ICP-OES和ICP-MS应用于石膏多元素分析时的样品微波消解方法研究

分别采用HNO3,HNO3/HF和HNO3/HF+H3BO3三种不同消解用酸微波消解石膏样品.用ICP-OES检测石膏中的Al,Ca,Fe,Mg,K,Na,S,Ti,Si和Sr,用ICP-MS检测石膏中的V,Cr,Mn,Zn,Se和Ce.采用GBW03109a,GBW03110和FGD-2作为石膏标准物质.检测值与样品标准值的对比结果表明,使用HNO3/HF+H3BO3样晶消解最完全.建立了用9 mL HNO3和1 mL HF分解0.2 g石膏,再加入10 mL 4%(ρ)的H3BO3中和过量的HF及氟化物沉淀的两步微波加热消解方法.该方法检测3种石膏标准物质时,元素回收率为88%～112%,RSD均小于3%.利用该方法测定了3种实际燃煤电厂脱硫石膏样品中的元素含量.     

微波消解-ICP-OES测定石灰石样品中的多种元素

采用微波消解预处理石灰石样品,并利用ICP-OES测定石灰石中Si、Ca、Al、Fe、Mg、K、Ti、Sr和Mn等矿物元素含量。以GBW07120和GBW07214a作为石灰石标准物质。对比了HNO3,HNO3/HF和HNO3/HF+H3BO33种不同消解用酸微波消解石灰石样品后对元素回收率的影响。通过检测值与样品标准值的对比,使用HNO3/HF+H3BO3后样品消解最完全。建立了用9mLHNO3和1mLHF分解0.2g石灰石,再加入10mL4%(W/V)的H3BO3中和过量的HF及氟化物沉淀的两步微波加热消解方法。本方法检测2种石灰石标准物质时,元素回收率在88.5%—104.1%之间,RSD均小于3%。     

ICP-OES/ICP-MS测定煤中多种元素的微波消解方法研究

对比了不同温度以及HNO3,HNO3/H2O2,HNO3/HF和HNO3/HF+H3BO3等四种用酸对煤样微波消解效果和元素检测的影响。以SARM20作为煤标准物质。建立了一套两步微波消解及多元素检测方法。即用9mL的HNO3与1mL的HF分解0.1g煤样,再加入10mL 4%(ρ)的H3BO3中和过量HF及氟化物沉淀。使用ICP-OES检测Al,Ca,Fe,Mg,K,Na,S,Si,Sr和Ti等十种矿物元素,元素回收率在87.5%～98.8%;使用ICP-MS检测Li,Be,Sc,V,Cr,Mn,Co,Ni,Cu,Zn,Ga,As,Se,Zr,Sn,Cs,Ba,Ce,Eu和Pb等20种重金属元素,元素回收率在85%～112.5%。各元素检测的RSD均小于3%。     

微波消解与ICP-OES/ICP-MS测定飞灰中的多种元素

研究了不同温度以及HNO3、HNO3/H2O2、HNO3/HF和HNO3/HF+H3BO34种酸对飞灰微波消解效果和元素分析的影响.以NIST-1633b为飞灰标准物质.建立了用HNO3/HF (9mL+ 1mL)分解0.05g飞灰,再加入10mL 4％(ρ)的H3BO3中和过量HF及氟化物沉淀的两步微波消解方法.并利用ICP-OES检测了Al、Ca、Fe、Mg、K、Na、S、Si和Ti等9种矿物元素,元素回收率在92％-105％之间;利用ICP-MS检测了V、Cr、Mn、Co、Ni、Cu、Zn、As、Se、Sr、Cs、Ba、Eu和Pb等14种重金属元素,元素回收率在83％-109％之间.各元素检测的RSD均小于3％.     

