十七种香烟中九种金属元素的含量分析

用原子吸收法测定了十七种香烟中锌、铜、铁、锰、铬、镍、钾、钙、镉的含量。结果表明,不同种类香烟中所含九种金属元素有一定的差异,低档香烟所含金属元素的量比高、中档香烟高,烤烟型香烟比外香型香烟低。本结果为烟草的栽培,炮制以及探讨香烟中金属元素对人体危害的研究提供了有用数据。     

Application of exploratory data analysis for the characterization of tubular wells of the North of Brazil

Roraima is located in the extreme North of Brazil, in the Western Amazon Region. The groundwater has an important role in the public supply of potable water on the Roraima State. The objective of this work is the application of PCA (Principal Component Analysis) and HCA (Hierarchical Cluster Analysis) for the characterisation of tubular wells of the Roraima State, as regards physical–chemical composition of water. The parameters analyzed in laboratory were the following ones: pH, electric conductivity, Total Hardness, Total Alkalinity, Bicarbonate, Calcium, Potassium, Magnesium, Nitrate, Chloride, Total Iron. The physical–chemical analyses, were carried out during the months of September and October 2000 (winter, period of rains). The laboratory analysis was performed using classical methods (titrimetry and uv–visible spectroscopy), the samples were processed in agreement with the Standard Methods for Examination of Water and Wastewater.The physical–chemical analyses, were accomplished in September and October 2000. In physical–chemical terms, the groundwater samples analyzed do not indicate any restriction to human consumption and the two chemometric methods of exploratory data analysis: PCA and HCA are efficient for the discrimination of bicarbonated (tubular wells locateds in the South of the Roraima State) and not bicarbonated (tubular wells locateds in the North of Roraima) groundwater.     

Thermochemistry of dissolution of sodium alkylsulfonates

The effect of temperature on the solubility of ionic surfactants was interpreted in terms of standard enthalpy and entropy of dissolution at reference temperature by considering the change in the heat capacity. The significant value of the latter quantity causes the curvature of the function logarithm of equilibrium constant (or solubility) vs. the reciprocal thermodynamic temperature. The solubility data for several sodium n-alkylsulfonates, published by Saito, Moroi, and Matuura, were interpreted by nonlinear regression analysis. It was found that both the enthalpy and entropy of dissolution decrease with the chain length. The heat capacity increases in the course of the dissolution process.     

青海湖区河谷灌丛主要植物微量元素含量特征

采集青海湖地区沙柳河河谷灌丛14种主要植物，采用AAS分析了其中7种微量元素含量。结果表明，元素Cu、Mn、Co含量有较大的植物种问差异，7种微量元素中Se含量最小，Fe含量最大。元素Mn和Fe、Co、Ni之间都具有极显著的正相关性，即相互之间具有协同性作用。     

竹材非等温热解动力学

利用热重分析技术对竹材在高纯N2条件下,从室温至1273K进行了非等温热解分析,研究了升温速率(5、10、20和40K/min)对热解过程的影响,探讨了其热解机理。研究表明,竹材非等温热解过程主要分为失水干燥、快速热解和缓慢分解三个阶段组成,其中第二阶段是整个过程的主要阶段,析出大量挥发分造成明显失重。升温速率对热解过程有显著影响,随着升温速率的增加,最大热解速度增大,对应的峰值温度升高,热滞后现象加重,热解各阶段向高温侧移动。热解机理满足一维扩散Parabolic法则,反应机理函数为g(α)=α2。不同升温速率下活化能为75.32-82.99kJ.mol-1,指前因子为1.17×105-1.12×106min-1。     

The use of thermal analysis in determination of some urinary calculi of calcium oxalate

The human urinary calculi are mainly constituted by calcium oxalate, magnesium ammonium phosphate hexahydrate, and uric acid. The ions or molecules are easily characterized by wet chemical methods. The difficulties appear in the differentiation of the hydrates of calcium oxalate (monohydrate COM or Whewellite, and dihydrate COD or Weddelite). A high level of COD in the urinary stones leads, often, inflammation, sharp pain and blood in urine. In the worse cases, they must be extracted by surgical way. The identification of the main components of urinary calculi, the knowledge of the true number of water molecules bounded to the calcium oxalate, and the determination of each hydrate in the mixture, are the interests of this memory. The thermal analysis (simultaneous DTA-TG) was applied on thirty-three urinary calculi. The determination of the calcium oxalate hydrates was confirmed by calorimetry (DSC). This revised version was published online in July 2006 with corrections to the Cover Date.     

