A Novel Approach to Synthesizing Porous ZnO Films: Inorganic Chelating Sol-Gel Method

Porous ZnO films are synthesized by inorganic chelating sol-gel method,which is a novel sol-gel technique using zinc nitrate as starting materials and citric acid as the chelating reagent.The crystal structure,surface morphology,porous and optical properties of the deposited films are investigated.X-ray diffraction pattern analysis shows that crystal structure of the ZnO films is hexagonal wurtzite.Scanning electron microscopy (SEM) shows that the ZnO film is porous.The curve of pore size distribution has two peak values at about 2.02nm and 4.97nm and BET surface area of the ZnO film is 27.57m2/g.In addition,the transmittance spectrum gives a high transmittance of 85% in the visible region and optical bandgap of the ZnO film (fired at 500℃) is 3.25eV.

Pitfalls of acid leaching method for determining organic and inorganic carbon contents in marine sediments

Organic and inorganic carbon contents of marine sediments are important to reconstruct marine productivity,global carbon cycle, and climate change. A proper method to separate and determine organic and inorganic carbons is thus of great necessity. Although the best method is still disputable, the acid leaching method is widely used in many laboratories because of its ease-of-use and high accuracy. The results of the elemental analysis of sediment trap samples reveal that organic and inorganic carbon contents cannot be obtained using the acid leaching method, causing an infinitely amplified error when the carbon content of the decarbonated sample is 12%±1% according to a mathematical derivation. Acid fumigation and gasometric methods are used for comparison, which indicates that other methods can avoid this problem in organic carbon analysis. For the first time, this study uncovers the pitfalls of the acid leaching method, which limits the implication in practical laboratory measurement, and recommends alternative solutions of organic/inorganic carbon determination in marine sediments.

Investigation on heat-transfer-coefficient between aluminum alloy and organic/inorganic sand mold based on inverse method

A kind of cylinder sand mold was designed to investigate the heat-transfer-coefficients（HTCs） between aluminum alloy and organic/inorganic binder bonded sand mold during the solidification processes. Temperature during the solidification process was recorded and input into the simulation software. The inverse model of MAGMA was used to calculate the HTC based on the actual temperature. Results show that the temperature of the inorganic sand mold increased faster than the organic sand mold; while the temperature of the casting part with the inorganic sand mold decreased faster. The optimal HTCs between Al and the organic/inorganic sand mold are confirmed to be 300 to 700 and 1000 to 1800 W·m-2·K-1, respectively, along with the change of solid-liquid phase line. The simulated temperature curves show the same trend as the measured ones. The maximum deviation between the two temperature curves are 17.32 °C and 18.77 °C for castings by inorganic and organic sand molds.

Mg-based inorganic nanofibers constructing fast and multi-dimensional ion conductive pathways for all-solid-state lithium metal batteries

Solid-state electrolytes(SSEs),which replace flammable and toxic liquid electrolytes,have attracted widely attention.However,there exist still some challenges in actual application such as poor interfacial compatibility and slow ionic migration.In this study,Mg O nanofibers and MgF;nanofibers were prepared via the electro-blow spinning and high-temperature calcination methods,and were applied to all-solid-state lithium metal batteries for the first time.The organic-inorganic composite SSEs exhibited continuous conduction paths based on the virtue of the nanofibers with high length-to-diameter ratio,which were designed and prepared by mixing prepared fillers into the poly(ethylene oxide)(PEO)/lithium bis(trifluoromethane)sulfonilimide(Li TFSI)system.The effect of filler with different morphologies,doping ratios and component on ionic conductivity,electrochemical stability and cycle performance were explored under two kinds of[EO]/[Li^(+)]ratios and ambient temperatures.The ionic conductivities of electrolytes containing Mg O and MgF;nanofibers can reach up to 1.19×10^(-4) and 1.39×10^(-4) S cm^(-1) at 30℃,respectively.They were attributed to specific ionic conductive enhancement at the organicinorganic interface,reduced crystallinity and Lewis acid interaction,which can effectively promote the dissociation of the lithium salts.Especially MgF_(2) nanofiber,combining low electronic conductance,excellent electrochemical stability and outstanding inhibition for lithium dendrites of fluorides,endowed the battery with an initial specific capacity of 140.6 m Ah g^(-1) and capacity decay rate per cycle of 0.055%after500 cycles at 50℃.The work can provide an idea to design SSE with fast and multi-dimensional Li conductive paths and excellent interfacial compatibility.