HF(X1Σ+)的光谱跃迁精细结构的Dunham方法研究

用从头计算法QCISD/6-311++G**得到了HF(X1Σ+)的势能曲线,基于Dunham方法得到了HF(X1Σ+)的光谱常数,从而得到了(3→1,2→0)的泛频跃迁精细结构,计算值与实验值吻合较好。用几种不同的方法计算了HF(X1Σ+)的各阶力常数,其计算结果比较一致。     

4-氟苯甲醛酪氨酸席夫碱的制备及其振动光谱的密度泛函理论和从头算理论计算的研究

4-氟苯甲醛酪氨酸席夫碱(4-FT)由4-氟苯甲醛和L-酪氨酸钾盐在室温条件下反应制得,4-FT的结构通过1HNMR,FTIR和Raman测试得到确认。分别用密度泛函(DFT,density functional theory)理论的B3LYP(Becke’s three-parameter exchange functional(B3)with Lee,Yang,Parr(LYP))方法和从头算(ab initio)理论的HF(Hartree-Fock)方法,选用标准的6-31G**和6-31G*基组对化合物4-FT的几何构型进行优化。同时分别在B3LYP/6-31G**,B3LYP/6-31G*,HF/6-31G**和HF/6-31G*水平下计算4-FT的振动波数。用密度泛函(DFT)的B3LYP方法计算并校正后的波长数据比用从头算(ab i-nitio)的HF方法计算的结果更与实验数据吻合。     

NH自由基与臭氧反应机理的理论研究

用量子化学从头计算方法,在HF／6－31＋＋G**水平研究了臭氧与NH三线态活性自由基反应的微观机理,优化得到反应物、过渡态、中间体和产物的几何构型。用MP2／6－31＋＋G**／／HF6－31＋＋G**方法计算能量,同时进行零点能校正。研究结果表明： NH三线态活性自由基与O3反应首先成稳定中间体NHO3,然后中裂解生成HNO和O2。     

HX（X=F，C1，Br）酸性强度的理论计算

中用Gibbs自由能ΔGacid定义了HX(g)的酸性强度。研究表明，用MP2、QCISD和B3LYP三种量化方法计算所得的HX酸性强度与献值对比，其最大的相对误差仅为2．45％。其中，B3LYP方法的计算结果与献值最为接近，其误差在0．37—1．09％范围内。HF气态分子有明显的氢键作用，其二聚体分子酸性强度ΔGacid与单体分子的△Gacid值相比降低了约-5～-11％，此时氟化氢气体的酸性强度已不能单从HF单体分子的△Gacid值来衡量，而应考虑HF分子的氢键作用。     

HX(X=F,Cl,Br)酸性强度的理论计算

本文用Gibbs自由能ΔGacid定义了HX(g)的酸性强度.研究表明,用MP2、QCISD和B3LYP三种量化方法计算所得的HX酸性强度与文献值对比,其最大的相对误差仅为2.45%.其中,B3LYP方法的计算结果与文献值最为接近,其误差在0.37-1.09%范围内.HF气态分子有明显的氢键作用,其二聚体分子酸性强度ΔGacid与单体分子的ΔGacid值相比降低了约-5～-11%,此时氟化氢气体的酸性强度已不能单从HF单体分子的ΔGacid值来衡量,而应考虑HF分子的氢键作用.     

等离子体发射光谱法测定地质样品中的硼

用HF－HNO3－HCl－H3PO4混合酸分解样品，在氨性条件下，以元素的磷酸盐沉淀分离样品中大量的Fe、Al、Ca、Mg 等基体元素，然后用ICP－AES法测定，可用于地质样品中硼的分析。     

FTIR spectra of the HF complexes with alkyl cyanides in solid argon

Ethyl-, i-propyl, and t-butyl cyanide were separately condensed at 9–12K with HF in excess argon producing complexes of the form RCNHF. Diffusion of HF was accomplished by warming the matrix above 18K which produced 1:2 and 1:3 complexes RCN(HF)₂ and RCN(HF)₃. The HF submolecule stretching frequencies for the 1:1 complexes were very similar, giving absorptions at 3515, 3530 and 3520 cm^?1, respectively, while the HF librational modes were observed centered around 650 cm^?1. The CN symmetric stretch in the complexes was perturbed to higher energy in each case implying a strengthening of the CN bond, with the C-C₃ symmetric stretch in t-butyl cyanide also shifted to higher energy.     

