扫描电化学显微镜（SECM）在腐蚀应用领域的重要性受到越来越多科研和商业部门的重视。SECM的高分辨率和定量分析能力为评估材料表面耐蚀性提供了一个新的方法。目前，该技术应用过程中经常受样品表面的较大形貌特征变化的影响，只能在有限的范围内实现恒高度扫描。 SECM结合非触式微区形貌测试系统（OSP），用户可以先做一个表面形貌测试，然后在SECM扫描过程中控制探针的位置。不用高度追踪，电流测量会受形貌和电化学活性的影响，获得的响应是两者的总和。用高度追踪，可以有效避免形貌的影响，测量样品电化学活性

生物柴油是替代石化柴油燃料的一种可再生的燃料。这种可生物降解、无毒性的生物柴油由豆油、蔬菜油、再循环冷却油及动物脂肪制成。由蔬菜油和动物脂肪制成的生物柴油与石油性能相似，但是它燃烧更完全并降低排放。高含量的自由基氨基乙酸和总氨基乙酸将导致沉积及差的发动性能。因此，氨基乙酸含量是生物柴油燃料质量的指标，为了客户方便，DPS生产了生物柴油气相色谱分析仪帮助客户确认自由基氨基乙酸和总氨基乙酸的含量，DPS配置了标准的冷柱上进样口、保护柱、分析柱和高灵敏度FID检测器。DPS公司的每个气相色谱仪均配有快速加热和快速冷却的柱温箱，可大量地增加样品通量。如果在仪器上安装一个110位液体自动进样器便于客户昼夜不懂地运行此分析系统。整体的生物柴油气体分析仪系统是一款外观小、重量轻、便于放置任何场合的仪器。所有的DPS气相色谱仪都是模块化的，便于扩展、升级以及方便维修。

当需要检测低浓度的气体时，推荐您使用DPS公司生产的高灵敏度气体分析仪。美国DPS气相色谱仪可根据您的分析要求，通过调整检测器灵敏度的动态范围，以满足从超低浓度的气体分析到常量气体分析。

利用带有圆二色检测器的jasco手性拆分液相色谱对(R)-和(S)-沙利度胺(反应停）体外羟基化代谢产物进行分析,得到所有代谢产物的绝对构型.

采用停流技术与光散射技术相结合研究了有机盐对甲苯胺盐酸盐（PTHC）诱导十二烷 基硫酸钠（SDS）小分子表面活性剂球-棒胶束转变的动力学过程于机理。在低盐浓度下，SDS 球状胶束转变为椭球状聚集体，动力学过程可用单指数方程拟合。高盐浓度时，聚集体形貌 向棒状胶束转变。慢过程的特征弛豫时间随着SDS 浓度增加而降低。这些表明该球-棒转变 过程遵循胶束融合/裂分机理。

We have comparatively studied the association of cyclic- and linear-poly(N-isopropylacrylamide) (c-PNIPAM and l-PNIPAM) chains with varying chain lengths and end groups in dilute aqueous solutions by laser light scattering (LLS) and stopped-flow temperature-jump measurements. Dynamic and static LLS results reveal that the heating leads to a microphase transition. The resultant structures of interchain aggregates depend on the heating rate and the chain topologies. In comparison with l-PNIPAM chains, a slow heating of c-PNIPAM chains in the solution results in stable mesoglobules with a lower average aggregation number, a looser structure, and a smaller average size (∼290 nm). The temperature-jump-induced association of c-PNIPAM chains in the stopped-flow measurement reveals two kinetic growth stages, which were tentatively ascribed to the loose packing of contracted c-PNIPAM chains and further contraction-induced fragmentation of initially packed c-PNIPAM chains due to the lack of interchain entanglements. On the other hand, for l-PNIPAM chains, the intrachain contraction and interchain penetration/entanglement simultaneously occur as the temperature increases, leading to larger and more compact aggregates whose size increases with the solution temperature.

