碳纤维表面特性对燃料电池用碳纤维纸性能的影响

本文使用SEM、BET和XPS对TC-33碳纤维、TC-28碳纤维、T300碳纤维表面特性进行了分析,并就纤维表面特性对燃料电池用碳纤维纸性能的影响进行了研究.表面形态分析表明,T300纤维表面沟槽深,比表面积大于TC-33和TC-28碳纤维;XPS分析表明,T300和TC-33纤维含氧基团数量多于TC-28纤维;碳纤维纸性能测试结果表明,T300和TC-33碳纤维纸的透气性能和导电性能较接近,力学性能方面T300碳纤维纸明显高于TC-33和TC-28碳纤维纸.     

不同有机物料对土壤和烟叶主要质量指标的影响

通过大田试验,研究了施用不同有机物料对土壤碳氮含量和烟叶碳/氮及感官质量的影响。结果表明,施用腐熟麦秸秆、绿肥和绿肥配施菌肥能提高土壤微生物商和前期土壤中有机碳、全氮、微生物量碳、微生物量氮含量,土壤微生物量碳/微生物量氮平均值在5左右。烟叶质量分析表明,烟叶碳/氮在移栽后60 d前增长缓慢,之后进入快速增长期,烘烤后下降,烤后烟叶感官质量得到改善。相关分析结果表明,土壤碳氮含量与评吸总分呈显著或极显著正相关,烟叶碳/氮与评吸总分不存在线性相关关系,但与香气量、刺激性、余味和劲头呈负相关,与香气质、浓度呈正相关。综合分析,以绿肥配施微生物菌剂的处理效果最好。     

表面涂覆壳聚糖对碳纤维在水中分散性的影响

在碳纤维表面物理性涂覆壳聚糖,改善了碳纤维在水中的分散性.通过显微镜和扫描电子显微镜(SEM)照片对涂覆壳聚糖前后的碳纤维形态及表面形貌进行观察,发现涂覆壳聚糖后,碳纤维表面形成了一层不均匀的壳聚糖膜,在引进羟基、氨基等亲水性基团的同时增加了碳纤维表面粗糙度;通过测定接触角的变化和分散实验表明,碳纤维的亲水性和在水中的分散性得到了改善.     

TOC检测法在羟乙基淀粉200/0.5氯化钠注射液设备清洁验证中的应用

目的建立生产系统中羟乙基淀粉200/0.5氯化钠注射液设备清洁验证的总有机碳(total organic carbon,TOC)分析方法。方法采用TOC分析仪检测清洁验证的样品,并建立了淋洗法与擦拭法结合的清洁操作规程。结果采用TOC法检测残留的羟乙基淀粉,具有良好的线性、回收率及精密度。结论 TOC法操作简便,灵敏度高,分析速度快,适用于羟乙基淀粉200/0.5氯化钠注射液设备的清洁验证。     

Variation of organic carbon and nitrogen in aggregate size fractions of a paddy soil under fertilisation practices from Tai Lake Region,China

Long‐term changes in agricultural management can affect soil organic carbon (SOC) and nutrient dynamics, which can be monitored by determining the distribution of microbial activity and nutrient pools in soil aggregates of different size fractions. The objective of the present study was to investigate the changes in SOC and total nitrogen (N_t) distribution in aggregates of different size fractions from a paddy soil (Ferric‐accumulic Stagnic Anthrosols) under a long‐term fertilisation trial. Undisturbed samples of topsoil (0–5 and 5–15 cm depths) were collected from a field experiment farm located in Tai Lake Region, China, with the plots receiving no fertiliser (NF), chemical fertilisers (CF), chemical fertilisers with straw return (CFS) or chemical fertilisers plus pig manure (CFM). In the surface layer, SOC and N_t concentrations appeared as a bimodal peak in the 2000–250 and < 2 µm fractions. SOC concentration increased by 38.6, 40.8 and 17.2% and N_t concentration by 30.0, 16.8 and 38.4% in the 2000–250 µm fractions under CFM, CFS and CF respectively as compared with NF treatment. There were slight changes in SOC and N_t in the < 2 µm fractions from different fertilisation plots. Continuous addition of manure or straw increased storage of SOC and N_t mainly in the coarser aggregate fractions. SOC increases due to straw or pig manure application predominated in the 2000–250 µm fractions, with SOC seeming to be physically protected within macro‐aggregates. Thus straw and manure are likely to play an important role in carbon and nitrogen storage in paddy soil under long‐term combined chemical and organic fertilisation. Copyright © 2007 Society of Chemical Industry     

