秸秆厌氧消化预处理技术综述

农作物秸秆是一种重要的富含有机质(80％～90％)的生物质能源,因其复杂的晶体结构,不能直接被厌氧菌群利用来生产沼气.因此以秸秆作为原料发酵时,需要进行预处理,使复杂的晶体结构得到破坏,从而易于被厌氧菌群利用.文章综述了国内外用物理法、化学法、生物法、物化法预处理秸秆的相关研究进展,考查了不同预处理方法对厌氧消化效果的影响.     

陕西农业生产效率评价以及影响因素分析—基于DEA-Tobit两步法

运用DEA-Tobit两步法对陕西农业11个市区2002-2008年农业生产效率及其影响因素进行了分析,并结合Malquist指数,对陕西省农业生产效率的变化进行了动态评价。结果表明,全省平均综合技术效率较高,但是各市区之间差异较大。最后,通过Tobit分析发现,陕西农业生产效率与农民文化水平以及农业生产中投入资金量呈正相关关系。     

茶叶中7种有机氯和拟除虫菊酯类农药残留检测技术研究

本文对茶叶中7种有机氯类和拟除虫菊酯类农药残留检测的前处理技术进行了研究,对比了2种不同的提取溶剂对农药回收率、净化效果的影响,建立了丙酮∶正己烷(1∶1,V/V)提取,Florisil固相萃取小柱净化的方法。本方法回收率在82.3～109.8%之间,变异系数3.3～10.22%,最低检出浓度为0.001mg/kg。该种残留分析前处理方法具有操作简便、成本低、回收率高、精密度好的特点。     

Quantitative Measurement of Organic Carbon in Mine Wastes: Methods Comparison for Inorganic Carbon Removal and Organic Carbon Recovery

The present study aims to evaluate carbon recovery and analytical precision of two methods based on dry combustion for organic carbon (OC) quantification in base metal mine tailings: (1) IC subtraction method (inorganic C(IC) measured and subtracted from total C) and (2) direct OC quantification after acid pretreatment. Results showed IC subtraction method effectively hydrolyzed a range of IC minerals [calcium carbonate (CaCO₃), magnesium carbonate (MgCO₃), dolomite, magnesite, calcite] with satisfactory IC (as CO₂ released) recovery (87–103 percent). In the direct OC quantification method, 5 M hydrochloric acid (HCl) pretreatment resulted in a satisfactory recovery (76–92 percent) of most organic compounds [ethylenediaminetetraacetic acid (EDTA), cellulose, plant litter, and charcoal], except for water-soluble OC (sucrose, 40 percent recovery). The precision of both methods declined when C levels were <5 g kg^?1 with RSD (Relative Standard Deviation) > 10 percent. The OC values in test samples of base metal mine tailings were comparable between the two methods. However, IC subtraction method is not applicable for tailings with low OC levels (<5 g kg^?1) until the precision is substantially improved. Moreover, compared to the IC subtraction method, OC values are significantly lower in direct OC quantification method for tailings with high OC levels.     

Improvement of the emulsifying properties of porcine sarcoplasmic proteins with a low-molecular weight surfactant by the two-step emulsification method

The emulsifying properties of porcine sarcoplasmic protein (SP) with or without low-molecular weight surfactants were examined. The emulsifying activity (EA) of SP was weaker than that of sodium caseinate (CA), blood plasma (BP) and whey protein isolates at a protein concentration of 0.5–3%. Sodium chloride decreased the EA of SP. The EA of SP was about one quarter that of CA in the presence of 3% sodium chloride. As homogenization time increased, the EAs of SP and BP decreased. The EA of SP was not influenced by sucrose stearate ester (SE) with a hydrophilic-lipophilic balance (HLB) value of 16 (SE-16) but was decreased by those with HLB values of 5 and 1. Low-molecular weight surfactants such as SE-16, Tween 80 and sodium cholate improved the EA of SP with the two-step emulsification method: corn oil was previously emulsified with the surfactant before addition of SP and homogenization. In the case of the addition of SE-16 as primary emulsifier, the EA was about twice as high as that of SP alone. The same effect was shown in the emulsions formed by CA and soy protein isolate. These results indicate that the emulsifying properties of meat protein would be improved by the addition of a low-molecular weight surfactant in a two-step emulsification.     