Analytical Errors in the Determination of Inorganic and Organic Phosphorus in Waters Based on Laboratory Experiences

Phosphorus has been closely associated with eutrophication, a growing ecological problem globally. Because bacterial and algae responds to organic and inorganic nutrients differently, developing an accurate analytical method for the determination of dissolved inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP) is critical for understanding eutrophication. This paper describes analytical variations observed in laboratory experiments for the determination of DIP and DOP. Several experimental parameters including phosphorus reagents’ temperature, water sample matrix, pH, and autoclave methods are investigated. With the optimization of the autoclave procedure, the recoveries of 8 model organic phosphorus compounds (i.e. adenosine-5-triphosphate di-sodium salt (ATP), phytic acid (PTA), sodium tripolyphosphate (STP), methyltriphenylphosphonium bromide (MPT), p-nitrophenyl phosphate magnesium salt (p-NPP), β-D-glucose-6-phosphate monosodium salt (G-6-P) and cocarboxylase (COCA)) are all well above 90% indicating significant analytical method improvement.

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.

The Course Reform and Internet Teaching of New Inorganic Materials

With the continuous demand of material performance,the development of materials is rapid,and the professional curriculum teaching of“new inorganic materials”as well as its teaching methods related to the internet mandate a reform,in order to meet the needs of innovative high-quality personnel training.The update and optimization of the teaching content and methods assisted by the internet meet the needs of modern teaching and research work.More than 90%of students believe that internet teaching is conducive to the understanding of classroom knowledge and the development of innovative projects.

Preparation and Optical Patterning of Organic-Inorganic Hybrid Color-Filter Films Using Latent Pigments by Utilizing Photo-Acid-Generator and Microwave Irradiation

Preparation and photo-patterning characteristics of organic-inorganic hybrid thin film containing latent pigment by using photo-acid-generator (PAG) and microwave irradiation have been investigated. The acrylic thin film modified with methoxysilane containing PAG was formed on a glass substrate and irradiated with ultraviolet rays to promote sol-gel reaction by catalytic action of acid which was generated from PAG. And then the film was hardened with microwave irradiation, yielding organic-inorganic hybrid polymer film having hardness, highly transparency and strong adhesion with a glass substrate. Since this reaction only occurred in the optically (UV) irradiated regions, by exploiting the difference between the adhesivenesses of these regions photo-irradiated through photomask with a glass substrate, it was possible to form a patterned film with pitch of 100 to 50 μm by a simple lift-off method. A pigment-containing film using latent pigments (with subtractive three primary colors of coloring materials) and a patterned film were prepared, and it was possible to make these films multi-colored by varying the mixing ratio of the pigments. This multi-colored film-preparation method is effective for simply and efficiently forming a color-filter film by applying optical and microwave irradiation.

北京典型绿化乔木对PM_(2.5)无机成分NH_(4)^(+)和NH_(3)^(-)的吸收和分配机制

植物能有效吸收大气中PM_(2.5)改善空气质量,探明其吸收和分配PM_(2.5)机理对提高植物生态功能和改善生态环境意义重大。利用一次性熏气法结合^(15)N示踪法探究北京典型绿化乔木油松(Pinus tabuliformis)、白皮松(Pinus bungeana)、旱柳(Salix matsudana)、银杏(Ginkgo biloba)、国槐(Styphnolobium japonicum)和栾树(Koelreuteria paniculata)对PM_(2.5)水溶性无机成分NH_(4)^(+)和NH_(3)^(-)吸收与分配特征。结果表明:(1)植物能有效吸收PM_(2.5)中NH_(4)^(+)(0.03—0.80μg/g)和NH_(3)^(-)(0.02—1.10μg/g)。对NH_(4)^(+)吸收能力表现为旱柳和油松最强,其次是银杏和栾树,白皮松和国槐最弱;对NH_(3)^(-)吸收能力表现为旱柳和油松最强,其次是白皮松和国槐,栾树和银杏最弱。(2)植物地上器官^(15)N吸收能力和分配率大于地下器官。叶片对两种离子的吸收能力(NH_(4)^(+):0.08—1.63μg/g,NH_(3)^(-):0.01—1.18μg/g)和分配率(NH_(4)^(+):18.95%—76.10%,NH_(3)^(-):6.86%—91.64%)最高。(3)不同浓度、树种及二者交互作用显著影响各器官^(15)N吸收能力和分配率(P<0.01),其中地上器官吸收能力随浓度升高而增加。(4)具有较小根冠比、粗根生物量比和较大枝生物量比特征的植物更利于吸收NH_(4)^(+);具有较小根冠比、粗细根生物量比和较大干生物量比特征的植物更利于吸收NH_(3)^(-)。研究结果进一步揭示植物吸收PM_(2.5)机制及其与自身因素(植物性状)和自然因素(PM_(2.5)浓度)的关系,对不同污染程度地区如何有效利用植物净化PM_(2.5)污染提供科学依据。

