Determining coastal mixing rates of western Taiwan Strait using 224Ra

²²⁴Ra concentrations in the coastal sea water of western Taiwan Strait in winter were measured using Mn-fiber adsorption—successive emanation scintillation method. ²²⁴Ra activities in the seawater of the western Taiwan Strait varied from 0.90 to 16.25 Bq/m³ with an average of 4.60 Bq/m³. The horizontal and vertical distributions of ²²⁴Ra were studied. The distributions of ²²⁴Ra in the surface water decreased gradually with increasing distance offshore. The apparent horizontal and vertical eddy diffusion coefficients estimated from the one dimensional steady state model of ²²⁴Ra were (5.0–55.4) × 10⁶cm²/s and (4.0–51.7) cm²/s, respectively.     

稻草与煤固定床共热解特性的研究

选取稻草为生物质原料,将其与两种不同煤阶的煤(内蒙褐煤和神府烟煤)分别以0∶100、20∶80、40∶60、60∶40、80∶20、100∶0的干基质量比均匀混合.借助固定床反应器,研究了稻草与两种煤的共热解特性,探讨了共热解过程中可能存在的协同作用.结果表明,稻草添加有利于共热解气体产物的生成,且对神府煤作用更明显;稻草含量越高,热解气体产量的实验值与加权平均计算值的偏差也越大,说明稻草与煤共热解过程发生了协同作用.而共热解所得焦产量的实验值与加权平均计算值基本一致.热解焦傅里叶红外光谱分析结果表明,稻草添加对热解焦的官能团未造成显著影响.     

煤中痕量元素在循环流化床锅炉中的迁移行为与富集特性

对天津市某电厂循环流化床(CFB)锅炉燃用的原煤及燃烧产物底灰、飞灰、细飞灰(≤50 μm)进行痕量元素含量的测定,分析了Be、Zn、Hg、V、Cr、Mn、Co、Ni、Cu、As、Se、Cd、Pb 13种痕量元素在燃烧过程中的迁移行为,揭示了痕量元素在CFB锅炉中的分配、富集特性。结果表明,CFB锅炉中,较低的炉温对于痕量元素的迁移富集产生了较大的影响。由相对富集系数得知,Be、V、Co、Se在底灰中耗散,在飞灰中富集,Zn、Mn倾向于在底灰中富集,元素Cd、Pb、Ni、Cu挥发性较强,在底灰和飞灰中均是耗散。As受钙氧化物影响,挥发性表现并不明显。Hg在底灰和飞灰中相对富集系数均很低,表明Hg在整个燃烧过程中以气态形式排放;Hg、As、Se、V、Cr、Mn、Co、Ni、Cu、Zn、Pb均有向小颗粒物中富集的趋势。根据相对富集系数以及研究的13种元素在低温CFB锅炉中的迁移行为,将这些元素分为三类:A类(E_R<0.1),主要是以气态形式排放元素Hg;B类(0.1R≤0.85),较易挥发元素As、Be、Ni、Cu、Se、Cd、Pb、Co、V;C类(E_R>0.85),主要残留在固体产物中元素Zn、Mn、Cr。     

基于滤纸微孔板的酶联免疫吸附测定方法研究

用光刻法在普通定量滤纸上制作出了疏水图案,得到了滤纸微孔板。将表面修饰后的SiO2微球负载在滤纸表面,以提高滤纸纤维吸附蛋白质的能力,基于此建立了以间接酶联免疫吸附法测定羊抗兔免疫球蛋白的方法。以酶标兔抗羊IgG为例,负载SiO2微球后,滤纸微孔板吸附该蛋白质的量提高了20%～700%;将SiO2负载法应用于羊抗兔IgG的检测时,可使信号增强20%～150%。在本实验条件下,测定羊抗兔IgG的线性范围为3×10-12～3×10-8mmol/孔。本方法使生物免疫试剂消耗量减少至3～5μL/孔、检测时间降至20 min/板、滤纸微孔板制作成本可低至约每板1.1美元,为研制准确、快速和低成本的疾病检测设备提供了新的思路和可能性。     

体积排阻色谱-电感耦合等离子体质谱分析富硒大米含硒蛋白组成

建立体积排阻色谱-电感耦合等离子体质谱(SEC-HPLC-ICP-MS)联用技术分析富硒大米含硒蛋白组成方法。通过水提、盐提、碱提和醇提方法提取,并用丙酮沉淀蛋白,硒的回收率分别为9.6%,16.8%,48.2%和14.9%,纯化后的蛋白结合硒的量由大到小依次为碱溶谷蛋白>球蛋白>醇溶蛋白>清蛋白。蛋白液经SEC-HPLC-ICP-MS检测,通过蛋白色谱峰(λ=280 nm)和ICP-MS硒峰(78Se)对比分析,利用分子量标准曲线测定出4类蛋白中含硒蛋白的分子量。结果表明,富硒大米中清蛋白和醇溶蛋白并不是硒的主要存在蛋白。硒主要存在于>7 kDa的碱溶谷蛋白和球蛋白,其中碱溶含硒蛋白主要组分F1分子量为199.8 kDa。     

