Erfassung des Proteinstoffwechsels mit dem Isotop 15N bei Herz-Kreislauf-Erkrankungen

From the set of experiments, where transfer factors for transuranic elements in soil-plant system and basic soil parameters were determined, Romney's and Eriksson's experiments were undergone a multiple correlation and regression analysis. Effect of soil properties on soil-to-wheat grain and soil-to-wheat straw in Romney's experiments was studied. Different uptake of transuraniums by wheat grain and wheat straw was found. Conclusions for uptake of ^239,240Pu by wheat in Romney's experiment were different from results obtained in Eriksson's experiment for ²³⁸Pu.     

New type of drift tubes for gas-discharge detectors operating in vacuum: Production technology and quality control

A device for fabricating thin-wall (straw) drift tubes using polyethylene terephthalate film 36 μm thick by ultrasonic welding is described together with the technique for controlling their quality. The joint width amounts to 0.4–1.0 mm. The joint breaking strength is 31.9 kg/mm². The argon leakage from a tube of volume 188.6 cm³ under a pressure gradient of 1.0 atm does not exceed 0.3 × 10^–3 cm³/min, which is mainly related to the absence of metallization in the joint vicinity. The high strength, the low tensile creep due to the absence of glued layers, the small value of gas leakage makes the new tubes capable of reliable and long-term operation in vacuum, which is confirmed by the operation of 7168 straw tubes for two years in the NA62 experiment.     

Multichannel prototype detector based on segmented straws

The design and technology of assembling a prototype detector based on segmented straws with a granularity of 4 cm² are considered. The prototype with a sensitive area of 400 × 200 mm contains two straw planes with a diameter of 4 mm shifted with respect to each other by the straw radius. The total number of registration channels is 360. The results of a test bench study of the prototype are presented.     

Growth rates in modern speleothems from Santana Cave,Brazil, by the 210Pb-method

The Santana Cave is located at the Upper Ribeira Touristic State Park (PETAR-Parque Estadual Turístico do Alto Ribeira) in southern São Paulo State, Brazil. This paper describes ²¹⁰Pb activity concentration data in soda straw stalactites samples collected at Salão das Flores in Santana Cave that is a fossil tributary of the cave river. Non-expensive alpha counting following some analytical steps for extracting and depositing ²¹⁰Po were used for providing the ²¹⁰Pb data. In the analyzed samples, ²¹⁰Pb values of increasingly older samples fitted an exponential curve, thus suggesting that the production of ²¹⁰Pb has been constant with time. Also, the near-ideal fit indicated that the growth was uniform and there was no break in the continuous growth. The soda straw growth rates were determined from the best fit to the exponential curve through the ²¹⁰Pb activity concentration. The results of the measurements allowed estimate a longitudinal rate corresponding to 1.3 mm/yr and a lateral rate of 0.01 mm/yr, which permitted calculate times of 70 years and 317–498 years for their formation, respectively. The lateral growth rate is compatible with values from studies of chemical weathering rates held under laboratory and natural conditions.     

Enzymatic Hydrolysis of Wheat Straw Irradiated by Electron Beam in Presence of Peracetic Acid Solution

Abstract

Radiation pretreatments of wheat straw in the presence of peracetic acid solutions were carried out using an electron beam accelerator, in which the effects of various treatment conditions on the enzymatic hydrolysis were investigated in detail. As irradiation dose was increased, the effect of a combination of peracetic acid and irradiation on the enzymatic hydrolysis was remarkable. The combination of irradiation and pulverization was effective for reducing the size of wheat straw. The enzymatic hydrolysis of wheat straw irradiated with high irradiation doses (500 kGy above) was accelerated by a water-washing treatment after irradiation.     

Effects of N-application on utilization of 15N and 13C and quality in two wheat cultivars

We studied N uptake and distribution in wheat, and the incorporation of nitrogen and carbon into gluten and non-gluten proteins using a double-labelling approach with ¹⁵N and ¹³C. Doses of N-fertilizer were split and applied at emergence, onset of stem elongation, and heading at rates of 280/140/140 mg N pot^?1, respectively simulating 90/45/45 kg N ha^?1. Five different combinations of N-fertilizations containing no or 10 % ¹⁵N were performed. The recovery of ¹⁵N added at the stages emergence, stem elongation or heading were 42, 60, and 64 %. Application of ¹⁵N at all three stages yielded in 51 % recovery. Remobilisation of straw N was greater for Golia. The ¹⁵N concentration in gluten proteins of Golia show higher values than Gönen. The ratio of ¹⁵N gluten/¹⁵N non-gluten proteins of Golia were higher, which implies a lower non-gluten protein activity during grain filling. The ¹³C concentration in gluten and non-gluten proteins did not differ between both cultivars.     

