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1.
红麻杆高吸油材料吸油特性的研究   总被引:5,自引:0,他引:5  
以红麻杆为原料,经热解处理制备出选择性亲油和高吸油量的吸油材料.研究了该吸油材料的吸油特性.结果表明,随着热解温度升高,所得吸油材料的吸油量增大,450 ℃热处理物的吸汽油倍率最大,达11.60 g·g-1;300 ℃热解处理试样的亲油选择性最佳,吸油速率最快.采用盘磨预处理再热解的工艺,所得热处理物的吸油量可以得到显著改善.该种吸油材料的亲油选择性可能与表面上焦油质的附着量、官能团的种类以及微孔构造等多因素相关.  相似文献   

2.
红麻杆热解物高吸油特性的形成机理   总被引:1,自引:0,他引:1  
以红庥杆为原料,经250℃-500℃热解,制备出了选择性亲油和高吸油量的吸油材料.利用元素分析、红外光谱分析和扫描电镜等手段,研究了红麻杆热解过程中高吸油性能的形成机制.结果表明,随着热处理温度的升高,试样中碳含量逐步升高,氧含量逐步降低.吸油性能的变化与苯-乙醇、热水和1%NaOH抽出物含量的变化呈对应关系.FTIR分析表明,热解处理后.-OH的红外吸收明显减少,亲油的芳香环结构的吸收显著增加.SEM观察表明,300℃热解物中大容量的孔结构和毛细管作用是其具有大的吸油容量和对油产生快速的吸附作用的主要原因.  相似文献   

3.
炒青绿茶热解吸特性   总被引:1,自引:1,他引:1  
刘新  殷鸿范 《茶叶科学》1997,17(1):47-52
对炒青绿茶杀青和炒干过程的热特性进行了跟踪测量。结果表明,杀青过程的热解吸具有等速特性;炒干过程的热解吸则呈现恒率失水和降率失水的双重特性。鲜叶的嫩度不同,其热解吸特性也不尽相同,杀青过程中一级鲜叶的热解吸速率大于三级叶,一级和三级鲜叶杀青前期(2min),茶叶吸热量分别占总吸热量的38%和42%;炒干过程中,一级原料解吸至15%含水率左右时,开始降率解吸,而三级原料的降率解吸含水率起始点则要提前至25%—30%含水率时。温度和解吸速度对炒青品质的形成起着推动作用,而解吸速率又受环境温度和相对湿度的制约  相似文献   

4.
以对低温吸胀敏感的黑河3号和黑河5号大豆种子为材料,经48℃热蒸汽处理3小时后,种子的发芽率、根长、根重及活力指数都有不同程度的提高。热蒸汽处理过的种子经低温吸胀后,仍能保持较高的活力水平,其膜系统功能、脱氢酶活性及过氧化物酶活性等都保持较高水平。  相似文献   

5.
油料作物秸秆快速热解及其生物油特性的研究   总被引:2,自引:0,他引:2  
以油菜秸秆、脱灰油菜秸秆、花生秸秆及芝麻秸秆等为原料,在小型流化床上进行了快速热解试验研究。从纤维素、半纤维素、木质素含量与灰分含量等原料品质方面,对热解产物分布以及生物油特性的影响进行了对比分析。结果表明,不同秸秆的纤维素、半纤维素、木质素的含量不同,其热解产物分布有所不同,纤维素与半纤维素含量高的秸秆,生物油产率较高。灰分对热解产物分布影响较大,脱除灰分有利于提高生物油的产率;脱除灰分对秸秆生物油品质有一定影响,其生物油的pH值、密度、运动粘度高于其它秸秆生物油。油菜秸秆、花生秸秆、芝麻秸秆生物油主要品质指标基本一致。  相似文献   

6.
橡胶种子油食用价值的研究   总被引:1,自引:0,他引:1  
1975—1976年,我们对橡胶种子油的食用价值,在北京劳动卫生研究所试验的基础上作了进一步研究,实验用大白鼠258只,小白鼠125只,分组喂以占饲料10%及20%油量的橡胶种子油。以相应油量的花生油作对照,试验结果如下: 橡胶种子油的营养效能略高于花生油。长期食用橡胶种子油对动物的生长、繁殖、肝功能、血清蛋白、血脂、血钙,以及对肝、肾、心、肺、肠、胃等形态,均无不良影响。细胞遗传学观察结果无潜在的遗传危害。食用10%及20%的橡胶种子油可以降低血脂。试验结果说明橡胶种子油是可以作为食用的新油源。  相似文献   

