Synthesis of crystalline g-C_(3)N_(4) with rock/molten salts for efficient photocatalysis and piezocatalysis

Graphitic carbon nitride(g-C_(3)N_(4))is emerging as a promising visible-light photocatalyst while the low crystallinity with sluggish charge separation/migration dynamics significantly restricts its practical applications.Currently,synthesizing highly crystalline g-C_(3)N_(4) with sufficient surface activities still remains challenging.Herein,different from using alkali molten salts which is commonly reported,we propose an approach for synthesis of highly crystalline g-C_(3)N_(4) with FeCl3/KCl rock/molten mixed salts.The rock salt can serve as the structure-directing template while molten salt provides the required liquid medium for re-condensation.Intriguingly,the synthesized photocatalyst showed further enhanced crystallinity and improved surface area along with high p/p*excitation compared with crystalline C_(3)N_(4) prepared from conventional molten-salt methods.These catalytically advantageous features lead to its superior photocatalytic and piezocatalytic activities with a high reactivity for overall water splitting that is not commonly reported for C_(3)N_(4).This work provides an effective strategy for structural optimization of organic semiconductor based materials and may inspire new ideas for the design of advanced photocatalysts.

Effect of high-energy Ne ions irradiation on mechanical properties difference between Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5)metallic glass and crystalline W

In this paper,high-energy Ne ions were used to irradiate Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) metallic glass(MG)and crystalline W to investigate their difference in mechanical response after irradiation.The results showed that with the irradiation dose increased,the tensile micro-strain increased,nano-hardness increased from 7.11 GPa to 7.90 GPa and 8.62 GPa,Young’s modulus increased,and H3/E2 increased which indicating that the plastic deformability decreased in crystalline W.Under the same irradiation conditions,the Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG still maintained the amorphous structure and became more disordered despite the longer range and stronger displacement damage of Ne ions in Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG than in crystalline W.Unlike the irradiation hardening and embrittlement behavior of crystalline W,Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG showed the gradual decrease in hardness from 6.02 GPa to 5.89 GPa and 5.50 GPa,the decrease in modulus and the increase in plastic deformability with the increasing dose.Possibly,the irradiation softening and toughening phenomenon of Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG could provide new ideas for the design of nuclear materials.

Crystallinity-defect matching relationship of g-C_(3)N_(4): Experimental and theoretical perspectives

Good crystallinity can reduce the charge recombination centers caused by defects,whilst structures with strong polycondensation have high charge mobility,leading to more charge transfer to the material surface for reaction.Much effort has been put into the preparation of a highly efficient g-C_(3)N_(4) with defects to improve its application potential under the premise in high crystallinity.Hence,this review paper emphasizes the importance to balance the defect and crystallinity of g-C_(3)N_(4).In addition,detailed discussion on the relationship between defects and activity of g-C_(3)N_(4) was carried out based on its applications in environmental purification(e.g.,VOCs oxidation,NO_(x) oxidation,H_(2)O_(2) evolution,sterilization,pesticide oxidation)and energy conversion(H_(2) evolution,N_(2) fixation and CO_(2) reduction).Lastly,the challenge in developing more efficient defective g-C_(3)N_(4) photocatalytic materials is summarized.

Shock-induced energy localization and reaction growth considering chemical-inclusions effects for crystalline explosives

