(TbDy)Fe2基定向凝固磁致伸缩合金的性能与组织和成分的关系

制备（ＴｂＤｙ）Ｆｅ２基磁致伸缩合金的过程中，采用改进的Ｂｒｉｄｇｍａｎ技术使（ＴｂＤｙ）Ｆｅ２基相形成沿〈１１０〉晶向取向生长的组织，控制Ｆｅ／（Ｔｂ＋Ｄｙ）＝１９０～１９５（原子比）以防止（ＴｂＤｙ）Ｆｅ３相出现，控制Ｄｙ／Ｔｂ≈０７０／０３０以减小（ＴｂＤｙ）Ｆｅ２相的磁晶各向异性，控制氧含量低于０５ｍｇ·ｇ－１以保证晶体的稳定性等技术措施，获得了最高磁致伸缩应变（８０ｋＡ·ｍ－１）达１５００×１０－６的产品。晶体直径为６～３０ｍｍ，最大长度达３００ｍｍ。     

聚1-甲基-2-吡咯烷酮修饰碘离子化学传感器的研究

研究了１－甲基－２－吡咯烷酮在玻碳（ＧＣ）电极表面聚合的条件，测试了Ｉ－－聚１－甲基－２－吡咯烷酮化学传感器的电化学性能。所制电极检测Ｉ－响应线性范围２４×１０－４～０１ｍｏｌ／Ｌ，检测下限为１０×１０－４ｍｏｌ／Ｌ，电极的重现性及稳定性都较好，重复测定７次相对标准偏差为０７１％，可连续使用２５天。Ｃｌ－、Ｂｒ－、ＮＯ－３、ＳＯ２－４等阴离子对测定干扰较小     

新试剂（MSBTAMB）双波长光度法测定微量铜（Ⅱ）的研究

研究了新试剂２－〔２＇－（６＇－甲磺酰－苯并噻唑）偶氮〕－５－二甲氨基苯甲酸（ＭＳＢＴＡＭＢ）与铜（Ⅱ）的显色反应。试验表明，在ｐＨ２．０～５．１和４０％乙醇介质中，Ｃｕ（Ⅱ）与ＭＳＢＴＡＭＢ形成１＋１稳定的配合物，其最大吸收波长为６４２ｎｍ，用单波长法测得配合物的Σ（６４２）＝６．７４×１０４·ｍｏｌ－１·ｃｍ－１，双波长法测得的Σ（６４２，５４６）＝１．０９×１０５Ｌ·ｍｏｌ－１·ｃｍ－１。铜量在０～０．７２μｇ／ｍＬ范围内合符比尔定律。制定的方法用于人发和纯铝中微量铜的测定，结果满意。     

Ni-Mo合金电沉积层织构及形成机理

在组成为：０．２２ｍｏｌ／Ｌ硫酸镍、０．０６ｍｏｌ／Ｌ钼酸钠和０．３ｍｏｌ／Ｌ柠檬酸钠的溶液,于纯铜片上采用恒电流沉积,所得Ｎｉ－Ｍｏ合金沉积层经Ｘ射线衍射测定,结果表明在温度为２５℃～５０℃,电流密度为１０ｍＡ·ｃｍ－２～３０ｍＡ·ｃｍ－２范围,Ｎｉ－Ｍｏ合金沉积层表现为（１１１）择优取向．循环伏安和电位阶跃实验表明镍钼合金电结晶过程按照连续成核和三维生长方式进行．Ｎｉ－Ｍｏ合金电沉积过程的电化学交流阻抗谱表明Ｎｉ－Ｍｏ共沉积过程经历了吸附中间产物步骤,由于吸附态物种氢氧化镍和钼的氧化物将阻化晶粒（１１１）晶面的生长,从而使镍钼沉积层表现为（１１１）择优取向．     

新显色剂N—烯丙基—N′—（氨基对苯磺酸钠）硫脲与金（Ⅲ）的显色反应

介绍了一种用新合成的显色剂Ｎ－烯丙基－Ｎ′－（氨基对苯磺酸钠）硫脲（ＡＳＡＴ）光度法测定微量金（Ⅲ）的方法。在ｐＨ３５～５５的ＨＡｃ－ＮａＡｃ缓冲体系中，该试剂和金（Ⅲ）形成一种稳定的水溶性配合物，其组成为ｎ（Ａｕ３＋）∶ｎ（ＡＳＡＴ）＝１∶２，配合物的最大吸收峰位于２９８６ｎｍ处，表观摩尔吸光系数为１１４×１０５Ｌ·ｍｏｌ－１·ｃｍ－１。Ａｕ３＋量在７２～５６８μｇ／Ｌ服从比尔定律，相关系数ｒ＝０９９９３。将该法应用于金矿石中微量金的测定，获得满意的结果。     