非链式重复频率HF激光器激光介质净化技术

开展了分子筛对非链式电激励重频HF激光器中基态HF分子吸附技术研究,设计了新型的分子筛吸附装置,进行了大量的吸附实验,结果表明: 3A分子筛为有效的吸附剂,实现了HF激光器在50 Hz/20 s条件下运行时平均激光能量下降率小于5%,大大提高了激光能量的稳定性,延长了激光介质的使用寿命。开展了激光器工作于不同频率条件下使用3A型分子筛吸附装置时的激光能量情况研究,并通过实验方法获得了3A型分子筛的再生活化方法。     

多晶硅表面酸腐蚀制备绒面研究

采用各向同性腐蚀法制备多晶硅绒面,腐蚀液为HF和HNO3的混合溶液,缓和剂为NaH2PO4.2H2O溶液.利用SEM、AFM和紫外分光光度计对硅片绒面进行检测和分析,初步探讨了酸腐蚀机理.结果表明:采用NaH2PO4.2H2O溶液作为缓和剂,腐蚀后的硅片表面具有均匀的腐蚀坑,表面陷光效果较好,通过优化各种参量,反应速度可以控制在2 μm/min左右,适合工业生产的要求.在富HF时,硅片表面易形成尖锐边缘的腐蚀坑,出现或多或少的小孔,反射率最低可达16.5%～17.5%|在富HNO3时,硅片表面易形成腐蚀坑较浅、尺寸偏大的气泡状绒面或光面,反射率较高.     

Effects of HearFones on speaking and singing voice quality

HearFones (HF) have been designed to enhance auditory feedback during phonation. This study investigated the effects of HF (1) on sound perceivable by the subject, (2) on voice quality in reading and singing, and (3) on voice production in speech and singing at the same pitch and sound level.

Test 1: Text reading was recorded with two identical microphones in the ears of a subject. One ear was covered with HF, and the other was free. Four subjects attended this test. Tests 2 and 3: A reading sample was recorded from 13 subjects and a song from 12 subjects without and with HF on. Test 4: Six females repeated [pa:p:a] in speaking and singing modes without and with HF on same pitch and sound level.

Long-term average spectra were made (Tests 1–3), and formant frequencies, fundamental frequency, and sound level were measured (Tests 2 and 3). Subglottic pressure was estimated from oral pressure in [p], and simultaneously electroglottography (EGG) was registered during voicing on [a:] (Test 4). Voice quality in speech and singing was evaluated by three professional voice trainers (Tests 2–4).

HF seemed to enhance sound perceivable at the whole range studied (0–8 kHz), with the greatest enhancement (up to ca 25 dB) being at 1–3 kHz and at 4–7 kHz. The subjects tended to decrease loudness with HF (when sound level was not being monitored). In more than half of the cases, voice quality was evaluated “less strained” and “better controlled” with HF. When pitch and loudness were constant, no clear differences were heard but closed quotient of the EGG signal was higher and the signal more skewed, suggesting a better glottal closure and/or diminished activity of the thyroarytenoid muscle.     

ICP-OES测定月季中矿质元素的五种前处理方法比较

采用五种不同的前处理方法(干灰化法、HNO3+ H2 O2微波消解法、HNO3 +H2O2 +HF微波消解法、HNC3+ HClO4微波消解法、HNO3+ HClO4+HF微波消解法),对月季样品进行消解,利用ICP-OES法测定九种常量和微量元素,加标回收结果显示:HN(3 +HClO4微波消解法是最优的处理方法,对...