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1.
在弱光条件下测定了5个黄瓜品种的生理性状。结果表明,津优30号叶面积增加最多,津优2号较多,寒月居中,绿宁3号和北极星最少;津优30号和寒月叶绿素含量增加较多,绿宁3号和津优2号居中,北极星最少;寒月光抑制程度较轻;津优30号和津优2号光合产物转化受抑最轻,叶片淀粉累积量最高;津优30号干物重累积量最多,寒月较多,津优2号居中,绿宁3号和北极星最少。综合比较得出,津优30号的适应性最强,寒月、绿宁3号和津优2号居中,北极星适应性最差。  相似文献   

2.
根据菜农试种结果,较耐盐碱的黄瓜品种有津春三号,锦早三号,北京密刺王,津优2号,爱帝FA,96-18、津绿1号,3号,爱帝FB,顶峰1号等。  相似文献   

3.
对抗病品种中农13号、津优3号、津优30号和感病品种中农6号、津研4号、秋棚4号接种黄瓜枯萎病病原菌,测定叶片内苯丙氨酸解氨酶(PAL)活性的动态变化过程。结果表明,苯丙氨酸解氨酶(PAL)活性变化具有周期性,抗病品种出现3次与抗性相关的峰值,感病品种出现两次与抗性有关的峰值。PAL酶活性与抗病性呈正相关关系。PAL酶活性的变化规律不仅与抗性有关,而且与感病与否有关。发病植株的PAL酶活性高于未发病植株。  相似文献   

4.
在营养液培养条件下,研究了水分轻度胁迫、氮素有限胁迫对冬小麦小偃22拔节期NR活性、根系活力等生理特性、养分累积及小麦产量的影响。结果表明,水分、氮素亏缺使叶绿素含量及叶片NR活性低于对照水平,根系活力,K3Fe(CN)6还原活性降低;水分胁迫影响大于氮素亏缺影响,水分和氮素亏缺之间有显著地交互作用。水分胁迫下,小麦植株地上部氮、磷、钾含量高于对照水平,但根系含量降低;氮素亏缺下,地上和根系的养分含量均低于对照水平;水分和氮素之间有极显著地交互作用。拔节时期水分、氮素亏缺使小麦成熟期的产量降低。  相似文献   

5.
研究了小麦生长期内土壤氮、钾与小麦根系活力变化及其相关性。结果表明,土壤速效氮、速效钾和非交换性钾含量随小麦生育进程呈现有规律的变化;小麦根系活力呈现先增加,孕穗期峰值出现后迅速下降,成熟时根系活力下降到最低值的变化规律,不同施肥处理小麦整个生育期内根系活力大小顺序为:MNPK、NPK>NK>N、NP>CK、M。土壤速效氮、速效钾、非交换性钾含量与小麦根系活力呈显著或极显著正相关,说明土壤N、K养分有效性的高低是影响小麦根系活力的重要因素。  相似文献   

6.
以蕹菜为试材,采用盆栽法,研究了不同用量的醌氢醌对蕹菜根系活性的影响,结果表明,醌氢醌使蕹菜根系活力、根系呼吸强度、根Na -K -ATP酶活力提高;蕹菜根系活性的增强,是蕹菜产量提高的生理基础之一,醌氢醌用量以40mgkg-1土为宜。  相似文献   

7.
1996~1997年采取田间小区试验和室内模拟试验相结合的方法,对3个小麦品种的抗旱形态生理特性进行了研究。结果表明:在水分胁迫条件下,郑旱1号胚芽鞘长、主胚根长、根系活力、叶片脯氨酸含量、细胞膜透性、旗叶SOD活性、Q_2~- 产生速率、MDA含量、成穗数、穗粒数、千粒重和产量的增减幅度最小,抗旱性最好;豫麦2号次之,豫麦41号的增减幅度最大,抗旱性最差。在众多抗旱形态生理指标中,用胚芽鞘长和主胚根长进行品种抗旱性鉴定和筛选具有较高的应用价值。  相似文献   

8.
以秋光和辽粳5号为试材,采用盆栽方法,研究了不同供氮水平对根系的影响。研究结果表明:生育前期各处理的水稻根数、最长根长、根体积、根干重及其根系活力差异不显;在拔节期,高氮素水平有利于促进根系生长,提高根系活力;抽穗期是水稻一生中根系生长和活力变化的转折点,抽穗期后根系各性状呈现大幅度下降趋势,但高氮水平下根系各性状降幅较小,这说明适当提高氮素供应水平有利于维持后期根系活力,延缓根系衰老。  相似文献   