结缕草种子预处理反应与耐藏性的探讨

为了提高结缕草种子发芽力和耐藏性,根据结缕草种子的特性,对不同贮藏期的种子,进行多种物理的和化学的预处理措施试验。     

杨树扦插苗耐盐性鉴定

本文利用水培方式对意大利４５、０５６７、迎春５号和白林３号四个品种杨苗期耐盐性及其利用激动素、萘乙酸、生根粉、吲哚乙酸、吲哚丁酸和赤霉素等六种激素预处理，对各品种杨生长及耐盐性的影响进行了研究。结果表明，赤霉素促进叶萌动的效果好于其它激素；生根粉和吲哚丁酸促进根萌动及发根数效果明显；随着盐浓度的升高，各品种杨萌动期、发根数量、叶绿素含量和叶表面积均延迟或下降，而白林３号下降幅度较小，因此，在四个品种杨中，白林３号耐盐性较强。     

基于近红外分析的样品预处理对油菜种子品质指标的影响

为了弄清样品量、水分含量、发霉率、芽粒率和成熟度对油菜种子品质指标的影响,采用近红外分析方法,对其进行试验分析。结果表明:样品量为5g、3.5g和3g时,2个品种(油研50和盛油15)的芥酸、含油量、硫甙、蛋白质和水分含量间的差异不明显;为1.5g和1g时,2个品种各指标含量差异随着样品量的减少而呈上升趋势。随着样品含水量的下降,2个品种的芥酸、含油量和水分含量呈明显的下降趋势,而硫甙和蛋白质含量则呈明显的上升趋势。随着发霉种子比例的增加,2个品种的芥酸、硫甙和水分含量呈逐渐上升的趋势,而含油量和蛋白质含量则呈逐渐下降的趋势。随着芽粒率种子比例的增加,2个品种的含油量和蛋白质含量呈明显的下降趋势,而硫甙含量则呈明显的上升趋势。随着成熟度的增加,2个品种的芥酸、硫甙和水分含量呈逐渐下降趋势,而含油量和蛋白质含量则呈逐渐上升的趋势。结论:样品量低于3g、含水量低于7%,发霉率和发芽率超过20%以及收获不够成熟的种子均不能反应待测样品真实的品质指标。     

不同纤维材料苄基化的比较及预处理对苄基化的影响

比较了微晶纤维素、纸浆、脱脂棉、杨木纤维、杨木刨花的苄基化反应,研究了多种预处理对苄基化产物增重率的影响。结果表明,不同纤维材料在同等条件下进行苄基化反应,产物增重率具有明显差异,在105℃下反应4 h,杨木刨花苄基化产物增重率为60.8%,而脱脂棉仅为13.5%。冷冻润胀、微波预处理以及减小原料的粒度都会增加苄基化产物增重率,在105℃下反应2 h,常温润胀时杨木刨花苄基化产物增重率为33.7%,冷冻润胀时为42.0%,微波预处理时为41.9%。     

预处理结合低温贮藏对康乃馨切花保鲜效果研究

为探讨康乃馨鲜切花最佳保鲜方法,在低温条件下,通过在保鲜液中添加蔗糖、8-羟基喹啉(8-HQ)、柠檬酸(CA)及外源激素6-BA和2,4-D等,研究康乃馨切花的采后保鲜效果。结果表明,2周4℃的低温保存结合预处理增加了康乃馨切花花径、花蕾长度、花枝鲜质量,提高了花瓣CAT活性,其中,5%蔗糖+100mg/L 8-HQ+200mg/L CA+100mg/L 6-BA配方组合保鲜效果最佳。由此说明,在低温条件下,预处理对康乃馨切花的保鲜和延缓衰老有较好的作用,且添加外源激素6-BA比2,4-D作用更佳。