We have comparatively studied the association of cyclic- and linear-poly(N-isopropylacrylamide) (c-PNIPAM and l-PNIPAM) chains with varying chain lengths and end groups in dilute aqueous solutions by laser light scattering (LLS) and stopped-flow temperature-jump measurements. Dynamic and static LLS results reveal that the heating leads to a microphase transition. The resultant structures of interchain aggregates depend on the heating rate and the chain topologies. In comparison with l-PNIPAM chains, a slow heating of c-PNIPAM chains in the solution results in stable mesoglobules with a lower average aggregation number, a looser structure, and a smaller average size (∼290 nm). The temperature-jump-induced association of c-PNIPAM chains in the stopped-flow measurement reveals two kinetic growth stages, which were tentatively ascribed to the loose packing of contracted c-PNIPAM chains and further contraction-induced fragmentation of initially packed c-PNIPAM chains due to the lack of interchain entanglements. On the other hand, for l-PNIPAM chains, the intrachain contraction and interchain penetration/entanglement simultaneously occur as the temperature increases, leading to larger and more compact aggregates whose size increases with the solution temperature.

A poly(glycerol monomethacrylate)-block-poly(2-(dimethylamino)ethyl methacrylate)-blockpoly( 2-(diethylamino)ethyl methacrylate) (GMA-DMA-DEA) triblock copolymer was synthesized via atom transfer radical polymerization (ATRP). The pH-induced micellization kinetics of this GMA-DMA-DEA triblock copolymer was investigated by employing a stopped-flow light scattering technique. Upon jumping from pH 4 to around 7-7.5, stopped-flow experiments revealed two distinct relaxation processes. The first relaxation mode had a positive amplitude, suggesting that the micelle size and/or micelle number density increases; in contrast, the second relaxation mode had a negative amplitude, which is assigned to the micelle formation-breakup process. However, upon jumping from pH 4 to pH >8, only relaxation processes with positive amplitude were observed. The relaxation curve can be well fitted with a doubleexponential function, leading to a fast relaxation time constant (ô1) and a slow relaxation time constant (ô2). ô1 is in the range 10-20 ms, which decreases with increasing polymer concentration. ô2 is around 110 ms, which is independent of concentration in the range studied. In the fast process (ô1), quick association of unimers into small micelles and fusion between small micelles result in the birth of quasiequilibrium micelles (with aggregation number per micelle still lower than that of equilibrium micelles) by consuming large amounts of excess unimers; the unimer concentration is close to the critical micellization concentration (cmc) at the end point of the fast process.

We report on novel type of responsive double hydrophilic block copolymer (DHBC)-based multifunctional chemosensors to Hg2þ ions, pH, and temperatures and investigate the effects of thermo-induced micellization on the detection sensitivity. Well-defined DHBCs bearing rhodamine B-based Hg2þ -reactive moieties (RhBHA) in the thermoresponsive block, poly(ethylene oxide)-b-poly(N-isopropylacrylamide-co-RhBHA) (PEO-b-P(NIPAM-co-RhBHA)), were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Nonfluorescent RhBHA moieties are subjected to selective ring-opening reaction upon addition of Hg2þ ions or lowering solution pH, producing highly fluorescent acyclic species. Thus, at room temperature PEO-b-P(NIPAM-co-RhBHA) DHBCs can serve as water-soluble multifunctional and efficient fluorescent chemosensors to Hg2þ ions and pH. Upon heating above the lower critical solution temperature (∼36
C) of thePNIPAM block, they self-assemble into micelles possessing P(NIPAM-co-RhBHA) cores and well-solvated PEO coronas, which were fully characterized by dynamic and static laser light scattering. It was found that the detection sensitivity to Hg2þ ions and pH could be dramatically improved at elevated temperatures due to fluorescence enhancement of RhBHA residues in the acyclic form, which were embedded within hydrophobic cores of thermo-induced micellar aggregates

Poly(N-isopropylacrylamide) (PNIPAM)-based tetrafunctional atom transfer radical polymerization (ATRP) macroinitiator (1b) was synthesized via addition reaction of mono-amino-terminated PNIPAM (1a) with glycidol, followed by esterification with excess 2-bromoisobutyryl bromide. Well-defined double hydrophilic miktoarm AB4 star copolymer, PNIPAM-b-(PDEA)4, was then synthesized by polymerizing 2-(diethylamino)ethyl methacrylate (DEA) via ATRP in 2-propanol at 45 °C using 1b, where PDEA was poly(2-(diethylamino)ethyl methacrylate). For comparison, PNIPAM-b-PDEA linear diblock copolymer with comparable molecular weight and composition to that of PNIPAM-b-(PDEA)4 was prepared via reversible addition-fragmentation chain transfer (RAFT) polymerization. The pH- and thermoresponsive ‘schizophrenic’ micellization behavior of the obtainedPNIPAM65-b-(PDEA63)4 miktoarm star and PNIPAM70-b-PDEA260 linear diblock copolymers were investigated by 1H NMR and laser light scattering (LLS). In acidic solution and elevated temperatures, PNIPAM-core micelles were formed

