Experimental Studies on Electrolyte-gated Carbon Nanotube Field Effect Transitors

Owing to unique structure and characteristic of carbon nanotubes, much more are attractions, especially in molecular elements, including field effect transitorsmade of carbon nanotubes. Carbon nanotube field effect transitors with electrolyte-gated are investgated. Carbon nanotubes on glass substrate in this study are fabricated by hot filament vapor deposition using Fe / Ni as catalyst. Optimized multi-walled carbon nanobute transistors are made with Ag contact electrodes, and the KCl solution is used as a gate. Experimental results show that the electrolyte-gated carbon nanotube transitors exhibited a good voltage-current characteristic. The transconductance is about 0.5 mA/V at 2 V. The results obtained are discussed.     

纳米碳管在电解法处理含铜废水中的应用研究

为了解决含铜工业废水对环境、土壤及生物的危害,以镀有纳米碳管的钢板为阴极,对含铜废液进行了电解研究。测定了不同影响因素下（电解时间及电流等）重金属铜的去除率,并分析了含纳米碳管阴极电解法去除Cu2+的机理。结果表明,在其它条件相同的条件下,随着时间和电流的增加,去除率逐渐上升。而且随钢板上纳米碳管的数量升高,去除率明显升高。本试验最佳情况下,含有纳米碳管的阴极钢板比没有含有纳米碳管的阴极钢板去除率高40%左右。     

Measurement of Resistivity and Investigation of Electronic Transport for Carbon Nanotube Film

Temperature-depended resistivity of carbon nanotube film is measured and the results show negative temperature effect because the resistivity is decreased as the temperature increased. An electronic transport model for the carbon nanotube film is set up and the resistivity calculation formula is deduced, whose calculating result is compared with experimental datum. It shows that theoretical calculation is well contented with experiment results. Then, the relationship between resistivity and diameter of the carbon nanotube is discussed.     

Experiment and analysis of an atmospheric DC glow discharge device

In order to reduce the volume and be used in portable instruments, a line-cylinder atmospheric glow discharge device with a 1.92 mm discharge gap is designed. It mainly consists of an inner line electrode and an outer cylinder electrode. The diameters of the line and cylinder electrodes are 0.16 and 4 mm, respectively. The transition from corona discharge to glow discharge is observed and explained. By using discharge waveform and photo, it has been verified that it is a glow discharge. The calculation methods of vibrational temperature and rotational temperature are deduced by use of the N2 second positive band system. The emission spectrum of the plasma is collected by spectrometer (Acton Spectrapro 2500i). From calculation, it is found that the vibrational temperature of the plasma is about 2 360 K and the rotational temperature of the plasma is about 830 K. The device is used as an ion source in the ambient mass spectrometer. The experiment results show that the plasma generated by DC glow discharge can well ionize the formic acid, acetic acid, and phenol, etc.     

Modeling and simulation based on open electrical impedance tomography

In order to improve the error in image reconstruction caused by changeable positions of the electrodes in closed electrical impedance tomography, we propose an open electrical impedance tomography (OEIT) model using fixed electrode array. The problem was approximately assumed to be a virtual field by defining certain local sensitive area instead of solving the boundary problem in the whole electromagnetic field strictly. Modeling and simulation of OEIT have been conducted to define reasonable boundary parameters and electrode array structure. The finite element method is used for forward computation while Newton one step error reconstructor is used for image reconstruction. The target position, area and conductivity change can be reflected by the relative change of the boundary voltage and the reconstructed image is clear. Better resolution and positioning accuracy can be obtained in the shallower surface of the body by OEIT, so it is valuable in clinical applications.     

苯酚降解菌DF51的分离鉴定，降解特性及其固定化的研究

从太原市郊苯酚污染的土样中分离到一株能以苯酚、苯甲酸、萘、联苯和苯并噻吩为唯一碳源和能源生长,并且具有同时分解单环和双环芳香类物质能力的菌株,经生理生化和16S rDNA基因序列分析鉴定为红球菌DF51(Rhodococcus sp. DF51). 在本实验条件下,菌株DF51能够有效降解浓度范围为100-800mg L-1的苯酚,该菌代谢苯酚主要是通过邻苯二酚1, 2-双加氧酶催化开环途径进行,同时辅以邻苯二酚2, 3-双加氧酶催化开环,表明菌株DF51兼有混浊红球菌(Rhodoccocus opacus R7)和红球菌PNAN5(Rhodoccocus sp. strain DF51)降解苯酚的途径. 菌株DF51固定化实验表明,该菌的固定化细胞具有降解苯酚的潜在应用价值.     

