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1.
在盐酸质子化条件下,采用超声微波协助法成功制备了可见光型复合催化剂WO3/g-C3N4。利用X射线多晶粉末衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)、紫外可见漫反射(UV-Vis)和BET比表面测试仪对样品进行了表征,并以罗丹明B(RhB)为目标降解物对其光催化性能进行研究。结果表明:复合催化剂样品是由片状的WO3纳米片负载在g-C3N4表面组成的。当WO3负载的质量分数为40%时,前驱物在500℃条件下煅烧2 h后所得样品的光催化性能明显好于同条件下制得的单一相WO3和g-C3N4,在可见光(波长大于420 nm)照射下,5 h内对100 mL浓度为10-5 mol/L罗丹明B橙溶液的降解高达98%。  相似文献   

2.
斯琴  同丽嘎  张靖 《中国农学通报》2017,33(11):112-118
为了研究呼和浩特市污染特征及其与气象条件的关系,利用大气环境监测数据和常规气象观测资料,分析2015年PM2.5、PM10浓度特征及与气象要素的关系;结合11月末呼和浩特市严重雾霾天气,对其成因进行初步分析。结果表明:(1)呼和浩特市冬季PM2.5与PM10浓度是四季中最高,夏季最低;2015年月均最大值出现在12月,PM2.5与PM10浓度变化趋势基本一致,年平均相关系数为0.711;(2)PM2.5浓度与能见度、气压、相对湿度的相关系数分别为:-0.887、0.815、0.501;与风向风速及降水量年均相关性不明显;(3)2015年呼和浩特市11月降水明显加强,而冷空气势力较弱,风速小,气温偏高,29日呼和浩特市上空形成了逆温层,维持时间较长,这正是雾霾持续出现及异常加强的一个重要原因,冬季采暖是11月污染物浓度加强的另一个重要原因。  相似文献   

3.
基于CuFe2O4纳米粒子能显著增强Luminol-EDTA体系的发光,首次建立了Luminol-EDTA-CuFe2O4 NPs化学发光新体系。紫外吸收光谱和化学发光光谱表明纳米CuFe2O4注入Luminol-EDTA体系后,未生成新发光物质,结合纳米CuFe2O4的特性,提出了CuFe2O4 NPs参与Luminol-EDTA体系可能的发光机理。研究发现芦丁能抑制Luminol-EDTA-CuFe2O4 NPs体系的化学发光,结合流动注射技术,将此化学发光体系应用于芦丁片中芦丁含量的测定。在优化实验条件下,芦丁浓度在2×10-8~2×10-5 mol/L范围内芦丁浓度的对数和相对化学发光值呈线性,芦丁浓度检出限(LOD)为1.21×10-9 mol/L。将本方法应用于芦丁片中的芦丁含量测定,回收率为97%~102%,RSD为2.54%(c=1×10-7mol/L,n=11)。  相似文献   

4.
贺俊杰 《中国农学通报》2014,30(34):107-111

为准确估算评价草原生态系统碳源/汇和合理利用草地资源提供科学依据。采用涡度相关法对锡林浩特典型草原生态系统CO2通量的日变化、牧草不同生育期CO2通量变化规律以及与环境因子的关系进行分析。结果表明,草原生态系统CO2通量具有明显的日变化特征,白天以吸收CO2为主,夜间表现为呼吸排放CO2,夜间较白天变化相对稳定;CO2通量晴天与阴天日变化趋势一致,但阴天变幅大于晴天;在牧草不同生育期和不同天气背景下,CO2通量的日变化特征不同。CO2通量波动晴天大于阴天,但无论晴天还是阴天,返青期、黄枯期为大气CO2的源;开花期为大气CO2的汇,且开花期CO2净吸收通量明显高于生长初期和黄枯期,而黄枯期CO2呼吸排放通量明显高于生长初期和开花期。牧草在不同生育期的CO2通量与光合有效辐射强度、平均气温、地表平均温度、5 cm平均地温和平均风速等环境因子密切相关。

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5.