A triblock copolymer, poly(ethylene glycol)-b-poly(glycerol monomethacrylate)-b-poly(2-(diethylamino) ethyl methacrylate) (PEG-PGMA-PDEA), was synthesized via atom transfer radical polymerization (ATRP) by successive polymerization of glycerol monomethacrylate (GMA) and 2-(diethylamino)ethyl methacrylate (DEA) using a PEG-based ATRP macroinitiator. Reacting the obtained triblock copolymer with varying amounts of cinnamoyl chloride in anhydrous pyridine yielded PEG-(PCGMA-co-PGMA)-PDEA triblock copolymer with photo-cross-linkable moieties, where PCGMA is poly(3-cinnamoyl glycerol monomethacrylate) and the mean degree of cinnamoylation ranges from 5 to 50 mol % relative to the PGMA block. All PEG-(PCGMAco- PGMA)-PDEA triblock copolymers molecularly dissolve in aqueous media at acidic pH; upon addition of NaOH, micellization occurred above pH 7-8 to form three-layer “onionlike” micelles comprising PDEA cores, PCGMA-co-PGMA inner shells, and PEG outer coronas. The pH-induced micellization kinetics of PEG113- (CGMA0.5-co-GMA0.5)50-DEA65 triblock copolymers was investigated by stopped-flow light scattering upon a pH jump from 3 to 10, and compared to that of PEG113-PGMA50-PDEA65. Facile cross-linking of the PCGMAco- PGMA inner shell was then conducted via UV irradiation. The PDEA cores of the resulting shell cross-linked (SCL) micelles exhibited reversible pH-responsive behavior. The extent of pH-induced swelling/shrinking and the colloidal stability of SCL micelles were mainly determined by the extent of cross-linking. The dissociation kinetics of the triblock copolymer micelles before and after shell cross-linking was also investigated employing the stopped-flow technique. It was found that SCL micelles prepared at higher degrees (>20 mol %) of crosslinking exhibited excellent colloidal stability to external pH changes.

This study discusses the second-order improperness in the frequency-domain colored signal model. After the realvalued and colored signal in the time-domain is transformed into the frequency domain, the convolutive blind source separation (BSS) methods may generate a window indexed vector, and minimum variance distortionless response (MVDR) beamforming may produce an array sensor indexed vector, and the trial structured EEG data set may provide a trial-indexed vector. These three complex-valued vectors have such similarities: 1) despite of resulting from the Fourier transformation, they are not indexed by the frequency bins; 2) its real part and image part are proved to be correlated. Hence, such a complex-valued vector is improper, and the pseudo-autocorrelation matrix of this improper vector exists. Moreover, if components of an improper complex-valued vector are uncorrelated, except the autocorrelation matrix, the pseudo-autocorrelation matrix should also be diagonal. This one more statistics could be useful to design better the complex-valued BSS algorithm and MVDR beamforming algorithm.

Efficient conversion of energy between sunlight, chemical bonds, and electricity is crucial towards a closed-loop energy cycle. We have applied synchrotron-based Xray spectroscopy and microscopy techniques to investigate the conversion of electricity to and from chemical bonds in fuel cells, electrolyzers, and intercalation batteries. Using these techniques, we have tracked the motions from electrons, oxygen ions, and lithium ions at interfaces and in the bulk of electrochemically-active materials. New insights in gas-solid surface electrochemistry, and solid-solid phase transformation are guiding the development of better materials for a wide range of energy conversion and storage devices.

In this contribution a SU8/glass-based microfluidic sensor is described with two closely spaced parallel electrodes for highly selective measurements using the redox cycling (RC) effect. Using this sensor, a RC amplification of ~2000x is measured using the ferrocyanide redox couple, which is much higher than the 400x reported so far [1]. Moreover, an analytical expression is derived that predicts the amplification factor based on the sensor geometry.

