Subsolidus Phase Relations in the Systems M2 +O–M2+O–V2O5(M+ = Li, Na, K, Rb, Cs; M2+ = Mg, Ca)

Subsolidus phase relations in the M₂O(M₂CO₃)–MgO–V₂O₅ and M₂O(M₂CO₃)–CaO–V₂O₅ (M = Li, Na, K, Rb, Cs) systems are studied. Twenty mixed vanadates are obtained, of which Rb₂CaV₂O₇, Cs₂CaV₂O₇, LiMg₄(VO₄)₃, RbCaVO₄, and CsCaVO₄ are identified for the first time. Structural data are summarized for all of the mixed vanadates: the space group and lattice parameters are indicated for 14 compounds (for 6 compounds, such data are obtained for the first time), and I and d data are presented for 8 compounds. Partial series of Ca₃(VO₄)₂-based solid solutions with the general formula Ca_{3 – x} M_2x (VO₄)₂ (M = Na, K, Rb, Cs) are identified in the range 0 < x 0.14. Six phase diagrams (M⁺ = Li, Rb, Cs; M²⁺ = Mg, Ca) are investigated and are compared with the phase diagrams of the other ternary systems in question. The key features of the ternary phase diagrams and, hence, the reactivity of the constituent oxides are shown to vary systematically in going from Li₂O to Cs₂O and from MgO to SrO, which is interpreted in terms of the variation in the ionic radius of the alkali and alkaline-earth metals.     

法律+标准,让个人信息更安全

正2017年6月1日,《中华人民共和国网络安全法》(以下简称《网安法》)的正式实施,标志着我国对个人信息保护规则逐步走向清晰和明确化,但是《网安法》具体实际应用层面仍需出台专门的法律法规及政策。2017年12月29日,国家标准委发布GB/T 35273-2017《信息安全技术个人信息安全规范》(以下简称《规范》),并将于2018年5月1日正式实施。该规范对从事网络信息业务相关人员,特别是互联网金融企业对于个人信息的获取及使用进行规范。     

High Pressure Phase Equilibria in the Systems Ammonia+Potassium Iodide, +Sodium Iodide, +Sodium Bromide, and +Sodium Thiocyanate: Solid–Liquid–Vapor and Liquid–Liquid–Vapor Equilibria

Solid salt–liquid–vapor equilibria and liquid–liquid–vapor equilibria were determined experimentally for the binary system NH₃+KI in the temperature range 333 to 673 K and at pressures up to 80 MPa. It is found that the system NH₃+KI belongs to Type V of fluid phase behavior according to the classification of van Konynenburg and Scott. The pressure of the three-phase curve solid salt–liquid–vapor is monotonically increasing in the temperature range investigated and reaches a value of 76 MPa at 670 K. The three-phase liquid–liquid–vapor curve starts in a lower critical end point at 407.3 K and 11.59 MPa and ends in an upper critical end point at 408.8 K and 11.92 MPa. For the systems NH₃+NaI, NH₃+NaBr, and NH₃+NaSCN, Type V fluid phase behavior is also found. In the system NH₃+NaI, the lower critical end point is found at 406.8 K and 11.52 MPa and the upper critical end point at 408.5 K and 11.86 MPa. For the system NH₃+NaBr, these coordinates are 404.6 K, 11.03 MPa and 408.8 K, 11.90 MPa, respectively, and, for the system NH₃+NaSCN, 409.2 K, 11.99 MPa and 409.6 K, 12.06 MPa.     

State of difficultly soluble uranosilicates MIHSiUO6 ? nH2O (M + = Li+, Na+, K+, Rb+, Cs+, NH4+) in saturated aqueous solutions

The solubility of uranosilicates M^IHSiUO₆ nH₂O (M^I = Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺, NH ₄ ⁺ ) in aqueous solutions at 25°C was studied experimentally. The equilibrium constants of reactions that occur at dissolution of uranosilicates in acidic and neutral solutions were calculated. The composition of the equilibrium solutions was studied. The standard Gibbs energies of formation of the compounds were calculated from the solubility data. The behavior of the uranosilicates under various conditions was predicted on the basis of the previously suggested quantitative physicochemical model of the state of the heterogeneous system crystalline uranosilicate-aqueous solution.Translated from Radiokhimiya, Vol. 46, No. 5, 2004, pp. 418–422.Original Russian Text Copyright © 2004 by Chernorukov, Nipruk, Knyazev, Pegeeva.     

