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磁性催化剂Na2O·SiO2/Fe3O4的制备及其催化酯交换反应 总被引:1,自引:0,他引:1
以Na2SiO3为活性物质,以纳米Fe3O4为磁核制备磁性固体碱催化剂Na2O·SiO2/Fe3O4,通过正交实验,得到催化剂的最佳制备条件为:硅与铁的摩尔比2.5,晶化时间2h,煅烧温度350℃,煅烧时间2.5h,并通过震动样品磁强计(VSM)对催化剂的磁性进行表征,结果表明,所制备的催化剂Na2O·SiO2/Fe3O4具有较好的磁性和顺磁性,抗水性能优于传统均相碱催化剂;将其应用于棉籽油酯交换反应制备脂肪酸甲酯的最优工艺参数为:醇油摩尔比7:1,催化剂加入量5%,反应温度65℃,反应时间1h,搅拌速度400r/min,在此条件下,催化棉籽油酯交换反应的转化率99.6%,连续使用11次后活性90%以上。 相似文献
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以等体积浸渍法制备负载型K2O固体碱催化剂,考察了不同制备条件对催化剂催化大豆油制备生物柴油性能的影响.结果表明:最佳制备条件为焙烧温度700℃,焙烧时间5h,负载量为7 mmol·g-1,固体碱粒度160目,在此条件下得到的固体碱催化大豆油制备生物柴油酯化率可达78%以上. 相似文献
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新型固体碱催化大豆油制备生物柴油的工艺研究 总被引:1,自引:0,他引:1
制备了新型固体碱催化剂KNO3/AlSBA-15,并以此催化大豆油与甲醇酯交换反应制备生物柴油,对其工艺条件进行了优化.结果表明:醇油物质的量比为12∶1,催化剂用量为大豆油质量的3%,反应温度65C,反应时间4h,生物柴油的产率可达81%以上.该催化剂对酯交换制备生物柴油具有较高的催化活性和良好的重复使用性. 相似文献
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老化的棉花种子经 K+和 H2 O2 处理后 ,幼苗长度、叶片叶绿素含量、根系活力、过氧化物酶(POD)活性、超氧化歧化酶 (SOD)活性明显提高 ,其中以 0 .1 %K+ +1 .5 %H2 O2 复配液效果最好。 相似文献
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花生油酸亚油酸比值(O/L)的遗传分析 总被引:8,自引:2,他引:8
应用植物数量性状主基因+多基因混合遗传模型,对花生品种“青苗豆×全州麻壳”、 “富川大花生×隆安宝湾花生”和“汕油162×Sunoleic95R”三个不同杂交组合的F2分离群体的油酸/亚油酸比值进行了单个分离世代的数量性状分离分析,结果表明:“青苗豆×全州麻壳”、“富川大花生×隆安宝湾花生”两个杂交组合结果一致,O/L受一对负向完全显性的主基因控制,F2群体表现为由主基因型AA和Aa+aa按1:3比例的混合;另一个组合“汕油162×Sunoleic95R”的油酸/亚油酸比值受两对加性-显性-上位性主基因控制遗传,两对主基因间的基因效应差异不大。第一对主基因加性效应(da)1.3586和第二对主基因加性效应(db)1.3580几乎相同。三个组合的主基因遗传力分别为61.27﹪、64.09﹪和64.66﹪,多基因的遗传力分别为33.85%、34.52%和33.45%。 相似文献
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超高产大豆氮磷钾吸收分配动态及模式的研究 总被引:2,自引:0,他引:2
以新大豆1号、中黄35为材料,通过2006、2007年的田间试验,研究了超高产大豆氮磷钾吸收动态及模型,并比较了年份和品种之间的差异.结果表明:不同生育阶段大豆植株叶片、叶柄、茎秆的N和P2O5含量在年度和品种间的变化趋势没有大的区别,2006年新大豆1号K2O的浓度一直表现出较高的水平;与2006年相比,2007年N、P2O5和K2O的吸收时间明显前移;新大豆1号每生产100 kg籽粒2 a平均需N素8.28 kg,P2O5 0.78 kg,K2O 8.25 kg,中黄35为N 8.13 kg,P2O5 0.58 kg,K2O 4.38 kg.与其它地区的结果相比,N的摄取量相当,P2O5只有三分之一,K2O的摄取量是内地的2倍;新大豆1号对K2O的需求明显比中黄35偏多.N、P2O5的最快积累时间为出苗后第70~84天,其绝对含量的积累可用Logistic曲线方程加以描述.结果证明不同品种、不同生态环境条件和栽培措施影响主要养分特别是P2O5和K2O的摄取. 相似文献
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冀东晚播高产冬小麦氮磷钾吸收特性的研究 总被引:1,自引:0,他引:1
为给冀东地区晚播冬小麦的高产栽培提供依据,以冀东地区主栽小麦品种京冬8号为材料,通过大田试验研究了晚播高产冬小麦氮磷钾吸收特性.结果表明,籽粒产量在8 111.5 kg/ha水平下,平均每生产100 kg籽粒植株需吸收N 2.780 kg、P2O5 1.458 kg、K2O 4.833 kg.拔节期~挑旗期是植株对N吸收强度最大的时期,占总吸收量的41.01%;挑旗期~开花期是植株对P2O5和K2O吸收强度最大的时期,分别占总吸收量的31.77%和35.49%.成熟时植株吸收的N和P2O5 主要贮存在籽粒中,分别占植株总吸收量的58.49%和57.02%;K2O主要贮存在茎秆中,占植株总吸收量的60.30%.不同时期各器官中N、P2O5、K2O的含量不同. 相似文献
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Poly(1-oxo-2-phenyltrimethylene) was successfully synthesized in the presence of palladium acetate and rare earth acetate
RE(OAc)3 (RE=Pr, Nd, Eu, Dy, Ho) multiplex catalyst system. The final products were characterized by elemental analysis, nuclear magnetic
resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). The effects of various reaction parameters including molar
ratio of rare earth/Pd2+, methanol usage, 2,2-bipyridyl,p-toluensulfonic acid, andp-benzoquinone were studied in detail, and the influence of different rare earths on the copolymerization was also discussed.
It is found that the rare earths have favorable co-catalytic properties and palladium-rare earth multiplex catalyst showed
higher catalytic activity than palladium catalyst in the copolymerization of carbon monoxide (CO) and styrene (ST). 相似文献
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通过用不同浓度的烟酰胺腺嘌呤二核苷酸磷酸(nicotinamide adenine dinucleotide phosphate, NADPH)合成酶抑制剂碘二苯(diphenylene iodonium, DPI)及过氧化氢(hydrogen peroxide, H2O2)清除剂二甲基硫脲(dimethylthiourea, DMTU)分别培养水稻(Oryza sativa L.)种子,研究内源H2O2对种子萌发过程胚根、胚芽和胚根根尖活力等的影响。结果表明,DPI及DMTU培养的水稻种子其胚根生长和胚芽生长均受到抑制,尤其是DPI对胚根生长的抑制作用更为显著。DPI和DMTU对水稻种子萌发的影响均呈现出浓度效应,即浓度越高,抑制作用越强。其中,DPI对水稻种子萌发的抑制作用比DMTU的更为明显。此外,胚根根尖的超氧阴离子(superoxide anion, O 2-)和H2O2含量随DMTU浓度增大而减少,根尖细胞受损也越严重。由此推测,内源H2O2可能参与调控水稻种子萌发过程。 相似文献
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玉米自交系C8605-2选育与利用 总被引:1,自引:0,他引:1
C8605-2的成功选育是近年来我国自交系选育的一个重要突破。C8605-2含有纯正的北美种质血缘,综合了双亲优良性状。继承了铁7922株型紧凑、秆强和沈5003矮秆、大粒的特点。表现株高穗位适中,株型紧凑,抗倒性强,抗病、抗逆性突出。雌雄协调,结实良好,制种产量高,一般配合力高。以C8605-2为亲本培育的玉米杂交种,产量高,稳产性好,适应性广;抗倒性、抗病性强,推广面积大,品种生命周期长。C8605-2是目前国内培育玉米杂交种和自交系的骨干自交系,已成为国内十分宝贵的优异种质资源。 相似文献
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从二穗短柄草中扩增得到一个2C型蛋白磷酸酶基因,命名为BdPP2C1。BdPP2C1与拟南芥中PP2C家族进行系统进化分析,结果表明,BdPP2C1与拟南芥A类PP2C家族成员的亲缘关系较近。利用实时荧光定量PCR表达分析系统,分析在非生物逆境胁迫及相关信号分子处理下BdPP2C1基因的表达情况。结果表明:该基因的表达受脱落酸(ABA)和双氧水抑制,并且受渗透和低温胁迫诱导。因此,BdPP2C1是非生物逆境胁迫中的一个应答因子,并且可能受相关信号分子调控。 相似文献
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《Plant Production Science》2013,16(2):139-149
AbsractThis technical report describes a gradient system for characterizing the vertical gradients of CO2, H2O, and air temperature within and above the canopy of plants. The system is low in cost and easy to use. The instruments were fitted and placed in one box with a total weight of about 10 kg. The box can be carried and moved from one site to another. The features of this apparatus are high frequency sampling cycle as short as 1 min per cycle for all six measurement levels and fast response gas analyzer for measurement as short as 10s per level. Two exhaust pumps, one sampling pump, six 3-way solenoid valves, and flow meter were used to insure simultaneous flow rate of air in all tubes from all measurement levels. This system transfers data from the data-logger directly to the add-in Spreadsheet of Microsoft Excel by using an Ethernet cable to automatically convert digital data to scientific units in less time. This system also allows the use of multiple