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1.
二步法催化高酸值大豆油制备生物柴油 总被引：1，自引：0，他引：1
采用两步法催化高酸值大豆油制备生物柴油.第一步在固定床反应器中,以002CR型阳离子交换树脂为催化剂,高酸值大豆油中游离脂肪酸和甲醇酯化生成脂肪酸甲酯(生物柴油);然后用氢氧化钾催化油中的甘油三酯和甲醇进行酯交换.结果表明,最佳酯化条件为:醇酸摩尔比2:1,反应温度60℃,进耕速度3 mL/min.该条件下大豆油酸值可降至1 mgKOH/g以下.酯交换条件为:催化剂用量1.5%,醇油摩尔比6:1,反应温度65℃.产品技术指标达到我国0#柴油(GB252-1994优级品)的要求. 相似文献
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近年来,生物柴油作为一种无毒的、可生物降解的、可再生的柴油机代用燃料倍受关注.为优化生物柴油的应用,对比分析了大豆油甲酯生物柴油与柴油混合液的低温流动性、雾化和蒸发性、安定性、腐蚀性、清洁性和互溶性.结果表明:与柴油相比,B5、B10、B15、B20、B25和B30的凝点和冷滤点保持不变;闪点、20℃运动粘度、40℃运动粘度、密度和50%馏出温度分别平均增加26.8%、7.2%、10.8%、1.3%和12.6%,而90%和95%馏出温度基本不变;胶质和残碳分别平均增加62.3%和6.5%;硫含量平均降低15.7%,但酸度平均升高4.1%;灰分平均增加22.7%.但机械杂质平均降低13.7%.经分析,大豆油甲酯生物柴油与柴油混合液基本符合国家标准GB252-2000对轻柴油的要求. 相似文献
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固定化脂肪酶催化合成生物柴油的研究 总被引：1，自引：0，他引：1
研究了固定化脂肪酶（LBK-H100）催化大豆油与甲醇合成生物柴油的反应。考察反应条件如醇油比、反应温度、反应次数对酯化率的影响。结果表明，固定化酶催化大豆油醇解反应最适醇油比为3:1，甲醇分3次加入，可避免酶在甲醇溶液中失活，在反应温度35℃条件下，酯化率可以达到90%以上；固定化酶重复使用15次(连续反应30d)，仍具有一定的催化活性。 相似文献
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基于新疆北疆主要植棉区10个气象站1961—2017年棉花生育期月平均气温、≥10 ℃积温、≥15 ℃积温、≥20 ℃积温、无霜期气象资料和棉花产量数据，采用线性趋势分析、突变检验等方法，对北疆主要植棉区的热量资源及产量变化进行分析。研究表明：（1）生育期月平均气温呈现自东向西升高趋势，相差较小；≥10 ℃、≥15 ℃、≥20 ℃积温和无霜期也呈现自东向西增多趋势，其中无霜期相差19.4 d。（2）生育期月平均气温呈波动性上升趋势，气候倾向率为0.30 ℃·（10 a）－1；≥10 ℃、≥15 ℃和≥20 ℃积温均呈现明显的波动上升趋势，累积距平最小值分别出现在1994年、1995年和2004年，气候倾向率分别为94.1 ℃·（10 a）－1、66.7 ℃·（10 a）－1和99.3 ℃·（10 a）－1；≥10 ℃、≥15 ℃、≥20 ℃积温的持续时间呈现增加趋势；初霜期延后，终霜期提前。（3）生育期月平均气温在1994年发生了突变；无霜期在1992年前后发生了突变，突变后延长了11.1 d；≥10 ℃积温在1995年发生突变，突变后增加了319.2 ℃；≥15 ℃积温突变不明显；≥20 ℃积温在2004年前后发生突变，突变后增加了418.7 ℃。（4）棉花单产与趋势产量呈明显上升趋势，气象产量波动性较大，单产与热量资源的相关性较高；热量资源的增加对棉花产量的增加具有正效应。（5）热量资源对棉花产量提升起重要作用：丰收年景普遍表现为积温较常年多，光热条件好；歉收年景表现为热量减少，无霜期缩短，光热条件差，降水量略偏少；平常年景表现为降水量接近常年，日照时间略多于常年，整体光热条件一般。 相似文献
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为了找出最适于延长油炸豆腐丝货架期的热处理条件,比较3种热处理条件(105℃/10 min;105℃/20 min;120℃/10 min)下油炸豆腐丝的贮藏情况。并通过对油炸豆腐丝的感官评价、菌落总数及脂肪氧化程度(过氧化值、p H、硫代巴比妥酸值)的测定,综合对比找出最适处理条件并给出合理建议及货架期。结果表明:在37℃贮藏条件下,105℃/10 min处理的样品的菌落总数在23 d超过国标限值,比105℃/20 min处理得样品延长10 d左右,120℃/10 min处理条件严重损坏样品的品质。105℃/10 min处理的样品的货架期最长,室温(25℃)下可贮藏92 d,与其它两个处理相比,该条件既能保证产品品质,又可以延长货架期,建议食品企业选用此条件进行灭菌。 相似文献
