁边区曲子县戒烟所是党领导的最早的强制性戒毒机构;中华人民共和国成立初期存在两种类型的戒烟所——群众互助戒烟所和政府戒毒所。党具有先进的戒毒理念和方法:戒毒机构实行戒毒人员自主管理,把受戒者当作病人看待,注重思想政治教育,把劳动作为戒治手段等。

Emission of organic carbon, elemental carbon and water-soluble ions from crop straw burning under flaming and smoldering conditions

Emissions from major agricultural residues were measured using a self-designed combustion system. Emission factors （EFs） of organic carbon （OC）, elemental carbon （EC）, and water-soluble ions （WSIs） （K＋, NH4＋, Na＋, Mg2＋, Ca2＋, Cl-, NO3-, SO42–） in smoke from wheat and rice straw were measured under flaming and smoldering conditions. The OC1/TC （total carbon） was highest （45.8% flaming, 57.7% smoldering） among carbon fractions. The mean EFs for OC （EFOC） and EC （EFEC） were 9.2 ± 3.9 and 2.2 ± 0.7 g/kg for wheat straw and 6.4 ± 1.9 and 1.1 ± 0.3 g/kg for rice straw under flaming conditions, while they were 40.8 ± 5.6 and 5.8 ± 1.0 g/kg and 37.6 ± 6.3 and 5.0 ± 1.4 g/kg under smoldering conditions, respectively. Higher EC ratios were observed in particulate matter （PM） mass under flaming conditions. The OC and EC for the two combustion patterns were significantly correlated （p 〈 0.01, R = 0.95 for wheat straw; p 〈 0.01, R = 0.97 for rice straw）, and a higher positive correlation between OC3 and EC was observed under both combustion conditions. WSIs emitted from flaming smoke were dominated by Cl- and K＋, which contributed 3.4% and 2.4% of the PM mass for rice straw and 2.2% and 1.0% for wheat straw, respectively. The EFs of Cl- and K＋ were 0.73 ± 0.16 and 0.51 ± 0.14 g/kg for wheat straw and 0.25 ± 0.15 and 0.12 ± 0.05 g/kg for rice straw under flaming conditions, while they were 0.42 ± 0.28 and 0.12 ± 0.06 g/kg and 0.30 ± 0.27 and 0.05 ± 0.03 g/kg under smoldering conditions, respectively. Na＋, Mg2＋, and NH4＋ were vital components in PM, comprising from 0.8% （smoldering） to 3.1% （flaming） of the mass. Strong correlations of Cl- with K＋, NH4＋, and Na＋ ions were observed in rice straw and the calculated diagnostic ratios of OC/EC, K＋/Na＋ and Cl-/Na＋ could be useful to distinguishing crop straw burning from other sources of atmospheric pollution.

Dynamics of arsenic in salt marsh sediments from Dongtan wetland of the Yangtze River estuary,China

The mobility and transformation of arsenic （As） in salt marsh sediments were investigated in Dongtan wetland of the Yangtze River estuary, China. As in surface water, pore water and the rhizosphere sediments were quantified. The microcosm incubation experiments were conducted during the flooding of the sediments to examine As dynamics that occurred during changing redox conditions. The concentrations of dissolved As in pore water （0.04--0.95 ixmol/L） were significantly greater than that in surface water （0.03-0.06 lunol/L）. Under anoxic conditions, the reactive As could be initially mobilized by the reductive dissolution of Fe（III） （hydr）oxides. Subsequently, most of the dissolved As was likely to be associated with secondary iron （hydr）oxide phases and remained in solid phases. The seasonal variability of acid volatile sulfide concentrations suggest the anoxic conditions are enhanced during summer by Spartina alterniflora compared to Phragmites australis and Scirpus mariqueter, causing a notable increase in As mobility. Generally, there was a typical variation in redox conditions with season in salt marsh sediments of Dongtan wetland, in which the dynamics of As mobility and transformation possibly were controlled by iron, and all of this could be significantly influenced by the rapid spread of S. alterniflora.

Porphyry Cu deposits linked to episodic growth of an underlying parental magma chamber

Saindak is one of the typical porphyry Cu deposits(PCDs)in the Chagai magmatic arc in Pakistan.Ore-forming porphyries at Saindak PCD are mainly composed of tonalite.Here,we use geochemistry of apatite enclosed in plagioclase phenocrysts from the ore-forming tonalite to constrain the releasing and recharging processes of S and Cl in the underlying parental magma chamber during PCD mineralization.Although apatite inclusions have homogeneous intra-grain S and Cl compositions,there is significant inter-grain S and Cl variations in apatite inclusions located from core to rim in the hosting plagioclase.Such inter-grain S and Cl variation in apatites are coupled with the core-to-rim trends of An,FeO and Mg contents of the hosting plagioclase phenocryst.It indicates that the Saindak PCD likely formed by episodic injection of primitive magmas during the growth of an underlying magma chamber,rather than by one major injection or by addition of mafic melt derived from different source region.Each primitive melt injection introduced essential ore-forming materials such as S and Cl,which were rapidly and effectively released to the coexisting fluids,causing mineralization.Once primitive melt injection stops,signaling the end of growth of underlying magma chamber,mineralization will cease quickly although the hydrothermal system can still survive for a long time.However,the later released fluids are relatively depleted in ore-forming materials,and thus have lower capability to generate mineralization.Accordingly,predominant porphyry-type mineralizations occurred during the growth rather than waning stage of a magmatic system.

Effects of solvent,supersaturation ratio and silica template on morphology and polymorph evolution of vanillin during swift cooling crystallization

Swift cooling crystallization of vanillin was investigated in water,ethanol,isopropanol and ethyl acetate.Morphology and polymorph evolution of vanillin were discussed in terms of solvent,supersaturation ratio and silica template.PXRD,DSC,FTIR and microscope were used to identify polymorphs of vanillin.Results showed that the nucleated polymorphs of vanillin depended largely on the solvent,supersaturation ratio and silica template.Low supersaturation ratios favor the nucleation of stable form I in water,and high supersaturation ratio exceeds 7 generating 100%metastable form II.However,if the supersaturation ratio is too high(S>8),liquid-liquid phase separation will occur,and no crystals could be obtained.In other solvents such as ethanol,isopropanol and ethyl acetate,only form I was obtained.However,it should be noted that the morphology of form I prepared in ethanol,isopropanol and ethyl acetate is distinct from that obtained in water,the former is flake-like and the latter is rod-like.The nucleation of vanillin from different solution was also studied with the presence of SiO_(2),SiO_(2)-NH_(2)and SiO_(2)−COOH templates,which did not change the nucleated polymorph of vanillin,but changed the nucleation and growth rate of stable form I.