野山杏果肉总有机酸对高脂血症大鼠血脂及相关基因表达的影响

目的：研究野山杏果肉总有机酸（total organic acids from wild apricot,TOAWA）对高脂血症大鼠的降血脂作用及机理。方法：建立高脂血症大鼠模型,以灌胃血脂康大鼠为阳性对照组,利用试剂盒测定血脂浓度和载脂蛋白质量浓度;利用实时荧光定量聚合酶链式反应（real-time polymerase chain reaction,qPCR）测定大鼠肝脏过氧化物酶体增殖物激活受体α（peroxisome proliferator-activated receptor-α,PPAR-α）和低密度脂蛋白受体（low-density lipoprotein receptor,LDL-R）的基因表达水平;制作实验大鼠的肝脏组织切片,观察其对肝脏组织结构的影响;探究TOAWA对高脂血症大鼠血脂的影响及作用机理。结果：TOAWA能极显著降低灌胃高脂乳剂实验大鼠的总胆固醇、甘油三酯和低密度脂蛋白胆固醇（low-density lipoprotein cholesterol,LDL-C）浓度（P＜0.01）,显著降低载脂蛋白（apoprotein,Apo）B质量浓度（P＜0.05）,极显著升高ApoA-I质量浓度和ApoA-I/Apo-B（P＜0.01）,显著升高高密度脂蛋白胆固醇浓度（P＜0.05）。qPCR结果显示,灌胃高脂乳剂实验大鼠肝脏PPAR-α和LDL-R基因表达量降低,给予TOAWA干预后,实验大鼠肝脏PPAR-α和LDL-R基因表达量有明显的升高。肝脏组织切片的观察结果显示,TOAWA可明显改善肝功能。结论：TOAWA能调节高脂血症大鼠的血脂浓度,其作用与TOAWA调节Apo质量浓度、上调肝脏PPAR-α和LDL-R基因表达量及改善肝功能有关。     

Effect of drought and irrigation on the fate of nitrogen applied to cut permanent grass swards in lysimeters: Leaching losses

Nitrogen losses were measured in water draining from cut permanent grass swards growing in monolith lysimeters containing clay loam (Salop series) or silt loam (Bromyard series) soils. The swards were cut at 6-week intervals during the summer and were fertilised with calcium nitrate at rates of 0 and 400 kg N ha^?1 in each of five successive years (1977–81); in the first year the fertiliser was labelled with ¹⁵N. Four differing rainfall regimes were imposed from spring to autumn in each year. Mean annual losses of nitrogen by leaching from unfertilised swards were 3.8 kg N ha^?1 with mean nitrate-N concentrations in the water of about 1 mg N litre^?1. In fertilised lysimeters where rainfall distribution was that of the long-term average the mean annual total nitrogen losses were 41 kg N ha^?1 in the Salop soil and 15 kg N ha^?1 for the Bromyard soil; mean nitrate-N concentrations were 11.6 mg N litre^?1 and 5.1 mg N litre^?1, respectively. Losses of nitrogen and nitrate concentrations were similar to these quantities when irrigation increased the rainfall total to 120% of average. Where a drought was imposed for 2 weeks before and after each cut, mean nitrate-N concentrations increased to 20.3 mg N litre^?1 on Salop soil and 13.1 mg N litre^?1 on Bromyard soils; total annual nitrogen losses were 74 kg N ha and 33 kg N ha^?1, respectively. The largest losses were recorded when the drought period extended for four weeks before each cut and mean nitrate-N concentrations increases to 28.8 mg N litre^?1 on Salop soil and 34 mg N litre^?1 on Bromyard soil, with total annual nitrogen losses of 104 kg N ha^?1 and 109 kg N ha^?1, respectively. Losses of nitrogen derived from the fertiliser labelled with ¹⁵N were 7.3–8.4% of that applied in the Salop soil (29–33 kg N ha^?1), with little effect by the differing rainfall distributions. On the Bromyard soil, losses were 3.7% (14 kg N ha^?1) of the applied fertiliser in lysimeters not subjected to droughts. When the period of the drought extended before and after each cut, losses were 8.2% (32 kg N ha^?1) and increased to 17.9% (70 kg N ha^?1) when the drought period occurred entirely before each cut. Fertiliser nitrogen contributed 48–69% of the total nitrogen in drainage water from both soils in the first year.     