太赫兹时域光谱技术的重金属离子吸附检测方法研究

随着工业化进程的不断推进,水体重金属污染问题日益严重。秸秆具有来源广泛、价格低廉、易再生等优点,故成为水体重金属污染处理的理想吸附剂。为研究太赫兹波技术在水体重金属污染检测的应用前景,实验选取原始秸秆和碱化秸秆分别对重金属离子进行吸附,利用太赫兹时域光谱技术(THz-TDS)在室温氮气环境下对原始秸秆样品、碱化秸秆样品、原始秸秆吸附重金属离子样品、碱化秸秆吸附重金属离子样品和碱化秸秆吸附重金属离子解吸后的样品进行光谱测量,秸秆经碱化处理后处于1.75～1.85 THz的杂合吸收峰带吸收系数有明显下降,并伴有肩峰式吸收带后移的现象,在吸附重金属离子后,原始秸秆样品中原有的1.75～1.85 THz杂合吸收带消失,却在1.8～2.05 THz形成了杂合吸收带。碱化秸秆在1.7～2.05 THz呈现复杂的多个肩峰式吸收,而碱化秸秆吸附重金属样品在1.7～2.05 THz呈现平滑的强吸收带,碱化秸秆吸附重金属离子水解吸后吸收谱线近乎平行。结合秸秆及碱化吸附重金属的化学反应过程对吸收谱进行分析,可得到不同组分样品的分子振动及官能团信息,并得到碱化秸秆吸附重金属应为络合吸附和静电吸附两种吸附方式。证明了太赫兹时域光谱技术在水体重金属污染检测中的可靠性和良好的应用前景。     

Equilibrium and kinetics of biosorption of oxalic acid by wheat straw

Biosorption equilibrium and kinetics of oxalic acid on wheat straw, Triticum aestivum, in an aqueous solution was investigated. Among the models tested, namely the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms, the biosorption equilibrium was best described by Freundlich model. It was also found the biosorption of oxalic acid by wheat straw followed second-order kinetics. The equilibrium amount of oxalic acid adsorbed onto the wheat straw increased with increasing the initial oxalic acid concentration and decreasing adsorbent weight. On the other hand, an increase of temperature decreased the biosorption of oxalic acid. Mean free energy of biosorption (10 kJ/mole) indicates that biosorotion of oxalic acid by wheat straw might follow a chemisorptions mechanism.     

Intensification of biogas production using pretreatment based on hydrodynamic cavitation

The present work investigates the application of hydrodynamic cavitation (HC) for the pretreatment of wheat straw with an objective of enhancing the biogas production. The hydrodynamic cavitation reactor is based on a stator and rotor assembly. The effect of three different speeds of rotor (2300, 2500, 2700 rpm), wheat straw to water ratios (0.5%, 1% and 1.5% wt/wt) and also treatment times as 2, 4 and 6 min have been investigated in the work using the design of experiments (DOE) approach. It was observed that the methane yield of 31.8 ml was obtained with untreated wheat straw whereas 77.9 ml was obtained with HC pre-treated wheat straw confirming the favourable changes during the pre-treatment. The combined pre-treatment using KOH and HC gave maximum yield of biogas as 172.3 ml. Overall, it has been established that significant enhancement in the biogas production can be obtained due to the pretreatment using HC which can also be further intensified by combination with chemical treatment.     