In this study, we demonstrate a novel approach;atomic layer deposition (ALD);for the synthesis and investigation of Pt-Ru catalyst structures toward the oxidation of stoichiometric (1:1) methanol solutions in advanced direct methanol fuel cells. Two types of thin-film materials are investigated as catalysts for methanol oxidation: Pt-Ru films of varying ruthenium content that are co-deposited by ALD, and Pt skin catalysts made by depositing porous platinum layers of different thickness byALDon sputtered ruthenium films. MeCpPtMe3 and Ru(Cp)2 are used as precursors for Pt and Ru ALD, respectively, together with pure O2 as the counter reactant. The electrochemical behavior of the co-deposited Pt-Ru catalysts and the Pt skin catalysts for methanol oxidation is characterized using chronoamperometry and cyclic voltammetry in a 0.5MH2SO4/16.6MCH3OH electrolyte at room temperature. The results illustrate that the optimal stoichiometric Pt:Ru ratio for the co-deposited catalysts is ∼1:1, which is consistent with our previous study on sputtered Pt-Ru catalysts using the same CH3OH concentration. Moreover, we report that the catalytic activity of sputtered ruthenium catalysts toward methanol oxidation is strongly enhanced by the ALD Pt overlayer, with such skin catalysts displaying superior catalytic activity over pure platinum. The mechanistic aspects of our observations are discussed.

The electrical conductivity of the system based on lignocellulose (LC) biopolymer matrix filled with electrodeposited copper powder has been studied. Galvanostatically produced copper powder, having highly porous, highly dendritic particles with high values of specific area was used as filler. Volume fraction of the electrodeposited copper powder was varied from 2.0-29.8 vol%. Analysis of the most significant properties of prepared composites and its components included measurements of electrical conductivity, impedance spectroscopy (IS) behavior, structural and morphological analysis. The composite preparation conditions allowed the formation of a random distribution of metallic particles in the polymer matrix volume. It was shown that percolation threshold depends on both particle shape and type of spatial distribution. IS measurements have shown that particle morphology having pronounced grain boundaries has great effect on appearance of electric conductive layers, i.e. ―movement‖ of percolation threshold towards lower filler volume fractions. IS response of the composites showed existence of electrical conductive layers, each having different resistivity which increases towards interior of the composite.

Highly crystalline, size-controlled Zn2SnO4 nanoparticles are synthesized by hydrothermal synthesis using two different mineralizers, viz., inorganic Na2CO3 and organic tert-butyl amine. The shape and surface properties of the two types of nanoparticles are totally different owing to the structure-directing abilities and the radicals in the mineralizers, even though both types of nanoparticles show a defect-free and highly crystalline structure. Na2CO3 induces faceted planar morphologies with negative surface charges, whereas tert-butyl amine induces roughly spherical shapes with positive surface charges; these changes have been analyzed by SEM, TEM, and zeta potential measurements. Electrochemical tests performed on these two types of nanoparticles indicate a capacity that gradually fades up to the 20th cycle due to the inevitable structural irreversibility. However, the specific discharge/charge capacities of both Zn2SnO4 anodes become almost constant after 20 cycles, and at 40th cycle, the specific discharge capacities of both nanoparticles are 521.4 mAh/g for nanoparticles synthesized using tert-butyl amine and 448.0 mAh/g for nanoparticles synthesized using Na2CO3 with Coulombic efficiencies higher than 96%. Such an excellent cycling stability and reversibility against lithium insertion/extraction can be attributed to the improved pulverization/agglomeration resistances of these materials, resulting from the surface residual charges, i.e., the repulsive forces between like-charged nanoparticles.

手性分子绝对构型的确定是一个极其重要且长期存在的问题. 振动圆二色谱是在红外波长区域测定分子圆二色 性的一种新方法, 极大地扩展了圆二色谱的应用范围. 振动圆二色谱法通过构象搜索、量子化学计算等手段准确预测 手性分子的振动圆二色谱图, 进而与实测谱图进行比较确定其绝对构型. 该方法已经得到了越来越广泛的应用, 必将 成为一种有效测定手性分子绝对构型的常规方法.

