V2O5/石墨复合材料的电容性能

溶胶凝胶法制备V2O5,采用球磨法将V2O5与石墨进行固相混合,经扫描电镜(SEM)、X射线衍射(XRD)、循环伏安、交流阻抗等测试手段分析,得出石墨可改变V2O5电极的微结构和组成;由20%V2O5/C复合材料和石墨组成的非对称电化学电容器,以1 mol/L LiClO4(EC:DEC=1:1)有机溶液为电解液,比能量可达到18.3 W.h/kg,比纯V2O5提高56.8%,循环400次后复合材料的容量衰减为25.68%,比容量和循环性能较掺杂前得到显著提高。     

Chiral sensing system based on the formation of diastereomeric metal complex on a homocysteine monolayer using field effect transistor

A self-assembled monolayer (SAM) of l-homocysteine (l-Hcy) formed on the surface of a gold-deposited gate of a field effect transistor (FET) was used to differentiate between enantiomers of amino acids, for which the formation of diastereomeric metal complexes is fundamental for chiral discrimination. Here, we focus our attention on the dependence of the FET response on the analyte amino acids, the central metal ions involved in complex formation, and the solution pH. Using the l-Hcy SAM-modified gate with added Cu(II), notable negative FET responses were enantioselectively observed for the l-enantiomers of alanine (Ala), phenylalanine, and tryptophan, whereas differences in the FET responses between enantiomers were negligible for asparagine and aspartic acid. Regarding the enantioselectivity for Ala, the addition of Cu(II) was demonstrated to show higher selectivity as compared to other metal ions such as Co(II) and Ni(II). Moreover, for the addition of l-Ala and Cu(II), a particularly strong negative FET response was observed at pH 5.5.     

多元杂多酸在仲辛醇制己酸中的催化作用

采用磷、钼、钒系列多元杂多酸作为硝酸氧化仲辛醇制己酸的催化剂,对其催化性能和选择性进行了实验研究。结果表明:H6PMo9V3O40、H10PMo5V7O40、H11PMo4V8O40等多元杂多酸均可提高仲辛醇的转化率、己酸产率和己酸选择性,并确定了这3种催化剂的最佳用量:当它们分别为仲辛醇质量的1 4%、1 0%、1 4%时,仲辛醇转化率可达98 3%、97 6%、100%;己酸的选择性可达85 7%、85 8%、78 8%;其性能明显优于钒催化剂。     

Hierarchical Cu4V2.15O9.38 micro-/nanostructures: a lithium intercalating electrode material

Hierarchical Cu4V2.15O9.38 micro-/nanostructures have been prepared by a facile "forced hydrolysis" method, from an aqueous peroxovanadate and cupric nitrate solution in the presence of urea. The hierarchical architectures with diameters of 10-20 μm are assembled from flexible nanosheets and rigid nanoplates with widths of 2-4 μm and lengths of 5-10 μm in a radiative way. The preliminary electrochemical properties of Cu4V2.15O9.38 have been investigated for the first time and correlated with its structure. This material delivers a large discharge capacity of 471 mA h g(-1) above 1.5 V, thus making it an interesting electrode material for primary lithium ion batteries used in implantable cardioverter defibrillators.     

聚乙二醇单全氟壬烯基醚的合成与表面性能

以硼酸、聚乙二醇(PEG)和全氟壬烯为主要原料制备了聚乙二醇单全氟壬烯基醚,以红外光谱表征,并研究了其水溶液的表面性能。硼酸与聚乙二醇酯化反应以四氢呋喃作溶剂,n(PEG)∶n(硼酸)=3∶1,80℃反应3h,生成硼酸三聚乙二醇酯。聚乙二醇另一未反应的羟基再与全氟壬烯进行醚化反应,N,N-二甲基苯胺作缚酸剂,n(C9F18)∶n(硼酸三聚乙二醇酯)=3∶1,80℃反应1h,得硼酸聚乙二醇单全氟壬烯醚三酯,然后在70℃水解反应8h,得聚乙二醇单全氟壬烯基醚,收率90%左右(以全氟壬烯计)。测定了聚乙二醇单全氟壬烯基醚[C9F17O(CH2CH2O)nH]的表面张力和临界胶束浓度(CMC)。C9F17O(CH2CH2O)nH能大大降低水的表面张力,n越小,其表面张力越低。C9F17O(CH2CH2O)8H的CMC、γCMC和浊点分别为1.26×10-4mol/L,24.4mN/m,54.3℃。     

