首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 156 毫秒
1.
采用不同浓度的H2O2处理小麦,研究H2O2对小麦叶片光合功能的影响.结果表明:1 mmol.L-1H2O2对小麦叶片光合作用基本无影响,10、100、200 mmol.L-1H2O2对小麦离体和连体叶片的光合作用均有不同程度的抑制作用,表现为光合速率、叶绿素含量下降.叶绿体超微结构显示10 mmol.L-1H2O2对其有影响,200 mmol.L-1H2O2处理后基粒明显破坏,类囊体膜无序.核酮糖-1,5-二磷酸羧化酶加氧酶(Rubisco)大小亚基和羧化活性在20 mmol.L-1H2O2逆境下变化小,100 mmol.L-1H2O2处理,Rubisco大小亚基降解明显,羧化活性微弱.说明H2O2诱导小麦叶片光合功能衰退.  相似文献   

2.
用组织培养技术获得黄瓜叶片的愈伤组织,进而培养其悬浮细胞,然后用Na^+、Ca^2+、H2O2分别诱导黄瓜叶片悬浮细胞凋亡,并用显微镜观察和琼脂糖凝胶电泳检测其DNA。Na^+(1.4mol/L),Ca^2+(500mmol/L),H2O2(10%)作用于黄瓜叶片悬浮细胞后,用显微镜观察到凋亡小体;DNA琼脂糖凝胶电泳检测出凋亡时形成的DNA ladder。结果表明:Na^2+(1.4mol/L),Ca^2+(500rmnol/L),H2O2(10%)都能诱导黄瓜叶片悬浮细胞凋亡。  相似文献   

3.
用镉处理离体的烟草叶片,0.005mmol/L镉处理就引起光合速率降低,0.027mmol/L镉处理引起叶绿素含量下降,0.1mmol/L镉处理引起膜透性增加,随着处理浓度的增加及处理时间的延长,光合速率、叶绿素含量下降程度增加,膜受损程度也增加,而呼吸速率则呈现出降低-增加-降低的变化。  相似文献   

4.
合成了钴钨酸(Co^ⅡW12)/SiO2复合催化剂,运用FTIR,CV,UV—vis/DRS等手段对其结构进行了表征.以染料橙黄Ⅱ为模型反应物,对Co^ⅡW12/SiO2-H2O2体系在近紫外光和可见光下的光降解脱色活性进行了研究.结果表明,在125W高压汞灯(λ≥310nm)辐照下,70mg/L橙黄Ⅱ溶液在pH为2.2~6、光照75min,脱色率为60.3%-70.1%;酸性条件下,脱色速率随H2O2浓度升高而升高,脱色过程符合表观一级反应动力学规律.在450W荧光汞灯(λ≥410nm)辐照下,15mg/L橙黄Ⅱ溶液在pH为2.2、光照105min,光脱色率为21.4%;光脱色率随pH升高而降低。  相似文献   

5.
用高浓度CO2气体胁迫处理药材甲Stegobium paniceum(L.)成虫及离体羧酸酯酶,通过终点法测定酶活性及其动力学参数变化,分析气调胁迫对羧酸酯酶性质的影响.结果显示,处理6,9,12h,羧酸醋酶比活力分别为0.412mmol/(mg·min)、0.439mmol/(mg·min)、0.418mmol/(mg·min),与对照0.358mmol/(mg·min)相比,分别升高了14.96%,22.58%,16.69%,差异均达到显著水平.处理时间延长至15h,比活力降低了2.73%.羧酸醋酶酶液经持续通人高浓度CO2于37℃水液中离体处理10min,比活力显著降低.离体处理亦导致羧酸酯酶动力学参数发生相应变化.  相似文献   

6.
重金属镉对叶绿体超微结构的影响   总被引:2,自引:0,他引:2       下载免费PDF全文
蒋文智 《广西科学》1995,2(2):21-23,20
重金属镉处理烟草植株引起叶片光合强度降低;处理离体叶绿体引起光合电子传递受阻,光化学活性降低。在经过电镜分析了镉对光合器超微结构的影响后认为,镉破坏光合膜结构.这可能是引起光合强度降低的主要原因之一。  相似文献   

7.
大量元素缺乏对小麦光合、呼吸作用和生理特性的影响   总被引:3,自引:3,他引:0  
对小麦幼苗分别进行缺氮、缺磷和缺钾处理10~30 d,研究大量元素缺乏对小麦叶片呼吸作用、光合活性和生理参数的影响.大量元素缺乏导致小麦叶片H2O2、丙二醛含量上升,含水量下降,抗氰呼吸被明显诱导.缺氮和缺磷还导致净光合速率(Pn)、PSⅡ光合电子传递量子效率(ΦPSⅡ)、PSⅡ原初光化学效率(Fv/Fm)、光适应下PSⅡ最大光化学效率(Fv′/Fm′)和非光化学猝灭系数(NPQ)下降.缺钾只导致NPQ下降,其它光合参数变化不大.通过对以上生理变化的分析,可以看出大量元素缺乏对植物体造成了显著的影响,但损  相似文献   

8.
ABA和H2 O2在NaCl诱导的气孔关闭中的作用   总被引:1,自引:1,他引:1  
以拟南芥野生型(wt)和ABA合成缺失突变体(aba3)为材料,采用表皮生物分析法研究了NaCl胁迫条件下,ABA和H2O2在气孔关闭中的作用。结果表明:100mmol/L的NaCl可有效诱导wt气孔关闭,而对aba3的气孔运动无明显影响;10^-2mmol/L的H2O2处理或100mmol/L的NaCl与10^-2mmol/L ABA共处理可有效诱导wt与aba3的气孔关闭,且幅度类似;H2O2的性清除剂CAT可部分逆转NaCl处理及NaCl与ABA共处理引起的气孔关闭,因此推测,NaCl胁迫条件下,植物保卫细胞内ABA浓度升高,诱导H2O2的产生,进而诱导了气孔关闭。  相似文献   

9.
小麦Ⅱ型胚性愈伤组织的获得及培养特性研究   总被引:1,自引:0,他引:1  
从小麦品系“鄂35816”幼穗愈伤组织中得到了Ⅱ型胚性愈伤组织。根据愈伤组织的状态和生长速度提高继代频率,可促使I型向Ⅱ型胚性愈伤组织转变,并保持植株再生潜能;1.0-2.0mg/L,2,4-D、CaC.2H2O3.0mmol/L和KH2PO43.0mmol/L的组合有利于Ⅱ型胚性愈伤组织的生长和植株再生。  相似文献   

10.
超声-非均相催化氧化法处理苯酚废水   总被引:1,自引:1,他引:0  
研究了超声/H2O2/CuO、超声/H2O2/Ni2O3及超声/H2O2/MnO2非均相体系对苯酚的去除效果。以初始浓度25mg/L的苯酚溶液为处理液.催化反应在带夹套的玻璃器中进行。在超声声强4.97W/cm^2、H2O2加入量300mg/L、催化剂的加入量均为1g/L、溶液温度30℃的处理条件下,3种体系中超声/H2O2/CuO组合对苯酚的去除效果最好。超声辐照240min时,单独超声、超声/H2O2、CuO/H2O2及超声/H2O2/CuO对苯酚的去除率分别为24.0%,53.3%,13.8%和89.5%,表明超声、H2O2与CuO具有协同作用。溶液温度从20℃上升到55℃时,3种组合下苯酚去除率均随温度升高有明显增大,表明温度较高时C6H5OH去除过程中催化作用起主要作用而非超声空化作用。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号