运用改性活性炭对烟叶氨基酸水解液进行脱色最佳工艺研究

为提高烟草综合利用率,以生产烟碱及茄尼醇后的烟叶废渣为原料,通过酸水解生产氨基酸,以不同酸碱溶液对活性炭进行改性,以改性后的活性炭为脱色剂对氨基酸水解液进行脱色.研究活性炭脱色处理中活性炭处理方式、pH、活性炭用量、脱色温度、脱色时间等因素对各种氨基酸收率和脱色率的影响.结果表明,最佳的脱色工艺为：0.25 % KOH处理活性炭、pH=10、活性炭用量为2.5 %、脱色温度20 ℃、脱色20 min,所得产物氨基酸收率79.14 %,脱色率达83.89 %.改性后的活性炭显著提高了Tyr、His、Lys、Ile和Leu这5种氨基酸的收率.     

土壤C/N比对烤烟碳氮代谢关键酶活性和烟叶品质影响的研究

2009年采用盆栽试验,在河南农业大学科教园区通过添加腐熟的小麦秸秆来调节土壤的碳氮比,进而研究土壤碳氮比对烤烟碳氮代谢关键酶活性和烟叶品质的影响。结果表明:随着土壤碳氮比的增加,硝酸还原酶、转化酶和淀粉酶的活性逐渐增加,烤后烟叶总糖和还原糖的含量、中性香气物质的总量、还原糖/烟碱有不同程度的增加,烟碱、总氮含量以及氮碱比逐渐减少。土壤碳氮比在24~28之间时,有利于促进烤烟碳氮代谢平衡,协调烤后烟叶化学成分。     

碳纳米管对纺织品还原液中可分解芳香胺的吸附研究

本文研究了碳纳米管对纺织品还原液中可分解芳香胺的吸附作用。样品按GB/T 17592的方法用柠檬酸盐提取后,加入连二亚硫酸钠将提取液中的禁用偶氮染料还原成芳香胺。之后在含有芳香胺的还原液中加入碳纳米管对芳香胺进行吸附,吸附后的溶液经浓缩后用气质联用仪测定其中的可分解芳香胺,计算吸附率。结果表明:碳纳米管能完全吸附纺织品还原液中的24种可分解芳香胺,吸附率接近100%。该结果为进一步研究纺织品中可分解芳香胺的快速、环保的检测方法提供了基础。     

偶联剂处理碳纤维对燃料电池用碳纤维纸性能的影响

本文对偶联剂处理碳纤维前后纤维表面基团的变化进行了分析,并就偶联剂处理碳纤维对碳纤维纸性能的影响进行了研究,结果表明:处理后,碳纤维表面的羟基和含氧基团的数量增多,在偶联剂用量为2%时,碳纤维纸的性能较优,此条件下的碳纤维纸透气性、强度性能优于未经处理的碳纤维纸,但导电性能有所下降。     

Effect of drought and irrigation on the fate of nitrogen applied to cut permanent grass swards in lysimeters: Nitrogen balance sheet and the effect of sward destruction and ploughing on nitrogen mineralisation

Fuor years after ¹⁵N labelled fertiliser nitrogen (as Ca(NO₃)₂ and equivalent to 400 kg N ha^?1) was applied to permanent grass swards growing in lysimeter monoliths, approximately one-quarter remained immobilised in soil organic matter. In the intervening years similar but non-labelled applications were made. Although differing rainfall regimes applied during the experiment had significantly affected nitrogen uptake by plants and nitrate loss in drainage, they caused no significant effect on the tracer nitrogen remaining in the soil, the ranges were 85–97 kg N ha^?1 and 79–94 kg N ha^?1 respectively for the 135 cm deep clay and silt loam soil monoliths. Labelled nitrogen unaccounted for in crop, drainage or soil was presumed to have been denitrified. These losses averaged 62 and 49 kg N ha^?1 on the clay and silt loam soils respectively; again the differing rainfall regimes caused no significant differences. The ratio between estimates of labelled nitrogen denitrified and of annual nitroux oxide loss was approximately 9:1 for both soils. The conversion from permanent grass to winter wheat in autumn 1981, involving killing and then burying the sward, resulted in no pronounced increase in net mineralisation of labelled nitrogen. However, the balance between crop uptake and the quantity leached did change. Labelled nitrogen assimilated was less for the wheat (growing without addition of fertiliser nitrogen) than for the grass in its last year, and the quantity leached was considerably greater than under grass swards that were supplied with an average rainfall distribution. Following the first wheat harvest total nitrogen leached averaged 51 and 44 kg N ha^?1 on the clay and silt loam soils respectively. Rates of nitrous oxide emissions during the autumn following sward destruction were greater than in earlier years, but this enhanced loss was of short duration. The crop clearly benefited from the succession of nitrogen applications made to grass, as grain yield and total nitrogen uptake exceeded 7 t ha^?1 and 120 kg N ha^?1 respectively on both soils. These quantities exceed the national averages for winter wheat and are also considerably greater than for crops from lysimeters which received no nitrogen fertiliser throughout the experiment.     