9.
雷州半岛深松中耕对甘蔗产量影响及其作用机理研究表明,深松打破了犁底层,降低了土壤容重和坚硬度,增加了土壤的蓄水保水能力,改善根系生长的生态条件,促进根系生长,使根系干物质和植株养分显著增加,提高甘蔗的根系活力和抗逆性。深松后的产量较常规中耕提高了16.08%。  相似文献   

10.
在水培条件下,探究了氮素形态对小麦营养生殖并进生长时期保护酶的影响。结果表明:铵、硝态氮单供和混合供应对小麦保护酶活性影响不同。在铵、硝态氮混合供应下,叶片SOD、CAT,根系SOD活性最高,同时叶片、根系可溶性蛋白含量最大,根系活力和根系表面K3Fe(CN)6还原活性最高,但MDA含量最高;单供硝态氮时叶片POD活性最高,根系MDA含量最高;单供铵态氮时根系POD、CAT活性最高。单供尿素时叶片仅CAT活性高于铵和硝态氮混合供给,但同时叶片MDA含量也高于铵和硝态氮混合供给。叶片以SOD、CAT和POD为主清除自由基,而根系以SOD和POD为主清除自由基。铵和硝态氮混合供给下,小麦成熟后,地上部干重,籽粒产量最大,根冠比最小。  相似文献   

11.
三维视频编码技术的发展与挑战   总被引:1,自引:0,他引:1  
介绍了三维视频编码的核心技术。首先比较了纯视频格式和深度增强格式三维视频编码技术的发展方向及面临的挑战,其中重点分析了深度估计技术和视点合成技术的研究思路;然后概括了国际3DV/FTV标准的制定现状;最后对三维视频编码技术进行了总结和展望。  相似文献   

12.
该文研究的重点是全光3R再生技术中的再整形方法。研究了一个利用光纤的非线性的基于交叉相位调制与自相位调制的40Gb/s归零信号的再整形方法。文中使用软件Optisystem 3.0分别对基于高非线性光纤中的自相位调制和交叉相位调制实现再整形,并进行了仿真实验。该文提出的方案整形后得到的3R再生信号的质量得到了大幅改善。  相似文献   

13.
IT服务成本不断上升及新服务商业模式的出现,促使传统PC厂商在服务市场上不断地变革。首先介绍了3G市场的强势发展,然后分析了消费者对3C服务的需求以及3C服务市场的现状.最后介绍了联想乐享3G平台及其所提供的服务。  相似文献   

14.
Recent advances in 3D technology have been accompanied by increasing complaints of visual fatigue. The usual explanation for such fatigue is that accommodation and convergence are mismatched during stereoscopic vision. The aim of this study was to measure fixation distances between lens accommodation and convergence in young subjects while they viewed real objects and 3D video clips. Measurements were made using an original instrument. The 3D video clips were presented to subjects using a liquid crystal shutter glass system. The results showed that when viewing real objects, the diopter values of subjects' accommodation and convergence were similar and changed periodically. This measurement method was thus considered to be appropriate for the measurement of stereoscopic vision. We also investigated lens accommodation and convergence when subjects viewed 3D video clips. Both accommodation and convergence were found to move along with the virtual position of 3D video clips. Therefore, there was little discrepancy between accommodation and convergence during the viewing of 3D images.  相似文献   

15.
With the promotion of technology, state-of-the-art TVs already possess the functions of 3D. This study applied fuzzy theory to construct a hierarchy of 3D TV image quality factors and got the weights for each of them. Several 3D TV image quality factors were selected based on a review of the literature. A fuzzy c-means algorithm was then used to classify these factors into the criteria, and the hierarchy of the fuzzy analytic network process (ANP) was established. Thirty participants were recruited to conduct the questionnaire survey and the rating of the overall ergonomics. Using the calculation of fuzzy ANP, the weights for 3D TV image quality factors and different brands of 3D TVs were obtained. The results indicated that binocular disparity, crosstalk, and resolution were the three most important factors affecting 3D TV image quality. Therefore, 3D TV manufacturers could consider these important factors in future 3D TV product designs in order to promote customers’ purchase intention.Relevance to industryBased on the results obtained from fuzzy ANP, this study found that the three most important factors affecting 3D TV image quality are binocular disparity, crosstalk, and resolution. The results of this study could serve as a reference for 3D TV manufacturers in designing future products.  相似文献   