The barrier properties of coatings are vitally important in the protection of metals against corrosion. Water and ion ingression (e.g. Cl-), which penetrate to the metal/coating interface, generate electrochemically active sites and corrosion follows. Presently various experimental techniques, such as salt spray tests, are used to study corrosion protection properties of coatings and to predict their performance. However, most corrosion tests only provide a qualitative estimation of the protective properties of coatings without any information on the mechanism of protection or failure. Electrochemical Impedance Spectroscopy is widely used, not only to examine and rank the corrosion protection performance of coatings, but also to obtain important information on the kinetics of coating degradation and corrosion activity during exposure to a corrosive media. Localised scanning methods like the Scanning Vibrating Electrode Technique can be used to acquire localised electrochemical details that cannot be obtained by conventional techniques, which can shed yet more light on coating performance. Although the above techniques have all been used to investigate coatings, correlation between the results has not been conducted comprehensively.

以纯锐钛矿型和纯金红石型TiO 为原料，通过超声分散制备复合晶态的TiO ， 研究纳米TiO 的晶相组成对光催化性能的影响．通过x射线衍射分析表征晶相组成与晶粒尺寸；以甲苯为目标降解物，采用气相色谱检测复合晶态的TiO，对甲苯的降解效果．结果表明：锐钛矿型TiO 的光催化性能明显地优于金红石型TiO，，但由于协同作用，一定比例的金红石能提高纳米多晶TiO，的光催化性能；当晶相中锐钛矿型与金红石型TiO，的质量比为83：17时，纳米多晶TiO，具有最佳光催化活性．

为了研究挥发性有机化合物的降解特性，将气态苯引入线－ 筒式介质阻挡放电反应器，利用双极性脉冲高压进行降解. 考察了放电间隙、放电长度和Mn /γ -Al2O3催化剂对苯降解的影响. 结果表明: 在相同电压下，小放电间隙注入的能量较大，有利于苯的降解，放电间隙对苯的降解效果影响由大到小依次为3. 5 mm、6 mm、8. 5 mm; 苯的降解率随着放电长度的增加而增大; 加入Mn /γ -Al2O3，进一步提高了苯的降解率，Mn 质量分数增大到15% 时，苯的降解率和碳氧化物选择性都有所提高，分别为91. 8%和94. 6%.

在常压固定床、石英反应器中，以丙烯直接气相氧化反应为探针，考察了硅烷化处理及ＴＳ１中模板剂对Ａｇ／ＴＳ１催化性能的影响．同时，采用ＵＶＶｉｓ、ＩＣＰ和ＴＥＭ 等手段对其进行了表征．结果表明：在丙烯直接 气相氧化过程中，载体ＴＳ１硅烷化后所制备的Ａｇ／ＴＳ１的催化性能增强．通过硅烷化处理负载２％ＳｉＯ２，制备的Ａｇ／ＴＳ１的丙烯转化率可达２．１％，环氧丙烷选择性９８．４％．用ＴＳ１原粉（含有模板剂）所制备的Ａｇ／ＴＳ１不具有环氧化性能．分子筛内外表面的银物种均具有环氧化性能，但内表面的银物种在丙烯气相氧化过程中起决定性的作用．

非临氢条件下用固定床反应器研究了环己烷、辛烯一1及正辛烷在超细HZSM一5上的芳构化反应，并与微米HZSM一5作了比较．结果表明，在三种反应物中，辛烯一1反应活性最高，正辛烷次之。环己烷最低．不同反应物在两种晶粒度的HZSM一5上生成的芳烃分布大致相同．超细HZSM一5对原料的转化率、芳构化率以及自身的活性稳定性均明显高于微米沸石．在相同反应条件下超细沸石的积炭量低于微米沸石．