油菜秸秆对水溶液中Pb(Ⅱ)吸附条件优化与机理的研究

探究油菜秸秆髓芯、外壳、籽荚对水溶液中Pb(Ⅱ)的吸附能力及其吸附机理。以水溶液中Pb(Ⅱ)最大去除率为评价指标,采用响应面法Box-Behnken Design实验来分析溶液pH、Pb(Ⅱ)初始浓度、粒径大小、油菜秸秆各部位投加量和时间因素对油菜秸秆吸附Pb(Ⅱ)的影响程度并建立多元回归模型,优化出最佳吸附条件参数组合;应用吸附动力学、等温吸附线模型来拟合油菜秸秆各部位对Pb(Ⅱ)吸附过程,评价其吸附行为;用红外光谱对吸附水溶液中Pb(Ⅱ)前后的油菜秸秆髓芯、外壳、籽荚进行表征,探讨其基团变化情况。结果表明： 水溶液pH与油菜秸秆髓芯、外壳、籽荚的投加量两个因素是影响油菜秸秆对水溶液中Pb(Ⅱ)去除的关键因素。模型回归决定系数分别是R2_髓芯=0.9664,R2_外壳=0.970 1,R2_籽荚=0.964 9,方程拟合较好,模型可用。油菜秸秆髓芯、外壳、籽荚对Pb(Ⅱ)的吸附行为符合二阶动力学方程与Langmuir等温线模型,对水溶液中Pb(Ⅱ)最大吸附量分别为135.14,78.74和90.09 mg·g-1。通过比较油菜秸秆髓芯、外壳、籽荚吸附水溶液中Pb(Ⅱ)前后红外光谱图发现,油菜秸秆各部位基团(羟基、羧基、酰胺等基团)发生了峰波数位移、强度降低的变化,提示这些基团在吸附水溶液Pb(Ⅱ)过程中发挥重要作用。     

Reduction effect of co-firing of torrefied straw and bituminous coal on PM1 emission under both air and oxyfuel atmosphere

Straw sample was torrefied at 260 °C and 300 °C in N₂, respectively, to prepare torrefied straw named as T-260 and T-300, and the reduction effect of co-firing straw or torrefied straw and steam coal on PM₁ is investigated. The combustion experiments were conducted in a high temperature drop tube furnace (DTF) at 1400 °C to collect the inorganic PM₁₀ for further analysis. Combustion atmosphere was air for all cases and 50% O₂/50% CO₂ (OXY50) for coal, T-260 and their blends of 1:1 and 4:1. The results show that all three biomass fuels show obvious emission reduction of PM with aerodynamic diameters of ≤?0.3?µm (PM_0.3) under both mix ratios. Reduction ratios of co-firing are overall higher at mix ratio of 1:1 than 4:1, and co-firing of T-260 or T-300 with coal shows higher reduction ratio than co-firing of straw. The higher ash content in torrefied straw leads to higher contents of alkali and alkaline earth metals (AAEM), which will further react with both Si and S during co-firing and coagulate into particles of larger sizes, leading to higher reduction ratios of PM_0.3 and unconspicuous reduction effects in PM_0.3–1 emitted from co-firing. During co-firing in oxyfuel atmosphere, a higher combustion temperature compared to air leads to an intensitive gasification, may resulting in effective and even higher reduction ratio in PM_0.3.     

Enlarging Surface/Bulk Ratios of NiO Nanoparticles toward High Utilization and Rate Capability for Supercapacitors

Reasonable design and delicate control of microstructures are critical to achieve high energy density of active materials for pseudocapacitors that seriously depend on usable reaction interface. This work shows the effect of ultrasmall particle size on enhancing utilization and rate performance of active materials. Three types of NiO nanocrystals with different sizes of 3.36, 6.24, and 7.18 nm in average diameter are uniformly distributed on mesoporous carbon nanosheets derived from corn straw piths. The nanosheets with 3.36 nm NiO particles present an extremely high NiO utilization of 93.4% (2404 F g⁻¹ at 0.5 A g⁻¹), which is 2–2.5-fold higher than materials with large sizes (6.24 and 7.18 nm). This enhancement is ascribed to more complete conversion and higher ionic/electronic conductivity from a preferable surface/bulk ratio of NiO. By coupling with commercial activated carbon, the asymmetric supercapacitors present high energy and power densities (28.53 Wh kg⁻¹ at 375 W kg⁻¹), with 78.3% capacitance retention after 10 000 cycles at 10 A g⁻¹.     

Hydrodynamic cavitation as a novel approach for delignification of wheat straw for paper manufacturing

The present work deals with application of hydrodynamic cavitation for intensification of delignification of wheat straw as an essential step in the paper manufacturing process. Wheat straw was first treated with potassium hydroxide (KOH) for 48 h and subsequently alkali treated wheat straw was subjected to hydrodynamic cavitation. Hydrodynamic cavitation reactor used in the work is basically a stator and rotor assembly, where the rotor is provided with indentations and cavitational events are expected to occur on the surface of rotor as well as within the indentations. It has been observed that treatment of alkali treated wheat straw in hydrodynamic cavitation reactor for 10–15 min increases the tensile index of the synthesized paper sheets to about 50–55%, which is sufficient for paper board manufacture. The final mechanical properties of the paper can be effectively managed by controlling the processing parameters as well as the cavitational parameters. It has also been established that hydrodynamic cavitation proves to be an effective method over other standard digestion techniques of delignification in terms of electrical energy requirements as well as the required time for processing. Overall, the work is first of its kind application of hydrodynamic cavitation for enhancing the effectiveness of delignification and presents novel results of significant interest to the paper and pulp industry opening an entirely new area of application of cavitational reactors.     