Treating phenol wastewater by hydrogen peroxide assisted with a cavitating water jet

We studied experiments on phenol wastewater treated by hydrogen peroxide assisted with a cavitating water jet. Removal efficiency factors were studied, and the intermediate products analyzed by High performance liquid chromatography (HPLC) to reveal the degradation mechanism. The optimal cavitating condition was obtained via experimentation. Based on the results, the removal ratio of phenol reaches 99.85% under when the initial phenol concentration is 100 mg/L, the pH value is 3.0, the hydrogen peroxide concentration is 300 mg/L, the confining pressure is 0.5 MPa, and the jetting pressure is 20 MPa. The HPLC analysis shows that the ultimate products of oxidized phenol are maleic acid and acetic acid with the intermediate products of catechol, hydroquinone and p benzoquinone.     

保护性耕作对土壤结构体有机碳氧化稳定性的影响

以7年不同耕作的定位试验为研究对象,研究了深松、旋耕、免耕等保护性耕作措施对关中塿土小麦-玉米轮作条件下结构体有机碳氧化稳定性的影响。结果表明,与传统耕作相比,深松、旋耕、免耕及秸秆还田+传统耕作均提高了各粒级结构体的有机碳和易氧化有机碳含量,且深松和旋耕效果达到显著水平,免耕作用不显著;深松、旋耕、免耕对难氧化有机碳含量的影响均不明显。由此可见,各保护性耕作对土壤结构体总有机碳含量的提高主要是通过结构体中易氧化有机碳含量的提高来实现。各保护性耕作降低了结构体有机碳的氧化稳定系数（Kos）,但未达到显著水平。土壤较小粒级（0.5～0.25mm和<0.25mm）结构体中的总有机碳,易氧化、难氧化有机碳含量均比大粒级结构体中（>0.5mm）的高,且其氧化稳定系数（Kos）较低。相关分析表明,除5～2 mm粒级结构体外,各粒级结构体的总有机碳之间、易氧化有机碳之间、总有机碳和易氧化有机碳之间均相关极显著,且以<0.25mm结构体的总有机碳、易氧化有机碳和各粒级结构体的总有机碳、易氧化有机碳之间的相关系数较大。关键词：保护性耕作,结构体,有机碳,氧化稳定性     

Case- carburization Numerical Modeling and Craft Optimization on Steel Parts of Various Shapes

According to the diffusion equation of carburizing process and its boundary conditionand initial condition, various shapes steel parts are modeled under various case carburize craft parameters, concentration distribution curves have been obtained. Various craft parameters are compared, and carburizing temperature has more influence on carbon concentration distribution. Various shapes steel parts' carbon concentration distribution curves have some difference. According to the carbon concentration distribution curve, craft parameters can be adjusted in order to obtain the best carburizing craft.     

Biochar as a strategy to sequester carbon and increase yield in durum wheat

Carbon sequestration in agricultural soils is a climate change mitigation option since most of cultivated soils are depleted of soil organic carbon and far from saturation. The management practices, most frequently suggested to increase soil organic carbon content have variable effects depending on pedo-climatic conditions and have to be applied for a long time periods to maintain their sink capacity. Biochar (BC), a carbon rich product obtained through carbonization of biomass, can be used for carbon sequestration by applying large amounts of carbon very resistant to decomposition. The BC remains into soil for a long time and there is evidence that the BC stores atmospheric carbon from centennial, to millennial timescales. However most of the agronomic studies on BC application have been made in tropical and sub-tropical climates, while there is a substantial lack of studies at mid-latitudes and in temperate climates. This paper presents the results on an investigation of large volume application of BC (30 and 60 t ha^?1) on durum wheat in the Mediterranean climate condition, showing the viability of BC application for carbon sequestration on this crop. BC application also has positive effects up to 30% on biomass production and yield, with no differences in grain nitrogen content. Moreover no significant differences between the two BC treatments were detected, suggesting that even very high BC application rates promote plant growth and are, certainly, not detrimental. The effect of the biochar on durum wheat was sustained for two consecutive seasons when BC application was not repeated in the second year.     