micro-environmental sensors that can be sampled at the same time. It is useful not only for agricultural ecosystems but is also adequately sensitive and rapidly responds to the gas analyzer with a modifiable flow rate meter for use in forest ecosystems. This system also has potential for use in the measurement of CO2, H2O, associated environmental elements, and CO2 storage flux within the canopy of plant, and other processes including a CO2 sink and source. 相似文献
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Baiping Liu Yongping Zhang Zhiyou Yang Meijun Liu Cai Zhang Yuntao Zhao Cai Song 《Marine drugs》2021,19(11)
Microglia M1 phenotype causes HPA axis hyperactivity, neurotransmitter dysfunction, and production of proinflammatory mediators and oxidants, which may contribute to the etiology of depression and neurodegenerative diseases. Eicosapentaenoic acid (EPA) may counteract neuroinflammation by increasing n-3 docosapentaenoic acid (DPA). However, the cellular and molecular mechanisms of DPA, as well as whether it can exert antineuroinflammatory and neuroprotective effects, are unknown. The present study first evaluated DPA’s antineuroinflammatory effects in lipopolysaccharide (LPS)-activated BV2 microglia. The results showed that 50 μM DPA significantly decreased BV2 cell viability after 100 ng/mL LPS stimulation, which was associated with significant downregulation of microglia M1 phenotype markers and proinflammatory cytokines but upregulation of M2 markers and anti-inflammatory cytokine. Then, DPA inhibited the activation of mitogen-activated protein kinase (MAPK) p38 and nuclear factor-κB (NF-κB) p65 pathways, which results were similar to the effects of NF-κB inhibitor, a positive control. Second, BV2 cell supernatant was cultured with differentiated SH-SY5Y neurons. The results showed that the supernatant from LPS-activated BV2 cells significantly decreased SH-SY5Y cell viability and brain-derived neurotrophic factor (BDNF), TrkB, p-AKT, and PI3K expression, which were significantly reversed by DPA pretreatment. Furthermore, DPA neuroprotection was abrogated by BDNF-SiRNA. Therefore, n-3 DPA may protect neurons from neuroinflammation-induced damage by balancing microglia M1 and M2 polarizations, inhibiting microglia-NF-κB and MAPK p38 while activating neuron-BDNF/TrkB-PI3K/AKT pathways. 相似文献
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2C型蛋白磷酸酶(PP2C)是ABA信号途径的关键组分,在ABA信号转导及植物对非生物逆境胁迫的应答过程中发挥着重要作用。为给TaPP2C59基因功能的研究奠定基础,同时为小麦对非生物胁迫应答的信号转导机理研究提供参考,本研究从小麦中克隆了第一个PP2C基因TaPP2C59,并对其在逆境胁迫以及多种信号分子处理下的表达模式进行研究。序列分析表明,该基因开放阅读框(ORF)为855bp,编码284个氨基酸。进化树分析表明,该基因编码的蛋白与水稻OsPP2C45蛋白和拟南芥AtPP2C59蛋白的亲缘关系最近。多序列比对分析表明,TaPP2C59具有PP2C家族蛋白的保守结构特征。实时荧光定量PCR分析表明,该基因的表达显著受ABA、低温和高盐胁迫抑制。因此,可以推测TaPP2C59可能作为负调控因子参与ABA信号及非生物逆境胁迫应答。 相似文献