纳米HZSM一5(20～50 rim)沸石晶粒经碱性介质水热处理、负载稀土和锌氧化物组合改性后，制备成降低FCC汽油烯烃的催化剂，并用TEM，XRF，NH3一TPD及IR等手段对其进行了表征．在温度为370℃ ，压力3 MPa，质量空速(WHSV)3 hI1 和氢油比(V(H2)／V(oil))为600的反应条件下，在固定床反应器上对催化剂的降烯烃性能进行了评价．结果表明。组合改性后的纳米HZSM一5催化剂表现出很强的降烯烃能力．全馏分FCC汽油中烯烃含量(妒，下同)从49．6％降至15．4％，芳烃(主要是 ～C9)含量从11．4％增加到33．5％ ，异构烷烃(主要是c4～C6)含量从17．4％增加到31．1％ ，异构烷烃与正构烷烃比从3．3增加到8．1，在烯烃大量降低的同时，汽油的辛烷值(RON)有所增加．同时汽油中苯的含量从2．84％降低到0．66％，而硫的含量从0．02％(w)降低到0．01％．催化剂具有降烯、除苯和脱硫的综合性能。且连续反应320 h仍保持性能稳定．

将四氯乙烯，间二甲苯气态混合物同时引入无声放电反应器，加工频正弦交流高压对混合污染物进行放电分解实验．结果发现：与单一组分污染物的降解特性相比，混合气体中四氯乙烯的降解率变化较大，最大降解率由单独处理时的76％下降到27％ ，而间二甲苯的降解率基本保持不变，最大降解率可达 90％左右；相同条件下，不锈钢棒高压电极对污染物的降解效果要略好于螺纹钢棒电极；3种电极间距对混合气体的降解效果依次为5 mm>7．5 n'lm>10 mm．

Abstract：Ratio of Lewis／Br~nsted acid sites(CYCb)on the surface of nano—sized HZSM一5 was successfully manipulated by means of steami ng and acid leaching． Significant enhancement of the deactivation durability of nano—sized HZSM一5 in the aromatization of fluid catalytic cracking(FCC) gasoline olefins seems to be closely related to the increase of Lewis／Br0nsted acid sites ratio．

采用浸渍法制备了Pd 促进ZnO/Al2O3 催化剂, 考察了该催化剂作用时, 在水醇摩尔比为3, 常压和450 °C工作条件下乙醇水蒸气重整(SRE)制氢反应性能. 研究结果表明, 在该催化剂体系作用下的SRE反应过程中, H2、CH3CHO为主要产物, 与ZnO/Al2O3催化剂不同, Pd能促使CH3CHO发生C－C键断裂反应, 显著 提高C2H5OH转化率及H2选择性, 分别达65%、55%. 还利用BET比表面积、透射电子显微镜(TEM)、热重-差示扫描量热-质谱(TG-DSC-MS)等表征手段考察了催化剂失活以及表面积炭情况, 发现Pd的加入对催化剂总积炭量并无明显影响.

Carbon nanotubes known as a novel discovered form of carbon. They are also expected to be excellent adsorbents for adsorption of trace pollutants from water or air.The objective of this paper is to study adsorption characteristics of isopropyl alcohol (IPA) vapor in the range of 40-800 ppmv from air stream with single-walled carbon nanotubes (SWCNTs).The test results indicated that the nature of the SWCNTs surface was greatly improved after purification by concentrated hypochlorous acid, which made SWCNTs become more hydrophilic and suitable for adsorption of IPA vapor from air stream. A significantly higher adsorption capacity of IPA vapor was found with purified SWCNTs than with raw SWCNTs. The BET isotherm is the best model to describe adsorption behavior of IPA vapor onto purified SWCNTs, followed by the Freundlich isotherm, and then the Langmuir isotherm.

将双极性脉冲高压引入介质阻挡反应器（螺旋棒式不锈钢电极，石英玻璃介质），分别对氯苯和甲苯的分解特性进行了实验研究。结果发现，这种放电形式可以高效注入能量，兼有脉冲电晕放电好介质阻挡放电的特点。脉冲高压使电场强度急剧增强，瞬间产生大功率放电和高能粒子，可以实现对VOCs化学键的高效裂解与工频交流高压，单极性脉冲高压的试验结果表明，双极性脉冲高压取得了最高的降解效果，氯苯比甲苯难以分解。

A new carbene ruthenium complex 1,3-bis(2,6-dimethylphenyl)4,5- dihydroimidazol -2- ylidene)(PPh3)(Cl)2Ru=CHPh was synthesized and used as catalyst for the metathesis of 1-hexene. The resulting complex exhibited very high catalytic activity of up to turn of frequency of 6680 h-1, but along with significant olefin isomerization, which could be surpressed by changing reaction conditions, such as temperature, time, alkene/Ru molar ratio and solvent.