三次系统x′=-y+8x+mxy+ny~2+a_1x~3+a_3xy~2,y′=x的极限环研究

本文研究了E_3~1系统,x=-y+δx+mxy+ny~2+a_1x~3+a_3xy~2,y=x的极限环,其中m≠0,a_1≠0,a_3≠0,利用Dulac函数法及地形系法得到了一系列无环性条件,并证明了系统在一定条件下至少可以存在一个及两个极限环,同时通过构造Poinear'e—Bendixson环域得到了系统存在大范围的极限环的条件。     

北方稀土:资源优势+技术创新,夯实龙头地位

<正>中国北方稀土(集团)高科技股份有限公司(1以下简称"北方稀土")是我国最大的稀土生产、科研、贸易基地,也是全球最大的轻稀土生产企业。作为稀土行业的龙头企业,北方稀土涵盖了从"选矿—冶炼分离—稀土金属—功能材料—稀土深加工及应用产品—科研"等完整产业链条。北方稀土依托白云鄂博稀土矿得天独厚的资源优势,以及包头稀土研究院等技术研发的平台,成为了行业的领导者。本文通过分析北方稀土的发展状     

“垃圾分类+”,加了什么?

<正>垃圾分类的强制性实施与我们每一个人的生活息息相关,较之以前垃圾分类确实给我们的生活增加了一些任务和负担,也难免会出现一些抱怨的声音。但不能否认,垃圾分类一定是人类文明发展的加分项,它会带给我们什么?是否还能够创造更多可能?垃圾不分类的那些年今年7月的上海人民有点忙,忙着学习新的《上海市生活垃圾管理条     

Synthesis,characterization, photocatalytic evaluation,and toxicity studies of TiO2–Fe3+ nanocatalyst

Based on our previous work on the green preparation of Ag–TiO₂ photocatalyst with bactericidal activity under visible light, we extended our studies to the synthesis of TiO₂–Fe³⁺ materials with enhanced photocatalytic activity for the degradation of recalcitrant organic pollutants in water. TiO₂–Fe³⁺ nanopowders were synthesized using a robust, environmentally friendly procedure. Established amounts of Fe(NO₃)₃·9H₂O and titanium tetraisopropoxide (TTIP) were mixed using glacial acetic acid as solvent. Hydrolysis of TTIP–Fe³⁺ was accomplished using a 30 % (W/V) Arabic gum aqueous solution. TiO₂–Fe³⁺ nanopowders were obtained by thermal treatment at 400 °C. In order to elucidate the structure of these photocatalysts, microscopic and spectroscopic characterization techniques were applied. The high resolution transmission electron microscopy (HRTEM) analysis indicated the presence of uniformly distributed particles with average particle size of about 9 nm. According to the HRTEM lattice fringes, ring pattern, and selected area electron diffraction pattern, the crystalline part of the samples consists of anatase (PDF 01-086-1157 with the lattice constant of 3.7852, 9.5139 Å and 90°) as dominant phase. X-ray photoelectron spectroscopy (XPS) was applied to determine the oxidation state of iron. The XPS provides evidence for Fe³⁺ surface species in the TiO₂–Fe³⁺ composite. Complete degradation of aqueous solutions (20 ppm) of methylene blue and/or methyl orange was accomplished after 4 h of treatment using 150 mg of TiO₂–Fe³⁺/150 mL of dye solution. The in vitro toxicity of the materials was tested. The materials showed no toxicity against human red blood cells.     

开拓进取,实现1+1大于2的整合目标

一、贵州计量测试院的基本情况 贵州省计量测试院现有在职职工108人,专业技术人员90人,其中高级职称22人(教授级1人),中级职称27人,技术人员比例占83%以上.     