新显色剂N-对甲苯基-N′-(氨基对苯磺酸钠)硫脲的合成及与钯(Ⅱ)的显色反应

合成了新试剂Ｎ－对甲苯基－Ｎ′－（氨基对苯磺酸钠）硫脲（ＰＭＰＴ）。经红外、紫外、核磁共振和元素分析等方法测试,确定了其组成和结构,并研究了新试剂与钯（Ⅱ）的显色反应,建立了光度法测定微量钯（Ⅱ）的新方法。在ｐＨ３．６～５．８的ＨＡｃ－ＮａＡｃ缓冲体系中,该试剂和钯（Ⅱ）形成一种稳定的组成比（摩尔比）为１∶２的水溶性配合物,其最大吸收峰位于３１８．６ｎｍ处,表观摩尔吸光系数为２．６６×１０５Ｌ·ｍｏｌ－１·ｃｍ－１。钯（Ⅱ）在８．０～４２４μｇ／Ｌ服从比尔定律,相关系数ｒ＝０．９９９７。将该法应用于阳极泥和矿石样品中微量钯的测定,获得满意的结果。     

2-(3,5-二氯-2-吡啶偶氮)-5-二甲氨基苯胺与铂(Ⅳ)显色反应的研究

研究了２－（３，５－二氯－２－吡啶偶氮）－５－二甲氨基苯胺（３，５－ｄｉＣｌ－ＰＡＤＭＡ）与铂（Ⅳ）的显色反应及铂配合物的质子化行为。结果表明，在０．０４～０．４８ｍｏｌ／Ｌ的Ｈ２ＳＯ４溶液中，于加热的条件下，试剂可与铂（Ⅳ）形成稳定的１∶２绿蓝色ＰｔＬ２Ｈ２＋２配合物，其最大吸收波长位于６３４ｎｍ，表观摩尔吸光系数为９．７３×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，桑德尔灵敏度为０．００２μｇ·ｃｍ－２。铂配合物的三级质子化常数分别为：ｌｇＫａ１＝３．９１，ｌｇＫａ２＝－２．２１，ｌｇＫａ３＝－３．３７。较大量的常见金属离子及除钯、钌外的其它贵金属离子不干扰测定。利用Ｐｔ，Ｐｄ与试剂反应所需的温度差异，可以用差减法消除微量Ｐｄ的干扰．铂（Ⅳ）浓度在每１０ｍＬ０～７．５μｇ范围内符合比尔定律。所拟方法用于二次合金管理样－８８及催化剂中微量铂的测定，结果满意。     

高效液相色谱法测定垃圾渗出液中的苯酚和对甲苯酚

介绍用气相色谱－质谱联用技术对垃圾渗出液中的酚类物质进行定性，然后用反相高效液相色谱法对苯酚和对甲苯酚进行定量分析。苯酚和对甲苯酚的线性范围分别为：５０×１０～４０×１０３ｍｇ·Ｌ－１，５０×１０２～１２×１０４ｍｇ·Ｌ－１；最低检出限为１６ｍｇ·Ｌ－１，４００ｍｇ·Ｌ－１；相对标准偏差为１１％和２９％。     

新显色剂1-(2.4-二硝基苯)-3-(2-噻唑)-三氮烯的合成及与汞的显色反应研究

报道了新显色剂１－（２．４－二硝基苯）－３－（２－噻唑）－三氮烯的合成及其与Ｈｇ（Ⅱ）的显色反应。实验表明，在非离子表面活性剂ＴｒｉｔｏｎＸ－１００存在下，于ｐＨ１１．７５的三酸缓冲介质中，试剂与Ｈｇ（Ⅱ）能生成蓝绿色配合物，最大吸收波长位于６９０ｎｍ处，试剂的最大吸收波长位于４１０ｎｍ处，对比度高达２８０ｎｍ，其配合比为１∶２，表观摩尔吸光系数为１．１×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，Ｈｇ（Ⅱ）含量在０～１８μｇ／２５ｍＬ范围内符合比耳定律。测定了废水中汞的含量，结果令人满意。     