Effect of Complexes of Cobalt With Aminoacids on the Replication of Herpes Simplex Virus Type 1 (HSV-1)

Cobalt, being essential metal, influences different physiological and enzymatic functions. As cobalt does not accumulate in the body, Co-compounds have relatively low toxicity. The aim of the present study is the effect of complexes of Co(II) with aminoacids - lysine, arginine, histidine and serine on HSV-1 replication. No effect of [O(2)Co(his)(4)].nH(2)O and [O(2)Co(arg)(2)].nH(2)O on HSV-1 infection in vitro was found. Both, [O(2)Co(lys)(2)].nH(2)O and [O(2)Co(ser)(2)].nH(2)O suppress the attachement of HSV-1 particles onto target cells and the viral replication as well. Moreover, the properties of the particular Co-complex (charge, stability, structure) are manifestated by their virucidal effect. Thus, [O(2)Co(ser)(2)].nH(2)O irreversibly inhibits the infectious activity of free HSV-1 virions, while virucidal effect of [O(2)Co(lys)(2)].nH(2)O is completely reversible after the 2h of contact.     

O-terminated nano-diamond ISFET for applications in harsh environment

The concept of an ion-sensitive FET (ISFET) on diamond with boron delta-doped channel and oxygen-terminated surface for pH sensing has been successfully transferred to large-area nano-crystalline diamond on silicon substrates. The nano-crystalline diamond layers, including the boron delta-doped channels of the FETs, were grown by hot-filament CVD. The fabricated layers were characterised by their peak concentration of boron of 3 × 10²⁰ 1/cm³ and FWHM of about 1 nm. This allowed approx. 50% modulation of the channel current within the gate potential range corresponding to the potential window of water electrolysis on the diamond surface. The O-termination by combination of oxygen-plasma and wet chemical treatments resulted in a pH sensitivity of the ISFETs close to the Nernst's limit in the range between pH1 and pH13. The ISFET characteristics were stable even after anodic treatment in KOH. This allows using nano-crystalline diamond ISFETs with O-termination also as electrodes and even at anodic overpotentials.     

固液反萃湿法磷酸生产磷铵的工艺研究

通过连续逆流萃取对原料湿法磷酸先进行净化,萃取后的有机溶剂相直接用氨反萃取生成磷铵晶体,再沉降使晶体与有机萃取剂分离,实现磷铵直接反萃结晶和萃取剂的循环利用。结果表明用氨直接固液反萃湿法磷酸生产磷铵的最佳工艺条件是：萃取剂组成为V(磷酸三丁酯)∶V(稀释剂)=1∶1,原料磷酸浓度为w（P₂O₅）=40%～50%,萃取剂用量为V(萃取剂)∶V(原料磷酸)≈3∶1,萃取搅拌时间约为5 min,氨用量控制为氨反萃结晶后的液相pH≈7,固液反萃-结晶温度为15～20 ℃。最终所得的磷铵晶体中w(氮)＞20%、w(五氧化二磷)＞50%,原料湿法磷酸中的五氧化二磷一次性利用率接近50%。该法所得磷铵晶体中氮磷含量均接近工业磷酸二铵(98%)标准,远大于国家肥料级农用磷铵产品标准。     

A review of recent developments in tin dioxide nanostructured materials for gas sensors

Gas sensors based on SnO₂ nanostructures have been extensively investigated in recent years. Many recent investigations have focused on synthesizing 0D, 1D, 2D and 3D SnO₂ nanostructures with high sensing capacity. This work presents a review of the recent developments in pure, doped and metal oxide functionalized SnO₂ nanostructured gas sensors, emphasizing the main SnO₂ preparation methods and the working principle of SnO₂ gas sensors. Most studies have shown that doping, coupled with a high surface area, can significantly improve SnO₂ sensing properties. Sensing response, response/recovery times, and operating temperature can be modulated by the synergistic effect between these two factors. In general, fine nanoparticles, mesoporous materials, hollow and 3D nanostructures combined with additives such as Pt, Pd, Cu, Ni, Ag and Al have shown the best improvements in gas sensing.     