为了提高巨大芽孢杆菌C2产芽孢的形成率,采用单因素和正交试验,通过摇瓶发酵培养,对影响巨大芽孢杆菌C2芽孢形成的发酵培养基成分和培养条件进行了优化。结果表明:巨大芽孢杆菌C2最优的产芽孢培养基配方为麸皮1.5%、豆粕1.5%、NaCl 0.5%、CaCO3 0.02%、MnSO4·H2O 0.02%、MgSO4·7H2O 0.02%;最适宜培养条件是:培养基初始pH 7.0,接种量0.5%,培养温度37℃,培养时间48 h。在此优化条件下,巨大芽孢杆菌C2芽孢形成率可达到100%,为下一步该茵株在复合生物肥料中的应用打下基础。

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6.
 选择4个棕色棉品种(系)与5个白色棉品种进行不完全双列杂交,得正反交组合各20个,测定了吐絮期正反交组合的净光合速率、胞间CO2浓度、叶绿素含量,叶绿素a/b、PSII的最大光化学效率,分析杂交F1代光合参数的杂种优势表现与正反交之间的差异。结果表明:吐絮期杂种F1各项光合参数没有明显的正向中亲优势、正向超亲优势。正反交组合之间,除胞间CO2浓度存在显著差异外,其它光合参数差异不显著,胞间CO2浓度受到细胞质效应影响。正交组合F1叶绿素含量与胞间CO2浓度存在显著正相关,反交组合F1净光合速率与胞间CO2浓度存在极显著正相关。  相似文献   

7.
转codA基因提高番茄植株的耐热性   总被引:3,自引:0,他引:3  
以野生型番茄(cv. Moneymaker)和转codA番茄为材料,用不同温度(25、30、35、40、45和50℃)分别处理2 h,测定叶片净光合速率(Pn)、PSII最大光化学效率(Fv/Fm)、过氧化氢(H2O2)含量、丙二醛(MDA)含量、相对电导率(REC)和抗氧化酶活性等生理指标;42℃高温处理0、3和6 h后,检测热响应基因的表达量以及D1蛋白的含量,研究高温胁迫对上述参数的影响,探讨转codA基因提高番茄叶片耐热性的机制。。结果表明,高温胁迫下,转codA基因番茄叶片Pn和Fv/Fm的抑制程度明显低于野生型,H2O2、MDA的积累量以及REC均低于野生型,而且明显增强了过氧化氢酶(CAT)、超氧化物歧化酶(SOD)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)的活性。此外,转codA基因番茄叶片中抗氧化酶基因和热胁迫基因的表达水平均高于野生型,而D1蛋白的降解水平低于野生型。转codA基因番茄体内合成的甜菜碱提高了转基因番茄的耐热性,这与提高和维持较高的抗氧化酶活性、促进热激响应基因的表达及减缓D1蛋白的降解等有关。  相似文献   

8.
高温胁迫对早稻根系质膜ATPase活性及NH4+吸收的影响   总被引:1,自引:0,他引:1  
选用高温耐性品种农大228、082和高温敏感品种茉莉占、协青早B,比较研究了高温胁迫对根系质膜ATPase活性和NH4+吸收速率的影响。结果表明,高温胁迫下,农大228和082根系质膜H+-ATPase和Ca2+-ATPase活性均比对照提高,而茉莉占和协青早B分别比对照大幅度下降,品种间差异显著(Duncan’s法检验)。根系质膜蛋白含量在高温胁迫后均表现下降。082的NH4+吸收速率不受高温影响,热敏感型品种NH4+吸收速率受高温胁迫明显下降。  相似文献   