大尺寸CsPbBr_(3)晶体的熔体法生长研究进展

由于出色的高能射线解析能力和优秀的环境适应性,全无机卤化物CsPbBr_(3)吸引了众多研究者的关注。然而由于结构相变和热应力的存在,大尺寸CsPbBr_(3)晶体生长过程中容易产生应力,从而导致晶体表面出现裂纹、亚晶界或孪晶等缺陷,严重影响其性能。目前大尺寸高质量CsPbBr_(3)晶体仍然无法通过有效的手段进行批量化生产,因此开展大尺寸CsPbBr_(3)晶体的生长与性能研究具有重大理论意义和实际价值。本文简要综述了CsPbBr_(3)晶体的基本性质、制备方法及研究进展,主要讨论了垂直布里奇曼法生长CsPbBr_(3)晶体的影响因素,并对高质量CsPbBr_(3)晶体的生长提出了新的思路。

ICP-MS法测定松花粉无机元素含量及安全性、健康风险评估

为测定松花粉中18种无机元素的含量,并对重金属及有害元素进行安全性和健康风险评估,采用微波消解法处理样品,利用电感耦合等离子体质谱法(ICP-MS法)进行测定,使用软件Origin 2021和微生信平台绘制松花粉无机元素特征谱图和相关系数矩阵图,通过计算重金属元素的单项污染指数P_(i)对松花粉的安全性进行评估,计算重金属元素的每日最大可耐受量、靶标危害系数和致癌风险,并对松花粉的健康风险进行评估。结果表明:松花粉中主要含有Na、Mg、K、Ca、Fe、Zn 6种无机元素;P_(i)结果显示松花粉样品未被污染,水平优良;松花粉样品中重金属及有害元素未对暴露人群产生健康风险。采用ICP-MS法对松花粉中18种无机元素进行测定分析,可为松花粉的质量安全评价和推广应用提供一定的理论依据。

Rapid communication Preparation of TiO_2 nanometer thin films with high photocatalytic activity by reverse micellar method

Two kinds of TiO_2 nanometer thin films were prepared on stainless steel bythe reverse micellar and sol-gel methods, respectively. The calcined TiO_ 2 thin films werecharacterized by X-ray diffraction (XRD), atomic force microscopy (AFM), BET surface area and X-rayphotoelectron spectroscopy (XPS). Photocatalytic activity was evaluated by photocatalyticdecoloration of methyl orange aqueous solution. The results showed that the TiO_2 thin filmsprepared by reverse micellar method (designated as RM-TiO_2 films) showed higher photocatalyticactivity than those by sol-gel method (designated as SG-TiO_2 films). This is attributed to the factthat the former is composed of smaller monodispersed spherical particles with a size of about 15 nmand possesses higher surface areas.

Yttrium aluminum garnet (Y_3A_(l5)O_(12)) nanopowders synthesized by the chemical method

The homogeneously dispersed, less agglomerated YAG nanopowders are synthesized by the citrate-gel method followed by low-temperature self-propagating combustion reaction, using Y2O3, Al(NO3)3?9H2O and citric acid as starting materials. This method effectively solves the problems caused by solid-state reaction at high temperature and the hard ag-glomerates brought by the chemical precipitation method. The powders are characterized by TG-DTA, XRD, FT-IR and TEM respectively. The experiments show that the forming temperature of YAG crystal phase is 850°C and the pseudo-YAG crystalline appears during the calcination and transforms to pure YAG at 1050°C. The powders with sizes less than 50 nm are observed by TEM micrography, which is consistent with the result calculated by Scherrer's formula. The powders consist of single grains.

Synthesis of Long Afterglow Photoluminescent Materials Sr_2MgSi_2O_7∶Eu^(2+), Dy^(3+) by Sol-Gel Method

Long afterglow photoluminescent materials Sr2MgSi2O7 doped with Eu2+, Dy3+ were prepared by sol-gel method. The synthesized samples were characterized by X-ray diffraction. The excitation spectrum, emission spectrum and long decay curve were measured and analyzed. XRD pattern indicates that phosphor is with Sr2MgSi2O7 crystal structure. The wide range of excitation wavelength indicates that luminescent material can be excited by light from ultraviolet ray to visible light. The main peak of emission spectrum is located at 466 nm. Sample excited by visible light can emit bright blue light, and the afterglow time lasts more than 8 h.