玉米蛋白质组研究中双向电泳技术条件的优化

为了优化玉米叶片双向凝胶电泳技术条件,通过比较3种总蛋白提取方法对玉米双向电泳结果的影响,并对蛋白质上样量、IEF等电聚焦条件及SDS-聚丙烯酰胺凝胶浓度等参数进行探索、优化;结果发现,与酚提取法和磷酸缓冲液法相比,采用改进的TCA/丙酮法提取总蛋白操作简单、方便,所得的2-DE图谱中蛋白质点数量多、背景清晰,是一种适用于提取玉米苗期叶片总蛋白的有效方法;同时筛选出:第一向IEF等电聚焦样品上样量为800μg,聚焦条件为20 000 V/h,在浓度为12.5%的SDS-聚丙烯酰胺凝胶中进行电泳,能够在17 cm的IPG胶条上获得背景低、分辨率较高、重复性好的双向电泳图谱,该优化体系适用于玉米叶片蛋白质组双向电泳分离,对玉米蛋白质组学研究具有重要参考价值。     

Calculation of lumped parameter of two-port network forvolume conduction energy transfer

Skin electrode unit is a channel through which energy can be transferred to the implanted device by volume conduction. The unit can be equivalent to lumped circuit, but so far there are no appropriate calculation methods of these circuit parameters, so variable load method based on field-circuit coupled is proposed. A skin electrode unit field circuit coupled model is established to obtain the relationship of the network parameters between voltage and current at electrode port, and the amplitude and phase of the power signal is extracted by the use of all phase FFT spectrum analysis. On this basis, equivalent circuit impedance parameters of the skin electrode unit under various conditions are obtained by the application of variable load method and the validity of the method is verified. As a result, the equivalent circuit impedance parameters obtained in this way can be used for the circuit analysis and optimization of the volume conduction energy transfer system.     

Study of Direct Methanol Fuel Cell for Portable Application

A technique of fabrication of air electrode for direct methanol fuel cells (DMFC) is proposed. The investigated air electrode is free of Teflon- containing and with ultra- thin catalyst layer. Catalysts PtRu/C for methanol electroxidation is electrochemically deposited on a Nafion- bonded carbon electrode. A concept, that is, methanol is oxidized at a relatively high potential, is proposed. Such a fabricated DMFC is characterized with a high utilization of noble metals and basically eliminating CO poisoning in operation.     

两种细菌粗多糖对草鱼的免疫调节作用

目的检测细菌多糖对草鱼的免疫调节作用。方法用酚水法分别从大肠杆菌和根癌农杆菌细胞壁中提取出粗多糖,注射草鱼,测定受试草鱼血液中白细胞数量,血清中抗体效价,肝脏、肾脏、脾脏、血清和粘液中过氧化物酶的活力。结果受试草鱼中的白细胞数量、血清抗体效价及过氧化物酶活力均具有明显提高。结论大肠杆菌和根癌农杆菌粗多糖对草鱼有免疫促进作用。     

Influence of Catalyst Thickness on Diameters of Carbon Nanotubes

Owing to unique structure and characteristic of carbon nanotubes, much more are attracted attentions since they were discovered .In recent years, carbon nanotubes have been successfully synthesized by various methods. Especially, highly aligned carbon nanotubes were grown by chemical vapor deposition (CVD). In the work, it is studied that different thickness of catalyst affects the diameters of carbon nanotubes. Carbon nanotubes were grown on silicon substrate coated with different thick NiFe films by bias-enhanced hot filament chemical vapor deposition and their growth was investigated by scanning electron microscopy,Onset of analyzing of deformation of different thick catalyst films during heating the filament. The results indicate that catalyst particles encapsulate the top ends of carbon nanotubes, and that the catalyst thickness greatly affects the diameters of carbon nanotubes, which increas with increment of the thickness of NiFe films.     

Investigation on the reaction characteristics of methane catalytic partial oxidation in a micro-channel

The reaction characteristics of fuel-lean CH4 catalytic partial oxidation over Rh are investigated numerically in a micro-channel, by using detailed elementary mechanism, focusing on the effects of inlet temperature, equivalence ratio of CH4/O2 and added H2O on catalytic partial oxidation of CH4. The results show that over Rh surface reaction of CH4 is kinetically controlled, while that of O2 is controlled by mass transport. Duo to the high reactivity of O2, CH4 is firstly oxidized and both complete and partial oxidation products are generated. After O2 is consumed, steam reforming begins, however, CO2 reforming does not appear. Increase of the equivalence ratio of C/O leads to increase of carbon deposition at reforming zoon, as thus both conversion of CH4 and production of syngas decrease, even the reforming process is stopped. The added H2O could dramatically inhibit carbon deposition, and promote the formation of H2 and CO2.     