9.
在纯净空气与H2O/ CO2污染空气来流对比试验结果基础上,采用数值计算方法和化学动力学方法,研究了H2O和CO2污染组分对煤油燃料超声速燃烧的影响,获得了试验手段难以得到的燃烧室流场参数和性能数据。完成了相应的煤油燃料超声速燃烧室二维数值计算,其中匹配了进口总温、总压、马赫数、氧气摩尔分数和工作当量油气比。将数值计算结果与相应试验测量值进行了对比分析,并结合燃烧室流场数据、性能参数分析了H2O和CO2污染的动力学影响、以及对燃烧室性能的影响。研究表明:(1)数值计算结果与实验测量值总体上吻合,两种手段均体现了纯净空气来流时不同煤油当量油气比的燃烧室性能,并反映了一致的“污染效应”影响趋势;(2) H2O污染、H2O+ CO2污染的存在降低了煤油燃料超声速燃烧室性能,体现在燃烧诱导压升、燃烧效率、流向冲量增量的下降,而且随着污染组分含量的增加,燃烧室性能下降越加显著。   相似文献   

10.

为了通过吸收光谱快速测量SO2胁迫下水稻叶片超氧化物歧化酶活性,采用小区试验研究了SO2毒害环境下水稻叶片超氧化物歧化酶活性与吸收光谱变量的相关性。结果表明:在整个生育期,相关曲线存在2个的波峰点,位于520~550 nm和720~750 nm 2个波段之间。计算720~ 750 nm和520~550 nm波段光谱吸收率的平均值A1A2,通过A1A2构建比值光谱变量(A1/A2)、相加光谱变量(A1+A2)及对数相加变量(lgA1+lgA2),利用光谱变量反演水稻叶片超氧化物歧化酶活性。研究发现:在水稻整个生育期,对数相加光谱变量与超氧化物歧化酶活性的相关性显著提高。选取对数相加变量构建水稻叶片超氧化物歧化酶活性的模型。为进一步提高吸收光谱快速测量SO2毒害环境下水稻叶片超氧化物歧化酶活性提出了探索性研究。

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11.
The relations between the extent of injuries in seedlings caused by a few day-long exposures to chill (5°C) and the leakage of K+, Mg2+ and Ca2+ ions from the leaves as well as the electric potential in seven maize hybrids, were investigated. The permeability of cells to ions was defined based on their absolute concentration in a water diffusate (Ct) and concentration expressed in relation to the total ion content in the leaves (IL index).
At lowered temperature the hybrids of higher resistance to chilling temperature were characterized by a lower value of the IL index for K+ and Mg2+ ions than the chill-sensitive hybrids. On the other hand, absolute concentration of the ions (Ct) Mg2+ and Ca2+ leaking from the leaves before chill exposure of the seedlings was positively and highly correlated with the extent of injuries in hybrids caused by 4 day-long exposures to chill. This observation is evidence that the chill injuries were predetermined through increased cell permeability to the mentioned ions at room temperature.
Changes in the electric potential of leaves in conditions of lowered temperature preceded the injuries of leaves, which became apparent after a longer period of exposure to chill. Thus, as the leakage of Mg2+ and Ca2+ ions occurs, changes in the electric potential may supply early information about the predisposition of the particular maize hybrids to chilling injuries. Leakage measurements of Mg2+ and Ca2+ ions from the leaves at room temperature may find application in the selection of chill-tolerant maize genotypes.  相似文献   

12.
This paper studies the electric potential of Solid Oxide Fuel Cell(SOFC).The activation over-potential,ohmic over-potential and concentration over-potential are solved by recently published equations.This paper also discusses the influence of operating temperature and steam to the SOFC's operating cell potential.Through the research,it is found that the temperature have great influence on SOFC's cell voltage.When the current density is high,the SOFC's cell voltage is higher with higher operating temperature.The steam ratio of the fuel have effects on SOFC's ideal electric potential and over-potentials.In summary,the less the steam ratio is,the greater the cell voltage we can achieve.  相似文献   