表面解吸常压化学电离质谱快速鉴别樟木制品

采用自行研制的表面解吸常压化学电离质谱(SDAPCI-MS),在无需样品预处理的情况下,对樟木制品及普通木材进行检测,在正离子模式及m/z 90～400范围内获得其化学指纹图谱,并通过主成分分析(PCA)方法对所获指纹谱图信息进行分析,进而对不同样品进行鉴别。结果表明,SDAPCI-MS能够对樟木表面多种特征化学成分(樟脑,香叶醇等)进行解吸电离,快速获得樟木的化学指纹谱图,并能够对目标组分做多级串联质谱鉴定。结合PCA方法,可对不同品质、不同种类的木材样品进行区分。结果表明,本方法灵敏度高,分析速度快(单个样品分析时间小于3 min),可望应用于珍贵木材快速无损分析及品质鉴定。     

碳一化工路线制备乙二醇研究进展

乙二醇(EG)是一种重要的化工原料,主要用来生产新型聚酯纤维.近年来由于我国聚酯产业发展迅速,极大的推动了对乙二醇的需求.碳一化工路线以资源丰富、价格便宜的天然气或煤为原料合成乙二醇,有着诱人的工业化前景.综述了以合成气为原料合成乙二醇的研究进展,包括合成气直接合成法、甲醛羰化法、CO偶联法、甲醛氢甲酰化法以及甲醛缩合法等.     

A Trinuclear Ni(Ⅱ) Mixed-ligand Complex Containing Pentadentate N-butylsalicylhydrazide and Monodentate Imidazole:Synthesis, Characterization and Crystal Structure

A novel trinuclear nickel(Ⅱ) complex [Ni3(bushz)2(Himdz)2(H2O)2]?2DMF (1, bushz=N-butylsalicylhydrazide, Himdz=imidazole, DMF=N,N-dimethyl-formamide) has been synthesized and characterized by X-ray single-crystal diffraction characterization. Complex 1 crystallizes in the monoclinic system, space group P21/c with a=7.706(7), b=14.882(6), c=18.639(6) , β=108.08(2)o, V=2032(1) 3, Dc=1.525 g/cm3, Mr=932.95, Z=2, F(000)=972, μ=1.442 mm-1, the final R=0.0359 and wR=0.0771. The three nickel(Ⅱ) atoms in 1 are arranged in a strictly linear structure and exhibit alternating square-planar and octahedral geometries. The complex is connected to form a supramolecule with an infinite three-dimensional network through intermolecular hydrogen bonds. The electrochemical studies reveal that redox of Ni3+/Ni2+ in the complex is a quasi-reversible process. The thermal stability of the title complex was also studied.     

Bonding of Hydroxyl and Epoxy Groups on Graphene： Insights from Density Functional Calculations

Density functional theory and GGA-PW91 exchange correlation function were performed to simulate the bonding behavior of hydroxyl and epoxy groups on the graphene surface. We compared the different binding energies for two epoxy groups, as well as one hydroxyl group and one epoxy group on all possible positions within a 6-fold ring, respectively. The calculated results suggest that two oxygen-containing groups always tend to bind with the neighboring carbon atoms at the opposite sides. Moreover, two hydroxyl groups on the meta position are unstable, and one of the hydroxyl groups easily migrates to the para position. In contrast to the disperse arrangement, the aggregation of multiply hydroxyl groups largely enhances the binding energy of every hydroxyl group. It is worth noting that the binding sites and hydrogen bonds play an important role in stability. Our work further points out the number of oxygen-containing groups and the location of oxide region largely influence the electronic properties of graphene oxide.     

Determination of Cr(VI) by portable tungsten coil electrothermal atomic absorption spectrometer after surfactant-assisted dispersive liquid-liquid microextraction

As a new developed instrument, a portable tungsten coil electrothermal atomic absorption spectrometer (W-coil ET-AAS) was first coupled with surfactant assisted dispersive liquid–liquid microextraction (SA-DLLME) to improve its analytical performance and expand its applications in this work. SA-DLLME was very simple, rapid and the extraction efficiency was considerably improved by the effect of surfactant, which was suitable to be coupled with the portable instrument in field analysis. After SA-DLLME, concentrated chromium in organic phase was directly determined on W-coil atomiser. The influence factors relevant to SA-DLLME and instrumental conditions were studied systematically. Under the optimal conditions, the limit of detection (LOD) for Cr(VI) was 0.016 µg L^?1, with sensitivity enhancement factor (EF) of 107. The relative standard deviation (RSD) for seven replicate measurements of 0.5 µg L^?1 of Cr(VI) was 4.6%. The recoveries for the spiked samples were in the acceptable range of 96.8–104%. The rapid, simple and high effective method greatly improved the sensitivity of this portable spectrometer for the determination of Cr(VI) and was applied to the analysis of ultra-trace Cr(VI) in real and certified water samples with satisfactory results.