7.
秸秆热解液化制备生物油技术   总被引:5,自引:0,他引:5  
介绍了秸秆快速热解液化技术及其动力学研究现状、生物油的性质与精制,提出了秸秆快速热解液化技 术存在主要问题及未来研究目标和建议。  相似文献   

8.
玉米不同基因型对低温吸胀的响应及幼苗生长分析   总被引:4,自引:1,他引:3  
以3类耐冷性不同的玉米组合为材料,在萌发期分别进行低温(6℃)和常温(25℃)24 h的浸种处理,测定吸胀时期的吸水速率、电导率、脱氢酶、α-淀粉酶活性以及发芽指标和苗期形态指标的变化,研究不同耐冷基因型对低温吸胀的反应及其对苗期生长的影响。结果表明,不耐冷型玉米的子粒吸胀迅速,造成种子吸胀损伤程度大,其电导率相应增大,脱氢酶活性较低,导致发芽率、发芽指数的降低;耐冷型吸胀缓慢,膜系统恢复的速度较快,上述指标的降低有很大程度的减轻;中耐冷型居中。相关分析表明,发芽率比率、根冠比比率均与电导率比率存在显著负相关关系,与种子脱氢酶比率呈显著或极显著正相关。说明膜的稳定性及脱氢酶活性的增强是耐冷性品种耐吸胀冷害的主要原因。  相似文献   

9.
野生花生高油基因资源的发掘与鉴定   总被引:1,自引:0,他引:1  
以花生属22个近缘野生物种87份种质为材料,系统鉴定和分析野生花生种子含油量。结果表明,野生花生中存在丰富的高油资源,其含油量最低值、最高值和平均值均高于栽培种花生资源的对应值。发掘出高油种质(含油量≥58%)12份,其中Arachis appressipila是目前所发现的花生资源中含量最高的种质,含油量达62.90%。不同物种以及同一物种不同资源的含油量差异很大,如A.appressipila的10-2含油量62.90%,11-7的含油量为55.92%。A.appressipila、A.macedoi和Arachissp的平均含油量较高,分别为57.54%,57.64%和57.68%。通过SSR分析表明,在所获得的高油野生花生材料中,四倍体野生种A.monticola与栽培种花生的亲缘关系最近,其次为花生区组的二倍体野生种A.villosa。根据SSR扩增结果,绘制了高油野生花生材料的指纹图谱。  相似文献   

10.
吸胀期低温与水分条件对油菜种子萌发的耦合效应   总被引:1,自引:0,他引:1  
为了探讨晚播油菜适宜播种的田间温度和水分条件,以华杂62和华双5号品种为材料,在土壤和PEG溶液两种介质中研究了吸胀温度与水势对种子萌发的影响。结果表明,吸胀期温度和水分条件对油菜种子的萌发具有显著影响。在5~15℃范围内,种子萌发活力随吸胀期土壤温度的升高而提高。在10℃和15℃下吸胀,土壤相对含水量为58.6%、水势为-0.1MPa时较适宜于种子萌发;在5℃低温下吸胀,适当降低土壤水势有利于种子萌发。华杂62种子具有吸胀冷害现象,在低温和高水势下吸胀,种子萌发活性降低,吸水速度加快,种子浸泡液K+渗漏量升高,而Na+渗漏量和Na+/K+比值降低。华双5号种子则具有较强的抗吸胀冷害能力,表现为在低温下吸胀受水势的影响较小。  相似文献   

11.
12.
Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.  相似文献   

13.
Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.  相似文献   

14.
15.
Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.  相似文献   

16.
Novel food and non-food uses for sorghum and millets   总被引:4,自引:3,他引:4  
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.  相似文献   

17.
Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.  相似文献   

18.
Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X1 (also called RXact).  相似文献   

19.
The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O2•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O2•− scavenging, (IC50 = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC25 = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC50 = 863 µg/mL; elastase, IC50 = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O2•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.  相似文献   

20.
The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.  相似文献   

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