水热法合成稀土氯化物的条件探讨

采用单因素控制法,分别制备了在不同温度及pH值下的DyCl3.nH2O(s)和LaCl3.nH2O(s);运用滴定分析及差减法,测定了不同条件下所得稀土氯化物的结晶水含量,以温度-结晶水含量及pH值-结晶水含量作图,结果表明稀土氯化物中结晶水的含量随温度的升高先减少后增加,在60℃时出现最小值;结晶水含量随pH的增加呈S型曲线递增。     

Electron field emission from semiconducting nanowires

In this paper we report on investigations of field emission (FE) properties of semiconducting (SiC, ZnO) one-dimensional (1D) nanostructures – nanowire/nanorod arrays, and fabrication of low-voltage field emission display (FED) devices based on these 1D nanomaterials. SiC nanowires were grown on Ni-coated Si substrates using a thermal metal-organic chemical vapor deposition (MOCVD) technique, and ZnO nanostructures were grown on gold-coated Si substrates by a thermal CVD method. Electron field emission properties of SiC and ZnO nanostructures were examined in plane geometry using a flat phosphor screen. The interrelation between the FE characteristics (emission thresholds, current density, surface uniformity, etc.) and microstructure and surface morphology of the produced 1D nanostructures was established. Diode-type FED devices (flat vacuum lamps) with SiC-nanowire-based cathodes were developed and fabricated. The FEDs are characterized by low threshold and operating electric fields – lower 2 V/μm and 5 V/μm, respectively, high current density and brightness, and stable performance of the nanowire-based cathodes.     

Compact Modeling of Graded N-Channel Independent Gate FET with Underlaps,Spacer and S/D Straggle for Low Power Application

Silicon - This paper presents an analytical modeling of a separated gate underlap graded N-channel FET to assess the short-channel effects. A 2D modeling scheme is employed to derive its surface...     

钒渣钠化焙烧熟料浸出液除磷工艺研究

以钒渣钠化焙烧熟料浸出后得到的含钒溶液为原料,分析了二水硫酸钙在碱性条件下对含钒溶液中磷的去除机制,研究了二水硫酸钙用量、溶液pH、反应时间、反应温度等因素对磷去除率、钒损失率以及溶液中五氧化二钒与磷质量浓度比的影响。研究结果表明：在弱碱性条件下,二水硫酸钙可有效去除含钒溶液中的磷,磷去除率达到70%以上、钒损失率小于1%、五氧化二钒与磷质量浓度比大于2 300,满足后续沉钒的要求。确定的除磷工艺条件：二水硫酸钙与磷物质的量比为5.3,溶液pH为9.0,反应时间为30 min,反应温度为25 ℃。除磷后的含钒溶液经沉钒、洗涤、煅烧得到五氧化二钒产品,沉钒率大于99%,五氧化二钒产品质量满足YB/T 5304—2011《五氧化二钒》中99级的要求。     

基于银/石墨烯纳米复合材料的柔性压力传感器——材料制备和微纳结构构建

柔性压力传感器是柔性可穿戴设备的核心部件,在医疗保健、运动健身、安全生产等领域极具应用潜力。二维材料石墨烯具有高载流子迁移率、超大比表面积和超高机械强度,被视为制备柔性压力传感器的优良敏感材料。然而石墨烯碎片引入晶界或堆叠等缺陷,用纯石墨烯制备柔性压力传感器存在灵敏度低、稳定性差、响应范围窄等问题。将零维银纳米颗粒或一维银纳米线与石墨烯构建复合材料,可有效跨越缺陷或搭接相邻片层,起到“桥梁”作用,石墨烯片层平铺到纳米银导电网络之间,起到“补丁”作用。本文综述了用于柔性电阻式压力传感器的银/石墨烯复合材料制备方法和工艺,并介绍了不同微纳结构的传感器构建方法。     

Performance Analysis of Heterojunction and Hetero Dielectric Triple Material Double Gate TFET

Silicon - The gate material work function engineering and hetero-dielectric engineering concepts are discussed in this paper to design a novel triple material DG Tunnel FET. The three different...     