13.
赵翔  汪延良  王亚静  王西丽  张骁 《作物学报》2008,34(11):1970-1976
研究了Ca2+ 对NaCl胁迫下蚕豆气孔运动及质膜K+通道的影响。结果表明,100 mmol L-1 NaCl可明显诱导气孔开放,该现象可被10 mmol L-1 CaCl2 显著抑制。为探讨盐胁迫下Ca2+对K+和Na+跨膜运输的调控机制,我们利用膜片钳技术记录全细胞K+ 电流发现,在100 mmol L-1 NaCl胁迫下,加入10 mmol L-1 CaCl2胞外处理,显著抑制质膜K+内向及外向通道电流,这种抑制可被1 mmol L-1 La3+ (Ca2+通道抑制剂)缓解。非盐胁迫下,10 mmol L-1 CaCl2 胞外处理也能显著抑制质膜内向K+通道,但明显激活其外向通道,加入1 mmol L-1 La3+并不能被缓解。用H2O2专一的荧光探针二氯荧光素二乙酸酯(H2DCF-DA)单细胞分析保卫细胞内H2O2含量变化显示,在100 mmol L-1 NaCl盐胁迫下,10 mmol L-1 CaCl2 处理明显诱导H2O2在保卫细胞中积累;100 mmol L-1 NaCl和10 mmol L-1 CaCl2单独处理并不能诱导H2O2积累。推测Ca2+在盐胁迫下可能先诱导H2O2在胞内积累,进而激活质膜Ca2+通道,迅速提高胞内Ca2+浓度以抑制Na+通过质膜K+通道跨膜内流,同时调节Na+外流,两种效应共同作用促使气孔关闭,减少盐胁迫下水分的过度散失。上述结果将为Ca2+调控作物抗盐机制研究提供新的思路。  相似文献   

14.
Increases in atmospheric carbon dioxide (CO2) concentration have stimulated interest in the response of agricultural crops to elevated levels of CO2. Several studies have addressed the response of C3 cereals to CO2, but the interactive effect of nutrient supply and CO2 on apical development and spikelet set and survival has not been investigated thoroughly. Hence, an experiment was conducted in the greenhouse to evaluate the effect of high (700 μmol CO2mol?1 air) and low (400 μmol mol?1) levels of atmospheric CO2 on apical development, spikelet set and abortion, and pre- and post-anthesis growth in spring barley (Hordeum vulgare L.) grown under high N (0.3 g N pot?1 before sowing ?1–0.11 g N pot?1 week?1) and low N (0.3 g N pot?1) regimes. The plants were grown in 5 L pots. Development of spike was hastened due to CO2 enrichment, and the C+ plants pollinated few days earlier than the C— plants. Carbon dioxide enrichment had no effect on date of ripening. Development of spike slowed following application of extra N, and plants pollinated 10 days later and matured 2 weeks later when compared with plants under low N. Carbon dioxide enrichment did not affect the number of spikelets at anthesis. Excess N decreased spikelet abortion and the increased maximum number of spikelets under both [CO2]. Barley plants did not tiller when grown in low [CO2] and low N. Increased endogenous IAA concentration in those plants, recorded three days before tillers appeared in other treatments, may have contributed to this. Carbon dioxide enrichment increased the C concentration of plants, but decreased the N concentration under high N regime. Both the C and N concentration of plants were increased under high N regime. Carbon dioxide enrichment increased the total dry matter of mature plants by 9 % under high N regime and by 21 % under low N regime. Under high [CO2] increased kernel number on tiller spikes, and increased kernel weight both on main stem and on tiller spikes resulted in a 23 % increase in kernel yield under low N regime and 76 % increase in kernel yield under high N regime. The rate of N application influenced growth and yield components to a greater extent than CO2 enrichment. At maturity, plant dry matter, kernel weight, the number of kernels per spike, and the number of spikes per plant were higher under high N regime than under low N regime. Long days (16 h), low light intensity (280 μmol m?2s?1), and at constant temperature of 20 °C high [CO2] increased kernel weight and the number of kernels on tiller spikes under high and low N application rate, but did not increase the number of kernels on main stem spike, or the number of tillers or tiller spikes per plant.  相似文献   