中望CAD+全球推出,打造行业应用方案

7月16日,广州中望数字化设计软件有限责任公司(以下简称"中望数字化")正式对外宣布,国内全新一代CAD平台软件中望CAD+,携同中望CAD机械版和龙腾模具,一起向全球80多个国家和地区同步推出。"历经6年精心研发的全新内核,使得中望CAD+软件的整体运行速度、复杂操作和大图纸运行效率都让人眼前一亮,并且功能开发灵活度更高,诸如手势精灵、最大化视口等新功能在前期公测时都受到一致认同和赞赏。"中望CAD+研发总监何先生在介绍中望CAD+时信心满满,但同时他也表示,"中望CAD+的这种优势能否持续,关     

CaF2:Yb3+/Er3+/X(X= Li+, Na+, K+)近红外二区发光性能研究

利用热分解法制备了CaF₂:Yb³⁺/Er³⁺纳米颗粒,通过改变Yb³⁺和Er³⁺的掺杂浓度对其近红外二区(NIR-II)发光性能进行调节,研究结果表明,当Yb³⁺掺杂浓度为20%,Er³⁺掺杂浓度为2%时,在980 nm光源激发下,NIR-II发光性能最强,且纳米颗粒分散性良好,尺寸均匀。然后,进一步研究了不同的碱金属离子(Li⁺、Na⁺、K⁺)共掺杂对其NIR-II发光性能的影响,研究结果表明,Li⁺掺杂因不利于纳米颗粒成核导致NIR-II发光性能降低,Na⁺和K⁺掺杂均有利于NIR-II发光性能提升。相比而言,K⁺离子半径更大,更有利于破坏晶体场的局部对称性,因此,在K⁺共掺杂的情况下NIR-II发光性能最强。     

Synthesis and properties of LnBaFeCoO5 + δ (Ln = Nd, Sm, Gd)

LnBaFeCoO_{5 + δ} (Ln = Nd, Sm, Gd) layered oxides have been synthesized and their crystal structure, thermal stability, thermal expansion, electrical conductivity, thermoelectric power, and magnetic susceptibility have been studied. The oxides have a tetragonal structure (sp. gr. P4/mmm) with unit-cell parameters a = 0.3909(2) nm and c = 0.7695(6) nm for Ln = Nd (δ = 0.65), a = 0.3908(3) nm and c = 0.7662(6) nm for Ln = Sm (δ = 0.37), and a = 0.3908(2) nm and c = 0.7613(6) nm for Ln = Gd (δ = 0.37). The LnBaFeCoO_{5 + δ} compounds are antiferromagnetic p-type semiconductors. With decreasing Ln³⁺ ionic radius, their electrical conductivity and linear thermal expansion coefficient decrease and their thermoelectric power and antiferromagnetic ordering temperature increase. Near 518–653 K, the linear thermal expansion coefficient of the LnBaFeCoO_{5 + δ} oxides increases from (12.9–16.6) × 10^?6 to (19.3–26.5) × 10^?6 K^?1, which is due to the release of weakly bound oxygen from the oxides. We have determined parameters of charge transport in the [Fe(Co)O₂] layers in the crystal structure of the LnBaFeCoO_{5 + δ} phases.     

专业+严打,保卫首都群众“舌尖上安全”

正自201 1年成立以来,北京市公安局经侦总队食品药品案件侦查支队在卫生、工商等行政执法部门的配合下,相继开展了多次专项行动,不断向危害人民群众生命安全的食品药品违法犯罪发起强力攻势。截至目前,他们参与并牵动全市公安机关破获食品、药品类犯罪案件5000余起,抓获涉案嫌疑人2000余名,打掉犯罪团伙570余个,捣毁窝点1400余个,缴获假冒伪劣食品、药品涉案值近6亿元。     

Room Temperature Ferromagnetism in Dual Doped (Mn 2+ , Ni 2+ ) ZnO Codoped with Li 1+ Prepared Using EDTASintered at Low Temperature

Nanopowders of Znl_x_y_zMnxNiyLizO [（x = 0.04, y = 0, z = 0）, （x = 0.04, y = 0.03, z = 0） and （x = 0.04, y = 0.03, z = 0.03）] have been synthesized by sol-gel precursor route using ethylene diamine tetraacetic acid （EDTA） as a metal chelating agent. X-ray diffraction analysis confirms the formation of wurtzite hexagonal structure for all the three compositions. Mn2＋ doped ZnO exhibits room temperature ferromagnetism （RTFM）, and it is found that further Ni2＋ doping has decreased Ms because of limit of solid solubility of transition metal in ZnO. But codoping of monovalent Li1＋, further increases the ferromagnetism （FM） value, due to introduction of free carriers compared to the dual doped samples. Photoluminescence （PL） spectra of the system, exhibit near band edge （NBE） emission peak at --464 nm due to the electron transition from interstitials to the valence band. Recombination of conduction electron with hole trapped at oxygen vacancy, leads to prominent defect emission peaks at --482 nm and 532 nm. The evidence of the formation of metaI-EDTA complexes are found from the Fourier transform infrared spectra at 2800-3800 cm-1 with shifting, splitting of the peak and also drastic variations in the intensity.     