16.
Human 14-3-3 proteins have isoform-specific expression and functions in different kinds of normal or tumor cells and tissues. However, the expression profiling of 14-3-3 proteins and isoform-specific biological functions are unclear in human glioma so far. In our study, the expression levels and characterization of 14-3-3 isoforms in human glioma tissues were investigated by a sensitive, accurate stable isotope labeling with amino acids in cell culture-based quantitative proteomic strategy. As a result, except unexpressed 14-3-3σ, the other six isoforms, with different expression levels, were existed in glioma tissues and para-cancerous brain tissues (PBTs). 14-3-3β and η were upregulated, whereas 14-3-3ζ was downregulated in glioma tissues compared with that in PBTs. And the other three isoforms 14-3-3ε, θ, and γ had similar expression levels in human glioma tissues and PBTs. Western blot and immunohistochemistry analysis were both consistent with the quantitative proteomic data. The loss of expression of 14-3-3σ was further discovered due to DNA high methylation in its coding region in glioma by methylation-specific PCR analysis. These results indicated that the four isoforms, including 14-3-3β, η, ζ, and σ, may play important roles in tumorigenesis of human glioma, which is probably used as potential biomarkers for diagnosis and targets for treatment of human gliomas in future.  相似文献   

17.
The molecular geometries and internal rotational barriers of the nitro group of 3-nitrotoluene (3-NT), 4-nitrotoluene (4-NT), 3-nitrophenol (3-NP), 4-nitrophenol (4-NP), 3-nitroaniline (3-NA), and 4-nitroaniline (4-NA) were calculated by five different types of density functional theory (DFT) methods with three different levels of basis sets. Analyses of the torsional angles of the nitro, methyl, amino, and hydroxyl groups indicate that 3-NP, and 4-NP are planar molecules, but 3-NT, 4-NT, 3-NA, and 4-NA are not planar molecules. Internal rotational barriers of the nitro group were calculated as the V2 barrier, and the NO2 torsional potentials for each molecule were given. The heights of the V2 barrier vary with the DFT methods, the basis sets, and the kinds and positions of substituents. The average values of the V2 barriers for 3-NT, 4-NT, 3-NP, 4-NP, 3-NA, and 4-NA are 6.44, 6.92, 6.64, 7.93, 6.38, and 9.13 kcal/mol, respectively. Torsional potentials of the OH and NH2 groups of nitrophenol and nitroaniline derivatives were also studied by a B3LYP/6-31G* approach. Except for the OH group in 2-NP, these derivatives have the V2 barrier.  相似文献   

18.
Five years of data from 1998 to 2002 of TRMM-3B42 version 5 (V5), 3B43 V5, 3B42 version 6 (V6), 3B43 V6, and the Bangladesh Meteorological Department rain-gauge network were analyzed to understand the climatic characteristics of rainfall over Bangladesh. TRMM-PR 2A25 data were used to obtain the precipitation field of the convection events. Daily rainfall measured by TRMM V5 3B42 was compared to that of rain-gauge values from pre-monsoon to post-monsoon months (March-November). The time sequence patterns of the daily rainfall determined by the V5 3B42 and those from rain gauges were remarkably similar. The spatial and temporal averages of rainfall revealed good estimations of rainfall: during March to November, the V5 3B42- and rain gauge-estimated daily rainfall was 8.12 and 8.34 mm, respectively. In annual scale, TRMM V5 3B42-, V5 3B43-, V6 3B42-, V6 3B43- and rain-gauge estimated rainfall was 6.9, 6.4, 6.6, 6.8 and 7.1 mm/day, respectively. The average percentage of rainy days determined by V5 3B42 data with respect to the rain-gauge value was 96%. TRMM is useful for estimating the average values of rainfall in Bangladesh. The prominent difference between rainfall estimated by rain-gauge and V5 3B42 was found to be period- and location-dependent. The V5 3B42 overestimated the rainfall during the pre-monsoon period and in dry regions but underestimated it during the monsoon period and in wet regions. The reason for the differences according to season and locations is considered to be the vertical cross section of convection obtained by TRMM-PR 2A25 data. The rainfall overestimation in pre-monsoon and underestimation in monsoon period measured by V5 3B42 is reduced to reasonable amount by V6 3B42 and V6 3B43. In this manner, the merit of using TRMM data for climatological studies of rainfall over Bangladesh is shown.  相似文献   

19.
运用三维动画制作软件3DS MAX 4.0对有机立体化学中的烷烃构象、环烷烃的构象及转化、各种构象之间的能量变化、构型异构及旋光异构体的空间结构及属性等内容进行了形象化的描述。对一些分子模型、仪器及部分实验予以三维空间模拟及动画处理,使抽象的概念具体化、可视化。  相似文献   

20.
第3接口是国际工作流管理联盟(WFMC)提出的工作流参考模型中,系统与外部组件通信的接口,在WFMC的说明文档中,不是工作流管理系统必须实现的功能,一个工作流系统缺乏对第3接口的气持,则缺乏一定的可用性。分析了外部组件的多样性导致第3接口的实现障碍,基于Java技术,提出了第3接口的两种实现方式,并比较其优缺点,提出了基于这两种方式的综合实现方案。  相似文献   

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