Chemical inclusions significantly alter shock responses of crystalline explosives in macroscale gap experiments but their microscale dynamics origin remains unclear.Herein shock-induced energy localization,overall physical responses,and reactions in a-1,3,5-trinitro-1,3,5-triazinane(a-RDX)crystal entrained various chemical inclusions were investigated by the multi-scale shock technique implemented in the reactive molecular dynamics method.Results indicated that energy localization and shock reaction were affected by the intrinsic factors within chemical inclusions,i.e.,phase states,chemical compositions,and concentrations.The atomic origin of chemical-inclusions effects on energy localization is dependent on the dynamics mechanism of interfacial molecules with free space volume,which includes homogeneous intermolecular compression,interfacial impact and shear,and void collapse and jet.As introducing various chemical inclusions,the initiation of those dynamics mechanisms triggers diverse decay rates of bulk RDX molecules and hereby impacts on growth speeds of final reactions.Adding chemical inclusions can reduce the effectiveness of the void during the shock impacting.Under the shockwave velocity of 9 km/s,the parent RDX decay rate in RDX entrained amorphous carbon decreases the most and is about one fourth of that in RDX with a vacuum void,and solid HMX and TATB inclusions are more reactive than amorphous carbon but less reactive than dry air or acetone inclusions.The lessdense shocking system denotes the greater increases in local temperature and stress,the faster energy liberation,and the earlier final reaction into equilibrium,revealing more pronounced responses to the present intense shockwave.The quantitative models associated with the relative system density(RD_(sys))were proposed for indicating energy-localization mechanisms and evaluating initiation safety in the shocked crystalline explosive.RD_(sys)is defined by the density ratio of defective RDX to perfect crystal after dynamics relaxation and reveals the global density characteristic in shocked systems filled with chemical inclusions.When RD_(sys)is below 0.9,local hydrodynamic jet initiated by void collapse dominates upon energy localization instead of interfacial impact.This study sheds light on novel insights for understanding the shock chemistry and physical-based atomic origin in crystalline explosives considering chemical-inclusions effects.

Constructing long-cycling crystalline C_(3)N_(4)-based carbonaceous anodes for sodium-ion battery via N configuration control

Carbon nitrides with two-dimensional layered structures and high theoretical capacities are attractive as anode materials for sodium-ion batteries while their low crystallinity and insufficient structural stability strongly restrict their practical applications.Coupling carbon nitrides with conductive carbon may relieve these issues.However,little is known about the influence of nitrogen(N)configurations on the interactions between carbon and C_(3)N_(4),which is fundamentally critical for guiding the precise design of advanced C_(3)N_(4)-related electrodes.Herein,highly crystalline C_(3)N_(4)(poly(triazine imide),PTI)based all-carbon composites were developed by molten salt strategy.More importantly,the vital role of pyrrolic-N for enhancing charge transfer and boosting Na+storage of C_(3)N_(4)-based composites,which was confirmed by both theoretical and experimental evidence,was spot-highlighted for the first time.By elaborately controlling the salt composition,the composite with high pyrrolic-N and minimized graphitic-N content was obtained.Profiting from the formation of highly crystalline PTI and electrochemically favorable pyrrolic-N configurations,the composite delivered an unusual reverse growth and record-level cycling stability even after 5000 cycles along with high reversible capacity and outstanding full-cell capacity retention.This work broadens the energy storage applications of C_(3)N_(4) and provides new prospects for the design of advanced all-carbon electrodes.

Preparation and Performance Study of Cementitious Capillary Crystalline Waterproof Materials

Cementitious capillary crystalline waterproof materials(CCCW for short)offer durability and excellent waterproofing properties,making them a popular option for building waterproofing.Some scholars have studied the proportioning of such materials.However,these studies lack the relationship between the impermeability pressure of mortar and the components,and the mechanism of action is somewhat debatable.Therefore,we adopted a two-step method in our experiments.Firstly,we screened out the components that significantly impact impermeability from a variety of active components by orthogonal test.We then optimized the design of the active group ratio using the simplex lattice method.Lastly,we conducted a performance test of the optimal ratio and explored the waterproofing mechanism of homemade CCCW.

Constructing Crystalline g-C_(3)N_(4)/g-C_(3)N_(4-x)S_(x)Isotype Heterostructure for Efficient Photocatalytic and Piezocatalytic Performances