镧系离子与5,7-二氯-8-羟基喹啉-藏红花三元离子缔合物的萃取-光度分析特性

以Ｓｍ３＋为例研究了Ｌｎ３＋５，７二氯８羟基喹啉（ＤＣＯ）藏红花（ＳＦＴ）形成三元离子缔合物的萃取光度特征。用平衡移动法测定了离子缔合物的摩尔比Ｌｎ３＋∶ＤＣＯ∶ＳＦＴ＝１∶４∶１。在ｐＨ６８０～７５０的范围内，萃取物的λｍａｘ＝５２４ｎｍ，εｍａｘ＝４７０×１０４Ｌ·ｍｏｌ－１·ｃｍ－１。Ｓｍ３＋在０２～１５μｇ·ｍｌ－１范围内符合比尔定律。研究表明镧系离子的相对吸光度（ＡＬｎ／ＡＬａ）随原子序数呈现奇偶变化规律。     

Low-load rotor-synchronised Hahn-echo pulse train (RS-HEPT) 1H decoupling in solid-state NMR: factors affecting MAS spin-echo dephasing times

Transverse dephasing times T(2)' in spin-echo MAS NMR using rotor-synchronised Hahn-echo pulse-train (RS-HEPT) low-load (1)H decoupling are evaluated. Experiments were performed at 300 and 600 MHz for (13)CH-labelled L-alanine and (15)NH(delta)-labelled L-histidine.HCl.H(2)O, together with SPINEVOLUTION simulations for a ten-spin system representing the crystal structure environment of the (13)CH carbon in L-alanine. For 30 kHz MAS and nu(1)((1)H) = 100 kHz at 300 MHz, a RS-HEPT T(2)' value of 17 +/- 1 ms was obtained for (13)CH-labelled L-alanine which is approximately 50% of the XiX T(2)' value of 33 +/- 2 ms. Optimum RS-HEPT decoupling performance is observed for a relative phase of alternate RS-HEPT pi-pulses, Deltaphi = phi'- phi, between 40 and 60 degrees . For experiments at 600 MHz and 30 kHz MAS with (13)CH-labelled L-alanine, the best RS-HEPT (nu(1)((1)H) = 100 kHz) T(2)' value was 3 times longer than that observed for low-power continuously applied sequences with nu(1)((1)H) < or =40 kHz, i.e. corresponding to the same average power dissipated in the probe. A marked improvement in RS-HEPT (1)H decoupling is observed for increasing MAS frequency: at 55.6 kHz MAS, a best RS-HEPT T(2)' value of 34 +/- 5 ms was recorded for (13)CH-labelled L-alanine. Much improved RS-HEPT broadband performance was also observed at 55.6 kHz MAS as compared to 30 kHz MAS.     

Para-hydrogen induced polarization of amino acids, peptides and deuterium-hydrogen gas

Signal Amplification by Reversible-Exchange (SABRE) is a method of hyperpolarizing substrates by polarization transfer from para-hydrogen without hydrogenation. Here, we demonstrate that this method can be applied to hyperpolarize small amounts of all proteinogenic amino acids and some chosen peptides down to the nanomole regime and can be detected in a single scan in low-magnetic fields down to 0.25 mT (10 kHz proton frequency). An outstanding feature is that depending on the chemical state of the used catalyst and the investigated amino acid or peptide, hyperpolarized hydrogen-deuterium gas is formed, which was detected with (1)H and (2)H NMR spectroscopy at low magnetic fields of B(0) = 3.9 mT (166 kHz proton frequency) and 3.2 mT (20 kHz deuterium frequency).     

1H-13C/1H-15N heteronuclear dipolar recoupling by R-symmetry sequences under fast magic angle spinning for dynamics analysis of biological and organic solids

Fast magic angle spinning (MAS) NMR spectroscopy is becoming increasingly important in structural and dynamics studies of biological systems and inorganic materials. Superior spectral resolution due to the efficient averaging of the dipolar couplings can be attained at MAS frequencies of 40 kHz and higher with appropriate decoupling techniques, while proton detection gives rise to significant sensitivity gains, therefore making fast MAS conditions advantageous across the board compared with the conventional slow- and moderate-MAS approaches. At the same time, many of the dipolar recoupling approaches that currently constitute the basis for structural and dynamics studies of solid materials and that are designed for MAS frequencies of 20 kHz and below, fail above 30 kHz. In this report, we present an approach for (1)H-(13)C/(1)H-(15)N heteronuclear dipolar recoupling under fast MAS conditions using R-type symmetry sequences, which is suitable even for fully protonated systems. A series of rotor-synchronized R-type symmetry pulse schemes are explored for the determination of structure and dynamics in biological and organic systems. The investigations of the performance of the various RN(n)(v)-symmetry sequences at the MAS frequency of 40 kHz experimentally and by numerical simulations on [U-(13)C,(15)N]-alanine and [U-(13)C,(15)N]-N-acetyl-valine, revealed excellent performance for sequences with high symmetry number ratio (N/2n > 2.5). Further applications of this approach are presented for two proteins, sparsely (13)C/uniformly (15)N-enriched CAP-Gly domain of dynactin and U-(13)C,(15)N-Tyr enriched C-terminal domain of HIV-1 CA protein. Two-dimensional (2D) and 3D R16(3)(2)-based DIPSHIFT experiments carried out at the MAS frequency of 40 kHz, yielded site-specific (1)H-(13)C/(1)H-(15)N heteronuclear dipolar coupling constants for CAP-Gly and CTD CA, reporting on the dynamic behavior of these proteins on time scales of nano- to microseconds. The R-symmetry-based dipolar recoupling under fast MAS is expected to find numerous applications in studies of protein assemblies and organic solids by MAS NMR spectroscopy.     