品种与栽培条件对小麦籽粒生物活性物质含量的影响

利用4个四川省主推小麦品种连续2年2地在不同施氮时期、施氮量、播期、施磷量条件下,测定小麦籽粒中生物活性物质植酸、γ–氨基丁酸、总酚含量的变化,期望找到提高小麦生物活性物质的含量合理的栽培措施。结果表明,影响小麦生物活性物质含量的主要因素是品种,施氮量、施氮时期、播期、施磷量等栽培措施只部分影响或不影响生物活性物质的含量。另外施氮量和施磷量的互作效应也会对生物活性物质含量产生显著影响。绵麦51的γ-氨基丁酸和总酚含量高于其他品种,抗营养物质植酸含量低于其他品种。在四川地区选用品种绵麦51,将150 kg hm~(–2)纯氮氮肥、75 kg hm~(–2) P_2O_5的磷肥全作底肥一次施用,于10月29日播种可获得生物活性物质含量最佳的小麦籽粒。     

Methane oxidation in non-flooded soils as affected by crop production — invited paper

Methane is an important greenhouse gas, which contributes approximately 20% to global warming. The atmospheric CH₄ concentration is increasing rapidly, resulting from an imbalance between CH₄ production and consumption. The only known biological CH₄ sinks are soils where methanotrophic bacteria consume CH₄ by oxidizing it. For several reasons the CH₄ uptake potential, particularly of arable soils and grassland, is only partly exploited, as several agricultural practices have adverse impacts on the activity of the CH₄ oxidizing bacteria. The kind of land use in general has a remarkable influence with much higher oxidation rates under forest than under grassland or arable soil. Regular soil cultivation by ploughing and fertilization with ammonium or urea have been identified as main factors. Immediately after ammonium application the methanotrophic enzyme system is blocked, resulting in an inhibition of CH₄ oxidation. In addition to this short-term effect a long-term effect exists after repeated ammonium fertilization, which is most likely caused by a shift in the population of soil microbes. Crop residues affect CH₄ oxidation differently, depending on their C/N ratio: with a wide C/N ratio no effects are expected, whereas with a narrow C/N ratio strong inhibition was observed. Animal manure, particularly slurry, can cause CH₄ emission immediately after application, whereas in the long run farmyard manure does not seem to have adverse impacts on CH₄ oxidation. The methanotrophic activity decreased markedly with soil pH, although in many cases liming of acidified soils did not show a positive effect. Arable soils have a rather small pH range which allows CH₄ oxidation, and the inhibitory effect of ammonium can partly result from a concomitant decrease in soil pH. Reduced tillage was identified as a measure to improve the methanotrophic activity of arable land, set aside of formerly ploughed soil points into the same direction. Plant growth itself is not primarily responsible for observed effects on CH₄ oxidation, but secondary factors like differential pesticide treatments, changes in pH, or cultivation effects are more likely involved. Although for the overall CH₄ fluxes the oxidation processes in agricultural soils are of minor importance, all available possibilities should be exhausted to improve or at least preserve their ability to oxidize CH₄.     

橡胶树C-乳清三种蛋白提取方法双向凝胶电泳分析

摘要：C-乳清是胶乳的主要组分,就双向凝胶电泳技术而言,目前仍无有效的蛋白提取方法,这严重制约了双向凝胶电泳技术在橡胶树蛋白组分析上的应用。本文选取3种方法提取C-乳清蛋白,通过对蛋白产量和提取蛋白的双向凝胶电泳图谱分析系统评价3种方法。就蛋白产量而言,三氯乙酸/丙酮沉淀法产量最高（0.86 mg/ml C-乳清）,三氯乙酸沉淀法次之（0.72 mg/ml C-乳清）,酚提取法最低（0. 66 mg/ml C-乳清）。双向凝胶电泳图谱分析表明：酚提取法可检测到447个蛋白点,图谱背景较暗且横纵向纹理多;三氯乙酸沉淀法可检测到821个蛋白点,图谱背景居中;三氯乙酸/丙酮沉淀法可检测到1052个蛋白点,图谱背景清晰且基本无纹理。综上所述,三氯乙酸/丙酮沉淀法最适合C-乳清蛋白提取。本文首次系统评价C-乳清蛋白提取方法,必将推动橡胶树C-乳清蛋白研究发展。     

番石榴叶中多酚物质含量测定条件的优化

研究了以没食子酸为标品测定番石榴叶多酚含量的适宜条件。结果表明,当福林试剂稀释10倍,使用质量分数为40%的Na2CO3,反应时间为7min,反应温度为50℃时,多酚含量在0～500mg内与吸光值呈良好的线性关系。测定方法的RSD为1.17%,平均回收率为98.4%,有较好的精密度和准确度。