Preparation of Y_2O_3 Nanoparticles Organosol by Microemulsion Method

Y 2O 3 nanoparticles organosol coated with DBS was prepared by microemulsion method. The optimum preparative conditions of Y 2O 3 nanoparticles organosol were obtained. TEM analysis indicates that the prepared Y 2O 3 nanoparticles are spherical in shape. The size is about 5 nm. The size distribution is in the narrow range and no agglomerates are observed. Y 2O 3 nanoparticles coated with DBS are easy to dissolve in weak polar solvents.

Synthesis of Long Afterglow Phosphors MAl_2O_4∶Eu^(2+), Dy~ (3+)(M=Ca, Sr, Ba) by Microemulsion Method and Their Luminescent Properties

Long afterglow phosphors MAl2O4：Eu^2＋ , Dy^3＋ （M = Ca, Sr, Ba） were synthesized by microemulsion method, and their crystal structure and luminescent properties were compared and investigated. XRD patterns of samples indicate that phosphors CaAl2O4：Eu^2＋, Dy^3＋ and SrAl2O4 ： Eu^2＋, Dy^3＋ are with monoelinie crystal structure and phosphor BaAl2O4：Eu^2＋ , Dy^3＋ is with hexagonal crystal structure. The wide range of excitation spectrum of phosphors MAl2O4： Eu^2 ＋ , Dy^3＋ （M = Ca,Sr, Ba） indicates that the luminescent materials can he excited by light from ultraviolet ray to visible light and the maximum emission wavelength of phosphors MAl2O4：Eu^2＋ , Dy^3＋ （M = Ca, Sr, Ba） is found mainly at λem of 440 nm （M = Ca）, 520 nm （M = Sr） and 496 nm （M = Ba） respectively, the corresponding colors of emission light are blue, green and eyna-green respectively. The afterglow decay tendency of phosphors can he summarized as three processes： initial rapid decay, intermediate transitional decay and very long slow decay. Afterglow decay curves coincide with formula I = At^ - n, and the sequence of afterglow intensity and time is Sr 〉 Ca 〉 Ba.

THE INTRINSIC ACIDITY CONSTANTS AND SPECIFIC SURFACE AREA OF MARINE SOLID PARTICLES I. A NEW METHOD

This paper proposes a new method for determining the intrinsic acidity constants K and K The new method is a great improvement over the modified Langmuir plot method generally adopted in that determination of these constants is not dependent on the specific surface area S of the marine solid particles. The new method was used to determine K, K and S for the main inorganic components of marine solid particles, including illite, montmorillonite, kaolinite, goethite, y-AlOOH. amorphous ferric oxide, MnO2, manganite, SiO 2 and calcium carbonate, and can facilitate the study on the effect of solution constituents, solution temperature, ionic strength, etc. on the value

Entropy engineering in inorganic non-metallic glass

Advances in developing high entropy alloys and ceramics with improved physical properties have greatly broadened their application field from aerospace industry,public transportation to nuclear plants.In this review,we describe the concept of entropy engineering as applicable to inorganic non-metallic glasses,especially for tailoring and enhancing their mechanical,electrical,and optical properties.We also present opportunities and challenges in calculating entropy of inorganic non-metallic glass systems,correlating entropy to glass formation,and in developing functional inorganic non-metallic glasses via the entropy concept.

Synthesis of piezoelectric nanocrystalline PZT powder by stearic acid gel method

PZT nanocrystalline powder was prepared by a stearic acid gel method. Thecrystallization process from the precursor was monitored by infrared spectroscopy, differentialthermal analysis, and thermogravimetric analysis. The nano-sized PZT powder was characterized byX-ray diffraction and transmission electron microscopy. It shows that pure single-phase PZT powdercould be obtained at 450 deg C for 1 h, and the particle size is about 20 nm. With an increase inthe calcination temperature, the PZT crystallite size increased.

The rule of four:anomalous distributions in the stoichiometries of inorganic compounds

Why are materials with specific characteristics more abundant than others?This is a fundamental question in materials science and one that is traditionally difficult to tackle,given the vastness of compositional and configurational space.We highlight here the anomalous abundance of inorganic compounds whose primitive unit cell contains a number of atoms that is a multiple of four.This occurrence—named here the rule of four—has to our knowledge not previously been reported or studied.Here,we first highlight the rule’s existence,especially notable when restricting oneself to experimentally known compounds,and explore its possible relationship with established descriptors of crystal structures,from symmetries to energies.We then investigate this relative abundance by looking at structural descriptors,both of global(packing configurations)and local(the smooth overlap of atomic positions)nature.Contrary to intuition,the overabundance does not correlate with lowenergy or high-symmetry structures;in fact,structures which obey the rule of four are characterized by low symmetries and loosely packed arrangements maximizing the free volume.We are able to correlate this abundance with local structural symmetries,and visualize the results using a hybrid supervised-unsupervised machine learning method.