生物强化活性炭滤床处理造纸过程水的参数优化研究

通过模型试验考察了生物强化活性炭工艺对造纸过程水除污染效能的影响因素。结果表明:温度降低对生物活性炭去除造纸过程水中的悬浮物、胶体物质和溶解性有机物有较大影响,温度为35℃时,生物活性炭对浊度、UV280吸光度的下降率分别为78.9%和79.2%;生物活性炭工艺采用底部曝气与顶部曝气运行方式对浊度、UV280吸光度、电导率的降低影响不大,但采用两种曝气运行方式的生物活性炭工艺对浊度和UV280吸光度下降率均高于无曝气时生物活性炭的下降率;试验表明空床接触时间为24 min时,生物活性炭工艺对造纸过程水中污染物质的去除能力明显。     

Trans-2-hexen-1-ol as a tool for the control of Fusarium verticillioides in stored maize grains

Fusarium verticillioides infects stored maize grains. In the present study, we first evaluated the effects of ten volatile organic compounds on F. verticillioides growth in culture medium. Subsequently, based on the antifungal activity obtained in the present study and the insecticidal effect against Sitophilus zeamais reported previously, trans-2- hexen-1- ol was selected to analyzed its effect on the fungus in stored maize. All the compounds tested showed inhibitory activity on fungal development, being the most active compounds geraniol, nerol, isovaleraldehyde and linalool, followed by trans-2-hexen-1-ol, cis-3-hexen-1-ol, cis-2-hexen-1-ol and trans-3-hexen-1-ol. Besides its antifungal activity against F. verticillioides, trans-2-hexen-1-ol inhibited FB₁ production. In this study it was also demonstrated that S. zeamais favors F. verticillioides dispersion, confirming the importance of these insects as mechanical vectors of fungal spores. These results reveal the ability of trans-2-hexen-1-ol as a potential tool to control F. verticillioides in a natural approach as an alternative to synthetic pesticides.     

多壁碳纳米管分散固相萃取净化在测定水产品中3 种微囊藻毒素的应用及与固相萃取法的比较

建立多壁碳纳米管净化-超高效液相色谱-串联质谱法对水产品中3?种微囊藻毒素残留量的测定方法。水产品用80%甲醇溶液提取,经多壁碳纳米管净化后,采用电喷雾正离子多反应监测模式进行分析。对不同性质碳纳米管进行考察,并对净化条件进行优化。将优化后的分散固相萃取条件与采用HLB柱固相萃取的净化方式进行比较,两者在1～50?μg/L范围内呈现良好的线性,线性相关系数均大于0.99,3?种微囊藻毒素的检出限为0.1～0.2?μg/kg。在不同浓度水平下进行加标实验,平均回收率在88.7%～95.5%之间,相对标准偏差不大于4.2%。该方法适用于水产品中微囊藻毒素的痕量检测。     

产酸丙酸杆菌发酵甘油提取物对冷藏调理猪肉饼品质的影响

以未添加抗氧化剂的调理猪肉饼作为对照,研究不同添加量的产酸丙酸杆菌发酵提取物（fermented extract of Propionibacterium acidipropionici,FEPA）对4 ℃冷藏调理猪肉饼品质的影响。将0.2%（以猪瘦肉质量计,下同）、0.3%、0.4%和0.5%的FEPA分别添加到调理猪肉饼中,测定其在1、4、7、10 d冷藏期间的pH值、色泽（L*、a*、b*值）、质量损失率、硫代巴比妥酸反应物（thiobarbituric acid reactive substances,TBARS）值、菌落总数和质构变化。结果表明：添加FEPA可显著提高调理猪肉饼冷藏期间的a*值（P＜0.05）,有利于猪肉饼色泽的改善,并能显著降低猪肉饼的咀嚼性、质量损失率、菌落总数（P＜0.05）,显著抑制蛋白和脂肪氧化（P＜0.05）;其中添加0.5%的FEPA可显著降低猪肉饼的硬度（P＜0.05）,且其抑制蛋白、脂肪氧化和抗菌效果最佳,因此在所有处理组中,0.5%的FEPA对调理猪肉饼的品质有较优的改善作用。     

Effect of different Bacillus strains on the profile of organic acids in a liquid culture of Daqu