Graphitic carbon nitride(g-C_(3)N_(4))is viewed as a promising visible-light photocatalyst for industrialization due to its low processing temperature and high chemical stability.However,serious charge recombination caused by incomplete polymerization during direct calcination of nitrogen-rich precursors significantly limits its photocatalytic performances.To boost charge separation,herein,we propose a rational strategy by constructing a crystalline g-C_(3)N_(4)/g-C_(3)N_(4-x)S_(x) isotype heterostructure through the molten salt method.Theoretical calculation reveals that apparent charge-transfer channels are formed between g-C_(3)N_(4) and S-doped g-C_(3)N_(4) layers in the heterostructure.Owing to high crystallinity for decreasing charge recombination and isotype heterostructure for efficient charge transfer,the as-prepared g-C_(3)N_(4)/g-C_(3)N_(4-x)S_(x) showed remarkable photocatalytic performances with the hydrogen production rate elevated by up to 12.3 times of its singular components.Another novelty of this work is we investigated for the first time the piezocatalytic activity of crystalline g-C_(3)N_(4) by characterizing its performance for H2O2 generation and KMnO4 reduction.Strikingly,its superior piezocatalytic performance over components can be further improved by NaBH4 treatment,which is uncovered to enhance the asymmetric structure of crystalline g-C_(3)N_(4) by introducing extra cyano groups and removing partial NHx species in its tri-s-triazine layer structure.This work opens up new strategies for the design of highly efficient polymeric photocatalysts and highlights the piezocatalytic studies of g-C_(3)N_(4).

Studies on Human Fetal Lens Crystallins Under Oxidative Stress and Protective Effects of Tea Polyphenols

Purpose: To investigate the oxidative modification of water-soluble crystallins of human fetal lens with H2O2 and fourteen metal ions with or without EDTA. Tea-polyphenols (TP) was added to above solutions in order to testing their antioxidative abilities. Methods: The experiments were performed at 37℃ with final concentration of 2.5mg/ml protein, 0.1 mM metal ions, 0.3 mM EDTA and 1.0 mM H2O2. Then the TP was added to the solution with CuSO4 and H2O2, after 5 or 24 hours, the crystallins were analysed with SDS-PAGE and IEF.Results : There were marked oxidative modifications of lens protein in H2O2 and copper without EDTA. In SDS-PAGE patterns, we found an increase in those species above of bands higher than 30 kD and some diffuse bands from 30 to 17 kD after 5 hours. In IEF patterns, there were a general increase on acidity with loss of the more basic species. When the TP was added, there was not any difference with control group.Conclusion: The results indicate that exposure of water-soluble

Transformation of Hexagonal Lu to Cubic LuH_(2+x)Single-Crystalline Films

With the recent report of near ambient superconductivity at room temperature in the N-doped lutetium hydride(Lu-H-N)system,the understanding of cubic Lu-H compounds has attracted worldwide attention.Generally,compared to polycrystals with non-negligible impurities,the single-crystalline form of materials with high purity can provide an opportunity to show their hidden properties.However,the experimental synthesis of single-crystalline cubic Lu-H compounds has not been reported so far.Here,we develop an easy way to synthesize highly pure LuH_(2+x)single-crystalline films by the post-annealing of Lu single-crystalline films(purity of 99.99%)in H_(2)atmosphere.The crystal and electronic structures of films were characterized by x-ray diffraction,Raman spectroscopy,and electrical transport.Interestingly,Lu films are silver-white and metallic,whereas their transformed LuH_(2+x)films become purple-red and insulating,indicating the possible formation of an unreported electronic state of Lu-H compounds.Our work provides a novel route to synthesize and explore more singlecrystalline Lu-H compounds.

Influence of substituting B_(2)O_(3) with Li_(2)O on the viscosity,structure and crystalline phase of low-reactivity mold flux

The low-reactivity mold flux with low SiO_(2)content is considered suitable for the continuous casting of high-aluminum steel since it can significantly reduce the reaction between Al in steel and SiO_(2)in mold flux.However,the traditional low-reactivity mold flux still presents some problems such as high viscosity and strong crystallization tendency.In this study,the co-addition of Li_(2)O and B_(2)O_(3)in CaO–Al_(2)O_(3)–10wt%Si O_(2)based low-reactivity mold flux was proposed to improve properties of mold flux for high-aluminum steel,and the effect of Li_(2)O replacing B_(2)O_(3)on properties of mold flux was investigated.The viscosity of the mold flux with 2wt%Li_(2)O and 6wt%B_(2)O_(3)reached a minimum value of 0.07 Pa·s.The break temperature and melting point showed a similar trend with the viscosity.Besides,the melt structure and precipitation of the crystalline phase were studied using Raman and X-ray diffraction spectra to better understand the evolution of viscosity.It demonstrated that with increasing Li_(2)O content in the mold flux from 0 to 6 wt%,the degree of polymerization of aluminate and the aluminosilicate network structure increased because of increasing Li+released by Li_(2)O,indicating the added Li_(2)O was preferentially associated with Al^(3+)as a charge compensator.The precipitation of LiAlO_(2)crystalline phase gradually increased with the replacement of B_(2)O_(3)by Li_(2)O.Therefore,Li_(2)O content should be controlled below 2wt%to avoid LiAlO_(2)precipitation,which was harmful to the continuous casting of highaluminum steels.