Application of Calcite Veins to Study of Newly-activated Faulting

The study of period and chronology of fault activity in major worksites in an area with exposed basement rocks is quite difficult. The authors have applied the combinative techniques of field investigation, microscopic observation and isotopic dating to studying the calcite veins filled in the fault zones in several major engineering regions and got successful results. The following conclusions are reached: (i) The last period of strong activity of fault F8 in the Tianshengqiao Hydropower Station, Nanpan River is 200 ka B. P. , and there has been, no obvious activity since 150 ka. (ii) The last period of strong activity for 5 faults in Shixiali Reservoir, Yangyuan County, Hebei Province is 200-300 ka B. P. , and there has been no obvious activity since 200 ka. The research results provide a sound basis of engineering geology for project designers.     

热预处理影响褐煤热解行为研究

采用固定床反应器研究了不同气氛热预处理对内蒙胜利褐煤结构的改变,及其对后续热解行为的影响。结果表明,与原煤相比,热预处理后煤中羟基含量和芳香氢与脂肪氢的比减少,脂肪氢的相对含量增加。与未经处理的煤热解相比,N2、N2+O2、CO2气氛下热预处理后热解水收率下降,热解气收率增加,热解气中CO2含量增高,导致高位热值下降。过热水蒸气热预处理后,焦油质量收率提高3～4个百分点。热解焦油组成的变化与预处理气氛、温度密切相关,过热水蒸气200℃下预处理使得焦油中轻质组分的含量(沸点低于360℃的馏分)比原煤焦油提高了约27个百分点;水蒸气和模拟烟气混合气氛下在200℃及250℃预处理后,其热解焦油中轻油和酚油含量分别提高约60和42个百分点。     

汽车漆皮的气相色谱指纹图谱比对方法及应用研究

采用在线热解吸/毛细管气相色谱联用方法建立了对汽车漆皮指纹图谱进行比对的方法,并将该方法应用于实际样品的鉴定。该方法通过将一定大小和质量的漆皮样品置于热解吸炉中进行加热解吸,自漆皮中解吸出来的挥发性有机物在色谱仪上得到分离检测。通过直观比较两张漆皮图谱的峰形轮廓是否一致进行初步判断,对外形相似的图谱进一步计算二者谱峰的重叠率,并以相对保留时间比值rt2/rt1和相对峰面积比值rA2/rA1来考察待比较图谱的相似度。当谱峰重叠率大于90%,rt2/rt1和rA2/rA1的相似度分别大于99%和70%时,可认定待比较的两个漆皮样品来自同一辆车。该方法操作简便,谱峰识别能力强,实现了对指纹图谱的定量表征描述,使漆皮的仪器分析数据成为法律上可采信的有力物证之一。     

高效液相色谱法测定山药样品中尿囊素的含量

用薄层扫描方法确定了山药中尿囊素的提取条件;用高效液相色谱方法测定了山药中尿囊素的含量,考察了不同产地山药样品中尿囊素含量的差异.该法平均回收率为96.8%,相对标准偏差为4.0%.生长环境、气候等外界条件对山药中尿囊素含量有明显的影响,不同产地山药中尿囊素含量有明显差异.此高效液相色谱法用于山药中尿囊素的含量测定,灵敏度高,重现性好,可供山药质量标准研究参考使用.     

Kinetics of thermal decomposition of hexanitrohexaazaisowurtzitane

Thermal decomposition of hexanitrohexaazaisowurtzitane (HNIW) in the solid state and in solution was studied by thermogravimetry, manometry, optical microscopy, and IR spectroscopy. The kinetics of the reaction in the solid state is described by the first-order equation of autocatalysis. The rate constants and activation parameters of HNIW thermal decomposition in the solid state and solution were determined. The content of N₂ amounts to approximately half of the gaseous products of HNIW thermolysis. The thermolysis of HNIW and its burning are accompanied by the formation of a condensed residue. During these processes, five of six nitro groups of the HNIW molecule are removed, and one NO₂ group remains in the residue, which contains amino groups and no C−H bonds. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 815–821, May, 2000.     