A reversed‐phase high‐performance liquid chromatography method for the analysis of malic, lactic, acetic, citric, succinic, propionic and butyric acids, during the incubation of Bacillus spp., was developed. All samples taken from cultivation were centrifuged (20 min, 11,500g at 5°C) and filtered through a 0.45 µm membrane filter before injection. A programme pumping phosphate buffer at pH 2.50 and acetonitrile was used to separate the compounds on a C₁₈ column. Various parameters affecting analysis were optimized to take less than 30 min with a good linearity (R > 0.999). Bacillus licheniformis or B. subtilis, isolated from Daqu, was inoculated to ferment a liquid culture of Daqu. Growth of bacteria and organic acid production during the fermentation were investigated. Although there were no significant differences in the production of organic acids between B. licheniformis and B. subtilis during the first 8 h, significant differences in the production rates of organic acids, except for citric acid, were observed between B. licheniformis and B. subtilis from 8 to 48 h, with the final concentration of each organic acid varying. Copyright © 2013 The Institute of Brewing & Distilling     

温度和姜精油对金枪鱼品质影响及生物胺相关性

将分别贮藏于不同温度(0、4、15℃)条件下的金枪鱼样品,以及4℃条件下用姜精油作为生物抗氧化剂处理过的样品作为研究对象,定期测定金枪鱼生物胺(腐胺Put、尸胺Cad、组胺His、酪胺Tyr)、反式尿刊酸的含量、挥发性盐基氮(total volatile basic nitrogen,TVB-N)值、K值和菌落总数,研究温度和姜精油对金枪鱼生物胺含量的影响及组胺与反式尿刊酸的关系。结果表明,温度对金枪鱼生物胺生成有较大影响,0℃条件下生物胺含量显著低于其他贮藏温度,到第6天时组胺、酪胺、腐胺和尸胺含量分别为28.25、5.47、14.84 mg/kg和17.05 mg/kg,而此时15℃条件下金枪鱼组胺、酪胺、腐胺和尸胺含量分别为135.4、14.63、29.49 mg/kg和41.55 mg/kg;生物胺中组胺含量最高,而酪胺含量始终处于低水平状态,即使在15℃条件下到第7天时其含量仍为16.24 mg/kg;结果同时表明,生物抗氧化剂对生物胺的产生和微生物生长有一定的抑制作用,并能有效地延缓蛋白质和ATP降解。相关分析和回归分析表明,组胺、酪胺、尸胺、与TVB-N值、K值和菌落总数高度相关,其相关系数r在0.804~0.981之间,且生物胺和菌落总数、TVB-N值之间存在重要对应关系,反式尿刊酸对组胺的产生影响不大,两者之间相关性较弱,在4℃时其相关系数r为0.630。     

有机相纳米辣根过氧化物酶传感器法测定植物油的过氧化值

研究有机相CS-FC/HRP/MWCNTs酶传感器的制备及其在植物油过氧化值测定中的应用。通过循环伏安法研究了HRP感器在二氯乙烷0.1 mol/L的氯化锂溶液中对脂质过氧化物的电催化作用,该酶传感器的电极过程属于表面电化学控制过程而非蛋白质扩散控制过程;利用电镜扫描技术研究发现该酶传感器修饰膜层内部形成有利于酶电化学催化反应三维的微网格结构,所制备的酶传感器具有良好的稳定性和重复性。过氧化月桂酰在该酶传感器上的催化还原峰电流增量与其在2.5×10－6～3.0×10－5 mol/L浓度范围内呈良好的线性关系,y =0.108 5x－0.354 8,R2=0.992 3,最低检测限为2.0×10－7 mol/L（RSN=3）。该方法应用于实际大豆油、玉米油等样品的过氧化值测定,其结果与国家标准中碘量法的测定结果一致,而且精度和准确度高于碘量法,所需油样少,检测速度快,不受油样颜色影响,该方法可用于过氧化值的快速、准确测定。     

Microbial Inactivation Kinetics during High‐Pressure Carbon Dioxide Treatment: Nonlinear Model for the Combined Effect of Temperature and Pressure in Apple Juice

ABSTRACT: Isobaric and isothermal semi‐logarithmic survival curves of natural microflora in apple juice treated with high‐pressure carbon dioxide at 7, 13, and 16 MPa pressures and 35, 50, and 60 °C temperatures were fitted with a nonlinear equation to find the values of the coefficient b(P ), b(T ), n(P ), and n(T ). Profiles of the model parameters were obtained as a function of pressure and temperature. The model fitted with good agreement (R² > 0.945), the survival curves. An empirical equation was proposed to describe the combined effects of pressure and temperature. The equation, derived from a power law model, was written in the form: . The proposed model fitted the experimental data well. At 7 MPa and 50 and 60 °C, 13 MPa and 35 and 60 °C, 16 MPa and 35 °C, the model provided log₁₀ reduction residual values (observed value – fitted value) lower than 0.284 showing a good agreement between the experimental and the predicted survival levels.