Crystalline framework nanosheets as platforms for functional materials

The integration of organic and inorganic materials has been widely used in various applications to generate novel functional nanomaterials characterized by unique properties.Functional crystalline framework nanosheets and their synergistic effects have been studied recently for possessing the advantages of functional species as well as crystalline framework nanosheets.Hence,we have focused on the preparation methods and applications of functional crystalline framework nanosheets in this review.We introduced crystalline framework nanosheets and discussed the importance of integrating functional species with nanosheets to form functional crystalline framework nanosheets.Then,two aspects of the preparation methods of functional crystalline framework nanosheets were reviewed:in situ synthesis and post-synthesis modification.Subsequently,we discussed the properties of the crystalline framework nanosheets combined with various functional species and summarized their applications in catalysis,sensing,separation,and energy storage.Finally,we have shared our insights on the challenges of functional crystalline framework nanosheets,hoping to contribute to the knowledge base for optimizing the preparation methods,expanding categories,improving stability,and exploring potential applications.

Comparative Studies of the Carbohydrate of Human Gamma-Crystallins from Fetal and Adult Lenses with Agglutinins

Using gel chromatography of Sephadex G-75 superfine connectedwith Sephadex G-50 fine column,three human γ- crystallins(γ1,γ2,γ3)couldbe obtained.Seven agglutinins(LCA,SBA,DBA,PNA,BSL,RCA and UEA)were used to detect the sugar of sub-γ-crystallins,which had been transferredto nitrocellulose membrane and finally stained with ABC reagents and the sub-strate of HPR.These results suggested that γ2-and γ3-crystallin contain sugar,but γ1-crystallin has no sugar.There is a decrease of carbohydrate of γ2 and γ3as...

Potassium Iodide and Acrylamide Fluorescence Quenching Studies on Gamma-Crystallins of Human Lenses in Development and Aging

γ_1-γ_2-and γ_3-crystallin(corresponding to γs-,γC-and γD- crys-tallin respectively)of human fetal,2 year and 20^+ year old lenses areseparated by Sephadex gel chromatography.lodide and acrylamide are usedto quench the tryptophane fluorescence of sub-γ-crystalline fractions and Ksvand fa values are calculated.The results show that iodide has no clear quench-ing effects on all γ-crystallins,the quenching effects of acrylamide on the tryp-tophan fluorescences of γ1-γ2-and γ3-crystallin from lenses of the ...

Transient vacuolar changes of the crystalline lens in patients using a dispersive ophthalmic viscosurgical device

AIM:To report the clinical prognosis and pathological findings of accidental lens vacuolar changes in eyes with intraoperative exposure to a dispersive ophthalmic viscosurgical device(OVD).METHODS:Two patients who developed transient lens vacuolar changes during uneventful persistent pupillary membrane(PPM)removal surgery were presented and followed up.This event was speculated to be associated with an intraoperative dispersive OVD DisCoVisc(hyaluronic acid 1.6%-chondroitin sulfate 4.0%)exposure.Then,to provide the pathological basis for our speculation,another four cataract patients were randomly exposed to different OVDs,and their anterior lens capsules were investigated with transmission electron microscopy(TEM).RESULTS:After months,the subcapsular vacuoles in both PPM cases were gradually disappeared without visual deterioration.For the cataract patients,similar lens changes were observed intraoperatively in those exposed to a dispersive DisCoVisc but not a cohesive OVD IVIZ(sodium hyaluronate gel 1.0%).In addition,marked ultrastructural changes,including chromatin condensation,extensive cytoplasmic vacuoles,and obvious intercellular space between lens epithelial cells in the anterior lens capsules of all eyes exposed to DisCoVisc,were observed by TEM.CONCLUSION:The lens vacuolar changes may be associated with a dispersive OVD exposure.Therefore,it is not preferable to use dispersive OVDs in patients with transparent lenses or without the intention of lens extraction.In addition,close follow-ups instead of immediate lens extraction are recommended for the occurrence of similar lens lesions.