一种过锂三元复合正极材料的合成及表征

以碳酸锂、硫酸锰,硫酸镍和硫酸钴为原材料,碳酸氢铵为沉淀剂,氨水为pH调节剂,共沉淀法制备了三元复合材料Li1.2Mn0.5Ni0.1Co0.2O2。将制得的材料组装成锂离子电池进行电化学性能测试。研究表明该材料在2.5～4.6V的电压下充放电测试具有258mAh/g的高容量,循环性能好且粒径分布分布均匀,中位粒径D50=9.285μm,振实密度为1.65g/mL。     

Probing the morphology-device relation of Fe₂O₃ nanostructures towards photovoltaic and sensing applications

A lot of research on nanomaterials has been carried out in recent years. However, there is still a lack of nanostructures that have a combination of superior properties; both efficient electron transport and high surface area. Here, the authors have tried to develop hybrid α-Fe(2)O(3) flower-like morphology which exhibits both superior electron transport and high surface area. Intrigued by the unique properties of Fe(2)O(3) at the nanoscale and its abundance in nature, we have demonstrated a facile template-free solution based synthesis of hybrid α-Fe(2)O(3) comprising nanopetals nucleating radially from a 3D core. Due to its simplicity, the synthesis process can be easily reproduced and scaled up. We carried out in-depth studies on gas sensing and dye-sensitized solar cell (DSSC) device characterization so as to gain an understanding of how surface area and transport properties are affected by variation in morphology. The hybrid α-Fe(2)O(3) nanostructures are studied as potential candidates for gas sensors and for the first time as a working electrode for DSSC.     

紫草油中亚麻酸的分离与提纯方法的研究

以中国东北地区产的紫草种籽为原料 ,气相色谱内标法进行跟踪定量分析 ,采用改进的尿素包合法 ,对从紫草种籽油中分离提纯亚麻酸的诸工艺条件进行了实验研究。实验结果表明 :每 2 0g紫草油最终可得不饱和脂肪酸甲酯 10 2g ,其中w(亚麻酸甲酯 ) =83 1%。最佳工艺条件为 :(1)水解反应 :m(KOH)∶m (CH3 CH2 OH)∶m(H2 O) =2∶15∶5 ,氮气保护 ,反应温度为 6 0℃ ,酸化时pH =3～ 4 ;(2 )甲酯化反应 :V(混合脂肪酸 )∶V(甲醇 )∶V(浓硫酸 ) =92∶4 0 0∶3;(3)尿素包合 :m(混合脂肪酸甲酯 )∶m(尿素 ) =1∶2 ,包合温度为 - 6℃ ,时间 8h。     

磷钼黄分光光度法测定过氧化氢中磷含量

研究采用磷钼黄分光光度法测定过氧化氢中磷含量。在硝酸介质中,磷酸根离子可以和钒酸根离子以及钼酸根离子作用生成可溶性的黄色配合物（P2O5·V2O5·22MoO3·nH2O）,在460nm波长处测量吸光度,结果表明磷含量在0．50～30μg／mL范围内时,磷含量与吸光度呈线性关系,线性回归方程是y=44．037x-0．0084,相关系数为0．9999,检出限为0．50μg／mL。     

酸雨侵蚀下水泥石物相组成变化的微观分析(英文)

用X射线衍射、Fourier变换红外光谱、扫描电子显微镜和X射线能量色散谱等方法研究了浸泡在pH值为2的模拟酸阿中硅酸盐水泥石物相组成的变化.结果表明:硬化水泥浆体的破坏土要是酸雨中H+与SO42-共同作用的结果..方面.H'使硬化水泥Fee的Ca(OH)2,水化硅酸钙(C-S-H)凝胶.xCaO·Al2O3·yH2O(CxAHy)等物质发生分解、转化.而引起结构溃散性腐蚀:另-方面,SO42-与水泥fi作用,生成膨胀性的物质CaSO4·2H2O, 向引起膨胀性腐蚀.在酸雨持续作用下,水泥石由表及里逐渐遭到侵蚀破坏,直至完全溃散,最终转变成由石膏、硅胶和铝胶等组成的一种白色稀泥状混合物.