Effect of dual frequency on sonochemical reaction rates

An ultrasonic reactor that combined a standing-wave-type transducer and a horn-type emitter was constructed and the ultrasonic frequency of the standing-wave-type transducer was varied and the sonochemical reaction rates were estimated. The synergy effect was observed below 100 kHz. In order to consider the mechanism of effect of synergy, the acoustic noise, the sonochemical luminescence and the bubble behavior in the reactor were investigated. The frequency spectrum of acoustic noise indicated that the synergy effect came from the increase of number of cavitation bubbles.     

Monitoring of a heterogeneous reaction by acoustic emission

The feasibility of monitoring the reaction of itaconic acid and 1-butanol by non-invasive acoustic emission measurements has been assessed. A piezoelectric transducer with a resonant mode at 90 kHz was attached to the external wall of a 1 L jacketed glass reactor. Acoustic emission from the oil jacket, stirrer and toluene was insignificant in comparison to that produced by the itaconic acid particles, which was transmitted through the glass walls and heating oil to the transducer. The transducer responded to acoustic emission from itaconic acid up to approximately 300 kHz, with the region around 90 kHz having the highest sensitivity. The effect of particle concentration and size on the acoustic emission generated has also been investigated, with higher concentrations and larger particles giving the greater signals. The detection limit for itaconic acid particles was 14 g dm(-3) of toluene. The effect of 1-butanol concentration and temperature on the progression of reactions was monitored using acoustic emission. It was possible to detect differences in the rate and extent of the reaction under different conditions, and also to identify when a combination of the concentration and/or size of itaconic acid particles had reached a steady state. However, it was not possible to differentiate between changes in particle size and concentration using the resonant transducer.     

Sensitivity enhancement and heteronuclear distance measurements in biological 17O solid-state NMR

In this contribution we present a comprehensive approach to study hydrogen bonding in biological and biomimetic systems through 17O and 17O-1H solid-state NMR combined with density functional theory calculations of 17O and 1H NMR parameters. We explore the signal enhancement of 17O in L-tyrosine.HCl using repetitive double-frequency swept radio frequency pulses in solid-state NMR. The technique is compatible with high magnetic fields and fast magic-angle spinning of the sample. A maximum enhancement by a factor of 4.3 is obtained in the signal-to-noise ratio of the selectively excited 17O central transition in a powdered sample of 17Oeta-L-tyrosine.HCl at an external field of 14.1 T and a spinning frequency of 25 kHz. As little as 128 transients lead to meaningful 17O spectra of the same sample at an external field of 18.8 T and a spinning frequency of 50 kHz. Furthermore we employed supercycled symmetry-based pulse sequences on the protons to achieve heteronuclear longitudinal two-spin-order (IzSz) recoupling to determine 17O-1H distances. These sequences recouple the heteronuclear dipolar 17O-1H couplings, where dipolar truncation is absent, while decoupling the homonuclear proton dipolar interactions. They can be applied at fast magic-angle-spinning frequencies up and beyond 50 kHz and are very robust with respect to 17O quadrupolar couplings and both 17O and 1H chemical shift anisotropies, which makes them suitable for the use at high external magnetic fields. The method is demonstrated by determining the 17Oeta-1H distance in L-tyrosine.HCl at a spinning frequency of 50 kHz and an external field of 18.8 T.     