卵磷脂反胶束体系中β-1，4葡萄糖苷酶的研究

测定了水、醋酸缓冲液和水杨苷醋酸 /醋酸钠缓冲液在水 /PC/庚烷 正丁醇反胶束体系中的饱和增溶量 ,利用UV、FT IR和NMR等技术考察了增溶到水 /PC/庚烷 正丁醇反胶束体系中的 β 1 ,4葡萄糖苷酶及水杨苷的结构变化 ,并研究了 β 1 ,4葡萄糖苷酶在水 /PC/庚烷 正丁醇反胶束中的活性 .发现了 β 1 ,4葡萄糖苷酶在水 /PC/庚烷 正丁醇反胶束中遵循米氏反应 ,最大反应速度vmax为 1 .475mg·min-1,是其在水中的 1 1 .8倍 ,米氏常数Km 为 0 .389mg·mL-1,是其在水中的 1 / 2 5 .β 1 ,4葡萄糖苷酶在水 /PC/庚烷 正丁醇反胶束中表现出的低底物浓度下的高催化速度 ,是微乳的界面发生的相互作用改变了 β 1 ,4葡萄糖苷酶的构象 ,增加了底物水杨苷的浓度 ,PC极性头部 -N (CH3 ) 3 正离子作用水杨苷糖苷键的氧有利于糖苷键的断裂等因素造成的 .     

Influence of extraction methods on stability of flavonoids

The LC-MS/MS was applied for the determination of flavonoids' stability under four types of solvent extraction methods (reflux heating, sonication, maceration and microwave) from maize samples. The 11 flavonoids belong to different groups: flavonols (kaempferol, myricetin, rhamnetin, quercetin, rutin), flavanones (naringenin, naringin, hesperedin), flavones (apigenin, luteolin), isoflavones (genistein) were studied. The effect of the degradation of flavonoids depended on extraction mode and chemical structure. The smallest decomposition was observed by heated reflux extraction procedure within 30 min in water bath and by microwave assisted extraction under 160 W during 1 min. The decomposition for flavonoids depends on number of substituents in flavonoid molecule. The most unstable compound (recovery below 50%) in tested condition was myricetin. The higher number of hydroxyl groups promote degradation of flavonoids, whereas sugar moiety and methoxyl groups protect flavonoids of degradation during microwave and ultrasonic assisted extraction.     

卷烟化学指标的因子分析

运用因子分析法对A牌号卷烟的18个化学指标进行分析,结果表明:烟丝的总糖、还原糖、总氮、总植物碱、水分、氯离子、钾离子、葡萄糖、麦芽糖、苹果酸、异戊酸、苯甲醇、茄酮、β-大马酮14个指标,及主流烟气的水分、CO、烟碱、焦油4个指标所含的信息可由8个因子来表示。该8个因子模型解释了试验数据总方差的86.7%;烟丝的致香成分、水分、糖类物质、有机酸类物质对卷烟A的质量风格具有重要影响,特别是致香成分在进行卷烟质量表征时应该重点关注。因子分析结果为卷烟的化学表征和质量控制提供了有用的参考。     

内蒙胜利褐煤腐殖酸对煤平衡复吸水的影响

研究了褐煤中重要的成分腐殖酸对褐煤水分的影响。测定了内蒙胜利褐煤中腐殖酸含氧官能团的含量,并分析了褐煤、棕黑腐殖酸和残余煤的等温吸附和脱附曲线。通过Dent吸附等温模型研究了褐煤和棕黑腐殖酸第一层吸附和第二层吸附。结果表明,胜利褐煤2/5羧基和1/5羟基是由腐殖酸提供的。棕黑腐殖酸相对褐煤孔径和孔容较小,不利于水簇的形成。腐殖酸对褐煤的复吸水是不利的     

Effects of casting temperature of Pb-Sb-Sn grid alloy on the polarization potential of oxygen evolution of lead acid batteries