视网膜α-crystallins在增生性视网膜疾病中的研究进展

α-crystallins是小分子热休克蛋白家族(small-molecule heat shock protein,sHSP)的重要成员,包括αA-crystallin和αB-crystallin,在各类组织细胞中具有细胞保护和分子伴侣功能。近年来,多项研究发现,视网膜组织α-crystallins可利用自身特性通过各种途径参与增生性视网膜病的血管新生、上皮/内皮细胞间质化等过程。本文主要介绍α-crystallins,尤其是αB-crystallin调节增生性视网膜疾病发展的分子机制,探讨其潜在的临床应用价值。

Petrology and Geochemical Features of Crystalline Rocks in Ora-Ekiti,Southwestern Nigeria

This research investigates and reports on the petrology and geochemical characteristics of crystalline basement rocks in Ora-Ekiti,Southwestern Nigeria.Exhaustive geological investigation reveals migmatite,banded gneiss,gran­ite gneiss and biotite gneiss underlie the area.In reducing order of abundance,petrographic examination reveals that migmatite contains quartz,muscovite and opaque minerals.Banded geniuses contain quartz,biotite,plagioclase,and opaque minerals.Granite geniuses contain quartz,plagioclase,biotite,microcline and opaque;while biotite geniuses contain biotite,plagioclase,opaque minerals,and quartz.Silica contents in migmatite(69.50%-72.66%;ca.71.23%),banded gneiss(71.66%-77.1%;ca.75.23%),biotite gneiss(72.32%-76.18%;ca.73.83%)and granite gneiss(69.82%-73.15%;ca.71.95%)indicate the rocks are siliceous.High alumina contents in migmatite(12.18%),banded gneiss(10.28%),biotite gneiss(11.46%)and granite gneiss(9.97%)are comparable to similar rocks in the basement com­plex.All the rocks show Ba,Sr and Rb enrichment.Harker diagrams of Al_(2)O_(3)versus SiO_(2)and CaO versus SiO_(2)show negative trends while Na_(2)O versus SiO_(2),K_(2)O versus SiO_(2)and TiO_(2)versus SiO_(2)plots showed positive trends.This var­iation probably depicts extensive crystal fractionation in the magmatic systems that produced the rocks prior to meta­morphism or partial melting of the precursor rock.SiO_(2)versus(Na_(2)O+K_(2)O)classifies the rocks as granite to granodi­orite.The rocks are high K-calc-alkaline and calc-alkalic on SiO_(2)-K_(2)O plot.This shows the rocks are potassic meaning that they are formed from a potassium-rich source.The plot of Al_(2)O_(3)/(Na_(2)O+K_(2)O)versus Al_(2)O_(3)/(CaO+Na_(2)O+K_(2)O)reveals the crystalline rocks are orogenic and originated from granitoid with meta luminous affinity.The rocks consist of gneisses of no economic minerals,but the petrology reveals them as common rocks typical of metamorphic terrains and geochemical features of the rocks reveal they are felsic and of granitic composition.