水稻秸秆接力处理过程中的红外光谱研究

作物秸秆就地焚烧已经和正在引起严重的大气污染,土壤微生物对作物秸秆的较难分解是作物秸秆农业利用的主要限制因子之一。文章采用傅里叶红外光谱(FTIR)分析技术对水稻秸秆接力处理(化学水解—微生物培养)过程进行了研究,分析探讨了接力处理的化学机理。由红外光谱的分析可见,经过接力处理,水稻秸秆半纤维素和纤维素大大降低,C／N比也降低到适合微生物生长的范围,硅元素的含量也降低,水溶性的物质含量升高,其结果与化学分析的结果一致。文章提出的水稻秸秆接力处理方法能为作物秸秆的农业利用提供有效途径。     

秸秆热值近红外光谱模型的外部验证结果间的统计比较分析

从全国24个省(市)收集到222个秸秆样品,包括172个稻秸样品和50个麦秸样品。采用近红外光谱技术,结合主成分回归、偏最小二乘回归和改进的偏最小二乘回归建立了秸秆热值的定量分析校正模型。近红外光谱模型的建立与优化过程中使用了不同的散射校正方法和光谱导数处理来帮助改善模型精度。对得到的54个模型采用统计学的方法分析外部验证的结果,通过比较外部验证的系统偏差(Bias)和Bias校正的预测标准差(SEP(C)),考察了不同光谱预处理和回归方法对秸秆热值的近红外模型预测性能的影响。结果表明:近红外光谱技术能够快速、准确地分析秸秆的热值,模型的SEP(C)在134～178 J·g-1之间;对外部验证结果的统计分析,能够有效地选择较好的建模方法,确定较优模型。     

Insight into KOH and KCl release behavior of burning wood and straw pellets using quantitative in situ optical measurements

Two-dimensional laser-induced photofragmentation fluorescence (LIPF) was employed to quantitatively visualize the potassium hydroxide (KOH) and potassium chloride (KCl) vapor in the plume above burning wood and straw pellets. In the LIPF measurement, two excitation lasers at 266 and 193 nm were adopted to discriminate KOH and KCl. Meanwhile, tunable diode laser absorption spectroscopy (TDLAS), laser-induced breakdown spectroscopy (LIBS) and two-color pyrometry were used to measure the atomic potassium concentration, total elemental potassium concentration and surface temperature of the burning pellets, respectively. The combustion environment had a temperature of 1550 K and an oxygen concentration of 4.6 vol.%. Two peaks were observed from the temporal potassium release profile of the burning wood, corresponding to the devolatilization and char oxidation stage, while only a single release peak was observed from the burning straw attributed to its high ash content. During the char oxidation and ash cooking stages, KOH was observed to be the dominant potassium species released from the wood, while only KCl was observed for the straw which had a high content of chlorine. About 45% of the total potassium in the wood samples and about 10% in the straw samples were measured to be released during the combustion process. The high content of silicon in the straw retained a considerable amount of potassium in the ash. The wood had the potassium release mainly in the char oxidation stage (∼53% of the total release), while the straw had the main release during the ash cooking stage (∼49% of the total release). During the char oxidation and ash cooking stages, about 32% of Cl was released from the straw pellets in KCl, while the other part of Cl was considered to be released during the devolatilization stage in other Cl species form, such as HCl.     