Factors affecting broadband acoustic emission measurements of a heterogeneous reaction

Broadband acoustic emission signals were obtained by attaching a piezoelectric transducer, sensitive up to 750 kHz, to the external wall of a 1 L jacketed glass reactor. Measurements were acquired of itaconic acid particles mixing in toluene; the total area of the acoustic emission signal from 55-500 kHz increased when the particle concentration, particle size or stir rate were increased. Signals at frequencies above 200 kHz were less sensitive to changes in particle size than those at lower frequencies. From calculation of the area of the signal in the range 55-200 kHz as a percentage of the signal area over the range 55-500 kHz, for mixtures of different size ranges of itaconic acid, it was possible to obtain an estimate of the mean particle size of a mixture. The heterogeneous esterification reaction of itaconic acid and 1-butanol was monitored non-invasively. A decrease in the overall acoustic signal area between 60 and 500 kHz was observed as the reaction progressed. Particle size and concentration information were contained in the amplitude of the acoustic emission signal, while the emission frequency yielded information on changes in the mean particle size.     

Cavitation mechanism in cyanobacterial growth inhibition by ultrasonic irradiation

To prevent cyanobacterial bloom in eutrophic water by ultrasonic method, ultrasonic irradiations with different parameters were tested to inhibit Spirulina platensis from growth. The experimental result based on cyanobacterial growth, chlorophyll a and photosynthetic activity showed that, the ultrasonic irradiation inhibited cyanobacterial proliferation effectively, furthermore the inhibition effectiveness increased in the order: 200 kHz>1.7 MHz>20 kHz and became saturated with the increased power. The inhibition mechanism can be mainly attributed to the mechanical damage to the cell structures caused by ultrasonic cavitation, which was confirmed by light microscopy and differential interference microscopy. The optimal frequency of 200 kHz in cavition and sonochemistry was also most effective in cyanobacterial growth inhibition. The higher frequency of 1.7 MHz is weaker than 20 kHz in cavitation, but has more effective inhibition because it is nearer to the resonance frequency of gas vesicle. The inhibition saturation with ultrasonic power was due to the ultrasonic attenuation induced by the acoustic shielding of bubbles enclosing the radiate surface of transducer.     

Enhanced pearl-chain formation by electrokinetic interaction with the bottom surface of vessel

Counterions in an electric double layer (EDL) around a colloidal particle accumulate on one side of the EDL and are deficient on the other side under an electric field, resulting in an imbalance of ionic concentration in the EDL, that is to say, the ionic polarization of EDL. It is well known that the ionic polarization of EDL induces electric dipole moments whereby the alignments of colloidal particles (e.g., pearl chains) are formed under alternating electric fields. In this study, we focus on the effect of the frequency of applied electric fields (100 Hz-1 kHz) on the alignment of silica particles settling at the bottom of a silica glass vessel. In digital imaging analyses for pearl chains of silica particles, it is confirmed that surface distances between two neighboring particles decrease but the number of particles in a pearl chain increases as the frequency of the applied electric field is lowered from 1 kHz to 100 Hz. More interestingly, electrical conductance measurements suggest that the induced ionic polarization of EDL around silica particles at the bottom of the silica vessel is enhanced as the frequency is lowered from 1 kHz to 100 Hz, whereas the ionic polarization around isolated silica particles in uniform dispersions is alleviated by the relaxation of ionic concentration in the EDL as a result of the diffusion of counterions. This curious phenomenon can be explained by considering that the ionic polarization of EDL of silica particles at the bottom of a vessel is affected by the electro-osmosis of the silica surface at the bottom of the vessel.     

Ca2+和Mn2+共掺杂Ba1-xSrxTiO3固溶体的制备及其电学性能研究

(Ca, Mn)-codoped Ba1-xSrxTiO3 (BST) solid solution, i.e. Ba0.4Sr0.5Ca0.08Mn0.02TiO3, was successfully synthesized via sol-gel process. The product was characterized by TG-DTA thermal analyses, XRD, TEM.The effects of both curing temperature and applied voltage on the resistance, etc. were investigated. It showed that the structure of BST was unable to be changed even though it was codoped by Ca2+ and Mn2+. TEM photographs demonstrated the influence of curing temperature on the morphologies of the tested samples. The dependence of resistance on the curing temperature illustrated that (Ca, Mn)-codoped BST was capable of exhibiting the positive temperature coefficient (PTC) effect at low frequency; nevertheless,it might display the negative temperature coefficient (NTC) effect at other frequencies. The relationships between the resistance and applied voltage revealed that the resistance property of (Ca, Mn)-codoped BST appeared at low frequencies, but its property of capacitive reactance might present at high frequency. These findings mean that the electrical property of BST can be adjusted by codoping method. These phenomena can be explained by the grain boundary resistance effect, Heywang model and ion polarization theory.