15.
Respiration is responsible for much of the sucrose loss that occurs during sugarbeet (Beta vulgans L.) storage. Genotypes with reduced storage respiration rates would provide an efficient method for reducing sucrose losses. However, the current techniques for measuring storage respiration are not adapted easily to breeding programs. Internal CO2 concentration has been recommended as an efficient method for measuring the respiration rate of individual sugar-beet roots in storage. This study examined the effectiveness of internal CO2 concentration as a selection criterion for reducing respiration rate of sugarbeet during storage. Lines resulting from four cycles of divergent selection for internal CO2 concentration were evaluated along with commercial hybrids and low internal CO2 germplasm lines. Selection was effective in shifting internal CO2 concentration. Relative differences in internal CO2 concentration were consistent throughout the 3-year study. Neither the fourth-cycle selections for low nor the fourth-cycle selections for high internal CO2 concentration were significantly different from the original population for evolved CO2. This lack of a close relationship between internal and evolved CO2 indicated that internal CO2 concentration is not an effective selection criterion in a breeding program.  相似文献   

16.
瞬时CO2浓度变化对杏属植物光合生理影响研究   总被引:1,自引:1,他引:0  
孙猛  刘威生 《中国农学通报》2014,30(16):108-112
为探讨CO2浓度瞬时变化对杏碳同化能力、水分利用能力的影响,进一步了解杏属植物在未来大气CO2浓度升高和全球变暖情况下的生长潜力和生态优势。作者利用Li-6400便携式光合测定仪对15个2年生杏品种进行瞬时CO2浓度倍降和倍升处理的光合参数测定。结果表明,瞬时CO2浓度变化显著影响杏属植物光合作用,在瞬时CO2浓度升高情况下,最大净光合速率(Amax)升高,呼吸速率(Rd)下降,光补偿点(LCP)降低,表光量子效率(AQY)提高,水分利用效率(WUE)显著增强,但光饱和点(LSP)变化不显著,不同品种Gs和Tr反应有一定差异。适当增加CO2浓度能提高杏属植物对弱光和水分的利用能力,促进光合作用,增加同化物积累,加速碳素循环。  相似文献   

17.
再生粗骨料混凝土的碳化是一个复杂的物理扩散和化学反应过程,其分析和预测较为困难。鉴于此,基于再生粗骨料混凝土的碳化机理,结合再生粗骨料混凝土中CO2的扩散定律和可碳化物质的质量守恒定律,综合考虑再生粗骨料混凝土中CO2的有效扩散系数、碳化反应速率系数、可碳化物质的量、再生粗骨料的表面附着砂浆等重要参数的影响,建立了再生粗骨料混凝土碳化分析的多场耦合模型,并通过试验数据验证了模型的有效性和适用性。  相似文献   

18.
以杂交棉石杂2号和新陆早43的F1、F2代及亲本NT2、H2、4-14为试材,通过测定不同生育时期各材料叶面积指数(LAI)、叶倾角(MTA)、冠层光截获率等指标,分析了各指标变化对群体光合物质生产的影响。结果表明,2个杂交棉F1代LAI具有超亲优势,冠层光截获率具有中亲优势; LAI和冠层光截获率具有明显的母系遗传特性,而MTA受到父本的显著影响。F2代冠层结构主要受F1代相关指标和衰退率的影响,LAI中亲优势减小了衰退率; 杂交棉F1代光合物质积累主要受亲本参数和超亲优势的影响,F2代主要受F1代参数的影响。杂交棉光合物质积累最大增长速率和直线增长期开始时间较晚,直线增长期及活跃增长期较长,最终积累量和最大增长速率较高。杂交棉F1代具有明显的光合生产和产量优势,F2代具有一定的产量优势。以选择具有优化冠层结构的亲本为基础,组配具有较大MTA的父本和较大LAI的母本,有利于改善杂交棉光合性能,提高群体光能利用率,进一步挖掘产量潜力,为杂交棉高光效组合的选育及提高F2代应用提供理论依据。  相似文献   

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