荧光光谱法测定生物炭/秸秆输入土壤后酶活性的变化

土壤α-葡萄糖苷酶、β-葡萄糖苷酶直接参与土壤有机物质的矿化过程,对维持生态系统碳和养分的循环起重要作用。秸秆或者秸秆炭化物还田是提高碳储量的一种有效措施,输入到土壤后对生物学活性产生一定影响,对碳库转化具有直接或者间接作用。采用荧光物质作为底物,将96微孔板和荧光检测法结合,利用多功能酶标仪测定生物炭/秸秆(2.5 g/50 g干土)添加条件下黑土中α(β)葡萄糖苷酶活性。结果表明,秸秆添加到土壤后,土壤α(β)葡萄糖苷酶活性增强,水稻秸秆处理β-葡萄糖苷酶活性高于玉米秸秆处理,40天后仍然保持较强活性,说明秸秆的输入有助于土壤碳素转化。可能是因为秸秆炭添加提高土壤中养分含量,促进微生物活性,使得土壤酶活性提高,水稻秸秆添加增强土壤酶活性,而玉米秸秆没有促进作用,可能与材料来源不同有关,材料来源与添加效应的关系有待进一步研究。而生物炭添加对黑土中α(β)葡萄糖苷酶活性影响不大,这与生物炭含速效养分少、自身难降解特性有关。与传统的分光光度法相比,微孔板荧光法可以灵敏的检测到土壤悬液中的酶活性,可批量检测样品,是一种快速、准确、简便的土壤酶活性测定方法。     

不同培肥土壤颗粒有机碳的13C核磁共振与红外光谱对比分析

为明确颗粒有机碳在土壤固碳中的作用机制,对比研究了不同有机培肥土壤颗粒有机碳的结构差异。以单施化肥处理为对照,选择了四种有机物料进行定位培肥试验,利用13C NMR和红外光谱技术对比分析不同有机培肥对土壤颗粒有机碳结构的影响。结果表明：颗粒有机碳以脂肪碳和含氧基团为主,脂化度高于75%,含氧官能团含量高于50%;不同有机培肥对土壤颗粒有机碳结构的影响差异性显著,树叶培肥在提高颗粒有机碳芳香度的同时,亲水性也大幅度提高,比单施化肥处理(对照)提高了0.78%;短期内,牛粪、秸秆和树叶培肥均可提高土壤颗粒有机碳的芳香度,但从长远角度分析,牛粪和秸秆培肥更利于土壤颗粒有机碳的稳定,尤其是秸秆培肥,其颗粒有机碳的芳香度分别比对照和牛粪培肥高0.35%和0.11%,而亲水性远低于二者;红外光谱与核磁分析的结果基本一致,红外光谱可用于大量样品的颗粒有机碳结构初步筛选。     

温度和铅离子对秸秆腐殖化溶解性有机质三维荧光光谱的干扰效应

秸秆还田是秸秆资源化和减量化的主要途径之一,是国家“十二五”期间的重要政策导向。还田秸秆能够发生天然腐殖化,逐步完成溶解性有机质(DOM)的生成和转化过程。现阶段,针对黄土地区环境因子对秸秆腐殖化调控作用的研究较少,从荧光光谱角度分析腐殖化组分与金属离子的结合特性也有待完善。以荧光光谱法为切入点,探讨温度和铅离子对秸秆腐殖化DOM三维荧光光谱峰位和峰强的影响,借助修正型Stern-Volmer方程推算Pb(Ⅱ)-DOM的配位参数,辅以Van’t Hoff方程揭示结合过程的热力学特性。结果表明：腐殖化温度没有引起DOM荧光峰位的明显偏移,三维荧光光谱中没有发现新荧光峰的出现或已有荧光峰的消失,荧光峰强随温度的升高而降低。铅离子浓度的增加导致DOM主要荧光峰强下降,这是铅离子对DOM组分的荧光猝灭作用。经修正型Stern-Volmer方程计算可知：铅离子对可见光区类富里酸组分的配位能力最强,较大的配位荧光基团比例f值暗示DOM中较多的活性基团与铅离子发生配位作用,猝灭机理以静态猝灭为主。配位过程自发、吸热,反应体系分子组成的复杂性和无序度较低。三维荧光光谱能够有效揭示温度和铅离子对秸秆腐殖化DOM性质的影响。     

Time-amplitude characteristics of thin-walled drift tubes (straws) for gas mixtures ArCO2 with CF4 and O2 additives

Results of the investigation of time-amplitude characteristics of thin-walled drift tubes (straws) of different diameters for gas mixtures ArCO₂ with CF₄ and O₂ additives are described. An essential reduction of the sensitivity time of the straw for CF₄ additive is shown, especially with increase the straw diameter. O₂ additive influences the time parameters of the straw insignificantly. CF₄ or O₂ additives with the so-called cleaning properties are of interest for optimization of parameters of detectors with small sensitivity time under the condition of high loadings.