MF2(M=Mg,Ca,Zn,Sr,Ba)对掺Yb3+磷酸盐玻璃性质的影响

熔制了60P₂O₅·6Al₂O₃·(33-x)BaO·xBaF₂·1Yb₂O₃(x=0,3,6,9)和60P₂O₅·6Al₂O₃·27BaO·6MF₂·1Yb₂O₃(M=Mg、Ca、Sr、Zn、Ba)(分子分数)玻璃,测试了其折射率、密度、转变温度、析晶温度、熔点温度、红外光谱和紫外吸收光谱,讨论了二价氟化物MF₂(M=Mg、Ca、Sr、Zn、Ba)对磷酸盐玻璃热稳定性及内部结构的影响,测试了Yb³⁺离子的吸收光谱、荧光光谱、荧光寿命,计算了光谱参数,讨论了MF₂对Yb³⁺磷酸盐玻璃光谱性质的影响,结果表明二价金属氟化物是作为网络外体进入到磷酸盐玻璃结构中,并没有改变磷酸盐玻璃内部的[PO₄]链状结构,二价金属氟化物还有助于提高Yb³⁺离子的受激发射截面,和自发辐射几率,荧光半高宽。     

Au-modified silicon nanowires for surface-enhanced fluorescence of Ln3+ (Ln = Pr, Nd, Ho, and Er)

The interaction of the surface plasmons of gold nanoparticles on silicon nanowires with fluorophores, lanthanide ions (praseodymium ions, Pr³⁺, neodymium ions Nd³⁺, holmium ions Ho³⁺, and erbium ions Er³⁺) was investigated. In the presence of Au/Si nanomaterials, the fluorescence peaks were significantly enhanced, which resulted in about 2 orders of magnitude enhancement. The photoluminescence studies revealed that the enhanced fluorescence originates from the local field enhancement around Ln³⁺ ions, caused by the electronic plasmons resonance of the gold nanoparticles. Results showed that this Au/Si nanostructure had larger enhancement factor than that caused by unsupported Au nanoparticles. These results might be explained by the local field overlap originated from the closed and fixed gold nanoparticles on silicon nanowires.     

钠基膨润土对废水中Ni2+,Cu2+的吸附效果

为了提高膨润土吸附废水中Ni2+,Cu2+的效果,对其改性制备了钠基膨润土,考察了吸附时间、废水pH值以及Ni2+和Cu2+初始浓度对自制钠基膨润土吸附Ni2+,Cu2+效果的影响,分析了吸附等温线,并探讨了吸附机理。结果表明:钠基膨润土对Ni2+,Cu2+都有较好的吸附性能;初始阶段(前10 min)吸附很快,之后随时间延长吸附量提高甚微;pH值为6.2时,处理后的水质即可达国家排放标准;随着Ni2+,Cu2+初始浓度增加,去除率先增加后降低,而吸附量迅速增加,Ni2+和Cu2+初始浓度分别为25 mg/L和40 mg/L时,钠基膨润土对Ni2+,Cu2+的去除率均可达98.6%;钠基膨润土对Ni2+,Cu2+的吸附等温线符合Freundlich吸附等温式。     

刺激+危险+浪漫+实惠+快乐=商业摄影--与杨旭谈商业摄影

想约到年纪虽轻但名气颇大的摄影师杨旭还真不容易．每次电话打过去，都是一个字“忙”，在忙什么呢?忙着拍片子。好不容易趁他这次来杭州办事才逮到了这么一个机会坐下来彼此交流一番。好在大家都是年轻人，也没有什么拘     

FAAS法测定大气降水中的k+、Na+、Ca2+和Mg2+

本文应用FAAS法直接测定大气降水中阳离子K+、Na+、Ca2+、Mg2+。通过对火焰状态的选择,以减少和抑制电离的干扰。方法简便、快速、准确。加标回收率在94.0%-105.2%之间,RSD<5.07%。