喜马拉雅造山带聂拉木地区渐新世深熔作用的厘定

喜马拉雅新生代淡色花岗岩记录了地壳深熔作用和花岗岩侵位的地球化学和构造物理效应。与形成于增厚地壳条件下和伸展背景下的始新世和中新世花岗岩相比,渐新世花岗岩分布比较局限,且源区和形成机制还存在着较大的争议。位于喜马拉雅造山带中部的聂拉木地区,可见32.1Ma的含电气石黑云母的花岗岩、29.8Ma的含黑云母的花岗岩、26.6Ma的含电气石黑云母的伟晶花岗岩侵入到高喜马拉雅岩系上部。这三组渐新世花岗岩具有以下特征:(1)较高的SiO_(2)、Al_(2)O_(3)、K_(2)O和Na_(2)O,A/CNK>1.0;(2)Ba、Nb、Ta、Sr和Ti的负异常;(3)略微富集轻稀土,亏损中稀土和重稀土,高度变化的Eu异常和微弱的负Nd异常;(4)均一的初始Sr-Nd同位素比值,^(87)Sr/^(86)Sr(t)=0.7463~0.7471,ε_(Nd)(t)=-15.0~-14.6。此外,含电气石黑云母的花岗岩和含电气石黑云母的伟晶花岗岩具有较高的Sr和Ba,较低的Rb/Sr比值,其Rb/Sr比值与Ba和Sr含量都无相关性,表明其为富B流体参与高喜马拉雅变沉积岩含水部分熔融作用的产物。而含黑云母的花岗岩具有较低的Sr和Ba,较高的Rb/Sr比值,且其Rb/Sr比值与Ba和Sr含量显示明显的负相关关系,表明其为变沉积岩发生脱水熔融作用的产物。综合喜马拉雅造山带已有的研究成果,得出以下认识:渐新世花岗岩的源区从下地壳基性物质转变为中地壳变泥质岩,展示了源区向上迁移的过程,并经历了一期重要的岩浆热液交代作用;渐新世深熔作用记录了造山带从缩短增厚向伸展垮塌转换阶段深部地壳的响应,从而促使了高喜马拉雅岩系的折返。

Distribution of Human Lens Crystallins and Their Sulphydryl Contents of Different Age in Two-dimension Electrophoresis

Purpose: To analyze water-soluble(WS) human lens proteins of fetus, adult and age-related cataract by two-dimensional IEF/SDSPAGE electrophoresis. Methods: DACM [ N- (7-Dimethylamino-4-methyl-3-coumarinyl) maleimide ] was used to determine the lens proteins sulphydryl (SH) content.Result: Protein SH contents in WS lens proteins have no significant difference among fetus, adult and age-related cataract lens. This is different from the relative published results obtained in lens proteins of animal cataract model using similar SH detecting methods.Conclusions: IEF/SDS-PAGE electrophoresis demonstrated that there were much more fragmentation of crystallins during lens development and cataractogenic process. It is suggested that this phenomenon is likely to be due to further conformational changes in the fragmented cyrstallins during aging and cataractogenic process. Eye Science 1999; 15:32-35.

战略性非金属矿产资源现状及加工技术研究进展

战略性非金属矿产是指对经济高质量发展和国家安全至关重要的非金属矿产,对促进战略性新兴产业发展、支撑制造强国的实现具有重要作用。对列入我国的4种战略性非金属矿在全球的储量及产能情况进行了统计,对资源形势和供给风险进行了研判,即:磷矿和石墨是我国的优势矿产;萤石由优势矿产转变为紧缺矿产;钾盐是我国的短缺矿产,对外依存度较高。从新工艺、新技术和新设备等方面对4种战略性非金属矿产的加工技术研究进展进行了总结,旨在为我国战略性非金属矿产的合理高效开发和资源安全保障提供参考。

PFI磨预处理提高桉木浆纤维反应活性的研究

采用PFI磨对桉木漂白化学浆进行预处理后,以丙烯酰氯为酯化试剂,在球磨机中进行酯化反应,通过纤维质量分析仪、光学显微镜、X射线衍射(XRD)和傅里叶红外光谱(FT-IR)对纤维的形貌和结构进行了分析,并进一步考察了酯化条件对纤维素反应活性的影响。研究结果表明:随着PFI磨转数的增加,纤维长度、纤维宽度减小,细小纤维比例显著提高,由19.86%增大至38.47%。经PFI磨打浆后,纸浆纤维表面纤丝化明显,其结晶区域部分遭破坏,结晶度由72.7%降低至66.9%;XRD结果表明:反应过程中酯化产物的结晶结构发生了改变。FT-IR结果表明:PFI磨解纤维与丙烯酰氯经球磨发生酯化反应得到丙烯酰基纤维素。酯化产物的取代度(D_(S))随着PFI磨转数的增加而增大;与未经预处理纤维相比,反应产物的D_(S)明显增加,最高可达2.38,此时的反应条件为PFI磨预处理24000 r,纤维素与丙烯酰氯的物质的量比1∶6,球磨反应时间48 h。