The electrochemical polarization potential of oxygen evolution at the surface of lead-antimony-tin alloy is varied in different casting temperature of electrode production, which is used in the most of battery manufacturer. Effect of the casting temperature on the polarization potential of oxygen evolution and electrochemical behavior of lead-antimony-tin alloy in low antimony grid (1.7%) of lead acid battery is studied by using cyclic voltammetry and linear sweep voltammetry in aqueous sulfuric acid solution. The grid morphology is studied by using scanning electron microscopy and optical microscopy at the different casting temperatures. Cyclic voltammograms of the Pb-Sb-Sn and lead-antimony electrodes are similar, and both alloys show the anodic excursion peak under the same experimental conditions. The oxidation of tin is done at the formation potential of PbO. The results show the polarization potential for oxygen gas evolution to vary with casting temperature for production of lead-antimony electrodes. Published in Russian in Elektrokhimiya, 2006, Vol. 42, No. 4, pp. 401–405. The text was submitted by the author in English.     

压力对塔里木原油四组分热解性能的影响

压力对深层油藏原油热化学过程的影响尚存在较大争议,为研究其在油藏原油热解成气过程中的作用机理,我们在450℃、5~40 MPa压力下对塔里木原油四组分(饱和分、芳香分、胶质和沥青质)进行了封闭体系的热解实验,通过气相色谱(GC)和气相色谱/质谱(GC/MS)分别对原油四组分热解反应的气体产物及饱和分热解过程的液态产物进行了分析。结果表明,在450℃、24 h及不同压力下,沥青质热解产气率高于胶质、芳香分和饱和分;四组分的气相热解产物中,C1的产率明显高于C2~C5组分。增大压力抑制沥青质、胶质及芳香分的热解产气过程而促进饱和分的热解产气过程。随压力的增大,饱和分热解的液态产物的主峰组分碳数先减小,再增大。压力低于20 MPa时,饱和分热解过程中以裂解反应为主;高于30 MPa时,增大压力有利于缩合反应。研究结果可为认识深层油藏原油的稳定程度及天然气的成因提供一定的理论参考。     

刺五加不同部位微量元素含量的分析测定

用硝酸、高氯酸混合酸消解样品,采用原子吸收光谱法,测定了刺五加根、茎、叶中Ca、Cu、Mg、Fe、Zn、K、Mn、Na等8种矿物质元素的含量,并对其结果进行了分析比较,以此研究了这几种金属元素在刺五加体内的分布。结果显示,各元素在实验范周内,线性关系良好,加标回收率在99％～109．6％之间,相对标准偏差为0．2％～1．8％;刺五加中不同部位的这8种元素间存在显著差异,根中各元素含量由高到低顺序为Ca,Mg,K,Fe,Na,Mn,Zn,Cu,其叶中的含量以K为高,而且各部位其它元素含量均较高。从微量元素的角度分析,刺五加的根、茎、叶均有一定的应用价值。     

溶剂化效应对6-亚甲基环戊二烯酮与HCN的反应机理影响的理论研究

在B3LYP/6-311+G**计算水平上, 采用导体极化连续模型研究了溶剂化效应对6-亚甲基环戊二烯酮与HCN反应生成主要产物b类酸的反应机理的影响. 计算结果表明, 在溶剂中的反应机理与在气相中的反应机理一致. 溶剂化效应使反应路径中各驻点的自由能降低, 稳定化了各物质. 溶液中的活化自由能与气相相比也有所降低, 反应更容易发生, 其中CC进攻方式的活化自由能降低得更多.     

铜藻膳食纤维可食用膜的制备及风味分析

以铜藻膳食纤维为原料制备可食用膜,促进对利用程度不高的铜藻膳食纤维的精深加工。研究了料液比、甘油含量、增稠剂含量对铜藻膳食纤维可食用膜透明度的影响,通过单因素试验确定最佳制备条件为:料液比1:30、甘油含量为2%,增稠剂羟甲基纤维素钠添加量为1%,在此条件下可食用膜的透明度最高为15.87%。对铜藻膳食可食用膜的风味成分进行分析,通过顶空固相微萃取法与气相色谱-质谱联用分析发现可食用膜风味物质丰富,含有69种化合物,这些物质是可食用膜中的主要香气成份,其中的醛类和醇类化合物对可食用膜整体的风味形成起重要作用。