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皖油10号不同施硼水平田间试验结果表明，苗期各器官NPK含量、蕾薹期各器官PK含量、盛花期花蕾和茎NP含量及各器官含B量、成熟期角果和籽粒含K量均随施B量增加（0～0．6mp／kg）而升高，再增加施B量，各元素含量均下降。籽粒NPB含量亦如此，其最大施B量为0．7mg／kg。蕾薹期和盛花期各器官含B量及叶含N量、花蕾含K量均随施B量增加而升高，而苗期植株含B量和盛花期根含N量、茎叶含K量却相反。不同生育期各元素分布是地上部分＞根，其地上部分在盛花期各元素分布是花蕾＞叶＞茎；在成熟期NP主要集中于籽粒，角果次之；KB主要集中于角果，籽粒和茎次之。 相似文献
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瑞士龙沙公司与广州农药厂合作生产的6％密达（Meta）颗粒剂为一种新的特效杀螺剂，它能杀灭蜗牛、蛞蝓、福寿螺等软体动物。该药具引诱特性。当蜗牛、蛞蝓等软体动物足部接触或进食后，即能产生触杀和胃毒作用，导致快速麻痹，分泌粘液，使体液大量流失，细胞被破坏而短时间内中毒死亡。该药通用名称：四聚乙醛；化学名称：2、4、6、8四甲基——l、3、5、7四氧杂环辛烷。原药白色，6％颗粒制剂浅蓝色，遇水软化；溶解度220（25C）；溶点246．2C；在10℃下稳定性3年，20C下月均分解率0～2％。半致死量：小鼠283GM／kg；大鼠425GM／kg。… 相似文献
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Lakshman Lal 《Potato Research》1987,30(2):329-334
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
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《Journal of Crop Improvement》2013,27(2):81-114
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
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Alexander N. Shikov Elena V. Flisyuk Ekaterina D. Obluchinskaya Olga N. Pozharitskaya 《Marine drugs》2020,18(11)
Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future. 相似文献
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M. I. Siri P. Villanueva M. J. Pianzzola L. Franco Fraguas G. Galván M. Acosta F. Ferreira 《Potato Research》2004,47(3-4):127-138
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
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Résumé
Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences
d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les
champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents
en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.
Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.
Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.相似文献
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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
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Alejandro Carlos Tozzini María Fernanda Ceriani María Verónica Saladrigas H. Esteban Hopp 《Potato Research》1991,34(3):317-324
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
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Alejandro M. S. Mayer Aimee J. Guerrero Abimael D. Rodríguez Orazio Taglialatela-Scafati Fumiaki Nakamura Nobuhiro Fusetani 《Marine drugs》2021,19(2)
The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories. 相似文献